Design and Synthesis of Novel Cereblon Binders for Use in Targeted Protein Degradation

Modulating the chemical composition of cereblon (CRBN) binders is a critical step in the optimization process of protein degraders that seek to hijack the function of this E3 ligase. Small structural changes can have profound impacts on the overall profile of these compounds, including depth of on-target degradation, neosubstrate degradation selectivity, as well as other drug-like properties. Herein, we report the design and synthesis of a series of novel CRBN binding moieties. These CRBN binders were evaluated for CRBN binding and degradation of common neosubstrates Aiolos and GSPT1. A selection of these binders was employed for an exploratory matrix of heterobifunctional molecules, targeting CRBN-mediated degradation of the androgen receptor.

Discovery of the Selective Protein Kinase C-θ Kinase Inhibitor, CC-90005

The PKC-θ isoform of protein kinase C is selectively expressed in T lymphocytes and plays an important role in the T cell antigen receptor (TCR)-triggered activation of mature T cells, T cell proliferation, and the subsequent release of cytokines such as interleukin-2 (IL-2). Herein, we report the synthesis and structure-activity relationship (SAR) of a novel series of PKC-θ inhibitors. Through a combination of structure-guided design and exploratory SAR, suitable replacements for the basic C4 amine of the original lead (3) were identified. Property-guided design enabled the identification of appropriately substituted C2 groups to afford potent analogs with metabolic stability and permeability to support in vivo testing. With exquisite general kinase selectivity, cellular inhibition of T cell activation as assessed by IL-2 expression, a favorable safety profile, and demonstrated in vivo efficacy in models of acute and chronic T cell activation with oral dosing, CC-90005 (57) was selected for clinical development.

Dietary Lactobacillus acidophilus positively influences growth performance, gut morphology, and gut microbiology in rurally reared chickens

In a market undergoing constant evolution, the production of chicken meat that consumers would perceive as “natural” and “animal friendly” is crucial. The use of probiotics in rurally reared chickens could represent a major opportunity to achieve mutual benefit for both the industry and consumers. A total of 264 male Kabir chicks were randomly distributed to one of 2 dietary treatments: the L group received a commercial feed supplemented with 2.0 g/100 kg of Lactobacillus acidophilus D2/CSL, while the C group received the same basal diet without the additive. To assess the effects of probiotic supplementation in the chickens’ diet, productive performance was evaluated at d 21 and 42, whereas microbiological analyses of the intestinal content and intestinal histology and morphometry were performed at the end of the trial (d 42). At d 21 and 42, L birds showed better (P < 0.001) performance in terms of body weight, average daily gain, and feed conversion ratio. Enterococci, staphylococci, and Escherichia coli populations were not influenced by dietary treatment. On the contrary, Lactobacillus population increased (P = 0.032) in the L group. Furthermore, a tendency (P = 0.069) was observed for the coliforms to be influenced by diet, with lower values in the L group in comparison to the C group. Histological techniques revealed that the number of goblet cell containing neutral mucins was lower in the C group. Morphometric evaluations demonstrated that the probiotic supplementation increased the height of the mucosal layer by improving (P = 0.040) villus height, while crypt depth was unaffected. In conclusion, the results obtained in this study demonstrate that it is possible to use Lactobacillus acidophilus D2/CSL (CECT 4529) in rurally reared chicken breeds with positive effects on performance and gut health.

