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Biomedical subjects

A Goel

Publications and source records attributed to A Goel.

At least 91 records · Page 5Linked to original sources
PubMed1999

Strain-specific recognition of live Leishmania donovani promastigotes by homologous antiserum raised against a crude membrane fraction of infected macrophages.

Surface antigens on Leishmania promastigotes and infected macrophages are obvious targets in immunoprophylaxis for leishmanial infection. We have recently demonstrated that the polyclonal antiserum and monoclonal antibodies generated by homologous immunizations with the crude membranes of parasite-infected cells react effectively with the 'neo-antigenic' determinants on the infected cell surface. In the present study, we investigated the utility of such polyclonal antisera for identifying 'minor' surface components of promastigotes. The reactivity of anti-Leishmania donovani-(strain RMRI68) infected macrophage membrane (anti-IMm) antiserum was compared with that of anti-promastigote (anti-Pr) antiserum towards the infected macrophage surface and promastigotes of three Indian strains of L. (donovani, RMRI68, AG83 and DD8. While anti-Pr antiserum showed no reactivity with the infected macrophage surface but reacted strongly with air dried and live promastigotes of all three strains, anti-IMm antiserum reacted with the infected cell surface and, interestingly, specifically recognized live promastigotes of the strain used for infection, i.e., strain RMRI68. The reactivity patterns of the two antisera with the immunodominant components of the L. donovani promastigote surface, i.e., purified LPG-KMP11 complex and gp63 molecules, indicated that unlike anti-Pr antiserum, the specificities in anti-IMm antiserum were mainly directed towards molecules other than the LPG-KMP11 complex and gp63. Antiserum generated in a similar fashion against the macrophage membrane of cells infected in vitro with strain AG83 also contained antibodies specific to strain AG83 promastigotes. The present approach may therefore greatly help in identifying specific antigen(s) important in clinical and epidemiological control of leishmaniasis.

Animals↗
PubMed1999

Basal lateral subtemporal approach for trigeminal neurinomas: report of an experience with 18 cases.

Subtemporal craniotomy centred on the external ear canal was used to surgically treat 18 trigeminal neurinomas. The approach was found to be suitable to deal with either or both the middle fossa and the posterior cranial fossa components of the tumour. The basal extension of the exposure was achieved by resection of the roots of the zygomatic arch, roof of the external ear canal and superior third of the mastoid bone. The temporalis muscle was rotated anteriorly. The direction of the approach to the tumour was the shortest and perpendicular from the surface and avoided any neural or vascular exposure or manipulation. The basal exposure was horizontally wide and significantly low which reduced the operating distance, limited the extent of temporal lobe retraction and provided additional space for manipulation of instruments. The exposure was manoeuvreable with anterior, posterior and medial expansion being possible during or prior to tumour resection. The approach had the advantage of being simple and relatively quick and of its familiarity to general neurosurgeons. The experience with the approach with trigeminal neurinomas and its possible advantages over other available approaches to these lesions are analysed in this report.

Adult↗
PubMed1999

Meralgia paresthetica secondary to limb length discrepancy: case report.

Meralgia paresthetica consists of pain and dysthesia in the lateral thigh caused by entrapment of the lateral femoral cutaneous nerve (L2-L3) underneath the inguinal ligament. Abdominal distension, tight clothing, and hip hyperextension are all described causes of this condition. To our knowledge this has never been attributed to a limb length discrepancy. We present a 51-year-old man with a long-standing history of right sided meralgia paresthetica. History and physical and radiological examination were unrewarding except that his left leg was shorter than the right by 2 cm. Nerve conduction studies of the lateral femoral cutaneous nerve on the left had a normal latency and amplitude but were absent on the right. To prove the hpothesis that the limb length discrepancy was responsible for the condition, a single subject study was performed. The presence or absence of pain and dysesthesia in the right thigh was the observed behavior. Intervention consisted of wearing a 1.5-cm lift in the left or right shoe for 2 weeks each with an intervening 2-week lift-free period. Pain was recorded on a numeric scale and numbness as being present or absent. There was continuing pain without and with the lift in the right shoe but no pain or numbness with the lift in left shoe. It was concluded that the limb length discrepancy was responsible for the meralgia paresthetica. Pertinent literature and possible pathomechanics are discussed.

Femoral Nerve↗
PubMed1999

Holocord intramedullary abscess: an unusual case with review of literature.

STUDY DESIGN: A rare case of a holocord intramedullary abscess with review of literature. OBJECTIVES: Summary of clinical presentation, radiology, microbiology, etiology and management of intramedullary spinal cord abscess. Abscess involving the entire spinal cord is extremely rare and awareness of such an event could avoid delay in evacuation of the absess. METHODS: The incidence, clinical presentation, radiological investigations, treatment and etiology of intramedullary spinal cord abscess in 100 consecutive cases are discussed. RESULTS: Intramedullary spinal cord abscesses are rare. Presently, only five cases of holocord intramedullary abscess are described. In our analysis of 100 cases of intramedullary abscess, a male preponderance was found. The first and the third decades were the most common age groups. Prognosis is poor if treatment is delayed. Contrast-enhanced MRI is the ideal investigation for diagnosis. Prompt surgical drainage of the abscess with appropriate antibiotic therapy is mandatory since the natural course of the disease has a very unfavourable outcome. Staphylococcus and Streptococcus were the most common causative organisms. CONCLUSION: Intramedullary spinal cord abscess along the entire length of spinal cord is rare. A thorough history with precise clinical localisation, a high index of suspicion, contrast-enhanced MRI at appropriate level and prompt surgical drainage with appropriate antibiotic therapy are key to the eventual outcome and prognosis.

