Expression of an AQP2 Cre recombinase transgene in kidney and male reproductive system of transgenic mice

A transgenic mouse approach was used to examine the mechanism of principal cell-specific expression of aquaporin-2 (AQP2) within the renal collecting duct. RT-PCR and immunocytochemistry revealed that murine AQP2 was expressed in principal cells in the renal collecting duct, epithelial cells of the vas deferens, and seminiferous tubules within testis. The vas deferens expression was confirmed in rats. RT-PCR and immunocytochemistry showed that 14 kb of the human 5'-flanking region confers specific expression of a nucleus-targeted and epitope-tagged Cre recombinase in the principal cells within the renal collecting duct, in the epithelial cells of the vas deferens, and within the testis of transgenic mice. These results suggest that cell-specific expression of AQP2 is mediated at the transcriptional level and that 14 kb of the human AQP2 5'-flanking region contain cis elements that are sufficient for cell-specific expression of AQP2. Finally, renal principal cell expression of Cre recombinase is the first step in achieving cell-specific gene knockouts, thereby allowing focused examination of gene function in this cell type.

Day case surgery trends in England: the influences of target setting and of general practitioner fundholding

OBJECTIVES

To describe the trends in the proportion of elective surgery carried out as day cases, and the impact of the setting of targets and the introduction of general practitioner (GP) fundholding on the use of day surgery.

METHODS

Cross-sectional analysis of Hospital Episode Statistics for England. 1990/1991 to 1994/1995, comparing procedures for which targets were and were not set, and comparing types of purchaser (GP fundholder and health authority).

RESULTS

Elective surgical procedures increased from 2.7 million in 1990/1991 to 3.9 million in 1994/1995, a 44% increase. Increased numbers of day cases (up 117%) accounted for almost all of the increased total activity. The proportion of day cases rose from 35% to 53% over the period. Those procedures for which targets were set (over 25% of elective surgery) had a slightly lower day case proportion in 1990/1991 (34% compared to 36%) but slightly higher by 1994/1995 (57% compared to 52%). GP fundholders generally had slightly lower proportions treated as day cases compared to health authorities.

CONCLUSIONS

Day cases were additional to, rather than a substitute for, inpatient treatments. Setting day case targets may have been associated with growth in use of day surgery, but there was no association with type of purchaser.

Basaloid follicular hamartoma, total body hair loss and SLE

We describe a patient with systemic lupus erythematosus (SLE) and antiphospholipid antibody syndrome (APLS) who developed a plaque-like lesion around the mouth and lost all body hair. Biopsies of the circumoral lesion and scalp, were originally reported as containing extensive basal cell carcinoma, but on review, both showed the typical appearance of a benign malformation of the hair follicle known as basaloid follicular hamartoma. Regrowth of hair and partial resolution of the peri-oral plaque occurred with more aggressive treatment of her SLE, but the basaloid follicular hamartomas in her scalp skin persisted. There is a known, but rare, association between this pattern of basaloid follicular hamartoma, alopecia and myasthenia gravis, but only two cases have been described in association with SLE and none with APLS.

A randomized double blind trial of verbal NSAID education compared to verbal and written education

OBJECTIVE

We performed a double blind randomized controlled trial to investigate whether patients taking nonsteroidal antiinflammatory drugs (NSAID) knew more about these drugs at followup depending on whether they were randomized to receiving or not receiving an NSAID information sheet. The patients were unaware they were in a study.

METHODS

All patients received verbal education on the side effects of NSAID that was standardized and always given by the same rheumatologist. Thirty patients randomly received an NSAID information sheet and 26 patients did not. At next clinic followup, after reading a letter of explanation about the study and signing a consent form, patients completed a questionnaire asking about their knowledge of NSAID.

RESULTS

Outcome variables assessed within the questionnaire included whether NSAID : (1) can decrease inflammation; (2) help with pain; (3) cause stomach upset and bleeding in the bowels. None of these variables were statistically significant. The only variable that was statistically significantly different between the groups was their report of whether they had received an information sheet about NSAID (p<0.00004). A greater proportion of patients who received the NSAID information sheet correctly reported they had received one compared to those who had not received one and who said they had not received one (85% in the former group, 70% in the latter group). The group who received the NSAID information sheet were more apt to say that NSAID can help with their pain (odds ratio 6.1, p<0.05). Education level was positively correlated with knowledge (p<0.04). However, level of education explained only 11% of the variance in overall knowledge scores (r=0.34) among all patients.

CONCLUSION

An information sheet may not add educational value over verbal information by a physician in a clinic setting.

PAPNET-assisted rescreening of cervical smears: cost and accuracy compared with a 100% manual rescreening strategy

CONTEXT

The Food and Drug Administration has recently approved several devices that use computerized image analysis to rescreen Papanicolaou (Pap) smears that have already been examined by cytotechnologists. Physicians and laboratories must decide whether the utility of these devices justifies the cost.

