Comparison of the pharmacokinetics of methohexital during cardiac surgery with cardiopulmonary bypass and vascular surgery

The aim of this study was to assess the pharmacokinetics of methohexital (ME) in major vascular surgery (VASC) and to compare these data with the pharmacokinetics of ME during hypothermic cardiopulmonary bypass (HCPB) (temperature: 28 degrees C) and normothermic cardiopulmonary bypass (NCPB) (temperature: 37 degrees C). An ME bolus (2 mg/kg) was administered to 8 VASC patients at the start of surgery and to 11 HCPB patients and 11 NCPB patients at the start of cardiopulmonary bypass (CPB). Twenty-one arterial blood samples were withdrawn over the following 24 hours for ME assays. All of the patients were given similar anesthesia (fentanyl, diazepam) and muscle relaxation (pancuronium). In the VASC group, ME total body clearance (TBC) was 6 +/- 2 mL/kg/min (mean +/- SD), which is less than in previous studies. When comparing HCPB and NCPB groups, elimination half-life (T1/2), TBC, volume of distribution (VD), area under the curve (AUC), and mean residence time (MRT) were similar. When comparing VASC and CPB patients, TBC and VD were greater in CPB patients than in VASC patients; thus, T1/2 (equal to 0.693 x VD/TBC) was similar. AUC was smaller in CPB patients because of hemodilution, but MRT was similar. It is concluded that ME clearance is lower in patients undergoing major vascular surgery than in healthy patients. The temperature and the duration of CPB do not seem to substantially influence the pharmacokinetics of ME when a bolus is administered. Parameters such as AUC, TBC, and VD appear modified by hemodilution during CPB; however, T1/2 and MRT, which allow comparisons between CPB and non-CPB patients, were similar in these patients.

Clinical and pharmacological study of intrahepatic artery infusion of thiotepa

Twenty patients with primary or metastatic liver cancer were treated on a clinical and pharmacological study with intrahepatic artery infusion of Thiotepa. Toxicity was tolerable and included nausea and fatigue. Uncommon side effects were myelosuppression, abdominal pain and anemia. One patient with gallbladder cancer had a partial response for 11 (+) months. Recommended dose of Thiotepa for future Phase II clinical trials is 1.0 mg/kg. Pharmacokinetics of intrahepatic Thiotepa revealed an extraction ratio similar to that reported for cisplatin. The data suggest increased hepatic clearance for Thiotepa either by binding or metabolism.

Phase I trial of a 5-day infusion of L-leucovorin plus daily bolus 5-fluorouracil in patients with advanced gastrointestinal malignancies

The combination of leucovorin [(6d,l)-5-formyl-tetrahydrofolate] and 5-fluorouracil (5-FU) has increased efficacy compared to 5-FU alone as treatment of advanced colorectal cancer. Leucovorin is metabolized to methylene tetrahydrofolate, which potentiates the antitumor actions of 5-FU by forming a ternary complex of thymidylate synthase, fluorodeoxyuridine and methylene tetrahydrofolate. Only l-leucovorin is metabolized to methylene tetrahydrofolate and forms this ternary complex. However, d-leucovorin may not be inert. d-Leucovorin may impair cellular uptake and metabolism of l-leucovorin, thereby inhibiting the actions of l-leucovorin. Because of this possible limitation to the effectiveness of racemic leucovorin, we have begun to explore the effects of the pure, biologically active isomer, l-leucovorin. In this phase I trial, patients with advanced gastrointestinal malignancies were treated with a 5-day continuous infusion of l-leucovorin and daily intravenous boluses of 5-FU at 370 mg/m2. The dose of l-leucovorin was escalated in groups of three patients at four doses, 200 mg/m2 per day, 400 mg/m2 per day, 700 mg/m2 per day and 1000 mg/m2 per day. Treatment was repeated every 28 days. Seventeen patients with advanced gastrointestinal cancers entered the trial. Sixteen patients were evaluable for toxicity. Toxicity was similar to that expected for leucovorin plus 5-FU. The most common severe toxicities (and the number of patents affected) were: diarrhea (2), mucositis (2), nausea/vomiting (1), and abdominal/rectal pain (2). The maximum tolerated dose of l-leucovorin was 700 mg/m2 per day. Twelve patients were evaluable for response. One complete, one partial and one minor response were observed. All responses occurred among the nine patients with colorectal carcinomas. The combination of l-leucovorin and 5-FU is well tolerated by patients and appears active for treatment of advanced colorectal carcinomas. Additional clinical trials are necessary to determine if l-leucovorin is more effective than d,l-leucovorin for modulating the effectiveness of 5-FU.

