Search

We describe the synthesis and biological evaluation of a series of novel aryl sulfonamides that exhibit potent inhibition of Na

Na

Variants implicated in childhood epilepsy have been identified in all four voltage-gated sodium channels that initiate action potentials in the central nervous system. Previous research has focused on the functional effects of particular variants within the most studied of these channels (NaV1.1, NaV1.2 and NaV1.6); however, there have been few comparative studies across channels to infer the impact of mutations in patients with epilepsy. Here we compare patterns of variation in patient and public databases to test the hypothesis that regions of known functional significance within voltage-gated sodium (NaV) channels have an increased burden of deleterious variants. We assessed mutational burden in different regions of the Nav channels by (1) performing Fisher exact tests on odds ratios to infer excess variants in domains, segments, and loops of each channel in patient databases versus public "control" databases, and (2) comparing the cumulative distribution of variant sites along DNA sequences of each gene in patient and public databases (i.e., independent of protein structure). Patient variant density was concordant among channels in regions known to play a role in channel function, with statistically significant higher patient variant density in S4-S6 and DIII-DIV and an excess of public variants in SI-S3, DI-DII, DII-DIII. On the other hand, channel-specific patterns of patient burden were found in the NaV1.6 inactivation gate and NaV1.1 S5-S6 linkers, while NaV1.2 and NaV1.6 S4-S5 linkers and S5 segments shared patient variant patterns that contrasted with those in NaV1.1. These different patterns may reflect different roles played by the NaV1.6 inactivation gate in action potential propagation, and by NaV1.1 S5-S6 linkers in loss of function and haploinsufficiency. Interestingly, NaV1.2 and NaV1.6 both lack amino acid substitutions over significantly long stretches in both the patient and public databases suggesting that new mutations in these regions may cause embryonic lethality or a non-epileptic disease phenotype.

Nonselective antagonists of voltage-gated sodium (Na

Using structure- and ligand-based design principles, a novel series of piperidyl chromane arylsulfonamide Na

The sodium channel Na

Hemangiopericytoma (HPC) is a rare tumor of the central nervous system. Primary spinal occurrence of this tumor is extremely uncommon and cases involving the intramedullary spinal cord are even more rare. The purpose of this study was to explore the clinical features, surgical strategies, outcome and pathology in a consecutive series of patients treated at a single institution.The authors performed a retrospective review of the clinicopathological characteristics of four patients with a pathological diagnosis of spinal HPC.Four cases with intradural as well as intra/extra-medullary components were identified. Gross total resection with no recurrence at the operative site was achieved in the majority of patients with a spinal HPC. One patient had significant recurrence and eventually, succumbed to the disease.Increased awareness of these tumors' capability to occur intradurally and intramedullarly can help surgeons accurately diagnose and choose an effective plan of care. Gross total resection of hemangiopericytomas is the mainstay of treatment and should be pursued if feasible. Histopathology is essential to the diagnosis.

Voltage-gated sodium (Nav) channels propagate action potentials in excitable cells. Accordingly, Nav channels are therapeutic targets for many cardiovascular and neurological disorders. Selective inhibitors have been challenging to design because the nine mammalian Nav channel isoforms share high sequence identity and remain recalcitrant to high-resolution structural studies. Targeting the human Nav1.7 channel involved in pain perception, we present a protein-engineering strategy that has allowed us to determine crystal structures of a novel receptor site in complex with isoform-selective antagonists. GX-936 and related inhibitors bind to the activated state of voltage-sensor domain IV (VSD4), where their anionic aryl sulfonamide warhead engages the fourth arginine gating charge on the S4 helix. By opposing VSD4 deactivation, these compounds inhibit Nav1.7 through a voltage-sensor trapping mechanism, likely by stabilizing inactivated states of the channel. Residues from the S2 and S3 helices are key determinants of isoform selectivity, and bound phospholipids implicate the membrane as a modulator of channel function and pharmacology. Our results help to elucidate the molecular basis of voltage sensing and establish structural blueprints to design selective Nav channel antagonists.

Few proteins have been described functionally in such detail as ion channels. All ion channels open and close their ion-conducting pores, a process referred to as gating. The recent crystallization of the P-loop-containing channel KcsA has cast channel function in a new light. Results relating to a variety of P-loop-containing channels are converging on a common mechanism in which separation of the inner helices that line the pore results in channel opening. At the same time, differences — some subtle and some perhaps more profound — have emerged between channel types. Here we highlight the evidence for a specific conformational change during the gating of cyclic nucleotide-gated channels, and compare and contrast this evidence to that obtained for other channels.

Potassium (K+) channels influence neurotransmitter release, burst firing rate activity, pacing, and critical dampening of neuronal circuits. Internal and external factors that further modify K+channel function permit fine-tuning of neuronal circuits. Humanether-à-go-go-related gene (HERG) K+channels are unusually sensitive to external calcium concentration ([Ca2+]o). Small changes in [Ca2+]oshift the voltage dependence of channel activation to more positive membrane potentials, an effect that cannot be explained by nonspecific surface charge screening or channel pore block. The HERG–calcium concentration–response relationship spans the physiological range for [Ca2+]o. The modulatory actions of calcium are attributable to differences in the Ca2+affinity between rested and activated channels. Adjacent extracellular, negatively charged amino acids (E518 and E519) near the S4 voltage sensor influence both channel gating and Ca2+dependence. Neutralization of these charges had distinct effects on channel gating and calcium sensitivity. A change in the degree of energetic coupling between these amino acids on transition from closed to activated channel states reveals movement in this region during channel gating and defines a molecular mechanism for protein state-dependent ligand interactions. The results suggest a novel extracellular [Ca2+]osensing mechanism coupled to allosteric changes in channel gating and a mechanism for fine-tuning cell repolarization.

