Microstructural characterization of micro- and nanoparticles formed by polymer-surfactant interactions

We have studied the nano- and microparticles formed by complexation of PDAC [poly(diallyldimethyl-ammoniumchloride)] and SDS (sodium dodecyl sulfate). The complexation phenomenon was characterized by light scattering and zeta-potential measurements. The nature of the complexes was revealed by direct-imaging cryogenic temperature transmission electron microscopy (cryo-TEM), showing nanometric details of the complexes formed around the point of neutralization. The images also reveal how those aggregates are solubilized by excess surfactant, first into faceted particles with threadlike micelles attached to their surfaces, prior to complete solubilization, then into lacelike aggregates, and finally into spheroidal micelles. The nanostructure of the complexes strongly suggests they are made of a hexagonal liquid crystalline phase. This was further supported by small-angle X-ray scattering (SAXS).

Sedation, sucralfate, and antibiotic use are potential means for protection against early-onset ventilator-associated pneumonia

To examine risk factors for early-onset ventilator-associated pneumonia (EOP) in patients requiring mechanical ventilation (MV), we performed a prospective cohort study that included 747 patients. Pneumonia was defined as a positive result for a protected quantitative distal sample. EOP was defined as pneumonia that occurred from day 3 to day 7 of MV. Eighty patients (10.7%) experienced EOP. Independent predictors of EOP were male sex (odds ratio [OR], 2.06; 95% confidence interval [CI], 1.18-3.63), actual Glasgow Coma Scale value of 6-13 (OR, 1.95; 95% CI, 1.2-3.18), high Logistic Organ Dysfunction score at day 2 (OR, 1.12 per point; 95% CI, 1.02-1.23), unplanned extubation (OR, 3.19; 95% CI, 1.28-7.92), and sucralfate use (OR, 1.81; 95% CI, 1.01-3.26). Protection occurred with use of aminoglycosides (OR, 0.36; 95% CI, 0.17-0.76), beta -lactams and/or beta -lactamase inhibitors (OR, 0.47; 95% CI, 0.28-0.83), or third-generation cephalosporins (OR, 0.33; 95% CI, 0.16-0.74). Sucralfate use and unplanned extubation are independent risk factors for EOP. Use of aminoglycosides, beta-lactams/ beta-lactamase inhibitors, or third-generation cephalosporins protects against EOP.

Spindle imaging: a new marker for optimal timing of ICSI?

BACKGROUND

The LC Polscope facilitates visualization of the meiotic spindle in human oocyte. This study aimed to investigate meiotic spindle assembly in correlation to time elapsed after HCG administration, and to determine whether spindle imaging may serve to indicate the likelihood of fertilization and embryo cleavage.

METHODS

Metaphase II (MII) oocytes from 103 couples who were being treated for male infertility were imaged with the Polscope prior to sperm injection. Spindle imaging was correlated to time elapsed from HCG administration, fertilization rate and embryo cleavage. The main outcome measures were spindle visualization, fertilization and embryo cleavage on day 3.

RESULTS

A total of 770 MII oocytes were imaged. A spindle was imaged in a significantly higher number of oocytes from >or=38 h after HCG administration compared with those in the <38 h group (78.1-81.5% versus 61.6%; P < 0.001). The fertilization rate in oocytes with a visible spindle was statistically higher compared with oocytes in which spindle could not be detected (70.4% versus 62.2%; P = 0.035). We found no relationship between spindle imaging and embryo cleavage on day 3.

CONCLUSIONS

Spindle imaging, in addition to first polar body appearance, is an accurate indicator for oocyte maturity. We suggest that spindle imaging be performed prior to sperm injection.

N-Acetyl Functions and Acetate Detected by Nuclear Magnetic Resonance Spectroscopy of Urine to Detect Renal Dysfunction following Aminoglycoside and/or Glycopeptide Antibiotic Therapy

BACKGROUND/AIMS

N-acetylneuraminidine (NeuNAc), N-acetylglutamine (GIcNAc) and acetate are metabolites present in normal urine. In patients treated with aminoglycosides and/or glycopeptides, elevation of these metabolites in urine suggests renal tubular injury. NeuNAc, GIcNAc and acetate are easily detected by magnetic resonance spectroscopy (MRS), in contrast to other bioanalytical methods. In the present study, these urinary metabolites were detected using MRS and compared with standard biochemical markers of renal injury in intensive care unit patients treated with aminoglycosides and/or glycopeptides.

