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Biomedical subjects

J M Russell

Publications and source records attributed to J M Russell.

At least 109 records · Page 6Linked to original sources
PubMed1985

Resolution of genetic and cultural inheritance in twin families by path analysis: application to HDL-cholesterol.

A path model and associated statistical method for the analysis of data on twin families are introduced and applied to high density lipoprotein cholesterol (HDL-c) observations in the Swedish Twin Family Study. The proposed path model incorporates both genetic and environmental sources of familial resemblance, maternal environmental effects, intergenerational differences in heritabilities, marital resemblance due to either primary or secondary phenotypic homogamy, and twin residual environmental correlations. Application of the model to HDL-c levels resulted in parameter estimates consistent with those reported in earlier reviews and in the analysis of nuclear family and twin data. Genetic heritability was estimated as h2 = .363 +/- .243, cultural heritability as c2 = .187 +/- .082, and the proportion of phenotypic variance due to residual environmental effects as r2 = .450 +/- .207. Although the parameter estimates were comparable, the statistical tests of hypotheses were, relative to other designs, of low statistical power. It appears that environmental indices are necessary for powerful tests of hypotheses.

Analysis of Variance↗
PubMed1984

Lithium transport across squid axon membrane.

This paper describes the pathways for lithium transport across the axonal membrane of squid. We were able to show that the membrane of this classical neuronal preparation possesses the lithium transport mechanisms previously identified in red blood cells. It is now possible to predict that the lithium treatment-induced changes in choline and lithium transport that have been observed in red blood cells of manic depressive patients also occur in nerve membrane.

Animals↗
PubMed1984

A family study of anthropometric traits in a Punjabi community: I. Introduction and familial correlations.

Data on 40 anthropometric measurements from 144 nuclear families in Chandigarh, India, are presented. Most families contain a pair of monozygotic or dizygotic twins, one or more singleton siblings, and their parents. Familial correlations for age-sex standardized, normalized measurements are estimated by maximum likelihood for marital, parent-child, sibling, and twin pairs. Heterogeneity tests for sex-specific subtype correlations male-male, male-female, female-female) indicate that the sex of the relative plays no significant role in the magnitude of the familial correlations except for maternal effects and differences among male and female twin pairs for a few of the variables. Marital correlations are high for body measurements, but not for head or face variables. Twin correlations seem to indicate a higher level of heritability than correlations from other family members.

Adolescent↗
PubMed1984

A family study of anthropometric traits in a Punjabi community: II. An investigation of familial transmission.

Path analysis is used to characterize family resemblance for anthropometrics in twins and nuclear families from the Punjabi population of India. Significant positive assortative mating exists with respect to many body measurements, but not for cranial or facial variables. Evidence of a maternal effect for five measurements of bone diameter is reported. Twin resemblance is increased by a component not found in other pairs of relatives for all variables except nasal height, facial length, ear length, and head breadth. Although all variables have significant transmissible components, many have parameter estimates which are not consistent with strictly polygenic inheritance. Some form of cultural transmission is implicated for such variables, especially for those related to fatness levels.

Adolescent↗
PubMed1984

Role of the microcirculation in ethanol-induced mucosal injury in the dog.

