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In this study we quantify economic benefits from projected improvements in worker productivity resulting from the reduction in children's exposure to lead in the United States since 1976. We calculated the decline in blood lead levels (BLLs) from 1976 to 1999 on the basis of nationally representative National Health and Nutrition Examination Survey (NHANES) data collected during 1976 through 1980, 1991 through 1994, and 1999. The decline in mean BLL in 1- to 5-year-old U.S. children from 1976-1980 to 1991-1994 was 12.3 microg/dL, and the estimated decline from 1976 to 1999 was 15.1 microg/dL. We assumed the change in cognitive ability resulting from declines in BLLs, on the basis of published meta-analyses, to be between 0.185 and 0.323 IQ points for each 1 g/dL blood lead concentration. These calculations imply that, because of falling BLLs, U.S. preschool-aged children in the late 1990s had IQs that were, on average, 2.2-4.7 points higher than they would have been if they had the blood lead distribution observed among U.S. preschool-aged children in the late 1970s. We estimated that each IQ point raises worker productivity 1.76-2.38%. With discounted lifetime earnings of $723,300 for each 2-year-old in 2000 dollars, the estimated economic benefit for each year's cohort of 3.8 million 2-year-old children ranges from $110 billion to $319 billion.

The importance of certain structural features of the 5' untranslated region of classical swine fever virus (CSFV) RNA for the function of the internal ribosome entry site (IRES) was investigated by mutagenesis followed by in vitro transcription and translation. Deletions made from the 5' end of the CSFV genome sequence showed that the IRES boundary was close to nucleotide 65: thus, the IRES includes the whole of domain II but no sequences upstream of this domain. Deletions which invaded domain II even to a small extent reduced activity to about 20% that of the full-length structure, and this 20% residual activity persisted with more extensive deletions until the whole of domain II had been removed and the deletions invaded the pseudoknot, whereupon IRES activity fell to zero. The importance of both stems of the pseudoknot was verified by making mutations in both sides of each stem; this severely reduced IRES activity, but the compensating mutations which restored base pairing caused almost full IRES function to be regained. The importance of the length of the loop linking the two stems of the pseudoknot was demonstrated by the finding that a reduction in length from the wild-type AUAAAAUU to AUU almost completely abrogated IRES activity. Random A-->U substitutions in the wild-type sequence showed that IRES activity was fairly proportional to the number of A residues retained in this pseudoknot loop, with a preference for clustered neighboring A residues rather than dispersed As. Finally, it was found that the sequence of the highly conserved domain IIIa loop is, rather surprisingly, not important for the maintenance of full IRES activity, although amputation of the entire domain IIIa stem and loop was highly debilitating. These results are interpreted in the light of recent models, derived from cryo-electron microscopy, of the interaction of the closely related hepatitis C virus IRES with 40S ribosomal subunits.

The Chernobyl nuclear disaster of April 26, 1986, triggered a chain of devastating events that later included an unexpected increase in childhood thyroid cancer and evidence of iodine deficiency (ID) in Russia. For the Russian people the Chernobyl event had profound psychological impacts, provoking anxiety about nuclear technology and mistrust of governmental control efforts. Frequently in public health a crisis is required to create the political will to manage longstanding problems, and public health officials must rapidly mobilize to take advantage of the opportunity. In this case, ID, previously not seen as a problem in Russia, was recognized to be potentially serious, and the Russian Federation, assisted by the catalytic bi-national effort of the U.S.-Russian Joint Commission on Economic and Technological Cooperation (Gore-Chernomyrdin Commission (GCC)) established a model salt iodization policy, developed a planning process, and implemented a program to prevent ID through a systematic approach that included the people, government, and private groups using open communication, dissemination of the findings, and action plans. By 1999, political will had been mobilized and over 20% of the nation's salt was being iodized, up from about 1% in 1996. Universal iodization of salt was not a specific objective of the GCC; however, the increasing availability of iodized salt is leading to the elimination of ID, which is now a political goal in Russia. The full realization of this goal will require more time for education, marketing, and possibly legislative action.

Background/purpose: Repair of recurrent diaphragmatic hernia continues to be a difficult problem. An innovative method using a nonabsorbable polypropylene prosthetic mesh plug placed via the thoracic approach using minimal dissection is presented., Methods: A retrospective analysis showed 39 children with congenital diaphragmatic hernia (CDH) who underwent repair between January 1997 and March 2000. Five children suffered a recurrence and underwent repair via the thoracic approach using the Bard Marlex Mesh Perfix Plug (C.R. Bard Inc, Billerica, MA). Follow-up was available in all children and ranged from 1 to 33 months (average, 13.8 months)., Results: Age at recurrence ranged from 2 to 48 months (average, 14.8 months), and the average time between initial repair and recurrence was 8.2 months (range, 2 to 16 months). There were no recurrences after the transthoracic mesh plug diaphragmatic hernioplasty. One child died of multiple congenital anomalies 6 months after repair., Conclusion: The transthoracic repair of recurrent diaphragmatic hernias using a nonabsorbable polypropylene prosthetic mesh plug represents an innovative approach to a difficult problem in which 5 repairs have been accomplished without recurrence in nearly 14 months of follow-up. J Pediatr Surg 36:1768-1769., (Copyright 2001 by W.B. Saunders Company.)

The slipping rib syndrome is an infrequent cause of thoracic and upper abdominal pain and is thought to arise from the inadequacy or rupture of the interchondral fibrous attachments of the anterior ribs. This disruption allows the costal cartilage tips to sublux, impinging on the intercostal nerves. Children with this entity are seldom described in the literature. We present a retrospective review of 12 children and young adults with slipping rib syndrome and a systematic approach for evaluation and treatment.

Background: Controversy surrounds the need for ICU admission, prolonged bed rest, and the duration of activity restrictions for children sustaining blunt trauma. Adult literature supports management based on hemodynamic status, not CT grade., Study Design: A 3-year prospective study of a standardized management algorithm for hemodynamically normal pediatric patients with blunt liver or spleen injury was performed. Patient selection was based on vital signs, irrespective of injury grade on CT. Patients requiring ICU admission for nonliver or nonspleen injury were excluded. Patients were admitted to a surgical ward with serial hematocrit levels. Discharge occurred 48 hours postinjury if patients had no abdominal tenderness, tolerated a regular diet, and had a stable hematocrit. Patients were allowed noncontact activity, including school, after discharge. Patients were followed up at 1 month with ultrasonographic imaging., Results: Eighty-nine patients sustained blunt liver or spleen injury. Forty-five patients were excluded for other injuries (Glasgow Coma Scale < 13, 32 of 45); the remaining 44 patients had a mean age of 8.9 years (range 2 to 17 years), Injury Severity Score 10.6 (range 4 to 33), liver grade 2.1, and splenic injury grade 2.3. Mechanisms of injury were predominately motor vehicle collisions (59%). All patients were managed nonoperatively without transfusion; 43 of 44 patients completed the algorithm. Mean observation was 55.2 +/- 12.3 hours. One-month followup occurred in 33 of 44 patients, with one complication detected and no delayed bleeding., Conclusion: Management of pediatric solid organ injury should be guided by hemodynamic status and not injury grade on CT. Hemodynamically normal children can be safely managed without intensive care monitoring, do not need prolonged hospitalization, and can resume school on discharge.