METHODS

16 patients with clinical and biochemical signs of renal dysfunction were included in the study. Proton magnetic resonance spectra were obtained from 134 urine samples. The resonance intensity of NeuNAc, GIcNAc and acetate were reported relative to the resonance intensity of creatinine (ct). These ratios were compared with classical parameters of renal dysfunction, such as plasma creatinine and urea concentration, and 24-hour urine volume, by logistic regression and general linear models.

RESULTS

Statistical analysis showed that changes in plasma creatinine and urea concentration were reliably reflected in changes in the NeuNAc/ct ratio, and that plasma urea concentration changes also correlated with the acetate/ct ratio; however, the GIcNAc/ct ratio was not related to these measures of overall renal function.

CONCLUSIONS

NeuNAc/ct may be a useful marker of renal dysfunction in patients treated with aminoglycosides and glycopeptides; by MRS it can be both straightforward and informative to follow the renal function of patients treated with these antibiotics.

Prognosis and outcome of 26 patients with systemic necrotizing vasculitis admitted to the intensive care unit

OBJECTIVES

To investigate presenting features, prognostic factors and outcomes of patients with systemic necrotizing vasculitis (SNV) admitted to the intensive care unit (ICU).

METHODS

We retrospectively reviewed the medical records of all 210 SNV patients followed in our university hospital and admitted to the ICU between 1982 and 2001, with respect to clinical features, ICU disease severity scores (APACHE II and SAPS II), the Birmingham vasculitis activity score (BVAS), the five-factors score (FFS) and outcomes.

RESULTS

Twenty-six patients (16 men, 10 women) with a mean age of 46.3+/-16.5 yr were included. The reasons for ICU admission were: active SNV, 20 (77%); infection, 3 (12%); others, 3 (12%). SNV was diagnosed in 11 (42%) patients in the ICU. The mean APACHE II and SAPS II scores were significantly higher for patients who died in the ICU (P = 0.01 and P = 0.01 respectively). After a mean follow-up of 31.4+/-29.2 months, the overall mortality rate was 39% (10 patients). Among patients admitted to the ICU with active SNV, BVAS calculated at ICU admission was significantly higher for non-survivors at the end of follow-up (26.9+/-13.0 vs 14.7+/-4.6, P = 0.02).

CONCLUSION

The main reason for admitting SNV patients to the ICU was active vasculitis, which was often the first manifestation of SNV and led to its diagnosis. ICU disease severity scores at admission were associated with mortality in the ICU but did not predict long-term outcome, unlike BVAS, which accurately predicted long-term outcome but not ICU prognosis for patients admitted to the ICU with active SNV.

Control of Moldy-Core Decay in Apple Fruits by β-Aminobutyric Acids and Potassium Phosphites

Alternaria alternata is the predominant fungal pathogen responsible for moldy-core decay in the 'Red Delicious' apple fruits. The failure of registered fungicides to control the disease necessitated the search for alternative methods. Here we report that DL-β-aminobutyric acids (BABA) and potassium phosphite are capable of controlling moldy-core in apple fruits in the laboratory and the field. Laboratory tests involving inoculation of wounded mature fruits revealed that decay by A. alternata was 40 to 58% inhibited by 50 μg/ml and completely inhibited by 500 μg/ml of potassium phosphite. DL-BABA, R-BABA, and S-BABA at a concentration of 500 μg/ml inhibited decay formation by 82 to 90%. Potassium phosphite, BABA, and S-BABA inhibited decay formation even when applied 6 to 48 h postinoculation. In vitro tests indicated that BABA compounds did not affect conidial germination or mycelial growth, whereas potassium phosphite partially inhibited both developmental stages of the fungus. Results suggest that BABA inhibits fruit decay development indirectly, probably by inducing resistance in the host tissue, whereas potassium phosphite may act directly against the fungus. A preliminary field trial in a commercial apple orchard showed that three foliar applications of BABA or potassium phosphite, starting from the beginning of bloom until petal fall, reduced the number of fruits infected with moldy-core by 40 and 60%, respectively, relative to fruits from nontreated control trees. Results suggest that potassium phosphite and BABA could provide adequate control of moldy-core disease in apple.

