[Comparison of clinical characteristics of patients with different types of laryngopharyngeal reflux disease].

Objective: To compare the clinical characteristics of patients with different type of laryngopharyngeal reflux disease in order to study the effect of non-acid reflux on laryngopharyngeal reflux disease. Methods: From January 2015 to January 2020, 349 inpatients or outpatients suspected of having laryngopharyngeal reflux underwent 24-hour multichannel intraluminal impedance pH monitoring (MII-pH). There were 303 male and 46 female patients, with an average age of 56.03 years old ranged from 25 to 81 years old. The reflux symptom index (RSI)and reflux findings score(RFS)were recorded before MII-pH monitoring. The number of acid reflux events and non-acid reflux events in hypopharynx were counted. It was defined mainly acid reflux type when the ratio of acid reflux to all reflux events was greater than 50%, mainly non-acid reflux type when the ratio of non-acid reflux to all reflux events was greater than 50%. The clinical characteristics of patients with different type of reflux were compared. SPSS 19.0 software was used for statistical analysis, and multiple independent samples were compared between groups. The quantitative data were analyzed by multivariate analysis of variance, and the counting data were analyzed by chi-square test, the difference was statistically significant when P<0.05. Results: The 24-hour MII-pH showed that there were 90 patients with no reflux events, 51 patients with mainly acid reflux type, 198 patients with mainly non-acid reflux type and 10 patients with equal acid reflux events and non-acid reflux events. Statistics showed that the RSI(10.72±4.40), RFS(7.70±2.73) and the average number of reflux events(0) in the group without reflux events were significantly lower than those in patients with mainly acid reflux type (RSI 13.16±6.62,RFS 10.08±3.03,average number of reflux events 5.33±3.15,P<0.05) and mainly non-acid reflux type(RSI 13.25±5.54,RFS 8.81±2.54,average number of reflux events 7.93±5.26, P<0.05). There was no significant difference in RSI between the mainly non-acid reflux type group and the mainly acid reflux type group, but the RFS of the mainly non-acid reflux type group was significantly lower than that of the mainly acid reflux type group. The average number of reflux events in the mainly non-acid reflux group was significantly higher than that in the mainly acid reflux type group (P<0.05). Conclusion: The results show that non-acid reflux plays a certain role in laryngopharyngeal reflux disease, but the effect of acid reflux is greater.

[Therapeutic effects of endoscopic posterior cordotomy for bilateral vocal cord paralysis].

Objective: To evaluate the efficacy of the endoscopic bilateral posterior transverse partial cordotomy in patients with upper airway obstruction due to bilateral vocal fold paralysis. Methods: A retrospective analysis of 48 cases of upper airway obstruction due to bilateral vocal fold paralysis, who were admitted to Department of Otolaryngology Head and Neck Surgery, the Sixth Medical Center of Chinese PLA General Hospital from July 2009 to July 2019, was performed, including 13 males and 35 females. Patients' ages ranged from 27 to 83 years old. All patients underwent bilateral vocal fold posterior resection. Results: Among the 48 patients, 1 patient was lost to follow-up, and the remaining 47 patients were followed up for 5 months to 10 years . None of the 47 patients had a recurrence or severe complications. 89.58% (43/48) patients reconstructed a reliable and effective airway and 88.89% (40/45) patients were decannulated in 1-3 months postoperatively, with the median decannulation time of 1 month. Recovery rate of swallowing function and satisfactory pronunciation were 97.92% (47/48) and 95.35% (41/43) respectively. Conclusions: Endoscopic bilateral posterior transverse partial cordotomy can establish a reliable and effective airway and maximize the protection of swallowing and voice functions. At the same time, it is a safe, reliable, simple and minimally invasive treatment option.

[The effect of regional neck dissection on positive cervical lymph node of cN0 laryngeal carcinoma].