Induction of mucosal immunity by oral immunization with protein antigen alone is difficult: potent mucosal adjuvants, vectors, or other special delivery systems are required. Cholera toxin (CT) has been shown to be an effective adjuvant for the development of mucosal vaccines and, when given with vaccine, induces both mucosal and systemic immune responses via a Th2 cell-dependent pathway. However, and in addition to potential type-I hypersensitivity, a major concern for use of mucosal adjuvants such as CT is that this molecule is not suitable for use in humans because of its inherent toxicity. When we examined the potential toxicity of CT for the central nervous system, both CT and CT-B accumulated in the olfactory nerves/epithelium and olfactory bulbs of mice when given by the nasal route. The development of effective mucosal vaccines for the elderly is also an important issue; however, only limited information is available. When mucosal adjuvanticity of CT was evaluated in aged mice, an early immune dysregulation was evident in the mucosal immune system. The present review discusses these potential problems for effective mucosal vaccine development. Tolerance represents the most common and important response of the host to environmental antigens, including food and commensal bacterial components, for the maintenance of an appropriate immunological homeostasis. We have examined whether Peyer patches could play a more important role for the maintenance of oral tolerance. Using Peyer patch-null mice, we found that mice lacking this gut-associated lymphoid tissue retained their capability to produce secretory IgA antibodies but did not develop normal oral tolerance to protein antigens.

The built environment embraces a wide range of concepts, from the design and integrity of housing, to land-use urban planning. A high-quality environment is essential for children to achieve optimal health and development. Building and land-use policies, including the quality and design of a child's physical environment, can cause or prevent illness, disability, and injury, and can degrade or preserve natural resources. Though many common pediatric conditions such as obesity, asthma, and lead poisoning, as well as injuries, are associated with risk factors within a child's built environment, this issue has received little attention from researchers or policymakers. This new field is ripe for etiologic and prevention research, and we need pediatric advocates to speak out for children's needs within this arena.

The question of whether translation initiation factor eIF4E and the complete eIF4G polypeptide are required for initiation dependent on the IRES (internal ribosome entry site) of hepatitis A virus (HAV) has been examined using in vitro translation in standard and eIF4G-depleted rabbit reticulocyte lysates. In agreement with previous publications, the HAV IRES is unique among all picornavirus IRESs in that it was inhibited if translation initiation factor eIF4G was cleaved by foot-and-mouth disease L-proteases. In addition, the HAV IRES was inhibited by addition of eIF4E-binding protein 1, which binds tightly to eIF4E and sequesters it, thus preventing its association with eIF4G. The HAV IRES was also inhibited by addition of m(7)GpppG cap analogue, irrespective of whether the RNA tested was capped or not. Thus, initiation on the HAV IRES requires that eIF4E be associated with eIF4G and that the cap-binding pocket of eIF4E be empty and unoccupied. This suggests two alternative models: (i) initiation requires a direct interaction between an internal site in the IRES and eIF4E/4G, an interaction which involves the cap-binding pocket of eIF4E in addition to any direct eIF4G-RNA interactions; or (ii) it requires eIF4G in a particular conformation which can be attained only if eIF4E is bound to it, with the cap-binding pocket of the eIF4E unoccupied.

Background: Adherence of bacteria and subsequent catheter-related infections (CRI) are greatly enhanced by the fibrin sheath that develops on indwelling catheters. Since the infection rate of catheters without fibrin sheaths is low and the fibrin sheath mediates bacterial adherence, catheter material is not thought to affect the incidence of late catheter-related infection., Methods: A total of 276 rats had catheters placed in the right jugular vein with the proximal end buried subcutaneously to eliminate exit site infection. Rats were divided into two groups: silastic catheters (SC; n = 133) and polyurethane catheters (PC; n = 143). Injections of 1 x 10(8) CFU/mL of Staphylococcus epidermidis were given via the tail vein on either the day of surgery, day 0 (n = 53 SC, n = 51 PC), or on postoperative day 10 (n = 50 SC, n = 62 PC). Thirty animals from each group (SC, PC) received sterile saline injections on day 10 and served as controls. Animals were sacrificed on postinjection day 3. Catheters were removed via the chest and placed into trypticase soy broth. Broth was incubated at 37 degrees C for 48 h. Microscopy for the fibrin sheath was done on 20 randomly selected catheters (10/group). Data were compared using Fisher's exact test, with p < 0.05 considered significant., Results: Incidence of CRI was equal prior to the formation of the fibrin sheath, while CRI was significantly higher in silastic catheters in the presence of a fibrin sheath. Without a fibrin sheath (day 0), 8/53 silastic catheters and 3/51 polyurethane catheters were infected (p = NS). With a fibrin sheath (day 10), 31/50 silastic catheters were infected versus 20/62 polyurethane catheters (p < 0.05). Control catheters were all culture negative (30/group). With light microscopy, 20/20 catheters had fibrin sheaths at day 10 with no visible difference between silastic and polyurethane catheters., Conclusion: Catheter material does affect the incidence of catheter-related infection even when catheters are coated with a fibrin sheath. This difference may relate to a difference in the fibrin sheath itself as it forms on different catheter materials.

Picornavirus proteases cleave translation initiation factor eIF4G into a C-terminal two-thirds fragment (hereafter named p100) and an N-terminal one-third fragment, which interacts with the cap-binding factor eIF4E. As the timing of this cleavage correlates broadly with the shut-off of host cell protein synthesis in infected cells, a very widespread presumption has been that p100 cannot support capped mRNA translation. Through the use of an eIF4G-depleted reticulocyte lysate system, we show that this presumption is incorrect. Moreover, recombinant p100 can also reverse the inhibition of capped mRNA translation caused either by m7GpppG cap analogue, by 4E-BP1, which sequesters eIF4E and thus blocks its association with eIF4G, or by cleavage of endogenous eIF4G by picornavirus proteases. The concentration of p100 required for maximum translation of capped mRNAs is approximately 4-fold higher than the endogenous eIF4G concentration in reticulocyte lysates. Our results imply that picornavirus-induced shut-off is not due to an intrinsic inability of p100 to support capped mRNA translation, but to the viral RNA outcompeting host cell mRNA for the limiting concentration of p100.

Stereotactic biopsy is often performed for diagnostic purposes before treating patients whose imaging studies highly suggest glioma. Indications cited for biopsy include diagnosis and/or the "inoperability" of the tumor. This study questions the routine use of stereotactic biopsy in the initial management of gliomas. At The University of Texas M. D. Anderson Cancer Center, we retrospectively reviewed a consecutive series of 81 patients whose imaging studies suggested glioma and who underwent stereotactic biopsy followed by craniotomy/resection (within 60 days) between 1993 and 1998. All relevant clinical and imaging information was reviewed, including computerized volumetric analysis of the tumors based on pre- and postoperative MRI. Stereotactic biopsy was performed at institutions other than M. D. Anderson in 78 (96%) of 81 patients. The majority of tumors were located either in eloquent brain (36 of 81 = 44%) or near-eloquent brain (41 of 81 = 51%), and this frequently was the rationale cited for performing stereotactic biopsy. Gross total resection (>95%) was achieved in 46 (57%) of 81 patients, with a median extent of resection of 96% for this series. Diagnoses based on biopsy or resection in the same patient differed in 40 (49%) of 82 cases. This discrepancy was reduced to 30 (38%) of 80 cases when the biopsy slides were reviewed preoperatively by each of three neuropathologists at M. D. Anderson. Major neurologic complications occurred in 10 (12.3%) of 81 surgical patients and 3 (3.7%) of 81 patients undergoing biopsy. Surgical morbidity was probably higher in our series than it would be for glioma patients in general because our patients represent a highly selected subset of glioma patients whose tumors present a technical challenge to remove. Stereotactic biopsy is frequently inaccurate in providing a correct diagnosis and is associated with additional risk and cost. If stereotactic biopsy is performed, expert neuropathology consultation should be sought.

