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Biomedical subjects

H B Ris

Publications and source records attributed to H B Ris.

At least 91 records · Page 5Linked to original sources
PubMed1991

Comparative evaluation of three ambulatory plethysmographic devices as regards accuracy and handling in daily practice.

We compared a computed strain gauge plethysmograph (SGP1) with a Gutmann strain gauge plethysmograph (SGP2) and a photoplethysmograph (PPG) in 24 normal and 12 radiologically proven postphlebitic limbs with respect to assessment of the calf pump function, discrimination between normal and pathologic values, and handling. Recovery time (RT50), refilling volume (RV) and the Index (RT50xRV) were measured at the ankle and the calf in each limb after 20 dorsiflexions of the feet in the sitting position. The PPG device could only measure RT50. There was a strong positive correlation in RT50, RV and Index values between SGP1 and SGP2 at the ankle and at the calf (p less than 0.001), but none in RT50 ankle and calf values between PPG and SGP1 (p = 0.1) and PPG and SGP2 (p = 0.1). The comparison between normal and postphlebitic limbs revealed significant differences for all three values RT50, RV and Index only for SGP1 ankle measurements (p less than 0.02, p less than 0.01, respectively). Ankle RT50 values were significantly longer than calf RT50 values for both strain gauge devices (p less than 0.01), where PPG results were not influenced by the site of measurement. The average number of tests required to obtain a valid curve in each limb at the ankle and calf was lowest for SGP1 measurements. Vein calf pump function is easily and accurately assessed by SGP1 ankle measurements. However a threshold limit between normal and pathologic values can not be defined either for RT50 or for RV values in the individual case, and the creation of an Index adds little to solve this problem.

Adult↗
PubMed1991

Photodynamic therapy with chlorins for diffuse malignant mesothelioma: initial clinical results.

Four patients underwent intraoperative photodynamic therapy after surgery with meso-tetra-(hydroxyphenyl)-chlorin (mTHPC-PDT) for diffuse malignant mesothelioma. Preliminary procedures were performed in two patients in order to establish the efficacy of mTHPC-PDT and to optimise its tumoricidal effect. The tumoricidal effect was related to the mTHPC dose, light dose and the time interval between sensitation and activation. 0.3 mg kg-1 mTHPC activated after 48 h with 10 Joules cm-2 of non-thermal laser light at 650 nm resulted in a 10 mm deep tumour infarction, due to tumour vessel necrosis and thrombosis. The mTHPC tissue concentration was up to 14 times higher in the tumour than in normal tissues. Skin photosensitivity was mild, dose dependent and occurred 3 to 10 days after administration of mTHPC. According to the results obtained, intraoperative mTHPC-PDT was performed following pleuropneumonectomy in two, pleurectomy and lobectomy in one and pleurectomy in one patient. Ten Joules cm-2 were delivered to the diaphragm and the costophrenic sulcus and 5 Joules cm-2 to the remaining thoracic cavity. The postoperative course was marked by loss of appetite, fluid retention, hypoproteinemia and severe chest pain. One patient succumbed from aspiration pneumonia. The remaining patients developed no neural or vascular alterations and no bronchial stump insufficiency during follow-up. mTHPC-PDT following surgical tumour resection deserves further evaluation in good risk patients with diffuse malignant mesothelioma.

Combined Modality Therapy↗
PubMed1991

Surgery and chemotherapy for pulmonary metastases: long-term results from a combined modality approach.

Eighty-three patients underwent pulmonary metastatectomy as part of a combined modality approach between 1. 1. 1972 and 31. 12. 1988 and 80 were followed up until 1. 1. 1990 or until death, with an average follow-up of 110 months. The estimated 5-, 10-, and 15-year survival rate was 38%, 32%, and 22% respectively. Recurrent pulmonary metastases were observed in 60% of the patients during follow-up with an estimated 24 months relapse-free survival rate of 50%. An additional 20% of the patients developed extrapulmonary recurrent tumor manifestation without evidence of pulmonary disease. One of five patients remained tumor free up to 207 months (an average of 87 months) after the initial pulmonary metastatectomy. A multivariate analysis identified completeness of tumor removal, the type of primary tumor, and a difference in histology between primary and metastatic neoplasm as three independent prognostic factors with significant impact on overall survival, the completeness of tumor removal being the most important one. Disease-free long-term survival for patients with pulmonary metastases treated by surgery and chemotherapy is related to completeness of tumor removal and the type of primary tumor.

