In vitro 3'-end endonucleolytic processing defect in a human mitochondrial tRNA(Ser(UCN)) precursor with the U7445C substitution, which causes non-syndromic deafness

Eukaryotic tRNAs are transcribed as precursors. A 5'-end leader and 3'-end trailer are endonucleolytically removed by RNase P and 3'-tRNase before 3'-end CCA addition, aminoacylation, nuclear export and translation. 3'-End -CC can be a 3'-tRNase anti-determinant with the ability to prevent mature tRNA from recycling through 3'-tRNase. Twenty-two tRNAs punctuate the two rRNAs and 13 mRNAs in long, bidirectional mitochondrial transcripts. Accurate mitochondrial gene expression thus depends on endonucleolytic excision of tRNAs. Various mitochondrial diseases and syndromes could arise from defective tRNA end processing. The U7445C substitution in the human mitochondrial L-strand transcript (U74C directly following the discriminator base of tRNA(Ser(UCN))) causes non-syndromic deafness. The sequence of the precursor (G/UCU) becomes G/CCU, resembling a 3'-tRNase anti-determinant. We demonstrate that a tRNA(Ser(UCN)) precursor with the U7445C substitution cannot be processed in vitro by 3'-tRNase from human mitochondria. A 3'-end processing defect in this tRNA precursor could thus be responsible for mitochondrial disease.

A randomized trial comparing the effectiveness and preference of a touch-screen computer system with a leaflet for providing women with information on urinary symptoms suggestive of detrusor instability

OBJECTIVES

To evaluate how well women learned and retained information given to them by either a leaflet or a computer-generated information system, and which system they preferred to use for obtaining information about urinary symptoms.

SUBJECTS AND METHODS

Forty women answered 11 questions on the aetiology, investigation and treatment of lower urinary tract symptoms. They were then randomized to use one of the information systems for 20 min, after which they answered the same urological questions. The women then crossed over to use the other information system for 20 min and afterwards completed a preference questionnaire.

RESULTS

The mean baseline scores from a possible total of 11 were 3.9 and 4.3 for the computer and leaflet groups, respectively. The mean improvements in scores were 3.6 (P < 0.001) and 2.8 (P < 0.001) for the computer and leaflet groups, respectively. Both information systems were well liked by all of the women and 26 (65%) said they would prefer to use a computer-generated system in the future if given a choice.

CONCLUSIONS

Women significantly increased their knowledge of urinary problems after using a computer-generated information system or a leaflet. Although there were few subjects, there appeared to be a trend for the computer system to be both better liked and slightly more effective.

Contractures in orthopaedic and neurological conditions: a review of causes and treatment

PURPOSE

To examine the techniques used for the treatment of contracture in the context of current scientific knowledge of muscle.

METHOD

Synthesis of data available from MEDLINE, RECAL, EMBASE, the Cochrane Library and relevant texts.

RESULTS

The development of contractures through immobilisation, muscle weakness and spasticity is described. The effects of passive stretching, continuous passive movement, serial plastering, splinting, electrical stimulation, botulinum injections and surgical tenotomies in the treatment of contractures in persons with neurological and orthopaedic conditions are identified. The strengths and weaknesses of these modalities are discussed.

CONCLUSION

Predisposing factors persist after treatment of contractures thus for treatment to be effective long-term management programmes need to be developed. New treatment techniques, used in series or combined, offer the prospect of improved management of contracture. Scientific and clinical research is needed to investigate the effect of contracture treatment.

