Diagnosis of infection by frozen section during revision arthroplasty

We assessed the efficacy of intraoperative frozen-section histology in detecting infection in failed arthroplasties in 106 hips and knees. We found inflammatory changes consistent with infection (an average of one or more neutrophil polymorphs or plasma cells per high-power field in several samples) in 18 cases; there was a significant growth on bacterial culture in 20 cases. Compared with the bacterial cultures, the frozen sections provided two false-negative results and three false-positive results (sensitivity, 90%; specificity, 96%; and accuracy, 95%). The positive predictive value was 88%, the negative value, 98%. These results support the inclusion of intra-operative frozen-section histology in any protocol for revision arthroplasty for loose components.

Revenue enhancement through total quality management/continuous quality improvement (TQM/CQI) in outpatient coding and billing

To survive and thrive, rural hospitals are seeking enhanced revenues. This study focuses on outpatient laboratory and radiology coding and billing accuracy in a nonrandom sample of seven rural hospitals in a Western state. Information was gathered on (1) procedures incorrectly coded, (2) potential revenue increases from correct coding and billing, (3) barriers to implementing changes, and (4) perceived audit value. The identified major source of potential revenue enhancement was increased fees from private payers. Correct coding and billing to Medicare and Medicaid offered the potential of additional revenue. Participating administrators appreciated the validation of coding and billing practices and identification of potential enhanced revenues. Five of seven hospitals (71.4%) selectively implemented recommended changes. Complete compliance with recommended changes was limited by barriers of tradition, competition, and reimbursement, which must be overcome to realize successful implementation. Joint Commission on Accreditation of Healthcare Organization's (JCAHO) new Total Quality Management/Continuous Quality Improvement (TQM/CQI) emphasis provides an opportunity for revenue enhancement through coding/billing assessments and interdepartmental focus and coordination.

The new nurse executive. An emerging role

In recent years, the nurse executive (NE) has become an integral part of the hospital administrative team. The position has taken on a higher profile, and many questions are surfacing about every facet of NE administration. Since 1991, the literature is replete with articles discussing the new NE role. This article is a review summary and consolidation of 19 recently published articles, selected from a much broader list of periodical articles. It also reflects the results of six focus groups with hospital administrators and NEs in both urban and rural healthcare delivery settings. The summary pinpoints attributes identified as essential to an NE and those areas in which more research is needed. It also discloses that to function effectively, the new NE must have flexible and action-oriented personality qualities, possess executive level business management skills, have completed some graduate level degree work, and be an expert on clinical affairs. Future research should concentrate on the diverse educational needs of NEs and how to best meet those needs.

A comparison of omeprazole and ranitidine in the prevention of recurrence of benign esophageal stricture. Restore Investigator Group

BACKGROUND/AIMS

Dilatation combined with subsequent pharmacological control of gastroesophageal reflux represents a logical but poorly documented approach to the management of benign esophageal stricture. This large trial (366 patients) aimed to assess whether omeprazole as the most effective available medication for gastroesophageal reflux disease prevents recurrent stricture formation.

METHODS

Patients (n = 366) were randomized in a double-blind study to undergo either omeprazole (20 mg once daily; 180 evaluable patients) or ranitidine therapy (150 mg twice daily; 185 evaluable patients) for 1 year after dilatation to 12-18-mm diameter (36-54F gauge). Subsequently, endoscopy and dilatation were performed when clinically indicated and endoscopy on completion. Symptoms were assessed at clinic visits every 3 months and using weekly diary cards.

RESULTS

Fewer patients undergoing omeprazole therapy required redilatation compared with those on ranitidine (43 of 143 [30%] vs. 66 of 143 [46%] by 12 months; P < 0.01), and patients in the omeprazole group needed fewer redilatations during the year (0.48 vs. 1.08; P < 0.01). On completion, symptom relief favored omeprazole: 76% of patients in the omeprazole group were free of dysphagia (compared with 64% in the ranitidine group; P < 0.05); 83% were able to accept a normal diet (69%; P < 0.01); and 65% were completely asymptomatic (43%; P < 0.001).

CONCLUSIONS

Omeprazole, 20 mg once daily, was more effective than ranitidine, 150 mg twice daily, as prophylaxis against stricture recurrence and in providing symptom relief.

Opioid peptides, adrenocorticotrophic hormone, and idiopathic (orthostatic) edema

The effect of dextroamphetamine sulfate (Dexedrine) on plasma opioid peptides, hormones, and other metabolites was studied in eight female subjects with idiopathic (orthostatic) edema and five healthy females. All subjects were given 20 mg of dextroamphetamine sulfate, a drug widely used in the treatment of this disorder, and blood samples were collected before and 30, 60, and 90 minutes after treatment. Patients with idiopathic (orthostatic) edema had significantly lower plasma sodium levels but higher blood urea nitrogen, aldosterone, and renin levels. D-amphetamine decreased aldosterone and renin levels in both groups. Plasma adrenocorticotropin levels were lower whereas met-enkephalin levels were higher in idiopathic (orthostatic) edema subjects compared to control subjects. D-amphetamine had no significant effect on plasma beta-endorphin, adrenocorticotrophic hormone, or enkephalins. Our data indicate that opioid peptides, especially enkephalins, and adrenocorticotrophic hormone may be involved in the pathogenesis of idiopathic (orthostatic) edema syndrome, but they seem uninvolved in the aldosterone- and renin-lowering action of amphetamine. It is possible that amphetamine is acting further down the chain, either directly on the adrenal and kidney or the microvasculature, rather than at hypothalamus-pituitary axis.