The aim of the present study was to assess the role of the intestinal microcirculation in the mucosal injury induced by intraenteric ethanol. Mucosal injury was assessed histologically in the ileum and jejunum and quantitated in the ileum by measuring clearance of albumin (37 A, radius) and beta-lactoglobulin A (27 A, radius). A steady-state analysis of the forces and flows governing transcapillary fluid movement was performed in autoperfused segments of jejunum and ileum. In the jejunum and ileum ethanol induced the formation of subepithelial blisters in 10%-40% of the villi. In the ileum, ethanol (5%, vol/vol) increased the clearance of both proteins but the ratio of lactoglobulin to albumin clearance decreased, indicating that the selectivity of the mucosal membrane was diminished. In both the jejunum and ileum ethanol produced similar alterations in the forces governing transcapillary fluid exchange. Ethanol increased the filtration coefficient (35%-40%), but did not alter the osmotic reflection coefficient of intestinal capillaries, indicating that surface area increased whereas vascular permeability was not affected. Capillary pressure increased (2-3 mmHg) whereas interstitial (lymph) protein concentration decreased resulting in an increase in the transcapillary oncotic pressure gradient (1-2 mmHg). The net result of the alterations in the forces governing transcapillary movement was only a doubling of the transcapillary filtration rate (lymph flow). It is concluded that the ethanol-induced increase in mucosal permeability to macromolecules cannot be explained solely on the basis of alterations in the forces and flows governing transcapillary fluid exchange in the small intestine.

Albumins↗
PubMed1983

Cultural and biological inheritance of plasma lipids.

A path analytic model for the analysis of nuclear family data is described and used to analyze the results of two major studies of cholesterol (CH) and triglyceride (TG), the Honolulu Heart Study (HHS) of Japanese-Americans and the Cincinnati Lipid Research Clinic (LRC) study of Caucasians. The studies were first analyzed separately to assess evidence for genetic and cultural transmission, marital resemblance, and maternal environmental effects for the two plasma lipids, and then simultaneously to identify the nature and sources of any between-study-heterogeneity. There were significant sources of heterogeneity between the two studies for CH (only marital environmental resemblance and non-transmitted sibling environmental resemblance) and for TG (only non-transmitted sibling environmental resemblance). The two studies were homogeneous with respect to the magnitude of genetic and cultural effects; for CH genetic heritability was estimated as h2 = .594 +/- .041 while cultural heritability was estimated as c2 = .035 +/- .008, and for TG the two heritabilities were estimated as h2 = .259 +/- .034 and c2 = .108 +/- .014. An additional bivariate analysis of the association between the two lipids revealed that all phenotypic resemblance could be explained in terms of an association of non-transmitted residual environments with little evidence for a genetic association. The relevance of these results for an understanding of the genetic epidemiology of plasma lipids is discussed.

Asian People↗
PubMed1983

Stoichiometry and ion dependencies of the intracellular-pH-regulating mechanism in squid giant axons.

The ion transport system responsible for intracellular pH (pHi) regulation in squid giant axons was examined in experiments with pH-sensitive microelectrodes and isotopic fluxes of Na+ and Cl-. In one study, axons were acid-loaded and the rate of the subsequent pHi recovery was used to calculate the acid extrusion rate. There was an absolute dependence of acid extrusion on external Na+, external HCO-3 (at constant pH), and internal Cl-. Furthermore, the dependence of the acid extrusion rate on each of these three parameters was described by Michaelis-Menten kinetics. Acid extrusion was stimulated by an acid pHi, required internal ATP, and was blocked by external 4-acetamido-4'-isothiocyanostilbene-2,2'-disulfonate (SITS). Under a standard set of conditions (i.e., [HCO-3]o = 12 mM, pHo = 8.00, [Na+]o = 425 mM, [Cl-]i = 150 mM, [ATP]i = 4 mM, pHi = 6.5, and 16 degrees C), the mean acid extrusion rate was 7.5 pmol X cm-2 X s-1. In a second study under the above standard conditions, the unidirectional Na+ efflux (measured with 22Na) mediated by the pHi-regulating system was found to be approximately 0, whereas the mean influx was about 3.4 pmol X cm-2 X s-1. This net influx required external HCO-3, internal Cl-, and acid pHi, internal ATP, and was blocked by SITS. In the final series of experiments under the above standard conditions, the unidirectional Cl- influx (measured with 36Cl) mediated by the pHi-regulating system was found to be approximately 0, whereas the mean efflux was approximately 3.9 pmol X cm-2 X s-1. This net efflux required external HCO-3, external Na+, an acid pHi, internal ATP, and was blocked by SITS. We conclude that the pHi-regulating system mediates the obligate net influx of HCO-3 (or equivalent species) and Na+ and the net efflux of Cl- in the stoichiometry of 2:1:1. The transport system is stimulated by intracellular acid loads, requires ATP, and is blocked by SITS.

