Canadian Kidney Transplant Professionals' Perspectives on Precision Medicine and Molecular Matching in Kidney Allocation

Background

Antibody-mediated rejection is an important cause of kidney transplant loss. A new strategy requiring application of precision medicine tools in transplantation considers molecular compatibility between donors and recipients and holds the promise of improved immunologic risk, preventing rejection and premature graft loss. The objective of this study was to gather Canadian transplant professionals' perspectives on molecular compatibility in kidney transplantation.

Methods

Seventeen Canadian transplant professionals (14 nephrologists, 2 nurses, and 1 surgeon) participated in semistructured interviews in 2021. The interviews were digitally recorded, transcribed, and analyzed using the qualitative description approach.

Results

Participants identified fair access to transplantation as the most important principle in kidney allocation. Molecular compatibility was viewed as a promising innovation. However, participants were concerned about increased waiting times, negative impact on some patients, and potential problems related to the adequacy of information explaining this new technology. To mitigate the challenges associated with molecular matching, participants suggested integrating a maximum waiting time for molecular-matched kidneys and expanding the program nationally/internationally.

Conclusions

Molecular matching in kidney transplantation is viewed as a promising technology for decreasing the incidence of antibody-mediated rejection and improving graft survival. Further studies are needed to determine how to ethically integrate this technology into the kidney allocation algorithm.

Lived Experiences of Hemodialysis Health Care Workers during the COVID-19 Pandemic: A Qualitative Study from the Quebec Renal Network

Key Points

Hemodialysis workers' well-being and work were affected by the COVID-19 pandemics. Effective communication strategies and taking into account psychological distress are ways to mitigate the challenges faced by health care workers.

Background

The COVID-19 pandemic has disrupted health systems and created numerous challenges in hospitals worldwide for patients and health care workers (HCWs). Hemodialysis centers are at risk of COVID-19 outbreaks given the difficulty of maintaining social distancing and the fact that hemodialysis patients are at higher risk of being infected with COVID-19. During the COVID-19 pandemic, HCWs have had to face many challenges and stressors. Our study was designed to gain HCWs' perspectives on their experiences of the impacts of the COVID-19 pandemic in hemodialysis units.

Methods

Semistructured interviews were conducted with 22 HCWs (nurses, nephrologists, pharmacists, social workers, patient attendants, and security agents) working in five hemodialysis centers in Montreal, between November 2020 and May 2021. The content of the interviews was analyzed using thematic analysis.

Results

Four themes were identified during the interviews. The first was the impact of COVID-19 on work organization, regarding which participants reported an increased workload, a need for a consistent information strategy, and positive innovations such as telemedicine. The second theme was challenges associated with communicating and caring for dialysis patients during the pandemic. The third theme was psychological distress experienced by hemodialysis staff and the psychosocial impact of COVID-19 on their personal lives. The fourth theme was recommendations made by participants for future public health emergencies, such as maintaining public health measures, ensuring an adequate supply of protective equipment, and developing a consistent communication strategy.

Conclusions

During the first and second waves of the COVID-19 pandemic, HCWs working in hemodialysis units faced multiple challenges that affected their well-being and their work. To minimize challenges for HCWs in hemodialysis during a future pandemic, the health care system should provide an adequate supply of protective equipment, develop effective communication strategies, and take into account the psychological distress related to HCWs' professional and personal lives.

Lived Experiences of Patients Receiving Hemodialysis during the COVID-19 Pandemic: A Qualitative Study from the Quebec Renal Network

Background

Hemodialysis patients have faced unique challenges during the COVID-19 pandemic. They face high risk of death if infected and have unavoidable exposure to others when they come to hospital three times weekly for their life-saving treatments. The objective of this study was to gain a better understanding of the scope and magnitude of the effects of the pandemic on the lived experience of patients receiving in-center hemodialysis.

Methods

We conducted semi-structured interviews with 22 patients who were undergoing dialysis treatments in five hemodialysis centers in Montreal from November 2020 to May 2021. Interviews were transcribed and then analyzed using thematic content analysis.

Results

Most participants reported no negative effects of the COVID-19 pandemic on their hemodialysis care. Several patients had negative feelings related to forced changes in their dialysis schedules, and this was especially pronounced for indigenous patients in a shared living situation. Some patients were concerned about contracting COVID-19, especially during public transportation, whereas others expressed confidence that the physical distancing and screening measures implemented at the hospital would protect them and their loved ones. Some participants reported that masks negatively affected their interactions with health care workers, and for many others, the pandemic was associated with feelings of loneliness. Finally, some respondents reported some positive effects of the pandemic, including use of telemedicine and creating a sense of solidarity.

Conclusions

Patients undergoing hemodialysis reported no negative effects on their medical care but faced significant disruptions in their routines and social interactions due to the COVID-19 pandemic. Nevertheless, they showed great resilience in their ability to adapt to the new reality of their hemodialysis treatments. We also show that studies focused on understanding the lived experiences of indigenous patients and patients from different ethnic backgrounds are needed in order reduce inequities in care during public health emergencies.

Kidney transplant candidates' and recipients' perspectives on the decision-making process to accept or refuse a deceased donor kidney offer: Trust and graft survival matter

BACKGROUND

The decision to accept a kidney from a deceased donor can be a difficult one. This study aims to capture the perspectives of transplant candidates (TCs) and kidney transplant recipients (KTRs) on the decision-making process when a deceased kidney is offered.

METHODS

We conducted six focus groups with KTRs and TCs. The content of the focus groups was analyzed using the qualitative thematic method.

RESULTS

KTRs reported that the experience of being offered a kidney could be difficult because of the circumstances of the offer and unpreparedness to participate in the discussion. Both KTRs and TCs trusted the medical expertise. Age and having experience with dialysis could influence the decision to accept an offer. In order to engage in the discussion, patients wanted to obtain estimates of expected graft survival. Patients did not express interest for a web-based calculator for patient use, but expected transplant physicians to summarize and explain the information that would impact graft survival time.

