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Biomedical subjects

M Sahin

Publications and source records attributed to M Sahin.

At least 55 records · Page 3Linked to original sources
PubMed2000

Evaluation of metastatic bone disease with pentavalent 99Tc(m)-dimercaptosuccinic acid: a comparison with whole-body scanning and 4/24 hour quantitation of vertebral lesions.

The aim of this study was to establish the value of 99Tcm(V)-DMSA scintigraphy in the detection of metastatic bone lesions and compare the results to 99Tcm-MDP bone scintigraphy. Thirty-four patients presenting with metastatic bone disease (Group 1) and 12 controls with degenerative skeletal lesions (Group 2) were studied. Conventional bone scanning and 99Tcm(V)-DMSA whole-body scanning were performed on all patients. All scans were interpreted visually. Furthermore, lesion-to-normal bone ratios (L/N) in vertebral metastases on the 4 and 24 h bone scans were obtained in 58 lesions of cancer patients and in 23 benign (degenerative) vertebral lesions of the control group. 99Tcm-MDP L/N ratios at 24 h (3.08 +/- 0.32) were significantly higher than those at 4 h (2.48 +/- 0.24) in the malignant foci (P < 0.001). No significant difference was observed in benign lesions (P > 0.05). In 167 (164 metastatic, 3 traumatic) of 186 99Tcm-MDP positive lesions (90%) of Group 1, 99Tcm(V)-DMSA uptake was observed. The remaining 19 lesions (10%) were 99Tcm(V)-DMSA negative. Fourteen of these 19 sites were diagnosed as benign. The remaining five foci were malignant. In four lung cancer metastases showing no 99Tcm-MDP uptake, 99Tcm(V)-DMSA uptake was observed. There was no 99Tcm(V)-DMSA accumulation in any of the 99Tcm-MDP positive degenerative lesions of Group 2. All quantitatively evaluated (n = 42) vertebral metastatic foci and two compression fractures in Group 1 showed 99Tcm(V)-DMSA accumulation and an increased 99Tcm-MDP L/N ratio at 24 h. A total of 36 degenerative lesions (Groups 1 and 2) and one compression fracture (Group 1) showed neither 99Tcm(V)-DMSA uptake nor an increased 99Tcm-MDP L/N ratio at 24 h. Our results indicate that quantitative 4/24 h analysis of vertebral lesions on 99Tcm-MDP scans has a similar diagnostic value to 99Tcm(V)-DMSA imaging in the detection of bone metastases. However, the accumulation of 99Tcm(V)-DMSA in four lung cancer metastases showing no 99Tcm-MDP uptake is encouraging and justifies further research in patients with proven bone metastases and negative bone scans.

Bone Neoplasms↗
PubMed2000

Closed-loop stimulation of hypoglossal nerve in a dog model of upper airway obstruction.

Electrical stimulation of upper airway (UAW) muscles has been under investigation as a treatment method for obstructive sleep apnea (OSA). Particular attention has been given to the electrical activation of the genioglossal muscle, either directly or via the stimulation of the hypoglossal nerve (HG), since the genioglossus is the main tongue protrusor muscle. Regardless of the stimulation site or method, an implantable electrical stimulation device for OSA patients will require a reliable method for detection of obstructive breaths to apply the stimulation when needed. In this paper, we test the hypothesis that the activity of the HG nerve can be used as a feedback signal for closed-loop stimulation of the HG nerve in an animal model of UAW obstruction where a force is applied on the submental region to physically narrow the airways. As an advantage, the method uses a single electrode for both recording and stimulation of the HG nerve. Simple linear filtering techniques were found to be adequate for producing the trigger signal for the electrical stimulation from the HG recordings. Esophageal pressure, which was used to estimate the size of the UAW passage, returned to the preloading values during closed-loop stimulation of the HG nerve. The data demonstrate the feasibility of the closed-loop stimulation of the HG nerve using its activity as the feedback signal.

