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Biomedical subjects

A C Mehta

Publications and source records attributed to A C Mehta.

At least 73 records · Page 4Linked to original sources
PubMed1994

Endobronchial radiation therapy with or without neodymium yttrium aluminum garnet laser resection for managing malignant airway obstruction.

BACKGROUND: Previous reports have shown low-dose-rate (LDR) afterloading Ir-192 endobronchial radiation therapy (EnBRT) to effectively palliate symptoms in patients with malignant airway obstruction. The authors retrospectively assessed the consequences of LDR EnBRT with or without neodymium yttrium aluminum garnet (Nd:YAG) laser resection in 37 patients. METHODS: Between February 1986 and June 1991, 37 patients with malignant airway obstruction were treated with LDR EnBRT at The Cleveland Clinic Foundation. Inclusion criteria for LDR EnBRT with or without Nd:YAG laser resection were patients with recurrent, symptomatic endobronchial lesions treated previously with external beam irradiation. Of the 37 patients, 21 patients with endobronchial lesions underwent Nd:YAG laser resection; 16 patients with mainly extrinsic lesions received EnBRT only. Before EnBRT, selected patients (7 of 16 in the nonlaser-treatment group and 14 of 21 in the laser-treatment group) received additional external beam treatments of 2000 cGy/10 fractions. The LDR afterloading Ir-192 technique was used to deliver approximately 30 Gy to a 1.0-cm radius target. RESULTS: All patients had one or more of the following symptoms: 1) dyspnea, 2) fever, 3) cough, and 4) hemoptysis. Good-to-excellent symptom relief was apparent in 16 of 21 (76.2%) laser-treated patients and in 12 of 16 (75%) nonlaser-treated patients. Follow-up bronchoscopy in 28 patients revealed tumor regression in 22 (79%). Median survival time was 16.3 weeks in the laser group and 11.7 weeks in the nonlaser group (P = 0.36). Longer median survival times were noted in laser-treated (22.8 weeks) and nonlaser-treated (16.4 weeks) patients receiving additional external beam treatments. Exsanguination occurred in 7 of 21 (33.3%) laser-treated patients and in 4 of 16 (25%) nonlaser-treated patients. The only factor affecting the exsanguination rate was implant location: 6 of 11 (54.5%) patients had lesions in the right or left upper lobe. CONCLUSIONS: EnBRT alone or with Nd:YAG laser resection provided good-to-excellent symptom palliation in these patients although a high rate of exsanguination occurred in both groups.

Adult↗
PubMed1994

At what 'infant-age' can levonorgestrel contraceptives be recommended to nursing mothers?

OBJECTIVE: Levonorgestrel (LNG), a low-dose progestin, does not affect lactation but like all drugs taken by breastfeeding mothers, it can be transferred to the infant via breast milk. How infants of various ages cope with this unwanted maternal drug would help in deciding when to recommend this method of contraception to breastfeeding mothers. METHODS: The study was conducted in 30 exclusively breastfeeding mothers and their 4-, 12- and 24-week-old infants. The mothers daily received 30 micrograms LNG over a five-week period, thus exposing their infants to maternal LNG for that period. RESULTS: Four-week-old infants could neither absorb nor metabolize LNG efficiently. Twelve-week-old infants could metabolize LNG more efficiently than absorb. Twenty-four-week-old infants could do both efficiently. CONCLUSION: It is safe to introduce LNG to breastfeeding mothers at 12 weeks postpartum.

Adult↗
PubMed1994

In vitro dissolution of piroxicam capsules.

The in vitro dissolution rates of 10- and 20-mg piroxicam capsules from different suppliers in the U.K. were measured in simulated gastric fluid using rotating basket apparatus. Seven brands were tested and all were found to be satisfactory with at least 75% dissolution in 45 min.

Capsules↗
PubMed1994

Stability of amoxycillin and potassium clavulanate in co-amoxiclav oral suspension.

A study was carried out using high performance liquid chromatography (HPLC) to determine the chemical stability of amoxycillin and potassium clavulanate in 250/62 co-amoxyclav oral suspension (Augmentin), stored at room temperature (RT, 20 degrees C) and 8 degrees C over a period of 11 days. The suspension was judged to be acceptable if its components maintained at least 90% of their label concentrations. During the test period, the amoxycillin component was found to be more stable than the clavulanate. Amoxycillin was stable for 7 days at both temperatures. Potassium clavulanate maintained at least 90% of its initial concentration for 7 days at 8 degrees C but showed more than 40% degradation in the same time period at RT. For potassium clavulate the shelf-life, or time taken for the original concentration to drop to 90% of its value (t90) at RT was found to be 2 days.

Amoxicillin↗
PubMed1994

Right-to-left interatrial shunt causing platypnea after pneumonectomy. A recent experience and diagnostic value of dynamic magnetic resonance imaging.

Shortness of breath after pneumonectomy is a common finding that has multiple causes. We report the cases of two patients with shortness of breath on assuming an upright posture (platypnea) that followed pneumonectomy; these individuals developed right-to-left shunt across a patent foramen ovale (PFO) with normal right-sided intracardiac pressures. Both contrast echocardiography and magnetic resonance imaging (MRI), including a recently introduced dynamic ultrafast imaging technique, proved helpful in diagnosing this condition noninvasively.

