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Biomedical subjects

A Zaher

Publications and source records attributed to A Zaher.

At least 19 recordsLinked to original sources
PubMed2003

High-grade intra-epithelial neoplasia and prostate cancer in Dibombari, Cameroon.

High-grade prostatic intra-epithelial neoplasia (HGPIN) occurs a decade earlier in men of African descent in the US and Brazil, compared to white men. Prostate cancer incidence and mortality is worse in the African-American than in US white men. Sub-Saharan Africa was thought to be a low incidence area. This disparity has been attributed to lifestyle factors such as diet. We report the results of prostatic biopsies, from an ongoing national prostate cancer survey. One hundred and eleven men aged 40 y and over were recruited for medical interview (AUA symptom score), prostate specific antigen (PSA) assay and digital rectal examination (DRE). Between six and 10 cores of random digitally guided needle biopsies were performed on 24 subjects that had either suspicious prostates on digital rectal examination +/ or PSA > or =4 ng/ml. All lesions of the prostate were described on routine histopathology. The Gleason score and proportion of tissue involved with cancer, was determined. Eight men had benign prostatic hyperplasia (BPH), six had cancer, another six had low grade intra-epithelial neoplasia, two had HGPIN, there was one case of BPH and chronic prostatitis and one case of chronic prostatitis only. The cancer patients were aged 58-75 y (mean 66.93 y). Gleason scores ranged from 5 to 9, there was one score of 3. Cancer made up 20-80% tissue samples. HGPIN was found in two cases (mean age 58 y). Significant prostate cancer and the pre-cancerous lesion HGPIN exist in Dibombari, Cameroon. The purported low incidence of prostate cancer may reflect cultural and economic barriers to health care.

Adult↗
PubMed2003

99mTc-MIBI in the assessment of response to chemotherapy and detection of recurrences in bone and soft tissue tumours of the extremities.

AIM: This prospective study is focused on the assessment of tumour response in a group of 28 bone sarcoma patients using (99m)Tc-MIBI scintigraphy. METHODS: The quantitative changes in MIBI uptake before and after chemotherapy were measured and associated with the pathological evaluation of the degree of tumour necrosis. Besides this, another group of 40 patients with bone and soft tissue tumours was studied in order to evaluate the diagnostic efficacy of (99m)Tc-MIBI scintigraphy versus computed tomography (CT) and/or magnetic resonance imaging (MRI) in detecting the status of the disease and its recurrences. After injection of 555-740 MBq of (99m)Tc-MIBI, regional and whole body images were acquired at 20 and 60 min. The lesion/normal (L/N) uptake ratio was calculated in both early and delayed images and the washout rate (WR%) of (99m)Tc-MIBI was obtained. Following 3-4 courses of chemotherapy, bone tumours were assessed by comparing the uptake ratio in the viable tumours with the amount of necrotic processes described in the surgically removed specimens. RESULTS: In the first group of patients the rate of tumour response to chemotherapy, calculated according to the percentage of necrosis and the (99m)Tc-MIBI uptake ratios, was as follows: complete response in 12 patients, partial response in 8 and no response in 8 patients. Linear regression analysis of quantitative changes in (99m)Tc-MIBI uptake (expressed as changes percent) and of (99m)Tc-MIBI uptake ratio showed a positive correlation (r=0.77), whereas it showed a negative correlation with the changes in the washout ratio (r=-0.32). In the second group of patients (40 patients) (99m)Tc-MIBI scintigraphy proved to be able to detect recurrences of bone and soft tissue tumours. The sensitivity, specificity and accuracy of (99m)Tc-MIBI scan versus CT and/or MRI were calculated and they resulted 93%, 95% and 92% versus 86%, 75% and 84%, respectively. CONCLUSION: The application of (99m)Tc-MIBI scan in the management of patients treated with chemotherapy may allow an early identification of the non-responder patients and lead to a choice of different strategies (alternative chemotherapy or salvage surgery).

Adolescent↗
PubMed2002

Vancomycin sequestration during cardiopulmonary bypass surgery.

