Biomedical subjects
C Waterhouse
Publications and source records attributed to C Waterhouse.
Midwifery care for orthodox Jewish women.
Midwives need to understand the restrictions that Shabbos (the Sabbath) and other Jewish Feasts place on a woman while she is in hospital. Jewish women usually decline alphafetoprotein (AFP) or Triple tests and would not wish to terminate a pregnancy for abnormality. However, most will take up the offer of an ultrasound scan. The husband may not support his wife physically during labour. Most Jewish women retire to bed for the 'lying-in' period of ten days, resting and establishing feeding. Most Jewish women breastfeed, and failure to do this is often kept secret. Contraception is generally not allowed in the Jewish faith.
Plasmodium relictum as a cause of avian malaria in wild-caught magellanic penguins (Spheniscus magellanicus).
Avian malaria (Plasmodium relictum) caused significant mortality in wild-caught Magellanic penguins (Spheniscus magellanicus) in 1986 at the Blank Park Zoo in Des Moines, Iowa (USA). In early winter, wild birds were captured off the southern coast of Chile and flown to Detroit, Michigan for a 38 day quarantine. After quarantine, 18 birds were dispersed to Lansing, Michigan, six to a facility in Maine, and 46 to Des Moines, Iowa. Upon arrival in Des Moines, several penguins became weak and inactive, had to be force-fed, and died after 2 days. Gross lesions at postmortem included splenomegaly, hepatomegaly, and pulmonary edema. Histopathological examination revealed numerous intraendothelial schizonts in spleen, lung, liver, heart and kidney. Schizonts were generally 16 to 28 micron by 11 to 16 micron and contained merozoites of two distinct sized (macromerozoites, nuclei 1.0 micron; micromerozoites, nuclei 0.5 micron). Based on the morphology of the abundant exoerythrocytic forms, a tentative diagnosis of avian malaria (Plasmodium sp.) was made. Subsequent transmission electron microscopic examination of schizonts in formalized tissue revealed merozoites with tear-shaped rhoptries. Antimalarial therapy was initiated early but deaths continued for 5 mo. Mortality, which eventually totaled 83%, occurred in three distinct waves, each separated by a hiatus of approximately 1 mo. Despite examinations of repeated blood smears, intraerythrocytic Plasmodium relictum was not detected until late in the outbreak. Diagnosis was based on morphologic characteristics including schizonts with eight to 12 merozoites/segmenter and round gametocytes that displaced and turned the infected erythrocyte nucleus. In addition to malaria, penguins showed evidence of aspergillosis, bacterial enteritis (Escherichia coli; Proteus sp.; and Edwardsiella sp.), and helminthiasis (Contracaecum sp. and Tetrabothrius sp.). Based on gross and histological lesions, disease prevalence in this group of penguins was malaria 58%, aspergillosis 61%, enteritis 60%, helminthiasis 26%. Epidemiologic investigation including group transport history, disease prevalence in co-quarantined birds not sent to Des Moines and climatological data implicated Des Moines as the likely site for initial exposure, although information is not conclusive. Stress and concurrent disease certainly contributed to the severe mortality in this group of penguins infected with P. relictum.
Leucine metabolism in patients with malignant disease.
Studies of the metabolism of the amino acid, leucine, have been carried out in six patients with progressive cancer and compared to similar studies in a group of control subjects. U-14C leucine was given by the single injection technique and the disappearance of radioactive leucine from the plasma as well as the appearance of the label in expired air was determined over a 3-hour interval in both the overnight fasting state and during glucose ingestion. Plasma leucine levels in the basal state were higher in the patients with malignant disease (193 +/- 17 mumol/L vs 135 +/- 16 mumol/L) as was the flux or rate of appearance of unlabeled leucine molecules into the plasma (136 +/- 5 mumol/kg hour vs 79 mumol/kg/hour). Oxidation of leucine resulted in the appearance of about 19% of the injected label in expired CO2 of control subjects with almost twice that amount being found in progressive cancer patients. When the irreversible disposal of leucine to a metabolic fate other than oxidation was calculated (perhaps an indicator of protein synthesis), this was also increased in the progressive cancer patients. Exogenous glucose administration resulted in a fall in both leucine level and flux in the control subjects, while these parameters were less affected in three of the cancer patients. The fall in oxidation when glucose was given was more pronounced in the control subjects. These data are interpreted to mean that all aspects of leucine metabolism, presumably an example of branched chain amino acid metabolism, appear to be accelerated in subjects with cancer and weight loss. In addition, the peripheral control of the metabolism of this group of amino acids, as affected by glucose and insulin, appears to be impaired.
Oxidation and metabolic interconversion in malignant cachexia.
Some patients with progressive malignant disease have an increase in basal metabolic expenditure as well as total caloric expenditure, but the findings are neither striking nor consistent. Studies of specific metabolic changes in such patients have shown the following. (a) The predominant substrate for energy in these subjects is fatty acid, as in normal humans. Comparative studies show, however, that greater proportions of the oxidative metabolism in patients with cancer are from fatty acids, particularly when exogenous glucose is available. While the free fatty acid levels in plasma decrease appropriately with glucose administration, current evidence suggests that the levels of free fatty acids themselves may not necessarily be directly related to the various disposal mechanisms. (b) Increased glycolysis and gluconeogenesis are present after overnight fasting in the patients with malignant disease, but these processes, which depend on liver metabolism, are appropriately suppressed with exogenous glucose. (c) Evidence is presented that leucine, an amino acid representative of branched-chain amino acids, is not under normal metabolic control in these subjects. For example, semistarvation does not result in diminished levels of branched-chain amino acids as it does in other patients. Also, glucose does not have its ordinary suppressive effect on branched-chain amino acid levels. Leucine turnover is increased in these patients as is the percentage of leucine flux which is oxidized. Limited data support the oxidation of this amino acid. All these data suggest that the peripheral effects of insulin and glucose may not be normally mediated in these subjects. They also suggest that amino acid metabolism and consequently protein metabolism may be unaffected by normal control factors in malignant disease.
