General pharmacology of clozapine.

Clozapine shows neuroleptic-like inhibition of locomotor activity and conditioned avoidance responding in rodents, although tolerance develops on repeated treatment. EEG-based studies show strong arousal-inhibiting activity of clozapine as well as neuroleptic-like effects on both caudate spindle duration and rat sleep-waking patterns. Effects such as apomorphine blockade, catalepsy and strong increases of plasma prolactin levels are not seen, however, and chronic treatment does not lead to dopamine D2 receptor supersensitivity. Binding studies show clozapine's highest affinities to be for dopamine D4, 5-HT1C, 5-HT2, alpha 1, muscarinic and histamine H1 receptors, but moderate affinity is also seen for many other receptor subtypes. Microdialysis studies indicate a preferential interaction with striatal D1 receptors, whereas autoradiographical studies indicate upregulation of D1 and downregulation of 5-HT2 receptors after chronic clozapine. Clarification of the mechanisms underlying clozapine's special attributes is often hampered by a failure to examine compounds which show a close chemical relationship to clozapine, but which produce extrapyramidal side-effects in man, such as clothiapine, loxapine and amoxapine.


Clinical management of clozapine patients in relation to efficacy and side-effects.

Medical charts of 480 schizophrenic in-patients (581 treatments) were analysed to evaluate the efficacy and side-effects of clozapine. Clozapine treatment lasted for mean 49 (s.d. 38) days. Of the sample, 11.0% showed worsening or no change, 31.5% slight improvement, 53.0% marked improvement and 4.5% almost total reduction of symptoms. At least one major side-effect occurred in 68.0% of patients. A combination of clozapine with classical neuroleptics, antidepressants, benzodiazepines or lithium is tolerated by most patients, but increases the incidence of some side-effects. Clozapine treatment had to be discontinued because of severe side-effects in 8.6% of patients. In 81 schizophrenic out-patients, clozapine significantly reduced the days of in-patient treatment and number of hospital readmissions. Two patients developed leucopenia but had no complications after clozapine withdrawal. This study indicates a satisfactory benefit/risk ratio and compliance in most of the patients.


Clinical aspects and distribution of immunologically active cells in the nasal mucosa of patients with nasal polyps after endoscopic sinus surgery and treatment with topical corticosteroids.

Clinical parameters of 72 patients who were operated upon for nasal polyps were evaluated as well as biopsy specimens of the mucosa of the middle and inferior turbinates of 41 of these patients. Biopsies were taken at the time of endoscopic sinus surgery (ESS), after 6 months and after 1 year in 23 patients. During the follow-up period the patients were treated with topical corticosteroids (budesonide). At the time of ESS significantly more CD8+ (suppressor/cytotoxic) cells than CD4+ (helper/inducer) cells were found in the middle and inferior turbinates. At 6 months significantly more CD4+ cells were found than at the time of ESS, whereas at 1 year the number of CD4+ cells had decreased and was lower than at 6 months. These data support the theory that the occurrence of nasal polyps is associated with T-cell-dependent disturbances. Clinical evaluation revealed that most of the patients with chronic airway obstruction had better pulmonary functions postoperatively or required less medication for lung disease. These findings show that ESS combined with topical corticosteroids has a positive effect on upper and lower respiratory tract pathology.


Presynaptic inhibition of miniature excitatory synaptic currents by baclofen and adenosine in the hippocampus.

Presynaptic inhibition of neurotransmitter release is thought to be mediated by a reduction of axon terminal Ca2+ current. We have compared the actions of several known inhibitors of evoked glutamate release with the actions of the Ca2+ channel antagonist Cd2+ on action potential-independent synaptic currents recorded from CA3 neurons in hippocampal slice cultures. Baclofen and adenosine decreased the frequency of miniature excitatory postsynaptic currents (mEPSCs) without affecting the distribution of their amplitudes. Cd2+ blocked evoked synaptic transmission, but had no effect on the frequency or amplitude of either mEPSCs or inhibitory postsynaptic currents (IPSCs). Inhibition of presynaptic Ca2+ current therefore appears not to be required for the inhibition of glutamate release by adenosine and baclofen. Baclofen had no effect on the frequency of miniature IPSCs, indicating that gamma-aminobutyric acid B-type receptors exert distinct presynaptic actions at excitatory and inhibitory synapses.


Bioavailability and analgesic effect of sustained release cetobemidone capsules in cancer patients with chronic pain of malignant origin.

Ever since its introduction in 1952, Ketogan has consisted of a combination of the opioid cetobemidone and a spasmolytic drug, A29, in the ratio of 1:5. Its main limitations are the relatively short duration of action and an apparent ceiling effect due to A29. We therefore developed a cetobemidone formulation with sustained release properties (cetobem. s.r.). Forty-seven patients with advanced cancer with moderate/severe pain, treated with regular doses of Ketogan tablets took part in an open phase 1 type pharmacologic/toxicologic study comparing Ketogan tablets and cetobem. s.r. The patients spent at least 4 days in the department. After evaluation during 12 h with Ketogan tablets (3-4 dosing intervals), a loading phase lasting for 36 h with cetobem. s.r. given twice/24 h (total dose of Ketogan tablets per 24 h divided by 2), and synchronous reduction of the dose of Ketogan tablets, a similar evaluation period of 12 h was performed when on treatment with cetobem. s.r. alone. Comparison of data from the two observation periods showed the following: Average relative bioavailability 0.77 SD 0.28. Only 2 patients were remedicated before 12 h when on cetobem. s.r. Duration of action mean 11.9 h, SD 0.3 h. There was no significant difference between Ketogan tablets and cetobem. s.r. periods concerning 'time with no pain'. Side-effects were few. The only significant difference was dry mouth being more severe during the tablet period. Vital signs were unaffected by treatment. It is concluded that cetobem. s.r. can be given every 12 h to cancer patients with chronic pain with satisfactory analgesic effect, a very modest change in side-effect profile and no significant effects on vital signs when substituting cetobem. s.r. for Ketogan tablets in equal daily doses.


Effects of nilvadipine on the cardiovascular responses to tracheal intubation.

To evaluate the efficacy of nilvadipine given orally in attenuating the hypertensive response to laryngoscopy and intubation. Controlled, randomized, double-blind study. Induction of anesthesia for elective surgery at a university hospital. Thirty normotensive patients (ASA physical status I) undergoing elective surgery were divided into three groups of ten patients each. Either 2 mg of nilvadipine, 4 mg of nilvadipine, or a placebo (control) was administered orally 90 minutes before induction of anesthesia. Anesthesia was induced with thiopental sodium 5 mg/kg intravenously, and tracheal intubation was facilitated with vecuronium 0.2 mg/kg. During anesthesia, ventilation was assisted or controlled with 1% enflurane and 50% nitrous oxide (N2O) in oxygen. Laryngoscopy lasting 30 seconds was attempted 2 minutes after administration of thiopental sodium and vecuronium. Patients receiving the placebo showed a significant increase in mean arterial pressure (MAP) and heart rate associated with tracheal intubation. The increase in MAP following tracheal intubation was significantly lower in nilvadipine-treated patients than in the control group (p less than 0.05). However, neither dose of nilvadipine attenuated the tachycardic response to intubation. Oral administration of nilvadipine before induction of anesthesia is a simple and practical method for attenuating pressor response to laryngoscopy and tracheal intubation after standard elective induction under additional 1% enflurane-N2O anesthesia.


Partial attenuation of the cardiovascular responses to tracheal intubation with oral nisoldipine.

To evaluate the efficacy and safety of nisoldipine given orally in attenuating the cardiovascular responses to laryngoscopy and tracheal intubation. Randomized, double-blind, placebo-controlled study. Induction of anesthesia for elective surgery at a university hospital. Thirty normotensive patients (ASA physical status I) undergoing elective surgery were assigned to one of three groups; placebo, nisoldipine 5 mg, or nisoldipine 10 mg. Each group consisted of ten patients. Either 5 mg of nisoldipine, 10 mg of nisoldipine, or a placebo was administered orally 2 hours before induction of anesthesia. Anesthesia was induced with thiopental sodium 5 mg/kg intravenously, and tracheal intubation was facilitated with vecuronium 0.2 mg/kg. During anesthesia, ventilation was assisted or controlled with 1% enflurane and 50% nitrous oxide in oxygen. Laryngoscopy lasting 30 seconds was attempted 2 minutes after administration of thiopental sodium and vecuronium. Patients receiving the placebo showed a significant increase in mean arterial pressure associated with tracheal intubation. These increases following tracheal intubation were significantly reduced in patients receiving nisoldipine 10 mg compared with patients receiving the placebo (p less than 0.05). Oral administration of nisoldipine before induction of anesthesia is a simple, practical, and safe method for attenuating pressor response to laryngoscopy and tracheal intubation.


Effect of esmolol on hemodynamics and intraocular pressure response to succinylcholine and intubation following low-dose alfentanil premedication.

To determine the effectiveness of esmolol hydrochloride (Brevibloc) as an additional adjunct to low-dose alfentanil premedication in controlling the hemodynamic response [heart rate (HR), mean arterial pressure (MAP), and intraocular pressure (IOP)] to succinylcholine and endotracheal intubation. Randomized, double-blind, placebo-controlled, prospective study. Ambulatory gynecologic surgery at a university medical center. Twenty ASA physical status I and II female patients scheduled for outpatient laparoscopy under general anesthesia. All patients received alfentanil 10 micrograms/kg as a preoperative medication 4 minutes prior to induction of anesthesia. Study patients (n = 10 in each group) received either esmolol 1.5 mg/kg or a placebo (normal saline) 30 seconds prior to induction (210 seconds after alfentanil and 90 seconds prior to endotracheal intubation). Anesthesia was induced with thiopental sodium 5 mg/kg and succinylcholine 1 mg/kg. Postintubation, 70% nitrous oxide, 30% oxygen, and 1% isoflurane were administered. Time of study drug administration was defined as time zero. Measurements of HR, MAP, and IOP were made at baseline (patient awake) and at each minute from minutes 1 through 6 after administration of the study drug (time zero). Analysis of variance was used to analyze the data, with a value of p less than 0.05 considered significant. Esmolol 1.5 mg/kg was found to blunt the maximum increase in HR but not MAP or IOP following low-dose alfentanil premedication. In an eye patient with coronary artery disease, or in any patient in whom tachycardia may be detrimental, esmolol may be a useful adjunct in combination with low-dose alfentanil to attenuate the increase in HR due to laryngoscopy and endotracheal intubation.


Central nervous system side-effects of antihistamines in schoolchildren.

There are no studies available in the literature on the effects of classical antihistamines on the central nervous system (CNS) in children. Clinical studies indicate that somnolence occurs more often with classical antihistamines than with placebo. There is no difference in inducing somnolence in children between placebo and astemizole or terfenadine, two new antihistamines that have thoroughly been shown to have no sedative effect greater than placebo in adults. A double-blind, cross-over trial investigating the CNS-effects of astemizole and chlorpheniramine in schoolchildren failed to show a negative effect of either of these drugs on performance.


