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Biomedical subjects

J C Williams

Publications and source records attributed to J C Williams.

At least 235 records · Page 13Linked to original sources
PubMed1989

Purification of human C-reactive protein by barium sulfate and preparative agarose electrophoresis.

A procedure is described for the purification of C-reactive protein (CRP) from human serum. The methods described take advantage of the barium sulfate adsorption property of CRP and the unique biophysical property of CRP migration during electrophoresis in agarose gels containing Ca2+. The purified CRP had an apparant molecular weight of 28,000 as determined by migration of the reduced protein during SDS polyacrylamide gel electrophoresis. The described procedure has the advantage of not requiring either molecular sieve or affinity chromatography for purification of homogenous CRP from human sera.

Adsorption↗
PubMed1989

Carotid sinus baroreflex control of beta-endorphin release in anesthetized dogs.

A quantitative assessment of the carotid sinus baroreflex release of endogenous plasma beta-endorphin-like immunoreactive material has been established. The carotid sinuses of 12 pentobarbital sodium-anesthetized dogs were isolated bilaterally and perfused with a constant pressure maintained by infusion or withdrawal of normal saline. Mean arterial pressure (MAP) and heart rate (HR) were monitored. Carotid sinus pressure (CSP) was changed from 200 to 50 mmHg in 25 mmHg steps before and after vagotomy. At each interval of CSP, 10 ml mixed venous blood were collected, and beta-endorphin-like peptides were extracted from plasma and assayed. Concentrations of plasma beta-endorphin-like material were determined by radioimmunoassay. Sigmoidal responses of MAP and HR were revealed during changes in CSP. No significant differences in beta-endorphin-like immunoreactivity (beta-END-L-I) were measured at CSP of 200 and 50 in the intact condition (35.9 +/- 3.9 and 35.0 +/- 6.4 fm/ml, respectively). However, after vagotomy, beta-END-L-I measured at 50 mmHg CSP was significantly elevated to 53.3 +/- 5.2 fm/ml compared with the value of 35.5 +/- 7.2 fm/ml at CSP of 200 mmHg. The results suggest that the release of beta-endorphin is modulated by the action of the carotid baroreflex as a normal component of an integrated efferent response. However, this response is normally buffered by reflexes with vagal afferents.

Animals↗
PubMed1989

Differential growth hormone responses to glucose and growth hormone releasing hormone in lactating dairy cows.

Dairy cows in early lactation were reported to secrete growth hormone in response to declining glucose concentrations at day 5 but not day 30 post-partum, whereas GH responses to TRH were reported to be enhanced after day 30 post partum. The present study examined GH response following glucose infusion and the effect of GHRH as well as effects of SRIH on GHRH-stimulated GH release. Declining plasma glucose concentrations after glucose infusion stimulated GH release at day 5 post partum but not in nonpregnant, nonlactating cows or in cows at days 30 and 90 post partum. GHRH stimulated GH release on all days tested, but the response was highest at day 30 post partum when compared to other days. Somatostatin infusion inhibited GHRH effects on GH concentrations only at day 30 post partum and in nonpregnant, nonlactating cows. Thus, a differential response of the GH regulatory system could be demonstrated between days 5 and 30 post partum utilizing different stimuli. Evaluation of plasma glucose and free fatty acid concentrations on days 5, 10, 20, and 30 post partum revealed a progressive decrease in FFA but not glucose as lactation progressed. Decreased plasma FFA concentrations were paralleled by a decrease in basal GH, somatomedin-C and epinephrine. Thus, a decline in FFA may be responsible for the disparity between effects of GHRH and glucose on GH release between days 5 and 30 post partum.

Animals↗
PubMed1989

Effects of ivermectin on control of gastrointestinal nematodes and weight gain in weaner-yearling beef cattle.

