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Biomedical subjects

F D Hofeldt

Publications and source records attributed to F D Hofeldt.

At least 55 records · Page 3Linked to original sources
PubMed1975

Ventilatory control in myxedema and hypothyroidism.

Alveolar hypoventilation is known to occur in myxedema. To clarify the role of hypoxic ventilatory drive and hypercapnic ventilatory drive in thyroid hormone insufficiency states, 10 patients with myxedema and seven with hypothyroidism (thyroid ablation) were studied before and after thyroid replacement. An index developed for hypoxic ventilatory drive was markedly reduced in myxedema: 17 plus or minus 4.7 (S.E.M.) (normal, 126 plus or minus 8.7) (P smaller than 0.01) and increased to 78 plus or minus 12.6 (p = 0.02) with thyroid hormone replacement. In the hypothyroid group this index was also depressed as compared to normal at 67 plus or minus 20 (p smaller than 0.01) and increased to 114 plus or minus 19 (p smaller than 0.02) with replacement. An index for hypercapnic ventilatory drive was depressed in myxedema, 0.69 plus or minus 0.01), but was not significantly depressed in hypothyroidism. With thyroid hormone replacement this index did not significantly increase in either group. We conclude that both myxedema and hypothyroid states produce depression of hypoxic ventilatory drive that is responsive to replacement therapy. This alteration in ventilatory control may contribute to the hypoventilation seen in myxedema.

Adult↗
PubMed1975

Reactive hypoglycemia.

The hypoglycemoses include a large category of distinctly unique entities. Guidelines for a clinical, physiological approach to these disorders is presented. Within this diagnostic spectrum of hypoglycemia lies the reactive hypoglycemic disorders that are characterized by their postprandial onset, adrenergic mediated symptoms, and relatively benign causes. The spectrum of reactive hypoglycemia includes early alimentary-reactive hypoglycemia, late diabetic-reactive hypoglycemia, hormonal deficiency states, and idiopathic hypoglycemia. A new postprandial hypoglycemic disorder, fructose 1-6 diphosphatase, can be added to this list. The frequent sampling of blood-glucose values in the postprandial state will frequently lead to the finding of a biochemically low blood-glucose value of below 50 ml/100 ml, and these individuals show no hypothalamic-pituitary-adrenal stress to the low blood sugar and do not manifest adrenergic symptoms. Their low blood-glucose value simply reflects the transition in intermediary metabolism between the fed and fasting state and provides a biochemical marker of this event. We refer to this asymptomatic biochemical event as transitional low blood-glucose state. It has no clinical implication and may frequently be confused with the bona fide reactive hypoglycemic disorders. Using a symptomatic, counter-regulatory model to define hypoglycemia as a bona fide disorder, findings are presented in patients with the varying types of reactive hypoglycemia, and their results are compared to normal controls and to a weight-matched and disease patient controls. Abnormalities in insulin secretion are discussed as relating to the pathophysiology causal in the hypoglycemia. An approach to therapy is presented based upon the classification of the patient as to the type of hypoglycemia and their abnormalities in insulin secretion.

Blood Glucose↗
PubMed1975

Growth hormone responses following double pulse oral glucose administration in various clinical states.

The 8-h double pulse oral glucose test is proposed as an alternative screening procedure for determining the adequacy of growth hormone (GH) release. The second pulse of glucose is timely in suppressing GH release and delaying it for a more predictable controlled elevation. Peak GH (mean plus or minus SD) values following the double pulse glucose test were 17 plus or minus 10.2, 16.5 plus or minus 2.2, and 1.3 plus or minus 0.5 ng/ml in normal controls, short stature patients and GH deficient patients, respectively. Peak GH values following insulin hypoglycemia were 36.9 plus or minus 13.8, 21.9 plus or minus 23.0 and 1.8 plus or minus 1.1 ng/ml in normal controls, short stature patients and GH-deficient patients. Peak GH values during a 5-h oral glucose tolerance test were 16.4 plus or minus 6.0 and 10.2 plus or minus 3.3 ng/ml in normal controls and short patients, respectively. These differences in peak GH values between the various clinical and control groups were not significantly different except for the greater GH peak values reached in short patients in the double pulse glucose test compared to the 5-h oral glucose tolerance test. The rise in GH following double pulse oral glucose is more timely predictab-e than after the 5-h oral glucose test and involves less professional time than the insulin tolerance test as it does not require close medical supervision.

Adolescent↗
PubMed1975

Altered hypothalamic-pituitary-adrenal responsiveness to dexamethasone-insulin tolerance test in active acromegaly.

Eight acromegalic patients showed a plasma cortisol (11-OHCS) rise after insulin hypoglycemia which was similar to that seen in control patients, with mean peak values (+/-SEM) of 23.2 +/- 3.5 mug/100 ml and 27.2 +/- 3.3 mug/100 ml, respectively. One mg of dexamethasone was given the evening prior to repeat insulin hypoglycemia (DEX-ITT). After dexamethasone, the control subjects showed a mean post hypoglycemic plasma 11-OHCS rise to 18.3 +/- 2.3 mug/100 ml. In contrast, acromegalic patients had a negligible rise is plasma 11-OHCS, despite a comparable degree of hypoglycemia. These data indicate that, in active acromegaly, abnormal hypothalamic-pituitary-adrenal suppressibility can be induced to insulin hypoglycemia after dexamethasone.

11-Hydroxycorticosteroids↗
PubMed1975

Postpartum galactorrhea-amenorrhea syndrome due to the limited thyroid reserve syndrome.

A case of postpartum amenorrhea and galactorrhea is reported, with several additional features leading to the diagnosis of primary hypothyroidism. Resolution of the amenorrhea and galactorrhea was noted coincident with adequate thyroid hormone therapy. The interrelationships of the many organ systems involved are discussed, and speculations advanced regarding the mechanisms operating in such cases. The diagnosis of the limited thyroid-reserve syndrome is elucidated.

Adult↗
PubMed1975

Clinical implications of lactose-positive breast secretions in nonpuerperal females.

Inappropriate milk-like secretion from the breasts is not infrequently encountered in patients. Usually these secretions have been identified as milk on the basis of their characteristic appearance, and only rarely has their identity as milk been proven by appropriate analysis. Since milk is chemically defined as a lactose-containing mammary secretion, the presence of lactose in a breast secretion identifies it as milk irrespective of its appearance or the presence of other constituents. Lactose can be readily identified by thin-layer chromatographic methods, which despite their inherent speed and sensitivity have not been widely utilized. A method using commercially prepared cellulose layers and a sandwich developing apparatus is presented in detail. This method utilizes current advances in chromatographic techniques and permits rapid and accurate identification of lactose in breast secretions. Such secretions from 10 nonpuerperal women were screened for the presence of lactose. The milk-like secretions from 8 contained varying amounts of lactose, which was not detectable in the secretions from the other 2. There was no correlation between the appearance of the secretion and the presence of lactose.

Breast↗