We have studied the functional effects of extracellular Cd(2+) on human ether-a-go-go-related gene (HERG) encoded K(+) channels. Low concentrations (10-200 microM) of extracellular Cd(2+) increased outward currents through HERG channels; 200 microM Cd(2+) more than doubled HERG currents and altered current kinetics. Cd(2+) concentrations up to 200 microM did not change the voltage dependence of channel activation, but shifted the voltage dependence of inactivation to more depolarized membrane potentials. Cd(2+) concentrations >or=500 microM shifted the voltage dependence of channel activation to more positive potentials. These results are consistent with a somewhat specific ability of Cd(2+) to destabilize the inactivated state. We tested the hypothesis that channel inactivation is essential for Cd(2+)-induced increases in HERG K(+) currents, using a double point mutation (G628C/S631C) that diminishes HERG inactivation (Smith, P. L., T. Baukrowitz, and G. Yellen. 1996. Nature (Lond.). 379:833-836). This inactivation-removed mutant is insensitive to low concentrations of Cd(2+). Thus, Cd(2+) had two distinct effects on HERG K(+) channels. Low concentrations of Cd(2+) caused relatively selective effects on inactivation, resulting in a reduction of the apparent rectification of the channel and thereby increasing HERG K(+) currents. Higher Cd(2+) concentrations affected activation gating as well, possibly by a surface charge screening mechanism or by association with a lower affinity site.

Objective To assess factors influencing uptake of amniocentesis after a positive Down's syndrome screening result. Methods Interviews of 53 Montana women with screening risks ≥1 in 300 after delivery. Results Thirty had accepted amniocentesis (“yes” group) and 23 had declined (“no” group) (57% uptake). Age at delivery was significantly higher (p=0.02) for the “no” than the “yes” group (mean 35.3 v 31.7 years). The mean risk of Down's syndrome ascertained by screening was 1 in 190 for the “no” group and 1 in 115 for the “yes” group (p=0.05). Statistically significant differences (p≤0.05) between opinions in the two groups included: ( a) desire to know if the fetus had Down's syndrome; ( b) perception of the burden of care for an affected child; ( c) support of doctor, spouse, and relatives for choice about amniocentesis; ( d) attitudes toward abortion; ( e) importance of religion; and ( f) concerns about the amniocentesis procedure. The most important factor for those choosing amniocentesis was knowing if the fetus had Down's syndrome, and for those not choosing amniocentesis, attitude about abortion. Conclusion Our results show the need for prescreening education to enable pregnant women to make informed decisions about screening for Down's syndrome and diagnostic testing.

A family with X linked inheritance of mental retardation (XLMR) is presented. There are 10 mentally retarded males and two affected females in two generations. There are four obligatory carriers, one of whom is described as "slow". Most affected males show macrocephaly and macro-orchidism, which are typical signs of the fragile X syndrome, but have been tested cytogenetically and by analysis of the FMR1 gene and do not have this syndrome. However, some normal males in the family also exhibit macro-orchidism and macrocephaly. Linkage analysis using markers derived from the X chromosome indicates that the causative gene in this family is located in the proximal long arm of the X chromosome, in the interval Xp11-q21. Maximum lod scores of 2.96 with no recombination were found at three loci in Xq13-q21: DXS1111, DXS566, and DXS986. Recombination was observed with DXS1002 (Xq21.31) and DXS991 (Xp11.2), loci separated by about 30 Mb. Although isolation of the gene in this family will be difficult because of the size of the region involved, the localisation should be helpful in investigating other similar families with XLMR, macrocephaly, and macro-orchidism not attributable to FMR1.

The past 20 years have seen major advances in the diagnosis and management of brain abscess, with a corresponding improvement in the survival rates. The advances in radiographic scanning, the availability of new antimicrobials, and the development of novel surgical techniques have all contributed to the decreases in associated morbidity and mortality. The relative rarity of brain abscess and the frequent delays in making the diagnosis render this condition a significant challenge for the clinician. A high index of suspicion is required so that effective therapy can be instituted as soon as possible. Close coordination of care between neurosurgeons and infectious diseases specialists is increasingly important in the complicated management of brain abscess. Adequate abscess drainage and appropriate antimicrobial therapy remain the cornerstones of proper treatment of this condition.

Among gastric cancer patients, the Rhesus D-negative phenotype correlated with increased tumour recurrence [all patients, n = 83, P = 0.026; curatively (R0) resected patients, n = 51, P = 0.093] and reduced overall survival time (all patients, log-rank P = 0.0028; R0 patients, log-rank P = 0.0003) and was identified in multivariate analysis as the most important independent prognostic marker in the R0 patient group (relative risk 9.1, P = 0.0013).

We describe a family with recurrent 11q23-qter deletion Jacobsen syndrome in two affected brothers, with unique mosaic deletion 'rescue' through development of uniparental disomy (UPD) in the mother and one of the brothers. Inheritance studies show that the deleted chromosome is of maternal origin in both boys, and microarray shows a break near the ASAM gene. Parental lymphocyte chromosomes were normal. However, the mother is homozygous in lymphocytes for all loci within the deleted region in her sons, and presumably has UPD for this region. In addition, she is mosaic for the 11q deletion seen in her sons at a level of 20-30% in skin fibroblasts. We hypothesize that one of her #11 chromosomes shows fragility, that breakage at 11q23 occurred with telomeric loss in some cells, but 'rescue' from the deletion occurred in most cells by the development of mitotic UPD. She apparently carries the 11q deletion in her germ line resulting in recurrence of the syndrome. The older son is mosaic for the 11q cell line (70-88%, remainder 46,XY), and segmental UPD11 'rescue' apparently also occurred in his cytogenetically normal cells. This is a novel phenomenon restoring disomy to an individual with a chromosomal deletion.

