Characterization of catecholamine-mediated relaxations in rat isolated gastric fundus: evidence for an atypical beta-adrenoceptor

1. Experiments were carried out in order to characterize the receptors mediating relaxant responses to catecholamines in the rat gastric fundus. The effects of noradrenaline, isoprenaline and the 'atypical' or beta 3-adrenoceptor agonist, BRL 37344, on methacholine-induced tone were measured. Prazosin, propranolol and cyanopindolol were used as antagonists. 2. Relaxant responses to noradrenaline, in the presence of propranolol (1 microM) were antagonized in a concentration-dependent manner by prazosin (0.01 to 1 microM), although this antagonism was weak and non-competitive in nature. Relaxant responses to isoprenaline, in the presence of prazosin (0.1 microM), were antagonized only by the highest concentration of propranolol (1 microM) giving a pKB of 6.3 BRL 37344 also relaxed the rat gastric fundus in the presence of prazosin (0.1 microM), and the responses to BRL 37344 were unaffected by propranolol (1 microM). 3. Tachyphylaxis to BRL 37344 was observed, a second concentration-response curve being significantly shifted to the right. Exposure of tissues to BRL 37344 (1 microM) between concentration-response curves also caused an 11 fold rightward shift in the response to isoprenaline. 4. In the presence of prazosin (0.1 microM) and propranolol (1 microM), the rank order of potency of the agonists was: (-)-isoprenaline (1.0) greater than (-)-noradrenaline (0.39) greater than BRL 37344 (0.10). 5. Responses to BRL 37344 in the presence of prazosin (0.1 microM) and propranolol (1 microM) were antagonized by (+/-)-cyanopindolol (1 microM), with a pKB of 6.56. Responses to isoprenaline, under the same conditions, were antagonized in a competitive manner by (+/-)-cyanopindolol (0.1-1 microM), with the slope of a Schild plot close to unity and a pA2 value of 7.44. 6. The resistance to blockade by prazosin and propranolol and the antagonism by cyanopindolol of the responses mediated by isoprenaline and BRL 37344 suggest that atypical beta-adrenoceptors similar to 'atypical',beta-adrenoceptors in rat adipocytes and other tissues are present in the rat gastric fundus.

Relationship between outlet obstruction constipation and obstructed urinary flow

Ten women with symptoms and radiological features of outlet obstruction constipation underwent urodynamic bladder studies. The results were compared with ten age- and sex-matched controls. The mean (s.e.m.) peak flow rate for patients was 19.4 (6.4) ml/s compared with 32.1 (7.2) ml/s for controls (P less than 0.05). The mean (s.e.m.) voiding time for patients was 62.9 (23.7) s against a corresponding value of 15.6 (6) for controls (P less than 0.05). The mean (s.e.m.) bladder volume in patients was 482 (80) ml compared with a control value of 254 (112) ml (P less than 0.03). The mean (s.e.m.) detrusor pressure during the voiding phase was 53.3 (12) cmH2O. These results demonstrate that patients with outlet obstruction constipation have a generalized pelvic floor disorder resulting in obstructed urinary flow.

Pre- and post-junctional alpha-adrenoceptor-mediated responses in the rat gastric fundus in-vitro

The effects of alpha 1- and alpha 2-adrenoceptor agonists on smooth muscle tone and on cholinergic excitatory and non-adrenergic, non-cholinergic inhibitory responses to field stimulation have been investigated in the rat gastric fundus in-vitro. None of the alpha-adrenoceptor agonists tested, noradrenaline, phenylephrine, cirazoline, guanoxabenz or UK-14,304 showed any contractile effects at concentrations up to 30 microM. In preparations where tone was raised by barium (0.5-2 mM), the mixed alpha 1- and alpha 2-adrenoceptor agonist noradrenaline (0.01-10 microM), and the selective alpha 1-adrenoceptor agonists cirazoline (0.01-10 microM) and phenylephrine (0.01-10 microM) produced concentration-dependent relaxations which were antagonized by the alpha 1-adrenoceptor antagonist prazosin (0.01-1.0 microM). The selective alpha 2-adrenoceptor agonists UK-14,304 (0.03-30 microM) and guanoxabenz (0.03-30 microM), had no relaxant effects in raised tone. UK-14,304 (0.03-1.0 microM) produced a concentration-dependent inhibition of cholinergic nerve-induced responses which was antagonized by the alpha 2-adrenoceptor antagonist idazoxan (0.03-1.0 microM) but not by prazosin (0.03-1.0 microM). Noradrenaline (0.03-1.0 microM) also produced an inhibition of cholinergic nerve-induced responses which was antagonized by idazoxan (0.03-1.0 microM). A small component of the noradrenaline inhibitory effects was antagonized by prazosin (10%). Cirazoline (0.03-1.0 microM) produced a small inhibition of cholinergic nerve-induced responses which was antagonized by prazosin (0.03-1.0 microM). The prazosin-sensitive components of the inhibitory effects of noradrenaline and cirazoline occurred at concentrations which also produced post-junctional relaxation.(ABSTRACT TRUNCATED AT 250 WORDS)

