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Surface-enhanced Raman spectroscopy (SERS) is a widely used sensing technique for ultrasensitivity chemical sensing, biomedical detection, and environmental analysis. Because SERS signal is proportional to the fourth power of the local electric field, several SERS applications have focused on the design of plasmonic nanogaps to take advantage of the extremely strong near-field enhancement that results from plasmonic coupling, but few designs have focused on how SERS detection is affected by molecular orientation within these nanogaps. Here, we demonstrate a nanoparticle-on-metal metasurface designed for near-perfect optical absorption as a platform for Raman detection of highly oriented molecular analytes, including two-dimensional materials and aromatic molecules. This metasurface platform overcomes challenges in nanoparticle aggregation, which commonly leads to low or fluctuating Raman signals in other colloidal nanoparticle platforms. Our metasurface-enhanced Raman spectroscopy (mSERS) platform is based on a colloidal Langmuir-Schaefer deposition, with up to 32% surface coverage density of nanogaps across an entire sensor chip. In this work, we perform both simulations of the local electric field and experimental characterization of the mSERS signal obtained for oriented molecular layers. We then demonstrate this mSERS platform for the quantitative detection of the drinking-water toxin polybrominated diphenyl ether (BDE-15), with a limit of detection of 0.25 μM under 530 μW excitation. This detection limit is comparable to other SERS-based sensors operating at laser powers over 3 orders of magnitude higher, indicating the promise of our mSERS platform for nondestructive and low-level analyte detection.

Background: There are significant limitations in Haiti for the diagnosis and management of sickle cell disease (SCD), including the non-availability of universal newborn screening (NBS) and transcranial Doppler (TCD) ultrasound screening, and the lack of diagnostic laboratory resources, oral penicillin and hydroxyurea (HU). Methods: Beginning in September 2019, CSHSCD (R01HL149121), a 5-year NIH-sponsored observational comparative study of children with SCD from Haitian ethnicity in Miami and in Haiti compared to children of African American ethnicity with SCD, was designed to increase access to care in Haiti. The study aims are 1) to compare the incidence of SCD among newborns from Haitian and African American ethnicity in Miami, 2) to establish NBS programs for hemoglobinopathies in Haiti, and 3) to compare cohorts of children in SCD at the study sites. The participating sites are the University of Miami (UM, Miami, Florida), Hôpital Saint Damien (HSD, Tabarre, Haiti), Hôpital de l'Université d'Etat d'Haïti (HUEH, Port-au-Prince, Haiti), Hôpital Universitaire Justinien (HUJ, Cap Haitien, Haiti), and Hôpital Sacré Coeur (HSC, Milot, Haiti). HUJ and HSC use two NBS screening methods (isoelectric focusing and Sickle SCAN rapid test) and HSD and HUEH use isoelectric focusing only. CSHSCD supplies penicillin and HU and trains TCD examiners to implement stroke risk screening. Data are collected in REDCap. Results: During the first 2 years and despite the COVID-19 pandemic, we established NBS sites with a cohesive network of physicians and nurses trained in the care of children with SCD in Haiti. This capacity building will support sustainability of the program. We successfully identified at least 15 new cases of SCD via newborn screening, trained six TCD examiners, and enrolled 130 children with SCD in follow up, providing them with penicillin prophylaxis and hydroxyurea for severe cases according to local protocols . Implementation activities which have helped are close communications between the investigators, monthly Zoom meetings to coordinate efforts with enrollment updates every month, the availability of rapid tests (Sickle SCAN and Gazelle miniature cellulose acetate electrophoresis) for the diagnosis of SCD, especially when there is no laboratory equipment on site. Implementation challenges we have faced are mostly two. The first is the timely completion of DUNS and SAM registration for the two public hospitals, with one site achieving this after 9 months and the other site taking 18 months to complete. The reasons for the delay are the inability for the UM site to direct these efforts, following strict rules, and the Haitian hospital officers' lack of familiarity with website requirements. We were able to achieve these registrations with the assistance of one Haitian study staff who is very acquainted with internet navigation and became familiarized with requirements. Outsourcing materials to Haiti is another major challenge, with either gaps in the delivery of supplies because of multiple steps involved in ordering and shipping or with delays in releasing equipment once it is at the Port-au-Prince customs, resulting in gaps in NBS in one of the sites for 8 weeks. We have minimized these issues by opening a one-year ticket to order materials from the different companies involved. Also, Haiti's lack of infrastructure, available materials and medications, and political instability limit health care delivery. Conclusion: Since its inception, we have achieved major milestones, including capacity building and implementation of NBS, TCD training, and enrollment of children with SCD into the prospective cohorts despite the current COVID-19 pandemic. Material outsourcing challenges have been the major implementation problem we have faced due to systemic factors. We anticipate that these factors will be corrected or minimized as we have learned how to handle them. These problems were expected as part of conducting an international study in a low-resource setting. Acknowledgment: We acknowledge NHLBI for supporting this work. Disclosures Alvarez: Forma Therapeutics: Membership on an entity's Board of Directors or advisory committees; GBT: Membership on an entity's Board of Directors or advisory committees. Romano: Genentech: Research Funding; Vycor: Current holder of individual stocks in a privately-held company; NovaVision: Consultancy.

