Neutralizing antibodies to interferon-α and circulating interferon in patients with chronic hepatitis C non-responding to pegylated interferon plus ribavirin re-treated by pegylated interferon-α-2a and ribavirin (ANRS HC16 GAMMATRI substudy)

A lack of antiviral response in patients with chronic hepatitis C treated with pegylated (PEG)‐interferon (IFN)‐α‐2a + ribavirin (RIBA) may be explained by neutralizing antibodies to IFN‐α‐2a. The aim of this study was to assess neutralizing antibodies to IFN‐α‐2a and IFN levels in non‐responder patients who were re‐treated by PEG IFN‐α‐2a and RIBA for 12 weeks. Non‐responders to a first‐line treatment of PEG IFN‐α‐2a + RIBA were included for treatment with PEG IFN‐α‐2a (180 µg/week) + RIBA (1,000 mg/day if <75 kg, 1,200 mg otherwise) for 48 weeks. HCV RNA was measured at week 12. IFN levels and neutralizing antibodies to IFN‐α‐2a were measured retrospectively on stored sera at baseline and weeks 4 and 12, using a quantitative sandwich ELISA for neutralizing antibodies to IFN‐α‐2a. Twenty‐three patients were non‐responders and 19 patients were responders at week 12 of the initial phase of the second‐line treatment. Non‐responders and responders did not differ statistically: baseline age (median age 47 vs. 50 years), HCV RNA (median 6.8 vs. 6.4 log₁₀ copies/ml), gender (70% vs. 73% males), genotype (genotype 1: 91% vs. 80%). The median IFN‐α‐2a levels (pg/ml) at weeks 0, 4, and 12 (interquartile range) did not differ between the 19 responders to initial phase of second‐line treatment and the 23 non‐responders: <3.3 (<3.3–371.4), 1457.3 (106.8–3284.8), and 1,652 (90.8–5,000); 84.5 (3.3–277.4), 1407.4 (120.2–2443.4), and 1620.1 (120.2–2287.1), respectively. Among non‐selected consecutive non‐responder patients, re‐treatment with PEG IFN‐α‐2a + RIBA is associated with virological response regardless of the presence of antibody‐mediated resistance to conventional IFN treatment. J. Med. Virol. 82:2027–2031, 2010. © 2010 Wiley‐Liss, Inc.     

Malabsorption and nutritional balance in the ICU: fecal weight as a biomarker: a prospective observational pilot study

Introduction  

Malabsorption, which is frequently underdiagnosed in critically ill patients, is clinically relevant with regard to nutritional balance and nutritional management. We aimed to validate the diagnostic accuracy of fecal weight as a biomarker for fecal loss and additionally to assess fecal macronutrient contents and intestinal absorption capacity in ICU patients.     

Morphine: double-faced roles in the regulation of tumor development

Morphine, a highly potent analgesic, is one of the most effective drugs for the treatment of severe pain associated with cancer. It directly acts on the central nervous system to relieve pain, but also cause secondary complications, such as addiction, respiratory depression and constipation due to its activities on peripheral tissues. Besides pain relief, morphine is of great importance on cancer management with its effect on tumor development being the subject of debate for many years with some contradictory findings. Morphine has shown both tumor growth-promoting and growth-inhibiting effects in many published research studies. And various signaling pathways have been suggested to be involved in these effects of morphine. Based on a thorough literature review, we summarized the double-faced effects of morphine in tumor development, including tumor cell growth and apoptosis, metastasis, angiogenesis, immunomodulation and inflammation. And we attempted to optimize morphine administration in cancer patients to attenuate its tumor growth-promoting effects.     

Properdin deficiency in a large Swiss family: identification of a stop codon in the properdin gene, and association of meningococcal disease with lack of the IgG2 allotype marker G2m(n).

