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Biomedical subjects

S Yilmaz

Publications and source records attributed to S Yilmaz.

At least 91 records · Page 5Linked to original sources
PubMed2000

Dizygotic twins with schizencephaly and focal cortical dysplasia.

The case reports of 17-year-old female dizygotic twins are presented. One of the twins had bilateral closed-lip schizencephaly, and the other had focal cortical dysplasia. Septum pellucidum was absent in both cases. The cortical dysplasia in case 2 corresponded to the same hemispheric location with the right schizencephalic cleft in case 1. The combination of schizencephaly and focal cortical dysplasia in siblings or twins has not been previously reported.

Abnormalities, Multiple↗
PubMed2000

Two cases of partial trisomy 10q syndrome due to a familial 10;20 translocation.

We describe an eleven day-old boy and his first degree double cousin who both have distal trisomy 10q syndrome. Their cytogenetic analysis using GTG-banding showed an unbalanced translocation 46, XY, -20, +der(20), t(10;20)(q22.3, p11) mat and 46, XX, -20, +der(20), t(10;20)(q22.3, p11) mat. The translocation was confirmed by FISH. We have found balanced translocation t(10;20)(q22.3; p11) with cytogenetic and FISH studies in the mothers and maternal grandfather of these children. Our cases had typical craniofacial and visceral anomalies of this syndrome. However case 1 had an agenesia of corpus callosum which was not previously described and case 2 had hypertrophied cardiomyopathy and cliteromegaly which were previously described as rare anomalies for this syndrome.

Abnormalities, Multiple↗
PubMed1999

Microbiological features and crevicular fluid aspartate aminotransferase enzyme activity in early onset periodontitis patients.

Gingival crevicular fluid (GCF) reflects the immune and inflammatory reactions and the specific host-microbe interactions that lead to periodontal diseases. Aspartate aminotransferase enzyme (AST) is one of the components of GCF that is released as a result of cell death. In this study, periodontal sites (4 sites/patient) with a probing depth of > or =5 mm in early onset periodontitis (EOP) patients were first examined for the AST levels in GCF by the Periogard periodontal tissue monitor. To be eligible for the study, each of the patients had at least 1 AST positive site with clinical inflammatory changes (AST+, CIC+) and 1 AST negative site with no or minimum clinical inflammatory changes (AST-, CIC-). In 15 EOP patients who met the entry criteria, 30 AST+, CIC+ sites (1st group) and 19 AST-, CIC- sites (2nd group) were evaluated for microbiological variables. Certain microbial species, including Porphyromonas gingivalis, Actinobacillus actinomycetemcomitans and Prevotella intermedia were detected more frequently (p<0.001, p<0.001 and p<0.05, respectively) in the 1st group, while gram-positive facultative organisms such as Actinomyces species were found more often (p<0.001) in the 2nd group. Parallel to the AST levels, the 2nd group had a lower number of total bacteria and proportion of obligate anaerobic and capnophilic micro-organisms than the first group (p<0.05 and p<0.05, respectively). Within the scope of this study, AST activity and microbiological data were found in agreement in the examined groups. These findings are encouraging and indicate the need for further studies to evaluate the ability of the AST test to differentiate the microbial flora of progressing sites and those that are inflamed, but not progressing.

Actinomyces↗
PubMed1999

Arteriovenous fistula and skin flaps.

An experimental study was done in a rat groin flap model to assess the possible effects of arteriovenous fistulas (AVF) on the viability of skin flaps. The animals were randomly divided into three groups. In Group 1, an island flap, and in Groups 2 and 3, peninsular flaps, including the superficial epigastric artery and vein, were elevated. In Group 2, the base of the peninsula was on the rectus side of the flap; in Group 3, the base of the peninsula was located on the lower extremity side. After elevation of the flap and following arteriovenotomy, an A-V fistula was produced by side-to-side anastomosis proximal to the pedicle at the level of the common femoral vessels. Then the flaps were sutured back into their beds. All the island groin flaps with the AVF failed to survive. In Group 3, there was a severe reduction of blood flow in the flap and no flaps survived; however, all the flaps in Group 2 survived totally with no problem. It was concluded that island skin flap circulation is negatively affected by an AVF proximal to the flap pedicle. If the flap and AVF are treated as in Group 2, then flap necrosis caused by reduced blood flow can be overcome in this model.