OBJECTIVE: The present study was designed to analyze vancomycin disposition in adult patients undergoing coronary bypass grafting during and following cardiopulmonary bypass (CPB). METHODS: Coronary bypass surgery was performed on 11 adults with a mean age (SD) of 62.9 (9.0) years old, who received a mean (SD) vancomycin prophylactic dose of 12.7 (1.0) mg/kg in a mean period of 41 (0.7) min. Using a two-compartment open model for pharmacokinetic analysis, the following parameters were obtained: alpha half-life, minutes (t(1/2alpha)); beta half-life, hours (t(1/2beta)); apparent volume of distribution, (V(d) l/kg); volume of the central compartment, (V(c) l/kg), constant between the "central to the peripheral" compartment, (k(12)); constant between the "peripheral to the central" compartment, (k(21)); total area under the concentration-time curve, (AUC mg/lxh) and a vancomycin clearance, (Cl(van) ml/min), respectively. RESULTS: The mean (SD) calculated pharmacokinetic parameters were: t(1/2alpha)17.6 (6) min, t(1/2beta) 8.4 (3.8) h, V(d) 0.803 (0.259) l/kg, V(c) 0.270 (0.162) l/kg, k(12) 0.03 (0.015), k(21) 0.012 (0.012), total AUC 10377.2 (3687.6) mg/lxh. The mean (SD) vancomycin clearance by the CPB machine was 9.51 (2.66) l/h, and the mean (SD) total vancomycin sequestrated by CPB was 331.7 (84) mg. A significant difference (6.3%; p = 0.001) was measured between the mean measured AUC during CPB (1088.1 +/- 253.9) and the same calculated parameter (1160.2 +/- 282). Five minutes after starting CPB, a decrease in vancomycin level was detected; this difference was found to be nearly 11% in absolute values. CONCLUSIONS: This confirmatory study demonstrated that the vancomycin blood concentrations obtained during the study allow recommending a safety prophylactic dose of 12mg/kg in adults who undergo open-heart surgery under CPB conditions. Sequestration of vancomycin by the oxygenator or/and tubing system of the CPB machine had occurred and had been measured in this study.

Aged↗
PubMed2000

Diagnostic value of immunocytochemistry in leptomeningeal tumor dissemination.

Differentiating chronic aseptic meningitis from leptomeningeal carcinomatosis or gliomatosis can be difficult, particularly when the differentiation is based solely on routine cytologic examination. The diagnosis of cerebrospinal fluid tumor dissemination in at-risk patients requires cytologic examination of cerebrospinal fluid and radiography of the leptomeninges. Routine cytologic examination alone has proven less than desirable, in most instances providing confirmation in as little as 50% of cases in the first lumbar puncture. This percentage increases to 85% to 90% after multiple lumbar punctures. We retrospectively reviewed 2 cases of leptomeningeal dissemination (one gliomatosis, the other carcinomatosis) with initial false-negative test results. However, after further examination of the cerebrospinal fluid by selected battery of immunocytochemical stains, both cases were identified as positive for malignancy (ie, false negatives). Immunocytochemistry can be useful in distinguishing chronic aseptic meningitis from leptomeningeal carcinomatosis or gliomatosis in patients at risk or when abnormal cells are seen on routine cerebrospinal fluid cytologic examination.

Adult↗
PubMed2000

Incidence of spontaneous echocontrast in left atrium in mitral stenosis detected by transoesophageal echo cardiography and related factors.

The incidence of left atrial (LA) spontaneous echo contrast (SEC) and the clinical and echocardiographic variables related to it were prospectively evaluated in a series of 60 patients with mitral stenosis (MS) undergoing transoesophageal echocardiography (TEE) with a 5 MHz multiplane transducer. LA-SEC was found in 39 patients (65%) employing TEE. Statistical analysis showed a significant relationship between the presence of SEC and MS without mitral regurgitation (MR) (P < 0.05), MS with < or = MR grade II (P < 0.05), atrial fibrillation (P < 0.001) and increased left atrial dimension (P < 0.05). Age, sex, mitral valve area and ejection fraction did not show any positive association (P > 0.05). Thus, it is concluded that LA-SEC is a common finding observed in approximately 65% of MS patients undergoing TEE and associated with conditions favouring stasis of left atrial blood.

Adolescent↗
PubMed1999

Infection by Rhodococcus equi in a patient with AIDS: histological appearance mimicking Whipple's disease and Mycobacterium avium-intracellulare infection.

Rhodococcus equi pneumonia with systemic dissemination is being reported increasingly in immunocompromised patients. This is the first case report of disseminated R equi infection with biopsy documented involvement of the large intestine. The patient was a 46 year old male with AIDS who was diagnosed with cavitating pneumonia involving the left lower lobe. R equi was isolated in culture from the blood and lung biopsies. Subsequently, the patient developed anaemia, diarrhoea, and occult blood in the stool. Colonoscopy revealed several colonic polyps. Histological examination of the colon biopsies showed extensive submucosal histiocytic infiltration with numerous Gram positive coccobacilli and PAS positive material in the histiocytes. Electron microscopy showed variably shaped intrahistiocytic organisms which were morphologically consistent with R equi in the specimen. Disseminated R equi infection may involve the lower gastrointestinal tract and produce inflammatory polyps with foamy macrophages which histologically resemble those seen in Whipple's disease and Mycobacterium avium-intracellulare infection.

