Search PubMed⌕ Search

Biomedical subjects

A Demirci

Publications and source records attributed to A Demirci.

At least 37 records · Page 2Linked to original sources
PubMed1998

Abdominal tuberculosis. A case report.

Tuberculous involvement of the abdominal parenchymatous organs is usually a diffuse process. The macronodular form of hepatosplenic tuberculosis and focal involvement of the pancreas are extremely rare. This report describes CT findings of abdominal parenchymatous organ involvement in a patient with pulmonary and vertebral tuberculosis. Although CT does not confirm a diagnosis of abdominal tuberculosis, it is a valuable examination that can support the diagnosis and define the extent of disease.

Abdomen↗
PubMed1997

Ethanol production by Saccharomyces cerevisiae in biofilm reactors.

Biofilms are natural forms of cell immobilization in which microorganisms attach to solid supports. At ISU, we have developed plastic composite-supports (PCS) (agricultural material (soybean hulls or oat hulls), complex nutrients, and polypropylene) which stimulate biofilm formation and which supply nutrients to the attached microorganisms. Various PCS blends were initially evaluated in repeated-batch culture-tube fermentation with Saccharomyces cerevisiae (ATCC 24859) in low organic nitrogen medium. The selected PCS (40% soybean hull, 5% soybean flour, 5% yeast extract-salt and 50% polypropylene) was then used in continuous and repeated-batch fermentation in various media containing lowered nitrogen content with selected PCS. During continuous fermentation, S. cerevisiae demonstrated two to 10 times higher ethanol production in PCS bioreactors than polypropylene-alone support (PPS) control. S. cerevisiae produced 30 g L-1 ethanol on PCS with ammonium sulfate medium in repeated batch fermentation, whereas PPS-control produced 5 g L-1 ethanol. Overall, increased productivity in low cost medium can be achieved beyond conventional fermentations using this novel bioreactor design.

Biofilms↗
PubMed1997

Ingredient selection for plastic composite supports for L-(+)-lactic acid biofilm fermentation by Lactobacillus casei subsp. rhamnosus.

Plastic composite supports containing 50% agricultural products (oat hulls, soybean hulls, yeast extract, soybean flour, dried bovine erythrocytes, bovine albumin, and/or mineral salts) and 50% (wt/wt) polypropylene were produced by high-temperature twin-screw extrusion. The research employed two half sets of a five-factorial fractional design (2(5 - 1)) to evaluate the effects of different agricultural components on the properties of the plastic composite supports and to select the best plastic composite support formulation for lactic acid fermentation. The biofilm population was affected by the contact angle and relative hydrophobicity of the supports (r = 0.79 to 0.82). Lactic acid was produced by the suspended cells (r = 0.96) and the biofilm on the plastic composite support discs (r = 0.85). Incorporation of yeast extract into plastic composite supports enhanced growth of free and attached cells in minimal medium (P < 0.0001). The presence of soybean hulls, yeast extract, or mineral salts in plastic composite supports produced less hydrophobic supports (P < 0.0001) and enhanced cell attachment (P < 0.03). Under all conditions, suspended-cell and polypropylene disc controls gave negligible lactic acid production and cell density. Plastic composite supports containing soybean hulls, yeast extract, soybean flour, bovine albumin, and mineral salts gave the highest biofilm population (2.3 x 10(9) CFU/g of support), cell density (absorbance of 1.8 at 620 nm), and lactic acid concentration (7.6 g/liter) in minimal medium.

Animals↗
PubMed1997

Nutrient leaching and end product accumulation in plastic composite supports for L-(+)-lactic Acid biofilm fermentation.