OBJECTIVE

To determine the effectiveness and cost of PAPNET-assisted rescreening in identifying cervical abnormalities not identified by manual rescreening.

DESIGN

PAPNET-assisted rescreening of 5478 Pap smears obtained in 1994 and 1995 previously identified as "within normal limits" or "benign changes" on both initial and random screening.

PATIENTS

Female service members and dependents aged 12 to 88 years.

SETTING

Air Force clinics in the United States and Japan.

INTERVENTION

Rescreening of Pap smears by PAPNET, followed by reevaluation of abnormal smears by the consensus panel, consisting of 3 cytotechnologists and 3 pathologists.

MAIN OUTCOME MEASURES

Proportion of Pap smears initially screened as normal identified as abnormal by both PAPNET and consensus panel; costs of rescreening.

RESULTS

PAPNET screening identified 1614 (29%) slides requiring additional microscopic review. On further review, 448 (8% of total) had possibly abnormal cells. Ultimately, 11 of these cases were reviewed by the consensus panel for potentially atypical cells. Of these 11 cases, 5 were reclassified as atypical squamous cells of undetermined significance (ASCUS) and 1 as atypical glandular cells of undetermined significance (AGUS). No additional squamous intraepithelial neoplasia (SIL) was identified in these smears; the patient with a diagnosis of AGUS on rescreening was diagnosed as having a low-grade SIL (LSIL) on follow-up. Costs were $5825 to $33781 for each additional ASCUS or AGUS diagnosis. A cost of $17475 to $101343 is expected for each case of LSIL identified by PAPNET-assisted rescreening and not by traditional manual rescreening.

CONCLUSIONS

PAPNET-assisted rescreening identified a few more cases of ASCUS than did manual rescreening, but at a relatively high cost. The costs of rescreening should be carefully compared with the expected efficacy in reducing cervical cancer mortality.

Effect of 4-aminopyridine and single-dose methylprednisolone on functional recovery after a chronic spinal cord injury

The demyelination process is an important factor contributing to long term sensory and motor impairments after spinal cord injury (SCI). Exposure of axonal K+ channels after demyelination may contribute to blockage of action potentials across the injury site. A K+ channel blocker, 4-aminopyridine (4-AP), has been effective in restoring some sensory and motor impairment in incomplete SCI patients. The long-term effect of this compound in chronic model of SCI is not known. In this study, after a compression injury of 50 grams in rats, a randomized treatment was initiated 3 weeks after the initial injury which was followed by daily administration of 4-AP at 2 mg/kg (n = 8), 4 mg/kg (n = 8), and 6 mg/kg (n = 8) for 4 weeks. A group of methylprednisolone (MP)-treated (30 mg/kg, n = 8) and non-treated animals (n = 8) were included for comparison. The functional motor outcome was measured in each animal at regular time points up to 4 weeks post-treatment. All animals receiving 6 mg/kg developed generalized seizure and were excluded from the study. In the other animal groups, analysis of the behavioral outcome and neuro-pathological changes were essentially similar and did not show any significant effect of treatment. Our data indicate that daily administration of 4-AP, over 4 weeks of treatment period, lacks any significant effect on axonal function in chronically injured rats. This could be due to (a) lack of significant numbers of demyelinated axons which could improve the functional outcome and (b) a treatment regimen that was not adequate to contribute to a better functional outcome. One time bolus-administration of MP at 30 mg/kg also did not ensure a better functional outcome.

Lithium toxicity in yeast is due to the inhibition of RNA processing enzymes

Hal2p is an enzyme that converts pAp (adenosine 3',5' bisphosphate), a product of sulfate assimilation, into 5' AMP and Pi. Overexpression of Hal2p confers lithium resistance in yeast, and its activity is inhibited by submillimolar amounts of Li+ in vitro. Here we report that pAp accumulation in HAL2 mutants inhibits the 5'-->3' exoribonucleases Xrn1p and Rat1p. Li+ treatment of a wild-type yeast strain also inhibits the exonucleases, as a result of pAp accumulation due to inhibition of Hal2p; 5' processing of the 5.8S rRNA and snoRNAs, degradation of pre-rRNA spacer fragments and mRNA turnover are inhibited. Lithium also inhibits the activity of RNase MRP by a mechanism which is not mediated by pAp. A mutation in the RNase MRP RNA confers Li+ hypersensitivity and is synthetically lethal with mutations in either HAL2 or XRN1. We propose that Li+ toxicity in yeast is due to synthetic lethality evoked between Xrn1p and RNase MRP. Similar mechanisms may contribute to the effects of Li+ on development and in human neurobiology.

