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.

Co-localisation of CCG repeats and chromosome deletion breakpoints in Jacobsen syndrome: evidence for a common mechanism of chromosome breakage

Folate-sensitive fragile sites are associated with the expansion and hypermethylation of CCG-repeats. The fragile site in 11q23.3, FRA11B, has been shown to cause chromosome deletions in vivo, its expression being associated with Jacobsen (11q-) syndrome. However, the majority of Jacobsen deletions are distal to FRA11B and are not related to its expression. To test the hypothesis that other unidentified fragile sites might be located in 11q23.3-24 and may cause these deletions, we have identified and characterised CCG-trinucleotide repeats within a 40 Mb YAC contig spanning distal chromosome 11q. Only eight CCG-repeats were identified within the entire YAC contig (not including FRA11B ), six of which map to the region of 11q23.3-24 that includes Jacobsen deletions. We have previously collated the deletion mapping data of 24 Jacobsen patients with the physical map of chromosome 11q, and accurately localised six breakpoints to short intervals corresponding to individual YAC clones. We now show that in each of these cases, YAC clones found to contain a deletion breakpoint also contain a CCG-repeat. The improved analysis of one of these deletions, together with those of several new Jacobsen cases, further strengthens this association by localising five breakpoints to individual PAC clones containing CCG-repeats. These data provide strong evidence for the non-random clustering of chromosome deletion breakpoints with CCG-repeats, and suggests that they may play an important role in a common mechanism of chromosome breakage.

Breastfeeding outcomes of women following uncomplicated birth in Hamilton-Wentworth

OBJECTIVE

To examine infant feeding practices up to 8 weeks postpartum in Hamilton-Wentworth.

METHODS

A cross-sectional survey of 227 women using a pre-discharge, self-administered questionnaire, medical record review and follow-up telephone interview.

RESULTS

Breastfeeding initiation rate was 85%. By 6-8 weeks postpartum, 30% of women had stopped breastfeeding; 55% had switched to formula within the first 14 days. Infants who did not receive supplementation in hospital were 2.49 times more likely than infants who received supplementation to breastfeed for at least 6 weeks. Although 54% of mothers who initiated breastfeeding reported receiving formula gift packs, no association was found.

CONCLUSIONS

The breastfeeding initiation rate appears to have increased in Hamilton-Wentworth since 1995. However, this study reinforces the need to address early cessation and infant supplementation, and raises concern about violation of the WHO/UNICEF International Code of Marketing of Breastmilk Substitutes through mailing of formula coupons.

Relationship between serum inositol concentration and development of retinopathy of prematurity: a prospective study

PURPOSE

To examine the relationship between the intake of sugar inositol, serum inositol levels, and ROP in three groups of low birthweight infants receiving feedings containing various concentrations of inositol.

METHODS

Infants with a birthweight <1500 g, with severe lung disease, were eligible for the study when they began enteral feedings. Infant formulas contained three different inositol concentrations: 2500, 710, and 242 micromol/L. Serum inositol concentrations were averaged over specific time intervals. A logistic regression model was used to investigate the confounding effect of duration of mechanical ventilation and oxygen therapy, birthweight, Apgar score, and serum inositol concentration on development of ROP.

RESULTS

Infants receiving high inositol formula and with higher serum inositol concentrations at birth and after 30 days had a statistically significant lower incidence of severe ROP than those receiving the lower inositol formula and with lower serum concentrations (P<.05). The effective serum inositol concentration (EC90) associated with lesser disease was >215 micromol/L. By logistic regression, the odds of developing severe ROP were greater among infants with low serum inositol concentration (odds ratio=4.7, 95% confidence interval 0.90-24.8, P=.017).

CONCLUSION

Inositol supplementation may help prevent the most severe form of ROP.

Pure stress leakage symptomatology: is it safe to discount detrusor instability?

OBJECTIVE

To determine whether the combination of a urological history and urinary diary, with rigorous selection criteria, can be used to define a group of women on whom urodynamic assessment is unnecessary prior to offering surgery for urinary stress incontinence.

DESIGN

Retrospective review of the urodynamic records of women attending for assessment between January 1992 and December 1996.

SETTING

Urodynamic Department, Southmead Hospital, Bristol.

POPULATION

5193 women who attended the urodynamic clinic during the five year study period.

METHODS

Self-completion of a urinary diary in the preceding week before urodynamic assessment and a detailed urological history before undergoing cystometry by all women in the study period. Data were entered onto a computer database. Women reporting stress incontinence in the absence of bladder filling symptoms, with a normal urinary diary showing daytime frequency of seven times or less and nocturia of no more than once, had the results of their filling cystometry analysed.

RESULTS

Of 5193 women, 555 had symptoms of pure stress incontinence and a normal urinary diary. Incontinence was confirmed objectively in 81%, with 9% having incontinence secondary to detrusor instability; 5% had detrusor instability as the sole cause of their incontinence with 4% having a mixed picture of detrusor instability incontinence and urethral sphincter weakness.

CONCLUSION

Genuine stress incontinence cannot be diagnosed reliably from a urological history, even when rigorous selection criteria are used in combination with a normal urinary diary. Without cystometry, incontinence secondary to detrusor instability will be missed.

Breastfeeding outcomes of women following uncomplicated birth in Hamilton-Wentworth

OBJECTIVE

To examine infant feeding practices up to 8 weeks postpartum in Hamilton-Wentworth.

METHODS

A cross-sectional survey of 227 women using a pre-discharge, self-administered questionnaire, medical record review and follow-up telephone interview.

