Rose T. T. Yeung

EFFECT OF SURGICAL STRESS ON PITUITARY‐TESTICULAR FUNCTION

The effect of surgical stress on the secretions of LH, FSH, testosterone (T) and oestradiol (E2) were studied in twelve male patients. During surgery LH rose significantly; post‐operatively, LH fell but remained persistently elevated a week after operation. However, T and E2 fell progressively to a nadir on the second and fifth post‐operative day respectively and remained suppressed. Serum FSH showed no significant change. Despite a post‐operative decrease in sex hormone binding globulin (SHBG) binding capacity, non‐SHBG bound T showed a decrease parallel to T. Multiple sampling studies showed that the secretions of LH were increased and that of T were decreased post‐operatively. Following surgery, LH responses to LHRH were magnified, FSH and T responses showed no significant change when compared with the pre‐operative responses. These data suggest that secretions of LH were increased during surgery. Following surgical stress, T and E2 concentrations were suppressed resulting in a compensatory elevation of LH concentrations.

EFFECT OF ACUTE MYOCARDIAL INFARCTION ON PITUITARY‐TESTICULAR FUNCTION

The effect of acute myocardial infarction on the secretions of LH, FSH and testosterone was studied in thirteen male patients. Plasma testosterone fell transiently on the fourth day after acute myocardial infarction. This was accompanied by a rise in LH on the same day which persisted for a week after infarction. Serum FSH showed no significant change. The data suggest that following the medical stress of myocardial infarction, testosterone concentration was suppressed resulting in a compensatory rise in LH.

Symptomatic hypothalamic-pituitary dysfunction in nasopharyngeal carcinoma patients following radiation therapy: A retrospective study

Endocrine assessment was performed in 32 relapse-free southern Chinese patients (21 males and 11 females, aged 27-50 years at the time of assessment) 5-17 years following radiation therapy (RT) alone for early nasopharyngeal carcinoma (NPC). Initial screening was done using questionnaires emphasizing on impaired sexual function and menstrual disturbance plus measurement of serum levels of thyroxine, free thyroxine index, thyrotropic hormone, prolactin, and additionally testosterone for males only. Those showing abnormalities were subjected to detailed pituitary function tests. Hypothalamic-pituitary dysfunction was found in 7 female patients and only 1 male patient. A delayed TSH response to thyrotropin releasing hormone suggesting a hypothalamic disorder was seen in 6 of the affected female patients, and hyperprolactinaemia in also 6. None of the patients had evidence of diabetes insipidus. Hypopituitarism became symptomatic 2-5 years after RT with a mean latent interval of 3.8 years. A practical protocol for regular endocrine assessment for NPC patients after RT has been proposed. Multiple linear regression analysis of the radiotherapeutic data from the 11 female patients indicates that the likelihood of late occurrence of symptomatic hypothalamic-pituitary dysfunction following RT is dependent on the TDF of the target dose to the nasopharyngeal region and the height of the upper margin of the opposed lateral facial fields above the diaphragma sellae (coefficient of multiple correlation = 0.9025). Except when the sphenoid sinus or the middle cranial fossa is involved, it is advisable to set the height of the upper margin of the lateral facial field at a level no higher than the diaphragma sellae. The hypothalamus and possibly the pituitary stalk as well may sustain permanent damage by doses of radiation within the conventional radiotherapeutic range for carcinomas.

Strong Association of HLA-DR3/DRw9 Heterozygosity With Early-Onset Insulin-Dependent Diabetes Mellitus in Chinese