Investigations on the leachate bioavailability, leaching rate, and lactic acid accumulation properties of plastic composite supports (PCS) were essential for large-scale or long-term lactic acid fermentation. Leachates from PCS and polypropylene discs (controls) were analyzed by the micro-Kjeldahl method; by absorbances at 260, 275, and 280 nm; and by bioassays with Lactobacillus casei subsp. rhamnosus (ATCC 11443). The amount of leached nitrogen in a 20-ml initial soaking solution had a high correlation with the soaking solution's cell density (r = 0.87) and absorbance at 260 nm (r = 0.95). Leaching rates of various PCS were evaluated by 20 20-ml simulated repeated-batch fermentations (RBF). PCS with only yeast extract as the minor agricultural ingredient had a high leaching rate and leached out 51 to 60% of the total nitrogen during the first RBF. PCS blended with dried bovine albumin, dried bovine erythrocytes, and/or soybean flour had slowed nutrient leaching (20 to 30% of the initial leached nitrogen). Hence, they could still maintain 1 g of lactic acid per liter and measurable cell density (absorbance at 620 nm, 0.4 to 0.6) at the 20th 20-ml RBF. Lactic acid accumulation properties of PCS were evaluated by soaking the supports in a 30% lactic acid solution for 72 h at 45(deg)C. The lactic acid-soaked supports were rinsed three times and then heat treated (121(deg)C, 15 min) in 15 ml of deionized water. The results showed that lactic acid accumulation in PCS was mainly due to absorption and had no correlation with lactic acid production or biofilm formation.

Journal Article↗
PubMed1996

Quantitative computed tomography for measuring bone mineral density in athletes.

We studied the effect of different training patterns on vertebral trabecular and cortical bone mineral density (BMD) in male athletes using quantitative computed tomography. Vertebral trabecular (t) and cortical (c) BMDs of the first three lumbar vertebrae were measured using single energy quantitative computed tomography in 51 athletes including 10 weight lifters (mean age 20 years), 13 soccer players (mean age 27 years), 28 wrestlers (mean age 17 years), and 45 age-matched volunteers (mean age 21 years). Measured BMDs were correlated with age, body height and weight, training hours per week, sports years, and type of physical activity. Vertebral tBMDs were found to be 44%, 23%, and 24% higher in the weight lifters, soccer players, and wrestlers, respectively, compared with the volunteers. The corresponding cBMDs were 18%, 6%, and 11% higher than that of volunteers. There was significant correlation between the trabecular and cBMD, and height of the athletes, sports years, training hours per week, and physical activity. The most significant correlation with BMD was the type of physical activity. Both the height of the subjects and physical activity variables showed variations of 47% and 32% in trabecular and cBMD, respectively. According to the multiple analysis of variance (MANOVA) only the physical activity factor was effective, with a significance level of P < 0.01; the other factors and interactions were not effective (P > 0.05) on trabecular and cBMD. Different training patterns have a different anabolic effect on both trabecular and cBMDs of the vertebrae, and this effect is more pronounced on the trabecular compartment. Weight lifting showed the highest anabolic effect on both trabecular and cBMDs compared with soccer playing and wrestling. Of the independent variables, physical activity showed the highest anabolic effect on the vertebrae. These results may have implications for devising exercise strategies to reduce the possibility of fracture in old age.

Adult↗
PubMed1995

Bone mineral density measurement by quantitative computed tomography in a normal Turkish population.

PURPOSE: To observe the trabecular and cortical bone mineral density values of a normal Turkish population, to examine the effect of age in males, and age and duration of menopause in a female population on bone mineral density. Also to compare Turkish population bone mineral density values with the reference values in developed countries. MATERIALS AND METHODS: Trabecular and cortical bone mineral densities were measured by the quantitative CT method in 255 (110 male and 145 female) normal cases. RESULTS: According to the linear regression test results, loss of bone mineral density per year was 1.97 mg/ml and 2.09 mg/ml for females and 1.37 mg/ml and 1.04 mg/ml for males in the trabecular and cortical bone compartments, respectively. A 70-year-old female loses 56.7% and 31.3% of the bone mass at 20 years of age for the trabecular and cortical compartments, respectively. These ratios were 41% and 16.1% for the male population. Most loss in bone mass was observed in the premenopausal and early postmenopausal period. In the postmenopausal period, duration of menopause had more effect on bone mass than age. Loss of trabecular bone mass per year in the postmenopausal period was 2.36 mg/ml and 2.84 mg/ml with respect to age and duration of menopause, respectively. CONCLUSIONS: Quantitative CT is a valuable method to determine bone mass because it allows to detect bone mass of trabecular and cortical bone separately. Loss in trabecular bone was found to be higher than in cortical bone for both sexes, while overall bone loss was higher in females. Rate of loss increases in the menopause period. Duration of menopause had more effect on bone mass than age. Bone mineral density values in Turkey were similar to reference values of western countries.

