Overcoming barriers and stigma: new frontiers in solid organ transplantation for people with HIV

There is a growing need for solid organ transplantation (SOT) for people living with human immunodeficiency virus (HIV). With the advent of antiretroviral therapy, people living with HIV are experiencing increased life expectancies and are, therefore, developing more comorbidities, including end-stage organ disease. In cases of advanced organ failure, SOT is often the best therapeutic option to improve quality of life and overall survival. As organ shortages persist, transplantation of organs from donors with HIV to recipients with HIV has become a potential therapeutic option. This article first reviews the current state of organ transplantation from donors without HIV to recipients with HIV (HIV D-/R+) by organ and discusses key lessons learned from these transplant trials, including those about drug-drug interactions, rejection, and opportunistic infections. It then explores transplantation from donors with HIV to recipients with HIV (HIV D+/R+), a new frontier. Finally, it investigates challenges of implementation, including public awareness and regulatory requirements, and explores future directions for SOT in people living with HIV.

A racial analysis of pain outcomes following microvascular decompression for trigeminal neuralgia

OBJECTIVE

Pain outcomes by race in trigeminal neuralgia (TN) are not well investigated. The authors aimed to compare microvascular decompression (MVD) outcomes in TN patients on the basis of self-identified race.

METHODS

The authors retrospectively reviewed all patients with TN who underwent MVD at their institution from 2007 to 2020. Each patient's self-reported race was recorded, and Barrow Neurological Institute (BNI) scores for pain and numbness were compared. Factors associated with pain recurrence were assessed using survival analyses and multivariate regressions.

RESULTS

Of 1011 patients, 925 reported their racial demographic characteristics, and patients who identified as Native American or American Indian and Native Hawaiian or Pacific Islander were excluded due to small sample sizes. Of the resulting 921 patients, 697 (75.7%) patients identified as White, 108 (11.7%) as Black or African American, 39 (4.2%) as Asian, and 77 (8.4%) as other. Compared with White patients, Black TN patients were more likely to present with type 1 TN (p = 0.02). At final follow-up, the mean BNI pain score of Black patients was significantly higher (p < 0.001) compared with that of White patients, although pain scores did not differ preoperatively. The adjusted multivariate ordinal regression model showed that Black patients were associated with higher BNI pain scores at final follow-up (p = 0.01). Furthermore, compared with White patients, Black patients were at increased risk for postoperative pain recurrence (p = 0.04), which additionally occurred after a shorter median pain-free duration (p = 0.03).

CONCLUSIONS

TN patients who identify as Black or African American exhibit worse postoperative pain outcomes after MVD compared with White patients. Future studies investigating the factors driving these racial differences are warranted.

Bioengineered particles expand myelin-specific regulatory T cells and reverse autoreactivity in a mouse model of multiple sclerosis

Multiple sclerosis (MS) is an autoimmune disease characterized by autoreactive immune cells damaging myelinated nerves, impairing brain function. Treatments aim for tolerance induction to reeducate the immune system to recognize myelin as "self" rather than "foreign." As peripheral immune tolerance is primarily mediated by regulatory T cells (Tregs), we developed a therapy to support Treg expansion and activity in vivo. To target, engage, and activate myelin-specific Tregs, we designed a biodegradable microparticle (MP) loaded with rapamycin and functionalized with a biased interleukin-2 (IL-2) fusion protein and a major histocompatibility complex (MHC) class II loaded with a myelin peptide. These tolerogenic MPs (Tol-MPs) were validated in vitro and then evaluated in a mouse model of MS, experimental autoimmune encephalomyelitis (EAE). Tol-MPs promoted sustained disease reversal in 100% of mice and full recovery in 38% of mice with symptomatic EAE. Tol-MPs are a promising platform for treatment of autoimmune diseases.

Organ Donors with Human Immunodeficiency Virus and Hepatitis C Virus: Expanding the Donor Pool

Using organs from donors with treatable infections is a strategy to increase the quality and number of organs for transplantation. For HIV, pilot studies of kidney and liver transplantation from donors with HIV to recipients with HIV demonstrate excellent early outcomes. However, the number of donors and transplants per year remains lower than projected due to several barriers. For HCV, the use of organs from donors with HCV has expanded to recipients without HCV due to safe, effective direct-acting antivirals for HCV, which are well-tolerated in transplant recipients. Studies across organ types demonstrate good outcomes and shorter wait times.

Sex-Specific Pain Outcomes Following Microvascular Decompression for Trigeminal Neuralgia

BACKGROUND

Trigeminal neuralgia (TN) is more prevalent among women. However, while microvascular decompression (MVD) is the most effective long-term surgical treatment for TN, it is unclear whether it is equally efficacious for men and women. We sought to characterize the relationship between sex and pain outcomes following MVD for TN.

METHODS

From 2007 to 2020, 938 unilateral TN patients were treated with MVD at our institution. Patient demographics, clinical characteristics, operative features, and pain outcomes were recorded. Differences between men and women were analyzed via t-test and chi-squared analyses. A multivariate ordinal regression was used to establish significant predictors of pain outcome. Differences in time to pain recurrence were assessed via Cox proportional hazards and Kaplan-Meier nonparametric survival analysis.

RESULTS

A majority (67%) of the 938 patients analyzed were female. Men and women presented with similar preoperative pain severity (P = 0.17). Female sex (P = 0.048) and younger age (P = 0.03) were independently associated with worsened Barrow Neurological Institute pain scores at 3-month follow-up on multivariate analysis. Women were also more likely to experience recurrence than men (P = 0.01), and time to recurrence was shorter among women (P = 0.02). Only female sex was independently associated with increased risk of postoperative pain recurrence on multivariate Cox proportional hazards regression (P = 0.01).