CONCLUSION

TCs and KTRs wanted to be involved in the decision to accept a deceased donor kidney. Tools that can help physicians communicate the risks and benefits of accepting an offer could improve patient participation in the decision-making process.

Perspectives of Kidney Transplant Recipients, Transplant Candidates, and Living Kidney Donors on the Role of Patients’ Self-Narratives and Experiences of Creative Writing Workshops: A Qualitative Study

Background:

Kidney transplantation is the best treatment for kidney failure but is associated with medical, psychological, and existential challenges for patients. Patients’ experiential knowledge can help other patients facing these challenges. Patients’ self-narratives and creative writings are ways to operationalize this experiential knowledge. Creative writing has been described as a therapeutic tool for patients with chronic disease. Over the past year, we conducted creative writing workshops with kidney transplant recipients (KTRs), living kidney donors (LKDs), kidney transplant candidates (KTCs), and professional writers. During these workshops, patients were invited to explore different aspects of their experiences of their transplant or donation journey through narrative-writing, poetry, comic art, and screenwriting.

Objective:

The objectives of this study were to gather the perspectives of KTRs, KTCs, and LKDs on the role of patients’ self-narratives and creative writing, and to collect patients’ experiences of the creative writing workshops.

Design:

Focus groups and individual interviews.

Setting:

The Center hospitalier de l’Université de Montréal (CHUM) kidney transplant program.

Participants:

KTRs, LKDs, and KTCs attending the CHUM kidney transplant clinic between February 2020 and January 2021.

Methods:

We conducted 2 focus groups and 8 semi-structured individual interviews with 7 KTRs, 8 LKDs, and 5 KTCs from the CHUM between June and November 2020, before the creative writing workshops. We also conducted 10 semi-structured interviews with 5 KTRs, 1 KTC, and 4 LKDs in March 2021, after their participation in the creative writing workshops. The interviews were recorded and transcribed. Thematic and content analyses were conducted.

Results:

KTRs, LKDs, and KTCs had multiple significant moments to share from their transplant/donation journey. These moments were highly emotional and marked by uncertainty. The creative writing workshops were described as therapeutic by participants, because they offered a safe space for group-facilitated reflection, including a discovery and learning process, and normalization, relativization, and appreciation of the transplant/donation experience. The creative writing workshops also provided an opportunity to give back to others (helping other patients, promoting kidney donation and continuing this process in the future through the web platform).

Limitations:

Our participants came from a single French-speaking urban transplant center in Quebec and were highly educated.

Conclusion:

The study set out to capture the perspectives of KTRs, LKDs, and KTCs through the sharing of self-narratives and their participation in creative writing workshops related to their transplant or donation journey. A website was set up to publish patients’ creative writings (https://recitsdudonetdelavie.lorganon.ca/les-recits/). Further study is needed to assess the website’s impact on other patients.

Trial registration:

Not registered.

Québec health care professionals' perspectives on organ donation after medical assistance in dying

Background

Medical assistance in dying (MAID) has been legal in Québec since December 2015 and in the rest of Canada since July 2016. Since then, more than 60 people have donated their organs after MAID. Such donations raise ethical issues about respect of patients’ autonomy, potential pressure to choose MAID, the information given to potential donors, the acceptability of directed donations in such a context and the possibility of death by donation. The objective of this study was to explore Québec professionals’ perspectives on the ethical issues related to organ donation after MAID.

Methods

We conducted semi-directed interviews with 21 health care professionals involved in organ donation such as intensivists and intensive care nurses, operating room nurses, organ donation nurses and coordinators.

Results

The participants were all favourable to organ donation after MAID in order to respect patients’ autonomy. They also favoured informing all potential donors of the possibility of donating organs. They highlighted the importance of assessing donors’ reasons for requesting MAID during the assessment. They were divided on directed donation, living donation before MAID and death by donation.

Conclusion

Organ donation after MAID was widely accepted among the participants, based on the principle of respect for the donor’s autonomy. The findings of this study only provide the perspectives of Québec health care professionals involved in organ donation. Future studies are needed to gather other stakeholders’ perspectives on this issue as well as patients’ and families’ experiences of organ donation after MAID.

Idiopathic sudden sensorineural hearing loss: classic cardiovascular and new genetic risk factors

BACKGROUND

The main causative process in idiopathic sudden sensorineural hearing loss (iSSNHL) has yet to be explained or demonstrated. The clinical picture supports vascular involvement, but obvious limitations of inner ear study make this difficult to corroborate.

OBJECTIVES

To determine the role of thrombophilic genetic variants that may affect platelet function and to assess the cardiovascular risk profile in a cohort of patients with iSSNHL.

PATIENTS AND METHODS

118 Caucasian patients with iSSNHL were recruited from the same geographical area and enrolled prospectively in this study. Clinical data were obtained for each patient. Polymorphisms of the platelet glycoprotein subunit IIIa gene, ITGB3 (PLA1/A2, rs5918), and of the platelet glycoprotein subunit Ia gene, ITGA2 (C807T, rs1126643) were analyzed. A control group of 161 age- and gender-matched healthy individuals from the same geographical area was recruited for genetic comparisons. In order to determine the cardiovascular risk profile of each patient and of our cohort, a cross-sectional assessment was performed by means of a calibrated Framingham coronary heart disease risk scale. Risk factor proportions were compared to those recommended in European guidelines for coronary prevention, which are also based on the Framingham function.

RESULTS

A significantly high prevalence of the 807T allele of platelet glycoprotein subunit Ia was found in patients compared to controls. There was a significant correlation between the 807TT homozygous genotype and a low probability of recovery. The PLA1/A2 polymorphism of platelet glycoprotein subunit IIIa was not associated with recovery, with a similar genotype prevalence being found in patients and controls. In terms of cardiovascular risk profile, patients did not present an excess of baseline coronary risk factors compared to the general population in the same geographical area.

