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Biomedical subjects

R Horstmann

Publications and source records attributed to R Horstmann.

31 records · Page 2Linked to original sources
PubMed1995

[Reliability of ultrasound ileus diagnosis].

We investigated in this study if we would be able to find the correct indication for laparotomy earlier by sonographical examination than by clinical and radiological findings. In 48 of 594 patients with unknown abdominal diseases we found an intestinal obstruction by laparotomy. The indication based on clinical and radiological findings in 37 patients (sensitivity: 77.1%). In comparison the indication for laparotomy was predetermined correctly only after sonographical examination in 45 patients (sensitivity: 89.6%). According to the number of sonographical findings the reliability of the indication for laparotomy increased. The examination by sonography is a valuable tool in the diagnosis of intestinal obstruction.

Adolescent↗
PubMed1993

[Critical ischemia of the extremities caused by ergotism. Treatment with intra-arterial prostaglandin E1 infusion].

Severe ischaemia of the left upper limb developed in a 42-year-old woman (who had suffered from migraine since the age of 6 years) after the intake of 12 mg ergotamine tartrate (six suppositories of Cafergot within 5 hours). The left hand became very painful and pale with loss of touch sensation, and she could not move her fingers. Selective catheter angiography demonstrated typical signs of vascular ergotism: arterial spasms, corkscrew-like collaterals and segmental arterial occlusions. The patient's symptoms began to improve 10 minutes after starting an intraarterial infusion of prostaglandin E1 (0.34 ng/kg per min over 10 hours). Sensory function in the fingers was restored after 24 hours and reactive hyperaemia had occurred. Radiological examination after 48 hours showed complete recovery. This case emphasizes the need for obtaining an exact history regarding drug intake in any case of acute peripheral vascular disorder, but especially if there is no pointer to arterial thromboembolism. Angiography is of value in the differential diagnosis of suspected ergotism. Intraarterial infusion of prostaglandin E1 has few side effects and is immediately effective.

Adult↗
PubMed1993

Effect of food on the pharmacokinetics of the active metabolite of the prodrug repirinast.

The effect of food on the pharmacokinetics of the active metabolite of the new antiasthmatic drug repirinast was investigated in two different studies after oral administration of 300 mg of repirinast. In each study, 12 healthy volunteers received the repirinast dose under fasting or fed conditions in a crossover manner. In one study, a high-fat meal (American breakfast) was used and in another study, a low-fat, high-carbohydrate meal (continental breakfast) was used. Concentrations of the active metabolite in plasma and urine were determined by reversed-phase high-performance liquid chromatography with UV detection. After administration of repirinast with a low-fat and a high-fat meal, the relative bioavailability of the active metabolite increased by factors of 1.9 and 2.4, respectively, as expressed by area under the curve of concentration versus time from 0 to 12 h. The amount excreted into urine doubled after drug administration with both types of food and accounted for approximately 8% of the dose under fasting conditions and approximately 16% of the dose under fed conditions. Maximum concentrations in plasma were different between the two studies: mean maximum concentrations in plasma increased by factors of 1.7 and 3.2 after administration of drug with a low-fat (drug intake immediately after breakfast) and a high-fat breakfast (drug intake just before breakfast), respectively, compared with fasting conditions.

Adult↗
PubMed1993

[Ultrasound dissection in laparoscopic cholecystectomy].

An ultrasound dissector especially developed for laparoscopic surgery was used during laparoscopic cholecystectomy on 34 patients. The ultrasound power, the volume of suction and irrigation could be determined individually at the generator and activated during the operation with a foot pedal. With the dissector it was possible to fragmentate, emulgate and aspirate simultaneously fat tissue as well as infected edematous structures. The cystic artery and cystic duct, small vessels, lymphatic and connective tissue were not damaged. Therefore this system seems to be excellent for the preparation of Calot's trigonum and blunt dissection of the gallbladder out of its bed, particularly in fatty, acute or chronic infected tissue. No complications were observed within the peri- and postoperative period.

