Circumventricular structures: CNS sensors of circulating peptides and autonomic control centres

Previous studies have suggested the subfornical organ (SFO) to be the CNS site at which circulating angiotensin (ANG) acts to influence a variety of regulatory control mechanisms. We have utilised electrophysiological techniques: 1. to examine the neural connections through which the SFO exerts such control over hypothalamic regulatory control centres; 2. to investigate the responsiveness of neurons in a second circumventricular organ, the area postrema (AP), to circulating peptides. In accordance with previous endocrine studies we have demonstrated excitatory influences of SFO efferents on hypothalamic neurosecretory neurons putatively identified as vasopressin, oxytocin, CRH, and LHRH secreting. In addition systemic ANG increased the activity of the former three groups of these neurons, an effect which was abolished by destruction of the SFO. Single unit recordings from AP neurons have demonstrated subpopulations of cells in this regions to be sensitive to either circulating ANG or changes in blood pressure.

Pirenzepine in non-ulcer dyspepsia: a double-blind multicentre trial

In a double-blind multicentre study to compare pirenzepine with placebo in non-ulcer dyspepsia, 71 patients were randomized to receive 50 mg pirenzepine or placebo given orally twice daily for 4 weeks. The trial was not completed by five patients in the pirenzepine group and six in the placebo group. There were no significant differences between the groups in respect to changes in total symptoms (upper abdominal pain, nausea and vomiting, early satiety and postprandial bloating, eructation and pyrosis) scores and outcome, although 27/35 (77%) patients receiving pirenzepine were cured or improved compared with 22/36 (61%) receiving the placebo. Adverse effects were reported by 13 (37%) patients treated with pirenzepine and by six (17%) treated with placebo, seven withdrawing due to adverse effects.

Salivary and serum antibodies to gliadin in the diagnosis of celiac disease

Salivary IgA and serum IgA and IgG antibodies to crude gliadin and alpha-gliadin were measured in adult patients with untreated celiac disease, ulcerative colitis, Crohn's disease and normal controls. Antibody levels in saliva and serum in untreated celiac disease were significantly higher than in other groups. Alpha-gliadin antibodies appeared to be a better discriminator for serum but not for saliva. The assay of salivary IgA antibodies to gliadin offers a non-invasive test which would be particularly useful in the investigation of celiac disease and for monitoring compliance with a gluten-free diet.

A prospective randomised controlled trial of tamoxifen and cyproterone acetate in pancreatic carcinoma

In a prospective controlled clinical trial, 108 patients with pancreatic adenocarcinoma were randomly allocated to receive tamoxifen 20 mg b.d., cyproteron acetate 100 mg t.d.s. or no active treatment. The median survival of those receiving tamoxifen was longer than either of the other two groups (5.25 compared to 4.25 and 3 months, respectively) but this difference did not achieve statistical significance. Cox regression analysis of 12 clinical and biochemical features showed that, for the entire group of patients, survival was significantly longer in younger patients, those undergoing surgical bypass and those with better initial performance status. However, even when adjustment was made to allow for the distribution of these prognostic variables within the three groups, the difference in survival still did not achieve statistical significance. No side-effects attributable to treatment was observed.

Effect of dietary carbohydrates on insulin and glucagon receptors in a new model of noninsulin-dependent diabetes-SHR/N-corpulent rat

A new congenic strain of rat, the SHR/N-corpulent, provides a good model for noninsulin-dependent diabetes and was used in the present study. Corpulent rats as compared to their lean littermates are obese, hyperlipidemic, and severely hyperinsulinemic, and show an age-dependent loss of glucose tolerance. Mild fasting hyperglycemia is seen only in corpulent rats fed sucrose. Since dietary sucrose is more lipogenic than starch and since insulin and glucagon are involved in lipid and carbohydrate metabolism, we studied the effect of the type of dietary carbohydrate on insulin and glucagon levels and their receptors in lean and corpulent SHR/N rats. A significant phenotypic effect was observed (corpulent greater than lean) on plasma levels of triglyceride, cholesterol, and insulin. Dietary sucrose increased these parameters in corpulent rats but not in lean rats. Insulin and glucagon binding to liver plasma membranes was lower in corpulent rats than in lean; decreases were due to fewer receptors without a significant change in affinity. Thus, in corpulent rats, in addition to hyperinsulinemia, fewer glucagon receptors and their failure to be regulated by plasma glucagon levels appear to contribute to the hyperlipidemia. Furthermore, the hyperglycemia observed in sucrose-fed corpulent rats may be due to extreme resistance to insulin despite lower plasma glucagon and fewer glucagon receptors.