CONCLUSIONS

Female TN patients undergoing MVD had worse pain outcomes, more frequent pain recurrence, and shorter time to recurrence. Our results indicate a sex-specific dimorphism in response to MVD among TN patients.

Doping evaluation of InP nanowires for tandem junction solar cells

In order to push the development of nanowire-based solar cells further using optimized nanowire diameter and pitch, a doping evaluation of the nanowire geometry is necessary. We report on a doping evaluation of n-type InP nanowires with diameters optimized for light absorption, grown by the use of metal-organic vapor phase epitaxy in particle-assisted growth mode using tetraethyltin (TESn) as the dopant precursor. The charge carrier concentration was evaluated using four-probe resistivity measurements and spatially resolved Hall measurements. In order to reach the highest possible nanowire doping level, we set the TESn molar fraction at a high constant value throughout growth and varied the trimethylindium (TMIn) molar fraction for different runs. Analysis shows that the charge carrier concentration in nanowires grown with the highest TMIn molar fraction (not leading to kinking nanowires) results in a low carrier concentration of approximately 10(16) cm(-3). By decreasing the molar fraction of TMIn, effectively increasing the IV/III ratio, the carrier concentration increases up to a level of about 10(19) cm(-3), where it seems to saturate. Axial carrier concentration gradients along the nanowires are found, which can be correlated to a combination of changes in the nanowire growth rate, measured in situ by optical reflectometry, and polytypism of the nanowires observed in transmission electron microscopy.

InAs Nanowire Transistors with Multiple, Independent Wrap-Gate Segments

We report a method for making horizontal wrap-gate nanowire transistors with up to four independently controllable wrap-gated segments. While the step up to two independent wrap-gates requires a major change in fabrication methodology, a key advantage to this new approach, and the horizontal orientation more generally, is that achieving more than two wrap-gate segments then requires no extra fabrication steps. This is in contrast to the vertical orientation, where a significant subset of the fabrication steps needs to be repeated for each additional gate. We show that cross-talk between adjacent wrap-gate segments is negligible despite separations less than 200 nm. We also demonstrate the ability to make multiple wrap-gate transistors on a single nanowire using the exact same process. The excellent scalability potential of horizontal wrap-gate nanowire transistors makes them highly favorable for the development of advanced nanowire devices and possible integration with vertical wrap-gate nanowire transistors in 3D nanowire network architectures.

Formation of nanogaps in InAs nanowires by selectively etching embedded InP segments

We present a method to fabricate nanometer scale gaps within InAs nanowires by selectively etching InAs/InP heterostructure nanowires. We used vapor-liquid-solid grown InAs nanowires with embedded InP segments of 10-60 nm length and developed an etching recipe to selectively remove the InP segment. A photo-assisted wet etching process in a mixture of acetic acid and hydrobromic acid gave high selectivity, with accurate removal of InP segments down to 20 nm, leaving the InAs wire largely unattacked, as verified using scanning electron and transmission electron microscopy. The obtained nanogaps in InAs wires have potential as semiconducting electrodes to investigate electronic transport in nanoscale objects. We demonstrate this functionality by dielectrophoretically trapping 30 nm diameter gold nanoparticles into the gap.

Evaluation of RAD51C as cancer susceptibility gene in a large breast-ovarian cancer patient population referred for genetic testing

Despite extensive analysis of the BRCA1 and BRCA2 genes, germline mutations are detected in <20% of families with a presumed genetic predisposition for breast and ovarian cancer. Recent literature reported RAD51C as a new breast cancer susceptibility gene. In this study, we report the analysis of 410 patients from 351 unrelated pedigrees. All were referred for genetic testing and we selected families with at least one reported case of ovarian cancer in which BRCA1&2 mutations were previously ruled out. We analyzed the coding exons, intron-exons boundaries, and UTRs of RAD51C. Our mutation analysis did not reveal any unequivocal deleterious mutation. In total 12 unique sequence variations were identified of which two were novel. Our study and others suggest a low prevalence of RAD51C mutations with an exception for some founder populations. This observation is in favor of the rare allele hypothesis in the debate over the nature of the genetic contribution to individual susceptibility to breast and ovarian cancer and further genome-wide studies in high risk families are warranted.

Distal myopathy with upper limb predominance caused by filamin C haploinsufficiency

OBJECTIVE

In this study, we investigated the detailed clinical findings and underlying genetic defect in 3 presumably related Bulgarian families displaying dominantly transmitted adult onset distal myopathy with upper limb predominance.

METHODS

We performed neurologic, electrophysiologic, radiologic, and histopathologic analyses of 13 patients and 13 at-risk but asymptomatic individuals from 3 generations. Genome-wide parametric linkage analysis was followed by bidirectional sequencing of the filamin C (FLNC) gene. We characterized the identified nonsense mutation at cDNA and protein level.

RESULTS

Based on clinical findings, no known myopathy subtype was implicated in our distal myopathy patients. Light microscopic analysis of affected muscle tissue showed no specific hallmarks; however, the electron microscopy revealed changes compatible with myofibrillar myopathy. Linkage studies delineated a 9.76 Mb region on chromosome 7q22.1-q35 containing filamin C (FLNC), a gene previously associated with myofibrillar myopathy. Mutation analysis revealed a novel c.5160delC frameshift deletion in all patients of the 3 families. The mutation results in a premature stop codon (p.Phe1720LeufsX63) that triggers nonsense-mediated mRNA decay. FLNC transcript levels were reduced in muscle and lymphoblast cells from affected subjects and partial loss of FLNC in muscle tissue was confirmed by protein analysis.

CONCLUSIONS

The FLNC mutation that we identified is distinct in terms of the associated phenotype, muscle morphology, and underlying molecular mechanism, thus extending the currently recognized clinical and genetic spectrum of filaminopathies. We conclude that filamin C is a dosage-sensitive gene and that FLNC haploinsufficiency can cause a specific type of myopathy in humans.

