Prostate biopsy sepsis prevention: external validation of an alcohol needle washing protocol.

PURPOSE: Transrectal ultrasound-guided prostate biopsy (TRUS-Bx) is associated with a 1-8% risk of post-biopsy sepsis (PBS). A recent study described an isopropyl alcohol needle washing protocol that significantly decreased PBS rates. The current study examined the efficacy of this technique in our clinic population. MATERIALS AND METHODS: Data were reviewed for 1250 consecutive patients undergoing TRUS-Bx at the Charlie Norwood VA Medical Center from January 2017 to January 2023. Needle washing was adopted in February 2021. Complications occurring within 30 days after TRUS-Bx were recorded. RESULTS: There were 912 patients in group 1 (without needle washing) and 338 in group 2 (with needle washing). Groups had equivalent demographic features, and men of African descent comprised 70% of patients. Standard 12 core biopsies were done in 83% and 82% in groups 1 and 2, respectively (p = 0.788). Total complication rates were 4% and 2% in groups 1 and 2, respectively (p = 0.077). There were 13 sepsis events in group 1 (1.4%) and none in group 2 (p = 0.027). Clavien-Dindo Grade I-III complications occurred in 25 (2.7%) and 7 (2.1%) patients in groups 1 and 2, respectively (p = 0.505). Standard antibiotic prophylaxis (PO fluoroquinolone and IM gentamicin) was given in 80% and 86% of patients in groups 1 and 2, respectively (p = 0.030). Subset analysis limited to patients who received standard prophylaxis showed a significant difference in sepsis rates (1.5% vs 0%; p = 0.036). CONCLUSIONS: Adoption of isopropyl alcohol needle washing was associated with a significant decrease in PBS events.

Efficiency evaluation of a SARS-CoV-2 diagnostic strategy combining high throughput quantitative antigen immunoassay and real time PCR.

OBJECTIVES: Laboratory testing for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has played an important role in the effort to prevent and contain local outbreaks. The aim of this study was to assess the diagnostic accuracy of a new fully automated SARS-CoV-2 laboratory-based antigen assay (CoV2Ag) and to explore the efficiency of a diagnostic algorithm combining antigen and conventional high-throughput molecular assays to address potential future challenges of the SARS-CoV-2 pandemic. METHODS: One thousand two hundred and twenty four consecutive nasopharyngeal swabs were tested using RT-PCR and CoV2Ag assay. RESULTS: The overall sensitivity and specificity of CoV2Ag were 79.1 and 97.8%, respectively. When the analysis was restricted to cases with Ct values ≤30, the sensitivity of the assay improved to 98.1%. Acceptable sensitivity was found when the analysis was limited to patients presenting within one or two to four days of symptom onset (80.5 and 84.8%, respectively). A retrospective analysis of the use of a two-step diagnostic approach combining the CoV2Ag assay and RT-PCR during an acute pandemic phase of 97 days showed a potential reduction in the number of RT-PCR tests by 36.1%, corresponding to savings in reagent costs and technician workload of approximately €8,000 and 10.5 h per day, respectively. CONCLUSIONS: Our data show that the proposed algorithm represents a valid alternative diagnostic approach to increase testing efficiency during future pandemic phases with high positivity rates (>20%) and elevated numbers of RT-PCR test requests.

Suspension of Oncology Randomized Clinical Trials during the COVID-19 Pandemic: A Cross-Sectional Evaluation of COVID-Related Suspensions.

We conducted a cross-sectional analysis of ClinicalTrials.gov-registered oncology randomized controlled trials between September 2019 and December 2021 to identify predictors of trial suspensions. The dataset included 1,183 oncology trials, of which 384 (32.5%) were suspended. COVID-19 accounted for 47 (12.2%) suspensions. Trials that were single center- or US-based had higher odds of COVID-19 (ORs: 3.85 and 2.48, 95% CIs: 1.60-11.50 and 1.28-4.93, respectively) or any-reason suspensions (ORs: 2.33 and 2.04, 95% CIs: 1.46-3.45 and 1.40-2.76, respectively). Phase two (OR 1.27), three (OR 6.45) and four trials (OR 11.5) had increased odds of COVID-19 suspensions, compared to phase one trials.

