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Biomedical subjects

C Bingham

Publications and source records attributed to C Bingham.

At least 19 recordsLinked to original sources
PubMed1991

Environmental factor(s) during suckling exert long-term effects upon blood pressure and body weight in spontaneously hypertensive and normotensive rats.

To define the role of nurse and pup strain (spontaneously hypertensive rats: SHR nurses and shr pups; Wistar-Kyoto rats: WKY nurses and wky pups) and dietary salt in nurses and pups (low salt and high salt) upon pup body weight and blood pressure, we cross-suckled shr and wky from birth. Nurses after delivery and pups after weaning received either low- or high-salt diets. Pup body weight indicated that WKY dams were better nurses than SHR and that high salt in the nurse and pup diet decreased body weight. At 7 days, WKY on a low-salt diet normalized shr blood pressure and SHR on a high-salt diet reduced shr blood pressure. At 100 days, pup strain strongly affected blood pressure. Salt sensitivity to pup dietary salt depended upon a low-salt diet in nurses. Salt resistance depended on a high-salt diet in WKY nurses. At 300 days, pup strain accounted for most of the blood pressure variability. However, pup diet, pup strain and nurse diet also affected blood pressure (P = 0.05); the blood pressure of shr on a high-salt diet was higher if the nurse was an SHR on a high-salt diet. Thus, nurse environment modulated shr hypertension throughout life.

Animals↗
PubMed1990

Further extensions of the cosinor approach to problems of the pharmaceutical industry.

The resolution of a more complex time structure than that described by the useful first approximation of a single cosinor is suggested herein. The cosinor serves the purpose of parsimony in the case of sparse and short time series, yet it can be usefully extended by assessing the variations in rhythm characteristics for treatment timing in the clinic rather than only for research.

Animals↗
PubMed1987

A special group of ultradian oscillations.

Based on results from our studies, including those on leaf movements, circummutations of shoots, levels of enzyme activity, and metabolites, and from an extensive review of the literature, we have identified a special group of ultradian oscillations. Collectively, these oscillations have periods that range from approximately 30 to 240 min. Their patterns seldom exhibit strict periodicity or constant waveform. They have been observed in various animals, human beings, plants, and microorganisms. These oscillations appear to be a ubiquitous phenomenon, present at various levels of organization, e.g., biochemical to behavioral, and provide a unifying paradigm for exploring biological dynamics.

Activity Cycles↗
PubMed1987

Individualized principal component analysis of endocrine circannual variability.

The technique of principal component (PC) analysis (PCA) of multivariate observations is a method that allows dimension reduction of multivariate data for further analysis. It is here introduced as a means of selecting chronobiologically important variables that can be further studied by an analysis of variance. The use of PCA is illustrated for a study of major temporal sources of human endocrine variability. Contributions to temporal variability by seven steroidal and six nonsteroidal hormones are compared in samples available at 100-min intervals for 24 hr in three seasons for each of three clinically healthy individuals: an adolescent woman, a menstrually cycling woman, and a postmenopausal woman. On an individualized basis, it is ascertained that the first principal component, a new variable, is primarily determined by steroids and that PCA can single out variables displaying interseasonal (circannual) differences validated as statistically significant by a subsequent analysis of variance. The variables here scrutinized and identified as contributing to the PC, however, need not all differ with statistical significance along the scale of the seasons. The steroids contributing the first principal component are DHEA-S and an estrogen in all three individuals studied, cortisol and aldosterone in two of them, and 17-OH progesterone in one case.

Adolescent↗
PubMed1987

Bootstrapped potential circadian harbingers if not determinants of cardiovascular risk.

Among 12 endocrine variables in blood from clinically healthy adult women sampled systematically around the clock and the year, discriminant analysis methods have singled out certain hormones in certain seasons as classifiers for a high or low risk of developing diseases associated with a high circadian rhythm-adjusted mean (midline estimating statistic of rhythm, MESOR, M) of blood pressure, i.e., risk of M-hypertension (RMH). Before extending the labor intensive, costly data base, showing circadian changes with RMH, we reanalyzed available data by circadian bootstrapping, complementing earlier circannual bootstrapping. Differences in circadian M for aldosterone in all four seasons and for TSH in spring and summer (the only seasons checked), but not for the cortisol M checked in spring and summer, are validated, as are differences in circadian amplitude for TSH in spring and summer and aldosterone in spring. Identification of classifiers provides cost-effective, time-specified endocrine checks complementing the targeted automatic monitoring of blood pressure as part of a system of chronobioengineering for health maintenance.

Adolescent↗
PubMed1984

Increased vascular density associated with lesions of canine globoid leukodystrophy.