135 NEW INSIGHTS ON THE ROLE OF 17β-ESTRADIOL IN CORPUS LUTEUM LIFESPAN OF NON-PREGNANT BITCHES

Canine corpus luteum (CL) is a transient endocrine gland responsible for the synthesis of 17β-oestradiol (E2) during diestrus and acts in an autocrine and/or paracrine manner within this structure. The mechanism of action of E2 depends on the expression ratio of its receptors ERa and ERβ. Binding to ERa has a proliferative effect and to ERβ an antiproliferative effect. The aim of this study was to better understand the possible signalling pathways mediated by ESR1 and ESR2 in the formation and regression of canine corpus luteum. The CL were collected via ovariosalpingohysterectomy from nonpregnant bitches (n = 30) on Days 10, 20, 30, 40, 50, and 60 (n = 5/group) post-ovulation. Eighteen CL (n = 3/group) were subjected to RNA sequencing (RNA-Seq) to identify differentially expressed (DE) genes during diestrus because 3 replicates per group is the minimum number required to obtain good results in the sequencing. The DE genes were submitted to oPOSSUM 3 software (http://opossum.cisreg.ca/oPOSSUM3/) for detection of over-represented conserved transcription binding sites (TFBS) related to ESR1 and ESR2 (coding genes for ERa and ERβ, respectively). We validated the expression from 10 of these genes by RT-PCR using GAPDH as the reference gene. Protein expression of the IGF-related genes was also evaluated by immunohistochemistry. The RNAseq results were analysed by Cufflinks. Data were tested for homogeneity and normality using the Kolmogorov-Smirnov test. The RT-PCR data were compared by the one-way ANOVA test. The correlations between the RNAseq and RT-PCR results were verified by Pearson correlation. The difference was considered significant when P < 0.05. All statistical analyses were performed with GraphPadPrism 5 (GraphPad Software Inc., San Diego, CA, USA). Differential gene expression analysis among groups during the luteal phase showed the presence of 5116 DE genes in at least one comparison, and 1106 genes that have not been recorded to the canine genome yet. Among all DE genes, we found 295 genes showing TFBS related to ESR1 and ESR2. Of these genes, 4 that had TFBS in common with ESR2 (LEF-1, PAPPA, NDGR2, and ATP1A1) and 1 with ESR1 (CAV1) were selected for validation, and the other 5 genes were chosen because they control cell proliferation (CTNNB1, CCND1, IGFBP3, IGFBP4, and IGFBP5). The selected genes belonged to IGF system-related genes (PAPPA, IGFBP3, IGFBP4, and IGFBP5), Wnt/betacatenin signalling (CTNNB1, LEF-1, and CCND1), and genes regulated by oestrogen hormones (NDRG2 and ATP1A1) and plasma membrane ER (CAV1). The results suggest that during the first half of diestrus, E2 signalling appears to be mediated by ERa via interaction with caveolin-1 (non-genomic pathways): IGF system and Wnt/β-catenin signalling were identified as one of the cascades activated by this interaction, with a major role in the proliferative process. During the second half of diestrus, ERβ appears to regulate NDGR2 and ATP1A1 gene expression, contributing to the regression of the CL. Therefore, the results suggest that E2 might activate both luteotrophic and regression-related factors in canine CL.

Optimization of a Series of Triazole Containing Mammalian Target of Rapamycin (mTOR) Kinase Inhibitors and the Discovery of CC-115

We report here the synthesis and structure-activity relationship (SAR) of a novel series of triazole containing mammalian target of rapamycin (mTOR) kinase inhibitors. SAR studies examining the potency, selectivity, and PK parameters for a series of triazole containing 4,6- or 1,7-disubstituted-3,4-dihydropyrazino[2,3-b]pyrazine-2(1H)-ones resulted in the identification of triazole containing mTOR kinase inhibitors with improved PK properties. Potent compounds from this series were found to block both mTORC1(pS6) and mTORC2(pAktS473) signaling in PC-3 cancer cells, in vitro and in vivo. When assessed in efficacy models, analogs exhibited dose-dependent efficacy in tumor xenograft models. This work resulted in the selection of CC-115 for clinical development.