Adult↗
PubMed1993

[Aortofemoral bypass and extensive profunda-plasty in combined arterial occlusive disease of the pelvic-femoral type--a stage oriented analysis].

121 patients with multilevel, lower extremity arterial occlusive disease were treated by aortofemoral reconstruction and extended profundoplasty. Early and late results of 201 limbs were analyzed according to their preoperative grade of ischemia. In the case of moderate claudication the success rate was 43% postoperatively and 81% after 5 years. When having severe claudication the success rate was 62% and 79% after 5 years. The revascularisation of the deep femoral artery helps developing the collateral arteries, responsible for an improvement after a considerable period of time. In limbs with rest pain we got a success rate of 78% postoperatively and 76% after 5 years. In the case of gangrene the primary success rate was 40% and 68% after 5 years. Angiographically, severe arteriosclerotic lesions were documented in the deep femoral artery and popliteal artery when limb-threatening ischemia was present. Nevertheless, the combined aortofemoral and extended deep femoral artery reconstruction was efficient in treating the multilevel occlusive disease; subsequent femoro-distal bypass was necessary only in case of threatening ischemia for 9.3% of limbs. Our findings show there is no indication for simultaneous aortofemoral and femoro-distal bypass grafting in the treatment of the multilevel disease.

Aorta, Abdominal↗
PubMed1992

Neuroendocrine effects of ipsapirone on the hypothalamic-pituitary adrenal axis: CRF, ACTH and cortisol in healthy volunteers.

The neuroendocrine effects (changes in plasma CRF, ACTH and cortisol) of single and multiple (t.d.s. for 2 days) doses of ipsapirone (BAY Q 7821) 5 and 10 mg have been investigated in 6 healthy male volunteers. The study followed a balanced complete block, placebo-controlled and double blind design with two baseline phases (pre and post-treatment). Volunteers were investigated on identical days during 5 successive weeks. The results do not show a specific effect of ipsapirone on the hypothalamic-pituitary-adrenal axis when doses in the range of 5-30 mg per day were given.

Adrenocorticotropic Hormone↗
PubMed1991

[Complications caused by use of balloon catheters in arterial thrombembolectomy].

Complications related to balloon catheter thrombembolectomy in 717 cases of arterial occlusion occurred in 4.3% (= 31) and are classified in 6 groups: 16 perforations resp. ruptures (2.2%), 2 AV-fistulas (0.3%), 10 dissections (1.4%), 3 aneurysms (0.4%), intimal lesion and catheter failure. Inadequate handling is probably responsible in the majority of cases. Intraoperative angiography usually permits to recognize the complication and displays the details required for additional procedures.

Aneurysm↗
PubMed1988

Increase in plasma atrial natriuretic factor and right atrial area during endogenous and exogenous volume loading in healthy volunteers: effect on plasma renin activity, aldosterone and antidiuretic hormone.

The mechanisms of atrial natriuretic factor (ANF) release and the effects of ANF on plasma renin activity (PRA), plasma aldosterone and plasma antidiuretic hormone were investigated in two groups of normal subjects. One group was studied before and after endogenous volume loading produced by 30 min of head-down tilt. The other group was studied before and after an exogenous volume load in the form of 1 litre of isotonic saline infused over 30 min. Measurements made included right atrial area by two-dimensional echocardiography, PRA, plasma aldosterone, plasma antidiuretic hormone and plasma levels of ANF. There was a significant correlation between the increase in atrial area and plasma ANF concentrations after endogenous and exogenous volume loading. Levels of PRA and plasma aldosterone were suppressed significantly after exogenous volume loading but not after endogenous volume loading. The concentration of plasma antidiuretic hormone was not affected by either procedure. Short-term changes in right atrial pressure appear to regulate the plasma levels of ANF in normal people.

Aldosterone↗
PubMed1983

The effects of probenecid on cyclic adenosine 3',5'-monophosphate levels in cerebrospinal fluid and on brain phosphodiesterase activity in the rat.

