Mycobacterium abscessus infection in transplant recipients

BACKGROUND

Mycobacterium abscessus is a ubiquitous, rapidly growing mycobacterium that colonizes organic surfaces. It is a potential pathogen, especially in immunosuppressed patients, including transplant recipients in whom disease can range from localized cutaneous lesions to disseminated infections. The purpose of this study was to describe the 12-year impact from January 1997 to December 2009 of M. abscessus infection among solid organ and bone marrow transplantations performed in adults and children.

METHODS

Information was obtained from the database of our Microbiology Department concerning samples, culture methods, and in vitro susceptibility testing. Isolates were classified as contaminants (C), colonization (CL), or disease (D) following standard criteria. We reviewed the medical records of affected subjects.

RESULTS

M abscessus was isolated in 76 patients (28 C, 18 CL, and 30 D), including 11 recipients, namely 8 (73%) classified as disease displaying 1 bone marrow case and solid organ cases--4 (50%) pulmonary (2 after cystic fibrosis), 2 renal, and 1 heart transplant patients. All were adults. The localization of infection showed 2 disseminated cases, both of whom shows cutaneous primary lesions, and 6 localized in 3 cases cutaneous and in 3, respiratory.

CONCLUSION

Diseases caused by M abscessus have increased in the last 5 years, possibly due to the greater number of transplants and the more focused search for the lesions. Most isolates were from lung cases, especially those with infections prior to transplantation. Respiratory and cutaneous samples were predominant, with skin lesions being an important site of primary symptom previous to dissemination of infection. Although the optimal regimen remains undefined, a favorable outcome depended mainly on a rapid diagnosis and inception of treatment following susceptibility test results.

Participation of the sperm proteasome during in vitro fertilisation and the acrosome reaction in cattle

In this work, we have investigated the role of the bovine sperm proteasome during in vitro fertilisation (IVF) and the acrosome reaction (AR). Motile spermatozoa, obtained by a swim-up method in Sperm-Talp medium, were capacitated for 3.5 h and incubated in the presence or absence of the specific proteasome inhibitor epoxomicin for 30 and 60 min. Then, the spermatozoa were co-incubated with mature bovine cumulus oocytes and after 48 h the cleavage rate of inseminated oocytes was evaluated. In addition, we evaluated the participation of the sperm proteasome during the progesterone-induced AR. Capacitated spermatozoa were incubated for 30 min with or without epoxomicin, then progesterone was added and the ARs were evaluated using the dual fluorescent staining technique 'Hoechst and chlortetracycline'. The results indicate that the proteasome inhibitor decreased the cleavage rate of oocytes inseminated with treated spermatozoa. In addition, acrosomal exocytosis levels were statistically significantly higher in the samples treated with the AR inducer progesterone than in control samples in the absence of the inducer. However, the progesterone-induced AR was significantly reduced by previous treatment of the spermatozoa with epoxomicin (P < 0.001). These observations indicate that the bovine sperm proteasome participates in the IVF and AR processes.

Prevalence of sensitization to lipid transfer proteins and profilins in a population of 430 patients in the south of Madrid

BACKGROUND

Lipid transfer proteins (LTPs) and profilins are the most important panallergens in the management of patients who are allergic to pollen and plant food in our area. LTPs are highly stable proteins that can induce systemic symptoms after ingestion. Profilins are labile proteins that are present in pollens and vegetables. Considered markers of several types of pollen sensitization, they are responsible for cross-reactivity between pollens and vegetables. The objective of this study was to assess the frequency of sensitization to LTP and profilin using skin prick tests (SPTs) in patients referred to our allergy unit for any complaint (not only pollen and plant food allergy).

METHODS

The study sample comprised 430 consecutive patients who were evaluated using their medical history and SPTs with pollen, date palm profilin, and peach extract enriched in Pru p 3 (30 g/mL) as an LTP marker.

RESULTS

We found that 52 (12.1%) patients were sensitized to profilin and 53 (12.3%) to LTP. Pollen allergy was diagnosed in 53% and plant food allergy in 11%. In the LTP-sensitized group and the profilin-sensitized group, 37.7% and 34.6% of the patients had plant food allergy, respectively. Thirty-three patients (62.3%) were sensitized to LTP but had no symptoms after eating vegetables.

CONCLUSIONS

To the best of our knowledge, this is the first study to analyze the real rate of sensitization to profilin and LTP in a population sensitized to allergens other than pollens and plant foods. Twelve percent of patients were sensitized to both profilin and LTP. A large proportion of LTP-sensitized patients had no symptoms at the time of the study.

