A comparison of physiological responses to two types of particle barrier, vapor permeable clothing ensembles.

Chemical protective clothing (PC) use while working results in elevated rectal temperatures (Tre) that limit work time. Particle barrier, vapor permeable (PBVP) PCs allow workers to cool themselves by evaporating some sweat. The purpose of this study was to compare the effects on worker productivity of two types of PBVP suits, a Kleenguard (PPPC) (Kimberly Clark), and a Tyvek (PEPC) (DuPont) suit. Fifteen males in a repeated measures design performed four work tests consisting of a walk/arm curl combination at a time-weighted work rate of 1.0 L/min (300 kcal/hr), two in a wet bulb globe temperature (WBGT) of 26 degrees C and two in a WBGT of 18 degrees C, with subjects wearing each suit once in each environment. No significant difference (p > 0.05) was observed between the suits at 18 degrees C WBGT, but a significant difference was found (p < 0.05) between the suits, with the PPPC having a lower Tre in the WBGT = 26 degrees C at the 80th, 100th, and 120th min. A significant difference (p < .05) was also seen in the 26 degrees C WBGT with the PPPC resulting in a lower heart rate (HR) at the 40th, 60th, 80th, 100th, and 120th min and rate of perceived exertion (RPE) at the 75th, 90th, and 120th min. Additionally, a significant difference (p < .05) was seen between PEPC and PPPC for Tre, delta Tre, mean skin temp (mTsk), delta mTsk, and HR, each regressed against time in the 26 degrees C WBGT. Twelve of the 15 subjects also reported feeling cooler in the PPPC versus the PEPC in either WBGT environment.     

Interactions between smokers and non-smokers in public places: a qualitative study

Few studies have employed a qualitative approach to better understand how both smokers and non-smokers experience and make sense of no-smoking restrictions in their daily lives. We describe qualitative research involving an examination of self-reported interpersonal interactions between smokers and non-smokers in public places regarding exposure to environmental tobacco smoke (ETS). Five focus group discussions and twenty individual in-depth interviews were conducted with smokers and non-smokers in the Metropolitan Toronto region as a complement to a quantitative survey of the adult population of Ontario. Strategies used by non-smokers in responding to ETS exposures included verbal confrontations, non-verbal cues, use of a third party, and moving away. The perceived consequences of such actions, as described by both smokers and non-smokers, are discussed, together with implications for tobacco control policy and practice.     

Cervical antibodies to herpes simplex virus proteins in pregnancy and puerperium: a pilot study

Objective: This study was undertaken to evaluate the changes in total and anti-herpes simplex virus (HSV)-specific cervical IgA and IgG antibody profiles during and after pregnancy.Methods: Serum and cervical secretions were obtained from pregnant patients before 20 weeks gestation, at 34-36 weeks gestation, and at 6 weeks postpartum and tested for total IgA and IgG antibody and for IgA and IgG to HSV proteins by Western blot.Results: Seven women were HSV seronegative, 14 HSV-1 seropositive, and 14 HSV-2 +/- HSV-1 seropositive. Minimal changes in the serum anti-HSV profiles were seen over the 3 visits. The total cervical IgA, IgG, and protein levels did not change between the 2 pregnancy visits but tended to increase at the postpartum visit. No consistent change in cervical HSV-specific IgA and IgG was seen during pregnancy, but the levels increased markedly at the postpartum visit.Conclusions: Lower cervical anti-HSV antibody levels may be related to the previously reported increased frequency of a reactivation of HSV during late pregnancy. Further evaluation is necessary to confirm and quantify the changes in genital immunity during pregnancy and to evaluate whether the increased levels at the postpartum visit are sustained.     

A child's rights to his own parents: a look at two value systems

Christians and humanists accept an evolutionary world view and respect those fundamental relations underlying evolutionary development. Both value systems should be able to discuss seriously the risks of altering one of the most fundamental of all relations: that of child to parent.     