Thoracoscopic discectomy is a minimally invasive procedure simulating a thoracotomy and is an alternative to the costotransversectomy and transpedicular approaches. In recent studies authors have concluded that thoracoscopic discectomy is the preferred procedure; however, relative historical comparisons were difficult to interpret. The authors conducted a prospective nonrandomized study in which they compared data on 36 patients undergoing thoracoscopic discectomy with eight patients undergoing thoracotomy between 1995 and 1999.Patients affected with one- or two-level lesions underwent a thoracoscopic discectomy, and patients with three-level lesions or more underwent thoracotomy and discectomy. Data were collected on operative time, blood loss, chest tube duration, narcotic agent use, and hospital length of stay (LOS). Longer-term follow-up study of pain-related symptoms and neurological function was conducted. Patients who underwent thoracoscopic discectomy had shorter operative times, less blood loss, a shorter period of chest tube drainage dependence, less narcotic usage, and a shorter LOS. These findings were statistically significant (p0.05) for narcotic usage and shorter LOS. Pain related to radiculopathy was improved by means of 75%, and no patients experienced worsened pain. In patients with myelopathy there was an improvement of two Frankel grades in the thoracoscopic group and one Frankel grade in the thoracotomy discectomy group, but patients in the thoracotomy group were significantly worse preoperatively. One myelopathic patient from each group suffered a worsened outcome postoperatively, although this was not attributed to the method of surgery. The incidence of complications (minor and major) was 31% in the thoracoscopic group and greater than 100% (that is, more than one complication per patient) in the thoracotomy/discectomy group.One advantage to thoracoscopic discectomy is its reduced incidence of morbidity compared with thoractomy, but its steep learning curve and unfamiliar surgical techniques make this procedure less practical for surgeons not performing it frequently. The more familiar costotransversectomy, transpedicular, and thoracotomy procedures remain viable alternatives for surgeons more experienced in these procedures.

Object Thoracic pedicle screw fixation is effective and reliable in providing short-segment stabilization. Although the procedure is becoming more widely used, accurate insertion of the screws is difficult due to the small dimensions of thoracic pedicles, and the associated risk is high due to the proximity of the spinal cord. In previous studies authors have shown the accuracy of image-guided lumbar pedicle screw placement, but there have been no reported investigations into the accuracy of image-guided thoracic pedicle screw placement. The authors report their experience with such an investigation. Methods To evaluate the accuracy of image-guided thoracic pedicle screw placement in vitro and in vivo, thoracic pedicle screws were placed with an image-guidance system in five human cadavers and 10 patients. In cadavers, the accuracy of screw placement was assessed by postoperative computerized tomography and visual inspection and in patients by postoperative imaging studies. Of the 120 pedicle screws placed in five cadavers pedicle violation occurred in 23 cases (19.2%); there was one pedicle violation (4.2%) in each of the last two cadavers. Of the 45 pedicle screws placed in 10 patients, pedicle violations occurred in three (6.7%). Conclusions In comparison with historical controls, the accuracy of thoracic pedicle screw placement is improved with the use of an image-guidance system. It allows the surgeon to visualize the thoracic pedicle and the surrounding structures that are normally out of the surgical field of view. The surgeon, however, must be aware of the limitations of an image-guidance system and have a sound basic knowledge of spinal anatomy to avoid causing serious complications.

In a series of gastric cancer patients twenty-eight percent of the primary tumors expressed high levels of the Lewis carbohydrate. This correlated significantly with clinicopathological parameters of advanced disease (tumor size of50 mm, M1 stage, UICC stage IIIB/IV). In multivariate analysis, high Lewis expression was found to be a new independent factor of poor prognosis. In addition, Lewis was expressed on solid metastases and micrometastatic cells originating from Lewis positive primary tumors. The data suggest that Lewis positive tumor cells may have an advantage in penetrating secondary organs because, like leukocytes, they can specifically adhere to activated vascular endothelia.

Object. In recent studies some authors have indicated that 20% of patients have at least one ectatic vertebral artery (VA) that, based on previous criteria in which preoperative computerized tomography (CT) and standard intraoperative fluoroscopic techniques were used, may prevent the safe placement of C1–2 transarticular screws. The authors conducted this study to determine whether frameless stereotaxy would improve the accuracy of C1–2 transarticular screw placement in healthy patients, particularly those whom previous criteria would have excluded. Methods. The authors assessed the accuracy of frameless stereotaxy for C1–2 transarticular screw placement in 17 cadaveric cervical spines. Preoperatively obtained CT scans of the C-2 vertebra were registered on a stereotactic workstation. The dimensions of the C-2 pars articularis were measured on the workstation, and a 3.5-mm screw was stereotactically placed if the height and width of the pars interarticularis was greater than 4 mm. The specimens were evaluated with postoperative CT scanning and visual inspection. Screw placement was considered acceptable if the screw was contained within the C-2 pars interarticularis, traversed the C1–2 joint, and the screw tip was shown to be within the anterior cortex of the C-1 lateral mass. Transarticular screws were accurately placed in 16 cadaveric specimens, and only one specimen (5.9%) was excluded because of anomalous VA anatomy. In contrast, a total of four specimens (23.5%) showed significant narrowing of the C-2 pars interarticularis due to vascular anatomy that would have precluded atlantoaxial transarticular screw placement had previous nonimage-guided criteria been used. Conclusions. Frameless stereotaxy provides precise image guidance that improves the safety of C1–2 transarticular screw placement and potentially allows this procedure to be performed in patients previously excluded because of the inaccuracy of nonimage-guided techniques.

The association of malignancy and various glomerulopathies is a well recognized phenomenon. We report a case of nephrotic syndrome secondary to minimal-change disease in a patient with chronic lymphocytic leukemia (CLL) and review the literature on nephrotic syndrome in this disorder. Since the relative distribution of etiologies differ from what might be expected for primary nephrotic syndrome in a similar aged population, we propose that nephrotic syndrome is a potential paraneoplastic phenomenon associated with CLL. We hypothesize a possible etiologic role of different cell surface markers of the lymphocyte to explain the diverse renal histologic manifestations.

