Effects of empagliflozin on progression of chronic kidney disease: a prespecified secondary analysis from the empa-kidney trial

BACKGROUND

Sodium-glucose co-transporter-2 (SGLT2) inhibitors reduce progression of chronic kidney disease and the risk of cardiovascular morbidity and mortality in a wide range of patients. However, their effects on kidney disease progression in some patients with chronic kidney disease are unclear because few clinical kidney outcomes occurred among such patients in the completed trials. In particular, some guidelines stratify their level of recommendation about who should be treated with SGLT2 inhibitors based on diabetes status and albuminuria. We aimed to assess the effects of empagliflozin on progression of chronic kidney disease both overall and among specific types of participants in the EMPA-KIDNEY trial.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA), and included individuals aged 18 years or older with an estimated glomerular filtration rate (eGFR) of 20 to less than 45 mL/min per 1·73 m2, or with an eGFR of 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher. We explored the effects of 10 mg oral empagliflozin once daily versus placebo on the annualised rate of change in estimated glomerular filtration rate (eGFR slope), a tertiary outcome. We studied the acute slope (from randomisation to 2 months) and chronic slope (from 2 months onwards) separately, using shared parameter models to estimate the latter. Analyses were done in all randomly assigned participants by intention to treat. EMPA-KIDNEY is registered at ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and then followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroups of eGFR included 2282 (34·5%) participants with an eGFR of less than 30 mL/min per 1·73 m2, 2928 (44·3%) with an eGFR of 30 to less than 45 mL/min per 1·73 m2, and 1399 (21·2%) with an eGFR 45 mL/min per 1·73 m2 or higher. Prespecified subgroups of uACR included 1328 (20·1%) with a uACR of less than 30 mg/g, 1864 (28·2%) with a uACR of 30 to 300 mg/g, and 3417 (51·7%) with a uACR of more than 300 mg/g. Overall, allocation to empagliflozin caused an acute 2·12 mL/min per 1·73 m2 (95% CI 1·83-2·41) reduction in eGFR, equivalent to a 6% (5-6) dip in the first 2 months. After this, it halved the chronic slope from -2·75 to -1·37 mL/min per 1·73 m2 per year (relative difference 50%, 95% CI 42-58). The absolute and relative benefits of empagliflozin on the magnitude of the chronic slope varied significantly depending on diabetes status and baseline levels of eGFR and uACR. In particular, the absolute difference in chronic slopes was lower in patients with lower baseline uACR, but because this group progressed more slowly than those with higher uACR, this translated to a larger relative difference in chronic slopes in this group (86% [36-136] reduction in the chronic slope among those with baseline uACR <30 mg/g compared with a 29% [19-38] reduction for those with baseline uACR ≥2000 mg/g; ptrend<0·0001).

INTERPRETATION

Empagliflozin slowed the rate of progression of chronic kidney disease among all types of participant in the EMPA-KIDNEY trial, including those with little albuminuria. Albuminuria alone should not be used to determine whether to treat with an SGLT2 inhibitor.

FUNDING

Boehringer Ingelheim and Eli Lilly.

Impact of primary kidney disease on the effects of empagliflozin in patients with chronic kidney disease: secondary analyses of the EMPA-KIDNEY trial

BACKGROUND

The EMPA-KIDNEY trial showed that empagliflozin reduced the risk of the primary composite outcome of kidney disease progression or cardiovascular death in patients with chronic kidney disease mainly through slowing progression. We aimed to assess how effects of empagliflozin might differ by primary kidney disease across its broad population.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA). Patients were eligible if their estimated glomerular filtration rate (eGFR) was 20 to less than 45 mL/min per 1·73 m2, or 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher at screening. They were randomly assigned (1:1) to 10 mg oral empagliflozin once daily or matching placebo. Effects on kidney disease progression (defined as a sustained ≥40% eGFR decline from randomisation, end-stage kidney disease, a sustained eGFR below 10 mL/min per 1·73 m2, or death from kidney failure) were assessed using prespecified Cox models, and eGFR slope analyses used shared parameter models. Subgroup comparisons were performed by including relevant interaction terms in models. EMPA-KIDNEY is registered with ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroupings by primary kidney disease included 2057 (31·1%) participants with diabetic kidney disease, 1669 (25·3%) with glomerular disease, 1445 (21·9%) with hypertensive or renovascular disease, and 1438 (21·8%) with other or unknown causes. Kidney disease progression occurred in 384 (11·6%) of 3304 patients in the empagliflozin group and 504 (15·2%) of 3305 patients in the placebo group (hazard ratio 0·71 [95% CI 0·62-0·81]), with no evidence that the relative effect size varied significantly by primary kidney disease (pheterogeneity=0·62). The between-group difference in chronic eGFR slopes (ie, from 2 months to final follow-up) was 1·37 mL/min per 1·73 m2 per year (95% CI 1·16-1·59), representing a 50% (42-58) reduction in the rate of chronic eGFR decline. This relative effect of empagliflozin on chronic eGFR slope was similar in analyses by different primary kidney diseases, including in explorations by type of glomerular disease and diabetes (p values for heterogeneity all >0·1).

