Impact of regulation on benzodiazepine prescribing to a low income elderly population, New York State

On 1 January 1989, in an effort to reduce diversion of benzodiazepines for illicit use and reduce inappropriate prescribing, a regulation was implemented requiring the reporting of all benzodiazepine prescriptions to the New York State Department of Health. To assess the impact of the regulation on prescribing practices to the elderly, we followed the number of benzodiazepines and other central nervous system medications prescribed to a cohort of participants in an elderly pharmaceutical insurance program. Benzodiazepines were prescribed for 4652 (22%) of the 20,944 patients studied. By the last quarter of 1989, benzodiazepines were prescribed for 3120 (15%) patients, a decrease of 33%. The number of prescriptions of benzodiazepines decreased by 5010 (45%), from 11,123 to 6113. Decreases in the number of prescriptions were similar across benzodiazepine brands (range 40-56%). Statistically significant (p < 0.05) decreases were seen in all sex, age, race and marital status groups. Increases in number (and percent increases) of prescriptions for miscellaneous anxiolytics (i.e. hydroxyzine (399, 69%), meprobamate (299, 149%), buspirone (263, 111%), chloral hydrate (138, 265%), antidepressants (658, 19%), barbiturates (150, 29%), and tranquilizers (198, 19%), some of which may be more toxic or less effective, were noted. New York State's reporting regulation was effective in reducing both the number of patients being prescribed benzodiazepines and the number of prescriptions given to those who remain on benzodiazepines in the elderly population studies.

Morphologic changes of the liver following chemotherapy for metastatic breast carcinoma: CT findings

Thirty patients with metastatic breast carcinoma to the liver underwent systemic chemotherapy. Twenty-four of these patients also received hepatic arterial infusion chemotherapy, three in conjunction with hepatic artery embolization. The morphologic changes of the liver believed to be due to chemotoxic effect of treatment occurred in 27 patients, and were evaluated by serial computed tomography (CT) examinations. These included fatty changes in seven patients, severe cirrhotic changes in four, localized atrophy with regional contour changes in three, and areas of low density in the regions of previously treated metastases in 13. The CT features of cirrhosis included density changes along with nodular irregularity of the hepatic borders with marked decrease in liver size and development of ascites.

AgSK1, a novel carcinoma associated antigen

An IgM human monoclonal antibody (HuMAb) SK1 was generated from mesenteric nodal lymphocytes of a colon cancer patient that were fused with a human B-lymphoblastoid cell line SHFP-1. The reactivities of HuMAb SK1 to various human cell lines were screened by cell enzyme linked immunosorbent assay and immunocytochemical staining. The HuMAb SK1 reacted strongly with all 11 human carcinoma cell lines that were tested and had no detectable binding with noncarcinoma cell lines of the following origins: fibroblast; fetal lung; melanoma; soft tissue sarcoma; neuroblastoma; and glioblastoma. Carcinoma preferred reactivity of HuMAb SK1 was further confirmed by immunoperoxidase staining of a large number of frozen tissues, both malignant and benign. The antigen SK1 (AgSK1) in human carcinoma detected by immunoperoxidase staining was also identified biochemically as a sialoglycoprotein that migrated at M(r) 42,000 with an isoelectric point (pI) of approximately 5.9. A preferential staining by HuMAb SK1 was seen among colorectal, gastric, pancreatic, and lung cancers. Competitive inhibition study in solid-phase immunoassay suggested that the HuMAb SK1 did not cross-react with other antibodies specific for CEA, CA 19-9, and TAG 72. The AgSK1 appears to be a novel carcinoma associated antigen which may be a useful tumor marker in cancer diagnosis and treatment.

Rheumatic fever and chronic rheumatic heart disease in Yarrabah aboriginal community, north Queensland. Establishment of a prophylactic program

OBJECTIVE

To establish a program for the prevention of rheumatic fever and rheumatic heart disease in a semi-isolated Aboriginal community in far north Queensland and to test its efficacy.

DESIGN

A prevalence study of acute rheumatic fever and chronic rheumatic heart disease was conducted in the community in 1985 and subjects with possible acute rheumatic fever were assessed. A prophylactic antibiotic program was instituted. Records were kept of the prevalence of acute rheumatic fever for six years after the 1985 survey. A second survey of the community was held in 1991 to detect chronic rheumatic carditis resulting from undetected acute rheumatic fever.

