PubMed Health⌕ Search

Biomedical subjects

R Butler

Publications and source records attributed to R Butler.

At least 55 records · Page 3Linked to original sources
PubMed1986

Resistance to Mycobacterium lepraemurium is correlated with the capacity to generate macrophage activating factor(s) in response to mycobacterial antigens in vitro.

The kinetics of cell-mediated immunity developed during the course of Mycobacterium lepraemurium infection were determined in resistant (C57BL) and susceptible (BALB/c) mice. Control of M. lepraemurium growth following footpad infection was T-cell dependent in C57BL mice as shown by the finding that T-cell deprived mice had enhanced bacterial counts in the footpad. In contrast, T-cell deprivation did not significantly alter the course of infection in BALB/c mice. However a T-cell dependent inflammatory response, resulting in an increase in size of the infected footpad, occurred in both strains, although it developed slightly later in BALB/c mice. Cells isolated from the lymph nodes, draining the infected foot-pads, were assayed for their proliferative responses to heat-killed M. lepraemurium (HK-MLM) antigens. Although lymph node cells from both mouse strains proliferated to HK-MLM early in the infection (1-2 weeks) both C57BL and BALB/c mice developed diminished in vitro proliferative reactivity within 4-6 weeks post-infection. Supernatants derived from cultures of lymph-node cells that had been stimulated with concanavalin A (Con A) or HK-MLM antigens, were assayed for the presence of macrophage-activating factor (MAF) activity using a tumour cytostasis assay and interferon (IFN) activity using a viral growth inhibition assay. Significantly higher levels of MAF and IFN were found in culture supernatants deprived from HK-MLM stimulated lymph-node cells from infected C57BL mice than from BALB/c mice during the first 8 weeks of infection. However, cells from infected mice of both strains produced similar amounts of both MAF and IFN in response to Con A.

Animals↗
PubMed1985

Sleep and nutritional deprivation and performance of house officers.

A study was conducted by the authors to compare cognitive functioning in acutely and chronically sleep-deprived house officers. A multivariate analysis of variance revealed significant deficits in primary mental tasks involving basic rote memory, language, and numeric skills as well as in tasks requiring high-order cognitive functioning and traditional intellective abilities. These deficits existed only for the acutely sleep-deprived group. The finding of deficits in individuals who reported five hours or less of sleep in a 24-hour period suggests that the minimum standard of four hours that has been considered by some to be adequate for satisfactory performance may be insufficient for more complex cognitive functioning.

Cognition↗
PubMed1979

A new grouping of intrafusal muscle fibers based on developmental studies of muscle spindles in the cat.

The development of muscle spindles was studied using the tenuissimus muscle of the cat. Observations show that the intrafusal muscle fibers develop as two separate groups: one group represented by a single nuclear bag fiber while the second group comprises the second nuclear bag fiber in association with all the nuclear chain fibers. This grouping is most pronounced in the fetus and is clearly seen in neonatal kittens (i.e., up to 2 weeks of age). As the intrafusal fibers begin to separate from each other, the groupings become less noticeable, although this basic pattern is often retained in the adult. The pattern of intrafusal fiber grouping is most noticeable in the equatorial regions of the spindle and least noticeable in the polar regions. This is not the grouping of fibers which would have been expected from a consideration of existing reports on muscle spindles. The implications for spindle form and function are considered.

Animals↗
PubMed1979

Effect of waterfowl (Anas platyrhynchos) on indicator bacteria populations in a recreational lake Madison, Wisconsin.

A public swimming beach in Madison, wis., experienced intermittent high fecal coliform counts during the late summer and early fall of 1978. Public health officials closed the beach on a number of occasions. A public health survey identified a combination of waterfowl wastes and meteorological events as the explanation for the high bacteria counts. Fecal coliform bacteria were deposited by mallard ducks and multiplied in the beach sands. The bacteria were subsequently transported into the lake and resulted in high fecal coliform counts in the swimming area.

Animals↗
PubMed1978

Antibody formation and transient immune complex glomerulopathy in A-strain mice with C1300 neuroblastoma tumors.

