Direct evaluation of Pseudomonas aeruginosa biofilm mediators in a chronic infection model

Biofilms contribute to Pseudomonas aeruginosa persistence in a variety of diseases, including cystic fibrosis, burn wounds, and chronic suppurative otitis media. However, few studies have directly addressed P. aeruginosa biofilms in vivo. We used a chinchilla model of otitis media, which has previously been used to study persistent Streptococcus pneumoniae and Haemophilus influenzae infections, to show that structures formed in vivo are biofilms of bacterial and host origin within a matrix that includes Psl, a P. aeruginosa biofilm polysaccharide. We evaluated three biofilm and/or virulence mediators of P. aeruginosa known to affect biofilm formation in vitro and pathogenesis in vivo--bis-(3',5')-cyclic dimeric GMP (c-di-GMP), flagella, and quorum sensing--in a chinchilla model. We show that c-di-GMP overproduction has a positive impact on bacterial persistence, while quorum sensing increases virulence. We found no difference in persistence attributed to flagella. We conclude from these studies that a chinchilla otitis media model provides a means to evaluate pathogenic mediators of P. aeruginosa and that in vitro phenotypes should be examined in multiple infection systems to fully understand their role in disease.     

Phase II trial of fenretinide (NSC 374551) in patients with recurrent small cell lung cancer

Background Alterations in retinoid signaling appear to be involved in the pathogenesis of small cell lung cancer (SCLC). Fenretinide [N-(4-hydroxyphenyl)retinamide], a synthetic retinoid, inhibits the growth of SCLC cells in vitro via the induction of apoptosis. Since these data suggested that SCLC is the adult solid tumor that is most susceptible to fenretinide, a trial to evaluate the clinical activity of fenretinide in patients with SCLC was considered the definitive test of its clinical potential in adult oncology. Methods Patients with progressive SCLC after one or two prior chemotherapy regimens and a performance status of 0–2 were eligible for the study. Patients with stable, treated brain metastases were eligible. Fenretinide 900 mg/m² twice daily was administered orally on days 1–7 of each 21-day cycle. Blood and saliva were collected pre-treatment and on day 7 of cycle 1 to measure fenretinide and retinol levels by high-pressure liquid chromatography (HPLC). Results Nineteen patients were enrolled. Fifteen patients had one prior chemotherapy regimen and four patients had two prior regimens. The median time from diagnosis to enrollment was 10 months. A median of two cycles of fenretinide was administered. There were no objective responses, but four of 17 evaluable patients (24%) had stable disease after 2–17 cycles. The median time to treatment failure was 5.7 weeks overall, while the four patients with stable disease demonstrated treatment failure at 11, 13, 19, and 52 weeks. Median survival was 25 weeks, with one patient alive 22 months after the start of treatment. The 1-year survival rate was 29%. Toxicity included mild, reversible visual changes (haziness, altered night vision), grade 1–3 nausea/vomiting, and grade 1–2 diarrhea. The mean day 7 plasma fenretinide level was 2.90 ± 1.66 μg/ml (7.40 ± 4.25 μM; n = 14). The mean pre-treatment and day 7 plasma retinol levels were 0.47 ± 0.16 μg/ml and 0.05 ± 0.07 μg/ml (n = 8), respectively. The mean day 7 salivary fenretinide level was 0.08 ± 0.18 μg/ml, with no correlation between salivary and plasma drug levels. Conclusions Fenretinide is well tolerated in patients with SCLC and stabilization of disease was noted in 24% of patients with this aggressive disease. However, after the first stage of enrollment, the response rate did not meet criteria to proceed with full trial accrual. Plasma concentrations of fenretinide that induce cytotoxicity in vitro in SCLC cell lines are clinically achievable, but there were no objective responses. Non-invasive drug monitoring using saliva underestimates systemic exposure.     