Control of acute cutaneous herpes simplex virus infection: T cell-mediated viral clearance is dependent upon interferon-gamma (IFN-gamma)

It is well established that T lymphocytes play a critical role in the control and clearance of herpes simplex virus (HSV) infections. However, the role of the CD4+ and CD8+ T cell subsets in the recovery process has not been clearly elucidated. Cutaneous HSV infection of the footpad tissue of C57BL/6 (B6) mice provides a model to determine the relative contribution of each T cell subset during the important early phase of the response to infection. In this study, we observed that the elimination of mature peripheral T lymphocytes by depletion in vivo with a combination of Cd4- and CD8-specific monoclonal antibodies prevented recovery from acute infection in this model. However, mice depleted of either the CD4+ or CD8+ subpopulation alone recovered completely, with only a slight delay in the total clearance of infectious virus. Adoptive transfer studies revealed that lymph node cells from donor mice selectively depleted of either CD4+ or CD8+ T cell subset in vivo, or from normal donors selectively depleted in vitro, were able to mediate recovery. As CD4-depleted mice fail to generate a CD8+ T cell-mediated cytolytic T lymphocyte (CTL) response, this suggested that the control of cutaneous HSV infections may be mediated by a cytokine-dependent mechanism common to both the CD4- and CD8+ T cell subpopulations. It was subsequently found that the neutralization of IFN-gamma in vivo diminished the ability of mice to clear infectious HSV from the skin, and treatment with anti-IFN-gamma in vivo ablated the ability of transferred T cells to mediate recovery. These studies suggested that IFN-gamma-mediated mechanisms play a critical role in the control of and recovery from acute cutaneous HSV infection.

Isolation and characterization of group-I isoallergens from Bermuda grass pollen

Two isoallergens of Cyn d I were isolated using preparative isoelectric focussing, and were designated Cyn d Ia and b. These isoallergens differ in their pI, molecular weight (Cyn d Ia, 32 kD and Cyn d Ib, 31 kD) and their NH2-terminal sequence. Four monoclonal antibodies (Mabs) were produced using Cyn d Ia as antigen. These Mabs recognized both Cyn d Ia and b. One of the Mabs recognized four different pI forms of Cyn d I on 2D gels. The Mabs also recognized cross-reactive epitopes on proteins from eight other grasses including rye grass, timothy grass, Kentucky bluegrass and Johnson grass.

Rapid healing of gastric ulcers with lansoprazole

BACKGROUND

Lansoprazole is a new proton pump inhibitor which powerfully decreases acid secretion.

METHODS

We compared the efficacy and short-term safety of lansoprazole against ranitidine in the healing of gastric ulcer. This was a parallel group, comparative multicentre, prospectively randomized, double-blind study which included 250 patients with gastric ulcer, 219 of whom had follow-up endoscopic data.

RESULTS

Both lansoprazole 30 mg and 60 mg daily produced significantly more rapid healing of gastric ulcer than ranitidine 300 mg nightly with healing rates after 4 weeks of 78% (P < 0.05), 84% (P < 0.01) and 61%, respectively. After 8 weeks, the corresponding healing rates were 99%, 97% and 91% (P = 0.08). Symptom relief was similar for all treatment groups, but fewer antacids were used by patients receiving lansoprazole. Sixty-nine patients experienced 91 adverse events; the incidence, pattern and severity was similar across all three treatment groups.

CONCLUSIONS

Lansoprazole 30 mg and 60 mg once daily had similar efficacy. Both were superior to ranitidine 300 mg nocte in healing gastric ulcer. The short-term safety profile of lansoprazole was similar to ranitidine. These data indicate that lansoprazole should be used at a dose of 30 mg once daily for the treatment of gastric ulcers.

Thapsigargin-induced Ca2+ mobilization in acutely isolated mouse lacrimal acinar cells is dependent on a basal level of Ins(1,4,5)P3 and is inhibited by heparin

