Suppression of B cell activation by cyclosporin A, FK506 and rapamycin.

The effects of the immunosuppressants cyclosporin A (CsA), FK506 and rapamycin have been compared using murine B cells activated with a variety of mitogens. FK506 is a macrolide antibiotic that has been recently shown to inhibit T cell activation by a mechanism that appears similar to that of CsA. Rapamycin is a macrolide structurally related to FK506 whose mechanism of T cell suppression appears to be distinct from that of FK506 and CsA. While CsA and FK506 were found to preferentially inhibit B cell activation caused by stimuli which induce a rise in intracellular calcium, rapamycin partially inhibited activation by all stimuli tested, including those which are not associated with a calcium flux. All three compounds were found to inhibit cell cycle progression within the G1 phase; however, the rapamycin-sensitive event within G1 was completed earlier than the G1 events inhibited by CsA and FK506. In addition, inhibition of anti-IgM-activated B cells with CsA and FK506, but not with rapamycin, resulted in cell death. These data suggest that although CsA, FK506 and rapamycin are all inhibitors of B cell activation, the inhibitory activity of rapamycin can be clearly distinguished from that of CsA and FK506. Although the suppressive effects of CsA and FK506 on B cell proliferation were nearly identical in this study, their biological activities were distinguishable since FK506, but not CsA, could antagonize rapamycin-mediated suppression.     

Waves earlier than P3 are more informative in putative subcortical Dementias: A study with mapping and neuropsychological techniques

Summary Thirty subjects (normal controls, patients with putative subcortical dementia and non-demented patient controls) were studied using advanced neurophysiological (16 scalp-electrode positions, computer-assisted brain electrical activity mapping, auditory oddball paradigm) and neuropsychological techniques. Our study suggests that waves earlier than P₃ (N₁, P₂ and N₂) are all correlated with global measures of cognitive functions. They are, however, differentially correlated with specific measures of cognitive functions, N₁ and P₂ with mental speed and N₂ with short-term memory. The abnormalities of these waves (earlier than P₃) may be an electrophysiologic marker of dementia in patients with putative subcortical states.     

Ovarian senescence in the rhesus monkey (Macaca mulatta)

BACKGROUND: A decline in fertility is evident in human females past their middle thirties. This 'reproductive senescence', marked by a sharp decline in pregnancy rates, may be attributed to reductions in numbers of available oocytes and their quality. Because Old World primates exhibit ovarian morphology and physiological control and timing of menstrual cycles closely resembling those of humans, the current study investigated the rhesus macaque as a potential model for human reproductive senescence. METHODS: Ovaries collected from females aged 1-25 years and divided into five age groups were analysed histologically. RESULTS: General ovarian morphology demonstrated significant changes as the females approached menopause. The proportions of primordial and primary follicles all demonstrated significant differences across age groups (primordial: 77.1, 79.9, 69.7, 62.9, 55.1%; primary: 21.5, 18.8, 28.5, 35.2, 43.1% for age groups 1 to 5 respectively; P<0.0001 for both). Samples from females approaching or undergoing the menopausal transition (aged 20-25 years) demonstrated evidence of ovarian senescence, having scattered and atretic follicles, low numbers of primordial follicles and reduced stromal tissue. CONCLUSION: This study supports the value of the rhesus monkey as a model for reproductive ageing because its ovary undergoes follicular reservoir depletion similar to that seen in humans.     

Bone marrow examination for the diagnosis of mycobacterial and fungal infections in the acquired immunodeficiency syndrome.