Studies of Caucasian and Japanese patients with insulin-dependent diabetes mellitus (IDDM) have shown that heterozygosity for certain HLA-DR antigens confers a high risk of developing the disease. The HLA antigens of 75 Chinese patients and 100 Chinese controls in Hong Kong were studied to investigate the role of HLA-DR heterozygosity in Chinese individuals. Some of the patients and controls were also tested for allotypic variation in the complement components C2, C4, and BF. Three alleles, Aw33, B17, and DR3, had increased frequencies in patients compared with controls and frequently occurred together in the same phenotype, which suggested their existence as a haplotype. There were no statistically significant differences in complement allotype frequencies between patients and controls, although the C4B null allele seemed to be associated with Aw33, B17, and DR3. No other HLA-DR antigen appeared to be associated with IDDM. However, when the patients were separated on the basis of age at onset, the frequency of DR3/DRw9 heterozygosity was markedly increased in patients presenting in the first decade of life, but there was no increase in patients presenting at greater than 20 yr of age. DRw9 is strongly associated with autoimmune disease in Chinese, whereas DR3 is not. We suggest that the major IDDM susceptibility locus in Chinese is associated with HLA-DR3 and that patients with HLA-DR3 and HLA-DRw9 have an added predisposition to autoimmune disease and therefore develop IDDM earlier than patients without DRw9.

EFFECTS OF HEROIN ADDICTION ON THYROTROPHIN, THYROID HORMONES AND PROLACTIN SECRETION IN MEN

Pituitary‐thyroid function in male heroin addicts and addicts after abstinence (exaddicts) was studied and compared with that of healthy euthyroid men. In heroin addicts the increases in circulating total thyroxine and triiodothyronine levels were accompanied by an increase in the thyroid hormone uptake test. These changes may reflect a quantitative increase in thyroxine binding globulin. Reverse triiodothyronine concentrations in heroin addicts were normal. The thyrotrophin‐releasing hormone elicited a diminished thyrotrophin response in heroin addicts which was significantly different from that in control subjects and ex‐addicts. An elevation of serum prolactin was noted in heroin addicts, while ex‐addicts had normal levels. Gradual recovery of pituitary‐thyroid function occurred after heroin withdrawal.

A study of carbohydrate metabolism in postnecrotic cirrhosis of liver

Intravenous glucose tolerance, insulin tolerance, tolbutamide, and glucagon tests were carried out in 21 patients with postnecrotic cirrhosis. Based arbitrarily on the bromsulphthalein retention they were divided into group A, nine patients with less impaired liver function, and group B, 12 patients with greater impairment of liver function. Intravenous glucose and insulin tolerances were reduced in both groups. The hypoglycaemic effect of tolbutamide was similar in the controls and in both groups of cirrhotic patients but this was achieved at higher plasma insulin levels in group B indicating resistance of the liver to the effect of endogenous insulin. The blood glucose response to glucagon was markedly impaired in group B patients which is consistent with this hypothesis. In contrast to the insulin response to glucose and tolbutamide, the insulin response to glucagon was reduced in the cirrhotic patients. Fasting human growth hormone and free fatty acid levels were elevated in both groups but they were not considered to be important factors in the production of insulin resistance.

Acute pancreatitis due to Clonorchis sinensis

Abstract In a series of 110 southern Chinese patients in Hong Kong, suffering from acute pancreatitis considered to be of undetermined aetiology, 91 (83%) were found to be infected with C. sinensis . In view of the limitations of the methods of diagnosis employed the infection rate was probably higher. However, the established incidence is more than double that encountered in a random sample of the population. Further, the ratio of males to females in the series was 3:2, a ratio similar to that encountered in clonorchiasis but the reverse of that in most reported series of pancreatitis. Evidence is presented that the adult flukes reside not only in the bile ducts but also in the pancreatic ducts. Obstruction to these latter is produced by the presence of the flukes per se and by secondary changes in the walls of the ducts. These changes, which include metaplasia of the epithelium, are described briefly and illustrated and it is considered that they can only be attributed to the infection. In 75% of the patients the attack of pancreatitis followed 1–3 hours after a meal, unusual in that the protein content of animal origin was greatly increased over the amount normally consumed. The evidence, in the light of present knowledge, suggests that, in the main, the pancreatitis was provoked by stimulation of the secretion of pancreatic juice by an unusual meal, in the presence of obstruction within the pancreatic ducts caused directly and indirectly by the presence of C. sinensis .

