BCL6 gene rearrangements also occur in marginal zone B-cell lymphoma

Marginal zone B-cell lymphoma (MZBCL) represents a distinct subtype of B-cell non-Hodgkin's lymphoma (NHL) which has been recently recognized and defined as a disease entity. Cytogenetically, these lymphomas reveal a high prevalence of trisomy 3, and recent data obtained by comparative genomic hybridization indicate that the chromosomal regions 3q21-23 and 3q25-29 might be of particular pathogenetic significance. We identified structural chromosomal abnormalities involving the region 3q27 and rearrangements of the BCL6 proto-oncogene in three out of 34 (9%) well-defined cases of extranodal, nodal and splenic MZBCL using cytogenetic analysis. Southern blot, and fluorescence in situ hybridization (FISH). All three cases were characterized by a t(3;14)(q27;q32). Two of them showed additional chromosomal abnormalities including trisomy 3, which was found in one case. The patients displayed extranodal disease and did not demonstrate any striking clinical and histological differences when compared with MZBCL lacking BCL6 rearrangement. The present study for the first time demonstrates the occurrence of t(3;14)/BCL6 gene rearrangement in MZBCL, thus suggesting a role of the BCL6 proto-oncogene in the pathogenesis of MZBCL.

Reliability and validity of the Asthma Quality of Life Questionnaire--marks in a sample of adult asthmatic patients in the United States

To render quality-of-life scores on an instrument acceptable for cross-national comparison, the instrument's reliability and validity must be established in all countries in question. The Asthma Quality of Life Questionnaire-Marks (AQLQ-M) was developed in Australia, where it was shown to have good reliability and validity. However, no attempt had been made to determine the psychometric properties of the AQLQ-M and its domains (i.e., Breathlessness, Mood, Social, and Concerns) in the United States. The objectives of the present study were to administer the AQLQ-M to a sample of adult asthmatic patients in the United States (N = 106) and assess (1) the acceptability of the AQLQ-M to respondents, (2) the internal consistency of the AQLQ-M and its domains, and (3) the construct validity of the AQLQ-M and its domains. Results indicated that respondents did not have difficulty answering the questions in the AQLQ-M. The Cronbach coefficient alpha value for the AQLQ-M was 0.94. The Cronbach coefficient alpha value for individual domains ranged from 0.84 to 0.91, providing evidence of good internal consistency reliability for the AQLQ-M and its domains. Pearson product-moment correlations between the domain scores ranged from 0.62 to 0.88, indicating that the domains were related but separate aspects of asthma-specific quality of life, as measured by the AQLQ-M. Spearman rank-order correlations of the AQLQ-M score and domain scores with an indicator of disease severity--number of different prescription medications taken for asthma in the preceding 3 months-were positive and significant. This indicated that subjects taking a greater number of prescription asthma medications had higher AQLQ-M and domain scores, or a greater negative impact of asthma on quality of life, a result consistent with previous findings and one that provides some evidence of convergent validity. Our findings support the use of the AQLQ-M as a decision-making tool in the United States and in cross-national comparisons between the United States and Australia.

The dynamics of bimanual circle drawing

A bimanual circle drawing task was employed to elucidate the dynamics of intralimb and interlimb coordination. Right-handed subjects were required to produce circles with both hands in either a symmetrical (mirror) mode (i.e. one hand moving clockwise, the other counter-clockwise) or in an asymmetrical mode (i.e. both hands moving clockwise or counter-clockwise). The frequency of movement was scaled by an auditory metronome from 1.50 Hz to 3.25 Hz in 8 (8-sec) steps. In the asymmetrical mode, distortions of the movement trajectories, transient departures from the target pattern of coordination, and phase wandering were evidence as movement frequency was increased. These features suggested loss of stability. Deviations from circular trajectories were most prominent for movements of the left hand. Transient departures from the required mode of coordination were also largely precipitated by the left hand. The results are discussed with reference to manual asymmetries and mechanisms of interlimb and intersegmental coordination.

