Genetic risk factors in diabetic retinopathy

Diabetic retinopathy is the leading cause of blindness in adults aged 30 to 65 years. However, 20% of the diabetic population does not develop significant retinopathy. To examine the influence of immune-related genetic factors on the development of diabetic retinopathy, we studied immunoglobulin allotypes in 102 subjects aged 8 to 20 years, who had had Type 1 (insulin-dependent) diabetes mellitus for 4.5 to 11 years (mean 7.3 years). HLA had been previously typed on 59 of these subjects. Retinopathy was assessed by expert review of retinal photographs. Among the 44 patients who had evidence of retinopathy, 33(75%) were G2m(23+), while among the 58 patients without retinopathy but with similar duration of disease, only 28(48%) were G2m(23+) (p = 0.006). The HLA-DR types of patients with and without retinopathy were not significantly different. We conclude that there is significant evidence of an association between G2m(23) at the locus encoding IgG2 subclass heavy chains and susceptibility to the development of diabetic retinopathy early in the clinical course of the disease. Our findings provide important independent confirmation of a previous report of association between Gm allotypes and predisposition to diabetic retinopathy. We are unable to determine if the Gm effect on development of retinopathy is due to the G2m(23) allotype itself, or due to genes that are closely linked to, and in linkage disequilibrium with, the locus encoding the G2m(23) allotype.

Recent Advances in the Treatment of Isosexual Precocious Puberty: Identifying all the problems

In isosexual precocious puberty, the changes that characterize puberty occur in roughly the same order, but at a much earlier age. The causes and clinical features of isosexual precocity and their evaluation and treatment are discussed in this article, the purpose of which is to provide a general review of the disorder, taking into account recent advances in its management.

Interaction between T cell receptor beta chain and immunoglobulin heavy chain region genes in susceptibility to insulin-dependent diabetes mellitus

Despite some reports of an association between insulin-dependent diabetes mellitus (IDDM) and a BglII RFLP in the T cell receptor beta chain (TCRB) constant region, results of several recent studies, including our own, have failed to support such an association. However, we here report evidence for an IDDM-TCRB relationship which is dependent on immunoglobulin heavy-chain-region genes. We analyzed 198 unrelated diabetics and 84 normal siblings (maximum one sibling per diabetic) typed for the BglII TCRB RFLP and Gm immunoglobulin allotypes Glm(1), Glm(2), G2m(23), and G3m(5), which identify the four common Gm haplotypes. The BglIII TCRB genotype frequencies were significantly different between diabetics positive and negative for G2m(23) (P = .017) and G3m(5) (P = .021) but were not different between normal siblings positive and negative for those allotypes (P = .94 and P = .77, respectively). Thus, there were significant interactions between TCRB, Gm, and IDDM for two of the four immunoglobulin allotypes examined. We have previously reported interactions between HLA, Gm (particularly G2m(23)), and IDDM and postulate that the TCRB-Gm-IDDM and HLA-Gm-IDDM interaction effects may be functionally related.

Predisposing effect of anti-beta cell autoimmune process in NOD mice on the induction of diabetes by environmental insults

In NOD mice. 50-70% of females and 10-20% of males develop diabetes, although almost all the animals show insulitis. To see if environmental insults could induce diabetes in subjects with pre-clinical anti-Beta cell autoimmunity, non-diabetic NOD mice were selected and injected with a sub-diabetogenic dose of streptozotocin at 6 or 20 weeks of age. The streptozotocin failed to induce diabetes in 16 male and 16 female NOD mice within 4 weeks when they were injected at the age of 6 weeks. In contrast, 6 of 16 male and 10 of 16 female NOD mice developed diabetes within 4 weeks when they were injected at the age of 20 weeks. In untreated age-matched control NOD mice, none of the male and only 2 of 16 female mice became diabetic during the same 4 week period. On histologic examination, the degree of insulitis in streptozotocin-treated NOD mice (at the age of 24 weeks) was not significantly different from that of untreated control NOD mice. However, the streptozotocin-treated animals showed significantly lower pancreatic insulin content than the control mice. These results show that an anti-Beta cell autoimmune process in NOD mice has a predisposing effect on the induction of diabetes by a sub-diabetogenic dose of streptozotocin, and suggest that the precipitation of clinical diabetes by some environmental insults in subjects with pre-existing pre-clinical autoimmune Beta-cell destruction may be one mechanism of disease presentation in human Type 1 (insulin-dependent) diabetes.