Evidence for the existence of 'atypical' beta-adrenoceptors (beta 3-adrenoceptors) mediating relaxation in the rat distal colon in vitro

1. Experiments were carried out to characterize the adrenoceptors mediating relaxant responses in the rat distal colon. Three agonists were used: noradrenaline, isoprenaline and the beta 3-adrenoceptor agonist BRL 37344. Phentolamine, propranolol and (+/- )-cyanopindolol were tested as antagonists. Tone in the rat distal colon was induced with KCl (30-40 mM) as a spasmogen, and relaxations of this KCl-induced tone produced by the agonists were measured. 2. Relaxant responses to noradrenaline that were obtained in the presence of propranolol (1 microM) were not antagonized by phentolamine (0.01 to 1 microM). Relaxant responses to isoprenaline that were obtained in the presence of phentolamine (1 microM) were antagonized in a concentration-dependent manner by propranolol (0.01 to 3 microM), although this antagonism was weak and non-competitive. Relaxant responses to BRL 37344 that were obtained in the presence of phentolamine (1 microM) were only weakly antagonized by high (1 microM) concentrations of propranolol. 3. Tachyphylaxis to BRL 37344 was observed, a second concentration-response curve being shifted to the right by 15 fold. Exposure of the tissues to BRL 37344 (1 microM) between concentration-response curves also caused rightward shifts in the responses to noradrenaline (18 fold) and isoprenaline (19 fold) but not to papaverine. 4. In the presence of phentolamine (1 microM) and propranolol (1 microM), the rank order of potency of the agonists was: (-)-isoprenaline (1.0) greater than or equal to BRL 37344 (0.93) greater than (-)-noradrenaline (0.3). 5. Responses to BRL 37344 in the presence of phentolamine (1 microM) and propranolol (1 microM) were antagonized by (+/-)-cyanopindolol (I microM), with an apparent pA2 value of 6.67. Responses to isoprenaline, under the same conditions, were antagonized in a competitive manner by (+/-)-cyanopindolol (0.1 to 10 microM), with the slope of the Schild plot close to unity and a pA2 value of 7.12. 6. The resistance of the relaxant responses to antagonism by phentolamine and propranolol, along with the relatively high potency of the beta 3-adrenoceptor agonist BRL 37344 and the antagonism of 'resistant' responses by (+/-)-cyanopindolol would suggest that 'atypical' beta 6-adrenoceptors, similar to the beta 3-adrenoceptors of rat adipocytes and other tissues, exist in the rat distal colon.

Production and response of a human prostatic cancer line to transforming growth factor-like molecules

Serum-free media conditioned by the androgen insensitive human prostate cancer cell line DU145 showed immunological transforming growth factor-alpha (TGF alpha) activity, as well as competing activity in epidermal growth factor (EGF) radioreceptor assays (RRA). Furthermore, there were factors in the conditioned media which inhibited and stimulated DNA synthesis by DU145 cells in a dose-dependent fashion. Fractionation of the concentrated conditioned media by reverse-phase high performance liquid chromatography revealed several peaks containing EGF-like competitive activity only one of which demonstrated TGF alpha activity. However, none of the peaks corresponded to immunoreactive EGF. Measurement of EGF receptors on DU145 cells by competition and saturation analysis revealed high levels of receptors (mean +/- s.d. = 2.5 +/- 1 x 10(5) surface receptors per cell) which were of high affinity (Kd +/- s.d. = 1.0 +/- 0.5 nmol l-1). Although DU145 cells express high levels of EGF receptors, DNA synthesis was only minimally affected by exogenous EGF and TGF alpha.