Serum inorganic fluoride: changes related to previous fluoride intake, renal function and bone resorption.
1. Inorganic fluoride concentrations were determined in serum and urine specimens of 24 subjects receiving a standardized low fluoride intake. Serum fluoride was directly correlated with previous intake and appeared to reflect bone fluoride stores. 2. A positive correlation between creatinine and fluoride clearance was found. However, striking reductions in fluoride clearance, which resulted in increases in serum fluoride, were not usually seen until the creatinine clearance was below 25 ml/min. 3. Parathormone produced an increase in serum fluoride and thyrocalcitonin a decrease, probably by their action on bone. 4. Six patients with chronic increased bone resorption had elevated fluoride concentrations. In five, when treatment was successful, serum fluoride fell. Interpretation of the data from this group of patients is complicated by initially low filtration rates associated with hypercalcaemia and hypercalciuria. 5. The sensitivity of the serum fluoride concentration to previous intake, glomerular filtration and the intensity of bone resorption suggests that the human organism exerts no direct homeostatic control over this ion.
Whole-blood and plasma amino acid analysis: gas-liquid and cation-exchange chromatography compared.
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Free amino acid levels in the blood of patients undergoing parenteral alimentation.
Free amino acid levels were determined in the blood of patients undergoing parenteral alimentation. During amino acid infusions, alanine, valine, glycine, isoleucine, leucine, proline, threonine, serine, methionine, phenylalanine, and lysine levels increased. Bivariate regression analysis was then done to determine the average rise in each amino acid when 1 mmole/hr of that amino acid was infused and when 1 mmole/hr of glucose was infused. This analysis was done on both arterial plasma and arterial wh-le blood increments. The average rise in the amino acid level with 1 mmole of infusion per hour varied from 32 to 133 mumole/liter. Only alanine levels were positively correlated with glucose infusion, while the branched chain levels were all negatively correlated. In no instance could a significant positive arteriovenous difference across the forearm be correlated with the infusion of an amino acid, despite amino acid levels as much as five times normal. Methionine, proline, valine, threonine, and lysine showed the greatest rise in blood concentration per millimole of amino acid infused per hour suggesting that their degradation or use in protein synthesis was limited. While the blood concentration rise in glycine was only about half as much per millimole per hour infused as was found in the previously mentioned group of amino acids, high rates of infusion of this amino acid resulted in large increments inglycine levels. It may be desirable to reduce the amounts of these amino acids in parenteral amino acid formulations.
Glucocorticoid effects in vitamin D intoxication.
Calcium balance studies and measurement of 25-hydroxyvitamin D3 (25[OH]D3) levels were performed on a vitamin D intoxicated, hypoparathyroid patient before, during, and after successful management of hypercalcemia with oral prednisone therapy. Prednisone effected a dramatic reduction in both mean serum calcium levels and mean 24-hour urinary calcium excretion within four days on two separate occasions. No changes were apparent in fecal calcium excretion. Calcium balance became less negative with prednisone treatment. Levels of 25(OH) D3 during the same period did not change. Decreased calcium mobilization from bone best accounted for the glucocorticoid-mediated amelioration of hypercalcemia.
In vivo metabolism of a monoclonal IgG cryoglobulin.
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Gluconeogenesis from alanine in patients with progressive malignant disease.
We have studied by tracer technique the conversion of the carbon skeleton of alanine to glucose in patients with progressive malignant disease. These data have been compared to similar studies done in patients with chronic undernutrition from other causes. The results show increased conversion of alanine to glucose in the overnight fasting state as compared to the control group. Whereas the percentage increases are comparable to those found with pyruvate-glucose cycling in such subjects, the total amount of carbon conversion is considerably less (alanine carbon, 5.6 mmol/hr, versus pyruvate carbon, 39 mmol/hr). Exogenous glucose resulted in good suppression of alanine-to-glucose conversion as it does in normal subjects. It did, however, result in increased glucose-to-alanine conversion, increased alanine levels, and increased flux of alanine from the circulation. Although these latter data may not have specificity for the patient with advanced cancer, a strong dependence for carbohydrate and protein metabolism is suggested. We conclude that uncontrolled gluconeogenesis from alanine is probably not significant in terms of energy expenditure in the patient with uncontrolled cancer.
Lactic acidosis and liver disease.
Both acute and chronic hepatic insufficiency can result in lactate accumulation and lactic acidosis; data from both types of patients were compared. In the chronic group, an acute precipitating event was identified in seven of nine subjects. Four had sepsis and three had gastrointestinal hemorrhage. In these patients, results from most tests of hepatic function were not altered dramatically. There were no long-term survivors in this group. In contrast, patients with acute hepatic failure had striking alterations in their results of hepatic function tests. Notable prolongation of the prothrombin time was always present initially and antedated other abnormalities of hepatic function. Three of seven patients in this group survived. Hypoglycemia was seen in both groups and in two subjects with acute hepatic insufficiency, glucose administration alone resulted in rapid lowering of lactate levels.
A circulatory model for human metabolism.
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