Human pancreatic islet cell specific 38 kilodalton autoantigen identified by cytomegalovirus-induced monoclonal islet cell autoantibody

Our previous finding that about 15% of newly diagnosed patients with Type 1 (insulin-dependent) diabetes mellitus had human cytomegalovirus genome in their lymphocytes and islet cell autoantibodies in their sera, suggests that autoimmune Type 1 diabetes is associated with persistent cytomegalovirus infection under certain circumstances. This investigation was initiated to see if cytomegalovirus can induce islet cell autoantibodies and if the autoantibodies react with any specific islet protein(s). Monoclonal antibodies were generated after immunizing Balb/c mice with human cytomegalovirus. When these monoclonal antibodies were tested for the presence of islet cell antibodies were tested for the presence of islet cell antibodies, one (MCMVA-51) of 13 monoclonal antibodies reacted strongly with the islets. The titer of islet cell antibodies was 1:2000. When this monoclonal antibody was reacted with the proteins from the solubilized fraction of human pancreatic islets using the western immunoblotting technique, a band with a molecular weight of 38 kilodalton was detected. The 38 kilodalton band was not observed when the monoclonal antibody was reacted with the proteins prepared from pancreatic islet tissues of rats and mice or from other human organs including stomach, liver, spleen and brain, indicating that the 38 kilodalton protein is human islet cell-specific. It is concluded that human cytomegalovirus can induce islet cell antibodies that react with a 38 kilodalton human islet cell protein and that this protein component may represent islet cell-specific target antigens associated with persistent cytomegalovirus infection.

Coxsackie B virus assays in IDDM families: the GAW5 data on antibody prevalence

There is evidence that infection by Coxsackie viruses can serve as an environmental "trigger" for insulin-dependent diabetes mellitus (IDDM). This background information is summarized briefly, and the data in the IDDM component of Genetic Analysis Workshop 5 (GAW5) concerning serum antibodies to Coxsackie B viruses are described.

Autosomal dominant hypoparathyroidism with intracranial calcification outside the basal ganglia

We describe a family with autosomal dominant hypoparathyroidism. The 3 affected individuals had no detectable serum parathyroid hormone on radioimmunoassay. The propositus presented with seizures and on CT scan had bilateral basal ganglion calcification and calcification in the frontal lobes. His similarly affected mother had even more intracerebral calcification. The latter manifestation has not been described previously in autosomal dominant hypoparathyroidism.

Genetic control of organ-reactive autoantibody production in mice by obesity (ob) diabetes (db) genes

Inbred strains of mice exhibited genetic and sex-dependent differences in spontaneous production of organ-reactive autoantibodies detected by indirect immunofluorescence. Antitestis autoreactivity was found primarily in sera from C57BL/6J (B6) mice, whereas antigastric autoreactivity was common to both CBA/J and 129/J strains. Autoantibodies against islet cell cytoplasmic antigens (ICAs) were uniquely expressed by C57BL/KsJ (BKs) males. Introduction of the diabetes (db) mutation into these various inbred-strain backgrounds induced expression of ICA, with stronger induction observed in males. The stress imposed by the db or obesity (ob) mutation induced ICA in BKs mice at a higher frequency than in B6 mice; this differential sensitivity was somehow related to a gene linked to the H-2 complex because BKs.B6 H-2b congenic mice resembled B6 mice. The db3J mutation increased the expression of these autoantibodies in 129/J mice, which, like B6, were H-2b and therefore presumably possessed the same H-2-linked inducibility allele as BKs. Cytotoxic autoantibodies against islet cell surface antigens were only observed in C3HeB/FeJ db/db males, and their presence was correlated with beta-cell necrosis. It is concluded that db and/or ob genes appear to play an important role in the production of autoantibodies to islet cells, and sex-linked factor(s) may modify the phenotypic expression of the autoantibodies.