Cardiovascular disease in African American and white physicians: the Meharry Cohort and Meharry-Hopkins Cohort Studies

Differences in cardiovascular disease (CVD) were studied in a cohort of medical students from the classes of 1958-65 of Meharry Medical College (n = 435), all African Americans, and the classes of 1957-64 of Johns Hopkins University (n = 580), all white. At baseline, African Americans were older (27 vs. 24 years, p = 0.001), more likely to smoke (71 vs. 47 percent), had greater body mass index (24 vs. 23 kg/m), and had higher systolic blood pressure (120 vs. 116 mmHg). At follow-up (23-35 years later), African American physicians had higher CVD risk (RR = 1.65, 95% CI = 1.3-2.41), higher incidence of coronary artery disease (1.4 times), and much higher case fatality (51.5 vs. 9.4 percent). Risk factor levels in youth can predict CVD events several years later; predictors may differ between racial groups. Best predictors were cigarette smoking, cholesterol, and paternal history in white physicians, and blood pressure in African American physicians.

A Ph-negative chronic myeloid leukemia patient with a non-classical BCR-ABL rearrangement characterized by fluorescence in situ hybridization

A patient with chronic myeloid leukemia (CML), a normal karyotype and a BCR-ABL rearrangement is presented. Southern blot analysis detected the rearrangement, whereas RT-PCR with b2a2 and b3a2 primers did not. Fluorescence in situ hybridization (FISH) with an ABL probe (9q34.2) and an Mbcr probe (22q11) showed ABL and BCR signals on chromosome 22. Subsequent FISH studies with cosmids mapping to 9q34.3 showed normal hybridization patterns to chromosome 9, suggesting an interstitial insertion of ABL containing DNA sequences into chromosome 22 in this patient. The lack of reciprocal translocation sequences was investigated with RT-PCR, primers a1b and c7. The absence of ABL-BCR gene expression in this and other patients described in the literature with this subtype of Ph-negative CML, does not seem to have an impact on the clinical course of the disease.

Gout and risk for subsequent coronary heart disease. The Meharry-Hopkins Study

BACKGROUND

Patients with gout are encountered frequently in clinical practice. Previous studies have suggested that hyperuricemia and gout may represent risk factors for coronary heart disease (CHD), the most common cause of death in American men.

METHODS

Prospectively collected data from 2 longitudinal cohort studies of former medical students--371 black men in the Meharry Cohort Study and 1181 white men in the Johns Hopkins Precursors Study--were analyzed. The development of gout and of CHD was determined by physician self-report, and validated by using published criteria. The risk for CHD associated with gout was evaluated using Cox proportional hazards analysis.

RESULTS

During a median follow-up of 30 years, there were 38 gout cases and 44 CHD events among the Meharry men, and 68 gout cases and 138 CHD events among the Hopkins men. Prior gout was not associated with an increased risk for incident CHD (relative risk = 1.20; 95% confidence interval, 0.37-3.92) among the Meharry men or among the Hopkins men (relative risk = 0.66; 95% confidence interval, 0.24-1.79). Multivariate analysis adjusted for known CHD risk factors did not alter these findings.

CONCLUSION

These results, in black and white male physicians, do not suggest a role in men for targeting gout identification in the primary prevention of CHD.

Pathogenic analysis of Aeromonas hydrophila septicemia

Aeromonas hydrophila has emerged as a potential pathogen in the immunocompromised host. Various aeromonal infections, including septicemia, have also been reported in apparently healthy individuals. For years, researchers have disagreed over the epidemiologic roles of aeromonads in gastroenteritis. Isolation rates of aeromonads by stool culture among patients with gastroenteritis are not consistently high. Carriers of this bacterium also exist. The septicemic course is, however, often fulminant and fatal, and may lack an obvious focus. Pathogenic mechanisms are complex and largely unresolved. The objective of this study is to report the necropsy findings from a uremic patient who presented with typical aeromonal septicemia of obscure origin asking if such investigation could give insight into some of the questions mentioned previously. Western blot immunostaining for aerolysin (beta-hemolysin of aeromonads) was used to evaluate whether or not such a virulence factor is involved in the process of septic dissemination. The autopsy showed that the skin and liver contained microabscesses. The upper gastrointestinal mucosae and spleen contain patchy putrefactive lesions with adjacent focal hemorrhage. Perimortem blood cultures grew Aeromonas hydrophila. A conventional Western blot analysis of the culture supernatant failed to show aerolysin. A control Aeromonas sobia American Type Culture Collection (ATCC) strain produces readily detectable aerolysin. It is concluded that this isolate may be aerolysin-deficient or one secreting low levels of aerolysin; these would require more sensitive methods of detection. The primary focus of infection might be the upper gastrointestinal tract. Other virulence factors including the bacterial proteases and/or phospholipases might be responsible for the pathogenesis of septic dissemination.