Combined Modality Therapy↗
PubMed1990

[Surgical thrombectomy versus conservative treatment of ileo-femoral phlebothrombosis. Functional comparison of long-term results].

The results of a retrospective study comparing two equally large groups of patients treated either surgically for restoration of venous patency and valvular function (24 patients) or medically with heparine, oral anticoagulants and compression stockings (25 patients) are presented. Follow-up time was 7.6 and 7.9 years respectively, operative mortality nil. Assessment of venous function was based on clinical observations as well as on measurements of haemodynamic parameters. Non-fatal pulmonary embolism after onset of treatment occurred in both cohorts with an equal frequency of 13%. Patients operated on for ilio-femoral deep venous thrombosis (DVT) were with few exceptions totally independent of any form of adjunctive hosiery which was in sharp contrast to the conservatively managed group. If onset of DVT had occurred more than three days earlier and extended from the ilio-femoral axis to the popliteo-crural level, surgery usually failed and patients were no better off than in the comparable medical subgroup. The same pattern of late outcome was found for all other clinical and haemodynamic parameters; i.e. clinical signs of venous hypertension, valvular competence as judged by sonography, patient's self-assessment and the expelled volume and refilling time measured by dynamic plethysmography after standardized leg-work. The mean expelled volume was 1.1 +/- 0.5 ml/100 g/min for the surgical subgroup treated early for ilio-femoral DVT and 0.7 +/- 0.5/100 g/min for the corresponding medical group (p = 0.05). Recovery or refilling time was 50 +/- 21 sec for the surgical group and 28 +/- 26 sec for the medical group (p = 0.03).(ABSTRACT TRUNCATED AT 250 WORDS)

Bandages↗
PubMed1990

[Evaluation of recent vascular prostheses in the arteriovenous shunt].

Prosthetic vascular replacement materials are still suboptimal especially for distal peripheral and coronary bypass grafts due to the small caliber and high occlusion rates. Therefore new vascular grafts have been assessed with respect to blood compatibility, thrombogenicity and host pretreatment. In 12 heparinized minipigs (25 kg), a total of 120 small caliber grafts (i.d. 3.0 mm) were perfused (6 min) in a femoro-femoral arteriovenous shunt (AVS). Materials included: Dacron (Atrium), PTFE (Gore), Polyurethanes (PU), Auto- and Xenografts. Animals were treated preoperatively with fishoil (3 g EPA/QD x 3 weeks = group I), perioperatively with prostaglandins (PGE1 = group II) or with fishoil and graft incubation in plasma proteins (= group III) and compared to controls without pretreatment (= group 0). We measured flow, deposition of marked thrombocytes (HMPAO-Tc* per area and per weight). - Blood flow was similar in AVS for all groups and materials (168 +/- 86 ml/min, p = NS). There was no significant correlation in deposition of marked thrombocytes and host pretreatments (group 0: controls = 7356 counts/area, group I: fishoil = 6807. group II: PGE1 = 7864). However graft incubation in plasma proteins significantly lowered deposition of marked thrombocytes (1766 in group III vs. 7356 in group 0: p less than 0.05). And significant differences of thrombocyte counts where found between the different materials: Autografts less than PTFE less than Xenografts less than Small Pore PU less than Dacron less than Large Pore PU.--AVS is a useful tool to determine early thrombogenicity in prosthetic vascular replacement materials and to assess the effect of different host pretreatments.

Animals↗
PubMed1990

[Ischemia in acute traumatic knee joint instability].