Pilot study: alterations of intestinal microbiota in obese humans are not associated with colonic inflammation or disturbances of barrier function

BACKGROUND

Obesity is associated with low-grade inflammation contributing to insulin-resistance. Gut barrier alterations, described in animal models of obesity, probably favour inflammation. This has not been hitherto described in obese humans.

AIM

To evaluate gut permeability in asymptomatic obese and its association with plasma (C-reactive protein (CRP), arachidonate/eicosapentaenoate ratio) and faecal (calprotectin and leptin) markers of inflammation and microbiota alterations.

METHODS

A total of 13 obese (age: 33.9 ± 11.5 years; BMI: 35.9 ± 5.0 kg/m²) and 11 control subjects (age: 30.3 ± 8.1 years; BMI: 23.5 ± 2.4 kg/m²) were recruited. Gut permeability was assessed by the lactulose-mannitol-sucralose test, plasma fatty acids by gas chromatography, faecal calprotectin and leptin by Elisa and faecal microbiota by G+C profiling.

RESULTS

C-reactive protein was increased in the obese subjects (P = 0.01), but neither the plasma arachidonate/eicosapentaenoate ratio, the faecal levels of calprotectin and leptin, nor the gut permeability were altered. The faecal microbiota was altered in the obese (P = 0.0002), with predominance of bacterial populations having a lower G+C content and decreased concentrations of high G+C populations.

CONCLUSIONS

Asymptomatic obese individuals with systemic low-grade inflammation do not have evidence of colonic inflammation or gut barrier alteration; however, the biodiversity of their intestinal microbiota is affected.

[Pseudoaneurysm of the superficial palmar arch, following endoscopic carpal tunnel release. A case report]

Pseudo-aneurysm of the superficial palmar arch following carpal tunnel release is exceptional and thus poorly reported. We present one observation, recorded on more than 1300 hands treated by endoscopic release using the "Chow" technique by a single surgeon. Ultra-sonography could be used in an attempt to locate the superficial palmar arch and thus prevent vascular damage at surgery.

VEGF in the muscular layer of placental blood vessels: immuno-expression in preeclampsia and intrauterine growth restriction and its association with the antioxidant status

The pathophysiology of preeclampsia (PE), a disorder occurring in 5% of all pregnancies, remains largely unknown, but early placental hypoxia and oxidative stress are known to be involved in the mechanism of the syndrome. Maternal plasma and placental tissue samples were collected from PE, intrauterine growth restriction (IUGR), and normotensive pregnant patients. The immunohistochemical expression of vascular endothelial growth factor (VEGF), malondialdehyde (MDA) production and the activity of antioxidant enzymes (superoxide dismutase, catalase and glutathione peroxidase GSH-Px) were determined in the placental tissue. F2-isoprostane concentration and the ferric reducing ability of plasma (FRAP) were determined in maternal plasma. We found that the PE and IUGR groups showed a higher expression of VEGF in the muscular layer of fetal chorionic vessels. In addition, increased plasma F2 isoprostane levels and a significant reduction of FRAP in the plasma of PE women, as well as a lower activity of SOD in PE placentas and a higher activity of GSH-Px in IUGR placentas were found. Additionally, lower PlGF and higher sFlt1 levels were observed in the maternal plasma of PE and IUGR than control. We concluded that in a hypoxic environment, the placenta expresses VEGF in the muscular layer of fetal vessels. The development of PE could be related to the increased expression of VEGF, with decreased placental SOD activity and a decrease of both plasma F2-isoprostane and FRAP levels. In turn, the development of IUGR could be related to the association of decreased plasma FRAP levels and increased placental GSH-Px activity.

Geometry influence on the transmission spectra of dielectric single layers of spheres with different compactness

The transmission of spectra of different dielectric spheres single layer arrangements has been measured. High dielectric permittivity (epsilon=7) spheres of several millimeters of diameter were used to build the samples whose transmission was measured in the microwave range. The behavior of lattices arranged in square and triangular geometries have been compared in a number of different compactness cases. The same patterns measured have also been calculated by finite-difference time-domain (FDTD) method. Spectra from different geometrical arrangements of the same compactness (measured with the same filling fraction value) are very similar in some cases. Based on the level of similarity we propose three compactness regions. The high compactness region, where the structure effect is important, presents spectra clearly different for the two geometries. In a medium compactness region spectra are almost identical, suggesting a dominant effect of single sphere effects. Finally, in the low compactness region, the spectra from the two geometrical configurations diverge again as the Bragg diffraction values are approached.