Polypyrimidine tract binding protein (PTB) is an RNA-binding protein that regulates splicing by repressing specific splicing events. It also has roles in 3'-end processing, internal initiation of translation, and RNA localization. PTB exists in three alternatively spliced isoforms, PTB1, PTB2, and PTB4, which differ by the insertion of 19 or 26 amino acids, respectively, between the second and third RNA recognition motif domains. Here we show that the PTB isoforms have distinct activities upon alpha-tropomyosin (TM) alternative splicing. PTB1 reduced the repression of TM exon 3 in transfected smooth muscle cells, whereas PTB4 enhanced TM exon 3 skipping in vivo and in vitro. PTB2 had an intermediate effect. The PTB4 > PTB2 > PTB1 repressive hierarchy was observed in all in vivo and in vitro assays with TM, but the isoforms were equally active in inducing skipping of alpha-actinin exons and showed the opposite hierarchy of activity when tested for activation of IRES-driven translation. These findings establish that the ratio of PTB isoforms could form part of a cellular code that in turn controls the splicing of various other pre-mRNAs.

Picornavirus internal ribosome entry sites (IRESs) are approximately 450 nt. RNA elements that direct internal initiation of translation, such that when placed between the two cistrons of a dicistronic construct, they drive independent translation of the downstream cistron. Consequently they have been widely used for coordinated expression of two or more proteins. All picornavirus IRESs have an AUG triplet at the very 3' end, which is thought to be the actual site of internal ribosome entry. However with some IRESs, such as foot-and-mouth disease virus, and especially poliovirus, the majority of ribosomes do not initiate translation at this putative entry site AUG, but at the next AUG further downstream, which is thought to be accessed by a process of linear ribosome scanning from the entry site. If this is so, then it should be possible to regulate IRES-dependent translation by inserting an iron responsive element (IRE) between the putative entry site AUG and the main functional initiation site. This should make IRES-dependent translation sensitive to the concentration of iron regulatory protein (IRP), the protein that specifically binds to the IRE. This has been attempted with both the foot-and-mouth disease virus and poliovirus IRESs, and was successful in so far as an inhibition specifically of IRES-dependent translation was observed that was strictly dependent on both the presence of IRP and of a functional IRE motif inserted in the sense orientation. However, the range over which expression could be varied was rather limited (three- to fourfold maximum), because some IRES-dependent translation remained completely refractory to inhibition by even very high IRP concentrations. In contrast, with a cap-proximal IRE in the 5' untranslated region of an mRNA translated by the scanning mechanism, addition of sufficient IRP results in complete inhibition. These results support the model of IRES-promoted ribosome entry at an upstream site followed by strictly linear scanning to the main functional initiation site for the majority of internal initiation events, but imply that some ribosomes must access the functional initiation site by another route, possibly a nonlinear shunting-like mechanism.

A method is described for depleting rabbit reticulocyte lysates and wheat germ extracts of endogenous tRNAs by affinity chromatography using a matrix generated by coupling ethanolamine to epoxy-activated Sepharose 6B. Greater than 90% depletion of tRNA is achieved with the result that translation becomes in effect absolutely dependent on added tRNA. This depletion procedure should prove very useful for studying the influence of tRNA concentration, and the spectrum of the tRNA population, on recoding events such as programmed frameshifting and readthrough of termination codons.

Transforming growth factor (TGF-beta) is an immunoregulatory cytokine produced by many different cell types, including lymphocytes and monocytes-macrophages. Two assays are described for the quantitation of TGF-beta activity in supernatant fluids. The bioassay for TGF-beta is based on the potent ability of TGF-beta to suppress lymphocyte proliferation. The radioreceptor assay is based on the ability of TGF-beta-containing supernatant fluids to inhibit the binding of radiolabeled TGF-beta to its cellular receptor. Two support protocols describe acid-activation and neutralization of TGF-beta.

It has been reported previously that the 5' untranslated region of the mRNA encoding Apaf-1 (apoptotic protease-activating factor 1) has an internal ribosome entry site (IRES), whose activity varies widely among different cell types. Here it is shown that the Apaf-1 IRES is active in rabbit reticulocyte lysates, provided that the system is supplemented with polypyrimidine tract binding protein (PTB) and upstream of N-ras (unr), two cellular RNA binding proteins previously identified to be required for rhinovirus IRES activity. In UV cross-linking assays and electrophoretic mobility shift assays with individual recombinant proteins, the Apaf-1 IRES binds unr but not PTB; however, PTB binding occurs if unr is present. Over a range of different cell types there is a broad correlation between the activity of the Apaf-1 IRES and their content of PTB and unr. In cell lines deficient in these proteins, overexpression of PTB and unr stimulated Apaf-1 IRES function. This is the first example where an IRES in a cellular mRNA has been shown to be functionally dependent, both in vitro and in vivo, on specific cellular RNA binding proteins. Given the critical role of Apaf-1 in apoptosis, these results have important implications for the control of the apoptotic cascade.

The highly purified saponin derivative, QS-21, from the Quillaja saponaria Molina tree has been proved to be safe for parenteral administration and represents a potential alternative to bacterial enterotoxin derivatives as a mucosal adjuvant. Here we report that p.o. administration of QS-21 with the vaccine protein tetanus toxoid elicited strong serum IgM and IgG Ab responses, which were only slightly enhanced by further oral immunization. The IgG Ab subclass responses were predominantly IgG1 followed by IgG2b for the 50-microg p.o. dose of QS-21, whereas the 250-microg p.o. dose also induced IgG2a and IgG3 Abs. Low oral QS-21 doses induced transient IgE Ab responses 7 days after the primary immunization, whereas no IgE Ab responses were seen in mice given the higher QS-21 dose. Further, low but not high p.o. QS-21 doses triggered Ag-specific secretory IgA (S-IgA) Ab responses. Th cell responses showed higher IFN-gamma (Th1-type) and lower IL-5, IL-6, and IL-10 (Th2-type) secretion after the high QS-21 p.o. dose than after low doses. Interestingly, the mucosal adjuvant activity of low oral QS-21 doses was diminished in IL-4(-/-) mice, suggesting a role for this cytokine in the initiation of mucosal immunity by oral QS-21. In summary, our results show that oral QS-21 enhances immunity to coadministered Ag and that different doses of QS-21 lead to distinct patterns of cytokine and serum Ab responses. We also show that an early IL-4 response is required for the induction of mucosal immunity by oral QS-21 as adjuvant.

