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Biomedical subjects

M Osman

Publications and source records attributed to M Osman.

At least 55 records · Page 3Linked to original sources
PubMed1995

Familial pancreatic cancer and the genetics of pancreatic cancer.

In our current understanding of pancreatic carcinoma, these neoplasms can arise either sporadically or in familial clusters. Extensive chromosome abnormalities are frequent, as is loss of heterozygosity at loci known to contain the tumor suppressor genes DCC, p53, and MTS1. Although the genetic examination of all pancreatic cancers is important, the examination of familial cases is especially useful in that these allow the identification of uniform genetic alterations that are inherited through the germ line. Much additional work needs to be done before the genetic basis of pancreatic cancer is completely understood. Although our knowledge is limited, it is clear that genetic analyses can be used to establish the prognosis for a patient with pancreatic cancer and, it is hoped, will someday be used in the management, treatment, and detection of pancreatic cancer.

Adenocarcinoma↗
PubMed1994

New artificial feeding technique for experimental infection of Argas ticks (Acari: Argasidae).

An artificial feeding technique using fetal bovine serum as a food source was established for the demonstration of West Nile virus transmission by Argas ticks in susceptibility studies. Fetal bovine serum does not coagulate and is free from contaminating microorganisms, antibodies, and anticoagulants, which are all known to reduce virus titers. This technique also compensates for the lack of suitable laboratory hosts as well as problems associated with disease agents, such as viruses that may not produce illness or antibodies after virus exposures.

Animal Feed↗
PubMed1994

Pregnancy after laparoscopic partial cystectomy for bladder endometriosis.

We report a case of partial laparoscopic cystectomy in a 31-year-old infertile patient presenting vesical endometriosis. This patient had suffered severe dysmenorrhoea for 10 years previously together with repeated episodes of urinary infection, mostly occurring during the menstrual period. A diagnostic laparoscopy performed in another centre diagnosed a stage IV endometriosis. Gonadotrophin-releasing hormone agonists were prescribed for 9 months. After failure of this treatment, the patient came to consult us. A solid mass in the left supratrigone was detected by pelvic ultrasonography and confirmed by cystoscopy. Transurethral resection was carried out. A recurrence of the symptoms 9 months later prompted operative laparoscopy under cystoscopic control. This confirmed recurrence of a 3.5 cm endometriotic nodule. Laparoscopic partial cystectomy was performed using the monopolar electrode. The bladder was then sutured via laparoscopy. No complications occurred. No postoperative treatment was given. Second-look cystoscopy 2 months later revealed that healing was perfect. Eight months later, the patient is well and has a normal intra-uterine pregnancy.

Adult↗
PubMed1994

Evidence that fibronectin-immunoglobulin complexes occur normally in plasma.

This study was done to ascertain whether complexes of plasma fibronectin (PFn) and immunoglobulins (Igs) are normally present in plasma. PFn preparations from plasmas of six random human donors were analyzed for IgG, IgM, and IgA by competitive ELISA procedures. To look for direct evidence of circulating complexes, two of the plasma samples were chromatographed on Sephacryl S-300. PFn prepared from a pool of three plasmas by cryoprecipitation was studied by crossed immunoelectrophoresis to detect PFn-Ig complexes. The Ig content of PFn ranged from 0.78% to 9.0% IgG; 0.25% to 4.9% IgM, and 0.15% to 0.71% IgA. The relative amounts were IgG > IgM > IgA in every sample, but the total Ig content of PFn varied with the plasma donor. The Sephacryl S-300 chromatogram of the plasma from which Ig-rich PFn was made showed distortion of the PFn peak by Ig peaks. PFn prepared by cryoprecipitation contained PFn-immunoglobulin complexes. Plasma from adult beagle dogs was used to prepare canine PFn. IgM was detected in canine PFn by SDS-Page and by double diffusion experiments against antiserum to canine IgM. By crossed immunoelectrophoresis, a PFn-IgM complex was detected in canine plasma. The cryoprecipitate recovered from a Sephacryl S-300 chromatogram of canine plasma contained equivalent amounts of IgM and PFn. These data suggest that complexes of Igs with PFn are normally present in plasma.

Animals↗
PubMed1993

Laparoscopic marsupialization of a simple renal cyst.