Analysis of FOXG1 Is Highly Recommended in Male and Female Patients with Rett Syndrome

We screened a cohort of 5 male and 20 female patients with a Rett spectrum disorder for mutations in the coding region of FOXG1, previously shown to cause the congenital variant of Rett syndrome. Two de novo mutations were identified. The first was a novel missense mutation, p.Ala193Thr (c.577G>A), in a male patient with congenital Rett syndrome, and the second was the p.Glu154GlyfsX301 (c.460dupG) truncating mutation in a female with classical Rett syndrome, a mutation that was previously reported in an independent patient. The overall rate of FOXG1 mutations in our cohort is 8%. Our findings stress the importance of FOXG1 analysis in male patients with Rett syndrome and in female patients when mutations in the MECP2 and CDKL5 genes have been excluded.

Sensitivity and specificity of a whole-blood RNA transcript-based diagnostic test for the diagnosis of prostate cancer (CaP) compared with prostate-specific antigen (PSA) alone

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Background: Screening for CaP with PSA testing is limited by a high number of false postives, particularly in the setting of benign prostatic hypertrophy (BPH). The goal of this study was to develop whole blood RNA transcript-based diagnostic tests that improve the diagnosis of CaP over PSA alone. Methods: From August 2006 to October 2008, three prospective cohorts of men consented to the collection of whole blood in PAXgene Blood RNA tubes for gene expression analysis: men with newly diagnosed, localized, untreated CaP, otherwise healthy men without CaP, and otherwise healthy men with BPH. 168 inflammation and CaP-related genes (Source MDx Precision Profiles) were assayed using optimized Q-PCR technology. Logistic regression methods were used to develop models to optimize prostate cancer diagnosis. Results: 182 men underwent expression analysis (n = 76, 76 and 30 for CaP, normal, and BPH cohorts, respectively). The CaP and normal cohorts were age matched (median age 60 yrs); the BPH cohort median age was 70. Considering only the CaP and normal cohorts, PSA alone (using a cut-off of 4 ng/ml) had a specificity of 94.7%, but sensitivity of only 71.1% for diagnosis of CaP, or 90.8% and 77.6%, respectively, when using age-adjusted PSA criteria. A model consisting of the expression analysis of 6 genes and PSA had a higher specificity (96.1%) and a much improved sensitivity (97.4%) for CaP diagnosis. When the BPH cohort was added, the improvement of the 6-gene model remained (sensitivity and specificity of 97.4% and 92.0% vs 77.6% and 88.1% using the age-adjusted PSA criteria). Further model development using the CaP and BPH cohorts yielded a 5-gene model which, integrated with PSA and age, correctly predicted 96.1% of the CaP pts and 93.3% of BPH pts. Conclusions: These results suggest that specific whole blood RNA transcript levels can assess abnormal gene expression associated with CaP. Such a molecular CaP biomarker would be a powerful tool to reduce unnecessary biopsies in patients without CaP and detect CaP in patients with PSA values below the current cutoff. Validation of these results is ongoing and will be available at the time of the meeting.

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An optimized DHPLC protocol for molecular testing of the EXT1 and EXT2 genes in hereditary multiple osteochondromas

Hereditary multiple osteochondromas (MO) is an autosomal dominant bone disorder characterized by the presence of bony outgrowths (osteochondromas or exostoses) on the long bones. MO is caused by mutations in the EXT1 or EXT2 genes, which encode glycosyltransferases implicated in heparan sulfate biosynthesis. Standard mutation analysis performed by sequencing analysis of all coding exons of the EXT1 and EXT2 genes reveals a mutation in approximately 80% of the MO patients. We have now optimized and validated a denaturing high-performance liquid chromatography (DHPLC)-based protocol for screening of all EXT1- and EXT2-coding exons in a set of 49 MO patients with an EXT1 or EXT2 mutation. Under the optimized DHPLC conditions, all mutations were detected. These include 20 previously described mutations and 29 new mutations - 20 new EXT1 and nine new EXT2 mutations. The protocol described here, therefore, provides a sensitive and cost-sparing alternative for direct sequencing analysis of the MO-causing genes.

Multiplex ligation-dependent probe amplification to detect subtelomeric rearrangements in routine diagnostics

Subtelomeric rearrangements are believed to be responsible for 5-7% of idiopathic mental retardation cases. Due to the relative complexity and high cost of the screening methods used till now, only preselected patient populations including mostly the more severely affected cases have been screened. Recently, multiplex ligation-dependent probe amplification (MLPA) has been adapted for use in subtelomeric screening, and we have incorporated this technique into routine diagnostics of our laboratory. Since the evaluation of MLPA as a screening method, we tested 275 unselected patients with idiopathic mental retardation and detected 12 possible subtelomeric aberrations: a der(11)t(11;20)(qter;qter), a 19pter duplication, a der(18)t(18;10)(qter; pter), a 15qter deletion, a 8pter deletion, a 6qter deletion, a der(X)t(X;1)(pter;qter), a der(X)t(X;3)(pter;pter), a 5qter duplication, a 3pter deletion, and two 3qter duplications. The patients can be subdivided into two groups: the first containing de novo rearrangements that are likely related to the clinical presentation of the patient and the second including aberrations also present in one of the parents that may or may not be causative of the mental retardation. In our patient cohort, five (1.8%) subtelomeric rearrangements were de novo, three (1.1%) rearrangements were familial and suggestively disease causing, and four (1.5%) were possible polymorphisms. This high frequency of subtelomeric abnormalities detected in an unselected population warrants further investigation about the feasibility of routine screening for subtelomeric aberrations in mentally retarded patients.