INTERPRETATION

In a broad range of patients with chronic kidney disease at risk of progression, including a wide range of non-diabetic causes of chronic kidney disease, empagliflozin reduced risk of kidney disease progression. Relative effect sizes were broadly similar irrespective of the cause of primary kidney disease, suggesting that SGLT2 inhibitors should be part of a standard of care to minimise risk of kidney failure in chronic kidney disease.

FUNDING

Boehringer Ingelheim, Eli Lilly, and UK Medical Research Council.

Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

Deeply Virtual Compton Scattering Cross Section at High Bjorken x_{B}

We report high-precision measurements of the deeply virtual Compton scattering (DVCS) cross section at high values of the Bjorken variable x_{B}. DVCS is sensitive to the generalized parton distributions of the nucleon, which provide a three-dimensional description of its internal constituents. Using the exact analytic expression of the DVCS cross section for all possible polarization states of the initial and final electron and nucleon, and final state photon, we present the first experimental extraction of all four helicity-conserving Compton form factors (CFFs) of the nucleon as a function of x_{B}, while systematically including helicity flip amplitudes. In particular, the high accuracy of the present data demonstrates sensitivity to some very poorly known CFFs.

Form Factors and Two-Photon Exchange in High-Energy Elastic Electron-Proton Scattering

We present new precision measurements of the elastic electron-proton scattering cross section for momentum transfer (Q^{2}) up to 15.75  (GeV/c)^{2}. Combined with existing data, these provide an improved extraction of the proton magnetic form factor at high Q^{2} and double the range over which a longitudinal or transverse separation of the cross section can be performed. The difference between our results and polarization data agrees with that observed at lower Q^{2} and attributed to hard two-photon exchange (TPE) effects, extending to 8  (GeV/c)^{2} the range of Q^{2} for which a discrepancy is established at >95% confidence. We use the discrepancy to quantify the size of TPE contributions needed to explain the cross section at high Q^{2}.

Deep Exclusive Electroproduction of π^{0} at High Q^{2} in the Quark Valence Regime

We report measurements of the exclusive neutral pion electroproduction cross section off protons at large values of x_{B} (0.36, 0.48, and 0.60) and Q^{2} (3.1 to 8.4  GeV^{2}) obtained from Jefferson Lab Hall A experiment E12-06-014. The corresponding structure functions dσ_{T}/dt+εdσ_{L}/dt, dσ_{TT}/dt, dσ_{LT}/dt, and dσ_{LT^{'}}/dt are extracted as a function of the proton momentum transfer t-t_{min}. The results suggest the amplitude for transversely polarized virtual photons continues to dominate the cross section throughout this kinematic range. The data are well described by calculations based on transversity generalized parton distributions coupled to a helicity flip distribution amplitude of the pion, thus providing a unique way to probe the structure of the nucleon.

Society of pediatric liver transplantation: Current registry status 2011-2018

BACKGROUND

SPLIT was founded in 1995 in order to collect comprehensive prospective data on pediatric liver transplantation, including waiting list data, transplant, and early and late outcomes. Since 2011, data collection of the current registry has been refined to focus on prospective data and outcomes only after transplant to serve as a foundation for the future development of targeted clinical studies.

OBJECTIVE

To report the outcomes of the SPLIT registry from 2011 to 2018.

METHODS

This is a multicenter, cross-sectional analysis characterizing patients transplanted and enrolled in the SPLIT registry between 2011 and 2018. All patients, <18 years of age, received a first liver-only, a combined liver-kidney, or a combined liver-pancreas transplant during this study period.

RESULTS

A total of 1911 recipients from 39 participating centers in North America were registered. Indications included biliary atresia (38.5%), metabolic disease (19.1%), tumors (11.7%), and fulminant liver failure (11.5%). Greater than 50% of recipients were transplanted as either Status 1A/1B or with a MELD/PELD exception score. Incompatible transplants were performed in 4.1%. Kaplan-Meier estimates of 1-year patient and graft survival were 97.3% and 96.6%. First 30 days of surgical complications included reoperation (31.7%), hepatic artery thrombosis (6.3%), and portal vein thrombosis (3.2%). In the first 90 days, biliary tract complications were reported in 13.6%. Acute cellular rejection during first year was 34.7%. At 1 and 2 years of follow-up, 39.2% and 50.6% had normal liver tests on monotherapy (tacrolimus or sirolimus). Further surgical, survival, allograft function, and complications are detailed.

