RNA binding proteins regulate anabolic and catabolic gene expression in chondrocytes

OBJECTIVE

Regulation of anabolic and catabolic factors is considered essential in maintaining the homoeostasis of healthy articular cartilage. In this study we investigated the influence of RNA binding proteins (RNABPs) in this process.

DESIGN

Using small interfering RNA (siRNA), RNABP expression was knocked down in SW1353 chondrosarcoma cells and human articular chondrocytes. Gene expression and messenger RNA (mRNA) decay of anabolic (SOX9, Aggrecan) and catabolic (matrix metalloproteinase (MMP)13) factors were analysed using reverse transcription quantitative polymerase chain reaction (RT-qPCR). RNA-electromobility shift assays (EMSAs) were used to investigate RNABP interactions with the SOX9 mRNA 3' untranslated region (UTR). Immunohistochemical localisation of MMP13 and the RNABP human antigen R (HuR) was performed in E13.5 and E16.5 mouse embryo sections.

RESULTS

SOX9 mRNA, mRNA half-life and protein expression were increased with siRNA targeting the RNABP tristetraprolin (TTP) in both HACs and SW1353s. TTP knockdown also stimulated aggrecan mRNA expression but did not affect its stability. RNA-EMSAs demonstrated that adenine uracil (AU)-rich elements in the SOX9 mRNA 3'UTR interacted with chondrocyte proteins with three specific elements interacting with TTP. HuR knockdown significantly increased MMP13 expression and also regulated the expression of a number of known transcriptional repressors of MMP13. HuR was ubiquitously expressed within mouse embryos yet displayed regional down-regulation within developing skeletal structures.

CONCLUSION

This study demonstrates for the first time how RNABPs are able to affect the balance of anabolic and catabolic gene expression in human chondrocytes. The post-transcriptional mechanisms controlled by RNABPs present novel avenues of regulation and potential points of intervention for controlling the expression of SOX9 and MMP13 in chondrocytes.

Comprehensive protein profiling of synovial fluid in osteoarthritis following protein equalization

OBJECTIVE

The aim of the study was to characterise the protein complement of synovial fluid (SF) in health and osteoarthritis (OA) using liquid chromatography mass spectrometry (LC-MS/MS) following peptide-based depletion of high abundance proteins.

DESIGN

SF was used from nine normal and nine OA Thoroughbred horses. Samples were analysed with LC-MS/MS using a NanoAcquity™ LC coupled to an LTQ Orbitrap Velos. In order to enrich the lower-abundance protein fractions protein equalisation was first undertaken using ProteoMiner™. Progenesis-QI™ LC-MS software was used for label-free quantification. In addition immunohistochemistry, western blotting and mRNA expression analysis was undertaken on selected joint tissues.

RESULTS

The number of protein identifications was increased by 33% in the ProteoMiner™ treated SF compared to undepleted SF. A total of 764 proteins (462 with≥2 significant peptides) were identified in SF. A subset of 10 proteins were identified which were differentially expressed in OA SF. S100-A10, a calcium binding protein was upregulated in OA and validated with western blotting and immunohistochemistry. Several new OA specific peptide fragments (neopeptides) were identified.

CONCLUSION

The protein equalisation method compressed the dynamic range of the synovial proteins identifying the most comprehensive SF proteome to date. A number of proteins were identified for the first time in SF which may be involved in the pathogenesis of OA. We identified a distinct set of proteins and neopeptides that may act as potential biomarkers to distinguish between normal and OA joints.

Cartilage damage involving extrusion of mineralisable matrix from the articular calcified cartilage and subchondral bone

