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Biomedical subjects

D Chadha

Publications and source records attributed to D Chadha.

At least 19 recordsLinked to original sources

Isolated gastric varices: ultrasound detection.

Isolated gastric varices (IGV) (resulting from varying etiologies) were diagnosed in six patients using ultrasound examination of the wall of the fluid-filled stomach. Small gastric varices are seen as circular or linear anechoic channels within the gastric wall without a significant intraluminal projection. Large varices are seen as anechoic, lobulated "bulging masses" projecting into the fluid-filled lumen of the stomach. Doppler technique assists in confirming the vascular nature of these lesions and thus avoids confusion with other hypoanechoic lesions of the gastric wall. The technique is simple, noninvasive, and extremely useful in diagnosing IGV in patients investigated for recurrent undiagnosed gastrointestinal bleeding.

Adolescent

Roundworm obstruction: sonographic diagnosis.

We describe the sonographic findings in five pediatric patients with roundworm obstruction. All patients were referred with a clinical diagnosis of acute appendicitis. On ultrasonography (US), an individual worm, when viewed along its longitudinal axis, appeared as a hypoechoic tubular structure with well-defined, echogenic walls. Frequently, the individual body segments could be distinctly visualized. The alimentary canal of the worm was seen either as a single central echogenic line (when in a collapsed state) or as two parallel hyperechoic bands with a hypoechoic center (when distended). When examined transaxially, the individual worm resembled a target with its circular, echogenic body wall and its central dot-like alimentary canal. On prolonged scanning, the worms always showed curling movements. In two patients, a bolus of worms mixed with fecal matter and air produced an unusual appearance of a complex, echogenic mass (helminthoma). Although, an individual worm occasionally resembled an inflamed appendix, visualization of the alimentary canal and individual body segments along with its curling movements helped establish the correct diagnosis. All patients promptly responded to a hypertonic saline enema and no patient was subjected to surgery. Sonographic findings in roundworm obstruction are fairly characteristics to advocate the routine use of sonography for diagnosing this entity.

Acute Disease

Sonographic detection of pneumoperitoneum: an experimental and clinical study.

The sonographic appearance of intraperitoneal air collection has been studied in 46 patients. In 30 patients (group I), a pneumoperitoneum had been iatrogenically induced either during aspiration of ascitic fluid or during laparoscopy. Three normal volunteers (group II) had been subjected to graded intraperitoneal air injection to quantify the smallest amount of air detectable by ultrasound (US). In eight patients (group III) the sonographic demonstration of free intraperitoneal air led to a diagnosis of hollow visceral perforation; whereas in another five patients (group IV) the sonographic findings reinforced the clinical suspicion of a 'sealed off' perforation in the presence of negative roentgenograms. In all patients intraperitoneal air was seen as an echogenic line with a posterior reverberation or ring down artefact. In patients with free air, this was best seen in the perihepatic spaces with the patient in the supine, left lateral decubitus or prone position. As little as 5 mL of air could be consistently detected in all three volunteers (group II). Artefacts leading to a pseudopneumoperitoneum on US included; (i) the artefacts distal to an overlying rib; (ii) ring-down artefact from air in the adjacent lungs; and (iii) hepatodiaphragmatic interposition of colon. With proper sonographic technique and principles of interpretation these can be distinguished from true intraperitoneal air. Although sonography may be more informative than conventional radiology in patients with hollow visceral perforation, we did not find it more sensitive than conventional roentgenograms in detecting free intraperitoneal air. Sonography, however, is distinctly superior in patients with a sealed off perforation in whom conventional roentgenograms are frequently negative.

Female

Cefepime concentrations in bronchial mucosa and serum following a single 2 gram intravenous dose.

The concentrations of cefepime in bronchial mucosa were measured after intravenous administration of a single 2 g dose in 20 patients undergoing diagnostic fibreoptic bronchoscopy. These concentrations were compared with simultaneous serum concentrations. The mean bronchial mucosal concentration was 24.1 mg/kg (s.d. 17.8 mg/kg) and the mean serum concentration was 40.4 mg/l (s.d. 28.1 mg/l). The mean percentage penetration was 59.8% (s.d. 12.5%). We conclude that a twice daily dosing of cefepime would be adequate for most respiratory infections although an 8-hourly dose may be necessary in pseudomonal infections.

Biological Assay