Infection control policies and procedures for meticillin-resistant Staphylococcus aureus in care homes for older people in Northern Ireland: a questionnaire study

ackground: Limited information is available regarding the role of infection control in the prevention of infection in nursing and residential care homes.

Objectives: To determine what infection control policies and procedures are in place in care homes for older people in Northern Ireland.

Methods: Anonymous postal questionnaire survey of all 410 nursing and residential homes in Northern Ireland that provide care to residents over the age of 65.

Results: A total of 318 (78%) questionnaires were returned. Visits from infection control nurses from health boards or community trusts were infrequent, with only 23% of homes receiving such a visit. Nearly all homes (99.7%) had a policy on infection control, with 72.4% and 84.3% of homes having a policy on the admission and care of residents with meticillin-resistant Staphylococcus aureus (MRSA) respectively. Of those respondents that had a policy on admission of persons with MRSA, only a small percentage (9.2%) would not admit residents with MRSA. Only 11% of respondents believed that MRSA was a problem in their particular home, but at least 30% agreed that there was a problem with MRSA in care homes. A desire was expressed for more information and support, with 75% of respondents agreeing that more information should be provided to homes on MRSA.

Conclusions: There is a clear need for additional infection control advice to be available to care homes and for the development of uniform policies and an infection control audit tool. The audit tool could then be used to ensure that the appropriate policies and standards are in place within care homes and that these standards are met on an ongoing basis.

Effect of ribotype on all-cause mortality following Clostridium difficile infection

BACKGROUND

Clostridium difficile infection (CDI) is significantly associated with subsequent all-cause mortality. Although a number of studies have investigated mortality associated with CDI, few have compared all-cause mortality between ribotypes.

AIM

We aimed to estimate all-cause mortality following CDI and to investigate the relationship between mortality, ribotype and other available variables.

METHODS

We undertook a retrospective cohort study. All patients with toxin-positive CDI in North East England between July 2009 and June 2011 were matched to death registration data. Differences in all-cause 30-day case fatality were explored using Poisson regression with robust error variances. For survival analysis, an accelerated failure time model with generalized gamma distribution was chosen.

FINDINGS

In total, 1426 patients were included. All-cause case fatality was 10.2%, 16.4%, 25.7% and 38.1% at 7, 14, 30 and 90 days respectively. In multivariate analysis, ribotype 027 (risk ratio: 1.34; 95% confidence interval: 1.02-1.75) and ribotype 015 (0.46; 0.26-0.82) were significantly associated with higher and lower all-cause 30-day case fatality rates, respectively. In survival analysis, only ribotype 015 had significantly lower predicted mortality (P = 0.008). Patients whose infection was hospital-acquired had significantly higher predicted mortality (P < 0.001).

CONCLUSION

This is the first population-based study of comparative mortality between multiple ribotypes. Our study identified a high rate of all-cause mortality following CDI. We found evidence of variability in mortality between ribotypes in this cohort with mortality significantly higher for ribotype 027 at 30 days following diagnosis and significantly lower for ribotype 015.

Derivation of factors for estimating the scatter of diagnostic x-rays from walls and ceiling slabs

Computed tomography (CT) scanning rooms and interventional x-ray facilities with heavy workloads may require the installation of shielding to protect against radiation scattered from walls or ceiling slabs. This is particularly important for the protection of those operating x-ray equipment from within control cubicles who may be exposed to radiation scattered from the ceiling over the top of the protective barrier and round the side if a cubicle door is not included. Data available on the magnitude of this tertiary scatter from concrete slabs are limited. Moreover, there is no way in which tertiary scatter levels can be estimated easily for specific facilities. There is a need for a suitable method for quantification of tertiary scatter because of the increases in workloads of complex x-ray facilities. In this study diagnostic x-ray air kerma levels scattered from concrete and brick walls have been measured to verify scatter factors. The results have been used in a simulation of tertiary scatter for x-ray facilities involving summation of scatter contributions from elements across concrete ceiling slabs. The majority of the ceiling scatter air kerma to which staff behind a barrier will be exposed arises from the area between the patient/x-ray tube and the staff. The level depends primarily on the heights of the ceiling and protective barrier. A method has been developed to allow tertiary scatter levels to be calculated using a simple equation based on a standard arrangement for rooms with different ceiling and barrier heights. Coefficients have been derived for a CT facility and an interventional suite to predict tertiary scatter levels from the workload, so that consideration can be given to the protection options available.