Anastomosis, Surgical↗
PubMed1999

Malignant triton tumor of the maxilla: a patient report.

Malignant Triton tumor (or malignant schwannoma with rhabdomyoblastic differentiation) is a rare entity with a very poor prognosis. This is the second report of this type of rare and aggressive sarcoma arising in the maxilla. The clinical course, therapeutic approach, and histopathological aspects of the case are presented.

Adult↗
PubMed1998

Mutations of the human P gene associated with Type II oculocutaneous albinism (OCA2). Mutations in brief no. 205. Online.

Mutations in the human P gene lead to oculocutaneous albinism type 2 (OCA2, MIM #203200), the most common type of albinism in humans. The P gene encodes a 110 kDa protein that is associated with melonosomal membranes and contains 12 potential membrane spanning domains. The specific function of the P protein is currently unknown. We report 7 new mutations in the P gene associated with OCA2. This includes 6 missense mutations (S86R, C112F, A368V, T592I, A724P and A787V) and one frameshift mutation (1047del7). We also report 8 polymorphisms including one amino acid substitution, D/A257. We and others have found many polymorphisms of the P gene in the coding region, several of which result in amino acid substitutions, making molecular diagnosis problematic. In contrast to this is the tyrosinase gene associated with OCA1, with a limited number of polymorphic variations in the coding region. There is also no apparent clustering of P gene missense mutations in contrast to the clustering observed by the tyrosinase gene missense mutations that define functional domains of the protein. Further mutational analysis is needed to help define the critical functional domains of the P protein and to allow a definitive diagnosis of OCA2.

Albinism, Oculocutaneous↗
PubMed1998

Renal colic: comparison of spiral CT, US and IVU in the detection of ureteral calculi.

The aim of our study was to compare non-contrast spiral CT, US and intravenous urography (IVU) in the evaluation of patients with renal colic for the diagnosis of ureteral calculi. During a period of 17 months, 112 patients with renal colic were examined with spiral CT, US and IVU. Fifteen patients were lost to follow-up and excluded. The remaining 97 patients were defined to be either true positive or negative for ureterolithiasis based on the follow-up data. Sensitivity, specificity, positive and negative predictive value and accuracy of spiral CT, US and IVU were determined, and secondary signs of ureteral stones and other pathologies causing renal colic detected with these modalities were noted. Of 97 patients, 64 were confirmed to have ureteral calculi based on stone recovery or urological interventions. Thirty-three patients were proved not to have ureteral calculi based on failure to recover a stone and diagnoses unrelated to ureterolithiasis. Spiral CT was found to be the best modality for depicting ureteral stones with a sensitivity of 94 % and a specificity of 97 %. For US and IVU, these figures were 19, 97, 52, and 94 %, respectively. Spiral CT is superior to US and IVU in the demonstration of ureteral calculi in patients with renal colic, but because of its high cost, higher radiation dose and high workload, it should be reserved for cases where US and IVU do not show the cause of symptoms.

Adult↗
PubMed1998

A comparative trial of two surface subunit recombinant hepatitis B vaccines vs a surface and PreS subunit vaccine for immunization of healthy adults.