Airway Obstruction↗
PubMed2000

The effects of splenic artery ligation in an experimental model of secondary hypersplenism.

OBJECTIVE: To induce hypersplenism in rats by splenic vein ligation and to investigate the effects of splenic artery ligation in this model. BACKGROUND: Selective arterial embolisation and splenic artery ligation (SAL) are used in the treatment of secondary hypersplenism in some medical centres but these methods are not common. MATERIALS AND METHODS: Thirty male Saprague-Dawley rats were allocated to three groups (n = 10). The first group underwent laparotomy, the second and third groups underwent laparotomy and splenic vein ligation. At the end of the third week, laparotomy was performed in the first and second groups and splenic artery ligation in the third group. Erythrocyte, leukocyte and platelet counts were performed weekly. At the end of the sixth week, the animals were sacrificed and the spleens were taken for histopathologic examination. RESULTS: In the second and third groups, after splenic vein ligation, the erythrocyte and platelet counts were significantly reduced at the end of the second week (p < 0.01). In the second group, which underwent splenic vein ligation only, the levels remained low throughout the experiment. In the third group, after splenic artery ligation, there were rises in both erythrocyte and platelet counts; the levels were similar to the levels in the control group at three weeks after splenic artery ligation (p > 0.05). No significant changes were observed in the leukocyte counts throughout the experiment (p > 0.05). CONCLUSIONS: Splenic vein ligation successfully induces experimental secondary hypersplenism. This state can be ameliorated by splenic artery ligation.

Animals↗
PubMed2000

[Mechanical intestinal obstruction caused by abdominal wall hernias].

Mechanical intestinal obstructions form important part of pathologies those necessitates emergent surgical intervention. Length of time between symptoms and surgery, preference of surgical procedure and prevention of recurrence are still under discussion. While the most frequent etiological factor is postoperative adhesions in developed countries, strangulated hernias are more common in developing countries. In this study, among 147 cases operated on with the diagnosis of mechanical intestinal obstruction between 1993-1999, 80 strangulated were 50 males (%62.5) and 30 females (%37.5). Mean age was 59 years (range 4-94). The most frequent type of hernia was inguinal hernia and observed in 49 cases. Small intestine was detected most frequently in hernia sac. In 14 cases (%17.5), beside hernia repair, additional surgical interventions were performed. Total morbidity was %22.5 and mortality was %7.5. Patients with mechanical intestinal obstruction should be evaluated for abdominal wall hernias because of high incidence of mech surgical intervention have high morbidity and mortality rates, elective surgery should be recommended when abdominal wall hernia is diagnosed.

Adolescent↗
PubMed1999

Comparison of Tc-99m MDP, Tc-99m HSA and Tc-99m HIG uptake in rheumatoid arthritis and its variants.

Tc-99m polyclonal immunoglobulin-G has been shown to be a successful agent in the depiction of active inflammation in rheumatoid arthritis (RA). The objective of this study was to compare the uptake behaviors of Tc-99m HIG and Tc-99m MDP in RA and variants of rheumatoid arthritis (VRA). Seventeen patients with RA and 8 patients with VRA presenting with active inflammation were included in this study. Ten subjects with well-diagnosed degenerative joint disease constituted the control group. All joints in patients were also imaged with Tc-99m HSA to evaluate the vascularization status of the joints. Tc-99m HIG and HSA scans were obtained at 2, 4 and 24 hours after the injection of 555 MBq Tc-99m HIG and 296 MBq Tc-99m HSA. Conventional bone scans were performed 4 hours after the injection of 740 MBq Tc-99m MDP. Target-to-background (T/B) ratios were obtained exclusively over the joint regions. Tc-99m HIG T/B ratios of the active joints in RA were significantly higher than those of the non-active joints and the control group (p < 0.05). Tc-99m HIG T/B ratios in active joints showed a progressive increase between 2 and 24 hour images (p < 0.05). In contrast, Tc-99m HSA T/B ratios decreased in all active joints significantly (p < 0.05) except the ankle joint region (p > 0.05). The T/B ratios in Tc-99m MDP bone scans were higher in all active joints than in non-active RA joints and joints of controls but significantly differences were only detected in wrist and elbow joints. All clinically active joints in VRA patients accumulated Tc-99m HIG and HSA, and showed increased Tc-99m MDP uptake. These joints had a very similar Tc-99m HIG retention pattern to the RA joints. The detection rate of active joint inflammation with Tc-99m HIG was much higher than that with Tc-99m MDP. The increasing Tc-99m HIG uptake ratio between 2 and 24 hours in contrast to Tc-99m HSA indicates the presence of other binding mechanisms besides increased vascularity in RA.