Eleven of 202 patients operated for acute knee instability from 1976 to 1988 showed an associated popliteal vascular injury. No patient with intact posterior cruciate ligament had a vascular lesion, and all patients with popliteal vascular injury had a ruptured posterior cruciate ligament. Our patients are analyzed with respect to clinical symptoms of the ischemia, management and results at assessment. Prompt recognition and early revascularisation with debridement of all grossly damaged arterial wall, a tension-free reconstruction and the liberal use of fasciotomy is the key to improved limb salvage.

Adult↗
PubMed1989

Surgical thrombectomy versus conservative treatment for deep venous thrombosis; functional comparison of long-term results.

It is known that deep venous thrombosis (DVT) of the ilio-femoro-popliteal axis is frequently associated with irreversible damage to valvular competence of the veins and consequently with varying degrees of chronic venous insufficiency. Because preservation of the valvular function of deep veins can play an important role in preventing the postphlebitic syndrome we analysed and compared the long-term functional outcome of two equally large cohorts of patients treated either surgically for restoration of venous patency and valvular function (24 patients) or medically with heparin, oral anticoagulants and compression stockings (25 patients). The study was also intended to examine the impact of duration and extent of DVT as predictive factors of late outcome. Follow-up time was 7.6 and 7.9 years respectively, operative mortality nil. Assessment of venous function was based on clinical observations as well as on measurement of haemodynamic parameters. Non-fatal pulmonary embolism after onset of treatment occurred in both cohorts with an equal frequency of 13%. Patients operated on for ilio-femoral DVT were with few exceptions totally independent of any form of adjunctive hosiery which was in sharp contrast to the conservatively managed group. If onset of DVT had occurred more than 3 days earlier and extended from the ilio-femoral axis to the popliteo-crural level, surgery usually failed and patients were no better off than in the comparable medical group. The same pattern of late outcome was found for all other clinical and haemodynamic parameters; i.e. clinical signs of venous hypertension, valvular competence as judged by sonography, patient's self-assessment and the expelled volume and refilling time measured by dynamic plethysmography after standardised leg work. The mean expelled volume was 1.1 +/- 0.5 ml/100 g/min. for the surgical group treated early for ilio-femoral DVT and 0.7 +/- 0.5 ml/100 g/min for the corresponding medical group (P = 0.05). Recovery or refilling time was 50 +/- 21 s for the surgical group and 28 +/- 26 s for the medical group (P = 0.03). Thus, the clinical and haemodynamic effect of surgical thrombectomy was significantly superior to conservative management in ilio-femoral thrombosis treated within 3 days. For extensive thrombosis treated early the advantage of surgical thrombectomy was also evident, but the difference between the two treatment groups was not significant. The advantage of surgery was however totally lost in patients operated on for extensive DVT of long duration (i.e. greater than 3 days).(ABSTRACT TRUNCATED AT 400 WORDS)

Bandages↗
PubMed1989

[How great is the risk of cancer and recurrence following benign breast biopsy?].

Four hundred and thirty-eight patients with biopsy-proven benign breast disease were followed annually in a prospective manner for 4-17 years, to analyze breast cancer risk, correlations with cancer development and recurrence during follow-up. Twelve breast cancers developed in 12 patients during follow-up, giving a 2.6 fold increased cancer risk over the reference population. No association was found between patients who developed cancer and those who did not with respect to the initial histologic feature (p = 0.9), the age at entry by decades (p = 0.4) and relative to menopause (p = 0.3), the presence of cysts (p = 0.5) or calcification (p = 0.2) in the biopsy specimen, a family history of breast cancer (p = 0.7) or the follow-up time (p = 0.9). Benign breast disease does not inevitably lead to recurrence. Moreover, 47% of the 438 patients never had any recurrence and were free of symptoms during follow-up, and 84% never required a further operation. We conclude that an aggressive approach to benign breast disease is not justified, for any type of lesion as defined in this report.

Adenofibroma↗
PubMed1989

[The mobile cecum syndrome: appendectomy and cecopexy or only appendectomy?].