High Raman enhancement factors (EFs) have been observed for surface-enhanced Raman spectroscopy (SERS) substrates fabricated from colloidal metal nanoparticles. Electrodynamic models of single nanoparticles often do not accurately predict the Raman EFs measured experimentally for such colloidal substrates, which often consist of nanoparticles that exhibit heterogeneity in both size and shape. Here, we investigate the size and shape dispersity of colloidal Ag nanocube samples and their effect on Raman EF. We generate an analytical model that incorporates nanocube size dispersion and calculates the Raman EF associated with an ensemble of differently sized nanocubes. For nanocubes that are ∼70–80 nm in size, this model is sufficient to correct the inaccuracies for electrodynamic simulations of a single nanocube model. For nanocubes >90 nm, size dispersity alone fails to account for the high EFs observed when these substrates are excited off-resonance. We hypothesize that shape defects may play a significant role in optical response at these larger sizes and discuss how these factors can play a role in our analytical model.

This study tests the hypothesis that therapist responsiveness in the first two sessions of therapy relates to three measures of early patient engagement in treatment. Using videotapes and data from the NIMH Treatment of Depression Collaborative Research Program (TDCRP), an instrument was developed to measure therapist responsiveness in the first two sessions of Cognitive Behavior Therapy and Interpersonal Psychotherapy. A factor measuring positive therapeutic atmosphere, as well as a global item of therapist responsiveness, predicted both the patient's positive perception of the therapeutic relationship after the second session and the patient's remaining in therapy for more than four sessions. A negative therapist behavior factor also predicted early termination. Factors measuring therapist attentiveness and early empathic responding did not predict the engagement variables.

Background: Infants exposed prenatally to alcohol are at increased risk for poor neurodevelopmental outcome including Sudden Infant Death Syndrome. Aim: To examine the relationship between prenatal alcohol exposure, sleep, arousal and sleep-related spontaneous motor movements in early infancy. Study design: Low-income women ( N =13) were interviewed regarding pre- and pregnancy rates of alcohol, cigarette smoking and other substance use in the perinatal period. Infants were examined in a laboratory nap study using EEG, videography and actigraphy at 6–8 weeks of age. Estimates of maternal pre- and pregnancy alcohol use were used to divide infants into high vs. low maternal alcohol use groups. Subjects: Mother–infant dyads recruited from a family practice clinic. Outcome measures: Sleep-related spontaneous movements, behavioral state, and maternal assessments of infant alertness and irritability. Results: Pre-pregnancy rates of alcohol consumption including binge drinking correlated with maternal report of poor infant alertness, and increased irritability. High maternal exposure groups showed increased sleep fragmentation, e.g. frequency and duration of wakefulness following sleep onset and decreased active sleep. Bout analysis of the temporal structure of sleep-related spontaneous movements showed significantly reduced bout duration associated with high maternal alcohol use. Conclusion: These results present evidence that prenatal alcohol exposure disrupts postnatal sleep organization and suppresses spontaneous movements during sleep, and increased sleep fragmentation promotes sleep deprivation. Results are consistent with the SIDS model of chronic sleep debt and suggest that attenuated sleep-related movements should be examined as an important modulator of cardiorespiratory functions during sleep in high-risk groups.

