Quantification of the expression of reference and alcohol dehydrogenase genes of some acetic acid bacteria in different growth conditions

AIMS

The aim of this study was to develop a reliable system to analyse the expression of the pyrroloquinoline quinone (PQQ)-alcohol dehydrogenase (ADH) and test its ability to predict the growth and oxidative activity of some acetic acid bacteria (AAB).

METHODS AND RESULTS

Specific primers were designed for use in RT-PCR to quantify ADH expression and several housekeeping genes in four species of AAB. 16S rRNA gene was selected as an internal control. The relative expression of adhA was measured in Acetobacter aceti, Acetobacter pasteurianus, Gluconacetobacter hansenii and Gluconobacter oxydans grown in two media that had glucose or ethanol as the carbon source. AAB adhA expression was shown to be related to the two Acetobacter species' ability to oxidise and grow on ethanol, whereas G. oxydans were unable to grow on ethanol and the growth of Ga. hansenii was not related to adhA expression.

CONCLUSIONS

The differential expression of ADH could be a marker to analyse both growth and oxidation ability in some AAB, especially those of the genus Acetobacter.

SIGNIFICANCE AND IMPACT OF THE STUDY

Several housekeeping genes were tested in AAB and after growth in different media and it was evident that only the ribosomal coding genes were adequate as reference genes for RT-PCR.

Response to creatine analogs in fibroblasts and patients with creatine transporter deficiency

Creatine transporter (CRTR) deficiency is one of the most frequent causes of X-linked mental retardation. The lack of an effective treatment for this disease, in contrast to creatine (Cr) biosynthesis disorders that respond to Cr monohydrate (CM), led us to analyze the efficacy of a lipophilic molecule derived from Cr, creatine ethyl ester (CEE), in fibroblasts and patients with CRTR deficiency. CM and CEE uptake studies were performed in six controls and four fibroblast cell lines from patients. We found a significant increase in Cr uptake after 72 h of incubation with CEE (500 micromol/L) in patients and control fibroblasts compared to incubation with CM. Subsequently, we assayed the clinical effect of CEE administration in four patients with CRTR deficiency. After 1 year of treatment, a lack of significant improvement in neuropsychological assessment or changes in Cr level in brain (1)H MRS was observed, and CEE was discontinued. In conclusion, this 12-month trial with CEE did not increase the brain concentration of Cr. Our in vitro data lend support to the idea of a certain passive transport of CEE in both pathological and control cells, although more lipophilic molecules or other cell systems that mimic the BBB should be used for a better approach to the in vivo system.

[Utility of the detection of nasal flaring in the assessment of severity of dyspnea]

OBJECTIVE

To determine if the presence of nasal flaring is indicative of severe respiratory insufficiency.

METHODS

Prospective observational study of patients consulting in the Emergency Department because of dyspnea whose triage level is II or III in the Spanish Triage System (MAT-SET). Vital signs, SpO2, arterial blood gases and nasal flaring presence were recorded, as well as the need for hospital admission and length of hospital stay. Data are presented as median (25-75th percentile).

RESULTS

A total of 43 patients were analyzed (70% men, aged 77 (67-82) years), 7 of whom showed nasal flaring. Those having flaring had higher respiratory rate (36 (34-40) vs. 25 (20-28) vs., p=0.001) and were more acidotic (pH 7.34 [7.23-7.40] vs. 7.42 [7.39-7.46] vs., p=0.03) than patients without this sign. There were no differences between groups in SpO2, PaCO2, heart rate and arterial pressure. There were no differences in the rate of hospital admission-(6 patients [85.7%] in nasal flaring group vs 29 patients [80.5%] in the non nasal flaring group [p=0,06], or in the length of the hospital stay-3 days [1-16] in nasal flaring group vs. 6 days [1-10] in the non nasal flaring group, p=0.6). All patients with nasal flaring had tachypnea.

CONCLUSION

In our study, nasal flaring does not indicate severity in dyspneic patients in spite of its association with tachypnea and acidosis.

[Annular plaques in the skin folds: 4 cases of lichen planus pigmentosus-inversus]

We report 4 patients with relatively asymptomatic, annular brownish plaques arising in the skin creases.The lesions had remained stable for months despite many topical treatments. Histological examination revealed an atrophic epidermis with a dermal lichenoid inflammatory infiltrate showing marked pigmentary incontinence.These clinical and pathological features were consistent with lichen planus pigmentosus-inversus,a rare, recently described variant of lichen planus, with only 10 cases reported to date. It has been suggested that he intensity and speed of onset of the inflammatory response could be modulated by keratinocyte surface markers, which could also determine the typical morphology of the lesions of this disease.