Expression of cytokine and chemokine genes by human middle ear epithelial cells induced by formalin-killed Haemophilus influenzae or its lipooligosaccharide htrB and rfaD mutants

To define the role of nontypeable Haemophilus influenzae (NTHI) lipooligosaccharide (LOS) in the induction of proinflammatory cytokine gene expression during otitis media, we compared the abilities of formalin-killed NTHI strain 2019 and its LOS htrB and rfaD mutants to stimulate human middle ear epithelial (HMEE) cell cytokine and chemokine gene expression and production in vitro. Strain DK-1, an rfaD gene mutant, expresses a truncated LOS consisting of only three deoxy-D-manno-octulosonic acid residues, a single heptose, and lipid A. Strain B29, an isogenic htrB mutant, possesses an altered oligosaccharide core and an altered lipid A. HMEE cells were incubated with formalin-killed NTHI 2019, B29, or DK-1. The supernatants and the cells were collected at 2, 4, 8, and 24 h after stimulation. Expression of genes for the cytokines tumor necrosis factor alpha (TNF-alpha), interleukin lbeta (IL-1beta), and IL-6 and for the chemokines macrophage inflammatory protein 1beta (MIP-1beta), monocyte chemotactic peptide 1 (MCP-1), and IL-8 was quantitated by real-time PCR. NTHI B29 did not significantly stimulate any cytokine or chemokine mRNA expression in HMEE cells. In striking contrast, NTHI 2019 induced up to 105-, 139-, and 187-fold increases in HMEE cell expression of IL-1beta, TNF-alpha, and MIP-1beta, respectively (P < 0.01 [2019 versus B29]). NTHI 2019 also induced upregulation of IL-8, IL-6, and MCP-1 mRNA expression (by 26-, 44-, and 14-fold, respectively [P < 0.05 (2019 versus B29)]). The significant induction of cytokine genes was confirmed by quantitating the secretion of cytokines in culture supernatants with an enzyme-linked immunosorbent assay. There were no significant differences in mRNA expression of IL-8, IL-6, and MCP-1 between the 2019- and DK-1-treated groups. The low levels of gene transcripts observed after incubation of HMEE cells with B29 indicate that products of the disrupted NTHI htrB LOS gene may play a major role in induction of these particular inflammatory mediators.

A randomized, double-blind, multicenter trial comparing fluticasone propionate cream, 0.05%, and hydrocortisone-17-butyrate cream, 0.1%, applied twice daily for 4 weeks in the treatment of psoriasis

The efficacy, safety, and tolerability of twice-daily fluticasone propionate (Cutivate) cream, 0.05%, and hydrocortisone-17-butyrate cream, 0.1%, were compared in 125 patients with moderate-to-severe psoriasis in a 4-week, multicenter, double-blind, randomized, active-control study. Clinical assessments of response to therapy, made at weekly intervals, included physicians' gross assessment of clinical response, improvement in signs and symptoms, and patients' assessment of treatment effects. Based on physicians' gross assessment, fluticasone propionate cream was superior to hydrocortisone-17-butyrate cream at day 22 (after 3 weeks' treatment) and at the end-of-treatment visit (P < .05). Cleared, excellent, or good end-of-treatment response rates were 50/63 (79%) for fluticasone propionate compared with 41/60 (68%) for hydrocortisone-17-butyrate. Adverse events were limited to mild-to-moderate pruritus with fluticasone propionate (3.2%) and hydrocortisone-17-butyrate (1.7%) and mild skin warmth with hydrocortisone-17-butyrate (1.7%).

Psychiatric status, somatisation, and health care utilization of frequent attenders at the emergency department: a comparison with routine attenders

Seventy-seven frequent attenders at an emergency department (ED) in an inner-city hospital in the UK (defined as seven or more visits in the previous 12 months) were compared with 182 patients who were attending the same department on a routine basis. Patients completed the Schedules for Clinical Assessment in Neuropsychiatry (SCAN) and the Short Form (SF)-36. Information was obtained on 64% of the frequent attenders and 45% underwent a detailed psychiatric assessment. Of the frequent attenders, 45% had psychiatric disorder and 49% had some form of an alcohol-related disorder. Compared with routine attenders, frequent attenders reported lower health status, had more psychiatric disorder (odds ratio: OR=8.2, 95% confidence interval: CI=3.8--18.1), had more general hospital admissions (OR=19.9, 95% CI=8.3--47.8), more psychiatric admissions (OR=167.5, 95% CI=9.5--2959.0), and more GP visits (95% CI for difference=-10.2 to -5.7). There was no evidence that frequent attenders had more somatisation than routine attenders. Specific treatment and management strategies need to be developed for this group of patients, although a substantial proportion may be difficult to engage in the treatment process.