Acids↗
PubMed1983

Cation-coupled chloride influx in squid axon. Role of potassium and stoichiometry of the transport process.

Evidence is presented showing that the Cl- uptake process in the squid giant axon is tightly coupled not only to Na+ uptake but also to K+ uptake. Thus, removal of external K+ causes both Cl- and Na+ influxes to be reduced, particularly when [Cl-]i is low, that is, under conditions previously shown to be optimal for Cl-/Na+-coupled influx. In addition, there exists a ouabain-insensitive K+ influx, which depends on the presence of external Cl- and Na+, is inversely proportional to [Cl-]i, and is blocked by furosemide/bumetanide. Finally, this ouabain-insensitive K+ influx appears to require the presence of cellular ATP. The stoichiometry of the coupled transport process was measured using a double-labeling technique combining in the same axon either 36Cl and 42K or 22Na and 42K. The stoichiometry of the flux changes occurring in response either to varying [Cl-]i between 150 and 0 mM or to treatment with 0.3 mM furosemide is, in both cases, approximately 3:2:1 (Cl-/Na+/K+). Although these fluxes require ATP, they are not inhibited by 3 mM vanadate. In addition, treatment with DIDS has no effect on the fluxes.

Animals↗
PubMed1983

Intracellular pH and Na fluxes in barnacle muscle with evidence for reversal of the ionic mechanism of intracellular pH regulation.

The ion transport mechanism that regulates intracellular pH (pHi) in giant barnacle muscle fibers was studied by measuring pHi and unidirectional Na+ fluxes in internally dialyzed fibers. The overall process normally results in a net acid extrusion from the cell, presumably by a membrane transport mechanism that exchanges external Na+ and HCO-3 for internal Cl- and possibly H+. However, we found that net transport can be reversed either by lowering [HCO-3]o and pHo or by reducing [Na+]o. This reversal (acid uptake) required external Cl-, was stimulated by raising [Na+]i, and was blocked by SITS. When the transporter was operating in the net forward direction (acid extrusion), we found a unidirectional Na+ influx of approximately 60 pmol . cm-2 . s-1, which required external HCO-3 and internal Cl- and was stimulated by cyclic AMP and blocked by SITS or DIDS. These properties of the Na+ influx are all shared with the net acid extrusion process. We also found that under conditions of net forward transport, the pHi-regulating system mediated a unidirectional Na+ efflux, which was significantly smaller than the simultaneous Na+ influx. These data are consistent with a reversible transport mechanism which, even when operating in the net forward direction, mediates a small amount of reversed transport. We also found that the ouabain-sensitive Na+ efflux was sharply inhibited by acidic pHi, being totally absent at pHi values below approximately 6.8.

Acid-Base Equilibrium↗
PubMed1983

Heterogeneity between populations for multifactorial inheritance of plasma lipids.

A general linear model was described for multifactorial inheritance of the two plasma lipids, total cholesterol (CH), and triglyceride (TG). Analyses of two separate studies, the Honolulu Heart Study (HHS) and the Cincinnati Lipid Research Clinic (LRC), indicated some heterogeneity. Whereas the sibling environmental effect (b) was the only source of heterogeneity between the two studies for TG, the correlation between marital environments (u) may also be considered as a source of heterogeneity for CH. Under parsimonious hypothesis, intergenerational differences in heritabilities were not found to be significant for either trait (y1 = y2 = z1 = z2 = 1). Maternal effects were significant for CH but not for TG. Correlations between marital environments (u1 and u2) were not significant for TG, and may be considered nonsignificant for CH also under parsimonious hypotheses. In any case, the genetic (h2) and cultural (c2) heritabilities cannot be considered to be heterogeneous between the two studies. Based on pooled data, parsimonious hypothesis yields: h2 = .594 +/- .041 and c2 = .035 +/- .008 for CH, and h2 = .259 +/- .034 and c2 = .108 +/- .014 for TG.