Graft-versus-host disease-like eruption in a patient with non-Hodgkin's lymphoma

Graft-versus-host disease (GVHD) is most commonly seen as a complication of bone marrow transplantation, although it can occur whenever tissue or blood products are given whereby immunologically competent donor lymphocytes react against host tissues. A 65-year-old man with non-Hodgkin's lymphoma developed a severe widespread erosive eruption of the skin and mucosal surfaces. Clinically and histologically it was identical to cutaneous GVHD even though the patient had never received tissue or blood products. He failed to respond to conventional therapy for GVHD, but his skin improved significantly on treating his underlying lymphoma, which eventually proved fatal. There are two previous reports of GVHD associated with malignancy but we believe this to be the first case secondary to a lymphoma.

Structural modifications of RNA influence the 5' exoribonucleolytic hydrolysis by XRN1 and HKE1 of Saccharomyces cerevisiae

Two 5' exoribonucleases, XRN1 and HKE1, of Saccharomyces cerevisiae have been found to have very important cellular roles, XRN1 playing a key role in mRNA turnover and HKE1 in pre-rRNA processing. Here, an analysis of strong secondary structures in RNA that cause blocks or stalls (accumulation of RNA fragments that are shortened from the 5' end to the site of the secondary structure insertion) in the processive exoribonucleolytic hydrolysis reactions is reported. With both enzymes, oligo(G) tracts of lengths 18, 16, and 9 stall quite effectively, and the stalls are close to the start of the oligo(G) stretch. Two strong stem-loop structures cause measurable but low-level stalls with both enzymes. If the stem-loop structure is placed close to the 5' end of the RNA, substantial inhibition of overall RNA hydrolysis occurs with HKE1 and less, but measurable, inhibition with XRN1. RNA structural modification caused by protein complexing has been investigated by using poly(A) binding protein. The hydrolysis of poly(A) by XRN1 is inhibited by poly(A) binding protein, while HKE1 activity is not affected.

Should general practitioners refer patients directly to physical therapists?

Several advantages have been claimed for general practitioners having direct access to physical therapy (defined as having a practice-based physical therapist or open access to a hospital-based physical therapist), and general practice fundholders are increasingly committing resources to ensure such services are available to their patients. This may lead to potential increases in costs as a larger total number of patients are treated owing to improved access and awareness of such services. A review of the available published literature found eight studies that compared two or more models of providing physical therapy services. Analysis of the studies revealed that there are several advantages for patients who are referred directly for physical therapy. The main advantages are significant reductions in waiting times, convenience, reduced costs for the patient and a lower cost per treated patient. There is also some evidence that the recovery time may be slightly better for patients who have direct access to a physical therapist.

Priority setting for health technology assessment. Theoretical considerations and practical approaches. Priority setting Subgroup of the EUR-ASSESS Project

This report is about setting priorities for health technology assessment (HTA). HTA examines systematically the consequences of the application of health technologies (broadly defined to include any health care intervention) to support decision making in policy and practice. Only a fraction of existing health technologies have been formally evaluated, and many more appear each year. Resources for HTA are, however, limited so that priorities have to be set, whether explicitly or implicitly. The aim of setting priorities for HTA should be to identify those assessments that offer the greatest benefits in relation to their cost, and thus to maximize the benefit derived from investments in HTA.

Estimating the burden of disease in an English region

BACKGROUND

Health Authorities seeking to make appropriate investments in health care require information about the nature of the burden of disease in their populations. The World Bank instrument called DALY-Disability Adjusted Life Year-has been used in the South and West Region to measure this burden.

METHOD

The burden of disease caused by a selection of diseases has been calculated using DALYs, which combine premature mortality and disability. An estimate of the total burden has been estimated by ICD chapter.

RESULTS

Premature mortality accounts for 52 per cent of the burden of disease and disability 48 per cent. Mental illness, for which its DALY value is largely derived from disability not premature mortality, contributes the third largest component of the total burden, after heart disease and cancer.

DISCUSSION

DALYs can be calculated using UK data, and, with an appreciation of the theoretical issues which surround the calculations, can be used to describe the burden of disease in a population. Although designed to assist investment decisions in developing countries, the DALY is likely to be valuable in established market economies.

Binding of 1-anilinonaphthalene-8-sulfonic acid to alpha-crystallin

alpha-Crystallin was found to exhibit a time-dependent uptake of the hydrophobic probe, 1-anilinonaphthalene-8-sulfonic acid (ANS), similar to that typically observed with lipid membranes. Analysis of the interaction of ANS with alpha-crystallin revealed two types of interactive processes, partitioning and binding. The predominant process involved partitioning, with a coefficient of 300 M-1. The binding component had the following characteristics: 1 binding site/24 subunits and a Kd of about 9 microM. The binding was unaffected by the number of subunits used in the assembly of the alpha-aggregate, since both the alpha m- and alpha c-forms had similar binding characteristics. No discernible differences were observed in the binding of ANS to homopolymers of alpha A and alpha B subunits, suggesting that the hydrophobic sites to which ANS bound were similar in both the A and B subunits. The majority of the fluorescence was lost when the protein was incubated in 3 M urea, a concentration of denaturant where the protein is still intact, suggesting that the ANS binding sites are located near the surface of the protein. The decrease was attributed to a decrease in the quantum yield of the bound dye.