Propofol in patients susceptible to malignant hyperthermia: a case report and review of the literature.

Propofol is an intravenous (IV) drug recently introduced into the United States for induction and maintenance of anesthesia. In spite of extensive laboratory evaluation, it is not possible to predict all the potential side effects that might be associated with a new drug. Because malignant hyperthermia (MH) remains a serious and potentially life-threatening complication of anesthesia, all new anesthetic drugs should be considered potential triggering drugs until proven otherwise. We report the use of IV propofol for the induction and maintenance of general anesthesia in an MH patient and review the literature on this subject.


Levocabastine: a new topical approach for the treatment of paediatric allergic rhinoconjunctivitis.

Levocabastine is a novel H1-receptor antagonist for topical use, which is being investigated in allergic rhinitis (nasal spray) and conjunctivitis (eye drops). Its anti-allergic effects have been demonstrated in nasal and ocular provocation tests. Clinical studies have been performed in 1,363 patients with allergic rhinitis and 1,218 patients with allergic conjunctivitis, comparing levocabastine mainly to placebo and cromoglycate. Levocabastine was effective when used at a dose of 2 sprays per nostril or 1 drop per eye twice daily, which if necessary can be increased up to four times daily. Levocabastine was superior to placebo in alleviating symptoms such as sneezing, itchy nose, runny nose, itchy eyes, red eyes and lacrimation. In global evaluations some 60% of patients had good to excellent results with the nasal spray and some 75% with the eye drops. Levocabastine was shown to be as good or even slightly better than cromoglycate. Onset of action was fast, with 73% of patients reporting symptom relief within 30 min after administration of levocabastine nasal spray. Adverse experiences were similar in type and incidence with levocabastine, cromoglycate and placebo, for nasal spray as well as eye drops. The most frequent complaints were nasal and ocular irritation, respectively, with a similar incidence for the three drugs. Limited data are available in children so far, but they indicate response rate and adverse-experience profile to be similar to what was observed in adults. Levocabastine, thus, is an interesting new antihistamine available for topical use in allergic rhinoconjunctivitis. It has been extensively evaluated in adults, and preliminary data indicate that it can also be useful in allergic children.


New strategies for the prevention and treatment of allergic rhinitis in children.

Allergic rhinitis (AR) is a very common disease in children, often underdiagnosed and with underestimated complications. Its prevalence has increased during the last years, due to changes in environmental factors. The therapeutic strategy will include prevention by identification and eviction of the main allergens, associated to pharmacological therapy. Among antirhinitic drugs, the new generation of non-sedative specific antihistamines represent the main choice. We report our own experience with astemizole, one of these new antihistamines which confirms that astemizole is an effective and safe drug for the management of AR in children.


The role of ecotoxicology in the assessment of human exposure to chemical substances.

In the late 1970s new legislation was established in many industrialized countries in order to protect the environment. This has led to the definition of a new branch of science: ecotoxicology. The development of predictive approaches for the hazard assessment of chemical substances has given increased relevance to exposure evaluation. This paper discusses the problems related to the environmental distribution and fate of chemicals and their potential use in the assessment and prediction of exposure of the general population, through air, drinking water and food. Collaboration between toxicologists and ecotoxicologists is urged to improve our capability to manage chemicals.


Determination of heavy metals in human liver.

The levels of Cr (2.49 +/- 0.89 ppm), Mn (5.08 +/- 1.60 ppm), Ni (1.81 +/- 0.95 ppm) and Pb (4.43 +/- 3.12 ppm) were measured in dessicated liver from 44 cases of sudden traumatic death considered as representative of the general population in our area, after ruling out the presence of any underlying disease. Atomic absorption spectrophotometry and electrothermal atomization was carried out after hot, acid digestion, of the dessicated samples. After cancelling the influence of age and cause of death, a significant, positive correlation between Cr/Mn (P = 0.0009; R = 0.493) and Cr/Ni (P = 0.0245; R = 0.347) levels was found.


Arsenic-copper interaction in the kidney of the rat.

1. The interaction between As and three toxic metals (Cd, Ni and Pb) and Cu (an essential trace metal) in the kidney was investigated in the rat by feeding diets containing various concentrations of As whilst maintaining constant concentrations of the other elements. After 1, 3, 7 and 15 weeks of feeding, metal contents in the renal cortex and medulla, red blood cells and plasma were determined by atomic emission spectrometry (ICP-AES). 2. As accumulated in the whole kidney, whereas Cu accumulated only in the cortex. Accumulation of Cu was found to depend on the feeding period and dietary As concentration. 3. As was also accumulated in red blood cells, where saturation was found at 550 micrograms As g-1 cells. 4. Although Cd was also accumulated in the cortex, its accumulation was independent of the dietary As concentration. Ni and Pb were not detected by ICP-AES. 5. Chromatography of the supernatants from cortical homogenates of control and As-treated rat kidney suggested that Cu accumulated in renal metallothionein (MT). Its accumulation in this fraction was independent of that of Cd, indicating that the As-Cu interaction was not a result of MT induction, but rather that it might result from altered renal handling of Cu with subsequent incorporation into MT.


Chronic exposure to n-hexane induces changes in nerve-specific marker proteins in the distal peripheral nerve of the rat.

1. After long-term n-hexane exposure (2000 ppm, 12 h d-1, 6 d week-1, for 24 weeks), the content of neuron-specific enolase (gamma-enolase), creatine kinase-B and beta-S100 protein in the cortex, cerebellum, spinal cord and proximal and distal sciatic nerves of rats was determined by enzyme immunoassay. 2. The amounts of the three proteins decreased significantly in the distal segment of sciatic nerve, whereas they remained unchanged in the brain and proximal sciatic nerve. The quantitative decline in these marker proteins in the distal sciatic nerve could be related to neurophysiological deficits in the peripheral nerves. 3. This study indicates that the biochemical changes observed are consistent with the clinical and pathological findings of n-hexane neuropathy. These nerve-specific marker proteins can be used to assess solvent-related peripheral neurotoxicity.


Aspects of orthodox medicines (therapeutic drugs) poisoning in urban Zimbabwe.

1. A retrospective study (extending over 10 years, 1980 to 1989 inclusively) of hospital admission cases, due to therapeutic drug poisoning was carried out at the six main hospitals of Zimbabwe's four cities. 2. The four cities have a total population of approximately 4 million. 3. A total of 1061 cases were recorded and analysed. This constituted 16.7% of all poisoning admission cases (i.e. the fourth biggest cause of poisoning after traditional medicines, household chemicals and snake/insect venom). 4. Of the 1061 cases, 31% were aged 21-30 years, 21.9% were aged 11-20 years, 14.9% were aged under 5 years and 12.8% were aged 31-40 years. Those aged over 80 years accounted for only 0.6% of the cases. 5. The major groups of drugs implicated were: the analgesics, 22% of the total; sedatives and hypnotics, 13.2%; antipsychotics, 11.6%; antimalarials, 9.3%; antidepressants, 9.0%; antimicrobials, 7.5%; and alcohol, 7.1%. The other drugs each accounted for the less than 7%; the least used group were the gastrointestinal drugs which formed only 0.6% of the total. Poisoning due to drug abuse was cited at 1.3%. Overdose, either accidental or in the course of treatment, accounted for 63.5% of the cases. 6. The mortality rate was 3.9% and most of the deaths were suicides. 7. Treatment consisted mainly of the administration of ipecacuanha in those under 5 years old age and supportive therapy in adults. A few cases were given an antidote if it was specifically indicated.


A pattern of acute poisoning in children in urban Zimbabwe: ten years experience.

1. A retrospective analysis was performed to evaluate the epidemiology of poisoning in children based on admissions to six of Zimbabwe's main urban hospitals over a 10-year period from 1980 to 1989 inclusive. 2. A total of 2873 cases were children aged between 0-15 years. This constituted 47.8% of poisoning cases from all age groups (6018) recorded during the study period. 3. All of the children (0-15 years) had signs and symptoms of poisoning on admission and, depending on their severity, were admitted to a ward or to an intensive care unit. A total of 4.9% (141) died. Most of those who died were suicide cases among the 11-15 year age group and accidental poisonings among the 0-15 year old group. 4. The under 0-5 age group constituted the majority of cases (75.4%) in the 0-15 age group, and most were between 1 and 3 years old. The 6-10 and 11-15 age groups formed 12.6% and 12% of the cases, respectively. The sex distribution showed that 53.1% were male. 5. Most incidences were accidental (93.2%). Suicides and parasuicides accounted for 1.9% and there were only two homicides. 6. The commonest toxic agents were: household products (27.2%), traditional medicines (23.%), venoms from snake bites and insect stings (16%) and therapeutic agents (12.4%). Of the therapeutic agents the most frequently implicated were antipsychotics 18.9%, analgesics 16.8%, anti-infectives 11.7%, anticonvulsants (8.2%) and benzodiazepines (7.7%).(ABSTRACT TRUNCATED AT 250 WORDS)


Individual differences in activity of glutathione peroxidase and catalase studied in monozygotic twins discordant for smoking.

1. Cigarette smoke contains free radicals. The enzymes glutathione peroxidase (GSH-px) and catalase are important parts of the anti-oxidative protecting system. 2. Ten pairs of monozygotic twins, who were discordant for smoking, were analysed in order to determine their erythrocyte glutathione peroxidase and catalase activities and their plasma concentrations of selenium. 3. Analysis of variance (ANOVA) revealed that the difference in activities of catalase and glutathione peroxidase was much less within pairs than between pairs, indicating a large individual variation due to genetic expression or shared environment and no major effect from smoking. 4. The plasma selenium levels of the investigated twins revealed sufficient intake of selenium to maintain maximal activity of GSH-px in erythrocytes. The mean +/- s.d. selenium concentration in plasma for smokers was 98 +/- 16 micrograms l-1 and for non-smokers 111 +/- 16 micrograms l-1. There was no correlation between plasma selenium and glutathione peroxidase in erythrocytes.


Sudden infant death syndrome (SIDS) and the toxic gas hypothesis: microbiological studies of cot mattresses.

