Biomedical subjects
Publications and source records attributed to M Saleem.
Endodermal sinus tumor is an uncommon malignant germ cell tumor that occurs in both gonadal and extragonadal tissues. Endodermal sinus tumors of the head and neck, exclusive of the central nervous system, are rare. We report a case of endodermal sinus tumor arising from the maxillary sinus in a 4-year-old boy. Combined treatment with radiation therapy and chemotherapy resulted in complete tumor regression.
UNLABELLED: The results of a prospective study on cytogenetic analysis of Chorionic Villus Samples (CVS) taken in early pregnancy (after 10 weeks) from pregnant ladies aged between 22 and 50 years are being presented. OBJECTIVE: To find out the prevalence of chromosomal defects with advancing age of the mother. SETTING: Department of Medical Genetics, Armed Forces Institute of Pathology, Rawalpindi. METHODS: A total of 48 samples have been studied. Ten patients were above the age of 35 years and 38 were below the age of 35 years. Chorionic villus samples were obtained after 10th week of pregnancy through transabdominal approach. Cytogenetic cultures were set up both by the direct and routine methods. RESULTS: Three out of the seven samples taken from expecting mothers aged above 35 and one culture from a patient aged less than 35, showed trisomy 21. CONCLUSION: This study highlights the fact that incidence of chromosomal aberrations and the Down's syndrome in particular, increases with the advancing maternal age. Prenatal studies can therefore be utilized to decrease the incidence of various chromosomal abnormalities.
Radical neck dissection is one of the commonest procedures performed in any unit dealing with head and neck surgery. Intracranial complications following this procedure are uncommon. Transverse sinus thrombosis and venous infarction of the brain following unilateral radical neck dissection have not been reported in the literature. We present a case in which this complication occurred following an uneventful radical neck dissection.
We present a case of malignant schwannoma (MS) of the parapharyngeal space which completely encircled the internal carotid artery in close proximity to the skull base and required resection of the internal carotid artery along with the excision of the tumour. There have been three previous case reports in the literature of malignant schwannoma of the parapharyngeal space of which one case was associated with neurofibromatosis. Our patient did not exhibit any feature of neurofibromatosis.
We describe a case of lingual thyroid (LT) with primary hypothyroidism, presenting during pregnancy and continuing beyond it with oropharyngeal obstructive symptoms and sleep apnoea syndrome (SAS) of mixed type. Although SAS of a combined obstructive and central type should not be too surprising in a case of LT with hypothyroidism, we were unable to find such a documentation previously. Only four weeks of L-thyroxin treatment resulted in a dramatic improvement in dysphagia, disturbed phonation, haemoptysis, arterial desaturation, sleep apnoea and overall sleep efficiency, in conjunction with a regression in the size of the lingual mass. This case highlights the vagaries confronted in the management of such a case and focuses on efforts towards accurate diagnosis and treatment.
We present a case of fibrous histiocytoma of the larynx in a young female who presented eight years ago and is still alive and well with no evidence of any regional invasion or distant metastasis. This rare lesion has been described in 30 cases previously of which 26 were malignant and four benign. Our case is unusual in a sense that histologically it has not been possible to determine its exact biological behaviour and growth potential. However, clinically it behaved as a low-grade malignant tumour.
Donor site morbidity for free fibula microvascular flaps is generally reported to be low and considered to be minor. We describe a case where the major complication of compartment syndrome occurred in a 15-year-old boy when the donor site defect was closed primarily after taking a skin paddle with a width of 4 cm. We recommend that when harvesting free fibula flaps in children, skin grafting of donor site should be considered irrespective of the width of the flap, if there is any doubt about the tightness of the closure.
We have studied whether there is natural genetic variation for mutation frequencies, and whether any such variation is environment-related. Mutation frequencies differed significantly between wild strains of the fungus Sordaria fimicola isolated from a harsher or a milder microscale environment in "Evolution Canyon," Israel. Strains from the harsher, drier, south-facing slope had higher frequencies of new spontaneous mutations and of accumulated mutations than strains from the milder, lusher, north-facing slope. Collective total mutation frequencies over many loci for ascospore pigmentation were 2.3, 3.5 and 4.4% for three strains from the south-facing slope, and 0.9, 1.1, 1.2, 1.3 and 1.3% for five strains from the north-facing slope. Some of this between-slope difference was inherited through two generations of selfing, with average spontaneous mutation frequencies of 1.9% for south-facing slope strains and 0.8% for north-facing slope strains. The remainder was caused by different frequencies of mutations arising in the original environments. There was also significant heritable genetic variation in mutation frequencies within slopes. Similar between-slope differences were found for ascospore germination-resistance to acriflavine, with much higher frequencies in strains from the south-facing slope. Such inherited variation provides a basis for natural selection for optimum mutation rates in each environment.
