Differential involvement of GABA system in mediating behavioral and neurochemical effect of acupuncture in ethanol-withdrawn rats

In our previous study we demonstrated that acupuncture at Shenmen (HT7) points suppressed a decrease of accumbal dopamine (DA) release in ethanol-withdrawn rats. Furthermore, here we found that it inhibited behavioral withdrawal signs of ethanol. In an effort to better understand the mechanisms underlying this inhibition, the potential role of GABA receptor system in acupuncture was investigated. Male Sprague–Dawley rats were treated with 3 g/kg/day of ethanol (20%, w/v) or saline by intraperitoneal injection for 21 days. Following 48 or 72 h of ethanol withdrawal, acupuncture was applied at bilateral HT7 for 1 min. The selective GABA_A antagonist bicuculline and the selective GABA_B antagonist SCH 50911 were injected intraperitoneally 20 min before acupuncture, respectively. Importantly, suppressive effects of acupuncture on DA deficiency were completely abolished by SCH 50911, but not by bicuculline, whereas ameliorating effects of acupuncture on ethanol withdrawal syndrome were completely blocked either by SCH 50911 or bicuculline. These results suggest that acupuncture at specific acupoint HT7 may normalize the DA release in the mesolimbic system and attenuate withdrawal syndrome through the GABA_B receptor system in ethanol-withdrawn rats.     

Debate on annual influenza vaccination in healthcare workers for the same subtype under the vaccine shortage.

BACKGROUND: Influenza vaccination is the primary method for preventing influenza and its severe complications. Healthcare workers (HCWs) are one of the priority groups for the influenza vaccination. OBJECTIVES: To determine whether healthy HCWs, who were vaccinated with the same subtype for the two previous years, could be given less priority for influenza immunization under the vaccine shortage. STUDY DESIGN: We measured hemagglutination-inhibition antibody titers from sequential serum samples in 50 pre-immune subjects and 50 age-matched vaccine-naive subjects: immediately prior to the administration of the vaccine, 4-6 weeks, and 6 months after the vaccination. RESULTS: Prevaccination titers were maintained above protective level and high protection rates were observed for all three strains in pre-immune subjects: A/H1N1, A/H3N2, and B strains. As for the sequential changes, the protection rates for all three strains still remained above 70% until 6 months following the vaccination. CONCLUSION: Skipping influenza vaccination for a year could be considered in healthy pre-immune HCWs under the epidemic of the same subtype as two previous years.     

Evaluation of phagocytic function in Mycobacterium lepraemurium infection

Infection of mice with Mycobacterium lepraemurium caused significant functional alterations of the mononuclear phagocyte system. Accelerated clearance of sheep red blood cells was consistently demonstrated throughout the infection and the infected mice showed progressive anaemia. Infected mice showed an enhanced ability to limit growth of phagocytosed Listeria monocytogenes in spleens during the early stages of infection, whereas moribund leprous mice lost this ability. Autoradiography showed that uninfected Kupffer cells and splenic macrophages of moribund mice could still phagocytose Listeria, suggesting that MLM infection did not affect the capacity of Listeria to localize to macrophages but interfered in some way with subsequent killing of such bacteria. The possible mechanisms underlying these observations are discussed.     

Comparative study on deletions of the dystrophin gene in three Asian populations

The frequency and distribution of deletions of 19 deletion-prone exons clustered in two hot spots in the proximal and central regions of the dystrophin gene were compared in three populations from Singaporean, Japan, and Vietnam. DNA samples obtained from 105 Singaporean, 86 Japanese, and 34 Vietnamese Duchenne muscular dystrophy patients were examined by polymerase chain reaction amplification. Deletions of the examined exons were found in 51.2% of Japanese patients but in 40.0% or less of the Singaporeans and Vietnamese. About two thirds of the deletions were localized in the central region and the remaining deletions were clustered at the proximal region. The most commonly deleted exons at the central deletion hot spot were exon 50 in the Singaporean, exons 49 and 50 in the Japanese, and exon 51 in the Vietnamese population. At the proximal deletion hot spot, the most commonly deleted exons were exons 6 and 8 in the Singaporeans, exons 12 and 17 in the Japanese, and exons 8 and 12 in the Vietnamese. Two cases each from Singapore and Japan had large-scale gross mutations spanning both deletion hot spots. Our results suggest that, although the presence and frequency of the two deletion hot spots may be similar in the three Asian populations analyzed, the distribution and frequency of deletions among the different exons can vary as a result of population-specific intronic sequences that predispose individuals to preferential deletion breakpoints. Received: May 20, 2002 / Accepted: July 1, 2002     