Objective:To evaluate the efficacy and safety of regional neck dissection in the treatment of cN0 laryngeal carcinoma with positive cervical lymph node. Method:A retrospective analysis of 120 cases with cN0 laryngeal squamous cell carcinoma who received the first time for primary tumor resection and regional neck dissection (Ⅱ-Ⅳ) in our hospital during the period of 2000.01-2016.06 were performed. Twenty-two patients with lymph node positive (pN+) were selected by postoperative paraffin pathology in Ⅱ-Ⅳ region and followed up to 2017.06. The recurrence rate, survival rate and survival related regression analysis of patients with stage cN0 pN+ laryngeal carcinoma were analyzed. Result:The cN0 laryngeal cancer occult metastasis rate was 18.33% (22/120) in regional neck dissection. Local recurrence, regional recurrence, distant metastasis rates of 3 and 5 years were 41.18%, 17.65%, 17.65% and 40.00%, 13.33%, 20.00%, respectively in cN0 pN+ patients. The overall survival rates of 3 and 5 years were 61.2% and 30.6% respectively, and the disease-free survival rate was 31.8% and 22.7%. There was no significant difference in overall and disease-free survival between the T staging or clinical classification (P>0.05). Cox regression analysis showed that overall survival was related to age and local-regional (RR=11.421, P=0.001, RR=5.211, P=0.022). Logistic multivariate regression analysis showed that local-regional recurrence was not related to each factor (P>0.05). Conclusion:Local recurrence rate and mortality rate of cN0 pN+ laryngeal carcinoma are higher, survival rate is lower, however, neck recurrence rate is low.Therefore, Ⅱ-Ⅳ neck dissection is a safe and effective treatment for neck of cN0 pN+ laryngeal carcinoma.

Phylogenetic analysis of the Mongolian gerbil (Meriones unguiculatus) from China based on mitochondrial genome.

Meriones unguiculatus (Gerbillinae, Rodentia) is widely used as an animal model of human disease. Here, we provide the first report of the complete mitochondrial genome sequence of M. unguiculatus (GenBank accession Nos. KF425526 and NC_023263). The sequence contained the conserved vertebrate pattern of 13 protein-coding genes, 2 ribosomal RNAs, 22 transfer RNAs, and 1 major noncoding region. We identified one extended termination-associated sequence and one conserved sequence block in the non-coding region. The putative origin of replication for the light strand (OL) was 35 bp long. The OL stem and adjacent sequences were highly conserved, but the loop region differed from those of other rodent species. Base composition and codon usage of the 13 protein-coding genes in M. unguiculatus were compared with those of 23 rodent species with previously sequenced mitochondrial genomes. An A+T content of 63.0% was present in M. unguiculatus; this is similar to the Murinae average (62.4 ± 0.8%) and falls between the average for Mus musculus (63.1 ± 0.1%) and Rattus sp (61.7 ± 0.4%). The AT and GC skew values of M. unguiculatus were 0.035 and -0.28, respectively, similar to those of Cricetinae species (0.057 ± 0.05 and -0.31 ± 0.05). The codon families exhibited similar abundance in all 24 species. Analysis of phylogenetic relationships with 23 other rodent species using neighbor-joining and maximum likelihood protocols and the 12 protein-coding regions on the H strand showed that M. unguiculatus should be classified as genus Meriones, sub-family Gerbillinae, family Muridae.

[Risk factors of level â ¥ lymph node metastasis in cN0 papillary thyroid carcinoma].