Characterization of two distinct intracellular GLUT4 membrane populations in muscle fiber. Differential protein composition and sensitivity to insulin

A major objective for the understanding of muscle glucose disposal is the elucidation of the intracellular trafficking pathway of GLUT4 glucose carriers in the muscle fiber. In this report, we provide functional and biochemical characterization of two distinct intracellular GLUT4 vesicle pools obtained from rat skeletal muscle. The two pools showed a differential response to insulin; thus, one showed a marked decrease in GLUT4 levels but the other did not. They also showed a markedly different protein composition as detected by quantitative vesicle immunoisolation analysis. The GLUT4 pool showing no response to insulin contained SCAMP proteins and the vSNARE proteins VAMP2 and cellubrevin, whereas only VAMP2 was found in the insulin-recruitable GLUT4 pool. SDS-PAGE and further silver staining of the immunoprecipitates revealed discrete polypeptide bands associated to the insulin-sensitive pool, and all these polypeptide bands were found in the insulin-insensitive population. Furthermore, some polypeptide bands were exclusive to the insulin-insensitive population. The presence of cellubrevin and SCAMP proteins, endosomal markers, suggest that the insulin-insensitive GLUT4 membrane population belongs to an endosomal compartment. In addition, we favor the view that the insulin-sensitive GLUT4 membrane pool is segregated from the endosomal GLUT4 population and is undergoes exocytosis to the cell surface in response to insulin. Intracellular GLUT4 membranes obtained from skeletal muscle contain cellubrevin, and VAMP2 and GLUT4-vesicles from cardiomyocytes also contain cellubrevin. This suggests that vSNARE proteins are key constituents of GLUT4 vesicles. The presence of the tSNARE protein SNAP25 in skeletal muscle membranes and SNAP25 and syntaxin 1A and syntaxin 1B in cardiomyocyte plasma membranes further suggest a role of the SNAREs in GLUT4 trafficking in muscle.

The feasibility of assessing women's perceptions of the risks and benefits of fertility drug therapy in relation to ovarian cancer risk

OBJECTIVE

To determine the feasibility of asking women undergoing fertility treatment the maximum increased risk of ovarian cancer they would be willing to tolerate in order to take ovulation-induction drugs.

DESIGN

A prospective pilot study of women attending fertility clinics over a 2-month period.

SETTING

Two tertiary care fertility clinics in Toronto.

PATIENT(S)

Sixty-one English-speaking women were approached and 85% (n = 52) were enrolled.

INTERVENTION(S)

A self-administered questionnaire with fertility-specific questions. Thirty-eight women also were asked to complete standardized scales of anxiety and optimism.

MAIN OUTCOME MEASURE(S)

Women's report of the maximum level of lifetime risk of ovarian cancer they were willing to tolerate in order to undergo fertility treatment.

RESULT(S)

Seventy-nine percent were willing to accept an increased risk of ovarian cancer. Only 24% understood that treatment for ovarian cancer usually was not curative.

CONCLUSION(S)

A majority of patients were willing to tolerate a modest increase in their lifetime risk of ovarian cancer because of fertility treatment, most basing their estimate of acceptable risk on limited awareness of the issue.

In vitro evaluation of the role of antibodies against Helicobacter pylori in inhibiting adherence of the organism to gastric cells

BACKGROUND

Once Helicobacter pylori infection is established, it is difficult to eradicate despite a persistent systemic and local immune response. It is not known whether immunisation can be used to prevent H pylori infection in humans.

AIMS

To evaluate the effect of the human immune response on adherence of H pylori to gastric cells.

