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Biomedical subjects

A Ahuja

Publications and source records attributed to A Ahuja.

At least 73 records · Page 4Linked to original sources
PubMed1996

Inhibition of the human neutrophil respiratory burst by native and synthetic surfactant.

Production of oxygen radicals by phagocytic cells and loss of surfactant function have each been implicated in the pathogenesis of acute lung injury. Therapeutic administration of exogenous surfactant to injured lungs in which neutrophils are the dominant cell type has been proposed. To understand the role of surfactant in modulating pulmonary inflammation and the impact of surfactant supplementation on diseased lungs, we studied the effect of native porcine and synthetic surfactant preparations on human neutrophil respiratory burst oxidase activity in vitro. We found that surfactant inhibited neutrophil superoxide production induced by either receptor-mediated [formylmethionylleucylphenylalanine (fMLP)] or non-receptor-mediated [phorbol myristate acetate (PMA)] agonists with an IC50 of approximately 0.015 mg phospholipid/ml for porcine surfactant or approximately 0.050 mg phospholipid/ml for synthetic surfactant. Surfactant had no effect on detection of superoxide generation in a noncellular system using xanthine and xanthine oxidase and only minimally inhibited superoxide generation by neutrophils that had been fully stimulated by prior exposure to PMA. There was no effect of surfactant on neutrophil calcium mobilization in response to fMLP, on lactoferrin release in response to PMA, or on membrane protein kinase C activity in response to PMA. Suspensions of dipalmitylphosphatidylcholine alone had no effect on neutrophil superoxide production. Taken together, these findings indicate that certain components of lung surfactant may effect relatively late steps in the activation of the respiratory burst or may alter subsequent steps involved in the assembly of the respiratory burst oxidase.

1,2-Dipalmitoylphosphatidylcholine↗
PubMed1996

High resolution sonographic detection of axillary lymph node metastases in breast cancer.

Axillary lymph node status is crucial in the evaluation of prognosis and in treatment planning of breast cancer. High-resolution real-time sonographic scans of the breast and both axillae were performed on 114 patients with breast carcinoma, all of whom had axillary lymph node dissection and histologic assessment. The sensitivity of high-resolution ultrasonography in the detection of axillary nodal metastases was 84.1%, with a specificity of 97.1%, accuracy of 92.1%, positive predictive value of 94.9%, and negative predictive value 90.7%. Ultrasonography of the axilla provides good information on anatomy and pathology and may have a potential role in the prognostic work-up of patients who are not surgical candidates.

Adult↗
PubMed1996

Sonographic appearance and distribution of normal cervical lymph nodes in a Chinese population.

In 100 normal subjects who had a sonographic examination of the neck, 1211 lymph nodes were detected. In all the subjects, at least five lymph nodes were seen. The distribution, number, echogenicity, shape, presence or absence of echogenic hilus, and the sharpness of nodal borders of normal cervical lymph nodes were determined. The usefulness of these sonographic features in understanding the normal distribution and characteristics of the nodes in the Chinese population is discussed. The relationship between the shape and size of lymph node also was assessed.

Adolescent↗
PubMed1995

Molecular basis of human mitochondrial very-long-chain acyl-CoA dehydrogenase deficiency causing cardiomyopathy and sudden death in childhood.

beta-Oxidation of long-chain fatty acids provides the major source of energy in the heart. Defects in enzymes of the beta-oxidation pathway cause sudden, unexplained death in childhood, acute hepatic encephalopathy or liver failure, skeletal myopathy, and cardiomyopathy. Very-long-chain acyl-CoA dehydrogenase [VLCAD; very-long-chain-acyl-CoA:(acceptor) 2,3-oxidoreductase, EC 1.3.99.13] catalyzes the first step in beta-oxidation. We have isolated the human VLCAD cDNA and gene and determined the complete nucleotide sequences. Polymerase chain reaction amplification of VLCAD mRNA and genomic exons defined the molecular defects in two patients with VLCAD deficiency who presented with unexplained cardiac arrest and cardiomyopathy. In one, a homozygous mutation in the consensus dinucleotide of the donor splice site (g+1-->a) was associated with universal skipping of the prior exon (exon 11). The second patient was a compound heterozygote, with a missense mutation, C1837-->T, changing the arginine at residue 613 to tryptophan on one allele and a single base deletion at the intron-exon 6 boundary as the second mutation. This initial delineation of human mutations in VLCAD suggests that VLCAD deficiency reduces myocardial fatty acid beta-oxidation and energy production and is associated with cardiomyopathy and sudden death in childhood.