Aged↗
PubMed1993

Concentric tracheal and subglottic stenosis. Management using the Nd-YAG laser for mucosal sparing followed by gentle dilatation.

Treatment of tracheal stenosis varies with the type and extent of the disease. Tracheostomy with stents, end-to-end anastomosis, or extensive reconstructive procedures often is required, especially when tracheomalacia is present. High recurrence rate is associated with relatively less invasive endotracheal treatments, such as bougie dilatation or total laser ablation. Mucosal sparing technique using Nd:YAG laser photodissection (LPD) and gentle dilatation (GD) can provide durable successful results in selected patients with benign concentric tracheal stenosis (CTS). In our study of 18 patients with CTS, 12 were successfully treated with Nd:YAG LPD and GD. Of these patients, eight required a single treatment while four required two or more treatments. No patients required new tracheostomy to carry out the procedure. Follow-up periods ranging from 2 to 85 months (mean: 32.6 +/- 1.5 months) for 12 successfully treated patients have revealed no recurrence of their stenosis. Lengthy scars (> 1 cm) and tracheomalacia were the clinical features common to those patients who failed the treatment. We advocate the use of Nd:YAG LPD in conjunction with "gentle" rigid bronchoscopic dilatation as the initial treatment of CTS.

Adult↗
PubMed1993

Sputum cytology.

Examination of sputum is the least invasive method of obtaining a cytologic diagnosis in a patient suspected of harboring lung cancer. Cytologic diagnosis has advanced to a point where it is of comparable value to histology. The authors discuss the sensitivity, specificity, reliability, and pitfalls of sputum cytology as well as the role it plays in screening of early lung cancer. The advantages and shortcomings of sampling and cytopreparatory techniques are also reviewed. Concluding remarks outline future developments in sputum cytology.

Forecasting↗
PubMed1992

Massive air embolism complicating Nd-YAG laser endobronchial photoresection.

A 63 year old male underwent 6,900 rads of external radiation for a squamous cell carcinoma of the left main bronchus. Recurrence of the tumor 8 months later was treated with 6,618 joules and patency of the left main bronchus was restored. Four months later, he developed complete atelectasis of the left lung requiring repeat laser. During the procedure he became hypotensive, bradycardic, and hypoxic due to a tension pneumothorax. Although treated promptly with thoracostomy tube drainage, the patient never awakened. CT scan of the brain demonstrated anoxic encephalopathy with air present in the right frontal lobe. Brain death was confirmed by an EEG and cerebral angiogram. Air embolism has been reported in conjunction with diagnostic procedures including therapeutic pneumothorax for tuberculosis, transthoracic needle biopsy of the lung, and positive pressure ventilation with or without pneumothorax. The only reported case of air embolism associated with laser was a small middle cerebral artery cerebro-vascular accident which was self limited. Its mechanism is unclear, but it is suspected to be due to a communication between a pulmonary vein and the atmosphere. A greater volume of air will enter the damaged vessel in the setting of positive pressure ventilation and/or a tension pneumothorax. When neurologic manifestations are present, hyperbaric oxygen therapy is the treatment of choice. Prompt institution in hemodynamically stable patients can minimize neurologic sequelae.

Bronchial Neoplasms↗
PubMed1992

High-performance liquid chromatographic determination of ciprofloxacin in plasma.

This paper describes an accurate, specific and sensitive high-performance liquid chromatographic (HPLC) method for the determination of ciprofloxacin in small samples (0.5 ml). The samples, after pretreatment by solvent extraction, were eluted on a reversed-phase column and detected by an ultraviolet detector. The results obtained on patient samples are presented.

Chromatography, High Pressure Liquid↗
PubMed1992

A critical appraisal of chromatographic and immunoassay techniques for clinical drug analysis.

Chromatography and immunoassays are the two principal techniques used in research and clinical laboratories for the measurement of drug concentrations in biological fluids. The purpose of this article is to provide the reader with a general overview of these techniques and to present their relative merits and limitations. A glossary of technical terms is included at the end of the review.

Chromatography↗
PubMed1991

Single-lung transplantation with atrial septal defect repair for Eisenmenger's syndrome.

Heart-lung transplantation has been used successfully for patients with pulmonary vascular disease but its application has been very limited due to the scarcity of donors. We report a patient with Eisenmenger's syndrome who underwent right single-lung transplantation with closure of atrial septal defect; postoperative convalescence was uneventful. Serial magnetic resonance imaging examinations demonstrate improved right heart function.

Adult↗
PubMed1991

Endobronchial and parenchymal juvenile laryngotracheobronchial papillomatosis. Effect of photodynamic therapy.

Juvenile laryngotracheobronchial papillomatosis (JLTBP) is a recurrent, prolonged disease usually confined to the upper airway. Rarely, tracheobronchial tree or lung parenchymal involvement occurs. The various therapeutic interventions are often unsuccessful once extralaryngeal involvement becomes apparent. Photodynamic therapy (PDT) has been successful in eradicating JLTBP in a few case reports. We present a case of extensive JLTBP with parenchymal involvement treated with multiple courses of PDT. We demonstrated temporary regression of endobronchial papillomas, but no change in parenchymal lesions. Recurrent endobronchial disease was most likely related to reinfection from parenchymal lesions inaccessible to PDT.

Adolescent↗