Small heat shock proteins (sHSPs) as potential drug targets

Small heat shock proteins (sHSPs) belong to a family of 12- to 43-kDa proteins that are ubiquitous and are largely conserved in amino acid sequence among all organisms. The principal heat-shock proteins that have chaperone activity (that is, they protect newly made proteins from misfolding) belong to five conserved classes: HSP100, HSP90, HSP70, HSP60 and the small heat-shock proteins (sHSPs). The sHSPs (which include alpha crystallin) can form large multimeric structures and have a wide range of cellular functions, including endowing cells with thermotolerance in vivo and being able to act as molecular chaperones in vitro; sHSPs do this by forming stable complexes with folding -or unfolding--intermediates of their protein substrates, probably the molten globule. This paper includes: a brief survey of the chaperone family, the small heat shock protein superfamily, transcription of sHSPs, sequence comparisons and structural models of small heat shock proteins--structural elements as potential drug targets, sHSPs as chaperone-like proteins, alpha crystallin chaperone-like activity, conformational diseases--the role of alpha crystallin small heat shock protein superfamily proteins, post-translational modification and useful pharmacological agents. Functionality of small heat shock proteins--targets and diseases where pharmacologically active agents are of importance, alpha crystallin--small heat shock proteins and prion diseases: specific targets for diagnostic tests and drug development, details of some specific small heat shock proteins as drug targets, structural and functional implications for treatment.

The use of echocardiographic colour kinetic wall motion to differentiate broad complex tachycardia

Discrimination between supraventricular tachycardia (SVT) with aberrant conduction from ventricular tachycardia (VT) is vital for the safe and effective management of both conditions. Electrocardiographic algorithms for the differentiation of broad complex tachycardia are complex and difficult to implement in the acute setting, with misdiagnosis occurring in up to 40% of acute presentations. This case study shows the potential for echocardiographic colour kinesis (eck) to support electrocardiographic differentiation. A 74-year old man in sinus rhythm with left bundle branch block (lbbb), a history of myocardial infarction and recurrent sustained VT underwent eck analysis of wall motion propagation during a programmed electrical ventricular stimulation study. Sequential 40 ms time frames of echocardiographic colour coded endocardial wall motion velocity were recorded on video during both induced VT of lbbb configuration and near isochronic atrially paced tachycardia in lbbb. During VT there was initial eck propagation of ventricular septal wall motion from the apex to the atria secondary to electrical depolarisation. During atrially paced tachycardia initial eck motion developed in the interatrial septum and atrial wall followed by propagation in the ventricular endocardial septal wall motion from the atria toward the ventricular apex. This eck technique potentially could be used to support the electrocardiographic diagnosis of a broad complex tachycardia.

NHE-RF, a merlin-interacting protein, is primarily expressed in luminal epithelia, proliferative endometrium, and estrogen receptor-positive breast carcinomas

NHE-RF, a regulatory cofactor for NHE (Na(+)-H(+) exchanger) type 3, interacts with ion transporters and receptors through its PDZ domains and with the MERM proteins (merlin, ezrin, radixin and moesin) via its carboxyl terminus. Thus, NHE-RF may act as a multifunctional adaptor protein and play a role in the assembly of signal transduction complexes, linking ion channels and receptors to the actin cytoskeleton. NHE-RF expression is up-regulated in response to estrogen in estrogen receptor-positive breast carcinoma cell lines, suggesting that it may be involved in estrogen signaling. To further understand NHE-RF function and its possible role in estrogen signaling, we analyzed NHE-RF expression in normal human tissues, including cycling endometrium, and in breast carcinomas, tissues in which estrogen plays an important role in regulating cell growth and proliferation. NHE-RF is expressed in many epithelia, especially in cells specialized in ion transport or absorption, and is often localized to apical (luminal) membranes. NHE-RF expression varies markedly in proliferative versus secretory endometrium, with high expression in proliferative (estrogen-stimulated) endometrium. Furthermore, estrogen receptor status and NHE-RF expression correlate closely in breast carcinoma specimens. These findings support a role for NHE-RF in estrogen signaling.

