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V Hegedüs

Publications and source records attributed to V Hegedüs.

At least 19 recordsLinked to original sources
PubMed2000

Structural evidence for counter-current flow in proximal tubules versus pertitubular capillaries in the rat kidney. Evaluation of the counter-current mechanism between the proximal convoluted tubules and the peritubular capillaries in the rat nephron.

BACKGROUND: In spite of the very high exchange of water and solutes between the proximal tubules and the peritubular capillaries, very little is known about flow directions in these two interrelated structures. We therefore developed a morphological technique suitable for the quantitative evaluation of a counter-current system between the proximal convoluted tubules and the peritubular capillaries in rat renal cortex. METHODS: In male pentothal-anesthetized Wistar rats (body weight 200-250 g), India ink was injected into the aorta above the renal arteries, followed by instant freezing of the right kidney in isopentane at -165 degrees C, and subsequent freeze-substitution in alcohol. In microscopic slides from kidneys in which only 20-55% of the cortical peritubular capillary loops was filled with ink--representing the arterial end of the capillaries--and in which the proximal tubular segmentation could be identified in PAS-stained sections, the segments of the convoluted proximal tubules were quantitatively compared with regard to the presence of ink-stained and unstained peritubular capillaries in nephrons from the whole renal cortex. RESULTS: In the microscopic specimens of the five animals used both the loops from the first segment (P1) of the proximal convoluted tubule and those of the second segment (P2) were systematically packed closely together, the transitional segment (P1-2) being interposed between the groups. Around the loops of P1, 8%+/-2% of the capillaries was stained with India ink. In contrast, surrounding the P2 loops 67%+/-5% of the capillaries contained ink, significantly exceeding that for P1 (p<0.01). CONCLUSION: Throughout the rat renal cortex, the most proximal fraction of the peritubular capillaries surrounds the second segments of the proximal convoluted tubules, while the first tubular segments are surrounded by the more distal fraction of the peritubular capillaries. Consequently, the flows in the peritubular capillaries and in the proximal convoluted tubules in the rat renal cortex are systematically arranged as a counter-current system. This feature was previously identified only in superficial nephrons.

Animals↗
PubMed1993

Defecographic findings in patients with anal incontinence and constipation and their relation to rectal emptying.

PURPOSE: The aim of this study was to examine defecographic findings in patients with anal incontinence and constipation and to compare these findings with rectal emptying. METHODS: One hundred seventy-five preoperative defecographies documented on videotape in patients with either anal incontinence or constipation were retrospectively reviewed. The examinations were evaluated with respect to anatomic abnormalities of the rectum or anal canal. The results were compared with a semi-quantitative assessment of rectal emptying as it appeared on the video sequence after one minute of strain. RESULTS: Anatomic abnormalities were found equally in incontinent and constipated patients, except for failure to open the anal canal, which was found only in constipated patients. Rectal intussusception was the most frequent finding. Abnormal defecograms were found in both sexes. Enteroceles, sigmoidoceles, and large rectoceles were found only in women. The presence of intussusception, lacking relaxation of the puborectalis muscle, and rectocele did not correlate with poor rectal emptying. Poor rectal emptying was also found in 19 of 58 patients with normal defecograms. CONCLUSIONS: Anatomic abnormalities of the rectum may be demonstrated independently of the clinical symptoms and are not always correlated to impaired rectal emptying. Since they may also be found in healthy controls, surgical correction of these abnormalities should be considered only with great caution.

Adult↗
PubMed1989

Monitoring of celiac plexus block in chronic pancreatitis.

Pharmacological, percutaneous celiac plexus blockade is often inefficient in the treatment of pain in chronic pancreatitis. Lack of efficiency could be due to incomplete denervation of the plexus; however, a method for measuring the completeness of celiac plexus blockade is not yet available. We have, therefore, monitored the physiological completeness of pharmacological percutaneous celiac blockade with 40 ml 25% ethanol by measuring the effect of posture on heart rate, blood pressure, hepato-splanchnic vascular resistance, and pancreatic hormone concentrations before and after celiac plexus block in 6 patients with chronic pancreatitis. Blood pressure decreased and heart rate increased after the block (P less than 0.025), whereas no significant change was found in hepato-splanchnic vascular resistance nor in the change of these parameters during transition from the supine to standing position. Pancreatic hormones (C-peptide, free insulin, glucagon, pancreatic polypeptide and somatostatin) did not change in response to standing, either before or after the block. The cardiovascular variables were normalized the day after the block, and all the patients were in their habitual state regarding pain after 1 week. In conclusion, pancreatic hormone concentrations in response to standing are not useful for monitoring celiac plexus block, whereas heart rate, blood pressure and hepato-splanchnic blood flow may yield useful information. From such measurements it was concluded that permanent denervation of the celiac plexus was not achieved in our patients after injection of 40 ml 25% ethanol.

Blood Pressure↗
PubMed1988

Evaluation of perineal descent by defaecography.