The cell adhesion molecule melonoma cell adhesion molecule (MCAM)/MUC18/CD146 is specifically up-regulated on tumors of neuroectodermal origin and in animal models confers metastatic capacity to human melanoma cells. To identify critical regions regulating MCAM expression in melanomas, 1 kilobase of the MCAM 5' region was analyzed for promoter activity and transcription factor binding in 1 glioma, 1 carcinoma, and 4 melanoma cell lines. The minimal MCAM promoter (-106/+22 base pair (bp)) consists of 4 Sp-1 sites, two AP-2 elements, one cAMP responsive element, and the initiator surrounding the transcriptional start site. Analysis of mutated constructs indicated that the cAMP-responsive element is a major transcriptional activator in the majority of cell lines. Site-directed mutagenesis revealed that, in AP-2 expressing cells, the AP-2 site within the core promoter (-23 bp) has an inhibitory influence on MCAM expression while the AP-2 sites at -131 and -302 bp are activating. Functional AP-2 was observed in both MCAM positive and MCAM negative melanoma cell lines indicating that expression of MCAM does not require loss of this transcription factor. Furthermore, all MCAM constructs were strongly expressed in MCAM negative as well as MCAM positive cells, indicating that the expression of this gene is not controlled solely by the presence of transactivating factors binding to the investigated region.

Cell adhesion molecules belonging to the integrin, cadherin and immunoglobulin superfamilies have been implicated in tumor progression in cutaneous melanoma. Expression of the alpha v beta 3 integrin first appears with the change from radial to vertical growth, a step which is associated with the development of metastatic potential. VLA-4 expression is characteristic of advanced primary tumors and may mediate interaction of the tumor cells with VCAM-1 on vascular endothelium. Expression of these integrins is a marker of poor prognosis in patients and can confer invasive (alpha v beta 3) and metastatic (VLA-4) properties to human melanoma cells injected into nude mice. Expression of the immunoglobulin superfamily molecules MUC18/MCAM and ICAM-1 are associated with primary tumors and metastases. MUC18/MCAM expression confers metastatic potential and increased tumorigenicity to human melanoma cells. Expression of ICAM-1 has been shown to be a marker of poor prognosis in stage I tumors and interfering with its expression inhibits experimental metastasis by melanomas in nude mice. E-cadherin is used by epidermal melanocytes to interact with neighboring keratinocytes. Changes in E-cadherin expression and cellular localization is first observed in the radial growth phase, the earliest stage in melanoma development. Loss of E-cadherin function is associated with upregulation or induction of MUC18/MCAM and alpha v beta 3 in melanocytic cells in vitro and with alterations in the levels and cellular distribution of the transcriptional regulator beta-catenin in melanomas in vivo. These observations suggest that disturbances in E-cadherin function is not only important in carcinomas but may also be a critical event in melanoma tumor progression.

Computer image-guided surgery has been widely accepted because it allows the surgeon to track an instrument through unvisualized critical structures of a patient in real-time, thus minimizing the risk of injury. Current spinal and cranial image-guided surgery is, however, limited by the lack of surgical instruments and software applications that would allow rapid interchange of useful instruments to perform the procedures. Most image-guided systems utilize a single standard probe or a few pre-defined instruments that are not necessarily useful for performing the actual surgical procedure. Present image-guided technology for screw placement in spinal surgery utilizes the standard probe only to confirm the entry point location and view the planned trajectory of the screw. The surgeon then resumes the procedure using standard surgical instruments to drill, tap and place screws without the benefit of image guidance. Our clinical laboratory experience with spinal image-guided surgery indicates that there is potential for error between each of these procedural steps of screw placement. Despite accurately locating an entry point, any deviation in the trajectory during drilling of a pilot hole, tapping or screw placement may result in significant errors in screw placement and potential neurovascular injury. We have developed custom software applications and universal hardware adaptation devices for spinal image-guided surgery that allow the use of standard instruments for intraoperative guidance. Utilizing universal dynamic registration hardware and software, standard surgical instruments are adapted for real-time image guided surgery. An array of light emitting diodes can be attached to essentially any rigid instrument with a definable tip and then calibrated to the system for intraoperative use. Laboratory tests using a cadaveric model indicate a difference in accuracy of less than 1.0 mm between the standard probe and a dynamically registered custom instrument and an absolute mean error of less than 2.0 mm for the image-guided system which is clinically insignificant in most cases. This technology is a significant step forward as it allows the surgeon to use a full array of instruments with image guidance and will ultimately make spinal and intracranial surgery safer and more accurate.

Human ether-à-go-go-related gene (HERG) encoded K+ channels were expressed in Chinese hamster ovary (CHO-K1) cells and studied by whole-cell voltage clamp in the presence of varied extracellular Ca2+ concentrations and physiological external K+. Elevation of external Ca2+ from 1.8 to 10 mM resulted in a reduction of whole-cell K+ current amplitude, slowed activation kinetics, and an increased rate of deactivation. The midpoint of the voltage dependence of activation was also shifted +22.3 +/- 2.5 mV to more depolarized potentials. In contrast, the kinetics and voltage dependence of channel inactivation were hardly affected by increased extracellular Ca2+. Neither Ca2+ screening of diffuse membrane surface charges nor open channel block could explain these changes. However, selective changes in the voltage-dependent activation, but not inactivation gating, account for the effects of Ca2+ on Human ether-à-go-go-related gene current amplitude and kinetics. The differential effects of extracellular Ca2+ on the activation and inactivation gating indicate that these processes have distinct voltage-sensing mechanisms. Thus, Ca2+ appears to directly interact with externally accessible channel residues to alter the membrane potential detected by the activation voltage sensor, yet Ca2+ binding to this site is ineffective in modifying the inactivation gating machinery.