Helicobacter pylori. Its role in the pathogenesis of peptic ulcer disease in a new animal model

The association and causative role of Helicobacter pylori infection of the stomach with gastric ulcer, duodenal ulcer, non-ulcer dyspepsia, and gastritis has remained controversial. The authors studied the effects of daily intragastric administration of H. pylori suspension in saline (10(8) CFU/ml) and bacteria-free filtrates of saline H. pylori suspensions in 85 Sprague-Dawley rats (weight, 150 to 200 g) with normal mucosa and with surgically produced experimental gastric ulcers. Group I rats (n = 30) with pre-existent experimental gastric ulcers received H. pylori suspension (ATCC 43504, 10(8) CFU/ml); Group II rats (n = 20) with experimental gastric ulcers received bacteria-free H. pylori filtrates; Group III rats with ulcers (n = 20) received saline alone; and Group IV control rats (n = 15) without ulcers received intact H. pylori organisms in suspension (ATCC 43504, 10(8) CFU/ml). At death, ulcer surface areas were measured with a dissecting microscope. Full-thickness sections were obtained for quantitative and qualitative histologic parameters, including the area of remaining mucosal necrosis; characteristics and cellular composition of restored mucosal architectures; and presence or absence of inflammation including counts of neutrophils and lymphocytes. H. pylori organisms were identified within the surface mucus and crypts using routine, special, and immunohistochemical stains. Our results indicate that the continued presence of either intact H. pylori organisms or bacteria-free H. pylori filtrates in the stomachs of rats with pre-existent gastric ulcers resulted in delayed healing of the ulcers and persistence of chronic active inflammation. Daily administration of suspensions of H. pylori organisms to sham-operated rats with intact gastric mucosa, however, resulted in no ulceration or inflammation despite identification of surface H. pylori organisms at death. The authors conclude that H. pylori alone causes little or no effect on an intact gastric mucosa in the rat, that either intact organisms or bacteria-free filtrates cause similar prolongation and delayed healing of pre-existing ulcers with active chronic inflammation, and that the presence of predisposing factors leading to disruption of gastric mucosal integrity may be required for the H. pylori enhancement of inflammation and tissue damage in the stomach.

Developmental regulation of insulin in the mammalian central nervous system

We delineated the ontogeny of rabbit brain insulin concentrations to define the regulatory role of development on this hormone in the central nervous system. Employing a sensitive ELISA, we observed higher concentrations in the late gestation fetal brain (approximately 80-90 ng/g) and early neonatal brain (approximately 195 ng/g) in comparison to the adult (approximately 32 ng/g; P less than 0.01). Further, we characterized this hormone to determine the identity of insulin (or an insulin-like substance) in brain. Employing porcine/bovine or rabbit insulin as standards, we observed that brain insulin mimicked authentic insulin in its migration on SDS-polyacrylamide and native gel electrophoresis, immunogenicity on Western blot analysis, and its elution profile on immunoaffinity column chromatographic, and high performance liquid chromatographic separation. We then examined the developmental effects on circulating and cerebrospinal fluid (CSF) radioimmunoassayable insulin levels. No statistically significant differences (ANOVA) existed through development in either the serum or CSF insulin levels. Employing multiple regression analysis, no correlation was evident between brain and either serum or CSF insulin concentration. A search for insulin mRNA by Northern blot analysis yielded minute amounts of atypical large sized transcripts. We conclude that the insulin peptide in the central nervous system closely resembles (or is identical to) circulating insulin in many properties and that there is a developmental increase in brain insulin concentrations, the maximal peak occuring in the late gestation fetus and early neonate. Insulin concentrations in brain demonstrate no conventional relationship to either the serum or CSF insulin levels, suggesting an additional source of peptide, which contributes beyond that which is available via the circulation. The amounts of insulin present within the central nervous system are minute (difficult to detect) but in the range (10-100 ng) where the hormone can interact with either insulin or insulin-like growth factor I (IGF-I) receptors that are abundantly present on developing brain cells, thereby executing the biological function of the hormone.