METHODS

Human milk from a woman infected with H pylori and milk from a non-infected woman were each fractionated by chromatography on DEAE cellulose. Bacteria were incubated with either serum, human milk, human milk fractions, or secretory IgA before incubation with Kato III cells (cells from a gastric adenocarcinoma cell line). Bacterial adherence to the cells was assessed using flow cytometry.

RESULTS

Serum from both the H pylori infected and non-infected women killed H pylori. This resulted from the action of complement as heating the serum to 56 degrees C for 30 minutes abolished the bactericidal activity. Immunoglobulin fractions from serum of both infected and non-infected women did not inhibit H pylori adherence to Kato III cells. Human milk from the woman infected with H pylori and from the non-infected woman inhibited binding of H pylori to Kato III cells by 50 to 70%. Secretory IgA isolated from human milk had minimal inhibitory effect on adherence and this was notably less than the inhibitory effect of whole human milk.

CONCLUSIONS

Human milk inhibits adherence of H pylori to Kato III cells and this inhibition is independent of whether or not the donor is infected with H pylori. Secretory IgA has minimal inhibitory effect on H pylori adherence.

A role for HDJ-2/HSDJ in correcting subnuclear trafficking, transactivation, and transrepression defects of a glucocorticoid receptor zinc finger mutant

All steroid receptors possess a bipartite nuclear localization signal sequence (NLS) that localizes within the second zinc finger of their DNA-binding domain. Fine-structure mapping of the rat glucocorticoid receptor (rGS) NLS identified a composite signal composed of three distinct proto-NLSs that function effectively when present in unique pairs. At least one of the rGR proto-NLSs appears to influence receptor trafficking within the nucleus, as revealed by a unique nuclear staining pattern of receptors possessing a point mutation (i.e., arginine at position 496; R496), at proto-NLS, pNLS-2. Specifically, carboxyl-terminal-truncated rGRs possessing various point mutations at R496 localized within a limited number of large foci in nuclei of transiently transfected COS-1 cells. R496 mutations did not affect subnuclear targeting when present in full-length rGR, reflecting a protective effect of the receptor's ligand-binding domain that can be exerted in cis and in trans. The effects of rGR R496 mutations on subnuclear targeting were not autonomous because we also observed a coincident localization of hsp70, the 70-kDa heat shock protein, within nuclear foci that include r496 mutant receptors. The elimination of R496 mistargeting by overexpression of an hsp70 partner (i.e., the DnaJ homologue, HDJ-2/HSDJ) suggests that the hsp70/DnaJ chaperone system is mobilized to specific sites within the nucleus in response to inappropriate targeting or folding of specific mutant receptors. HDJ-2/HSDJ overexpression also corrects defective transactivation and transrepression activity of R496 mutant GRs. Thus, molecular chaperones, such as members of the hsp70 and DnaJ families, may survey the nucleus for misfolded proteins and actively participate in their refolding into biologically active conformational states.

Characteristic pattern of chromosomal gains and losses in marginal zone B cell lymphoma detected by comparative genomic hybridization

Marginal zone B cell lymphoma (MZBCL) represents a distinct subtype of B cell non-Hodgkin's lymphoma, which has been recently recognized and defined as a disease entity. We investigated 25 cases (18 at primary diagnosis and seven during the course of disease) of MZBCL by comparative genomic hybridization (CGH) and compared these results with cytogenetic, fluorescence in situ hybridization (FISH), and Southern blot data. Twenty of the 25 cases (80%) showed gains (total 49) or losses (total 15) of genetic material. In extranodal, nodal, and splenic MZBCL, material of chromosomes 3 (52% of cases), 18 (32%), X (24%), and 1q (16%) was most frequently gained, whereas losses predominantly involved chromosomes 17 (16%) and 9 (12%). High-level amplifications involving the regions 18q21-23 and 18q21-22, respectively, were detected in two cases. Gains of chromosomes 1q and 8q and losses of chromosome 17 or 17p occurred more frequently in relapsed or progressive lymphomas. For all of the frequently affected chromosomes, CGH allowed narrowing of the relevant subregions including 3q21-23, 3q25-29 and 18q21-23. By Southern blot analysis, the BCL2, BCL6, and CMYC proto-oncogenes were found to be a part of the over-represented regions in two cases, one case, and two cases, respectively, with gains involving 18q, 3q or 8q. In 13 cases, CGH revealed chromosomal imbalances which were not detected by cytogenetic analysis but could be confirmed by FISH or Southern blot analysis in all cases investigated. On the other hand, CGH failed to detect trisomy 3, trisomy 18, and deletion 7q in three cases with a low proportion of tumor cells bearing these abnormalities, as shown by interphase FISH. The characteristic pattern of chromosomal gains and losses detected in this study confirms the distinct nature of MZBCL and may point to chromosomal regions involved in the pathogenesis of these neoplasms.

