Open mitral valve commissurotomy, 1968 - 1978.
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Biomedical subjects
Publications and source records attributed to H Spencer.
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Tumours arising in the bronchial mucous glands closely resemble tumours arising in the mixed salivary glands. Bronchial mucous gland tumours account for less than 0.5 per cent of all lung tumours. Twenty six tumours are reviewed and they have been divided into five types, (a) adenoidcystic carcinomas, (b) muco-epidermoid tumors, (c) mixed (pleomorphic) tumors, (d) cystadenomas and (f) oxyphilic adenoma. The clinical features, and postoperative course of the patients are reviewed. Adenocystic carcinomas, arising in the bronchus frequently involve the neighbouring trachea and spread mainly by direct infiltration. Most muco-epidermoid bronchial tumours were confined to young persons, and the only malignant muco-epidermoid tumour occurred in an elderly person. The prognosis in young persons is good provided the tumours are completely excised. The two mixed bronchial tumours resembled their salivary counterparts and one subsequently behaved as a carcinoma and metastasised. Bronchial cystadenomas all proved to be benign tumours but in two cases were associated with surface papillary proliferation. The only example of an oxyphil cell adenoma was discovered at post mortem examination. The histogenesis of the tumours is considered.
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Balance studies of cadmium, copper, manganese, and zine were carried out under constant dietary conditions in eight adult males during two calcium intake levels of 200 and 800 mg/day and in an additional single case during a calcium intake of 1500 mg/day. The dietary content and the excretions of these elements in urine and stool were determined. The mean dietary content of cadmium was 32.9 micrograms/day, of copper 1020 micrograms/day, of manganese 2130 micrograms/day, and of zinc 12.4 mg/day. The ratio of the fecal/urinary cadmium excretion was approximately 1.5 and the main pathway of excretion of the other three elements was via the intestine, while the urinary excretions were very low. The different trace element balances were either slightly negative or in equilibrium, except that the zinc balances was positive in 50% of the cases. All balances should be considered maximal values, as the losses in sweat were not determined. The calcium intake level had little effect on the excretion and retention of these trace elements.
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The metabolism of aluminum was followed in patients who were receiving strictly controlled diets, either unaltered or supplemented with aluminum-containing antacids. Aluminum was determined by atomic absorption spectrophotometry with a graphite furnace. All food, water, and medications were analyzed, as were aliquots of urine and stool collected throughout six-day periods. Patients were usually studied for five consecutive six-day periods on the same diet and aluminum intake. This study included six patients who were studied for seven to 21 such six-day periods. During control periods, when the patients were receiving less than 5 mg of aluminum per day, the balance was usually slightly negative, but when the diet was supplemented with antacids to contain 1--3 g of aluminum per day, an average positive balance of 23 to 313 mg of aluminum per day was observed for the total time on the same intake. Consecutive six-day periods while a subject was receiving antacids might show either positive or negative balances, but the average retention for 18--84 days on antacids was always positive. Thus the potential effects of the storage of aluminum in the tissues must be considered in the chronic administration of antacids.
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The effect of a high protein (meat) intake of 2 g/kg on the calcium excretions and retention and on the intestinal calcium absorption was studied in man. In the control study the protein intake averaged 1 g/kg. The studies were carried out during a low calcium intake of 200 mg/day and a normal calcium intake of 800 mg/day. Two additional studies were carried out during a calcium intake of 1100 mg/day and one during a 2000 mg calcium intake. During the high protein-low calcium intake and during the 800 mg calcium intake the urinary calcium did not significantly increase. It increased moderately in two studies during the higher calcium intakes, however, these excretions decreased with time to control levels. The lack of a significant increase of the urinary calcium in the majority of the studies is probably due to the higher phosphorus content of the high protein intake. The calcium absorption, determined with 47Ca, the fecal calcium and calcium balances did not differ significantly during the high protein intake. In studies carried out during a low protein (meat) intake of 0.5 g/kg the urinary calcium changed little and the fecal calcium, the 47Ca absorption, and the calcium balance remained unchanged.
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The effect of magnesium on the fluoride balance was investigated in man by determining metabolic balances of fluoride and magnesium in control studies and during magnesium supplementation. The magnesium intake averaged 264 mg/day in the control studies and 825 in the experimental studies. The studies were carried out during four calcium intakes that ranged from 200 to 2,200 mg/day and during phosphorus intakes ranging from 800 to 2,000 mg/day. The studies were carried out during a fluoride intake of about 4 mg/day that was due to the dietary fluoride content and the intake of water and during a high fluoride intake of 25 mg/day that was due to the addition of sodium fluoride. During the high magnesium intake, both the urinary and fecal magnesium excretions increased and the magnesium balances became more positive. These changes were not associated with any significant changes of either the urinary or fecal fluoride excretions or of the fluoride balances during the different intakes of calcium phosphorus, or fluoride.
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Metabolic balances of fluoride and magnesium were determined in man in control studies and during fluoride supplementation. The studies were carried out during three intake levels of calcium (200, 1,400, and 2,200 mg/day) and during two intake levels of phosphorus (800 mg and 1,400 mg/day). The intake of about 10 mg fluoride per day, given as NaF, resulted in a two- to threefold increase of the urinary and fecal fluoride excretion. However, during the high fluoride intake, the urinary magnesium remained about the same, the fecal magnesium increased slightly, and the magnesium balances did not differ significantly. This was the case whether fluoride was given during a low or high calcium intake in the absence or presence of added phosphorus. Similar results were obtained with large doses of fluoride (40-45 mg/day) given to patients with osteoporosis. The studies have shown that supplemental fluoride ranging from 10 to 45 mg/day did not affect the magnesium balance during calcium intakes that ranged from 200 to 2,200 mg/day and during phosphorus intakes that ranged from 800 to 1,400 mg/day.
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