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S Rohr

Publications and source records attributed to S Rohr.

At least 73 records · Page 4Linked to original sources
PubMed1992

Quantitative image analysis of angiogenesis in rats implanted with a fibrin gel chamber.

Angiogenesis, a fundamental process in various physiological and pathological events, is generally studied using in vivo models, such as the chick chorioallantoic membrane or the rabbit cornea, which are difficult to quantitate. We developed the quantitation of angiogenesis in an in vivo model previously described by Dvorak et al [6]. Perforated plexiglass chambers filled with human or rat fibrin were implanted into the dorsal subcutaneous space of a Wistar rat. After four days of implantation, a sequentially organized invasion of the fibrin gel by various blood cell types occurred through the holes and neovascularized granulation tissue buds appeared. These buds presented mature neovessels and a new collagen matrix. Three dimensional computer image analysis of the chambers was performed using macroscopic and microscopic parameters: total vascularized area, bud height and equivalent diameter, number of vessels per bud and percentage of central vessels. The time course of the angiogenic response to rat or human fibrin gel was studied and 14 days was found to be the optimum period of implantation. The bud height and number of neovessels were not found to be significantly different when rat or human fibrin gels were used. This quantitative study was a prerequisite for further investigations of the effects of biological and pharmacological agents on angiogenesis.

Animals↗
PubMed1992

[Value of a "floppy" Nissen in the treatment of gastroesophageal reflux. Apropos of 117 cases].

The Nissen fundoplication is the most widely used antireflux procedure. However this operation is associated with several specific complications. To prevent these complications, an alternative antireflux procedure ("floppy" Nissen) has been designed. This investigation was conducted to investigate the effects of the floppy Nissen performed on 117 patients, between 1978 and 1990. Indication for surgery was the endoscopic discovery of stage I and II oesophagitis (59 cases), III and IV oesophagitis (25 cases) or an associated disease (gallstones: 25 cases, duodenal ulcer: 8 cases), pH monitoring used preoperatively in 47 cases showed an important reflux in 33 cases (70%). Preoperative manometry exploration (71 cases) showed a low pressure of the low oesophageal sphincter (LOS) in 63 cases (89%). The "floppy" Nissen procedure was performed over a length 4 to 6 cm. The folds of the diaphragm were closed back behind the oesophagus in 40 cases. During the postoperative period the pH-data were restored to normal range in 73% (18/26 cases), and the value of the LOS was restored in 74% (19/26 cases). The mean duration of clinical follow-up study of 99 patients was 3.22 years. Improvement in clinical symptoms was noted for 86%; 13% had specific Nissen complications (9 gall-bloat syndrome, 4 intermittent dysphagia). Six patients had to be reoperated. This technique allowed good control of the reflux symptoms, with a low incidence of mechanical complications.

Adult↗
PubMed1991

Patterned growth of neonatal rat heart cells in culture. Morphological and electrophysiological characterization.

A culture method was developed that permits patterning of the growth of ventricular myocytes of neonatal rats. Regions were created on the culture substrate that either prevented (photoresist coat) or supported (glass surface) attachment of cells. In this way the geometry of interconnecting growth channels could be specified. Single-layered myocyte strands of variable length and with widths of as little as 65 micron (three to four cells wide) were obtained. The shape and orientation of the individual myocytes were a function of growth-channel width: the narrower the channel, the more elongated the cells and the more likely was the long axis to be oriented along the channel axis. In channels with width of 100 micron or less, cells were aligned longitudinally and cross-striated as in vivo. A high degree of morphological cell differentiation required the presence of contractile activity. Maximal diastolic potential (-71 mV), action potential amplitude (93 mV), and maximal upstroke velocity (140 V/sec) did not change with increasing culture age. Mean longitudinal conduction velocity was 0.39 m/sec. No electrophysiological or morphological evidence of photoresist toxicity was seen, and the data indicate a high degree of cell differentiation in the patterned cell cultures. The method thus is suitable for the study of the relation between impulse propagation and structure at a cellular level in artificial networks of predefined shape.

Action Potentials↗
PubMed1991

[Liver injuries].

Explore the source record for details and available documents.

Abdominal Injuries↗
PubMed1991

[B-image sonography in lymph node staging of the head and neck area. A comparison with palpation, computerized and magnetic resonance tomography].

The results of palpation, CT and MRI and high resolution ultrasound were compared in 100 patients with malignancy of the head and neck. Ultrasound detected far more lymph nodes than the other methods. These diagnostic findings were compared with the operative and histological results in 62 patients. Ultrasound proved superior to the other methods: a lymph node metastasis was missed in only 2 patients by sonography, whereas in 20 patients metastases were overlooked by CT and MRI scans, and in 27 patients by palpation. High resolution ultrasound is at present the most reliable method for the detection of lymph nodes in the head and neck.