Acyl-CoA Dehydrogenase, Long-Chain↗
PubMed1995

The application of ultrasound criteria for malignancy in differentiating tuberculous cervical adenitis from metastatic nasopharyngeal carcinoma.

Tuberculous adenitis and metastatic nodes from Nasopharyngeal carcinoma may have a similar clinical presentation. Clinical examination and laboratory tests alone are unable to differentiate the two. However, ultrasound is a useful initial investigation in differentiating these two conditions. We present ultrasound appearances in 33 patients with proven tuberculous cervical adenitis and 32 patients with proven metastatic nasopharyngeal carcinoma. The ultrasound features we found useful were the distribution of the nodes, cystic change, matting and surrounding soft tissue oedema. The size, shape and internal architecture of the nodes, previously described criteria in differentiating benign from malignant nodes, did not help.

Adolescent↗
PubMed1995

Angioplasty for symptomatic radiation-induced extracranial carotid artery stenosis: case report.

A patient with cervical lymphoma received chemotherapy and radiation to the neck. He later presented with crescendo transient ischemic attacks. Angiography demonstrated bilateral cervical carotid stenosis, which was presumed to be the result of previous radiation therapy. Percutaneous transluminal angioplasty with balloon dilation of the symptomatic lesion resulted in an immediate cessation of the patient's transient ischemic attacks. Nine months later, he developed a symptomatic cervical carotid stenosis of the contralateral carotid artery, which also was treated successfully with angioplasty, resulting in a good clinical outcome. The patient has experienced no further ischemic events in the 2 years after treatment.

Adult↗
PubMed1995

Lumbar discectomy: use of an epidural morphine sponge for postoperative pain control.

A technique for extended ambulatory epidural pain control after lumbar discectomy is described; preliminary results with 45 patients are reported; and alternative methods of narcotic analgesia are reviewed. In this technique, an absorbable gelatin sponge (Gelfoam, Upjohn Co., Kalamazoo, MI) is contoured to the laminotomy defect, placed in methylprednisolone acetate (40-80 mg), and then injected with 2 to 4 mg of preservative-free morphine (a small needle was used to fill the sponge). The sponge is placed over the defect before closure. A review of office and hospital records was conducted. The series consisted of 33 men and 12 women (mean age, 39 yr; range, 24-57 yr); records showed narcotic use in 34 patients (parenteral in 3) and work-related injuries in 14 patients. Thirty-three patients were ambulatory postoperatively on the day of surgery; all were ambulatory by postoperative day (POD) 1. On the day of surgery, 18 patients did not require any postoperative analgesics; on POD 1, 22 patients did not require analgesics. Six patients received parenteral narcotics; four received one dose only, and two had two or more doses. Thirty-one patients were discharged from the hospital on POD 1, and 10 were discharged POD 2. The other patients were discharged from the hospital on POD 3 (three patients) or POD 4 (one patient). When they were discharged, all patients received a limited supply of acetaminophen with codeine for pain control at home. After discharge, phone follow-up (at 1 week) and office follow-ups (at 3-5 weeks) revealed only one patient with more than mild discomfort. Three patients required one-time bladder catheterization, and one patient had presumed discitis 1 month postoperatively. In a control group who had undergone surgery 3 months previously, the average day of discharge had been POD 3.07; no control patient had been discharged on POD 1, and only 20% had been discharged on POD 2. This method provides effective, safe, and extended analgesia after lumbar discectomy.

Adult↗
PubMed1995

Ultrasonographic demonstration of normal axillary lymph nodes: a learning curve.

