Reingreso precoz después del trasplante renal: lecciones aprendidas / Early readmissions post kidney transplantation: Lessons learned

Introducción El trasplante renal es el tratamiento de referencia para los pacientes con enfermedad renal terminal. Los reingresos hospitalarios tras el trasplante son una complicación frecuente y pueden considerarse un indicador de morbilidad evitable y de la calidad de la asistencia hospitalaria, y existe una correlación significativa entre reingreso hospitalario precoz (RHP) y resultados adversos para los pacientes. Este estudio pretende evaluar la tasa de reingresos tras el trasplante renal, las causas subyacentes y las posibles maneras de prevenirlo. Material y métodos Se revisaron retrospectivamente las historias clínicas de los receptores desde enero de 2016 hasta diciembre de 2021 en un único centro. El objetivo principal de este estudio es determinar la tasa de reingreso después del trasplante renal y las variables que contribuyen al reingreso. Las complicaciones postrasplante que dieron lugar al reingreso se clasificaron en complicaciones quirúrgicas, complicaciones relacionadas con el injerto, infecciones, trombosis venosa profunda (TVP) y otras complicaciones médicas. Resultados Cuatrocientos setenta y cuatro receptores de aloinjerto renal cumplieron nuestros criterios de inclusión y se adhirieron al estudio. De estos, 248 (52,3%) tuvieron al menos un reingreso durante los primeros 90días tras el trasplante. Un total de 89 (18,8%) receptores de aloinjerto tuvieron más de un episodio de reingreso en los primeros 90días postrasplante. La colección líquida perirrenal fue la complicación quirúrgica más frecuente (52,4%), y la infección del tracto urinario fue la infección más común (50%) entre las causas de reingreso en los primeros 90días postrasplante. El cociente de probabilidades (odds ratio [OR]) de reingreso fue significativamente mayor en los pacientes mayores de 60años y en los riñones con KDPI ≥85, así como en los receptores con RFI (AU)

Introduction Kidney transplantation (KT) is the gold standard treatment for end-stage renal disease (ESRD) patients. Hospital readmissions post-transplant is a common complication and can be considered an indication of avoidable morbidity and hospital quality, and there is a significant correlation between early hospital readmission (EHR) and adverse patient outcomes. This study aimed to assess the readmission rate following kidney transplants, the underlying causes, and possible ways to prevent it. Material and methods We retrospectively reviewed the medical records of recipients from January 2016 to December 2021 in a single center. The primary objective of this study is to find the readmission rate for kidney transplants and the variables that contribute to readmission. Post-transplant complications that were resulted in the readmission categorized into surgical complications, graft-related complications, infections, DVT, and other medical complications. Results Four hundred seventy-four renal allograft recipients met our inclusion criteria and were included in the study. 248 (52.3%) of the allograft recipients had at least one readmission during the first 90days after the transplantation. 89 (18.8%) allograft recipients had more than one readmission episode in the first 90days post-transplant. The perinephric fluid collection was the most common surgical complication (52.4%), and UTI was the most common infection (50%), causing readmission in the first 90days post-transplant. The readmission odd ratio was significantly higher in patients above 60years old and in kidneys with KDPI ≥85, and in recipients with DGF. Conclusion EHR following a kidney transplant is a common complication. Identifying the causes not only helps the transplant centers to take further steps to prevent some incidents and help to improve the patients’ morbidities and mortalities, but also it can reduce the unnecessary costs of readmissions (AU)

Early readmissions post kidney transplantation: lessons learned.

INTRODUCTION: Kidney transplantation (KT) is the gold standard treatment for end-stage renal disease (ESRD) patients. Hospital readmissions post-transplant is a common complication and can be considered an indication of avoidable morbidity and hospital quality, and there is a significant correlation between EHR and adverse patient outcomes. This study aimed to assess the readmission rate following kidney transplants, the underlying causes, and possible ways to prevent it. MATERIAL AND METHODS: We retrospectively reviewed the medical records of recipients from January 2016 to December 2021 in a single center. The primary objective of this study is to find the readmission rate for kidney transplants and the variables that contribute to readmission. Post-transplant complications that were resulted in the readmission categorized into surgical complications, graft-related complications, infections, DVT, and other medical complications. RESULTS: Four hundred seventy-four renal allograft recipients met our inclusion criteria and were included in the study. 248 (52.3%) of the allograft recipients had at least one readmission during the first 90 days after the transplantation. 89 (18.8%) allograft recipients had more than one readmission episode in the first 90 days post-transplant. The perinephric fluid collection was the most common surgical complication (52.4%), and UTI was the most common infection (50%), causing readmission in the first 90 days post-transplant. The readmission odd ratio was significantly higher in patients above 60 years old and in kidneys with KDPI ≥ 85, and in recipients with DGF. CONCLUSION: Early hospital readmission (EHR) following a kidney transplant is a common complication. Identifying the causes not only helps the transplant centers to take further steps to prevent some incidents and help to improve the patients' morbidities and mortalities, but also it can reduce the unnecessary costs of readmissions.