157 EFFECT OF DENSITY GRADIENT SELECTION ON EMBRYO RECOVERY RATES OF FRESH AND COOLED STALLION SEMEN

The aim of this study was to improve the spermatic kinetic parameters from stallions with poor quality of fresh and chilled semen by the use of density gradient Equipure™ (Nidacon, Mölndal, Sweden). Semen from 5 Quarter Horse stallions aged 8 and 16 years with history of low embryo recovery rates were used. The kinetics sperm evaluation was performed by computerized semen analysis (CASA) and plasma membrane integrity with fluorescent probes. The average motility parameters for fresh semen before selection were total motility (MT) 60%, progressive motility (PM) 30%, and plasma membrane integrity (IMP) 60% and for cooled semen (24 h at 5°C) were: MT 50%, MP 18%, and 50% IMP. For the group of fresh and cooled semen with no density gradient selection (NS), mares were inseminated with 1 billion viable sperm diluted in skim milk extender in the uterine body, 24 h after ovulation induction with 1 mg of deslorelin. For EquipureTM selection group (SE) semen was concentrated through Spermfilter membrane™ and resuspended in 5 mL of BotuSemenTM (BotupharmaTM, Brazil). In a 15 mL conic tube 5 mL of EquipureTM was added and another part containing 5 mL of the resuspended sperm was slowly added over the EquipureTM column. The 15 mL conic tube was centrifuged at 400g for 20 min. After centrifugation, the sperm pellet was carefully aspirated and to the pellet was resuspended in 4 mL of BotucrioTM. The sperm recovery rate with EquipureTM was 40%. Deep uterine AI was performed 24 h after ovulation induction with 1 mg of deslorelin. Data were analyzed by ANOVA followed by Tukey’s test (P < 0.05). The analysis of semen after EquipureTM selection resulted in average: 75, 35, 65, and 40%, respectively, for MT, MP, and IMP index and sperm recovery. The embryo recovery rate from the 5 stallions showed the following results: Stallion 1 (fresh semen): 12 mares (NS)/4 embryos (33%) and for group SE 22 mares/16 embryos, (72%; P ≤ 0.05). Stallion 2 (fresh semen): 9 mares (NS)/4 embryos, (44%) and for group SE, 12 mares/8 embryos (66%; P > 0.1). Stallion 3 (fresh semen): 4 mares (NS)/1 embryo (25%) and 7 mares for SE/4 embryos (57%; P > 0.1). Stallion 4 (chilled semen): 4 mares (NS)/0 embryo 0% and for SE group 8 mares/6 embryos 75%; P ≤ 0.001). Stallion 5 (chilled semen): 10 mares (NS)/2 embryos (20%) and for SE 6 mares/3 embryos (50%; P > 0.1). For the overall results, 39 inseminations were performed on the no selected group and 11 embryos recovered (28%) for the selected group 55 inseminations and 37 embryos recovered (67%; P < 0.01). The results clearly showed that selection by sperm density gradient EquipureTM was a very effective technique that allowed an improvement on semen quality and fertility. The authors acknowledge support from FAPESP and Botupharma.

Clinical outcome and tolerability of duloxetine in the treatment of major depressive disorder: a 12-week study with plasma levels

Duloxetine (DLX) is a dual serotonin and norepinephrine reuptake inhibitor that has been recently approved for the treatment of major depressive disorder (MDD). However, little is known about the relationship between DLX plasma levels and clinical response. The aims of this open-label study were 1) to assess clinical outcome and tolerability of DLX by means of clinician and patient assessments and 2) to evaluate the value of plasma DLX levels as predictors of clinical response and tolerability. This was a naturalistic, open-label study of 45 outpatients affected with MDD (16 men and 29 women), who received DLX at doses of 30-120 mg/day and were evaluated at baseline (T0) and after 2, 4 and 12 weeks (T1-3). The assessments included the Hamilton Rating Scales for Depression (HRSD) and Anxiety (HRSA), Clinical Global Impression-Severity (CGI-S), Beck's Depression Inventory (BDI) and a mood visual analogue scale (VAS). Compared with T0, there were significant improvements in HRSD at T1, T2 and T3 (P < 0.001), in HRSA, CGI-S and the self-administered BDI at T2 and T3 (P < 0.001), and in the VAS scores shown at T3 (P = 0.01). DLX treatment was safe and well tolerated. Plasma DLX levels at T2 ranged from 5 to 135 ng/mL (mean +/- SD = 53.56 +/- 39.45) and correlated almost significantly with the DLX dose (r = 0.35; P = 0.069). There was a significant curvilinear quadratic relationship between the improvement of HRSA scores and plasma DLX levels (R(2) = 0.27; P = 0.02). The incidence of anxiety or irritability was associated with the highest plasma levels. Our findings suggest that monitoring plasma DLX levels may be helpful in predicting better treatment responses and tolerability. The present data seem to suggest an optimal anxiolytic efficacy of DLX at intermediate plasma levels.

Ziprasidone outcome and tolerability: a practical clinical trial with plasma drug levels

INTRODUCTION

The aim of this study was to evaluate clinical outcomes and the tolerability of ziprasidone in relation to its plasma levels.

METHODS

Thirteen inpatients affected by schizophrenia were included in the study after an acute exacerbation phase. Ziprasidone monotherapy was administered for a period of eight weeks at a mean dose of 123.07+/-30.38 mg/day. Plasma concentrations were measured by high-performance liquid chromatography.

