Recombinant tissue-plasminogen activator (rt-PA) in acute myocardial infarction in the Chinese in Hong Kong.

Eighty-nine consecutive Chinese patients (69 males, 20 females) with acute myocardial infarction treated by 100 mg recombinant tissue-plasminogen activator (rt-PA) (7 intracoronarily, 82 intravenously) at 3.7 +/- 1.0 hours after onset, and intravenous heparin or dipyridamole therapy started at 3 hours, were studied prospectively. Their mean age was 59.6 +/- 10.6 years. Forty-six patients (51.7%) had anterior and 39 patients (43.8%) had inferior infarcts. Clinical evidence of reperfusion was seen in 63 patients (72.8%), while new complications included hypotension (5.6%), heart failure (6.7%), cardiac arrhythmias (76.4%), hematoma around vascular access sites (23.6%), melena (2.2%) and cerebral infarction (2.2%). Maximal changes in coagulation profiles were seen at 3 hours, including a decrease in fibrinogen (by 64.2%), an increase in FDP by 11.7 times and D-dimers by 4.4 times. Nine patients (10.1%) had recurrence of angina and 6 patients (6.9%) died due to pump failure (5) and reinfarction (1). Angiogram at 14 days confirmed TIMI (2 or 3) patency of infarct related arteries in 62/81 (76.5%) patients, with a mean global ejection fraction of 52.5 +/- 12.4%. Nearly all survivors could maintain class I-II functional status after discharge. The safety and promises of rt-PA for acute myocardial infarction in the Chinese were confirmed.

     

Michaelis-Menten metabolite formation kinetics: equations relating area under the curve and metabolite recovery to the administered dose

A computational approach which concomitantly determines the capacity-limited rate constants of parent drug elimination and metabolite formation is presented. The approach applies both the presently derived total excretory recovery versus dose relationships of the metabolite and the AUC versus dose relationships of the parent drug to identify the parameters. Three parent drug elimination conditions were assessed: pooled first-order, pooled Michaelis-Menten, and parallel first-order and pooled Michaelis-Menten kinetics. Model and parameter identification criteria are discussed. Literature data for theophylline and two of its metabolites in rats were examined to reveal pooled Michaelis-Menten elimination kinetics of theophylline and capacity-limited formation of the metabolites. The proposed technique is useful for quantitating commonly obtained nonlinear drug disposition data such as AUC and amount of metabolites excreted.     

Rat liver regeneration after partial hepatectomy: effects of insulin, glucagon and epidermal growth factor.

This study evaluated the role of insulin, glucagon and the epidermal growth factor (EGF) on liver regeneration after partial hepatectomy. Male Wistar rats, weighing approximately 200 g, were used. A partial hepatectomy, with resection of the medial and left lateral lobes (67.31%), was performed on the control group and seven hormone-treated groups: insulin, glucagon, EGF, insulin plus glucagon, insulin plus EGF, glucagon plus EGF, and a combination of the three hormones. The hormones were administered subcutaneously two days prior to the partial hepatectomy. The groups administered insulin were allowed to drink 20% glucose in water. Another group of rats received simulated operations, i.e., only a laparotomy was performed. The rats were killed at six, 24, 48 and 72 hours after the operation. Remnant liver weight, deoxyribonucleic acid (DNA) content, rate of DNA synthesis, mitotic index, blood glucose and serum insulin levels were measured. The results showed that: 1) the effects of single hormone administration on posthepatectomy liver regeneration were not obvious; 2) combined administration of insulin and glucagon increased the weight of the remnant liver, the DNA content, and the rate of DNA synthesis; 3) the combined administration of insulin, glucagon, and EGF increased the regeneration based on the remnant liver weight and mitotic index; and 4) there was no concordance between the change in blood glucose levels and the effect of hormones during liver regeneration.     

Effects of alkyl chain length on the inhibition of NNK-induced lung neoplasia in A/J mice by arylalkyl isothiocyanates

Six homologous arylalkyl isothiocyanates were evaluated fortheir abilities to inhibit pulmonary adenomas induced by thetobacco-specific nitrosamine 4-(methylnitrosamino)-l-(3-pyridyl)-1-butanone(NNK) in A/J mice. Four consecutive daily doses (5 µmol/mouse)of phenyl isothiocyanate (PITC), benzyl isothiocyanate (BITC),phenethyl isothiocyanate (PETTC), 3-phenylpropyl isothiocyanate(PPITC), 4-phenylbutyl isothiocyanate (PBITC), 4-oxo-4-(3-pyridyl)-butylisothiocyanate (OPBITC) and corn ofl were administered to miceby gavage. Two hours following the final dosing, mice were administeredsaline or 10 µmol of NNK in saline i.p. Pulmonary adenomaswere counted at 16 weeks after NNK administration. The miceadministered only corn oil prior to NNK developed an averagemultiplicity of 9.2 tumors/ mouse. Pretreatment with PITC, BITCand OPBITC had no significant effects on NNK-induced lung neoplasia.However, PEITC pretreatment resulted in a 64% reduction of lungtumor multiplicity, but did not affect the percentage of micethat developed tumors. Both PPITC and PBITC decreased tumormultiplicity by 96% and the percentage of tumor-bearing animalsby >60%. These results, in conjunction with our previouswork, demonstrate a general trend of increasing inhibition ofNNK-induced lung neoplasia by arylalkyl isothiocyanates withincreasing alkyl chain length. This study also demonstratesthe remarkable inhibitory activities of PPITC and PBITC, twoisothiocyanates that had not previously been tested as chemopreventiveagents.     