Effects of the addition of non-fibre carbohydrates with different rumen degradation rates in dairy cow high-forage diets using the Rumen Simulation Technique.

Nutrient synchronisation of protein and carbohydrates is a promising practice to improve ruminal nutrient utilisation. However, dietary sources supplying these nutrients can vary in ruminal nutrient availability due to differing degradation rates, therefore potentially affecting utilisation of nitrogen (N). The effects of the addition of non-fibre carbohydrates (NFCs) with different rumen degradation rates in high-forage diets on ruminal fermentation, efficiency and microbial flow were investigated in vitro using the Rumen Simulation Technique (RUSITEC). Four diets were tested: control with 100% ryegrass silage (GRS) and substitution of 20% on a DM basis of ryegrass silage with corn grain (CORN), processed corn (OZ) or sucrose (SUC). The four diets were assigned to 16 vessels in two sets of RUSITEC apparatuses in a randomised block design over a 17 d experimental trial; 10 d consisted of adaptation and 7 d for sample collection. Rumen fluid was collected from four rumen-cannulated dry Holstein-Friesian dairy cows and was treated without mixing. Then, rumen fluid from each cow was used to inoculate four vessels, and diet treatments were randomly allocated to each one. This was repeated for all cows resulting in 16 vessels. The inclusion of SUC in ryegrass silage diets improved DM and organic matter digestibility. The only diet to significantly lower ammonia-N concentration compared with GRS was SUC. The outflows of non-ammonia-N, microbial-N, and efficiency of microbial protein synthesis were not affected by diet type. However, the efficiency of nitrogen utilisation was improved by SUC compared with GRS. This indicates that the inclusion of an energy source with a high rumen degradation rate in high-forage diets improves rumen fermentation, digestibility, and N utilisation. Specifically, this effect was observed for the more readily available energy source, SUC, compared with the more slowly degradable NFC sources, CORN and OZ.

Personalised nutrition for older adults: design challenges, SME barriers, and options and competencies for innovation.

Personalised nutrition (PN) products and services have the potential to enhance the health and quality of life of older adults. However, PN innovation is challenging and requires specific competencies and supportive collaborations. This paper reports findings from a Collective Intelligence Scenario-Based Design session conducted with PN experts as part of the Horizon 2020 project INCluSilver, which aims to support the development of products, services, and systems that improve the health and quality of life of older adults through innovation in PN. Experts identified challenges to the design of PN products and services and barriers that small and medium enterprises (SMEs) face when innovating PN products and services for older adults. Options to address these barriers were generated and specific SME competencies supporting PN innovation were identified. This study provides a useful framework for understanding the challenges, opportunities, and key competencies needed to innovate PN products and services for older adults.

Effects of addition of nutritionally improved straw in dairy cow diets at 2 starch levels.

The objective of this experiment was to explore the effects of different dietary neutral detergent fiber sources within diets of high-producing dairy cattle with low or high starch concentrations on milk yield and composition, dry matter intake (DMI), total-tract digestibility, nitrogen (N) partitioning, and rumen function and health. Holstein-Friesian cows in early- to mid-lactation (n = 12; 666 ± 67 kg of body weight at the start of the experiment) and dry cannulated Holstein-Frisian cows (n = 4; 878 ± 67 kg of body weight at the start of the experiment) were used in multiple 4 × 4 Latin square design experiment and were offered 4 different diets. The treatments were 50:50 forage-to-concentrate diets within a total mixed ration (TMR) consisting, on a dry matter (DM) basis, of 42.4% grass silage as the main forage, 7.6% chopped untreated wheat straw, or sodium hydroxide (NaOH) wheat straw pellets, known as nutritionally improved straw (NIS), and 50.0% of 1 of 2 different concentrates with low or high starch level (TMR starch level of 16.0 vs. 24.0% of DM, respectively). Four experimental periods were used, each consisting of a 21-d adaptation period and 7 d of sampling. Dry matter intake and milk yield were both affected by the type of straw included in the diet. A 1.6 kg/d higher DMI was seen when NIS was fed compared with untreated straw, resulting in a 1.7 kg/d higher milk yield. Milk protein concentration was affected by straw type and starch level, and it was 4 and 3% higher when NIS and high-starch diets were fed, respectively. Diets with NIS were more positively effective when fed with low levels of starch. These results illustrate that feeding NIS to high-producing lactating dairy cows fed low or high starch concentrations has a positive effect on performance.