CONCLUSIONS

Patients with iSSNHL had a higher prevalence of the 807T thrombophilic polymorphism of platelet glycoprotein Ia/IIa. Patients homozygous for this polymorphism are less likely to recover from iSSNHL. Classical cardiovascular risk factors were not related to iSSNHL.

Horizontal visibility graphs: exact results for random time series

The visibility algorithm has been recently introduced as a mapping between time series and complex networks. This procedure allows us to apply methods of complex network theory for characterizing time series. In this work we present the horizontal visibility algorithm, a geometrically simpler and analytically solvable version of our former algorithm, focusing on the mapping of random series (series of independent identically distributed random variables). After presenting some properties of the algorithm, we present exact results on the topological properties of graphs associated with random series, namely, the degree distribution, the clustering coefficient, and the mean path length. We show that the horizontal visibility algorithm stands as a simple method to discriminate randomness in time series since any random series maps to a graph with an exponential degree distribution of the shape P(k)=(1/3)(2/3)(k-2), independent of the probability distribution from which the series was generated. Accordingly, visibility graphs with other P(k) are related to nonrandom series. Numerical simulations confirm the accuracy of the theorems for finite series. In a second part, we show that the method is able to distinguish chaotic series from independent and identically distributed (i.i.d.) theory, studying the following situations: (i) noise-free low-dimensional chaotic series, (ii) low-dimensional noisy chaotic series, even in the presence of large amounts of noise, and (iii) high-dimensional chaotic series (coupled map lattice), without needs for additional techniques such as surrogate data or noise reduction methods. Finally, heuristic arguments are given to explain the topological properties of chaotic series, and several sequences that are conjectured to be random are analyzed.

Is there an overlap between sudden neurosensorial hearing loss and cardiovascular risk factors?

INTRODUCTION

Sudden sensorineural hearing loss (SSHL) has been proposed as a symptom of underlying vascular problems. The purpose of this work is to evaluate the genetic and acquired risk factors.

METHODS

Ninety-nine patients were tested for the presence of common polymorphisms related to thrombophilia (prothrombin and factor V Leiden) in order to assess genetic risk factors, and several parameters classically associated with vascular disorders (cardiovascular events, brain stroke and antiphospholipid syndrome) were evaluated. Additional assessments of personal and familial history risk factors for vascular disorders were performed in each patient.

RESULTS

Thrombophilia studies did not demonstrate statistically relevant differences between the patients and control group. However, lipidemia profile and directed personal and familial histories showed positive trends for SSHL.

CONCLUSION

The lack of clear relationships between SSHL and other vascular risk factors suggests multicausality as a predominant disease profile. Although preliminary results point at a vascular involvement in SSHL, a long-term prospective study is necessary to demonstrate that SSHL represents an early vascular symptom.

Predicting intramuscular fat, moisture and Warner-Bratzler shear force in pork muscle using near infrared reflectance spectroscopy

Partial least-squares (PLS) models based on visible (Vis) and near infrared reflectance (NIR) spectroscopy data were explored to predict intramuscular fat (IMF), moisture and Warner Bratzler shear force (WBSF) in pork muscles (m. longissimus thoracis) using two sample presentations, namely intact and homogenized. Samples were scanned using a NIR monochromator instrument (NIRSystems 6500, 400 to 2500 nm). Due to the limited number of samples available, calibration models were developed and evaluated using full cross validation. The PLS calibration models developed using homogenized samples and raw spectra yielded a coefficient of determination in calibration (R2) and standard error of cross validation (SECV) for IMF (R2=0·87; SECV=1·8 g/kg), for moisture (R2=0·90; SECV=1·1 g/kg) and for WBSF (R2=0·38; SECV=9·0 N/cm). Intact muscle presentation gave poorer PLS calibration models for IMF and moisture (R2<0·70), however moderate good correlation was found for WBSF (R2=0·64; SECV=8·5 N/cm). Although few samples were used, the results showed the potential of Vis-NIR to predict moisture and IMF using homogenized pork muscles and WBSF in intact samples.

Combining visible and near-infrared spectroscopy with chemometrics to trace muscles from an autochthonous breed of pig produced in Uruguay: a feasibility study

Visible (Vis) and near-infrared reflectance (NIR) spectroscopy combined with chemometrics was explored as a tool to trace muscles from autochthonous and crossbreed pigs from Uruguay. Muscles were sourced from two breeds, namely, the Pampa-Rocha (PR) and the Pampa-Rocha x Duroc (PRxD) crossbreed. Minced muscles were scanned in the Vis and NIR regions (400-2,500 nm) in a monochromator instrument in reflectance. Principal component analysis (PCA), discriminant partial least square regression (DPLS), linear discriminant analysis (LDA) based on PCA scores and soft independent modelling of class analogy (SIMCA) were used to identify the origin of the muscles based on Vis and NIR data. Full cross validation was used as validation method when classification models were developed. DPLS correctly classified 87% of PR and 78% of PRxD muscle samples. LDA calibration models correctly classified 87 and 67% of muscles as PR and PRxD, respectively. SIMCA correctly classified 100% of PR muscles. The results demonstrated the usefulness of Vis and NIR spectra combined with chemometrics as rapid method for authentication and identification of muscles according to the breed of pig.

The impact of bronchiectasis associated to sinonasal disease on quality of life

BACKGROUND

Bronchiectasis (BQs) is an uncommon disease with the potential to cause devastating complications. All patients with BQs have cough and chronic sputum production that may have a great impact on patient's quality of life. Upper airway symptoms are also frequent in patients with BQs. Associations between upper and lower airways diseases have been demonstrated in allergic rhinitis and asthma, nasal polyposis and asthma, chronic obstructive lung disease and chronic rhinosinusitis.