SETTING

The Yarrabah Aboriginal community in north Queensland (latitude 17 degrees S). The program was conducted by the Yarrabah Health Team, a part of the North Queensland Aboriginal Health Division.

PARTICIPANTS

The whole Yarrabah community (population 1250) was invited to participate. In 1985, after the completion of an educational program, 89% of the community cooperated in the survey. There was no educational program before the 1991 survey and the compliance rate was much lower. Importantly, however, 87% of the vulnerable group (4-16 year olds) were examined.

INTERVENTIONS

After the 1985 survey, all community members aged 4-16 years had throat swabs taken three times each year. Those with swabs showing Group A streptococci were treated; their contacts were also swabbed and treated if Group A streptococci were found.

RESULTS

Before the institution of the swabbing program there were four new cases of acute rheumatic fever each year in the Yarrabah community. In the six years after the program was introduced only one case of acute rheumatic fever occurred. This was at a time when swabbing had temporarily lapsed for a three-month period.

CONCLUSIONS

These results support the use of a prophylactic antibiotic program in Aboriginal communities as a cost effective and efficient method for the prevention of rheumatic fever. The cooperation of the community is an integral part of its success and this can be obtained by community education.

Structure and genomic sequence of the myotonic dystrophy (DM kinase) gene

The mutation causing myotonic dystrophy (DM) has recently been identified as an unstable CTG trinucleotide repeat located in the 3' untranslated region of a gene encoding for a protein with putative serine-threonine protein kinase activity. In this report we present the genomic sequences of the human and murine DM kinase gene. A comparison of these sequences with each other and with known cDNA sequences from both species, led us to predict a translation initiation codon, as well as determine the organization of the DM kinase gene. Several polymorphisms within the human DM kinase gene have been identified, and PCR assays to detect two of these are described. The complete sequence and characterization of the structure of the DM kinase gene, as well as the identification of novel polymorphisms within the gene, represent an important step in a further understanding of the genetics of myotonic dystrophy and the molecular biology of the gene.

UCSD's MedPics: implementation and impact on the curriculum

MedPics is a computer-based image delivery system with supporting text fields and on-screen graphics to assist in key feature identification. It has been used by the University of California, San Diego as an integral part of the Human Disease course since 1992. Initially created to support pathology and histology, the program has now expanded to include hematology. MedPics has had a positive impact on the second year curriculum for which it was created. Moreover, use of this program has improved student attitudes toward computer-based resources and increased faculty interest in instructional development.

The usefulness of cell surface markers in predicting the prognosis of non-Hodgkin's lymphomas

The Working Formulation for classification of non-Hodgkin's lymphomas provides useful prognostic information. Since this scheme was published in 1982, many studies have investigated the prognostic significance of various cell surface markers in lymphoma cases. This article reviews the value of distinguishing T cells from B cells, CD5+ B cells, immunoglobulin light chain types, proliferation antigens such as Ki 67, other markers of B-cell differentiation, and chromosomal anomalies. Each of these contributes some further prognostic significance to that already determined by the Working Formulation.

Transfer of human chronic lymphocytic leukemia to mice with severe combined immune deficiency

B chronic lymphocytic leukemia (CLL) cells were transferred into mice with severe combined immunodeficiency (SCID). Leukemia cells injected into the peritoneal cavity of these animals may survive for at least 10 weeks in vivo. In contrast, leukemia cells do not survive for long periods when injected intravenously. Despite the longevity of CLL cells injected i.p., these cells apparently do not migrate to other lymphoid tissues. Eight to sixteen weeks after receiving CLL cells, SCID mice develop human IgG autoantibodies to human red blood cells and/or high serum levels of human Ig. Soon thereafter, these animals develop lethal human B-cell tumors. In contrast to the original CLL cells, these human B-cell tumors are CD5-negative, have genomic DNA of Epstein-Barr virus (EBV), express antigens associated with latent EBV infection and have distinctive Ig gene rearrangements by Southern. We conclude that bystander B cells may generate tumors in CLL-reconstituted SCID mice that emulate the EBV-associated lymphoproliferations noted in SCID mice reconstituted with normal human PBL.

