Restoration of blood pressure by choline treatment in rats made hypotensive by haemorrhage

1. Intracerebroventricular (i.c.v.) injection of choline (25-150 micrograms) increased blood pressure in rats made acutely hypotensive by haemorrhage. Intraperitoneal administration of choline (60 mg kg-1) also increased blood pressure, but to a lesser extent. Following i.c.v. injection of 25 micrograms or 50 micrograms of choline, heart rate did not change, while 100 micrograms or 150 micrograms i.c.v. choline produced a slight and short lasting bradycardia. Choline (150 micrograms) failed to alter the circulating residual volume of blood in haemorrhaged rats. 2. The pressor response to i.c.v. choline (50 micrograms) in haemorrhaged rats was abolished by pretreatment with mecamylamine (50 micrograms, i.c.v.) but not atropine (10 micrograms, i.c.v.). The pressor response to choline was blocked by pretreatment with hemicholinium-3 (20 micrograms, i.c.v.). 3. The pressor response to i.c.v. choline (150 micrograms) was associated with a several fold increase in plasma levels of vasopressin and adrenaline but not of noradrenaline and plasma renin. 4. The pressor response to i.c.v. choline (150 micrograms) was not altered by bilateral adrenalectomy, but was attenuated by systemic administration of either phentolamine (10 mg kg-1) or the vasopressin antagonist [beta-mercapto-beta,beta-cyclopenta-methylenepropionyl1, O-Me-Tyr2,Arg8]-vasopressin (10 micrograms kg-1). 5. It is concluded that the precursor of acetylcholine, choline, can increase and restore blood pressure in acutely haemorrhaged rats by increasing central cholinergic neurotransmission. Nicotinic receptor activation and an increase in plasma vasopressin and adrenaline level appear to be involved in this effect of choline.     

In situ localization and quantification of mRNA for 92-kD type IV collagenase and its inhibitor in aneurysmal, occlusive, and normal aorta

Ninety-two-kilodalton type IV collagenase (MMP-9) is present in aortic aneurysms and may be important to the pathogenesis of this disease. Alteration in expression of MMP-9 or its inhibitor, the tissue inhibitor of metalloproteinase type 1 (TIMP-1), could increase degradation of extracellular matrix and lead to aneurysm formation. The purpose of this study was (1) to measure tissue levels of MMP-9 and TIMP-1 mRNA in aneurysmal (AAA), atherosclerotic occlusive (AOD), and normal (NL) human infrarenal aorta; (2) to test for their expression by cultured AAA and NL vascular smooth muscle cells (VSMCs); and (3) to locate in situ the cells responsible for mRNA production within AAA, AOD, and NL aortic wall. Total RNA extracted from AAA (n = 8), AOD (n = 8), and NL (n = 7) tissue was subjected to Northern analysis. Signals for MMP-9 and TIMP-1 were normalized to alpha-tubulin. Mean values +/- SEM were compared by ANOVA. NL and AAA VSMCs were cultured, passaged, and grown to confluence before RNA extraction and Northern analysis. In situ hybridization with digoxigenin-labeled RNA probes localized cells responsible for MMP-9 and TIMP-1 mRNA expression within sections of AAA (n = 5), AOD (n = 2), and NL (n = 2) aorta. MMP-9 mRNA levels were significantly greater in AAA (0.855 +/- 0.180) than NL (0.046 +/- 0.23) (P < .02), but differences between AOD (0.406 +/- 0.196) and AAA or AOD and NL were not significant.(ABSTRACT TRUNCATED AT 250 WORDS)     

Efficacy of measles vaccine during the 1993 measles epidemic in Korea

Immunization to eliminate measles is recommended at 15 months of age with the option of giving vaccine at 6 to 9 months of age during measles outbreaks in Korea. Because of the recent resurgence of measles and concern about the possibility of reduced vaccine efficacy caused by genomic differences between vaccine virus and contemporary wild measles viruses, we conducted a measles vaccine efficacy study involving children with household exposure ages 1 to 5 years during measles outbreak that had occurred 1993 in Seoul and Seong-nam city, with the demographic analysis of patients brought to the hospitals. A total of 380 patients (M:F = 216:164) were included in this study. Two hundred nine cases (55.0%) occurred in children less than 5 years of age, and 167 (43.9%) were younger than 16 months of age. The recorded age-specific incidence rates showed bimodal patterns, i.e. highest peak in those below 16 months of age and second peak in those ages 6 to 9 years of age. Only 9.6% (16 of 167) of the measles cases less than 16 months, 59.5% (25 of 42) of those 16 months to 4 years and 91.8% (157 of 171) of the cases in school age children have been vaccinated. Attack rates among the 122 vaccinated siblings and 12 unvaccinated siblings ages 1 to 5 years who contacted measles were 5.7 and 75%, respectively, and the clinical vaccine efficacy was 92.4% (95% confidence interval, 83.6, 96.4). The high vaccine efficacy in household exposures suggests that measles outbreaks in Korea are not caused by reduced vaccine efficacy.