A hemodynamically responsive antitachycardia system. Development and basis for design in humans

Current automatic implantable cardioverter-defibrillators detect tachyarrhythmias primarily by rate-only algorithms and cannot adequately distinguish hemodynamically stable from unstable tachyarrhythmias. The responses of right atrial (mean) and right ventricular pressures (mean, systolic, diastolic, and pulse) to 64 induced and paced supraventricular and ventricular tachyarrhythmias were studied in 10 patients (left ventricular ejection fraction of 32 +/- 6%) to develop an algorithm capable of differentiating stable from unstable rhythms. Tachyarrhythmias were defined as hemodynamically unstable when mean arterial pressure decreased by 25 mm Hg or more during 15 seconds. Mean right atrial, right ventricular systolic, and right ventricular pulse pressures were found to be useful in distinguishing the hemodynamic significance of a tachyarrhythmia. A combined detection algorithm was developed that identified a hemodynamically unstable rhythm when the heart rate was 150 beats/min or more and mean right atrial pressure increased by 4 mm Hg or more and right ventricular systolic pressure decreased by 5 mm Hg or more during 15 seconds. This algorithm was then applied to the next 20 consecutive patients (left ventricular ejection fraction of 34 +/- 4%) and compared with the current rate-only algorithm (heart rate of 150 beats/min or more) in 143 tachyarrhythmias, and the sensitivity and specificity for detection of hemodynamically unstable tachyarrhythmias were determined. The rate-only detection algorithm had 100% sensitivity but only 68% specificity for detection of unstable tachyarrhythmias, whereas the combined rate-mean right atrial pressure-right ventricular systolic pressure detection algorithm had sensitivity and specificity of 100%. Therefore, the performance of an antitachycardia system may be significantly improved by detection algorithms that integrate hemodynamic and rate criteria.     

Screening for ‘window‐period’ acute HIV infection among pregnant women in rural South Africa

Objectives

The aim of this study was to evaluate the HIV‐1 RNA pooled nucleic acid amplification testing (NAAT) strategy to screen pregnant women in the ‘window period’ of acute HIV infection (AHI) in rural South Africa.

Methods

In 2007 and 2008, 750 consecutive pregnant women on their first antenatal care visit to a primary health care clinic were tested anonymously for HIV infection. HIV‐1 RNA pooled NAAT was performed on HIV antibody‐negative samples. All positive pools were tested individually and positive samples were classified as incident cases to calculate HIV incidence.

Results

The overall HIV prevalence was 37.3% [95% confidence interval (CI) 34.3–41.3]. Of the 467 HIV antibody‐negative samples, four (0.9%) were HIV‐1 RNA‐positive. The mean viral load in the four samples was 386 260 HIV‐1 RNA copies/mL (range 64 200–1 228 130). The HIV incidence was 11.2% per year (95% CI 0.3–22.1) and all women with AHI were ≤21 years of age.

Conclusions

Identifying AHI in pregnancy is important for health interventions to reduce perinatal and heterosexual transmission of HIV, and to estimate HIV incidence for epidemiological surveillance.     

二甲双胍和瑞格列奈对非肥胖的2型糖尿病患者非血糖性心血管危险标志的影响比较

在2型糖尿病患者中，反映炎症和内皮功能障碍的生物标志已经与心血管疾病和代谢调节联系起来。二甲双胍和促胰岛素分泌剂被证明有相同的抗高血糖作用。此研究比较了二甲双胍和促胰岛素分泌剂瑞格列奈在非肥胖的2型糖尿病患者的心血管疾病生物标志上的效能。     

Meningitis and midline facial deformity

A baby with unilateral cleft lip, midline cleft palate and hypertelorism developed meningitis in the first 48 h of life. Examination of the nasopharynx showed a soft tissue mass, which was confirmed as a basal encephalocele by computed tomography. There was also congenital hydrocephalus and the corpus callosum was absent. Surgical treatment included repair of the anterior basal skull defect, repair of the lip and palate, and ventriculo-peritoneal shunt. There is currently evidence of developmental delay and right-sided visual impairment due to Morning Glory syndrome. This case demonstrates that basal encephalocele should be considered in any baby with midline facial deformity who develops meningitis.     

