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Biomedical subjects

A C Mehta

Publications and source records attributed to A C Mehta.

At least 91 records · Page 5Linked to original sources
PubMed1990

Ultrasonographically observed preterm grade III placenta and perinatal outcome.

Ultrasound studies of placenta were conducted in 270 singleton normal pregnancies. Women were enrolled between 31 and 34 weeks of gestation and were followed up for the outcome of pregnancy. Women with grade III placental maturity comprised the study group (n = 64) and those with grade I placenta were enrolled as control group (n = 206). Another 100 normal women were enrolled to note the prevalence of grade III placenta at term. There was an increased incidence of intrauterine growth retardation (6.20%) and fetal distress (7.8%) in the study group compared with the control group (nil), which was statistically significant. The incidence of low birth weight was also higher (34.37%) in the study group compared with the control group (22.33%). Three women in the study group developed preeclampsia at subsequent follow up visit but none in control group (P less than 0.01). Prevalence rate of grade III placenta at term was 28%. In view of these findings preterm grade III placenta is found to be a sensitive predictor of poor perinatal outcome.

Adult↗
PubMed1990

Intrathoracic lymph node evaluation by CT and MRI with histopathologic correlation in non-small cell bronchogenic carcinoma.

Twenty patients with non-small cell bronchogenic carcinoma were prospectively studied for intrathoracic lymphadenopathy using computed tomography (CT) and magnetic resonance imaging (MRI). The CT and MRI results were correlated with the surgical histopathology results of 103 harvested lymph nodes. Based on node dimension (utilizing a 1-cm cutoff value), neither imaging modality was accurate in predicting the histopathology of the nodes. CT had a sensitivity of 21%, specificity of 95%, and an overall accuracy of 85%; MRI had a sensitivity of 14%, specificity of 97%, and an overall accuracy of 85%. Moreover, CT and MRI detected preoperatively only 17% and 14%, respectively, of the harvested nodes. In summary, lymph node sizes measured by CT and MRI are inaccurate in predicting the benignity or malignancy of lymph nodes. Lymphadenopathy can be present even with a "negative" CT or MRI scan of the thorax.

Carcinoma, Bronchogenic↗
PubMed1990

Chiral high performance liquid chromatography of drug molecules.

The individual enantiomers of racemic drugs frequently differ in their biological effects. For pharmacological studies of such drugs there is therefore a need for an effective means of separating and quantifying the enantiomers in biological samples. As their physicochemical properties are similar, the assay of enantiomers is generally regarded as difficult, time-consuming and error-prone. However, recent developments in high performance liquid chromatography (HPLC) chiral stationary phase technology overcome some of these problems and provide a more efficient and reliable way of assaying enantiomeric drugs.

Chromatography, High Pressure Liquid↗
PubMed1990

Effect of photodynamic therapy and external beam radiation therapy on juvenile laryngotracheobronchial papillomatosis.

Treatment of juvenile laryngotracheobronchial papillomatosis is currently unsatisfactory and typically involves frequent endoscopic removal of the lesion with cup forceps and laser therapy. Malignant transformation of these lesions is a known complication. A case is reported of an adult patient with persistent juvenile laryngotracheobronchial papillomatosis who developed carcinoma in situ of the trachea and right upper lobe bronchus. He underwent experimental photodynamic therapy using dihematoporphyrin ether and rhodamine B dye laser. In addition, he received external beam radiation therapy. Bronchoscopy revealed no evidence of carcinoma in situ or recurrence of the underlying papillomas for a follow-up period of 24 months. This observation suggests that photodynamic therapy with dihematoporphyrin ether, either alone or in combination with radiation therapy, may have a role in the ablation of juvenile laryngotracheobronchial papillomatosis.

Adult↗
PubMed1990

Amyloidosis and pleural disease.

Pleural involvement with systemic amyloidosis has been reported rarely in the literature. Diagnosis of this entity by percutaneous needle biopsy of the pleura has been described only in two prior case reports. We describe five patients in whom the diagnosis of pleural amyloidosis was established by Cope needle biopsy during evaluation of pleural effusions of indeterminate cause. Three patients presented with a history suggestive of multiorgan disease and a pleural biopsy performed despite a transudative effusion demonstrated amyloid infiltration of the pleura, obviating the need for other organ biopsies. We conclude that in patients with pleural effusions, if history suggests multiorgan involvement and there is suspicion for amyloidosis, then a closed pleural biopsy with special stains for amyloid should be performed even if the effusions are transudative. This may be the diagnostic procedure of choice in such patients.

Aged↗
PubMed1990

Evaluation of wheezing in the nonasthmatic patient.

Wheezing is a nonspecific manifestation of airway obstruction. Even though bronchial asthma is the most common cause of wheezing, a variety of pulmonary and nonpulmonary conditions can present with this symptom. In recent years methacholine provocation challenge has simplified detection of bronchial asthma; however, establishing accurate diagnosis of other causes of wheezing is important because each condition requires specific treatment. This article describes a methodical approach to the diagnosis of wheezing in patients who are not asthmatic.

