Fenestration and occlusion of the posterior semicircular canal for benign positional vertigo

Benign positional vertigo is a potentially disabling condition characterized by episodic vertigo following certain provocative head movements. In most patients it is self limiting; however, in a few it may prove intractable, causing considerable social morbidity. In these patients surgery may be considered. Surgery previously involved section of the vestibular or singular nerves, involving a significant risk to hearing and to the facial nerve. Ablation of the labyrinth may even be considered. The new surgical technique of occlusion of the posterior semicircular canal has proved to be curative in most patients with benign positional vertigo with little risk to hearing. This paper describes our experience of fenestration and occlusion of the posterior semicircular canal in four patients.     

Lung dose rate and interstitial pneumonitis in total body irradiation for bone marrow transplantation

The effect of dose rate to the lungs and development of interstitial pneumonitis (IP) was evaluated in 114 bone marrow transplant patients receiving fractionated total body irradiation (TBI) (1200 rads TD in 6 fractions twice daily over 3 days) as part of their pre-conditioning regimen. The tumour dose (TD) was calculated as the mean lung dose as previously described (1). A 6MV linear accelerator at a mid-line dose rate of 7.5 rads/minute was used between March 1981 and June 1985 and a Co-60 source at 5 rads/minute thereafter. This resulted in a range of dose rates to the lung of between 6.9 and 8.9 rads/minute and 2.9 and 6.5 rads/minute respectively. In the majority of patients the aetiology of IP was investigated by lung biopsy with histology and culture. There was no statistically significant difference in the incidence of IP over the two sets of dose rates. Our study suggests tat the incidence of IP using fractionated TBI is not influenced by dose rates below 8.9 rads per minute.     

Nitrobenzene poisoning and spurious pulse oximetry

The successful management of nitrobenzene poisoning in a 21-year-old patient is presented. We report our experience of ventilatory care with additional intravenous methylene blue and ascorbic acid therapy. Pulse oximeters available at present are not useful in patients treated with methylene blue and should be used cautiously in the presence of cyanosis of unknown aetiology.     

Hepatic Uptake and Metabolism of 2,3,7,8-Tetrachlorodibenzo-p-dioxin and 2,3,7,8-Tetrachlorodibenzofuran

The pharmacokinetics of TCDD and related compounds is congener,dose, and species specific, with urinary and biliary excretionbeing dependent on the metabolism of these compounds. Isolatedhepatocytes and liver slices in suspension culture and hepaticmicrosomes were used as in vitro models to assess the hepaticuptake and metabolism of [³H]- and [¹⁴C]- TCDD and [³H]TCDF(0.01–1.0 µM) in control and induced (5 µgTCDD/kg, 3 days earlier) male Sprague-Dawley rats. TCDD pretreatment,with an increase in cytochromes P450 1A1 and 1A2 (CYP1 Al, CYP1A2),produced an increase in the hepatic uptake of TCDD, while noincrease in the hepatic uptake of TCDF was observed. The resultsare consistent with CYP1A2 serving as a hepatic binding proteinfor TCDD but not for TCDF. The rates of metabolism of TCDD andTCDF were directly proportional to their concentrations, indicatingthat the reaction follows first order kinetics at concentrationsfrom 0.01 to 1.0 µM. Very limited metabolism of TCDD andTCDF was observed in control rat liver (0.45 and 3.2 pmol/hr/ghepatocyte wet wt at 0.1 µm, respectively). TCDD inducedits own rate of metabolism about two- to fivefold at 1.0 µMbut no induction was observed at 0.01 and 0.1 µM. In contrast,TCDD markedly induced the rate of TCDF metabolism at all substrateconcentrations. While the results support the role of rat CYP1A1in TCDF metabolism, the data suggest that CYP1 Al or CYP1A2may not metabolize TCDD. These results also support the hypothesisthat the more rapid metabolism and excretion of TCDF accountsfor the relative resistance of the rat to the acute toxicityof TCDF. Comparative studies in rat and human liver microsomesfound that TCDF metabolism exhibited first order kinetics inboth species. Furthermore, the rate of TCDF metabo-lism in humanliver microsomes was similar to that of control rat liver microsomes.Together the results suggest that TCDF will be far more persistentin rats, and possibly humans, following exposure at low doseswhich do not significantly induce cytochrome P450 1A1 and/or1A2.     