1. Fifty infants' mattresses were studied to investigate the occurrence of viable fungal and bacterial propagules, with particular reference to Scopulariopsis brevicaulis which had been suggested to be implicated in SIDS cases. A total of 19 SIDS cases mattresses, 1 non-SIDS death, 20 used controls, and 10 new unused controls were examined. 2. Differences were found between SIDS and used controls in the variety of fungal species isolated and the numbers isolated from fillings; bacterial numbers were similar. 3. S. brevicaulis was isolated from only four mattresses, three of which were SIDS cases. It was not found in most of those on which death had occurred. 4. A number of potentially pathogenic or allergenic fungi, including Aspergillus fumigatus, were isolated more frequently from SIDS cases mattresses than new or used controls. 5. Scanning electron microscopy of mattress covers and fillings showed microbial 'biofilms' in the head areas of all SIDS cases examined. This was not seen on other samples. 6. The limited number of mattresses studied and the use of unmatched controls precludes the drawing of any general conclusions as to the significance of the biofilms or other fungi isolated. 7. Reports of the existence of a dimorphism in general growth forms of S. brevicaulis were investigated by growing and transferring authentic strains between a variety of growth media. 8. No 'slimy' state of this fungus was observed and dimorphism was not confirmed.


Lack of acipimox-digoxin interaction in patient volunteers.

1. A study was carried out to find out if digoxin and acipimox interact. 2. Six elderly patients on digoxin were each given acipimox 150 mg three daily for a week, after informed consent. Digoxin and acipimox plasma concentrations and urinary excretion were measured after the first dose of acipimox and after a week of treatment. 3. Data were fitted to a one-compartment oral absorption model. Areas under the plasma concentration-time curve, plasma and renal clearances, and elimination half-life were computed. 4. There was no significant difference in digoxin plasma concentrations and kinetic parameters before and after acipimox administration. Acipimox kinetics were not affected by the concomitant ingestion of digoxin. 5. The patients' clinical condition remained stable during the study. 6. Thus there was no evidence for an adverse interaction between digoxin and acipimox in human subjects under the conditions of this study.


Persistence of metaldehyde during acute molluscicide poisoning.

A case is presented in which a 37-year-old man took an overdose of Slugit, liquid containing metaldehyde. Significant concentrations were found in his serum and urine for several days afterwards. Acetaldehyde and ethanol were not detected. The significance of these findings is discussed.


Determination of amitriptyline in the hair of psychiatric patients.

A study was conducted on 60 psychiatric patients to evaluate the reliability of a drug-exposure screening test based on gas chromatography/mass spectrometry analysis of hair samples for amitriptyline, and the possibility of using the hair concentrations of amitriptyline to monitor patients' therapeutic compliance. The qualitative test was found to be very reliable (sensitivity 93.3%; specificity 100%; positive and negative predictive values 100 and 93.8%) in assessing the consumer status of patients over a period of 2 months before analysis. Hair levels of amitriptyline ranged from 0 to 17.21 ng mg-1. A significant relationship (r = 0.563; P < 0.002) was found between the hair concentrations and the cumulative intake of amitriptyline over the studied period, but was not judged close enough to estimate one individual's therapeutic compliance. The results are discussed in the light of existing literature.


Flow cytometric characterisation of proliferating cell nuclear antigen using the monoclonal antibody PC10.

Anti-PCNA antibodies have aroused considerable interest recently as potential immunohistochemical markers of proliferation for use on clinical samples. PC10 is a monoclonal antibody which has been shown to recognise its epitope on formalin-fixed, paraffin-embedded, archival material. However, whilst PC10 gives the expected labelling pattern for growth fraction in normal tissues and some tumours, discrepant results have been obtained, for example, in carcinoma of the breast. By means of flow cytometry, we have attempted to characterise the different staining patterns that can be obtained with PC10. Intact fixed cells from proliferative mammalian cultures show 100% labelling, consistent with a growth fraction estimate. In contrast, detergent-extracted nuclei show S-phase specific staining. Nuclei extracted by treatment of fixed cells with pepsin show a different staining pattern again, with many G1 cells weakly stained and staining intensity increasing through S-phase into G2. The results demonstrate that multiparametric flow cytometry can define the cell populations which label with proliferation-related antibodies, such as PC10, under a variety of experimental conditions.


Assessment of bronchial effects following topical administration of butylamino-phenoxy-propanol-acetate, an oculoselective beta-adrenoceptor blocker in asthmatic subjects.

1. Butylamino-phenoxy-propanol-acetate (BPPA) is a new topical oculoselective beta-adrenoceptor blocker for the reduction of intraocular pressure (IOP) in man. Its potency on the airways of normal subjects was identical with that of placebo. A study was carried out to determine the potential of BPPA to cause bronchoconstriction in mild asthmatics (FEV1 greater than or equal to 60% predicted) with normal IOP. 2. Twelve nonsmoking outpatients who bronchoconstricted to 0.25 or 0.50% of timolol eye drops (fall in FEV1 23.33 +/- 1.20% (mean +/- s.e. mean), range 16-30) were investigated in this double-masked, randomized, 3-period, crossover study. On three different occasions six incremental concentrations of BPPA (range: 0.1-2%; maximum cumulative concentration 4%), timolol (0.1-1%; 2%), and placebo were administered bilaterally until bronchoconstriction (decrease in FEV1 greater than or equal to 20% and in specific airway conductance (sGaw) greater than or equal to 35% simultaneously) or the maximum cumulative concentration was reached. 3. Airway response was measured as change in FEV1 and sGaw and dose-response curves to timolol, BPPA and placebo were performed. IOP was measured 3 h after the highest concentration of each study day. 4. Timolol caused dose-dependent falls in FEV1 and sGaw as well as clinical symptoms of respiratory distress in all subjects. The median cumulative concentrations of timolol required to decrease FEV1 by 20% and sGaw by 35% were 0.98% and 1.53%. Neither placebo (P greater than 0.05) nor BPPA (P greater than 0.05) caused a significant change in sGaw. A fall in FEV1 by 20% not accompanied by a simultaneous fall in sGaw by 35% was found in four subjects following BPPA and in five subjects following placebo.(ABSTRACT TRUNCATED AT 250 WORDS)


Beta blockers and quality of life.

Hypertension is an asymptomatic conditions which can be life threatening. It is thus important that hypertensive patients maintain compliance with their therapy. This can be put at risk if the patient experiences adverse affects or if the patient's lifestyle is significantly altered in some way. The ability to perform daily activities and derive satisfaction is referred to as quality of life. With this in mind the published literature is reviewed here with regard to comparative studies involving beta-blockers. The balance of the evidence reviewed indicates that there are differences in quality of life between ACE inhibitors and the non-selective, lipophilic beta blocker, propranolol, favouring the former. However, this is clearly not a class difference as atenolol, which is beta 1 selective and hydrophilic, results in a similar quality of life profile to that with either captopril or enalapril. This difference between atenolol and propranolol probably arises out of their differing pharmacology, as opposed to any fundamental difference in their blood pressure lowering ability. There are probably too few studies to compare beta blockers and either calcium antagonists or diuretics definitively with regard to quality of life. What little evidence there is suggests a difference between propranolol and verapamil, with the latter giving the better quality of life. However, no difference was observed between verapamil SR and atenolol. Although data are very limited it appears that atenolol impacts more favourably than thiazide diuretics.


c-erbB-2 positive breast tumours behave more aggressively in the first years after diagnosis.

In a retrospective study the expression of the c-erbB-2 oncogene was determined immunohistochemically in 276 breast cancer samples from 253 patients with the antibody 21N. The follow-up period was between 7 and 12 years. This study showed a trend for an inverse relationship between c-erbB-2 positive tumours and estrogen receptors (ER). A correlation was assessed between c-erbB-2 positive tumours and histological grade, liver metastases as first site of metastases, disease free survival time (DFS) in the second and third year after diagnosis and overall survival time (OST) in the third and fourth year after diagnosis. A trend was seen between c-erbB-2 positive tumours and tumour size. No correlation was found between c-erbB-2 positive tumours and age at diagnosis. The method of operation and lymph node involvement. From this study we conclude that there is a significant difference in prognosis the first years after diagnosis, but this difference seems to vanish in a longer follow-up period of 12 years. This provides us with an explanation for the discrepancies in literature concerning c-erbB-2 expression and prognosis in breast cancer. Some investigators did not show differences in prognosis between positive and negative cases after a long follow-up period whereas investigations with a short term follow-up period up to 2-3 years have indeed established a more aggressive behaviour of c-erbB-2 overexpressionary tumours.


Adhesion of Salmonella typhimurium var. copenhagen in the intestines of pigeons.

The attachment of Salmonella typhimurium var. copenhagen to the intestinal epithelium of pigeons was studied. After experimental infection, the intestines of both young and adult pigeons were examined in vivo and in vitro. Investigations were carried out by electron and immunofluorescence microscopy. Attachment of the Salmonella strain to duodenal epithelium was established. Following repeated washing after inoculation, bacterial cells could be seen by SEM and TEM in association with the surface structure of the tissue. The adhesive properties of fimbriae, which are also involved in haemagglutination, could be demonstrated.


Proliferating cell nuclear antigen (PCNA) as a prognostic factor in non-Hodgkin's lymphoma.

The prognostic value of immunoperoxidase staining for proliferating cell nuclear antigen (PCNA) was studied in a series of 140 non-Hodgkin's lymphomas with median follow-up of 9 years. Lymphomas where > 50% of cells showed positive staining for PCNA had inferior 5-year survival as compared with those with less than 50% of positive cells (57% vs 41%, P = 0.008). The presence of > 50% of positively staining cells for PCNA was strongly associated with a larger than the median size of the SPF (median, 8.3%), and high histological grade of malignancy (P < 0.0001 for both). Lymphomas with both a large percentage (> 50%) of PCNA positive cells and a larger than the median SPF had inferior outcome as compared with lymphomas where either one or both of these factors were small. Although PCNA staining was not an independent prognostic factor in a multivariate analysis, it appears to be supplementary to the SPF even if determined from old paraffin-embedded tissue material.


Restriction fragment length polymorphism analysis of Listeria monocytogenes and its application to epidemiological investigations.

The restriction fragment length polymorphisms (RFLPs) of 64 random and potentially related strains of Listeria monocytogenes were analysed and compared using a probe comprised of two L. monocytogenes chromosome fragments cloned into a lambda vector. Twelve RFLP types were defined using 14 isolates of clinical origin, 42 food isolates and eight food associated environmental strains. Of the RFLP types, some were common to a particular serovar and source, whereas others were widespread amongst all serovars and sources. One of the two most common RFLP patterns was associated with serovar 1/2 isolates from food or the environment, whereas another dominant pattern was associated most commonly with serovar four isolates from all sources. The potential relationships between epidemiologically related strains were examined, with the analysis of types from a suspected listeriosis outbreak, from clinical maternal-foetal cases, and from an ice-cream factory environmental study. Serotyping alone was not a sufficient marker for the comparison of these strains whereas further discrimination of strains was possible with RFLP analysis.


The effect of therapeutic drugs used in inflammatory bowel disease on the incidence and growth of colonic cancer in the dimethylhydrazine rat model.