In rats, probenecid exhibits a dose-dependent increase in the concentration of cyclic adenosine 3',5'-monophosphate (cAMP) in cisternal cerebrospinal fluid (CSF). Maximal accumulation is reached 2 h after IP administration at a dosage of 150 mg/kg body weight. Serum levels of cAMP are unchanged after 200 mg/kg probenecid. In vitro investigations show an inhibitory effect of probenecid on the uptake of cAMP into the isolated choroid plexus of the rabbit. A non-competitive inhibition of probenecid on a high affinity fraction of cyclic nucleotide phosphodiesterase from rat brain homogenates is demonstrated with an inhibitor constant of 3.4 X 10(-3M. The results appear to validate the "probenecid test" for cAMP in clinical diagnostics.

Animals↗
PubMed1982

[The indication for the use of an endobronchial double lumen tube in the intensive care of unilateral pulmonary complications].

Experiences gained in 5 patients subjected to endobronchial intubation with a double-lumen tube on account of several causes are reported. The mean length of application was 45.3 (6.5-67.5 h), and depending on the underlying diagnosis, several techniques of controlled ventilation or spontaneous breathing were used. In all cases arterial blood pressure and central venous pressure were continuously monitored throughout the duration of the treatment, and in some cases the airway pressures were measured. Frequent blood gas analyses were carried out and x-rays of the chest regularly taken. In one case the haemodynamic patterns were studied via a Swan-Ganz catheter. In all cases an improvement of the predominantly unilateral pathology of the lungs was observed under independent ventilation or spontaneous breathing, as assessed by blood gas analysis and of x-ray examination. Irrespective of synchronization, the simultaneous application of 2 ventilators for the controlled ventilation of the patient had clinically no relevant effects on haemodynamics. In cases of unilateral pulmonary complications we therefore see at present the following indications for using a double lumen endobronchial tube: 1. Therapy resistant resorption atelectasis, 2. interstitial or intraalveolar pulmonary edema, 3. therapy resistant pulmonary fistula, 4. pulmonary infiltrations and 5. pulmonary contusions with endobronchial bleeding. We believe that double lumen endobronchial plastic tubes with hi-lo cuffs are, when properly applied, an advance in long term intubation and mechanical ventilation managements.

Adult↗
PubMedDate not supplied

Laparoscopic fluorometry: a new minimally invasive tool for investigation of the intestinal microcirculation.

The aim of this study was to develop and establish a new system of laparoscopic fluorometry for the purpose of investigating the intestinal microcirculation. In 25 pigs (German Landrace, 16-25 kg body weight), ischemia was established in two segments (A, irreversible; B, reversible ischemia; C, internal control) of the small intestine by a laparoscopic technique. Microcirculation in the segments was assessed by laparoscopy at a second-look operation 24 h later by means of the fluorescence system Endoscan. The fluorescence of the three bowel segments was measured by arbitrary dye fluorescence units (DFU) 15 min after starting reperfusion, before and after injection of sodium fluorescein (NaFlu, 0.25 mg/kg body weight). The dividing line between viable and nonviable bowel tissue was established from the inflow and outflow rates of NaFlu with the aid of ROC (receiver operating characteristic) curves. The specificity and sensitivity of the new method were evaluated by correlating the results with the viability of each intestinal segment as predicted by three laparoscopically experienced surgeons and by histological examination. By means of the calculated separation sharpness (fluorescence index at 2 min >0.5, outflow factor of NaFlu at 10 min >20%), the overall predictions of intestinal viability in all 25 animals achieved a sensitivity of 93.5% and a specificity of 94.1% by laparoscopic fluorometry, versus a sensitivity of 70.8% and a specificity of 87.5% for the prediction of bowel viability by ordinary laparoscopic technique. Used as an adjunct to conventional laparoscopy, laparoscopic fluorometry brought significant gains in sensitivity and specificity in the distinction between reversible and irreversible intestinal ischemia.

Animals↗