Adolescent↗
PubMed1995

Cerebral dural sinus thrombosis. A case report.

Cerebral dural sinus thrombosis is an uncommon syndrome that a patient presents with severe headache, which may be associated with complex physical and neurologic findings. The authors present a thirty-two-year-old woman with severe headache, focal motor seizures, and subsequent hemiparesis when she was ten weeks pregnant, diagnosed as having a dural sinus thrombosis by magnetic resonance imaging and magnetic resonance angiography. In this report, the application of magnetic resonance techniques, including angiography to diagnose and monitor therapy for dural sinus thrombosis, is presented.

Adult↗
PubMed1995

MR of parenchymal neurocutaneous melanosis.

Two cases of neurocutaneous melanosis are presented. MR showed hyperintense areas in the brain on short-repetition-time/short-echo-time sequences, compatible with intraparenchymal melanin deposits. No leptomeningeal abnormality was seen.

Brain Neoplasms↗
PubMed1995

Primary Burkitt's lymphoma of the cranial vault in a child.

Non-Hodgkin s lymphoma in the cranial vault is rare, particularly in children. This report describes a 12-year-old boy who had a palpable and painless occipital skull mass and left hypoglossal nerve paralysis as the initial manifestations of Burkitt s lymphoma. Plain radiography, computed tomography and magnetic resonance imaging findings are presented.

Burkitt Lymphoma↗
PubMed1993

Lactic Acid production in a mixed-culture biofilm reactor.

Novel solid supports, consisting of polypropylene blended with various agricultural materials (pp composite), were evaluated as supports for pure- and mixed-culture continuous lactic acid fermentations in biofilm reactors. Streptomyces viridosporus T7A (ATCC 39115) was used to form a biofilm, and Lactobacillus casei subsp. rhamnosus (ATCC 11443) was used for lactic acid production. For mixed-culture fermentations, a 15-day continuous fermentation of S. viridosporus was performed initially to establish the biofilm. The culture medium was then inoculated with L. casei subsp. rhamnosus. For pure-culture fermentation, L. casei subsp. rhamnosus was inoculated directly into the reactors containing sterile pp composite chips. The biofilm reactors containing various pp composite chips were compared with a biofilm reactor containing pure polypropylene chips and with a reactor containing a suspension culture. Continuous fermentation was started, and each flow rate (0.06 to 1.92 ml/min) was held constant for 24 h; steady state was achieved after 10 h. Lactic acid production was determined throughout the 24-h period by high-performance liquid chromatography. Production rates that were two to five times faster than those of the suspension culture (control) were observed for the pure- and mixed-culture bioreactors. Both lactic acid production rates and lactic acid concentrations in the culture medium were consistently higher in mixed-culture than in pure-culture fermentations. Biofilm formation on the chips was detected at harvest by chip clumping and Gram staining.

Journal Article↗
PubMed1993

Aicardi syndrome: a variant example with new clinical findings.

Aicardi syndrome, which shows X-linked dominant inheritance, is characterized by corpus callosum agenesis, infantile spasms, chorioretinitis, chorioretinal lacunae, psychomotor retardation, microphthalmy, cerebral atrophy and vertebral abnormalities. A 3/12 year-old girl with Aicardi syndrome who has dilated right lateral ventricle and leucomalacy in the right frontal lobe on magnetic resonance imaging (MRI) is presented. As far as we know, this combination of symptoms was not described previously in the literature.

Agenesis of Corpus Callosum↗
PubMed1991

A primary intraocular hydatid cyst.

Ultrasonography and computerized tomography (CT) of the painful and blind right eye of a 13-year-old girl showed a cystic mass almost filling the vitreous cavity and narrowing the anterior chamber. The histopathologic diagnosis of the enucleated eye was an echinococcus cyst. Abdominal ultrasonography, brain CT and chest X-rays gave no abnormal findings when first examined, nor during the follow-up 18 months after surgery. Indirect hemagglutination test was negative at the last control. The case was accepted as a primary hydatid cyst (echinococcosis) of the eyeball.

Adolescent↗