Two control dogs and 2 dogs that had globoid cell leukodystrophy (GLD) were studied to document vascular alterations associated with the leukodystrophic lesion. Spinal white matter was sampled by transverse and frontal planes of section from dorsal and ventral halves of the lateral funiculus of five spinal segments. Vessel profiles were classified as capillaries or larger vessels. GLD lesion was associated with an increase in capillary mean diameter. Vascular density, estimated by profiles per area, was compared in affected and control tissues. Capillary density was not significantly different, but the density of larger vessels was increased in proportion to the extent of GLD lesion. The increased density is presumed to be the result of lengthening or proliferation of vessels which had normal density prior to lesion formation.

Animals↗
PubMed1984

Quantitative investigation of hepatic genomic response to hormonal and pathophysiological stimuli by multivariate analysis of two-dimensional mRNA activity profiles.

We have applied techniques of multivariate analysis to the characterization and comparison of the effects of various pathophysiological and hormonal stimuli on the expression of the rat hepatic genome at a pretranslational level. In vitro translated products were resolved by two-dimensional gel electrophoresis. We analyzed 10 pathophysiological states brought about by variation in thyroidal status, starvation, administration of high carbohydrate diet, and the production of experimentally induced diabetes mellitus. Each state differed significantly from every other state in the two-dimensional electrophoretic profiles. The set consisting of the minimal number of products necessary for maintaining the distinctive patterns was identified. The analysis also defined those clusters of products that behaved in a coordinate fashion in response to the various stimuli. Lastly, the similarity and dissimilarity of hepatic mRNA activity profiles to each other could be geometrically represented in three-dimensional space. Our finding that the hepatic mRNA activity profile could distinguish reliably between closely related hormonal and pathophysiological stimuli indicates the specificity of hepatic genomic expression. A systematic analysis of such profiles may be useful as an overall index of the biologic response at the hepatocellular level.

Animals↗
PubMed1984

Hepatic messenger ribonucleic acid activity profiles in experimental azotemia in the rat. Relationship to food intake and thyroid function.

We have studied the hepatic messenger RNA (mRNA) activity profile in chronically azotemic rats and sought to determine whether the observed changes could be mediated either by reduced food intake or diminished thyroid function at the tissue level. mRNA activity profiles were produced by two-dimensional gel electrophoretic separation of radioactively labeled products of an in vitro reticulocyte lysate system which had been programmed by hepatic RNA. Of the approximately 240 translational products identified in this system, seven sequences were consistently altered in azotemia. In pair-fed animals six of these also decreased, but the alterations in three were depressed to a significantly lesser extent in the pair-fed group. Moreover, analysis of covariance suggested that food intake could account for the differences in only one sequence. The possibility that the mRNA activity profile in azotemia could represent the effects of diminished thyroid function was minimized by the finding that the reductions in plasma thyroxine (T4) and triiodothyronine (T3) levels observed were due largely to reduced plasma protein binding, with maintenance of the mean free T4 and free T3 concentrations within the normal range. The changes in only one mRNA sequence could be related to free T3 levels alone. Our findings, therefore, indicate that although diminished food intake and reduced thyroid function may contribute to some of the observed changes in the mRNA activity profiles, the bulk of alterations in azotemia appear to be mediated by other mechanisms. The striking overlap between the sequences affected by azotemia and pair-feeding raises the speculation that altered gene expression in azotemia may reflect an impaired hepatic response at the pretranslational level to metabolic signals associated with food intake.

Animals↗
PubMed1983

The volume density of cells and capillaries of the normal stria vascularis.

The purpose of this study was to provide morphometric (i.e. quantitative anatomical) data on the normal chinchilla stria vascularis. Five normal chinchillas were used in the present investigation and four regions of the cochlea were examined in each animal. The width, radial area and number of marginal cells across the stria's width increased from the cochlear apex toward the base. The increase in strial width and area appeared to be due to hyperplasia of the marginal cells. The mean total endolymphatic surface area of the stria vascularis was estimated to be 7.4 mm2 (S.E. = 1.23). The mean total volume of the stria vascularis was estimated to be 0.15 microliter (S.E. = 0.01). In addition, using a stereological method we found that the volume density of the cells and capillaries of the stria vascularis was constant along the length of the scala media. The mean (+/- S.E.) volume density of the stria cells and capillaries was estimated to be: marginal cells = 0.528 (0.013), intermediate cells = 0.212 (0.026), basal cells = 0.163 (0.009) and capillaries = 0.097 (0.009).

Animals↗
PubMed1983

Infectivity in sheep of blood lymphocytes from bovine leukemia virus-infected cows with different nuclear pocket prevalences.