Epidemiological survey of Clostridium difficile ribotypes in the North East of England during an 18-month period

During an 18-month period, 1606 stool specimens from laboratory-confirmed cases of Clostridium difficile infection in the North East of England were ribotyped using unrestricted polymerase chain reaction. Of these, 87.6% grew C. difficile on culture; 70% had one of 10 recognizable ribotypes of which 001, 106 and 027 were the most prevalent. The proportions of ribotypes 002 and 015 declined during the study period, whereas ribotypes 016 and 023 increased. Ribotype 005 was significantly more numerous in males and ribotype 027 was associated with significantly higher mean age. Our findings differ from national data derived from more selective testing.

Implementation of vascularized composite allografts in the United States: recommendations from the ASTS VCA Ad Hoc Committee and the Executive Committee

Like all other areas of transplantation, vascularized composite allografts (VCA) has the capacity to transform the lives of patients, for the better or for the worse. It is this duality that mandates VCA be performed in centers prepared for the intricacies accompanying other transplant procedures. Similarly, the complexities of VCA require that the procedures be driven by surgeons and physicians with experience in the multidisciplinary management of immunocompromised postsurgical patients. Furthermore, the grafts should be considered as organs rather than tissues from a regulatory and a biological standpoint. The ASTS supports the field of VCA and has demonstrated its support and leadership by actively formulating a strategy for its systematic development. The goal of this document is to provide a framework for the prospective, thoughtful realization of VCA in the United States from the American Society of Transplant Surgeons (ASTS) perspective.

Glomerular filtration rate following pediatric liver transplantation--the SPLIT experience

Impaired kidney function is a well-recognized complication following liver transplantation (LT). Studies of this complication in children have been limited by small numbers and insensitive outcome measures. Our aim was to define the prevalence of, and identify risk factors for, post-LT kidney dysfunction in a multicenter pediatric cohort using measured glomerular filtration rate (mGFR). We conducted a cross-sectional study of 397 patients enrolled in the Studies in Pediatric Liver Transplantation (SPLIT) registry, using mGFR < 90 mL/min/1.73 m(2) as the primary outcome measure. Median age at LT was 2.2 years. Primary diagnoses were biliary atresia (44.6%), fulminant liver failure (9.8%), metabolic liver disease (16.4%), chronic cholestatic liver disease (13.1%), cryptogenic cirrhosis (4.3%) and other (11.8%). At a mean of 5.2 years post-LT, 17.6% of patients had a mGFR < 90 mL/min/1.73 m(2) . In univariate analysis, factors associated with this outcome were transplant center, age at LT, primary diagnosis, calculated GFR (cGFR) at LT and 12 months post-LT, primary immunosuppression, early post-LT kidney complications, age at mGFR, height and weight Z-scores at 12 months post-LT. In multivariate analysis, independent variables associated with a mGFR <90 mL/min/1.73 m(2) were primary immunosuppression, age at LT, cGFR at LT and height Z-score at 12 months post-LT.

What defines a transplant surgeon? A needs assessment for curricular development in transplant surgery fellowship training

This study compares the perceptions of transplant surgery program directors (PDs) and recent fellowship graduates (RFs) regarding the adequacy of training and relevancy to practice of specific curricular content items in fellowship training. Surveys were sent to all American Society of Transplant Surgery approved fellowship PDs and all RFs in practice <5 years. For operative procedures, the RFs considered the overall training to be less adequate than the PDs (p = 0.0117), while both groups considered the procedures listed to be relevant to practice (p = 0.8281). Regarding nonoperative patient care items, although RFs tended to rank many individual items lower, both groups generally agreed that the training was both adequate and relevant. For nonpatient care related items (i.e. transplant-related ethics, economics, research, etc.), both groups scored them low regarding their adequacy of training although RFs scored them significantly lower than PDs (p = 0.0006). Regarding their relevance to practice, while both groups considered these items relevant, RFs generally considered them more relevant than PDs. Therefore, although there is consensus on many items, significant differences exist between PDs and RFs regarding their perceptions of the adequacy of training and the relevance to practice of specific curriculum items in transplant surgery fellowship training.

The Ludwig pattern of androgenetic alopecia is due to a hierarchy of androgen sensitivity within follicular units that leads to selective miniaturization and a reduction in the number of terminal hairs per follicular unit

BACKGROUND

Hair follicles exist within follicular units (FUs). In utero the central primary hair follicles are surrounded by smaller secondary follicles. Each FU is nourished by a single arborizing arrector pili muscle that attaches circumferentially around the primary follicle with variable attachment to other follicles. Androgenetic alopecia (AA) miniaturizes susceptible scalp hair follicles in a distinctive and reproducible fashion manifesting in different patterns between men and women.