Adolescent↗
PubMed1999

The impact of oral feeding on the severity of acute pancreatitis.

BACKGROUND: In the management of acute pancreatitis, oral feeding is prohibited and either enteral or parenteral feeding is commenced for the patients in an effort to not increase the secretion of the pancreatic enzymes. PURPOSE: This study was undertaken in an attempt to determine the impact of oral feeding on the severity of acute pancreatitis and to compare this impact with that of parenteral feeding. MATERIALS AND METHODS: Twenty-four female Sprague-Dawley rats were divided into two groups. In both groups, acute pancreatitis was induced by ligation of the main biliopancreatic duct. The rats in group I were fed orally and the rats in group II were fed parenterally. The rats were sacrificed at 48 hours, and blood samples were obtained from the heart upon exposure of the abdominal and thoracic cavities. The pancreas and the left lung were removed for histopathological examination. The levels of lactic dehydrogenase (LDH), serum glutamic oxaloacetic transaminase (SGOT), glucose, calcium and blood urea nitrogen, base deficit, partial oxygen pressure, leukocyte count, and hematocrit level among Ranson criteria and the level of amylase were measured. The pancreas and the lung were examined under a light microscope. RESULTS: The levels of LDH, SGOT, and calcium for the rats in group I were significantly higher when compared with the rats in group II (P <0.05). Similarly, the levels of amylase for the rats in group I were found to be higher when compared with the rats in group II, but the difference was not significant. Inflammatory changes observed in the pancreas were less severe whereas inflammatory changes observed in the lung were more severe for the rats in group I when compared with the rats in group II. CONCLUSION: The blood levels of the enzymes were adversely affected for the rats fed orally. In contrast, inflammatory changes observed in the pancreas were more severe for the rats fed parenterally. The study suggests that certain hormones released from the duodenum upon stimulation by oral nutrient intake lessens the severity of pancreatitis through protective effects on the pancreas, whereas the elevated levels of the enzymes cause endothelial damage resulting in destruction in distant organs such as the lung.

Acute Disease↗
PubMed1999

Hydrocephalus associated with glycogen storage disease type II (Pompe's disease).

The authors describe a case of hydrocephalus in an 8-month, 2-week-old infant who had been previously diagnosed with glycogen storage disease type II. Cranial imaging revealed no evidence of obstruction within the ventricular system. This case adds to the central nervous system complications associated with this disorder. Several possible mechanisms for the hydrocephalus observed in this infant are discussed.

Brain↗
PubMed1999

Effect of octreotide (Sandostatin 201-995) on bile flow and bile components.

Octreotide (Sandostatin 201-995) has an inhibitory effect on gastric, intestinal, and pancreatic secretions and hepatic and splachnic blood flow. We examined the effects of octreotide on bile flow and bile components in 10 patients with T-tube choledochostomy. A Fogarty balloon catheter was inserted distal to the T-tube of these patients for measurement of bile flow and bile components. Bile samples were obtained to analyze bile acid, phospholipid, lipoprotein, and cholesterol, and bile flow measurements were performed every 15 min for a period of 90 min before study and after normal saline and octreotide administrations. While octreotide had an inhibitory effect on bile flow, the concentrations of bile acid, phospholipid, and lipoprotein in bile were increased with octreotide.