The infectivity for the bovine leukemia virus (BLV) of bovine blood lymphocytes, with varying lymphocyte nuclear pocket (LNP) prevalence, was studied by intradermal injection of buffy coat leukocytes from cows into sheep. Thirty-five sheep were assigned to 3 groups of 9, 11, and 15, respectively, as recipients of blood leukocytes from individual cows as follows: 9 leukocyte donor cows included 3 BLV-seropositive cows with high (greater than or equal to 2.0%) LNP prevalence (group 1); 3 BLV-seropositive cows with low (less than 0.5%) LNP prevalence (group 2); and 3 BLV-seronegative cows with increased (greater than or equal to 0.5%) LNP prevalence (group 3). The 9 sheep in group 1 became BLV-seropositive by postinoculation day (PID) 57 as determined by the agar-gel immunodiffusion test; 2 of 11 sheep in group 2 became agar-gel immunodiffusion seropositive by PID 40; none of the 15 sheep of group 3 became seropositive by PID 92. Seemingly, there is a real difference in infectivity among BLV-seropositive cattle which is related to LNP prevalence, and seronegative cattle with increased LNP prevalence may be noninfectious, ie, were not carrying covert BLV virogene.

Animals↗
PubMed1981

Quantification of microvasculature in the canine spinal cord.

Capillary density and capillary orientation in canine spinal cords were estimated by calculating actual lengths, surfaces, and volumes of capillary segments in tissue sections. Transverse, sagittal, and frontal section planes were samples from dorsal, ventral, and lateral funiculi and from dorsal and ventral gray horns of spinal segments C3, T6, and L3 from three dogs. Capillaries were defined as vessels less than 10 micrometer in diameter. Electron microscopy of 104 such vessels revealed no muscle coat but collagen fibrils between endothelium and astrocyte process in 68% of the white matter capillaries and 16% of those in gray matter. Capillary diameter was significantly different among regions in some cases, but consistent patterns of variation were not found. Capillary density was four to five times greater in gray matter than in white matter. Capillary density differed significantly among the same-size dogs, but within dogs, density was similar among segments and within gray matter and white matter regions. In 62% of the transverse sections, capillary orientation was always along the craniocaudal axis of the spinal cord. The craniocaudal orientation was significant in 96% of the white matter sections and 78% of the gray sections, and in 97% of the cervical and thoracic sections but only 73% of the lumbar sagittal and frontal sections. Because capillary orientation is neither isotropic nor regular, unbiased, low-variance estimates of capillary density cannot be expected without resorting to excessive sampling. An efficient method of quantifying spinal capillaries for comparative purposes by counting number of profiles per unit area is recommended.

Animals↗
PubMed1981

Correlation of blood lymphocyte nuclear pocket prevalence with enzootic bovine leukemia p24 viral antibody titers.

The quantitative relationship between radioimmunoassay serotiters to p24 enzootic bovine leukemia viral antigen and the prevalence of lymphocytic nuclear pockets (LNP) was studied in 554 clinically normal dairy cows and bulls. Of the animals, 69% were seronegative. Of the seronegative animals, 44% had no observed LNP, whereas 93% of the seronegative animals had less than 1% LNP. However, 2.3% of the seronegative animals had substantially increased (greater than 2%) numbers of LNP, and conversely, 24% of the seropositive animals had no observed LNP. Statistical evaluation of the data, using contingency table and regression methods, provide significant (P less than 0.0001) evidence for a positive association between LNP prevalence and p24 bovine leukemia viral serotiters. Although significant, the association was weak, and hence LNP number had little value for predicting serotiter.

Animals↗
PubMed1980

Rhythm-adjusted age effects in a concomitant study of twelve hormones in blood plasma of women.

The concentrations of luteinizing hormone, prolactin, estrone, estradiol, 17-hydroxyprogestrone, cortisol, aldosterone, dehydroepiandrosterone, thyrotropic hormone, triiodothyronine, thyroxin and insulin were determined in blood plasma obtained from women aged 15 to 59 years. Blood was sampled at intervals of 20 to 100 min throughout 24-hour spans in each of the four seasons and (in the case of cycling women) in four different stages of the menstrual cycle. With such sampling allowing for rhythmic and other fluctuations over a broad time scale it was possible to demonstrate statistically significant effects of age on hormones associated with the menstrual cycle (luteinizing hormone, prolactin, estrone, estradiol and 17-hydroxyprogesterone) and on dehydroepiandrosterone, but not on the remainder. The amplitude of circadian rhythms in several of the hormones also varied with age, thus affirming the value of sampling throughout this particular rhythm.

Adolescent↗
PubMed1980

Enzootic bovine leukosis: prevalence of blood lymphocyte nuclear pockets in dairy bulls in the United States and foreign countries.

Studies of the incidence of enzootic bovine leukosis-related blood lymphlymphocyte nuclear pockets (LNP) were made of 743 dairy breed bulls in the United States and foreign countries. Statistical evaluation disclosed that the prevalence of these anomalous nuclear forms in the studs observed is significantly greater in the United States than in other countries. In particular, the average percentage of LNP-containing cells in each United States stud is estimated to be more than twice the level found in all but two non-United States studs studied and more than three times the level in the majority (10 of 19) of them. Moreover, United States studs exhibited a higher proportion of LNP-suspicious and -positive cases than almost all of the non-United States studs. We believe this is valid evidence that serves to reinforce the expressed need for a federal surveillance program for enzootic bovine leukosis in the United States.

Animals↗