The largest excess in tumor incidence due to pollution (616%) was observed in the fish species: Ictalurus nebulosis (the brown bullhead). Extensive analysis of waters on the Fox River in Illinois disclosed a heavy chemical and physical organic and inorganic materials far exceeding State and Federal minimal safety standards. Additional tests showed the presence of numerous human viral agents in the Fox River. Certain chemicals in the water appear to be potential carcinogens for fish. Two types of leukemia were found in 11% of the Esox lucius caught in the Fox River. It is hypothesized that these leukemias might also be of viral etiology. Experiments were conducted on Esox lucius caught in the Fox River. It is hypothesized that these leukemias might also be of viral etiology. Experiments were conducted on Esox lucius (Northern Pike). Interest centered around the possible viral origin of lymphosarcoma of the jaw in that species. Cell-free filtrates of this tumor were inoculated into a test group of fish from pollution-free waters. At the end of seven weeks, lymphosarcoma developed in 89% of the fish inoculated with cell-free homogenates. Control fish receiving inoculation of either Hank's balanced salt solution (HBSS) or normal tissues and kept in separate tanks at all times did not develop lymphosarcomas.

Adaptive management is a heuristic approach to treating stream restoration projects as continuous, cyclic experiments, yielding results to be incorporated into future decisions. This comprehensive assessment views failures as surprises that are valuable lessons. Monitoring, evaluation of data, and communication of results are critical; the monitoring results trigger feedback mechanisms to invoke adaptation to the newly acquired information and communication of new hypotheses, treatments, or policies. The principles of adaptive management were applied to a monitoring study of three urban stream restoration sites in Maryland. Data were collected and evaluated for various restoration techniques, including vanes, cross vanes, step pools, root wads, imbricated riprap walls, and coir fiber rolls. Improvements to the existing Maryland design guidelines and policies were developed as the feedback mechanism. With the increasing application of adaptive management in stream restoration efforts, it is likely that repeated failures will be prevented and future restoration projects will be more successful in achieving their goals.

The number of stream restoration and enhancement projects being implemented is rapidly increasing. At road crossings, a transition must be created from the restored channel through the bridge or culvert opening. Given conflicting design objectives for a naturalized channel and a bridge opening, guidance is needed in the design of the transition. In this paper we describe the use of vanes, cross vanes, and w-weirs, commonly used in stream restoration and enhancement projects, that may provide an adequate transition at bridges. Laboratory experiments were conducted on vanes and cross vanes to provide a transition for single span bridge abutments and on w-weirs to provide a transition for double span bridges which have a pier in mid-channel. The results of the experiments provided design criteria for transitions using each of the three structures. Prior field experience provided guidance on appropriate applications in terms of the stream and bridge characteristics.

The designs of stream channel naturalization, rehabilitation, and restoration projects are inherently fraught with uncertainty. Although a systematic approach to design can be described, the likelihood of success or failure of the design is unknown due to uncertainties within the design and implementation process. In this paper, a method for incorporating uncertainty in decision-making during the design phase is presented that uses a decision analysis method known as Failure Modes and Effects Analysis (FMEA). The approach is applied to a channel rehabilitation project in north-central Pennsylvania. FMEA considers risk in terms of the likelihood of a component failure, the consequences of failure, and the level of difficulty required to detect failure. Ratings developed as part of the FMEA can provide justification for decision making in determining design components that require particular attention to prevent failure of the project and the appropriate compensating actions to be taken.

Although culverts have traditionally been an economical means of conveying stream flow at a road crossing, they can hinder fish and wildlife passage in the channel and on the floodplain and can create or augment localized channel instabilities. A possible solution to these problems is to use a multiple-cell arrangement, in which one or more culverts placed in the channel convey all flows up to the dominant discharge and one or more culverts positioned in the floodplain convey overbank flows up to the design discharge. This arrangement results in a reduction of flow concentration through the culvert and a properly functioning floodplain, thereby improving fish and wildlife passage and reducing erosional problems. For this system to function properly, a well-established and active floodplain is required; the multicell system will not perform adequately in an incised channel. In this paper, a method to determine appropriate physical environments for multicell culvert systems, based on stream-channel stability and stage-of-channel evolution, is presented.

An acid-catalyzed intramolecular [4 + 2] cycloaddition of a non-natural bisabolene is reported. The key cyclocondensation was developed to access cyclic sesquiterpenes from linear phenolic precursors by generating a reactive o-quinone methide intermediate to initiate a cascade reaction. The new method was applied to the first total synthesis of (±)-heliol.