An 8 cm. symptomatic simple renal cyst, recurrent despite previous aspiration and injection of sclerosing agents, was marsupialized using laparoscopic techniques. No complications occurred and followup by ultrasonography confirmed resolution of the lesion. We suggest that laparoscopic management of symptomatic simple renal cysts may be an attractive alternative to open surgical techniques.

Aged↗
PubMed1993

Estimating renal function from the visual analysis of Tc-99m DTPA images.

Eleven visual parameters of Tc-99m DTPA imaging studies were evaluated to identify scintigraphic findings that best detect changes in renal function, to determine at which GFR levels they appear, and to establish criteria for visual estimation of renal function. Visual parameters were compared to in vitro GFR determinations in 41 patients. Three visual parameters offered best discrimination. The first one appeared at GFR values below 70 mL/min (sensitivity: 76%). The renal peak activity on the flow study (normally equal or greater than aortic) no longer reached the intensity of the aortic peak (pK < pA). The second parameter appeared at GFR values below 50 mL/min (sensitivity: 85%). The estimated kidney-to-liver ratio in the 2-minute image (usually 3 or greater) decreased to values less than 3. The third scintigraphic finding, pelvicalyceal system nonvisualization, appeared at GFR levels below 20 mL/min (sensitivity 100%). Use of these 3 scintigraphic findings allows categorization of patients into four functional groups: 1) severe dysfunction (GFR: 0-20 mL/min), 2) moderate to severe dysfunction (GFR: 21-50 mL/min), 3) moderate dysfunction (GFR: 50-70 mL/min), and 4) Normal study (GFR > 70 mL/min). Visual analysis of Tc-99m DTPA images does not identify patients with mildly decreased renal function (GFR: 70-90 mL/min).

Glomerular Filtration Rate↗
PubMed1993

West Nile virus (Flaviviridae:Flavivirus) in experimentally infected Argas ticks (Acari:Argasidae).

To better define the possible role of argasid ticks in the epidemiology of West Nile virus, adult Argas arboreus, A. persicus, and A. hermanni were fed through a membrane on fetal bovine serum containing 10(5.5) 50% tissue culture infective doses (TCID50)/ml of West Nile virus. The virus was detected for three and four days after feeding in A. persicus and A. hermanni, respectively. The virus titers then decreased to undetectable levels in both species. When the infective dose was increased to 10(6.2), virus was detected until days 6 and 8, respectively. In A. arboreus, virus titers in whole tick homogenates reached a peak of 10(4.0) on day 4 postfeeding and remained constant at 10(3.0) after day 6 throughout the 20- or 50-day observation periods. Virus was detected by isolation, indirect fluorescent antibody, and histochemical techniques in the salivary glands, ovaries, synganglia, and coxal fluids. Infected ticks successfully transmitted virus to clean chickens on day 20 postfeeding. No evidence of transstadial transmission from nymph to adult was detected. Larvae from experimentally infected females successfully transmitted virus to clean chicks and virus was recovered from F1 larvae. Venereal transmission was not detected. Virus was present in coxal fluids secreted by infected females after infective meals. This study demonstrates West Nile virus infection in experimentally infected A. arboreus ticks and documents horizontal and vertical transmission in this species.

Animals↗
PubMed1993

Studies on human fascioliasis in Egypt. 2. Serum iron and copper in chronic fascioliasis.

Twenty-three patients diagnosed as established fascioliasis were enrolled in the present study. Fasciolia cases were investigated for serum iron, copper and their carrier proteins together with haemoglobin and some blood indices. A significant reduction in serum iron was detected in the examined group. This reveals the occurrence of iron deficiency anaemia in patients with chronic fascioliasis.

Adolescent↗
PubMed1992

A homolog of Escherichia coli RecA protein in plastids of higher plants.

Studies of chloroplast DNA variations, and several direct experimental observations, indicate the existence of recombination ability in algal and higher plant plastids. However, no studies have been done of the biochemical pathways involved. Using a part of a cyanobacterial recA gene as a probe in Southern blots, we have found homologous sequences in total DNA from Pisum sativum and Arabidopsis thaliana and in a cDNA library from Arabidopsis. A cDNA was cloned and sequenced, and its predicted amino acid sequence is 60.7% identical to that of the cyanobacterial RecA protein. This finding is consistent with our other results showing both DNA strand transfer activity and the existence of a protein of the predicted molecular mass crossreactive with antibodies to Escherichia coli RecA in the stroma of pea chloroplasts.