Adult↗
PubMed1999

Chronic recordings of hypoglossal nerve activity in a dog model of upper airway obstruction.

The activity of the hypoglossal nerve was recorded during pharyngeal loading in sleeping dogs with chronically implanted cuff electrodes. Three self-coiling spiral-cuff electrodes were implanted in two beagles for durations of 17, 7, and 6 mo. During quiet wakefulness and sleep, phasic hypoglossal activity was either very small or not observable above the baseline noise. Applying a perpendicular force on the submental region by using a mechanical device to narrow the pharyngeal airway passage increased the phasic hypoglossal activity, the phasic esophageal pressure, and the inspiratory time in the next breath during non-rapid-eye-movement sleep. The phasic hypoglossal activity sustained at the elevated level while the force was present and increased with increasing amounts of loading. The hypoglossal nerve was very active in rapid-eye-movement sleep, especially when the submental force was present. The data demonstrate the feasibility of chronic recordings of the hypoglossal nerve with cuff electrodes and show that hypoglossal activity has a fast and sustained response to the internal loading of the pharynx induced by applying a submental force during non-rapid-eye-movement sleep.

Airway Obstruction↗
PubMed1999

Can sensitivity of voided urinary cytology or bladder wash cytology be improved by the use of different urinary portions?

OBJECTIVE: To improve sensitivity by using different portions of voided urine cytology (VUC) and bladder wash material cytology (BWC). MATERIALS AND METHODS: 52 patients with biopsy-proven superficial transitional cell carcinoma (TCC) of the bladder were studied. Voided urine specimens were divided into a first stream, mid-stream and terminal stream. Bladder wash material was also divided into a first portion, mid-portion and last portion. All portions were investigated for cytology abnormalities. RESULTS: Sensitivity for the detection of malignant cells was 34.6, 38.5 and 38.5% for the first, mid- and terminal stream of VUC and 34.6, 38.5 and 34.6% for the first, mid- and last portion of BWC, respectively. The sensitivity of VUC was 20-25% for grade I, 30-40% for grade II, and 50-75% for grade III tumors, respectively. The sensitivity of BWC was 25% for grade I, 35-45% for grade II, and 33-50% for grade III tumors, respectively. There was no statistical significant difference for sensitivities between either grades (p = 0.06) or portions or streams (p = 0.3) of VUC and BWC. CONCLUSIONS: In this small group of patients, we did not find any significant difference, but we found highest sensitivity in grade III tumors with the terminal portion of the voided urine when compared to other portions of VUC. Therefore, we believe that further study in a large series is necessary to investigate this approach of differentiated BWC and especially VUC.

Carcinoma, Transitional Cell↗
PubMed1998

Kzf1 - a novel KRAB zinc finger protein encoding gene expressed during rat spermatogenesis.

Two novel KRAB (Krüppel associated box) type zinc finger protein encoding cDNAs, named Kzf1 and Kzf2 (Kzf for KRAB zinc finger), were identified by screening of a rat embryonic brain cDNA library with a human ZNF91 KRAB probe. Kzf1 and Kzf2 encode proteins with an amino-terminal KRAB domain and a carboxy-terminal zinc finger cluster containing 9 and 13 zinc finger units, respectively. While Kzf2 appears to be ubiquitously expressed, Kzf1 is preferentially expressed in the testis. Within the testis, Kzf1 mRNA is restricted to germ cells. The Kzf1 protein exhibits DNA binding activity and its KRAB domain can function as a repressor module in transcription. Using somatic cell hybrid analysis, the Kzf1 gene was mapped to chromosome 6.

Amino Acid Sequence↗
PubMed1998

Omental fibroma: CT and US findings.