OBJECTIVE

(1) To investigate the impact of bronchiectasis and nasal symptoms on quality of life. (2) To evaluate the added impact of nasal polyposis on quality of life in patients with BQs.

METHODS

Sixty patients with bronchiectasis and upper airway symptoms were included. Patients were evaluated for nasal symptoms, nasal polyp size by endoscopy, and quality of life using the SF-36 generic questionnaire.

RESULTS

In comparison with the Spanish general population, patients with BQs had worse scores in all SF-36 domains (P<0.05). Males reported significantly higher quality of life scores on physical functioning and social functioning than females did. Although the age, pulmonary function, presence of nasal polyps, upper airway symptoms, tobacco smoking history, and disease duration was similar between them. Males with BQs had worse quality of life than males from the Spanish general population on body pain, general health, and vitality (P<0.05). Females with BQs had worse quality of life than females from the Spanish general population on physical function, body pain, general health, vitality, social function, and emotional role (P<0.05). Nasal polyps were found in 25 (41.6%) of 60 patients with BQs. No significant differences were observed on quality of life outcomes between patients with BQs with and without nasal polyposis.

CONCLUSION

These results suggest that BQs has a considerable impact on quality of life while nasal polyposis has no additional impact on the quality of life of patients with BQs.

Bulky cervical liposarcoma associated with sleep apnea syndrome

Sarcomas of the head and neck are relatively infrequent tumors. Liposarcomas represent 10-16% of all soft tissue sarcomas and <5% of them arise from the head and neck. The retropharyngeal area is rarely involved. We present the case of a middle-aged male with clinical symptoms of sleep apnea. A fiber-optic examination revealed a soft submucosal lesion compressing the posterior pharyngeal wall, with partial obstruction of the airway tract. CT showed a large heterogeneous prevertebral mass (6 x 20 cm(2)) occupying the posterior mediastinum. A transoral submucosal biopsy was performed. Histological findings were compatible with a low-grade liposarcoma. The mass was removed in monoblock using a classical laterocervical neck incision. The surgical specimen weighed 500 g. After 24 months of follow-up no signs of tumor recurrence or sleep apnea syndrome were noted.

Hyoid and laryngeal chondrosarcomas have different clinicopathologic features

Hyoid chondrosarcomas (CSs) are uncommon cervical tumours with different features compared to laryngeal CSs. Herein we report a hyoid CS in a 36-year-old male and review the literature. Only eight cases of hyoid CS have been reported to date. We have found important differences between hyoid and laryngeal CSs in terms of the age at presentation, gender, clinical symptoms, time before diagnosis, histologic findings and tumour size.

Prospective evaluation of a dot-blot enzyme immunoassay (Directigen RSV) for the antigenic detection of respiratory syncytial virus from nasopharyngeal aspirates of paediatric patients

This study investigated the efficacy of a commercial enzyme immunoassay (Directigen RSV, ColorPAC) in comparison with the shell vial culture method (using Hep-2 cells) for the detection of respiratory syncytial virus (RSV) in nasopharyngeal aspirates from children with bronchiolitis. During the period 1995-2002, 4950 samples were examined. RSV was detected in 1660 (33.5%) samples, with a sensitivity of 80.9%, a specificity of 97.5%, a positive predictive value of 93.8%, a negative predictive value of 91.6%, and a testing efficiency value of 92.2% compared with shell vial culture. In 83 (5%) samples, the ColorPAC was positive and the shell vial assay was negative. Of these, 71 (85.6%) were false-negative by cell culture. The true false-positive results obtained by ColorPAC represented only 0.7% of all RSV-positive samples. In general, no statistically significant differences were detected between the different months and epidemic periods studied. Compared with ColorPAC, the shell vial culture method displayed a sensitivity of 95.8% and a specificity of 100%. Overall, the ColorPAC assay was an acceptable, simple and rapid method for the antigenic detection of RSV in paediatric respiratory samples.

Plexiform ameloblastoma presenting as a sinonasal tumor

Ameloblastomas are the most frequent odontogenic tumours, accounting for 1% of all tumours of the maxilla and mandible. Sinonasal ameloblastomas are most common between the ages of 55 and 65, and mandibular ameloblastomas between 40 and 50. Incidence is higher in males than in females, and there are no differences between races. These locally aggressive tumours originate in the mandible in 80% of cases and in the maxilla in 15-20%. We report an unusual primary nasosinusal ameloblastoma presented in a 68-year-old male. The tumour was completely resected by (para)lateral rhinotomy and treated with postoperative radiotherapy. Histological analysis demonstrated a plexiform ameloblastoma. The patient remains well without disease after 50 months of postoperative follow-up.

[Bronchiolitis caused by influenza type A virus. An emerging infectious disease]

OBJECTIVES

To prospectively study the emergence and diagnostic problems of bronchiolitis caused by influenza A virus among children durign the 1999-2000 influenza epidemic.

MATERIALS AND METHODS

Negative respiratory syncitial virus (RSV) specimens (ELISA dot-blot) were seeded in the MDCK cell line for the isolation of influenza A virus, by the shell-vial technique. Vials were revealed by indirect immunofluorescence with antibodies directed against the influenza A virus nucleoprotein (Monofluookit IA, Pasteur Diagnostics). The clinical and epidemiologic features of patients with viral recovery were studied. A theoretical cost/benefit study was performed on the usefulness of the rapid antigenic detection of the influenza A virus.

RESULTS

A total of 117 cases of respiratory infection caused by influenza A virus were detected. In 62 cases (52.9%) the diagnosis was bronchiolitis. Of them, 80.6% of cases were aged less than 6 years. Subtype H3N2 predominated in all respiratory infections, paticularly in bronchiolitis. During the 1999-2000 season, a significant emergence of bronchiolitis caused by influenza A virus was observed (week 3, 30% cases of influenza A versus 24% of RSV). The cost/benefit study disclosed that the antigenic detection of RSV and influenza A virus in all respiratory specimens would amount up to 30.83 Euros/specimen.