Objective:To study the risk factors related to level Ⅵ lymph node metastasis in clinical N0 (cN0) papillary thyroid carcinoma (PTC). Method:A total of 107 cases with cN0 PTC treated in the same group were analyzed retrospectively. The frequency and risk factors for level Ⅵ lymph node metastasis in these patients were analyzed. Result:Level Ⅵ lymph node metastasis existed in 51.40% (55/107) cases. In univariate analysis, level Ⅵ lymph node metastasis was associated with age (χ²ï¼9.090,P<0.01), gender (χ²ï¼5.061,P<0.05), tumor maximum diameter (χ²ï¼8.772,P<0.01), tumor multifocality (χ²ï¼8.120,P<0.01), capsular invasion (χ²ï¼4.960,P<0.05), and surrounding tissue invasion (χ²ï¼3.858,P<0.05), but not with nodular goiter or Hashimoto's thyroiditis. Multivariate logistic analysis indicated that age,tumor maximum diameter, multifocal tumors and surrounding tissue invasion were independent risk factors for level Ⅵ lymph node metastasis. Conclusion:A high risk level Ⅵ lymph node metastasis exists in DTC with clinical N0. Prophylactic level Ⅵ neck dissection is strongly recommended in patients with PTC who are younger, tumor size more than 2 cm, multifocal tumor and surrounding tissue invasion.

Expression of EpCAM and Wnt/ ß-catenin in human colon cancer.

The aims of this study were to explore the correlation between the expression of EpCAM and the Wnt/ß-catenin pathway in human colon cancer and its clinical significance for the evaluation of cancer prognosis. Samples from colon cancer, para-carcinoma, or benign intestinal tissue from individual patients (50) and from normal intestinal mucosal tissues (20) were obtained from the Pathology Department of the Shandong Province Binzhou People's Hospital (Shandong, China). Immunohistochemistry was used to detect the expression levels of EpCAM and ß-catenin proteins in these tissues, and the prognoses of the patients from whom the samples were derived were determined on follow-up examination. The corresponding in vitro mechanistic siRNA experiments were subsequently performed in the human colon cancer cell line HCT116 to observe the regulatory effects of silencing EpCAM expression on the Wnt/ß-catenin pathway. From these analyses, we determined that the expression levels of EpCAM and ß-catenin were higher in cancer tissues compared with other tissues from the same patient, and that the expression of EpCAM and Wnt/ß- catenin in colon cancers were positively correlated. The prognostic analysis showed an inverse correlation between EpCAM and Wnt/ß- catenin expression and patient prognosis. A further examination of cellular mechanisms confirmed that the silencing of EpCAM led to decreased expression of Wnt/ß-catenin, and thus reduced proliferation and increased the apoptosis ratio in the cells. These results suggest that suppression of EpCAM might be a new approach for treating colon cancer.

Activation of NF-kappaB by the human herpesvirus 8 chemokine receptor ORF74: evidence for a paracrine model of Kaposi's sarcoma pathogenesis.

Infection with human herpesvirus 8 (HHV-8), also known as Kaposi's sarcoma (KS)-associated herpesvirus, is necessary for the development of KS. The HHV-8 lytic-phase gene ORF74 is related to G protein-coupled receptors, particularly interleukin-8 (IL-8) receptors. ORF74 activates the inositol phosphate/phospholipase C pathway and the downstream mitogen-activated protein kinases, JNK/SAPK and p38. We show here that ORF74 also activates NF-kappaB independent of ligand when expressed in KS-derived HHV-8-negative endothelial cells or primary vascular endothelial cells. NF-kappaB activation was enhanced by the chemokine GROalpha, but not by IL-8. Mutation of Val to Asp in the ORF74 second cytoplasmic loop did not affect ligand-independent signaling activity, but it greatly increased the response to GROalpha. ORF74 upregulated the expression of NF-kappaB-dependent inflammatory cytokines (RANTES, IL-6, IL-8, and granulocyte-macrophage colony-stimulating factor) and adhesion molecules (VCAM-1, ICAM-1, and E-selectin). Supernatants from transfected KS cells activated NF-kappaB signaling in untransfected cells and elicited the chemotaxis of monocytoid and T-lymphoid cells. Expression of ORF74 conferred on primary endothelial cells a morphology that was strikingly similar to that of spindle cells present in KS lesions. Taken together, these data, demonstrating that ORF74 activates NF-kappaB and induces the expression of proangiogenic and proinflammatory factors, suggest that expression of ORF74 in a minority of cells in KS lesions could influence uninfected cells or latently infected cells via autocrine and paracrine mechanisms, thereby contributing to KS pathogenesis.