The tumour-promoting agent thapsigargin has been shown to inhibit the microsomal Ca(2+)-ATPase and cause Ca2+ mobilization in a variety of cell types including exocrine acinar cells [Bird, Obie and Putney (1992) J. Biol. Chem. 267, 18382-18386]. When applied to acutely isolated lacrimal acinar cells, thapsigargin caused a slow biphasic activation of both the Ca(2+)-dependent K+ and Cl- currents measured using the whole-cell patch-clamp technique. If the only action of thapsigargin is to inhibit sequestration into Ca2+ pools, then Ca2+ mobilization following exposure to thapsigargin indicates that there is a significant 'leak' of Ca2+ into the cytoplasm, which is normally countered by Ca(2+)-ATPase activity. In the present study, we introduced the Ins(1,4,5)P3 receptor antagonist heparin (200 micrograms/ml) into lacrimal acinar cells via the patch-clamp pipette. Following a 5 min preincubation in the presence of heparin, neither acetylcholine (1 microM) nor thapsigargin (1 microM) caused any significant increase in either Ca(2+)-dependent current. Caffeine has been shown to suppress basal Ins(1,4,5)P3 levels in exocrine acinar cells [Toescu, O'Neill, Petersen and Eisner (1992) J. Biol. Chem. 267, 23467-23470]. Preincubation with caffeine (10 mM) also inhibited the response to subsequent exposure to thapsigargin. These data suggest that, in acutely isolated lacrimal cells, the source of the Ca2+ leak which gives rise to Ca2+ mobilization following inhibition of Ca2+ re-uptake by thapsigargin is Ca2+ release, from Ins(1,4,5)P3-dependent Ca2+ pools, caused by resting Ins(1,4,5)P3 levels.

Immunological relationships among group I and group V allergens from grass pollen

Specific IgE antibodies have been affinity-purified from recombinant grass pollen allergens, and used to identify isoforms of the two major allergens of rye-grass pollen, Lol p I and Lol p V and cross-reactive allergens in other grasses. Lol p I-specific IgE (affinity-purified from the recombinant protein expressed by clone 13R which encodes amino acids 96-240 of Lol p I) identified four isoforms of the allergen. The same probe recognized cross-reactive epitopes in pollen proteins from 14 out of 16 grasses. The allergens identified by Lol p V-specific IgE (affinity-purified from the recombinant protein expressed by clones 12R or 19R which encode the full Lol p V protein) varied more in their physicochemical characteristics than the Group I isoforms. At least eight isoforms of Lol p V were identified by the Lol p V-specific IgE. The same probe recognized cross-reactive epitopes in pollen protein from 13 out of 16 grasses. Group I proteins were identified in grasses from two sub-families of the Poaceae, while the Group V allergens were only identified in pollen of grasses from one sub-family, the Pooideae.

Circulating vasopressin influences area postrema neurons

Extracellular single-unit recordings were obtained from 107 area postrema and 74 nucleus tractus solitarius neurons in sodium pentobarbital anaesthetized rats. Systemic administration of vasopressin (1-10 ng) decreased the firing frequency of 45.8% of area postrema neurons and 58.1% of nucleus tractus solitarius neurons tested while the firing frequency of 38.3% of area postrema neurons and 21.6% of nucleus tractus solitarius neurons was increased by this peptide. To determine whether these neurons were specifically influenced by vasopressin or the accompanying pressor response, the effects of alpha-adrenergic agonists on neuronal activity were also determined. Cells that responded similarly to vasopressin and the change in blood pressure elicited by alpha-adrenergic agonists were classified as "blood pressure-sensitive", whereas those neurons that responded differently to both agents were classified as "vasopressin-sensitive" neurons. The majority (85.2%) of area postrema cells that decreased firing frequency in response to vasopressin were determined to be "vasopressin-sensitive", while 68.8% of area postrema neurons responding to vasopressin with increases in firing frequency were classified as "blood pressure-sensitive". In contrast, 78.6% of nucleus tractus solitarius neurons that decreased firing frequency in response to vasopressin and 55.5% of those that increased firing frequency were classified as "blood pressure-sensitive" neurons. To determine whether the actions of vasopressin in the area postrema were mediated by V1 receptors the effect of vasopressin after V1 receptor blockade was examined in seven "vasopressin-sensitive" area postrema neurons. All seven neurons tested showed no response to vasopressin after such V1 receptor blockade. These data suggest that there exists a population of area postrema neurons specifically responsive to circulating vasopressin as a result of actions of this peptide at V1 receptors. They also implicate these neurons in the physiological mechanisms through which circulating vasopressin acts in the area postrema to influence baroreceptor reflex sensitivity.

Methods for optimizing revenue in rural hospitals

Rural hospitals have been failing over the last two decades, and one of the biggest reasons has been lack of attention paid to detail and accuracy in the coding and pricing of services rendered. Most research that has explored the problems of coding accuracy and its impact on reimbursement has focused on coding by medical record professionals, but many coding procedures are performed by "front line" lower-level employees working in a hospital's laboratory, radiology department, pharmacy, or other ancillary service departments. This article explains how rural hospitals can optimize their reimbursement and adhere to Medicare/Medicaid and other third-party payer regulations by training coders properly and by reviewing their pricing policies to make sure that prices charged accurately reflect the true cost of services.

Detecting patients with Alzheimer's disease suitable for drug treatment: comparison of three methods of assessment

BACKGROUND

Therapy to enhance cholinergic function in the brain is under evaluation for the treatment of Alzheimer's disease. Tetrahydroaminoacridine (tacrine) has recently received a product licence in the United States of America for the treatment of Alzheimer's disease, and the licence application in the United Kingdom will shortly be reviewed. It is therefore possible that this drug will become available for use in the UK in due course. There will then be a need for screening procedures for a large number of elderly patients to decide whether or not they have dementia and, if so, whether it is the result of Alzheimer's disease and is suitable for treatment with the new drug.

