Cardio-respiratory adjustments and cost of locomotion in school children during backpack walking (the Italian Backpack Study)

The use of a school backpack is one of the possible causes of back pain in children. Oxygen consumption ( ), pulmonary ventilation, and heart rate (f _c) were measured in 35 pre-pubertal subjects [17 girls and 18 boys, mean (SD) age 11.3 (0.6) years]. They took part in a four-step experiment: (1) standing for 5 min, (2) walking at 3 km·h^–1 for 7 min, (3) walking at 3 km·h^–1 for 7 min carrying a school backpack weighing 8 kg, and (4) walking at 7 km·h^–1 for 5 min with no load. The occurrence of back pain in the last 2–3 years and during the last 15 days was assessed for the subjects by means of a questionnaire. Mean (SD) standing was 215 (45) ml^.min^–1 during walking at 3 km·h^–1, 503 (101) ml^.min^–1 during walking without a load, and increased to 541 (98) ml^.min^–1 during walking with a load (P<0.01). Carrying a backpack increased f _c only minimally. The energy cost of walking at 3 km^.h^–1 without the backpack was 10.0 (2.0) ml O₂ ^.m^–1, and with the backpack was 10.8 (1.9) ml O₂ ^.m^–1 (P<0.01). The net energy cost of locomotion was 0.129 (0.032) ml^.kg body mass^–1.m^–1 for the unloaded condition and slightly lower, at 0.123 (0.025) ml^.kg body mass^–1.m^–1 during loaded walking (P<0.05). Ventilation did not change significantly between unloaded and loaded conditions. When the data were assessed according to the occurrence of back pain, the f _c/ slope was significantly lower in children without back pain, even though the net energy cost of locomotion was similar. Overall, these data suggest that the cardiovascular effortrequired for locomotion while carrying a backpack is minimal. However, fatigability and back pain are more likely to take place in less physical performing subjects. Thus, the occurrence of back pain in schoolchildren during locomotion while carrying a backpack may improve with an improvement in their level of fitness. Electronic Publication     

Condom distribution in Bali: assuring supply meets demand

Hundreds of thousands of tourists visit Bali each year, many of whom pay to have sex with local residents. Kuta, one of Bali's major tourist resort towns, has manifested an higher demand for condoms than other studied areas in Indonesia. Such demand is laudable in the context of a growing HIV/AIDS epidemic, but demand must encounter supply to be worthwhile. The Citra Usadha Indonesia Foundation (YCUI) has been conducting outreach education in Kuta and other areas of Bali since February 1992. Over that time, outreach workers have found that street youths' and prostitutes' main sources for condoms, pharmacies, supermarkets, and YCUI outreach workers, are either closed or potentially unavailable at night, when most sexual transactions occur. Pharmacies and supermarkets close at 10 pm. YCUI therefore initiated a six-month condom distribution program in 1994 to encourage the approximately 150 street vendors working in Kuta to sell condoms. Street vendors who enrolled in the program were provided with a monthly supply of 30 free condoms for the period of six months and invited to sell them to the public at whatever price the market set. Concurrently, YCUI promoted condom sales and increased awareness of the new condom source through social marketing techniques and their network of outreach workers. After six months, 122 vendors had participated in the program selling 10,255 condoms. Vendors were able to sell more and more condoms as the program progressed. A final evaluation will be conducted October 1994 to determine how many vendors still sell condoms now that the free supplies have been discontinued.     

Importance of specimen size in accurate needle liver biopsy evaluation of patients with chronic hepatitis C.