Novel organizational features, captured cellular genes, and strain variability within the genome of KSHV/HHV8.

Strong serologic and molecular probe correlations indicate that the newly discovered gamma herpesvirus KSHV or HHV8 is the likely etiologic agent of all forms of Kaposi's sarcoma as well as BCBL/PEL and MCD in patients with acquired immunodeficiency syndrome (AIDS). Two large segments of HHV8 DNA from an AIDS-associated BCBL tumor covering genomic positions 0-52 kilobase [kb] and 108-140 kb have been cloned, mapped, and partially sequenced. Our studies have focused on novel viral proteins encoded within a 13-kb divergent locus (DL-B) by nine captured homologues of cellular genes, including vIL-6, vDHFR, vTS, vBcl-2, three C-C beta chemokines (vMIP-1A, vMIP-1B, and vBCK), and two LAP/PHD subclass zinc finger proteins (IE1A and IE1B). The HHV-8 vIL-6, vDHFR, vTS, and vBcl-2 proteins have all been shown to be active in a variety of appropriate functional assays, and transcripts from vIL-6, vMIP-1B, vIE1-A, vIE1-B, and vDHFR genes are all expressed as abundant single messenger RNA species after butyrate or phorbol ester (TPA) induction of the lytic cycle in HHV8-positive BCBL cell lines. All of these genes lie within a divergent transcriptional domain that contains a single central enhancer and associated untranslated leader region plus seven distinct proximal promoters, some of which are negatively regulated through AP-1 and ZRE motifs by the EBV ZTA transactivator. This region also encompasses a predicted complex oriLyt domain of 1050 bp that is duplicated in inverted orientation adjacent to the T0.7 latency RNA in another large divergent locus (DL-E). We have previously described three distinct subtypes of the HHV8 genome that differ by 1.0%-1.5% at the nucleotide level within the ORF26 and ORF75 genes. Certain strains or clades appear to have preferential geographic distributions, but it is not known as yet whether there are any specific disease associations. Interestingly, the A, B, and C subtypes of HHV-8 also proved to differ dramatically in coding content at both the extreme left and right ends of the unique segment of the genome as well as in the positions of the junctions with the terminal repeats. On the left-hand side, the receptor-like ORF-K1 protein is highly variable with A-strain subtypes displaying 15% amino acid differences from C strains and up to 30% differences from B strains. On the right-hand side, two unrelated alternative types of the putative multiple membrane spanning ORF-K15 protein are found.

Expression of human herpesvirus 8-encoded cyclin D in Kaposi's sarcoma spindle cells.

BACKGROUND: Human herpesvirus 8 (HHV-8) DNA sequences have been detected in Kaposi's sarcoma, in primary effusion lymphoma (an unusual high-grade non-Hodgkin's lymphoma seen primarily in patients with acquired immunodeficiency syndrome [AIDS]), and in Castleman's disease (a rare lymphoproliferative disorder); however, proof that HHV-8 is involved in the pathogenesis of these diseases remains to be established. HHV-8 contains a gene, i.e., v-cyclin D, that is a homologue of the cellular cyclin D2 gene, which encodes a protein that promotes passage through G1 phase of the cell cycle. Previous studies have identified v-cyclin D messenger RNA (mRNA) in biopsy specimens of Kaposi's sarcoma. In this study, we isolated a full-length v-cyclin D complementary DNA and characterized the pattern of v-cyclin D mRNA expression in Kaposi's sarcoma. METHODS: Standard methods were used to construct and to screen HHV-8 genomic and complementary DNA libraries. Reverse transcription-polymerase chain reaction (RT-PCR) methods and in situ hybridization with RNA probes were used to examine v-cyclin D mRNA expression. RESULTS: RT-PCR demonstrated the presence of v-cyclin D mRNA in biopsy specimens of AIDS-related Kaposi's sarcoma, in early-passage spindle cells from classical (i.e., not AIDS-related) Kaposi's sarcoma, and in spindle cells isolated from the peripheral blood of patients with AIDS-related Kaposi's sarcoma. In situ hybridization indicated that mRNAs for v-cyclin D and kaposin, an HHV-8 latency-associated gene, were present in approximately 1% of the spindle cells in early patch lesions and approximately 60% of the spindle cells in late nodular lesions of Kaposi's sarcoma. CONCLUSIONS: Spindle cells of Kaposi's sarcoma, which have been regarded as the tumor cells of this cancer, contain v-cyclin D mRNA. Expression of v-cyclin D protein may be involved in the pathogenesis of Kaposi's sarcoma by promoting cell proliferation.

