The role of the posterior cricoarytenoid muscle in phonation: an electromyographic investigation in dogs

The activity of the posterior cricoarytenoid muscle during respiration has been well investigated electromyographically. Its activity during phonation, however, has not been studied systematically. We, therefore, focused our attention on the phonatory activity of the posterior cricoarytenoid muscle to confirm whether it also contracts during phonation, as has been reported by some researchers. In our series of 12 adult dogs, the posterior cricoarytenoid was active in 11 dogs and inactive in one dog during phonation. Our present study also showed that the posterior cricoarytenoid activity was stronger for phonation than for inspiration in 6, stronger for inspiration than for phonation in 3, and the same for phonation and inspiration in 2 dogs. The results obtained from the present electromyographic evaluation demonstrated that the posterior cricoarytenoid is activated during phonation. The authors believe that the posterior cricoarytenoid muscle has phonatory function and that the phonatory effect of this muscle on the vocal cord may play an important role in precise glottis control.     

聋儿自信心的培养

由于家庭教育方式不当，使许多聋儿胆小．懦弱，缺乏自信心。本文通过调查研究，分析了聋儿缺乏自信心的原因，并在实践的基础上归纳出提高聋儿自信心的几项措施。     

脐带夹对防止脐部感染和出血的临床与实验研究

目的应用国产脐带夹用于农村山区破伤风高发区，并经离体试验验证其可靠性。方法经湖南、江西、广西等省基层接生员临床应用、并与当地同期或前一年未用夹者进行对照；同时经离体脐带用脐带夹、气门芯或纱线结扎阻断血管后进行金黄色葡萄球菌和破伤风毒素通透试验以及测试承受气压程度试验。结果1年临床使用2296例中，无1例发生破伤风和败血症。可靠性试验结果证明，粗纱线结扎最差，气门芯虽优于前者，但不如脐带夹。结论该脐带夹由于夹持力持久有力，细菌、毒素难以通过、安全可靠，因此能降低新生儿“病从脐入”的发病率和死亡率，有利干优生优育的贯彻．这是一项花费少、收效大的简而易行的适宜技术，值得推广。     

Pineal response after pyridoxine test in children

Summary To characterize the pineal response to pyridoxine, plasma melatonin was measured in one hundred and twenty children 3 hours after vitamin B₆ administration. The children, aged between 1.5 and 8 years, were divided in four groups as follows: a) control day group, grouping 27 children sampled at 9:00 and at 12:00; b) control night group, grouping 29 children sampled at 21:00 and at 24:00; c) pyridoxine day group, grouping 30 children sampled at 9:00, then intravenously (i.v.) injected with 3mg/kg of pyridoxine, and sampled at 12:00; and d) pyridoxine night group, grouping 34 children sampled at 21:00, i.v. injected with 3mg/kg of pyridoxine, and sampled at 24:00. Melatonin concentration was measured by radioimmuno assay. The data obtained showed a significant increase in melatonin levels after pyridoxine administration in the pyridoxine night group (39.87 ± 8.02pg/ml basal vs 88.45 ± 9.21 pg/ml after pyridoxine, p < 0.001). The other groups did not showed significant differences in melatonin concentrations. Statistical analysis shows that the administration of pyridoxine during the nocturnal hours represents a stimulating factor to increase the pineal production of melatonin in children.     

Stomatitis from dentures: etiopathological and therapeutic considerations

Infection of the oral mucous membrane is frequent in patients with removable prostheses, either totally of partially, and particularly when the prostheses is palatal. The principal etiological factor causing the infection is accepted to be "Candidas" aided by the presence of plaque bacteria (in patients with poor oral hygiene care), and a poor fit of the prostheses to the soft tissues. Treatment of the infection must proceed in the following order: a) use of effective medication against oral fungus such as Nystatin or Ketoconazole. b) Meticulous oral hygiene care in the mucous membrane as well as in the prostheses, but using the prostheses as little as possible during the treatment period. c) A total cure of the infection (denture stomatitis) before proceeding to the next phase of the treatment. d) Determination of the adjustment and occlusion of the prostheses in order to determine those areas of the prostheses which need to be refilled because of maladjustment of the prostheses to the soft tissues of the patient.     

Classification of Breast Masses Using Selected Shape,Edge-sharpness,and Texture Features with Linear and Kernel-based Classifiers

Breast masses due to benign disease and malignant tumors related to breast cancer differ in terms of shape, edge-sharpness, and texture characteristics. In this study, we evaluate a set of 22 features including 5 shape factors, 3 edge-sharpness measures, and 14 texture features computed from 111 regions in mammograms, with 46 regions related to malignant tumors and 65 to benign masses. Feature selection is performed by a genetic algorithm based on several criteria, such as alignment of the kernel with the target function, class separability, and normalized distance. Fisher's linear discriminant analysis, the support vector machine (SVM), and our strict two-surface proximal (S2SP) classifier, as well as their corresponding kernel-based nonlinear versions, are used in the classification task with the selected features. The nonlinear classification performance of kernel Fisher's discriminant analysis, SVM, and S2SP, with the Gaussian kernel, reached 0.95 in terms of the area under the receiver operating characteristics curve. The results indicate that improvement in classification accuracy may be gained by using selected combinations of shape, edge-sharpness, and texture features.     

Transmission of HIV-1 infection between trophoblast placental cells and T-cells take place via an LFA-1-mediated cell to cell contact

HIV-1 vertical transmission is thought to mainly take place by virus crossing the placental barrier. However, the mechanism by which HIV-1-infects placental cells remains to be elucidated. We have found that purified cytotrophoblasts as well as trophoblastic cell lines are susceptible to infection by different HIV-1 isolates as detected by DNA-PCR and release of infectious virus, although with very low efficiency. Purified trophoblast or trophoblastic cell lines express low levels of chemokine receptors CCR-5 and CXCR-4 but not CD4 on the cell surface. To test if those molecules were used as receptors for HIV-1 infection, placental cells were pretreated with antibodies to CD4, CC-chemokines, C-X-C chemokines. None of those treatments inhibited HIV-1 infection. In contrast, we have found that HIV-1 infection of placental cells was increased in cocultures of infected T-cell blasts and placental cells. More interestingly, antibodies to beta(2) integrins and to LFA-1 were able to significantly block infection of placental cells. Cell surface expression of ICAM-1, an adhesion molecule involved in attachment of leukocytes to placenta, was upregulated in HIV-1-infected placental cells. Placental cells were able to transfer HIV-1 infection to T-cell blasts. This transmission required cell to cell contact and was also inhibited by anti-LFA-1 antibodies. In summary our results suggest that placental trophoblast could be infected by HIV-1 by a mechanism involving T cell to placental contact. Moreover, placental infection enhanced ICAM-1 expression and leukocyte adherence, an event which was required to transfer HIV-1 infection to T cells. This provides an explanation of the virus passing through the placental barrier during in utero HIV-1 vertical transmission.     

Virilizing mature ovarian cystic teratomas

 Three further cases of mature benign cystic teratomas of the ovary associated with virilization are added to the three previously reported in the literature. They were found in postmenopausal, obese, diabetic women aged 52, 61, and 67 years. The patients presented with hirsutism and voice changes and clitoromegaly was present in one. Testosterone and androstenedione levels were elevated but promptly regressed after removal of the tumours. Histologically, sheets of stromal luteinized cells were found peripherally at the interface between the neoplasm and ovarian tissue. Luteinization of ovarian stroma induced by an unknown factor related to diabetes mellitus is the origin of the virilization. Received: 8 January 1997 / Accepted: 28 February 1997