Carcinoma, Squamous Cell↗
PubMed1991

[Mechanical trans-sutural colorectal anastomosis in the treatment of cancers of the rectum. Apropos of 70 cases].

The reduction in the acceptable length of distal margin below the tumor makes low anterior resection more suitable for rectal cancers. The technical difficulties of low anastomosis are reduced by performing stapled colorectal anastomosis through the suture. Seventy patients were submitted to this procedure. There was no operative mortality, while the reported morbidity was 14%. Sixteen patients underwent preoperative radiotherapy of 30 Gy without any subsequent leakage. This technique is discussed in relation to the hand-sewn colo-anal anastomosis.

Adenocarcinoma↗
PubMed1991

[Surgical treatment of pyloric stenosis of ulcerous origin. Apropos of 68 cases].

The study turns about 68 cases of post ulcerous pyloric stenosis operated from 1970 to 1990, that means 8.5% of the duodenal ulcers (796 cases) operated during this period. The stenosis was entire or strangled in 27 cases (39.7%) with an important gastric dilatation in 34 cases (50%). The treatment has been composed of a gastroenterostomy (30 cases--44%), most of the time with a troncular vagotomy, of a pyloroplasty with vagotomy in 20 cases (29.5%) and of an inferior polar gastric resection in 18 cases (26.5%). The operative mortality was 2 cases (3%). The at distance-results (average follow-up of 7 years) show that 71% of the re-examined patients (45 cases) are classified Visick 1 or 2 and 9% visick 4. Ones concludes to the value of troncular vagotomy with gastroenterostomy which can be realised in all of the occasions and gives good functional results when the vagotomy with pyloroplasty seems to lie more frequently in state to uncertain functional results.

Adult↗
PubMed1990

A computerized device for long-term measurements of the contraction frequency of cultured rat heart cells under stable incubating conditions.

A new computer-controlled measurement system for assessing beat rates of spontaneously contracting cultured heart cells is presented. The system overcomes several disadvantages of established techniques such as: (i) lack of precise control of the environment (pH, temperature, humidity); (ii) restriction to the measurement of one culture at a time; (iii) inability to obtain long-term measurements. The beat rate is recorded by subjecting monolayer cultures to dark field illumination and recording contraction-related changes in light scattering. A maximum of environmental stability is achieved because measurements are performed in the incubator. Beat rates of up to 16 individual culture dishes can be assessed repeatedly during freely selectable time intervals. Control of the experiments, data acquisition and data analysis are carried out by a computer. The specific advantage of the method lies in the ability to measure the beat rate of several culture dishes continuously over time intervals limited only by the viability of the cultures, i. e. up to several weeks.

Animals↗
PubMed1990

Effects of arachidonic acid on the gap junctions of neonatal rat heart cells.

Myocytes were isolated from neonatal rat hearts and grown in tissue-culture dishes for 1-2 days. Spontaneously formed cell pairs were used to study the conductance of gap junctions. The experiments involved a double voltage-clamp approach and whole-cell, tight-seal recording. Exposure to arachidonic acid (AA) produced a quasi dose-dependent decrease in junctional conductance, gi (binding constant, Kd = 4 microM; Hill coefficient, n = 0.75). AA-dependent uncoupling was reversible. Addition of 1 mg/ml albumin to the bath solution accelerated the recovery. During control, cell pairs exhibited a gradual decrease in gi (16.4% in 6 min). Exposure to 20 microM 4-bromophenacyl bromide, a phospholipase inhibitor, suppressed the decay in gi (1.8% in 6 min), suggesting that endogenous AA may be involved in spontaneous uncoupling. The effect of AA on gi was specific. Arachidic acid (100 microM) and arachidonamide (10 microM), structural analogues of AA, had no effect on gi. Currents recorded shortly before complete uncoupling caused by AA, or early during recovery from uncoupling, revealed random opening and closing of single channels. The single channel conductance, gamma i, was not affected by the concentration of AA (1 microM - 100 microM). The mean gamma i turned out to be 33.5 pS. The results suggest that AA-dependent uncoupling was caused via decrease in open channel probability, presumably mediated by a direct action on channel proteins.

Acetophenones↗
PubMed1990

[Severe acute intestinal hemorrhage. Value of investigation tests].

Episodes of intestinal bleeding likely to endanger vital functions require detailed etiological and topographical examination before surgical intervention. Forty-two cases of serious haemorrhage of the lower digestive system in adults were studied retrospectively. The origin of the bleeding was localized preoperatively in 37 cases (88%). Four exploratory laparotomies were carried out after etiological examination including at least digestive arteriography. Hence it was always possible to localize the source of bleeding. We found it convenient to establish the order of the complementary pretherapeutic tests by taking into account two symptoms, acute active bleeding (AAB) and haemorrhage with acute anemia (HAA).

Acute Disease↗
PubMed1989

["Wheeling-off" of the duodenum in gastric resection in hemorrhagic duodenal ulcer].