CONCLUSIONS

During the last influenza epidemic, an emergence of bronchiolitis caused by influenza A virus among children was observed and confirmed. Based upon this observation, a dual strategy should be followed. On the one hand, a prophylactic approach (immunization of pregnant women); on the other hand, a diagnostic approach with a rapid antigenic detection of the influenza A virus.

Evaluation of different continuous cell lines in the isolation of mumps virus by the shell vial method from clinical samples

AIMS

To compare prospectively the efficacy of the Vero, LLC-MK2, MDCK, Hep-2, and MRC-5 cell lines in the isolation of the mumps virus from clinical samples by means of the shell vial method.

METHODS

During an epidemic outbreak of parotiditis 48 clinical samples (saliva swabs and CSF) were studied. Two vials of the Vero, LLC-MK2, MDCK, MRC-5, and Hep-2 cell lines were inoculated with 0.2 ml of the samples by the shell vial assay. The vials were incubated at 36 degrees C for two and five days. The vials were then fixed with acetone at -20 degrees C for 10 minutes and stained by a monoclonal antibody against mumps virus by means of an indirect immunofluorescence assay.

RESULTS

The mumps virus was isolated from 36 samples. The Vero and LLC-MK2 cell lines showed a 100% isolation capacity, MDCK showed 77.7%, MRC-5 showed 44.4%, and Hep-2 showed 22.2%. The Vero and LLC-MK2 lines were significantly different to the other cell lines (p < 0.001). The sensitivity for the Vero and LLC-MK2 lines at two and five days of incubation was identical (100%). The values obtained in the study of the quantitative isolation capacity (positive isolation with > 5 infectious foci) were 94.4% for Vero, 97.2% for LLC-MK2, 5.5% for MDCK, 5.5% for Hep-2, and 0% for MRC-5.

CONCLUSIONS

The Vero and LLC-MK2 cell lines are equally efficient at two and five days incubation for the isolation of the mumps virus from clinical samples, and the use of the shell vial method considerably shortens the time of aetiological diagnosis with higher specificity.

Molecular epidemiological typing of Enterobacter cloacae isolates from a neonatal intensive care unit: three-year prospective study

Since 1992, there has been an increase in the incidence of Enterobacter sepsis in the neonatal intensive care unit (NICU) of the authors' hospital. From 1995 to 1997, a prospective molecular epidemiological survey of the colonizing and infecting strains isolated from neonates was conducted. Enterobacter cloacae was the most frequent cause of neonatal sepsis, accounting for 19.2% of all neonatal infections, reaching a peak incidence of 2.2/1000 during 1996. Fifty isolates from the NICU and four epidemiologically unrelated strains were characterized by pulse-field gel electrophoresis (PFGE), ribotyping, enterobacterial repetitive intergenic consensus (ERIC)-PCR and plasmid profiling. PFGE was the most discriminatory technique and identified 13 types (two of them classified into two and three subtypes) compared with ERIC-PCR, plasmid profiling and ribotyping that identified 11, 11 and seven types, respectively. A good correlation was found between all techniques. Five different clones caused 15 cases of sepsis. Clones A and B were prevalent in 1995 and 1996, but they were not isolated in 1997. An outbreak caused by clone G in 1997 was controlled by cohort nursing and hygienic measures, without changing the antibiotic policy. Strains were characterized by their antibiotic resistance pattern and divided into three groups. Group I correlated with PFGE types A, B1 and B2, which hyperproduced Bush type 1 chromosomal beta-lactamase and expressed extended-spectrum ?-lactamases (ESBLs). Group II only hyperproduced Bush type 1 chromosomal beta-lactamase and correlated with PFGE-types D1, D2, D3 and I. Finally, Group III, with inducible beta-lactamases, correlated with the rest of PFGE types. The sudden disappearance of E. cloacae after reinforcement of hygienic measures confirms the importance of patient-to-patient transmission.

[Characteristics of hospitalization of patients with rheumatic diseases admitted to a tertiary care hospital]

BACKGROUND

The diagnostic profile of patients with rheumatic diseases admitted to a general hospital is variable.

AIM

To report the epidemiological profile of patients with rheumatic diseases admitted to a tertiary care hospital.

MATERIAL AND METHODS

All admissions to a Medicine ward of a general hospital and seen by the Rheumatology team were prospectively registered during one year in 1999. Patients were classified as primarily admitted for a rheumatic disease or admitted for other cause that required a consultation with the Rheumatology team.

RESULTS

One hundred forty five admissions due to rheumatic diseases were registered. Of these, 82 were due to primary rheumatic diseases. Systemic lupus erythematosus, rheumatoid arthritis and vasculitis were the main diagnoses and the mean hospital stay was 18.5 days. Sixty three patients required a consultation with the Rheumatology team specially due to osteoarthritis and crystal induced diseases.

CONCLUSIONS

Admissions due to rheumatic diseases are prolonged, correspond to 0.46% of all admissions and the main responsible disease is systemic lupus erythematosus.

Increase of Enterobacter in neonatal sepsis: a twenty-two-year study

BACKGROUND

Data on the incidence of Enterobacter infections in neonates over prolonged periods of time are scant. We determined the epidemiology of Enterobacter sepsis and/or meningitis and the trends of infection in a neonatal unit.

METHODS

Retrospective review of sepsis and/or meningitis in inborn neonates admitted to Son Dureta University Hospital during a 22-year period. Molecular study by ribotyping of the Enterobacter strains isolated from 1995 to 1997.