OBJECTIVES

We hypothesized that there is an additional layer to the patterning in AA, with a hierarchy of susceptibility within FUs to AA, and that the diffuse hair loss seen in women with AA is due to a reduction in the number of terminal hairs per FU rather than uniform miniaturization of entire FUs.

METHODS

We compared the mean numbers of FUs and terminal hairs per FU in 4-mm scalp punch biopsies in 24 women with AA with those in 21 controls.

RESULTS

There was no significant difference in the number of FUs; however, women with AA had 2.40 terminal hairs per FU compared with 3.38 in the control group (P=0.0001) associated with a mean increase of 0.6 vellus hairs per FU. Complete miniaturization of all hairs within the FU was not seen.

CONCLUSIONS

Diffuse hair loss in women with AA is due to a reduction in the number of terminal hairs per FU and an increase in the number of vellus hairs. This supports the hypothesis of a hierarchy of susceptibility within FUs to AA. Further investigation is required to ascertain whether secondary and tertiary hair follicles are more susceptible than primary follicles.

Long-term clearance of patch-stage mycosis fungoides with the 308-nm laser

In order to investigate the effectiveness of the 308-nm xenon chloride laser in the treatment of patch-stage mycosis fungoides that is refractory to topical steroids, we conducted a prospective, histologically controlled, open-label pilot study. Eight patients with stage 1A or 1B cutaneous T-cell lymphoma that was unresponsive to application of potent topical steroids received 20 treatments with the laser over 10 weeks and were then followed up for a minimum of 30 months. Three patients had a complete clinical and histological response and remained free of disease after 30 months A further three patients had complete clinical and histological clearance of disease, but experienced relapse within the 30 months follow-up period. One patient withdrew from the study and one had a partial response. Further research to establish the role of the 308-nm laser in the treatment of MF appears justified.

The stability of micro-organisms preserved in LENTICULE discs, demonstrated by repeat sample distributions of the EQUAL Scheme for Indicator Organisms (water microbiology)

AIMS

To demonstrate the stability of microorganisms preserved in LENTICULE discs, employed by the EQUAL Scheme for Indicator Organisms.

METHODS AND RESULTS

Five sample batches containing several indicator organism parameters were each despatched in two separate distributions at intervals of up to 24 months apart. A comparison of participants' median counts and bar charts of their cumulated results was then made.

CONCLUSIONS

The results demonstrated that LENTICULE discs provided a remarkably stable preparation format for the maintenance of viable organisms in reproducible numbers.

SIGNIFICANCE AND IMPACT OF THE STUDY

Complex mixtures of organisms can be maintained in stable numbers for extended periods of time at a freezer temperature of -20 degrees C and satisfactorily transported without the requirement for cold chain conditions.

The lack of significant changes in scalp hair follicle density with advancing age

BACKGROUND

Age-related reduction in hair is seen in the axillary and pubic regions as well as the scalp; however, it has not been investigated qualitatively on the scalp. Horizontally sectioned scalp biopsy is an ideal tool to investigate the impact of advancing age on scalp hair follicle density and morphology.

OBJECTIVES

To examine the effect of age and follicle miniaturization on total hair count in 1666 horizontally sectioned mid-scalp biopsies from 928 women aged between 13 and 84 years with hair loss.

METHODS

SETTING

Specialist hair loss referral clinic in a teaching hospital.

DESIGN

Analysis of data set. Methods: All scalp biopsies were 4 mm in diameter and taken from the crown. Miniaturization was assessed by calculating the ratio of terminal to vellus-like hairs (T/V) at the mid-isthmus level and considered significant if the ratio was < or = 4 : 1. Fibrosis was documented when present. Linear regression was used to examine the association between total hair count, age and miniaturization.

RESULTS

The average number of hair follicles per biopsy was 39.6 (SD +/- 10.8). A highly significant negative association (P < 0.0001) was found between age and total follicle number, although the predictive value of age in total hair count was found to be small [root error mean square (R2) < 2%]. Controlling for T/V < or = 4 : 1, the association was weakened, but remained significant. The relationship unconfounded by T/V < or = 4 : 1 shows that for every additional year of ageing, 0.077 total hair follicles (0.22%) are lost per biopsy.

CONCLUSIONS

Age and follicular miniaturization were found to be extremely weak predictors of total hair count in women with hair loss.