1159 patients underwent appendectomy via a McBurney incision from 1972 to 1983 at our institution. 115 patients (10%) had a mobile cecum syndrome (CMS) as defined by Nicole, without evidence of appendicitis or other pathologic findings at operation. 102 patients were followed up to 15 years after the operation. 82% of the 102 patients were free of symptoms at assessment. 36 patients underwent appendectomy and 63 appendectomy and cecopexy. The two cohorts were comparable with respect to sex, age at operation, duration of right lower abdominal pain, operative findings and length of follow-up. There was no significant difference in the postoperative result of patients with appendectomy alone and those with appendectomy and cecopexy. Moreover, we were not able to identify patients who may benefit from an additional cecopexy, on the basis of patient related factors or intraoperative findings.

Adolescent↗
PubMed1988

Long-term follow-up of patients with biopsy-proven benign breast disease.

Three hundred sixty-five patients with biopsy-proven benign breast disease were followed annually in a prospective manner for 4-15 years to analyze breast cancer development, recurrence, and efficacy of management during follow-up. Eleven breast cancers developed in 11 patients during follow-up, giving a 2.6-fold increased cancer risk over the reference population. No association was found between patients who developed cancer and those who did not with respect to the initial histologic feature (p = 0.62), the age at entry by decades (p = 0.40), and relative to menopause (p = 0.54), the presence of cysts (p = 0.87), or calcification (p = 0.74) in the biopsy specimen, a family history of breast cancer (p = 0.80), or the number of observation years (p = 0.27). We conclude that an aggressive approach to benign breast disease is not justified for any type of lesion as defined in this report. Benign breast disease does not inevitably lead to recurrence. Moreover, 41% of our patients never had any recurrence and were free of symptoms during follow-up; 67% never had a mammogram and 82% never required a further operation. There was no association with initial histologic feature in patients who had clinical examination only and those who had mammogram, biopsy, or both during follow-up (p = 0.93). Mammograms were mainly used to clarify a clinical recurrence than as a screening tool, regardless of histologic feature (p = 0.76). Mammograms were mainly used in premenopausal patients (p less than 0.001) having lumps (p less than 0.001), namely, the most difficult patients for radiologic interpretation. This may be one important reason for the rather low sensitivity (75%) and specificity (40%) of mammography in this report. In conclusion, clinical examination is the outstanding investigational tool to follow patients with biopsy-proven benign breast disease, especially in young premenopausal patients.

Age Factors↗
PubMed1988

[Morbidity of Z-plasty in the treatment of pilonidal sinus].

21 patients were followed up on an average of 28 months following excision of pilonidal sinus and Z-plasty. There were 2 recurrences (10%), 3 hypertrophic scars (14%) and hypaesthesia of the skin flaps in almost every patient. 2 out of 3 patients (67%) were satisfied with the results. 5 suffer from the cosmetic appearance, 5 from pruritus, 3 (14%) have problems with clothing. About 1/3 experience discomfort when sitting and sporting. This morbidity causes us to recommend Z-plasty only in cases of a recurrence with strong discomfort or frequent recurrences.

Adolescent↗
PubMed1988

[Long-term results following surgery of varicose veins].

In a long-term follow-up after operation for primary varicose vein disease, patients were revisited 5, 10 and 15 years after their operation, in an attempt to define the goal of the treatment and the result. The results were analyzed as well as those factors which had a significant influence on the findings at assessment. The long-term results were good with respect to the patient's self-judgement and relative to improvement of trophic disturbances, especially of venous ulceration, however recurrent superficial varicose veins increase significantly with increasing follow-up time. The outstanding role of incompetent communicating veins is discussed with respect to trophic disturbances and recurrent varicose veins.

Adult↗
PubMed1987

[10 years' experience using a modified Shouldice surgical technic for inguinal hernia in adults. II. Which factors modify the recurrence of inguinal hernia?].

Many factors seem to influence the recurrence rate after adult inguinal hernia repair. A statistical analysis of data derived from 726 transversalis fascia repairs examined by the authors (with a follow-up rate of 82.5% and a mean follow-up time of 5.5 years) revealed a significantly higher recurrence rate in patients with chronic bronchitis (p less than 0.05) or with postoperative complications (p less than 0.001). Lower recurrence rates were found after resection of lipomas of the cord (p less than 0.01) or cremasteric muscle resection (p less than 0.05). No significant difference of recurrence rate could be established for following parameters: Sex, side, age distribution, profession, prostatism, obesity, type of hernia (direct, indirect, combined, sliding), suture material (silk, polyglycolic acid), surgeon, anesthesia (local, spinal, full), elective or emergency operation, and whether the repair was unilateral or simultaneously bilateral. Recurrent repairs showed no significantly higher recurrence rate than primary repairs.

