Testosterone treatment of constitutional delay in growth and development: effect of dose on predicted versus definitive height

The outcome of treatment in 3 groups of boys with constitutional delay in growth and development given monthly intramuscular injections of testosterone enanthate 200 mg (22 subjects) 100 mg (10 subjects) and 50 mg (12 subjects) was compared with the outcome in a control group (14 subjects) without treatment. The 4 groups were similar in chronological age, height, height age, bone age, height age/bone age ratio, pubertal development and had similar predicted adult heights. All treated subjects achieved an excellent growth response with growth velocities reflecting androgen dose. Bone age advanced commensurate with height age in all the treated groups and delta height age/delta bone age ratios at the end of therapy did not differ significantly. Nor was there a significant difference in the height prediction by the RWT method before and at the end of treatment. However, the year following treatment, growth velocities reversed so that those who received the largest steroid dose and had grown the fastest, decelerated the most and eventually ended up significantly shorter than their predicted adult height. In contrast the control group and those treated with smaller doses of testosterone achieved their predicted heights. The present study confirms that large doses of androgens compromise adult height and are contraindicated in the treatment of constitutional delay in growth and development. Testosterone enanthate 50 mg/mo did not affect predicted adult height adversely, but to the contrary, permitted it to be fully realised. The data caution against drawing conclusions based on changes observed during androgen therapy in the absence of extended follow-up.

The anti-sickling drug lawsone (2-OH-1,4-naphthoquinone) protects sickled cells against membrane damage

The ability of an anti-sickling drug lawsone, 2-OH-1,4-naphthoquinone, and two related compounds to inhibit the haematoporphyrin-sensitised photohaemolysis of normal and sickle cell erythrocytes has been investigated. The compounds appear to protect the erythrocyte membranes by reaction with transient oxidative species. Differential effects between normal and sickle cells are shown and these are attributed to the different membrane composition of irreversibly sickled erythrocytes. This report describes a possible basis for the decreased formation of irreversibly sickled cells in the presence of lawsone.

Acquisition of Digestive Enzymes by Siricid Woodwasps from Their Fungal Symbiont

Larvae of the woodwasp, Sirex cyaneus, contain midgut digestive enzymes that enable them to utilize the major fungal and plant polysaccharides found in their food. At least two classes of enzymes, the C(chi)-cellulases and the xylanases, are not produced by the larvae. Instead, larvae acquire these enzymes while ingesting tissue of Amylostereum chailletii, the fungal symbiont that occurs in the wood on which the larvae feed.

Continuous infusion of insulin vs repeated S.C. injections in the treatment of diabetic ketoacidosis in children

Thirty-two episodes of diabetic ketoacidosis in 30 children treated with conventional repeated s.c. injections of insulin every 4 h are compared with 18 episodes in 14 children treated with continuous i.v. insulin infusion. Fluid therapy, bicarbonate and potassium supplementation were essentially the same for both groups. Recovery as reflected in serum glucose, bicarbonate and the rate of rehydration, was smoother and more rapid in the children receiving continuous i.v. insulin, though the difference just failed to attain statistical significance in this small series of cases. There was, however, a marked difference in insulin administered (0.58 U/kg +/- 0.05 SEM in the children treated with continuous i.v. insulin infusion vs 2.54 +/- 0.27 SEM in the children treated with repeated s.c. injections). Hypoglycemia was noted in 11 and hypokalemia in 10 children on conventional insulin therapy given every 4 h s.c. In contrast, there was no hypoglycemia and only one case of hypokalemia with the i.v. insulin infusion.

Effect of large amounts of vitamin E during pregnancy and lactation

The effects of excessive intake of vitamin E during gestation and lactation on female rats and their progeny were studied. Pregnant rats receiving large doses of vitamin E (22.5 to 2252 mg/kg per day) had larger livers, higher levels of lipids and vitamin E in plasma, and higher concentrations of vitamin E in the livers than did controls. These deviations from normal were not, however, observed for all levels of supplementation. No obvious teratogenic effects were observed in the newborn young of the vitamin E-supplemented rats. Some eye abnormalities were seen in the older pups of rats given extremely high amounts of the vitamin. The survival rate, weight of the pups, and litter size were unaffected. However, the pups of the mothers who had received 500 mg of vitamin E per day (2252 mg/kg per day) during gestation and lactation had a much higher concentration of vitamin E in their livers and plasma than did controls. This study also confirmed the observation that vitamin E transfer across the placenta is negligible and that mammary transfer of this vitamin is quite efficient.