Torsades de pointes is a polymorphic ventricular arrhythmia resulting from congenital or drug-induced (acquired) QT prolongation. Pharmacologic suppression of repolarizing potassium currents is one mechanism causing the acquired long QT (LQT) syndrome. Recent studies have linked mutations in a gene encoding a potassium channel subunit (HERG) to the LQT syndrome. Clinical experience indicates that intravenous magnesium sulfate is effective in reversing torsades de pointes, but the molecular basis of this effect is not understood. This study was designed to investigate the effects of extracellular magnesium (Mg2+) on HERG potassium currents. HERG potassium channels were expressed in Xenopus oocytes and in a human cell line and were examined by voltage-clamp methods. Extracellular Mg2+ (0.3-10 mM) caused a concentration-dependent shift in the membrane-potential dependence of HERG channel opening, causing a reduction in K+ current. This effect was much greater than that observed in another human delayed rectifier K+ channel, hKv1.5, suggesting a specific interaction with the HERG channel. Quinidine is an antiarrhythmic drug that also causes torsades de pointes under certain conditions. Quinidine (3 microM) inhibited HERG currents expressed in oocytes by 32.1 +/- 3.2% (n = 5), whereas 1 microM quinidine inhibited HERG currents in tsA201 cells by 75.8 +/- 2.4% (n = 12). Increasing extracellular Mg2+ did not relieve the inhibition by quinidine, but caused additional suppression. These results indicate that extracellular Mg2+ exerts a direct action on HERG potassium channels, resulting in suppression of outward repolarizing potassium current. It is concluded that modulation of this important K+ current is not the mechanism by which intravenous magnesium terminates drug-induced LQT and torsades de pointes. Potent suppression of HERG channel current by quinidine, compared with that of I(Ks) and I(Na), is a likely contributor to torsades de pointes arrhythmias.

Object. This study was conducted to evaluate the results of shunting procedures for syringomyelia. Methods. In a follow-up analysis of 42 patients in whom shunts were placed in syringomyelic cavities, the authors have demonstrated that 21 (50%) developed recurrent cyst expansion indicative of shunt failure. Problems were encountered in patients with syringomyelia resulting from hindbrain herniation, spinal trauma, or inflammatory processes. A low-pressure cerebrospinal fluid state occurred in two of 18 patients; infection was also rare (one of 18 patients), but both are potentially devastating complications of shunt procedures. Shunt obstruction, the most common problem, was encountered in 18 patients; spinal cord tethering, seen in three cases, may account for situations in which the patient gradually deteriorated neurologically, despite a functioning shunt. Conclusions. Placement of all types of shunts (subarachnoid, syringoperitoneal, and syringopleural) may be followed by significant morbidity requiring one or more additional surgical procedures.

Pseudomeningocele in the lumbar spine due to spinal fractures or surgical procedures are well-recognized complications. We treated a 24-year-old man who fell from a horse, landing on his buttocks, and developed headaches, back pain, and a large lumbar subcutaneous fluid collection. Plain radiographs and magnetic resonance (MR) imaging revealed a midline defect in the sacral lamina and a large fluid collection in the subcutaneous space consistent with cerebrospinal fluid (CSF). He was treated conservatively, his symptoms resolved, and follow-up MR imaging showed resolution of the CSF accumulation. To our knowledge, there have been no cases of traumatic pseudomeningocele related to spina bifida occulta reported in the literature. The authors postulate that congenital defects in the neural arch contribute to the occurrence of this entity, and nonsurgical treatment should be the initial course.

To extend previous studies on the anti-inflammatory role of interleukin (IL)-10 in vivo, mice pretreated with IL-10 were subjected to ionizing radiation (IR), lipopolysaccharide (LPS), or both and assessed for the expression of the intercellular adhesion molecule 1 (ICAM-1) in immunohistochemical analyses. IL-10 was able to almost fully protect LPS+IR-treated animals against ICAM-1 up-regulation. Because LPS and IR also increased adhesion of peripheral blood mononuclear cells, transendothelial migration assays were performed to investigate the functional significance of these findings. IR was found to induce transendothelial migration, and this effect could be enhanced by cotreatment with LPS, in the same fashion as peripheral blood mononuclear cell adhesion. Also in this system, IL-10 proved to act as a potent LPS antagonist. Finally, in vivo immunohistochemical analyses revealed an infiltration of CD3+ T lymphocytes into organs that were the target of transplant-related complications after LPS+IR treatment. This infiltration could also be completely reversed by IL-10 pretreatment.

Propylthiouracil (PTU), used to treat Graves' disease, occasionally induces a lupus-like syndrome. A 39-year-old woman developed clinical manifestations of systemic lupus erythematosus with rash, serositis, myocarditis, and acute renal insufficiency, associated with serologies for lupus, after 3 wk of exposure to the drug. Renal biopsy revealed diffuse proliferative lupus nephritis. This article reviews the side effects of PTU and the literature on PTU-induced nephrotoxicity. Possible mechanisms and management of drug-induced lupus nephritis are also reviewed. To facilitate early and specific intervention, clinicians should be aware of the propensity of PTU to cause lupus-like syndromes with renal involvement.

The cell surface adhesion molecule MCAM (MUC18) is strongly expressed by advanced primary and metastatic melanomas but is weaker and less frequent in nevus cells. Previous studies have shown that MCAM expression correlates with tumor thickness and metastatic potential of human melanoma cells in nude mice. To provide direct evidence that MCAM plays a role in tumor growth and metastasis of human melanoma, the nonmetastatic MCAM-negative primary cutaneous melanoma SB-2 cells were transfected with MCAM cDNA and analyzed subsequently for changes in their tumorigenic and metastatic potential. Enforced expression of MCAM in SB-2 cells rendered them highly tumorigenic and increased their metastatic potential in nude mice as compared with parental and control transfected cells. The transfected cells displayed increased homotypic adhesion, increased attachment to human endothelial cells, decreased ability to adhere to laminin, and increased invasiveness through Matrigel-coated filters. Anti-MCAM monoclonal antibody reversed these functions in the transfected cells but not in control cells. The above changes in function attributed to the expression of MCAM may underlie the contribution of MCAM/MUC18 to the malignant phenotype.

