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Biomedical subjects

A Khalil

Publications and source records attributed to A Khalil.

At least 127 records · Page 7Linked to original sources
PubMed1996

[Imaging of digestive involvements after irradiation].

The main limiting factor of the abdominal and pelvic radiotherapy is radiation damage of the digestive organs. The intestinal abnormalities resulting from irradiation are due to damaged blood vessels and connective tissue. Radiation changes in the small bowel and the recto-sigmoid are frequent and often symptomatic. Imaging is able to detect the induced radiation damage, even the asymptomatic scars. It is relevant to differentiate them from tumoral recurrence. The lesion location within the irradiated volume is important in the evaluation of post-radiotherapy imaging. Computerized tomography (CT) and magnetic resonance imaging (MRI) detect asymptomatic lesions in the liver, spleen and pancreas. We insist on the CT-imaging of induced radiotherapy changes, which are of major importance during the follow-up of irradiated patients.

Acute Disease↗
PubMed1996

Distribution of proteoglycans in the trabecular tissue of eyes with neovascular glaucoma.

We investigated histo-chemically the composition and distribution of proteoglycans in the trabecular tissue of eyes with neovascular glaucoma. Cupromeronic blue in combination with a series of enzyme digestions and nitrous acid treatment were used. The spaces between the trabecular beams were lined by a single layer of vascular endothelium and were filled with red blood cells. A basal lamina and microfibrils were detected just beneath the newly formed vascular endothelial cells. Chondroitin-sulfate- and dermatan-sulfate-type proteoglycans were present in association with collagen fibrils in the extracellular matrix. Heparan-sulfate-type proteoglycans were present in association with the basal lamina of both the vascular endothelial cells and the trabecular cells. It is unlikely that these abnormalities in the type or distribution of proteoglycans in the trabecular meshwork have a major role in the pathogenesis of glaucoma.

Adult↗
PubMed1995

Lead concentration and the level of glutathione, glutathione S-transferase, reductase and peroxidase in the blood of some occupational workers from Irbid City, Jordan.

Blood samples were collected from 263 lead-exposed suspected males living in Irbid area in the northern part of Jordan. The blood lead concentrations in the samples were determined by atomic absorption and were related to the type of work performed by the workers. The blood lead concentration was higher in metal casters, 41.6, and radiator welders, 32,8 micrograms/dl, compared to non-suspected lead-exposed university students, 5.7 micrograms/dl. Workers such as mechanics, bus drivers, car painters and gas station workers showed slightly higher but not significant blood lead. The blood glutathione content and the activities of glutathione reductase, glutathione peroxidase and glutathione S-transferase were also determined in non-suspected subjects and in those with occupational exposure to lead. With increasing blood lead concentration, glutathione content decreases as well as the activities of the glutathione utilizing enzymes.

Adult↗
PubMed1995

Inhibin in normal and abnormal pregnancy: maternal serum concentration and partial characterization.

OBJECTIVE: This study evaluated maternal serum inhibin concentration and molecular distribution in normal and abnormal pregnancies. STUDY DESIGN: Serum inhibin levels were measured by radioimmunoassay in 33 abnormal pregnancies (23 singleton and 10 multiple gestations) and 33 matched controls and were compared with pregnancy variables. RESULTS: In the controls serum inhibin concentrations rose with gestational age (correlation coefficient 0.358, p < 0.01) and were higher in mothers with female fetuses (p < 0.05). Inhibin levels were higher in the abnormal singleton pregnancies (2.69 +/- 1.41 ng/ml) than in controls (1.26 +/- 0.32 ng/ml, p < 0.0001) and increased more rapidly with gestational age in multiple pregnancies (p < 0.05). Gel filtration chromatographic analysis of immunoreactive inhibin revealed three peaks with the major form having an apparent molecular weight of 55 to 60 kd. CONCLUSION: Maternal serum inhibin concentrations are affected by gestational age, fetal gender, and complications of pregnancy. Most of the immunoreactive inhibin in maternal circulation is a large-molecular-weight form.

Case-Control Studies↗
PubMed1995

Recurrent molar pregnancies in a family with extensive intermarriage: report of a family and review of the literature.