Increased duration and altered topography of EEG microstates during cognitive tasks in chronic schizophrenia

The surface EEGs of 32 medicated chronic schizophrenic patients, 12 unmedicated chronic schizophrenics and 35 matched healthy controls were analyzed by adaptive segmentation of continuous EEG during a rest condition, a mental arithmetic task, and a CNV paradigm. Results indicate increased duration of brain microstates in both unmedicated and medicated schizophrenics as well as reduced topographic variability. These findings did not vary across the different tasks. Comparing different cognitive tasks, schizophrenics and controls alike showed task-related changes of electric field topography, of EEG microstate duration and of the number of very short microstates (single-peak segments). However, the topography of the microstates during the tasks differed significantly in both medicated and unmedicated schizophenics from that of controls. Age, sex and educational levels did not influence these findings. Neuroleptic medication correlated negatively with microstate duration in a dose-dependent way. There was an inverse relationship between topographic variability and negative symptoms as well as BPRS scores. It is concluded that the temporo-spatial characteristics of brain electric activity indicate an impoverished array of functional modes and enhanced stability of brain electrical microstates in schizophrenia.

Identifying new health care technologies in the United Kingdom

We aimed to establish a 1996 baseline of new health care technologies that are predicted to have an impact on the United Kingdom's National Health Service in the next five years. One thousand and ninety-nine health care technologies were identified from a variety of sources. Further work will attempt to determine the most efficient method of identifying and monitoring new health care technologies.

Increased pigmentation in scleroderma

OBJECTIVE

Increased pigmentation is found in patients with scleroderma (systemic sclerosis, SSc) even in areas that have never clinically been involved with skin thickening. We wanted to determine if the pigmentation is due to subclinical sclerodermatous changes, or a systemic factor such as an increase in adrenocorticotropic hormone (ACTH).

METHODS

To determine if clinically uninvolved skin that is pigmented differs from nonpigmented skin, skin biopsies were taken from patients with scleroderma from 2 different sites: (1) from pigmented but otherwise clinically normal skin, and (2) from nonpigmented clinically normal skin adjacent to the first site. Biopsies were examined by a dermatopathologist for evidence of dermal and epidermal changes. Cosyntropin stimulation tests were performed after baseline cortisol and ACTH samples were obtained.

RESULTS

Six patients with diffuse SSc (dSSc) and 4 with limited SSc (ISSc) had skin biopsies. Patients with dSSc were more likely than those with ISSc to have increased pigmentation in uninvolved skin. Pigmented skin specimens had either a higher content of epidermal melanin and/or a more severe degree of pigmentary incontinence with a higher number of dermal melanophages in the superficial dermis. The cosyntropin stimulation tests were normal and there were no differences between subjects with diffuse and limited SSc or between those with and without increases in pigmentation.

CONCLUSION

Clinically uninvolved skin in many of these patients with SSc was abnormal, and subtle changes of SSc were present, especially in the pigmented biopsies. There was no evidence of adrenal deficiency in these patients. It is difficult pathologically to differentiate the changes in pigmented compared to unpigmented skin in patients with SSc, except for changes of increased melanin and pigmentary incontinence.

Mutations in trans-acting factors affecting mRNA decapping in Saccharomyces cerevisiae

The decay of several yeast mRNAs occurs by a mechanism in which deadenylation precedes decapping and subsequent 5'-to-3' exonucleolytic decay. In order to identify gene products required for this process of mRNA turnover, we screened a library of temperature-sensitive strains for mutants with altered mRNA degradation. We identified seven mutations in four genes that inhibited mRNA turnover. Two mutations were alleles of the XRN1 5'-to-3' exoribonuclease known to degrade mRNAs following decapping. One mutation defined a new gene, termed DCP1, which in subsequent work was demonstrated to encode a decapping enzyme or a necessary component of a decapping complex. The other mutations defined two additional genes, termed MRT1 and MRT3 (for mRNA turnover). Mutations in the MRT1 and MRT3 genes slow the rate of deadenylation-dependent decapping, show transcript-specific effects on mRNA decay rates, and do not affect the rapid turnover of an mRNA containing an early nonsense codon, which is degraded by a deadenylation-independent decapping mechanism. Importantly, cell extracts from mrt1 and mrt3 strains contain normal levels of the decapping activity required for mRNA decay. These observations suggest that the products of the MRT1 and MRT3 genes function to modulate the rates of decapping that occur following deadenylation.