OBJECTIVE : We describe a continuous microneurosurgical irrigation and suction technique. This technique automatically clears the operative field, frees the surgeon to perform microdissection with both hands, and actually aids in dissection of the arachnoid layer. TECHNIQUE : The suction catheter (MicroVac ; P.M.T., Inc., Hopkins, MN) described by Spetzler and Iverson and an additional continuous microirrigation technique are discussed. The catheter design has a sump effect and is secured in a dependent position in the operative field to continuously remove blood, irrigate the area, and reduce cerebrospinal fluid accumulation. The irrigation system consists of standard intravenous tubing with an angiocatheter used to direct a precise stream into the operative field. RESULTS AND CONCLUSION : The irrigation and suction system, when properly adjusted, continuously clears the operative site of minute amounts of blood that may obscure the surgeon's view and assists in dissection of the arachnoid layer. It has been used since 1991 with excellent success and satisfaction.

Mader is a novel delayed early response gene encoding a nuclear protein. Upregulation of the Mader 2.7 kb mRNA requires protein synthesis and can be induced in a variety of human cell lines by serum stimulation and in freshly isolated lymphocytes by mitogens. mRNA levels reach a maximum by 2 h and return to basal levels by 6 h. Mader is highly conserved as cross-hybridizing DNA sequences were observed in species as diverse as Rhesus and S. cerevisiae. The Mader protein of approximately 55 kD has two proline rich domains and contains 15 potential phosphorylation sites, a nuclear localization signal, and multiple S(T)PXX motifs that are characteristic of regulatory DNA binding proteins. Monoclonal antibodies produced against Mader confirm that it is localized to the nucleus. These features of Mader suggest that it may play a role in growth regulation. Although Mader mRNA can be detected in most cell lines, only occasional immunoreactive cells were detected in normal human tissues. In contrast, uniform strong nuclear staining was observed in all malignant melanomas examined. The fact that only one of six benign melanocytic nevi examined showed evidence of Mader expression suggests that over-expression of Mader protein may be associated with the malignant transformation of melanocytes.

Diverse pathogenetic factors may lead to the complex syndrome of early graft dysfunction, an important determinant of later renal graft outcome. That humoral factors could play a prominent role in the development of the syndrome was suggested by the capillary deposition of complement fragment C4d in about 50% of graft biopsies. This study investigates whether the presumed classical activation of complement is derived from preformed antibodies that would possibly react against endothelial HLA-class II molecules. Such antibodies were detectable by flow cytometry using a representative collection of 11 DR-typed lymphoblastoid cell lines (LCL) as targets. Simultaneous discrimination between complement-activating and -nonactivating antibodies was achieved by two-color FACS analysis. Using this method, 44 out of 86 pretransplant serum samples from recipients with early dysfunction showed reactivity against LCL (18 complement-activating, 14 nonactivating, 12 complement-activating non-IgG). Conventional panel-reactivity was observed in 20 sera only (14 also LCL-reactive). Evaluation of corresponding graft biopsies revealed that capillary C4d was associated with LCL (P = 0.018) and panel reactivity (P = 0.015) alone and in combination (P = 0.001; Pearson's chi-square test). Thirteen subsequent graft losses within one year were observed in the LCL-reactive group as compared with seven losses in the nonreactive group (panel-reactive: 7; nonreactive: 13). Thus, measurement of LCL-reactive antibodies in prospective transplant recipients improves the assessment of an individual immunological risk. The results further demonstrate that performed antibodies do not simply reflect the enhanced overall immune reactivity of certain recipients but rather act locally in vivo, thus emphasizing the role of humoral factors in the development of early graft dysfunction.

The Townes-Brocks syndrome (TBS) is comprised of a triad including characteristic anal, thumb, and ear anomalies. There are many other organ system abnormalities which may be present. However, the literature does not emphasize craniofacial findings except with reference to the typical ear configuration. A three-generation family is described in which craniofacial manifestations were prominent and a Goldenhar-like condition was considered as the most likely diagnosis. However, with the recent birth of an affected male who had an imperforate anus, the diagnosis of TBS was also considered. The family manifests a variety of Goldenhar-like findings, including epibulbar dermoids, hemifacial microsomia, preauricular tags, macrostomia, and micrognathia in addition to classical ear, radial, and anal findings of TBS. We report on this family to point out a possible biological relationship of these two conditions.

Ectopic expression of carcinoembryonic antigen (CEA) by the melanoma cell line Mel Wei led to alterations in cell morphology and to changes in the expression of two melanoma-associated cell adhesion molecules, neural cell adhesion molecule and MUC18. The normally flat, triangular cells developed neurite-like extensions and exhibited a less organized growth pattern. When compared to untransfected Mel Wei cells or to those transfected with an irrelevant cDNA, two independent CEA transfectants showed a decrease in the expression of neural cell adhesion molecule and an increase in the expression of MUC18. These changes, which are characteristic of the metastatic phenotype in melanomas, were observed at the cell surface and at the level of mRNA and were independent of adherent growth. Steady-state levels of neural cell adhesion molecule mRNA were reduced in CEA-expressing cells by approximately 5-fold, while MUC18 mRNA showed an 8-fold increase. No significant differences in the expression of intercellular adhesion molecule-1 or beta-2 microglobulin were observed between Mel Wei and CEA-Mel Wei. These data indicate that changes in the expression of a single cell adhesion molecule such as CEA can lead to alterations in the expression of unrelated cell adhesion molecules and may contribute to the general derangement of adhesive interactions observed frequently in tumor cells.