Properdin deficiency was demonstrated in three generations of a large Swiss family. The concentration of circulating properdin in affected males was < 0.1 mg/l, indicating properdin deficiency type I. Two of the nine properdin-deficient males in the family had survived meningitis caused by Neisseria meningitidis serogroup B without sequel. Two point mutations were identified when the properdin gene in one of the properdin-deficient individuals was investigated by direct solid-phase sequencing of overlapping polymerase chain reaction (PCR) products. The critical mutation was found at base 2061 in exon 4, where the change of cytosine to thymine had generated the stop codon TGA. The other mutation was positioned at base 827 in intron 3. The stop codon in exon 4 was also demonstrated by standard dideoxy sequencing in three additional family members. The question was asked if genetic factors such as partial C4 deficiency and IgG allotypes could have influenced susceptibility to meningococcal disease in the family. No relationship was found between C4 phenotypes and infection. Interestingly, the two properdin-deficient males with meningitis differed from the other properdin-deficient persons in that they lacked the G2m(n) allotype, a marker known to be associated with poor antibody responses to T-independent antigens. This implies that the consequences of properdin deficiency might partly be determined by independent factors influencing the immune response.     

How pediatricians can respond to the psychosocial implications of disasters. American Academy of Pediatrics. Committee on Psychosocial Aspects of Child and Family Health, 1998-1999

Natural and human-caused disasters, violence with weapons, and terrorist acts have touched directly the lives of thousands of families with children in the United States.1 Media coverage of disasters has brought images of floods, hurricanes, and airplane crashes into the living rooms of most American families, with limited censorship for vulnerable young children. Therefore, children may be exposed to disastrous events in ways that previous generations never or rarely experienced. Pediatricians should serve as important resources to the community in preparing for disasters, as well as acting in its behalf during and after such events.     

Rehospitalization of Psychiatric Patients in a Managed Care Environment

This study examined predictors of readmission to a general hospital psychiatric unit that provided acute inpatient care. Participants were 370 patients admitted to the inpatient unit over a 15-month period. During this period, 105 (28%) patients were readmitted to the unit. Readmitted patients were compared to patients who were not readmitted on (a) symptom improvement during hospitalization, (b) psychosocial and clinical variables, and (c) length of hospitalization. The readmitted patients presented with levels of psychological symptoms similar to those of patients who were not readmitted. Moreover, readmitted patients and patients who were not readmitted reported comparable relief in symptom severity during hospitalization. Readmitted patients were more likely to have at least one previous psychiatric hospitalization, be unemployed, be participating in day treatment, and receiving medicare and social security disability insurance. Rehospitalization is a significant problem and the patients' self-reported symptomatology is not a major determinant of readmission for inpatient treatment.     

GWAS with longitudinal phenotypes: performance of approximate procedures

Analysis of genome-wide association studies with longitudinal data using standard procedures, such as linear mixed model (LMM) fitting, leads to discouragingly long computation times. There is a need to speed up the computations significantly. In our previous work (Sikorska et al: Fast linear mixed model computations for genome-wide association studies with longitudinal data. Stat Med 2012; 32.1: 165–180), we proposed the conditional two-step (CTS) approach as a fast method providing an approximation to the P-value for the longitudinal single-nucleotide polymorphism (SNP) effect. In the first step a reduced conditional LMM is fit, omitting all the SNP terms. In the second step, the estimated random slopes are regressed on SNPs. The CTS has been applied to the bone mineral density data from the Rotterdam Study and proved to work very well even in unbalanced situations. In another article (Sikorska et al: GWAS on your notebook: fast semi-parallel linear and logistic regression for genome-wide association studies. BMC Bioinformatics 2013; 14: 166), we suggested semi-parallel computations, greatly speeding up fitting many linear regressions. Combining CTS with fast linear regression reduces the computation time from several weeks to a few minutes on a single computer. Here, we explore further the properties of the CTS both analytically and by simulations. We investigate the performance of our proposal in comparison with a related but different approach, the two-step procedure. It is analytically shown that for the balanced case, under mild assumptions, the P-value provided by the CTS is the same as from the LMM. For unbalanced data and in realistic situations, simulations show that the CTS method does not inflate the type I error rate and implies only a minimal loss of power.     

成纤维细胞的力学生物学(下)

一、肌腱内成纤维细胞的力学生物学反应 肌腱内的成纤维细胞可以合成胶原蛋白及其他一些大分子。成纤维细胞可以将这些分子排列成组织性较高的单元，并使纤维的方向与张力方向平行。无论是培养的肌腱还是独立的成纤维细胞都可以对力做出相应的反应。