Genetic resistance to clinical mousepox (ectromelia virus) varies among inbred laboratory mice and is characterized by an effective natural killer (NK) response and the early onset of a strong CD8(+) cytotoxic T-lymphocyte (CTL) response in resistant mice. We have investigated the influence of virus-expressed mouse interleukin-4 (IL-4) on the cell-mediated response during infection. It was observed that expression of IL-4 by a thymidine kinase-positive ectromelia virus suppressed cytolytic responses of NK and CTL and the expression of gamma interferon by the latter. Genetically resistant mice infected with the IL-4-expressing virus developed symptoms of acute mousepox accompanied by high mortality, similar to the disease seen when genetically sensitive mice are infected with the virulent Moscow strain. Strikingly, infection of recently immunized genetically resistant mice with the virus expressing IL-4 also resulted in significant mortality due to fulminant mousepox. These data therefore suggest that virus-encoded IL-4 not only suppresses primary antiviral cell-mediated immune responses but also can inhibit the expression of immune memory responses.

Object: Renal cell carcinoma (RCC) is an aggressive malignancy that frequently metastasizes. When RCC metastasizes to the spine, significant pain and neurological dysfunction often follow. Because systemic therapy and radiotherapy have a limited effect in controlling spinal disease, surgery is frequently required; however, there are very few published series specifically addressing the role and benefits of the surgical treatment for this disease. The authors conducted a retrospective study to review their experience with the surgical treatment of metastatic RCC of the spine, paying particular attention to methodology and patient neurological status, pain relief, and survival., Methods: Between January 1993 and April 1999, 79 patients (63 men and 16 women patients; average age 55 years, range 16-82 years) underwent 107 spinal operations for metastatic RCC. Indications for surgery included disabling pain (94 [88%] of 107 procedures) and/or neurological dysfunction (55 [51%] of 107 procedures). The anatomical location and extent of tumor determined the choice of an anterior, posterior, or combined surgical approach. Internal fixation was performed in all but three patients. Preoperative embolization was required in approximately one half of the patients. Radiotherapy was performed in 40 patients prior to surgery, and immuno- and chemotherapy were administered in 70 patients either pre- or postoperatively. After an average follow-up duration of 15 months, 57 patients had died. Kaplan-Meier analysis revealed a median postoperative survival of 12.3 months. Significant pain reduction, as indicated by a visual analog pain scale, was achieved in 84 (89%) of the 94 cases presenting with disabling pain. Neurological improvement was seen in 36 (65%) of the 55 patients. The major morbidity and 30-day mortality rates were 15% (16 of 107 procedures) and 2% (two of 107 procedures), respectively., Conclusions: In selected patients with metastatic RCC of the spine, resection followed by stabilization can provide pain relief and neurological preservation or improvement.

Background/purpose: The authors hypothesized that gastric acidity is protective because it is bactericidal. They tested acidified formula for protection against gut colonization and bacterial translocation., Methods: In vitro: Formula was acidified to pH of 2, 3, 4, 5 and innoculated with Enterobacter. Growth over time was quantitatively assessed. In vivo: 442 premature rabbit pups were sorted randomly and fed formula of pH 2, 3, 4, or 7, with ranitidine. Two models were utilized: (1) with bacterial challenge using a known acid sensitive organism, (2) without bacterial challenge to simulate natural gut colonization and to test against organisms of unknown acid sensitivity. Normal acid animals received pH 7 formula, no ranitidine. On day 3, the mesenteric lymph nodes (MLN), spleen, liver, and cecum were harvested and cultured., Results: Bacterial growth was inhibited at pH 2 and 3, growth was logarithmic above pH 4 (P<.001). Total and organ-specific translocation was reduced at pH 3 and below in both models (P<.05). Translocation with formula pH 3 equaled normal acid animals. Quantitative cecal colonization was reduced in pups receiving pH 3 and below in both models (P<.05)., Conclusion: Acidification of formula below pH 4 is bactericidal to enteric organisms. Acidified formula decreases bacterial translocation and gut colonization.

Thermostable glucose isomerases are desirable for production of 55% fructose syrups at >90 degrees C. Current commercial enzymes operate only at 60 degrees C to produce 45% fructose syrups. Protein engineering to construct more stable enzymes has so far been relatively unsuccessful, so this review focuses on elucidation of the thermal inactivation pathway as a future guide. The primary and tertiary structures of 11 Class 1 and 20 Class 2 enzymes are compared. Within each class the structures are almost identical and sequence differences are few. Structural differences between Class 1 and Class 2 are less than previously surmised. The thermostabilities of Class 1 enzymes are essentially identical, in contrast to previous reports, but in Class 2 they vary widely. In each class, thermal inactivation proceeds via the tetrameric apoenzyme, so metal ion affinity dominates thermostability. In Class 1 enzymes, subunit dissociation is not involved, but there is an irreversible conformational change in the apoenzyme leading to a more thermostable inactive tetramer. This may be linked to reversible conformational changes in the apoenzyme at alkaline pH arising from electrostatic repulsions in the active site, which break a buried Arg-30-Asp-299 salt bridge and bring Arg-30 to the surface. There is a different salt bridge in Class 2 enzymes, which might explain their varying thermostability. Previous protein engineering results are reviewed in light of these insights.

Our studies examined the effects of p27(kip1) and p21(cip1) on the assembly and activity of cyclin D3-cdk4 complexes and determined the composition of the cyclin D3 pool in cells containing and lacking these cyclin-dependent kinase inhibitors. We found that catalytically active cyclin D3-cdk4 complexes were present in fibroblasts derived from p27(kip1)-p21(cip1)-null mice and that immunodepletion of extracts of wild-type cells with antibody to p27(kip1) and/or p21(cip1) removed cyclin D3 protein but not cyclin D3-associated activity. Similar results were observed in experiments assaying cyclin D1-cdk4 activity. Data obtained using mixed cell extracts demonstrated that p27(kip1) interacted with cyclin D3-cdk4 complexes in vitro and that this interaction was paralleled by a loss of cyclin D3-cdk4 activity. In p27(kip1)-p21(cip1)-deficient cells, the cyclin D3 pool consisted primarily of cyclin D3 monomers, whereas in wild-type cells, the majority of cyclin D3 molecules were complexed to cdk4 and either p27(kip1) or p21(cip1) or were monomeric. We conclude that neither p27(kip1) nor p21(cip1) is required for the formation of cyclin D3-cdk4 complexes and that cyclin D3-cdk4 complexes containing p27(kip1) or p21(cip1) are inactive. We suggest that only a minor portion of the total cyclin D3 pool accounts for all of the cyclin D3-cdk4 activity in the cell regardless of whether the cell contains p27(kip1) and p21(cip1).

Subepithelial and intraepithelial lymphocytes of human adenoids and tonsils were characterized and directly compared to determine the potential contribution of these tissues to mucosal and systemic immune responses. The distribution of T and B cell subsets, cytokine patterns, and antibody (Ab) isotype profiles were similar for adenoids and tonsils. Both tissues contained predominantly B cells ( approximately 65%), approximately 5% macrophages, and 30% CD3(+) T cells. The T cells were primarily of the CD4(+) subset ( approximately 80%). Tonsillar intraepithelial lymphocytes were also enriched in B cells. The analysis of dispersed cells revealed a higher frequency of cells secreting IgG than IgA and the predominant Ig subclass profiles were IgG1 > IgG3 and IgA1 > IgA2, respectively. In situ analysis also revealed higher numbers of IgG- than IgA-positive cells. These IgG-positive cells were present in the epithelium and in the subepithelial zones of both tonsils and adenoids. Mitogen-triggered T cells from tonsils and adenoids produced both Th1- and Th2-type cytokines, clearly exhibiting their pluripotentiality for support of cell-mediated and Ab responses. Interestingly, antigen-specific T cells produced interferon-gamma and lower levels of interleukin-5. These results suggest that adenoids and tonsils of the nasopharyngeal-associated lymphoreticular tissues represent a distinct component of the mucosal-associated lymphoreticular tissues with features of both systemic and mucosal compartments.