In a series of 342 bone marrow examinations from 314 patients with human immunodeficiency virus infection, 70 examinations (20%) detected opportunistic mycobacterial or fungal infections. One hundred eleven of the 314 patients had such infections, and, hence, 63% (70/111) were detected by bone marrow examination. Special stains for microorganisms detected 16 (32%) of 50 Mycobacterium avium complex infections, 10 (22%) of 45 Mycobacterium tuberculosis infections, eight (73%) of 11 Histoplasma capsulatum infections, and five (83%) of six Cryptococcus neoformans infections. Bone marrow cultures detected 36 (72%) of the 50 M avium complex infections, 13 (29%) of the 45 M tuberculosis infections, and 63% of the fungal infections. Marrow examination revealed infection in only one of the 70 specimens (1%) collected to evaluate thrombocytopenia alone or hematologic malignancy, but in 69 (25%) of 274 with fever, neutropenia, anemia, or miscellaneous other indications for marrow examination. Granulomas were detected in 102 (30%) of the biopsy specimens, including 71 (64%) of those in cases with mycobacterial or fungal infection. The granulomas showed caseous necrosis in nine cases, all in patients with tuberculosis, and the 27 cases with tuberculosis-associated granulomas tended to show large, tightly cohesive granulomas. The presence of granulomas correlated with opportunistic infection in 82 (80%) of 102 cases. Without granulomas, special stains were positive in only eight (3%) of 240 specimens. These results suggest that (1) bone marrow granulomas are a common and valuable histologic clue to opportunistic infection; (2) without them, special stains may not be a cost-efficient way to diagnose such infection; and (3) bone marrow examination can be a useful method of diagnosing opportunistic mycobacterial and fungal infections in patients with fever, anemia or neutropenia, and underlying human immunodeficiency virus infection.     

Differential processing of neuropeptides influences Drosophila heart rate

Peptides that play critical physiological roles are often encoded in precursors that contain several structurally-related gene products. Differential processing of a precursor by cell-specific processing enzymes can yield multiple messengers with diverse distributions and activities. We have reported the isolation of SDNFMRFamide, DPKQDFMRFamide, and TPAEDFMRFamide from adult Drosophila melanogaster. The peptides are encoded in the FMRFamide gene and have a common C-terminal FMRFamide but different N-terminal extensions. In order to investigate the processing of the FMRFamide polypeptide protein precursor, we generated antisera to distinguish among the structurally-related neuropeptides. Utilizing a triple-label immunofluorescent protocol, we mapped the distribution of the peptides. Each peptide has a unique, non-overlapping cellular expression pattern in neural tissue suggesting that the precursor is differentially processed. In order to identify a biological activity of the peptides, we established an in vivo heart rate assay. SDNFMRFamide decreases heart rate but DPKQDFMRFamide and TPAEDFMRFamide do not, indicating that the N-terminal residues are critical for this activity. SDNFMRFamide immunoreactivity is present in the aorta, implying that SDNFMRFamide acts locally to affect heart rate; DPKQDFMRFamide and TPAEDFMRFamide antisera do not stain cardiac tissue. Our data support the conclusion that Drosophila contains cell-specific proteolytic enzymes to differentially process a polypeptide protein precursor resulting in unique expression patterns of structurally-related, yet functionally distinct neuropeptides.     

Risk of infection after penetrating abdominal trauma

To identify the risk factors for the development of postoperative septic complications in patients with intestinal perforation after abdominal trauma, and to compare the efficacies of single-drug and dual-drug prophylactic antibiotic therapy, we studied 145 patients who presented with abdominal trauma and intestinal perforation at two hospitals between July 1979 and June 1982. Logistic-regression analysis showed that a higher risk of infection (P less than 0.05) was associated with increased age, injury to the left colon necessitating colostomy, a larger number of units of blood or blood products administered at surgery, and a larger number of injured organs. The presence of shock on arrival, which was found to increase the risk of infection when this factor was analyzed individually, did not add predictive power. Patients with postoperative sepsis were hospitalized significantly longer than were patients without infection (13.8 vs. 7.7 days, P less than 0.0001). Both treatment regimens--cefoxitin given alone and clindamycin and gentamicin given together--resulted in similar infection rates, drug toxicity, duration of hospitalization, and costs.     