Perineal descent was studied by defaecography with the patients in the sitting position in 55 healthy volunteers, 21 women with idiopathic faecal incontinence and 8 women with obstructed defaecation. This technique provides data necessary for the evaluation of defaecation disorders, i.e. morphological changes during defaecation as well as the dynamics of the pelvic floor. It was found that the pelvic floor position during rest and during straining is almost the same in women with incontinence and in women with obstructed defaecation. Furthermore patients with normal position of the pelvic floor during rest may exhibit considerable descent during straining while patients with abnormal position of the perineum during rest may show normal descent during straining. This observation may indicate that the first sign of abnormal function may be an increased descent during straining, only later following by descent during rest. The importance of establishing control data is emphasized since differences in defaecographic techniques between different centres may render comparison difficult.

Adult↗
PubMed1988

Management of obstructive small-bowel lesions.

By means of a 350 cm long intestinal tube with a balloon at its distal tip, surgically significant stenoses of the small intestine can be selectively identified and differentiated from changes not requiring surgical intervention. The balloon is inflated with 40 ml of air at the site of the obstruction, thereby serving as a marker for the surgeon in order to limit the intervention and avoid complications due to unnecessary manipulations. The tube offers a significant improvement in the management of chronic intestinal obstructive disease. Details of the technique and results from successful use in 24 patients are presented.

Catheterization↗
PubMed1987

Sex differences in anorectal angle and perineal descent.

To elucidate whether sex differences have a significant influence on anorectal angle (ARA) and perineal descent (D), female and male asymptomatic volunteers were examined, using cinedefecography. We found ARA generally bigger in male than in female patients. Mean male values resembled those measured in females with anal incompetence. We also found that the spread of normal ARA in male patients was nearly twice that in female patients, suggesting little value of this variable. D, however, is similar in the 2 groups. Our conclusion is that ARA measured in males has no clinical value. D can probably be useful in both male and female patients for preoperative evaluation of corrective surgery.

Adult↗
PubMed1986

Radiologically guided dilatation of stenotic gastroduodenal anastomosis.

A successful balloon catheter dilatation of stenotic gastroduodenal anastomosis is reported. The timing of such postoperative dilatations is crucial for avoiding rupture of the anastomosis or--in the late phase of healing--hard fibrous tissue inhibiting the dilatation. It is recommended that balloon catheter dilatation be the procedure of choice before making a decision about a second look operation.

Aged↗
PubMed1986

Dislodgement of impacted oesophageal foreign bodies with carbonated beverages.

Carbonated beverages release sufficient carbon dioxide when ingested, to distend the oesophagus, relax the lower oesophageal sphincter and to force the passage of impacted meat and other foreign bodies into the stomach. Of 28 patients with foreign bodies in the oesophagus, eight had them dislodged after ingestion of barium sulphate suspension, whereas carbonated soda water was used successfully in 16 out of 20 patients with a normal oesophagus or with oesophageal motility disorders and organic strictures. Carbonated beverages may be used as the first-line treatment of acute episodes of oesophageal obstruction due to foreign bodies and could also be integrated into the long-term management of oesophageal disease.

Adult↗
PubMed1984

Evaluation of intravenous radionuclide angiography in detection of occlusive disease of the iliac arteries.

Radionuclide angiography (angioscintigraphy) of the iliac arteries was performed in 173 patients consecutively referred for arterial insufficiency of the legs. In 83 of the patients femoral angiography was also performed. The interobserver variation was evaluated by the agreement indices, kappa (K) and weighted kappa (Kw). For angiography the interobserver agreement was high (K and Kw 0.65 and 0.77 respectively). For angioscintigraphy the agreement between observers was fair (K = 0.52, Kw = 0.68), and equal to the intraobserver agreement (K = 0.55, Kw = 0.65). The comparison between angioscintigraphy and angiography gave K-values of 0.22-0.31 and Kw-values of 0.37-0.48. The nosographic sensitivity of angioscintigraphy was 61%, the nosographic specificity was 93%, and the predictive value for both a positive and a negative test was 83%. The prevalence of occlusion or severe stenosis was 34%. Inguinal pulse palpation detected 48% of iliac occlusions. It is concluded that the reliability of angioscintigraphy in the diagnosis of iliac arterial occlusive disease is acceptable for a non-invasive, rapid, inexpensive and widely available screening procedure. Although anatomical details are not visualized the information obtained is useful for the detailed planning and choice of subsequent diagnostic and therapeutic procedures. The method is well suited for repeat studies and may be modified to include the femoral arteries.

Adult↗
PubMed1984

Validity in diagnosing osteoporosis. Observer variation in interpreting spinal radiographs.

Observer variation in interpreting radiograph of the spine in 70-year-old Danish women has been examined. The women joined a general health investigation as part of an epidemiologic screening for osteoporosis. Two experienced radiologists examined independently 280 sets of lateral radiographs of the spine to disclose fractures. The radiographs were examined four times, each examined at two different occasions by each radiologist. Overall intra-observer agreement was 88% and 87% when asked for presence or absence of fractures, irrespective of fracture localization. When accidental occurrence of agreement was taken into account (kappa analysis) intra-observer variation was reduced to 64% and 62%. The overall inter-observer agreement was 75%, but reduced to 47% when accidental occurrence of agreement was noted. Kappa analysis in testing observer variation indicates that a considerable part of agreement can be ascribed to chance alone. This seriously questions the hitherto used definition of osteoporosis.

Aged↗