Dietary fat and menstrual-cycle effects on the erythrocyte ghost insulin receptor in premenopausal women

The effect of high- and low-fat diets with different levels of fatty acid unsaturation on insulin receptors of erythrocyte ghosts was studied during different phases of the menstrual cycle in 31 healthy premenopausal women. Subjects were divided into two groups and consumed controlled diets containing 39% fat with a ratio of polyunsaturated to saturated fatty acids (P:S) of either 0.30 or 1.00 for four menstrual cycles. They were switched to 19% fat at the same P:S for another four cycles. Fasting blood samples were collected during the follicular and luteal phases. Insulin receptors were measured from right-side-out ghosts. Insulin binding was significantly lower due to fewer receptors when subjects were fed the low-fat, high-carbohydrate diet compared with the high-fat, low-carbohydrate diet. There was no significant effect of level of unsaturation or time of menstrual cycle on insulin binding. Thus, insulin receptors on erythrocytes respond to dietary lipids.

Organic anion and cation transport in crab urinary bladder

Crab urinary bladder, a simple, flat-sheet epithelium, is structurally and functionally analogous to vertebrate renal proximal tubule. Like proximal tubule, crab bladder plays an important role in the excretion of potentially toxic, charged metabolites and xenobiotics. Bladders from Cancer borealis secrete monovalent, organic anions and cations in vivo and in vitro. For organic cations, secretion is a two-step process, with mediated and energetically downhill uptake into cells at the serosal membrane and uphill exit at the luminal membrane. The uptake step may be driven by the electrical potential difference across the serosal membrane, the luminal step by organic cation-proton exchange. Monovalent organic anions are also secreted by a separate two-step process. Recent experiments with intact bladder tissue and isolated membrane vesicles show that (as in mammalian proximal tubule) uphill serosal uptake can be coupled indirectly to the Na+ gradient. Organic anion (p-aminohippurate; PAH) uptake is driven by exchange for certain divalent organic anions, e.g., glutarate and alpha-ketoglutarate. The divalent anion gradient (in greater than out) is in turn maintained by Na+-coupled divalent uptake. The PAH exist step at the luminal membrane is mediated and downhill; it may involve anion exchange.

Hormones regulating lipid and carbohydrate metabolism in premenopausal women: modulation by dietary lipids

The effect of high- and low-fat diets with different levels of fatty acid unsaturation on plasma hormones involved in lipid metabolism was studied during different phases of the menstrual cycle in 31 premenopausal women. Subjects were divided into two groups and were fed controlled diets containing 39% fat with a ratio of polyunsaturated to saturated fatty acids (P:S) of either 0.3 or 1.0 for four menstrual cycles and then switched to a 19% fat diet with the same P:S for another four cycles. Blood samples were analyzed during both the follicular and luteal phases. A significant direct effect of level of dietary fat was observed on plasma cortisol and dehydroepiandrosterone-sulphate whereas an inverse relationship was seen for plasma insulin. Both plasma insulin and growth hormone levels were higher during the luteal compared with the follicular phase of the menstrual cycle. None of the hormones was affected by the level of unsaturation of dietary fats.

A theoretical and experimental study of low-loss SAW filters with interdigitated interdigital transducers

A study of low-loss surface-acoustic-wave (SAW) interdigitated interdigital transducer (IIDT) structures is presented. A model based on mixed scattering matrices was used in the analysis. It is shown that the inherent comb frequency response of the IIDT can be smoothed by slanting the transducers in the structure. Alternatively, the combs can be enhanced to produce a compact low-loss feedback element for potential application in multimode oscillators. Experimental verification of the analysis is provided by a 3:2 slanted-finger IIDT filter with a 10% relative bandwidth of 5.9-dB insertion loss, and a comb filter with 13.4-dB insertion loss and comb spacing of about 3 MHz. The measured responses agree quite well with the theory.

Simultaneous extraction of beta-endorphin and leu- and met-enkephalins from human and rat plasma

A simple, rapid and reliable procedure is described to simultaneously concentrate and purify beta-endorphin, leu- and met-enkephalins from small volumes of human and rat plasma before radioimmunoassay is performed. It uses C18 Sep-Pak reverse phase cartridges. The effectiveness of different protease inhibitors in preventing degradation of opiates by plasma and different solvent systems for eluting opiates is also evaluated.