Hypoglycaemia in suppurative pancholanghtis due to Clonorchis Sinensis

Abstract Over a period of 16 years, to the University Department of Medicine, Queen Mary Hospital, 11 patients were admitted deeply unconscious, with high fever and showing varying degrees of jaundice. In all the coma was associated with severe hypoglycaemia, and correction of this resulted in restoration of consciousness. The histories of the last 10 patients were remarkably similar. After 1–4 days of fever and right upper abdominal discomfort there were repeated rigors associated with distressing distending pain over the liver coupled with vomiting. All lost consciousness within 24 hours of the onset of rigors. The laboratory findings are briefly described. The findings at necropsy in 9 and at laparotomy in 2 were those of a diffuse suppurative pancholangiitis associated with obstruction tot he extrahepatic ducts by large numbers of dead Clonorchis sinensis . It is concluded that surgical removal of the plug of dead flukes and drainage of the biliary tree are essential in the management of the condition and that it should be carried out as early as possible. An investigation of the cause of the hypoglycaemia is described and it is concluded that it results from a hepatectomy-like effect. How the infection exerts this effect has not been determined. It is not due to necrosis of liver cells and is rapidly reversible through adequate treatment.

Sustained improvement in diabetic control on long-term self-monitoring of blood glucose

The benefits of self-monitoring of blood glucose (SMBG) were assessed in 38 Chinese adults on conventional insulin regimens who had been performing SMBG for a mean duration of 26 months (range 15-40). For analysis patients were divided into 2 groups. Group A consisted of 27 insulin-requiring patients who were referred for SMBG because of poor control or young age (less than or equal to 35 years). Group B consisted of 11 IDDM patients who were on SMBG from diagnosis. Mean age and duration of SMBG were similar in the 2 groups though group A had longer duration of disease. In group A, mean haemoglobin A1 (HbA1) decreased from 12.4 +/- 0.5% before SMBG to 10.9 +/- 0.5% at 6 months (P less than 0.005), 10.7 +/- 0.5% at 12 months (P less than 0.005) and 10.3 +/- 0.4% after long-term SMBG. This was accompanied by a significant reduction in insulin requirement from 0.82 +/- 0.07 U/kg/day to 0.72 +/- 0.07 U/kg/day (P less than 0.05). In group B, insulin requirement progressively decreased in the first 6 months. At 12 months, mean HbA1 was 9.0 +/- 0.5% and insulin requirement was 0.58 +/- 0.08 U/kg/day. No significant change in HbA1 or insulin requirement was observed beyond the first year. After long-term SMBG, 82% of patients in group B had good control (HbA1 less than or equal to 10%) compared to 45% only in group A (P less than 0.05). Long-term SMBG is associated with sustained improvement in diabetic control and is particularly beneficial if introduced to diabetic patients right from diagnosis.

DISSOCIATED THYROXINE, TRIIODOTHYRONINE AND REVERSE TRIIODOTHYRONINE LEVELS IN PATIENTS WITH FAMILIAL GOITRE DUE TO IODIDE ORGANIFICATION DEFECTS

The thyroid function of patients with three different types of organification defect was studied. All patients were characterized by a high thyroidal 13 I uptake and a positive perchlorate discharge. Patients with Pendreds syndrome who had goitre and congenital nerve deafness were mostly euthyroid with normal circulating thyroid hormone levels. Only two of them had compensated euthyroidism with elevated total T3, high basal TSH and delayed return to basal value after TRH. The patients who were euthyroid with large goitres and normal hearing had elevated total T3 and an exaggerated TSH response to TRH. The thyroid function of these two groups of patients contrasted with that of goitrous cretins, who were clinically hypothyroid with low circulating total T4, increased T3 and decreased rT3 levels. The data suggest that in patients with intrathyroidal iodine deficiency secondary to organification defect, there is preferential T3 production in an effort to maintain euthyroid state, and this is further substantiated in the case of gross thyroid insufficiency either by enhanced peripheral conversion of T4 to T3, or reduced metabolic clearance of T3 and increased clearance of rT3, resulting in elevated T3 and decreased rT3 levels.