Determination of consensus k Q values for megavoltage photon beams for the update of IAEA TRS-398.

The IAEA is currently coordinating a multi-year project to update the TRS-398 Code of Practice for the dosimetry of external beam radiotherapy based on standards of absorbed dose to water. One major aspect of the project is the determination of new beam quality correction factors, k Q , for megavoltage photon beams consistent with developments in radiotherapy dosimetry and technology since the publication of TRS-398 in 2000. Specifically, all values must be based on, or consistent with, the key data of ICRU Report 90. Data sets obtained from Monte Carlo (MC) calculations by advanced users and measurements at primary standards laboratories have been compiled for 23 cylindrical ionization chamber types, consisting of 725 MC-calculated and 179 experimental data points. These have been used to derive consensus k Q values as a function of the beam quality index TPR20,10 with a combined standard uncertainty of 0.6%. Mean values of MC-derived chamber-specific [Formula: see text] factors for cylindrical and plane-parallel chamber types in 60Co beams have also been obtained with an estimated uncertainty of 0.4%.

Thickness uniformity measurements and damage threshold tests of large-area GaAs/AlGaAs crystalline coatings for precision interferometry.

Precision interferometry is the leading method for extremely sensitive measurements in gravitational wave astronomy. Thermal noise of dielectric coatings poses a limitation to the sensitivity of these interferometers. To decrease coating thermal noise, new crystalline GaAs/AlGaAs multilayer mirrors have been developed. To date, the surface figure and thickness uniformity of these alternative low-loss coatings has not been investigated. Surface figure errors, for example, cause small angle scattering and thereby limit the sensitivity of an interferometer. Here we measure the surface figure of highly reflective, substrate-transferred, crystalline GaAs/AlGaAs coatings with a custom scanning reflectance system. We exploit the fact that the reflectivity varies with the thickness of the coating. To increase penetration into the coating, we used a 1550 nm laser on a highly reflective coating designed for a center wavelength of 1064 nm. The RMS thickness variation of a two inch optic was measured to be 0.41 ± 0.05 nm. This result is within 10% of the thickness uniformity, of 0.37 nm RMS, achieved with ion-beam sputtered coatings for the aLIGO detector. We additionally measured a lower limit of the laser induced damage threshold of 64 MW/cm 2 for GaAs/AlGaAs coatings at a wavelength of 1064 nm.

Altered metabolic pathways regulate synovial inflammation in rheumatoid arthritis.

Rheumatoid arthritis is characterized by synovial proliferation, neovascularization and leucocyte extravasation leading to joint destruction and functional disability. The blood vessels in the inflamed synovium are highly dysregulated, resulting in poor delivery of oxygen; this, along with the increased metabolic demand of infiltrating immune cells and inflamed resident cells, results in the lack of key nutrients at the site of inflammation. In these adverse conditions synovial cells must adapt to generate sufficient energy to support their proliferation and activation status, and thus switch their cell metabolism from a resting regulatory state to a highly metabolically active state. This alters redox-sensitive signalling pathways and also results in the accumulation of metabolic intermediates which, in turn, can act as signalling molecules that further exacerbate the inflammatory response. The RA synovium is a multi-cellular tissue, and while many cell types interact to promote the inflammatory response, their metabolic requirements differ. Thus, understanding the complex interplay between hypoxia-induced signalling pathways, metabolic pathways and the inflammatory response will provide better insight into the underlying mechanisms of disease pathogenesis.

A Quality Improvement Approach to Reducing the Caesarean section Surgical Site Infection Rate in a Regional Hospital.