Oesophageal tears during pneumatic balloon dilatation for the treatment of achalasia

Fifty-eight contrast studies of the oesophagus, performed in patients shortly after balloon dilatation for the treatment of achalasia, were reviewed for evidence of perforation. Forty-nine examinations (85%) were normal and nine studies (15%) were abnormal. Three main radiological patterns were observed. Complete rupture of the oesophagus occurred in two cases. Incomplete tears of the oesophageal wall were present in seven cases: in one patient there was a linear mucosal tear while in six patients there was a localised outpouch or diverticulum. All patients with abnormal contrast studies were successfully managed conservatively. The range of radiological appearances of the distal oesophagus following balloon dilatation should be recognised to avoid unnecessary surgical intervention.

A submucosal mechanism for catecholamine-induced increases in fluid absorption in rabbit ileum in vitro

1. The effects of clonidine and dopamine on water movements across the mucosal and serosal surfaces of rabbit ileum have been investigated using a high-resolution method for monitoring water flows in vitro. 2. Theophylline (10 mM) and carbamyl choline (10 microM) caused a reduction in fluid inflow across the mucosal surface and a smaller decrease in fluid outflow across the serosal surface. Addition of the alpha 2-adrenergic agonist clonidine or dopamine fully reversed the theophylline, or carbamyl choline-induced decrease in mucosal inflow in a dose-related manner. 3. The effects of clonidine on mucosal inflow are blocked by the alpha 2-adrenergic antagonist, yohimbine. Yohimbine was much less effective than pimozide or d-butaclamol in blocking the effect of dopamine on mucosal inflow. These findings support the view that there are separate alpha 2-adrenergic and dopaminergic receptors. 4. The hydraulic conductance (Lp) of the serosal surface was measured directly from the change in serosal exit flow following addition of 2 mosmol kg-1 of polyethylene glycol (molecular mass 20,000 Da) to the serosal bathing solution. Theophylline reduced the Lp by 35%. Clonidine (1 microM) added to theophylline-treated tissues increased the Lp by 66%. This effect was prevented by yohimbine (1 microM). 5. The effects of theophylline, clonidine and dopamine on the permeability of the mucosal and serosal surfaces of the tissue to [3H]mannitol were measured. These showed that theophylline increased the rate of labelled mannitol loss across the mucosal surface but reduced the mannitol permeability across the serosal surface. This latter effect was reversed by clonidine and dopamine. 6. Changes in transepithelial electrical potential difference (PD), short-circuit current and resistance were monitored. Theophylline caused a rapid increase in PD and short-circuit current and a slower increase in resistance. Clonidine (5 microM) reversed the effects on PD and resistance but was without significant effect on short-circuit current. The results suggest that a major component of secretagogue-induced reduction in fluid transport in vitro is due to mechanical changes in the submucosa, probably induced by modulation of neurotransmitter release within the tissue.

Membrane potential drives organic cation transport into teleost renal proximal tubules

The relationship between organic cation uptake and basolateral membrane potential was studied in renal tubules from two marine teleost fish, Southern flounder (Paralicthys lethostigma) and killifish (Fundulus heteroclitis). Carrier-mediated uptake of the model organic cation, tetraethylammonium (TEA), increased when K+ was changed from 2.5 to 0.2 mM and decreased when medium K+ was increased to 20 mM. Uptake was also reduced by the K+ channel blocker barium (1 mM). Furthermore, basolateral membrane potential hyperpolarized 15-25 mV in low-K+ medium and depolarized 30-40 mV in high-K+ medium. Barium also depolarized. Finally, basolateral membrane potential was depolarized in a concentration-dependent manner by addition of 100-500 microM TEA or Darstine. Thus treatments that hyperpolarize the basolateral membrane potential increase carrier-mediated TEA uptake, whereas those that depolarize basolateral membrane potential reduce uptake. Furthermore, organic cation transport into tubular cells involves the net influx of positive charge. Together, these findings support the argument that carrier-mediated organic cation uptake at the basolateral membrane is a potential-driven, electrogenic process.

Inositol phosphates: proliferation, metabolism and function

After the initial discovery of receptor-linked generation of inositol(1,4,5)trisphosphate (Ins(1,4,5)P3) it was generally assumed that Ins(1,4,5)P3 and its proposed breakdown products inositol(1,4)bisphosphate (Ins(1,4)P2) and Ins1P, along with cyclic inositol monophosphate, were the only inositol phosphates found in significant amounts in animal cells. Since then, three levels of complexity have been introduced. Firstly, Ins(1,4,5)P3 can be phosphorylated to Ins(1,3,4,5)P4, and the subsequent metabolism of these two compounds has been found to be intricate and probably different between various tissues. The functions of Ins(1,4,5)P3 and Ins(1,3,4,5)P4 are almost certainly to regulate cytosolic Ca2+ concentrations, but the reasons for the labyrinth of the metabolic pathways after their deactivation by a specific 5-phosphatase remain obscure. Secondly, inositol pentakis- and hexakisphosphates have been found in many animal cells other than avian erythrocytes. It has been shown that their synthesis pathway is entirely separate from the inositol phosphates discussed above, both in terms of many of the isomers involved and probably in the subcellular localization; some possible functions of InsP5 and InsP6 are discussed here. Thirdly, cyclic inositol polyphosphates have been reported in stimulated tissues; the evidence for their occurrence in vivo and their possible physiological significance are also discussed.