The human tuftelin gene and the expression of tuftelin in mineralizing and nonmineralizing tissues

Tuftelin has been suggested to play an important role during the development and mineralization of enamel, but its precise function is still unclear. This article reviews major milestones in the discovery, structural characterization, expression, localization, and conservation of tuftelin in different vertebrate species. It focuses on the structure of the human tuftelin gene, which has recently been deciphered [12]. It describes the exon-intron organization, sizes and structure, the promoter structure, and the newly discovered alternatively spliced human tooth-bud tuftelin mRNA transcripts. It also examines information on the structural motifs in the human-derived tuftelin protein and how they relate to tuftelin from other species. It reviews our recent results on the transcription of tuftelin mRNA and protein expression in several nonmineralizing soft tissues, using reverse-transcription polymerase chain reaction (RT-PCR) followed by DNA cloning and sequencing, indirect immunohistochemistry, immunohistochemistry combined with confocal microscopy, and in situ hybridization. These results and earlier Northern blot results show that tuftelin, in addition to being expressed in the developing and mineralizing tooth, is also expressed in several nonmineralizing soft tissues, suggesting that tuftelin has a universal function and/or a multifunctional role.

Adjuvant treatment of high-risk stage II breast cancer with doxorubicin followed by high-dose chemotherapy and autologous stem-cell transplantation: a single-institution experience with 132 consecutive patients

Several studies have shown conflicting results with the use of intensive consolidation chemotherapy for breast cancer. The aim of the present study was to investigate the efficacy, feasibility and toxicity of high-dose chemotherapy with stem cell support in patients with high-risk stage II breast cancer. From February 1994 to November 1998, 132 consecutive patients with multinode positive breast cancer were entered to the study. In total, 86 patients had >or=10 positive axillary lymph nodes, and 46 had 4-9 positive axillary lymph nodes with at least two additional predetermined risk factors at diagnosis. All patients were offered adjuvant chemotherapy (doxorubicin, 75 mg/m(2) x 4) followed by high-dose chemotherapy (cyclophosphamide 6000 mg/m(2), carboplatin 800 mg/m(2) and thio-tepa 500 mg/m(2)) and autologous stem cell support with growth factor. In all, 131 patients also received local radiation therapy and tamoxifen based on receptor status. After a median follow-up of 51 months (range 27-87), the disease-free and overall survival rates were 72 and 81%, respectively. There was no difference in the outcome for high-risk patients with > or < than 10 positive axillary lymph nodes. On Cox regression analysis only progesterone receptor status was predictive of disease-free, but not overall survival. There were no treatment-related deaths; grades III-IV toxicity was relatively low. This combined approach of doxorubicin followed by high-dose chemotherapy and stem-cell support, followed by locoregional radiotherapy, was safe and seems to be effective in patients with multinode positive stage II breast cancer. In previous trials of adjuvant high-dose therapy in this patient population, treatment-related morbidity and mortality markedly influenced the outcome. For this high-risk patient population, further testing of intensive chemotherapy regimens with a lower toxicity profile is warranted.

[Infections by Candida sp. in intensive care. Survey of French practices]

OBJECTIVE

The isolation of Candida sp in nosocomial infections is on the increase and over the past 10 years many guidelines for "good" practices and recommendations have been published on the modalities for the management of systemic candidiasis. The aim of this paper was to assess the habits in the intensive care units in this domain in France.

METHOD

A transversal survey on the habits was conducted from March to May 2001, using a questionnaire mailed to 200 intensive care units.

RESULTS

One hundred eighty questionnaires (surgical reanimation: 12%, medical: 18%, medico-surgical: 70%) out of 200 (92.5%) were returned. The indirect diagnostic examinations: serology, search for antigenemia and PCR (Polymerase Chain Reaction) were never used in 21, 35 and 65% of cases. The systematic search for colonisation (a mean of 4 areas sampled) was conducted in all the patients by 19% of the investigators, in some patients by 53%, and never by 28%. An antifungal treatment was prescribed: in the presence of a positive haemoculture alone, once out of twice if the sample had been taken from a central catheter and in 2 cases out of 3 when the sample was peripheral. It was prescribed 6 times out of 10 after isolation of Candida sp following surgery or on needle aspiration of an intra-abdominal abscess, varyingly in the case of cadiduria, isolation of a Candida sp in a broncho-pulmonary sample or in abdominal draining and positive culture of a catheter, depending on the intensity of the colonisation, the severity of the clinical picture and the presence of factors of risk for Candida infection. It is still prescribed empirically depending on the same elements and the absence of explanation for worsening. When faced with candidemia in a non-neutropenic patient, a central catheter is not changed in 18% of cases. Depending on the microbiology, fluconazole is prescribed in: the identification of yeast without further precision (78% of cases), Candida sp without further precision (86% of cases), Candida non albicans without further precision (57% of cases), C. albicans (93% of cases), Candida non albicans other than C. krusei and C. glabrata (62% of cases), C. glabrata (36% of cases) with an increase in dose in 1 out of 2 cases. In the presence of C. glabrata or C. krusei, amphotericin B is the choice in respectively 51 and 75% of cases. To adapt the treatment.

