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Biomedical subjects

W H Adams

Publications and source records attributed to W H Adams.

52 records · Page 3Linked to original sources
PubMed1977

Anaemia of pregnancy in Kathmandu, Nepal. A clinical appraisal of statistical predictions of anaemia in a population.

A detailed clinical study of 151 women in the third trimester of pregnancy in Kathmandu, Nepal (altitude 1450 m), indicates a previously reported statistical approach via mass screening of a population without regard to potential haematologic abnormalities appears valid in establishing (a) the lower limit of a normal hemoglobin (Hb) level in pregnancy, (b) the approximate percent of the population which is anaemic, and (c) the distribution of anaemic values. The existing WHO criterion regarding low normal Hb levels in pregnancy was misleading when used to diagnose the most common cause of anaemia. It was found that a pregnant woman with a Hb of 9.0 g% could conceivably not be anaemic at this altitude.

Altitude↗
PubMed1977

Induction of thrombocytopenia by thrombopheresis in man: patterns of recovery in normal subjects during ethanol ingestion and abstinence.

Using the technique of thrombophoresis (TP), platelet and megakaryocyte dynamics following acute thrombocytopenia were studied in two normal subjects during periods of ethanol ingestion and abstinence. Thrombocytopenia was induced over a period of 12 hr. A logarithmic decline in platelet count during TP and the serial morphologic changes in megakaryocytes during recovery from thrombocytopenia are described. Although these parameters were not affected by ethanol ingestion, platelet counts after TP did not return to normal until ethanol was discontinued. 51Cr-labeled platelet survival was normal in one subject studied, and no evidence of increased platelet sequestration was found. It is concluded that heavy ethanol ingestion induces, augments, or sustains thrombocytopenia by impairing megakaryocytopoiesis in man. The mechanism by which ethanol induces thrombocytopenia may be due, in part, to "ineffective thrombopoiesis," impairment of the differentiation of precursor cells into the megakaryocytic compartment, or a combination of these factors.

Adult↗
PubMed1976

Erythrocyte 2,3-diphosphoglycerate and adenosine-triphosphate in cretins living at high altitude.

A comparison of concentrations of 2,3-diphosphoglycerate (2,3-DPG) and adenosine-triphosphate (ATP) in the red cells of cretins and normal controls living at 3,700 m in the Nepal Himalayas has shown that 2,3-DPG and ATP levels were higher in the cretins. A negative correlation between hemoglobin and 2.3-DPG level was found. Chronic hypoxia appears to have provided the additional stress required to differentiate the significance of thyroid hormone deficiency in producing anemia from its effect on 2,3-DPG levels. If thyroid hormone is in fact one regulator of 2,3-DPG, the anemia of hypothyroidism appears to be more significant. This also suggest that the anemia of hypothyroidism, is at least in part, "pathologic" as opposed to "adaptive".

Adenosine Triphosphate↗
PubMed1975

Hematologic observations on the yak.

The uak has two hemoglobins sharing a common globin chain. Hb slow appears unique to the yak among the ruminants studied. It is not known if Hb slow is important in high altitude adaptation, but physilogic rather than hematolgoic adjustments may be more important agter acute blood loss, as 2,3-DPG remains nit and no disproportionate hemolgoin production occurs.

Adenosine Triphosphate↗
PubMed1975

Hemoglobin levels in persons of tibetan ancestry living at high altitude.

The mean hemoglobin level of persons of Tibetan ancestry living at 4000 m in the Nepal Himalayas was found similar to that expected at an altitude of 2300 m and an arterial O2 saturation of 92%. Plasma volumes were normal, and deficiency states and hemoglobinopathies were not significant. Possible reasons for this finding are discussed.

Adolescent↗
PubMed1975

Recurring hemolytic anemia, babesiasis, and influenza A viruses in a yak at low altitude in Nepal.

Episodes of hemolysis and leukocytosis which were associated with Babesia bigemina followed each of 3 challenge exposures to influenza A viruses. It is possible that viral infection altered the immunologic host-parasite equilibrium. Acute thrombocytopenia and rouleaux formation were also observed. Death, attributed to liver flukes, occurred 168 days after the yak was transferred from high to low altitude. A 2nd yak died of foot-and-mouth disease, thus supporting the Nepali belief that yaks will not survive at the lower altitudes of Kathmandu.

Altitude↗
PubMedDate not supplied

Coagulation studies of viral hepatitis occurring during pregnancy.

A study of coagulation disorders due to hepatitis A infection occurring during pregnancy was undertaken to determine if the unique coagulation status produced by pregnancy (elevated clotting factors and decreased fibrinolytic activity) was responsible for the increased severity of hepatitis A infections reported for pregnant women from various parts of the world. Of 49 patients studied, 12 (24%) developed hepatic failure and 9 (18%) died. A prolonged prothrombin time and low fibrinogen level were found to be as frequent as previously reported for nonpregnant patients with and without hepatic failure. Thrombocytopenia was less common and a long thrombin time was more common. Although intravascular coagulation was suggested by a lower mean fibrinogen level than expected in late pregnancy, mean platelet counts were similar to controls. The frequency of a positive protamine sulfate paracoagulation test for intravascular coagulation (DIC) was similar to that reported for uncomplicated pregnancy, and was of no prognostic value when performed on admission. We conclude that the severe clinical course of hepatitis during pregnancy in this epidemic was not attributable to a predisposition for DIC. However, once fulminant hepatitis occurred, DIC may have been a clinically significant factor.