An increased incidence of colonic cancer is associated with chronic inflammatory bowel disease. Sulphasalazine, metronidazole and more recently, modified forms of 5-aminosalicylic acid are used for maintenance therapy of inflammatory bowel disease. In a series of experiments, we used the 1,2-dimethylhydrazine animal model of colonic cancer in conjunction with these drugs, to study the effect on the development of colon cancer. Inbred male Wistar rats were divided into groups receiving orally: metronidazole 18 mg Kg-1 dy-1; sulphasalazine 60 mg Kg-1 dy-1; 5-aminosalicylic acid 30 and 60 mg Kg-1 dy-1 and olsalazine 60 mg Kg-1 dy-1 administered daily. Half of each group also received weekly injections of DMH 40 mg Kg-1. Metronidazole, sulphasalazine and 30 mg Kg-1 dy-1 5-aminosalicylic acid were co-carcinogenic, increasing either the number of cancers or tumour size. In contrast 60 mg Kg-1 dy-1 5-aminosalicylic acid inhibited tumour size and olsalazine had no effect. These results may have a bearing on long term maintenance therapy in inflammatory bowel disease.


A comparison of membrane properties and composition between cell lines selected and transfected for multi-drug resistance.

Cell lines selected (CHRC5) and transfected (LR-73-1A) for multi-drug resistance have total lipid compositions which are indistinguishable between resistant and parental cells. Lipid composition was evaluated by 1H NMR and the total fatty acid content by GLC. No change in surface hydrophobicity, as measured with the fluorescent probe dansyl-PE, was observed as a result of transfection of CHO cells with the mdr1 gene. However, the selected cell line, CHRC5, showed a decreased surface hydrophobicity. This decreased surface hydrophobicity was indicated by an 8 nm increase in the fluorescence emission of dansyl-PE in the CHRC5 cell line compared with the AB1. Both resistant cell lines showed an increase in the polarisation of the fluorescent probe, TMA-DPH in the plasma membranes corresponding to a 14% and a 24% change in fluorescence polarisation for the selected and transfected cell lines, respectively. This is indicative of reduced mobility of the acyl chains in the resistant cell lines. Both the CHRC5 and the transfected cell lines showed almost a 2-fold increase in the initial rate of membrane cycling. The membrane cycling could be inhibited by a known bilayer stabiliser, the N-carbobenzoxy-D-Phe-L-Phe-Gly. These results indicate that the properties of the plasma membrane from resistant cells are altered compared with their parental cell line.


Tumour-associated hypoglycaemia in a murine cachexia model.

Animals bearing a cachexia-inducing tumour, the MAC16 adenocarcinoma, showed a progressive decrease in blood glucose levels with increasing weight loss, while animals bearing a histologically similar tumour, the MAC13 adenocarcinoma, showed no change in either body weight or blood glucose levels with growth of the tumour. The effect of the MAC16 tumour on blood glucose levels appeared to be unrelated to food intake, glucose consumption by the tumour, or to the production of increased levels of IGF-I and IGF-II mRNA by the tumour cells. The relationship between the induction of cachexia and alteration in blood glucose levels remains unknown.


High-dose tamoxifen as an enhancer of etoposide cytotoxicity. Clinical effects and in vitro assessment in p-glycoprotein expressing cell lines.

Twenty-six patients with relapsed or drug-resistant cancer were treated with a combination of oral etoposide (300 mg day-1 for 3 days) and high-dose oral tamoxifen as a potential modulator of drug resistance (480 or 720 mg day-1 for 6 days beginning 3 days before etoposide). One patient with relapsed high-grade lymphoma and one with adenocarcinoma of unknown primary site has a partial response. Toxicity consisting of nausea, vomiting and subjective dizziness, unsteadiness of gait and malaise occurred during tamoxifen treatment. Serum levels of tamoxifen averaged 3-3.5 microM on day 4 of all courses of treatment at both 480 and 720 mg day-1. N-desmethyltamoxifen levels were lower than tamoxifen during the first course (2 microM) but increased to equal tamoxifen levels during the second course. Didesmethyltamoxifen levels remained below 1 microM. In vitro, both tamoxifen and the standard modulator of multidrug resistance, verapamil, produced minor enhancement of etoposide cytotoxicity in the MCF-7 wt cell line but produced no enhancement with any other cell line. High, intermittent doses of tamoxifen can be given with acceptable toxicity and produce serum levels that have been shown to modulate drug resistance in vitro. In vitro, however, such levels have no significant effect on etoposide cytotoxicity towards a range of wild-type and MDR cell lines.


Beta-thalassaemia minor and porphyria cutanea tarda.

A case of porphyria cutanea tarda occurring in association with beta-thalassaemia minor is reported in a 33-year-old Northern-Irish woman. Aetiological factors in this case included oral and parenteral iron therapy for refractory anaemia which was subsequently diagnosed as beta-thalassaemia minor, and the use of an oestrogen-containing oral contraceptive pill.


Inhibition of chick embryo lysyl oxidase by various lathyrogens and the antagonistic effect of pyridoxal.

Lysyl oxidase, which cross-links collagen and elastin, was obtained from chick embryo bone and cartilage and its substrate, elastin, from aorta. The enzyme was studied using an improved assay which enabled the stability of the substrate to be monitored. The enzyme was fully inhibited in vivo by beta-aminopropionitrile, semicarbazide, thiosemicarbazide and isoniazid and in vitro by beta-aminopropionitrile and semicarbazide but only partially by thiosemicarbazide and isoniazid. Penicillamine, which solubilizes collagen by labilizing Schiff base cross-links in vivo and which prevents stable cross-link formation in vitro indirectly by binding to aldehyde groups on collagen, was shown to have no direct inhibitory effect on lysyl oxidase in vivo or in vitro. Homocysteine, which also solubilizes collagen by a mechanism similar to penicillamine does not inhibit lysyl oxidase either in vivo or in vitro. Pyridoxal reversed the inhibition of lysyl oxidase by semicarbazide and isoniazid in vivo but was unable to reverse that produced by either beta-aminopropionitrile or thiosemicarbazide. These results can be explained by the presence of a sulphydryl group near the active site of lysyl oxidase, which can form a complex with the nitrile group on beta-aminopropionitrile or with the thiol group on thiosemicarbazide leading to irreversible inhibition.


Detection of activity of P-glycoprotein in human tumour samples using rhodamine 123.

Based on the fluorescent properties of the dye rhodamine 123 (Rh123), which is transported by the membrane efflux pump P-glycoprotein (P-gp), we developed a functional flow cytometric assay for the detection of multidrug-resistant (MDR) cells. Using drug sensitive cell lines (KB-3-1) and MDR mutants (KB-8-5, KB-C1) experimental conditions were established that enabled demonstration of significant differences in Rh123 efflux and accumulation. Subsequently we investigated the applicability of this functional assay for the prediction of MDR in human peripheral blood and bone marrow samples. Using two-colour flow cytometry, the leukaemic blast cells of six patients suffering from acute myeloid leukaemia (AML) were analysed. In three cases the blast cells showed a rapid and marked Rh123 efflux. In the presence of MDR inhibitors these cells retained Rh123. To determine whether the efflux of Rh123 was associated with P-gp expression, the leukaemic cells were stained with the monoclonal antibody MRK-16. In addition extracted RNA was analysed by polymerase chain reaction to evaluate the expression of mdr 1 mRNA. In all three Rh123+ cases mdr 1 mRNA was detectable whereas only one AML case expressed P-gp. In comparing Rh123 with daunorubicin, which also allows the detection of MDR cells, accumulation studies proved Rh123 to be the more sensitive drug for flow cytometric MDR screening. Additionally, two-colour flow cytometry was much easier to perform with Rh123 than with daunorubicin. Our results indicate that flow cytometric measurement of Rh123 accumulation/efflux proves applicable to detect MDR cells in heterogenous clinical samples.


Activin A induced expression of a fork head related gene in posterior chordamesoderm (notochord) of Xenopus laevis embryos.

A gene family encoding the fork head/HNF-3 domain has been identified in the South African clawed frog, Xenopus laevis. Screening of genomic DNA and gastrula stage derived cDNA libraries with a DNA fragment encoding the Drosophila fork head domain led to the isolation of a number of different clones encoding this motif. While one of the Xenopus fork head sequences, XFD-3, represents the Xenopus counterpart to rat HNF-3 beta, all other sequences encode novel types of fork head related proteins. Here we report on XFD-1, a DNA binding protein which can bind to the HNF-3 alpha target sequence. Analysis of temporal and spatial expression revealed that the gene is activated at blastula stage and that transcripts are localized in a rather thin stripe of cells invaginating the dorsal blastopore lip (organizer) during gastrulation. XFD-1 mRNA is localized within the notochord and, by the end of neurulation, is no longer detectable. In the animal cap assay the gene is activated by incubation with the vegetalizing factor (activin A) but not with bFGF.


Comparison of two molecular weight markers used in DNA-profiling.

DNA-profiling was performed on DNA from human blood samples. Restriction was performed with HinfI and the fragments were analysed with the single locus probes MS1, MS31, MS43a, and YNH24. Calculations of the sizes of DNA-fragments in the range from 1.4 to 22 kilobase pairs (kb) were performed with two different size markers: the Amersham marker SJ5000 and the Gibco BRL marker 4401SA. The standard deviation of the difference between duplicate determinations was significantly lower with the Gibco BRL marker than with the Amersham marker. Calculation of the fragment lengths with the two markers differed significantly, especially in the high molecular weight region (> 8 kb). Fragment lengths were 3-8% (kb) higher with the Amersham marker than with the Gibco BRL marker which corresponds to a difference of 1.0-1.8 mm in migration distance. The difference was enhanced in the presence of ethidium bromide. The consequences of the replacement of the Amersham marker by the Gibco BRL marker in practical casework is discussed.


pMCT 118 (D1S80): a new allelic ladder and an improved electrophoretic separation lead to the demonstration of 28 alleles.

Population data studies carried out on caucasians from Northwest Germany (n = 218) using the AMPFLP system pMCT 118 (D1S80). The method used in a previous study (Rand et al. 1992) for pMCT 118 could be improved by increasing the electrophoretic separation length from 10 to 20 cm and by using an extended allelic ladder which allowed the distinction of 8 additional alleles (a total of 28 alleles). Out of the 8 additional alleles 5 could be differentiated which differed within the 16 bp repeat sequence. The allele frequencies found were compared to population data from American caucasians, Hispanics and black Americans (Eisenberg and Maha 1991). All populations with the exception or black Americans, showed good agreement.


Severe psychosis and the adrenal androgens.

Past literature suggests a link between certain psychotic states and adrenal androgen production, including Dehydroepiandrosterone (DHEA). A group of severely psychotic androgenized females, refractory to substantial amounts of neuroleptics, has been identified for whom endocrine testing revealed abnormally high levels of DHEA. A similar group has been identified among the severely psychotic male population. Improvement in psychosis appears to occur as DHEA returns to its normal range using standard low dose Dexamethasone suppression.


A ligand for the erbB-2 oncogene product (gp30) induces differentiation of human breast cancer cells.