A single 13-kilobase divergent locus in the Kaposi sarcoma-associated herpesvirus (human herpesvirus 8) genome contains nine open reading frames that are homologous to or related to cellular proteins.

Two small fragments of a novel human gammaherpesvirus genome known as Kaposi's sarcoma (KS)-associated herpesvirus or human herpesvirus 8 (HHV-8) have been shown to be present in virtually all AIDS and non-AIDS KS lesions, as well as in body cavity-based lymphomas (BCBL) and in multicentric Castleman's disease. We have extended those studies by identifying and sequencing a third fragment of HHV-8 DNA encoding a viral thymidylate synthetase (TS) gene. Use of this viral TS fragment as a probe led to the identification and mapping of a cluster of overlapping phage lambda clones from a BCBL tumor DNA genomic library that spanned 48 kb on the left-hand side of the HHV-8 genome between the equivalents of open reading frame 6 (ORF6) and ORF31 of herpesvirus saimiri (HVS). DNA sequencing of a 17-kb segment encompassing a gammaherpesvirus divergent locus (DL-B) between ORF11 and ORF17 revealed the presence of nine viral ORFs with predicted gene products related to cellular proteins. These include the complete TS gene and a dihydrofolate reductase (DHFR) gene, four novel cytokine genes (encoding viral interleukin-6, viral MIP-1A, viral MIP-1B, and BCK) that have not previously been found to be encoded by a virus, and a bcl-2 homolog. This region in HHV-8 also contains the T1.1 abundant lytic cycle nuclear RNA gene and encompasses two genes (or exons) encoding proteins with C4HC3 zinc finger domains of the PHD/leukemia-associated protein subtype. The latter are related to the spliced immediate-early IE1 protein of the gamma-2 class herpesvirus bovine herpesvirus type 4 and a similar motif found in HVS ORF12. Although genes for TS and DHFR enzymes are also encoded by HVS (ORF70 and ORF2), both occur at different genomic loci than in HHV-8, and the HHV-8 DHFR protein is much farther diverged from human DHFR than is the HVS version, implying that they were probably acquired as host cell cDNAs by independent evolutionary events. Transcripts from the IE1-A, IE1-B, DHFR, and MIP-1B genes were all detected by Northern blot hybridization analysis in a BCBL cell line at 12 h after induction with butyrate but were not present before induction, indicating that these are all primarily lytic cycle genes. We conclude that the DL-B locus of gammaherpesviruses displays considerably more variability that previously appreciated and that expression of many of these genes is likely to have important implications for HHV-8 biology and therapy.

Kaposi's sarcoma-associated human herpesvirus-8 encodes homologues of macrophage inflammatory protein-1 and interleukin-6.