Mono- and diglucuronide formation from chrysene and benzo(a)pyrene phenols by 3-methylcholanthrene-inducible phenol UDP-glucuronosyltransferase (UGT1A1)

Mono- and diphenols of chrysene and benzo(a)pyrene are suspected substrates of a 3-methylcholanthrene (MC)-inducible phenol UDP-glucuronosyltransferase (UGT1A1). Mono- and diglucuronide formation from these compounds was studied in two systems, (a) livers of MC-treated rats (homologous expression) and (b) a Chinese hamster lung fibroblast cell line (V79) containing rat UGT1A1 cDNA and stably expressing this isozyme (heterologous expression). In liver microsomes of MC-treated rats, glucuronidation of 6-hydroxychrysene was stimulated 11-fold by MC treatment. With 3,6-dihydroxychrysene, formation of its 3-hydroxy-6-monoglucuronide and of the diglucuronide was increased 24- and 310-fold, respectively. Induction factors obtained for monoglucuronide formation (but not for diglucuronide formation) were in line with published data on the increase of immunodetectable UGT1A1 protein and of its mRNA. It is suggested that the high induction factors for diglucuronide formation are the result of a combination of the induction of UGT1A1 and facilitated interaction of neighboring UGT1A1 molecules in endoplasmic reticulum membranes. Glucuronidation of 6-hydroxychrysene, 3-hydroxybenzo(a)pyrene, and 3,6-dihydroxybenzo(a)pyrene to their mono- and diglucuronides was clearly detectable in V79 cells expressing UGT1A1. However, conjugation of 3,6-dihydroxychrysene to its monoglucuronides was low and diglucuronide formation was not detectable, suggesting that UGT isozymes other than UGT1A1 are responsible for these reactions.

Characterization of the myotonic dystrophy region predicts multiple protein isoform-encoding mRNAs

The mutation underlying myotonic dystrophy (DM) has been identified as an expansion of a polymorphic CTG-repeat in a gene encoding protein kinase activity. Brain and heart transcripts of the DM-kinase (DMR-B15) gene are subject to alternative RNA splicing in both human and mouse. The unstable [CTG]5-30 motif is found uniquely in humans, although the flanking nucleotides are also present in mouse. Characterization of the DM region of both species reveals another active gene (DMR-N9) in close proximity to the kinase gene. DMR-N9 transcripts, mainly expressed in brain and testis, possess a single, large open reading frame, but the function of its protein product is unknown. Clinical manifestation of DM may be caused by the expanded CTG-repeat compromising the (alternative) expression of DM-kinase or DMR-N9 proteins.

Changes in beta-adrenergic receptor distribution on immunocytes during differentiation: an analysis of T cells and macrophages

The ability of cells of the immune system, immunocytes, to receive signals from the nervous as well as the endocrine system is dependent on the cells' expression of receptors for neurotransmitters and neurohormones. The number of receptors, especially beta adrenergic receptors (BARs), varies with the functional subset of immunocytes. However, little is known about how receptor number may vary during the life span (stem cell to mature activated immunocyte) of a given cell type. In this study, we have addressed this question by examining the affinities (Kd's) and the changes in receptor number (Bmax) on (1) clones of T cells and macrophages, (2) fresh thymocytes and splenocytes before and after activation with Concanavalin A (Con A) and phorbol myristate acetate (PMA)/Ca2+ ionophore (A23187), and (3) the cloned human monocyte U937 and the murine thymic lymphoma cell BW5147, in the presence and absence of PMA and A23187 ionophore. Drug treatments of fresh and cloned immunocytes alter the number but not the affinity of beta-receptors. Con A increases the number of beta-adrenergic receptors per cell, whereas PMA/ionophore decreases it. Similar decreases in BAR number are induced by PMA on cell lines BW5147 and U937. These data indicate that changes in receptor number can be regulated with different states of cell maturation and function. Thus, the immunological status of a given cell can influence the expression of BARs, thereby modulating its ability to respond to signals from the nervous and endocrine systems.