BACKGROUND: Familial recurrent molar pregnancies are exceedingly rare. The genetic basis for recurrent moles is not well understood, and its association with major human lymphocytic antigen histocompatibility is debatable. The purpose of this report is to present a family with extensive intermarriage and recurrent molar pregnancies with some emphasis on the result of the human lymphocytic antigen-typing. CASE: Two sisters, both married to first-degree cousins, had three and five pathologically confirmed molar pregnancies, respectively. A second-degree cousin, also married to her first-degree cousin, is also reported to have had five consecutive moles. Chromosomal analysis and human lymphocytic antigen-typing on the two sisters and their spouses was performed. Human lymphocytic antigen-typing was compared to a cross-sectional sample of our population. This showed a high incidence of unusual human lymphocytic antigens in these family members. CONCLUSION: In families with extensive intermarriage and recurrent molar pregnancies, patients and their spouses may have unusual human lymphocytic antigen histocompatibility, which supports the possibility of a strong genetic predisposition expressed at the level of major histocompatibility class I and II gene translation.

Adult↗
PubMed1995

Detection, isolation, and stability of megaplasmid-encoded chloroaromatic herbicide-degrading genes within Pseudomonas species.

Dicamba is used as a model system for microbial degradation of chloroaromatic benzoic acids. The detection, isolation, and stability of a megaplasmid within a Pseudomonas sp. is described as the first step in optimizing the growth of this microorganism and other microorganisms similar to it. A large plasmid, pDK1, consisting of approximately 250 kb, was purified from dicamba-degrading Pseudomonas sp. PXM. This plasmid was purified by the method of Allen (personal communication, 1994), which is a modified version of several that have been attempted for the isolation of large plasmids (Lee and Rasheed, 1990). The restriction analysis of this plasmid (pDK1) from PXM. revealed many distinctive bands on agarose gel electrophoresis. Based on the preliminary restriction enzyme analysis, the estimated size of this plasmid is 250 kb, which could make it one of the largest procaryotic plasmids encoding for chloroaromatic degrading enzymes. Allen's methodology results in very high purity and reproducibility compared to the other methods used in this study. As described in this work, the method of Kado and Liu (1981) is easier to perform and results in a more reproducible plasmid preparation than the method of Casse et al. (1979). Casse's protocol requires the use of a highly alkaline SDS solution (pH 12.45) in order to eliminate the chromosomal DNA. However, only incomplete removal of the chromosomal DNA results. Compared to the Casse et al. protocol, the Kado and Liu protocol requires the use of a highly alkaline solution (pH 12.6) and a high temperature (55-65 degrees C) to eliminate the chromosomal DNA. This results in a nearly complete removal of the chromosomal DNA. The high temperature treatment also quickly eliminates the RNA. Another advantage of the protocol of Kado and Liu over the protocol of Casse et al. is that the former uses phenol-chloroform extraction while the latter uses only phenol extraction. The phenol-chloroform extraction step denatures the DNA along with the proteins. In addition to this, the phenol-chloroform mixture minimizes the formation of a brown oxidation pigment that usually occurs with phenol extraction alone. Finally, the time needed to complete the Kado and Liu protocol is much shorter (2 hr) than the time needed to complete the Casse protocol (8 hr). As described previously, a highly purified plasmid preparation with minimal chromosomal DNA was prepared by following the suggestions of L. Allen.(ABSTRACT TRUNCATED AT 400 WORDS)

Biodegradation, Environmental↗
PubMed1995

Irreversible inhibition of rat liver mitochondrial MAO A and MAO B by enantiomers of deprenyl and alpha-methylpargyline.

Using rat liver mitochondrial monoamine oxidase (MAO) A and MAO B, the possible influence of stereochemical factors upon the irreversible inhibition by propargylamine derivatives has been studied using the enantiomers of deprenyl and of alpha-methylpargyline. Whether studying the inhibition of MAO A or MAO B, little difference was found among enantiomeric pairs in the first-order rate constant (k2) for formation of the enzyme inhibitor adduct. Similarly, and with the exception of (S)-D-(+)-deprenyl (k2 = 0 or an extremely low value at MAO A), the computed value of k2 for the individual enantiomers showed little variation between MAO A and MAO B. These results suggest that inhibitor selectivity towards a particular form of the enzyme is determined predominantly at the competitive phase of the inhibition.

Animals↗
PubMed1995

Assessment of the infectivity of corneal buttons taken from hepatitis B surface antigen seropositive donors.

Sixty one corneas taken from 33 hepatitis B surface antigen (HBsAg) seropositive donors and 20 control corneas taken from 12 HBsAg seronegative donors were tested for the presence of HBsAg using reversed passive haemagglutination (RPHA) and enzyme linked immunosorbent assay (ELISA) and for the presence of hepatitis B virus core DNA (HBVcDNA) using the hybridisation technique in their epithelium, stroma endothelium, and storage media. HBsAg was detected by ELISA in the epithelium of one cornea (1.6%), in the stroma endothelial suspensions of six corneas (9.8%), and in the storage media of five corneas (8.2%). HBVcDNA was detected for the first time in the cornea; in the epithelium of four corneas (6.6%), stroma endothelium of nine corneas (14.8%), and the storage media of five corneas (8.2%). The control corneas were negative for HBsAg, while HBVcDNA was detected in the stroma endothelium of two corneas (10%) and in the media of two corneas (10%). This study confirmed that HBV can be present in the human cornea. Preservation in corneal storage media for up to 6 days could not eliminate the virus from the cornea. The possibility of HBV transmission through corneal transplantation should not be overlooked.