Human herpesvirus-8 (HHV-8) has been detected in Kaposi's sarcoma (KS) lesions of all types (AIDS-related, classical and endemic), in body-cavity-based B-cell lymphomas (BCBLs) and in lesions of multicentric Castleman's disease (MCD). We have identified a major gamma-herpesvirus-divergent locus (DL-B) in HHV-8 DNA encoding several HHV-8 unique open reading frames (ORFs), including a homologue of interleukin-6 (IL-6) and two homologues of macrophage inflammatory protein MIP-1. We show that the HHV-8-encoded IL-6 homologue (vIL-6) shares functional properties with endogenous IL-6 proteins and that both vIL-6 and vMIP-1 transcripts are present at high levels following butyrate induction of an HHV-8' BCBL cell line. Low amounts of constitutive vIL-6, but not vMIP-1, mRNA were also detected. The presence of a functional IL-6 homologue encoded by HHV-8 may provide a mechanistic model for the hypothesized role of HHV-8 in KS, MCD and BCBL that involves the mitogenic effects of vIL-6 on surrounding cells. MIP-1 proteins may enhance these effects through the chemotactic recruitment of endogenous cytokine-producing cells into affected tissues and could potentially influence HIV disease progression in coinfected individuals through interactions with the HIV co-receptor CCR-5.

Characterization of a chemokine receptor-related gene in human herpesvirus 8 and its expression in Kaposi's sarcoma.

Human herpesvirus 8 (HHV-8) is a recently discovered, virus that is highly associated with Kaposi's sarcoma (KS) and AIDS-associated body cavity lymphomas, although it is also found in some normal individuals. HHV-8 is related by nucleotide sequence homology to herpesvirus saimiri (HVS), which causes T cell lymphomas in some New World monkeys, and to Epstein-Barr virus (EBV), a human herpesvirus linked etiologically with Burkitt's lymphoma and nasopharyngeal carcinoma. We report that, like HVS but unlike EBV, HHV-8 contains a gene (ORF74) with significant sequence homology to the high-affinity IL-8 receptor, a member of the alpha (CXC) chemokine receptor family of transmembrane G protein-coupled receptors. We also show by reverse transcription PCR that the chemokine receptor-related HHV-8 gene is detectable in some RNA samples from KS tissue, and that its expression varies independently from that of ORF26, a minor capsid protein. The presence of a potential chemokine receptor in HHV-8 and its expression in KS tissue suggests that it may be important in the regulation of viral gene expression and may play a role in the etiology of KS and AIDS-related body cavity lymphomas.

A Bcl-2 homolog encoded by Kaposi sarcoma-associated virus, human herpesvirus 8, inhibits apoptosis but does not heterodimerize with Bax or Bak.

The Bcl-2 protein family is characterized by the ability to modulate cell death, and members of this family share two highly conserved domains called Bcl-2 homology 1 (BH1) and 2 (BH2) which have been shown to be critical for the death-repressor activity of Bcl-2 and Bcl-xL. Through sequence analysis we identified a novel viral Bcl-2 homolog, designated KSbcl-2, from human herpesvirus 8 (HHV8) or Kaposi sarcoma-associated herpesvirus. The overall amino acid sequence identity between KSbcl-2 and other Bcl-2 homologs is low (15-20%) but concentrated within the BH1 and BH2 regions. Overexpression of KSbcl-2 blocked apoptosis as efficiently as Bcl-2, Bcl-xL, or another viral Bcl-2 homolog encoded by Epstein-Barr virus, BHRF1. Interestingly, KS-bcl-2 neither homodimerizes nor heterodimerizes with other Bcl-2 family members, suggesting that KSbcl-2 may have evolved to escape any negative regulatory effects of the cellular Bax and Bak proteins. Furthermore, the herpesvirus Bcl-2 homologs including KSbcl-2, BHRF1, and ORF16 of herpesvirus saimiri contain poorly conserved Bcl-2 homology 3 (BH3) domains compared with other mammalian Bcl-2 homologs, implying that BH3 may not be essential for anti-apoptotic function. This is consistent with our observation that amino acid substitutions within the BH3 domain of Bcl-xL had no effect on its death-suppressor activity.

