Use of a mouth gag instrument to facilitate bite block insertion and prevent finger and probe bites during transesophageal echocardiography

Transesophageal echocardiography greatly enhances the examination of patients difficult to image transthoracically. While of low patient risk, a potential for harm from human bites to the echocardiography staff and to the transesophageal probe remains, particularly when dealing with uncooperative patients. This risk potential prompted implementation of additional anti-bite protection in our universal precautions policy beyond use of a standard mouth guard. A mouth gag instrument was modified by placing latex rubber tubing over the instrument blades. This instrument was inserted into the mouth and set in an open position giving the operator safe access for probe and mouth bite guard insertion. This technique improved access to the patient's mouth and visualization of probe insertion without the mouth bite guard. The mouth gag instrument provided an insertion of the transesophageal probe in impaired or otherwise uncooperative patients, which was safer for the patient, laboratory staff, and the probe itself.     

A longitudinal study of the IgG antibody response to HIV-1 p17 gag protein in HIV-1+ patients with haemophilia: titre and avidity.

The IgG response to HIV-1 p17 gag protein was studied for up to 6 years in 12 HIV-1-infected patients with haemophilia, who had seroconverted between 1982 and 1985. To assess any prognostic value, p17 IgG titres were compared with p24 IgG titres, CD4 cell counts and p24 antigenaemia. p17 IgG avidity index was also examined. A strong similarity was found between the IgG titre to HIV-1 p17 and that to p24. In patients who developed AIDS the decline in p17 IgG titres could precede by several years the drop in CD4 cells to under 200 cells/microliters; whereas some long-term asymptomatic patients (CDCII) had increasing p17 IgG titres and stable CD4 cell counts. Declining p17 and p24 IgG titres were not always associated with an increase in p24 antigenaemia. IgG titres were found to be better predictors of disease progression than CD4 cell counts or p24 antigenaemia. Patients who developed AIDS during the study were also characterized by a lower p17 IgG avidity than patients who remained asymptomatic. This result suggests that IgG avidity could have prognostic relevance and be of importance for host resistance to AIDS onset.     

The affinity of IgG antibodies to gag p24 and p17 in HIV-1-infected patients correlates with disease progression.

The affinity of anti-gag antibody was studied for up to 9 years (1984-1993) in sera from 15 HIV-1+ patients with haemophilia. On the basis of their 1993 clinical status patients were divided into two groups: (i) patients who remained asymptomatic (n = 9); and (ii) those who progressed to AIDS between late 1987 and 1993. The affinity constants of antibody for p24 and p17 were determined by a double isotope fluid-phase radioimmunoassay; and the relationships between antibody affinity and titre, patient clinical course, CD4 cell counts and p24 antigenaemia were analysed. The affinity of p24- and p17-specific antibody was up to 100 times greater in asymptomatic patients than in patients who progressed to AIDS. Patients who developed AIDS either lost or failed to develop high-affinity antibodies early in the infection. Asymptomatic patients maintained high-affinity antibodies for several years; however, in some of these patients the affinity of anti-p24 and p17 antibodies subsequently fell later in the study period. The presence of low-affinity antibody and progressive reduction in the titre of specific antibody were earlier predictors of disease onset than CD4 cell counts. The failure to either develop or maintain high affinity gag-specific antibody suggests an early impairment of T helper function in individuals who progressed to AIDS. The presence of antibody of high affinity could be essential in controlling virus replication and the onset of AIDS.     

HIV-1 matrix protein p17 enhances the proliferative activity of natural killer cells and increases their ability to secrete proinflammatory cytokines

We investigated the effects of human immunodeficiency type-1 virus (HIV-1) matrix protein p17 on freshly isolated and purified human natural killer (NK) cells. HIV-1 p17 increased the cytokines interleukin (IL) 2, IL-12 and IL-15, and induced natural killer cell proliferation, but not cytotoxicity. This effect was specific because it was abrogated by anti-p17 monoclonal antibody. Moreover, HIV-1 p17 enhanced the cytokine-induced production of tumour necrosis factor (TNF)-alpha and interferon (IFN)-gamma by NK cells. IL-4 downregulated IFN-gamma and TNF-alpha secretion in IL-2- and IL-15-treated NK cells. HIV-1 p17 restored the ability of NK cells to produce both cytokines when added to the cultures simultaneously with IL-4. The property of p17 to increase the production of TNF-alpha and IFN-gamma might be a mechanism used by HIV-1 to modulate the immune system to support its replication and spreading.     