Transparency of racial participation reporting in randomized controlled trials of minimally invasive surgical techniques.

BACKGROUND: Enrolment of racial/ethnic minorities in randomized controlled trials (RCTs) has historically been poor, despite efforts at improving access to RCTs. Under-representation of racial/ethnic minorities limits the external validity and generalizability of trials. Our objective was to determine to what extent are published RCTs of minimally invasive surgical techniques reporting the racial composition of their study cohorts and to describe the racial composition of patients enrolled in these trials, where data were available. METHODS: EMBASE (OvidSP®), MEDLINE (OvidSP®), and Cochrane (Wiley®) databases were systematically searched from inception to December 22, 2017 to identify all RCTs comparing minimally invasive and classical surgical techniques. The Mann-Kendall trend test was used to evaluate reporting trends over the study period. Predictors of racial reporting were evaluated using logistic regression analyses. RESULTS: Our search strategy yielded 9,321 references of which 496 RCTs met our inclusion/exclusion criteria. Racial information was reported in 20 (4.03%) studies. There was no significant improvement in racial reporting over the study period (p for trend = 0.31). Of the 17 different patient populations accounting for the 20 RCTs, 14 (82.4%) originated from the USA. Multicenter RCTs had significantly increased likelihood of reporting racial composition of the patient cohort (odds ratio 5.10, p = 0.025). White/Caucasian patients accounted for 84.5% of the pooled patient population, with Black/African American, Asian and Latin/Hispanic patients accounting for 7.9%, 1.2%, and 2.1%, respectively. CONCLUSIONS: Among RCTs assessing minimally invasive surgical techniques over the past 30 years, data on included patients' race is poorly reported. In addition to important efforts to improve access to clinical trials for racial and ethnic minorities, efforts aimed at improving reporting and transparency of surgical RCTs are sorely needed.

Objective gustatory and olfactory dysfunction in COVID-19 patients: a prospective cross-sectional study.

PURPOSE: To determine the prevalence of objective gustatory (GD) and olfactory (OD) dysfunction in COVID-19 patients. METHODS: This is a prospective, cross-sectional study of 51 COVID-19 positive patients diagnosed using RT-PCR-based testing. Of these study participants, 41 reported having present GD and OD at the time of enrollment and ten patients were without symptomatic OD and GD. All participants were objectively tested for OD by Brief Smell Identification Test (BSIT) and for GD by Burghart taste strip test, which were mailed to the participants. The subjective presence and severity of COVID-19 symptoms of smell loss, loss of taste, nasal obstruction, rhinorrhea/mucus production, fever, cough and shortness of breath were also assessed. RESULTS: Of the 41 patients with GD and OD, only 25.6% (10/39; p ≤ 0.0001) objectively presented GD and 39.1% (16/41; p ≤ 0.0001) OD at the time of their subjective dysfunction. Regarding GD, 23.1% (9/39) suffered from total hypogeusia, 2.6% (1/39) from ageusia. A significant loss of sour (33.3% (13/39)) and salty taste (17.9% (7/39)) could be recognized. Only 10.3% (4/39) showed a reduction in sweet and bitter taste. Concerning OD, 9.8% (4/41) showed a deficit relative to younger age in the BSIT and 29.3% (12/41) results abnormal relative to age. CONCLUSION: Subjective and objective findings in GD and OD differ significantly. Most patients suffering from objective dysgeusia present a deficit in sour and salty taste. TRIAL REGISTRATION NUMBER: DRKS00021516; 22/04/2020.

The cysteine S-H stretching mode reports on long-range conformational changes in pyruvate oxidase from E. coli.