Two enteric coated microspheres in cystic fibrosis

In a randomised single blind crossover study in children with cystic fibrosis and pancreatic insufficiency, two enteric coated microsphere preparations of pancreatin were compared on a capsule for capsule basis, by measuring the coefficient of fat absorption, nitrogen excretion, weight change, and symptom scores after four weeks' treatment with each preparation. Thirty nine subjects were randomly allocated to receive Pancrease followed by Creon or vice versa. Each individual subject received the same number of capsules per day in each study period. Data from 27 children (Pancrease/Creon, n = 13 and Creon/Pancrease, n = 14) wer suitable for analysis. Results showed no significant differences between the two preparations in any variable studied. We conclude that there is no significant difference between Pancrease and Creon when compared on a capsule for capsule basis.

The effect of introducing endoscopic therapy on surgery and mortality rates for peptic ulcer hemorrhage. A single center analysis of 1,125 cases

The introduction of early endoscopic diagnosis has not been associated with a reduction in either surgical intervention or overall mortality for peptic ulcer hemorrhage. Recent studies have suggested that endoscopic therapy can reduce rebleeding rates from peptic ulceration. We report a 2-year experience of the influence of endoscopic heater probe (HP) (Olympus CD 10Z) therapy on the outcome of patients admitted with peptic ulcer hemorrhage. Eight hundred and sixty-two patients admitted with peptic ulcer hemorrhage over a 5-year period (1978/9 and 1983/5) before endoscopic therapy (PRE-HP), and 263 patients admitted with peptic ulcer hemorrhage after introduction of endoscopic therapy (POST-HP: 1986-1988) were assessed. All 1,125 patients were managed by a joint physician/surgeon team. The introduction of HP therapy was associated with a reduction in surgical intervention and overall mortality rates for gastric ulceration from 16% and 8.9% PRE-HP to 7% and 2.6% POST-HP respectively (p less than 0.05). A similar but non-significant trend was noted for duodenal ulceration. The beneficial effects of HP therapy appear to be due to a reduction in the need for surgical hemostasis in patients with an ulcer base visible vessel. Our results suggest that a more widespread use of endoscopic therapy may result in an improved outcome from peptic ulcer hemorrhage.

Bond strength and durability of glass ionomer cements used as bonding agents in the placement of orthodontic brackets

One potential risk of orthodontic treatment is the development of surface decalcification in association with use of brackets and bands. A bonding agent that could render tooth structure more resistant to the caries process clearly would reduce the negative iatrogenic outcomes of orthodontic therapy and thereby benefit the patient. Glass ionomer cement (GIC) bonds chemically to both enamel and dentin. In addition its high fluoride content makes enamel more resistant to caries. The purpose of this study was to evaluate the bond strength and durability of GIC when used as a bonding agent in the placement of orthodontic brackets. The materials tested were three GICs (Ketac-Fil, Ketac-Cem, and Chelon) and a standard bonding agent currently in widespread use (Rely-A-Bond). Brackets were attached to the facial surface of 96 premolar specimens and half the specimens for each bonding agent were thermocycled. Bond shear strength was determined with an Instron testing device by applying a load to the occlusal margin of each bracket to the point of failure. A two-way ANOVA indicated a significant bonding agent by thermocycling interaction (F = 4.78, p less than 0.01). Thermocycling decreased bond strength significantly for all materials, but had the greatest impact on Rely-A-Bond. However, Rely-A-Bond provided the strongest bond with and without thermocycling. Although bond strength for the standard orthodontic bonding agent deteriorates significantly under thermal stress, these results suggest that it is still greater than the bond strength provided by GIC materials.

Induction of an allergic reaction to alcohol metabolites by immunization

Acetaldehyde, a product of alcohol metabolism, is known to bind covalently to plasma and red cell proteins, yielding stable adducts which have recently shown are recognized as foreign by the immune system. The present study demonstrates that immunization of mice with protein-acetaldehyde adducts in aluminum hydroxide gel results in the production of reaginic antibodies that recognize the adducts and trigger an allergic-anaphylactic reaction. These findings may lead to new approaches in the treatment of excessive alcohol consumption in humans.