Three generations of high-density lipoprotein cholesterol assays compared with ultracentrifugation/dextran sulfate-Mg2+ method

We report on the analytical performance of three generations of HDL-cholesterol assays: phosphotungstic acid/Mg2+, Spinpro, and a homogeneous method, N-geneous. The run-to-run imprecision (CV) of all assays was < or = 4.9%, and all results correlated highly with those of a modified reference procedure (r > or = 0.96). At triglycerides concentrations < 4000 mg/L, these field methods showed an acceptable systematic error (y = 1.12x - 47, 1.05x - 23, and 0.96x + 8 for the phosphotungstate, Spinpro, and N-geneous assays, respectively), and the total error of the field methods met the current National Cholesterol Education Program (NCEP) performance goal of < or = 22%. Regression analyses of results for samples with triglycerides > 4000 mg/L produced the following results for the above respective assays: y = 1.08x - 4.2, 1.02x + 3.6, and 0.85x + 108. In this hypertriglyceridemic group, only the N-geneous assay (at an HDL-cholesterol content of 240 mg/L) had a total error (35%) that exceeded the NCEP limit. Bilirubin and ascorbate produced a negative interference with the phosphotungstate and Spinpro assays but had little effect on the N-geneous assay.

Pharmacodynamic modeling of the in vivo interaction between cefotaxime and ofloxacin by using serum ultrafiltrate inhibitory titers

The pharmacokinetics (PK) and pharmacodynamics (PD) of cefotaxime and ofloxacin and of their combination were examined in a three-period randomized crossover study involving 12 healthy adults. The PK of cefotaxime and ofloxacin were modeled. PD was assessed from the predicted concentrations in serum and serum untrafiltrate inhibitory titers for 10 test organisms. An inhibitory sigmoid Emax model based on the probability of bacterial growth was used, where Emax = 1 and EC50 is the concentration resulting in a 50% probability of growth. The total body clearance (CL(T)) and volume of distribution at steady state (V(SS)) for cefotaxime were 0.236 liters/kg/h and 0.207 liters/kg, respectively, for the monotherapy and 0.231 liters/kg/h and 0.208 liters/kg for the combination therapy. Ofloxacin exhibited PK parameters of 0.143 liters/kg/h for CL(T) and 1.20 liters/kg for V(SS) following the monotherapy and of 0.141 liters/kg/h for CL(T) and 1.16 liters/kg for V(SS) following combination therapy. For the combination therapy, an interaction term, theta, defined the type and relative extent of interaction. The range of observed theta values (-0.033 to 0.067) is consistent with an additive PD interaction according to standards similar to those used for the in vitro fractional inhibitory concentration index.

Insulin-induced recruitment of glucose transporter 4 (GLUT4) and GLUT1 in isolated rat cardiac myocytes. Evidence of the existence of different intracellular GLUT4 vesicle populations

