Hearing impairment in diabetics

Bekesy audiometry, impedance audiometry with stapedius reflex test, speech discrimination and the recording of electrocochleography (ECochG) and brain stem auditory evoked potentials (BAEP) were performed in 43 diabetics and 43 strictly sex- and age-matched nondiabetic controls. The results revealed that the average pure-tone thresholds, subjective click threshold and AP reactive threshold were significantly elevated in the diabetics. The average speech discrimination maximum score was significantly decreased in the diabetics. The diabetic hearing impairment was characterized by high frequency sensorineural hearing loss. Both the cochlear and retrocochlear pathology existed in the diabetics with hearing impairment.

[Primary treatment of contaminated syringes and needles in a ward]

Body fluid transmitted viruses become the major enemies of human health. These viruses have been reported as occupational hazards for health care personnel, and they may become environmental hazards as well. We conducted this study to examine the primary treatment of used syringes and needles in a ward, and to evaluate the effects of re-education. For questions such as "The used syringes with bloody contamination should isolated from those without" and "The cover of used needles should not be put back on", we recorded error rates during the 1st one-week observation. A lecture about the standard treatment methods of discarding instruments was given to all nurses in this ward after the 1st observation. The 2nd and 3rd one-week observations were repeated one day and one month after the lecture, respectively. The misclassification rates of discarded syringes were 4.4% (33/758), 1.4% (9/661) and 3.9% (18/616). There was a significant decrease between the 1st and 2nd observations (p less than 0.05), but no significant difference between the 1st and 3rd observations (p greater than 0.05). The rates of covered discarded needles were 50.4% (287/569), 44.3% (198/447) and 38.5% (269/699), respectively. These rates showed a trend to decrease (p less than 0.05). The misclassification rates of discarded syringes were low. Although re-education achieved only temporary effects, self-protective education on not re-covering used needles was effective. However, about 40% of all discarded syringes were still being covered after use. Based on our finding, some improvements have been made in this ward.

Application of pyridostigmine in evaluation of growth hormone reserves in children and adolescents

There is evidence that the cholinergic system positively modulates growth hormone (GH) secretion. In the present study, we observed the effects of cholinergic enhancement by pyridostigmine (PD), a cholinesterases inhibitor, on GH release in both normal (n = 13) and GH deficient children and adolescents (n = 10). Responses of GH to insulin hypoglycemia (Ins) were also observed. In the normal subjects, PD-induced serum GH peak level was significantly higher than that induced by Ins (P less than 0.01), while the GH level in the patients with pituitary dwarfism showed no increase in both tests. This study indicates that PD test may be considered a sensitive dynamic test in evaluating pituitary function of GH secretion in children and adolescents.

Effects of aminoglutethimide on hypothalamic-pituitary-adrenal functions

This study was performed on four groups of subjects, including 10 patients with Cushing's disease, 10 patients with simple obesity, 8 patients with hypopituitarism and 13 normal subjects. The study was conducted by measuring the sequential changes of plasma ACTH, serum cortisol, 24-h UFC, 24-h 17 KS and 24-h 17 KGS following aminoglutethimide (AG) administration. The results suggest that normal subjects showed sequential changes of hypothalamic-pituitary-adrenal hormone concentrations with normal feedback regulation of the axis following AG administration. Patients with Cushing's disease had obvious autonomy in the production of ACTH from the pituitary. Patients with simple obesity might display abnormality to some degree in the production from the pituitary. Patients with hypopituitarism lost the capacity of ACTH production in various degrees because of pituitary lesions.

Non-specific response of serum growth hormone to thyrotropin-releasing hormone in diabetics

It is well known that growth hormone (GE) secretion and regulation in diabetics are abnormal. In order to evaluate the response of GH to nonphysiological stimuli in diabetics, a thyrotropin-releasing hormone (TRH) test (500 micrograms by IV bolus injection) was carried out in 12 patients with insulin-dependent diabetes (IDD, 6 males and 6 females). 11 noninsulin-dependent diabetes (NIDD, 5 males and 6 females), and 10 normal controls (6 males and 4 females). The results showed that the basal serum GH levels in diabetics were higher than that in normal controls and it was even higher in IDD than in NIDD. Following the TRH stimulus, the mean peak level of GH in IDD was the highest among the three groups, the differences being statistically significant (F = 9.323, P less than 0.01). It was concluded that a nonspecific response to TRH of GH did occur in IDD, and the peak values were even higher in female than in male subjects. A negative correlation existed between the GH peak values and the age of the patients as well as in the controls. This supported the view that GH responsiveness to TRH has a tendency of progressive decline with age. However, no significant correlation was found between the peak value of GH and the blood glucose level or the microangiopathic complications. The mechanism of TRH stimulation on GH release in diabetics is discussed.

Human epidermal keratinocytes in culture convert thyroxine to 3,5,3'-triiodothyronine by type II iodothyronine deiodination: a novel endocrine function of the skin

Cultured human keratinocytes converted T4 to T3 by type II iodothyronine deiodination. Homogenates of keratinocytes cultured from neonatal foreskin or adult arm skin had similar mean T4 5'-deiodinating activities. Conversion of T4 to T3 by intact cells was demonstrable in cultures from neonatal and adult donors. Only phenolic ring deiodination occurred in the cultured cells and their homogenates, the apparent Michaelis constant for T4 was 12 nmol/L, and T4 and rT3 each inhibited 5'-deiodination of the other. T4 5'-deiodination was unaffected by addition to the assay mixture of 1 mumol/L T3, but was inhibited less than 10% by 1 mmol/L 6-n-propyl-2-thiouracil, 50% by 270 nmol/L iopanoic acid, 50% by 9.4 mumol/L 3,5-diiodo- 3',5'-dimethyl-L-thyronine, and 33% by 42 mumol/L amiodarone. When keratinocytes were cultured for 3-4 days in medium containing iodothyronine-free fetal calf serum, the T4 5'-deiodination rates in homogenates doubled; this increase was prevented by restoring a physiological free T4 concentration, but not by a supraphysiological T3 concentration. Homogenates of fresh whole skin or fetal cadaveric epidermis did not convert T4 to T3 in measureable amounts, although one epidermal homogenate had low level T3 typrosyl-ring deiodinating activity. These results suggest that human epidermal type II iodothyronine deiodination in man might conceivably contribute to the intracellular T3 content of the skin and even to serum T3 concentrations, especially in hypothyroidism.