Xanthochromia revisited: a re-evaluation of lumbar puncture and CT scanning in the diagnosis of subarachnoid haemorrhage

The CT and cerebrospinal fluid (CSF) findings of 100 patients with ruptured intracranial aneurysms were reviewed. Forty six percent of the 68 patients who had a lumbar puncture had blood stained CSF but with no xanthochromia. There was no blood visible on the CT scan in 20 patients: seven of these 20 had blood in their CSF, but no xanthochromia. It is concluded that it is blood stained CSF that is important in the diagnosis of subarachnoid haemorrhage (SAH), and not xanthochromia, and that a normal CT scan (EMI 1010) and the absence of xanthochromia in the CSF do not exclude a ruptured intracranial aneurysm. To diagnose SAH, it may be necessary to perform both investigations; the CT scan as the primary investigation in those patients in whom lumbar puncture is judged to be hazardous; the lumbar puncture as the secondary investigation in those patients with a normal CT scan.

An outbreak of Q fever probably due to contact with a parturient cat

Thirty-three cases (24 definite, nine probable) of Q fever were diagnosed in Victoria County, Cape Breton, Nova Scotia from May to August, 1985. Twenty-six of the cases occurred in residents of Baddeck (population 900, attack rate 2.8 percent), and 21 of the cases occurred during the month of June. There was geographic clustering of the cases: 14 of the 33 (42 percent) lived or worked in four buildings located side by side in the center of town. A case control study revealed that 25 of 29 cases were exposed to a cat that gave birth to stillborn kittens on June 8, 1985 and had bled per vaginum for three weeks prior to delivery. The cat lived in one of the buildings where geographic clustering occurred and frequently visited the other buildings. None of the 40 control subjects was so exposed (p less than 0.001). This cat had an antibody titer of 1:512 to Coxiella burnetii phase 1 antigen and a titer of 1:1024 to phase 2 antigen. Exposure to cattle, sheep and goats, the traditional reservoirs of Q fever, was uncommon among patients and control subjects and none of eight cattle tested had antibodies to C burnetii phase I antigen. We conclude that the infected parturient cat was probably responsible for this outbreak of Q fever affecting 2.8 percent of the population of the town of Baddeck.

A normal fat diet for cystic fibrosis: is a dietitian still needed?

The dietary intakes of 90 patients receiving various degrees of dietetic support were assessed by a 7-day dietary history. Patients who had contact with a dietitian at least twice a year achieved higher energy and protein intakes than patients with little or no dietetic help. Patients who had one intensive interview with a specialist CF dietitian but had little local dietetic support attained better nutrient intakes than patients with no dietetic support. Dietary misconceptions, which led to restriction of fat and even sugar, were common when patients or parents of CF children received little dietary advice.

Superiority of alternating non-cross-resistant chemotherapy in extensive small cell lung cancer. A multicenter, randomized clinical trial by the National Cancer Institute of Canada

The National Cancer Institute of Canada Clinical Trials Group conducted a prospective randomized study comparing standard chemotherapy with alternating chemotherapy in patients with extensive small cell lung cancer. "Standard" treatment consisted of cyclophosphamide (1000 mg/m2 body surface area); doxorubicin (50 mg/m2), and vincristine (2 mg) every 3 weeks for six courses. Alternating chemotherapy was cyclophosphamide, doxorubicin, and vincristine alternating with etoposide (100 mg/m2 on days 1 to 3) and cisplatin (25 mg/m2 on days 1 to 3) every 3 weeks for six treatment cycles. Two hundred eighty-nine patients were eligible and evaluable for response to therapy and survival. Best response was higher in patients on alternating chemotherapy (complete plus partial response, 80% compared with 63.2%; p less than 0.002). Progression-free survival for patients on alternating chemotherapy was superior (p less than 0.0001) as was overall survival (p = 0.03). Major toxicities were equally frequent in both treatment groups. These results show a modest superiority of alternating chemotherapy over standard therapy in extensive small cell lung cancer.

Food intolerance: our practice

This paper describes the clinical presentation of food allergy and/or intolerance (F.A.I.). The role of a diagnostic dietary trial is reviewed. Finally dietary management is discussed.

Autotransfusion: quality of blood prepared with a red cell processing device

The quality of blood salvaged at operation and prepared with the Dideco Autotrans BT 795 autotransfusion device was compared with that of donor blood in 41 patients having cardiac surgery involving cardiopulmonary bypass. Saved blood had a higher haemoglobin concentration (17.3 v. 13.1 g dl-1; P less than 0.001), a higher 2,3-diphosphoglycerate concentration (5.3 v. 1.1 mmol litre-1; P less than 0.00001), higher white cell count (17.1 X 10(9) litre-1 v. 4.1; P less than 0.00001), higher pH (7.5 v. 6.6; P less than 0.00001) and a more physiological potassium concentration (5.4 v. 8.8 mmol litre-1; P less than 0.00001) than donor blood. Saved blood platelet count was 34.5 X 10(9) litre-1 compared with 146.24 X 10(9) litre-1 (P less than 0.00001) and its heparin concentration was 0.64 u. ml-1. We conclude that this autotransfusor is a useful aid to blood conservation, producing good quality red cells with relatively normal pH and potassium values. However, modification of the centrifugation and washing is required to lessen the high white cell count and heparin concentrations found in the saved blood.