Abscess↗
PubMed1999

Fluid-fluid levels in intracranial schwannomas.

Intracranial cystic neurogenic tumours constitute an uncommon subset of tumours with a distinct clinico-biological behaviour. The presence of fluid-fluid levels within the tumours, although rare, confirms the cystic nature of the neoplasms. Barring the acoustic schwannomas, cystic cranial nerve schwannomas are exceptionally uncommon. Imaging findings of fluid-fluid levels in two non-acoustic cranial nerve schwannomas are described; one was a cystic trigeminal schwannoma and the other was a glossopharyngeal nerve schwannoma. The causes of the fluid-fluid level and its implications are analysed.

Adult↗
PubMed1999

Subversion of antigenic expression in neoplasia: lessons from immunohistology of teratomas.

Many examples of inappropriate expression of intermediate filaments and other cell identity markers are known to occur in diagnostic tumor pathology. In the present study, this subversion of antigenic differentiation in tumors has been investigated using teratomas as a model, as these unique tumors not only mimic developing tissues but also show carcinomatous elements. Ten cases of teratoma (eight immature, two mature) were studied immunohistochemically using a panel of 13 commonly used cell identity markers, including intermediate filaments. Examples of antigenic coexpression and transbarrier expression in various morphologically mature and immature tissues were noted to be similar to those seen in various tumors. Carcinomatous elements in teratomas were non-reactive rather than showing antigenic aberrations. Hence, this study strengthens the proposition that antigenic subversion in neoplasia is related to the process of maturation and differentiation, rather than malignant transformation.

Adolescent↗
PubMed1999

Extended lateral subtemporal approach for petroclival meningiomas: report of experience with 24 cases.

Subtemporal craniotomy centred on the external ear canal and its basal extension, involving resection of the roots of the zygomatic arch, roof of the external ear canal and superior third to half of the mastoid bone was used to treat surgically 24 meningiomas located in the petroclival region, having their maximum bulk at the level of tentorium. The approach was found to be suitable for dealing with middle fossa extensions of the tumour in addition to the part extending up to the mid-clivus or vertebrobasilar junctional region. The direction of the approach to the petroclival region was the shortest and most perpendicular from surface and avoided any neural or vascular exposure or manipulation. The basal exposure was horizontally wide and significantly low, which reduced the operating distance, limited the extent of temporal lobe retraction and provided additional space for manipulation of instruments. The exposure was manoeuverable with anterior, posterior and medial expansion being possible during or prior to tumour resection. The approach had the advantage of being simple and relatively quick, and of its familiarity to general neurosurgeons. The experience with the approach with petroclival meningiomas and its possible advantages over other available approaches to these lesions are analysed in this report.

Adolescent↗
PubMed1999

Trochlear nerve neurinoma presenting as pathological laughter.

A case of trochlear nerve neurinoma in a 48-year-old women is reported. She presented with pathological laughter as her principal symptom which was cured by tumour resection. A brief review of the available literature on the subject is reported.

Affective Symptoms↗
PubMed1999

A trigeminal neurinoma involving the lacrimal nerve: case report.

An isolated neurinoma involving the entire length of the lacrimal nerve is reported. The tumour was large and involved both the intracranial cavernous sinus, as well as the extracranial intraorbital part of the nerve. The patient, a 45-year-old housewife had a painless progressive proptosis associated with marginally decreased lacrimation of the affected eye. There was no evidence of neurofibromatosis.

Female↗
PubMed1999

Bilateral endolymphatic sac papillary carcinoma.

We report a case of bilateral and almost symmetrical endolymphatic sac papillary adenocarcinoma. A 22-year-old male patient presented with bilateral sixth, seventh, eighth and lower cranial nerve paresis and ataxia. Radiological investigations revealed extensively vascular tumours in the region of both jugular bulbs. The literature on this rare entity is briefly discussed.

Adenocarcinoma, Papillary↗
PubMed1999

Primary staphylococcal pneumonia in young children: a review of 100 cases.