RESULTS

There were 513 cases of culture-proved sepsis and/or meningitis in neonates. In late onset infections Klebsiella pneumoniae and Staphylococcus epidermidis were the most frequent isolates in the period 1977 through 1991. Enterobacter was the most common isolate in the period 1992 through 1998. During this latter period Candida infections also increased, and the resistance rate of Enterobacter to cefotaxime was higher (59.2%). Decrease in early onset infections and increase in late onsets (4.6/1,000 live births) were observed in the second period. From 1977 to 1998, 45 episodes of sepsis and/or meningitis by Enterobacter species were identified in 44 patients (8.7% of all neonatal bacteremias). Three patients with Enterobacter bacteremia died (6.6%, 0.03/1,000 live births). During 1995 through 1997 5 different clones causing sepsis were identified and 3 were predominant. In 1997 there was an outbreak of Enterobacter disease. After cleaning, cohort nursing and hygiene reinforcement, Enterobacter was not isolated in the next 2 years. No change in the antibiotic policy was made.

CONCLUSIONS

We observed a resurgence of Enterobacter infections in our neonatal intensive care unit. The sudden disappearance of this microorganism after reinforcement of hygienic measures, without withdrawing cefotaxime, confirms the importance of patient-to-patient transmission of this nosocomial infection. Further studies are needed to establish the role of antibiotics in the emergence of microorganisms in neonatal intensive care units.

[Efficiency of the extraction method with saline dextran in the pp65 antigenemia assay against human cytomegalovirus]

BACKGROUND

To prospectively evaluate the efficacy of the saline dextran extraction method in the human cytomegalovirus (CMV) pp65 antigenemia assay (Ag-pp65).

MATERIAL AND METHODS

In a 2 months period we studied all the blood samples from immunodepressed patients. The extraction of leukocytes polymorphonuclear (LPMN) was obtained with a 6% dextran solution in 0.9% saline. The total leukocytes population was counted and the percentage of LPMN obtained was established. Simultaneously the LPMN were cultivated into the MRC-5 cell line by the shell vial method (SVC).

RESULTS

The 144 blood samples studied were divided in three groups depending of the positivity in the pp65-AG and/or in the SVC. The patients with both assays positive presented the lower overall leukocyte and LPMN counting, with a difference statistically significance with the pp65-Ag negative. No statistically difference was observed in the overall count of leukocytes in the pp65-Ag negative group. The overall percentage of LPMN obtained was 87%. The median value of pp65-Ag positive samples was 48/100,000 LPMN, this value would be 51/100,000 LPMN with the application of the real percentage of LPMN obtained (p > 0.05).

CONCLUSIONS

The saline dextran extraction method presented a high efficacy in the majority of blood samples studied. The immunological status and the presence of a CMV infection or disease in the patient were the principal factors that influence the extraction method. In general there is no need to adjust the pp65-Ag value obtained with this method to the real one.

Usefulness of pp65 antigenemia and viremia in the follow-up of renal transplant recipients with cytomegalovirus disease treated with ganciclovir

We prospectively evaluated the usefulness of the pp65 antigenemia assay (AGA) and viremia (isolation) in the follow-up of 15 renal transplant recipients with a cytomegalovirus disease treated with ganciclovir. The AGA was performed with the extraction of PMNL with saline dextran, and the viremia detected by the inoculation of them in the MRC-5 cell line (shell-vial). Sixty-nine blood samples were studied, and 55 (79.7%) positive AGA and 42 (60.8%) positive viremia detected. The AGA needed a median of 9 days to negativize, and the viremia only 4 days. In eight patients (53%) the AGA and viremia were negative simultaneously. In seven patients (47%) the viremia was negative before the AGA (median 10.7 days). In this group, three patients (43%) presented a paradoxal rising of the AGA values after the negativization of the viremia. For the follow-up of renal transplant recipients treated with ganciclovir, the viremia was the most useful method of control. The viremia was negative before the AGA in many patients, demonstrating the therapeutic efficacy of ganciclovir.

[Nocardia asteroides infection in a patient with systemic lupus erythematosus]

Nocardia asteroides infection are unusually observed in systemic Lupus erithematous (SLE) patients. They are generally associated to steroidal and immunosuppressive therapy. We report a 24 years old female with SLE diagnosed in 1994 who developed a severe preeclampsia in her first pregnancy requiring emergency caesarean section. Post partum acute renal failure and type IV lupus nephropathy were treated with hemodialysis, methylprednisolone, cyclophosphamide and prednisone. Three months later, while she was receiving the fourth cyclophosphamide dose, she presented with a pleuro pneumonia and occipital abscess, both caused by Nocardia asteroides. She was treated with cotrimoxazole + cefixime and pleural decortication was required. Five months later, she developed Meningitis caused by Nocardia asteroides and hydrocephalus. She was treated with ceftriaxone, vancomycin, cotrimoxazole and ventricular shunting procedure. Two months later, a retroperitoneal abscess was diagnosed and surgically drained but the patient died, due to a methicillin-resistant Staphylococcus aureus septicemia.

[Evaluation of different clinical samples and cell lines in the isolation of enterovirus in pediatric patients]

BACKGROUND

To evaluate prospectively the efficacy of different clinical samples and cellular lines in the isolation of Enteroviruses from pediatric patients.

METHODS

In the period july-1997 to july-1999 we analyze the samples of 102 pediatric patients (< 2 years old) with an unknown febrile etiology syndrome. After the process of decontamination the samples were inoculated in the MRC-5, Hep-2 and Vero cell lines by the shell-vial assay. After 2-3 days of incubation the monolayers were stained by a monoclonal antibody against VP1; then the strains were identified as Poliovirus, ECHO-virus or Coxsacke by specific antibodies.