RESULTS

Nine patients completed the study. A significant clinical improvement was observed, especially in negative symptoms ( P<0.05), and there was a significant improvement in extrapyramidal symptoms ( P<0.01). Clinical laboratory tests, such as ECG and weight, did not significantly change from baseline. Plasma ziprasidone levels ranged from 20 ng/mL to 160 ng/mL (mean: 75.8 ng/mL) and were significantly related to the improvement in negative symptoms.

DISCUSSION

The study showed that ziprasidone was effective and tolerable, that use of ziprasidone was characterized by an absence of extrapyramidal symptoms and weight gain, and that no alterations in clinical laboratory tests occurred. The findings suggest a relationship between plasma levels and the clinical response to negative symptoms of schizophrenia.

The genetic resistance to gastro-intestinal strongylids in Appenninica sheep: preliminary results

Heritability parameters of resistance to gastro-intestinal strongylids, measured as FEC (Faecal Egg Count), were evaluated in the Appenninica sheep breed. FEC heritability coefficient was 0.11 +/- 0.061 while FEC repeatability coefficients were 0.58 +/- 0.085 and 0.76 +/- 0.223 in adult females and lambs respectively. Subjects were classified, based on FEC, into three different levels of resistance to strongylids. Ewes belonging to the 'resistant class' should be conveniently exploited in mating schemes, in order to provide a method, alternative to drug administration, for a long-term parasite control; this would result particularly helpful under those production systems, such as organic farming, where the use of drugs is not allowed or limited.

66 HISTIOTROPHIC NUTRITION AND IRON TRANSFER ACROSS THE MATERNO-FETAL INTERFACE IN NUCLEAR TRANSFER-DERIVED SOMATIC CATTLE CLONES

The histiotrophic nutrition by the endometrial glands and the materno-fetal interface in the cloned cattle placenta were analyzed in order to investigate the iron transfer. Placentomes and intercaruncular region samples were recovered at term Caesarean delivery from 14 cloned cattle and 10 controls, fixed in 4% paraformaldehyde and 10% formaldehyde in PBS, processed and stained for light microscopy (hematoxylin-eosin, picrosirius, and Masson's trichrome), histochemistry [Perls, acid phosphatase and periodic acid Schiff (PAS) reactions], and immunohistochemistry (with rabbit anti-pig uteroferrin antibody because the uteroferrin is an iron transporter protein). In the controls we verified blood extravasations in the materno-fetal interface between the uterine and the trophoblast epithelium characterized by hemophagous areas with consequent erythrophagocytosis by the adjacent trophoblast. This content presented extravasated erythrocytes, plasm, cell debris, and cells in a probable apoptotic process. The Perls histochemical reactions that exposed the ferric iron in the placentomes were positive, as was the uteroferrin immunohistochemistry in the trophoblast cytoplasm and in other deep points in the placentomes. The histochemical reactions, demonstrating the acid phosphatase enzyme that detects the phagocytic activity, were positive in the mesenchyme and trophoblast, with a weak stain in an endometrial stroma. In the top of fetal villi, mainly in the binucleate cells, we visualized accumulations of PAS-positive secretions, indicating the presence of mucoid material. The uterine gland epithelium was columnar-type and in the gland lumina there were cell debris and PAS-positive mucoid secretions. We confirmed the reactivity of the uterine glands to the acid phosphatase enzyme and to the Perls reaction in the epithelium and in the gland lumina. The uteroferrin immunohistochemistry showed a strong stain in the cytoplasm of the endometrial glands cells and in the lumina. In the NT bovine placentae, the blood extravasations between uterine and trophoblast epithelium were aberrant. There was also the remodeling of the maternal connective tissue (endometrial stroma) in this area. We also demonstrated phagocytic uptake of uteroferrin by the trophoblast, although the histochemical and immunohistochemical reactions were weak in the trophoblast of the placentomes and in the endometrial glands of the intercaruncular region, when compared with the controls. The results obtained by the histochemistry and immunohistochemistry indicated that these sites of transfer substances from mother to fetus are very important in providing adequate nutrition to the fetus, key to a successful pregnancy in NT bovines. This work was funded by FAPESP, Brazil.