Adult↗
PubMed1989

Potential of wide bore open tubular columns in gas chromatographic analysis of drugs.

The recent introduction of wide bore flexible fused silica columns and the development of chemically bonded stationary phases for gas chromatography (GC) has opened up new possibilities for carrying out medium resolution capillary GC on packed column instruments. The favourable chromatographic properties of wide bore capillary columns make them ideal for applications in many areas of GC. This review discusses the characteristics of more popular 0.53 mm I.D. wide bore columns, experimental conditions necessary for their use and their applications in the pharmaceutical field with an emphasis on the analysis of drugs in biological fluids.

Chromatography, Gas↗
PubMed1989

Preanalytical considerations in drug assays in clinical pharmacokinetic studies.

Many hospital pharmacy laboratories undertake drug analysis in biological fluids for the production of pharmacokinetic data. The success of such an undertaking very much depends on the selection of a suitable analytical method and a proper approach to sample collection and handling. This paper surveys the main types of biological specimens taken from the patients for pharmacokinetic drug analysis and discusses factors that affect them during or subsequent to their removal. Guidelines are provided in specimen handling and dealing with many problems which could arise prior to actual analysis. By its very nature this paper brings in many disciplines, the full details of which are well beyond its scope, however, some discussion on pharmacokinetic and bioavailability methods in relation to sampling procedures is included to put the matter into a proper perspective.

Body Fluids↗
PubMed1989

The validation criteria for analytical methods used in pharmacy practice research.

An integral part of analytical method development is validation, i.e. once the method has been devised it is necessary to evaluate it under the conditions expected for real samples before being used for a specific purpose. Although the validation stage is crucial in method development, the importance of this step is often overlooked. This paper attempts to clarify the nomenclature of method validation and describes the validation procedure for analytical methods used for the determination of drugs in biological fluids and formulations.

Calibration↗
PubMed1989

Nd-YAG laser-induced endobronchial burn. Management and long-term follow-up.

Endobronchial fires are a rare complication of Nd-YAG laser photoresection. Short-term morbidity is secondary to sloughing mucosa and mucous plugging. Aggressive pulmonary hygiene, including frequent bronchoscopies and possibly a tracheostomy, may be required. The major long-term complication is obstruction of the airways from granulation tissue. Long-term follow-up is required to evaluate and treat clinically significant granulation tissue in the airways.

Aged↗
PubMed1989

Endobronchial Mycobacterium avium-intracellulare infection in a patient with AIDS.

The pulmonary manifestations of AIDS are well described in the medical literature; however, MAI infection presenting as an endobronchial lesion has not, to our knowledge, been reported in a patient with AIDS. We report a unique case of an AIDS patient who developed endobronchial polypoid lesions secondary to MAI infection. Complications resulting from these lesions included hemoptysis and later bronchiectasis.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Transbronchial needle aspiration for histology specimens.

Fine-gauge (22-G) transbronchial needle aspiration (TBNA) has significantly added to the diagnostic yield of FOB, and in some institutions has become routine in staging bronchogenic carcinoma. Cytologic examination of the specimen obtained by n228G TBNA, however, has several limitations. The mediastinal aspirate can be contaminated by tumor cells from respiratory secretions, giving false positive diagnoses of unresectability. The diagnosis of benign conditions can seldom be made. Using 18-G TBNA, we can obtain specimens for histologic examination from paratracheal, peribronchial, and carinal areas by FOB. Both 18-G and 22-G TBNA were performed in 34 patients with radiographic abnormalities involving mediastinal or hilar areas. Tissue for histologic examination was obtained in 17 patients (50 percent) using 18-G TBNA and was diagnostic in 11 (32 percent), including three patients with benign conditions. The overall diagnostic yeild of 18-G TBNA was 41 percent (14/34 patients), increasing the yield of FOB from 50 percent to 58 percent. There were no false positive results and few minor complications. 18-G TBNA is effective in obtaining tissue for histologic examination and diagnosing benign conditions. In selected cases this technique increases the diagnostic yield of FOB.

Adenocarcinoma↗
PubMed1988

Peripheral small cell undifferentiated carcinoma of the lung. Clinicopathologic features of 17 cases.

Seventeen cases of resectable peripheral small cell undifferentiated carcinoma of the lung were studied (average size, 2.1 cm; range, 0.9-3.5 cm). The carcinomas exhibited predominantly mixed intermediate and fusiform/spindle subtypes; in seven carcinomas there were at least some foci of oat cell subtype. There was no histologic evidence of typical carcinoid tumor. Seven cases were fixed in solutions appropriate for immunohistologic study; these exhibited prominent neuron-specific enolase activity but less prominent and more variable staining for the carcinoembryonic antigen and cytokeratins. All 17 cases were deemed resectable and had no clinical or radiologic evidence of metastasis. Seven (41%) patients died with recurrent and/or metastatic carcinoma (average survival, 1.7 years); five of these patients had carcinomas with at least some foci of oat cell foci subtype.

Adult↗