Arthropathy of the distal articular surfaces of the third metacarpal (Mc3) and metatarsal (Mt3) bones in the Thoroughbred racehorse (Tb) is a natural model of repetitive overload arthrosis. We describe a novel pathology that affects the articular calcified cartilage (ACC) and subchondral bone (SCB) and which is associated with hyaline articular cartilage degeneration. Parasagittal slices cut from the palmar quadrant of the distal condyles of the left Mc3/Mt3 of 39 trained Tbs euthanized for welfare reasons were imaged by point projection microradiography, and backscattered electron (BSE) scanning electron microscopy (SEM), light microscopy, and confocal scanning light microscopy. Mechanical properties were studied by nanoindentation. Data on the horses' training and racing career were also collected. Highly mineralised projections were observed extending from cracks in the ACC mineralising front into the hyaline articular cartilage (HAC) up to two-thirds the thickness of the HAC, and were associated with focal HAC surface fibrillation directly overlying their site. Nanoindentation identified this extruded matrix to be stiffer than any other mineralised phase in the specimen by a factor of two. The presence of projections was associated with a higher cartilage Mankin histology score (P<0.02) and increased amounts of gross cartilage loss pathologically on the condyle (P<0.02). Presence of projections was not significantly associated with: total number of racing seasons, age of horse, amount of earnings, number of days in training, total distance galloped in career, or presence of wear lines.

Investigation into the prevalence of bovine cryptosporidiosis among small-holder dairy households in Dagoretti Division, Nairobi, Kenya

OBJECTIVES

To determine the prevalence of bovine cryptosporidiosis and knowledge of this disease among smallholder dairy households in Dagoretti Division, Nairobi, Kenya.

DESIGN

Cross-sectional survey of 299 dairy households and 149 non-dairy neighbouring households.

SETTING

Dagoretti Division, a mixed urban and peri-urban area of Nairobi.

SUBJECTS

Dairy householders and their immediate, non-cattle keeping neighbours.

RESULTS

There were 50 positive households from 285 households where a fecal sample was collected giving an apparent prevalence of 18% [13, 23]%. Positive households were positively associated with watering cattle with well water, presence of shallow well, cemented cattle shed flooring and number of household cattle. (p < 0.05) Knowledge of cryptosporidiosis was generally low with more dairy respondents, 19% (56/292), who said they had heard of the disease than their non-dairy neighbours, 4% (6/146).

CONCLUSION

This 18% bovine cryptosporidiosis prevalence does not constitute a risk to human health unless Cryptosporidium parvum is present. Typing of these positive samples is needed to assist in accurately determining the risk and enable evidence based management of urban dairy farming.

Isolation of E. coli O157:H7 from milk and cattle faeces from urban dairy farming and non dairy farming neighbour households in Dagoretti Division, Nairobi, Kenya: prevalence and risk factors

OBJECTIVE

To estimate the prevalence of E. coli O157:H7 in milk and cattle faecal samples dairy and non dairy neighbouring households and to relate this prevalence to the risk to human health.

DESIGN

Cross sectional study.

SETTING

Urban and peri-urban households of Dagoretti, Division, Nairobi, Kenya.

SUBJECTS

Dairy farming households and non dairy farming neighbouring households.

RESULTS

E coli O157:H7 was isolated from milk samples at three of 136 non-dairy neighbour households (2.2% C.I. 0.5%,6.3%) but was not found in any of the milk samples from the 260 milk samples from dairy households (0% C.I. 0.0%,1.4%). E.coli O157:H7 was also found in fifteen of 285 pooled household cattle faecal sample (5.2%, C.I. 3.1%, 8.7%). One of the faecal isolates was found to have the marker for the production of VT1. Discussions with focus groups revealed that the participants had limited knowledge about E. coli O157:H7. Focus group discussions and household questionnaires revealed practices increasing risk of E. coli infections to humans are associated with milking hygiene, drinking water source and treatment, and manure handling.

CONCLUSIONS

E. coli O157:H7 exists in urban setting and continuous surveillance is needed in case conditions and practices change favoring an increase in its prevalence and transmission to people.

Phenol red thread test vs Schirmer's test: a comparative study

AIM

To measure the agreement between Schirmer's and phenol red thread tests in detecting dry eyes.

PATIENTS AND METHODS

A total of 103 patients attending preoperative cataract assessment clinic who agreed to be involved in the study were recruited. Each patient had one eye examined by both tests in a random order by two different investigators who were unaware of the results of the other test. Dry eye symptoms were assessed using an interviewer-administered questionnaire. The data were collected after the study period and analysed using kappa statistics to assess the agreement between the two tests.

RESULTS

Schirmer's test was positive in 25 patients when a cutoff point of 5 mm was used and positive in 41 patients with a cutoff point of 10 mm. Phenol red thread test was positive in four patients when a cutoff point of 10 mm was used and in 32 patients with a cutoff point of 20 mm. Kappa ranged from 0.067 to 0.3 indicating very weak agreement between the two tests. In all, 27% of the patients had symptoms of dry eyes; however, the agreement between each test and the symptoms was very poor.