Autopsy findings in two siblings with infantile Refsum disease

Summary Recognition of adrenal atrophy during a review of autopsy findings in two sisters who died at 8 months and 3 1/2 years prompted estimation of very long chain fatty acids, phytanic acid and pristanic acid on wet liver fixed in formalin for 12 years. These were shown to be markedly increased and defects in multiple peroxisomal functions and decrease in particulate catalase were shown in cultured fibroblasts, confirming an abnormality of peroxisomal biogenesis. The patients had presented with failure to thrive, recurrent diarrohea and vomiting, poor mental development, retinal pigmentation, blindness and in the older patient deafness, with only mild dysmorphic features. Autopsy in the older patient showed adrenal atrophy, cirrhosis, and foamy histiocytes in multiple organs. The brain showed no demyelination, little cytoarchitectural abnormality, occasional perivascular histiocytes in the grey matter and meninges and prominent Purkinje cells in the molecular layer of the cerebellum. In the younger patient the changes were very subtle in spite of the marked clinical similarity. Despite the young age at death the clinicopathological features are most suggestive of infantile Refsum disease. In many situations anatomical pathology can be very useful in the recognition and study of peroxisomal disorders.     

Treatment of ureter injuries after obstetric-gynecologic surgery]

The article presents an analysis of 21 patients with ureter injuries originated during obstetric-gynaecological operations treated in Urology Clinic in Medical Academy Poznań. Attention was particularly focused on prevention and fast diagnosis of injuries based on intra-operation examination usg, urography, and ascending pyelography. This fast diagnosis is of crucial importance for the cure.     

Conservative treatment of neonatal hydronephrosis.

From February 1990 to January 1991, 19 cases of hydronephrosis in children of less than one year of age were managed at Mackay Memorial Hospital. In the majority of these patients, there were evident causes such as ureteropelvic junction stenosis, ureterovesical reflux or a posterior urethral valve for which definite therapeutic measures were performed. However, some cases had no obvious origins and the hydronephrosis was speculated to be from nonobstructive or physiologic dilatation of the kidneys. The conventional tools, such as intravenous pyelogram or renal ultrasound, which comprise the mainstay of diagnosis, provide limited information on renal functional status. Recent introduction of the Tc-99m diethylene triamine penta-acetic acid (DTPA) diuretic renal scan has enabled us to distinguish between obstructive and nonobstructive hydronephrosis and helps us to determine whether or not surgery is necessary. In the past year, eight patients with hydronephrosis of less than one year of age were diagnosed as nonobstructive after a series of evaluations using renal ultrasound, voiding cystourethrography (VCUG) and Tc-99m DTPA diuretic renal scan. Follow-up studies by echography or DTPA renal scan revealed spontaneous resolution of the dilated collecting systems in these cases and confirms our belief that some hydronephrosis in neonates and infants may resolve spontaneously and may just be a manifestation of physiologic change during development. The value of the Tc-99m DTPA diuretic renal scan in the diagnosis of obstructive uropathy is discussed.     

Determinants of elderly residential mobility in Southern China: Exploration and implications

It is a widely accepted observation that many older Hong Kong residents have lived periodically on the Chinese mainland since the relaxation of restrictions on cross-border mobility and the closer connection between Hong Kong and the mainland. This paper explores and compares the determinants of various modes of residential mobility by Hong Kong retirees to the Pearl River Delta based on the data of two samples—one from Hong Kong and the other from the mainland. The findings support those of studies in Western societies that the decision of elderly residential mobility can be effectively predicted by the personal attributes, place ties, and person ties of the retirees, and that the effects of these factors vary with different modes of retiree mobility. The implications of these findings for the formulation of migration and housing policies for the older population and the economic development of amenity communities are discussed. He is also a Research Associate at the Joint Centre of Excellence for Research on Immigration and Settlement in Toronto, Canada. His research interests are elderly residential mobility, gerontology and geriatrics education, and the help-seeking behavior of older people. Dr. Ma’s latest study concerns the utilization and accessibility of human services for older residents in Hong Kong. He is also a reviewer of several international journals. Dr. Chow’s research interests are social security policies and practice, social policies and services for older people, and family support. The focus of his latest research project is the service needs of new immigrants to Hong Kong.     

Thiamin and vitamin B6 intakes and erythrocyte transketolase and aminotransferase activities in morbidly obese females before and after gastroplasty.

To assess the need for postoperative vitamin supplements, intakes and nutritional status of thiamin (B1) and vitamin B6 were studied in 18 female gastroplasty patients who received a placebo or different levels of supplemental vitamins. Postoperative erythrocyte transketolase basal (BA) and thiamin pyrophosphate-stimulated (SA) activities and activity coefficients (AC) correlated significantly with B1 intake. Despite a decrease in apotransketolase, low thiamin intakes were associated with increased AC values during the first 3 months. With return to low B1 intakes following repletion during month 4, the AC values remained normal with low total activities. Both alanine (EALT) and aspartate (EAST) aminotransferase apoenzyme levels declined and AC values increased significantly during the first 3 months. Although the EALT-indices were more sensitive to changes in B6 intake than the EAST-indices, the EASTBA and SA correlated most consistently with the intake. Postoperative dietary intakes of both vitamins were inadequate for maintenance of normal activities of these erythrocyte enzymes. Although B1 intake of greater than or equal to 1.0 mg/day was adequate for maintenance of normal thiamin status in most subjects of this study, supplementation with greater than or equal to 1.5 mg/day is prudent even though it may not prevent the early postoperative loss of apotransketolase. Vitamin B6 intake at the current recommended dietary allowance (1.6 mg) was not adequate to maintain coenzyme saturation of the erythrocyte aminotransferases. Marginal intake of other nutrients may have affected the utilization of both thiamin and vitamin B6.