SOMATIC NEUROPATHY IN DIABETES MELLITUS

One hundred patients of Diabetes Mellitus (70 with and 30 without clinical somatic neuropathy) were studied to correlate clinical severity with the magnitude of nerve conduction abnormalities. Age range was 10-79 years (mean 49) with equal number of males and females. Incidence of neuropathy was more in patients over 40 years of age (60 out of 70 patients) with duration of disease over two years (78.33%). The grades of severity were mild in 22 (31.33%), moderate in 25 (35.71%) and severe in 23 (32.86%) patients. Nerve conduction studies were carried out in 48 (27 with and 21 without clinical neuropathy) patients, using the apparatus Dantec (Cantata TM). The nerves (median, peroneal and sural) were stimulated at two points and the recording of latency; amplitude (micro V) and motor and sensory nerve conduction velocities (m/s) were done under identical environmental conditions. Sensory nerve conduction velocity was more affected than motor velocity. In the 21 patients without clinical neuropathy, 14 showed abnormalities indicating early involvement of peripheral nerves. Reduction of motor nerve conduction velocity was more in patients with moderate and severe grades. The reduction was more in lower than in upper limbs. Nerve conduction abnormality helps in diagnosis in diabetic neuropathy even in preclinical state and correlates with severity, in clinical neuropathy.KEY WORDS: Diabetic neuropathy, Nerve conduction abnormality, Peripheral neuropathy     

克拉霉素治疗慢性鼻-鼻窦炎的临床效果及安全性评价

目的 研究慢性鼻-鼻窦炎(CRS)患者行克拉霉素治疗的临床效果.方法 选择2019年1月～2019年12月间襄阳市第一人民医院收治的84例CRS患者,采用随机数表法分为观察组(克拉霉素)与对照组(鼻用激素布地奈德)各42例,比较两组白细胞介素-6(IL-6)、肿瘤坏死因子-α(TNF-α)、血清总IgE(TIgE)、嗜...     

Complications of laparoscopic radical cystectomy during the initial experience

AIM: Radical cystectomy is the standard of care for patients with muscle invasive bladder cancer. While open radical cystectomy is now a standard procedure, laparoscopic radical cystectomy is still in its infancy. We performed this surgery laparoscopically in 11 patients and review the procedure specific complications. METHODS: Beginning in February 1999, 11 patients underwent laparoscopic radical cystectomy at the Department of Urology, All India Institute of Medical Sciences, New Dehli. Urinary diversion was performed by an open-hand sewn ileal conduit. RESULTS: There were three intraoperative complications specifically related to the laparoscopic radical cystectomy. These included injury to the external iliac vein in one patient and a small rectal tear in two. All were repaired with laparoscopic free hand suturing with normal postoperative recovery. Other laparoscopy-related complications were subcutaneous emphysema in one patient and hypercarbia necessitating conversion to open surgery in a patient who, four weeks after surgery, died of multiple organ failure. One patient had margins positive and received cisplatinum-based chemotherapy. All patients had normal renal function and preserved upper tracts with no evidence of metastasis at a mean of 18.4 months follow up (range 1-48 months). CONCLUSIONS: Though there were three complications specific to the laparoscopic radical cystectomy, none necessitated a conversion to open surgery or hampered the overall outcome. Absence of local recurrence or metastatic disease at four years of follow up suggests that the procedure is oncologically valid. Laparoscopic radical cystectomy is a new procedure and it is important to critically analyze the complications in order to reduce their occurrence and allow the development of a better technique.