Association of cytomegalovirus infection with autoimmune type 1 diabetes

The lymphocytes from 59 newly diagnosed type 1 diabetic patients and 38 normal control subjects were examined for the presence of human cytomegalovirus (CMV) genome by molecular hybridizations with human CMV specific probe. The CMV specific viral genome was found in 13 (22%) of 59 diabetic patients, but in 1 (2.6%) of 38 control subjects. Of the patients, 39% had islet cell antibody (ICA) and 41% had cytotoxic beta cell surface antibody (CBSA) in their serum; of the controls the corresponding rates were 2.6% and 2.6%. 62% and 69% of CMV genome-positive patients had ICA and CBSA, respectively, compared with 33% and 33% of CMV genome-negative patients. The single CMV genome-positive control subject did not have either ICA or CBSA whereas only 1 of the 37 CMV genome-negative control subjects had ICA. The strong correlation between CMV genome and islet cell autoantibodies detected in diabetic patients suggests that persistent CMV infections may be relevant to pathogenesis in some cases of type 1 diabetes.

The relationship between Coxsackie-B-virus-specific IgG responses and genetic factors (HLA-DR, GM, KM) in insulin-dependent diabetes mellitus

IgG antibody titres to Coxsackie B1-B6 were measured in 113 insulin-dependent diabetes mellitus (IDDM) patients whose mean age was 12.2 years and mean duration of IDDM was 4.6 years, and in 87 normal sibling controls whose mean age was 13.8 years. Compared with their normal siblings, the diabetics had a significantly increased frequency of high response (titre greater than or equal to 320) to Coxsackie B2 (8% versus 1%, p = 0.028), to Coxsackie B4 (15% versus 1%, p = 0.0006), and to Coxsackie B viruses in general (25% versus 5%, p = 0.0001). The frequencies of HLA-DR and immunoglobulin (GM, KM) antigens did not differ between diabetics with and without a high response to Coxsackie B2, B4, or B viruses in general. We conclude that there is an association between IDDM and IgG response to Coxsackie B2, B4, and B viruses in general, a finding which is consistent with the interpretation that infection with Coxsackie B viruses, especially B4, may initiate the development of IDDM in a portion of individuals who have HLA-DR region susceptibility genes.

Diminished complications in a non DR3 DR4 family with insulin-dependent diabetes

A family is reported in which the mother and both of her children developed insulin-dependent diabetes mellitus between 9 and 19 months of age, reflecting the importance of heredity in the natural history of this disease. That overt complications of diabetes were not present in any of the individuals, and that blood sugars were maintained close to normal on relatively small amounts of exogenous insulin, suggests a protective function in these patients related to residual secretion of insulin by beta cells. Human lymphocyte antigen (HLA) typing in this family showed that, although the diabetic children had identical HLA types, neither the mother nor her children possessed the diabetes-associated antigen HLA-DR3 or HLA-DR4. This raises the possibility that selective loss of diabetes-susceptible fetuses (suggested to be responsible for the low risk of diabetic mothers producing diabetic offspring) may be influenced by the HLA type of the mother.

Effects of environmental factors on the development of insulin-dependent diabetes mellitus

The development of insulin-dependent diabetes mellitus is thought to be dependent on either the autoimmunity or the interaction of environmental agents with the pancreatic beta cells, or both in a genetically susceptible host. As environmental factors affecting the induction of type I diabetes, diabetogenic chemicals and viruses are likely candidates as primary injurious agents for pancreatic beta cells in man and animal. A number of structurally diverse chemicals including alloxan, streptozotocin, chlorozotocin, vacor, and cyproheptadine are diabetogenic mainly in rodents and sometimes in man. The possible mechanisms for the beta cell destruction by these chemicals include (a) generation of oxygen free radicals and alteration of endogenous scavengers of these reactive species; (b) breakage of DNA and consequent increase in the activity of poly ADP ribose synthetase, and enzyme depleting NAD in beta cells; and (c) inhibition of active calcium transport and calmodulin-activated protein kinase activity. Regarding viruses, a number of different viruses including encephalomyocarditis virus, Mengovirus, Coxsackie B viruses, and Reoviruses can infect and destroy pancreatic beta cells mainly in rodents and sometimes in humans. In the murine model, the development of encephalomyocarditis and Coxsackie B virus-induced diabetes is dependent on the genetic background of the host and the genetic makeup of the virus. Mengo-2T virus has caused diabetes in strains of mice resistant to encephalomyocarditis virus-induced diabetes. In contrast to encephalomyocarditis virus, Coxsackie B viruses, and Mengovirus, reovirus type 1 seems to be somewhat associated with an autoimmune response in the induction of diabetes. In addition to the murine model, cotton rats become diabetic when inoculated with Mengovirus 2T. Furthermore, cumulative environmental insults with Coxsackie B viruses and chemicals result in diabetes in non-human primates. In man, there may be 2 possible roles for viruses in the pathogenesis of insulin-dependent diabetes mellitus. The one is acute cytolytic infection of beta cells (e.g., Coxsackie B viruses), which may sometimes induce diabetes in genetically predisposed individuals, and the other one is slow and persistent infection (e.g., congenital cytomegalovirus and Rubella), which may induce autoimmunity, leading to type I diabetes.