Peripartum cardiac failure in The Gambia

Twenty-seven patients with peripartum cardiac failure were seen at the Royal Victoria Hospital, Banjul over a 2-year period while one further patient presented 6 months after delivery with a cerebral embolus secondary to a dilated cardiomyopathy. Five (18%, P less than 0.001) patients had twin pregnancies. Seventeen (63%) patients attended for follow-up, of whom eight had evidence of continuing cardiac dysfunction and required treatment with diuretics; two patients were known to have died. In five asymptomatic patients the electrocardiogram had reverted to normal and three patients had further pregnancies without relapse. The bipolar distribution of onset of symptoms in relation to pregnancy was suggestive of two different pathological processes. There was no evidence that cultural habits played any significant part in the aetiology of peripartum cardiac failure in The Gambia.

Diabetes mellitus in The Gambia, west Africa

A register of diabetic patients attending the Royal Victoria Hospital, Banjul, The Gambia, was kept and data on hospital admissions recorded over a 1-year period. Two hundred and sixty-nine patients (110 men, 159 women) were registered of whom 66 (25%) were receiving insulin. Seventy-five patients (28%: 40 men, 35 women) were newly diagnosed. There were significant differences in age (p less than 0.001) and obesity (p less than 0.001) between men and women and between patients with different types of diabetes. There were 95 hospital admissions (5.2%) related to diabetes, as were a fifth of medical out-patient attendances. Ketoacidosis was the major cause of death while foot infections were more common (p less than 0.01) in women. Diabetes imposed a heavy burden on the health services of The Gambia, a small developing country in West Africa; more than 3.6% of the annual health budget was spent on the treatment of diabetic patients.

Fragmentation of 1- and 3-methoxypropene ions another part of the C4H 8O (+•) potential energy surface

The fragmentation mechanisms of metastable ionized 1- and 3-methoxypropene have been examined in detail by using ionization and appearance energy measurements, metastable ion and collisional activation mass spectra, and a variety of isotopically labeled molecules. These metastable C4H8O(+•) ions fragment by loss of H; CH3, and H2CO, and the experimental observations allowed the construction of the potential energy diagram which describes their interconversion and the participation of four other distonic and carbene C4H8O(+•) ions. It was found that these two methyl alkenyl ether ions had no common reaction channel with either the 2-methoxy isomer or with any of the alcohol, keto, or enol C4H8O(n+•) isomers which previously have been extensively studied.

The LCR-like alpha-globin positive regulatory element functions as an enhancer in transiently transfected cells during erythroid differentiation

A positive regulatory element (PRE) similar to the locus control region (LCR) of the human beta-globin gene cluster has recently been identified 40 kb upstream of the human zeta-globin mRNA cap site (Higgs D.R. W.G. Wood, A.P. Jarman, J. Sharpe, J. Lida, I.M. Pretorius, and H. Ayyub. 1990). We investigated the influence of the alpha PRE on human alpha-globin promoter activity in transiently transfected cells. The introduction of the alpha PRE into alpha-globin promoter/CAT expression constructs increased alpha-globin promoter activity by 15-30 fold in a human erythroid cell line (Putko) as well as in mouse erythroleukemia cells (MELCs) induced with hexamethylene bisacetamide (HMBA). When these constructs were introduced into uninduced MELCs or HeLa cells, only a 2-3 fold increase in alpha-globin promoter activity was observed. Deletion of 600 bp of alpha-globin 5' flanking sequences containing six putative SP1-binding sites had no significant effect on levels of alpha-globin promoter enhancement by the alpha PRE. We further demonstrated that the alpha PRE and HS2 of the beta-LCR could similarly enhance transcriptional activity of the SV40 early promoter in HMBA induced MELCs. Finally, we showed that alpha-globin promoter activity in the presence of the alpha PRE increased with continued HMBA exposure and was coincident with transcriptional activation of endogenous globin genes.