High b value q-space-analyzed diffusion MRI in vascular dementia: a preliminary study

High b value diffusion weighted magnetic resonance imaging (high-b DWI) was used to characterize white matter changes in the brain of patients with vascular dementia (VaD). Hyperintense white matter areas detected by T2-weighted magnetic resonance imaging (MRI) represent lesions, also termed leukoaraiosis that are very common in VaD as well as in other types of dementia. Therefore, the role of white matter changes in the cognitive and memory decline that occurs in VaD patients is still under debate. High-b DWI, analyzed using the q-space approach, is a more sensitive MRI method for detection of white matter changes. High-b DWI revealed massive white matter loss in VaD patients that surpassed the boundaries of T2 hyperintensities. This technique, therefore, might serve as a better indication for the extensive nerve fiber loss in the white matter that is caused by vascular disease.

Gonadotropin response to GnRH during sexual ontogeny in the common carp, Cyprinus carpio

This study was designed to reveal whether gonadotropic response to GnRH in the common carp (Cyprinus carpio) changes during sexual ontogeny and whether the response of FSHbeta and LHbeta subunits is uniform or differential. The study comprised fish at the following stages: juveniles (4-month-old females with primary oocytes and early spermatogenic males); maturing (9-month-old previtellogenic females and advanced spermatogenic males); and mature (16-month-old postvitellogenic females and spermiating males). Fish were injected with superactive salmon GnRH analogue (sGnRHa; 25 microg/kg) and blood was sampled 6, 12 and 24 h later for cGtH (LH) and sex steroid levels. Pituitaries were taken for determination of FSHbeta and LHbeta mRNA levels by slot-blot hybridization and for cGTH content in the same glands by radioimmunoassay (RIA). Values were compared with the levels prior to sGnRHa administration and with control fish sampled at the same intervals. Juvenile fish did not respond at all to sGnRHa. In maturing females, FSHbeta mRNA increased by >300%, while that of LHbeta increased by 200%. In maturing males, FSHbeta mRNA did not change and only a slight increase occurred in that of LHbeta. In 16-month-old postvitellogenic females, there was no response of FSHbeta mRNA, while that of LHbeta dramatically increased. In spermiating males of the same age, mRNA of both FSHbeta and LHbeta increased following sGnRHa injection. Immunoreactive cGtH was present in the pituitary and plasma of all fish examined, but in juveniles it did not change following sGnRHa injection. In maturing and mature fish of both genders, sGnRHa administration was followed by a marked increase in circulating cGtH, concomitant with a decrease in its pituitary content, indicating the limited amount of the hormone stored in the gland. In conclusion, the response of the gonadotropin subunit mRNAs in the common carp was found to be differential and dependent on the gender and the phase of sexual ontogeny.

Unusual cytomegalovirus complications after autologous stem cell transplantation for large B cell lymphoma: massive gastrointestinal hemorrhage followed by a communicating hydrocephalus

Unusual cytomegalovirus (CMV)-related complications were seen after autologous stem cell transplantation (SCT) in a 50-year-old patient with diffuse large B cell lymphoma. One month after SCT, the patient developed life-threatening upper gastrointestinal tract (GIT) bleeding with several episodes of hemorrhagic shock. Endoscopy and subsequent explorative laparotomy revealed deep-seated bleeding ulcers containing intracellular CMV inclusion bodies distributed extensively in the GIT, from the lower esophagus to the small bowel. Later, she developed gradual loss of consciousness with communicating hydrocephalus which was possibly secondary to CMV-induced ventriculitis. She recovered completely after insertion of a ventriculostomy and subsequent V-P shunt.