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J Finger

Publications and source records attributed to J Finger.

17 recordsLinked to original sources
PubMed2001

Nifedipine inhibits sphinogosine-1-phosphate-induced renovascular contraction in vitro and in vivo.

Sphingosine-1-phosphate (SPP) can constrict isolated intrarenal blood vessels in vitro and reduce renal blood flow in vivo. The present study has investigated the role of extracellular Ca2+ and dihydropyridine-sensitive Ca2+ channels in SPP-induced renovascular contraction. In isolated intrarenal microvessels, cumulative addition of SPP (0.1-100 microM) caused concentration-dependent vasoconstriction (maximum effect 5.0 +/- 1.1 mN). In the presence of nifedipine (300 nM, added 30 min before SPP) or EGTA (5 mM, added 1 min before SPP), SPP-induced vasoconstriction was almost completely abolished. In thiobutabarbitone-anaesthetized rats, i.v. bolus injections of SPP (1-100 microg/kg) dose-dependently lowered renal blood flow from basal values of approximately 4.8 ml/min by up to 2.2 +/- 0.2 ml/min but had only little effect on mean arterial pressure. Pretreatment with nifedipine (10-100 microg/kg per min, i.v.) dose-dependently attenuated SPP-induced renal blood flow reductions. We conclude that SPP-induced renovascular contraction requires the influx of extracellular Ca2+ which may occur largely via nifedipine-sensitive L-type Ca2+ channels.

Animals↗
PubMed2001

Preliminary evaluation of epidural morphine for treatment of heroin withdrawal.

OBJECTIVE: To evaluate the efficacy of epidural morphine in treating heroin withdrawal in patients who failed to detoxify by the other methods. DESIGN: Prospective study. SETTING: Department of Psychiatry of a general hospital. PATIENTS: 8 ASA physical status I patients, aged 26 to 42 years, not having concurrent diseases requiring medication, and who had previously failed other methods of detoxification. INTERVENTIONS: Epidural catheters were inserted at the L(3)-L(4) interspace. Bolus injections of morphine sulfate, 3.0 mg in normal saline, were administered epidurally at 24-hour intervals. Treatment continued for 10 to 12 days. MEASUREMENTS: Withdrawal symptoms, such as mydriasis, insomnia, rhinorrhea, arthralgia, muscular pain, tooth pain, vomiting, diarrhea, dysphoria, and drug craving were monitored. MAIN RESULTS: Withdrawal symptoms ceased within 10 days. Withdrawal symptoms were diminished or entirely abolished by the treatment, and no patient requested to drop out of the program. Discontinuation of the epidural injections did not cause relapse of withdrawal. All patients reported that withdrawal with epidural morphine was considerably easier compared to other methods that they had previously experienced. CONCLUSIONS: A preliminary evaluation of epidural morphine in addicts that failed previous detoxifications showed high effectiveness of this method in reducing withdrawal symptoms.

Adult↗
PubMed1994

Preemptive effect of fentanyl and ketamine on postoperative pain and wound hyperalgesia.

The aim of this study was to test the hypothesis that the induction and maintenance of anesthesia with the use of fentanyl or ketamine reduces postoperative pain and wound hyperalgesia beyond the period when these effects can be explained by the direct analgesic action of these drugs. Twenty-seven patients scheduled for elective hysterectomy were investigated in a double-blind, randomized study. Patients were divided into three groups. In the fentanyl group, anesthesia was induced with fentanyl 5 micrograms/kg combined with thiopental 3 mg/kg and maintained with isoflurane and fentanyl 0.02 microgram.kg-1.min-1. In the ketamine group, anesthesia was induced with ketamine 2 mg/kg in combination with thiopental 3 mg/kg and maintained with isoflurane and ketamine 20 micrograms.kg-1.min-1. In the control group, anesthesia was induced with thiopental 5 mg/kg and maintained with isoflurane only. Patients in all three groups received identical postoperative pain treatment. The intensity of spontaneous incisional pain and movement-associated pain was measured with a visual analog self-rating method. The surgical wound hyperalgesia was assessed by measuring pain threshold to pressure on the wound by using an algometer, and also by measuring the intensity of pain to suprathreshold pressure on the wound with the visual analog self-rating method. Forty-eight hours after surgery, the pain threshold was 0.90 +/- 0.06 kg in controls, 1.69 +/- 0.19 kg (P < 0.001) in the fentanyl group, and 1.49 +/- 0.15 kg (P < 0.01) in the ketamine group.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Propofol and fentanyl act additively for induction of anaesthesia.

The induction dose-response of propofol was compared with the dose-response of its combination with fentanyl and with that of fentanyl alone in three groups of 60 women undergoing minor gynaecological surgery. Dose-response curves were determined for each group using bootstrap and isobolographic analyses. Propofol was found to act additively with fentanyl for induction of anaesthesia. Twenty-three percent of the ED50 of fentanyl was required in combination with 75% of the ED50 for propofol to achieve the ED50 of the combination. This indicates that, for induction of anaesthesia, propofol and fentanyl are not synergistic.

Adult↗
PubMed1989

Midazolam acts synergistically with methohexitone for induction of anaesthesia.

