Prediction of clinically relevant safety signals of nephrotoxicity through plasma metabolite profiling.

Addressing safety concerns such as drug-induced kidney injury (DIKI) early in the drug pharmaceutical development process ensures both patient safety and efficient clinical development. We describe a unique adjunct to standard safety assessment wherein the metabolite profile of treated animals is compared with the MetaMap Tox metabolomics database in order to predict the potential for a wide variety of adverse events, including DIKI. To examine this approach, a study of five compounds (phenytoin, cyclosporin A, doxorubicin, captopril, and lisinopril) was initiated by the Technology Evaluation Consortium under the auspices of the Drug Safety Executive Council (DSEC). The metabolite profiles for rats treated with these compounds matched established reference patterns in the MetaMap Tox metabolomics database indicative of each compound's well-described clinical toxicities. For example, the DIKI associated with cyclosporine A and doxorubicin was correctly predicted by metabolite profiling, while no evidence for DIKI was found for phenytoin, consistent with its clinical picture. In some cases the clinical toxicity (hepatotoxicity), not generally seen in animal studies, was detected with MetaMap Tox. Thus metabolite profiling coupled with the MetaMap Tox metabolomics database offers a unique and powerful approach for augmenting safety assessment and avoiding clinical adverse events such as DIKI.

PhRMA survey of pharmacogenomic and pharmacodynamic evaluations: what next?

Interindividual variation in pharmacodynamic (PD) response to drugs is an ongoing area of research for drugs in clinical development, pre- and postapproval. To characterize how pharmacogenomic (PG ) variations can serves a predictor of differences in PD outcomes, the pharmaceutical industry has incorporated PG /PD analysis into clinical drug development. The Pharmaceutical Research and Manufacturers of America (PhRMA ) and the Industry Pharmacogenomics Working Group (I-PWG) conducted a survey of 16 pharmaceutical companies to ascertain to what extent PG/PD research is being incorporated into drug development. The survey results showed that, while the industry has made some attempt to incorporate PG/PD studies into drug development, application has been inconsistent. Nevertheless, several valid PG/PD markers have since emerged in drug labels. The I-PWG considers PG/PD research an important approach to improving success rates in drug development. This article reports the results of the survey and proposes steps toward increasing the use of PG/PD research by the industry.

DNA dose and sequence dependence in sperm-mediated gene transfer.

We have tested three parameters in sperm-mediated gene transfer assays with mice and pigs: (i) the epididymal versus ejaculated origin of sperm cells, (ii) the primary structure, and (iii) the amount of the challenging foreign DNA. We have found that the pVLCNhGH construct, of retrotransposon origin, causes a massive embryo lethality and yet increases the yield of genetic transformation among born animals of both species compared to viral constructs. Arrest of embryonic development is a DNA dose-dependent effect, which is observed with high DNA doses, while lower doses are compatible with development. Finally, the overall efficiency of sperm-mediated gene transfer is higher when ejaculated, versus epididymal, spermatozoa are used. We suggest that this difference is related to the highly efficient apoptotic response in epididymal compared to ejaculated spermatozoa, triggered by the interaction of exogenous DNA molecules with the sperm membrane.

Reverse transcriptase-polymerase chain reaction for prostate-specific antigen may be a prognostic indicator in breast cancer.

Among women with node-negative breast cancer and small tumours, it is important to identify those with tumours that will recur, so that they may receive adjuvant therapy, while sparing those with tumours that will not recur the hazards of adjuvant treatment. A reverse transcriptase-polymerase chain reaction (RT-PCR) for prostate-specific antigen (PSA) may be used to identify circulating metastatic cells in patients with prostate cancer. Approximately 30% of breast cancer cells also produce PSA. Therefore, we tested the PSA RT-PCR assay on blood specimens from women with breast cancer. We evaluated 78 women at Mount Sinai Medical Center with histologically confirmed breast cancer. Venous blood (5 cm3) from the women was collected in ethylene diaminetetraacetic acid (EDTA)-treated collection tubes and approximately 400 ng of RNA from each sample was subjected to an RT-PCR. We were able to detect the amplified PSA fragment in 18 of 78 women with breast cancer; 7 of the 18 women with the PSA fragment had localised, small, node-negative tumours, both oestrogen receptor (ER) positive and ER negative. We could not detect the amplified PSA fragment in 20 normal women and 22 normal men. We conclude that PSA RT-PCR may be a useful method for determining the presence of circulating metastatic cells in some women with node-negative breast cancer, and therefore the potential for these women to develop recurrent disease and thus benefit from adjuvant therapy.

Hypertonic saline fluid therapy following brain stem trauma.