The genetics of susceptibility to insulin-dependent diabetes mellitus--possible new markers

It is well established that the HLA-DR3 and HLA-DR4 genes at the HLA-DR locus on chromosome 6 are strongly associated with increased susceptibility to insulin-dependent diabetes, and that the predisposition is greatest among individuals who possess both of these genes (that is, are HLA-DR3/4 heterozygotes). We report evidence from our Alberta study that the HLA-DR1 gene is also associated with increased susceptibility, primarily when it occurs in heterozygous combination with HLA-DR4 (frequency of HLA-DR1/4 heterozygotes among diabetics: expected = 3%, observed = 11%, p = 0.03). In addition, we report evidence that genes in the region of the GM locus on chromosome 14 also influence susceptibility by interacting with HLA-DR region genes. Alberta diabetics who were HLA-DR3/4 heterozygotes had an increased frequency of the G1m(1) antigen and the G1m(2) antigen compared with non-DR3/4 diabetics; the latter increase was statistically significant (p = .025). When data from all three previously published studies, our Alberta study, and an unpublished American study were pooled. HLA-DR3/4 diabetics had significantly increased frequencies of both G1m(1) (p = 0.001) and G1m(2) (p = 0.014). Finally, we report possible evidence (not statistically significant) that genes in the region of the KM locus on chromosome 2 may exert HLA-dependent effects on susceptibility to diabetes: in our Alberta study and the one other study which employed control subjects, DR4-positive diabetics had higher frequencies of Km(1) than either DR4-positive controls or DR4-negative diabetics.

Role of cyclosporin A in macromolecular synthesis of beta-cells

Wistar rats developed hypoinsulinemia and hyperglycemia within 7 days when treated daily with 40 mg/kg body wt of cyclosporin A (CsA) and recovered from the metabolic alteration within 1 wk when CsA treatment was terminated. By light microscopy, there was no lymphocytic infiltration, but cytoplasmic vacuolization in the islets of Langerhans from the CsA-treated rats was seen. By electron microscopy, severe degranulation, cytoplasmic vacuolization, and dilation of endoplasmic reticulum were clearly seen in the pancreatic beta-cells. Islet cells isolated from the CsA-treated rats showed greater than 50% reduction in mRNA synthesis. A similar inhibitory pattern of mRNA synthesis was observed in in vitro CsA-treated (10 micrograms/ml) human pancreatic islet cells from one biopsy sample and in similarly treated rat insulinoma cells (RINm5F). The inhibitory effect of CsA on mRNA synthesis in RINm5F cells was dose dependent, with a 50%-inhibiting dose of 5 micrograms/ml. In addition to the inhibition of mRNA synthesis, CsA also inhibited protein and DNA syntheses, although the inhibitory effect on these macromolecular syntheses was significantly less than that on mRNA synthesis. However, there was only a minor effect of CsA on in vitro transcription and translation compared with that on RINm5F and islet cells. It is concluded that CsA-induced degranulation of the beta-cells in Wistar rats, accompanied by hypoinsulinemia and hyperglycemia, may be due to indirect, reversible interference of the cellular function primarily involved in mRNA synthesis.