Evolutionary conservation of redundancy between a diverged pair of forkhead transcription factor homologues

The Caenorhabditis elegans gene pes-1 encodes a transcription factor of the forkhead family and is expressed in specific cells of the early embryo. Despite these observations suggesting pes-1 to have an important regulatory role in embryogenesis, inactivation of pes-1 caused no apparent phenotype. This lack of phenotype is a consequence of genetic redundancy. Whereas a weak, transitory effect was observed upon disruption of just T14G12.4 (renamed fkh-2) gene function, simultaneous disruption of the activity of both fkh-2 and pes-1 resulted in a penetrant lethal phenotype. Sequence comparison suggests these two forkhead genes are not closely related and the functional association of fkh-2 and pes-1 was only explored because of the similarity of their expression patterns. Conservation of the fkh-2/pes-1 genetic redundancy between C. elegans and the related species C. briggsae was demonstrated. Interestingly the redundancy in C. briggsae is not as complete as in C. elegans and this could be explained by alterations of pes-1 specific to the C. briggsae ancestry. With overlapping function retained on an evolutionary time-scale, genetic redundancy may be extensive and expression pattern data could, as here, have a crucial role in characterization of developmental processes.

Development of soluble glasses for biomedical use Part II: the biological response of human osteoblast cell lines to phosphate-based soluble glasses

Soluble glasses are considered to be of potential clinical value in orthopaedic and dental surgery. However, the biological response to these materials is not well understood. To determine the effects of these glasses, two human osteoblast cell lines, MG63 and HOS (TE85), were incubated in vitro in the presence of increasing concentrations of extracts of the glasses. The effects of the extracts on cell growth was measured using the MTT assay and an ELISA assay was used to measure the expression of bone sialoprotein (BSP), osteonectin (ON) and fibronectin (FN), antigens which play a fundamental part in the integrity and function of hard connective tissue. The results showed that the proliferation of the cells was adversely affected only by the more soluble glasses, which also down-regulated the expression of the bone-associated proteins. In contrast, the extract of the glass with the lowest dissolution rate, which contains relatively elevated levels of Ca2+, was found to enhance bone cell growth and antigen expression. These findings suggest that the compositions of these glasses at least partly determine the response of cells and thus, that the glasses could be modified to elicit a more optimal biological response and clinical efficacy.

Ten years of liver transplantation at Groote Schuur Hospital

INTRODUCTION

Liver transplantation has evolved from an experimental procedure to being the treatment of choice for many patients with end-stage liver disease, and is performed on a routine basis in most major centres throughout the world. However, certain situations peculiar to developing countries have a major impact on liver transplant programmes in these countries. We present the results of the liver transplant programme in Cape Town.

PATIENTS AND METHODS

All patients undergoing orthotopic liver transplantation at Groote Schuur Hospital and Red Cross War Memorial Children's Hospital were included in this report. Standard surgical techniques were used for procuring the donor liver, the recipient hepatectomy and the subsequent implantation of the liver. All patients received standardised peri-operative management; in particular, the immunosuppressive protocol consisted of cyclosporin, steroids and azathioprine. Since October 1988, 83 patients have undergone 89 orthotopic liver transplants. There were 44 adults and 39 children, the age range being from 6 months to 56 years. The commonest indications for hepatic transplantation in adults included cryptogenic cirrhosis, auto-immune hepatitis and primary sclerosing cholangitis. In children biliary atresia was the commonest cause of liver failure.