METHOD

A total of 246 patients aged 75 years or over in two general practices in Bristol were assessed to investigate the potential workload such screening would engender. Three different assessment schedules for the diagnosis of dementia were compared--the mini-mental state examination, the Kew test, and the abbreviated mental test score.

RESULTS

None of the assessment schedules was found to be particularly onerous, with median times for administration of five, three and two minutes, respectively. A score of 23 or less on the mini-mental state examination was taken as the main cut-off point for further evaluation. Sixty six patients obtained this score--in 25 the low score reflected factors other than dementia, and 11 others declined further assessment. Of the remaining 30 patients only four had probable Alzheimer's disease at an appropriate level of severity for treatment, and lived with a carer who could ensure compliance and monitor side effects. Two of these patients were receiving conflicting medical treatment and a third declined therapy, leaving only one person for whom treatment could be prescribed.

CONCLUSION

It seems likely that of those medically suitable for treatment, it may not be possible to prescribe tacrine for an appreciable proportion. Nevertheless, all potential patients should be screened as the procedures involved are not onerous and at least some of those found suitable for treatment are likely to benefit from this new approach.

Nitric oxide actions in paraventricular nucleus: cardiovascular and neurochemical implications

We have examined potential functions of nitric oxide (NO) within the paraventricular nucleus (PVN) in urethan-anesthetized male Sprague-Dawley rats. Initial experiments demonstrated microinjection of 50 pmol of the NO donor, sodium nitroprusside (SNP), directly into the PVN resulted in significant decreases in mean blood pressure (BP) (-3,312 +/- 1,189 mmHg/s over 300-s response time; P < 0.05). To determine whether such effects were attributable to SNP-induced NO release, NO was administered into PVN directly by bilateral microdialysis of NO-containing artificial cerebrospinal fluid (NO-aCSF), a process that results in delivery of approximately 50 pmol NO.PVN-1 x min-1. Such microdialysis resulted in significant decreases in BP (-5,121 +/- 817 mmHg/s over 1,200-s response time; P < 0.005), while aCSF microdialysis was without effect (1,298 +/- 1,071 mmHg/s over 1,200-s response time; P > 0.1). Amino acid concentrations were measured in dialysates collected during perfusion of the same PVN sites with either aCSF or NO-aCSF by high-performance liquid chromatography (HPLC) analysis. NO-aCSF induced significant increases in aspartate (aCSF 31 +/- 7 pmol/30 min; NO-aCSF 134 +/- 33 pmol/30 min; P < 0.05), glutamate (aCSF 36 +/- 5 pmol/30 min; NO-aCSF 417 +/- 108 pmol/30 min; P < 0.02), gamma-aminobutyric acid (aCSF 4.1 +/- 0.7 pmol/30 min; NO-aCSF 104 +/- 29 pmol/30 min; P < 0.02), and taurine (aCSF 34 +/- 3 pmol/30 min; NO-aCSF 117 +/- 24 pmol/30 min; P < 0.01) concentrations, while alanine, glutamine, and serine concentrations were unaffected.(ABSTRACT TRUNCATED AT 250 WORDS)

Ca2+ oscillations in pancreatic acinar cells: spatiotemporal relationships and functional implications

The pancreatic acinar cells are of particular interest for the study of cytosolic Ca2+ signals, since they are morphologically polarized and generate agonist-specific Ca2+ oscillation patterns. Recent data obtained by combining digital video imaging of Fura-2 fluorescence with patch-clamp whole-cell current recording have provided new information on the spatiotemporal relationships of the cytosolic Ca2+ signals and the Ca(2+)-activated ionic currents. Low agonist concentrations evoke repetitive short-lasting local Ca2+ spikes in the secretory pole region that activate shortlasting current spikes. In the case of acetylcholine stimulation the spikes are confined to this region. When cholecystokinin is used the shortlasting local spikes precede longer Ca2+ transients that spread to the whole of the cell. Infusion of non-metabolizable inositol trisphosphate analogues can mimic these responses. The shortlasting local Ca2+ spikes are particularly sensitive to blockade by the inositol trisphosphate receptor antagonist heparin. These results show that the secretory pole region has a particularly high sensitivity to inositol trisphosphate probably due to clustering of high affinity receptors.

The computed tomographic appearances of angiosarcoma of the liver

The computed tomographic (CT) appearances are described in five vinyl chloride workers with hepatic angiosarcoma subsequently confirmed at post-mortem. The tumour was multifocal in four patients. Non-enhanced scans were available in four cases showing hypodense masses relative to background liver. Dynamic scanning during intravenous contrast injection was performed in all five patients showing peripheral or central foci of enhancement within the tumour. On delayed post-contrast scans performed in three patients the angiosarcoma became wholly or partly isodense compared to normal liver. The CT appearances of angiosarcoma of the liver are non-specific but are consistent with a vascular tumour, and the differential diagnosis is discussed. Due to the vascularity of angiosarcoma, liver biopsy may be hazardous and can be avoided when there is a history of exposure to vinyl chloride monomer and the CT findings are consistent with the diagnosis.