BACKGROUND & AIMS: In patients with chronic hepatitis C (CHC), percutaneous needle liver biopsy examination establishes the severity of necroinflammatory activity and fibrosis, thus guiding treatment decisions. Optimal biopsy specimen size remains controversial. We sought to determine how varying lengths of biopsy specimens influence the grading and staging of CHC. METHODS: We used 100 liver biopsy specimens from patients with CHC. The slides were evaluated blindly using the METAVIR scoring system, after being covered with paper, so that only specific specimen lengths (5 mm, 10 mm, 15 mm, and > or =20 mm) were visible. In each case, the scores obtained with biopsies 5 mm, 10 mm, or 15 mm long were compared with the scores at 20 mm or greater by weighted kappa statistics (kappa of >.75 signified excellent agreement). A subset of specimens 20 mm or greater was selected for a blinded repeat scoring to assess intraobserver agreement. The kappa statistics for the designated features and lengths were compared using analysis of variance. RESULTS: In assessing the stage of fibrosis, the weighted kappa statistics for agreement with the 20-mm or greater score at 5 mm, 10 mm, and 15 mm were .75, .85, and .92, respectively. In assessing the histologic activity score, the corresponding figures were .73, .81, and .77, respectively. Average kappa statistic comparisons showed that intraobserver agreement was significantly better than agreement between the 20-mm or greater scores and those at shorter lengths; the 5-mm kappa scores were significantly lower than the others; and there was no significant difference between the 10-mm and 15-mm kappa scores. CONCLUSIONS: Liver biopsy specimens measuring at least 10 mm usually reflect the grade and stage of CHC reliably. Relatively little improvement in diagnostic accuracy is obtained with longer specimens.     

Acute respiratory failure in obesity

Obstructive sleep apnea, obesity-related hypoventilation - a hypoventilation which is independent of apneas and increased by sleep -, and hypoxemia related to local ventilation-perfusion disorders are the main mechanisms of respiratory failure occurring during acute respiratory decompensation following an often minimal triggering event. Non-invasive ventilation has been found to be an effective treatment, particularly with a ventilator capable of maintaining positive expiratory and pressure. The level of the expiratory positive airway pressure must be adapted to cure episodes of obstructive apnea or hypopnea. The level of the inspiratory positive airway pressure (pressure support ventilator), or the tidal volume (volume-controlled ventilator) must be adapted to correct the residual hypoventilation. These adaptations can be made by proper assessment of nocturnal SaO(2) recordings. In particularly severe cases, use of endotracheal ventilation may be necessary to control a state of shock or consciousness disorders incompatible with the patient cooperation necessary for non-invasive ventilation.     

A glance at the von Willebrand factor in dengue virus infection

To identify the level of von Willebrand factor (vWF) in dengue infection, especially severe DHF, and correlate the increase in vWF with thrombocytopenia, children admitted with dengue fever/DHF were examined for hemoglobin, hematocrit, platelet, and vWF for three consecutive days. Anti-dengue IgM and IgG were determined. Correlations between vWF and thrombocytopenia were analyzed using multivariate analysis. Forty-one patients were eligible for the study; of whom almost three fourths had a secondary infection, as proved serologically. At the beginning of the study, a high level of vWF along with a low platelet count were seen, which seemed to fit the hypothesis that an increase in vWF in the serum will be followed by a decrease in platelets, as a result of the platelet aggregation process in the peripheral blood vessels, predisposed by the immune complex events in DHF. Observations for three consecutive days revealed significant changes of vWF levels (p = 0.000) as well as platelet counts (p = 0.002). However in the context of dengue infections, these changes did not correlate well (p = 0.988). Could there have been a significant correlation if cases were followed for a longer period of time? Being a part of a more comprehensive study, it appeared that in patients with dengue infections, vWF and platelets were not the only factors involved in bleeding, indicating that activation of endothelium is one factor in a multifactorial process.     