The human erbB-2 oncogene encodes a tyrosine kinase receptor. A ligand for the erbB-2 receptor (gp30), with an apparent molecular weight of 30,000, was reported to modulate the growth of cells overexpressing erbB-2. Whereas low concentrations of gp30 induced proliferation of these cells, higher concentrations inhibited their growth. To elucidate the cellular mechanisms underlying cell growth inhibition by gp30, we tested the effect of this ligand on cell growth and differentiation of the human breast cancer cells AU-565 and MDA-MB-453 (which overexpress erbB-2) and MCF-7 cells (which express low levels of this protooncogene). Ligand concentrations that inhibited growth in cells overexpressing erbB-2 induced apparent differentiation of cells with a more mature phenotype, i.e., with characteristics such as inhibited cell growth, altered cytoplasmic and nuclear morphology, and increased synthesis of milk components (casein and lipids). No significant effect of the ligand was observed in the human breast cancer cell line MCF-7. Concomitant with the induction of differentiation in AU-565 and MDA-MB-453 cells, the erbB-2 protein was translocated from membrane to the cytoplasm and perinuclear sites. These findings indicate that ligand-induced growth inhibition in cells overexpressing erbB-2 is associated with an apparent induction of differentiation.


Negative symptoms and EEG alpha activity in schizophrenic patients.

Quantitative analyses of electroencephalographic (EEG) recordings in schizophrenic patients have often demonstrated reduced alpha band (8-13 Hz) activity. However, this finding is not universal and there is some evidence that subgroups of schizophrenics may differ in overall or lateralized levels of EEG alpha activity. To investigate this issue, the authors examined relationships between clinical ratings performed at the time of EEG recording and resting alpha power and coherence in 14 medication free schizophrenic patients. Nine channels of previously recorded resting (eyes open) EEG were transformed to average reference prior to spectral analysis and transformed to source derivation prior to calculation of inter-electrode coherences. Patients were rated with the Brief Psychiatric Rating Scale (BPRS), from which subscales corresponding to negative symptoms, positive symptoms, paranoia, and anxiety/depression were derived. Ratings and EEG measures were also obtained on 10 of the schizophrenic patients after neuroleptic treatment. Multiple regression with repeated measures was used to examine the influence of the subscale scores on bilateral log alpha power and both within- and between-hemisphere alpha coherence at selected locations. Prior to treatment, negative symptoms varied inversely with alpha power (p < 0.02), within-hemisphere alpha coherence (p < 0.03), and between-hemisphere coherence (p = 0.053). The effect of negative symptoms on alpha power was bilateral, but the effect on within-hemisphere coherence tended (p = 0.053) to be right-sided. After treatment these relationships were no longer present. The possible implications of and the effects of drug treatment on an association between negative symptoms and reduced alpha activity are discussed.


EEG-brain mapping. A method to optimize therapy in schizophrenics using absolute power and center frequency values.

In this study EEG-spectral parameters like mean alpha-power values and center frequency values are computed as maps and compared using significant probability mapping. The parameters are used to describe changes of the functional state of the brain after neuroleptic depot injection (Haldol-Decanoate) in schizophrenic patients. The absolute alpha-power increased significantly (p < 0.01), especially within the first week after injection mostly in the left hemispheric regions. The center frequency decreased most significantly (p < 0.02) between the first and second week after haldol depot injection at the right occipital regions. Both parameters are efficient to describe functional changes correlated with clinical symptomatology, even 3-5 days earlier. Thus, EEG power and center frequency mapping can be used very efficiently to estimate the optimal time between sequential neuroleptic depot injections.


Abnormal premovement brain potentials in schizophrenia.

We assessed scalp-recorded movement related potentials (MRPs) generated prior to voluntary movements in chronic, medicated schizophrenics (n = 9) and age matched normal controls (n = 9). MRPs were recorded in a self-paced button press task in which subjects pressed a button with either their right, left or both thumbs (experimental condition I, II and III respectively). Controls generated a slowly rising readiness potential (RP) at about 1000 ms, a negative shift (NS') at about 450 ms and a motor potential (MP) at about 100 ms prior to movement. The initial MRP components (RP and NS') were reduced in schizophrenics indicating an impairment of the voluntary preparatory process in schizophrenia. Results of the present study indicate a similarity of MRP findings in schizophrenics and reported MRPs (Singh and Knight, 1990) in patients with unilateral lesions of the dorsolateral prefrontal cortex. These findings provide further support for frontal lobe dysfunction in schizophrenia.


Schizophrenia and porphobilinogen deaminase gene polymorphisms: an association study.

A genetic case-control study was conducted in a group of patients with schizophrenia (n = 67; DSM-III) and psychiatrically normal controls matched for ethnicity (n = 84), living in the same geographical area. Using three different DNA polymorphisms of the gene encoding porphobilinogen deaminase (PBGD), a candidate gene for schizophrenia, an association with schizophrenia could not be detected. No significant associations were detected even after sub-division of the cohort by ethnicity and by gender.


Gender differences in cognition in schizophrenia.

Gender differences in cognition were investigated in schizophrenic inpatients and outpatients using the Dementia Rating Scale. Females displayed greater impairment on Attention and Conceptualization than males. Gender interacted with patient group for construction: females performed worse than males among inpatients and better among outpatients. Results may be related to the atypically early age of onset of females relative to males; attention to sampling and selection biases is needed in evaluating gender differences in cognition in schizophrenia.


Clonal unresponsiveness results from an interaction between staphylococcal enterotoxin B and T cells expressing unexpected V beta elements.

The ability of staphylococcal toxins to stimulate large numbers of T cells has led to their designation as a superantigen. Previous studies have indicated that activation of T cells bearing particular V beta elements may be responsible for the toxic effects of these bacterial products. However, the widespread expression of functionally similar proteins by unrelated bacterial species suggests the possibility that these products may represent a successful microbial strategy for subversion of the host antibacterial response. We have examined the effects of the staphylococcal enterotoxin B (SEB) on T cell clones that express different V beta elements. We note that SEB stimulates clones bearing previously defined V beta elements to proliferate and to produce cytokines. In addition, we demonstrate that an interaction between SEB and the TCR of clones that express additional V beta elements, including V beta 2 and V beta 6, results in a sterile form of immunological activation. This activation phenotype is characterized by proliferation without detectable cytokine production and is followed by profound immunological unresponsiveness in vitro and in vivo. We propose that reduced levels of antibacterial responses resulting from this form of T cell unresponsiveness may account for the highly conserved expression of superantigens by diverse bacterial species.


Glycosylphosphatidyl inositol-linked membrane protein expression by intestinal intraepithelial lymphocytes.

Murine intestinal intraepithelial lymphocytes (ilEL) represent a heterogeneous population of cells which contains both TCR alpha beta+ and TCR gamma delta+ cells. In contrast to the TCR alpha beta+ cell population in peripheral lymphoid organs, the TCR alpha beta+ ilEL contain high numbers of Thy-1- cells. This negativity of ilEL for Thy-1, a glycosylphosphatidyl inositol (GPI)-linked membrane protein, is not the result of conformational changes of the Thy-1 molecule. The absence of Thy-1 on TCR gamma delta+ and a subset of TCR alpha beta+ ilEL is furthermore not caused by a general defect in the processing of GPI-linked proteins, since Thy-1- ilEL mainly express another GPI-linked protein, Qa-2. However, TCR alpha beta+ and TCR gamma delta+ ilEL are also virtually negative for two other members of this family of activation-associated GPI-linked proteins, Ly-6A and Ly-6C. This unusual pattern of GPI-linked protein expression on TCR+ ilEL may be related to differences in cellular activation and signal transduction pathways between TCR+ ilEL and regular peripheral T cells.


Do antigenic drift residues in influenza hemagglutinins of the H3 subtype qualify as contact sites for MHC class II interaction?

We have previously reported that a majority of hemagglutinin-specific and class II (Ak or Ad)-restricted T cell clones, elicited by natural infection with X31 virus (H3N2 subtype), focus on regions of the HA1 subunit that have featured in antigenic drift and exhibit extensive diversity in their ability to discriminate between variant viruses with amino acid substitutions in these sites. The structural basis for the loss of recognition of a major antigenic site, HA1 120-139, was investigated by (i) comparing the effects of amino acid substitutions in mutant hemagglutinins (HA1 129 Gly----Glu; 132 Gln----Glu; 135 Gly----Arg) with the corresponding substitutions in synthetic peptides or (ii) by assessing the effects of single amino acid substitutions (to Ala) in the alpha k chain (residues 50-79) on the ability of Ak transfectants to present peptides. Despite the failure to recognise mutant viruses, mutant peptides were recognised as efficiently as wild-type peptides in association with wild-type Ak. However, the mutant Ak transfectants identified a different set of alpha k residues (positions 56, 65, and 72) as being critical for presentation of mutant peptides. Taken together with our previous findings that defects in antigen presentation of mutant hemagglutinin are reversed by single substitutions in the alpha k chain (residues 56 and 62), it would seem that the antigenic drift residues in mutant hemagglutinins alter the profile of contact sites with class II.


Structural analysis of human anti-mouse H-2E xenorecognition: T cell receptor bias and impaired CD4 interaction contribute to weak xenoresponses.

T lymphocyte responses to the MHC of an evolutionarily distant species are known to be weak compared with responses against allogeneic MHC products within a species. This fact was used to examine the regions of human MHC class II molecules required for the stimulation of strong primary immune responses against MHC alloantigens. A panel of mouse DAP.3 transfectants expressing the products of wild-type and recombinant DR1/H-2Ek MHC class II genes paired to either DR alpha or H-2E alpha genes was generated, and tested as stimulator cells for purified human T cells. A strong proliferative response to DAP.3 transfectants expressing allogeneic HLA-DR molecules was seen. In contrast, weak or absent responses were recorded against DAP.3 cells expressing H-2E molecules. Substitution of the DR1 beta chain with H-2E beta k led to a dramatic loss of recognition; alpha chain substitution had a less marked effect. Furthermore, replacement of the beta 2 domain of DR1 with H-2E sequence caused 90% inhibition, whereas introduction of the beta 2 domain of DR1 into H-2Ek led to a 10-fold increase in T cell response. These results are most readily explained if the beta 2 domain contributes to the interaction site for the CD4 molecule. Substitution of either half of the beta 1 domain led to a marked loss of response. This was more impressive following substitution of the TCR-contacting alpha-helical region of the domain.(ABSTRACT TRUNCATED AT 250 WORDS)


Most residues on the floor of the antigen binding site of the class I MHC molecule H-2Kd influence peptide presentation.