Four groups of 16 crossbred beef calves were used in evaluating different anthelmintic treatment schedules: group 1 was given ivermectin (IVM) at weaning only (October 31) and grazed on initially safe pasture; group 2 was given IVM at weaning, on January 28, and on April 22, and grazed on contaminated pasture; and group 3 was given IVM at weaning and on April 22, and grazed on contaminated pasture; and group-4 was group treated with fenbendazole (FBZ) at weaning only, with provision for individual salvage treatment, and grazed on contaminated pasture. The investigation was from Oct 31, 1984, to Oct 9, 1985. Initially high fecal egg counts at weaning were more effectively reduced by IVM than by FBZ, and the effect of safe pasture was evident in minimal worm burdens in tracer calves grazed with group-1 cattle during November and least amount of weight loss in group-1 yearlings during winter. Fecal egg counts, pasture larval counts, and plasma pepsinogen concentrations remained low in group 2 after the January treatment. Fecal egg counts of the other groups increased substantially during late winter and spring, but pasture larval counts increased only on group-1 and group-4 pastures. During spring, highest worm burdens were found in group-1 and group-4 tracer calves (grazed in April) and in group-3 and group-4 yearlings (slaughtered in early April). Six cattle of group 4 were salvage treated with FBZ in February and April. Greatest gains were observed from March through June, with group-2 and group-1 cattle gaining the most.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

Echocardiographic abnormalities in the mucopolysaccharide storage diseases.

The mucopolysaccharide storage diseases express themselves clinically with a wide variety of abnormalities, including growth and mental retardation, skeletal abnormalities, clouded corneas, nerve compression syndromes, upper airway obstruction and cardiovascular involvement, to name the most common. In most cases the cause of early death is cardiorespiratory failure secondary to cardiovascular involvement and upper airway obstruction. The findings of cardiac ultrasound examination in 29 children, adolescents and young adults are presented. In addition to the previously well-described abnormalities of the mitral and aortic valves in several types of mucopolysaccharide storage disease, we report patchy involvement in some cases, 3 instances of asymmetric septal hypertrophy not previously reported in mucopolysaccharide storage diseases, cardiac involvement in half of our patients with Sanfilippo syndrome and a lack of age-related severity of cardiac involvement even within the specific syndromes.

Adolescent↗
PubMed1988

Morphometry of feline neutrophil granule genesis.

During neutrophil granule genesis, the formation of primary granules is generally thought to be limited to the promyelocyte stage; whereas synthesis of secondary granules is thought to occur only at the myelocyte stage. This hypothesis was tested morphometrically in feline neutrophils that are known to contain both granule types. Marrow specimens obtained from six cats were stained with peroxidase for identification of neutrophil primary granules and counterstained with periodic acid-thiocarbohydrazide-silver proteinate (PA-TCH-SP) for identification of secondary granules. By regression analysis using arithmetic models, numbers of cytoplasmic granules in 311 cells were correlated with the degree of nuclear chromatin condensation, which was shown to be an adequate parameter for cell maturation. Promyelocytes and myelocytes had similar mean numbers of peroxidase-positive granules per unit area. A significant increase (p less than or equal to 0.0001) in the numbers of peroxidase-positive granules was noted between the metamyelocyte and the mature neutrophil stage, despite the lack of peroxidase activity in endoplasmic reticulum and Golgi lamellae. By contrast, a significant increase of peroxidase-negative granules between the metamyelocyte and the mature neutrophil stage was not clearly established with these methods. The increase in peroxidase-positive granules may indicate continued production of peroxidase-containing granules and/or redistribution of peroxidase among lysosomal organelles in late feline neutrophils.

Animals↗
PubMed1988

Hereditary spherocytosis in the elderly.

Five patients with hereditary spherocytosis diagnosed in their seventh to ninth decades of life are presented. These patients are remarkable for absent or mild clinical manifestations of disease. Splenectomy is the recommended treatment for hereditary spherocytosis to avoid the complications of aplastic or hemolytic crisis. When the diagnosis is made in the elderly, the treatment of choice may be careful observation with folic acid supplementation rather than splenectomy. This recommendation is based on the incidence of complications of splenectomy in the elderly in comparison to the severity and incidence of complications from the disease itself.

Age Factors↗
PubMed1988

Epidemiology of Ostertagia ostertagi in warm temperate regions of the United States.

