Apolipoprotein E polymorphism and Alzheimer's disease

We aimed to determine the association and related factors of the apolipoprotein E (ApoE) genotype and Alzheimer's disease (AD) in Taiwan. We examined ApoE genotypes in 50 Chinese patients with AD and 50 age- and sex-matched controls. The patients met the criteria of probable AD of the National Institute of Neurological and Communicative Disorders and Stroke-Alzheimer's Disease and Related Disorders Association (NINCDS-ADRDA) and AD of the Diagnostic and Statistical Manual of Mental Disorders 4th edition (DSM-IV). There were 28 females and 22 males in the case and control groups. The mean age of onset of AD was 72. 62 years. The average interval between onset and research was 3.85 years. The frequency of ApoE epsilon 4 in the AD group was significantly higher than that in the controls (0.13 versus 0.02, p < 0.05). The odds ratio for AD in individuals with at least one ApoE epsilon 4 allele was 6.0 (95% CI 1.34 to 55.3, p < 0.001). The linear trend for AD in proportion to alleles of ApoE epsilon 4 was significant (chi 2 = 8.3, p = 0.004). The risk of ApoE epsilon 4 allele for the late-onset AD patients, males, or those who received less education was higher than that for the early-onset AD patients, females, or those who had received more education. The sensitivity of the epsilon 4 allele was 24%, the specificity 96%, the positive predictive value 86%, and the negative predictive value 56%. Our results supported that the ApoE epsilon 4 allele is related to AD in Taiwan. In addition, sex and education may play important roles in the presence of ApoE epsilon 4 allele. The epsilon 4 allele seemed helpful as an adjunct for diagnostic testing of AD.

Functional characterization of beta-adrenoceptor subtypes in rabbit right atria

The advent of radioligand binding studies has allowed the classification of receptor subtypes in various tissues. However, the presence of a receptor subtype in a heterogenous tissue does not insure that the receptor has a significant physiological role. beta 1- and beta 2-Adrenoceptors have been reported to coexist in the rabbit right atria. The purpose of the present investigation was to determine the physiological role of beta-adrenoceptor subtypes in catecholamine-induced chronotropic responses in the rabbit right atria through comparison of data from functional and radioligand binding studies. Rank order of potency was determined using isoproterenol, epinephrine and norepinephrine for both chronotropic and inotropic responses in the rabbit right atria and right ventricular papillary muscles, respectively. These studies indicated that the beta 1-adrenoceptor was primarily responsible for catecholamine-induced responses. Next, the beta 1-selective antagonist, atenolol, was found to inhibit the chronotropic responses of the nonselective beta-agonist, isoproterenol, and the beta 2-selective agonist, terbutaline, to the same extent. These data indicate that terbutaline produces its chronotropic effects in the rabbit right atria through stimulation of beta 1-, not beta 2-adrenoceptors. Finally, competition studies for [125I]iodocyanopindolol and the relatively selective beta 1- and beta 2-adrenoceptor antagonists (ICI 89406 and ICI 118551, respectively) indicated that the ratio of beta 1- to beta 2-adrenoceptor subtypes is 6:1. It is concluded that while both receptors may be present in the rabbit right atria, the beta 1-adrenoceptor is the predominant subtype both in density and physiological significance, while the beta 2-adrenoceptor plays little, if any role, in the chronotropic responses induced by catecholamines.

Characteristics of Crimean-Congo hemorrhagic fever virus (Xinjiang strain) in China

Virus strains isolated from blood of patients during a hemorrhagic fever outbreak in 1968 in southern Xinjiang, China, from Hyalomma asiaticum and from sheep, were found to be identical or closely related to Crimean-Congo hemorrhagic fever (C-CHF) virus by complement fixation and indirect immunofluorescence tests with convalescent sera of patients and with C-CHF reference antibody. The virus was inactivated by ether and acid. Viral synthesis was not suppressed by 5-iododeoxyuridine suggesting an RNA-containing genome. The buoyant density in sucrose was 1.16-1.18 g/cm3. The particle weight was estimated at 3.26 +/- 0.46 X 10(8). The diameter of the virus particles was 85-105 nm.

Effects of synthetic parathyroid hormone on hemodynamics and regional blood flows

In pentobarbital anesthetized dogs, synthetic bovine parathyroid hormone, containing the amino terminal 34 amino acids (bPTH-(1-34] in doses of 0.1-0.8 microgram/kg i.v. caused dose-related decrease in arterial blood pressure, increase in cardiac output and prominent reduction of total peripheral resistance. Marked increase of coeliac, coronary and renal blood flows and decrease of vascular resistances in these beds occurred. Mesenteric and iliac blood flows usually decreased. Changes in mesenteric resistance were minimal while iliac resistance increased substantially. The increase of renal blood flow was still obvious 10-20 min or longer after arterial blood pressure had returned to control levels. Mesenteric and iliac vasoconstriction were attributable to reflex increase in sympathetic activity since some decrease in resistances in these beds were seen in response to bPTH-(1-34) after ganglionic blockade. Renal vasodilation was not related to a prostaglandin mechanism as similar dilation occurred after prostaglandin synthesis inhibition with indomethacin. In summary, bPTH-(1-34) has prominant effects on the circulation, and does not affect all vascular beds similarly. The exact mechanism of the vasodilating action of bPTH remains to be elucidated.

Parathyroid hormone (PTH) fragments relax the guinea-pig trachea in vitro

Synthetic bovine parathyroid hormone fragment containing the N-terminal 1-34 amino acids (bPTH-(1-34) ) relaxed the guinea-pig trachea constricted with histamine in vitro. Peptides with bovine and human sequences purchased from Peninsula Laboratories and Beckman Bioproducts produced similar effects. Substitution of methionine in positions 8 and 18 by norleucine did not affect this property of bPTH-(1-34). However, when the methionines were oxidized by treating the peptide with hydrogen peroxide, the peptide could no longer produce relaxation in the trachea. Oxidation of the methionine-replaced analog did not affect the action of the peptide on the trachea. It seems that the methionines per se are not necessary, but once oxidized the conformation of the molecule may be sufficiently altered to affect its ability to relax the trachea. While propranolol can block the relaxing action of isoproterenol, this blocking agent produces no inhibition of the bPTH-(1-34) effect. This action of PTH on the trachea may be related to cAMP because isobutyryl-methylxanthine, a phosphodiesterase inhibitor, potentiates and imidazole, a phosphodiesterase stimulator, inhibits the trachea relaxing action of bPTH-(1-34).