Phylogenetic associations of human and simian T-cell leukemia/lymphotropic virus type I strains: evidence for interspecies transmission.

Homologous env sequences from 17 human T-leukemia/lymphotropic virus type I (HTLV-I) strains from throughout the world and from 25 simian T-leukemia/lymphotropic virus type I (STLV-I) strains from 12 simian species in Asia and Africa were analyzed in a phylogenetic context as an approach to resolving the natural history of these related retroviruses. STLV-I exhibited greater overall sequence variation between strains (1 to 18% compared with 0 to 9% for HTLV-I), supporting the simian origin of the modern viruses in all species. Three HTLV-I phylogenetic clusters or clades (cosmopolitan, Zaire, and Melanesia) were resolved with phenetic, parsimony, and likelihood analytical procedures. Seven phylogenetic clusters of STLV-I were resolved with the most primitive (deeply rooted) divergence involving several STLV-I strains from Asian primate species. Combined analysis of HTLV-I and STLV-I revealed that neither STLV-I clusters nor HTLV-I clusters recapitulated host species specificity; rather, multiple clades from the same species were closer to clades from other species than to each other. We interpret these evolutionary associations as support for the occurrence of multiple discrete interspecies transmissions of ancestral viruses between primate species (including human) that led to recognizable phylogenetic clades that persist in modern species. Geographic concordance of divergent host species that harbor closely related viruses reinforces that physical feasibility for hypothesized interspecies virus transmission in the past and in the present.

Analysis of a new subtype of HIV-1 gag sequence from a case of vertical transmission in Taiwan.

A Taiwanese woman who lived with a presumably bisexual man of German nationality, and her infant daughter were found to be seropositive for HIV-1. From DNA preparations of peripheral blood mononuclear cells of the mother-infant pair, we amplified a segment, about 560 base pairs (bp), of gag portion of HIV-1 provirus by using polymerase chain reaction (PCR). The high degree of homology (94.7-97.5%) among clones (TM-1 and TM-2 from the mother, and TC-1 and TC-2 from the infant) of gag sequence provided a molecular epidemiological evidence for vertical transmission. However, these sequences exhibited lower degrees of homology (85.1-87.0%) with the corresponding gag segment of a North American HIV-1 subtype (HXB2), and that of a Zairean HIV-1 subtype (Z2Z6). The disparity of sequences between these Taiwanese clones and those of HXB2 and Z2Z6 was particularly prominent in the first (5' proximal) 200 bp, as shown by the low degree of homology (74.8-79.6%) when sequences of TM and TC clones which represented the first 200 bp were compared with those of HXB2 and Z2Z6. The sequence dissimilarity of these clones as compared with HXB2 manifested as transitions more frequently than transversions. Transitions involving G/A to A/G changes were more frequent than those involving T/C to C/T. Transversions involving G/A to T/C changes were slightly more frequent than those involving T/C to G/A changes for all clones except for TM-2 which showed an equal frequency. Presence of stop codons in each of the reading frames of these clones suggests that these may represent defective viral quasispecies. The deduced amino acid sequences from available open reading frames of these clones showed also distinct dissimilarities to HXB2 or Z2Z6. These findings indicate the presence of a gag subtype of HIV-1 which, according to the phylogenetic tree analysis, would represent a new subtype distinct from other known subtypes.

[Stapedial reflex test for gerontal sensorineural hearing loss].

The purpose of this investigation was to find a method that can diagnose sensorineural hearing loss early. Fifty subjects, aged more than 60 years, with hearing level ranged from normal to profound deafness, were examined. The noise-tone difference (NTD) were calculated at 0.5, 1, 2, and 4kHz from these data. The results indicated that NTD at 1kHz was more sensitive than others for diagnosing gerontal sensorineural hearing loss in early stage.