Single-nucleotide polymorphism-based differentiation and drug resistance detection in Mycobacterium tuberculosis from isolates or directly from sputum

The rapid technique of pyrosequencing was used to examine 123 samples (in the form of DNA extracts and inactivated sputum) of Mycobacterium spp. Of 99 Mycobacterium tuberculosis samples investigated for single-nucleotide polymorphisms (SNPs), 68% of isoniazid-resistant isolates analysed had an AGC --> ACC mutation in katG at codon 315, resulting in the Ser --> Thr substitution associated previously with isoniazid resistance. Of the rifampicin-resistant isolates, 92% showed SNPs in rpoB at codons 516, 531 or 526. Inactivated sputum samples and DNA extracts could both be analysed by pyrosequencing, and the method was able to differentiate rapidly between the closely related species of the M. tuberculosis complex (M. tuberculosis, Mycobacterium bovis, Mycobacterium africanum, Mycobacterium canetti and Mycobacterium microti), except between M. tuberculosis, M. canetti and one of two M. africanum strains. This low-cost, high-throughput technique could be used as a rapid screen for drug resistance and as a replacement for some of the time-consuming tests used currently for species identification.

Audit of scope and culture techniques applied to samples for the diagnosis of Mycobacterium bovis by hospital laboratories in England and Wales

This audit examines the ability of English and Welsh laboratories to diagnose Mycobacterium bovis infection. All 164 clinical laboratories submitting samples to the PHLS Mycobacterium Reference Unit and Regional Centres for Mycobacteriology were surveyed. Twenty per cent of responding centres did not use a pyruvate-containing medium or incubate for the minimum recommended period of 8 weeks. This study demonstrates the potential for the underdiagnosis of M. bovis infection in England and Wales. Possible reasons for underdiagnosis are discussed together with strategies to optimize recovery of M. bovis.

Results of a phase I trial evaluating a liver support device utilizing albumin dialysis

BACKGROUND

We have previously reported the clearance of protein-bound and water-soluble hepatic toxins, in vitro and in an animal model, using albumin dialysis as an extracorporeal hepatic support (ECHS) device.

OBJECTIVE

The objective of this study was to evaluate albumin dialysis through a phase I clinical trial. We hypothesized that albumin dialysis would (1) decrease elevated levels of hepatic toxins, (2) increase the Fischer ratio, and (3) decrease hepatic encephalopathy (HES) and intracranial pressure (ICP), while (4) maintaining stable hemodynamics.

METHODS

Patients with acute liver failure were treated with an ECHS device utilizing continuous hemodiafiltration with continuous albumin dialysis. Mean arterial blood pressure (MAP), heart rate (HR), systemic venous oxygen saturation (Svo(2)), ICP, and HES were recorded. Blood samples were evaluated for hepatic toxins and factor VII levels.

RESULTS

Nine patients were enrolled (status I, n = 5; status IIA, n = 4). There was no significant change in MAP, HR, or Svo(2) (MAP: Pre = 81 +/- 5.6 mm Hg, Post = 79 +/- 5.9 mm Hg, P =.70; HR: Pre = 104 +/- 5.2 bpm, Post = 107 +/- 6.2 bpm, P =.62; Svo(2): Pre = 72 +/- 3.5, Post = 71 +/- 1.7, P =.77). There was a decrease in the ammonia and total bilirubin levels (NH(3): Pre = 129.8 +/- 23.8 mg/dL, Post = 63.9 +/- 16.1 mg/dL, P =.01; total bilirubin: Pre = 20.3 +/- 2.5 mg/dL, Post = 17.6 +/- 2.7 mg/dL, P =.4). There was a significant increase of the Fischer ratio and factor VII levels (Fischer ratio: Pre = 0.98 +/- 0.2, Post = 2.17 +/- 0.5, P =.038; factor VII: Pre = 13.9 +/- 4.9, Post = 23.2 +/- 4.8, P =.015). There was a significant decrease in the HES and ICP (HES: Pre = 3.8 +/- 0.1, Post = 2 +/- 0.7, P =.02; ICP: Pre = 37 +/- 3.9, Post = 13.3 +/- 2.8, P =.048). Of 5 status I patients, 1 recovered native hepatic function and 3 were bridged to transplantation.

CONCLUSIONS

This phase I study suggests that albumin dialysis as a liver support device is safe and effective in clearing hepatic toxins, with an associated decrease in the HES and ICP. This encouraging efficacy data warrant further investigation with a phase II/III trial.

Bringing the human genome and the revolution in bioinformatics to the medical school classroom: a case report from Washington University School of Medicine

The human genome project is revolutionizing medical research and the practice of clinical medicine. To understand and participate in this revolution, physicians must be fluent in human genomics and bioinformatics. At Washington University School of Medicine (WUSM), the authors designed a module for teaching these skills to first-year students. The module uses clinical cases as a platform for accessing information stored in GenBank, Online Mendelian Inheritance in Man (OMIM), and PubMed databases at the National Center for Biotechnology Information (NCBI). This module, which is also designed to reinforce problem-solving skills, has been integrated into WUSM's first-year medical genetics course.