Medialization thyroplasty window creation using an ultrasonic surgical aspirator

OBJECTIVES/HYPOTHESIS: The aim of the study was to investigate the use of an ultrasonic surgical aspirator for creation of the laryngeal cartilage window during medialization thyroplasty. STUDY DESIGN: Basic science. METHODS: Forty thyroplasty windows were constructed in fresh, unpreserved cadaver larynges. A 6 x 13-mm rectangular window and a 4 x 4-mm round window were created on each side of the larynges in a symmetrical fashion. A standard surgical drill with a 3-mm cutting burr was used on one side; the ultrasonic surgical aspirator was used on the contralateral side. The time required for window construction was recorded, as was the status of the inner perichondrium at window completion. RESULTS: For creation of the 6 x 13-mm window, a mean time of 128 seconds was required using a standard surgical drill. The mean time using the ultrasonic aspirator device was 91 seconds for the window of the same size (P < .008). For the 4-mm round window, drilling completed the task in a mean time of 63 seconds, compared with 40 seconds (P < .016) for the ultrasonic aspirator. On creation of the 6 x 13-mm window, there were 4 of 10 perichondrial violations in the drilled specimens, and there were no violations in creation of the window of the same size with the ultrasonic aspirator (P = .12). The 4-mm round window had no perichondrium violations in the standard drill group and only 1 of 10 violations in the ultrasonic aspirator group (P = .99). CONCLUSION: The study suggested that the ultrasonic surgical aspirator device may be an effective, efficient alternative to the standard drill for medialization thyroplasty window creation. Prospective clinical trials are warranted to better characterize its applicability.     

Prognostic significance of p53 and FHIT in advanced oropharyngeal carcinoma

OBJECTIVE: To determine the prognostic significance of p53 and fragile histidine triad (FHIT) expression in advanced oropharyngeal squamous cell carcinoma. STUDY DESIGN: A retrospective collection of clinical data was correlated with the protein expression. METHOD: The expression of p53 and FHIT in specimens from patients with previously untreated advanced squamous cell carcinoma of the oropharynx was determined by immunohistochemistry. The expression of p53 and FHIT was statistically correlated with survival outcome. The primary endpoints were overall survival and disease-free survival. RESULTS: Thirty-four patients were analyzed in this study. Overexpression of p53 was observed in 41.2% (14/34) of tumors and was associated with a trend toward an improved overall survival using univariate (P =.1088, risk ratio [RR] = 0.503) and multivariate (P =.1533, RR = 0.470) analyses. Marked reduction or complete absence of FHIT expression was observed in 57.6% (19/33) of tumors. Patients with tumors showing no reduction in FHIT expression had a lower overall survival using univariate (P =.04, RR = 2.27) and multivariate (P =.013, RR = 4.41) analyses. CONCLUSION: Overexpression of p53 predicted a trend toward an improved prognosis, whereas no reduction in FHIT expression predicted a significantly poorer outcome in patients with advanced oropharyngeal cancer.     

Contemporary diagnostic and management techniques for extraesophageal reflux disease

PURPOSE OF REVIEW: To review recent advances in the diagnosis and treatment of extraesophageal reflux. RECENT FINDINGS: For most patients, the diagnosis of extraesophageal reflux relies on history and laryngoscopic exam. The reliability and reproducibility of reporting these measures may be improved with validated symptom questionnaires and standardized scoring of physical exam findings. Though dual probe pH monitoring has been the gold standard for diagnosis, it does not measure non-acid reflux events. Intraluminal impedance monitoring has the capability of measuring all esophageal reflux events (liquid, solid, gas) and may be useful in the diagnosis of non-acid reflux.Proton pump inhibitors have replaced histamine receptor antagonists as the mainstay of treatment for extraesophageal reflux. Histamine receptor antagonists are used predominantly for nocturnal acid breakthrough, or step-down therapy. Promotility and cytoprotective agents are used less commonly. Baclofen is currently being evaluated for its ability to decrease the incidence of transient lower esophageal sphincter relaxations and reduce post-prandial acid and non-acid reflux events. For individuals refractory to medical therapy, laparoscopic fundoplication techniques have proven efficacy in relieving some symptoms; the long-term benefit is not yet known. There is yet no established data on the effects of endoluminal therapies on extraesophageal reflux symptoms. SUMMARY: The diagnosis of extraesophageal reflux for most patients relies on history and laryngoscopic exam. The diagnosis can be further verified by dual probe pH and impedance monitoring. Proton pump inhibitors are the mainstay of treatment. Laparoscopic fundoplication is proven to relieve symptoms, but there is yet no data on the effects of endoluminal therapies on extraesophageal reflux symptoms.