The US, CT, and X-ray findings in a patient with omental fibroma of the lesser omentum are described. Ultrasound showed a solid mass with cystic areas in the central region. At CT the lesion showed peripheral enhancement and central hypodensity. On X-ray studies with barium, there was border distortion in the lesser curvature of the stomach. The mass was resected surgically. A pathologic diagnosis of fibroma was confirmed.

Aged↗
PubMed1998

Does large-bowel enema reduce septic complications in acute pancreatitis?

BACKGROUND: The source of septic complications in acute pancreatitis was unknown until recent years. The pathogenesis of bacterial translocation from the gut has been accepted as the main source of pancreatic or peripancreatic infection. This study was designed to investigate the role of large bowel enema during acute pancreatitis in preventing bacterial translocation. MATERIALS AND METHODS: Twenty-four Spraque-Dawley rats were used in this study. The rats were divided into two groups. Group I animals received biliopancreatic duct ligation plus colon cleansing by rectal enemas; group II animals received only biliopancreatic duct ligation. Rectal enemas were applied to the first group of animals three times, at 6, 24, and 48 hours after the operation using 10 cc sodium hydrogen phosphate solutions. All animals were sacrificed 72 hours later, and tissue samples were taken from mesenteric lymph nodes, pancreas, spleen, and liver for bacteriologic cultures via a midline laparatomy. Blood and cecum cultures were also prepared. RESULTS: Positive mesenteric lymph node cultures were found in all 12 animals in group II but in only 3 of 11 animals of group I (P <0.05). Distant organ cultures were positive in 9 of group II, but the only infected distant organ culture found in group I was the positive liver culture (P <0.05). CONCLUSION: As a result of this study, we believe that large bowel enema can reduce the frequency of septic complications in acute pancreatitis by reducing bacterial translocation.

Acute Disease↗
PubMed1998

Improved nerve cuff electrode recordings with subthreshold anodic currents.

A method has been developed for improving the signal amplitudes of the recordings obtained with nerve cuff electrodes. The amplitude of the electroneurogram (ENG) has been shown to increase with increasing distance between the contacts when cuff electrodes are used to record peripheral nerve activity [9]. The effect is directly related to the propagation speed of the action potentials. Computer simulations have shown that the propagation velocity of action potentials in a length of a nerve axon can be decreased by subthreshold extracellular anodic currents. Slowing the action potentials is analogous to increasing the cuff length in that both result in longer intercontact delays, thus, larger signal outputs. This phenomenon is used to increase the amplitudes of whole nerve recordings obtained with a short cuff electrode. Computer simulations predicting the slowing effect of anodic currents as well as the experimental verification of this effect are presented. The increase in the amplitude of compound action potentials (CAP's) is demonstrated experimentally in an in vitro preparation. This method can be used to improve the signal-to-noise ratios when recording from short nerve segments where the cuff length is limited.

Action Potentials↗
PubMed1998

Effect of albendazole sulfoxide solution on the scolices and the hepatobiliary system.

The use of scolocidal solutions in the hepatobiliary system may result in caustic sclerosing cholangitis. In this study, the effectivenes of a biological metabolite of albendazole, albendazole sulfoxide, on scolices and the hepatobiliary system was evaluated. In the in vitro study, it was found that 100 microg/ml albendazole sulfoxide solution had strong scolocidal effect in 15 min. In the in vivo study, two experimental groups, each consisting of 8 rabbits aged 3-4 months and weighing 2,500 +/- 250 g, 100 microg/ml albendazole sulfoxide and normal saline were given into the biliary tract. ALP, GGT, SGOT and SGPT values on days 7, 30 and 60 were not found to be significantly increased compared to preoperative values. Total bilirubin values were high in the working group 7 and 30 days postoperatively and on day 30 in the control group, returning back to normal levels on day 60 in both groups. Histopathological evaluation of the liver parenchyma and the biliary system on day 60 revealed no differences between the groups. Consequently, albendazole sulfoxide solution may be used intraoperatively for scolocidal purposes.

Alanine Transaminase↗