Palatopharyngeal incompetence in association with esophageal dysmotility, acquired glucocorticoid deficiency, and deficient tear production

An 8 1/2-year-old male is described with the rare triad of acquired adrenal insufficiency, esophageal dysfunction, and alacrima. In addition, he had velopharyngeal insufficiency, which is a previously unreported feature of this syndrome. Although the pathophysiology of this disorder remains to be demonstrated, a defect may be present, linking hormone-receptor cyclic AMP-mediated processes with abnormalities in parasympathetic and voluntary neuronal innervation or transmission.

Usefulness of gas chromatographic profiles of plasma total lipids in diagnosis of phytosterolemia

A Cambodian male (aged 5 years and 9 months) presented with subcutaneous and tendon xanthomas in association with hypercholesterolemia. He was erroneously diagnosed as having familial hypercholesterolemia and treated with a low cholesterol diet (+/- cholestyramine) to which he did not respond. A determination of plasma total lipid profile by high-temperature gas chromatography revealed elevated plasma levels of free and esterified plant sterols along with the hypercholesterolemia. Introduction and maintenance of a diet low in cholesterol and plant sterols resulted in significant reduction in the blood concentration of these sterols, which returned to pretreatment level upon discontinuation of the low sterol regimen. The rapid identification and quantitation of the plant sterols by high-temperature gas chromatography provides a sensitive means of distinguishing phytosterolemia, which might be more common than previously suspected, from other forms of dyslipidemia, and for following the course of any treatment.

Fatty acid composition of individual plasma steryl esters in phytosterolemia and xanthomatosis

The bulk of the plasma plant sterol in phytosterolemia occurs in the esterified form and is carried mostly in the low and high density lipoproteins. We have determined the fatty acid composition of the individual plasma steryl esters from a newly discovered subject with phytosterolemia and xanthomatosis. For this purpose the intact steryl esters were subject to high temperature gas liquid chromatography (GLC) on a polar capillary column, which separated the major esters on the basis of molecular weight and degree of unsaturation of the fatty acids. The saturated and unsaturated sterols esterified to saturated, monoenic, dienoic and tetraenoic fatty acids were identified by GLC analysis of the sterol moieties of the corresponding AgNO3-TLC fractions of the steryl esters. The GLC results were confirmed by reversed phase high performance liquid chromatography combined with mass spectrometry via direct liquid inlet interface. It was found that, in general, each fatty acid was esterified to the same complement of sterols, and that the esterified sterols possessed a composition comparable to that of the free plasma sterols, which was comprised of about 75% cholesterol, 6% campesterol, 4% 22,23-dihydrobrassicasterol and 15% beta-sitosterol. The fatty acid composition of the steryl esters differed from that of the 2-position of the plasma phosphatidylcholines, which contained significantly less palmitic and oleic and more linoleic acid. On the basis of these results and a review of the literature it is suggested that the plasma cholesteryl and plant steryl esters in phytosterolemia originate from both synthesis in plasma via the lecithin-cholesterol acyltransferase and synthesis in tissues via the acylCoA-cholesterol acyltransferase.

The natural history of familial hypopituitarism

Familial hypopituitarism in the Hutterite Brethren is an autosomal recessive disorder involving sequential loss of anterior pituitary tropic hormones. Five individuals from two closely related families have been followed for 19 years. Both families are well integrated into the Hutterite community. Three sibs elected not to be treated with growth hormone and sex steroids. These sibs developed growth hormone and gonadotropin deficiency in the first decade of life, with subsequent loss of TSH function and finally ACTH deficiency in the third decade. The pattern of hormone loss differed in the second family, in that deficiency of growth hormone, gonadotropins, and TSH was evident in the first decade. A third family has been reported to have the same disorder and is from a different endogamous subdivision from that of the two families described here. Genealogical analysis of the three families shows that there are four ancestral couples common to the six parents. Thus all affected individuals are likely to be identical by descent for the same ancestral allele. The gene for hypopituitarism is not closely linked to the gene for growth hormone nor to the HLA region.

Resolution of prepubertal male gynecomastia following removal of a giant pigmented nevus

A male infant is reported in whom substantial gynecomastia resolved following removal of a giant pigmented nevus. Endocrinological studies were normal. It is postulated that the nevus contributed to the development of gynecomastia. Surgeons should be aware of a possible relationship between these two seemingly unrelated conditions when making evaluation and management decisions.