CONCLUSION

There is very weak agreement between Schirmer's test and phenol red thread tests and between each test and symptoms of dry eyes.

Analysis of correlated discrete observations: background, examples and solutions

The goal of this paper is to highlight the use and interpretation of statistical techniques that account for correlation in epidemiological data. A conceptual statistical background is provided, and the main types of regression models for correlated data are highlighted. These models include marginal models, random effect models and transitional regression models. For each model type an example with data from the veterinary literature is provided. The examples are specifically used to highlight estimation procedures for parameters, and the interpretation of the estimated parameters. This paper emphasizes that statistical techniques and software to fit them are more widely available now, but that parameters have different interpretations in different model types. Consequently, we stress the importance of focusing on choosing the most appropriate model for the specific purpose of the analysis.

The impact of Theileria parva infections and other factors on calf mean daily weight gains in smallholder dairy farms in Murang'a District, Kenya

The association between mean daily weight gain, Theileria parva infections, clinical East Coast fever and other possible determinants of weight gain were examined in a longitudinal observational study that was conducted in cohorts of female calves from five agro-ecological zone (AEZ)-grazing strata. The strata were upper-midlands (UM) 1 zero-grazing, UM 1 open-grazing, UM 2 zero-grazing, UM 4 zero-grazing and UM 4 open-grazing. In total, 225 calves on 188 smallholder dairy farms were visited within the first 2 weeks of life and thereafter at biweekly intervals up to the age of 6 months between March 1995 and August 1996. During each visit, the calves were weighed and other calf-management practices in the farm during the visit such as housing, feeding and tick control also were recorded. Other events such as morbidity and mortality between or during the visits were also recorded. The overall mean daily weight gains were 0.24-0.29 kg (S.D.=0.17-0.22 kg) and were lower than the recommended targets for smallholder farms of 0.40-0.50 kg. The major tendency in variability of daily weight gains was due to visit-to-visit variation (especially in calves >3 months old). Differences in mean daily gains were associated with AEZ-grazing strata and calf-level factors that included breed of calf, calf sickness, incidence of ECF, feeding of milk, concentrate feeds and minerals and interaction between calf age and AEZ-grazing strata (P<0.05). ECF and other calf sicknesses exerted a temporal effect on calf-growth at the height of illness and immediately after; calves later recovered the lost growth except where other factors such as poor calf nutrition prevailed. Improvement in calf-growth in Murang'a District is achievable and extension services should continue to target individual-calf-level management practices.

Heterogeneity of the psychoses: is there a neurodegenerative psychosis?

Whereas etiological heterogeneity of the various types of schizophrenia has been repeatedly proposed, relatively few attempts have been made to separate the component diseases. Using a strategy focusing on bimodal distributions within several relevant domains of schizophrenia, we demonstrate that currently available data on schizophrenia patients are consistent with the hypothesis that some of these patients have an ongoing neurodegenerative disease, whereas others do not. We review studies (longitudinal and cross-sectional) documenting progressive increases in ventricular size, accelerated loss of brain tissues, progressive delays in treatment response, and neurochemical (magnetic resonance spectroscopy) and neurophysiological (P300) indices, all of which are consistent with ongoing cerebral degeneration in a significant subgroup of schizophrenia patients. These lines of evidence converge on a conceptualization of schizophrenia as being composed of several etiologically distinct processes, with one subset of psychotic patients evidencing progressive brain degeneration. We conclude with a discussion of possible etiologies for this condition.

Positive effect of bumetanide on contractile activity of ventricular cardiomyocytes

Although the beneficial effects of loop-diuretics in relieving congestive heart failure and essential hypertension are well established, there has been limited investigation into the direct cardiac effect of these drugs. The aim of the present study was to investigate mechanical and electrophysiological effects of three loop-diuretics, namely, frusemide, bumetanide and torasemide, in ventricular cardiomyocytes isolated from rabbit myocardium. Contractile performance was assessed using a video edge detection method and effects on L-type Ca(2+) currents were determined using a 'perforated' patch-clamp technique. Unlike frusemide and torasemide, bumetanide produced concentration-dependent (3x10(-8) to 10(-5) M) increases in cell shortening and velocity of cell shortening. Neither frusemide, bumetanide nor torasemide exerted any action on peak Ca(2+) current amplitudes. In summary, the present investigation provides evidence for a direct contractile effect of the loop diuretic, bumetanide, in contrast to absence of effects by frusemide and torasemide, in ventricular cardiomyocytes isolated from rabbit myocardium.

