The proximity of the lesion to cell bodies determines the free radical risk induced in rat rubrospinal neurons subjected to axonal injury

To find out whether close axonal injury resulted in greater free radical risk to cord-projection central neurons than distant ones, we studied the expressions of nitric oxide synthase, calcineurin, and superoxide dismutase in rat rubrospinal neurons following brainstem, C2 and T10 axotomies using immunohistochemical methods. We found that nitric oxide synthase expression was upregulated more following brainstem than C2 lesion while T10 lesion triggered no detectable changes. This response peaked at 1 week and returned to control level by 8-week-post-injury. At the same time, calcineurin, which activated nitric oxide synthase, was increased 1 week following brainstem and C2 axotomies. These suggest that close, but not distant, axotomy enhanced NO production, which appeared to be cytotoxic since blocking NO synthesis with N-nitro-l-arginine methyl ester reduced brainstem axotomy-induced rubrospinal cell loss. On the other hand, the mitochondrial Mn-superoxide dismutase, which competes with NO to prevent the formation of the cytotoxic free radical peroxynitrite, was notably reduced after brainstem but almost unaltered following C2 axotomy. Meanwhile, the cytosolic Cu/Zn-superoxide dismutase was not altered following C2 but increased after brainstem axotomy. Ultrastructurally, in rubrospinal neurons more mitochondria became swollen following brainstem than C2 axotomy. Based on these, we proposed that besides the NO-overproduction-induced toxicity, superoxide-loading-induced mitochondrial damage also added to hampering the survival of the closely axotomized neurons.     

The role of glottal gap in predicting aspiration in patients with unilateral vocal paralysis

Aspiration has been frequently noted among patients suffering from vocal-fold paralysis. The association between a defect of glottal closure and aspiration in patients with unilateral vocal paralysis appears to have been rarely reported. The current study reviews collected data consisting of videotaped flexible nasoendoscopy and stroboscopy for patients with a unilateral vocal-fold paralysis. Mean normalized glottal gap areas for patients suffering vocal paralysis with associated aspiration are significant greater than that for the non-aspiration group. Subsequent to the surgical correction of the glottal gap, all patients recovered well from their earlier aspiration. The investigation of objectively derived data revealed that poor airway protection due to incomplete closure of the vocal fold was the major cause of aspiration for patients suffering unilateral vocal-fold paralysis. Intracordal autologous fat injection can successfully improve the breath control and eliminate aspiration in patients with vocal-fold paralysis.     

Sclerosant extravasation as a complication of sclerosing endotherapy for bleeding gastric varices

We report here the case of a 65-year-old woman who suffered intraperitoneal sclerosant leakage after endoscopic injection sclerotherapy for bleeding gastric varices. In total, 3 ml of N-butyl-2-cyanoacrylate and Lipiodol mixture was injected. The patient developed mild fever and pain over the left upper quadrant and flank after the procedure. In addition to a Lipiodol-filled gastric varix, the imaging studies disclosed a wide spread of Lipiodol over the left peritoneal cavity. The patient was kept fasting with parenteral antibiotics and nutrition. She responded well to the treatment, and all of the symptoms had subsided 6 days later.     

Issues in the design of a clinical trial with a behavioral intervention--the Zambia exclusive breast-feeding study

PURPOSE: We present the rationale and design of the Zambian Exclusive Breast-feeding Study (ZEBS), a randomized trial evaluating the efficacy of short-duration exclusive breast-feeding (EBF) as a strategy to reduce postnatal human immunodeficiency virus (HIV) transmission while preserving the other health benefits of this important mode of infant feeding. METHODS: One thousand two hundred HIV-positive pregnant women were recruited in Lusaka, Zambia, and followed with their infants for 24 months. In addition to Nevirapine (NVP), all women received intensive and frequent clinic- and home-based counseling to support exclusive breast-feeding. When the infant was 1 week of age, half of the women were randomly assigned to a group encouraged to abruptly (<24 h) cease all breast-feeding at 4 months. The primary outcome of the experimental (randomized) comparison is HIV-free survival at 24 months. The design is also observational and will compare HIV transmission rates between those who do and do not adhere to the counseling intervention promoting exclusive breast-feeding. CONCLUSION: Our study aims to quantify the benefit-risk ratio of early cessation of exclusive breast-feeding to interrupt mother-to-child transmission of HIV with an intensive behavioral intervention and has both observational and experimental analytic approaches. Our study design assesses efficacy and also has a prominent applied component that if the intervention is effective, it will permit rapid and sustainable adoption within low-resource communities.     