Absence of constitutional Y chromosome AZF deletions in patients with testicular germ cell tumors

OBJECTIVES

To investigate the frequency of azoospermia factor (AZF) deletions in Dutch patients with testicular germ cell tumors (TGCTs). Reduced fertility is associated with TGCTs and reduced fertility and TGCTs might share genetic risk factors according to the testicular dysgenesis hypothesis. Up to 8% of infertility and reduced fertility in the general male population can be explained by the presence of constitutional deletions of part of the long arm of the Y chromosome (Yq11), referred to as the AZF region.

METHODS

In 112 patients with TGCT, screening for constitutional deletions in the AZF region was performed by multiplex polymerase chain reaction analysis in DNA extracted from peripheral blood lymphocytes. A set of 24 primer pairs, of which 20 primer pairs are homologous to previously identified and mapped sequenced tag sites within the AZF region were used.

RESULTS

No deletions in the Yq11 region were detected in any of the 112 patients.

CONCLUSIONS

Large Y chromosome microdeletions in the AZF region are not a major contributor to the development of TGCT and TGCT-associated reduced fertility.

A Psychometric Analysis of the Maslach Burnout Inventory-General Survey in the South African Police Service

The objectives of this study, which was undertaken by two members of the WorkWell Research Unit, were to validate the Maslach Burnout Inventory-General Survey (MBI-GS) for the South African Police Service and to determine the construct equivalence of this Inventory and bias for different race groups. A cross-sectional survey design was used. Stratified random samples ( N=2396) were taken of police members from nine provinces in South Africa. The study was based on the MBI-GS and a biographical questionnaire. Structural equation modelling confirmed a 3-factor model of burnout, consisting of Exhaustion, Cynicism and Professional Efficacy. All three factors showed acceptable internal consistencies. An exploratory factor analysis with target rotations confirmed the construct equivalence of the three factors for different race groups in the SAPS. No evidence was found for uniform or non-uniform bias of the items of the MBI-GS for different race groups.

A psychometric analysis of the Utrecht Work Engagement Scale in the South African police service

The objectives of this research were to validate the Utrecht Work Engagement Scale (UWES) for the South African Police Service (SAPS) and to determine its construct equivalence and bias in different race groups. A cross-sectional survey design was used. Stratified random samples (N = 2396) were taken of police members of nine provinces in South Africa. The UWES and a biographical questionnaire were administered. Structural equation modelling confirmed a 3-factor model of work engagement, consisting of Vigour, Dedication and Absorption. These three factors have acceptable internal consistencies. Exploratory factor analysis with target rotations showed equivalence of the three factors for different race groups in the SAPS. No evidence was found for uniform or non-uniform bias of the items of the UWES for different race groups. Opsomming Die doelstellings van hierdie navorsing was om die Utrecht- werksbegeesteringskaal (UWES) te valideer vir die Suid- Afrikaanse Polisiediens (SAPD) en die konstrukekwivalensie daarvan vir verskillende rassegroepe te bepaal. ’n Dwarssnee opname-ontwerp is gebruik. Gestratifiseerde ewekansige steekproewe (N = 2396) is van polisielede uit nege provinsies geneem. Die UWES en ’n biografiese vraelys is afgeneem. Strukturele vergelykingsmodellering het ’n 3-faktormodel, bestaande uit Energie, Toewyding en Absorpsie, aangetoon. Hierdie drie faktore het aanvaarbare interne konsekwentheid getoon. Eksploratiewe faktoranalise met teikenrotasies het konstrukekwivalensie vir die drie faktore vir verskillende rassegroepe in die SAPD getoon. Bewyse is nie gevind vir uniforme of nie-uniforme sydigheid van die items van die UWES vir verskillende rassegroepe nie.

Coping, stress and burnout in the South African police service in Kwazulu-natal

The objective of this research was to determine the relationship between coping, stress and burnout in the South African Police Service. A survey design was used. The study population (N = 257) consisted of police personnel in Kwazulu-Natal. The COPE, Police Stress Inventory and Maslach Burnout Inventory – General Survey (MBI-GS), were used as measuring instruments. Structural equation analysis showed that job demands (as stressors) are associated with exhaustion. Passive coping strategies contributed to exhaustion and cynicism, while seeking emotional support led to lower exhaustion. Exhaustion contributed to cynicism. Stress because of a lack of resources, active coping strategies and not coping passively seem to impact on professional efficacy. Opsomming Die doelstelling van hierdie navorsing was om die verband tussen coping, stres en uitbranding binne die Suid-Afrikaanse Polisiediens te ondersoek. ’n Opname-ontwerp is gebruik. Die studiepopulasie (N = 257) het bestaan uit polisiepersoneel in Kwazulu-Natal. Die COPE, die Polisiestres-Opname en die Maslach-uitbrandingsvraelys – Algemene Opname (MBI-GS) is as meetinstrumente gebruik. Strukturele vergelykingsmodellering het aangetoon dat werkseise (as stressore) geassosieer word met uitputting. Passiewe coping- strategieë het bygedra tot uitputting en sinisme, terwyl die soeke na emosionele ondersteuning tot laer uitputting gelei het. Uitputting het tot sinisme bygedra. Stres a.g.v. ’n tekort aan hulpbronne (invers), aktiewe coping-strategieë en passiewe coping-strategieë (invers) blyk ’n uitwerking op professionele doeltreffendheid te hê.