Now that the cystic fibrosis (CF) gene has been identified, direct genetic testing for this disorder is available. The current lack of precision has generated a controversy concerning whether population screening is advisable. However, there is general agreement that testing for CF carriers should be offered to CF-affected families. The purpose of this study was to explore levels of understanding and feelings about carrier status and genetics of CF in affected families. Fifty-four adult CF siblings and their 30 spouses drawn from Children's Hospital, Oakland, and Children's Hospital, Boston, were interviewed, and transcripts were coded on various categories. The relationship between birth order and beliefs about carrier status was significant, with last-born siblings more likely to believe they are not carriers. Higher sibling resentment was found to be significantly related to willingness to abort an affected fetus, to more guilt, and to assumption of carrier status. Thirty percent of siblings believe that carrier status implies health difficulties. Increased feelings of guilt were significantly related to the belief that carrier status implies health problems and to the wish to be a carrier. Interestingly, beliefs regarding carrier status and the wish to be a carrier are not influenced by educational or income level. Some siblings have had their child tested for carrier status and others are planning to do so before the child reaches the age of 18 years. Perception of carrier status is strongly influenced by psychological factors.(ABSTRACT TRUNCATED AT 250 WORDS)

Retinoic acid (RA) and 1,25-(OH)2-vitamin D3 (1,25-D3) induced U937 cell maturation into distinct monocytic phenotypes, as demonstrated by up-regulation of CD23 by RA and CD14 by 1,25-D3. Differentiation by RA but not by 1,25-D3 was associated with reduction of basal and complete suppression of interferon-γ (IFN-γ)–stimulated intercellular adhesion molecule 1 (ICAM-1) expression. Induction of cyclooxygenase activity by RA and attenuation of basal ICAM-1 expression exhibited similar kinetics. Treatment with indomethacin prevented and prostaglandin E2 (PGE2), dibutyryl-cAMP, or forskolin mimicked reduction of basal ICAM-1 expression by RA, indicating that this effect of RA is mediated by PGE2 synthesis and subsequent cAMP elevation. In contrast, suppression of IFN-γ-induced ICAM-1 expression by RA was only partly reversible by indomethacin, suggesting that inhibition of IFN-γ stimulation was not completely due to cyclooxygenase induction. RA did not always counteract IFN-γ, as it cooperated with IFN-γ in down-regulating very late activation antigen 4. Specific polymerase chain reaction and Northern blotting of ICAM-1 mRNA revealed that RA suppressed ICAM-1 induction by IFN-γ at the transcriptional level. RA also blocked ICAM-1 induction by IFN-γ in isolated human blood monocytes. In conclusion, inhibition of basal and stimulated ICAM-1 expression in monocytic cells may provide a mechanism for beneficial anti-inflammatory effects of retinoids. J. Leukoc. Biol. 57: 401–406; 1995.

Loss and gain of cell surface molecules determines the mobilization, emigration and invasiveness of epithelial cancer cells. As a first approach to gain further insight into these processes, we have followed two strategies: (1) to identify tumour cells which have disseminated early from primary carcinomas and to obtain information about the phenotype and prognostic significance of these cells; and (2) to identify molecular changes occurring in primary tumour cells at the time they develop their metastatic potential. Our analyses indicate that changes in the adhesive properties of solid tumour cells, such as down-regulation of desmosomal proteins (e.g. plakoglobin) and neo-expression of ICAM-1 or MUC18, are important determinants of the metastatic capability of individual malignant cells. The expression pattern of these cell adhesion molecules during tumour progression appears to reflect a disturbance at the level of the molecular elements normally responsible for controlling their expression. The outlined current strategies for detection, characterization and antibody therapy of cancer micrometastasis can be applied to the secondary prevention of metastatic disease in patients with minimal residual cancer.

Human ICAM-1 expression is up-regulated by IFN-gamma and TNF-alpha and synergistically increased by a combination of both. Transient expression of ICAM-1/luciferase constructs led to definition of the regulatory regions mediating the cytokine response and showed that both are necessary for synergism. Immunochemical electromobility shift assays identified the TNF-alpha-dependent complexes that bound to the NF-kappa B like sequence at -187 as p65/p50 and p65/c-Rel. The interferon responsive region at -75 was bound by a Stat1 alpha (p91) containing complex that was activated by both IFN-gamma and IFN-alpha. Although both regions were required for synergism, no additional or enhanced binding complexes were observed.

The MUC18 protein, a member of the immunoglobulin superfamily and related to several adhesion molecules, shows an expression pattern in human malignant melanoma which is closely associated with tumor progression and the onset of metastasis. To determine the expression pattern of MUC18 in normal human tissues, immunohistochemical analysis was performed on frozen sections of a variety of normal human tissues using monoclonal antibodies against three different epitopes. This analysis showed that expression of MUC18 is limited to smooth muscle cells and to vascular endothelium. No reactivity could be observed with epithelial cells or with quiescent or activated hemopoetic cells. Smooth muscle cells in lung, skin, and in the gastrointestinal tract express MUC18 as does vascular smooth muscle, whereas myocardium or skeletal muscle appeared negative. Comparison of MUC18 staining with that of the panendothelial marker CD31 showed that MUC18 is expressed on the endothelia of a subset of blood capillaries and in tumor vessels but is absent on the endothelium of arterial vessels and large veins. The regulation of MUC18 expression was investigated in vascular smooth muscle cells and endothelial cells cultured in vitro. These studies revealed induction of the gene in endothelial cells upon proliferation. The observation that the MUC18 protein is not only present on melanoma cells but also on the endothelia of blood vessels penetrating primary and metastatic melanomas suggests a complex involvement of this potential cell adhesion molecule in tumor angiogenesis and metastasis.

