Search PubMed⌕ Search

Biomedical subjects

D A Hall

Publications and source records attributed to D A Hall.

At least 109 records · Page 6Linked to original sources
PubMed1982

The effect of enzyme therapy on plasma lipid levels in the elderly.

(1) An enzyme preparation, Vasolastine, administered intramuscularly, to a group of elderly subjects (mean age 81.7) reduced fasting plasma cholesterol and triglyceride levels by amounts which were proportional to their initial concentration. (2) Triglyceride levels 3 h after a fat-rich meal were also directly dependent on the initial fasting level. This relationship is lowered significantly after 25 days of Vasolastine treatment. (3) It is suggested that these observations, taken in conjunction with the results of in vitro studies, confirm that Vasolastine acts synergistically with endogenous lipoprotein lipase.

Aged↗
PubMed1982

Observations on the distensibility of the common bile duct.

This series describes 9 patients in whom a rapid change in bile duct caliber was documented by ultrasonography, intravenous or direct cholangiography, or endoscopic retrograde cholangiopancreatography. Two major observations were made: (a) the capacity of the common duct to distend and collapse over a short period, and (b) discordant measurements of bile duct diameter on successive examinations with different modalities (i.e., ultrasonography followed by cholangiography). It is thought that these discrepant measurements can be explained by the ability of the common duct to distend rapidly in response to pathologic and physiologic fluctuations in biliary pressure.

Adolescent↗
PubMed1982

Sonography of the bile ducts after a fatty meal: an aid in detection of obstruction.

The sonographic response of the biliary tree to a fatty meal was assessed in 78 individuals by measuring common hepatic duct caliber before and after fat ingestion. In the normal cases, the common hepatic duct remained the same or decreased in caliber. Abnormal responses consisted of a normal-caliber duct that increased in size or a slightly dilated duct that remained the same or increased in size. By employing these criteria, we discovered patients with ampullary stenosis, common duct stones, cholangiocarcinoma, and chronic pancreatitis. It is concluded that biliary sonography after ingestion of a fatty meal can aid in the evaluation of a common hepatic duct that is equivocally or mildly dilated and can indicate the need for further invasive studies.

Cholecystectomy↗
PubMed1981

Changes in skinfold thickness with increasing age.

Skinfold thickness measurements on 626 normal subjects of both sexes between the ages of 5 months and 73 years demonstrated a tri-phasic relationship between loss of skin thickness and age. Measurements for infants of either sex were indistinguishable and high, falling rapidly to levels which only changed slightly over the period 20-60 years. Thereafter, massive loss of skin-thickness occurred in both sexes. Throughout the major portion of adult life the values obtained for females were significantly lower than those for males. It is suggested that the three phases may be associated with progressive dehydration, failure to synthesize collagen and frank degradation of the collagen of the dermis.

Adolescent↗
PubMed1981

Vitamin E--its significance in mouse ageing.

A small colony of C3H/He and LAF1 mice was set up with 50% of all stock being given a dietary supplement of 0.25% w/w vitamin E to study the range of ageing variables over which anti-oxidant administration has an effect. An increase in mean but not maximum lifespan with vitamin E was attributable to fewer fatalities early in life. This may have been due to low anti-oxidant levels in the controls. Lower fatal tumour incidence in both strains and a decrease in collagen content of LAF mice were noted. Lipofuscin levels in heart tissue were, as expected, reduced but the significance of lipid peroxidation to ageing of the organism is questioned.

Aging↗
PubMed1981

Tissue vitamin E levels and lipofuscin accumulation with age in the mouse.

To study the deposition of lipofuscin (age pigment) in relation to tissue Vitamin E content a small colony of C3H and LAF mice was set up, one-half being fed a supplement of 0.25% w/w Vitamin E. At intervals between 2.5 and 28 months of age samples of the stock were culled to allow the fluorimetric determination of lipofuscin in heart muscle and an assay of Vitamin E levels in liver tissue. Vitamin E levels in the supplemented stock were found to be 4 X those of the controls although dietary intake was 250 X control. Lipofuscin levels of supplemented stock were lower than controls throughout the lifespan culminating at 28 months when the levels were consistent with the 23 month levels of the controls. Lack of any concomitant effects on longevity, however, raises doubts concerning the relevence of lipid peroxidation to the aging process in the organism as a whole.

Aging↗
PubMed1981

The effects of vitamin E on mouse fitness and survival.

A small colony of C3H/He and LAF1 mice, of which 50% were receiving a diet supplemented with vitamin E (0.25%, w/w, dl-alpha-tocopherol), was set up for investigation of the reported action of antioxidants on increasing longevity. It was found that vitamin E exerted no effect on maximum longevity, but increased the numbers of both genotypes surviving to 24 months. The beneficial effects appeared to act by reducing the incidence of fatal tumours late in life and by counteracting a debilitating condition early in life. It is suggested that this debility may have resulted from low antioxidant in the control diet. The relevance of free radicals to ageing is questioned.

Animals↗
PubMed1981

Tissue core biopsy of abdominal tumors with a 22 gauge cutting needle.