The relationship between burnout, personality traits and coping strategies in a corporate pharmaceutical group

The objective of this research was to determine the relationship between burnout, personality traits and coping strategies. A survey design was used. The study population consisted of 131 employees in a corporate pharmaceutical group. The Maslach Burnout Inventory, NEO Personality Inventory Revised and COPE were administered. Active coping strategies were associated with Emotional Stability, Extraversion, Openness to Experience and Conscientiousness, while passive coping strategies were associated with Neuroticism, low Agreeableness and low Conscientiousness. Emotional Stability, Extraversion, Openness to Experience, Agreeableness and Conscientiousness were associated with lower emotional exhaustion and depersonalisation and higher personal accomplishment. Constructive coping strategies were associated with personal accomplishment. Opsomming Die doelstelling van hierdie navorsing was om te bepaal of daar ’n verband tussen uitbranding, persoonlikheidstrekke en coping-strategieë bestaan. ’n Opnameontwerp is gebruik. Die ondersoekgroep het bestaan uit 131 werknemers van ’n korporatiewe apteekgroep. Drie vraelyste is gebruik, naamlik die Maslach-Uitbrandingsvraelys, die NEO Personality Inventory Revised en die COPE. Aktiewe coping-strategieë is geassosieer met Emosionele Stabiliteit, Ekstroversie, Openheid vir Ervaring en Konsensieusheid, terwyl passiewe coping-strategieë geassosieer is met Neurotisisme, lae Inskiklikheid en lae Konsensieusheid. Emosionele Stabiliteit, Ekstroversie, Openheid vir Ervaring, Inskiklikheid en Konsensieusheid is geassosieer met lae emosionele uitputting, lae depersonalisasie en hoë persoonlike bereiking. Konstruktiewe coping-strategieë is geassosieer met persoonlike bereiking.

The M34T allele variant of connexin 26

GJB2 encodes the protein Connexin 26, one of the building blocks of gap junctions. Each Connexin 26 molecule can oligomerize with five other connexins to form a connexon; two connexons, in turn, can form a gap junction. Because mutations in GJB2 are the most common cause of congenital severe-to-profound autosomal recessive nonsyndromic hearing loss, the effect of the Connexin 26 allele variants on this dynamic 'construction' process and the function of any gap junctions that do form is particularly germane. One of the more controversial allele variants, M34T, has been hypothesized to cause autosomal dominant nonsyndromic hearing loss. In this paper, we present clinical and genotypic data that refutes this hypothesis and suggests that the effect of the M34T allele variant may be dependent on the mutations segregating in the opposing allele.

The clinical pharmacokinetics of a new pharmacokinetically enhanced formulation of amoxicillin/clavulanate

BACKGROUND

A new oral pharmacokinetically enhanced formulation of the broad-spectrum antibiotic amoxicillin/clavulanate has been developed to provide more effective therapy against resistant pathogens than is provided by currently available formulations by maintaining therapeutically useful plasma amoxicillin concentrations for a longer period after dosing.

OBJECTIVE

This study explored the pharmacokinetics of the new oral formulation of amoxicillin/clavulanate in healthy male and female subjects.

METHODS

A single oral dose of pharmacokinetically enhanced amoxicillin/clavulanate (2000/125 mg; 16:1 ratio) was administered to subjects at the start of a meal. After dosing, blood samples were collected at frequent intervals up to 12 hours, and plasma was assayed for amoxicillin and clavulanate concentrations using validated procedures. The new formulation consisted of 1 layer of immediate-release amoxicillin and clavulanate and another of sustained-release amoxicillin in a proportion such that for an amoxicillin minimum inhibitory concentration (MIC) of 4 microg/mL, the time above the MIC (T >MIC) would be approximately > or = 40% over a 12-hour dosing interval.

RESULTS

The study enrolled 24 and 31 healthy male and female subjects, respectively. Their mean age was 35 years (range, 18-58 years) and mean body weight was 69 kg (range, 51-86 kg). After the expected sharp peak in plasma amoxicillin concentration, there appeared to be a slower decline with the pharmacokinetically enhanced formulation than is usually seen with conventional formulations, and there was evidence of a second amoxicillin absorption phase. The mean T >MIC for an amoxicillin MIC of 4 microg/mL was 49.4% of a 12-hour dosing interval, a value that cannot be achieved with existing approved doses and formulations of amoxicillin/clavulanate. By 12 hours, plasma amoxicillin concentrations were very low (approximately 0.05 microg/mL), suggesting no expectation of notable dose-to-dose accumulation on repeat dosing with a BID regimen. The terminal half-lives of amoxicillin (1.27 hours) and clavulanate (1.03 hours) with the new formulation were similar to those of existing formulations of amoxicillin/clavulanate. No deaths or serious adverse events were reported.

CONCLUSIONS

The enhanced pharmacokinetic profile of amoxicillin/clavulanate seen in this study suggests that this formulation is likely to be highly effective for the oral treatment of infections caused by bacteria--including beta-lactamase-producing organisms--and strains with amoxicillin MICs < or = 4 microg/mL.

Determination of the carrier frequency of the common GJB2 (connexin-26) 35delG mutation in the Belgian population using an easy and reliable screening method

Mutations in the gene GJB2, encoding the gap-junction protein connexin-26, have been shown to be a major cause of nonsyndromic recessive deafness (NSRD). A single mutation in the GJB2 gene accounts for the majority of NSRD in many different populations. This mutation represents a deletion of a guanine within a stretch of six Gs between nucleotide positions +30 and +35 of the GJB2 cDNA (35delG). Molecular detection of the 35delG mutation is usually performed by direct sequencing analysis of PCR products, or by allele-specific PCR analysis. To screen for this mutation, we developed an easier and more reliable method, based on the principle of PCR-mediated site-directed mutagenesis (PSDM), followed by a BsiYI digestion. We tested 360 unrelated unaffected Belgian individuals for heterozygosity of the 35delG mutation and found a carrier frequency of 1 in 40 (95% CI, 1 in 30 to 1 in 60). As our new screening method is simple and reliable in use, and detects a mutation responsible for a significant part of NSRD, it may find widespread use in DNA diagnostics.

