Effect of myasthenic IgG on degradation of junctional acetylcholine receptor

We investigated the effect of the lgG from patients with myasthenia gravis (MG) on the degradation of normal rat junctional acetylcholine receptor (AChR) labeled with ¹²⁵l-α-bungarotoxin (BuTx) and calculated the degradation rate (DR). The DR for the lgG from these patients was significantly higher than that from healthy volunteers and patients with other autoimmune diseases. For MG, DR was significantly correlated with the severity of the disease but not with anti-AChR antibody titer. DR was accelerated by lgG from patients with generalized MG whose antibody titers were in the normal range and by lgG from patients with ocular MG. These results indicate that measurement of the DR of junctional AChR in normal rats is more closely correlated with the severity of the disease than is measurement of anti-AChR antibody and that the former is a sensitive and confirmatory method for evaluating MG. © 1993 John Wiley & Sons, Inc.     

Prevention of hepatitis B virus recurrence after liver transplantation

Abstract:  Liver transplantation for hepatitis B virus (HBV)-related liver disease has changed from a contraindication to outcomes comparable with non-HBV-related liver transplantations during the last two decades. Mainly the implementation of immunoprophylaxis with hepatitis B immunoglobulin (HBIG) and the use of nucleoside analogs such as lamivudine and adefovir account for this dramatic change. The standard of care in most centers today consists of lamivudine treatment in replicating hepatitis B pre-orthotopic liver transplantation (OLT) and a combination regimen of lamivudine and HBIG post-OLT. With adefovir, a potent antiviral drug became available in recent years that allows for the treatment of patients with lamivudine-resistant tyrosine-methionine-aspartate-aspartate (YMDD)-mutant HBV. In the transplantation setting, first studies indicate that a triple prophylactic therapy consisting of lamivudine, adefovir, and HBIG will become the standard of care for YMDD-mutant-related hepatitis B. With new drugs emerging for the treatment of chronic HBV, there is optimism for new options also in the transplant setting.     

抗晶状体蛋白的特异性抗体免疫示踪研究

目的：了解针对晶状体组织的特异性抗体到达眼前节的途经、部位及其对晶状体生理功能的影响。方法：采用荧光标记抗体，观察被动免疫动物眼前节组织中荧光反应的变化，测定晶状体调节力和进行眼前节裂隙灯检查。结果：特异性抗体(IgG)首先到达睫状体部，而后出现在晶状体囊膜、虹膜和角膜内皮上；眼前节抗体含量峰值与裂隙灯观察的房闪、即同时出现；晶状体上皮细胞的损伤与晶状体的调节力下降则出现于转移免疫后2w。结论：针对晶状体组织抗原的特异性抗体可通过体循环先到达睫状体部，然后随房水而作用于晶状体上皮细胞。     

Accentuated antagonism by angiotensin II on guinea-pig cardiac L-type Ca-currents enhanced by β-adrenergic stimulation

 To examine mechanism(s) underlying the accentuated antagonism by angiotensin II (A-II) on twitch tension, we recorded L-type Ca²⁺ currents (I _Ca,L) using conventional patch-clamp techniques in single, guinea-pig, ventricular myocytes. I _Ca,L was recorded by a step-pulse protocol after eliminating K⁺ conductances (internal Cs⁺ plus tetraethylammonium chloride and K⁺-free extracellular solution). A-II (100 nM) did not affect basal I _Ca,L, but inhibited I _Ca,L that had been enhanced (approximately 200% of control) by (ISO, isoproterenol 100 nM). The inhibitory action of A-II was concentration dependent (concentration eliciting 50% inhibition 88±9 pM, n=41) and the ISO-enhanced component of I _Ca,L was completely blocked by A-II at concentrations above 10 nM. CV-11974 (500 nM), an A-II type-1 receptor (AT₁) antagonist, prevented the inhibitory action of A-II. Pre-incubation with pertussis toxin (PTX) abolished the inhibitory effect of A-II. A-II also inhibited the I _Ca,L enhanced by histamine (500 nM) and forskolin (1 μM), but failed to affect I _Ca,L enhanced by intracellular cyclic adenosine monophosphate (1 mM). The inhibitory action of A-II may therefore involve AT₁ receptors/PTX-sensitive, guanine nucleotide-binding (G) proteins (Gi)/adenylate cyclase and partially explains the A-II-dependent accentuated antagonism of inotropy.     