Familial nephrosis, nerve deafness, and hypoparathyroidism

Two male siblings with nephrotic syndrome, nerve deafness, and hypoparathyroidism are described. Each child, one at five years of age and the other at eight years, died in renal failure. At autopsy the parathyroid glands were absent in one child and hypoplastic in the other one. Two twin male siblings presented with similar findings and died at the age of three years. At autopsy their parathyroid glands were fibrotic, and glomerular basement membranes were thickened. This may be the first recorded association of familial nephrosis, nerve deafness, and hypoparathyroidism. The mode of transmission is compatible with autosomal recessive inheritance.

Continuous low-dose infusion of insulin in the treatment of diabetic ketoacidosis in children

Twelve diabetic children--eight in ketoacidosis, three with insulin refractory hyperglycemia, and one postoperative patient--were treated with continuous, low-dose, intravenous infusion of insulin. The eight ketoacidotic children with a mean serum glucose concentration on admission of 631 mg/dl and bicarbonate value of 6.8 mM/1 were given regular insulin, 0.1 U/kg, slowly by bolus injection followed by a sustaining infusion of 0.1 U/kg/hour. Plasma glucose concentration fell at a mean rate of 82 mg/dl/hour. Euglycemia with concomitant improvement in the metabolic disorder was achieved with a mean dose of insulin, 0.68 U/kg, given over four to 10 hours. Mean plasma insulin in those children who had not previously received insulin was 55 muU/ml, well within the normal physiologic range. Growth hormone and serum triglyceride levels, low initially, rose with insulin therapy before returning to control values. Continuous low-dose insulin infusion is simple, safe, and effective, avoids confusion and empiricism, and appears to be the method of choice for the treatment of diabetic ketoacidosis or insulin resistance.

Influence of castration and testosterone replacement on hypothalamic tyrosine hydroxylase activity in the rat

Hypothalamic tyrosine hydroxylase (TH) activity of castrate rats is modulated by testosterone propionate (TP) in vivo. Kinetic studies revealed that both Vmax and Km were virtually unaltered for substrate tyrosine in the presence of an excess of DMPH4 cofactor. TP replacement to castrate rats increased the Km for added DMPH4 cofactor, while Vmax decreased. These results suggest that TP decreases TH activity of castrate rats by inhibiting the enzyme-reduced pteridine cofactor complex.

The syndromes of insulin resistance and acanthosis nigricans. Insulin-receptor disorders in man

In six patients with acanthosis nigricans variable degrees of glucose intolerance, hyperinsulinemia and marked resistance to exogenous insulin were found. Studies of insulin receptors on circulating monocytes suggest that the insulin resistance in these patients was due to a marked decrease in insulin binding to its membrane receptors. When these patients were fasted, there was a fall in plasma insulin but no increase in insulin binding, suggesting that the receptor defect was not secondary to the hyperinsulinemia. The clinical features shared by these cases and several similar ones previously reported may be divided into two unique clinical syndromes: Type A, a syndrome in younger females with signs of virilization or accelerated growth, in whom the receptor defect may be primary, and Type B, a syndrome in older females with signs of an immunologic disease, in whom circulating antibodies to the insulin receptor are found.

Familial Addison's disease

Familial prepubertal Addison's disease is presented in two sets of brothers. Predominance of males with normal sex differentiation, lack of defects in steroid biosynthesis and absence of antibodies and associated endocrinopathies, separate this entity from other forms due to enzyme deficiencies or disordered cellular immune response. Distributed as a Mendelian recessive characteristic, familial Addison's disease of childhood may represent a milder form of the same genetic disorder responsible for congenital adrenal hypoplasia of infancy.

Clinical and metabolic characteristics of hyperosmolar nonketotic coma

Clinical and metabolic data of twenty patients with hyperosmolar nonketotic coma (HNC) and ten patients in keto-acidosis (DA) are compared. HNC patients were older; fewer were previously known diabetics; more had multiple chronic diseases. Common precipitating factors in HNC included infection, dehydration and administration of diabeto-genic drugs. Blood glucose and urea nitrogen, plasma sodium, bicarbonate and osmolarity were significantly higher in HNC. Plasma potassium and chloride levels were similar in both groups. Patients with HNC had significantly lower plasma levels of free fatty acids, cortisol and growth hormone.

Plasma insulin levels in HNC were low and not significantly different from those observed in KA. Patients with HNC required more fluids and less insulin therapy. Mortality was 20 per cent in HNC, lower than that generally observed in this condition, but higher than that of KA, 0 per cent.

On the basis of the above findings, it is suggested that dehydration and hyperosmolarity may play significant roles in the etiology of HNC, and that therapy should, therefore, be directed at restoration of normal osmolarity and correction of water deficits with 0.45 per cent saline and moderate amounts of insulin.