Using isolated rat cardiomyocytes we have examined: 1) the effect of insulin on the cellular distribution of glucose transporter 4 (GLUT4) and GLUT1, 2) the total amount of these transporters, and 3) the co-localization of GLUT4, GLUT1, and secretory carrier membrane proteins (SCAMPs) in intracellular membranes. Insulin induced 5.7- and 2.7-fold increases in GLUT4 and GLUT1 at the cell surface, respectively, as determined by the nonpermeant photoaffinity label [3H]2-N-[4(1-azi-2,2,2-trifluoroethyl)benzoyl]-1, 3-bis-(D-mannos-4-yloxy)propyl-2-amine. The total amount of GLUT1, as determined by quantitative Western blot analysis of cell homogenates, was found to represent a substantial fraction ( approximately 30%) of the total glucose transporter content. Intracellular GLUT4-containing vesicles were immunoisolated from low density microsomes by using monoclonal anti-GLUT4 (1F8) or anti-SCAMP antibodies (3F8) coupled to either agarose or acrylamide. With these different immunoisolation conditions two GLUT4 membrane pools were found in nonstimulated cells: one pool with a high proportion of GLUT4 and a low content in GLUT1 and SCAMP 39 (pool 1) and a second GLUT4 pool with a high content of GLUT1 and SCAMP 39 (pool 2). The existence of pool 1 was confirmed by immunotitration of intracellular GLUT4 membranes with 1F8-acrylamide. Acute insulin treatment caused the depletion of GLUT4 in both pools and of GLUT1 and SCAMP 39 in pool 2.

IN CONCLUSION

1) GLUT4 is the major glucose transporter to be recruited to the surface of cardiomyocytes in response to insulin; 2) these cells express a high level of GLUT1; and 3) intracellular GLUT4-containing vesicles consist of at least two populations, which is compatible with recently proposed models of GLUT4 trafficking in adipocytes.

[Deficit in selective attention and its evolution in depression]

Selective attention was measured in 34 depressed patients and 34 controls using a computerized version of the Stroop test, that included a manipulation of the stimulus onset asynchrony (SCA) in order to explore the efficacy of cognitive inhibition as a function of depression and of clinical amelioration of degression after therapy. Clinical tests included a measure of psychomotor slowing [Echelle de Ralentissement de Widlöcher (ERD), the Hamilton (Psychiatric Rating Scale for Depression (HAMD), and the Brief Psychiatric Rating Scale (BPRS)]. Selective attention was measured with the Stroop test, which includes four measures: Word, Color, Color-Word, and Color-Word minus Color, or interference. All of these measures were deficient in the depressed patients, particularly Stroop interference. Even when additional time was given to inhibit the Stroop distractor in the SOA condition, depressed subjects still showed significantly inferior performance. After four weeks of anti-depressive treatment, fifteen of the patients were retested, and showed significant improvement on all the Stroop measures, particularly on Stroop interference. The improvement in performance on the attentional measures was comparable in magnitude to that seen on the clinical scales, and suggests that the interference measure can be a sensitive indicator of clinical status in depressed patients.

Characterization of the MODY3 phenotype. Early-onset diabetes caused by an insulin secretion defect

Maturity-onset diabetes of the young (MODY) type 3 is a dominantly inherited form of diabetes, which is often misdiagnosed as non-insulin-dependent diabetes mellitus (NIDDM) or insulin-dependent diabetes mellitus (IDDM). Phenotypic analysis of members from four large Finnish MODY3 kindreds (linked to chromosome 12q with a maximum lod score of 15) revealed a severe impairment in insulin secretion, which was present also in those normoglycemic family members who had inherited the MODY3 gene. In contrast to patients with NIDDM, MODY3 patients did not show any features of the insulin resistance syndrome. They could be discriminated from patients with IDDM by lack of glutamic acid decarboxylase antibodies (GAD-Ab). Taken together with our recent findings of linkage between this region on chromosome 12 and an insulin-deficient form of NIDDM (NIDDM2), the data suggest that mutations at the MODY3/NIDDM2 gene(s) result in a reduced insulin secretory response, that subsequently progresses to diabetes and underlines the importance of subphenotypic classification in studies of diabetes.

