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Biomedical subjects

C Bingham

Publications and source records attributed to C Bingham.

At least 55 records · Page 3Linked to original sources
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↗
PubMedDate not supplied

From experimental units to unique experiments: chronobiologic pilots complement large trials.

The timing of treatment affects outcome. For mapping multi-frequency rhythm spectra first to optimize chronochemotherapy, 1000 marker determinations on the subject are more informative than a few determinations on each of hundreds of patients. N-of-6 subgroups should follow, with one subject assigned to each of 6 marker rhythm stages, 60 (e.g. 4 hours on a 24-hour scale) apart. Once the time structure has been mapped, minimal sampling requirements determined, and guidelines for treatment established, the information gained from chronobiologic n-of-1 and n-of-6 test pilot designs can be built cost-effectively into randomized controlled trials to benefit large patient populations. Sequential tests combined with marker rhythmometry and cosinor analysis on single test subjects, small groups and eventually on each patient are powerful tools that can extract information otherwise unattainable even at great cost and bring the P-value from publications to the patients.

Antineoplastic Agents↗
PubMedDate not supplied

Chronosynergistic effects of lighting schedule-shift and cefodizime on plasmacytoma growth and host survival time.

Lighting regimen shifts can modify the effects of cefodizime, for the purpose of a chronoimmunomodulation. Two experiments were carried out on male and female LOU rats inoculated subcutaneously with plasmacytoma cells. Some rats were kept on their original LD12:12 regimen, whereas others, after tumor implantation, were subjected every second day to 6-h shifts, instituted, in alternation, as advance or delay. Daily treatment with cefodizime or placebo started when, overall, about 50% of the animals had developed a palpable tumor. A subgroup of animals contributed daily smears for the determination of the estrus cycle and further provided core temperature and activity data by telemetry. In Experiment I, the repeated shifting of the LD regimen was associated with survival time prolongation (p less than 0.05), irrespective of drug administration. Moreover, in those (female) rats repeatedly exposed to shifts of the lighting schedule, cefodizime was found to prolong survival time (p less than 0.05). The effects of cefodizime vs placebo on survival time were found to be circadian stage-dependent. In Experiment II, differing from Experiment I in the initial conditions before the institution of the shifts, cefodizime treatment was associated with a prolongation of survival time of the female rats kept on a fixed LD12:12 regimen. Both male and female rats again showed a circadian stage-dependence of the cefodizime effect. These results suggest that interactions between synchronizers of rhythms (such as shifts of the lighting regimen, the latter simulating the daily routine) and immunomodulating agents such as cefodizime may be optimized to improve treatment strategies against cancer and other diseases.

Animals↗
PubMedDate not supplied

Testing period for single cosinor: extent of human 24-h cardiovascular 'synchronization' on ordinary routine.

A clinically healthy woman monitored her systolic and diastolic blood pressure and pulse for 26 days at approximately 10-min intervals, with interruptions. Data over subspans of varying length were analyzed by single cosinor. A method for testing a period assumed to characterize data analyzed by single cosinor was introduced and programmed to compute a 95% confidence interval for the circadian period. Statistically significant deviations from precisely 24 h were found. The likelihood of their occurrence was found to vary as a function of the length of the interval analyzed. Under ordinary conditions in health, the circadian period may vary around 24 h, indicating that strict frequency-synchronization with the environment need not occur on a short-term basis. Deviations from an average circadian period may be brought about in part by infradian components modulating the circadian rhythm and by day-to-day changes in waveform.

Blood Pressure↗
PubMedDate not supplied

Chronobiologic serial sections of several orders.

The chronobiologic serial section is described. Its applicability to the analysis of nonequidistant data is emphasized. Its ability to detect and quantify multiple components is discussed and exemplified on simulated series with various amounts of additive Gaussian noise. This least-squares method is discussed in the context of a number of complementary procedures such as complex demodulation and linear-nonlinear least-squares rhythmometry.

Animals↗
PubMedDate not supplied

Construction of rhythm-specified reference intervals and regions, with emphasis on 'hybrid' data, illustrated for plasma cortisol.

Time-specified reference intervals, so-called chronodesms for the interpretation of single samples, have heretofore been proposed for longitudinal data, consisting of repeated samples from a single individual, and for transverse data: single time-specified samples from many individuals. Herein the problem of dealing with hybrid data, namely time series of data collected on a group of subjects, is considered for a derivation of reference intervals that take into account both inter- and intra-individual variability. The formulae are applied to cortisol data (72 samples from each of 10 healthy young adult North American women) with interpretation from both Bayesian and frequentist viewpoints. The provision of reference limits for both single samples and paired rhythm characteristics offers the opportunity of introducing an overdue time-specification and time-structure evaluation into microscopic chronobiology and through it into medical, veterinarian and other practice.

Adult↗
PubMedDate not supplied

Cross-spectral coherence between geomagnetic disturbance and human cardiovascular variables at non-societal frequencies.

A 35-year-old cardiologist monitored himself with an automatic ABPM-630 (Colin Electronics) monitor, mostly at 15-minute intervals around-the-clock for three years with a few interruptions. In this subject with a family history of high blood pressure and stroke, a cross-spectral analysis revealed a statistically significant coherence at 27.7 days between systolic and diastolic blood pressure and heart rate vs. the geomagnetic disturbance index, Kp. A lesser peak in coherence was found for systolic blood pressure with Kp at a trial period of 4.16 days (P = 0.046). These results suggest that changes in geomagnetism may influence the human circulation, at least in the presence of familial cardiovascular disease risk, and they may do so at frequencies that have no precise human-made cyclic worldwide match.

Adult↗