To better understand the mode of action of omega 3 fatty acids in cell membranes, human foreskin fibroblasts were grown in serum-free medium supplemented with 50 microM oleic acid linoleic acid, eicosapentaenoic acid (EPA) or docosahexaenoic acid (DHA), and the effects on membrane composition, fluorescence polarization and enzyme activities were followed. The cells were enriched with EPA and DHA up to 7 and 13% of total lipids, respectively, of which95% was associated with phospholipids. In addition, the concentration of 22:5n-3 increased with both EPA and DHA to 7.5, and 2.1% of the total fatty acids, respectively. When compared to controls (oleic acid), cells treated with DHA showed a decrease in cholesterol, phospholipids, arachidonic acid (AA) and free cholesterol/phospholipid ratio (P0.05). In the presence of EPA, only decreases in AA and cholesterol were significant (P0.05). Membrane fluidity, assessed by fluorescence anisotropy, was increased 16% in cells enriched with DHA (P0.05), but showed no change with EPA or linoleic acid. There was an increase in membrane-associated 5'-nucleotidase (+27%) and adenylate cyclase (+19%) activities (P0.05), in DHA-enriched, but not in EPA-enriched cells, when compared with oleate controls. The studies show that incorporation of DHA, but not EPA, into cell membranes of fibroblasts alters membrane biophysical characteristics and function. We suggest that these two major n-3 fatty acids of fish oils have differential effects on cell membranes, and this may be related to the known differences in their physiological effects.

Total syntheses of two structures purported as (+)-heliananes were completed in six pots. Spectral comparisons, between the synthetic and natural compounds, revealed a misassignment of the eight-membered ring in the heliananes. The key step in the syntheses of the proposed structures and the confirmation of their actual structures was a diastereoselective inverse-demand Diels-Alder reaction between an optically active enol ether and an ortho-quinone methide species, which was generated in situ at low temperature by the sequential addition of methylmagnesium bromide and di-tert-butyl dicarbonate to a salicylaldehyde.

A. Pathogenesis. The diagnosis and management of pelvic inflammatory disease (PID) is based upon clinical signs and symptoms. PID encompasses infections of the uterus (endometritis or myometritis), fallopian tubes (salpingitis), ovaries (oophoritis), broad ligaments (parametritis), and pelvic peritoneum (peritonitis). PID affects up to one million women each year in the United States and is the number one reason for hospital admissions among women of reproductive age. PID is a polymicrobial disorder that results from ascending infection of bacterial flora from the vagina and cervix. The two initiating pathogens include Neisseria gonorrhoeae and Chlamydia trachomatis. PID initiated by N. gonorrhoeae tends to be more acute and severe than that caused by C. trachomatis. Risk factors for PID include young age, history of multiple sexual partners, and a history of sexually transmitted diseases. Patients with PID commonly present with acute or subacute diffuse abdominopelvic pain and fever during or after their menses. Additional clinical criteria for PID include cervical motion or adnexal tenderness, and cervical or vaginal discharge.

Neuropsychologic test scores from a group of children with epilepsy were compared to the standardization sample of the NEPSY: A Developmental Neuropsychological Assessment, a relatively new neuropsychologic testing instrument. Nineteen children with a confirmed diagnosis of epilepsy (11 boys, 8 girls), aged 3-12 years, participated. Attention/executive function, language, sensorimotor, visuospatial, and learning/memory domain scores were examined, as well as individual subtest scores. The mean scores on the attention/executive function, language, and sensorimotor domains were1.5 standard deviations below the normative mean, and significantly lower than the mean visuospatial domain score (P0.05). The mean language domain score was also significantly lower than the learning/memory score (P0.05). Mean subdomain scores varied, with impairment on two tasks measuring rapid automatic processing and graphomotor precision, respectively. On the majority of subtests, 15% or more of the sample scored in the impaired range. Associations between patient age, seizure onset age, seizure frequency, and antiepileptic medication status were not associated with outcome, perhaps due in part to the small sample size. The strengths and weaknesses of the NEPSY as a measure of neuropsychologic functioning in children with epilepsy, and its utility in highlighting risks to academic achievement are discussed.