The pyruvate oxidases from Escherichia coli (EcPOX) and Lactobacillus plantarum (LpPOX) are both thiamin-dependent flavoenzymes. Their sequence and structure are closely related, and they catalyse similar reactions-but they differ in their activity pattern: LpPOX is always highly active, EcPOX only when activated by lipids or limited proteolysis, both involving the protein's C-terminal 23 residues (the 'α-peptide'). Here, we relate the redox-induced infrared (IR) difference spectrum of EcPOX to its unusual activation mechanism. The IR difference spectrum of EcPOX is marked by contributions from the protein backbone, reflecting major conformational changes. A rare sulfhydryl (-SH) difference signal indicates changes in the vicinity of cysteines. We could pin the Cys-SH difference signal to Cys88 and Cys494, both being remote from the moving α-peptide and the redox-active flavin cofactor. Yet, when the α-peptide is proteolytically removed, the Cys-SH difference signal disappears, together with several difference signals in the amide range. The remaining IR signature of the permanently activated EcPOXΔ23 is strikingly similar to the simpler signature of LpPOX. The loss of the α-peptide 'transforms' the catalytically complex EcPOX into the catalytically 'simpler' LpPOX.

A rare case of emphysematous cystitis due to Candida glabrata.

Emphysematous cystitis (EC) is a rare condition characterized by gas within the bladder wall or lumen. EC is most commonly seen in elderly women with poorly controlled diabetes mellitus (DM). Escherichia coli and Klebsiella pneumoniae are most commonly implicated. We present a 68-year-old woman with poorly controlled DM who presented with altered mental state with growth of Candida glabrata in urine and blood cultures. CT abdomen and pelvis revealed air in the bladder lumen and the extraperitoneal space. Bladder rupture was suspected and bladder decompression was managed conservatively with a foley catheter.

Pudendal nerve block prior to inflatable penile prosthesis implantation: decreased intra-operative narcotic requirements.

The opioid epidemic has proven to be a public health crisis over the past two decades and efforts to decrease opioid exposure are sorely needed. Our objective was to determine whether pudendal nerve block utilization in the immediate pre-operative setting decreases intra-operative opioid analgesic requirements in veteran patients undergoing a primary inflatable penile prosthesis implantation. We performed a retrospective cohort analysis of all patients undergoing penile prosthesis implantation between January 2017 and July 2020 at the Charlie Norwood Veterans Affairs Medical Center in Augusta, GA. Univariable and multivariable gamma regression analyses were performed to evaluate the association between pudendal nerve block utilization and intra-operative opioid analgesic requirements. The study cohort consisted of 110 patients, 35 (31.8%) of whom underwent a pudendal nerve block. Median intra-operative opioid analgesic requirements were significantly lower in the pudendal nerve block group (16.3 versus 25.8 morphine milliequivalents, p = 0.037). Receipt of the nerve block was associated with significantly lower intra-operative opioid analgesic requirements on multivariable (coefficient 0.84, p = 0.038) regression analysis. There was no significant difference in post-operative opioid analgesic requirements (p = 0.18). In conclusion, pre-operative pudendal nerve blocks decrease intra-operative opioid analgesic requirements in veteran patients undergoing a primary inflatable penile prosthesis implantation.

The Role of Alumni Networks and Career Advising in Early Career Stability of Urologists: Results of a Multi-institutional Study.