Intravenous hypertonic fluid therapy has been proposed to improve secondary ischemic injury after cerebrospinal trauma. We report the case of a 14-year-old boy with vasospasm of the intracranial vertebral arteries and ischemic brain stem damage following head trauma. The patient presented with severe tetraparesis and somatosensory (SSEPs) and brain stem auditory evoked potentials (BAEPs) impairment. The patient was treated with two subsequent hypertonic saline (HS) infusions, 2.7% and 5.4%, respectively, for a period of 48 sp, followed by standard hypervolemic therapy. After the first treatment with 2.7% HS, improvement of SSEPs without neurological improvement was apparent. Relative hypervolemia was subsequently maintained by administration of crystalloids and 20% albumin for 48 h. During standard hypervolemic therapy, no clinical and/or electrophysiological change occurred. The second infusion of 5.4% HS was concomitant with further amelioration of SSEPs and improvement of motor performance. Twelve hours after the second HS infusion, the neurological status returned to preinfusion levels, while SSEPs showed no further changes. BAEPs never changed during fluid therapy. No complication occurred secondary to the infusion of HS. This case report suggests that local improvement of brain stem perfusion following hypertonic fluid therapy accounts for or relevantly contributes to the neurological and SSEPs improvement of the patient.

Cerebral ischemia after venous air embolism in the absence of intracardiac defects.

Cerebral air embolism occurred in a patient undergoing posterior fossa surgery performed in the sitting position for acoustic neuroma removal. The patient experienced two episodes of venous air embolism, as evidenced by precordial Doppler, end-tidal carbon dioxide reduction, and oxygen desaturation. In both cases, air was aspirated from the central venous catheter; during the second episode there was arterial hypotension and electrocardiogram changes, and air bubbles were visualized in the cerebellar arteries. The patient did not regain consciousness after surgery and developed early tonic-clonic convulsions and electroencephalogram status epilepticus, which was treated with barbiturate coma. Intracardiac septal defects were not detected by transesophageal echocardiography, and computerized tomography of the brain demonstrated multifocal discrete ischemic areas in the cerebral hemispheres. The patient died 6 days after surgery without having regained consciousness. This case appears to represent the occurrence of transpulmonary passage of venous air embolism.

Mouse and rat B-myc share amino acid sequence homology with the c-myc transcriptional activator domain and contain a B-myc specific carboxy terminal region.

B-myc is a member of the myc gene family. Previous studies indicate that the rat B-myc gene contains a single exon which shows 77% nucleotide homology to the second exon of the rat c-myc gene. Its open reading frame (ORF) encodes a polypeptide with a predicted molecular weight of 20 kD. We have isolated a new, larger rat B-myc genomic clone. Sequence analysis of this clone confirmed the presence of one single coding exon. Furthermore, a genomic mouse B-myc clone was identified and compared to the rat homolog. Nucleotide analysis of B-myc coding and non-coding sequences suggests that it may be a functional gene evolved by selective duplication of part of the second c-myc exon. Analysis of the rodent B-myc open reading frames revealed two in-frame amino acid duplications in mouse B-myc and a 96% conservation at the amino acid level. Both rat and mouse B-myc proteins contain an identical and unique stretch of 14 carboxy terminal amino acid residues not found in other myc proteins. In vitro translation of rat and mouse B-myc ORF's yielded proteins that migrated as 26 kD bands in SDS-PAGE and could be immunoprecipitated by a polyclonal panmyc antiserum. Immunostaining of human lymphoma cells transiently transfected with a B-myc expression vector showed that the protein was mainly localized to the nucleus.

[Antibioprevention of recurrent cystitis. A randomized double-blind comparative trial of 2 dosages of pefloxacin]. / Antibioprophylaxie des cystites récidivantes. Essai comparatif randomisé en double-insu de deux modalités posologiques de péfloxacine.

OBJECTIVES: The aim of this randomized double-blind trial was to compare two 400 mg pefloxacin regimens either once-a-week or once-a-month applied for 48 weeks for the prophylaxis of recurrent urinary tract infection in women. METHODS: The main outcome measures were symptomatic and bacteriological reinfections during the period of prophylaxis and rates of reinfections during the three months of surveillance following the end of prophylaxis. 361 women of 18 to 51 years of age suffering from recurrent lower urinary tract infection were randomly allocated to receive pefloxacin 400 mg once-a-week (group A: n = 185) or 400 mg once-a-month (groupe B: n = 176) for 48 weeks. RESULTS: Seventeen of the 185 patients in group A (9.1%) and 52/176 patients in group B (29.5%) experienced at least one reinfection during the period of prophylaxis (p < 0.0001). The rates of reinfection during the three months of surveillance following the end of the treatment were not significantly different between the two groups with 14/101 (13.8%) patients with at least a reinfection in group A and 8/75 patients (10.6%) in group B (p = 0.51). In group A, 49/174 (28.1%) patients reported at least an adverse event compared with 33/169 (19.5%) patients in group B (p = 0.06). CONCLUSIONS: Once-a-week treatment with 400 mg of pefloxacin can be considered as a new effective and well tolerated approach for the prophylaxis of recurrent urinary tract infection in women and does not entail excessive emergence of pefloxacin resistant bacteria, even after 48 weeks of treatment.

