Effects of N-alkyl-N,N-dimethylamine-N-oxides on the activity of purified sarcoplasmic reticulum Ca(2+)-transporting ATPase

N-alkyl-N,N-dimethylamine-N-oxides (CnNO, n = 10-20 is the number of alkyl carbon atoms) stimulate the skeletal sarcoplasmic reticulum (SR) Ca(2+)-transporting ATPase activity at low concentrations and inhibit it at high concentrations. The minimum concentration (cmin), at which CnNO inhibits the ATPase, continuously decreases up to n = 16-18 and then increases. The values of Cmin are smaller than the CnNO critical micelle concentration (cmc) for C10NO-C14NO homologs, but larger than cmc for C18NO-C20NO homologs. The ATPase inhibition is caused by the CnNO-induced lipid bilayer structural perturbation in the ATPase annular region, modulated by the partition equilibria of the CnNO molecules between the bilayer and aqueous phase for short alkyl chain (n = 10-16) CnNO homologs, and between the bilayer, micelles and aqueous phase for long alkyl chain (n = 18-20) CnNO homologs.     

Quality-adjusted life years was a poor predictor of women's willingness to pay in acute and chronic conditions: results of a survey

OBJECTIVE: We investigated the relationship between quality-adjusted life years (QALYs) and willingness to pay (WTP) in acute and chronic conditions. STUDY DESIGN AND SETTING: Face-to-face interviews were used to collect data in a convenience sample of women. Participants completed one interview evaluating preferences for an acute condition, post-chemotherapy nausea and vomiting (PCNV), and the other interview for a chronic condition (breast cancer). Preferences were elicited for QALYs using visual analogue scale (VAS), and standard gamble in addition to WTP. Because QALYs and WTP are purportedly based on the same underlying theoretical foundations, WTP was regressed onto change in QALYs, age, income, and health status. RESULTS: Regression analysis reported statistically significant models for all breast cancer (P < .001) and PCNV (P < .05) conditions tested. However, QALY was not a significant predictor of WTP. CONCLUSION: The results of this study indicate QALYs was a poor predictor of WTP for the conditions tested. Linear combinations of change in QALYs, age, income, and health status were a better predictor of WTP for chronic than acute conditions. This can be attributed to violations of underlying assumptions in measurement of QALYs with acute conditions and to problems with the use of WTP with chronic conditions.     

Phototargeting oral black-pigmented bacteria

We have found that broadband light (380 to 520 nm) rapidly and selectively kills oral black-pigmented bacteria (BPB) in pure cultures and in dental plaque samples obtained from human subjects with chronic periodontitis. We hypothesize that this killing effect is a result of light excitation of their endogenous porphyrins. Cultures of Prevotella intermedia and P. nigrescens were killed by 4.2 J/cm2, whereas P. melaninogenica required 21 J/cm2. Exposure to light with a fluence of 42 J/cm2 produced 99% killing of P. gingivalis. High-performance liquid chromatography demonstrated the presence of various amounts of different porphyrin molecules in BPB. The amounts of endogenous porphyrin in BPB were 267 (P. intermedia), 47 (P. nigrescens), 41 (P. melaninogenica), and 2.2 (P. gingivalis) ng/mg. Analysis of bacteria in dental plaque samples by DNA-DNA hybridization for 40 taxa before and after phototherapy showed that the growth of the four BPB was decreased by 2 and 3 times after irradiation at energy fluences of 4.2 and 21 J/cm2, respectively, whereas the growth of the remaining 36 microorganisms was decreased by 1.5 times at both energy fluences. The present study suggests that intraoral light exposure may be used to control BPB growth and possibly benefit patients with periodontal disease.     

Relapsing polychondritis studied by computed tomography

Computed tomographic findings in a patient with relapsing polychondritis are described. Collapse of the cartilage of the nose and calcification in cartilages of the ears were clearly demonstrated. CT scanning was also helpful in evaluating the tracheobronchial tree for airway compromise, which could prove fatal in this condition.     

CT of the paranasal sinuses

Summary CT scanning has allowed the radiologist to image paranasal sinus disease with an accuracy and detail never before attainable. This information has made the imager an important member of the physician team that evaluates the operability and treatment planning of these patients. The protocol of the CT examination is discussed, the normal CT anatomy is reviewed and an approach to evaluating both inflammatory and malignant disease is presented.     

Follicular adenoma in a juxtathyroidal thyroglossal duct cyst with papillary carcinoma in the adjacent thyroid gland

This patient presented with a neck mass diagnosed as a papillary thyroid carcinoma by fine-needle aspiration. Preoperative computed tomography revealed a papillary carcinoma within a juxtathyroidal thyroglossal duct cyst. After surgery, the initial diagnosis was papillary thyroid carcinoma. After correlation with the computed tomography, the diagnosis was revised to a papillary thyroid carcinoma plus a follicular adenoma in a juxtathyroidal thyroglossal duct cyst. This case demonstrates the need for close clinical and radiographic correlation in such a complex case.     