Attachment loss and serum antibody levels against autologous and reference strains of Actinobacillus actinomycetemcomitans in untreated localized juvenile periodontitis patients

Abstract Immunological data have been suggested to be a potential tool in the diagnosis, classification and monitoring of periodontal diseases. However, the role of circulating antibodies in periodontal patients is poorly understood. Patients suffering from localized juvenile periodontitis (LJP) are often reported to show high titers of serum IgG antibodies against Aetinobaeillus actinomycetemcomitans (A. actinomycetemcotnitans), but several affected patients do not. Most studies use well-known reference strains of the bacterium for testing against the patients' sera. The aim of the present investigation was to study the relationship between serum IgG antibody levels to autologous A. actinomycetemcomitans strains and clinical attachment loss (CAL). In addition, we wanted to assess the patients’serum titers against 4 well-known reference strains of the bacterium as well as their general potential immunoglobulin response. Intravenous blood samples were taken from 23 LJP patients and 10 healthy individuals, and autologous A. actinomycetemcomitans strains were cultured from 18 of the L.JP patients. CAL was measured at 4 different sites around ail present teeth and assessed as a % of teeth with at least 1 site moderately ≥2<5 mm) or severely (≥5 mm) involved. An enzyme-linked immunosorbent assay (ELISA) was performed to evaluate the serum titers of IgG antibodies to A. actinomycetemcomitans antigens. No significant correlation was found between serum IgG antibody titers to autologous strains and CAL. However, there was a trend that low responders had more moderately affected teeth than had high responders and patients with undetectable A. actinomycetemcomitans levels, which is in agreement with a hypothetically protective role of the antibodies. The total counts of immunoglobulin assessed in all participants showed that the predominant class was IgG and the reference group displayed significantly less (p<0.05) IgG and IgG1 counts than the LJP patients. Both the reaction pattern against reference and autologous strains varied widely. We conclude that the specific antibody response against A. actinomycetemcomitans shows a weak correlation to clinical attachment levels in LJP patients.     

Intravenous Immunoglobulin Treatment of Recurrent Miscarriage： an Update of Placebo-controlled Trials

Recurrentmiscarriage (RM) isdefined as three ormoreconsecutivemiscarriagesand affects 0 .5～ 1 .0 % of all women.In less than 1 0 % of the couples a parentalchromosome abnormality ora significantuterine abnormality can be demonstrated ascauses.Some cases …     

中国汉族人VKORC1 G3673A基因多态性研究

目的检测汉族人VKORC1 G3673A基因的分布情况。方法应用PCR技术对正常人外周血VKO-RC1 G3673A基因进行扩增,以Msp I进行限制性酶切图谱分析。结果219名（男112人,女107人）中国汉族人VKORC1 G3673A基因中,表现型A/A的频率是81.3%（男90人,女88人）,表现型G/A是18.7%（男22人,女19人）,表现型G/G是0。VKORC1 G3673A基因A的频率是90.6%,基因G的频率是9.4%。结论中国汉族人VKORC1 G3673A基因的分布有自己的特点,为研究VKORC1 G3673A基因在华法林个体化给药方案的制定提供了可靠的理论资料。     

The Effects of Serum from Patients with Acute Liver Failure on the Growth and Metabolism of Hep G2 Cells

In many bioartificial liver systems currently being designed and evaluated for use in fulminant hepatic failure, direct contact is required between the patient's blood and the liver cells in the device. The efficacy of such devices will be influenced by the interaction of fulminant hepatic failure (FHF) patient serum with the cells. We have found that FHF serum inhibits the growth rate and the synthesis of DNA, RNA, and protein; disturbs glutathione homeostasis; and induces morphological changes in cultured human Hep G2 cells. These interactions should influence the design of bioartificial liver devices based on proliferating cell lines and indicate the requirement to pretreat FHF patient plasma to reduce the toxin load.     

Inhibition of ligand binding to g protein-coupled receptors by arachidonic acid

Arachidonic acid (AA), released in response to muscarinic acetylcholine receptor (mAChR) stimulation, previously has been reported to function as a reversible feedback inhibitor of the mAChR. To determine if the effects of AA on binding to the mAChR are subtype specific and whether AA inhibits ligand binding to other G protein-coupled receptors (GPCRs), the effects of AA on ligand binding to the mAChR subtypes (M₁, M₂, M₃, M₄, and M₅) and to the μ-opioid receptor, β₂-adrenergic receptor (β₂-AR), 5-hydroxytryptamine receptor (5-HTR), and nicotinic receptors were examined. AA was found to inhibit ligand binding to all mAChR subtypes, to the β₂-AR, the 5-HTR, and to the μ-opioid receptor. However, AA does not inhibit ligand binding to the nicotinic receptor, even at high concentrations of AA. Thus, AA inhibits several types of GPCRs, with 50% inhibition occurring at 3–25 μM, whereas the nicotinic receptor, a non-GPCR, remains unaffected. Further research is needed to determine the mechanism by which AA inhibits GPCR function.     

广东地区肝炎患者血清中庚型肝炎病毒RNA的检测

目的了解庚型肝炎病毒（ＨＧＶ）感染在不同临床类型肝炎患者中的存在状况。方法用逆转录－聚合酶链反应（ＲＴ－ＰＣＲ）技术对７２１例肝炎患者血清进行了ＨＧＶＲＮＡ检测。结果发现８０例ＨＧＶＲＮＡ阳性，以非甲、乙、丙、丁或戊型肝炎中阳性率为高；慢性丙型肝炎（ＨＣＶ）和慢性乙型混合丙型肝炎（ＨＢＶ＋ＨＣＶ）次之；在慢性重型肝炎和肝硬化时较低。结论庚型肝炎病毒在广东地区现症肝炎患者中有一定程度的流行