Comparison of four pancreatic extracts in cystic fibrosis

Four different pancreatin products, Pancrease, Creon, Pancrex V Forte, and Pancreatin Merck, were compared in a random crossover trial in children with cystic fibrosis. The results of our study showed that patients who received Creon and Pancrease had fewer gastrointestinal symptoms than patients who received Pancrex V Forte and Pancreatin Merck. Fat absorption was significantly improved with Pancrease when compared with Pancrex V forte and Pancreatin Merck. Also the fat absorption with Creon was superior to that with Pancrex V Forte. There was no significant difference in fat absorption between Pancrease and Creon. Pancrex V Forte and Pancreatin Merck, or Pancreatin Merck and Creon. Faecal nitrogen content was less with both Creon and Pancrease compared with Pancreatin Merck. Creon and Pancrease allow the patient with cystic fibrosis to take a high energy diet without any dietary restrictions.

Italian version of the organic brain syndrome and the depression scales from the CARE: evaluation of their performance in geriatric institutions

The Organic Brain Syndrome (OBS) and the Depression (D) scales derived from the Comprehensive Assessment and Referral Evaluation (CARE) were translated into Italian and used in a survey of geriatric institutions in Milan. During the survey validity and reliability tests of the scales were conducted. Inter-rater reliability (total score weighted kappa) was highly satisfactory for both scales (0.96 for OBS and 0.83 for D scale). Reliability was assessed three times during the survey and showed good stability for both scales, with a slight but significant trend towards reduction over time for the D scale. Reliability of the D scale was significantly lower when the subjects interviewed scored highly on the OBS scale (severe cognitive impairment). Criterion validity was highly satisfactory both for the OBS scale (cut-off point 4/5: sensitivity 77%, specificity 96%, positive predictive value 91%) and the D scale (cut-off point 10/11: sensitivity 95%, specificity 92%, positive predictive value 84%). Results are discussed with special reference to longitudinal assessment of reliability, the choice of the cut-off point, and the context-dependent properties of questionnaires.

The medium chain triglyceride diet and intractable epilepsy

Fifty children with drug resistant epilepsy were treated with the Medium Chain Triglyceride (MCT) Emulsion diet. Eight achieved complete control of seizures (four without anticonvulsant drugs), and with the addition of anticonvulsants four had seizures reduced in frequency by 90% and 10 by 50-90%. The best results were obtained with astatic myoclonic and absence seizures, but control of seizures was improved in four children with tonic-clonic and three with complex partial seizures. Food given at the same time as MCT helped to reduce side effects, and an extra dose of MCT before bedtime improved control of nocturnal seizures.

The cost of nutrition and diet therapy for low-income families

The DHSS special dietary allowance system for those receiving supplementary benefit is explained. The cost of normal and common therapeutic diets are calculated. Inadequacies and shortcomings of the current dietary allowance are identified.

Methods for determination of ionophore-type antibiotic residues in animal tissues

Methods for the analysis of polyether antibiotics in animal tissues and fluids are described. For monensin and nigericin, only methods based on bioautography are available. For lasalocid, in addition to TLC bioautography for quantitation in chicken skin and fat, LC methods based on fluorescence detection have been developed for quantitation in animal blood, milk, liver, skin, and fat. In addition, a confirmatory method for lasalocid is described; this is based on purification by LC followed by silylation and pyrolysis gas chromatography-positive chemical ionization mass spectrometry.