For many years our general knowledge on the epidemiology of Ostertagia ostertagi in the U.S.A. was based on research conducted in Scotland and England. During the last 10 years, epidemiologic investigations on O. ostertagi and other gastrointestinal nematodes of cattle have been conducted in various sections of the U.S.A. and Canada. Definite seasonal patterns of O. ostertagi larval inhibition have been demonstrated, but occurrences of the Type I and Type II clinical entities have not been adequately described and associated with the epidemiology of the parasite. All information to the present time suggests that there are seasonal differences in ostertagiasis based on a north and south plane, with larval inhibition occurring during autumn in the north and during spring in the south and parts of the west. Under environmental and management conditions of the south and those other regions where O. ostertagi is significantly and summer is the dominant season, some minimal numbers of inhibition-prone O. ostertagi may be acquired during autumn and winter. However, the early pre-Type II phase (acquisition of inhibition-prone larvae) begins in late winter and reaches peak levels during spring. From January to April, young cattle between weaning and 16 months of age may be affected by Type I disease. Pasture transmission basically ceases from late spring into autumn with consistent high temperature and alternating wet and dry periods. From late summer through autumn (occasionally earlier), Type II disease is possible primarily in yearling cattle and also in older cattle. September and October are months of greatest prevalence. The probability of Type II disease effects occurring, i.e. effects ranging from mild clinical signs and minimal production loss to acute disease and deaths, is dictated by numbers of worms present and characteristics of maturation of inhibited larvae, which in turn may be influenced by current weather factors and management conditions, as well as those of the previous winter and spring.

Animals↗
PubMed1988

Experimental infections of Ostertagia ostertagi in goats.

In order to determine the usefulness of the goat as a model host for Ostertagia ostertagi, a series of experiments was conducted in which young goats and calves were experimentally infected with L3 of calf-source and goat-source isolates. The goat-source isolate was derived from a continuous passage of the bovine parasite in goats. Patent infections resulted in 73 out of 86 inoculated goats (85%). The largest number of patent infections was observed when inoculation consisted of a single dose of goat-source larvae. Percentage establishment of infection was generally low in goats inoculated with either larval source. Time taken to achieve patency in goats was frequently within the range normal for cattle infections, but was often extended (21-67 days). With the exception of the generally higher level of establishment of goat- or calf-source isolates in calves and the low frequency of the vulval flap in adult female worms established in goats, little difference was observed in percentage establishment or worm population characteristics of the two isolates in goats.

Animals↗
PubMed1988

Preliminary report: immunodiagnosis of pre-type II ostertagiasis.

Ostertagia ostertagi soluble antigens were prepared by gel electrophoresis and electrophoretic transfer onto nitrocellulose for enzyme-linked immunosorbent assays with serum probes. Serologic responses to L3-derived antigen of approximately 32 kDa may be unique and diagnostic for cattle harboring inhibited larvae, or pre-Type II ostertagiasis. Specificity was evaluated by comparing sera from pre-Type II cattle to sera from Type I, uninfected, Fascioloides magna infected, Fasciola hepatica infected or Cooperia oncophora infected cattle.

Animals↗
PubMed1988

Sequential histopathologic changes of type I, pre-type II and type II ostertagiasis in cattle.

Yearling cattle in Louisiana were examined at monthly intervals for abomasal nematode burdens and histological lesions over a year. Tracer calves were grazed for 3 to 4 weeks and removed from pasture for 2 to 3 weeks, then slaughtered; a few animals were killed in extremis shortly after removal from pasture. Histological changes were correlated with worm burdens and characterized according to the type of Ostertagia ostertagi infection present. In cattle with acute Type I ostertagiasis, changes varied from eosinophil infiltration to glandular dilation and slight mucous cell hyperplasia with submucosal edema. During the summer months the cattle had worm burdens that were primarily early 4th stage larvae (EL4), with changes characterized by minimal glandular dilation and mucous cell metaplasia and moderate lymphoid cell proliferation and with intramucosal migration of EL4. In the autumn, the maturation of EL4 produced the Type II syndrome with severe glandular changes, prominent mucosal hyperplasia and marked lymphoid cell accumulation. With increased duration of the pre-Type II interval, there was greater development of the subepithelial lymphoid tissue and increased frequency of epithelial globule leukocytes. The lymphoproliferation which occurred during the prolonged pre-Type II interval appeared to be related to the increased severity and mortality seen with the Type II ostertagiasis syndrome.

Abomasum↗
PubMed1988

Exposure to parturient cats: a risk factor for acquisition of Q fever in Maritime Canada.