Aged↗
PubMed1981

Management of the papillae during intrarenal surgery.

The intersegmental nature of renal incisions is axiomatic. Deviation from the intersegmental plane is hazardous. If divided along intra-arterial planes papillae appear to heal with little structural or functional impairment.

Adult↗
PubMed1981

Recurrent urolithiasis following anatrophic nephrolithotomy.

Analysis of 18 patients who suffered recurrent urolithiasis after anatrophic nephrolithotomy is presented. These patients form a subgroup of 80 patients who underwent 100 consecutive extensive anatrophic nephrolithotomies between 1967 and 1972. Careful documentation of the 18 patients who had recurrent calculi was done in an effort to delineate the causative factors. The recurrence interval varied from less than 6 months to more than 8 years during an over-all followup period of 9.94 years. Marked differences in the characteristics between 14 male and 4 female patients were noted. In the male patients a significant relationship among recurrent staghorn calculi, anomalous urinary drainage and Pseudomonas urinary tract infections was noted. The female patients had recurrent or persistent urinary tract infections or undiagnosed metabolic problems as the primary reason for the recurrent urolithiasis.

Adult↗
PubMed1981

Cyclic AMP-stimulated chloride fluxes in dialyzed barnacle muscle fibers.

Unidirectional chloride efflux and influx were studied in giant barnacle muscle fibers that were internally dialyzed. When cyclic 3'5'-adenosine monophosphate (cAMP) was included in the dialysis fluid, both unidirectional fluxes were stimulated by about the same amount. This stimulation was not associated with measurable changes either in membrane electrical conductance or with net movements of chloride. The stimulation required the trans-side presence of chloride. The stimulated flux was inhibited by the sulfonic acid stilbene derivatives 4-acetamido-4'-isothiocyanostilbene-2',2'-disulfonate (SITS) and 4,4'-diisothiocyanostilbene-2,2'-disulfonate (DIDS) or by furosemide. When cAMP was presented in high concentrations (10-5 M), the effect on chloride fluxes was characterized by a desensitization phenomenon. This desensitization was not the result of an increased amount of phosphodiesterase activity, but may be related to ATP and/or intracellular calcium levels. These results further support the hypothesis that the barnacle sarcolemma possesses a specialized chloride transport mechanism that largely engages in Cl-Cl exchange under conditions of normal intracellular pH.

8-Bromo Cyclic Adenosine Monophosphate↗
PubMed1981

Monitoring induction of ovulation by rapid radioimmunoassays of oestrogen and pregnanediol glucuronides.

To increase the sample-handling capacity for an induction of ovulation programme, direct urinary radioimmunoassays (RIA) for three steroid glucuronides, pregnanediol-3-glucuronide (Pd-3-G), oestrone-3-glucuronide (E1-3-G), and oestriol-16 alpha-glucuronide (E3-16-G), were established. Results obtained for urinary Pd-3-G measured by direct RIA show an excellent correlation (r = 0.98, N = 46) with those for urinary pregnanediol measured by gas-liquid chromatography. Estrone-3-glucuronide (E1-3-G) and estriol-16 alpha-glucuronide (E3-16-G) values, measured by direct RIA, closely paralleled the total urinary oestrogen measured fluorimetrically. Ovarian response to ovulation induction therapy can be monitored by observing the changes in the levels of E1-3-G in urine. Pre-ovulatory levels of urinary E3-16-G were found to be too low for use in this regard. Direct RIA for E1-3-G and Pd-3-G are recommended as reliable indices of ovarian function in the monitoring of patients receiving treatment for the induction of ovulation.

Animals↗