OBJECTIVE: To characterize training program and early career factors that impact decision-making and job retention following graduation in a diverse population of urologists. MATERIALS AND METHODS: We performed a computer-based survey distributed to residency graduates from 25 urology training programs. Five focus institutions were identified with a goal >30% response rate. The survey included questions about training program specifics and post-training employment characteristics. RESULTS: We obtained 180 responses from urology residency graduates of 25 programs. Overall, 72% (N = 129) remain in their initial post-training position at a median of 6years postgraduation (Interquartile Range (IQR) 3-10). On Cox-regression analysis stronger trainee-rated formal career advising was associated with lower risk of changing jobs (HR 0.77, 0.60-0.99, P = .048). Location/proximity to family was the most consistently cited as the top reason for selecting a job (41%). Sixty-three respondents (35%) joined practices employing graduates of the same residency program. Cox regression analysis showed that joining a practice with alumni of the same program was associated with lower risk of changing jobs from one's initial post-training position (HR 0.39, 95% CI 0.17-0.91, P = .03). CONCLUSION: In this multi-institutional study of urologists, we observed a high rate of job retention out to a median of 6years following completion of training, with formal career advising and joining alumni in practice being associated with job retention. Collectively, our data highlights that training programs should emphasize advising programs and alumni networking in guiding their graduates in the job search process.

Quality of MALDI-TOF mass spectra in routine diagnostics: results from an international external quality assessment including 36 laboratories from 12 countries using 47 challenging bacterial strains.

OBJECTIVES: Matrix assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry (MS) is a widely used method for bacterial species identification. Incomplete databases and mass spectral quality (MSQ) still represent major challenges. Important proxies for MSQ are the number of detected marker masses, reproducibility, and measurement precision. We aimed to assess MSQs across diagnostic laboratories and the potential of simple workflow adaptations to improve it. METHODS: For baseline MSQ assessment, 47 diverse bacterial strains, which are challenging to identify by MALDI-TOF MS, were routinely measured in 36 laboratories from 12 countries, and well-defined MSQ features were used. After an intervention consisting of detailed reported feedback and instructions on how to acquire MALDI-TOF mass spectra, measurements were repeated and MSQs were compared. RESULTS: At baseline, we observed heterogeneous MSQ between the devices, considering the median number of marker masses detected (range = [2-25]), reproducibility between technical replicates (range = [55%-86%]), and measurement error (range = [147 parts per million (ppm)-588 ppm]). As a general trend, the spectral quality was improved after the intervention for devices, which yielded low MSQs in the baseline assessment as follows: for four out of five devices with a high measurement error, the measurement precision was improved (p-values <0.001, paired Wilcoxon test); for six out of ten devices, which detected a low number of marker masses, the number of detected marker masses increased (p-values <0.001, paired Wilcoxon test). DISCUSSION: We have identified simple workflow adaptations, which, to some extent, improve MSQ of poorly performing devices and should be considered by laboratories yielding a low MSQ. Improving MALDI-TOF MSQ in routine diagnostics is essential for increasing the resolution of bacterial identification by MALDI-TOF MS, which is dependent on the reproducible detection of marker masses. The heterogeneity identified in this external quality assessment (EQA) requires further study.

Bottlenecks and the maintenance of minor genotypes during the life cycle of Trypanosoma brucei.

African trypanosomes are digenetic parasites that undergo part of their developmental cycle in mammals and part in tsetse flies. We established a novel technique to monitor the population dynamics of Trypanosoma brucei throughout its life cycle while minimising the confounding factors of strain differences or variation in fitness. Clones derived from a single trypanosome were tagged with short synthetic DNA sequences in a non-transcribed region of the genome. Infections were initiated with mixtures of tagged parasites and a combination of polymerase chain reaction and deep sequencing were used to monitor the composition of populations throughout the life cycle. This revealed that a minimum of several hundred parasites survived transmission from a tsetse fly to a mouse, or vice versa, and contributed to the infection in the new host. In contrast, the parasites experienced a pronounced bottleneck during differentiation and migration from the midgut to the salivary glands of tsetse. In two cases a single tag accounted for > or =99% of the population in the glands, although minor tags could be also detected. Minor tags were transmitted to mice together with the dominant tag(s), persisted during a chronic infection, and survived transmission to a new insect host. An important outcome of the bottleneck within the tsetse is that rare variants can be amplified in individual flies and disseminated by them. This is compatible with the epidemic population structure of T. brucei, in which clonal expansion of a few genotypes in a region occurs against a background of frequent recombination between strains.