Membrane topology of epoxide hydrolase

The amino acid sequences of epoxide hydrolase from rat, rabbit and human have been subjected to hydropathy analysis and a novel model for the membrane topology of this enzyme is presented. The enzyme would appear to be retained in microsomal membranes by a single transmembrane segment located at the N-terminus and the majority (96%) of the protein is exposed at the cytosolic membrane surface. This model is significantly different from a scheme suggested by analysis of the rat enzyme alone which proposed six transmembrane domains (Porter et al. (1988) Arch. Biochem. Biophys. 248, 121-129). Experiments with rat microsomal membranes were conducted to distinguish between the two models and used proteolytic enzymes and non-permeant chemical probes. Epoxide hydrolase of intact and permeabilised membranes was resistant to digestion by a number of proteinases. However, this is likely to be related to a compact fold of the protein rather than membrane association since purified, delipidated enzyme preparations were also resistant to proteolysis. While the use of proteinases did not provide useful membrane topological information, experiments with the fluorescent probe, 3-azido-2,7-naphthalenedisulphonate strongly support the view that the majority of the protein is indeed exposed at the cytosolic surface of the membranes. The analysis illustrates the caution which must be employed in the formulation of topological models based on hydropathy plots alone and the value of considering homologous proteins.

Graded neuropsychological impairment and elevated gamma-glutamyl transferase in chronic alcoholic men

This study hypothesizes that distinct biochemical and metabolic disturbances associated with liver injury may be related to specific cognitive changes in alcoholics. In 132 alcoholic men admitted to an alcohol treatment program, increases in gamma-glutamyl transferase (GGT) values were correlated with impairment in several measures of visuoperceptual and visuoconceptual functioning. The association between plasma levels of GGT and neuropsychological performance was independent of the relative contribution of other laboratory measures of liver injury and of alcohol consumption histories. These observations support the hypothesis that elevated levels of GGT are distinctly associated with neuropsychological deficits and suggest that possible mechanisms beyond severe hepatic dysfunction and alcohol consumption underlie cognitive deficits in alcoholics.

MOHS for head and neck mucosal cancer: report on 111 patients

Microscopically Oriented Histologic Surgery (MOHS) has been applied to primary epidermoid cancers of the mucosal tissues of the head and neck since 1979. In that time we have treated 170 patients and maintained excellent records, losing no patients to follow-up. One hundred three patients have been followed for 2 years. Of this group, only nine patients have developed local recurrences; three were salvaged, six were not. This presentation reviews the concept of MOHS and its application to head and neck mucosal lesions. The results are analyzed, and conclusions are drawn regarding what we have learned about the biologic behavior of head and neck tumors and the role of MOHS in treating these neoplasms.

Use of laboratory tests to monitor heavy drinking by alcoholic men discharged from a treatment program

Changes in blood test values from the time of discharge from an alcohol treatment program to 3-month follow-up were studied in two consecutive series of alcoholic men. The parallel combination of a percent increase in gamma-glutamyltransferase (GGT) of greater than or equal to 20%, in aspartate aminotransferase (SGOT) of greater than or equal to 40%, and in alanine aminotransferase (SGPT) of greater than or equal to 20% over discharge values was developed as a rule and then cross-validated to identify those alcoholic men who had resumed drinking at follow-up. Serial determination of these three test values in combination can be used to distinguish recovering alcoholics who remain abstinent from those who resume drinking.

Microscopically oriented histologic surgery for head and neck mucosal cancer

Frozen section directed surgery, called MOHS, has been successfully utilized in the resection of primary epidermoid tumors of the head and neck. For the 93 cases reviewed in this study, 70% had microscopically identified tumor 1 cm away from clinically evident disease. Tumor spread was along planes of least resistance, most commonly in the submucosa. Microscopically directed excisions were able to trace and remove these tumor extensions. Local control in 93 patients with 2-year follow-up was 91% and, with salvage of recurrences, was 95%. The authors' observations suggest three important concepts. First, epidermoid cancer of the head and neck grows as a continuous neoplasm. Second, this work casts serious doubt on the concept of "field cancerization" or multiple primaries as a cause of local recurrence. Third, conventional frozen section analysis of surgical margins is highly unlikely to discover microscopic extensions because many tumor extensions are thin, finger-like projections which require examination of the entire surgical margin to detect.