Mode selection in a multimode SAW oscillator using FM chirp mixing signal injection

Mode-selection control of a multimode surface-acoustic-wave (SAW) oscillator has been obtained using SAW linear FM chirp signal injection. The prototype 60-100-MHz SAW oscillator design employed a single-phase unidirectional transducer (SPUDT) low-loss comb filter in the feedback loop, with minimum insertion loss of approximately 3.7 dB. Mode selection was achieved using an injection signal derived from the mixed output of two 27.5-52.5-MHz up- and down-chirp SAW filters. Mode switching times of less, similar2 mus were obtained. The device could be useful as a local oscillator on frequency-agile radars, where hopping is required over a moderate number of frequencies.

Effects of theophylline, choleragen and loperamide on rabbit ileal fluid and electrolyte transport in vitro

1 The effects of theophylline and cholera toxin on water and anion movements across rabbit ileum in vitro and the reversal of these effects by the opiate action of loperamide have been investigated. Water movement across the mucosal and serosal surfaces of the tissue was measured continuously by a high resolution method. 2 Theophylline caused an increase in short circuit current and reversed the direction of net C1- movement, due mainly to a decrease in mucosal-serosal flux. It also caused a rapid, but transient, reversal in the direction of fluid movement across the mucosal surface. Fluid outflow across the serosal surface was decreased but not reversed. Cholera toxin caused a slow inhibition of water movement across both mucosal and serosal surfaces. 3 Theophylline increased the exit rate of 77Br across the mucosal surface and decreased the exit rate of 77Br across the serosal surface. Theophylline increased the exit rate of 3H-labelled mannitol across the mucosal surface. 4 Loperamide reversed the effects of theophylline and cholera toxin on water flow across the mucosal and serosal surfaces and on net transepithelial C1- flux; it also increased the rate of 77Br exit across the serosal surface of theophylline-treated tissue. These effects of loperamide could be reversed by naloxone. 5 The hydraulic conductivity, Lp of the serosal surface was measured directly by determining the osmotic flow generated by low concentrations of polyethylene glycol (mol. wt. 20,000 and 90,000). Theophylline reduced the Lp by 57%. Loperamide added to theophylline-treated tissues increased the Lp by 340%. This effect was reversed by naloxone. 6 These results indicate that modulation of intestinal smooth muscle tone affects transepithelial ion and water flows in vitro. The increase in tone induced by secretagogues increases ion and water reflux via wide shunt channels in the mucosa and thereby reduces net absorption. The increased net fluid and electrolyte absorption induced by loperamide results from the opiate-dependent inhibition of acetylcholine release from intrinsic ganglia which reduces smooth muscle tone and thereby enhances the fluid and electrolyte conductance of the submucosal layers.

A model for accelerated uptake and accumulation of sugars arising from phosphorylation at the inner surface of the cell membrane

A model transport system for cellular accumulation of sugar coupled to phosphorylation is described. Sugar permeates the cell membrane via a passive facilitated transport system. On the inside surface of the membrane the bound sugar is either phosphorylated to form impermeable hexose phosphate, which is released into the intracellular solution, or released directly into the cytosol. Sugar may be regenerated from hexose phosphate in the cytosol via a phosphatase reaction. The reduction of the proportion of sites on the inner membrane surface occupied by permeable sugar, caused by the kinase reaction, increases both net and unidirectional passive inflow and reduces both net and unidirectional exit of sugar, thereby permitting large stationary state gradients of free sugar to be maintained between the cytosol and bathing solution. In cells where there is a high passive membrane permeability to free sugar, steady-state accumulation of free sugar within the cytosol, linked to metabolism is inexplicable in terms of conventional transport kinetics based on equilibrium thermodynamic assumptions. This phenomenon is analysed in terms of non-equilibrium stationary state flows of ligands via a probability network. The effects of metabolism on exchange transport are also examined. The model provides a framework to explain how sugar transport is loosely coupled to phosphorylation in mammalian epithelial cells, adipocytes, yeasts and bacteria, so that a high rate of substrate accumulation is maintained without requiring a reduction in the intracellular concentration of permeable substrate below that in the external solution.