Differential induction of stromelysin mRNA by bovine articular chondrocytes treated with interferon-gamma and interleukin-1 alpha.

Articular chondrocytes from rheumatoid joints have been shown to express class II major histocompatibility (MHC) antigens that were correlated with the presence of interferon-gamma (IFN-gamma) in the inflamed joint. Chondrocytes expressing MHC antigens function as antigen presenting cells and thus stimulate lymphocyte proliferation. These responses suggest a powerful role for the IFN-gamma stimulation of chondrocytes. The present studies were designed to examine the functional role of chondrocytes exposed to IFN-gamma during cartilage degradation that occurs in synovial disease. Destruction of cartilage in arthritis is partially attributable to metalloproteinases released by the chondrocytes in response to interleukin-1 (IL-1). Bovine articular chondrocytes treated with interleukin-1 alpha (IL-1 alpha) produced enhanced levels of stromelysin mRNA, however, Northern blots could not determine the percentage of cells responding. Exposure of bovine articular chondrocytes to IFN-gamma induced the expression of bovine HLA-DR (boHLA-DR) antigen in 50% of the cells. Using a modified cell sorting technique, chondrocytes that expressed class II MHC antigens produced two fold greater stromelysin mRNA than chondrocytes that did not express this antigen. In contrast, collagen type II mRNA levels were similar in chondrocytes, regardless of the expression of class II MHC antigens. In situ hybridization studies showed that less than half of all cartilage chondrocytes were induced to synthesize stromelysin mRNA. These observations suggest that IFN-gamma stimulates specific subpopulations of chondrocytes to be functionally active in inflammation-induced metalloprotease secretion.

[Development and trends from 1986 to 1993 of the attitude of intercontinental travellers on departure from France, with respect to malaria prophylaxis]. / Evolution et tendances de 1986 a 1993 de l'attitude des voyageurs intercontinentaux au départ de France, vis-a-vis de la prophylaxie du paludisme.

Simultaneously to information campaigns on malaria prevention in France, 5 successive surveys were performed from 1986 to 1993 on the knowledge and attitudes of travellers regarding malaria prevention. French travellers (principally towards Sub Saharan Africa) know the risk of malaria and the measures of prevention (96%). Chimioprophylaxis using chloroquine has been progressively replaced by mefloquine and then by the association mefloquine-proguanil; 25% of travellers know mosquito prevention measures (repellents and impregnated bed nets) and 27% know the stand-by treatment. Passive attitude of travellers has been modified (in part due to their education) and tend to emphasize today their own responsibility.

[An indirect hemagglutination study of total IgE and complement fractions C3c and C4 in patients with hepatic hydatidosis and undergoing therapy]. / Studio dell'emoagglutinazione indiretta, delle IgE totali e delle frazioni del complemento C3c e C4 in pazienti affetti da idatidosi epatica e sottoposti a terapia.

The trend of antibodies tested with indirect hemagglutination, of total IgE and complement fraction was examined in patients with liver hydatid disease, treated with surgery and benzoimidazoles.

Rapid diagnosis by immunofluorescence of Chlamydia trachomatis cervical infections.

In this study the MicroTrak (Syva Co.) system has been evaluated in comparison with the isolation of Chlamydia trachomatis onto McCoy cell monolayer, testing 120 endocervical samples taken from an unselected women population. The overall results show a higher incidence of positivity in women under 30 years of age; a sensitivity of the immunofluorescence of 76.3% and a specificity of 89.8%. The agreement between the two methods is significative when we test symptomatic patients.

Reflex partitioning of inputs from stretch receptors of bronchi and thoracic trachea.

A selective block of slowly adapting stretch receptors in anesthetized rabbits was induced by exposing to SO2 all thoracic airways (T) or the carina and bronchi alone (B). Increment of inspiratory time (TI) relative to control was 61% greater under B than T. The reverse would have happened if input responsible for Breuer-Hering inflation reflex originated from both bronchi and trachea. Hence, bronchial input activates inspiratory off-switch, while tracheal input delays its activation. During single inspiratory efforts with airways closed at end expiration diaphragm activity (Adi) decreased and TI0 increased relative to control equally under B and T. Hence, the input facilitating central inspiratory activity at end expiratory volume does not stem from trachea. At end of inspiratory ramp Adi stopped within 43 msec at control and 57 msec under B and T. Hence, bronchial input speeds up off-switching of inspiration. Postinspiratory Adi was greater under B than T, and nearly nil at control. Hence, bronchial input inhibits postinspiratory Adi, while tracheal input facilitates it. Inspiratory and expiratory flows were more damped under B than T, and under T than at control.