Paediatric assessment in a residential child and adolescent psychiatry unit

OBJECTIVE

To document the health status, comorbidity and functional impairments experienced by a group of psychiatrically disturbed children and adolescents.

METHODOLOGY

A detailed study of consecutive admissions to a residential unit over a two-year period was undertaken. All admissions had a comprehensive paediatric, speech pathology and psychiatric assessment.

RESULTS

Compared to the general population, there was a significant history of developmental delay and low birthweight, but only a slightly greater prevalence of antenatal problems. Clumsiness (37%), severe speech and language disorder (32%), and hearing loss (15%) were prominent. Only 25% had no history of comorbid medical or neurological disorders.

CONCLUSION

Children and adolescents presenting with moderate to severe mental health morbidity may have pre-existing comorbid medical problems, as well as unrecognised difficulties and impairments in other skills areas. Multidisciplinary assessment and intervention should be an integral part of the residential programme.

Power evaluation of small drug and vaccine experiments with binary outcomes

Power analysis based on the Fisher exact test is used to evaluate the usefulness of alternative designs for small drug and vaccine experiments with a binary, success or failure, outcome. The emphasis is on the comparison between designs with equal and unequal allocations of animals to treated and control groups having the same total sample size, and between designs with equal and unequal allocations but with one or two fewer animals in the control than the treated group. Designs with unequal allocation can sometimes be more powerful at a given level of statistical significance alpha than designs with equal allocation. Graphs and a table are presented to aid the choice of suitable designs for (1-beta) = 0.80 and alpha = 0.05.

A profile of children and adolescents in a psychiatric unit: multidomain impairment and research implications

OBJECTIVE

The scientific literature has not kept pace with the evolution of child and adolescent psychiatric inpatient units, including their nature, patient profile, philosophical orientation and efficacy. This study aims to establish a comprehensive, multimodal description of the population served by an inpatient psychiatric treatment facility for children and adolescents.

METHOD

A multidisciplinary assessment regime including psychiatric, medical, speech and language examination, observer rating and patient self-report of psychopathology was used to assess 58 consecutive patients over a 20-month period.

RESULTS

In addition to a prevalence of disruptive behaviour disorders of 67% and a high rate of comorbidity with other psychiatric conditions, a breadth of impairment was demonstrated in many areas. Significantly decreased measures of socialisation, communication, daily living skills, self-esteem, intelligence and physical health are reported. Moderate to severe language handicap was found in 40% of patients.

CONCLUSIONS

The inpatient population of children and adolescents exhibited not only a high rate of disruptive behaviour disorders, frequently comorbid with other psychiatric conditions, but also high levels of physical, speech, language and living skills impairment. This finding supports the need for multimodal, multidisciplinary evaluation and treatment in this population. Outcome research evaluating treatment effectiveness must also account for the wide-ranging disabilities of these children and adolescents.

Psychiatric findings among child psychiatric inpatients grouped by public and private payment

OBJECTIVE

The study compared school-age psychiatric inpatients whose care was publicly funded with those whose care was privately funded to determine whether the public patients presented with more psychiatric risk factors and more psychiatric problems.

METHODS

Retrospective chart review was used to collect data on the demographic and personal characteristics, behavior in the hospital, and response to milieu treatment of 40 public patients and 40 private patients. Half of each group were admitted during 1985-1986, and half during 1991-1993. Characteristics of the two groups were compared, and trends over time were examined.

RESULTS

The public group presented for hospitalization with significantly more risk factors and psychiatric problems. Public status predicted the use of certain interventions, such as time-outs and physical holding. Public patients responded less positively to the treatment program. They had three times the number of bed-days as the private group during 1991-1993.

CONCLUSIONS

Public patients require more intensive and extensive inpatient treatment and will be more profoundly affected by the restrictions on psychiatric inpatient care in the current climate of fiscal restraint.