AIDS-Related Opportunistic Infections↗
PubMed1998

The gene expression index c-myc x E2F-1/p21 is highly predictive of malignant phenotype in human bronchial epithelial cells.

Recent methodological developments allow expression measurement of many genes simultaneously, thereby revealing patterns of gene expression that can be related to phenotype. We hypothesized that through the use of such methods we could identify patterns of gene expression associated with the malignant phenotype in human bronchial epithelial cells (BEC). To test this hypothesis, a recently developed quantitative reverse transcriptase polymerase chain reaction method was used to assess simultaneously expression of 15 genes mechanistically associated with cell-cycle control (c-myc, E2F-1, p21, rb, PCNA, cyclin D2, cyclin D3, cyclin E, cdc2, CDK2, CDK4, mad, max p21, max p22, and p53) in normal cell cultures from five individuals and in nine different malignant BEC lines. Relative to the mean expression levels in cultured normal cell populations, expression of c-myc, E2F-1, PCNA, cyclin E, and CDK4 messenger RNA (mRNA) were significantly increased and expression of p21 and p53 mRNA were significantly decreased in one or two, but not all three subtypes (squamous, adenocarcinoma and small cell) of carcinoma cell lines evaluated. No single cell-cycle control gene discriminated all three subtypes from normal cell populations. In contrast, the gene expression index c-myc x E2F-1/p21 separated all carcinoma cell lines from all normal cell populations initially evaluated. This malignancy index was validated in an additional three cultured normal BEC and three carcinoma cell lines, as well as three pairs of matched primary normal bronchial epithelial and primary bronchogenic carcinoma samples, and three pairs of matched primary normal lung parenchyma and primary bronchogenic carcinoma tissue. Again, the c-myc x E2F-1/ p21 index successfully discriminated all cultured and primary normal from malignant samples and thereby had a predictive value of 1 (no false positives and no false negatives). We hypothesize that because of functional mutations in cell-cycle regulatory genes (e.g., p53 and/or rb), cells lose the ability to maintain a pattern of gene expression mechanistically associated with normal, division-limited homeostatic equilibrium. Because the c-myc x E2F-1/p21 gene expression index has high specificity for malignant tissue, it will allow confirmation that there is a significant amount of tumor tissue present in small (e.g., fine-needle) biopsy specimens prior to evaluating them for expression of other genes, such as those involved in chemoresistance or radioresistance. In addition, the goal of most gene therapy efforts is to alter levels of gene expression quantitatively. This index and others derived in a similar manner may better define potential gene therapy targets as well as response of targeted genes to therapy.

Aged↗
PubMed1998

Expression of the plasminogen activation system in kidney cancer correlates with its aggressive phenotype.

Malignant tumors contrast with benign ones in their ability to invade adjacent tissue and to metastasize. The urokinase plasminogen activator is a proteolytic enzyme that can facilitate these processes. In many carcinomas, the concentration of the urokinase plasminogen activator system is high. The high expression of these enzymes is related to tumor grade. In this study, we have investigated whether secretion of the urokinase plasminogen activator, urokinase plasminogen activator receptor, and plasminogen activator inhibitor 1 in normal kidney tissue and kidney cancer tissue follows this pattern. We have found that urokinase plasminogen activator, urokinase plasminogen activator receptor, and plasminogen activator inhibitor 1 were expressed in higher levels in kidney cancers (squamous cell carcinoma and renal cell carcinoma) than in normal kidney tissue and that these differences were statistically significant (P < or = 0.05). In renal cell carcinomas, we have observed differences between normal kidney tissue and renal cell carcinomas in males and Caucasians but not in females and African Americans (P < or = 0.05). Expression of the urokinase plasminogen activator system was also higher in grade III tumors when compared with lower-grade tumors or normal tissue.

Adolescent↗
PubMed1997

ERIC-PCR typing profiles of Enterobacter cloacae are stable after development of advanced cephalosporin resistance.

Enterobacterial repetitive intergenic consensus (ERIC) sequence polymerase chain reaction genotype profiles of Enterobacter cloacae were prepared for paired isolates which were obtained before and after the high level expression of the chromosomal cephalosporinase. These profiles were homologous within strain pairs which suggests that the acquired resistance does not lead to major chromosomal alterations. ERIC genotypes are therefore reliable markers in epidemiological investigations where antibiogram modifications may arise as a consequence of antibiotic exposure and beta-lactamase over-production..

Bacterial Typing Techniques↗