RESULTS

96 clinical samples were studied (45 pharyngeal swabs, 28 feces, 13 cerebrospinal fluid, 5 bloods, 4 urines and one bronchoalveolar lavage). Enteroviruses were isolated in 48 patients (47%), corresponding to 60 clinical samples (62.5%). The enteroviruses were isolated in 75.5% of pharyngeal swabs, 71.4% of feces, 30.7% of cerebrospinal fluid, one blood (20%) and the bronchoalveolar lavage. 28 patients presented simultaneously both pharyngeal and rectal swabs; in this group the use of both samples permitted the isolation of Enteroviruses in 26 cases (92.8%). Of 60 Enteroviruses, 59 (98.3%) were isolated in the MRC-5 cell line, 23 (38.3%) in the Hep-2, and 14 (23.3%) in the Vero; the MRC-5 demonstrated a significant difference in the isolation of Enteroviruses compared with the other cell lines. The Enteroviruses were identified as 30 (50%) ECHO-virus, 15 (25%) as Poliovirus vaccine, 12 (20%) could not to be identified and in 3 cases (5%) no growth of virus was detected in the culture. The MRC-5 cell line was significatively superior to the other in the isolation of the different Enteroviruses.

CONCLUSIONS

To obtain the maximum diagnostic efficacy in front a patient with a possible infection by Enteroviruses, is necessary to use different clinical samples, specially the more related to the infection focci (cerebrospinal fluid or blood). The MRC-5 cell line has been the most efficace in the isolation of Enteroviruses independently of the type of clinical sample or the viral genus. The shell-vial assay is a good method for the isolation and identification of Enteroviruses isolated from clinical samples.

[Comparison between centrifugation and sedimentation prior to cultures in the isolation of cytomegalovirus in the urine of renal transplant recipients]

BACKGROUND

To compare the capacity of conventional centrifugation and spontaneous sedimentation to detect the presence of cytomegalovirus (CMV) in urine samples.

MATERIAL AND METHODS

We studied urine samples from 45 renal transplant recipients. After decontamination half of each sample was centrifuged (1,500 rpm for 10 minutes) and the other half was allowed to sediment at room temperature for 30 minutes. From the supernatant of each of these 250 microliters was inoculated in a shell-vial (MRC-5). Cultures were incubated for 48 hours at 37 degrees C and stained by an indirect immunofluorescence assay. The samples considered totally toxic were re-inoculated after dilution 1:1 with maintainance medium.

RESULTS

Of 845 urine samples analyzed, 743 (88%) were negative and 102 (12%) positive. 66 (7.8%) were considered toxic: 35 (4.1%) partially toxic and 31 (3.6%) totally toxic. Of the centrifuged urine samples 86.2% were positive against 98% of the sedimented samples (p = 0.004). Of the 31 samples considered totally toxic, 17 (2.2%) corresponded with negative urine samples and 14 (13.7%) with positive samples. Off these, 12 (85.7%) were detected in centrifuged samples and 2 (14.3%) in sedimented samples (p = 0.001).

CONCLUSIONS

The percentage of toxicity in the urine samples was low (7.8%) which does not seem to suggest the need for systematic dilution of all samples. The sedimentation process enabled us to detect a greater number of urine samples positive for CMV with a lower rate of toxicity of the monolayers. The use of this process would reduce the number of samples requiring reinoculation.

[Education of patients with rheumatoid arthritis. Assessment of a survey of interests]

BACKGROUND

The congruence of interests between health care providers and clients is essential if subjects with chronic diseases will be educated.

AIM

To assess, in patients with rheumatoid arthritis, those fields in which they would like to receive education.

PATIENTS AND METHODS

Eighty eight patients with rheumatoid arthritis were surveyed about the topics in which they would like to be educated. The inquiry included medical aspects, handicap overcoming, social issues and labor aspects.

RESULTS

Eighty two percent of patients were interested in medical aspects, 77% in social issues and 71% in handicap overcoming. Eighty three percent of patients with greater handicaps preferred handicap overcoming, 75% social aspects and 74% medical aspects. Younger patients had a greater interest in labor aspects, those with a recently diagnosed disease were interested in their legal rights and those with a prolonged disease wanted information about self help groups.

CONCLUSIONS

The greater educational interests of patients with rheumatoid arthritis were on medical aspects. However, those impaired by the disease were interested in handicap overcoming. Age and duration of the disease also influenced the educational interests of patients. Thus, education in these patients must be individualized.

Epizootiology of sarcoptic mange in a population of cantabrian chamois (Rupicapra pyrenaica parva) in northwestern Spain

In May of 1993, an epizootic of sarcoptic mange (Sarcoptes scabiei) was detected in the chamois (Rupicapra pyrenaica parva) population of the Cantabrian Mountains in northwestern Spain. The epizootic initially spread across an area inhabited by some 1600 chamois. Mortality was lower than reported for other populations of ungulates. The maximum number of animals were affected from February to May. Four red deer (Cervus elaphus) and a roe deer (Capreolus capreolus), were diagnosed with sarcoptic mange from the same area in 1995. In these chamois mange was not correlated with host age or sex. The health and physiological status of this chamois population were not predisposing factors in the appearance of the mange epizootic. The clinical, epidemiological, serological, pathological and parasitological findings of this epizootic from May 1993 to June 1995 are described in this report.

Retinal detachment in AIDS: long-term results after repair with silicone oil

AIMS

To study the long-term results of vitrectomy and silicone oil injection in AIDS patients with retinal detachment due to viral retinitis.

METHODS

A consecutive series of 83 eyes in 75 AIDS patients who were treated with vitrectomy and silicone oil for retinal detachment due to viral retinitis was studied prospectively and followed until the last patient in the series had died.

RESULTS

Median postoperative survival was 6 months, but 20% of patients survived 12 months or more. Whereas best corrected visual acuity was 20/100 or better in over half the patients 1-2 months after operation, there was a distressing decrease in acuity by 6 months, owing to a variety of factors. Patients operated on before macular detachment did not have significantly better postoperative vision than those operated within a week after macular detachment. Almost all patients who had already lost vision in the fellow eye and many who had cytomegalovirus retinitis in the fellow eye with retention of good vision had their quality of life improved by the surgery in that the operated eye eventually became the better seeing eye. In no patient whose fellow eye was normal and free of retinitis, however, did the operated eye ever become the better eye.