RESULTS

Of the 81 patients transplanted, 50 are alive and well with follow-up ranging from 2 months to 9.5 years. The cumulative graft survival rate was 72% at 1 year and 61% at 5 years. Six patients have undergone re-transplantation and 4 patients have had combined liver/kidney transplants. De novo hepatitis due to hepatitis B virus (HBV) has occurred in 8 patients following transplantation. Subsequent investigation has shown that 5 of the donors of these livers were hepatitis B core antibody (HBcAb)-positive, while information on the remaining 3 was not available. Tuberculosis (TB) has been a significant problem in 4 patients, with 2 deaths precipitated by anti-TB drug-induced hepatitis. Post-transplant lymphoproliferative disorder was also responsible for significant postoperative morbidity.

CONCLUSION

Orthotopic liver transplantation has been established at Groote Schuur Hospital as the treatment of choice for selected patients with chronic end-stage liver disease. However, hepatitis B and TB appear to present a problem. The particularly high prevalence of HBV carrier status in our donor population may necessitate the use of living donors in the future.

Chronic relapsing pancreatitis in a child. Use of the Puestow procedure to achieve ductal drainage

A case of chronic relapsing pancreatitis presenting in an 8-year-old African Jamaican girl is outlined. Aggressive supportive management failed to control pain and vomiting. The Puestow Procedure effectively procedure aborted these symptoms. The use of the Puestow procedure should not be inordinately delayed in chronic relapsing pancreatitis if symptoms persist, since it may not only control pain but also halt declining pancreatic function.

A comparison of home care clients and nursing home residents: can community based care keep the elderly and disabled at home?

Admission cohorts from the Michigan Medicaid Home and Community-Based Waiver program and Ohio nursing homes were compared on measures of resource utilization including a modified Resource Utilization Groups (RUG-III) system, Activities of Daily Living (ADLs), and overall case mix. We found that, contrary to previous research, the two samples were remarkably similar across RUG-III categories. However, the nursing home sample was more functionally impaired on measures of ADL functioning and overall case mix. Results of this study may inform policymakers and providers of the potential for maintaining the appropriate population in the home with government-funded home care.

Health care in the upcoming 2000 election

Health care will be one of the top issues in the year 2000 election, but voters' interest in health care is not as great as it was in 1992. There is no single unifying theme to the health care issue. Rather, there are multiple concerns: making Medicare financially sound, providing coverage for prescription medicines for seniors, covering the uninsured, and addressing patients' rights. Voters favor an incremental approach to expanding health insurance coverage rather than a major program. They express about equal levels of support for plans similar in concept to those proposed by presidential candidates Al Gore and George W. Bush.

Role of ambulatory urodynamic monitoring in clinical urological practice

A retrospective review was conducted of 125 ambulatory monitoring (AM) studies performed on 111 women and 11 men between 1992 and 1996. All patients had had conventional cystometry prior to AM. All tests were interpreted with the aid of event markers and urinary diaries. Ambulatory traces were reported using the definitions derived from Coolsaet's work. To assess the role of AM in routine clinical urological practice, ambulatory diagnoses were compared with those of conventional cystometry. A survey of patient management was carried out by postal questionnaire or review of hospital notes to determine whether AM had influenced patient management. The study showed that 53 of 94 (56.3%) patients with symptoms suggestive of detrusor overactivity had detrusor instability diagnosed on AM. Of those with symptoms suggestive of stress incontinence, 5 (29%) had genuine stress incontinence and 5 (29%) had detrusor instability. The remainder (42%) had normal tests. Overall in 79 of 125 tests (63.2%), additional urodynamic findings were made that correlated with symptoms. Following the survey of patient management, AM was shown to influence management in all but 8.7% patients. In summary, AM was felt to have been shown to be a useful additional tool in clinical urological practice for those patients where conventional cystometry had failed to explain their symptoms.