Effect of occupational exposure to rayon manufacturing chemicals on skin barrier to evaporative water loss

To evaluate the effects of the occupational exposure to rayon manufacturing chemicals (RMC, containing predominantly carbon disulfide (CS(2)) and minor sulfuric acid) in a rayon factory on the basal transepidermal water loss (TEWL), barrier integrity (BI), and sequential increasing TEWL profiles. Six Thais and five Chinese workers in the spinning department of a rayon manufacturing plant and five healthy unexposed controls were recruited as the test subjects. An area of 4.5 x 5.5 cm on the mid-side of the volar forearm on the right hand was stripped by means of moderate pressure with commercially available adhesive tape by the same technician throughout the experiment. The skin was progressively stripped until glistening. TEWL was measured at every three and five tape strips on the right hand. The corresponding site on the left hand was measured parallel as the self-control. We found significant differences in basal TEWL and in BI between Chinese workers and Chinese controls, and between Thai workers and Chinese workers, respectively. Two-stage patterns of progressive TEWL profiles were found in such a chronic and repeated occupational exposure to RMC containing CS(2). The occupational exposure to RMC could result in the perturbation of the skin barrier function. Basal TEWL might be more sensitive to chronic skin irritant exposure. The TEWL profile achieved to the glistening stage might be necessary to avoid erroneous pattern estimation. Due to the lack of Thais control in this study, the racial difference in response to the RMC warrants further study.     

Mortality patterns among residents in Louisiana's industrial corridor, USA, 1970-99

Background: Because of the high concentration of oil refining and petrochemical facilities, the industrial area of the lower Mississippi River of South Louisiana has been termed the Industrial Corridor and has frequently been referred to as the "Cancer Corridor".

Aims: To quantitatively assess the "Cancer Corridor" controversy based on mortality data available in the public domain, and to identify potential contributing factors to the observed differences in mortality.

Methods: Age adjusted mortality rates were calculated for white and non-white males and females in the Industrial Corridor, Louisiana, and the United States for the time periods 1970–79, 1980–89, and 1990–99.

Results: All-cause mortality and all cancer combined for white males in the Industrial Corridor were significantly lower than the corresponding Louisiana population while Louisiana had significantly higher rates than the US population for all three time periods. Cancer of the lung was consistently higher in the Industrial Corridor region relative to national rates but lower than or similar to Louisiana. Non-respiratory disease and cerebrovascular disease mortality for white males in the Industrial Corridor were consistently lower than either Louisiana or the USA. However, mortality due to diabetes and heart disease, particularly during the 1990s, was significantly higher in the Industrial Corridor and Louisiana when compared to the USA. Similar mortality patterns were observed for white females. The mortality for non-white males and females in the Industrial Corridor was generally similar to the corresponding populations in Louisiana. There were no consistent patterns for all cancer mortality combined. Stomach cancer was increased among non-whites in both the Industrial Corridor and Louisiana when compared to the corresponding US data. Mortality from diabetes and heart disease among non-whites was significantly higher in the Industrial Corridor and Louisiana than in the USA.

Conclusions: Mortality rates in the Industrial Corridor area were generally similar to or lower than the State of Louisiana, which were increased compared to the United States. Contrary to prior public perceptions, mortality due to cancer in the Industrial Corridor does not exceed that for the State of Louisiana.