263 IN VITRO FERTILIZATION AND EMBRYO DEVELOPMENT OF CUMULUS - OOCYTE COMPLEXES COLLECTED BY ULTRASOUND-GUIDED FOLLICULAR ASPIRATION IN LLAMAS TREATED WITH GONADOTROPIN

We have previously documented that both FSH and eCG are equally effective in inducing ovarian superstimulation in llamas, resulting in the recovery of a high number of expanded COC suitable for in vitro fertilization (Ratto et al. 2005 Theriogenology 63, 2445-2457). The objective of the study was to evaluate the ovarian response, morphology, and competence of COC collected by ultrasound-guided follicular aspiration in llamas treated with FSH or eCG. Llamas were assigned randomly into 2 groups (n = 16 per group) and treated for 48 h after follicle ablation with (1)25 mg of FSH (Folltropin, Bioniche Animal Health Canada Inc., Belleville, Canada) i.m. twice daily for 4 d; or (2) 1000IU of eCG (Novormon, Bioniche Animal Health Canada) as a single i.m. dose. The starting of gonadotropin treatment was considered Day 0. Both groups were given an i.m. dose of 5 mg of Armour Standard LH (Lutropin, Bioniche Animal Health Canada) on Day 6, and COC were collected by transvaginal ultrasound follicle aspiration of all follicles ≥7 mm on Day 7. The ovarian response was assessed by transrectal ultrasonography using a 7.5-MHz linear-array transducer (Aloka SSD-500, Clinics, Santiago, Chile) immediately before oocyte collection at 24 to 26 h after LH treatment in both groups. The COC were classified as expanded, compact, denuded, or degenerated. Expanded COC collected from FSH- (n = 147) and eCG-treated llamas (n = 141) were fertilized in vitro using epididymal sperm as previously described (Ratto et al. 2006 Anim. Reprod. Sci. 97, 246-257). Gametes were co-incubated at 38.5°C in air with 5% CO2 and high humidity for 18 h. After in vitro fertilization, presumptive zygotes were co-culture in SOF medium supplemented with 0.6% of BSA with llama granulosa cells at 39°C, 5% CO2, 5% O2, and 90% N2 for 7 days. Embryo development was evaluated on Days 2, 5, and 7 of in vitro culture (Day 0 = IVF). Data were analyzed by Student’s t-test or Fisher’s exact test and presented as mean ± SEM. The FSH and eCG treatment groups did not differ with respect to the number of follicles ≥7 mm at the time of COC collection (16.0 ± 2.7 v. 14.0 ± 1.9; P = 0.5), the number of COC collected (11.5 ± 1.9 v. 9.7 ± 1.2; P = 0.4), or the collection rate per follicle aspirated (77.0 v. 71.5%; P = 0.2). No difference was detected between FSH and eCG-treated llamas in the number of expanded COCs (9.8 ± 1.4 v. 9.4 ± 1.2; P = 0.8). The percentage of presumptive zygotes to develop into 2 to 8 cells on Day 2 (65.3 v. 63.1), morulas on Day 5 (46.2 v. 42.5), and blastocyst stage on Day 7 (23.1 v. 20.5) did not differ (P > 0.05) between FSH and eCG-treated llamas, respectively. In conclusion, FSH and eCG treatments were equally effective for ovarian superstimulation and oocyte collection. The recovery of a high number of expanded COC can be used directly for in vitro fertilization and their competence is not affected by gonadotropin treatment. The study was supported by Convenio Desempeño en Investigacion (2007-DGI-CDA-04), Universidad Catolica de Temuco.

Myricetin, quercetin, (+)-catechin and (-)-epicatechin protect against N-nitrosamines-induced DNA damage in human hepatoma cells

The aim of this study was to investigate the protective effect of myricetin, quercetin, (+)-catechin and (-)-epicatechin, against N-nitrosodibutylamine (NDBA) and N-nitrosopiperidine (NPIP)-induced DNA damage in human hepatoma cells (HepG2). DNA damage (strand breaks and oxidized purines/pyrimidines) was evaluated by the alkaline single-cell gel electrophoresis or Comet assay. (+)-Catechin at the lowest concentration (10 microM) showed the maximum reduction of DNA strand breaks (23%), the formation of endonuclease III (Endo III, 19-21%) and formamidopyrimidine-DNA glycosylase (Fpg, 28-40%) sensitive sites induced by NDBA or NPIP. (-)-Epicatechin also decreased DNA strand breaks (10 microM, 20%) and the oxidized pyrimidines/purines (33-39%) induced by NDBA or NPIP, respectively. DNA strand breaks induced by NDBA or NPIP were weakly reduced by myricetin at the lowest concentration (0.1 microM, 10-19%, respectively). Myricetin also reduced the oxidized purines (0.1 microM, 17%) and pyrimidines (0.1 microM, 15%) induced by NDBA, but not the oxidized pyrimidines induced by NPIP. Quercetin did not protect against NDBA-induced DNA damage, but it reduced the formation of Endo III and Fpg sensitive sites induced by NPIP (0.1 microM, 17-20%, respectively). In conclusion, our results indicate that (+)-catechin and (-)-epicatechin at the concentrations tested protect human derived cells against oxidative DNA damage effects of NDBA and NPIP. However, myricetin at the concentrations tested only protects human cells against oxidative DNA damage induced by NDBA and quercetin against oxidative DNA damage induced by NPIP.