Surgical site infection (SSI) rates are used extensively by hospitals as a basis for quality improvement. A 30-day post-discharge SSI programme for Caesarean section operations has been implemented in Our Lady of Lourdes Hospital since 2011. It has been shown that skin antisepsis and antibiotic prophylaxis are key factors in the prevention of SSI. Using quality improvement methodology, an infection prevention bundle was introduced to address these two factors. Skin antisepsis was changed from povidone-iodine to chlorhexidine-alcohol. Compliance with choice of antibiotic prophylaxis increased from 89.6% in 2014 to 98.5% in 2015. Compliance with timing also improved. The SSI rate of 7.5% was the lowest recorded to date, with the majority of SSIs (64%) diagnosed after hospital discharge. The level of variation was also reduced. However, the continued presence of variation and possibility of lower infection rates from the literature imply that further improvements are required.

Incidence of central line related/associated bloodstream infections in an acute hospital.

Bloodstream infection related to a central venous catheter in the intensive care unit is a substantial clinical and economic problem. The aim of the study was to examine the incidence of central line related bloodstream infections and central line associated bloodstream infections in Our Lady of Lourdes Hospital, Drogheda, during a six month period, using an active patient based prospective surveillance method. CLRBSI rate in ICU/HDU was 0.93/1000 central line days. There was no CLABSI identified in the studied time period. However, further interventions are needed, particularly with CVC care bundle. Also, the implementation of 2% chlorhexidin in 70% isopropylalcohol use for skin asepsis, which is recommended by the Irish national guidelines, would be beneficial.

Therapeutic implications of activation of the host gene (Dleu2) promoter for miR-15a/16-1 in chronic lymphocytic leukemia.

Genetic lesions and other regulatory events lead to silencing of the 13q14 locus in a majority of chronic lymphocytic leukemia (CLL) patients. This locus encodes a pair of critical proapoptotic microRNAs, miR-15a/16-1. Decreased levels of miR-15a/16-1 are critical for the increased survival exhibited by CLL cells. Similarly, in a de novo murine model of CLL, the NZB strain, germline-encoded regulation of the syntenic region resulted in decreased miR-15a/16-1. In this paper, we have identified additional molecular mechanisms regulating miR-15a/16-1 levels and have shown that the transcription factor BSAP (B-cell-specific activator protein) directly interacts with Dleu2, the host gene containing the miR-15a/16-1 loci, and by negative regulation of the Dleu2 promoter, results in repression of miR-15a/16-1 expression. CLL patient B-cell expression levels of BSAP were increased compared with control sources of B cells. With the use of small interfering RNA-mediated repression, the levels of BSAP were decreased in vitro in the NZB-derived malignant B-1 cell line, LNC, and in ex vivo CLL patient peripheral blood mononuclear cells (PBMCs). BSAP knockdown led to an increase in the expression of miR-15a/16-1 and an increase in apoptosis, and a cell cycle arrest in both the cell line and patient PBMCs. Moreover, using Dleu2 promoter analysis by chromatin immunoprecipitation assay, we have shown that BSAP directly interacts with the Dleu2 promoter. Derepression of the Dleu2 promoter via inhibition of histone deacetylation combined with BSAP knockdown increased miR-15a/16-1 expression, and also increased malignant B-cell death. In summary, therapy targeting enhanced host gene Dleu2 transcription may augment CLL therapy.

Transverse sinus stenting for idiopathic intracranial hypertension: a review of 52 patients and of model predictions.

BACKGROUND AND PURPOSE: Transverse sinus stenosis is common in patients with IIH. While the role of transverse sinus stenosis in IIH pathogenesis remains controversial, modeling studies suggest that stent placement within a transverse sinus stenosis with a significant pressure gradient should decrease cerebral venous pressure, improve CSF resorption in the venous system, and thereby reduce intracranial (CSF) pressure, improving the symptoms of IIH and reducing papilledema. We aimed to determine if IIH could be reliably treated by stent placement in transverse sinus stenosis. MATERIALS AND METHODS: We reviewed the clinical, venographic, and intracranial pressure data before and after stent placement in transverse sinus stenosis in 52 of our own patients with IIH unresponsive to maximum acceptable medical treatment, treated since 2001 and followed between 2 months and 9 years. RESULTS: Before stent placement, the mean superior sagittal sinus pressure was 34 mm Hg (462 mm H(2)0) with a mean transverse sinus stenosis gradient of 20 mm Hg. The mean lumbar CSF pressure before stent placement was 322 mm H(2)O. In all 52 patients, stent placement immediately eliminated the TSS pressure gradient, rapidly improved IIH symptoms, and abolished papilledema. In 6 patients, symptom relapse (headache) was associated with increased venous pressure and recurrent stenosis adjacent to the previous stent. In these cases, placement of another stent again removed the transverse sinus stenosis pressure gradient and improved symptoms. Of the 52 patients, 49 have been cured of all IIH symptoms. CONCLUSIONS: These findings indicate a role for transverse sinus stent placement in the management of selected patients with IIH.