Truncal vagotomy associated with antrectomy is required in the treatment of terebrant and haemorrhagic ulcers of the first duodenum. The main problem lies in the closure of the duodenal stump. The "wheeling-off" procedure is a reliable technique which consist of separating the duodenum from the pancreas by carrying out dissection into the posterior wall of the duodenum, between its two muscular layers. Closure is obtained by means of a stappler. This procedure was performed in 23 patients without leakage or recurrent bleeding.

Adult↗
PubMed1989

[Perforations of the colon. Apropos of 74 cases].

74 colic perforations were surgically handled between 1975 and 1988. Among the non-traumatic perforations, which represent 74% of this series, 39 cases (71%) complicated the course of acute diverticulitis, 9 cases (15%) were due to cancers and 7 cases (13%) were of miscellaneous origin. Traumatic perforations (26%) were iatrogenically induced in 84% (16 cases). In 78% the perforation was located in the sigmoid or recto-sigmoid. The treatment consisted in performing either a diverting colostomy (30 cases--40%) or a colic resection (44 cases--60%) with or without immediate anastomosis (respectively 10 cases--13.5% and 34 cases--46%). The overall mortality was 10.8%, which referred to etiology, turns to be 15% (3/19 cases) in traumatic perforations, 13% (5/39 cases) in diverticulitis and 0% in cancer. Related to treatment, mortality reached 23% for derivation and drainage procedure and 2% for resection. Post-operative complications were respectively 10% and 47%. Among post operative complications (22 cases--29%) 11 patients were reoperated on with an additional mortality of 18%. These results give strong evidence to the reliability and value of urgent colic resection in perforated colon and enhance the necessity of undelayed operation.

Adolescent↗
PubMed1989

[Injuries of the spleen: conservative treatment or exeresis?].

The authors report their experience with splenic preservation in a series of 36 patients. 77 patients with splenic injury were seen during the period from 1982 to 1987. In 41 cases splenectomy had to be carried out. This was for splenic contusions secondary to road traffic accidents in 36 cases and iatrogenic per-operative lesions in 5 cases. Intra-omental splenic autotransplantation was performed in 4 cases. In 36 other patients, the spleen was able to be preserved. Hemostasis was fairly obtained using infra-red photocoagulation (24 cases), splenorrhaphy (8 cases), surrounding the spleen with a resorbable mesh (3 cases) or by partial splenectomy (1 case). Only 1 case of transient and moderate secondary hemorrhage was seen and did not require further surgery. The authors define the legitimacy of splenic preservation and its indications and also stress its limitations. They insist on the following contraindications: preexisting splenic disease, subject on anticoagulants, labile blood pressure, multiple intra-abdominal lesions, presence of intra-peritoneal infection, severe cranio-encephalic lesions, age over 70 years. Study of this series shows that conservative treatment is most often justified for splenic trauma. Nevertheless, in view of the real but rare risk of OPSI, it is better to have a correct splenectomy than an incorrectly preserved spleen.

Aged↗
PubMed1989

[Colonic occlusion. Apropos of a surgical series of 63 cases].

63 colonic occlusions were operated on from 1975 to 1988. Cancer and stenotic diverticular sigmoiditis were found to be the main causes of colonic obstruction in respectively 36 cases (55%) and 8 cases (13%). Other etiologies were represented by neoplasic gynecologic diseases (9.5%). The rectosigmoid was involved in 50% of the cases (31) while transverse colon and caecum were respectively concerned in 25% and 17%. The 2 main therapeutical procedures used were colic resection (35 cases-55%) with immediate anastomosis in 1 case out of 3 and derivation (26 cases 41%) mostly in the proper from of a colostomy (20 cases). Operation was undertaken during the first 48 hours in 65% of the cases. Death occurred in 8 patients (12.5%). Related to etiology the death rate was 11% in cancers and 25% in stenotic diverticulitis. Where linked to treatment this mortality rate reached 27% in derivations and 3% in colic resections. 38% of non lethal complications were recorded, two-third being due to the bad general conditions of the patients. Several times operations, such as first colostomy or resection without anastomosis, should remain the basic rule one should not depart from without great carefulness. However a new interesting trend toward one time surgery with intraoperative colonic lavage is taking shape.

Adolescent↗
PubMed1989

[Locoregional recurrence of breast cancer. Long-term course of 49 cases treated by excision and omentoplasty].

Extensive local recurrence of breast cancer may require wide parietal resection, demanding the use of other tissues to compensate for the loss of substance. We preferably resort to omentoplasty when the defect is larger than 300 cm2. A group of 49 patients with recurrence of the tumor in the breasts (treated with omentoplasty) has been studied, with special emphasis on long-term results. In our series, 86% of the patients were followed up for more than 4 years, with an actuarial survival rate of 46% after 7 years. It thus appears that this procedure can be advocated for slow-developing cancers, the local recurrence of which is extensive and usually isolate for various reasons (most often a deficient initial local treatment).

Aged↗