Contraindications↗
PubMed1995

Guillain-Barré syndrome following meningococcal meningitis.

A case of Guillain-Barré syndrome following meningococcal meningitis is reported. The diagnosis was made on clinical grounds and the results of electrophysiological studies. The patient recovered spontaneously. Guillain-Barré syndrome following meningococcal infection has not to our knowledge been reported previously.

Child↗
PubMed1995

Vascular endothelial growth factor plays a role in hyperpermeability of diabetic retinal vessels.

In rat diabetic retinas, we immunohistochemically looked for vascular endothelial growth factor (VEGF) which is also known as vascular permeability factor (VPF). In nondiabetic retinas, VEGF immunoreactivity was weak and restricted to the nerve fiber and ganglion cell layers. On the other hand, in diabetic retinas, VEGF immunoreactivity was markedly increased and was observed in all layers of the retina, especially in the perivascular area. Hyperpermeability of these vessels was confirmed by immunohistochemically detecting extravasation of albumin. These findings indicate that vascular endothelial growth factor plays an important role in blood-retinal barrier breakdown in diabetic retinopathy.

Actins↗
PubMed1995

Tecogalan sodium inhibits corneal neovascularization induced by basic fibroblast growth factor.

The antiangiogenic effect of tecogalan sodium on corneal neovascularization was investigated. Tecogalan sodium, a sulfated polysaccharide peptidoglycan complex isolated from an Arthrobacter species, has been reported to inhibit angiogenesis induced by basic fibroblast growth factor (bFGF) as well as tumor angiogenesis related to Kaposi's sarcoma. Corneal neovascularization induced by bFGF was inhibited by tecogalan sodium in a dose-dependent manner. Since bFGF is known to have a promoting effect on corneal neovascularization, tecogalan sodium may be possible therapeutic agent for corneal neovascularization, which can cause severe visual disturbances.

Animals↗
PubMed1995

Bronchogenic cyst presenting as mediastinal mass with pleural effusion.

Mediastinal bronchogenic cysts are usually identified on computed tomography (CT) as well-defined masses of variable density that may contain rim calcifications. Pleural effusion has never been described in association with these cysts. We report two cases of bronchogenic cysts with unusual presentation because of an association with a pleural effusion not explained by pulmonary infection. The patients were studied with CT scan (n = 2) and magnetic resonance imaging (MRI) of the chest (n = 1). In the first case, the pleural effusion directed diagnosis towards lung tumour; and the diagnosis of bronchogenic cyst was made on thoracotomy. In the second case, bronchogenic cyst was suspected on MRI findings. Inflammatory reaction was also suspected on the CT scan, which showed enhancement of the cyst edge. In both cases, surgical excision of the cyst was difficult because of pericystic adhesions to adjacent organs. Therefore, solely on the finding of a pleural effusion, pericystic inflammation had to be suspected.

Bronchogenic Cyst↗
PubMed1995

Pilot study of high-dose mitoxantrone and busulfan plus autologous bone transplantation in patients with advanced malignancies.

We performed a pilot trial of high-dose mitoxantrone 15 mg/m2 by i.v. infusion daily on days -6 to -4 and busulfan 1 mg/kg orally every 6 h (16 doses) on days -7 to -4 plus autologous bone marrow transplantation (BMT) in 10 patients with advanced cancer to determine the safety and feasibility of the combination. The median age of the study group was 42 years, all were women and all had progressed after prior chemotherapy (including doxorubicin in seven cases). Disease types included adenocarcinoma of the breast (n = 6) or ovary (n = 3), and non-Hodgkin's lymphoma (n = 1). The median time to an absolute neutrophil count > or = 0.5 x 10(9)/L and platelets > or = 50 x 10(9)/L were 16.5 and 28 days, respectively. There was a high degree of severe regimen-related toxicity, including severe mucositis (n = 7) and veno-occlusive disease (VOD) of the liver (n = 3). Three patients developed multisystem failure and died within 90 days of autologous BMT from complications related to VOD of the liver (n = 2) or septic shock (n = 1). We conclude that the dose and schedule of busulfan and mitoxantrone used in this study was associated with a high degree of unacceptable regimen-related toxicity.

Adenocarcinoma↗