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.

     

Polymorphisms in manganese superoxide dismutase and catalase genes: functional study in Hong Kong Chinese asthma patients

BACKGROUND: Reactive oxygen species may contribute to the pathogenesis of asthma. Functional genetic polymorphisms of antioxidant enzymes, superoxide dismutase (SOD) and catalase are good candidates for asthma susceptibility. OBJECTIVE: To investigate the association of the manganese-containing form of SOD (MnSOD) gene at amino acid position 16 (Val16Ala) and catalase gene in the promoter at A-21T and C-262T polymorphisms and asthma in a Hong Kong Chinese population. METHODS: The association study was conducted in a case-control design in asthma patients (n=251) and healthy controls (n=316) by genotyping. The functional significance was assessed by determining erythrocyte SOD and catalase activity. RESULTS: The Val allele of MnSOD at Val16Ala and the A allele of catalase gene at A-21T were not different between patients and controls, while the C allele of catalase gene at C-262T was found to be significantly different between patients and controls (P=0.033). The less frequent variant of catalase gene (-262T) was found to be protective from the development of asthma in a Hong Kong Chinese non-smoking population (adjusted odds ratio=0.35, 0.15-0.85; P=0.017). Asthma patients had elevated erythrocyte SOD and catalase activities in comparison with healthy controls (P<0.01). However, their activities were not associated with different genotypes within healthy controls or asthma patients. CONCLUSION: This is the first report showing that SOD and catalase functional activities are not associated with their respective genetic polymorphisms but related to the presence of asthma in a Hong Kong Chinese population.     

Heterogeneity of human blood monocyte: two subpopulations with different sizes, phenotypes and functions.

Human blood mononuclear cells from normal adults were collected after density-cut centrifugation and monocytes were then isolated by removal of lymphocytes using the techniques of E-rosetting and cell adhesion. The purified monocytes were further analysed by velocity sedimentation, and two distinct subpopulations with different cell sizes were obtained. The larger monocytes were 17.0 +/- 1.8 microns in diameter with a mean sedimentation rate (SR) of 7.0 +/- 0.6 mm/hr, while the smaller monocytes were 9.5 +/- 0.8 microns in size and 4.1 +/- 0.2 mm/hr in SR. The population ratio of larger:smaller cells was approximately 2:1 (66 +/- 2.8%:34 +/- 1.6%). Both cell populations exhibited a high positive rate (> 98%) in both the non-specific esterase and the peroxidase stain. However, the larger cells had much higher phagocytic activity than the smaller ones. Furthermore, the expression of monocyte-associated antigens was also different between these two subpopulations. Thus, while most of the larger monocytes (98%) could be recognized by monoclonal antibodies MY7 and OKM1, only some (35 and 61%, respectively) of the smaller monocytes could react with those antibodies. In addition, the larger monocytes secreted a significant amount of monokines including interleukin-1 beta (IL-1 beta), tumour necrosis factor-alpha (TNF-alpha) and prostaglandin E2 (PGE2) and their production increased in proportion to the level of stimulation by bacterial lipopolysaccharide (LPS), whereas the production of monokines by the smaller monocytes remained at low levels and did not respond to LPS stimulation. These results reveal the existence of phenotypic and functional heterogeneity in human blood monocytes.     

Serum intact parathyroid hormone levels in elderly Chinese females with hip fracture

Summary Serum intact parathyroid hormone (PTH), 25 hydroxyvitamin D(25OHD), 1,25 dihydroxyvitamin D (1,25(OH)₂D), albumin, and ionized calcium were measured in 61 Chinese female patients with hip fracture and 61 control subjects. Hip fracture patients had low albumin, ionized calcium, and 250HD levels. Serum PTH and 1,25 (OH)₂D values were not different between the two groups. We conclude that although 250HD level in hip fracture patients is low, there is no evidence of secondary hyperparathyroidism, suggesting that the low 250HD levels may be a secondary phenomenon in response to the fracture.     

The antiparkinson efficacy of deprenyl derives from transient improvement that is likely to be symptomatic.

We undertook an analysis of the hazard functions derived from results published by the Parkinson Study Group following their investigation of deprenyl. Our findings indicate that the action of deprenyl is transient rather than sustained. We also infer that this effect may be mediated through alleviation of symptoms rather than by neuroprotection.     

Benefits of transfer primary angioplasty are durable, so why are we waiting?

Myocardial infarction is an important public health problemworldwide. Rapid restoration of flow remains as the foundationfor life-saving treatment of patients with ST-segment elevationmyocardial infarction (STEMI). In Europe, it is heartening tonote that the utilization of reperfusion therapies was increasingly,with the proportion rising from 55.8% in 2000–2001 to63.9% in 2004, based on the first and second Euro Heart Surveysof Acute Coronary Syndromes, respectively.¹ Notably, patientswere more likely to receive primary percutaneous coronary intervention(increased from 37 to 59% over the same period),¹ probably becauseof the favourable results derived from     

Insulin, branched-chain amino acids, and growth failure in uremia

Insulin and branched-chain amino acid (BCAA) metabolism was studied in 14 adolescents with uremia on hemodialysis. Glucose tolerance was measured by intravenous glucose tolerance tests. Insulin sensitivity was measured by the euglycemia clamp technique. Insulin secretion during constant hyperglycemia was measured by the hyperglycemic clamp technique. Fasting plasma BCAA concentrations were compared with data from 8 adolescent controls, whereas insulin indices were compared with 8 young adults controls and with published normal data in adolescents. The patients could be further sub-divided into two groups with respect to their growth velocity standard deviation score (GVSDS). Group 1 consisted of 7 patients with GVSDS less than −2. This group demonstrated insulin resistance, glucose intolerance, and low insulin secretion. This group also had low plasma valine, leucine, and isoleucine concentrations compared with control values. Group 2 consisted of 7 patients with GVSDS more than −2. This group demonstrated insulin resistance, but normal glucose tolerance and normal insulin secretion. Plasma valine, leucine, and isoleucine concentrations in group 2 were not different from control values. Total plasma BCAA correlated with glucose tolerance index and with insulin secretion, but not with insulin sensitivity. Growth failure in uremia is associated with glucose intolerance, hypoinsulinemia, and low plasma BCAA concentrations. Impaired utilization of conventional energy sources leading to preferential oxidation of BCAA may contribute to reduced anabolism and growth failure in uremia. Received October 8, 1997; received in revised form February 3, 1998; accepted February 6, 1998