Plasticity of hippocampus following perinatal asphyxia: effects on postnatal apoptosis and neurogenesis

Asphyxia during delivery produces long-term deficits in brain development, including hippocampus. We investigated hippocampal plasticity after perinatal asphyxia, measuring postnatal apoptosis and neurogenesis. Asphyxia was performed by immersing rat fetuses with uterine horns removed from ready-to-deliver rats into a water bath for 20 min. Caesarean-delivered pups were used as controls. The animals were euthanized 1 week or 1 month after birth. Apoptotic nuclear morphology and DNA breaks were assessed by Hoechst and TUNEL assays. Neurogenesis was estimated by bromodeoxyuridine/MAP-2 immunocytochemistry, and the levels and expression of proteins related to apoptosis and cell proliferation were measured by Western blots and in situ hybridization, respectively. There was an increase of apoptosis in CA1, CA3, and dentate gyrus (DG) and cell proliferation and neurogenesis in CA1, DG, and hilus regions of hippocampus 1 week after asphyxia. The increase of apoptosis in CA3 and cell proliferation in the suprapyramidal band of DG was still observed 1 month following asphyxia. There was an increase of BAD, BCL-2, ERK2, and bFGF levels in whole hippocampus and bFGF expression in CA1 and CA2 and hilus at P7 and P30. There was a concomitant decrease of phosphorylated-BAD (Ser112) levels. The increase of BAD levels supports the idea of delayed cell death after perinatal asphyxia, whereas the increases of BCL-2, ERK2, and bFGF levels suggest the activation of neuroprotective and repair pathways. In conclusion, perinatal asphyxia induces short- and long-term regionally specific plastic changes, including delayed cell death and neurogenesis, involving pro- and antiapoptotic as well as mitogenic proteins, favoring hippocampal functional recovery.

Proteinuria after kidney transplantation, relationship to allograft histology and survival

Proteinuria is associated with reduced kidney allograft survival. Herein we assessed the association between proteinuria, graft histology and survival. The cohort included 613 kidney allograft recipients who had proteinuria (measured) and surveillance biopsies at 1-year posttransplant. Proteinuria >150 mg/day was detected in 276 patients (45%) and in 182 of these, proteinuria was below 500. In >84% of patients even low levels of proteinuria were associated with albuminuria. Proteinuria was associated with the presence of graft glomerular pathology and the use of sirolimus. Eighty percent of patients with proteinuria >1500 mg/day had glomerular pathology on biopsy. However, lower levels of proteinuria were not associated with specific pathologies at 1 year. Compared to no sirolimus, sirolimus use was associated with higher prevalence of proteinuria (40% vs. 76%, p < 0.0001) and higher protein excretion (378 + 997 vs. 955 + 1986 mg/day, p < 0.0001). Proteinuria was associated with reduced graft survival (HR = 1.40, p = 0.001) independent of other risk factors including, glomerular pathology, graft function, recipient age and acute rejection. The predominant pathology in lost allografts (n = 57) was glomerular, particularly in patients with 1-year proteinuria >500. Thus, proteinuria, usually at low levels (<500 mg/day), is present in 45% of recipients at 1 year. However, and even low levels of proteinuria relate to poor graft survival. Proteinuria and glomerular pathology relate independently to survival.

Successful recovery after disseminated infection due to mycobacterium abscessus in a lung transplant patient: subcutaneous nodule as first manifestation--a case report

Mycobacterium abscessus infection following lung transplantation (LT) has been described in a few cases. It is characterized by a variable initial location and subsequent course in this special risk group of patients, particularly those with cystic fibrosis (CF). Herein we have presented the case of a patient subjected to LT due to CF, who 1 year after transplantation developed a subcutaneous nodule produced by M abscessus, with subsequent hematogenous spread as well as bronchial and bone marrow involvement. Antecedents prior to LT included Staphylococcus aureus colonization and sputum positivity for Aspergillus fumigatus and Scedosporium apioespermum. Treatment with ciprofloxacin and linezolid was started on the basis of the antibiogram findings. The latter antibiotic was replaced by clarithromycin for 6 months. Two years later, the patient remains asymptomatic with respiratory function parameters in the normal range. The infected patient described herein was our only case with sepsis and multisystemic spread. The important mortality among such cases reported in the literature makes early diagnosis and treatment essential.