Serological evidence for simultaneous occurrences of Lyme disease and babesiosis

Babesia microti and Borrelia burgdorferi, the spirochetal agent of Lyme disease, are both transmitted by the tick Ixodes dammini. Serological evidence has shown that 54% of the patients with babesiosis tested have IgG and IgM antibodies to the spirochete causing Lyme disease. Likewise, 66% of randomly selected patients with Lyme disease from geographic areas endemic for both diseases, but not from areas where babesiosis does not occur, also have IgM and IgG antibodies to B. microti. Antigenic cross-reactivity is not the reason for these findings, as laboratory animals experimentally infected with B. microti do not develop antibodies to B. burgdorferi, and laboratory animals immunized with organisms derived from pure cultures of spirochetes do not develop antibodies to B. microti. We suggest that these patients are concurrently exposed to both organisms by doubly infected tick vectors.

Activation of the right ventricular apical electrogram during ventricular tachycardia: suitability for synchronizing intracavitary cardioversion

An intravascular catheter positioned in the right ventricular apex has been used for intracavitary cardioversion in patients with recurrent ventricular tachycardia. We examined the timing of the right ventricular apical electrogram during sinus rhythm and ventricular tachycardia (VT) in order to determine if this signal could be used to synchronize the delivery of a countershock. Sixty-three distinct morphologies of VT were observed in 33 patients undergoing electrophysiologic testing with programmed stimulation. Regardless of VT morphology or site of origin, the bipolar right ventricular electrogram always occurred within the peripheral QRS complex during ventricular tachycardia. Relative timing occurred within the QRS ranging from the initial 13% of the QRS to the last 12%. When all episodes of VT were examined, the timing of the right ventricular electrogram did not correlate linearly with the peak of the ECG, but the right ventricular electrogram occurred within 60 ms of the peak ECG in 83% of episodes of ventricular tachycardia. In one case of arrhythmogenic right ventricular dysplasia, the right ventricular electrogram occurred 160 ms after the peak ECG in ventricular tachycardia, a time when delivery of a countershock may have precipitated ventricular fibrillation. Six of these patients underwent cardioversion utilizing an intracavitary catheter and external generator. Acceleration of VT, or conversion to ventricular fibrillation, occurred following two of 27 shocks (7.4%). The right ventricular electrogram occurred the latest within the QRS complex in the two patients who developed acceleration of the tachycardia.(ABSTRACT TRUNCATED AT 250 WORDS)

Increased loss and decreased synthesis of hepatic glutathione after acute ethanol administration. Turnover studies

The effect of acute ethanol administration on rates of synthesis and utilization of hepatic glutathione (GSH) was studied in rats after a pulse of [35S]cysteine. A 35% decrease in hepatic GSH content 5h after administration of 4 g of ethanol/kg body wt. was accompanied by a 33% increase in the rate of GSH utilization. The decrease occurred without increases in hepatic oxidized glutathione (GSSG) or in the GSH/GSSG ratio. The rate of non-enzymic condensation of GSH with acetaldehyde could account for only 6% of the rate of hepatic GSH disappearance. The increased loss of [35S]GSH induced by ethanol was not accompanied by an increased turnover; rather, a 30% inhibition of GSH synthesis balanced the increased rate of loss, leaving the turnover rate unchanged. The rate of acetaldehyde condensation with cysteine in vitro occurred at about one-third of the rate of GSH loss in ethanol-treated animals. However, ethanol induced only a minor decrease in liver cysteine content, which did not precede, but followed, the decrease in GSH. The characteristics of 2-methylthiazolidine-4-carboxylic acid, the condensation product between acetaldehyde and cysteine, were studied and methodologies were developed to determine its presence in tissues. It was not found in the liver of ethanol-treated animals. Ethanol administration led to a marked increase (47%) in plasma GSH in the post-hepatic inferior vena cava, but not in its pre-hepatic segment. Data suggest that an increased loss of GSH from the liver constitutes an important mechanism for the decrease in GSH induced by ethanol. In addition, an inhibition of GSH synthesis is observed.

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A medical evaluation of the effects of computer assisted muscle stimulation in paraplegic patients

An examination of the medical and physiological effects of functional electrical stimulation (FES) applied to the quadriceps muscle of five paraplegic male volunteers with complete spinal cord injuries was performed. FES training was provided three days a week over a 12-week period using a progressive resistive exercise protocol. Stimulation was applied through use of a closed-loop microprocessor-based FES system. Prior to the start of and immediately following the 12-week training period, subjects were assessed on several measures, including quadriceps muscle bulk and histochemistry, laboratory studies, echocardiography, and arm ergometry exercise. Results of the study indicated substantial increases in muscle strength and muscle bulk. At the outset of the study one patient suffered a patellar fracture. No significant changes in pretraining and posttraining general examinations, laboratory studies, echocardiography, or arm ergometry exercise testing were noted.