Glucose transport and glucose transporter GLUT4 are regulated by product(s) of intermediary metabolism in cardiomyocytes

Alternative substrates of energy metabolism are thought to contribute to the impairment of heart and muscle glucose utilization in insulin-resistant states. We have investigated the acute effects of substrates in isolated rat cardiomyocytes. Exposure to lactate, pyruvate, propionate, acetate, palmitate, beta-hydroxybutyrate or alpha-oxoglutarate led to the depression of glucose transport by up to 50%, with lactate, pyruvate and propionate being the most potent agents. The percentage inhibition was greater in cardiomyocytes in which glucose transport was stimulated with the alpha-adrenergic agonist phenylephrine or with a submaximal insulin concentration than in basal or fully insulin-stimulated cells. Cardiomyocytes from fasted or diabetic rats displayed a similar sensitivity to substrates as did cells from control animals. On the other hand, the amination product of pyruvate (alanine), as well as valine and the aminotransferase inhibitors cycloserine and amino-oxyacetate, stimulated glucose transport about 2-fold. In addition, the effect of pyruvate was counteracted by cycloserine. Since reversible transamination reactions are known to affect the pool size of the citrate cycle, the influence of substrates, amino acids and aminotransferase inhibitors on citrate, malate and glutamate content was examined. A significant negative correlation was found between alterations in glucose transport and the levels of citrate (P < 0.01) or malate (P < 0.01), and there was a positive correlation between glucose transport and glutamate levels (P < 0.05). In contrast, there was no correlation with changes in [1-(14)C]pyruvate oxidation or in glucose-6-phosphate levels. Finally, pyruvate decreased the abundance of GLUT4 glucose transporters at the surface of phenylephrine- or insulin-stimulated cells by 34% and 27 % respectively, as determined by using the selective photoaffinity label [3H]ATB-BMPA [[3H]2-N-[4-(1-azi-2,2,2-trifluoroethyl)benzoyl]-1,3-bis-(D-man nos-4-yloxy)propyl-2-amine]. In conclusion, cardiomyocyte glucose transport is subject to counter-regulation by alternative substrates. The glucose transport system appears to be controlled by (a) compound(s) of intermediary metabolism (other than glucose 6-phosphate), but in a different way than pyruvate dehydrogenase. Transport inhibition eventually occurs via a decrease in the amount of glucose transporters in the plasma membrane.

On the essential involvement of neutrophils in the immunopathologic disease: herpetic stromal keratitis

Corneal infection with herpes simplex virus-1 in immunocompetent mice induces an immunopathologic response termed herpetic stromal keratitis (HSK). The earliest sign of disease is neutrophil infiltration, which lasts for 48 to 72 h and then disappears. However, a secondary neutrophil infiltration, this time more massive, occurs, beginning 8 to 9 days postinfection, a time in which HSK becomes clinically evident. The role of neutrophils in HSK expression was investigated by eliminating such cells using a specific mAb (RB6-8C5). In neutrophil-depleted immunocompetent mice, virus replicated more abundantly, but no effects on HSK expression were observed, possibly because sustained neutropenia could not be maintained. However, using a severe combined immunodeficient mouse model, in which HSK does not occur unless given adoptive transfer of CD4+ T cells, the effects of neutrophil depletion were more pronounced. There were significantly less incidence and severity of HSK in CD4+ T cell-reconstituted severe combined immunodeficient mice that were depleted of neutrophils as compared with controls. Neutrophil-depleted mice displayed moderate to severe periocular skin lesions, progressively became cachetic, and developed signs of encephalitis. Virus was recovered at higher titers and for longer periods from eyes of neutrophil-depleted animals. Brain virus titers were also significantly higher on day 12 postinfection as compared with control animals. These results suggest that herpes simplex virus infection of the cornea rapidly invokes recruitment of neutrophils that may aid in viral clearance, and that neutrophils directly or indirectly serve as agonists in perpetuating a CD4+ T cell-mediated inflammatory reaction.

Acute transverse myelitis

Acute transverse myelitis is a relatively uncommon neurological disease in which affected patients exhibit acute dehabilitating symptoms associated with the loss of spinal cord segment function. During January 1996, a 23-year-old black female college student, who had been previously healthy, presented to our clinic with acute onset of symptoms typical of acute transverse myelitis. These symptoms included bilateral lower extremity paresthesias, back pains in the thoracic and lumbar areas and pronounced lower extremity weakness. This article is a review of literature to learn about the presenting symptoms, postulated etiologies, diagnostic studies, laboratory findings, management, and variable prognosis for acute transverse myelitis.