Cost effectiveness analysis of screening for sight threatening diabetic eye disease

OBJECTIVE

To measure the cost effectiveness of systematic photographic screening for sight threatening diabetic eye disease compared with existing practice.

DESIGN

Cost effectiveness analysis.

SETTING

Liverpool.

SUBJECTS

A target population of 5000 diabetic patients invited for screening.

MAIN OUTCOME MEASURES

Cost effectiveness (cost per true positive) of systematic and opportunistic programmes; incremental cost effectiveness of replacing opportunistic with systematic screening.

RESULTS

Baseline prevalence of sight threatening eye disease was 14.1%. The cost effectiveness of the systematic programme was 209 pound sterling (sensitivity 89%, specificity 86%, compliance 80%, annual cost 104996 pound sterling) and of the opportunistic programme was 289 pound sterling (combined sensitivity 63%, specificity 92%, compliance 78%, annual cost 99 981 pound sterling). The incremental cost effectiveness of completely replacing the opportunistic programme was 32 pound sterling. Absolute values of cost effectiveness were highly sensitive to varying prevalence, sensitivity and specificity, compliance, and programme size.

CONCLUSION

Replacing existing programmes with systematic screening for diabetic eye disease is justified.

Active ERK/MAP kinase is targeted to newly forming cell-matrix adhesions by integrin engagement and v-Src

Integrin engagement generates cellular signals leading to the recruitment of structural and signalling molecules which, in concert with rearrangements of the actin cytoskeleton, leads to the formation of focal adhesion complexes. Using antisera reactive either with total ERK or with phosphorylated/activated forms of ERK, in rat embryo fibroblasts and embryonic avian cells that express v-Src, we found that active ERK is targeted to newly forming focal adhesions after integrin engagement or activation of v-Src. UO126, an inhibitor of MAP kinase kinase 1 (MEK1), suppressed focal adhesion targeting of active ERK and cell spreading. Also, integrin engagement and v-Src induced myosin light chain kinase (MLCK)-dependent phosphorylation of myosin light chain downstream of the MEK/ERK pathway, and MLCK and myosin activities are required for the focal adhesion targeting of ERK. The translocation of active ERK to newly forming focal adhesions may direct specificity towards appropriate downstream targets that influence adhesion assembly. These findings support a role for ERK in the regulation of the adhesion/cytoskeletal network and provide an explanation for the role of ERK in cell motility.

Adhesion-dependent tyrosine phosphorylation of (beta)-dystroglycan regulates its interaction with utrophin

Many cell adhesion-dependent processes are regulated by tyrosine phosphorylation. In order to investigate the role of tyrosine phosphorylation of the utrophin-dystroglycan complex we treated suspended or adherent cultures of HeLa cells with peroxyvanadate and immunoprecipitated (beta)-dystroglycan and utrophin from cell extracts. Western blotting of (β)-dystroglycan and utrophin revealed adhesion- and peroxyvanadate-dependent mobility shifts which were recognised by anti-phospho-tyrosine antibodies. Using maltose binding protein fusion constructs to the carboxy-terminal domains of utrophin we were able to demonstrate specific interactions between the WW, EF and ZZ domains of utrophin and (beta)-dystroglycan by co-immunoprecipitation with endogenous (beta)-dystroglycan. In extracts from cells treated with peroxyvanadate, where endogenous (beta)-dystroglycan was tyrosine phosphorylated, (beta)-dystroglycan was no longer co-immunoprecipitated with utrophin fusion constructs. Peptide ‘SPOTs’ assays confirmed that tyrosine phosphorylation of (beta)-dystroglycan regulated the binding of utrophin. The phosphorylated tyrosine was identified as Y(892) in the (beta)-dystroglycan WW domain binding motif PPxY thus demonstrating the physiological regulation of the (beta)-dystroglycan/utrophin interaction by adhesion-dependent tyrosine phosphorylation.