Effects of P-Aminophenyl Dichloroarsine on Reduced High-affinity [3H]Nicotine Binding Sites from Chick Brain: A Covalent,Yet Reversible,Agent for Neuronal Nicotinic Receptors

Neuronal nicotinic acetylcholine receptor (nAChR) α-subunits contain a conserved disulphide that is essential for function. Here, we have examined the effects of sulphydryl redox reagents on [³H]nicotine binding to chick brain nAChR immunoisolated with the monoclonal antibody mAb35. The disulphide reducing agent, dithiothreitol (DTT), inhibited [³H]nicotine binding [50% inhibitory concentration (IC₅₀) = 146 μM] but this effect was reversed (93±1.5%) by subsequent reoxidation with 1 mM dithio-bis(nitrobenzoic acid) (DTNB). The trivalent arsenical, p -aminophenyl dichloroarsine (APA), which reacts with pairs of spatially close sulphydryls, was a potent inhibitor of reoxidation by DTNB (IC₅₀= 35 nM). However, application of the 'anti-arsenical', 2,3-dimercaptopropane sulphonic acid (DMPS), restored agonist binding after APA treatment (50% effective concentration = 120 μM). Paradoxically, DMPS was also found to be a potent oxidizing agent of these receptors. Affinity alkylation of reduced nAChRs with bromoacetylcholine (BAC; 100 μM) irreversibly blocked nicotine binding (>90%). We propose (but have not proven) that APA interacts with the cysteines homologous to Cys192–193 in Torpedo AChRs, since APA pretreatment of reduced neuronal receptors protected against irreversible BAC alkylation, as shown by subsequent reversal of DMPS (2 mM; 20 min). This study illustrates the potent and reversible nature of the arsenical's covalent interaction with an isolated nAChR and suggests that modified arsenicals could be useful nAChR probes.     

Value of a radionuclide limb blood flow technique in the assessment of percutaneous balloon and dynamic angioplasty

In a prospective study, a radionuclide technique was used to evaluate the limb blood flow (LBF) changes in 30 patients undergoing dynamic (n=15) or balloon (n=15) angioplasty for arterial occlusions or stenoses, respectively. The results were compared with Doppler Ankle Brachial Index (DABI) and treadmill exercise tests. Whilst LBF values (ml of blood flow per 100 ml of limb volume per min) were significantly lower in limbs with arterial occlusion than stenosis (4.5±0.46 and 6.4±0.74, respectively; P<0.05), DABI provided no discrimination. Immediately after balloon angioplasty, there was a fall in DABI, from 0.60±0.05 to 0.47±0.04 (P<0.05), which rose 24 h later to 0.73±0.02 (P<0.01). Following dynamic angioplasty, DABI improved from 0.60±0.05 to 0.66±0.02 (P<0.05). At 3 weeks, the LBF improved from 4.6±0.66 to 11.1±0.53 (P<0.001) following dynamic angioplasty and from 6.2±0.68 to 8.53±0.81 (P<0.001) following balloon angioplasty. Normal LBF (> 10 ml/100 ml per min) was achieved in 80% of patients who underwent successful dynamic angioplasty but in only 36% of the balloon group (P<0.05, ²-test). Reproducibility of repeated LBF measurements in control limbs was superior to that of DABI. This was indicated by a lower coefficient of variation, 13.8% compared with 25.2%, and a higher correlation coefficient, r=0.79 compared with 0.27. Treadmill exercise tests were invalid or impossible in 30% of all occasions. There was a good correlation between the improvement in maximum walking distance on the treadmill and that in LBF (r=0.84, P<0.05). In conclusion, measurement of LBF using radionuclide technique is a potentially valuable method for the assessment of patients undergoing percutaneous angioplasty. LBF results are reproducible and correlate well with the improvement in walking ability, which cannot always be assessed objectively. Offprint requests to: A.A. Gehani     

Partial tears of prostatomembranous urethra in children.

Five boys having sustained a pelvic fracture were found to have incomplete tears of the prostatomembranous urethra. Three patients were treated with suprapubic cystostomy drainage alone and fared better than 2 who were treated with urethral catheter stenting and drainage. A recommendation is made for the "hands-off" approach to the evaluation and management of membranous urethral injuries.     

Results of a phase II upfront window of pharmacokinetically guided topotecan in high-risk medulloblastoma and supratentorial primitive neuroectodermal tumor.