Laparoscopy in the contemporary management of acute appendicitis

BACKGROUND: We sought to compare laparoscopic appendectomy (LA) with open appendectomy (OA) focusing on the negative appendectomy rate (NAR), emergency department (ED) to operating room (OR) time, procedure length, and histopathological correlation. METHODS: All appendectomies for appendicitis over a 6-year period at a single hospital were reviewed. Open and laparoscopic procedures were compared. RESULTS: There were 1,312 appendectomies (54.6% OA and 45.4% LA) Mean ED to OR time was as follows: LA 10.8 hours (standard deviation [SD] +/- 9.0) versus 9.8 hours (SD +/- 8.5) OA (P = .0333). Mean OR time was 61.2 minutes (SD +/- 29.1) LA versus 57.7 minutes (SD +/- 28) OA (P = .0293). NAR was 18.3%, LA 23.3% versus 14.0% OA (P < .0001). Postoperative correlation with histopathology was 86% for LA versus 92% OA (P = .0003). In the LA group, 9.9% with a "normal" appendix had appendicitis by histopathology. CONCLUSIONS: LA is associated with increased presentation to procedure time, operative time, and negative appendectomy rate. Removing a "normal" appendix during LA in the absence of alternate pathology is recommended.     

Polymorphism of the homologous recombination repair genes RAD51 and XRCC3 in breast cancer

The RAD51 protein and its paralog, XRCC3, play an important role in the repair of DNA double-strand breaks (DSBs) by homologous recombination. Since DSBs may contribute to the pathogenesis of breast cancer and variability in DNA repair genes may be linked with some cancers, we performed a case-control study (135 cases and 175 controls) to check the association between the genotypes of the Thr241Met polymorphism of the XRCC3 gene and the 135G>C polymorphism of the RAD51 gene and breast cancer occurrence and progression. Genotypes were determined in peripheral blood lymphocytes by RFLP-PCR. We did not find any association between either polymorphism singly and breast cancer occurrence. Both polymorphisms were not related to tumor size, estrogen and progesterone receptors status, cancer type and grade. However, the Thr241Met genotype of the XRCC3 polymorphism slightly increased the risk of local metastasis in breast cancer patients (OR 2.56, 95% CI 1.27-5.17). The combined Thr241Met/135G>C genotype decreased the risk of breast cancer occurrence (OR 0.22, 95% CI 0.08-0.59). Our results suggest that the variability of the DNA homologous recombination repair genes RAD51 and XRCC3 may play a role in breast cancer occurrence and progression, but this role may be underlined by a mutual interaction between these genes.     

Association between vascular endothelial growth factor gene polymorphisms and age-related macular degeneration in a Polish population

The pathogenesis of age-related macular degeneration (AMD) is thought to be determined by an array of environmental and genetic factors. The association of increased expression of vascular endothelial growth factor (VEGF) with AMD, especially the wet form of AMD, was reported in several studies. The VEGF gene is highly polymorphic and some of its polymorphisms may affect its expression. In our work, we searched for an association between the −460C> (rs833061) and −634G>C (rs2010963) polymorphisms of the VEGF gene and the occurrence of AMD and its dry and wet forms. We have chosen these polymorphisms because they were shown to be significant in other studies and we previously showed their association with diabetic retinopathy. A total of 401 individuals were enrolled in this study: 136 controls, and 88 patients with dry and 177 with wet AMD. The polymorphisms were determined with DNA from peripheral blood lymphocytes by allele-specific and restriction fragment length polymorphism polymerase chain reaction. The significance of the polymorphisms was assessed by multiple logistic regression, producing odds ratios (ORs) and 95% confidence intervals (CIs). We observed a weak association (OR 2.90) between AMD occurrence and the C/T genotype of the −460C>T polymorphism. An association (OR 3.77) between the C/T genotype of the −460C>T polymorphism and the occurrence of dry AMD was observed. The T/T genotype considerably lowered the risk of dry AMD (OR 0.19). Dry AMD was associated with the C/C genotype of the −634G>C polymorphism (OR 3.68). Another weak association (OR 2.63) was found between the C/T genotype of the −460C>T polymorphism and the occurrence of wet AMD. The occurrence of AMD was correlated with the presence of the combined C/T–G/G genotype of both polymorphisms (OR 2.41), whereas the T/T–G/G and T/T–G/C genotypes exerted a protective effect against the disease (OR 0.22 and 0.48, respectively). The presence of the C/T–G/G and C/T–C/C combined genotypes increased the risk of dry AMD (OR 2.08 and 3.77, respectively), whereas the presence of the T/T–G/G and T/T–G/C genotypes decreased the risk (OR 0.15 and 0.28, respectively). In the wet form of AMD, the combined genotype C/T–G/G slightly favored the disease (OR 2.61) and the T/T–G/G genotype had a protective effect (OR 0.25). Analysis of haplotypes of both polymorphisms yielded similar results for AMD in general as well as for the dry and wet forms of the disease: the CG haplotype favored both forms of AMD, whereas the TG haplotype protected against both forms of AMD. The results obtained indicate that the −460C>T and −634G>C polymorphisms of the VEGF gene may be associated with the dry and wet forms of AMD in a Polish population.     