Structure of a Bacillus subtilis endo-beta-1,4-glucanase gene

The nucleotide sequence of the portion of a Bacillus subtilis (strain PAP115) 3 kb Pst I fragment which contains an endo-beta-1, 4-glucanase gene has been determined. This gene encodes a protein of 499 amino acid residues (Mr = 55,234) with a typical B. subtilis signal peptide. Escherichia coli which has been transformed with this gene produces an extracellular endoglucanase with an amino-terminus corresponding to the thirtieth encoded amino acid residue. The gene is preceded by a cryptic reading frame with a rho-independent terminator structure, and itself has such a structure in the immediate 3'-flanking region. We have also identified, in the 5'-flanking region, nucleotide sequences which resemble promoter elements recognized by Bacillus RNA polymerase E sigma 43. Comparison of the encoded amino acid sequence to other known beta-glucanases reveals a small region of similarity to the encoded protein of the Clostridium thermocellum celB gene. These similar regions may contain substrate-binding and/or catalytic sites.

Lack of correlation between the accumulation of plus-strand leader RNA and the inhibition of protein and RNA synthesis in vesicular stomatitis virus infected mouse L cells

The inhibition of protein synthesis in mouse L cells infected by vesicular stomatitis virus (VSV) requires expression of two regions (one large and one small) of the viral genome, as determined by target size analysis. The inhibition of host RNA synthesis was also shown to be dependent on expression of two regions of the VSV genome, most likely the same ones. In some cases, such as in cells infected by mutants T1026R1, or tsG41 at 40 degrees, or moderately uv irradiated VSV, only one of the two regions was expressed, yet cellular protein and RNA synthesis was decreased. This suggests that the product of each region of the viral genome can act independently. In these instances the severity of the inhibition was dependent on both the length of the infection period and the multiplicity of infection. The identity of neither gene product is known, but it has been suggested that small product is plus-strand leader RNA. As shown herein, however, there was no correlation between the extent of host macromolecular synthesis inhibition and the quantity of leader RNA in infected cells.

Glucanase gene diversity in prokaryotic and eukaryotic organisms

A number of bacteria and eukaryotes produce extracellular enzymes that degrade various types of polysaccharides including the glucans starch, cellulose and hemicellulose (xylan). The similarities in the modes of expression and specificity of enzyme classes, such as amylase, cellulose and xylanase, suggest common genetic origins for particular activities. Our determination of the extent of similarity between these glucanases suggests that such data may be of very limited use in describing the early evolution of these proteins. The great diversity of these proteins does allow identification of their most highly conserved (and presumably functionally important) regions.

The genetic control of grain esterases in hexaploid wheat : 1. Allelic variation

Analysis of grain esterase isozymes in Chinese Spring aneuploid genotypes by IEF confirmed that genes on the long arms of chromosomes 3A, 3B and 3D (Est-5) control the production of 19 isozymes. Allelic variants have been found for the isozyme pattern controlled by each chromosome. Segregational data involving null alleles and complex phenotypic differences indicate that the wheat grain esterases are encoded by three compound and probably homoeoallelic loci, each capable of producing at least six different isozymes. In a sample of 138 hexaploid genotypes, seven alleles were distinguished.

Characterization of a monoclonal antibody that reacts with an activation antigen on human B cells: reactions on mitogen-stimulated blood lymphocytes and cells of normal lymph nodes

We describe a monoclonal antibody that reacts with human B-lymphoid cells. We have characterized the reactions of this antibody on normal blood lymphocytes, with and without pokeweed mitogen stimulation, bone marrow lymphocytes, and on frozen sections of normal lymph nodes. The antibody, B532, appears to recognize an activation antigen on human B cells. This activation antigen can apparently be induced both by infection with Epstein-Barr virus and by stimulation with antigens and mitogens, but it is lost on plasma cells. In normal lymph nodes, the antigen is confined to germinal center cells and some of the cells of the "mantle" that surrounds germinal centers. The antigen is not present on T cells.