桂林市经性传播的HIV-1的流行特征和亚型分析

目的：了解桂林市2008年及以后确诊的经性传播的人类免疫缺陷病毒1型( HIV-1)感染者的流行病学及亚型的分布情况。方法选取样本100例,收集流行病学资料,采集抗凝全血,提取病毒RNA,RT-PCR法行gag基因扩增,对产物进行测序和分析。结果100例样本中男女比例为2．125∶1;青壮年年龄组(20~49岁)患者为54%,>50岁年龄组患者为45%;职业为农民的患者为40%,学生为6%;初中及以下文化水平患者占69%;经异性和同性性接触途径传播的分别为93%、7%。100例样本最终成功扩增得到61例样本的 gag 基因序列, CRF01-AE 重组亚型48例, CRF07-BC重组亚型8例,B亚型5例。结论应更加重视婚检、孕检的艾滋病抗体筛查;关注老年人群经性接触途径感染艾滋病的现象;采取针对低素质人群的有效防治措施;随着主要传播途径和主要亚型的变化,迫切需要对高危人群进行宣传教育和行为干预以阻断HIV/AIDS的流行和传播。     

Synthesis and immunological characterization of a 134-mer synthetic peptide corresponding to the N-terminal half of the HIV-1 nucleoprotein,p24

A 134-mer peptide corresponding to the N-terminal sequence of p24 (residues 146–279 of the gag gene product of the LAV strain) was chemically synthesized using highly optimised protocols on an ABI 430A synthesizer. The crude peptide was obtained by treating the peptide-resin with HF, then purified by a combination of size exclusion and RP-HPLC. One hundred milligram of 90% pure 134-mer can be obtained within a month. Both mice and rabbit polyclonal antisera raised against a commercial preparation of recombinant p24, and a pooled sera from HIV-1 infected individuals reacted strongly with the 134-mer peptide in ELISA. Both mice and rabbits immunized with the free peptide emulsified in Freund's complete adjuvant generated strong anti-peptide and anti-p24 antibody responses as judged by immunoblots and ELISAs. Immunodominant epitopes were mapped to residues 201–227 (LKETINEEAAEWDRVHPVHAGPIAPG). These B-cell epitopes had previously been identified by mouse monoclonal antibodies raised against HIV-1 virus or gag gene products. Furthermore, murine T-cell lines generated against the 134-mer peptide were found to respond to two short peptides, P24B (residues 195–215) and P24D1 (residues 268–279). These two T-cell epitopes were previously reported as human helper T-cell and CTL epitopes, respectively. These results clearly indicate that the synthetic 134-mer peptide could elicit both T- and B-cell responses to HIV-1 similar to those obtained with the natural viral gag protein, and could be useful for the development of a synthetic HIV vaccine     

2种气道开放方法在院前昏迷患者急救中的通气效果观察

目的观察采用咽通气管和开口器并舌钳气道开放方法在院前深昏迷患者急救中的通气效果。方法将128例格拉斯哥昏迷评分(GCS)3～8分的深昏迷伴呼吸道梗阻患者随机分为观察组和对照组各64例。观察组安置口咽通气管开放气道,对照组则使用开口器并舌钳开放气道。比较2组通气效果、气道有效开放时间及血氧饱和度(SpO2)改善值。结果观察组气道开放后有效通气率为95.31%高于对照组的67.19%,差异有统计学意义(P<0.01)。观察组开放气道所需时间为(3.61±1.05)s短于对照组的(18.13±1.15)s,差异有统计学意义(P<0.01)。观察组SpO2改善程度明显优于对照组,差异有统计学意义(P<0.01)。结论院前昏迷患者急救时使用口咽通气管开放气道的通气效果优于使用开口器并舌钳开放气道,值得在院前急救中推广应用。     

Modification of Heister Jaw Opener

Heister introduced a mouth gag of incentric pattern which is still being used. Heister jaw opener has narrow blades which rest on the occlusal surface of molar teeth. The force of mouth gag is not equally distributed on all the teeth, therefore there is great risk of tooth avulsion in periodontally compromised dentition and fracture of tooth while using standard Heister appliance. To overcome this modification of Heister mouth gag is done.     

The gag reflex and aspiration: a retrospective analysis of 120 patients assessed by videofluoroscopy

An absent gag reflex is often employed clinically as an indicator of aspiration risk. Dysphagia clinic records of 120 neurological patients who had undergone speech therapy and ENT assessment, followed by videofluoroscopy, were retrospectively analysed to ascertain if any link between an absent gag reflex and aspiration could be demonstrated. No association between an absent gag reflex and aspiration or laryngeal overspill was found (Mann-Whitney U-test: 2-tailed P= 0.11). Abnormalities on indirect laryngoscopy were seen in 34/120 patients (28%), and these were more closely related to aspiration risk (Mann-Whitney U-test: 2-tailed P= 0.06). An absent gag reflex is not a useful predictor of aspiration, and assessment of the gag reflex should not be relied upon to predict airway safety. However, indirect laryngoscopy is a useful adjunct to standard speech therapy assessment of the dysphagic patient.