On the essential involvement of neutrophils in the immunopathologic disease: herpetic stromal keratitis

Corneal infection with herpes simplex virus-1 in immunocompetent mice induces an immunopathologic response termed herpetic stromal keratitis (HSK). The earliest sign of disease is neutrophil infiltration, which lasts for 48 to 72 h and then disappears. However, a secondary neutrophil infiltration, this time more massive, occurs, beginning 8 to 9 days postinfection, a time in which HSK becomes clinically evident. The role of neutrophils in HSK expression was investigated by eliminating such cells using a specific mAb (RB6-8C5). In neutrophil-depleted immunocompetent mice, virus replicated more abundantly, but no effects on HSK expression were observed, possibly because sustained neutropenia could not be maintained. However, using a severe combined immunodeficient mouse model, in which HSK does not occur unless given adoptive transfer of CD4+ T cells, the effects of neutrophil depletion were more pronounced. There were significantly less incidence and severity of HSK in CD4+ T cell-reconstituted severe combined immunodeficient mice that were depleted of neutrophils as compared with controls. Neutrophil-depleted mice displayed moderate to severe periocular skin lesions, progressively became cachetic, and developed signs of encephalitis. Virus was recovered at higher titers and for longer periods from eyes of neutrophil-depleted animals. Brain virus titers were also significantly higher on day 12 postinfection as compared with control animals. These results suggest that herpes simplex virus infection of the cornea rapidly invokes recruitment of neutrophils that may aid in viral clearance, and that neutrophils directly or indirectly serve as agonists in perpetuating a CD4+ T cell-mediated inflammatory reaction.

Neuropsychological correlates of syndromes in schizophrenia

BACKGROUND

On the basis of Liddle's three-syndrome model of schizophrenia, it was predicted that: (1) symptoms of psychomotor poverty would be particularly correlated with impaired performance on neuropsychological tests likely to reflect functioning of the dorsolateral prefrontal cortex; (2) disorganisation would be particularly correlated with impaired performance on tests sensitive to medio-basal prefrontal functioning; and (3) reality distortion would be particularly correlated with measures sensitive to temporal lobe functioning.

METHOD

The above hypotheses were tested on 87 subjects with a confirmed diagnosis of schizophrenia. Patients' symptoms were scored for each of the three syndromes. Patients completed six neuropsychological tests designed to measure impairment in specific areas of the brain.

RESULTS

There was no support for the first two hypotheses. There was, however, evidence of a specific relationship between reality distortion and neuropsychological performance usually considered to be related to left temporal lobe functioning.

CONCLUSIONS

Although not directly supporting the first two hypotheses; the results are, in general, consistent with there being different cortical-subcortical circuits associated with each of psychomotor poverty and disorganisation. Temporal lobe functioning appears to have particular significance for the reality distortion syndrome.

In bone marrow derived Baf-3 cells, inhibition of apoptosis by IL-3 is mediated by two independent pathways

The inhibition of cell death by growth factors plays a key role in the maintenance of the haematopoietic system homeostasis. However the mechanisms involved in this inhibition are still poorly understood. In order to determine if inhibition of apoptosis by growth factors is dependent only on the expression of survival genes, we have studied that process in the bone marrow derived IL-3 dependent cell line Baf-3. We show that, following IL-3 starvation, mRNA and protein levels of Bcl-X but not Bcl-2 decrease rapidly preceeding the onset of death. The death of IL-3 starved cells is asynchronous, starting between 6 to 8 h with 50% death being reached after 10 to 12 h. At any time point, apoptosis can be rapidly inhibited by growth factor re-addition. This has allowed us to determine that the inhibition of apoptosis by growth factor takes place at two levels. The first one, which we have called short term inhibition, is independent of mRNA and protein synthesis i.e. it takes place in the absence of survival gene neosynthesis and can be demonstrated during the first 6 h following growth factor re-addition. The second one corresponds to long-term survival-more than 24 h survival-and is strongly correlated with the induction of Bcl-X but not Bcl-2 gene expression. This induction of Bcl-X by IL-3 is shown to be dependent on MAP-kinase activation.