One to three-month-old A-strain mice, inoculated subcutaneously with 2 x 10(6) viable syngeneic C1300 neuroblastoma cells (clone NB9R) developed a palpable tumor within 9-12 days and died within 28-30 days. A transient glomerulopathy developed after 16-24 days. Despite a normal histologic appearance, the nephropathy was clearly demonstrated by electron microscopy and was classified as a focal mesangiopathic glomerulonephritis. Deposits of host 7S-G immunoglobulins and C3 complement fragments were detected in these same kidneys by immunofluorescence. Radioimmunoprecipitin determinations on sera obtained from mice at different intervals from tumor cell inoculation, revealed that untreated mice contained circulating antibodies capable of reacting with 125I-labeled gp69-71 glycoprotein from Gross murine leukemia virus (MuLV). Antibodies to p30 MuLV antigen and to crude membrane antigen (s) (CMA) solubilized from NB9R cells were found in sera only after tumor cell inoculation. Circulating immune complexes formed by host 7S-G immunoglobulins were clearly detected from day 16 to 22. Antibodies eluted from kidneys with nephropathy were shown to react with NB9R cells in vitro and to react specifically with CMA and the p30 MuLV antigen.

Animals↗
PubMed1978

Prevalence of Giardiasis: a study at upper-gastrointestinal endoscopy.

The prevalence of giardiasis was assessed in 1000 consecutive adult patients undergoing upper-gastrointestinal endoscopy for the usually accepted indications. Patients with upper-gastrointestinal bleeding were excluded. The diagnosis was established by examination of duodenal aspirate and duodenal mucosal impression smears. In 21 patients (2.1%) trophozoites were detected both in the duodenal juice and stained mucosal impression smears. All were treated with metronidazole or tinidazole. In 14 of 16 patients who had subsequent duodenal intubation, eradication of the parasite was confirmed. In five patients previously existent abdominal pain disappeared with clearing of the parasite, and no other cause for their abdominal pain was discovered. A search for Giardia lamblia infestation may be a worthwhile additional procedure at the time of endoscopy when no other cause for abdominal pain is found.

Abdomen↗
PubMed1977

A tryptic digestion fragment of nerve growth factor with nerve growth promoting activity.

A peptide, isolated from the acid-insoluble portion of a tryptic digest of cyanogen bromide cleaved nerve growth factor, favors life maintenance of sensory target cells and promotes rapid neurite outgrowth from 7-day-old chick embryo sensory ganglia. The fragment has been identified as a 30 amino acid peptide consisting of two linear oligopeptides linked by a disulphide bridge and corresponding to residues 10-25 and 75-88 of the amino acid sequence of nerve growth factor. On a molar basis the fragment is about 100 times more effective than intact nerve growth factor. Other peptides isolated from the digest are biologically inactive.

Amino Acids↗
PubMed1975

Arthritis in the prehistoric Southeastern United States: biological and cultural variables.

Recent research shows that a bacterial life form, Erysipelothrix insidiosa, can produce rheumatoid arthritis in deer, swine, and dogs, and that a number of animals, including man, birds, and fish, may be infected by the organism. Examination of the archaeological record suggests that both cultural and biological variables may be interrelated in the maintenance of some forms of arthritis over long periods of time in geographically disparate populations. Re-examination of Cherokee folk beliefs concerning arthritis suggests that they had some recognition of this connection, and it also suggests that they had some recognition of this connection, and it also suggests that the term "magical" may relate more to the world view of the observer than to any actual inability of preliterate peoples to draw causal relations on the basis of their own intimate knowledge of their environments.

Alabama↗
PubMed1974

Enhanced phagocytic capacity. The biologic basis for the elevated histochemical nitroblue tetrazolium reaction.

The biologic basis for the elevated histochemical reduction of nitroblue tetrazolium dye (NBT) in neutrophils from patients with acute bacterial infection or polycythemia vera was studied. A precipitin reaction followed mixing NBT with heparin. NBT was reduced after phagocytosis of this complex (H-NBT) by polymorphonuclear leukocytes (PMNs). Ingestion required divalent cations and was facilitated by the presence of complement. H-NBT incubated with normal but not with C2-deficient human serum converted native C3 to its inactive form. Phagocytic indices were determined in patients and controls by measuring O(2) utilization and hexose monophosphate shunt activity and by visually counting cell-associated latex particles. Significant elevations above controls were observed in phagocytes isolated from all patients with elevated histochemical NBT scores when H-NBT complex, latex, or zymosan was employed as the phagocytic particle. Increased indices were observed in the presence of fresh AB serum, heat-inactivated AB serum, or without serum. Serum from patients with elevated NBT scores did not alter phagocytosis in control phagocytes. With NADH and NADPH as substrates, total NBT diaphorase activity of sonicated leukocytes was normal in all patients. These results suggest that increased phagocytic capacity of PMNs is the primary cause of increased histochemical NBT reduction. The PMNs of patients with acute bacterial infection or polycythemia vera may have alterations in their cell membranes which lead to an enhanced rate of phagocytosis.

Animals↗