Reproduction of epigastric pain of duodenal ulceration by adenosine

Intravenous boluses of adenosine produced transient epigastric discomfort indistinguishable from spontaneous pain in five of six patients with endoscopically confirmed duodenal ulcer, an effect which was slightly but significantly antagonised by aminophylline. These findings may be relevant to the pathophysiology of peptic ulcer pain.

Fulminant hepatitis B in successive female sexual partners of two anti-HBe-positive males

In two separate families, consecutive, unrelated female sexual partners of a symptom-free, male, HBsAg-positive carrier died of fulminant hepatitis B. Although one man was HBeAg positive on the first occasion, both men were considered of low infectivity, being anti-HBe positive, negative for serum DNA polymerase activity, and negative for serum hepatitis B virus (HBV) DNA when their second partners presented with fulminant hepatitis B. By means of molecular hybridisation techniques, both men were found to have HBV DNA (3.2 kb) in seminal fluid, sputum, saliva, peripheral blood leucocytes, and liver.

Depression and functional bowel disorders in gastrointestinal outpatients

Although depression has been linked with both the irritable bowel syndrome and non-organic abdominal pain, which are common in gastrointestinal outpatients, the prevalence of depression in most surveys of outpatient practice has been low. Use of the Beck Depression Inventory to screen new referrals to a general medical and gastrointestinal clinic and to a minor surgical clinic showed that 50 of 100 medical patients were rated as having some degree of depression, compared with 14 of 75 (19%) of the surgical patients in whom abdominal pain and bowel dysfunction were rare (X2 = 9.6, p less than 0.01). In the medical clinic no organic disorder was detected in 64% of the depressed patients, the majority of whom presented with abdominal pain or irritable bowel syndrome. Depression was significantly commoner in this group of patients than in those with other conditions, (X2 = 6.63, p = 0.01). That depression is common in gastrointestinal outpatients is not always appreciated and its symptoms should be sought in all patients with bowel dysfunction and chronic abdominal pain.

Study of obesity in dogs visiting veterinary practices in the United Kingdom

A total of 8268 dogs were surveyed in 11 veterinary practices in the United Kingdom during a period of six months in 1983. The primary purpose of the survey was to assess the level of obesity on a five point scale with properly identified criteria. Information on the clinical condition of each dog was also recorded as well as proportions of food types fed, particulars of breed, sex, age, sexual status and the dog's name. Results showed that 21.4 per cent of dogs in the survey were judged to be obese and 2.9 per cent gross; 1.9 per cent were judged as thin, 13.5 per cent lean and 60.3 per cent were optimum. Labradors were found to be the most likely breed to become obese. Neutered females were about twice as likely to be obese as entire females. The same trend was evident with neutered males. Circulatory problems were associated with dogs over 10 years old and those which were gross, rather than obese. A similar trend was discernable with articular/locomotor problems. Skin and reproductive problems showed little relationship with age or obesity. Neoplasia was much more prevalent in dogs over 10 years old but had little relationship with either sexual status or obesity rating. There was a high rate of usage of prepared food for all categories. The amount of fresh food fed decreased rapidly as the proportion of canned food increased, but the obese and non-obese dogs showed very little difference in the type of food fed.

High molecular weight kininogen: localization in the unstimulated and activated platelet and activation by a platelet calpain(s)

High mol wt kininogen (HMWK), the major cofactor-substrate of the contact phase of coagulation, is contained within and secreted by platelets. Studies have been performed to localize platelet HMWK in both the unstimulated and activated platelet and to ascertain the effect of platelet enzymes on HMWK itself. On platelet subcellular fractionation, platelet HMWK was localized to alpha-granules, and platelets from a patient with a deficiency of these granules (gray platelet syndrome) had 28% normal platelet HMWK. Platelet HMWK, in addition to being secreted from the platelet, was also localized to the surface of the platelet when activated. Using a competitive enzyme-linked immunosorbent assay for HMWK as an indirect antibody consumption assay, the external membrane of thrombin-activated platelets as well as the releasate from these stimulated platelets had 17 ng HMWK antigen/10(8) platelets available, whereas unstimulated platelets and their supernatant had only 4.9 and 4.2 ng HMWK/10(8) platelets present, respectively. The anti-HMWK antibody consumption by activated normal platelets was specific for membrane-expressed platelet HMWK, since activated platelets from a patient with total kininogen deficiency did not adsorb the anti-HMWK antibody. Enzymes in the cytosolic fraction of platelets cleaved 125I-HMWK (mol wt 120,000) into a mol wt 100,000 polypeptide as well as smaller products at mol wt 74,000, mol wt 62,000, mol wt 47,000, and a few components below mol wt 45,000. No cleavage products were observed when DFP and leupeptin were present. The cleavage of HMWK was specifically prevented by inhibitors of calcium-activated cysteine proteases (leupeptin, N-ethylmaleimide, iodoacetamide, and EDTA) but not by inhibitors of serine proteases (DFP, benzamidine, soybean trypsin inhibitor, or aprotinin). Platelet cytosol increased the coagulant activity of exogenous purified HMWK with maximum HMWK coagulant activity (35-fold) occurring within ten minutes of exposure to platelet cytosol. Treatment of platelet cytosol with leupeptin prevented the increase in the coagulant activity of exogenous HMWK. These studies indicate that activated platelets express platelet HMWK on their external membrane and platelet enzymes can cleave and increase the coagulant activity of exogenous HMWK.