A monoclonal antibody defining a binary N-acetyllactosaminyl structure in lactoisooctaosylceramide (IV6Gal beta 1----4GlcNAcnLc6): a useful probe for determining differential glycosylation patterns between normal and transformed human fibroblasts

Monoclonal antibodies A5 and C6 have been reported previously to recognize developmentally regulated determinants involving N-acetyllactosamine [Fenderson B. A., O'Brien D. A., Millette C. F. and Eddy E. M. (1984) Devl Biol. 103, 117-128]. In the present study, the specificity of these antibodies was determined by solid-phase radioimmunoassay and by thin-layer chromatography immunostaining using purified glycolipid standards. Antibody A5 recognized N-acetyllactosamine (type 2 chain; Gal beta 1----4GlcNAc beta 1----3R), irrespective of branching status. In contrast antibody C6 recognized the binary N-acetyllactosamine structure carried on lactoisooctaosylceramide. Antibody C6 did not react with sialosyl or alpha-galactosyl derivatives of the isooctaosyl structure, including human G10, G8 and bovine G9. Thus, unlike other anti-I antibodies, C6 provides a specific probe for both branching status and absence of terminal chain modification. Monoclonal antibodies A5, C6 and anti-I(Ma) were used to investigate glycosylation changes associated with oncogenic transformation. In contrast to results with lectins, these antibodies preferentially labeled the major glycoproteins of SV40-transformed human embryonic lung fibroblasts, including GP80, GP180, GP200 and GP250. The results suggest that increased expression of unsubstituted polylactosamine core structure at the cell surface follows SV40-transformation.     

Complex chromosome rearrangements and congenital anomalies

Congenital complex chromosome rearrangements (CCR) compatible with life are rare in man. Thus patients with CCR usually present considerable diagnostic difficulties both clinically and cytogenetically. We studied a 12-year-old mentally retarded male with minor congenital anomalies as described below and his first-degree relatives. The propositus had an unbalanced karyotype with eight break points and seven derivative chromosomes; two deletions, del(6) (q25----qter) and del(14) (q31----qter), and four translocations, t(2;11), t(5;15), t(6;11), t(6;20) were present. Parental chromosomes were normal; however, the mother had a few metaphases with abnormal chromosomes suggestive of chromosome instability. These findings and a review of reported patients with CCR are presented with regard to speculations about etiology, pathogenesis, phenotypic expression, and prognosis. Physicians should be aware of CCR and broader indications for cytogenetic studies appear warranted in view of these data.     

Interleukin 2 receptor targeted fusion toxin (DAB486-IL-2) treatment blocks diabetogenic autoimmunity in non-obese diabetic mice.

Insulin-dependent diabetes mellitus (IDDM) is strikingly similar in the non-obese diabetic (NOD) mouse and humans. In IDDM, the systematic autoimmune destruction of insulin-producing beta cells within the pancreas is dependent on autoreactive T cells. This autoimmune process can be accelerated by transferring spleen cells from diabetic donors into irradiated syngeneic NOD mice. In a previous study we established that interleukin 2 receptor (IL 2R)-bearing cells propagated from pre-diabetic NOD mice promote IDDM. Therefore, we reasoned that specific elimination of IL 2R+ T cells should abort the diabetogenic process. T cell expressing IL 2R can be selectively destroyed with a diphtheria toxin-related IL 2 fusion protein (DAB486-IL-2). We set DAB486-IL-2 the challenging task of preventing fulminant IDDM accelerated by the adoptive transfer of diabetic spleen cells. Eight weeks after the adoptive transfer only 10% and 20% of NOD mice treated with 10 and 5 micrograms/day of DAB486-IL-2, respectively, became diabetic while 100% control mice (vehicle buffer) became diabetic within 5 weeks. A dose of 1 microgram/day of DAB486-IL-2 had no protective effect. Although the protection conferred by DAB486-IL-2 is not permanent, it is maintained for at least 4 weeks following cessation of treatment. Furthermore, even though these NOD mice do eventually become diabetic, the tempo of expression and severity of diabetes, as assessed by the level of hyperglycemia, is dramatically reduced. Although histologic examination of pancreas revealed minimal degree of mononuclear infiltrate within the islets in both groups, the vehicle control mice had fewer islets per section indicating many islets had already been destroyed. In addition, spleen cells from diabetic NOD mice which were pre-treated with DAB486-IL-2 (10 micrograms/day) for 1 week lost their ability to transfer disease. Taken together, these studies strongly support the concept that IL 2R-bearing T cells are essential for the induction of IDDM and suggest that DAB486-IL-2 would be a promising therapeutic approach in the treatment of human IDDM.