Post-natal development of functional neurotransmission in rat vas deferens

Responses of the rat vas deferens to drugs and to field stimulation were examined in sexually immature rats. The vasa from immature rats often exhibited spontaneous contractions and displayed greater sensitivity to the contractile effects of alpha-adrenoceptor agonists. The responses of the vasa from immature rats to single pulse field stimulation lacked the adrenergic component of the response although the non-adrenergic component was present. The responses were antagonized by alpha 2-adrenoceptor agonists. In the presence of cocaine, an adrenergic component of the response did appear. During trains of pulses the pre- and postjunctional effects of adrenergic transmission which are found in adult rats were absent in vasa from immature rats. Electron microscopic studies showed no qualitative differences in adrenergic innervation in vasa from immature and adult rats. It is concluded that a state of 'pre-innervation supersensitivity' associated with a lack of functional adrenergic transmission exists in the vas deferens of immature rats. The supersensitivity disappears and functional transmission develops during the period in which testosterone secretion increases in the rat. The reason for the lack of functional transmission at a time when the innervation appears to be morphologically mature is not clear but may be due to the noradrenaline release mechanism not being fully operative.

Separation of adrenergic and non-adrenergic contractions to field stimulation in the rat vas deferens

Adrenergic and 'non-adrenergic' nerve-induced contractions in rat vas deferens were separated pharmacologically. Responses to single stimuli comprised two components, an alpha-noradrenergic component (IIs), dominant in the epididymal portion, and a 'non-adrenergic' component (Is), dominant in the prostatic portion. Is but not IIs was blocked by nifedipine. A combination of adrenergic blockade and nifedipine virtually abolished all components. After cocaine, a third component (IIIs) emerged which was abolished by either adrenergic blockade or nifedipine. The response to trains of stimuli consisted of 'twitch' and 'secondary' components. This biphasic time course was modified by adrenergic blockade or nifedipine to reveal the time course of the 'non-adrenergic' and adrenergic components, respectively: these did not correspond to the 'twitch' and 'secondary' components. A combination of adrenergic blockade and nifedipine virtually abolished the whole response. Prejunctional alpha 2-adrenoceptor-mediated inhibition of the contractile responses could be blocked by selective alpha 2-adrenoceptor antagonists. The adrenergic contractile response demonstrated this 'feed-back' even on the second pulse at 0.5 Hz. Endogenous inhibition of the 'non-adrenergic' contraction required higher frequencies or enhancement of the extracellular concentration of noradrenaline by blockade of its neuronal uptake. Contractile responses to exogenous noradrenaline were abolished by nifedipine, at a concentration that did not affect the adrenergic (IIs) neurotransmission. These results reinforce the view that part of the motor transmission in rat vas deferens is non-adrenergic and allow the disentanglement of the various postjunctional and prejunctional elements contributing to the complex response to a train of stimuli.

Chemical and ultrastructural changes in tapetum of beagles with a hereditary abnormality

We have defined the defect in the tapetum of beagles with an inherited tapetal abnormality to be the absence of both zinc and cysteine from the tapetal rods. This was demonstrated by direct measurement of zinc and cysteine and by histochemical localization of zinc. The latter method also indicated an interesting substructure in tapetal rods from normal beagles, in which the zinc is apparently distributed in two concentric rings. The chemical changes involved in different methods of fixing this unique tissue have been examined and correlated with the ultrastructure.

Food intolerance and food allergy in children: a review of 68 cases

The clinical and laboratory features of 68 children with food intolerance or food allergy are reviewed. Young children were affected the most with 79% first experiencing symptoms before age 1 year. Forty-eight (70%) children presented with gastrointestinal symptoms (vomiting, diarrhoea, colic, abdominal pain, failure to thrive), 16 (24%) children with skin manifestations (eczema, urticaria, angioneurotic oedema, other rashes), and 4 (6%) children with wheeze. Twenty-one children had failed to thrive before diagnosis. A single food (most commonly cows' milk) was concerned in 28 (41%) cases. Forty (59%) children had multiple food intolerance or allergy; eggs, cows' milk, and wheat were the most common. Diagnosis was based on observing the effect of food withdrawal and of subsequent rechallenge. In many children food withdrawal will mean the use of an elimination diet which requires careful supervision by a dietician. Laboratory investigations were often unhelpful in suggesting or confirming the diagnosis.