There is little evidence for significant intellectual deterioration in well-controlled seizure disorders. With recurrent convulsive seizures, the picture is less clear and depends on severity, type, age of onset, and frequency of toxic levels of antiepileptic drugs (see Table 1). In the interictal state, deficits in verbal language and memory have been observed, especially in patients with complex partial seizure foci in the left (dominant) hemisphere. The memory deficits appear to affect new learning and retention of material; the verbal deficits are more subtle, affecting word-finding, verbal fluency, and comprehension abilities. Both of these changes may either go unnoticed by the patient in day to day activities or be attributed to the effects of antiepileptic medication. Antiepileptic drugs can also affect interictal cognitive functioning. The worst of these appears to be phenobarbital; phenytoin has an intermediate effect; valproic acid and carbamazepine as single agents seem to produce fewer adverse effects. However, individual patients may be particularly sensitive to cognitive side effects of certain drugs. Finally, attention deficits and slowing of cognitive processes, either chronically or intermittently, appear to affect all seizure patients to some extent. The syndrome is more prominent in frontal or generalized seizure patterns. The intermittent nature of these disturbances has been emphasized in recent research on subclinical interictal spike-wave electrical phenomena.

Studies were conducted on the frequency of oncogenic disease in fishes in polluted waters and interrelationships of human pathogens to aquatic problems. Chemical surveys were made of the polluted Fox River and the pollution-free Canadian Lake of the Woods. A table is presented to show fish diseases in polluted and nonpolluted waters. An experiment on the effects of certain minerals on bluegills showed a deleterious effect on longevity of the fish. The following diseases are discussed with regard to causative organism, symptoms, and incidence: columnaris disease, hemorrhagic disease, Dee (kidney) disease, saprolegnia, black spot, catfish virus disease, lymphocystis, lymphoreticular neoplasms, and hepatoma. To determine the efficiency and toxicity of disinfectants used in the treatment of sewage, minnows were raised in effluent from sewage treatment plants and additionally treated with disinfectants. Polio types 1-3 were present in intestinal tracts of fish raised in effluent that was not disinfected and in fish exposed to effluent treated with bromochloride and ozone. Levels of chlorine used were capable of eliminating a potential health hazard; other treatments such as bromochlorination and ozonation were not able to eliminate this possibility. Studies on the toxicity of vinyl chloride to northern pike showed that the fish were killedmore » rapidly by this chemical. (HLW)« less

This article presents an explanatory model of reading competence, correlating different levels of linguistic, procedural, and neurological description in an information-processing paradigm. The overall design is an orthographic-to-phonological base form coding, differentiated lexical access, syntactic-structural derivation by means of an analysis-by-synthesis algorithm, and optional phonological and semantic interpretive processes at the level of syntactic surface structure. The model seeks to integrate and explain a representative sample of experimental phenomena. Major conclusions are that intact simultaneous functioning and awareness of abstract linguistic entities are necessary elements in the development of adult reading competence.

Anti-herpesvirus effects of Isoprinosine were found to be condition-dependent in vitro and in vivo. A herpes type 1 strain, grown in primary rabbit kidney cells, was not susceptible to Isoprinosine when cytopathic effect was evaluated, but was modestly inhibited when plaque-forming methocel overlay was used in the same cell line. However, the growth of a herpes type 2 strain was inhibited by Isoprinosine in this system when cytopathic effect was evaluated. Both viruses produced an encephalitis in hamsters after application by corneal abrasion. The encephalitis produced by a 1.5 mean lethal dose of herpesvirus was strikingly suppressed by large doses of Isoprinosine given ad libitum in the drinking water; this protection was not seen, however, at 15 mean lethal doses. Anti-herpes effects of Isoprinosine were suppressed by additional treatment with cortisone, both in tissue culture and in vivo. Isoprinosine, in the absence of virus infection, produced significant effects on the metabolism, structure, and function of brain ribosomes. In vivo, RNA components were labeled more rapidly and gave up their radioactivity more slowly after treatment with Isoprinosine. This enhanced cytoplasmic radioactivity was associated with a loss of incorporated radioactivity located in the nucleus and an increase in radioactivity located in a ribonucleo-protein fraction >4 S and S . Ribosomes from treated brains gave physical evidence of being more compact (less orthochromic). Isoprinosine treatment increased the incorporation of [ 14 C]phenylalanine into nascent protein in a cell-free system examining protein synthesis in brain polyribosomes. The addition of the exogenous messenger ribonucleic acid, polyuridylic acid, produced a significant age-dependent inhibition in the incorporation of [ 14 C] phenylalanine. This inhibition was significantly greater when ribosomes were isolated from animals pretreated with Isoprinosine. These and other observations suggest that the Isoprinosine stimulation of host ribonucleic acid metabolism may be coupled to the production of ribosomes that do not effectively translate exogenous messenger ribonucleic acid.