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BACKGROUND: The invariant chain plays a crucial role in antigen presentation by influencing the expression and peptide loading of major histocompatibility complex (MHC) class II molecules. Therefore, coordinate expression of these molecules is important for antigen presentation. METHODS: Immunohistological studies were performed on frozen sections of many rat tissues in order to examine expression of invariant chain and MHC class II antigens. RESULTS: Although coordinately regulated in most tissues, the interstitial dendritic cell (and the renal tubular epithelial cell) was always negative for invariant chain, while strongly positive for MHC class II antigens. However, renal tubular epithelial cells strongly expressed invariant chain during kidney graft rejection. CONCLUSIONS: The absence of invariant chain in interstitial dendritic cells is unexpected, in view of their presumed function as sentinel antigen-presenting cells in the connective tissues. This might have important implications for antigen presentation for tolerance and immunity.
To investigate the potential relationship of socioeconomic status with the prevalence of Epstein-Barr virus (EBV) and to understand the significance of del-LMP-1 within EBV+ cases of Burkitt's lymphoma (BL), we studied 10 cases of BL, 30 cases of diffuse large cell lymphoma (DLCL) arising in nonimmunocompromised patients, and 30 reactive tonsillar biopsy specimens from Pakistan. Each lymphoma was analyzed for EBV by EBER1 RNA in situ hybridization (EBV-RISH). Cases showing hybridization signal within neoplastic cells and all reactive tonsillar tissues were analyzed for EBV strain type by EBNA-2 polymerase chain reaction (PCR) and for the presence of a del-LMP-1 by PCR. Eight of 10 (80%) of BL were EBV+, each containing EBV strain A and a wild-type LMP-1 gene. In contrast, only 4 of 30 DLCL (13%) cases were EBV positive (three strain A, one strain B), each containing a wild-type LMP-1 gene. Fifteen of 30 tonsillar biopsy specimens contained EBV, all of which were strain A and wild-type for LMP1. The prevalence of EBV in BL from Pakistan is slightly lower than in BL in endemic regions, but significantly higher than in BL in North America. EBV positivity probably reflects the socioeconomic status of the patient population and age at seroconversion. The absence of del-LMP-1 within all EBV+ BL cases is consistent with the view that del-LMP-1 is not involved in the pathogenesis of BL, and the presence of del-LMP-1 in EBV+ cases of BL reported in other studies may likely reflect the prevalence of a viral strain containing the 30-bp deletion within the respective population studied.
A case of severe inflammation with an exuberant granulation lesion of the larynx that mimicked laryngeal tumour is presented. A patient who was a chronic smoker, with a history of hoarse voice underwent multiple endoscopies and biopsies, confirmed histopathologically as acute and, subsequently, as chronic inflammation. The tumour-like tissue in the larynx responded dramatically to prolonged antibiotic treatment. We emphasize the importance of histological confirmation before embarking on removal of an essential organ or part of the body which could lead to physical or emotional scarring.
We have tried to elucidate the significance of so called non-infiltrative changes in order to find their place in the staging procedure particularly in countries where facilities for elaborate clinical staging are not available. Seventy nine out of 88 patients were classified into 3 groups depending upon the histological findings in their bone marrow trephine biopsies. Bone marrow in Group-I (n = 20) patients was essentially normal. The established criteria of bone marrow involvement were fulfilled in Group III patients (n = 25); while bone marrow in Group-II patients (n = 34) showed non-infiltrative changes. The clinical presentation, peripheral blood parameters and LDH levels of the 3 groups of patients were compared. There was progressive anaemia, neutrophilic leucocytosis and increase in ESR from Group I to III. The change was statistically significant when Group I was compared with Group II or Group III but non-significant when Group II was compared with Group III. It is, therefore, postulated that both Groups II and III reflect the bone marrow involvement although the changes observed in Group II do not satisfy the previously established criteria for this purpose.
To make bone marrow aspiration and trephine biopsy less painful and more acceptable in children a short acting anaesthetic ketamine was used in a dose of 1-2 mg/kg body weight intravenously or 4-5 mg/kg intramuscularly. One hundred cases aged 2 to 13 years were studied. The actual procedure time ranged between 20 seconds and 3 minutes, adequate samples were obtained in 80% of children on first attempt. Vomiting was the only side effect noted in two children. Ketamine is safe and recommended in all children undergoing bone marrow aspiration and trephine biopsies.
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Indirect T cell allorecognition has been shown to play an important role in the rejection of allografts in experimental animals. Although there has been much speculation as to its role in clinical transplantation, especially with regard to chronic rejection, indirect T cell allorecognition has been difficult to demonstrate in transplant patients. In this paper, we looked for in vitro T cell proliferation to synthetic peptides corresponding to donor HLA-A and HLA-B incompatible antigens. Twelve 15 amino acid peptides corresponding to the hypervariable regions of six of the most common HLA class I alleles in Caucasian populations (A1, A2, A3, B7, B8 and B44) were studied. Blood was taken from 12 adult patients following one or more episodes of acute kidney graft rejection, and from three pediatric patients undergoing chronic rejection of heart/lung transplants. The donor-recipient combinations were selected such that at least one of the six HLA antigens above was present in the donor and absent in the recipient. Peripheral blood mononuclear cells from these patients responded strongly in proliferation assays to phytohemagglutinin. However, none responded to the incompatible donor HLA peptides. Compartmentalization of responding T cells, the effects of immunosuppression, and assay sensitivity are discussed as possible explanations for the negative results.