Over a 34-mo period we studied 51 patients with Q fever and 102 control subjects (with various lower-respiratory-tract infections) who were matched for age, sex, and time of onset of infection. By univariate analysis (not adjusted for multiple comparisons), cases differed significantly from controls in the following activities: working on a farm; slaughtering or dressing animals; and contact with cats, cattle, and sheep. The strongest association was with exposure to stillborn kittens--11 of 51 cases vs. none of 102 controls (P less than .00000)--and with exposure to parturient cats (odds ratio, 10.3; 95% confidence interval, 3.5-31.8). Exposures to newborn animals (chiefly kittens) and stillborn kittens were significant risk factors by multivariate analysis, as were rural residence and slaughtering or dressing animals. In 13 Q fever incidents following exposure to parturient cats, 80 people became ill, 52 of whom had serological evidence of recent Coxiella burnetii infection (most of the others were not tested).

Animals↗
PubMed1988

The Mycobacterium tuberculosis 65-kilodalton antigen is a heat shock protein which corresponds to common antigen and to the Escherichia coli GroEL protein.

Monoclonal hybridoma antibodies directed against a 65-kilodalton (kDa) mycobacterial protein could detect similarly sized antigens in many other bacterial species. In Pseudomonas aeruginosa, the cross-reacting protein corresponded to a 62-kDa antigen that has been called Common Antigen. The mycobacterial 65-kDa antigen and Common Antigen are similar in that both (i) are highly immunoreactive molecules, (ii) contain species-specific and genus-specific epitopes in addition to the broadly cross-reactive epitopes, (iii) can be isolated as homomultimers of greater than 240 kDa, and (iv) have similar amino acid compositions. In Escherichia coli, the cross-reactive protein corresponded to the GroEL protein. Both the GroEL protein and the mycobacterial 65-kDa protein are expressed as heat shock proteins.

Antigens, Bacterial↗
PubMed1988

A heat shock operon in Coxiella burnetti produces a major antigen homologous to a protein in both mycobacteria and Escherichia coli.

A gene library from the DNA of Coxiella burnetii has been constructed in the cosmid vector pHC79. A particular clone, pJB196, reacted strongly with Coxiella-specific antibodies elicited in a number of different species of animals. This clone produced two abundant C. burnetii-specific polypeptides, a 14-kilodalton nonimmunoreactive protein and a 62-kilodalton immunoreactive protein. Sequencing identified two open reading frames, encoding polypeptides of 10.5 and 58.3 kilodaltons. The only transcriptional control element observed on the 5' side of the initiation codon resembled a heat shock promoter. This heat shock promoter was functionally regulated in Escherichia coli, since both proteins were produced by growth conditions at 37 degrees C and neither protein was detected at 23 degrees C. There were four sequences from the literature that were highly homologous (greater than 50%) to the 62-kilodalton protein from C. burnetii. Three were from Mycobacterium species and represent the immunodominant antigen of this genus. The other was from E. coli, detected as a gene that complements or suppresses a temperature-sensitive RNase activity. Since the recombinant protein was immunogenic, it may serve as an efficacious vaccine against C. burnetii and other pathogenic microorganisms that express the conserved antigen.

Amino Acid Sequence↗
PubMed1988

Cortical interstitium as a site for solute polarization during tubular absorption.

The possibility that significant concentration differences could exist between the interstitial fluid and capillary plasma was investigated by modeling the renal cortex as the following three compartments: tubular lumen, interstitium, and capillary lumen. A simple analysis of this system suggests that for the interstitium surrounding a proximal tubule, the concentration in the interstitium of a solute like glucose could be well over 1 mM greater than in the peritubular capillary if the solute permeability of the peritubular capillary were like that measured in other organs (i.e., less than 10 micron/s). The effect of varying capillary permeability on the interstitial concentrations of several solutes was examined using a modification of a model of the proximal tubule, and results were found to be similar to those obtained with the simpler analysis for glucose. This model was also used to see if placing an osmotic difference between the tubule lumen and capillary could cause significant solute polarization within the interstitium, as might occur in an experiment to measure the osmotic water permeability (Pf) of the proximal tubule in vivo. The results show that an apparent Pf calculated from the difference between the osmolalities of tubular perfusate and peritubular plasma is likely to underestimate the true Pf of the proximal tubule. Even for a high value of capillary permeability (10 micron/s, which allows relatively rapid diffusion between capillary and interstitium), the model predicts that the apparent Pf may underestimate the true value by half. Thus the analyses presented suggest that if the permeability of renal peritubular capillaries is similar to that measured in other organs the composition of the interstitium may be significantly different from capillary plasma, a situation that would have great impact on our view of the mechanism of volume absorption in the proximal tubule in vivo.

Absorption↗