Identifying sputum specimens of high priority for examination by enhanced mycobacterial detection, identification, and susceptibility systems (EMDISS) to promote the rapid diagnosis of infectious pulmonary tuberculosis

AIMS

To compare clinical information and sputum microscopy as methods for the selection of samples for enhanced mycobacterial detection, identification, and susceptibility systems (EMDISS) to promote the rapid diagnosis of patients with infectious pulmonary tuberculosis.

METHODS

Two thousand, two hundred and sixty four specimen request forms were examined for clinical details, which were then used to identify specimens likely to yield Mycobacterium tuberculosis on culture. These results were compared with the results of sputum microscopy for acid fast bacilli (AFB). Both methods were assessed against the results of culture using a combination of continuous automated mycobacterial liquid culture (CAMLiC) and conventional solid culture.

RESULTS

Classification based on clinical details was an inefficient method of identifying high priority specimens for EMDISS. Although, when given, clinical details were often consistent, a substantial proportion of specimens arrived with no details. This approach would result in the referral of at least 16% of the workload but lead to the detection by culture of only 46% of the M tuberculosis present within it. In contrast, microscopy for AFB defined a much smaller number of specimens (4.8% of the total), which contained 90% of the M tuberculosis isolates.

CONCLUSIONS

Microscopy for AFB is the most efficient method for defining sputum specimens suitable for referral for enhanced mycobacteriological techniques. However, it is essential that the methods used for smear preparation and microscopy are of the highest possible standard, otherwise some patients with infectious pulmonary tuberculosis will be denied, unnecessarily, the benefits of important advances in mycobacteriology.

Adolescents and smoking: evidence from France and Spain

Until recently detailed evidence on smoking and its reduction was found mainly in the U.S.A. and the U.K. Now there is active research in a much wider range of countries which increases the potential for international comparison and international learning. In this paper we focus on the recent evidence now available from France and Spain for the smoking behaviour of adolescents and young people.

The 1997 list. Proposed new bacterial taxa and proposed changes of bacterial names published during 1997 and considered to be of interest to medical or veterinary bacteriology (an informational note)

A list of names published or validated in 1997 is presented. We also comment on the tendency to base names of new taxa on a single bacterial strain, and the consequences for reliable descriptions that this tendency implies.

The 1998 list. Proposed new bacterial taxa and proposed changes of bacterial names published during 1998 and considered to be of interest to medical or veterinary bacteriology (an informational note)

A list of names published or validated in 1998 is presented.

The 1997 list. Proposed new bacterial taxa and proposed changes of bacterial names published during 1997 and considered to be of interest to medical or veterinary bacteriology. An informational note

A list of names published or validated in 1997 is presented. We also comment on the tendency to base names of new taxa on a single bacterial strain, and the consequences for reliable descriptions that this tendency implies.

The 1997 list. Proposed new bacterial taxa and proposed changes of bacterial names published during 1997 and considered to be of interest to medical or veterinary bacteriology. An informational note

A list of names published or validated in 1997 is presented. We also comment on the tendency to base names of new taxa on a single bacterial strain, and the consequences for reliable descriptions that this tendency implies.

Electrical and calcium signaling in dendrites of hippocampal pyramidal neurons

This review discusses recent data regarding the different types of voltage-gated Na+, Ca2+, and K+ channels in dendrites of CA1 pyramidal neurons and their function for synaptic integration and plasticity. Na+ and Ca2+ channels are uniformly distributed throughout the dendrites, although Na+ channels in the soma and proximal dendrites differ in their inactivation properties from Na+ channels in more distal regions. Also, different regions of the neuron express different subtypes of Ca2+ channels. K+ channels are unevenly distributed, with the distal dendrites expressing a more than fivefold greater density of a transient A-type K+ channel than proximal regions. These K+ channels exert profound control over the excitability of the pyramidal neurons and the spread of synaptic potentials throughout the dendrites. The ways in which the active properties of dendrites may contribute toward the induction and maintenance of long-term synaptic plasticity are discussed.

The effect of subcutaneous edema on transcutaneous oximetry

A rabbit animal model of tissue edema was created to determine its effect on transcutaneous oximetry (T-com). Measurements of T-coms were performed before and at 5-minute intervals after the injection of body temperature saline into the skin and subcutaneous tissues of 5 rabbits. Photomicrographs were obtained to document the morphological appearance of edema. The injection of saline had no effect on relative T-com values. This investigation suggests that edema alone does not influence T-com measurements.