The incidence of concha bullosa and its relationship to nasal septal deviation and paranasal sinus disease

BACKGROUND AND PURPOSE: The incidence of middle turbinate pneumatization, or concha bullosa, has been well described in the literature. However, to our knowledge, no study has evaluated concha bullosa in relation to nasal septal deviation. We sought to analyze the incidence of concha bullosa and any correlation with nasal septal deviation and paranasal sinus disease. METHODS: Three neuroradiologists retrospectively reviewed findings of 1095 consecutive paranasal sinus CT studies conducted between 2001 and 2002. All examinations were performed for evaluation of a symptom referable to the sinonasal region. Paranasal sinus inflammatory disease was identified and graded as mild, moderate, or severe. Sphenoid, ethmoid, maxillary, and frontal sinuses were each graded separately on both sides. If a concha bullosa was present, it was graded in size as small, moderate, or large. If bilateral concha were present, sizes were compared and when one was larger, it was identified as dominant. When nasal septal deviation was present, it was graded as mild, moderate, or severe. The direction of nasal septal deviation was identified as the face of the convex surface. RESULTS: There was a clear association between the presence of a unilateral concha, or a dominant concha (in the case of bilateral concha), and the presence of nasal septal deviation (P < .0001). Moreover, there was a significant relationship between the presence of concha bullosa and deviation of the nasal septal to the contralateral side (P < .0001). This inverse association was present regardless of the size of the concha bullosa or degree of septal deviation. In every case, there was some preservation of air channels between the dominant concha and the nasal septum. Seventy-three percent of patients with concha bullosa had paranasal sinus inflammatory disease; 78% of patients without concha bullosa also had some form of inflammatory disease. CONCLUSION: Concha bullosa is a common anatomic variant. There is a strong association between the presence of a concha bullosa and contralateral deviation of the nasal septum. Nasal septal deviation away from the dominant concha, with preserved adjacent air channels, suggests that the deviation is not a direct result of mass effect from the concha. No increased incidence of paranasal sinus disease exists in patients with concha bullosa.     

Surgical removal of unilateral vestibular schwannomas after failed Gamma Knife radiosurgery

One of the primary criticismes of vestibular schwannoma (VS) radiosurgery is that the risk of surgical morbidity is increased for patients whose tumor progresses after the procedures. We reviewed the French experience of operated patients after failed Gamma Knife radiosurgery. From July 1992 to January 2002, 25 out of the 1000 treated patients underwent another treatment procedure for a gamma knife failure. Excluding the NF2 patients, 21 patients have been operated and the present study shows the data collected for 20 of them. In order to analyze the difficulties observed during the surgery, a questionnaire was filled by the surgeons. The mean interval between radiosurgery and removal was 36 Months, from 10 to 83 Months. The mean increase in Volume was 559% (37 to 3036%, median 160%). Evolution of the Koos grading was found from 8 grade II, 10 grade III et 2 grade IV to 10 grade III and 10 grade IV. Patients have been operated for radiological tumor growth in 7 cases and for clinico-radiological evolution in 13 cases. In 9 cases, the surgeon considered that he had to face unusual difficulties mainly because of adhesion of the tumor to neurovascular structures. Tumor removal was total in 14 cases, near total in 4 cases and subtotal in 2 cases. One case of venous infarction was noticed at the second day following surgery responsible of hemiparesis and aphasia that gradually recovered. At last follow-up examination, facial nerve was normal (House and Brackmann grade I and II) in 10 cases while it was a grade III in 7 cases and grade IV and V in 3 cases. We recommend that the decision for surgical removal of growing vestibular schwannoma after Gamma Knife treatment should be done after a sufficiently long follow-up period. Our results show that the quality of removal and of facial nerve preservation might be impaired by radiosurgery in half of cases. However these results do not support a change in our policy of radiosurgical treatment of small to medium size vestibular schwannoma.     

Effect of socio-economic and biological variables on birth weight in Madhya Pradesh

A study on a few selected socio-biological and demographic determinants of birth weight was conducted at a hospital in Sagar town, Madhya Pradesh. Records of 2,680 single live births over a period of one year (1st January to 31st December 2000) were analysed. It was found that male infants were 124 g heavier than female infants. Tabular representation of data showed that maternal age, education, ethnicity, father's income and occupation, infant's sex and parity were strongly associated with birth weight of infants. Regression analysis gave a comprehensive picture of such associations and confirmed the above findings. The study showed that the socio-economic and biological variables considered in the analysis have significant effect on birth weight.