Electrogenic colonic ion transport in Hirschsprung's disease: reduced secretion to the neural secretagogues acetylcholine and iloprost

The effects of the abnormal innervation in Hirschsprung's disease on colonic ion transport were examined in vitro using Ussing chambers. The response of the mucosal/submucosal preparations to different secretagogues were investigated in aganglionic and ganglionic rectosigmoid and transverse colon from children with Hirschsprung's disease and compared with normally innervated colon from children with anorectal anomalies. Basal values were similar in aganglionic and ganglionic rectosigmoid colon. Neurally mediated secretion with iloprost (10(-6) M) and acetylcholine (900 and 9 microM) was considerably reduced in aganglionic colon compared with normally innervated ganglionic colon. The ganglionic colon proximal to the aganglionic colon also had a reduced response to acetylcholine despite a normal acetylcholinesterase staining pattern. The responses to Escherichia coli STa enterotoxin (50 MU/ml) and isobutylmethylxanthine (10(-3) M) were similar in ganglionic and aganglionic colon. The response to STa enterotoxin was not changed by the nerve blocking agent tetrodotoxin (10(-6) M). The data show that colonocytes from aganglionic colon are capable of a normal secretory response if stimulated directly by cAMP or cGMP acting secretagogues but secretion in response to neurally mediated secretagogues is impaired. The hypertrophied acetylcholinesterase positive nerve fibres that infiltrate the aganglionic colon are likely to contribute to the reduced secretion to acetylcholine.

Local and global cytosolic Ca2+ oscillations in exocrine cells evoked by agonists and inositol trisphosphate

Submaximal stimulation with agonists generating inositol 1,4,5-trisphosphate (IP3) evokes cytosolic Ca2+ oscillations in many different cell types. In general, each Ca2+ rise is initiated from a specific region near the plasma membrane and then spreads as a wave throughout the cell. We now demonstrate that low (physiological) agonist concentrations evoke local cytosolic Ca2+ spikes in the secretory pole of single mouse pancreatic acinar cells that are particularly sensitive to blockade by the IP3 receptor antagonist heparin. These spikes can occur alone or repetitively or can precede longer lasting Ca2+ signals that spread throughout the cell. Intracellular IP3 application mimics these agonist actions. The short-lasting local Ca2+ spikes provide an economical signaling mechanism and are of physiological significance since they activate Ca(2+)-dependent Cl- and cation currents important for control of fluid secretion.

Social work role in an early ovarian cancer detection program

Social Work intervention in an early ovarian cancer detection program has helped women who are at high risk for the disease because of family history, make full use of the clinic's medical resources. It has provided an enabling component for their participation in required medical procedures; has assisted them in dealing with unresolved emotions precipitated by their relative's death from cancer earlier in their lives; and has helped them move into the next indicated stages of medical intervention.

A comparison of workloads of physician-gastroenterologists and other consultant physicians. Prepared on behalf of the Clinical Services Committee, British Society of Gastroenterology

In response to a workload questionnaire, carried out as part of an enquiry into manpower needs in gastroenterology, replies were received from 17 health regions, relating to 86 hospitals and 135 consultant gastroenterologists. The average yearly number of deaths and discharges of patients under the care of gastroenterologists was 992, while that of patients cared for by consultant physicians in other specialties was 679. When daycase admissions were also included, there were 1,553 annual discharges per gastroenterologist as compared with 871 for other physicians. These 682 extra cases per gastroenterologist largely represent the additional workload of gastrointestinal endoscopy.

Acetylcholine- and caffeine-evoked repetitive transient Ca(2+)-activated K+ and C1- currents in mouse submandibular cells

1. Resting and acetylcholine-induced membrane currents were measured in single mouse submandibular acinar cells using the patch-clamp whole-cell current recording technique. 2. Micromolar ACh activated a large, sustained outward, Ca(2+)-dependent K+ current and a single transient inward Ca(2+)-dependent C1-current. 3. Nanomolar ACh induced a series of transients in both the K+ and C1- currents; C1- current activation was now observed throughout the period of agonist application. We consider this repetitive transient current activation better able to support sustained fluid and electrolyte secretion than the response elicited by a high dose of agonist. 4. Repetitive K+ and C1- current transients were also induced by 1 mM-caffeine, consistent with caffeine-induced Ca2+ release from the Ca(2+)-sensitive Ca2+ stores which are thought to comprise part of the pathway for activation of secretion. 5. The ACh-induced current transients were inhibited by 10 mM-caffeine, 100 microM-IBMX and 10 microM membrane-permeable cyclic AMP. Therefore, it seems likely that caffeine is able to inhibit agonist-induced calcium mobilization via a cyclic AMP-dependent pathway.