Dual effects of endothelin-1 on the L-type Ca2+ current in ventricular cardiomyocytes

The effects of endothelin-1 on the L-type Ca2+ current were studied in rabbit ventricular cardiomyocytes, using both the 'perforated' and the conventional 'ruptured' whole-cell patch-clamp techniques. Endothelin-1 exerts a dual effect on ventricular cardiomyocytes using experimental conditions which minimize intracellular dialysis; endothelin-1 produced both an increase (10(-9) M) and a decrease (10(-8) M) in the L-type Ca2+ current using the perforated patch-clamp technique. However, using the ruptured patch-clamp technique, endothelin-1 produced a similar decrease in L-type Ca2+ current at 10(-8) M, but no effect was observed at a concentration of 10(-9) M. These effects suggest multiplicity in the receptor-effector coupling mechanism.

Phase I/II trial of biweekly paclitaxel and cisplatin in the treatment of metastatic breast cancer

PURPOSE

To determine the maximum-tolerated dose of escalating doses of paclitaxel (Taxol; Bristol-Myers Squibb, Princeton, NJ) administered biweekly with a fixed dose of cisplatin, to assess the toxicity, and to evaluate the activity of this combination in a phase I/II trial in metastatic breast cancer.

PATIENTS AND METHODS

Twenty-nine women with metastatic breast cancer were enrolled; 27 were assessable for response and 29 for toxicity. All but two of the women had received prior adjuvant chemotherapy, with 23 receiving anthracyclines and six previous cisplatin.

RESULTS

The initial starting dose of paclitxel 90 mg/m2 and cisplatin 60 mg/m2 became the phase II dose due to dose-limiting neutropenia. Responses were seen in 85% of assessable patients, with three patients (11%) achieving a complete response (CR) and 20 patients (14%) a partial response (PR), for an overall response rate of 85% (95% confidence interval [CI], 66% to 96%). The time to disease progression for patients who achieved a CR was 110 to 200 days, and for those with a PR, it was 96 to 377+ days, with a median time to progression of 7.1 months and a median response duration of 7.9 months. Sites of CR were skin, soft tissue, and lung, and all occurred in women with previous exposure to anthracyclines. Septic events were rare, with two grade 3 infections (7%), only one of which required hospital admission. There were no grade 4 nonhematologic toxicity and minimal grade 3 toxicity. A total of 251 chemotherapy cycles were given -- 16 with paclitaxel alone in five patients. Forty-five percent of patients required dose reductions, while 52% had delays due to neutropenia.

CONCLUSION

Biweekly paclitaxel and cisplatin is an active combination in the treatment of metastatic breast cancer, including for patients with previous exposure to anthracyclines.

Homomeric interactions between transmembrane proteins of Moloney murine leukemia virus

We have studied homomeric interactions between transmembrane proteins (TM) of the Moloney murine leukemia virus envelope using the Saccharomyces cerevisiae two-hybrid system. TM interacts strongly with itself but not with various control proteins. Deletional and mutational analyses indicated that the putative leucine zipper motif in the extracellular domain of TM is essential and sufficient to mediate the binding. The first three repeats of the leucine zipper-like motif are the most important in mediating the interaction. The TM-TM interaction detected in this system may play a role in several stages of viral replication.

The course of DSM-III-R schizophreniform disorder

This study compared the course of illness of 36 patients who received a diagnosis of either DSM-III-R schizophreniform disorder or schizophrenia. Approximately 3.5 and 4.0 years after their index hospitalization, the two groups were compared for differences in positive and negative symptoms of psychosis, interpersonal and occupational role functioning, and other aspects of the deficit state. Multivariate data analyses indicate that the course of illness of the two groups is significantly different (p < .007), and the data also indicate that patient symptoms and functioning changed significantly over time (p < .008). The schizophreniform patients showed a low level of negative symptoms at both follow-ups; schizophrenics initially showed a higher level of negative symptoms, but these symptoms decreased significantly over time (p < .04). These data indicate that the course of DSM-III-R schizophreniform disorder is distinct from the course of schizophrenia.