The injection of extracts of leukemic and Hodgkin’s disease tissues of man elicit an antibody reaction in both man and rabbit. This response is similar to that elicited by leukemic mouse tissues when injected into rabbits. The antibody reaction may be demonstrated by the technics of passive cutaneous anaphylaxis, immunodiffusion, microprecipitin and immunofluorescence. Tissue extracts from non-leukemic individuals do not elicit a similar response. Rabbits immune-tolerant to normal human tissues produce antibodies specific to leukemic human antigens. Antibodies develop in those individuals who are exposed for a long time to either human or mouse leukemia. These immunologic studies demonstrate specific antigenic differences between normal and leukemic tissue extracts. It is postulated that the difference between normal and leukemic extracts is the consequence of the presence of viruses or the alterations caused by them.

A hypothesis predicting that increase in the rate of synthesis of host messenger RNA would be associated with antiviral activity was examined. Biochemically, Isoprinosine or NPT-10381 (methisoprinol) increased the rate of rapid labeling of polyribosomal RNA and protein in uninfected monkey kidney cells in tissue culture. In tissue-culture systems, Isoprinosine exerted antiviral effects against influenza virus, PR-8 and A2 strains; herpes virus, LU strain; polio virus 3; and adenovirus 10. In in vivo mortality studies, Isoprinosine was observed to exert therapeutic antiviral effects against the A2 strain of influenza and, as well, against a herpes infection of newborn mice. Experiments were carried out which demonstrated a correlation between the in vivo anti-influenza (PR-8) effects of Isoprinosine and reduction in the virus titer in lungs of infected mice.

This experiment investigated the predictability of pause time in a 1537 word spoken message. A professionally read rendition paced at 164 wpm was analyzed from three points of view: ( a ) an immediate constituent, or surface structure, syntactic analysis; ( b ) a stochastic information analysis of all lexical items in context; and ( c ) a deep structure analogue or clause analysis. Results indicated that 64% of the pause variance could be predicted from the syntactic measures. Both the surface structure and deep structure analogue measures of syntactic complexity yielded reliable predictive variance not accounted for in the overlap of the two variables, suggesting that both levels of linguistic representation were important determiners of pause structure in an oral reading performance.

Various physicochemical characteristics and the biological activity of two murine lymphoma viruses (S-63 and GC), originally isolated in this laboratory and previously reported as sharing common antigenic properties with human and bovine lymphomas, are defined. These viruses are stable at temperature ranges from −70 °C to +4 °C and are inactivated after incubation at +56 °C for 30 min. They withstand lyophilization and are inactivated by treatment with ethanol, acetone, ethyl ether, formalin, and phenol. Both agents are of the ribonucleic acid, double-membraned viruses, similar to myxoviruses, and are approximately 100 mμ in size.

SummaryA fluorescent-antibody system is reported which allows rapid analysis of the minor antigenic differences between mouse mammary tumor agent (MTA) extracts obtained from different sources. This method correlates very well with the bio-assay method reported by Bittner and associates. An analysis of the antigenic component can be made within a few hours after receiving the MTA extract. In the older bio-assay method up to 2 years of observations were necessary for proper evaluation. The disadvantages of the fluorescent-antibody system include, a) interference by non-specific fluorescence, b) limitations imposed by antisera employed, c) removal of normal tissue antibodies, and d) selection of appropriate fluorescent dyes for conjugation to the sera. These disadvantages can be partially overcome by carefully selecting the antigens to be used for preparing antisera, adsorption of antisera with mouse liver powder extracts, concentration of globulin fractions prior to conjugation, and use of sharply contrast...