CAG repeat contraction in the androgen receptor gene in three brothers with mental retardation

We report on three brothers with mental retardation and a contracted CAG repeat in the androgen receptor (AR) gene. It is known that expansion of the CAG repeat in this gene leads to spinal and bulbar muscular atrophy (SBMA or Kennedy disease); however, contracted repeats have not yet been implicated in disease. As the range of the length of CAG repeats in the AR gene, like those of other genes associated with dynamic mutations, follows a normal distribution, the theoretical possibility of disease at both ends of the distribution should be considered.

Classical Friedreich's ataxia and its genotype

Fourteen patients with classical features of Friedreich's ataxia (FRDA) were examined. The clinical diagnosis of FRDA was afterwards confirmed in all patients by the appropriate DNA investigation which showed markedly increased amounts of GAA repeats on both alleles of the frataxin gene. None of our patients presented with atypical features such as late-onset FRDA, FRDA with retained deep tendon reflexes or with a very slow course. Five of them are not yet confined to a wheelchair. But for 1 patient who died at age 36 years and had the largest number of GAA repeats on both alleles, there was no significant correlation between number of repeats in the shortest allele, age at onset, age at wheelchair dependence, duration of the disease and main clinical signs. All patients but 3 had between 500 and 1,050 GAA repeats. The 3 patients with, respectively, 400, 450 and 500 repeats on the shortest allele had a clinical course comparable to the other patients. Even in the case of variations in the number of repeats in the same sibship, there were only modest differences between the siblings concerning age at onset of the disease, symptoms and signs and age at wheelchair dependence. There were no qualitative differences in the main clinical features and laboratory investigations in the full-blown phase of the disorder. Molecular biology has become a major element in the diagnosis of FRDA. DNA testing for FRDA should be applied to every case of idiopathic autosomal recessive or sporadic ataxia. However, the clinical features of FRDA remain fully characteristic in many patients and keep their diagnostic value.

Incomplete EcoRI digestion may lead to false diagnosis of fragile X syndrome

Molecular diagnosis of fragile X syndrome is usually performed using Southern blot analysis of DNA digested with EcoRI. In the course of diagnostic studies, we observed that a specific EcoRI restriction site in the fragile X gene (FMR1) is sometimes refractory to digestion, generating additional fragments on a Southern blot suggestive of a full mutation in FMR1. This may lead to a false-positive diagnosis of fragile X syndrome. Such additional bands are avoided by the use of HindIII instead of EcoRI. Therefore, we recommend the use of HindIII for the molecular diagnosis of fragile X syndrome.

Copper treatment increases recombinant baculovirus production and polyhedrin and p10 expression

Treatment with 2 mM CuSO4 was used to induce a Drosophila melanogaster metallothionein (Mtn) promoter that had been cloned into a recombinant baculovirus. Careful study revealed that the Mtn promoter functioned as an inducible, if somewhat "leaky" promoter within the context of baculovirus-infected cells. In the process of generating a recombinant-baculovirus, it was discovered that post-transfection treatment with copper resulted in a 10-fold increase in the production of recombinant virus. This effect on virus production was specific to transfection, as treatment of infected cells with copper did not increase the production of virus. Treatment of infected cells with copper did, however, extend the period of expression of the polyhedrin and p10 proteins by at least 12 h. These findings have practical applications for the production of recombinant baculoviruses and the subsequent expression of foreign proteins using baculovirus expression vectors.

Mildly impaired water maze performance in male Fmr1 knockout mice

Fmr1 knockout mice constitute a putative model of fragile X syndrome, the most common form of heritable mental disability in humans. We have compared the performance of transgenic mice with an Fmr1 knockout with that of normal littermates in hidden- and visible-platform water maze learning, and showed that knockouts exhibit subnormal spatial learning abilities and marginal motor performance deficits. During 12 training trials of the hidden-platform task, escape latency and path length decreased significantly in knockouts and control littermates, and no effect of genotype was found. During four ensuing reversal trials, however, significant differences were found between knockouts and control littermates both in escape latency and path length. During the visible-platform condition, the reversal trials also revealed a difference between knockouts and normal littermates in escape latency, but not in path length. Possibly due to marginal motor incapacity, knockouts swam significantly slower than controls during these latter trials. During both probe trials of the hidden-platform task, knockouts as well as normal littermates spent more time in the target quadrant than in the other quadrants, and percent of time spent in the target quadrant was the same in both groups; swimming velocity was not significantly different between knockouts and normal littermates during these trials. Entries in the target area during the probe trials did show a significant effect of genotype on number of entries. The present results largely confirm and extend our previous findings. Impaired spatial abilities in Fmr1 knockouts might have been due to relatively low response flexibility or high memory interference in Fmr1 knockouts. It remains unclear, however, which brain region or neurochemical system might be involved in these disabilities. We conclude that Fmr1 knockout mice might be a valid model of fragile X mental retardation.

Overexpression of actin in AcMNPV-infected cells interferes with polyhedrin synthesis and polyhedra formation

Autographa californica M nuclear polyhedrosis virus (AcMNPV) terminates host protein synthesis during the late stage of infection, at approximately 14 hr postinfection (hpi). If infection takes place in the presence of cytochalasin D (CD), however, host actin synthesis is transiently stimulated and continues to be synthesized until approximately 30 hpi, and the hyperexpression of polyhedrin is delayed from about 20 hpi until about 36 hpi (S. N. Talhouk and L. E. Volkman, Virology 182, 626-634, 1991; N. Wei and L. E. Volkman, Virology 191, 42-48, 1992). To investigate whether these events are causally related, i.e., whether actin synthesis negatively affects polyhedrin synthesis, we constructed recombinant viruses that expressed actin at various levels during infection. We found that the expression of actin by a strong promoter interfered with polyhedrin synthesis at a posttranscriptional level. It also interfered with polyhedra formation, which may suggest a mechanism for the observed paucity of polyhedra in infected midgut columnar epithelial cells in vivo.