X-linked severe combined immunodeficiency syndrome: the first Korean case with gamma c chain gene mutation and subsequent genetic counseling

X-linked severe combined immunodeficiency (X-SCID) is a rare, life-threatening immune disorder, caused by mutations in the gamma c chain gene, which encodes an essential component of the cytokine receptors for interleukin-2 (IL-2), IL-4, IL-7, IL-9, IL-15, and IL-21. A 13-month-old boy with recurrent infections who had reduced serum immunoglobulin levels and decreased numbers of CD3, CD16/56 cells was evaluated for gamma c chain gene mutation and protein expression. The patient had a C-to-T point mutation at nucleotide position 690, one of the hot spots, resulting in a single amino acid substitution of cysteine for arginine (R226C), as determined by direct sequencing and PCR-RFLP. The patient's mother was a heterozygous carrier. Percutaneous umbilical cord blood sampling was performed at the 6-month of gestation in a subsequent pregnancy. As the immunophenotype of the fetus showed an identical pattern, the pregnancy was terminated and genetic analysis of the abortus confirmed recurrence. This is the first report of the molecular diagnosis of X-SCID in Korea. Genetic analysis of the gamma c chain gene is useful for definite diagnosis and genetic counseling for X-SCID.     

IL-15 and IL-15Rα gene deletion: Effects on T lymphocyte trafficking and the microglial and neuronal responses to facial nerve axotomy

IL-15 is a potent T cell chemoattractant, and this cytokine and its unique α subunits, IL-15Rα, can modify immune cell expression of several T cell chemokines and their receptors. Facial nerve axotomy in mice leads to T cell migration across an intact blood–brain-barrier (BBB), and under certain conditions T cells can provide neuroprotection to injured neurons in the facial motor nucleus (FMN). Although chemokines and chemoattractant cytokines are thought to be responsible for T cell migration to the injured cell bodies, data addressing this question are lacking. This study tested the hypothesis that T cell homing to the axotomized FMN would be impaired in knockout (KO) mice with the IL-15 and IL-15Rα genes deleted, and sought to determine if microglial responsiveness and motoneuron death are affected. Both IL-15KO and IL-15RαKO mice exhibited a marked reduction in CD3⁺ T cells and had fewer MHC2⁺ activated microglia in the injured FMN than their respective WT controls at day 14 post-axotomy. Although there was a relative absence of T cell recruitment into the axotomized FMN in both knockout strains, IL-15RαKO mice had five times more motoneuron death (characterized by perineuronal microglial clusters engulfing dead motoneurons) than their WT controls, whereas dead neurons in IL-15KO did not differ from their WT controls. Further studies are needed to dissect the mechanisms that underlie these observations (e.g., central vs. peripheral immune contributions).     

Multifunctional initiation of lactide polymerization by stannous octoate/pentaerythritol

L -Lactide was polymerized with stannous 2-ethylhexanoate (stannous octoate) in the presence of pentaerythritol to investigate multifunctional initiation. The prepared oligomers contain starshaped 4-arm molecules when the mole ratio of [lactide]/[pentaerythritol] is above 32. The molecular weight of oligomers coincides with the [lactide]/[pentaerythritol] ratio, indicating that pentaerythritol in conjugation with stannous octoate is an initiator for the “living” polymerization of L-lactide.