MHC2TA rs4774C and HHV-6A active replication in multiple sclerosis patients

BACKGROUND AND PURPOSE

In a previous report, a strong gene-environment interaction between human herpesvirus 6A (HHV6A) active replication and MHC2TA rs4774C was demonstrated. The objectives of this study were: (i) to reappraise the association that was found in the previous study; (ii) to evaluate if MS patients with minor allele C and HHV-6A active infection had different clinical behavior; and (iii) to analyze the possible association of MHC2TA rs4774C with Epstein-Barr virus (EBV).

METHODS

A total of 149 MS patients were analyzed both at the MHC2TA locus and by HHV-6A status in serum. We studied a G/C polymorphism (rs4774) by a TaqMan Assay-on-Demand. HHV-6A genomes in serum were evaluated by quantitative PCR. A control group of 562 healthy Spanish individuals was included for comparative purposes in the genetic analyses. A battery of clinical data was collected for all the MS patients included in the study.

RESULTS

(i) MHC2TA/HHV-6A interaction: we found the same strong association of the rs4774C allele with HHV-6A active replication than in the previous study (P = 0.0001). (ii)

CLINICAL DATA

the two main statistical significant differences for MS patients with HHV-6A active infection and minor allele C were: (a) a significant number of them were not free of progression (EDSS = 0) 2 years after the diagnosis (P = 0.01); (b) only a third of them responded to interferon beta treatment (P = 0.05).

CONCLUSIONS

This study has verified previous results about the strong gene-environment interaction between HHV6A active replication and MHC2TA rs4774C. Furthermore, a different clinical behavior for MS patients with HHV-6A active infection and minor allele C was found.

Liver transplantation for hepatitis B virus. Pre-emptive and peri-operative prophylaxis

In the past, reinfection of the graft by hepatitis B virus (HBV) after liver transplantation for HBV-related liver disease was often followed by severe liver damage and reduced survival. The long-term administration of hepatitis B immunoglobulin (HBIG) dramatically reduced this risk. However, this procedure was ineffective in most patients with active viral replication pre-transplant. The use of lamivudine in the pre-transplant setting partially solved this problem. The emergence of resistant mutants to lamivudine was also solved by the addition of adefovir. At present, combination therapy by oral antivirals pre-transplant and HBIG plus the same drugs post-transplant achieves nearly 100% of protection against graft reinfection. In a recent study, a new intravenous HBIG, Niuliva has shown high efficacy in achieving protective anti-HBs levels after liver transplantation for HBV-related liver diseases, as well as a good safety profile. Using combination therapies, the doses of HBIG can be reduced or even stopped after several weeks or months post-transplant, continuing with oral antivirals alone. The recently introduced antivirals achieve a very high antiviral potency and low risk of resistance. This may further increase the efficacy in preventing graft reinfection in the post-liver transplantation setting.

Arginine supplementation in four patients with X-linked creatine transporter defect

BACKGROUND

Treatment with oral creatine monohydrate has not shown efficacy in patients with creatine transporter deficiency (CRTR-D). Another therapeutic option proposed is L-arginine, the substrate for the enzyme L-arginine:glycine amidinotransferase (AGAT). We evaluate clinical characteristics and cerebral creatine replenishment after L-arginine therapy in four patients with CRTR-D.

PATIENTS AND METHODS

Four boys with genetically confirmed diagnosis of CRTR-D (ages 9-16 years) were supplemented with L-arginine (0.4 g/kg per day) for a period of 9 months. Treatment efficacy was evaluated by clinical and neuropsychological assessment and determination of creatine signals by brain proton magnetic resonance spectroscopy ((1)H-MRS).

RESULTS

Epileptic seizures remained well controlled with antiepileptic drugs in three cases, both before and after L-arginine supplementation. Vineland Adaptive Behaviour Scale did not show any change in communication, daily living skills, socialization or motor skills, and a lack of improvement in brain (1)H-MRS follow-up was observed. L-Arginine was discontinued at the end of the observation period.

CONCLUSIONS

Nine months of L-arginine supplementation did not show effectiveness in the four patients affected with CRTR-D in this protocol.

Risk of acute liver injury associated with the use of drugs: a multicentre population survey

BACKGROUND

Acute liver injury of uncertain aetiology is often drug related and quantitative information about the associated risk is scarce.

AIM

To estimate the risk of acute liver injury associated with the use of drugs.