Transgenic mouse model for the fragile X syndrome

Transgenic fragile X knockout mice have been constructed to provide an animal model to study the physiologic function of the fragile X gene (FMR1) and to gain more insight into the clinical phenotype caused by the absence of the fragile X protein. Initial experiments suggested that the knockout mice show macroorchidism and cognitive and behavioral deficits, abnormalities comparable to those of human fragile X patients. In the present study, we have extended our experiments, and conclude that the Fmr1 knockout mouse is a reliable transgenic model to study the fragile X syndrome.

Severe mental retardation and macroorchidism without mutation in the FMR1 gene

Only one missense mutation, an Ile304Asn, has been reported in the fragile X gene (FMR1). This mutation is located in the second KH domain of FMR1, and has led to the discovery of the function of the FMR1 gene product as an RNA-binding protein. The patient carrying this mutation has profound mental retardation, macroorchidism, and an "acromegalic" face with prominent supraorbital ridges, enlarged jaw, heavy brow ridges, thick lips, and a broad nose. We have studied the possible involvement of FMR1 in two maternal half-brothers with a phenotype similar to that of the patient with the Ile304Asn mutation. Both brothers had an identical number of CGG repeats in the normal size-range, and shared the same maternal Xq27 haplotype. Southern blot analysis with two overlapping FMR1 cDNA clones, spanning the total FMR1 open reading frame, showed no major deletions, insertions, or gross rearrangements. Single-strand conformation pattern (SSCP) analysis of the KH domains showed no aberrant patterns. The total open reading frame of the FMR1 gene was cloned and sequenced, but no mutation was found. Northern blot analysis showed mRNA in the normal size-range, and immunocytochemistry on individual lymphocytes indicated that FMRP, the protein product of FMR1, was present. In conclusion, it is unlikely that FMR1 plays a role in the phenotype of this patient. Other genes may be responsible for the combination of mental retardation and macroorchidism.

[Knowledge about asthma among Danish primary school teachers. Results of a questionnaire study]

An anonymous questionnaire inquiry performed among 324 school teachers in the Randers area with the purpose of elucidating teachers' knowledge about asthma is presented. To a series of statements about asthma, the teachers should answer yes, no or don't know. A limited knowledge about asthma in children was found. The knowledge about medicamental treatment was particularly limited. Only 57 per cent knew that wheezing after physical exertion is a strong indicator of asthma. Only five per cent had received proper instruction. This latter group had a significantly better knowledge of medical treatment (p < 0.0001-0.05). It is recommended that instruction in children's diseases, especially asthma should be reintroduced in teachers' training colleges.

Epileptic fits or infantile masturbation?

Two infants, one girl, 5 months old, and one boy, 6 months old, presented with rhythmic and sustained motor activities of a stereotyped nature accompanied by moaning and grunting, facial flushing and altered awareness. The episodes occurred frequently and were initially believed to be epileptic. Normal electroencephalograms during the fits, lack of response to antiepileptic medication given to one child and careful reviewing of videotape recordings, enabled us eventually to diagnose the 'seizure-like' episodes as masturbatory activity.

Cord blood IgE. II. Prediction of atopic disease. A follow-up at the age of 18 months

Screening of total IgE in 2814 cord blood samples was analysed by Phadebas IgE PRIST in 2 1-year birth cohorts (1983-1984 and 1985-1986) in Denmark (n = 1189 + 1625). For follow-up we chose all infants with cord blood IgE greater than or equal to 0.5 kU/l and a randomly chosen group of the same size with cord blood IgE less than 0.5 kU/l. A total of 762 infants were clinically evaluated at 18 months of age. A diagnosis of definite atopy, probable atopy or no atopy, including both IgE and non-IgE mediated disease was established. Applying different cord blood IgE cut-off values (0.3, 0.5, 0.8, 1.1) we did not find an excess of atopic infants among those with elevated cord blood IgE irrespective of the chosen cut-off value. Atopic predisposition or family history of atopic disease was defined as at least one parent or older sibling with atopic disease. Significantly more infants with a family history developed atopy at 18 months. In the 2 series the positive predictive values of cord blood IgE greater than or equal to 0.5 were 43% and 46% and the sensitivities were 17% and 15%. The predictive values of having a family history were 48% and 44% and the sensitivities were 55% and 58%.

Cord blood IgE. III. Prediction of IgE high-response and allergy. A follow-up at the age of 18 months

Screening of total IgE in 2814 cord blood samples was analysed by Phadebas IgE PRIST in 2 1-year birth cohorts (1983-1984 and 1985-1986) in Denmark (n = 1189 + 1625). For follow-up we chose all infants with cord blood IgE greater than or equal to 0.5 kU/l and a randomly chosen group of the same size with cord blood IgE less than 0.5 kU/l. A total group of 762 infants were clinically evaluated at 18 months of age, and in 688 of these we evaluated total and specific IgE. A diagnosis of definite atopy, probable atopy or no atopy was established. In the present study we defined allergic disease as atopic disease combined with elevated total IgE. We found a statistically significant correlation between cord blood IgE and IgE at 18 months of age. Significantly more infants with elevated cord blood IgE had developed allergic disease at 18 months. A cut-off value of 0.3 kU/l for cord blood IgE was superior to the originally suggested 0.5 kU/l. Significantly more infants with elevated cord blood IgE had developed specific IgE antibodies at 18 months. The most frequent specific IgE antibody was towards cow's milk. Specific IgE antibodies were very rarely found when total IgE was not elevated. A total IgE at the age of 18 months greater than 26 kU/l could be regarded as elevated. With regard to allergic disease the positive predictive values of cord blood IgE greater than or equal to 0.3 kU/l in the 2 series were 21% and the corresponding sensitivities 67% and 46%, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Cord blood IgE. I. IgE screening in 2814 newborn children