SARS-CoV-2 mRNA Vaccination in People with Multiple Sclerosis Treated with Fingolimod: Protective Humoral Immune Responses May Develop after the Preferred Third Shot.

Evidence suggests limited development of protective IgG responses to mRNA-based vaccines in sphingosine-1-phosphate receptor (S1PR)-modulator treated individuals with multiple sclerosis (MS). We studied the extent of the humoral immune response after the preferred third mRNA SARS-CoV-2 vaccine in S1PR-modulator treated people with MS (pwMS) and insufficient IgG responses after the standard immunization scheme. Eight pwMS that were treated with fingolimod received a third homologous SARS-CoV-2 mRNA vaccine dose, either the Moderna's mRNA-1273 or Pfizer-BioNTech's BNT162b2 vaccine. We quantified the serum levels of IgG antibodies against the receptor-binding domain of SARS-CoV-2 four weeks later. An antibody titer of 100 AU/mL or more was considered protective. After the third vaccination, we found clinically relevant IgG titers in four out of eight individuals (50%). We conclude that the humoral immune response may reach protective levels after the third preferred dose of the homologous SARS-CoV-2 mRNA vaccine. Vaccine shots in S1PR-modulator treated pwMS ahead of schedule may be a strategy to overcome insufficient humoral immune responses following the standard vaccination scheme.

Direct antimicrobial resistance prediction from clinical MALDI-TOF mass spectra using machine learning.

Early use of effective antimicrobial treatments is critical for the outcome of infections and the prevention of treatment resistance. Antimicrobial resistance testing enables the selection of optimal antibiotic treatments, but current culture-based techniques can take up to 72 hours to generate results. We have developed a novel machine learning approach to predict antimicrobial resistance directly from matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) mass spectra profiles of clinical isolates. We trained calibrated classifiers on a newly created publicly available database of mass spectra profiles from the clinically most relevant isolates with linked antimicrobial susceptibility phenotypes. This dataset combines more than 300,000 mass spectra with more than 750,000 antimicrobial resistance phenotypes from four medical institutions. Validation on a panel of clinically important pathogens, including Staphylococcus aureus, Escherichia coli and Klebsiella pneumoniae, resulting in areas under the receiver operating characteristic curve of 0.80, 0.74 and 0.74, respectively, demonstrated the potential of using machine learning to substantially accelerate antimicrobial resistance determination and change of clinical management. Furthermore, a retrospective clinical case study of 63 patients found that implementing this approach would have changed the clinical treatment in nine cases, which would have been beneficial in eight cases (89%). MALDI-TOF mass spectra-based machine learning may thus be an important new tool for treatment optimization and antibiotic stewardship.

Humoral Immune Response after the Third SARS-CoV-2 mRNA Vaccination in CD20 Depleted People with Multiple Sclerosis.

CD20 depletion is a risk factor for unfavorable outcomes of COVID-19 in people with MS (pwMS). Evidence suggests that protective IgG response to mRNA-based vaccines in B cell-depleted individuals is limited. We studied the seroconversion after the third mRNA SARS-CoV-2 vaccine in B cell-depleted pwMS with limited or no IgG response after the standard immunization. Sixteen pwMS treated with ocrelizumab or rituximab received a third homologous SARS-CoV-2 mRNA vaccine, either the Moderna mRNA-1273 or Pfizer-BioNTech's BNT162b2 vaccine. We quantified the response of IgG antibodies against the spike receptor-binding domain of SARS-CoV-2 four weeks later. An antibody titer of 100 AU/mL or more was considered clinically relevant. The median time between the last infusion of the anti-CD20 treatment and the third vaccination was 22.9 weeks (range 15.1-31.3). After the third vaccination, one out of 16 patients showed an IgG titer deemed clinically relevant. Only the seroconverted patient had measurable B-cell counts at the time of the third vaccination. The development of a humoral immune response remains rare in pwMS on anti-CD20 therapy, even after third dose of the homologous SARS-CoV-2 mRNA vaccine. It remains to be determined whether T-cell responses can compensate for the lack of seroconversion and provide sufficient protection against CoV-2 infections.