Evidence for non-uniform distribution of D-glucose within human red cells during net exit and counterflow

The kinetic parameters of net exit of D-glucose from human red blood cells have been measured after the cells were loaded to 18 mM, 75 mM and 120 mM at 2 degrees C and 75 mM and 120 mM at 20 degrees C. Reducing the temperature, or raising the loading concentration raises the apparent Km for net exit. Deoxygenation also reduces the Km for D-glucose exit from red blood cells loaded initially to 120 mM at 20 degrees C from 32.9 +/- 2.3 mM (13) with oxygenated blood to 20.5 +/- 1.3 mM (17) (P less than 0.01). Deoxygenation increases the ratio Vmax/Km from 5.29 +/- 0.26 min-1 (13) for oxygenated blood to 7.13 +/- 0.29 min-1 (17) for deoxygenated blood (P less than 0.001). The counterflow of D-glucose from solutions containing 1 mM 14C-labelled D-glucose was measured at 2 degrees C and 20 degrees C. Reduction in temperature, reduced the maximal level to which labelled D-glucose was accumulated and altered the course of equilibration of the specific activity of intracellular D-glucose from a single exponential to a more complex form. Raising the internal concentration from 18 mM to 90 mM at 2 degrees C also alters the course of equilibration of labelled D-glucose within the cell to a complex form. The apparent asymmetry of the transport system may be estimated from the intracellular concentrations of labelled and unlabelled sugar at the turning point of the counterflow transient. The estimates of asymmetry obtained from this approach indicate that there is no significant asymmetry at 20 degrees C and at 2 degrees C asymmetry is between 3 and 6. This is at least 20-fold less than predicted from the kinetic parameter asymmetries for net exit and entry. None of the above results fit a kinetic scheme in which the asymmetry of the transport system is controlled by intrinsic differences in the kinetic parameters at the inner and outer membrane surface. These results are consistent with a model for sugar transport in which movement between sugar within bound and free intracellular compartments can become the rate-limiting step in controlling net movement into, or out of the cell.

Ovulation induction

Ovulation induction has developed as a valuable noninvasive therapy for the infertile couple. The nurse's role focuses on assisting the couple, as a unit, to understand and cope with the necessary regimen, tests, examinations, and therapies necessary to reach the goal of conception. The physiologic regulation of the menstrual cycle, current pharmacologic therapy, treatment protocols, and the unique role of the infertility nurse are reviewed.

The radiological appearances of the oesophagus after sclerotherapy for varices

Fifteen patients, whose oesophageal varices had been obliterated by injection sclerotherapy, were examined by double-contrast barium swallow. In nine patients (60%) the oesophagram was abnormal and demonstrated sharp-edged, longitudinal tramline filling defects and an irregular, patchy nodularity with loss of the normal longitudinal folds. These appearances represent redundant epithelial folds, epithelial tags and healed ulcers produced by endoscopic sclerotherapy.