Ins(1,3,4,5)P4 promotes sustained activation of the Ca(2+(-dependent Cl- current in isolated mouse lacrimal cells

Infusion of 50 microM-Ins(1,3,4,5)P4 in addition to 500 microM-Ins(1,4,5)P3 into mouse lacrimal cells via a patch-clamp pipette promoted sustained activation of the Ca(2+)-dependent Cl- current, which could not be achieved with 500 microM-Ins(1,4,5)P3 alone. It has been proposed that Ins(1,3,4,5)P4 facilitates Ca2+ influx in the presence of Ins(1,4,5)P3 [Morris, Gallacher, Irvine & Petersen (1987) Nature (London) 330, 653-655], but a subsequent study in mouse lacrimal cells [Bird, Rossier, Hughes, Shears, Armstrong & Putney (1991) Nature (London) 352, 162-165] showed that a high concentration of Ins(1,4,5)P3 could mobilize both intra- and extra-cellular Ca2+ in the absence of Ins(1,3,4,5)P4. My data confirm these findings, but also show that Ins(1,3,4,5)P4 can stimulate additional Ca2+ influx even when the Ins(1,4,5)P3-dependent intracellular Ca2+ pools have been depleted.

Incidence of ulcerative colitis in Cardiff over 20 years: 1968-87

The annual incidence of ulcerative colitis in the city of Cardiff was examined over a 20 year period. In the decade 1968-77, the mean annual incidence was 6.4 per 10(5) of the population compared with 6.3 for the period 1978-87. There was no difference in the distribution or extent of the disease between decades or between sexes. This contrasts with the increased incidence of Crohn's disease during the same period. The study included a survey of family practitioners which identified a further 19 patients (11% of the total).

The effect of dietary supplementation with cysteic acid on the plasma taurine concentration of cats maintained on a taurine-restricted diet

The biochemical impairment in the taurine anabolic pathway of the cat has not yet been fully elucidated; however, a number of key enzymes are known to have reduced activity in the cat compared to the rat. There are a series of possible routes resulting in the formation of taurine, one of which is the decarboxylation of cysteic acid. The aim of this study was to investigate the effect of cysteic acid, as a precursor, on the circulating concentration of taurine. A group of twelve adult cats was fed a basal, canned diet containing 0.22 g taurine/kg fresh weight for a period of eighty-four days. The diet was supplemented with 2.0 g/kg fresh weight L-cysteic acid on day fifteen through fifty six and plasma taurine concentration was measured every two weeks throughout the study. The results showed that when the dietary intake of taurine was inadequate to maintain the plasma concentration above 40 mumol/L, the addition of L-cysteic acid to the diet gave rise to an increase in plasma taurine concentration in some cats. Eight of the twelve cats showed a significant rise in plasma taurine after dietary supplementation for six weeks (52.0 +/- 22.3 vs 212.4 +/- 97.9 mumol/L, p less than 0.01) and a subsequent decrease in plasma levels when the cysteic acid was withdrawn (65.6 +/- 37.1 mumol/L). The other four cats showed no significant rise in plasma taurine after six weeks supplementation (13.5 +/- 4.2 vs 35.5 +/- 19.4 mumol/L, ns). However, withdrawal of the cysteic acid resulted in a subsequent decrease in circulating levels of taurine (11.8 +/- 1.5 mumol/L, ns). These data indicate that the addition of cysteic acid to a taurine-restricted, canned diet will, in some cats, result in the biosynthesis of taurine. The plasma taurine concentration of the remaining cats, although not apparently increasing significantly, was maintained at a slightly higher constant level until the cysteic acid was withdrawn. These results suggest that cats are able to synthesise taurine via an alternative pathway utilising L-cysteic acid as a precursor, although the efficiency of this process differs considerably among individual animals.

Injection locking techniques for a 1-GHz digital receiver using acoustic-wave devices

The use of surface-transverse-wave (STW) resonator-based oscillators as amplifiers and as carrier recovery elements is discussed. It is demonstrated that these oscillators can amplify phase-shift-keyed signals with very little added noise, while providing a constant output power. Their performance in carrier recovery amplifications is analyzed. Experimental results showing the amplification with more than 80 dB of dynamic range of a 2 Mb/s BPSK signal and the carrier recovery of an 8 Mb/s signal with a 1-GHz STW oscillator are shown.

Transverse modes in one-port SAW resonators

The S(11) and equivalent S(21) frequency responses of a one-port surface acoustic wave (SAW) resonator with transverse modes derived from one-dimensional coupling-of-modes and transmission-matrix analysis. The two-dimensional nature of the problem is approximated by a summation of one-dimensional mode responses for each transverse mode. Comparison between theory and experimental data for a commercial 280-MHz one-port SAW resonator shows good agreement for the placement of transverse modes.

Aspects of modeling the frequency response of a two-port waveguide-coupled SAW resonator-filter

Coupling-of-modes-in-time and coupling-of-modes-in-space analyses are applied to the modeling of a two-port two-pole waveguide-coupled SAW resonator filter. Modeling is applied to a lumped equivalent circuit and a distributed circuit. While the accuracy of the coupling estimation dictates the exact mode-splitting and bandwidth, the ensuing computations can give a good representation of the amplitude and phase response, including the effect of degenerate transverse modes.