Olfactory Dysfunction and Sinonasal Symptomatology in COVID-19: Prevalence, Severity, Timing, and Associated Characteristics.

OBJECTIVE: Olfactory dysfunction (OD)-hyposmia or anosmia-is a symptom of coronavirus disease 2019 (COVID-19), caused by the novel coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We sought to better determine prevalence, severity, and timing of OD in COVID-19 relative to other sinonasal and pulmonary symptoms. STUDY DESIGN: Prospective, cross-sectional. SETTING: Regional/cantonal hospital. SUBJECTS: In total, 103 patients diagnosed with COVID-19 with reverse transcription polymerase chain reaction (RT-PCR)-based testing. METHODS: All patients testing positive for COVID-19 at Kantonsspital Aarau over a 6-week period were approached. Timing and severity (at its worst, on scale of 0 [none], 1 [mild], 2 [moderate], and 3 [severe]) of OD, loss of taste, nasal obstruction, rhinorrhea/mucus production, fever, cough and shortness of breath (SOB) were assessed for each patient. RESULTS: Prevalence of OD was 61.2%, and severity of OD was strongly correlated with severity of loss of taste experienced (ρ = 0.87, P < .001). OD was experienced on the first day of COVID-19 by 8.7% and overall occurred at median infection day 3 (mean, 3.4; range, 0-12). Most experiencing OD reported anosmia, and mean severity of all with OD was moderate to severe (mean [SD], 2.7 [0.6]). Nasal obstruction (49.5%) and rhinorrhea (35.0%) were frequently reported but not correlated with OD. SOB was more severe in patients with OD. OD was associated negatively with older age (OR, 0.96; 95% CI, 0.93-0.99; P = .007) and positively with female sex (OR, 2.46; 95% CI, 0.98-6.19; P = .056). CONCLUSIONS: OD is highly prevalent during COVID-19, occurring early and severely, often in conjunction with loss of taste. OD is associated negatively with older age and positively with female sex. Patients with OD may also experience more severe SOB.

Mood, Anxiety and Olfactory Dysfunction in COVID-19: Evidence of Central Nervous System Involvement?

OBJECTIVE: The objective of this study was to determine the burden of depressed mood and anxiety in COVID-19, and associated disease characteristics. MATERIALS AND METHODS: This is a prospective, cross-sectional study of 114 COVID-19 positive patients diagnosed using RT-PCR-based testing over a 6-week period. The two-item Patient Health Questionnaire (PHQ-2) and the two-item Generalized Anxiety Disorder questionnaire (GAD-2) were used to measure depressed mood and anxiety level, respectively, at enrollment and for participants' baseline, pre-COVID-19 state. Severity of smell loss, loss of taste, nasal obstruction, rhinorrhea/mucus production, fever, cough, and shortness of breath (SOB) during COVID-19 were assessed. RESULTS: PHQ-2 and GAD-2 significantly (P < .001) increased from baseline to enrollment. PHQ-2 was associated with smell loss (adjusted incidence rate ratio [aIRR] = 1.40, 95% CI, 1.10-1.78, P = .006), age (aIRR = 1.02, 95% CI, 1.01-1.04, P = .006), and baseline PHQ-2 score (aIRR = 1.39, 95% CI, 1.09-1.76, P = .007). GAD-2 score was associated with smell loss (aIRR = 1.29, 95% CI, 1.02-1.62, P = .035), age (aIRR = 1.02, 95% CI, 1.01-1.04, P = .025) and baseline GAD-2 score (aIRR = 1.55, 95% CI, 1.24-1.93, P < .001). Loss of taste also exhibited similar associations with PHQ-2 and GAD-2. PHQ-2 and GAD-2 scores were not associated with severities of any other symptoms during the COVID-19 course. CONCLUSIONS: Despite the occurrence of symptoms-such as SOB-associated with severe manifestations of COVID-19, only the severities of smell and taste loss were associated with depressed mood and anxiety. These results may raise the novel possibility of emotional disturbance as a CNS manifestation of COVID-19 given trans-olfactory tract penetration of the central nervous system (CNS) by coronaviruses. LEVEL OF EVIDENCE: 3 Laryngoscope, 130:2520-2525, 2020.