Upregulation of the cyclin-dependent kinase inhibitor p21WAF1/CIP1 and subsequent cell growth arrest or senescence is one mechanism by which normal cells are believed to respond to stress induced by the constitutively activated GTPase Ras. We hypothesize that in the absence of p21, the onset of Ras-dependent oncogenesis is accelerated. To test this hypothesis, we crossed MMTV/v-Ha-ras transgenic mice into a p21-deficient background. By 63 days of age, all 8 ras/p21-/- mice developed either malignant (mammary and/or salivary adenocarcinomas) or benign (Harderian hyperplasia) tumors. In contrast, by the same age, only one out of nine of the ras/p21+/+ mice developed a tumor. Furthermore, by 94 days of age, half of the ras/p21-/- mice, but none of the ras/p21+/+ mice, developed mammary tumors. p21-deficiency also accelerated the development of salivary (T50=66 days for ras/p21-/- vs T50=136 days for ras/p21+/+) and Harderian (T50=52 days for ras/p21-/- vs T50>221 days for ras/p21+/+) tumors. Furthermore, two out of the eight ras/p21-/- mice had metastatic lesions, one in its lungs, the other in its abdomen. None of the nine ras/p21+/+ mice had metastatic lesions. By 4 months of age, the mammary tumor multiplicity was 10-fold greater in ras/p21-/- (average 3.40 tumors/mouse) than in ras/p21+/+ (average 0.33 tumor/mouse) mice. However, once the tumors appeared, their growth rate, apoptosis level, and mitotic index were not affected by the loss of p21, suggesting that loss of p21 is critical in early but not late events of Ras oncogenesis. Altogether, the results show that tumor onset in MMTV/v-Ha-ras mice is p21-dependent with loss of p21 associated with earlier tumor appearance and increased tumor multiplicity and aggressiveness.

We tested the notion that the mucosal adjuvant cholera toxin (CT) could target, in addition to nasal-associated lymphoreticular tissues, the olfactory nerves/epithelium (ON/E) and olfactory bulbs (OBs) when given intranasally. Radiolabeled CT ((125)I-CT) or CT-B subunit ((125)I-CT-B), when given intranasally to mice, entered the ON/E and OB and persisted for 6 days; however, neither molecule was present in nasal-associated lymphoreticular tissues beyond 24 h. This uptake into olfactory regions was monosialoganglioside (GM1) dependent. Intranasal vaccination with (125)I-tetanus toxoid together with unlabeled CT as adjuvant resulted in uptake into the ON/E but not the OB, whereas (125)I-tetanus toxoid alone did not penetrate into the CNS. We conclude that GM1-binding molecules like CT target the ON/E and are retrograde transported to the OB and may promote uptake of vaccine proteins into olfactory neurons. This raises concerns about the role of GM1-binding molecules that target neuronal tissues in mucosal immunity.

Using a novel and highly selective technique, we measured monoester metabolites of seven commonly used phthalates in urine samples from a reference population of 289 adult humans. This analytical approach allowed us to directly measure the individual phthalate metabolites responsible for the animal reproductive and developmental toxicity while avoiding contamination from the ubiquitous parent compounds. The monoesters with the highest urinary levels found were monoethyl phthalate (95th percentile, 3,750 ppb, 2,610 microg/g creatinine), monobutyl phthalate (95th percentile, 294 ppb, 162 microg/g creatinine), and monobenzyl phthalate (95th percentile, 137 ppb, 92 microg/g creatinine), reflecting exposure to diethyl phthalate, dibutyl phthalate, and benzyl butyl phthalate. Women of reproductive age (20-40 years) were found to have significantly higher levels of monobutyl phthalate, a reproductive and developmental toxicant in rodents, than other age/gender groups (p < 0.005). Current scientific and regulatory attention on phthalates has focused almost exclusively on health risks from exposure to only two phthalates, di-(2-ethylhexyl) phthalate and di-isononyl phthalate. Our findings strongly suggest that health-risk assessments for phthalate exposure in humans should include diethyl, dibutyl, and benzyl butyl phthalates.

SERP-1 is a secreted serpin (serine-proteinase inhibitor) encoded by myxoma virus, a poxvirus pathogen of rabbits. SERP-1 is required for myxoma-virus virulence, and the purified protein has been shown to possess independent anti-inflammatory activity in animal models of restenosis and antigen-induced arthritis. As an inhibitor of serine proteinases, SERP-1 acts against tissue-type plasminogen activator, urokinase-type plasminogen activator, plasmin, thrombin and Factor Xa. In the present study, examination of SERP-1 glycosylation-site mutants showed that the N-linked glycosylation of Asn(172) was essential for SERP-1 secretion, whereas mutation of Asn(99) decreased secretion efficiency, indicating that N-linked glycosylation plays an essential role in the processing and trafficking of SERP-1. Furthermore, comparison of SERP-1 from wild-type myxoma virus and a virus containing a targeted disruption of the MST3N sialyltransferase locus demonstrated that SERP-1 is specifically modified by this myxoma-virus-encoded sialyltransferase, and is thus the first reported viral protein shown to by modified by a virally encoded glycosyltransferase. Sialylation of SERP-1 by the MST3N gene product creates a uniquely charged species of secreted SERP-1 that is distinct from SERP-1 produced from other eukaryotic expression systems, though this has no apparent effect upon the kinetics of in vitro proteinase inhibition. Rather, the role of viral sialylation of SERP-1 likely relates to masking antigenicity or targeting SERP-1 to specific sites of action in vivo.

Cadmium was measured in urine specimens from 22,162 participants in the Third National Health and Nutrition Examination Survey (NHANES III 1988-1994). Urine cadmium, expressed either as uncorrected (microg/L) or creatinine corrected (microg/g creatinine) increased with age and with smoking. The arithmetic mean value for urine cadmium in the U.S. population was 0.57 microg/L or 0.48 microg/g creatinine. Based on our estimates, about 2.3% of the U.S. population have urine cadmium concentrations greater than 2 microg/g creatinine, and 0.2% have concentrations greater than 5 microg/g creatinine, the current World Health Organization health-based exposure limit.

The substrate specificity of an alpha2,3-sialyltransferase (v-ST3Gal I) obtained from myxoma virus infected RK13 cells has been determined. Like mammalian sialyltransferase enzymes, the viral enzyme contains the characteristic L- and S-sialyl motif sequences in its catalytic domain. Analysis of the deduced amino acid sequences of cloned sialyltransferases suggests that v-ST3Gal I is closely related to mammalian ST3Gal IV. v-ST3Gal I catalyzes the transfer of sialic acid from CMP-NeuAc to Type I (Galbeta1-3GlcNAcbeta) II (Galbeta1-4GlcNAcbeta) and III (Galbeta1-3GalNAcbeta) acceptors. In addition, the viral enzyme also transfers sialic acid to the fucosylated acceptors Lewis(x) and Lewis(a). This substrate specificity is unlike any sialyltransferases described to date, though it is most comparable with those of mammalian ST3Gal IV enzymes. The products from reactions with fucosylated acceptors were characterized by capillary zone electrophoresis, (1)H-NMR spectroscopy and mass spectrometry. They were shown to be 2,3-sialylated Lewis(x) and 2,3-sialylated Lewis(a), respectively.