Examination of concordance between maternal and youth reports in the diagnosis of pediatric bipolar disorder

Objective:  While concordance between mother and child report continues to be the gold standard in the assessment of pediatric bipolar disorder, uncertainty develops when a mother's report is not endorsed by the youth. To this end we compared discordant (mother positive and youth negative) and concordant (mother and youth positive) cases.
Methods:  Subjects were 98 adolescents (12–19 years of age) derived from family studies of bipolar disorder in youth who had both self-reported and mother-reported assessments. Comparisons were made between discordant (n = 35) and concordant (n = 59) cases on a wide range of clinical correlates.
Results:  Mothers in both groups reported similar rates of symptoms of mania and depression. Within the concordant group, mothers and youth reported similar rates of symptoms of mania. There were no differences between the concordant and discordant groups in onset, duration, or impairment of mania, rates of psychiatric hospitalization, cognitive variables, or rates of disorders in family members.
Conclusions:  The similarities between discordant and concordant reports in symptomatology of mania and depression, rates of comorbidities, treatment needs, and other clinical correlates suggest that a mother-based diagnosis of mania should not be discounted in discrepant cases in which the youth fails to endorse the diagnosis.     

Clinical and neurocognitive course in early-onset psychosis: a longitudinal study of adolescents with schizophrenia-spectrum disorders

Aim: Adolescents with psychotic disorders show deficits in IQ, attention, learning and memory, executive functioning, and processing speed that are related to important clinical variables including negative symptoms, adaptive functioning and academics. Previous studies have reported relatively consistent deficits with varying relationships to illness status and symptoms. The goals of this study were to examine these relationships in a larger sample at baseline, and also to examine the longitudinal course of these deficits in a smaller subset of adolescents. Method: Thirty‐six subjects, aged 10 to 17 years, were included at baseline. All had Diagnostic and Statistical Manual‐Fourth Edition diagnoses of schizophrenia, schizoaffective disorder, schizophreniform disorder and psychosis – not otherwise specified, as determined by Kiddie‐Schedule for Affective Disorders and Schizophrenia for School‐Age Children structured interviews. Patients were administered a neuropsychological battery, and Positive and Negative Syndrome Scale ratings were completed at baseline and again at 1 year (n = 14). Most participants were inpatients at baseline, and 13 of 14 were on atypical antipsychotic medication during both sessions. Results: At baseline, the patients demonstrated impairments in working memory, processing speed, executive function and verbal learning. No significant cognitive change was detected at 1‐year follow‐up. In contrast, clinical symptoms were variable across 1 year, with an improvement in positive symptoms at 1 year. No relationships between clinical and cognitive symptoms were observed, with the exception of baseline IQ predicting negative symptoms at 1 year. Conclusions: Young patients with schizophrenia‐spectrum disorders displayed neurocognitive impairments at baseline. Despite measurable fluctuations in clinical symptoms over the year, no significant changes were measured in cognition. Lower IQ at baseline was predictive of more negative symptoms at 1 year.     

Antitumor efficacy of PD115934 (NSC 366140) against solid tumors of mice

PD115934 (NSC 366140) is a soluble pyrazoloacridine derivative presently undergoing preclinical toxicology evaluation with the anticipation of Phase I human investigation. The agent displayed both human and murine solid tumor selectivity in vitro in a soft agar disk diffusion assay, relative to its activity against murine L1210 leukemia. In vivo it was highly active against solid tumors colon adenocarcinoma 38 and pancreas ductal carcinoma 03, which was consistent with the cellular cytotoxicity seen in the disk diffusion assay. A log cell kill of greater than 4.0 was demonstrated in vivo against both models. PD115934 was administered by both bolus and infusional therapy. After completion of these trials, it was determined that this compound was a schedule category III agent, i.e., a schedule-independent agent with peak plasma level toxicity. The main toxicity encountered with infusional therapy was myelosuppression. With bolus therapy, central nervous system toxicities were dose limiting. On the basis of our preclinical infusion studies, we recommend a 2-h infusion twice weekly in humans in order to obtain a total dose of 360 mg/m2 over 8 weeks.