Chemoprotective effects of capsaicin and diallyl sulfide against mutagenesis or tumorigenesis by vinyl carbamate and N-nitrosodiinethylamine

Capsalcin (trans-8-methyl-N-vanillyl-6-nonenamide) is a majorpungent and irritating ingredient of hot chill peppers, whichare frequently consumed as spices. This dietary phytochemicalhas been found to interact with microsomal xenobiotic metabolizingenzymes in rodents. Capsalcin and its saturated analog dihydrocapsaicin(trans 8-methyl-N-vanlllyl-6-nonanamide) have been proposedto inactivate cytochrome P-450 IIE1 by irreversibly bindingto the active sites of the enzyme. Besides cytochrome P 450IIE1, other isoforms of the P-450 superfamily were also reportedto be inhibited by capsaicin. The inhibition by capsaicin ofmicrosomal monooxygenases involved in carcinogen activationimplies its chemopreventive potential. As part of a programto investigate chemoprotective properties of capsalcin we initiallydetennined the effect of capsalcin on vinyl carbamate (VC)-and N-nitrosodlmethyl amine (NDMA)-induced mutagenesis in Salmonellatyphi murium TA 100. Capsaicin (0.42 mM) attenuated the bacterialmutagenicity of VC and NDMA by 50% and 42% respectively. Diallylsulfide, a thloether found in garlic with selective P-450 IIE1inhibitory activity, also lessened the mutagenicity of the abovecarcinogens in a concentration-dependent manner. The suppressionof VC- and NDMA Induced mutagenesis by capsaicin and diallylsulfide correlated with their inhibition of P-450 IIE1-mediatedp-nltrophenol hydroxylation and NDMA N-demethylation. Pretreatmentof female ICR mice with a topical dose of capsalcin loweredthe average number of VC-induced skin tumors by 62% at 22 weeksafter promotion. A similar degree of protection was attainedwith oral administration of diallyl sulfide before carcinogentreatment. The results of this study suggest that capsaicinand diallyl sulfide suppress VC- and NDMA-induced mutagenesisor tumorigenesis In part through inhibition of the cytochromeP-450 IIE1 isoform responsible for activation of these carcinogens.     

Humeral avulsions of the glenohumeral ligament: imaging features and a review of the literature

OBJECTIVE: We describe the radiologic findings of the humeral avulsion of the glenohumeral ligament (HAGL lesion) and its commonly associated injuries. MATERIALS AND METHODS: A retrospective review of six cases of HAGL lesion diagnosed at our institution from October 1996 to February 2001 was performed. We reviewed the radiology reports, radiologic examinations, medical records, and operative notes. All patients had undergone radiography, and four patients had undergone MR imaging of the shoulder before diagnostic arthroscopy. RESULTS: All the patients were men who ranged in age from 19 to 41 years (mean, 26 years). Four patients (67%) had an anterior shoulder dislocation. Three of the HAGL lesions (50%) were detected on radiologic examinations, either by radiography or MR imaging. One patient had a bony HAGL. All patients had associated injuries. The most common associated abnormalities were osteochondral injury of the humeral head (n = 3), rotator cuff tear (n = 3), Bankart lesion (n = 3), Hill-Sachs lesion (n = 2), avulsion of the middle glenohumeral ligament (n = 1), partial tear of the biceps brachii tendon (n = 1), and comminuted fracture of the clavicle (n = 1). CONCLUSION: With an incidence of 7.5% and 9.4% in two large series of patients, the HAGL lesion is an important cause of anterior instability of the glenohumeral joint. The majority (68%) of patients with an HAGL lesion have associated injuries.     

Prophylactic cranial irradiation revisited: cost-effectiveness and quality of life in small-cell lung cancer.

PURPOSE: To investigate the therapeutic usefulness and cost-effectiveness of prophylactic cranial irradiation (PCI) in patients with limited-stage small-cell lung cancer (SCLC) who had achieved a complete remission. METHODS: A retrospective chart review was undertaken of all patients diagnosed in Saskatchewan with SCLC between 1987 and 1998 inclusive. Patients who achieved a complete remission were divided into two groups, depending on whether they underwent PCI (PCI+ and PCI-, respectively). The quality-of-life-adjusted survival was estimated by the Q-TWiST method (quality time without symptoms and toxicity). The mean incremental costs per month of incremental OS were calculated in a cost-effectiveness analysis. RESULTS: Among the 98 complete remission patients, the median OS for PCI+ and PCI- patients was 20.0 and 19.0 months, respectively (p > 0.05, nonsignificant). The median disease-free survival was 14.7 and 10.0 months, respectively (p < 0.05). The difference in the mean Q-TWiST survival was significant (p < 0.01). The mean marginal cost was $18,834/PCI+ patient and $17,885/PCI- patient (p > 0.05, nonsignificant). The cost-effectiveness ratio was $70/mo of incremental OS if u(tox) and u(rel) (the utility coefficients to reflect the value of time in health states of toxicity and relapse) were assumed to be 1.0. CONCLUSION: PCI is a cost-effective treatment that improves the quality-of-life-adjusted survival for patients with a complete remission of SCLC.