Growth retardation: an approach to management

The physician who looks after children and teenagers is often confronted with the problem of short stature or growth failure. A major concern is when, and how extensively, to investigate the problem. From a practical standpoint, assessment can be related to height percentiles. The aims of treatment are to identify and treat appropriately the patients in whom there is an organic cause and to provide psychologic counselling and support. Common causes of growth failure are identified and a simple approach to management is outlined.

Primary adrenocortical nodular dysplasia as a cause of Cushing's syndrome in infants and children

Two patients with Cushing's syndrome due to primary adrenocortical nodular dysplasia (PAND) are described. Both patients, an infant and a 14-year-old boy at the time of diagnosis, were treated by total bilateral adrenalectomy. On gross inspection, the adrenal glands of the infant did not appear to be abnormal but those of the older patient showed numerous dark nodules. Microscopically, the adrenal glands of each patient manifested multiple micronodules with internodular atrophy. The extreme internodular atrophy suggest that primary adrenocortical nodular dysplasia is a non-ACTH-dependent condition. Since the disorder appears to involve primarily the cortex of both adrenals, adrenalectomy followed by steroid replacement is the recommended treatment.

Serum immunoreactive somatomedin levels in normal adults, pregnant women at term, children at various ages, and children with constitutionally delayed growth

Immunoreactive somatomedin (IRSM) levels in term pregnancy material sera (MS) and newborn cord sera (CS) were higher and lower, respectively, than those in normal adults. IRSM levels in MS and CS were not correlated, suggesting that SM dose not cross the placenta. The similar levels of IRSM in arterial and venous CS suggest that the placenta does not produce SM. IRSM levels in CS were higher than those in newborn sera and were correlated with day 1 newborn sera, suggesting that the placenta may regulate fetal serum IRSM levels. Serum IRSM levels in normal children gradually increased from birth to peak levels at puberty. The mean levels of serum IRSM reached peak levels 2 yr earlier in females. Males near pubertal age with constitutionally delayed growth had lower serum IRSM levels than age-matched controls. Diagnostic measurements of serum IRSM in children requires comparison with age- and sex-matched controls. Serum SM levels may only approximately reflect the local concentrations or activities of SM in various tissues.

Hypersecretion of gastric inhibitory polypeptide in nondiabetic children with cystic fibrosis

Failure of secretion of an insulinotropic enteric hormone has been postulated as a cause for the impaired insulin secretion observed following a glycemic stimulus in children with cystic fibrosis (CF). Gastric inhibitory polypeptide (GIP), a hormone located primarily in the duodenum, is the main hormonal stimulus to insulin release from the gastrointestinal tract. To determine whether hyposecretion of GIP was present in CF subjects, GIP secretion was measured in 15 control children and ten children with CF, following a standard oral glucose tolerance test. None of the subjects was diabetic but the CF children demonstrated significant insulinopenia compared to the normal control subjects. GIP secretion in the CF children was significantly greater than in the normal control subjects (normal, 38.8 +/- 4.6 ng/ml . min; CF, 54.9 +/- 6.1 ng/ml . min, P less than .01). These findings indicate that there is increased production of GIP in CF children rather than impaired secretion as had been postulated. The demonstration of hypersecretion of GIP in nondiabetic insulinopenic individuals adds further support to the hypothesis that insulin exerts feedback control on GIP secretion.

Circulating antidiuretic hormone during labour and in the newborn

Using a high specificity radioimmunoassay, antidiuretic hormone (ADH) concentrations were measured in the plasma of 33 expectant mothers during labour, in cord arterial and venous plasma of their infants at the time of delivery (19 delivered vaginally; 14 delivered by Cesarean section) and in the plasma of the same infants in the first few days of life. Extremely high concentrations of ADH (about 50 times higher than adult basal concentrations) were present in cord arterial blood indicating active fetal production of ADH. Plasma ADH decreased rapidly within an hour after birth and usually fell to adult basal levels during the first day of life. Stressed babies and babies subjected to difficult deliveries had higher plasma levels of ADH.