Alterations for acid and alkaline phosphatase levels and their pattern of splenic and lymph node activity in normal and virus-induced lymphoblastic leukemia were studied. Enzyme levels were examined by using both cytochemical and biochemical procedures. The GC leukemia virus, a ribonucleic acid murine virus antigenically related to the Rauscher-Moloney viruses, was used to stimulate acid and alkaline phosphatase by producing lymphomaceous disease in Ha/ICR mice. With the Burstone and Gomori cytochemical procedures, both enzymes were found in higher than normal levels in lymphomaceous spleen and lymph nodes. Confirmation of the cytochemical studies was obtained by enzyme assay of cell-free homogenates in each case with the exception of spleen acid phosphatase. The discrepancy between the cytochemical tests which showed significant elevation of spleen acid phosphatase and the enzyme assays which failed to reveal such elevation could be due to a labile acid phosphatase isozyme which is lost on cellular disruption during homogenate preparation. A significant spleen alkaline phosphatase specific activity elevation above normal was found with a 50% incidence only when leukemic spleen wet weight increased nearly threefold its normal value. This result suggests that alkaline phosphatase elevation is a secondary event occuring after the onset of disease and is not a fundamental metabolic alteration concerned with the onset of murine lymphoblastic leukemia.

The present studies are an extension of earlier reports on the antibody response of mice to a leukemogenic virus (S-63). These investigations were designed to show whether a correlation exists between in vivo and in vitro determinations, and whether protective antibodies against the virus could be produced in immune-tolerant animals. Viral neutralization and protection studies in mice were compared with passive cutaneous anaphylaxis (PCA), immunodiffusion, microprecipitin, and immunofluorescent tests using similar antigens and antibodies. As shown in tables 1, 2 and 3, antibody could be demonstrated by both in vivo and in vitro methods, and these studies showed (table 2) that the antibody was protective. The S-63 leukemia virus was isolated in 1963 from a mouse ascites cell leukemia line. That cell line had been carried in the laboratory for over 3 years. The virus has been carried in ICR mice since its isolation. Immunologic studies were carried out to determine the relation between the virus and the originating ascites cell. Studies of antibodies produced in normal rabbits against the S-63 virus were unsatisfactory for purposes of these experiments because of cross reaction with normal mouse tissue. Immune-tolerant animals have yielded valuable information: Antibodies produced in immune-tolerant rabbits injected with the S-63 virus do not cross react against intact ascites cells from which the virus was originally isolated. Conversely, antibodies similarly produced against the ascites cells do not react against the virus antigen. Antibodies produced in immune-tolerant rabbits against ascites cells protect mice against ascites cell-induced leukemia, but not against the disease induced by S-63 virus. Mice challenged with ascites cells and treated with antiascites cell gamma globulin are protected against the disease. The best therapeutic advantage is obtained when treatment is started either at the time of cell inoculation or in the early stages of the disease. Antibodies which protect newborn animals from infection develop in adult ICR mice recovering from S-63 virus leukemia. These antibodies produced by convalescent mice are similar, from the standpoint of protection, to those produced in immune-tolerant rabbits.

Antikorper bei genesenden Mausen nach Infektion mit Leukamie-Viren (S-63) erzeugt, zeigen eine Kreuzreaktion mit den Leukamie-Antigenen aus Rinder- und Menschenserum und Gewebe. Diese Befunde sprechen dafur, dass die Viren-Antigene in den drei Systemen sehr ahnlich sind.

We undertook an extensive review of world-wide clinical reports of leukemia in twins. Our survey was a careful one; exclusions are inevitable, but, if so, are inadvertent, except for undocumented “personal communication” cases. These have sometimes been included in large reviews of either leukemia or leukemia in twins. Also excluded are cases mentioned only tangentially in reports of cancer in large population groups, if no clinical details were given. In some instances, we were able to adapt available clinical information to our tables.Leukemia appears to occur at four periods in the lives of twins: (1) the perinatal-congenital period; (2) early childhood; (3) late childhood; and (4) adulthood. Those cases occurring around the time of birth and the first year of life are combined under the title: Perinatal-Congenital. In Tab. I, Early Childhood extends from about 2 to 7 years, and Late Childhood from 7 through 12 years. All other cases have been considered as Adult. Two cases occurring in teenagers have been placed in this group in accordance with clinical practice. We have compiled 62 cases of leukemia in twins from clinical reports from the world publications in the following categories: Perinatal-Congenital, 15; Early Childhood, 26; Late Childhood, 9; Adulthood, 12. Comparative clinical details of all these cases will be published in a subsequent report.Except for those instances about which writers admitted that the diagnosis of zygosity was in question, most reported clinical cases occurred in MZ twins. There were 39 cases of leukemia in MZ twins, 13 cases in DZ twins and 10 cases in whom zygosity was in doubt.