A panel of 15 single alanine substitutions on the floor of the peptide binding groove of the murine class I histocompatibility molecule H-2Kd has been analyzed. All but two mutant molecules were expressed on the cell surface, and were tested for peptide binding and presentation to specific cytotoxic T lymphocytes. Eleven out of 13 mutant molecules appeared to be functionally altered. Five of the substituted residues were involved in the presentation of all peptides tested. Three participated in the presentation of certain peptides but not others. Three other residues participated in epitope formation through indirect interactions. Only two mutations had no detectable effect.


Photodamage of the conjunctiva in patients with porphyria cutanea tarda.

Ninety two patients with porphyria cutanea tarda (PCT) were examined ophthalmically in a paired case control study. The incidence of pinguecula and of pterygium was 8 and 2 times higher respectively, in PCT patients than in the control group. The photodamage to the conjunctiva is considered to be a result of the photoactivity of uroporphyrin in the tissues.


Prolongation of rat corneal graft survival by treatment with anti-CD4 monoclonal antibody.

A rat model of orthotopic corneal graft rejection was used to investigate the effect of depletion of subpopulations of immune cells by treatment with monoclonal antibodies. Though CD4+ cells were not eliminated completely by anti-CD4 monoclonal antibodies there was a profound delay in the rejection times of orthotopic corneal allografts. Furthermore a third of the CD4+ depleted animals failed to reject corneal allografts by 100 days post grafting. Despite an almost complete depletion of circulating CD8+ cells, the anti-CD8 antibody treated animals rejected corneal allografts in a similar time course to allografted controls treated with a non-reactive control antibody OX21. These results demonstrate that CD8+ T-cells are not required for rejection of corneal allografts whereas CD4+ T-cells play a critical role in the rejection response. Treatment with anti-CD4 antibodies may have a useful clinical application.


Characterization of bovine MHC class II polymorphism using three typing methods: serology, RFLP and IEF.

Various methods, with different strengths and weaknesses, are currently used to define polymorphism of the bovine major histocompatibility complex (MHC) class II genes. A more complete characterization of bovine lymphocyte antigen (BoLA) haplotypes can be achieved by combining several of these methods. In this study BoLA class II polymorphism was characterized using three typing methods: serology, restriction fragment length polymorphism (RFLP), and isoelectric focusing (IEF). Twenty six Holstein-Friesian and 15 Angus cattle that carried an array of serologically defined BoLA haplotypes were selected for the study. The panel included 12 BoLA complex homozygotes. The three class II typing methods recognized polymorphism associated with the same or very tightly linked genes in the DQ-DR class II subregion. In total 25 BoLA-A locus (class I)--DQ-DR subregion (class II) haplotypes were defined. Three of the serological class II specificities, Dx1, Dx3, and Dx4, were associated with more than one RFLP defined DQ-DR haplotype. The other 4 class II specificities behaved as private specificities. One BoLA haplotype was found in both Holstein and Angus cattle. Two other BoLA haplotypes defined here have previously been described in other breeds. This suggests that these haplotypes exist in strong linkage disequilibrium.


Monomorphic organization of human diversity (DH) heavy chain variable genes.

While recent evidence indicates that human immunoglobulin heavy chain variable (VH) genes exhibit a high degree of heterogeneity, little is known concerning the polymorphism of the diversity (DH) gene complex. This locus comprises two clusters, major and minor, which are physically linked with the VH locus. In assessing the variability of the human major and minor DH clusters, we found no evidence for a substantial restriction site polymorphism. We also noted that, in contrast to what was found in the Japanese population, the DH1 gene is not deleted in an appreciable proportion of the European population. We propose that, because DH genes impart the critical functions associated with the third complementarity-determining region, the genomic organization of the human DH locus has been evolutionarily conserved through selection pressure mechanisms.


Human natriuretic peptide receptor-A guanylyl cyclase is self-associated prior to hormone binding.

The human natriuretic peptide receptor-A (NPR-A) guanylyl cyclase is specifically activated to synthesize cGMP by binding of atrial natriuretic peptide (ANP) to the receptor's extracellular domain. In this report, NPR-A monoclonal and polyclonal antibodies were used to assess the aggregation status of wild-type NPR-A and a truncation mutant lacking most of the NPR-A cytoplasmic domain. On intact human embryonic kidney 293 cells, in the absence of ANP, recombinant human NPR-A is self-aggregated through disulfide bonds in an M(r) > 500,000, possibly tetrameric, complex. Under nonreducing conditions, truncated NPR-A was a monomer, indicating that the cytoplasmic domain is necessary for NPR-A self-association. In the presence of the homobifunctional cross-linker dithiobis(succinimidyl propionate), or disuccimidyl suberate, truncated NPR-A could be cross-linked as a dimer and trimer only in the presence of ANP. Wild-type NPR-A was cross-linked with disuccinimidyl suberate to an M(r) > 500,000 species in the absence of ANP, and with ANP, a smaller, M(r) approximately 400,000 receptor trimer cross-linking product was observed, together with the larger, possibly tetrameric complex. When whole cell stimulation of cGMP production by ANP was tested on the low level of endogenous 293 cell NPR-A, maximal stimulation was observed regardless of truncated NPR-A overexpression. The absence of a dominant negative effect by the truncated NPR-A, together with the cross-linking data, demonstrates that preassociated NPR-A is the functionally relevant form of this receptor.


Effects of lithium on basal and modulated activities of the particulate and soluble guanylate cyclases in retinal rod outer segments.

A large amount of information regarding the kinetics of biochemical reactions involved in visual transduction was derived from electrophysiological studies on dark-adapted rod outer segments. Hodgkin et al. [(1985) J. Physiol. 358, 447-468] observed that when Na was replaced with Li in the perfusion solution bathing the rod outer segment, the dark current slowly declined to zero. This decline was thought to result from a rise in intracellular calcium which was hypothesized to inhibit guanylate cyclase activity and reduce the cyclic GMP concentration. Rod outer segments contain membrane and soluble guanylate cyclase activities, and we show here that Li directly inhibits both types of activities very strongly. Both the basal (at high calcium) and the stimulated (at low calcium) activities of the membrane enzyme were inhibited by Li. Half-maximal inhibition of the stimulated enzyme was at 30 mM Li while for the basal activity it was at 100 mM. Over 80% of the activated enzyme was inhibited at 110 mM Li. The soluble guanylate cyclase activity was stimulated by nitroprusside. One hundred millimolar Li inhibited the basal activity by 20-30%, but the inhibition of the nitroprusside-stimulated (soluble) enzyme was much stronger, resembling that of the activated membrane enzyme. Half-maximal inhibition occurred at 30 mM, and about 80% inhibition was found at 100 mM Li. Stimulation of the soluble enzyme by nitroprusside was independent of calcium in the physiological range. The inhibition of the stimulated enzyme by Li was similarly independent of calcium, except at unphysiologically high concentrations.(ABSTRACT TRUNCATED AT 250 WORDS)


Energy-dependent conversion of transformed cytosolic glucocorticoid receptors from soluble to particulate-bound form.

We have recently published that soluble cytosolic glucocorticoid receptors are converted to a particulate form when they are incubated at 37 degrees C in a tubulin-polymerizing buffer [Pratt, W. B., Sanchez, E. R., Bresnick, E. H., Meshinchi, S., Scherrer, L. C., Dalman, F. C., & Welsh, M. J. (1989) Cancer Res. (Suppl.) 49, 2222s-2229s]. In this work, we further define this phenomenon and demonstrate that the L-cell glucocorticoid receptors are binding to a protein particulate composed largely of cytoskeletal proteins. Incubation of L-cell cytosol with glutamate at 37 degrees C converts the glucorticoid receptor to a form that pellets when cytosol is centrifuged at 150000g. The particulate material formed in a temperature-dependent and glutamate-dependent manner contains a large amount of tubulin, actin, and vimentin, but it is not the product of a cold-labile, colchicine-sensitive polymerization process. Very few cytosolic proteins are present in this complex, but the glucocorticoid receptor is tightly bound to it. Binding of the receptor to the cytoskeletal complex occurs after receptor transformation and is at least partially energy-dependent. Examination of the behavior of beta-galactosidase receptor fusion proteins and the nti glucocorticoid receptor demonstrates that residues 445 to the COOH-terminus of the receptor (DNA-binding and hormone-binding domains) contain the features required for binding to the cytoskeletal complex. Although it is the transformed receptor that associates tightly with the complex, DNA-binding activity is not required for association with the cytoskeletal particulate.(ABSTRACT TRUNCATED AT 250 WORDS)


Carrier-mediated glutamate secretion by Corynebacterium glutamicum under biotin limitation.

Previous studies have demonstrated the involvement of a carrier system in glutamate secretion by Corynebacterium glutamicum under biotin limitation (Hoischen, C. and Krämer, R. (1989) Arch. Microbiol. 151, 342-347). In a detailed analysis of the export process we found secretion to be independent of secondary forces: (i) glutamate was secreted at high rate even when external glutamate exceeded the internal concentration, (ii) movement of neither protons nor potassium or chloride ions was found to be coupled to glutamate secretion, and (iii) secretion continued unaffected after breakdown of the membrane potential. Instead, under conditions leading to variation of glutamate secretion activity, a correlation of secretion rate and the intracellular ATP-pool was observed. Thus, ATP or a related high-energy metabolite is thought to be involved in the activity of the glutamate secretion system.


Characterization of three arylsulfatases in semen: seminolipid sulfohydrolase activity is present in seminal plasma.

Sperm cells and seminal plasma of various mammals contain high levels of arylsulfatase. In the present study, we investigated the composition of soluble AS in these compartments of boar semen by analysing sperm cells and seminal plasma using anion-exchange chromatography. Seminal plasma contained both arylsulfatase B (2.4 units per ml), an enzyme which desulfates sulfoglycosaminoglycans and probably sulfoglycoproteins, and arylsulfatase A (10.2 units per ml), an enzyme which desulfates sulfogalactolipids. Sperm cells contained only arylsulfatase A, which differed biochemically from the extracellular arylsulfatase A of seminal plasma (2.6 units per ml). Both types of arylsulfatase A desulfate seminolipid, the natural sulfolipid substrate in sperm, as well as two brain sulfatides. The possible physiological consequences of the presence of extracellular arylsulfatases in seminal plasma for spermatozoa are discussed.


Nucleotide sequence and expression in Escherichia coli of the cephalosporin acylase gene of a Pseudomonas strain.

The gene encoding cephalosporin acylase, which hydrolyzes 7-beta-(4-carboxybutanamido)-cephalosporanic acid (GL-7ACA) to 7-aminocephalosporanic acid (7ACA) and glutaric acid, was cloned from a Pseudomonas sp. strain V22 and expressed in Escherichia coli, in a two-cistron system, and the enzyme was purified and characterized. The purified enzyme was composed of two non-identical subunits, their molecular weights were estimated by SDS-PAGE to be 40,000 and 22,000, and had a pI of 4.6. The amino acid sequence of the enzyme, deduced from the nucleotide sequence, showed high similarity (97%) with that of a previously reported acyI-encoded cephalosporin acylase. Cephalosporin acylase also resembles the bacterial gamma-glutamyl transpeptidases (GGTs) with respect to their molecular organization and amino acid sequence, but differs from them with respect to catalytic and immunological properties. Purified enzyme exhibited not only cephalosporin acylase activity, but also GGT activity. The Km values of the enzyme for GL-7ACA and L-gamma-glutamyl-p-nitroanilide were 6.1 and 3.8 mM, respectively. Cephalosporin acylase was not recognized by antibodies prepared against bacterial GGTs.