CONCLUSIONS

Although the majority of patients recovered macular vision in the first 1-2 months after operation, there was a gradual decline in acuity thereafter, sometimes without obvious cause. The results of this series suggest that it may be reasonable to postpone surgery until the macula detaches and that patients whose fellow eye is free of retinitis with normal vision are unlikely to have their quality of life improved significantly by the surgery.

[Impact of an educational manual on knowledge and attitudes of rheumatic patients and health care workers]

BACKGROUND

Education may induce voluntary behavioral changes in patients that lead to an improvement in health status.

AIM

To assess the impact of the educational manual "Aches and Pain" on knowledge and attitudes of patients with chronic rheumatism and paramedics, using an instrument with 40 asseverations extracted from the manual.

PATIENTS AND METHODS

Seventy seven patients and 42 paramedics were studied. The assessment instrument was responded before and after reading chapters of the manual, selected by the authors. Knowledge was quantified according to the number of correct answers. Adaptation to disease, optimism and self help capacity were the evaluated attitudes, using a five point scale.

RESULTS

The study was completed by 48 patients and 42 paramedics. Knowledge improved from 19.9 +/- 5.3 to 25.6 +/-6.15 correct answers in the former and from 23.6 +/- 4.9 to 30.3 +/- 5.5 in the latter (p < 0.001). In patients there were improvements in the degree of adaptation to disease from 3.6 +/- 0.9 to 4.0 +/- 0.8 and in self-help capacity from 4.0 +/- 0.8 to 4.3 +/- 0.8; optimism did not improve significantly.

CONCLUSIONS

The educational manual had an impact on knowledge and improved rheumatic patient's attitudes towards the disease.

[Intra-articular treatment of osteoarthrosis of the knee with betamethasone dipropionate and disodium phosphate. Non-controlled, open 5 years' experience]

We reviewed the result of treatment of knee osteoarthritis with intraarticular injection of betamethasone derivatives in 100 patients over a 5 year period. Knee involvement was bilateral in 34 of these patients. 1 ml of a mixture of betamethasone dipropionate and betamethasone phosphate was injected intraarticularly in each patient and repeated if needed at 3 week intervals. A total of 496 injections (mean 3.7 per knee, minimum 1 and maximum 18) were performed. Clinical and radiological evaluation before and midway through therapy revealed no side effects. The clinical response in terms of pain, mobility and functional capacity was good. We conclude that the therapy described results in good clinical and functional results over long periods of time in patients with knee osteoarthritis.

[Acute polyarthritis in a patient with AIDS. Clinical report]

A homosexual patient known to be HIV positive for 2 years developed fever, herpes labialis, salmonellosis and symmetric polyarthritis. No specific cause was documented for the arthritis which was ascribed to the AIDS syndrome. Partial improvement in symptoms was observed after therapy with cotrimoxazole and indomethacin. Musculoskeletal complications of AIDS are reviewed.

Natural immunity to measles, rubella and mumps among Spanish children in the pre-vaccination era

Prior to the start of mass vaccination campaigns against measles, rubella and mumps, a prevalence study of natural immunity to these diseases was undertaken in a sample of 1700 unvaccinated Spanish children. They were representative of the 3-7 year-old population in terms of age, regional distribution and urban or rural environment. Measles infection prevalence was significantly higher than that for rubella and mumps from 3 (48.3%, 14.2%, 25.5%, respectively) through 7 years of age, (64%, 40.9%, 39%). As a function of age, naturally-acquired immunity increased according to parabolic progressions. In the 3-5 year-old group, rural environment, low socioeconomic status, no school attendance and lack of brothers were associated with statistically lower levels of measles, rubella, or mumps infection. In the 6-7 year-old group, only 12% of the children showed antibodies against the three diseases and 18.7% exhibited triple susceptibility.

Growth of Azotobacter vinelandii in dialysed soil medium: studies upon the life cycle

Azotobacter vinelandii ATCC 12837 cultured in dialysed soil medium with addition of 0.5% glucose showed four distinct morphological cell types: large cells, precyst forms, mature cysts and filterable corpuscles (0.3 micron in diameter). These results indicate that Azotobacter is a bacterium with a complex life cycle under certain culture conditions. Intracellular levels of RNA and poly-beta-hydroxybutyric acid were significantly affected when cells grown in dialysed soil were compared with those obtained after growth on defined medium (N-free). Further studies showed that the chemical composition of filterable corpuscles obtained from dialysed soil medium were different from the composition of normal Azotobacter cells produced in both culture media (dialysed soil and defined media). We suggest that filterable corpuscles represent a stage in the life cycle of Azotobacter in their natural environment.

Calculation of half-lives of proteins in vivo. Heterogeneity in the rate of degradation of yeast proteins

A method is given for the calculation of half-lives of proteins in vivo from the measurement of the decrease of radioactivity in pulse-labelled proteins with time. This method could be particularly useful for the study of the degradation of proteins in cells that have a low growth rate. The method applied to growing yeast indicates that there are two major classes of protein. The class with low turnover constitutes the bulk of yeast protein and has a half-life of 160 h in a medium with glucose or galactose and of 50 h in a medium with ethanol. The class of proteins with high turnover (half-life between 0.8 and 2.4 hours) represents from 1% of total protein in yeast growing on glucose to 7% in yeast growing on ethanol. It is shown that some proteins which are depressed during growth on ethanol or induced during growth on galactose are particularly susceptible to degradation in a medium which contains glucose. It is proposed that protein degradation is regulated by a coarse control at the level of protease activity and a fine control on the susceptibility of individual proteins to proteases.