Statistical analysis of individual assignment tests among four cattle breeds using fifteen STR loci1

Assignment tests based on multilocus genotypes are becoming increasingly important to certify quality and origin of livestock products and assure food safety and authenticity. The purpose of this study was to determine the potential of microsatellites (STR) for determining the breed origin of beef products among cattle breeds present in the market. We typed 19 STR in 269 animals from 4 cattle breeds. Based on Wright's F-statistics, 4 loci were discarded, and the remaining 15 loci (FIT = 0.101, FST = 0.089, and FIS = 0.013) were used to compute the likelihood that each multilocus genotype of the total sample was drawn from its true breed instead of another breed. To avoid occurrence of zero likelihood when one or more alleles were missing from a tested breed, sample allele frequencies were estimated assuming uniform prior distributions. Log-likelihood ratio [log(LR)] distributions of the individual assignments were determined for all possible breed contrasts, and their means and SD were used to infer the true-positive and false-positive rates at several values of the log(LR). The posterior probability that the animals of a presumed breed were actually drawn from that breed instead of any another breed was then calculated. Given an observed value of log(LR) > 0 and assuming equal priors, these probabilities were > 99.5% in 10 of 12 possible breed contrasts. For the 2 most closely related breeds (FST = 0.041), this probability was 96.3%, and the probability of excluding the origin of an animal from an alleged breed when it was actually derived from another breed was similar.

118 TRANSFER OF IRON FROM MOTHER TO FETUS IN WATER BUFFALO: ERYTROPHAGOCYTOSIS AND UTEROFERRIN

The transplacental transport of iron by uteroferrin (Uf), and the hemophagous areas in the water buffalo placenta were analyzed to clarify the mechanism of blood extravasation in the materno-fetal interface with consequent transfer of iron to the fetus through the trophoblastic erythrophagocytosis (Murai and Yamauchi 1986 Nippon Juigaki Zasshi 48, 75–88) and in the endometrial glands (Bazer et al. 1991 Exp. Hematol. 19 910–19 915). In the water buffalo placenta this mechanism remains unclear; uteroferrin is very important in this process because it is both an iron transporter and a progesterone-induced hematopoietic growth factor. Our objective was to characterize these hemophagous areas and the endometrium of the water buffalo, focusing in the materno-fetal transfer of iron. Small pieces of the placentomes and interplacentomal region of water buffaloes (Bubalus bubalis bubalis, n = 51) in all of the gestation periods were fixed in 4% paraformoldehyde, and 2.5% glutaraldehyde in PBS, processed, and stained for light and transmission electron microscopy to characterize the hemophagous areas and endometrial glands morphologically, histochemically (Perls, acid phosphatase reaction), and immunohistochemically with rabbit anti-pig uteroferrin antibody to confirm the iron transfer. The hemophagous areas were present in the placentome from 4–10-months-pregnant placentae. The Perls reaction for ferric iron staining was negative in the placentome and positive in the endometrial glands, and the acid phosphatase reaction to detect phagocytic activity was positive in the placentome as well as in the interplacentomal region. The uteroferrin immunohistochemical reaction was positive in the trophoblast, mainly in determined regions of the materno-fetal interface and in other points deep in the placentome, and the endometrial glands showed a strong reaction in the epithelium and in the lumina. The ultrastructure of the hemophagous areas revealed ingested erythrocytes inside the epithelial cells of trophoblasts, endocytic vesicles, and caveolae. The endometrial gland epithelium is of the columnar type with microvilli and basal nuclei. The results obtained mainly by histochemistry and immunohistochemistry indicated that the hemophagous areas and endometrial glands are very important sites for iron transfer in water buffalo, and are thus involved in the regulation of fetal hematopoiesis. This work was funded by FAPESP.