Analysis of B-cell antigens in normal reactive lymphoid tissue using four B-cell monoclonal antibodies

Lymph nodes from 13 cases of reactive hyperplasia were examined with four different monoclonal antibodies to B cells. B-1 recognizes an antigen of 30,000 daltons on B cells. CB-2 was prepared with normal spleen and binds to a glycolipid. BA-1 labels surface immunoglobulin-positive cells, but not T lymphocytes or monocytes. B-532 recognizes an antigenic determinant of 45,000 daltons. Using the immunoperoxidase method on frozen sections of reactive lymph nodes, the staining patterns of these four unique antibodies showed dramatic differences. B-1 labeled 80%-90% of the germinal center cells and 10%-50% of the mantle region. Few interfollicular cells were positive. CB-2 stained predominantly in the mantle area (50%-90% positive cells), with moderate staining in the germinal center as well and less than 1% positive cells in the diffuse cortex. BA-1 exhibited predominant labeling in the mantle (50%-90%), with little staining in the germinal center. A large number of cells in the interfollicular, subcapsular, and medullary regions expressed the BA-1 antigen. The B-5 antibody demonstrated intense staining in the follicle (50%-95%). This staining often appeared to be polarized within the germinal center. The mantle zone demonstrated staining of 30%-50% of the cells. The different staining patterns of the B-cell antibodies, as demonstrated by the in situ distribution of positive cells within the lymph node, may reflect stages of development or activation of the B-cell population.

Monoclonal antibodies to murine leukemia virus gp 70 recognize the same T lymphoma cell surface molecules as anti-immunoglobulin

Chicken antisera to mouse immunoglobulin (anti-Ig) detect molecules on T lymphocytes of mice consisting of "heavy chains" similar in size to IgM mu chains and "light chains" similar in size to lambda or kappa chains. Because these T cell-derived proteins react with anti-Ig and are composed of Ig-like heavy and light chains, these molecules have been viewed as candidates for "IgT," the putative T lymphocyte receptor for antigen. We have demonstrated, by immunoprecipitation and two-dimensional gel analysis, that the lymphoma surface molecule precipitated by chicken anti-Ig is identical to the viral 70,000 dalton glycoprotein (gp 70) expressed by that lymphoma and is unassociated with any "light chain" or equivalent. For each of the three lymphomas analyzed, the gp 70 two-dimensional gel pattern was individually distinctive, and, in each case, the molecules precipitated by anti-Ig exhibited the same pattern as the gp 70. The viral gp 70 does have cross-reacting determinants with mouse IgM as seen by the chicken antiserum. We have substantiated these results by demonstrating that monoclonal antibodies to viral gp 70 precipitate the same molecules as chicken anti-Ig. These findings demonstrate that these T lymphoma cell surface molecules do not represent the T cell immunoglobulin receptor for antigen unless gp 70 itself is an antigen receptor.

Monoclonal antibodies to murine leukemia virus gp 70 recognize the same T lymphoma cell surface molecules as anti-immunoglobulin

Chicken antisera to mouse immunoglobulin (anti-Ig) detect molecules on T lymphocytes of mice consisting of "heavy chains" similar in size to IgM mu chains and "light chains" similar in size to lambda or kappa chains. Because these T cell-derived proteins react with anti-Ig and are composed of Ig-like heavy and light chains, these molecules have been viewed as candidates for "IgT," the putative T lymphocyte receptor for antigen. We have demonstrated, by immunoprecipitation and two-dimensional gel analysis, that the lymphoma surface molecule precipitated by chicken anti-Ig is identical to the viral 70,000 dalton glycoprotein (gp 70) expressed by that lymphoma and is unassociated with any "light chain" or equivalent. For each of the three lymphomas analyzed, the gp 70 two-dimensional gel pattern was individually distinctive, and, in each case, the molecules precipitated by anti-Ig exhibited the same pattern as the gp 70. The viral gp 70 does have cross-reacting determinants with mouse IgM as seen by the chicken antiserum. We have substantiated these results by demonstrating that monoclonal antibodies to viral gp 70 precipitate the same molecules as chicken anti-Ig. These findings demonstrate that these T lymphoma cell surface molecules do not represent the T cell immunoglobulin receptor for antigen unless gp 70 itself is an antigen receptor.