[Vascular effects of urapidil administrated during extracorporeal circulation]

Urapidil exerts a combined central sympathetic and peripheral alpha-1 adrenergic receptor inhibition. Urapidil induces arterial vasodilation but its effects on venous capacitance are more difficult to assess. During cardiopulmonary bypass with constant perfusion index (2.4 l.min-1 x m-2) total peripheral resistance varies similarly as to arterial pressure and, as the apparatus venous reservoir is filled continuously by simple gravity from the right atrium, a decrease in venous blood reservoir level reflects an increased venous capacitance. Twenty-six patients undergoing cardiac surgery were anaesthetized with fentanyl and midazolam and randomly assigned to one of two groups. During normothermic cardiopulmonary bypass, group 1 was administered i.v. urapidil 12.5 mg and group 2 a placebo. In group 1, arterial pressure decreased by 33 +/- 14% (mean +/- SD) at the second minute while total peripheral resistance decreased from 1,384 +/- 255 to 927 +/- 193 dyn.s.cm-5. Then this two parameters regained group 2 values after the eighth minute. Reservoir blood level was lower in group 1 than in group 2 from the second to the eight minute (p < 0.05) with maximum effect at 7 minutes. It is concluded that urapidil exerts arterial and venous dilation. Its arterial effects seem greater during normothermic cardiopulmonary bypass than in normal conditions and its maximum venous effects seem to occur after its maximum arterial effects. The short duration of action may be due to the small dose administered.

Preliminary evidence for methamphetamine-induced behavioral and ocular effects in rat offspring following exposure during early organogenesis

Gravid Sprague-Dawley CD (VAF) rats received 50 mg/kg (d,l)-methamphetamine (MA) HCl (expressed as free base, N = 15) or distilled water (N = 6) by SC injection x 2/day in a 3 ml/kg volume on embryonic (E) days 7-12. Control rats were pair-fed to MA-exposed dams on days E7-18. No control dams failed to deliver; however, of 15 MA-exposed dams 4 did not deliver (2 died and 2 had completely resorbed litters). One additional MA litter had all the offspring die shortly after birth. There was no difference between groups on offspring postnatal (P) body weight. The offspring exposed prenatally to MA had significantly lower olfactory orientation scores (P9, 11, 13) to their home cage scent. In a test of early activity (P10, 12, 14) the MA-exposed progeny were marginally less active than controls. MA-exposed offspring exhibited hyperreactivity and marginally shortened response latency on a test of acoustic startle (P27). Motor activity showed no differential response in MA treated or control offspring to MA (P63) or fluoxetine challenge (P70). However, the MA offspring were more active than controls with respect to central and side activity during the second week of testing. No group differences were found for performance in a straight swimming channel or on the number of errors committed or latency to escape in a complex (Cincinnati) water maze (P84). Prenatal exposure to MA also induced eye defects (i.e., anophthalmia, microphthalmia and folded retina) in 16.7% of the progeny. However, MA did not effect hippocampal or neostriatal monoamine levels when measured on P28.(ABSTRACT TRUNCATED AT 250 WORDS)

Helicobacter pylori affects the quality of experimental gastric ulcer healing in a new animal model

Helicobacter pylori has been implicated in the genesis of human gastritis, dyspepsia, and peptic ulcers. However, its influence in the quality of experimental gastric ulcer healing has not been previously investigated. Standardized gastric fundic ulcers were produced in 50 male Sprague-Dawley rats (150-200 g) by a 4 mm in diameter focal, serosal application of 100% acetic acid. Thirty rats were administered 2 ml H. pylori suspension (urease producing, ATCC 43504) in normal saline (10(8) CFU/ml) 2x/day for 7 days. Twenty rats (controls) received 2 ml normal saline 2x/day for 7 days. Gastric ulcer surface area was measured under a dissecting microscope and mucosal specimens were obtained for qualitative and quantitative histology. No gross or microscopic duodenal abnormalities were identified at sacrifice. Ninety percent of control rats showed grossly and microscopically entirely healed ulcers. The remaining 10% showed partially reepithelialized ulcers (area, 0.78 to 1.77 mm2; mean, 1.27 +/- 0.7 mm2). The grossly "healed" mucosa demonstrated marked dilatation of gastric glands lined with mature surface epithelial cells. Parietal cells were scanty (5-10% of all cells). One hundred percent of the H. pylori-exposed rats showed persistence of chronic active ulcers (area, 1.76 to 19.63 mm2; mean, 8.95 +/- 6.15 mm2). The ulcer beds were infiltrated by acute and chronic inflammatory cells, abundant fibroblasts, and capillary networks. The raised ulcer borders were characterized by dilated glands lined by mature surface epithelial cells. Various special stains demonstrated the presence of H. pylori in the surface mucus and within the crypts.(ABSTRACT TRUNCATED AT 250 WORDS)