Regulation of Corpus Luteum-function in the Bitch

Functional lifespan of the corpus luteum (CL) in non-pregnant dogs exceeds that of pregnant animals and may last for more than 80 days. Prolactin and LH act luteotropic, however, luteolytic mechanisms are poorly understood. Other than in life stock there is no uterine luteolysine and it was postulated that local paracrine/autocrine mechanisms might play a major role. In following this hypothesis the present investigations have clearly demonstrated that up-regulation of prostaglandin synthesis in the CL as indicated by the expression of cyclo-oxygenase II occurs with its formation and not regression, pointing towards a luteotropic rather than luteolytic action. Throughout dioestrus luteal and other cells of the CL express the oestrogen (ERalpha) and progesterone receptor (PR). While ERalpha expression was not cycle-related, PR concentrations were high in the early and late-luteal phase and a regulatory role of both steroids on CL-function is assumed. As in other species also in the dog the immune system seems to participate in the mechanisms regulating CL-function as an increased presence of lymphocytes within the CL could be detected at the beginning [CD4- CD8-, major histocompatibility complex (MHC)II-antigen expressing cells] and during the latter half of dioestrus (CD8- and MHCII-antigen expressing cells). Thus, leucocyte-derived cytokines may be important and the expression of the mRNA for interleukin (IL)8, IL10, IL12, tumour necrosis factor (TNF)alpha and transforming growth factor (TGF) beta1 was observed throughout dioestrus. Electron microscopy confirmed the slow process of luteolysis; first distinct signs of degeneration were seen on day 60, accompanied by some apoptotic events. From these data it is concluded that luteal regression as monitored by the gradual decrease of systemic progesterone concentrations in the dog is not an actively regulated but rather a permissive process. Immune-mediated events may play a key role. Changes in the vascular supply, as indicated by the expression of endoglin, seem to be of lower importance.

Comprehensive Drug Screening by Integrated Use of Gas Chromatography/Mass Spectrometry and Remedi HS

The authors evaluated an integrated approach for the screening of drugs in biosamples consisting of gas chromatography/mass spectrometry analysis of serum or whole blood (SB/GC-MS) and of high-performance liquid chromatographic and ultraviolet (HPLC-UV) analysis of urine with the REMEDi HS Biorad system (U/REM) (Bio-rad; Segrate, MI, Italy). Urine and blood samples from 26 suspected intoxicated patients and from 22 suspected lethal poisoning cases were examined. Eighty-one of the 99 parent drugs/main metabolites detected were identified by SB/GC-MS and 54 with U/REM. Thirty-six drugs/metabolites were identified with both methods, 45 by SB/GC-MS alone, and 18 by U/REM alone. Absence of the mass spectrometry (MS) spectra in the reference library and high polarity of the analytes were the main reasons for failed identification by SB/GC-MS. Unsuccessful identifications with U/REM were basically caused by the absence of the UV spectra in the reference library or by low chromatographic and spectroscopic selectivity as in the case of barbiturates and benzodiazepines (BZD), which represented 11% and 51%, respectively, of the 45 SB/GC-MS unique identifications. Urine samples of 14 BZD-positive cases were also submitted to enzymatic hydrolysis and analyzed with the REMEDi UBz assay, and results were compared with those obtained by SB/GC-MS: 14 of the 22 identified BZD were detected with both methods, three by U/REM only, and five by SB/GC-MS only. In conclusion, the integrated use of SB/GC-MS and U/REM approaches greatly enhances the amount and quality of analytical information obtainable by applying either method alone.

Long-term treatment of chronic schizophrenia with risperidone: a study with plasma levels

Twenty-four chronic schizophrenic outpatients with a mean age of 37.21 years +/- 9.96 SD were treated with risperidone (RSP) at the dosage of 2-9 mg/die (mean 4.46 mg/die +/- 1.30 SD, mean 0.06 mg/kg +/- 0.01 SD) for a year. Clinical evaluation was assessed with the Brief Psychiatric Rating Scale (BPRS), Positive and Negative Symptoms Scale (PANSS), Extrapyramidal Side Effects Rating Scale (EPSE) and a checklist for Anticholinergic Side Effects (ACS) at T0, then after 1 (T1), 2 (T2), 3 (T3), 6 (T6), 9 (T9) and 12 (T12) months. RSP and 9-hydroxy-risperidone (9OH-RSP) plasma levels were determined at T12 by the HPLC method. BPRS and PANSS mean values showed a significant improvement during the study. No correlation between RSP dosage (mg/kg) and RSP, 9OH-RSP plasma levels or active moiety resulted. A positive correlation between age and active moiety was observed. A positive correlation between RSP and 9OH-RSP plasma levels was observed. A curvilinear relationship between active moiety and PANSS improvement (%) was observed. Patients with the higher PANSS amelioration showed RSP + 9OH-RSP plasma levels ranging from 15 to 30 ng/mL. RSP seems to be quite an effective drug. It seems, however, difficult to devise appropriate dose schedules and plasma level determination seems to be necessary in some cases.

