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Biomedical subjects

I Karnak

Publications and source records attributed to I Karnak.

63 records · Page 4Linked to original sources
PubMed1996

Tissue hypoxia in ipsilateral and contralateral testes undergoing surgically induced maldescent.

The mechanism of deterioration of ipsilateral and contralateral testes during unilateral maldescent remains controversial. Proposing that alterations in tissue perfusion may play a role in ipsilateral and contralateral testicular deteriorations, an experimental study has been planned to evaluate the status of parameters of tissue hypoxia in ipsilateral and contralateral testes following surgically induced maldescent, in rats which preoperatively underwent placebo or chemical sympathectomy. 60 male albino rats were used for the experiment. At the age of 21 days each 30 rats that were treated by placebo or chemical sympathectomy agent were divided into 3 groups undergoing sham operation, abdominal fixation of one testis or abdominal fixation of both testes. At the age of 3 months the rats underwent bilateral orchidectomies and lactic acid (LA) and hypoxanthine (HX) levels were measured in testicular tissues. Maldescent of the testis resulted in a marked increase of LA and HX values in the ipsilateral testis compared to controls, and also resulted in increased levels of LA and HX in the contralateral testis. Although the levels of LA and HX were lower compared to ipsilateral undescended counterparts the levels in contralateral testis were significantly elevated compared to the contralateral testes of rats undergoing sham operation following placebo treatment. Bilateral maldescent resulted in similar elevations of LA and HX in both of the testes. Administration of 6-hydroxydopamine did not result in decreased levels of LA and HX values in the ipsilateral testis following unilateral testicular undescendence. However the LA levels in the contralateral descended testis did not reveal a significant difference compared to the contralateral testis of rats undergoing sham operation. The present experimental design reveals that abdominal fixation of the testis results in tissue hypoxia not only in the ipsilateral but also in the contralateral testis. Chemical sympathectomy has some protective effects on contralateral testicular hypoxia during unilateral maldescent. Tissue hypoxia during maldescent may result from relative inadequacy of testicular blood flow to overcome the increased metabolic demands under hyperthermic conditions.

Animals↗
PubMed1996

Esophageal ligation: effects on the development of fetal organic systems.

The role of amniotic fluid ingestion on the development of various fetal organic systems was evaluated in the rabbit model. The fetuses from 24 New Zealand white rabbits were studied on the 23rd day of gestation. Right ovarian-end fetuses underwent esophageal ligation (EL) or sham (SH) operations. Rabbits were submitted to hysterectomy on gestational day 30, and various organic systems of live fetuses were examined by weight and histological evaluations. Additionally, small intestinal enzymes were determined. Three fetal deaths, one in EL and two in SH groups, occurred with a total survival rate of 85%. EL resulted in increased amniotic fluid volume. Although fetal body weights (BW), lung, heart, liver and renal weights and liver weight/BW, lung weight/BW ratios did not differ, gastric, small intestinal and total gastrointestinal tract weights significantly decreased in EL group (p < 0.05). Additionally, gastric weight/BW, small intestinal weight/BW, total gastrointestinal tract weight/BW and renal weight/BW ratios were also significantly decreased (p < 0.01). Sucrase and maltase activities were not detectable in either group. Lactase activity in proximal small intestinal tissue was significantly decreased in EL group (p < 0.05). Mid and distal small intestinal tissue lactase activities did not reveal any significant difference among groups. Histologically, alveolar enlargement and alveolar thickening in fetal lungs, decreased glomerular count and tubular degeneration in fetal kidneys, and slight changes in fetal livers such as cellular vacuolization and reduction in central vein count were observed in the fetuses with esophageal ligation. While small intestinal tissues showed no marked changes, fetal stomach tissues in EL group revealed marked histological alterations consistent with erosive gastritis. This study suggests that amniotic fluid ingestion has no important effects on fetal somatic growth but effects the development of various fetal organic systems. Since the nutritional role of amniotic fluid is obscure, changes in amniotic fluid dynamics, and/or impairment of release of some possible fetal organotrophic factors, and/or unused states of the organs may be responsible for the morphologic changes secondary to esophageal ligation.