Screening of total IgE in 2814 cord blood samples was analysed by Phadebas IgE PRIST in 2 1-year birth cohorts (1983-1984 and 1985-1986) in Denmark (n = 1189 + 1625). 48.6% of the sera contained less IgE than the detection limit 0.1 kU/l. Cord blood IgE values greater than or equal to 0.5 kU/l were regarded as elevated. 13.2% of the sera contained at least 0.5 kU/l of IgE, with a significant preponderance in boys. Geometric mean cord blood IgE was 0.13 kU/l and 0.12 kU/l, respectively. Geometric mean cord blood IgE was significantly higher in boys. A significant seasonal variation with lowest IgE values in the autumn was found. No correlation between cord blood IgE and birth weight or gestational age was demonstrated. Only few newborns had cord blood IgA values greater than 0.014 g/l, calculated as geometric mean cord blood IgA + 2 SD among children with no detectable cord blood IgE, indicating infrequent contamination with maternal blood.

Danish primary schoolteachers' knowledge about asthma: results of a questionnaire

We present an anonymous questionnaire inquiry involving 334 primary schoolteachers in the Randers area with the purpose of elucidating teachers' knowledge about asthma. To a series of statements about asthma, the teachers answered yes, no or don't know. A limited knowledge of different aspects of asthma in children was found, although 57% had asthma children in their classes. Specially limited was knowledge about medical treatment. Five percent had received proper instruction about asthma and had a significantly better knowledge of medical treatment (p less than 0.001-0.05). Only 57% knew that wheezing after physical exertion is a strong indicator of asthma and only 33% knew that exertion in cold weather increases the risk of an attack. It is recommended that instruction in children's diseases, especially asthma, is introduced in teacher training colleges.

Neurologic manifestations of Schönlein-Henoch purpura

The presence of a possible cerebral involvement in Schönlein-Henoch Purpura was investigated in a prospective study comprising 26 children. A hampering headache accompanied by behavioural changes was present in 8 patients (31%). No cases of seizures, aphasia, ataxia, pareses or cerebral haemorrhage were found. EEG-abnormalities like slow wave foci, sharp waves, and paroxysms were demonstrated in 12 patients (46%) during the acute phase of the disease. The EEG-changes were transient but persisted in 4 patients during a follow-up period lasting one year. A significant association was found between the presence of headache and an abnormal EEG-tracing.

[Infection as the precipitating factor in Schönlein-Henoch purpura]

Shönlein-Henoch's purpura (SHP) is a form of generalized vasculitis. SHP is characterized by a haemorrhagic eruption, colicky abdominal pain, renal involvement with haematuria and proteinuria, arthralgia and cerebral symptoms in the form of headache and seizures. Retrospective investigations have revealed that infection with microorganisms may precipitate SHP. The authors were able to support this observation by means of a prospective investigation. 2/3 of the 26 children in the investigation had symptoms of infection one to two weeks prior to the onset of symptoms of SHP. Ten children had definite positive signs of prior infection. The course of the sedimentation rate and leukocyte counts also support the assumption of previous infection.

[Spontaneous perforation of the biliary tract during the neonatal period]

Spontaneous perforation of the biliary passages is a rare condition during the first months of life. The course of the condition may be acute or more chronic. The symptoms are jaundice, clay-coloured stools, dark urine, distended abdomen, regurgitation and failure to thrive. The diagnosis can be established by scanning of the abdomen and 99mTc-HIDA-scintigraphy of the biliary passages. The perforation is usually found to be localized to the transition between the cystic duct and the common hepatic duct and is probably due to a localized development defect in the biliary passages. Operation is always required. The prognosis is good and the infants do well after operation.

[Intervertebral discitis in children]

Intervertebral discitis in children is a benign inflammatory condition with a varied clinical picture and quite characteristic radiographic findings. The etiology is still unknown and infectious and traumatic geneses have been discussed. A case in a girl aged three years is described and treatment with antibiotics and immobilisation are discussed.

Lack of association between HLA and Schoenlein-Henoch Purpura

The occurrence of HLA-A, -B, and -C antigens was investigated in an unselected group of 26 consecutively admitted patients with Schoenlein-Henoch Purpura. No significant associations were demonstrated.

Diagnostic value of a glass fibre-based histamine analysis for allergy testing in children

The aim of this study was to compare the diagnostic value of common allergy tests with basophil histamine release in 124 children with symptoms of asthma. The patients were evaluated by case history, skin prick test, RAST-analysis, and basophil histamine release using a glass fibre-based histamine assay to 10 common inhalant allergens. The bronchial provocation test was used as a reference of "true" IgE-mediated asthma. To compare the various diagnostic parameters each absolute test value was classified into a scoring system. The concordance between the tests varied between 85-97%. In general, the best concordance was found between basophil histamine release and RAST. Sensitivity, specificity and predictive values were calculated on the basis of 104 bronchial provocation tests. It was found that histamine release was the best single analysis, followed by RAST and prick testing. The sensitivity of RAST and histamine release was very high (1.00) for pollen and house dust mites. Histamine release showed a predictive value between 0.91 and 1.00 for pollen and house dust mites, thus indicating the possibility of omitting the bronchial provocation test. In the dander group histamine release gave the best sensitivity (0.91), however at the expense of specificity (0.64), whereas RAST and skin prick test gave a specificity of 1.00. In the mould group histamine release also showed the best diagnostic value. The combination of skin testing with histamine release or RAST was of no additional diagnostic help. It is concluded that the glass fibre-based histamine analysis, which makes routine histamine release testing possible, is a reliable diagnostic test in children.