Staphylococcus aureus (S. aureus) is responsible for a small proportion of acute respiratory infections in children. Nevertheless a high index of suspicion is required because of the potential for rapid progression, the need for antibiotics different to those routinely administered in the treatment of pneumonia, and the high incidence of complications. There are few data from developing countries. The objective of this retrospective review was to document the natural history of primary staphylococcal pneumonia at Red Cross Childrens' Hospital in Cape Town over a 7-year period (1989-1995). Staphylococcal pneumonia was defined as acute pneumonia with microbiological evidence of S. aureus or with characteristic radiological features. One hundred patients were identified. The median age was 5 months, 78 patients being below one year of age. Cough and fever were present in almost all patients at the time of presentation. Tachypnoea, recession, dullness, and crepitations were commonly elicited signs. Initial chest radiographs revealed empyema, pleural effusion, or pyopneumothorax in 67 patients. A further 26 patients developed such changes on subsequent chest radiographs. Pneumatocoeles were identified in 37 patients--most of these were only noted on radiographs taken some days after admission. Microbiological confirmation was obtained in 92 cases. S. aureus was isolated in 23/98 blood cultures, 62/67 pleural aspirates, and from tracheal aspirates in 16 cases. Intercostal drains were inserted in 67 cases and 20 children underwent thoracotomy. The case fatality rate was 7 per cent. This study shows that primary staphylococcal pneumonia is chiefly a disease of infants. Symptoms and signs were similar as for other forms of acute pneumonia, although in the majority of cases chest radiographs taken at the time of admission suggested the diagnosis. Treatment with antibiotics and drainage of empyema resulted in a good outcome in the majority of cases.

Child, Preschool↗
PubMed1999

Past and present scenario of hepatoprotectants.

The liver plays a significant role not only in metabolism and disposition of the chemicals to which it is exposed directly or indirectly but also plays a pivotal role in the metabolism of fats, carbohydrates, proteins and immunomodulations. The impairment of liver generally results from viral or portozoal infections, excessive use of alcohol, drugs and xenobiotics. This review provides an overall view about the past and present status of the hepatoprotectants resulted from synthetic and plant origins.

Humans↗
PubMed1999

Glioblastoma multiforme following prophylactic cranial irradiation and intrathecal methotrexate in a child with acute lymphoblastic leukaemia : a case report.

A 12 year old boy with acute lymphoblastic leukaemia had received prophylactic cranial irradiation (2000 cGy/15 days) and intrathecal methotrexate. Six years later he was diagnosed to have glioblastoma in left temporoparietal region. There is a strong possibility that the glioma may have been radiation and/or chemotherapy induced.

Antimetabolites, Antineoplastic↗
PubMed1999

Hyperthyroidism due to papillary carcinoma of the thyroid--a case report.

A rare case of papillary carcinoma of the thyroid producing hyperthyroidism is presented. A young patients presented seven years after a thyroid operation with metastatic disease in the cervical lymph nodes and a history of deteriorating vision in the left eye. He also had a lesion in the base of the skull which could not be established to be metastasis from the thyroid cancer. There was clinical and biochemical evidence of hyperthyroidism. Radionuclide scan revealed uptake in the residual thyroid tissue and patchy uptake by the cervical lymph nodes. The patient underwent a complete thyroidectomy and radical neck dissection of the left side and 'berry-picking' of the lymph nodes on the right side. Although the patient became euthyroid post-operatively, his general condition deteriorated and he rapidly lost vision in both eyes before any ablative therapy could be instituted for the tumour in the base of the skull. The patient was lost to follow-up.

Adult↗
PubMed1999

Effects of genetic engineering on the pharmacokinetics of antibodies.

Monoclonal antibodies (MAbs) may be considered 'magic bullets' due to their ability to recognize and eradicate malignant cells. MAbs, however, have practical limitations for their rapid application in the clinics. The structure of antibody molecules can be engineered to modify functional domains such as antigen-binding sites and/or effector functions. Advances in genetic engineering have provided rapid progress in the development of new immunoglobulin constructs of MAbs with defined research and therapeutic application. Recombinant antibody constructs are being engineered, such as human-mouse chimeric, domain-dispositioned, domain-deleted, humanized and single-chain Fv fragments. Genetically-engineered antibodies differ in size and rate of catabolism. Pharmacokinetic studies show that the intact IgG (150 kD), enzymatically derived fragments Fab' (50 kD) and single chain Fv (28 kD) have different clearance rates. These antibody forms clear 50% from the blood pool in 2.1 days, 30 minutes and 10 minutes, respectively. Genetically-engineered antibodies make a new class of immunotherapeutic tracers for cancer treatment.

Adenocarcinoma↗
PubMed1999

Intracranial hydatid cyst: a report of five cases and review of literature.

The authors present five cases of intracranial hydatid cysts managed at the department of Neurosurgery, King Edward Memorial Hospital, Mumbai, between 1984-1997. The mean age of presentation was 13.4 years. Four patients (80%) were in the first decade of life. All patients presented with focal neurological deficit and clinical features of raised intracranial pressure. Radiological investigations included computerised tomography (CT) scan in three cases, CT and magnetic resonance (MR) scan in one case and accidental cystogram in one case. Two patients had multiple intracranial cysts. One patient had a solitary cyst in the lateral ventricle. Commonest location was in the parietal lobe (3 cases). Total excision of the cyst was done in all five cases. Recurrence was seen in two cases, probably as a result of rupture of the cyst during first surgery. The features of this rare disease are retrospectively analyzed in this presentation and the literature is reviewed.

Adolescent↗