Percutaneous needle sampling of malignant tumors carried out by fine-needle cytologic aspiration and large-needle cutting techniques both possess certain limitations. A fine caliber 22 gauge cutting needle and a modified sampling technique used in 78 patients with suspected abdominal neoplasms are described. Both cytologic and histologic samples were sought in each case and overall successful diagnoses were made in 88% of 50 proved cases, with specific histologic diagnoses in 56%. Cytologic specimens were more sensitive in 14 cases in the detection of malignancy, while histologic results were more specific in nine cases. No significant complications were encountered. This modified method has not replaced the former cytologic aspiration technique in this institution.

Abdominal Neoplasms↗
PubMed1980

Temperature effect on ADH response of isolated perfused rabbit collecting tubules.

The time course of the water permeability response to synthetic arginine vasopressin (AVP) was examined in isolated perfused rabbit collecting tubules. When experiments were conducted at 37 degrees C, addition of AVP in a concentration of 100 microU/ml increased hydraulic water permeability (Lp) from 18 +/- 4 X 10(-7) to 153 +/- 15 X 10(-7) cm x s-1 x atm-1. However, in contrast to results obtained at 25 degrees C, the Lp immediately decreased in spite of the continued presence of AVP, reaching half the peak value in 67 +/- 6 (SE) min. A similar decline was observed at 37 degrees C when a cyclic 3',5'-adenosine monophosphate analogue was added to the bathing medium. Corticosteroids greatly enhanced the peak water absorption but did not stabilize the subsequent response to AVP at 37 degrees C. A decline in diffusional water permeability measured in the absence of a transtubule osmotic gradient excluded the possible roles of cellular hypotonicity, increased cell volume, or osmotic water absorption in the unstable response to hormone. The peritubular membrane remained highly permeable to water, independent of AVP and temperature. Duration of exposure to 37 degrees C was more important than AVP in determining the unstable response. On the basis of these studies we conclude that isolated rabbit cortical collecting tubules progressively become insensitive to AVP at 37 degrees C, possibly due to alterations in the responsiveness of the urinary plasma membrane to cAMP.

Aldosterone↗
PubMed1980

Serum elastase levels following a stroke in elderly subjects.

The elastase content of the serum of stroke patients is appreciably higher immediately after the cerebral incident and, in the case of those destined to survive, falls subsequently back to the normal level for their age group. The degree of elevation of the elastase content, the period which elapses before it is attained and the rate at which the level returns to normal are all age related. Those patients who die within 1 week of their initial stroke suffer a dramatic rise in serum elastase content immediately prior to death.

Aged↗
PubMed1980

Effect of vasopressin on electrical potential difference and chloride transport in mouse medullary thick ascending limb of Henle's loop.

Medullary thick ascending limbs of Henle's loop of the Swiss-Webster mouse were perfused in vitro with an isotonic perfusate and a Ringer's bathing medium. In five studies, addition of a supramaximal concentration of synthetic arginine vasopressin (AVP) to the bathing medium resulted in an increase in electrical potential difference (PD) from 5.0 +/- 1.5 mV, lumen positive, to 10.7 +/- 1.4 mV (P < 0.001). When AVP was removed, the PD returned to 2.6 +/- 0.9 mV (P < 0.001), then increased again to 6.9 +/- 1.7 mV (P < 0.01) when AVP was added a second time. A significant, but submaximal, increase in PD of 2.3 +/- 0.6 MV (P < 0.05) was observed in five medullary thick ascending limbs when AVP was added to the bathing medium at a concentration of 10 microunits/ml. This increase was approximately one-third of the response observed at a concentration of 100 microunits/ml in the same tubule. No further increment in PD was observed in five medullary thick ascending limbs when the AVP concentration was increased from 100 to 1,000 microunits/ml. In seven thick ascendcing limbs, the effect of AVP on PD was reproduced by the addition of 8-[p-chlorophenylthio]-cyclic 3',5'-adenosine monophosphate to the bathing medium at a final concentration of 0.1 mM. AVP increased unidirectional chloride flux from lumen to bath from 29.3 +/- 3.2 to 69.8 +/- 6.2 peq/cm per s (P < 0.001) in spite of an increase in the lumen positive PD from 1.6 +/- 0.5 mV to 7.0 +/- 0.6 mV (P < 0.001). Unidirectional chloride flux from bath to lumen was not affected by AVP. In another series of experiments, net chloride flux increased from 15.6 +/- 3.0 to 41.7 +/- 5.3 peq/cm per s (P < 0.05) after addition of AVP. The effect of AVP on hydraulic water permeability (Lp) was examined by adding raffinose to the bathing medium in both the presence and the absence of AVP. The calculated Lp of 16 +/- 2 nm/s per atm in the absence of AVP, although very low, was significantly different from zero (P < 0.01). However, the Lp did not increase significantly when AVP was added to the bathing medium. These results suggest that AVP has a second site of action in the kidney to increase chloride transport by the medullary thick ascending limb in addition to its well-known effect on the water permeability of the collecting tubule. The former effect would contribute to urinary concentrating ability by increasing the axial osmotic gradient in the renal medulla.

Animals↗
PubMed1979

Mittelschmerz. Sonographic demonstration.

Ultrasonography of the pelvis at mid-menstrual cycle in normal women has demonstrated small quantities of free fluid in 40% of cycles. Two thirds of the cycles associated with pain had ultrasonically demonstrated fluid at ovulation. These sonographic findings at Mittelschmerz confirm the physiological trauma of ovulation.

Diagnosis, Differential↗