METHODS

In a population survey study, 126 cases of acute liver injury were prospectively assembled from January 1993 to December 1999, in patients over 15 years of age, in 12 hospitals in Barcelona (Spain). We estimated the relative risk for each drug as the ratio between the incidence of acute liver injury among the exposed population to the drug and the incidence of acute liver injury among those not exposed to it. Drug consumption data were used to estimate the exposed population.

RESULTS

Isoniazid, pyrazinamide, rifampicin, amoxicillin with clavulanic acid, erythromicin, chlorpromazine, nimesulide, and ticlopidine presented the highest risk (point relative risk > 25). Amoxicillin, metoclopramide, captopril and enalapril, furosemide, hydrochlorothiazide, fluoxetine, paroxetine, diazepam, alprazolam, lorazepam, metamizole, low-dose acetylsalicylic acid and salbutamol showed the lowest risk (point relative risk < 5).

CONCLUSIONS

This study provides a risk estimation of serious liver disease for various drugs that will be useful in its diagnosis and management, and when comparing with the drug therapeutic benefit in each indication. Some observed associations would be worth specific studies.

Study on the Efficacy and Safety of Adefovir Dipivoxil Treatment in Post–Liver Transplant Patients With Hepatitis B Virus Infection and Lamivudine-Resistant Hepatitis B Virus

Hepatitis B virus (HBV) recurrence and de novo HBV infection are frequent events in liver transplantation recipients. Treatment with lamivudine is initially efficient in both infections but the incidence of lamivudine-resistant HBV emergence increases over time. Adefovir appears to be promising in post-liver transplantation patients with recurrent HBV infection and lamivudine-resistant HBV. This study analyzed adefovir treatment in 42 post-liver transplantation patients who developed recurrent HBV or de novo HBV infection with lamivudine-resistant HBV (54.8% HCV-coinfected). Patients received 10 mg of oral adefovir once daily for a mean period of time of 21.5 months (range from 12 to 31 months). In 62.9% of patients, ALT levels decreased significantly. Serum HBV-DNA was undetectable in 64% of the cases. Twenty percent of patients lost HBeAg marker and 13.3% of them developed anti-HBe. In 9.5% of recipients, HBsAg became negative. There was no significant change in serum creatinine levels. In only one patient was worsening of the renal function detected, making dose adjustment necessary. No other side effects were reported. Our results confirm the efficacy and safety of adefovir treatment in post-liver transplantation patients with lamivudine-resistant HBV, neither were adefovir-resistant mutations identified in patients after 21 months of therapy, nor were there adverse events, especially renal toxicity.

Invasive pulmonary aspergillosis in solid organ and bone marrow transplant recipients

BACKGROUND

Invasive pulmonary aspergillosis (IPA) remains a major cause of mortality in transplant recipients. New strategies in therapy are needed.

METHODS

We prospectively followed all solid organ and bone marrow transplant recipients from January 1998 to January 2003 who showed pulmonary infiltrates. We retrospectively analyzed all of the patients diagnosed as having IPA. Clinical and epidemiological data were collected. Influence of new treatment strategies on survival was also analyzed.

RESULTS

Thirty-one cases of API were found: 8 definite, 18 probable, 5 possible among recipients of liver (11), bone marrow (9), kidney (7), kidney-pancreas (3), and heart (1) transplants. Five patients (16%) were previously receiving antifungal prophylaxis. The most common symptoms were fever (74%) and dyspnea and dry cough (48%). Six cases (19%) showed dissemination to extrapulmonary sites: central nervous system (CNS) in five and bone in one. The most common radiographic patterns were alveolar infiltrates (58%); the lesions were usually diffuse and bilateral (58%). The most common Aspergillus species identified was A. fumigatus (74%). The test to detect Aspergillus antigen (galactomannan) in serum performed in 13 cases, was positive in eight (61%). The crude mortality rate was 61% (19 of 31), but in patients on mechanical ventilation, it was 94% (OR 88, IC 95%: 7.1-1094), and in patients with CNS involvement, it was 100%. The influence of the different treatment regimens on survival was analyzed in definite and probable cases: Group 1 (12) included patients who received conventional monotherapy and group 2 (12) patients received combination antifungal therapy or liposomal amphotericin B (1-AMB) at high doses. The mortality in group 1 was 83% (10 of 12), and in group 2 it was 42% (5 of 12) (P < 0.05).

CONCLUSIONS

The mortality rate of IPA remains high, especially among patients with CNS involvement or those under mechanical ventilation. Combined antifungal therapy or monotherapy with 1-AMB at high doses significantly reduced mortality compared with conventional monotherapy.