RESULTS

Breastfeeding initiation rate was 85%. By 6-8 weeks postpartum, 30% of women had stopped breastfeeding; 55% had switched to formula within the first 14 days. Infants who did not receive supplementation in hospital were 2.49 times more likely than infants who received supplementation to breastfeed for at least 6 weeks. Although 54% of mothers who initiated breastfeeding reported receiving formula gift packs, no association was found.

CONCLUSIONS

The breastfeeding initiation rate appears to have increased in Hamilton-Wentworth since 1995. However, this study reinforces the need to address early cessation and infant supplementation, and raises concern about violation of the WHO/UNICEF International Code of Marketing of Breastmilk Substitutes through mailing of formula coupons.

QTc dispersion and complex ventricular arrhythmias in untreated newly presenting hypertensive patients

Increased dispersion of ventricular repolarisation (increased QT dispersion) is believed to predispose to arrhythmias associated with sudden death in certain cardiac diseases. Hypertension is also associated with increased risk of sudden death, particularly in those with left ventricular hypertrophy (LVH). Therefore, the first aim of this study is to look into the possible pathogenic role of QT dispersion on the ventricular arrhythmias occurring in a group of never-treated hypertensive patients. The second aim is to look at other possible determinants of QT dispersion (ie, level of blood pressure, hypokalaemia, electrocardiographic LVH and presence or absence of strain pattern) in hypertensive patients, and their relevance to complex ventricular arrhythmias. QTc (corrected QT) was measured in 70 newly presenting (never-treated) hypertensive patients (47 male, 23 female, mean age 51.9 +/- 12.5 years) from a standard 12-lead surface electrocardiogram (ECG). Blood pressure measurements and 24-h ECG holter recordings were performed in all patients. Serum potassium level was measured in 51 of the patients. Ventricular arrhythmias were classified using a modified Lown's scoring system. Maximum QTc, minimum QTc and QTc dispersion for all patients were 442 +/- 30.3 ms, 380 +/- 26.7 ms and 61.5 +/- 21.6 ms respectively. High grade ventricular arrhythmias (Lown's score >/=3) were found in 43% of the patients. The QTc dispersion was strongly correlated with the Lown's classification of arrhythmia and the age of the patients. Patients with more severe ectopy (Lown's score >/=3) were significantly older (57.4 +/- 10.3 years) compared to those with score </=2 (48.3 +/- 12.6 years) (P = 0.0067) and had a significantly greater QTc dispersion (69.9 +/- 22.5 ms vs55.2 +/- 18. 8 ms; P = 0.002). Presence of electrocardiographic strain did not affect the severity of arrhythmia, as 29% of the patients with LVH and strain had grade >/=3 Lown's score compared to 39% in the group with LVH but without strain. In the presence of relative hypokalaemia, hypertensive patients with LVH showed more QTc dispersion (85.7 +/- 15.5 ms) and a greater tendency for complex ventricular arrhythmias (100% grade >/=3 Lown's score) compared to those with LVH and normal serum potassium levels (64.1 +/- 22.6 ms and 35%, QTc dispersion and Lown's score >/=3, respectively P = 0. 05). The level of blood pressure had no effect on either the QTc dispersion or the prevalence of complex ventricular arrhythmias. Prevalence of complex ventricular arrhythmias in hypertensive patients is strongly correlated with QTc dispersion and age. When hypertensive patients with LVH have low potassium levels the risk of developing complex ventricular arrhythmias is significantly increased.

The structures of picornaviral proteinases

Picornaviruses are a family of positive-strand RNA viruses the members of which include poliovirus, hepatitis A virus, rhinovirus, foot-and-mouth disease virus and encephalomyocarditis virus. The genetic information contained in the single-stranded, positive sense RNA genome is expressed as a single protein of around 2000 amino acids. This primary product of protein synthesis, designated the polyprotein, is subsequently cleaved into the mature viral proteins by proteinases present within it. The properties of the three defined proteolytic activities present in the picornaviruses are reviewed and the three-dimensional structures of the hepatitis A 3C proteinase and the leader proteinase of foot-and-mouth disease virus as well as a model of the structure of the HRV2 2A proteinase are compared with those of chymotrypsin, papain and streptomyces griseus A proteinase, respectively.

Why do preterm infants die in the 1990s?

OBJECTIVES

To describe the mortality rate for preterm infants (born 23-36 completed weeks' gestational age) and to determine the causes of death, focusing on avoidable causes.

DESIGN AND SETTING

Prospective cohort study of preterm infants born at Royal Women's Hospital, Melbourne (a tertiary referral hospital with a neonatal intensive care unit and a special care nursery) from January 1994 to December 1996.

SUBJECTS

2475 consecutive liveborn infants with gestational ages from 23 to 36 weeks.

MAIN OUTCOME MEASURES

Mortality rate during the primary hospitalisation, and causes of death.

RESULTS

The total mortality rate was 4.8% (118/2475). The mortality rate declined with increasing maturity. The decrease in mortality was rapid between 23 and 28 weeks' gestational age, from 64.5% at 23 weeks to 4.0% at 28 weeks, then slower, falling to 0.4% at 36 weeks. Fifty of the 118 infants who died had lethal congenital anomalies. Lethal anomalies accounted for three-quarters of deaths in infants aged 28-36 weeks. The mortality rate in infants free of lethal anomalies was 2.8% (68/2425) and only 0.2% (4/1759) for infants aged 32-36 weeks. In the 68 infants without lethal anomalies who died, few obvious preventable causes were identified.

CONCLUSIONS

Mortality rates fell rapidly between 23 and 28 weeks' gestational age. Survival rates for preterm infants born after 31 weeks' gestational age approached the survival rates of term infants. Lethal congenital anomalies were the most common cause of death; preventable causes of death were rare.