Amino Acid Sequence↗
PubMed1992

Hysteroscopic and hysterosalpingographic study after intrauterine insertion of quinacrine pellets for non-surgical sterilization.

60 fertile females seeking permanent contraception were included in this study. All cases received 3 applications of 7 36 mg quinacrine hydrochloride pellets during the proliferative phase of 3 consecutive menstrual cycles. The patients were randomly divided into 3 groups. Hysterosalpingography was performed on the 8th day of menstruation and hysteroscopy on the 10th day of the same cycle after 1st application in group A, after the 2nd application in group B, and after the 3rd application in group C. Hysterosalpingography showed 17 cases of bilateral obstruction, 1 case of bilateral patency, and 2 cases of unilateral patency in group A, while in groups B and C, all elicited bilateral tubal occlusion. Cornual obstruction was seen in 33%, 65%, and 85% in groups A, B, and C, respectively. Intramural obstruction was seen in 50%, 33%, and 10% in 3 groups. Hysteroscopy showed no abnormal findings in group A, while 35% and 85% of cases in groups B and C showed some changes. 4 types of ostial appearances could be recognized hysteroscopically: Type 0 (patent tubes), type I (distal tubal blockage), type II (intramural obstruction), and type III ( cornual obstruction). In group A, type 0 was seen in 10%, type I 80%, type II 50%, and type III 33%. The respective figures in group B were 0%, 2.5%, 33%, and 65%, while in group C, 0%, 5%, 10%, and 85%. 2 applications of quinacrine are 100% effective, the hysteroscopic endometrial changes detected were transient. The possibility of reversal of the procedure is outlined.

Africa↗
PubMed1991

Bioenergetic consequences of glucoamylase production in carbon-limited chemostat cultures of Aspergillus niger.

Aspergillus niger has been grown in glucose- and maltose-limited continuous cultures to determine the bioenergetic consequences of the production of the extracellular enzyme glucoamylase. Growth yields (g biomass per mol substrate) were high, indicating that growth was very efficient and protein production for biomass was not exceedingly energy consuming. It has been found that the energy costs for the production of this extracellular enzyme is very high. Depending on the efficiency of energy conservation the glucoamylase protein yield on ATP is between 1.3 and 2.6 g protein per mol ATP, which is equal or less than 10% of the theoretical maximum of 25.5. These high energy costs most probably have to be invested in the process of excretion. A comparison between an industrial over-producing strain and the wild type Aspergillus niger showed that this over-producing strain most probably is a regulatory mutant. Two regions of specific growth rates could be determined (one at specific growth rates lower and one at specific growth rates higher than 0.1 h-1), which are characterized by differences in mycelium morphology and a significant deviation from linearity in the linear equation for substrate utilization. Analysis of the region of specific growth rates higher than 0.1 h-1 yielded maintenance requirements of virtual zero. It has been concluded that for a good analysis of the growth behaviour of filamentour fungi the linear equation for substrate utilization is not suitable, since it contains no term for the process of differentiation.

Adenosine Triphosphate↗
PubMed1991

Sweetness-dependent facilitation of sucrose drinking by raclopride is unrelated to calorie content.

Previous studies have reported that dopamine receptor antagonists increase the intake of solid or liquid diets containing high concentrations of sucrose. In Experiment 1, different groups of rats were trained in two-bottle tests (sweet solution vs. water), using three concentrations of either sucrose (0.7, 7 or 34%) or saccharin (0.02, 0.2 or 0.8%). Both sweeteners showed an inverted-U-shaped concentration-intake function. Raclopride increased intake of 34% sucrose, but not of 0.8% saccharin. In Experiment 2, raclopride had similar effects in three-bottle tests (all 3 concentrations available concurrently). However, whereas 34% was the most preferred sucrose solution, 0.2% saccharin was preferred to 0.8%. Thus, 0.8% saccharin differs from 34% sucrose in two ways, being not only noncaloric, but also aversive. In Experiment 3, 34% sucrose was rendered aversive by the addition of 0.08% quinine. Intake of this cocktail was not increased by raclopride. These results suggest that the difference between sucrose and saccharin in the effects of raclopride is related to the aversive properties of a concentrated solution of saccharin, rather than to its lack of calories.

Animals↗
PubMed1991

Early changes in lung tissue hyaluronan (hyaluronic acid) and hyaluronidase in bleomycin-induced alveolitis in hamsters.