PURPOSE: To assess the antitumor efficacy of pharmacokinetically guided topotecan dosing in previously untreated patients with medulloblastoma and supratentorial primitive neuroectodermal tumors, and to evaluate plasma and CSF disposition of topotecan in these patients. PATIENTS AND METHODS: After maximal surgical resection, 44 children with previously untreated high-risk medulloblastoma were enrolled, of which 36 were assessable for response. The topotecan window consisted of two cycles, administered initially as a 30-minute infusion daily for 5 days, lasting 6 weeks. Pharmacokinetic studies were conducted on day 1 to attain a topotecan lactone area under the plasma concentration-time curve (AUC) of 120 to 160 ng/mL.h. After 10 patients were enrolled, the infusion was modified to 4 hours, with dosage individualization. RESULTS: Of 36 assessable patients, four patients (11.1%) had a complete response and six (16.6%) showed a partial response, and disease was stable in 17 patients (47.2%). Toxicity was mostly hematologic, with only one patient experiencing treatment delay. The target plasma AUC was achieved in 24 of 32 studies (75%) in the 30-minute infusion group, and in 58 of 93 studies (62%) in the 4-hour infusion group. The desired CSF topotecan exposure was achieved in seven of eight pharmacokinetic studies when the topotecan plasma AUC was within target range. CONCLUSION: Topotecan is an effective agent against pediatric medulloblastoma in patients who have received no therapy other than surgery. Pharmacokinetically guided dosing achieved the target plasma AUC in the majority of patients. This drug warrants testing as part of standard postradiation chemotherapeutic regimens. Furthermore, these results emphasize the importance of translational research in drug development, which in this case identified an effective drug.     

The palliative benefits of MVP (mitomycin C, vinblastine and cisplatin) chemotherapy in patients with malignant mesothelioma.

BACKGROUND: With the rising incidence of malignant mesothelioma (MM), it is important to optimise treatment to control symptoms, maintain quality of life and, if possible, prolong life. We have analysed prospectively collected data to evaluate a frequently used palliative chemotherapy regimen. PATIENTS AND METHODS: Between October 1986 and May 2002 all patients with inoperable pleural mesothelioma were considered for treatment with MVP (mitomycin C 8 mg/m2 every 6 weeks, vinblastine 6 mg/m2 every 3 weeks and cisplatin 50 mg/m2 every 3 weeks) chemotherapy. Symptoms were assessed by physician assessment at baseline and after each cycle of chemotherapy. RESULTS: One hundred and fifty patients were treated with MVP for mesothelioma. Forty-three per cent had a performance status (PS) 2 or worse. The response rate was 15.3%, with 68.6% having stable disease. Sixty-nine per cent reported an improvement in symptoms; in particular there were good responses for pain (71%), cough (62%) and dyspnoea (50%). The most common grade 3/4 toxicity was neutropenia (22%). Median overall survival was 7 months, with 1-year survival 31% and 2-year survival 11%. Median survival for patients with PS 0/1 was 10 months, and was 6 months for patients with PS 2/3. Poor prognostic factors in univariate analysis included poor PS, weight loss, mixed or sarcomatoid histology, low haemoglobin and high white blood cell count. Excluding pathological subtype, the prognostic significance of poor PS and weight loss were retained in multivariate analysis. CONCLUSIONS: Palliation of symptoms in MM is achievable with current cisplatin-based treatments.     

Use of the KTP-532 Laser in Acoustic Neuroma Surgery

The potassium titanyl phosphate (KTP-532) laser has been applied to otologic surgery with a proven record of both safety and efficacy. The aim of this study was to demonstrate the use, safety, and advantages of laser dissection in the surgical treatment of acoustic neuromas. The authors' experience with 111 patients in whom laser surgery was used in acoustic neuroma is presented, with emphasis on surgical technique employed and facial nerve functional outcome. The method of laser dissection did not result in deleterious neurologic sequelae or laser-specific complications. In addition, laser dissection afforded certain advantages to traditional techniques, especially in larger tumors. The facial nerve functional outcome as assessed by the House-Brackmann grading system revealed that 90.2% of small tumors, 72.2% of medium tumors, and 75.0% of large tumors achieved satisfactory (grades I and II) functional results. These results compare favorably with the literature describing nonlaser dissection techniques. The observations and results reported in this article demonstrate the safety of the KTP-532 laser in the posterior cranial fossa, and specific advantages that this technology may offer to the surgical armamentarium of the neuro-otologist are outlined.