A phase I trial of 14-day continuous intravenous infusion mitoxantrone

Based on clinical evidence that prolonged exposure to anti-neoplastic agents may ameliorate dose-limiting toxicity while facilitating anti-tumor activity, we conducted a phase I trial of 14-day continuous intravenous infusion mitoxantrone. Study objectives were to: (1) determine the maximally tolerated dose for phase II trials; (2) determine the incidence and severity of side effects; and (3) study the pharmacokinetics of continuous infusion mitoxantrone. Sixteen patients with drug-resistant advanced cancers were entered into the trial. Three or more patients were treated at each dose level (1.0, 1.25, and 1.5 mg/m2/day) for a total of 33 courses (mean 2.1 courses/patient, range, 1-4). Courses were repeated every 4 weeks. The maximally tolerated dose (MTD) was found to be 1.5 mg/m2/day. At this dose four of six patients had grade III or IV leukopenia (mean WBC nadir 1900/microliters, range, 800-3600/microliters). Other toxicities were grade I or II stomatitis (two patients), grade I diarrhea (one patient), and grade I nausea (one patient). Renal and hepatic toxicity were not observed. No alopecia or infectious complications occurred. Pharmacokinetic studies were performed using high-performance liquid chromatography (HPLC). Steady-state plasma levels at the 1.5 mg/m2/day dose were reached by 48 h, with a mean steady-state plasma concentration of 3.2 +/- 0.7 ng/ml, mean total body clearance of 340 +/- 79 ml/min/m2, and mean area under the plasma disappearance curve (AUC) of 955 +/- 185 micrograms h/l. No responses were observed, although no patients with mitoxantrone-sensitive tumors were treated.(ABSTRACT TRUNCATED AT 250 WORDS)

The use of cerebral activation procedures with single photon emission tomography

Single photon emission tomography allows the imaging of dynamic brain functioning. The use of cerebral activating procedures within the scan protocol enables investigation of the mechanisms involved in specific brain functions in health and disease. Activation studies involve the comparison of at least two data sets describing brain activity generated in conditions that differ for the specific function in question. When designing an activation study, decisions regarding methodology include: the nature of the activation regime, the tracer-ligand utilized, the SPET instrument and the manner of subsequent data analysis. These issues are discussed in this review, both theoretically and with reference to published studies. Means of activating particular cerebral structures and functions are reviewed, as are the limitations of the techniques with respect to temporal and spatial resolution and the potentially confounding nature of preconceived ideas regarding the mechanisms of brain function.

[Hemodynamic effects of amrinone in low cardiac output after mitral valve replacement]

The efficacy of amrinone was assessed in the treatment of low cardiac output states occurring within 24 h after mitral valve replacement in an open prospective trial. It included 7 women and 5 men, aged 58 +/- 10 years. Four patients had also had simultaneous aortic valve replacement. Patients entered in the study if their cardiac index (CI) remained less than 2.2 l.min-1.m-2 after pulmonary wedged pressure (Ppw) had been increased to at least 15 mmHg, the patient having a temperature greater than 36 degrees C. Amrinone was given so as to increase Cl by at least 30% and to decrease Ppw by at least 30%. Patients were given a mean of 1.5 mg.kg-1 amrinone during the first hour, followed by a constant rate infusion of 9 +/- 3 micrograms.kg-1.min-1 over at least 24 h. The usual haemodynamic parameters were measured and calculated before giving amrinone, and after 1, 3, 6, 24, and 48 h. After 1 h of treatment, systolic arterial pressure, cardiac index, systolic index and left ventricular stroke work increased by 22, 42, 23, and 47% respectively, whilst Ppw decreased by 27% (p less than 0.01). Heart rate rose and systemic vascular resistance decreased but not significantly. Right atrial pressure, right ventricular stroke work, pulmonary artery pressure and pulmonary vascular resistance did not change. These effects were all maintained throughout the 48 h infusion. Amrinone had to be replaced by another agent (a beta-agonist) in 3 cases because of arrhythmia, lack of efficacy or thrombocytopaenia. In this setting, amrinone increased left ventricular performance with little effect on the right ventricle.