Intratracheal instillation of bleomycin in hamsters initiates a series of events that mimic human interstitial pulmonary fibrosis. Because glycosaminoglycans and particularly hyaluronan (hyaluronic acid, HA), may play an important role in the extracellular matrix response to early injury and subsequent fibrosis, this study was undertaken to define the early time course of changes in HA and hyaluronidase. Hamsters were given either 1 unit bleomycin sulfate in 0.2 ml saline or 0.2 ml saline (control), and randomly selected animals from both groups were killed at Days 3, 5, 6, 7, 9, and 17. Glycosaminoglycan fractions prepared from lung tissue of individual animals were analyzed for HA. The maximal HA content was reached 6 days after instillation of bleomycin and was 14.6-fold the normal value. The weight of injured lungs was 2.3-fold the control value. Thus, the increase in HA content was 30-fold. By Day 7 the HA content had dropped sharply. It then declined gradually to approximately double control values at Day 17. The specific activity of lysosomal hyaluronidase was the same in bleomycin-treated lungs and control lungs. Total units of the enzyme were increased in injured lungs, even at the time of maximal HA content, indicating active turnover of HA. The maximal HA content occurs prior to the rise in collagen and elastin biosynthesis. This observation in addition to the magnitude of the increase and its abrupt decline suggest that HA may be an important initiating factor for pathologic changes in lung extracellular matrix components.

Animals↗
PubMed1990

An autoradiographic study of the uptake and distribution of iron by the brain of the young rat.

Rats aged 15, 28, or 42 days were injected intraperitoneally with iron-59 and were sacrificed at varying intervals. Total acquisition of iron-59 by the brain, when compared to levels of iron-59 in blood sampled 48 h after injection, diminished with increasing age at injection. Cerebral levels of iron-59 in animals injected at age 15 days did not change with postinjection interval despite rapidly decreasing serum levels of iron-59. Thus, iron acquired by the brain early in postnatal development becomes sequestered in that organ. However, autoradiography of the brains of animals injected at age 15 days showed definite changes over time in the anatomic distribution of the isotope. This suggests that mechanisms may exist for the translocation of iron from one area of the brain to another.

Aging↗
PubMed1990

Molecular analysis of the Drosophila nuclear lamin gene.

A complete nucleotide sequence of a 4.2-kb genomic fragment containing the Drosophila lamin gene and flanking sequences is presented. Primer extension experiments and sequence analysis revealed that transcription starts from a single promoter. The lamin maternal 2.8-kb transcript and the 3.0-kb zygotic transcript are generated from two alternative polyadenylation sites. The gene contains four exons. The first intron is 7 bp upstream of the first AUG site. The two other introns are located within the alpha-helical rod domain of the protein: one in coil 1B in the 42-amino-acid domain that is absent in vertebrate cytoplasmic intermediate filament proteins and the other in coil 2 at a position different from intron positions within the vertebrate intermediate filament genes. Together with the sequence homology analysis, the data suggest either that the lamin gene was the ancestral gene of intermediate filament genes or that the lamin gene diverged from other intermediate filament genes early in evolution.

Amino Acid Sequence↗
PubMed1989

Comparison of oral and subcutaneous routes of cocaine administration on behavior, plasma drug concentration and toxicity in female rats.

Oral and subcutaneous routes of administration of cocaine HCl were investigated in female Wistar rats for food and water consumption, locomotor activity, stereotypic behaviors, plasma drug concentrations and injection site pathology. Animals received either 40 or 80 mg/kg/day by gastric intubation (PO-40 and PO-80 respectively) or 20 or 40 mg/kg/day subcutaneously (SC-20 and SC-40). All groups received the drug or the vehicle for 16 consecutive days. Locomotor activity and stereotypy were evaluated on Days 1, 5, 10, and 15. Plasma drug concentrations and injection site pathology were determined on Day 16. Subcutaneous administration was associated with a sensitization to the effects of cocaine on locomotion and stereotypy, higher blood levels than oral administration at the same dose, and severe dermal lesions. However, there were no differences in any measure between the SC-20 and SC-40 groups. Oral cocaine was also associated with behavioral sensitization. However, unlike the SC route, oral cocaine was characterized by dose-related increases in locomotion and stereotypy in the absence of gastrointestinal pathology. Inasmuch as oral administration resulted in dose-response relationships and low toxicity while subcutaneous administration did not, these factors should be considered in future studies utilizing chronic cocaine administration.

Administration, Oral↗