Use of the Fractional Excretion of Urea in an Azotemic Nonoliguric State: Type 1 Cardiorenal Syndrome.

The fractional excretion of urea is a useful tool to evaluate renal function in oliguric states; however, it remains unexplored in nonoliguric states. We evaluated its use to predict responses in patients with type 1 cardiorenal syndrome. This was a prospective observational study of 116 patients with type 1 cardiorenal syndrome referred over a 4-year period. Fractional excretion of urea and sodium, ejection fraction, mean arterial pressure, age, sex, diabetes, brain natriuretic peptide (BNP), serum sodium and blood urea nitrogen were analyzed for effects upon serum creatinine and survival. Improvement of renal function correlated most significantly with FeUrea (P = 0.00001) followed by the FeNa (P = 0.005) but no other variable studied reached significance. Survival was best predicted by improvement of the serum creatinine at 24 h (P = 0.005) and 7 days after all inotropes were stopped (P = 0.001). A limitation of this study is that it cannot be extrapolated to all cardiorenal syndrome patients other than type 1. Also, the study was not randomized and those with potentially worse disease have had worse outcomes due merely to worse underlying disease. The success of the FeUrea may possibly be related to interference of dobutamine on creatinine levels. Despite being a nonoliguric state, the FeUrea appears to provide insight to those patients with type 1 cardiorenal syndrome whose renal function (as measured by serum creatinine) and survival might improve.

Isolation and propagation of Trypanosoma brucei gambiense from sleeping sickness patients in south Sudan.

This study aimed at isolating Trypanosoma brucei gambiense from human African trypanosomiasis (HAT) patients from south Sudan. Fifty HAT patients identified during active screening surveys were recruited, most of whom (49/50) were in second-stage disease. Blood and cerebrospinal fluid samples collected from the patients were cryopreserved using Triladyl as the cryomedium. The samples were stored at -150 degrees C in liquid nitrogen vapour in a dry shipper. Eighteen patient stabilates could be propagated in immunosuppressed Mastomys natalensis and/or SCID mice. Parasitaemia was highest in SCID mice. Further subpassages in M. natalensis increased the virulence of the trypanosomes and all 18 isolates recovered from M. natalensis or SCID mice became infective to other immunosuppressed mouse breeds. A comparison of immunosuppressed M. natalensis and Swiss White, C57/BL and BALB/c mice demonstrated that all rodent breeds were susceptible after the second subpassage and developed a parasitaemia >10(6)/ml by Day 5 post infection. The highest parasitaemias were achieved in C57/BL and BALB/c mice. These results indicate that propagation of T. b. gambiense isolates after initial isolation in immunosuppressed M. natalensis or SCID mice can be done in a range of immunosuppressed rodents.

An attempt to model the human body as a communication channel.

Using the human body as a transmission medium for electrical signals offers novel data communication in biomedical monitoring systems. In this paper, galvanic coupling is presented as a promising approach for wireless intra-body communication between on-body sensors. The human body is characterized as a transmission medium for electrical current by means of numerical simulations and measurements. Properties of dedicated tissue layers and geometrical body variations are investigated, and different electrodes are compared. The new intra-body communication technology has shown its feasibility in clinical trials. Excellent transmission was achieved between locations on the thorax with a typical signal-to-noise ratio (SNR) of 20 dB while the attenuation increased along the extremities.