Blood Coagulation Tests↗
PubMedDate not supplied

Changes in renal function in cats following treatment of hyperthyroidism using 131I.

Changes in renal function of twenty-two cats treated for hyperthyroidism using radioiodine were evaluated. Serum thyroxine (T4), serum creatinine, blood urea nitrogen (BUN) and urine specific gravity were measured before treatment and 6 and 30 days after treatment. Twenty-two cats had pretreatment and 21 cats had 6 day posttreatment measurement of glomerular filtration rate (GFR) using nuclear medicine imaging techniques. There were significant declines in serum T4 at 6 days following treatment, but the changes in GFR, serum creatinine and BUN were not significant. At 30 days following treatment, there were significant increases in BUN and serum creatinine and further significant declines in serum T4. Nine cats were in renal failure prior to treatment and 13 cats were in renal failure 30 days following treatment. Renal failure was defined as BUN greater than 30 mg/dl and/or serum creatinine greater than 1.8 mg/dl with concurrent urine specific gravity less than 1.035. These 13 cats included eight of 9 cats in renal failure prior to treatment and 5 cats not previously in renal failure. Follow up information beyond 30 days following treatment on 9 of these 13 cats indicated that all remained in renal failure. Based on receiver operating curve analysis of pretreatment glomerular filtration rate (GFR) in predicting posttreatment renal failure, a value of 2.25 ml/kg/min as a point of maximum sensitivity (100%) and specificity (78%) was derived. Fifteen of 22 cats had pretreatment GFR measurements of less than 2.25 ml/kg/min. These 15 cats included all 9 cats in renal failure and 5 cats with normal renal clinicopathologic values prior to treatment. At 30 days following treatment, 13 of these 15 cats were in renal failure. The 2 cats not in renal failure had persistently increased serum T4 values. Seven of 22 cats had pretreatment GFR measurements greater than 2.25 ml/kg/min. None of these 7 cats was in renal failure at 30 days following treatment, all cats having normal BUN, serum creatinine, and urine specific gravity values. It was concluded that significant declines in renal function occur after treatment of hyperthyroidism and this decline is clinically important in cats with renal disease. Pretreatment measurement of GFR is valuable in detecting subclinical renal disease and in predicting which cats may have clinically important declines in renal function following treatment.

Animals↗
PubMedDate not supplied

Quantitative 99mTc-pertechnetate thyroid scintigraphy in normal beagles.

This study was done to investigate the validity of published canine thyroid/salivary (T/S) ratios of approximately 1 in normal dogs and to determine thyroid uptake of 99mTc-pertechnetate (pertechnetate) measured as percent uptake of injected dose. These parameters were evaluated in 13 Beagle dogs over a 4 hour period. Mean +/- standard deviation (SD) and median T/S ratios of 1.2 +/- 0.3 and 1.1 were essentially the same at twenty minutes and 1 hour. T/S values ranged from 0.9 to 2.2 at 20 minutes and from 0.8 to 2.4 at 1 hour. T/S ratio values progressively declined over the subsequent time intervals with mean +/- SD and median values of 0.6 +/- 0.2 and 0.6, respectively, measured at 4 hours. The mean +/- SD maximum percent dose uptake of pertechnetate within the thyroid gland was 0.55% +/- 0.15% with a range of 0.28% to 0.90%. The mean +/- SD time interval from injection of pertechnetate to maximum uptake within the thyroid gland was 160 +/- 55 minutes with a range 31-240 minutes. The data derived from this study of normal dogs may be useful in the evaluation of dogs with thyroidal diseases including hypothyroidism.

Animals↗
PubMedDate not supplied

Magnetic resonance imaging appearance of intracranial hemorrhage secondary to cerebral vascular malformation in a dog.

A 14-year-old dog developed an acute onset of depression, disorientation, left hemiparesis,left hemianopia, left facial hypoesthesia, and a tendency to turn to the right. Based on these findings, a lesion affecting the right forebrain was suspected. Magnetic resonance imaging showed a mass within the right cerebral hemisphere resulting in compression of the right lateral ventricle and shifting the longitudinal fissure to the left. The lesion was hyperintense on T1-weighted images and hyperintense with focal regions of hypointensity on proton density-, and T2-weighted images, consistent with a subacute hemorrhage. At necropsy, there was a hematoma in the parietal portion of the right cerebral hemisphere. The hemorrhage was surrounded by numerous thin-walled veins, most likely a venous malformation. Magnetic resonance imaging of intracranial hemorrhage is reviewed.

Animals↗
PubMedDate not supplied

Naturally occurring tumors in dogs as comparative models for cancer therapy research.

The United States pet population has been a vastly underutilized resource for cancer therapy studies. Naturally occurring tumors in dogs develop twice as frequently as in man, have histopathologic features and a biologic behavior similar to tumors in man, and progress at a more rapid rate than in man. Cancer is one of the leading causes of death in man and dogs. The canine malignancies that are of practical use for comparative therapeutic studies include lymphoma, mammary tumors, oral melanoma, lung tumors, nasal tumors, soft tissue sarcomas, and osteosarcoma. This report will discuss the comparative nature of these malignancies and the current trends in clinical cancer research, namely dose intensification and biomodulation, using naturally occurring tumors in client-owned dogs.

Animals↗