Adult↗
PubMed1987

[10 years' experience using a modified Shouldice surgical technic for inguinal hernia in adults. I. Method and results in 726 operations with follow-up].

Since 1973 we have used a modified Shouldice repair to treat inguinal hernias in adults. The repair was performed on unselected patients. The procedure was performed by both senior surgeons and surgeons in training. Over a 10-years period, 880 transversalis fascia repairs were done and 726 (82.5%) were examined by the authors 12-142 months after the operation (mean time 66.1 months). In 94.2% of the 726 repairs the patients were satisfied with the result. Follow-up studies revealed testicular atrophy in 0.6%, deep wound infection in 0.8% and an overall recurrence rate of 5.8%. The recurrence rate was not significantly different after direct, indirect, combined or sliding hernias. In 25% of recurrences the patients were asymptomatic and unaware of the recurrence.

Adult↗
PubMed1983

[The anti-arrhythmia drug quinidine as an alternative in the treatment of severe falciparum malaria].

Parenteral quinine is the most effective treatment for severe falciparum malaria. It is not easily available in Switzerland and so dangerous delays treating patients may occur. The antiarrhythmic drug quinidine, usually stocked by hospitals, is an alternative drug for malaria treatment. We report the cases of two patients with severe malaria imported from Kenya. They were treated first with intravenous quinidine sulfate over 3 days and for another 4 days with peroral quinidine sulfate. The therapeutic response was excellent. During the 2 months posttherapeutic period no recrudescence of Plasmodium falciparum occurred. 20 mg/kg b.w./die of quinidine given intravenously seems to be an adequate dose in severe falciparum malaria.

Administration, Oral↗
PubMedDate not supplied

Determination of 5,10,15,20-tetra-(m-hydroxyphenyl)chlorin in human plasma by high performance liquid chromatography.

A high performance liquid chromatographic method for the determination of the photodynamic chemotherapeutic agent 5,10,15,20-tetra(m-hydroxyphenyl)chlorin (m-THPC) in human plasma following intravenous infusion is described. The procedure involves extraction of the drug in plasma with methanol/dimethyl sulphoxide (4:1 v/v) containing 5,10,15,20-tetra(p-hydroxyphenyl)chlorin as the internal standard and separation on a C18 reversed phase column with acetonitrile:0.1% trifluoroacetic acid (77:23 v/v) as the mobile phase. The drug was detected specifically and sensitively at its absorption maximum of 423 nm with a detection limit of 15 ng/mL (signal-to-noise ratio of 5). The intra- and inter-assay coefficients of variation (CV) on analysis of a plasma spiked with m-THPC (1 micrograms/mL) were 2.3 and 3.4% (n = 6), respectively.

Antineoplastic Agents↗
PubMedDate not supplied

Determination of 5,10,15,20-tetra-(m-hydroxyphenyl)chlorin in tissues by high performance liquid chromatography.

A procedure for the extraction and high performance liquid chromatographic (HPLC) determination of the photodynamic therapeutic agent 5,10,15,20-tetra(m-hydroxyphenyl)chlorin in human, rat and mouse tissues following intravenous administration of the drug is described. The tissue (tumour, skin, muscle and liver) was homogenized and extracted into a mixture of methanol:dimethyl sulphoxide:water (32:8:1 by vol.) containing, 5,10,15,20-tetra(p-hydroxyphenyl)chlorin as the internal standard. The precipitated proteins were removed by centrifugation and the supernatant was separated by reversed phase HPLC on a Hypersil-ODS column with 77% (v/v) acetonitrile in 0.1% trifluoroacetic acid as the mobile phase. The solute was detected with high sensitivity and specificity by a UV-VIS detector set at 423 nm.

Animals↗