Amplification and direct sequencing of a cDNA encoding human cytosolic 3-hydroxy-3-methylglutaryl-coenzyme A synthase.

Cytosolic 3-hydroxy-3-methylglutaryl CoA (HMG-CoA) synthase (E.C. 4.1.3.5) is a highly regulated enzyme involved in isoprenoid biosynthesis and therefore a potential target for cholesterol-lowering drugs. Up to now, primary structure data have only been available for chicken, rat and hamster HMG-CoA synthase. Using in vitro amplification and direct sequencing, we have determined the nucleotide sequence of the coding region of the human cytosolic 3-hydroxy-3-methylglutaryl CoA synthase cDNA.


Cloning and sequencing of the human homeobox gene HOX4A.

The HOX4A gene, one of the homeobox-containing genes on human chromosome 2, has been isolated by screening a genomic cosmid library with a HOX4B cDNA probe. The HOX4A gene consists of at least two exons separated by a long intron of 1860 bp. According to conceptual translation, the HOX4A protein is predicted to be composed of 416 amino acid residues. Interestingly, the HOX4A protein has a sequence, Pro-Ala-Ser-Gln-Ser-Pro-Glu-Arg-Ser, eight amino acids downstream from the homeodomain, which is similar to that containing a phosphorylation site in pp60c-src, Pro-Ala-Ser-Gln-Thr-Pro-Asn-Lys-Thr. However, the HOX2G protein, which exhibits a paralogous relationship with the HOX4A protein, does not possess the sequence which is similar to that in pp60c-src. A comparison of the predicted HOX4A protein with the HOX2G protein revealed four regions of amino acid sequence similarities: an N-terminal tetrapeptide, a pentapeptide (pre-box) upstream of the homeodomain, the homeodomain and a C-terminal octapeptide.


Recoverin, a novel calcium-binding protein from vertebrate photoreceptors.

Photoreceptor guanylyl cyclase activity is modulated by an endogenous calcium-binding protein called recoverin. A modified isolation procedure for recoverin using gel-filtration chromatography instead of a heat denaturation step is presented. The elution volume of recoverin corresponds to a monomer. Recoverin exhibits a calcium-dependent mobility shift in a native gel electrophoresis. Isoelectric focusing revealed a pI of 5.25. No subspecies of recoverin were detected.


Arachidonic acid regulates unsaturated fatty acid synthesis in lymphocytes by inhibiting stearoyl-CoA desaturase gene expression.

This work was based upon the observation that a reduction in the level of serum, provided to murine lymphocytes in culture, augmented endogenous unsaturated fatty acid (UFA) synthesis. Since the phospholipids of BW5147 cells grown in 1% serum were especially deficient in arachidonic acid (20:4), and given the findings of previous workers, we suspected that the availability of exogenous 20:4 in serum might correlate with the squelching of UFA synthesis. Indeed, after a 5 h exposure to 4-28 microM 20:4, the 20:4 content of BW5147 cell phospholipids increased from 1% to 15% of the total fatty acids with a coincident reduction in 18:1 synthesis to approx. 30% of starting values. Subsequent studies were done to define the mechanism by which 20:4 down-regulates 18:1 synthesis. The results indicated that 20:4 inhibited endogenous 18:1 synthesis by reducing stearoyl-CoA desaturase (SCD) enzyme activity. Moreover, as determined by Northern blot analyses, the inhibitory effect of 20:4 on stearoyl-CoA desaturase activity coincided with decreased stearoyl-CoA desaturase mRNA levels. Exposure of BW5147 cells to either 20:4, actinomycin D, or both, resulted in a temporal decay of stearoyl-CoA desaturase mRNAs with half-lives ranging from 4.0 h to 4.4 h. Such a similarity in decay times implied that 20:4 regulates stearoyl-CoA desaturase expression by inhibiting transcription. This was confirmed by nuclear run-on studies in which 20:4 was found to inhibit transcription of nascent stearoyl-CoA desaturase mRNA. Collectively, these findings implicate 20:4 as an important regulator of stearoyl-CoA desaturase gene expression, and hence UFA synthesis, in lymphoid cells.


P-glycoprotein genes in the winter flounder, Pleuronectes americanus: isolation of two types of genomic clones carrying 3' terminal exons.

In mammals, P-glycoprotein (P-gp) is encoded by two or more highly conserved genes that differ in their abilities to transport drugs. One isoform class (class I) is consistently associated with the multidrug resistance phenotype, while the other (class III) is not. This study was designed to enumerate the P-gp genes in fish and determine how they are related to the two functional classes already defined in mammals. Southern blot analysis using a conserved single exon from the 3' terminal region of hamster P-gp cDNA (pEX1-172) as a probe indicated that there were two P-gp genes in right-eye flounders. Subsequently, two sets of clones were isolated from a winter flounder genomic library that correspond to the 3' ends of the two flounder P-gp genes. Sequence analysis was done on two key areas: the 3' ATP binding site and the 3' terminal exon, both of which were found to be homologous with their mammalian counterparts. Despite high levels of sequence identity in the predicted coding regions of the gene fragments it has not been possible to use these sequences to relate the homologs to particular mammalian classes of P-gp genes, perhaps because of gene conversion between mammalian P-gp genes. These cloned sequences are the first set of P-gp genes reported in lower vertebrates and will be useful for delineating the expression of P-gp genes in fish and understanding the role of P-gp in fish physiology.


Utility of the parent-neutral loss scan screening technique: partial characterization of urinary metabolites of U-78875 in monkey urine.

Metabolites of an antianxiety-sedative drug candidate (U-78875; 3-(5-cyclopropyl-1,2,4-oxadiazol-3-yl)-5-(1-methylethyl)-imidazo[1 ,5-alpha] quinoxalin-4(5H)-one (I)) present in the urine of monkeys were detected using tandem mass spectrometry (MS/MS) by application of parent ion scans and characterized or partially characterized by performing daughter ion scans of the pseudo-molecular ions of suspected metabolites. The use of liquid secondary ion mass spectrometry ionization of crude urinary extracts in combination with tandem quadrupole MS/MS analyses using parent ion scans of m/z 69 and subsequent daughter ion scans characterized unmetabolized I and N-dealkyl I (U-85466) and partially characterized aryl hydroxyl, aryl hydroxyl-N-dealkyl, aryl O-glucuronide, aryl O-glucuronide-N-dealkyl, aryl O-sulfate and aryl O-sulfate-N-dealkyl metabolites. From these data it was concluded that some of the metabolic pathways involved in the biotransformation of U-78875 include N-dealkylation, aryl hydroxylation and conjugation of aryl hydroxides. Several other metabolites of U-78875 not detected using this analytical approach were subsequently identified by alternative mass spectrometric approaches. These data clearly demonstrated both the utility and, just as important, the limitations of the parent-neutral loss scan screening technique in detecting drug metabolites in complex biological milieux.


The chiral chromatographic separation of beta-adrenoceptor blocking drugs.

Over 100 chromatographic procedures for the separation of beta-blocker enantiomers are reviewed including a large number for the analysis of biological samples. All the principal chiral chromatographic procedures have found use, namely Chiral Mobile Phase Additives (CMPA), Chiral Derivatization Agents (CDA) and Chiral Stationary Phases (CSP). Chiral Mobile Phase Additives are less frequently employed than the other two procedures and many of the earlier methods were based on the use of CDAs. However, the recent development of sophisticated custom-made CSPs has allowed the separation of native (underivatized) analytes and this approach appears to be gaining in popularity. The beta-blockers are an extensive group of drugs and stereoselective separations have been reported for 40 different structures.


Oestrogen, progesterone, and glucocorticoid receptors in normal and neoplastic parathyroid glands.

To verify the presence or absence of steroid receptors in the parathyroid glands of patients undergoing operations on the parathyroid and thyroid glands. Open experimental study. Karolinska Hospital, Stockholm, Sweden. 165 parathyroid glands from 137 patients, 108 of whom underwent operations on the parathyroid glands and 29 on the thyroid gland. Normal and neoplastic parathyroid tissue was analysed for its content of oestrogen and progesterone and glucocorticoid receptors using either ligand binding or antibodies raised against oestrogen and progesterone receptors. Positive reactions to female sex steroid receptors (defined as > 0.05 fmol/microgram DNA) were uncommon (9%) regardless of the morphological classification of the glands or the age, sex, and menopausal status of the patients. Glucocorticoid receptors were detected in 107/163 (66%) of all glands analysed (mean value 0.43 fmol/micrograms DNA, range 0-44). Seventy of the 96 diseased glands (73%) contained receptors, as did 27/67 normal glands from patients with primary hyperparathyroidism or those undergoing thyroid operations. The difference was again not associated with age, sex, and menopausal status. It seems unlikely that sex steroid hormones play a physiological part in the secretion of parathyroid hormone, but our finding of glucocorticoid receptors in normal as well as diseased parathyroid tissue suggests that they may have a role in the regulation of parathyroid function.


Biochemical variables associated with bone density in patients with primary hyperparathyroidism.

To clarify the association between primary hyperparathyroidism and cortical osteopenia. Open study. Department of Surgery, University of Lund, Sweden. 38 patients with primary hyperparathyroidism. Correlation between bone density (measured by single photon absorption) and age; sex; serum concentrations of parathyroid hormone and ionised calcium; serum alkaline phosphatase activity; and serum concentration of calcium, phosphate, creatinine, urea, osteocalcin, 25 hydroxycholecalciferol, and 1,25 dihydroxycholecalciferol. There was no difference in bone density between men and women. There was no correlation between bone density and severity of hypercalcaemia or age. No biochemical abnormality was peculiar to the seven patients whose bone density was more than two SD below the population mean. Serum concentrations of 1,25 dihydroxycholecalciferol and osteocalcin both correlated significantly with bone density (p < 0.05) and there was a strong correlation between serum osteocalcin and serum intact parathyroid hormone (p < 0.001). Serum osteocalcin had the strongest correlation with bone density of any of the biochemical variables. There is little association between bone density and serum concentration of parathyroid hormone.


Effect of perioperative blood transfusion and cell saver on the incidence of postoperative infective complications in patients with an aneurysm of the abdominal aorta.