Amniotic Fluid↗
PubMed1995

Fetal penile and urethral development subsequent to vascular insult in the last trimester of gestation: an experimental study in goat fetuses.

OBJECTIVE: To investigate a possible mechanism (the vascular theory) in the development of congenital anomalies of the penis and urethra in the fetus of the goat. MATERIALS AND METHODS: Fifteen male Angora goat fetuses underwent an operation at 110-114 days of gestation whereby branches of the internal pudendal artery within the superficial compartment of the perineum were ligated. Five male fetuses served as controls in which the perineum was explored with no ligation. RESULTS: Five treated and three control live offspring were delivered spontaneously. Although no genitourinary anomalies were observed on gross examination, histopathological examination of the penises of treated animals revealed smaller penises with increased fibrosis. CONCLUSION: A defective vascular supply can partly explain the morphogenesis of some aspects of the congenital anomalies of the penis and urethra.

Animals↗
PubMed1994

In utero defecation of the nondistressed fetus: a roentgen study in the goat.

An experimental study was performed to investigate gastrointestinal motility and meconium passage, with simultaneous blood gas measurements, in the fetuses of eight pregnant goats at 110 to 114 days' gestation (full term, 147 to 155 days). With the goats under halothane anesthesia, a nasogastric tube and a heparinized central venous catheter were inserted into the fetuses. 24 hours after surgery, 10 mL of gastric juice from the fetus was replaced with a nonhydrosoluble contrast medium, and serial roentgenograms and blood samples (for pH, PO2, and PCO2 measurement) were taken every 4 hours. All fetuses began to pass the contrast medium into the amniotic cavity within 16 to 22 hours, and central venous blood gas values were normal. The results of this study suggest that the fetus, which urinates routinely, also defecates routinely into the amniotic cavity, even in the absence of distress. The increased incidence of meconium staining in fetal distress conditions may be indicative of impaired clearance of amniotic fluid.

Animals↗
PubMedDate not supplied

Alimentary tract duplications in children: report of 26 years' experience.

Duplications of the alimentary tract are one of the rare anomalies of the gastrointestinal system. Because of the wide spectrum of the signs and symptoms, preoperative diagnosis frequently cannot be made. A close familiarity with clinical and surgical characteristics provides appropriate management and treatment of duplications. A retrospective clinical study was conducted to evaluate clinical and surgical characteristics and the treatment of duplications of the alimentary tract. During a 26-year period between 1971 and 1997, 38 patients with duplications of alimentary tract underwent operation at the Hacettepe University Department of Pediatric Surgery. Forty-two duplications in 38 patients (20 male, 53%; 18 female, 47%) were encountered. Sixty-nine percent of the patients were symptomatic under the age of one year, with 24 percent presenting with symptoms in the neonatal period. There were one sublingual, nine intrathoracic (including 2 thoracoabdominal) and 32 intraabdominal duplications. Abdominal mass, abdominal distention, constipation, vomiting and respiratory distress were the most frequently encountered signs and symptoms. Plain thoracic and abdominal X-rays, ultrasonography, and computed tomography of the chest and abdomen were the most commonly used diagnostic radiological methods. Thirty-three duplications (79%) were spherical and nine (21%) were tubular. Multiple duplications were encountered in two patients (5.3%). Fourteen duplications (33%) contained heterotopic mucosa, mostly gastric type. More than one type of heterotopic mucosa in the same duplication was encountered in four duplications (10%). Additional malformations were encountered in 26 percent of patients. Six patients (15.8%) died from unrelated causes. The signs and symptoms vary among duplications. Signs and symptoms leading to diagnosis and surgery varied according to the age of patient, location of the duplication, type of mucosal lining, duration of disease and presence of complication. The ideal surgical treatment of duplication is complete excision. However, the other treatment options should be well known.

Digestive System Abnormalities↗