Background/purpose: To establish a neonatal animal model of multiorgan failure (MOF) for the histological study of the sequence and severity of neonatal MOF in comparison to a model of adult MOF., Methods: Neonatal and adult Sprague-Dawley rats received a single intraperitoneal injection of the inflammatory agent Zymosan. Rats were weighed; randomly killed on days 1 through 6; and heart, lung, liver, kidney, spleen, and ileocecum harvested for histological examination., Results: Neonatal animals receiving Zymosan showed a significant increase in total body weight not seen in adults. The sequence and severity of MOF-induced organ damage were strikingly different in adult and neonatal animals. Mild lung damage was seen as early as day 1 in adult rats receiving Zymosan. This progressed to moderate damage by day 2 and severe damage by day 6. Lungs of neonatal rats receiving Zymosan showed only mild damage by day 4, which had progressed no further by day 6. Mortality rate was not significantly different between adult and neonatal animals receiving Zymosan., Conclusions: Zymosan can be used in a neonatal animal model to incite MOF. In the neonatal animal model of MOF there is (1) substantial early capillary leak as shown by increased body weight; (2) a unique progression of organ involvement-liver, kidney, lung compared with adult animals with MOF-lung, liver, kidney; and (3) relative sparing of the lung from injury. These findings are consistent with previous clinical observations of a difference in neonatal and adult MOF.

The purpose of the present study was to determine the immunologic responses, particularly immunopathologic reactions, associated with nasal immunization with the mucosal adjuvant, cholera toxin (CT). BALB/c mice were nasally immunized with tetanus toxoid (TT) combined with CT, and the responses of these mice were determined. After nasal immunization, mice produce a serum antibody response, primarily of the immunoglobulin G (IgG) isotype of predominantly IgG1 subclass, against both TT and CT. Along with the antibody responses, we also found that inflammatory reactions, which could be potentially fatal, developed within the lung. Furthermore, IgE responses were also induced after nasal immunization, and these responses were associated with the detection of interleukin 5 in the serum. Thus, nasal immunization with TT plus CT likely results in the activation of Th2 cells, which may contribute to serious immunopathologic reactions in the lung.

Object: Primary and metastatic neoplasms of the lumbosacral junction frequently pose a complex problem for the surgical management and stabilization of the spine because of the anatomical and biomechanical factors of this transition zone between spine and pelvis. The authors have used a modification of the Galveston technique, originally described by Allen and Ferguson in the treatment of scoliosis, to achieve rigid spinal-pelvic fixation in patients with lumbosacral neoplasms. The authors retrospectively reviewed their experience, with particular attention to method, pain relief, and neurological status., Methods: From July 1994 through December 1998, 13 patients at the authors' institution have required spinal-pelvic fixation secondary to instability caused by primary (eight cases) or metastatic (five cases) neoplasms. Previous treatment included spinal surgery in 10 (77%), radiation therapy in seven (54%), and/or chemotherapy in six (46%). Following tumor resection, fixation was achieved by intraoperative placement of contoured titanium rods bilaterally into the ilium. These rods were attached to the lumbar spine with pedicle screws and subsequently crosslinked. Arthrodesis was performed. In the follow-up period of 3 to 50 months (average 20 months), nine (69%) of 13 patients were still alive. There were no cases of surgery-related death. Seven weeks postoperatively instrumentation failure occurred in one patient and was corrected by performing double L-rod spinal-pelvic fixation. Two patients experienced neurological dysfunction (ankle weakness and neurogenic bladder) that was thought to be related to tumor resection rather than the fixation procedure. Neurological status improved in four patients and remained unchanged in seven patients. Ambulatory status improved in 62% (eight patients), remained unchanged in 23% (three patients), and worsened in 15% (two patients). Spinal pain, as measured by a visual analog pain scale and determined by medication consumption was significantly reduced in 85% (11 cases)., Conclusions: In selected patients with primary or metastatic lumbosacral tumors, resection followed by modified Galveston L-rod spinal-pelvic fixation is an effective means of achieving stabilization that can provide significant pain relief and preserve ambulatory capacity.

In rural Georgia, a nurse and an environmental health specialist from the local health department visit the home of a young nursing mother to evaluate her home for the presence of lead hazards. The mother's older child, a 3-year old girl, has a blood lead level of 22 micrograms per deciliter, which was discovered through routine (EPSTD) health department screening. In examining the home, the specialist finds classic environmental risks; peeling and chipping lead-based paint on windows and door frames, lead dust on window wells and floors, and a backyard that serves as a burial ground for defunct car parts and dead batteries. In the course of talking with the mother about the lead hazards he has found, he notices that she and her 8-week-old infant seem quite listless, so he asks the mother how she's coping with her new baby. Eventually, the mother discloses that during her pregnancy she craved dirt and that she had eaten bowels of it scooped from her backyard. Once she had the baby, she says, she lost her craving. The nurse immediately contacts the physician involved in this case, who arranges for the mother and infant to be admitted to a nearby medical center for chelation therapy. Testing reveals the mother's lead level at 90 micrograms per deciliter; the infant's level is staggering 85 micrograms per deciliter. Once lead levels are reduced,the physician and public health nurse arrange for a host of social services, including psychological and nutritional counseling for the mother and periodic retesting of the children. The family moves from the dilapidated rental home. However, the mother misses her appointments, and despite repeated attempts to locate her, the family is lost to follow-up.

Resistance to the growth inhibitory effects of transforming growth factor beta (TGFbeta) has been associated with decreased levels of the TGFbeta type II receptor (TbetaR-II) and has been correlated with tumorigenicity. Previously, we reported an A --> G mutation at position -364 in the TbetaR-II promoter in A431 tumor cells which results in reduced TbetaR-II promoter activity. In this study, we show that the CDP/Cut (CCAAT displacement protein) transcription factor, a transcriptional repressor, binds both the wild type and the mutant TbetaR-II promoter. We also demonstrate that the A --> G mutation increases CDP/Cut binding affinity, and that overexpression of CDP/Cut reduces transcription from TbetaR-II promoter reporter constructs. Increased binding of the CDP/Cut repressor protein, as a result of a mutation at position -364, represents a novel mechanism of regulation in a neoplastic cell of the promoter of a tumor suppressor gene, TbetaR-II., (Copyright 1999 Academic Press.)