Hepatitis B virus (HBV) infection is the leading cause of chronic hepatitis and cirrhosis in Turkey. The prevalence of hepatitis B surface antigen (HBsAg) positivity in Turkey is 5 to 10%. HBV is almost completely preventable with the use of hepatitis B vaccines. The most commonly used vaccine is that which contains the predominant viral surface (S) polypeptide. It elicits protective antibodies in greater than 90% of healthy subjects. A vaccine containing the PreS1 and PreS2 antigenic domains has recently been reported as being more efficient in achieving successful immunization in individuals who have not previously responded to the isolated S-antigen vaccine. In this study, the efficacy of a S and PreS-containing vaccine was compared with that of two different standard isolated S-antigen-containing vaccines in terms of the immunization protection produced against HBV in normal healthy adults who had not previously been immunized. Seventy-six young adults (aged 17-22) were randomly assigned to receive 1 ml (20 micrograms) of either one of two standard S-subunit recombinant hepatitis B vaccines (Engerix B. or Hepavax) or the combined S and PreS subunit vaccine (Gen Hevac B) intramuscularly in the deltoid muscle at 0, 1 and 2 months. Hepatitis B surface antigen antibody titres were measured at 1, 2 and 12 months. A titre > or = 10 IU ml-1 was considered to be protective. All subjects receiving the two standard isolated S-antigen-containing vaccines responded to the vaccination with reasonable antibody titres. One-half to two-thirds of those vaccinated developed high antibody titres (> 100 IU ml-1). In contrast, 9% of those receiving the combined PreS1 and PreS2 plus S antigens failed to respond, as demonstrated by antibody titres below the level considered to be protective. The mean titres at 12 months were 107 +/- 12 IU ml-1 (Engerix B), 102 +/- 12 IU ml-1 (Gen Hevac B) and 117 +/- 12 IU ml-1 (Hepavax Gene). Hence, no important difference in term of response to vaccination was found between the two different types of vaccines. As recombinant S-subunit vaccines are less expensive than those that combine S and PreS antigens, it is suggested that, when immunizing normal healthy adults, a standard isolated S-antigen-containing vaccine should be used.

Adolescent↗
PubMed1998

Low overall mortality of Turkish residents in Germany persists and extends into a second generation: merely a healthy migrant effect?

OBJECTIVE: To test the hypothesis that as a minority with lower socio-economic status, Turkish residents in Germany might experience a higher mortality than Germans. METHODS: All-cause mortality rates by age group and sex of Turkish and German adults for the time period 1980-94 were calculated from death registry data and mid-year population estimates. RESULTS: The age-adjusted mortality rate (per 100000) of Turkish males aged 25-65 years resident in Germany was 299 in 1980 and 247 in 1990, consistently half that of German males. The mortality of Turkish females in Germany was 140 in 1990, half that of German females. Mortality of Turkish males/females in Ankara was 835 and 426 in 1990. CONCLUSION: In view of the socio-economic status of Turkish residents in Germany the large mortality difference compared to Germans is unexpected. It cannot be fully explained by a selection at the time of hiring (healthy migrant effect) because it lasts over decades and extends into the second generation. A healthy worker effect is unlikely because Turkish residents have a lower employment rate than Germans. There is little evidence for movement of gravely ill persons back to Turkey. An 'unhealthy re-migration effect' in which socially successful migrants with a lower mortality risk stay in the host country while less successful ones return home even before becoming manifestly ill would partly explain our findings.

Adult↗
PubMed1998

The effects of tissue expansion on skin lymph flow and lymphatics: an experimental study in rabbits.

Histomorphological, physiological, and biomechanical changes of the skin and tissue that are being expanded have been extensively studied in the past. The purpose of this study was to investigate whether the skin lymph flow and lymphatics may be influenced during tissue expansion, and also to study different pattern of vascular supply of skin on lymph flow during tissue expansion. The skin lymph flow was quantitatively assessed by 99mTc-dextran lymphoscintigraphy, and the structure of dermal lymphatics was evaluated by histological examination in 12 rabbits. Lymphoscintigraphic results showed that lymph flow is significantly reduced both in expanded and non-expanded (sham-operated) skin. Histologically, we saw widespread lymphatic distension in both expanded and non-expanded skin. There were no quantitative differences in the number of lymphatic vessels compared with control skin. We did not see any lymphatic capillaries in the subdermal capsule of either expanded or non-expanded skin. These results show that lymphostasis has an obstructive (mechanical) aetiology, and the tissue expander itself reduces the lymph flow regardless of expansion, and interferes with the formation of new lymphatic vessels.

Animals↗