The genetics of β-amylase isozymes in wheat : 1. Allelic variation among hexaploid varieties and intrachromosomal gene locations

Thirty-three β-amylase isozymes were separated in 'Chinese Spring' by IEF and the structural genes encoding seventeen of these were located by nullisomic analysis. The locations of the previously reported β-Amy-1 loci on chromosome arms 4Aβ (β-Amy-A1) and 4DL (β-Amy-D1) were confirmed and another set, β-Amy-2, was found on the group 5 chromosomes. A locus on 5AL (β-Amy-A1) was identified by nullisomic analysis and another on chromosome 5B (β-Amy-B2) was identified by analysis of inter-varietal chromosome substitution lines. The loci are complex, each coding for several isozymes, and allelic variation occurs at all four. Two alleles were identified at β-Amy-A1, five at β-Amy-D1, five at β-Amy-A2 and two at β-Amy-B2. Eleven different β-AMY phenotypes were distinguished amongst the 46 wheat varieties screened. The β-Amy-A2 locus was mapped by employing chromosome 5A recombinant lines and found to be closely linked and proximal to the awn inhibitor, B1, on the long arm. An attempt to map the β-Amy-D1 locus on chromosome 4D showed the gene to be located in the distal region of the long arm.

Induction of lymphoma in athymic mice: a model for study of the human disease

A murine lymphoma, designated L1, was produced in immunologically deficient nude mice after chronic antigenic stimulation by infection with the pinworms Aspiculuris tetraptera and Syphacia obvelata. In vivo, L1 involves primarily the spleen and lymph nodes, with infiltration of liver, kidney, and bone marrow also observed. It is characterized by large clusters of B cells and null cells, and by rare T cells. The lymphoma cells express murine leukemia virus antigens (gp70 and p30) on the surface. L1 can be passaged successfully both in vivo and in vitro. The lymphoblasts that proliferate in vitro are null, but injecton back into the mouse produces a similar pattern of B cells, null cells, and occasional T cells as seen in the mouse-to-mouse transfers. Infectious viruses have been isolated from L1 cells and from tissue culture supernates and have been identified as a B-tropic murine leukemia virus and a xenotropic virus. The possibilities of this model for studying the etiology of human lymphoma are discussed.

Hypothalamo-pituitary-thyroid axis function during cardiopulmonary bypass

Marked alterations in levels of circulating thyroid hormone were found in patients undergoing cardiopulmonary bypass with a rise in the free thyroxine and a fall in the free triiodothyronine levels. Studies using thyrotropin-releasing hormone during bypass demonstrated a blunted response to this stimulus. This reduced response is related to changes in thyroid hormone levels and it is suggested that bypass surgery may have a direct inhibitory action on thyroid-stimulating hormone release at the hypothalamo-pituitary level. The potential significance of these hormonal changes is discussed.

The pattern of involvement of murine lymphoid tissues by primary lymphomas of different cell lineage

Murine virally induced lymphomas with T cell surface antigens migrate in the lymph nodes and spleen in the same regions as normal recirculating T lymphocytes. Non-T cell lymphomas have different patterns of migration.

Evidence that MuLV-induced thymic lymphoma cells possess specific cell membrane binding sites for MuLV

Cell-surface binding sites specific for thymotropic murine leukemia viruses were found in high concentrations on thymic lymphoma cell lines induced by this class of virus, but were detectable in much lower concentrations (if at all) in several non-T leukemias, plasmacytomas, and normal thymocytes or spleen cells. By specific comparison, Moloney leukemia virus (M-MuLV) binds to a lymphoma induced by M-MuLV, but not to a thymic lymphoma induced by Gross leukemia virus (G-MuLV); and G-MuLV binds to an AKR lymphoma but not to the M-MuLV-induced lymphoma. The material which binds to these T-lymphoma membrane sites is input virus, rather than a contaminant which copurifies with virus. Autoradiographic analysis demonstrates that a high proportion of T-lymphoma cells possess binding sites, whereas only a rare cell in the thymus binds murine leukemia virus to the same degree. We raise and discuss the hypothesis that each T lymphoma induced by thymotropic leukemia viruses may represent the clonal descendants of the few rate cells in the normal thymocyte population which also bind these viruses.