The biochemical basis of the fungus-attine ant symbiosis

The natural history of the fungus-growing ants provides a spectacular example of a symbiotic association of two very different types of organisms. An anthropomorphic description is difficult to resist. The ants are efficient and industrious farmers. Their single crop is a fungus, grown on a substrate of leaves in carefully fertilized, welltended gardens. Virtually every facet of the ants' behavior and life cycle has been shaped by their association with the fungus they culture. A characteristic feature of the ants' gardening technique is the application of their fecal material to the garden and to substrate being prepared for incorporation into the garden. We have established the biochemical significance of this behavior. The fecal material contains proteolytic enzymes which compensate for a deficiency of such enzymes in the fungus. In addition, the nitrogenous components in the fecal material facilitate the initial growth of the fungus. In biochemical terms, then, one can say that the ants contribute their enzymatic apparatus to degrade protein and the fungus contributes its enzymatic apparatus to degrade cellulose. As in the case of so many other natural symbiotic and parasitic associations, the basis is an integration of complementary metabolic capabilities and deficiencies.

The biochemical basis of the fungus-attine ant symbiosis

The natural history of the fungus-growing ants provides a spectacular example of a symbiotic association of two very different types of organisms. An anthropomorphic description is difficult to resist. The ants are efficient and industrious farmers. Their single crop is a fungus, grown on a substrate of leaves in carefully fertilized, welltended gardens. Virtually every facet of the ants' behavior and life cycle has been shaped by their association with the fungus they culture. A characteristic feature of the ants' gardening technique is the application of their fecal material to the garden and to substrate being prepared for incorporation into the garden. We have established the biochemical significance of this behavior. The fecal material contains proteolytic enzymes which compensate for a deficiency of such enzymes in the fungus. In addition, the nitrogenous components in the fecal material facilitate the initial growth of the fungus. In biochemical terms, then, one can say that the ants contribute their enzymatic apparatus to degrade protein and the fungus contributes its enzymatic apparatus to degrade cellulose. As in the case of so many other natural symbiotic and parasitic associations, the basis is an integration of complementary metabolic capabilities and deficiencies.

The lipids of the common house cricket,Acheta domesticus L. I. Lipid classes and fatty acid distribution

The lipids of the common house cricket,Acheta domesticus L., have been examined with the following results. The fatty acids associated with the lipid extracts do not change significantly from the third through the eleventh week of the crickets' postembryonic life. The major fatty acids are linoleic (30-40%), oleic (23-27%), palmitic (24-30%), and stearic acids (7-11%). There are smaller amounts of palmitoleic (3-4%), myristic ( approximately 1%), and linolenic acids (<1%). The fatty acid composition of the cricket lipids reflects but is not identical to the fatty acids of the dietary lipids: linoleic (53%), oleic (24%), palmitic (15%), stearic (3%), myristic (2%), and linolenic acid (2%).The amount of triglycerides present in the crickets increases steadily from the second through the seventh or eighth week of postembryonic life, then drops sharply. Other lipid classes, such as hydrocarbons, simple esters, diglycerides, monoglycerides, sterols, and free fatty acids remain about constant. The composition of the fatty acids associated with the tri-, di-, and monoglycerides and the free fatty acid fraction are all about the same. The fatty acids associated with the simple esters are high in stearic acid.

The lipids of the common house cricket,Acheta domesticus L. III. Sterols

Sterols constitute 1.95% of the total extractable lipids ofAcheta domesticus L., of which 18% are esterified. The free sterols consist of cholestane-3beta-ol (0.5%), Delta(5)-cholestene-3beta-ol (83.5%), Delta(7)-cholestene-3beta-ol (2.3%) Delta(5,7)-cholestadiene-3beta-ol (3%), Delta(5,22)-cholestadiene-3beta-ol (4%), Delta(5,7,22)-cholestatriene-3beta-ol (0.2%), campestane-3beta-ol (0.03%), Delta(5)-campestene-3beta-ol (1.0%), Delta(7)-campestene-3beta-ol (trace), Delta(5,7)-campestadiene-3beta-ol (0.2%), stigmastane-3beta-ol (0.09%), Delta(5)-stigmastene-3beta-ol (2.1%), Delta(7)-stigmastene-3beta-ol (0.04%), Delta(5,7)-stigmastadiene-3beta-ol (0.4%), Delta(5,22)-stigmastadiene-3betaol (0.1%). The same sterols are present in the esterified sterol fraction. Delta(7)-Sterols and Delta(5,7)-sterols are present in significantly larger amounts in the esterified fraction than in the free sterol fraction. By a comparison with the sterols of the cricket food, it is clear thatA. domesticus is capable of removing methyl and ethyl groups from C-24 of sterols of the campestane and stigmastane type. The ability to introduce a Delta(7) double bond into saturated and Delta(5)-sterols is indicated, and it is suggested that Delta(7)-sterols of the C(27), C(28), and C(29) sterol series may be intermediates in the conversion of Delta(5)-sterols to Delta(5,7)-sterols.