To find out if there was an association between perioperative blood transfusion and the development of infective complications, and whether the use of the cell saver for autologous transfusion had any influence. Retrospective study. University Hospital. 102 consecutive patients who had been operated on for aneurysms of the abdominal aorta. Morbidity and mortality. 32 of the 102 patients developed infective complications. Thirteen patients died (six after emergency and seven after elective operations). Nine died as a direct result of infection, one of intra-abdominal bleeding, one of necrosis of the colon, and two of cardiopulmonary complications. The incidence of infective complications was directly related to the number of units of blood transfused, being 0 when 0 or 1 was given; 11 (20%) when 2-4 units were given; 12 (55%) when 5-8 units were given; and 9 (69%) when the number was 9 or more. The cell saver had no influence on the incidence. Other factors associated with higher rates of infective complications were the insertion of a bifurcated prosthesis (p = 0.03), and emergency operation (p < 0.001). These results confirm the association between blood transfusion and the incidence of infective complications. It may be that more intensive use of the cell saver and preoperatively saved autologous blood could reduce the rate of infective complications.


Fibrin sleeve formation after long term brachial catheterisation with an implantable port device. A prospective venographic study.

To evaluate the risk of thrombosis after long term venous access with an implantable port device (PAS-Port system). Open study. University Hospital, Linköping, Sweden. Sixteen patients who required central venous catheters for long term chemotherapy were prospectively followed for 218 patient months (median 12.5 months/patient, range 3-34). Venogram taken while the catheters were being withdrawn. Venography was also done in 10 patients 1-29 months after the catheter had been removed. The venograms showed that fibrin sleeves had developed along the route of the catheter in all cases (cubital vein to the superior vena cava n = 7; to subclavian vein alone n = 8; and basilic vein alone n = 1). One of the 10 patients who underwent venography 1-29 months later had developed an occlusive subclavian vein thrombosis with well developed collateral vessels 10 months after the catheter had been removed. Because of the high incidence of formation of extensive fibrin sleeves, implantable port devices should be removed as soon as they have served their purpose. If catheters malfunction they should be evaluated radiographically.


Combined sclerotherapy and operation for the treatment of bleeding oesophageal varices.

To identify prognostic factors in a consecutive series of patients with bleeding oesophageal varices and develop an optimum regimen of treatment. Retrospective review. I Department of Surgery, University Hospital, Vienna, Austria. 301 consecutive patients with bleeding oesophageal varices. Median survival and survival at one year after sclerotherapy alone (n = 213), or sclerotherapy with portosystemic shunt (n = 54), Hassab's devascularisation (n = 29), or liver transplantation (n = 5). Prognosis was dependent on the severity of liver damage at the start of treatment. Median survival for Child's class A was 47 months, for Child's class B 54 months, and for Child's class C 2 months. The overall one year survival for patients in Child's class C was 33%, for sclerotherapy alone 28%, and for sclerotherapy and portosystemic shunt 42%, Hassab's devascularisation 50%, and liver transplantation 80%. Despite the small number of patients who underwent liver transplantation and their poor initial prognosis (Child's class C, n = 4; class B, n = 1) our results suggest that liver transplantation should be considered for the treatment of patients with end stage cirrhosis and bleeding varices.


Association between permeability of the colonic wall and azoxymethane induced cancer of the colon in rats.

To investigate the association between colonic permeability and the development of azoxymethane induced colonic cancer in rats. Seventy-three male Fischer-Cooper hybrid rats. Measurement of the concentrations of sodium fluorescein in plasma as an indication of its passage across the bowel wall in control rats, and six weeks and six months after injection of azoxymethane. Forty-seven rats were given azoxymethane, and 26 acted as controls. Sodium fluorescein was instilled into segments of right (n = 46) and left (n = 27) colon and measured in peripheral blood; significantly higher concentrations were recorded after instillation into the left than into the right colon. No tumours developed in the 15 rats that were given azoxymethane and were examined after six weeks. At six months, however, 29 of the remaining 32 had developed 94 macroscopic tumours (range 1-12 tumours/rat), and 89 of these (95%) were in the left colon. The greater permeability of the left colon in rats compared with the right may be associated with the higher incidence of carcinomas in the left compared with the right colon.


Morbidity after immediate and delayed opening of sigmoid end colostomy: a randomised trial.

To see if sigmoid end colostomies that were opened immediately carried a higher early morbidity than those in which opening was delayed for 10 days. Randomised trial. University department of surgical gastroenterology. All patients for whom a temporary or permanent end sigmoid colostomy was done between December 1986 and May 1989. 51 patients had their colostomies opened immediately, and in 49 opening was delayed. Presence of ischaemia, retraction, separation or infection, and length of stay in hospital. Two patients from each group died within the first week; none of the deaths was associated with complications of the colostomy. One patient whose colostomy had been opened immediately developed gangrene of the stoma, and one in whom the opening had been delayed developed retraction. There was no difference between the groups in length of stay in hospital. As we could find no differences in morbidity whether the colostomy was opened immediately or whether it was delayed, we now recommend that it should be done immediately. The question of late complications (stenosis and hernia), however, cannot be answered yet.


Maximum anal sphincter strength measured by the solid sphere test and anal pressure profiles.

To evaluate two methods of quantifying external anal sphincter function. Open study. Helsingborg Hospital, Sweden. 73 patients (63 women and 10 men), of whom 25 were incontinent of gas and liquid or solid stool. Anal pressure profiles and the "solid sphere" test. Correlation between results of tests and presence of incontinence. Continent patients were younger than incontinent ones. The correlation between the maximum force the patient could retain and the maximum anal squeeze pressure was good (r = 0.67, p < 0.001). Younger continent patients (n = 48) and significantly higher pressures than incontinent patients (n = 25), but the range and overlap were wide. The reproducibility of both methods was good. Although the solid sphere test is easier and quicker to do, anal pressure profiles yield more information that is important in the evaluation of incontinence.


Haemangiomas of the breast in children.

Capillary hemangioma of the breast parenchyma is a rare finding in the pediatric age group. The condition was diagnosed in two children, aged 18 months and three years. Such lesions have occasionally been found during histologic surveys among asymptomatic adult women. Although vascular tumors in the adult breast are often found to be sarcomatous, the pediatric lesion is benign and responds well to simple excision.


Trophic effects of neurotransmitters during brain maturation.

Besides their neurotransmitter and/or neuromodulatory roles, many neuroactive substances synthesized and released during brain development can also directly influence neuronal differentiation. Transitory expression of neurotransmitters, their metabolic enzymes and their receptors is only one aspect of this trophic role. The most considerable progress in neurotrophic factor research has been made with the use of primary cultures of neuronal cells, and numerous studies have focused on the effects of neurotransmitters on the differentiation of cells at various stages of development. Thus, several neuropeptides like VIP, substance P, enkephalins, somatostatin, and monoamines, can modulate neuronal differentiation, but only during a limited period of fetal life. Among the monoamines, it was shown that, depending on the target, 5-HT stimulates the development of the neuropile, the myelinization of axons, the differentiation of the synaptic contacts, induces markers of monoaminergic neuron differentiation, inhibits the development of the growth cone, decreases the branching of neurites, and influences the survival, cell body size, and neurite outgrowth in several neuronal cultures. 5-HT can also indirectly influence the differentiation of serotonergic neurons by the intermediate of astrocytes, and it was shown in our laboratory that 5-HT1A agonists can stimulate the cholinergic parameters of primary cultures of rat fetal septal neurons. At the molecular level, the events triggered by neurotransmitters that underlie their neurotrophic action probably involve the transmembrane influx of calcium. To date, calcium regulation of cellular processes is one of the most rapidly expanding areas of research in developmental neurobiology.


Role of excitatory amino acid antagonists in the management of birth asphyxia.

Birth asphyxia is an important cause of permanent neuro-developmental disability. Asphyxia sets in course a progression of intracellular events which culminates in neuronal death, and this process may take up to 48 h to complete. Entry of calcium into the neurone appears to be the key to the cell death, and it is known that during asphyxia, excessive glutamate is released which stimulates the voltage-dependent N-methyl-D-aspartate (NMDA) receptor to open with an accumulation of excess intracellular calcium. MK-801 is a very effective NMDA receptor antagonist, and it has been shown that this drug prevents or significantly reduces the extent of cortical neurone infarction following experimental asphyxia in 7-day-old rat pups. Unfortunately, MK-801 is toxic to the pup, but newer NMDA receptor antagonists may offer the opportunity for neuroprotection in the human infant who has suffered severe birth asphyxia.


GABA agonist-induced changes in motor, oculomotor, and attention measures correlate in schizophrenics with tardive dyskinesia.

Saccadic distractibility, Stroop color-word scores, and serial dyskinesia assessments were obtained on 10 schizophrenic patients with tardive dyskinesia during a pharmacologic challenge with placebo or 7 mg muscimol, a potent, direct-acting GABA agonist. Although no significant difference in the measures was evident between conditions, a significant correlation was found between GABA agonist-induced changes in saccadic distractibility and dyskinesia scores where no correlation existed between these measures on placebo. Improvement in saccadic distractibility was also correlated with reduction in attention performance, as measured by Stroop. These effects are not due to sedation. The correlation between dyskinesia and saccadic distractibility is consistent with a model of parallel motor and oculomotor cortico-striatal-thalamic circuits in humans. This work supports the hypothesis that a dysfunction in GABA-mediated neurotransmission may be the basis for tardive dyskinesia.


The effect of alpha-1-adrenoreceptor agonist and antagonist administration on human upper gastrointestinal transit and motility.

To explore the role of alpha-1-adrenoreceptor-mediated pathways on human upper gut motor function in vivo, we studied the effects of the alpha-1-agonist phenylephrine and the alpha-1-antagonist thymoxamine on oro-caecal transit and antroduodenal motor activity. Transit was measured using a standard exhaled-breath hydrogen method, and motility was measured by intraluminal manometry. Oro-caecal transit was unaffected by 80 mg thymoxamine [median 63 min (range 35-164 min) vs. control, 65 min (range 30-155 min), P greater than 0.1]. However, phenylephrine (2.4 micrograms/kg/min) consistently delayed oro-caecal transit time to 103 min (50-215 min), P greater than 0.005. Co-administration of thymoxamine abolished this phenylephrine-induced delay. The mean amplitude of antral postprandial contractions was reduced by phenylephrine from 29 (13-37) to 10 (3-13) mmHg (P less than 0.02). In contrast, neither the pattern nor the mean inter-contraction interval was altered. Responses to phenylephrine in the duodenum were similar to those in the antrum, with reduction in amplitude from 12 (3-18) to 6 (5-13) mmHg without alteration in the pattern or interval between contractions. Nutrient transit through the upper gut can thus be inhibited via activation of an alpha-1-adrenoreceptor-mediated pathway. Failure of alpha-1-antagonist administration to alter oro-caecal transit suggests that this pathway is not tonically active, and it is therefore unlikely to play a major role in nutrient passage under normal circumstances.