Platelet C1- inhibitor. A secreted alpha-granule protein

In order to characterize which proteins of the contact phase of coagulation interact with platelets, human platelets were studied immunochemically and functionally to determine if they contain C1- inhibitor. By means of monospecific antibody to C1- inhibitor, a competitive enzyme-linked immunosorbent assay (CELISA) was developed to measure directly platelet C1- inhibitor. With the CELISA, from 33 to 115 ng of C1- inhibitor antigen per 10(8) platelets from 15 normal donors was quantified in lysates of washed human platelets solubilized in nonionic detergent. The mean concentration in 10(8) platelets was 62 +/- 33 ng (SD). Plasma C1- inhibitor either in the platelet suspension medium or on the surface of the platelets could account for only from 6.5 to 16% of the total antigen measured in the solubilized platelets. Upon functional studies, platelets contained 84 +/- 36 ng (SD) of C1- inhibitor activity in 10(8) platelets. As assessed by the CELISA, platelet C1- inhibitor antigen was immunochemically identical to plasma and purified C1- inhibitor. In contrast, the mean concentration of platelet C1- inhibitor antigen in platelets from four patients with classical hereditary angioedema was 8.3 ng/10(8) platelets (range, 5.3 to 11.3 ng/10(8) platelets). 25 and 31% of the total platelet C1- inhibitor was secreted without cell lysis from normal platelets after exposure to collagen (20 micrograms/ml) and thrombin (1 U/ml), respectively, and this secretion was blocked by metabolic inhibitors. Platelet subcellular fractionation showed that platelet C1- inhibitor resided mostly in alpha-granules, similar to the location of platelet fibrinogen. Thus, human platelets contained C1- inhibitor, which became available by platelet secretion. The identification of platelet C1- inhibitor suggests that platelets may modulate the activation of the proteins of early blood coagulation and the classical complement pathways.

Perforating veins and blood flow in oesophageal varices

Blood-flow patterns in oesophageal varices were studied by doppler ultrasound (18 patients) and injection radiography (34 patients). Both techniques demonstrated that blood flow is not always in the expected cephalad direction but is often towards the stomach. Doppler studies indicated that there are functioning perforating veins joining oesophageal varices to the peri-oesophageal veins, particularly at the lower end of the oesophagus. The presence of these perforators was confirmed by intravariceal injection radiography and also at necropsy. The turbulent flow caused by these veins may explain why variceal rupture commonly occurs just above the gastrooesophageal junction. Successful treatment of oesophageal varices with the minimum of sclerotherapy treatments may depend on early obliteration of the incompetent perforating veins.

Pneumococcal vaccine in elderly patients with COPD

Antibody levels to 12 serotypes of the 14 valent pneumococcal vaccine were measured in 12 patients (mean age of 70) with chronic obstructive pulmonary disease (COPD), approximately one year postvaccination and in 17 additional patients with COPD (mean age 70) who were not vaccinated. In the vaccinated group, the geometric mean antibody concentration (GMAC) 13 months postvaccination was above the presumed postvaccination minimally protective level (250 to 300 ng of antibody nitrogen per milliliter) for all serotypes except 6A and 19F. Antibody levels exceeded 700 ng for nine of 12 types. The GMAC for all 12 types was 927. In the nonvaccinated group, GMAC were slightly higher than seen with healthy younger persons (395 vs 217). It is concluded that elderly persons with COPD have adequate antibody titers for at least one year after vaccination.

Factors affecting successful endoscopic sclerotherapy for oesophageal varices

Forty patients with bleeding oesophageal varices were studied during treatment by endoscopic sclerotherapy to discover what factors determine successful outcome. Large varices required more injections than small varices for obliteration, and rebleeding during treatment occurred only in patients with large varices. Radiological studies with sclerosant contrast mixture showed that in two groups of varices of comparable size, intravenous sclerosant was significantly more effective, leading to thrombosis in 8/10 as opposed to only 3/10 after paravasal injection (p less than 0.05). Intravenous contrast was rapidly cleared upwards, whereas paravasal contrast formed a rounded opacity alongside the vein that persisted for approximately 90 minutes, responsible for the complications of oesophageal ulceration and stenosis.

A prospective randomised controlled trial of diazepam (valium) vs emulsified diazepam (diazemuls) as a premedication for upper gastrointestinal endoscopy

Two hundred and forty four patients were randomised to receive either diazepam or emulsified diazepam (diazemuls) intravenously prior to routine upper gastrointestinal endoscopy. The groups were comparable with regard to age, sex, medical condition, vein size, and amount of drug administered. A quantitative assessment of symptoms at the injection site during the ensuing week was made by analysing questionnaires on pain and tenderness, which the patients graded each day, on a scale 0-3. Twenty-one out of 82 patients who received diazepam (25.6%) and 22 out of 84 who received diazemuls (26.2%) had local symptoms. Although the mean symptom scores over 7 days for the two groups were not different (5.95 +/- 5.19 and 7.27 +/- 6.30 respectively), more patients who received diazepam reported induration (P = 0.033). In 112 patients, signs of thrombosis in the injected veins were looked for 3-7 weeks later without knowledge of the preparation given. Thrombosis was present in 13 (25%) patients who had received diazepam and two (3.6%) who had received diazemuls (P less than 0.002). Only eight (53%) patients with thrombosed veins had symptoms. Thrombosis after intravenous injection of diazepam or diazemuls may be symptomless, and is significantly less likely following diazemuls.