Does storage of sputum specimens adversely affect culture results?

It has been recommended that samples submitted for microbiological examination should be retained for 48 hours after issue of the final report. In order to ascertain whether reproducible results could be achieved following storage of sputum specimens, two laboratories each re-cultured 100 samples 48 hours after their report had been issued and a further laboratory re-cultured 100 samples 48 hours after receipt. Discordant results were obtained in only 5-25% of specimens, indicating that potential respiratory pathogens could survive storage.

Integration of positional signals and regulation of wing formation and identity by Drosophila vestigial gene

Appendage formation is organized by signals from discrete sources that presumably act upon downstream genes to control growth and patterning. The Drosophila vestigial gene is selectively required for wing-cell proliferation, and is sufficient to induce outgrowths of wing tissue from eyes, legs and antennae. Different signals activate separate enhancers to control vestigial expression: first, in the dorsal/ventral organizer through the Notch pathway, and subsequently, in the developing wing blade by decapentaplegic and a signal from the dorsal/ventral organizer. Signal integration must be a general feature of genes like vestigial, that regulate growth or patterning along more than one axis.

Unsafe practices in the treatment of pediculosis capitis

The purpose of this descriptive study was to identify unsafe uses of prescription, over-the-counter and home remedies used in the treatment of pediculosis. Twenty-seven families with 119 children were visited at home and interviewed about their use of remedies for head lice. In addition to prescription and over-the-counter products home remedies were commonly used. Kerosene, alcohol, insecticides, and head shaving were some of the home remedies reported.

Effect of diflubenzuron on the maturation and reproductive success of the copepod Eurytemora affinis

: The insect growth regulator diflubenzuron (DFB) may have substantial effects on non-target organisms, especially crustaceans. By targeting the moulting process, DFB would be expected to elicit the most obvious effects on subadult crustaceans which moult frequently. Previous studies in this laboratory have demonstrated acute and chronic effects of DFB on survival and development of nauplii of the estuarine copepod Eurytemora affinis at water concentrations of less than 1 p.p.b. The present study examines the effects on maturation to adulthood and brood production. Effects on brood production were observed at 0.8 p.p.b. DFB in individuals exposed only during the copepodite stages. Significant effects on production of nauplii were documented only in the early exposure to 0.93 p.p.b. DFB. Inability of post-moult copepodites to completely cast exuviae also was documented in the exposed treatments. At salinities of 2, 10 and 15 p.p.t., survival from naupliar to adult stages was significantly reduced at 0.84 p.p.b. and none survived to adulthood at 1.7 p.p.b. These results suggest that DFB has substantial effects on survival and development of E. affinis at a water concentration of less than 1 p.p.b. DFB concentrations exceeding this concentration have been reported from Chesapeake Bay surface waters although there is no current evidence of potentially toxic concentrations overlapping with the known distribution of E. affinis in the bay.

Properties and significance of a riboflavin-binding hexamerin in the hemolymph of Hyalophora cecropia

A riboflavin-binding hexamerin isolated from pupal hemolymph of Hyalophora cecropia has a native M(r) of 510,000, subunit M(r) of 85,000, and a 5% carbohydrate content. An intrachain cross-link was confirmed in protease limit digests. Ellman titration confirmed the presence of a sulfhydryl group, which is needed for this linkage. Though Cu2+ is known to promote the linkage, heavy metals were not detected in the isolate. Heat denaturation released ligand with the absorbency, fluorescence spectra, and chromatographic behavior of riboflavin. Binding resulted in substantial quenching of the fluorescence of both the isoalloxazine in riboflavin and of aromatic groups in the apoprotein. Kinetic analysis indicated a KD of 2.5 x 10(-7) M for riboflavin, 1.3 x 10(-7) M for lumiflavin, and greater than 1 x 10(-6) M for FMN and FAD. Over four moles of flavin were bound per mole of hexamerin. The amount of riboflavin in pupal hemolymph is sufficient to occupy only 2-3 of these sites. Riboflavin is also associated with lipophorin and vitellogenin, but the molar ratios after protein isolation were low. On a standard laboratory diet, riboflavin is in great excess, but most of it is apparently excreted before the apoprotein first appears in the hemolymph, just before wandering. The concentration of riboflavin-binding hexamerin rises to 15-30 mg/ml in pupae; relative to other hexamerins, very little is stored in the fat body. All of the apoprotein and 75% of riboflavin disappear from the hemolymph during adult development. An amount of flavin at least equal to that stored in pupal hemolymph is transferred to the eggs formed during this period.