Familial differences between rapid neuroleptic response psychosis and delayed neuroleptic response psychosis

Recent data suggest that latency of neuroleptic response may be used to separate distinct subtypes of psychotic disorders. In this preliminary study we contrast family patterns of illness of rapid neuroleptic response psychotics and delayed neuroleptic response psychotics. The data show that first-degree relatives of delayed neuroleptic response psychotics evidence higher levels of psychiatric disorder than rapid responders: relatives of delayed neuroleptic response psychotics evidenced a morbid risk for schizophrenic-spectrum disorder that was more than twice as high as the morbid risk for such disorders among relatives of rapid neuroleptic response psychotics. Relatives of delayed neuroleptic responders that received a diagnosis of schizophrenia, schizoaffective, or schizophreniform disorder evidenced significantly more residual impairment than schizophrenic-spectrum relatives of rapid neuroleptic responders. These preliminary data indicate the possibility that latency of therapeutic response to neuroleptic medication may be used to discriminate two familially distinct psychotic disorders and they suggest that delayed neuroleptic response may characterize a familially transmitted poor-outcome disease.

Continuous vincristine infusion as part of a high dose chemoradiotherapy regimen: drug kinetics and toxicity

A 5-day continuous infusion of vincristine (VCR; total dose 4 mg/m2) has been given as part of a high-dose chemoradiotherapy regimen with bone marrow transplantation. Evidence of neurotoxicity, such as weakness, paraesthesia and intestinal hypomotility, was evaluated prospectively in nine patients. Five patients had advanced neuroblastoma and four, relapsed sarcomas, and all had responded to initial conventional-dose therapy. VCR was combined with high-dose melphalan (180 mg/m2) and fractionated total-body irradiation. Plasma concentrations of VCR were measured by radioimmunoassay during and up to 24 h after the infusion. Serum and urine electrolytes and liver function tests were measured during VCR treatment and at regular intervals thereafter. VCR concentration at 1 h ranged from 1.8 to 10.9 (median 6.6) ng/ml, and a steady state was achieved by 13-30 h (median 16 h). Levels above 1 ng/ml were maintained throughout the 5-day period with a mean steady-state concentration of 1.7 ng/ml (range 1.3-2.15). After cessation of the infusion, serum concentrations fell to below 0.25 ng/ml within 24 h. Abdominal pain occurred in one patient, but neither constipation nor ileus was seen. In two patients severe muscle pain occurred in the lower limbs towards the end of the infusion. Significant electrolyte problems did not occur and, in particular, there was no evidence of inappropriate ADH secretion. Transient increases in liver enzymes were common but bilirubin was not elevated during the period of monitoring. This regimen allows a two-fold escalation in the dose of VCR to be administered, producing sustained high serum drug levels without major toxicity.

The pharmacokinetics of sulphasalazine in young and elderly patients with rheumatoid arthritis

The clinical pharmacokinetics of enteric-coated sulphasalazine (Salazopyrin-EN) were studied after acute and chronic dosing in 20 patients with 'active' rheumatoid arthritis. 12 elderly (mean age 74.4 +/- 1 yr; range 71-83) and 8 young (mean age 40.5 +/- 1.4 yr; range 35-46) patients were given a single 2 g oral dose of sulphasalazine after an overnight fast. Serum and urine samples were collected at regular intervals over a 96 hour period for estimation of concentrations of sulphasalazine, sulphapyridine and its metabolites. This procedure was repeated after 17 days of continuous treatment with salazopyrin-EN 2 g daily in order to compare the drug's kinetics at 'steady-state'. Whilst the interindividual variation in kinetic parameters was large, age and acetylator status had a significant influence on a number of factors. The elimination half-life of sulphasalazine was prolonged in the elderly whilst renal clearance was increased in slow acetylators at 'steady-state'. The tmax and apparent volume of distribution of sulphapyridine were increased in the elderly after a single drug dosage but these differences disappeared with regular dosing. The Cmax, elimination half-life, 'steady-state' serum concentration, apparent volume of distribution and total clearance of sulphapyridine were all affected by acetylator status. We conclude that old age has only a minor effect on the body's handling of sulphasalazine and sulphapyridine but that acetylator phenotype plays a significant role in determining the 'steady-state' serum concentrations of sulphapyridine. This is likely to have practical implications with regard to some of the drug's adverse effects.