Comparative digestible energy requirements of adult beagles and domestic cats for body weight maintenance

Digestible energy (DE) needs for body weight maintenance (BWM) of six adult Beagles and six domestic cats were comparatively assessed by using data from thirteen 14-day and nine 21-day consecutive apparent digestibility trials, respectively. In each trial the Beagles and cats were given different commercial foods, and feces were quantitatively collected excluding the first 7 days. The relationship between mean daily body weight change (delta BW) per trial and DE intake was examined by regression analysis of data for individual animals. Pooled mean (n = 6) data from 223 Beagle and 143 cats digestibility trials were analyzed by the same method. Significant (P less than 0.05) linear regressions between delta BW and DE intake were obtained (R2 = 0.43-0.93) for all individual Beagles, five of six cats and pooled mean data for both Beagles and cats. Mean (range) daily DE needs for BWM of six individual Beagles were 70 (63-78), 140 (127-146) and 173 (156-187) kcal for data scaled to kilograms, kilograms0.75 and kilograms0.67 BW, respectively. Respective values for six individual cats were 76 (56-89), 104 (86-114) and 114 (95-122) kcal. Analysis of group mean data for Beagles and cats generated daily DE costs for BWM of 76 and 66 kcal/kg, respectively, equivalent to 148 and 95 kcal/kg0.75. Thus adult cats had significantly (P less than 0.001) lower energy costs of BWM than Beagles when scaled to metabolic BW (kilograms0.75 or kilograms0.67), but not on an absolute BW basis.

Sampling and analysis of cerebrospinal fluid for chronic studies in awake rats

A method is described whereby cerebrospinal fluid (CSF) may be sampled repeatedly from awake rats over a period of 1 to 10 wk. Stainless steel or Teflon catheters (22-gauge) were implanted in the cisterna magna of anesthetized rats (n = 19) via a midline hole immediately rostral to the interparietal-occipital suture. Several days later almost simultaneous CSF and blood samples from the same air-breathing animals were slowly drawn into glass capillary tubes. pH was determined immediately by electrode and total CO2 by microgasometer. Because sampling via Tygon microbore tubing attached to the implanted catheters allowed part of CSF CO2 content to be lost through the tube wall, stainless steel tube is preferred to make this connection. For mock CSF, total CO2 calculated from pH and PCO2 values was closely comparable to that directly measured by microgasometer. CSF pH, PCO2, and [HCO-3] in five awake rats were found to be similar to those reported in the literature for the briefly anesthetized rat. The sampling procedure did not of itself significantly alter breathing patterns (n = 14). Thus, chronic CSF sampling is feasible in awake rats for purposes of studies of ventilatory control.

Squamous cell carcinoma of bladder. A review of 114 patients

A retrospective review of 114 cases of squamous cell carcinoma of bladder presenting in Glasgow between 1964 and 1978 is described with emphasis on treatment and survival. Ninety-seven patients (92.4%) were found to have invasive tumours (T2-T4) at diagnosis. Metastatic disease was confirmed in only 10 patients (8.8%). Only 23.8% of patients were alive one year after diagnosis, the overall 5-year survival rate being 1.9%. The 5-year survival rates for patients with T2 and T3 disease following radical radiotherapy were 16.7 and 4.8% respectively. No conclusions concerning the role of total cystectomy could be drawn from this series because of the small number of patients undergoing the operation, but a review of the literature suggests this may be the treatment of choice.

Progression of vinyl chloride induced hepatic fibrosis to angiosarcoma of the liver

ABSTRACT Two vinyl chloride monomer (VCM) workers, who developed non-cirrhotic portal fibrosis and portal hypertension, died from angiosarcoma of the liver five and ten years later respectively, despite withdrawal from occupational exposure. We suggest that non-cirrhotic portal fibrosis caused by exposure to VCM is potentially premalignant and that those workers who already have the condition should be carefully monitored.

Oesophageal varices treated by sclerotherapy: a histopathological study

Of 31 cases of haemorrhage from oesophageal varices treated by sclerotherapy eight came to necropsy. The oesophagus and proximal stomach were studied by means of a serial block technique and the histopathological findings in each case were recorded on two full-scale maps: one representing superficial tissues including the submucosa and the other the deeper tissues. The patterns of thrombosis, ulceration, necrosis, and fibrosis were studied in relation to the time interval since injection. Thrombosis and tissue necrosis were present within 24 hours of sclerotherapy, ulceration after seven days, and fibrosis after a month. Fibrosis was sometimes associated with stricture formation, which readily responded to dilatation. Patients with fibrosis had a reduced incidence of rebleeding.