The induction dose-response of midazolam was compared with the dose-response of its combination with methohexitone sodium and with that of methohexitone alone. Three groups of 60 unpremedicated ASA physical state I or II women undergoing minor gynaecological interventions were studied. The end-point of induction of anaesthesia was inability to open eyes upon command. Dose-response curves were determined for each group with a probit procedure and compared with an isobolographic analysis. Midazolam was found to act in synergism with methohexitone for induction of anaesthesia. Twenty-seven percent ED50 for methohexitone was required in combination with 33% of ED50 for midazolam to achieve the ED50 of the combination. This degree of synergism is in agreement with that described in animal research.

Adult↗
PubMed1989

A non-human primate model for the study of oral iron chelators.

Recent studies have demonstrated that parenteral deferroxamine can prolong life in patients with iron overload. We have developed a non-human primate model of iron overload and have accurately determined negative iron balance in parenteral and oral studies of deferroxamine and a new chelator, desferrithiocin. Cebus monkeys were loaded with iron dextran (10 mg/kg twice weekly) until their serum contained a transferrin saturation greater than 75%, and (in two animals) liver biopsies showed iron loading. When complete iron balance studies were performed at this time, basal iron balance was -53 +/- 11 micrograms (N = 4), providing a low background for provocative studies. Iron balance was determined for intramuscular (N = 2) and oral (N = 3) deferroxamine, as well as intramuscular (N = 1) and oral (N = 4) desferrithiocin. The pattern of iron excretion after parenteral deferroxamine strongly resembled that of the iron-loaded, transfused human. Desferrithiocin was found to have significant activity as an oral chelator. This Cebus monkey model accurately determines negative iron balance and readily permits precise comparison of iron chelators given parenterally or orally. This model may offer an important step between rodent and human trials of promising new iron chelators.

Administration, Oral↗
PubMed1984

Diversion of bile and pancreatic secretion in the rat and its effect on cysteamine-induced duodenal and peptic ulcer development under maximal acid secretion.

In this investigation we assess whether diversion of bile and pancreatic secretion protects rats from ulceration under maximal acid secretion as it does in cysteamine-induced ulcers. The rats were divided into a cysteamine-group (Cy) comprising 16 rats and a secretagogue group (PC) with 18 white male rats. Half of the animals of each group were submitted to the diversion-operation (division of the duodenum distally from the pylorus, jejuno-duodenostomy and entero-y-anastomosis), Cy2 and PC2 respectively. The other animals were not operated (Cy1 and PC1). In the cysteamine group the rats were given twice cysteamine-HC1 injections subcutaneously and the PC group were given a 24 h infusion with pentagastrin and carbachol. All animals of the Cy1 group had duodenal ulcers, 3 perforated. However, only 2 rats had one ulcer each in the Cy2 group (p less than 0.01). The PC1 group totalled 30 duodenal ulcers in the 9 animals with 10 perforations, 13 ulcers in 6 animals with 3 perforations in PC2. Furthermore in PC1 group 34 gastric ulcers were found in 7 rats and only 4 ulcers in the PC2 group. It is therefore concluded, that the diversion operation provided protection against cysteamine-induced duodenal ulcers (p less than 0.01) and ulcer formation under maximal acid stimulation in the duodenum (p less than 0.02) as well as in the rat stomachs (p less than 0.05). In the PC group the restraint haltering of the animals promoted presumably a stress situation with bile reflux in the non-operated whereas in the operated animals (PC2) reflux did not occur.

Animals↗
PubMed1984

The role of bile salts in cysteamine-induced duodenal ulcer in the rat and the ulceroprotective property of lysolecithin.

UNLABELLED: Cysteamine induces duodenal ulcers in rats, but bile diversion inhibits ulcer formation. Since lysolecithin inhibits stress ulceration in rats, it is assessed now whether lysolecithin inhibits cysteamine-induced ulcers, too. Male rats were operated: division of the duodenum distally to the pylorus, duodenojejunostomy. Roux-en-Y duodenojejunostomy. 4 groups comprising 10 animals. Drinking solution for group 1, 3 and 4: Na taurocholate and glycocholic acid (5 mmol/l). For group 2 addition of 0.2 mmol/l lysolecithin. Cysteamine-HCl (10%) twice subcutaneously on the 19th day in group 1, 3 and 4, isotonic NaCl in group 2. In group four 1 ml lysolecithin per gastric tube 1 h before cysteamine. RESULTS: Group 1: 8 animals with 16 ulcers, group 2: 7 with 10 ulcers, group 3: no ulcers, group 4: 3 with 5 ulcers (p less than 0.05/p less than 0.02). CONCLUSION: Lysolecithin, a substance produced during fat digestion, exerted an ulceroprotective property (lyso-protection) under experimental conditions, as shown here for the first time, to the author's knowledge. The enhancement of cysteamine-induced duodenal ulcer development by bile salts is again documented.

Animals↗
PubMed1981

The role of taurocholic acid, glycocholic acid and lysolecithin in experimental stress ulcer in the rat.