The management of variceal bleeding

Variceal bleeding has a high mortality, as the majority of patients have cirrhosis, with hepatic coma, renal failure, ascites and clotting deficiencies as complicating factors. Bleeding varices must therefore be treated as an emergency. Resuscitation, endoscopic diagnosis and haemostasis are the cornerstones of treatment. Once bleeding varices have been identified, attempts to stop the bleeding must be made at once as this will lessen the chances of hepatic failure developing. Endoscopic sclerotherapy at the time of diagnosis is the best available treatment at present, although profusely bleeding varices can be difficult to see and inject. In these circumstances the passage of a Sengstaken tube should stop the bleeding, allowing later sclerotherapy to be successful. If rebleeding recurs and cannot be controlled, oesophageal transection with a stapling gun may be life-saving, although the varices may later recur and long-term endoscopic follow-up will be necessary. Portacaval shunting and the distal splenorenal shunt involve arduous surgery and are followed by a significant incidence of hepatic encephalopathy; they should be reserved for those few cases when simpler measures have failed, although shunts do lead to permanent decompression of the portal system. The acute variceal bleed may also be dealt with pharmacologically. Vasopressin, used in combination with nitroglycerin to lessen the harmful side-effects, is cheaper and as effective as terlipressin or somatostatin and its synthetic analogue octreotide. Several courses of injection sclerotherapy will be required to eliminate oesophageal varices. Thereafter, long-term follow-up will be necessary to deal with any recurrence. The place of non-selective beta-blockers is still contentious, but they do reduce portal pressure and may lessen the chance of rebleeding. There is also a growing role for hepatic transplantation, which not only eliminates the varices but also restores liver function to normal and greatly reduces the risk of subsequent hepatoma development.

The effect of dietary taurine content on the plasma taurine concentration of the cat

The essential role of taurine in the diet of the cat has been well documented and a deficiency of this nutrient is known to be responsible for a number of clinical conditions. At present, the National Research Council (1986) recommendation for the minimum dietary requirement of the kitten is 400 mg/kg dry matter and for a pregnant cat is 500 mg/kg dry matter. However, these minima were established by feeding the animals on semi-purified diets and, therefore, may be inappropriate for other dietary regimens. The aim of the present study was to investigate the effect of feeding a series of specially prepared diets containing different concentrations of taurine (canned diets 1475-5750 mg/kg dry matter, dry diets 811-1240 mg/kg dry matter) on the plasma taurine concentration of the cat. All diets were fed solus for 6 weeks and plasma taurine concentration was measured every 2 weeks. The results showed that to maintain plasma taurine values in the 'normal' range (less than 60 mumol/l), a canned diet must supply at least 39 mg taurine/kg body-weight per d and a dry diet at least 19 mg/kg body-weight per d; a cat fed on a semi-purified diet need only achieve a daily intake of at least 10 mg taurine/kg body-weight to maintain an adequate circulating level of taurine. The cause of the reduced availability of taurine from these diets is not yet known. Furthermore, repletion of plasma concentration above 60 mumol/l can be achieved within 2 weeks of feeding an adequate diet.

Poisoning with oxybutynin

A case of poisoning with 100 mg of oxybutynin in a 34-year-old female is reported. The main features were anticholinergic effects, including stupor, followed by disorientation and agitation on awakening, dilated pupils, dry skin and retention of urine. She had a sinus tachycardia which resolved 3 h after admission, and in addition ventricular ectopics and bigeminy which continued for a further 30 h. She recovered fully on symptomatic treatment alone.

CD4-positive T lymphocytes are required for the generation of the primary but not the secondary CD8-positive cytolytic T lymphocyte response to herpes simplex virus in C57BL/6 mice

To understand the cellular basis for recovery from HSV infection, it is critical to identify functional interactions between HSV-specific T lymphocyte subpopulations involved in the generation of the optimal response. To this end, the requirement for CD4+ (L3T4+) T lymphocytes in the development of the primary and secondary CD8+ (Lyt-2+) cytolytic T lymphocyte (CTL) response following HSV infection in C57BL/6 mice was investigated. It was found that chronic depletion of CD4+ cells in vivo by treatment with the mAb GK1.5, which resulted in greater than 95% depletion of peripheral CD4+ T lymphocytes in treated animals, caused a profound decrease in the levels of cytolytic activity obtained during the primary response in the draining popliteal lymph nodes of mice responding to infection in the hind footpads. However, treatment did not affect the levels of in vivo secondary CTL activity in the popliteal lymph nodes, nor the in vitro secondary response in the spleen. The decreased CTL activity observed during the primary response was not due to an inability to prime HSV-specific CTL precursors (CTLp), as full cytolytic activity was obtained following culture of lymphocytes in the presence of exogenous IL-2 and antigen, and the response could be reconstituted by treatment with recombinant IL-2 in vivo. Analysis of the secondary CTL response in the spleen indicated that CD4+ cells were not required for either the generation or maintenance of this aspect of the response. However, blockade of IL-2 utilization by CTL using anti-IL-2R antibodies indicated that this lymphokine was absolutely essential for secondary CTL expansion in vitro. Finally, mice that had been infected 12 months previously exhibited a decreased ability to generate secondary HSV-specific CTL in vitro following CD4-depletion in vivo. Taken together, these results suggest two distinct stages of CTL development during the response: an early primary stage dependent upon the presence of CD4+ cells, and a later, CD4-independent stage operative during the secondary response, which decays with time postinfection.