Cell surface melanoma-associated antigens can mediate cell-cell or cell-substrate adhesion, signal transduction, proteolysis, or immune recognition and play a key role in determining invasive and metastatic competence of the tumor cells. The melanoma-associated antigen, A32, was defined by a murine monoclonal antibody and was immunoprecipitated as a single 113 kDa integral membrane glycoprotein containing sialic acid and HNK-1 carbohydrate moieties. Immunohistochemistry revealed the presence of A32 antigen on most melanomas and nevi but not on normal epidermal melanocytes. Of the normal tissues tested, only endothelium, smooth muscle, cerebellum, and hair follicles expressed the A32 antigen. Tryptic peptides of the A32 antigen obtained after immunoaffinity chromatography showed sequence identity to MUC18 antigen, a member of the immunoglobulin supergene family. Melanoma cells adhered to affinity-purified A32 antigen immobilized to a solid phase, and the adhesion was blocked by either soluble A32 antigen or monoclonal antibody against the HNK-1 carbohydrate moiety. These findings, together with the observation that A32 antigen is concentrated in cell-cell contact borders, suggest that this antigen is an adhesion molecule with a possible role in tumor invasion and metastasis.

Transcription regulation of the human intercellular adhesion molecule-1 gene by the phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA), tumor necrosis factor alpha (TNF alpha), and the glucocorticoid dexamethasone was studied using transient transfections in 293 cells with intercellular adhesion molecule-1 promoter-luciferase constructs (together with a glucocorticoid receptor expression vector). TPA and TNF alpha induced promoter activity, which was repressed by dexamethasone. Four TPA-responsive DNA regions were identified, each containing a potential TPA-responsive enhancer sequence: 1) -677/-340 an AP3-like sequence; 2) -290/278 a TPA-response element (TRE); 3) -227/-175 an NF kappa B-like sequence; 4) -105/-38 an AP2-like sequence. TNF alpha enhanced transcription only through region 3. The TRE in region 2 appeared to be functionally coupled to a distal TATA box at -313 and differed from the consensus TRE with respect to binding characteristics for members of the AP1 family. The newly identified NF kappa B enhancer (TGGAAATTCC) is bound by a TNF alpha-induced nuclear protein and appears to be the key element in rapid transcription induction by TNF alpha (and TPA), while transactivation of this element is repressed by the ligand-bound glucocorticoid receptor. We propose a negative cross-talk between the NF kappa B transcription factor and the glucocorticoid receptor.

To determine the incidence, cause, and patterns of diarrhea during the first 2 years of life among infants infected perinatally with the human immunodeficiency virus (HIV).A cohort study in which infants were enrolled shortly after birth and followed up longitudinally using biweekly surveillance for the occurrence of diarrhea. Stool specimens collected at the onset of diarrhea were evaluated for enteropathogens. Infants who were infected with HIV were compared with uninfected infants.Infants born to HIV-infected women at the University of Maryland Hospital, Baltimore, were recruited at 0 to 3 months of age. This analysis included 58 infants enrolled in the cohort and followed up at least 15 months (unless death intervened) whose HIV status was established (18 HIV-infected infants and 40 HIV-uninfected infants).The overall incidence of diarrhea in HIV-infected infants was 3.2 episodes per 12 child-months compared with 1.5 episodes per 12 child-months among HIV-uninfected infants (incidence density ratio, 2.2; P.05). An enteropathogen was identified in stool specimens collected during 20% of diarrheal episodes occurring in HIV-infected infants and during 25% of diarrheal episodes occurring in HIV-uninfected infants. Episodes that persisted for 14 days or longer were significantly more common among HIV-infected infants. The peak incidence of diarrhea occurred at 0 to 5 months of age for HIV-infected infants compared with 6 to 11 months for HIV-uninfected infants. Early onset of diarrhea (6 months old) in HIV-infected infants was associated with the later development of persistent episodes of diarrhea, and those with persistent episodes had more severe HIV infection, characterized by a significantly higher frequency of opportunistic infections and lower CD4+ T-lymphocyte counts by 1 year of age.Both acute and persistent episodes of diarrhea are major sources of morbidity in HIV-infected infants. Moreover, persistent diarrhea is a marker for rapid progression of HIV disease.

Differential antibody reactivity has been used to identify molecules which change in expression or which are modified during tumor progression in human malignant melanoma. Such molecules may play a role in the development of the metastatic capacity of this tumor. Two of these molecules (ICAM-1 and MUC18) have been identified as cell adhesion molecules which are potentially involved in tumor-leukocyte-endothelial interactions.

To assess the influence of human immunodeficiency virus (HIV) infection on pregnancy outcome and the effect of pregnancy on the short-term course of HIV infection.Pregnant women with identified risk factors for HIV infection but without AIDS were tested serologically for HIV antibodies. Seropositive women were compared to seronegative patients with similar risk factors and demographic characteristics at enrollment, at delivery, and 6-8 weeks postpartum. One hundred one seropositive and 97 seronegative subjects were evaluated for symptoms or physical manifestations of HIV infection; evidence of immune dysfunction; historical, physical, or laboratory evidence of related infections; and maternal and neonatal outcome. Both groups were compared to the entire obstetric population delivering at the University of Maryland Hospital during 1 year.There was a significant reduction in reported risk behaviors in both groups during pregnancy as compared to the period before pregnancy (P.001). The majority of women in both groups were asymptomatic, but seropositive women were more likely to have a history or physical evidence of condylomata (13 versus 4%; P.05) and higher temperatures on admission to the labor suite (98.6 +/- 1.0 versus 98.3 +/- 0.8F; P = .02). Seropositive women were not at greater risk for antepartum medical complications. Only one woman developed an AIDS-defining opportunistic infection. Although hematologic indices in seropositive women were abnormal, these did not progress over the course of pregnancy. At delivery, seropositive women were more likely to receive antibiotics (25 versus 10%; P = .006) and less likely to have an episiotomy (25 versus 40%; P = .03), but obstetric outcome was unaffected. Neonatal status was independent of antibody status.Our findings support a growing body of evidence that pregnancy has no discernible effect on the early progression of HIV disease in asymptomatic women, and infection does not influence perinatal outcome.