Development of immunocontraceptives for wild rabbit populations requires selection of both effective antigens and effective delivery systems. Recombinant rabbit zona pellucida glycoprotein B (ZPB) produced in eukaryotic cells in vitro was an effective antigen and induced sustained infertility in 70% of female rabbits. This required two boosts and serum antibody titers of 12 800 or greater. Antibody titers in females were low after the initial immunization, as might be expected with a self-antigen; however, male rabbits had a strong antibody response, indicating that the protein was immunologically foreign. To develop a delivery system, ZPB was delivered by infection with a recombinant myxoma virus. In contrast to the results with ZPB protein, infection of rabbits induced a similar serum antibody response to ZPB in both sexes. This indicated that presentation of ZPB in the context of a virus infection was able to overcome tolerance in females. However, the antibody titers were lower than 12 800, and only 25% of female rabbits were infertile. This antibody response was boosted by injections of recombinant ZPB protein, after which 80% of female rabbits were infertile. Infertility was associated with antibody binding to zonae and varying degrees of ovarian pathology characterized by follicular degeneration and substantial depletion of primordial follicles. Oocyte and follicular degeneration appeared to be the principal mechanism of infertility and may be primarily induced by antibodies to ZPB.

The internal ribosome entry site (IRES) of enteroviruses, and especially human rhinoviruses (HRV), functions very inefficiently in rabbit reticulocyte lysates, but can be stimulated by addition of HeLa cell extracts. Two HeLa cell activities have been identified: the A-type activity is due to polypyrimidine tract binding protein and the B-type to unr. In addition HRV and enterovirus IRES function requires a third RNA binding protein, poly(rC) binding protein 2, but this is present in reticulocyte lysates in non-limiting amounts. IRES activity can also be stimulated by the cleavage of initiation factor eIF4G mediated by either HRV 2A protease, or foot-and-mouth disease virus (FMDV) L protease. This raises the question of whether this stimulation is independent of that effected by the three RNA binding proteins, or whether cleaved eIF4G functionally mimics one or more of these proteins. It is shown here that the stimulation of HRV IRES activity resulting from cleavage of eIF4G is additive with the stimulation effected by HeLa cell A- and B-type activities. It is proposed that the role of the RNA binding proteins is to maintain or attain the appropriate 3-dimensional structure of the IRES RNA element, whereas the function of eIF4G is to deliver the 40S ribosomal subunit to the correct site on the IRES, a function which, for reasons not yet fully understood, is fulfilled more efficiently by the C-terminal cleavage product of eIF4G than by the intact factor.

Increasing evidence suggests that anxiety sensitivity (AS) may be a premorbid risk factor for the development of anxiety pathology. The principal aim of this study was to replicate and extend a previous longitudinal study evaluating whether AS acts as a vulnerability factor in the pathogenesis of panic (N. Schmidt, D. Lerew, & R. Jackson, 1997). A large nonclinical sample of young adults (N = 1,296) was prospectively followed over a 5-week, highly stressful period of time (i.e., military basic training). Consistent with the authors' initial study, AS predicted the development of spontaneous panic attacks after controlling for a history of panic attacks and trait anxiety, and AS was found to possess symptom specificity with respect to anxiety versus depression symptoms. AS 1st-order factors differentially predicted panic attacks, with the Mental Concerns factor being the best predictor of panic in this sample.

Cost reduction in the management of common surgical diseases such as appendicitis has become paramount for the survival of children's hospitals. We designed a clinical pathway to treat appendicitis with the goal of reducing cost and hospital length of stay (LOS) while maintaining quality of care. From September 1995 through December 1996, patients with nonperforated appendicitis (NPApp) and perforated appendicitis with peritonitis (PApp) were enrolled into a clinical pathway. NPApp patients were discharged when tolerating a regular diet. PApp patients were discharged if the following criteria were met: temperature < 38.5 degrees C for 24 hours, WBC < 14,000 on postoperative day 3, tolerating diet, and transition to oral analgesics accomplished. Hospital LOS and actual hospital costs in pathway patients were compared with those of historic controls. Patients with appendicitis from the Pediatric Health Information Systems (PHIS) database, a consortium of 20 children's hospitals in the United States, served as concurrent controls. Hospital LOS and hospital charges in PHIS NPApp and PApp patients from our institution were compared with national PHIS database patients. Mean LOS and hospital costs for both NPApp and PApp pathway patients were significantly decreased compared with historic controls (P < 0.05). Mean LOS and hospital charges in our institution's PHIS NPApp and PApp patients were also significantly decreased compared with the national PHIS database (P < 0.05). Innovative approaches such as these are necessary for the survival of children's hospitals in an increasingly cost competitive healthcare market.

Objective: Three theoretically derived cognitive risk factors were evaluated to determine whether they predicted the development of stress responding in the context of Basic Cadet Training (BCT)., Method: A large sample of cadets (N = 1,401) was prospectively followed for the 5-week BCT period., Results: All risk factors were found to significantly and independently predict the development of psychopathology and impairment as well as changes in symptoms during basic training. Risk factors conveyed approximately two to five times greater likelihood of experiencing clinically significant levels of symptoms at the end of BCT., Conclusions: These data provide strong evidence for three psychological risk factors in the development of anxiety and mood symptoms. Implications for screening and primary prevention are discussed.

Object: Occipitocervicothoracic (OCT) fixation and fusion is an infrequently performed procedure to treat patients with severe spinal instability. Only three cases have been reported in the literature. The authors have retrospectively reviewed their experience with performing OCT fixation in patients with neoplastic processes, paying particular attention to method, pain relief, and neurological status., Methods: From July 1994 through July 1998, 13 of 552 patients who underwent a total of 722 spinal operations at the M. D. Anderson Cancer Center have required OCT fixation for spinal instability caused by neoplastic processes (12 of 13 patients) or rheumatoid arthritis (one of 13 patients). Fixation was achieved by attaching two intraoperatively contoured titanium rods to the occiput via burr holes and Luque wires or cables; to the cervical spinous processes with Wisconsin wires; and to the thoracic spine with a combination of transverse process and pedicle hooks. Crosslinks were used to attain additional stability. In all patients but one arthrodesis was performed using allograft. At a follow-up duration of 1 to 45 months (mean 14 months), six of the 12 patients with neoplasms remained alive, whereas the other six patients had died of malignant primary disease. There were no deaths related to the surgical procedure. Postoperatively, one patient experienced respiratory insufficiency, and two patients required revision of rotational or free myocutaneous flaps. All patients who presented with spine-based pain experienced a reduction in pain, as measured by a visual analog scale for pain. All patients who were neurologically intact preoperatively remained so; seven of seven patients with neurological impairment improved; and six of seven patients improved one Frankel grade. There were no occurrences of instrumentation failure or hardware-related complications. In one patient a revision of the instrumentation was required 13.5 months following the initial surgery for progression of malignant fibrous histiosarcoma., Conclusions: In selected patients, OCT fixation is an effective means of attaining stabilization that can provide pain relief and neurological preservation or improvement.

We measured uranium and thorium in urine of 500 U. S. residents to establish reference range concentrations using a magnetic-sector inductively coupled argon plasma mass spectrometer (ICP-MS). We found uranium at detectable concentrations in 96.6% of the urine specimens and thorium in 39.6% of the specimens. The 95th percentile concenetration for uranium was 34.5 ng/L (parts per trillion); concentrations ranged up to 4080 ng/L. Thorium had a 95th percentile concentration of 3.09 ng/L; concentrations ranged up to 7.7 ng/L., (Copyright 1999 Academic Press.)