An improved nipple prosthesis

A nipple-areola reconstruction of prosthesis completes the process of breast reconstruction. Reconstructions are technically difficult and have poor long-term results, whereas commercial nipple prostheses are unsatisfactory in matching the normal colour and shape. We describe a simple technique for the manufacture of a custom made nipple-areola prosthesis.

Cloning and sequencing of Lol pI, the major allergenic protein of rye-grass pollen

We have isolated a full length cDNA clone encoding the major glycoprotein allergen Lol pI. The clone was selected using a combination of immunological screening of a cDNA expression library and PCR amplification of Lol pI-specific transcripts. Lol pI expressed in bacteria as a fusion protein shows recognition by specific IgE antibodies present in sera of grass pollen-allergic subjects. Northern analysis has shown that the Lol pI transcripts are expressed only in pollen of rye-grass. Molecular cloning of Lol pI provides a molecular genetic approach to study the structure-function relationship of allergens.

Isolation of cDNA encoding a newly identified major allergenic protein of rye-grass pollen: intracellular targeting to the amyloplast

We have identified a major allergenic protein from rye-grass pollen, tentatively designated Lol pIb of 31kDa and with pI 9.0. A cDNA clone encoding Lol pIb has been isolated, sequenced, and characterized. Lol pIb is located mainly in the starch granules. This is a distinct allergen from Lol pI, which is located in the cytosol. Lol pIb is synthesized in pollen as a pre-allergen with a transit peptide targeting the allergen to amyloplasts. Epitope mapping of the fusion protein localized the IgE binding determinant in the C-terminal domain.

Nonoperative management of blunt splenic trauma in adults

The management of isolated blunt splenic trauma in adults is controversial. The authors present a series of 17 patients with blunt splenic trauma who were selected for nonoperative management. Only one patient eventually required surgery, for a ruptured spleen. Complications included pneumonia (two cases) and pleural effusion, atelectasis and ileus (one case each). There were no deaths. Five patients required transfusion, for a total of 17 units of blood. The mean length of hospital stay was 9.4 days. Comparison with a group of 17 patients treated operatively during the same period showed that those treated nonoperatively had fewer complications, required less blood and had a similar length of hospital stay. The authors conclude that nonoperative management of selected patients with isolated blunt splenic trauma is safe, if the patient's condition is closely monitored.

A surface transverse wave-based MSK system

A minimum-shift-keyed (MSK) system using one 1-GHz surface-transverse-wave (STW) resonator in the transmitter and two identical STW resonators in the receiver is described. It is shown to operate with data rates of over 100 kb/s and consume 150 mW. The system has a very high sensitivity and is tolerant to additive noise. Since the signal is never up- or down-converted. this system eliminates high power consumption. The system should find applications in cellular radios and in industrial communications.

Sodium-coupled organic anion transport by Cancer borealis urinary bladder

Recently, p-aminohippurate (PAH) transport by rat renal basolateral membrane (BLM) vesicles was shown to be coupled indirectly to the Na+ gradient through PAH-glutarate exchange and Na(+)-glutarate cotransport. We have examined the mechanism of PAH transport in Cancer borealis urinary bladder, a simple flat-sheet epithelium that is functionally analogous to vertebrate renal proximal tubule. These experiments indicate that crab bladder is capable of both Na(+)-coupled glutarate uptake and PAH-glutarate exchange and that PAH uptake may be coupled to Na+ in the intact tissue. First, glutarate uptake by intact bladder was lithium sensitive, Na(+) dependent, and inhibited by other dicarboxylates. In flux chambers, the bladder exhibited net glutarate secretion and tissue accumulation occurred primarily from the basolateral side. Furthermore, both BLM and brush-border membrane (BBM) vesicles also exhibited lithium-sensitive Na(+)-coupled glutarate uptake. Second, imposition of an in greater than out glutarate gradient markedly stimulated PAH uptake by bladder BLM vesicles, demonstrating PAH-glutarate exchange. In contrast, exchange was absent in BBM vesicles. Third, in intact bladder tissue, external glutarate increased the steady-state tissue-to-medium ratio for PAH from 14 +/- 1 to 19 +/- 1.5. This increase was both lithium inhibitable and Na+ dependent. Thus not only do bladder BLM show all the elements needed for indirect coupling of PAH transport to the Na+ gradient, but indirect coupling to Na+ can also drive uphill PAH transport in the intact epithelium.

Hepadnavirus envelope proteins regulate covalently closed circular DNA amplification

Primary duck hepatocytes were infected with a mutant duck hepatitis B virus defective in envelope protein but competent for viral DNA synthesis. Cells infected by this mutant accumulated higher levels of viral covalently closed, circular DNA (cccDNA) than those infected by wild-type virus. The accumulation of high levels of cccDNA was due to a failure of the mutant-infected cells to suppress de novo cccDNA synthesis compared with suppression by cells infected by the wild type. The envelope-defective virus failed to establish a persistent infection in vitro, possibly because of a virus-mediated cell death. Therefore, one or both viral envelope proteins are required for regulation of cccDNA synthesis and for maintenance of persistent infection in vitro.