High frequency transducers with near field resolution allow visualization of superficial structures in the axilla, such as the lymph nodes, which could not be visualized with older equipment. We have been able to observe normal axillary nodes in 61.5% of 26 women who had histologic correlation of normal lymph nodes at axillary dissection. We studied 663 women with a clinically palpable breast lump using breast and axillary ultrasonography. They were divided into four groups. The first group consisted of all women who had undergone surgery and had histologic correlation of axillary nodes. The second, third, and fourth groups were made up of three consecutive series of 221 women examined. Women from group one were included in groups two, three, and four. A steep learning curve of 7.1 to 41.9 to 64.7% was observed in the detection of normal axillary nodes, suggesting that these appearances can be recognized easily.

Axilla↗
PubMed1995

Balloon test occlusion of the internal carotid artery with hypotensive challenge.

PURPOSE: To evaluate the usefulness of provocative testing with hypotensive challenge during balloon test occlusion of the internal carotid artery before carotid sacrifice and to correlate tolerance of balloon test occlusion with clinical outcome after carotid artery sacrifice. METHODS: Forty-seven consecutive cases of balloon test occlusions performed at our institution during the past 4 years were retrospectively reviewed. Occlusion was performed under normotensive conditions with distal perfusion of heparinized saline for 20 minutes, or until a deficit was perceived. If 20 minutes of normotension was tolerated, hypotension was induced to two thirds of mean arterial pressure for 20 minutes, or until a deficit was perceived. RESULTS: Of 47 patients, 4 (9%) had deficits at normotension. Of the remaining 43 patients, 9 (21%) had deficits at hypotension. One patient with a positive hypotensive test occlusion underwent carotid artery sacrifice after extracranial-intracranial bypass without sequelae. In one of the 19 patients who clinically tolerated test occlusion with hypotension and had carotid sacrifice (surgical ligation of the intracranial carotid artery), a mild embolic stroke developed, probably from the giant carotid wall aneurysm. This patient fully recovered; MR imaging showed mild changes consistent with emboli distal to the aneurysm. Symptomatic complications were noted in 2 (4%) patients, and asymptomatic arterial dissections were noted in 3 (6%) patients. CONCLUSION: Balloon test occlusion with hypotensive challenge is safe, economical, and greatly increases the sensitivity of balloon test occlusion. The predictive value of a negative test is high. However, to determine the test's specificity compared with quantitative imaging, controlled trials will be necessary.

Adult↗
PubMed1995

Cerebellomedullary ganglioglioma: CT and MR findings.

We present a case of cerebellomedullary ganglioglioma in a young child with indolent clinical symptoms. CT demonstrated a region of hypodensity with central contrast enhancement in the right cerebellar hemisphere and the inferior peduncle. On MR the lesion was iosintense on T1-weighted images with fairly homogeneous enhancement with gadolinium, and of high signal intensity on T2-weighted images.

Cerebellar Neoplasms↗
PubMed1995

Heart rate & blood lactate response in amateur competitive boxing.

The heart rate (HR) and blood lactate response were studied on 26 senior national level boxers in competitive bouts to explore the aerobic-anaerobic metabolism as well as the training status of the players. The aerobic capacity (VO2 max) of the players were determined using graded running protocol on a treadmill. Heart rate and blood lactate concentration were measured during warm up and boxing rounds. The mean relative VO2 max of the heavy weight category boxers was lower (P < 0.05) than the other two weight categories. No interweight category as well as inter-round differences were observed in the heart rate and blood lactate concentration of the boxers, excepting in the 48-57 kg category, the mean lactate levels in the second and third rounds were higher (P < 0.05) than in the first round. When all weight categories were pooled the mean HR and blood lactate levels were 178 beats/min and 8.24 mMol/l respectively. The study highlights that in amateur boxing, irrespective of the weight category and aerobic capacity, the anaerobic adaptability of the boxers was the same. The training requirements of the boxers demand that they should be also to tolerate a high blood lactate level (approx. 9.0 mMol/l) and a high HR (approx. 180 beats/min) over a total duration of one bout.