Objective: To compare the modified Rossetti fundoplication with the classic Nissen., Summary Background Data: The traditional surgical treatment of gastroesophageal reflux in children has been the classic Nissen fundoplication, defined by liver mobilization, crural repair, takedown of short gastric vessels, and floppy wrap. The authors have progressed in our technique of fundoplication and now perform a modified Rossetti fundoplication, defined by liver retraction without mobilization, no crural repair, short gastric vessels left intact, and 2-cm floppy wrap., Methods: A retrospective chart review was performed on 407 pediatric patients who had open fundoplications (Jan. 13, 1993, to Feb. 25, 1998). Two groups were analyzed: the Nissen group (171 patients) and the Rossetti group (236 patients). Groups were compared for incidence of recurrent reflux, dysphagia, hiatal hernia, need for esophageal dilation, revision of fundoplication, time to discharge, and operative time., Results: Incidence of dysphagia (3.7% vs. 3.3%), postoperative hiatal hernia (1.9% vs. 1.4%), need for esophageal dilation (1.2% vs. 0.5%), and need for fundoplication revision (2.5% vs. 2.3%) were similar between the groups. The mean operative time was significantly decreased in the Rossetti group (65 +/- 25 minutes) versus the Nissen group (73 +/- 33 minutes). Recurrent reflux occurred significantly more often in the Nissen group (11.2%) than in the Rossetti group (5.1 %)., Conclusion: The modified Rossetti fundoplication has a low complication rate and is the authors' preferred method for the surgical treatment of gastroesophageal reflux in children.

The internal ribosome entry segment (IRES) of picornaviruses consists of approximately 450 nt of 5'-untranslated region, terminating at the 3' end with an approximately 25 nt element consisting of an absolutely conserved UUUC motif followed by a more variable pyrimidine-rich tract and G-poor spacer, and finally an AUG triplet, which is considered to be the actual ribosome entry site. Events following entry at this site differ among picornaviruses: in encephalomyocarditis virus (EMCV) virtually all ribosomes initiate translation at this site (AUG-11); in foot-and-mouth-disease virus (FMDV), one-third of the ribosomes initiate at this AUG (the Lab site), and the rest at the next AUG 84 nt downstream (Lb site); and in poliovirus (PV), the AUG at the 3' end of the IRES (at nt 586 in PV type 1) is considered to be a silent entry site, with all ribosomes initiating translation at the next AUG downstream (nt 743). To investigate what determines this different behavior, chimeras were constructed with a crossover at the conserved UUUC motif: the body of the IRES, the sequences upstream of this UUUC motif, was derived from one species, and the downstream sequences from another. When the body of the FMDV or PV IRESes was replaced by that of EMCV, there was a marked increase in the absolute and relative frequency of initiation at the upstream AUG, the Lab site of FMDV and 586AUG of PV, respectively. In contrast, when the body of the EMCV IRES was replaced by that of PV, initiation occurred with no preference at three AUGs: the normal site (AUG-11), AUG-10 situated 8 nt upstream, and AUG-12, which is 12 nt downstream. Thus although the context of the AUG at the 3' end of the IRES may influence initiation frequency at this site, as was shown by improving the context of 586AUG of PV, the behavior of the ribosome is also highly dependent on the nature of the upstream IRES. Delivery of the ribosome to this AUG in an initiation-competent manner is particularly efficient and accurate with the EMCV IRES.

Objective: The appropriate timing, as well as the type of intervention, for the treatment of empyema in children is controversial. The advent of video-assisted thoracic surgery (VATS) has changed the way we treat these children. Therefore, we reviewed our experience with the early use of VATS in the treatment of empyema and formulated a treatment algorithm., Methods: We retrospectively reviewed medical records of all patients undergoing VATS for empyema at Arkansas Children's Hospital from December 1994 to February 1997. All patients were treated by the pediatric surgical service and had the diagnosis of empyema confirmed at surgery. Results are reported as means, unless otherwise noted., Results: Twenty-five children with empyema were treated with VATS during the review period. Their age was 48.3 months, and the duration of symptoms was 7.4 days. All the patients had parapneumonic empyemas and had received preoperative antibiotics for 10.1 days. Preoperative imaging included chest radiography in 25 (100%), ultrasonography in 20 (80%), and computed tomography in 10 (40%). All patients with documented loculated parapneumonic fluid collections underwent VATS within a mean of 2 days of hospitalization. Chest tubes were removed in 3.2 days, resulting in a postoperative length of stay of 4.9 days. Total length of stay was 7.3 days. One patient required conversion to minithoracotomy and required a transfusion. There were no other complications or deaths. Follow-up was available for 22 (88%) children, and there was resolution of symptoms in all children with no recurrences., Conclusions: Earlier intervention with VATS in the treatment of empyema in children is safe and may reduce hospital charges by shortening hospital stay. A treatment algorithm based on early use of VATS is also described.

The rotational spectra of cis- and trans-1-hydroxynaphthalene and trans-1-DO-naphthalene have been recorded between 6 and 18 GHz using a pulsed microwave spectrometer. Most of the transitions detected are a type; hyperfine splittings from the electric quadrupole interaction were observed for some transitions of the deuterated isotopomer. The frequencies were well modeled with an S-reduced asymmetric rotor Hamiltonian. The rotational constants were determined much more accurately than previously. In addition, the quartic centrifugal distortion parameters were determined for the first time. Their values were very small, consistent with the rigid framework of this aromatic molecule. Theoretical calculations were carried out to support the assignment of the two forms to the cis and trans conformers. These calculations suggested that the cis conformer is slightly nonplanar in its equilibrium configuration, a property which is not inconsistent with its rotational constants. Copyright 1999 Academic Press.

Vaccines able to induce both secretory IgA for protection of mucosal surfaces and systemic immunity to pathogens invading the host are of great interest in the war against infectious diseases. Mucosal vaccines trigger immune cells in mucosal inductive sites and thus can induce immunity in both the mucosal and systemic compartments. This review presents a critical survey of adjuvants and delivery systems currently being tested for mucosal immunization. A better understanding of cellular and molecular factors involved in the regulation of mucosal immunity will help in the design of safer mucosal vaccines to elicit the appropriate protective immune response to a given pathogen.

Initiation of translation of the animal picornavirus RNAs is via a mechanism of direct internal ribosome entry, which requires a substantial segment of the viral 5'-untranslated region, generally known as the IRES (for "internal ribosome entry site"). Because, however, translation of the RNAs of members of the enterovirus, and more especially, the rhinovirus subgroups of the Picornaviridae is restricted in the reticulocyte lysate system, but is greatly stimulated by the addition of HeLa cell extracts, the implication is that, in these cases, internal initiation also requires cellular trans-acting factors that are more abundant in HeLa cell extracts than in rabbit reticulocytes. This was used as the basis of a functional assay for the purification of the HeLa cell factors required for translation dependent on the human rhinovirus-2 (HRV) IRES. There are two such HeLa cell factors separable by ion-exchange chromatography, each of which is individually active in the assay, although their combined effect is synergistic. One of these activities is shown to be polypyrimidine-tract binding protein (PTB) on the grounds that (1) the activity copurifies to homogeneity with PTB and (2) recombinant PTB expressed in Escherichia coli stimulates HRV IRES-dependent translation with a specific activity similar to that of the purified HeLa cell factor. Furthermore, it is shown that recombinant PTB also stimulates the translation of RNAs bearing the poliovirus type 1 (Mahoney) IRES.