Potential organ donor audit in Ireland.

As increasing demand for organs is a challenge for transplant services worldwide it is essential to audit the process of organ donation. To address this, a national audit of potential organ donors was undertaken across hospitals with Intensive Care Units (N = 36). Questionnaires were returned on all patients (n = 2073) who died in these units from 1/9/07-31/8/08; 200 (10%) of these patients were considered for Brain Stem Testing (BST), 158 patients (79%) were diagnosed Brain Stem Dead (BSD) and 138 patients (87%) became potential donors. Consent for donation was given by 92 (69%) next of kin and 90 potential donors (65%) became organ donors. There was no evidence of a large number of potential organ donors being missed. Recommendations included completion of BSTs on all appropriate patients, development of support on BST, referral of all BSD patients to the Organ Procurement Service; enhanced co-ordination within hospitals and sustained information/education campaigns.

WITHDRAWN: Acellular vaccines for preventing whooping cough in children.

BACKGROUND: Routine use of whole cell pertussis vaccines was suspended in some countries in the late 1970s and early 1980s, leading to a resurgence of whooping cough. Acellular pertussis vaccines containing purified or recombinant Bordetella pertussis antigens were developed in the hope that they would be as effective but less toxic than the whole cell vaccines. OBJECTIVES: The objective of this review was to assess the effects of acellular pertussis vaccines in children. SEARCH STRATEGY: The Cochrane Controlled Trials Register and Medline were searched up to January 1998. SELECTION CRITERIA: Double-blind randomised efficacy and safety trials of acellular pertussis vaccines in children, with active follow-up of participants and laboratory verification of pertussis cases. DATA COLLECTION AND ANALYSIS: One reviewer assessed trial quality and extracted data. MAIN RESULTS: Six efficacy trials and 45 safety trials were included. Acellular pertussis vaccines with three or more pertussis vaccines were more effective than those with one or two antigens. They were also more effective than one type of whole cell pertussis vaccine, but less effective than two other types of whole cell vaccines. Differences in trial design precluded pooling of the efficacy data and results should be interpreted with caution. Most systemic and local adverse events were significantly less common with acellular than with whole cell pertussis vaccines. AUTHORS' CONCLUSIONS: Multi-component acellular pertussis vaccines are effective, and show less adverse effects than whole cell pertussis vaccines. However in areas where whooping cough is more likely to be fatal, the higher toxicity of some whole cell vaccines may be offset by their increased effectiveness.

A boarding school outbreak of pertussis in adolescents: value of laboratory diagnostic methods.

Culture for Bordetella pertussis (B. pertussis) is the traditional gold standard for laboratory diagnosis of pertussis but is insensitive, especially later in the course of illness and in vaccinated persons. Interpretation of serology is limited by the lack of an appropriate reference standard. An outbreak of pertussis in a crowded boarding-school dormitory allowed evaluation of laboratory correlates of infection. Questionnaires, serum samples and throat swabs were collected from members of the exposed group. Serum samples from unexposed controls of a similar age group were used for comparison. B. pertussis PCR was performed on throat swabs, and sera were tested for IgA antibodies against whole-cell (WC) B. pertussis antigen and IgG antibodies to pertussis toxin (PT). The Centers for Disease Control and Prevention definition for pertussis was used to define clinical cases. We evaluated the use of a previously published cut-off for PT IgG of 125 EIA units (EU)/ml. Completed questionnaires were obtained from 115 students, of whom 85 (74%) reported coughing symptoms, including 32 (28%) who met the clinical case definition for pertussis. B. pertussis was detected by PCR in 17 (15%) and WC IgA in 22 (19%) students; neither correlated with symptoms, but dormitory of residence strongly predicted PCR status. The mean PT IgG geometric mean concentration, in this situation of high pertussis exposure, correlated with severity of symptoms and was significantly higher in both symptomatic and asymptomatic children exposed during the outbreak (P < 0.001) than in control children. A cut-off for PT IgG of 125 EU/ml was too high in an outbreak situation to be sensitive enough to identify pertussis cases. A case of pertussis in a crowded boarding-school dormitory resulted rapidly in an outbreak. Serology and PCR were useful in identifying the outbreak and commencing disease control measures. The use of serology has mostly been evaluated in community serosurveys, where it is not possible to determine if immunity reflects vaccination, asymptomatic disease or symptomatic disease. This outbreak gave us the opportunity to evaluate the value of serology and PCR in the presence of confirmed exposure to pertussis.