Aerobiosis↗
PubMed1994

Endovascular embolization and surgical excision for the treatment of cerebellar and brain stem hemangioblastomas.

Hemangioblastomas are histologically benign tumors that comprise 7%-10% of all posterior fossa lesions in the adult. Treatment of these lesions is often complicated by significant vascularity and difficulty of surgical resection in sensitive neural tissue, especially when the tumor has a significant solid component. We report the combined use of endovascular embolization of feeding pedicles and subsequent operative resection in two patients with solid hemangioblastomas of the cerebellum and brain stem. Preoperative embolization facilitated operative excision in sensitive neural areas and allowed complete surgical resection of tumors involving the lateral brain stem and cervicomedullary junction. Goals of preoperative embolization are control of inaccessible arterial supply and reduction of tumor vascularity.

Adult↗
PubMed1994

Radiology in survivors of traumatic atlanto-occipital dislocation.

Traumatic atlanto-occipital dislocation is fatal, but survivals are reported. Six cases of survival after atlanto-occipital dislocation are presented. Lateral cervical spine radiographs demonstrated retropharyngeal swelling in all patients, and Powers' ratio was abnormal in five of six patients. Reformatted computed tomography (CT) images or three-dimensional CT were useful in confirming the diagnosis. Initial treatment consisted of immobilization with halo or collar, and, in one patient, Crutchfield tongs. Reduction of the dislocation was associated with decreasing Powers' ratio in five long-term survivors. Residual neurologic deficits, however, were seen in these patients. Atlanto-occipital dislocation should be suspected in trauma patients with findings of brain stem injury--especially agonal respirations, irregular heart rate, lower cranial nerve abnormality, and asymmetrical motor deficits.

Accidents, Traffic↗
PubMed1994

Retrieval of a Guglielmi detachable coil after unraveling and fracture: case report and experimental results.

Unraveling and fracture of electrolytically detachable coils (Guglielmi detachable coils) may occur during treatment of intracerebral aneurysms. Retrieval of the detached coil is difficult using existing snare technology, and the intraluminal coil may cause parent vessel thrombosis or distal embolization. We report a case of unraveling and fracture of a Guglielmi detachable coil that was successfully retrieved using a dual guidewire technique. The technique was evaluated in an in vitro model using 10 coils of varying sizes and diameters, and allowed successful coil retrieval in all trials.

Aged↗
PubMed1994

Case report: asymmetrical development of the gyri recti presenting as a suprasellar mass: case report and description of six further cases.

Asymmetrical appearances of normal anatomical structures can sometimes mimic pathology. We present a case where asymmetry of the gyri recti was interpreted as a suprasellar mass on axial CT scanning. The true nature of the apparent abnormality was revealed by coronal magnetic resonance imaging (MRI). We also present six further cases where asymmetrical gyri recti were noted as incidental findings on coronal MRI scans. This is a common, but important, normal anatomical variant, which should not be mistaken for pathology.

Adult↗
PubMed1994

Endovascular therapy of central nervous system tumors.

This article discusses the presentation of various central nervous system lesions and the role of endovascular techniques in their treatment. Basic principles of endovascular technique are described. The normal arterial anatomy of the spine is reviewed.

Brain Neoplasms↗
PubMed1993

The linear echogenic hilus in cervical lymphadenopathy--a sign of benignity or malignancy?

The linear echogenic hilus seen within lymph nodes on ultrasound examination has been proposed as a sign of benignity. The echogenic line is thought to represent the converging sinuses within the medulla of the lymph node. Forty-six cases with a linear echogenic hilus within a cervical lymph node are presented, where a cytological or histological diagnosis was obtained. In 27 cases (58.7%) the diagnosis was malignancy, in seven cases (15.2%) tuberculosis and the remaining 12 cases (26%) were benign. In our experience the linear echogenic hilus should not be regarded as a sole criterion for benignity. A cytological diagnosis, preferably by an ultrasound-guided fine needle aspiration, should always be sought.

Adult↗