Idiopathic, sustained, inappropriate secretion of ADH with associated hypertension and thirst

A 15 year old girl presented with excessive thirst and hypertension (170/110 mm Hg). Biochemical investigations revealed serum sodium 118 meq/liter, serum osmolality 238 mosmol/liter, urine sodium 90 meq/liter, urine osmolality 700 mosmol/liter, persistenly elevated serum antidiuretic hormone (ADH) levels (5.8 to 11.9 pg/ml) and no obvious cause for the hypertension. The hypertension is, at least in part, volume-related, diminishing with fluid restriction. Features of gross water intoxication (e.g., confusion, coma) have not occurred. The etiology of the inappropriate secretion of ADH is not obvious but is not thought to be due to "resetting of osmoreceptors" as evidenced by failure to maximally dilute urine following a water load test and persistently elevated serum ADH levels. A similar patient described by Epstein and associates in 1962 is presently well with persistent features of inappropriate secretion of ADH.

Childhood Cushing disease: results of bilateral adrenalectomy

In view of the published reports of the successful correction of hypercortisolism in adult patients with Cushing disease by external pituitary irradiation and transsphenoidal pituitary microsurgery, leaving the patients with intact pituitary and adrenocortical function, we have reviewed the results of adrenalectomy in childhood Cushing disease seen at the Mayo Clinic. Twenty-seven patients were treated with total (16 patients) or subtotal (11 patients) bilateral adrenalectomy before the age of 20 years. Follow-up ranged from one to 27 years. Although hypercortisolism was corrected in all but one patient, 12 (45%) patients had roentgenographic evidence of a pituitary tumor and six (22%) of these required pituitary surgery. An additional six patients (22%) were pigmented, but had no abnormality on roentgenographic studies. The remaining nine patients (33%) were well, without evidence of pituitary tumor. We conclude that alternate forms of therapy should be considered for childhood Cushing disease.

Albright's syndrome with rickets

Four patients are reported who had Albright's syndrome, hypophosphatemia, and inappropriately low renal tubular reabsorption of phosphate. Three of the patients had radiologic evidence of rickets or osteomalacia, and the fourth had a bone biospy, which showed microradiographic evidence of a previous mineralization defect. Serum parathormone values were elevated before treatment in two patients. Intravenous infusions of calcium in one patient, and of calcium and parathormone in a second patient, showed appropriate target-organ responsiveness. Patients generally showed radiologic improvement of rickets after treatment with large doses of vitamin D, but such treatment failed to restore normal serum values of phosphorus and alkaline phosphatase. It is postulated that a substance elaborated from the dysplastic bone may be interfering with phosphate reabsorption in the renal tubule.

T3 toxicosis in children

Triiodothyronine (T3) toxicity has been well documented in adults, but only isolated cases have been reported in children. Two girls presented with firm goitres and overt hyperthyroidism. In each patient, total serum thyroxine (T4) values by competitive protein binding were normal, however total T3 values by radioimmunoassay were elevated. One patient had Graves' disease, the second patient had Hashimoto's disease which has been only infrequently associated with T3 toxicity in adults. Both patients responded to therapy with propylthiouracil. The mechanisms by which T3 is preferentially secreted in thyrotoxic states in man are poorly understood, but iodine deficiency and poor iodination of thyroglobulin may be important factors.

An approach to solving problems of growth retardation in the child and teenager

The physician who looks after children and teenagers is often confronted with the problem of short stature or growth failure. Common causes of growth failure include genetic background, intrauterine disease, malnutrition, chronic illness and hormonal disorders; some cases are attributed to mental retardation or primary central nervous system disease. A major concern in the evaluation of these patients is when, and how extensively, to investigate the problem. From a practical standpoint assessment can be related to height percentiles. The aims of treatment are a) to identify and treat appropriately the patients in whom there is an organic cause and b) to provide psychologic counselling and support.

Management of diabetes mellitus in children

In many respects the management of diabetes mellitus in children differs from the management in adults. Guidelines for the short- and long-term management of the child with diabetes mellitus, particularly as it relates to clinical presentation, treatment of ketoacidosis, long-term therapy and psychological counseling, are presented. The specific aspects of diabetes management that are unique to the child are best met by an increased understanding of the problems by the child and the family and an integrated approach by the physician and allied health personnel.

Hypothyroidism in one of monozygotic twins

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