Diagnostic testing and discharge coding for whooping cough in a children's hospital.

OBJECTIVE: To evaluate the diagnostic pathways for whooping cough in a large urban paediatric hospital to inform assessment of the relative merits of notification and hospitalization data for measuring pertussis disease burden in Australian children. METHODS: All laboratory requests for Bordetella pertussis (BP) culture or serology between 30 June 1997 and 30 June 1999 were reviewed and cross-checked against discharge diagnoses with International Classification of Disease (ICD) codes A37.0, 033.0 (whooping cough due to BP) or 37.9, 033.9 (whooping cough due to unspecified organisms). Culture-positive (CP) cases were defined as a positive culture or polymerase chain reaction for BP. Culture-negative (CN) cases either fulfilled the current Australian clinical case definition (>/=14 days of cough with one or more of paroxysms, whoop, post-tussive vomiting), or had a cough illness with either positive BP serology or documented contact with an individual coughing for >14 days. In infants <6-months-old, a coughing illness with apnoea and negative investigations for other causes was also accepted. Culture positive and CN cases were cross-referenced with notification data. RESULTS: During the study period, laboratory tests for BP were performed in 677 children, of whom 230 were hospitalized and 71 (31%) had an eligible ICD code at discharge; 29 were CP, 40 CN, and two (3%) were misclassified. A further 14 CP children were not admitted. Although 61 hospitalized cases (88%) fulfilled notification criteria, including 32 (80%) of CN cases, only 26 (90%) of CP and eight (20%) of CN cases were notified. CONCLUSIONS: Notifications substantially under-enumerate hospitalized infant cases, especially those without positive laboratory tests. Hospital discharge data add significantly to surveillance for pertussis, particularly in infancy where most severe cases occur.

Serological diagnosis of pertussis: evaluation of IgA against whole cell and specific Bordetella pertussis antigens as markers of recent infection.

In Australia, notification of pertussis cases in older children or adults has increased significantly in recent years. In most cases, laboratory diagnosis is based only on a positive serological test for IgA antibody against whole cell Bordetella pertussis. During a 3-month period, 318 consecutive sera submitted for diagnosis of pertussis were tested for IgA antibody against whole cell (WC) sonicated B. pertussis, pertussis toxin (PT), filamentous haemagglutinin (FHA) and pertactin (PRN). Results of one or more of these tests were positive in sera from 175 subjects and clinical information was obtained by telephone interview from 90 subjects. Using a clinical case definition as the reference standard, the sensitivities of the four IgA assays were variable but quite low (24-64%), but the specificities were high (93-98%). For diagnosis of pertussis in subjects with a compatible clinical illness, these and other findings support the use of serological testing for IgA antibody.

Structure and function of voltage-dependent ion channel regulatory beta subunits.

Voltage-dependent K(+), Ca(2+), and Na(+) channels play vital roles in basic physiological processes, including management of the action potential, signal transduction, and secretion. They share the common function of passively transporting ions across cell membranes; thus, it would not be surprising if they should exhibit similarities of both structure and mechanism. Indeed, the principal pore-forming (alpha) subunits of each show either exact or approximate 4-fold symmetry and share a similar transmembrane topology, and all are gated by changes in membrane potential. Furthermore, these channels all possess an auxiliary polypeptide, designated the beta subunit, which plays an important role in their regulation. Despite considerable functional semblences and abilities to interact with structurally similar alpha subunits, however, there is considerable structural diversity among the beta subunits. In this review, we discuss the similarities and differences in the structures and functions of the beta subunits of the voltage-dependent K(+), Ca(2+), and Na(+) channels.