The stress ulcer formation is enhanced significantly in rats operated with pyloro-jejunostomy and Roux-en-Y anastomosis by taurocholic acid or a mixture of taurocholic and glycocholic acid. However, the incidence of stress ulcers is significantly reduced by adding lysolecithin to the drinking solution containing these bile acids in the same concentration, though lysolecithin alone induces significantly more stress ulcers than tap water in rats with the same operation submitted to immobilisation stress.

Animals↗
PubMed1981

Inhibition of experimental stress ulcer formation in rats.

We present an operation model in rats, which according to our opinion prevents duodenogastric reflux effectively. The duodenum is divided distally from the pylorus and a pyloro-jejunostomy performed combined with a Roux-en-Y anastomosis. Rats operated this way and submitted to restraint stress developed significantly less stress lesions than operated control under same conditions. However, operated rats submitted to the operation and offered a 5 mMol/l drinking solution of crude taurocholic acid during 20 days before submitted to stress had significantly more stress lesions than operated animals with tap water before restraint stress.

Animals↗
PubMed1980

Experimental microsurgical model in rats preventing duodenogastric reflux. A preliminary report.

For the purpose of studying the significance of the bile and duodenal reflux into the stomach in rats we present an experimental animal model which--in contrast to the procedures reported until now--can exactly be reproduced due to the advantage of microsurgical techniques, thus reducing the operative trauma and accidental results during experimentation. The surgical procedure consists of a pylorojejunostomy with a Roux-en-y loop. This experimental model offers the possibility to discern a great deal of the problems and conditions which may be responsible in the adverse effect of bile and/or duodenal juice on the gastric mucosa.

Animals↗
PubMedDate not supplied

Subarachnoid bupivacaine blockade decreases midazolam and thiopental hypnotic requirements.

STUDY OBJECTIVE: To test the hypothesis that subarachnoid bupivacaine blockade decreases hypnotic requirements for thiopental sodium and midazolam. DESIGN: Randomized, double-blind, placebo-controlled study. SETTING: Teaching hospital. PATIENTS: 53 nonpremedicated ASA physical status I and II adult male patients scheduled for elective lower abdominal, pelvic, or lower limb surgery. INTERVENTIONS: Intravenous injections of midazolam or thiopental were administered with or without subarachnoid bupivacaine blockade (12.5 mg) at the L3-L4 level. Thiopental or midazolam hypnotic requirements were determined using loss of ability to open eyes in response to verbal command as an endpoint. The thiopental requirements were determined by titration; the midazolam requirements were determined from dose-response curves obtained with bolus injections of predetermined doses of the drug. MEASUREMENTS AND MAIN RESULTS: Subarachnoid bupivacaine blockade decreased the hypnotic dose of thiopental from 3.40 +/- 0.68 mg/kg (mean +/- SD) with a dose range of 2.3 to 4.5 mg/kg (intramuscular saline) to 2.17 +/- 0.48 mg/kg with a dose range of 1.3 to 2.8 mg/kg (p < 0.005 for the difference). The ED50 value of midazolam decreased with the bupivacaine blockade, from 0.23 mg/kg (95% confidence limits: 0.08 to 0.38 mg/kg) to 0.06 mg/kg (0.01 to 0.14 mg/kg), with p < 0.0001 for the difference. CONCLUSION: Subarachoid bupivacaine blockade decreases hypnotic requirements for both thiopental and midazolam. The results suggest that the reduction in hypnotic requirements is due to the decrease in afferent input induced by spinal anesthesia.

Adult↗
PubMedDate not supplied

Effect of epidural bupivacaine block on midazolam hypnotic requirements.

BACKGROUND AND OBJECTIVES: The aim of the study was to determine the effect of epidural bupivacaine block on midazolam hypnotic requirements. METHODS: Sixty unpremedicated, ASA physical status I or II male patients, aged 45-65 years and scheduled for elective lower abdominal, pelvic, or lower limb surgery participated in this randomized, double-blind, placebo-controlled study. The study population was composed of three groups: Before administration of midazolam, patients in the first group received an intramuscular injection of 15 mL saline (M), those in the second group an intramuscular injection of 15 mL 0.5% bupivacaine (MIB), and those in the third group an epidural injection of 15 mL 0.5% bupivacaine at the L3-L4 level (MEB). Loss of the ability to respond to verbal command was used as an endpoint for the effect of midazolam injected intravenously in predetermined doses (five patients per dose) 30 minutes after a bupivacaine (or saline) injection. Midazolam dose-response curves were obtained by probit analysis. RESULTS: The midazolam median effective dose values for the hypnotic effect were 0.20 mg/kg (95% confidence limit, 0.10-0.27 mg/kg) in the M group; 0.10 mg/kg (0.06-0.22 mg/kg) in the MIB group; and 0.04 mg/kg (0.03-0.07 mg/kg) in the MEB group. The differences between the midazolam median effective dose values had high levels of significance: P < .00001 for MEB versus M, P < .002 for MEB versus MIB, and P < .01 for MIB versus M. CONCLUSIONS: Epidural bupivacaine block profoundly decreases midazolam hypnotic requirements. The most likely explanation for this effect is the reduction in afferent input induced by the block.

Aged↗