[Comparison of the hemodynamic effects of dobutamine and enoximone in the treatment of low cardiac output after valvular surgery]

Forty patients developed low cardiac output states after surgery for mitral valve disease or with associated cardiac disease and were randomly allocated to two treatment groups, one group to receive Dobutamine (D) and the other Enoximone (E), a phosphodiesterase inhibitor. Haemodynamic assessment covered a 24 hour period but treatment was continued for as long as was necessary. An improvement was observed from the 15th minute of treatment. At the second hour, the cardiac index had increased by 55% in Group E and by 59% in Group D whilst the heart rate increased by only 12% in Group E compared to 30% in Group D. The right and left heart filling pressures decreased by 25 to 27% in the 2 groups. The systemic arterial resistances fell by 36 to 37% without any significant changes in systemic or pulmonary arterial pressures. No significant difference was demonstrated in the haemodynamic responses to Dobutamine and Enoximone in this study. The duration of treatment was significantly shorter in Group E than in Group D (59 +/- 22 hrs vs 86 +/- 49 hrs) as was the patient's stay in the intensive care unit (92 +/- 37 hrs vs 155 +/- 129 hrs). The duration of assisted ventilation was the same in the two groups. These results suggest that Enoximone is as effective as Dobutamine in the treatment of low cardiac output after mitral valve surgery.(ABSTRACT TRUNCATED AT 250 WORDS)

[Arrhythmia in patients with low cardiac output after valvular surgery. Randomized, double-blind comparative study of dobutamine versus enoximone]

Forty patients with low cardiac output (cardiac index less than 2.2 l/mn/m2 and pulmonary wedge pressure greater than 15 mmHg) after valvular surgery were randomised into two groups. Patients in Group 1 were given 5 to 10 micrograms/Kg/mn of Dobutamine (D) and those In Group 2 a bolus of Enoximone (E) 1 mg/kg followed by an intravenous infusion of 5 to 10 micrograms/Kg/mn. Holter ECG monitoring over 42.65 +/- 6.02 hrs (24-48 hours) was obtained and interpreted blindly in 37/40 patients (19 Group D and 18 Group E). The results were analysed by the t and X2 tests. A p value of less than .05 was considered statistically significant. The two groups were comparable. No deaths occurred during the protocol period. The total duration of inotropic therapy (86 +/- 49 hours) and the period spent in the intensive care unit (155 +/- 129 hours) were longer in Group D than in Group E (60 +/- 23 hrs and 92 +/- 37 hrs, respectively; p less than .05). Antiarrhythmic therapy was used more often in Group D (4 patients) than in group E (1 patient) (p = 0.09).(ABSTRACT TRUNCATED AT 250 WORDS)

Rural community mental health consumer satisfaction and psychiatric symptoms

This study examined the impact of therapy on psychiatric symptoms and consumer satisfaction in a rural community mental health center. Utilizing the Brief Symptom Inventory (BSI) and an evaluation of service questionnaire (EOS), designed by the authors, results indicated positive outcomes for both measures (88 subjects). Small but significant correlations were obtained for the BSI and EOS (r's .29 to .59). Implications for future research and treatment are discussed focusing on time of intervention and symptom quality.

Relationship between preoperative amiodarone treatment and complications observed during anaesthesia for valvular cardiac surgery

Two groups of ASA physical status class III and IV patients undergoing cardiac surgery were reviewed in an attempt to obtain more conclusive data concerning dangerous interactions between amiodarone and anaesthesia. The amiodarone group (Group 1, ten patients, cumulative dose 10 g) was compared with a control group (nine patients, Group 2). Amiodarone (A) and desethylamiodarone (NA) concentrations in plasma and myocardium were measured and haemodynamic and antiarrhythmic effects were analysed. Throughout anaesthesia haemodynamic status was similar in both groups. No correlation was found between A/NA and cardiac index changes. No patients needed intraaortic blood pressure augmentation or developed low systemic vascular resistances. Pacemaker dependency was similar in both groups and there was no evidence of increased anaesthetic risk. An excellent antiarrhythmic effect was obtained during the postoperative period. We conclude that preoperative treatment with amiodarone is effective against postoperative arrhythmias.