Population pharmacokinetics of rifabutin in human immunodeficiency virus-infected patients

Rifabutin pharmacokinetics were studied by the population approach (NONMEM) with 40 human immunodeficiency virus-infected patients receiving rifabutin at different doses for prophylaxis or therapy of mycobacterial infections. A two-compartment open model with first-order absorption was used as the structural pharmacokinetic model. Parameter estimates were the absorption rate constant (0. 201/h), clearance/bioavailability (CL/F; 60.9 liters/h), volume of the central compartment/bioavailability (231 liters), intercompartmental clearance (60.3 liters/h), and volume of the peripheral compartment/bioavailability (Vp/F; 1,050 liters). The distribution and elimination half-lives were 1.24 and 25.4 h, respectively. The covariates tested for influence on CL/F and Vp/F were sex, age, weight, height, body surface area, tobacco smoking, drug addiction, alanine aminotransferase levels, creatinine clearance, total protein, bilirubin, numbers of CD4(+) cells, presence of diarrhea, cachexia index, rifabutin use (prophylaxis versus therapy), rifabutin dose, study site, and the concomitant administration of clarithromycin, fluconazole, phenobarbital, ciprofloxacin, azithromycin, or benzodiazepines. The only statistically significant effects on rifabutin pharmacokinetic parameters were a 27% decrease in Vp/F due to the concomitant administration of azithromycin and a 39% increase in Vp/F due to tobacco smoking. Such effects may be considered clinically unimportant. Our results confirm the lack of a correlation of rifabutin pharmacokinetic parameters with parameters of disease progression and gastrointestinal function. Also, the lack of a correlation with covariates which were previously found to be significant, such as concomitant fluconazole and clarithromycin use, may suggest that the effect of such covariates may be less important in the real clinical setting, in which several concomitant factors may influence pharmacokinetic parameters, with an overall effect of no apparent correlation.

Buflomedil interference with the monoclonal EMIT d.a.u. amphetamine/methamphetamine immunoassay

The interference of buflomedil with the monoclonal and polyclonal EMIT d.a.u. amphetamine immunoassays was investigated. Urine samples collected from 20 patients taking 600 mg of buflomedil daily gave false positive results with the monoclonal EMIT d.a.u. assay, as did urine specimens collected 2 hours after the first oral dose of buflomedil. Conversely, no false positive results occurred with the polyclonal EMIT d.a.u. amphetamine assay. Urine samples with buflomedil added at concentrations greater than 100 mg/l gave false positive results with the monoclonal immunoassay. Buflomedil concentrations found in the patient urines (56-400 mg/l) failed to correlate to EMIT assay responses: this result suggests that one or more buflomedil metabolites, besides the unchanged drug, probably interfere in the monoclonal EMIT d.a.u. assay.

A pilot program of contraceptive continuation in six school-based clinics

PURPOSE

Few school-based health centers (SBHC) in the United States dispense contraceptives on-site and little is known about contraceptive continuation in these health centers.

METHODS

An 11-month contraceptive continuation pilot project offering monthly reproductive health assessment and counseling to students enrolled in Baltimore school clinics was evaluated. One hundred-forty-three women voluntarily enrolled in the study over a seven month period. A monthly contraceptive calendar was developed to collect data on contraceptive use, pregnancy and STD risk, sexual behavior and parental support for contraceptive use. Physical assessment was provided as needed to assess the presence of STD's or pregnancy. Data were analyzed for the month prior to enrollment in the program and eleven months after entry into the program.

RESULTS

Both contraceptive (OCP) use and abstinence increased over the course of the program. Condom use remained at approximately 30% with frequent use of OCP's and condoms, condoms or abstinence. Program drop-out was common. Thirteen students became pregnant while enrolled in the program and 35% of the students were diagnosed with one or more sexually transmitted diseases. Partner-switching was common, although two or more partners within any one month was rare.

CONCLUSIONS

Monthly follow-up provided through SBHCs can improve contraceptive use although dropout rate and contraceptive failure remain high.

Nonoperative management of solid organ injuries in children. Is it safe?

OBJECTIVE

The authors reviewed their experience with life-threatening blunt injuries in approximately 2900 children (0-14 years) admitted to the designated state pediatric shock trauma unit between 1990 and 1993.

METHODS

During this time, the authors treated all severely injured children with a prospective, nonoperative protocol if they were hemodynamically stable after less than 40 mL/kg fluid replacement, had proven evidence of solid organ injuries and remained stable in the pediatric intensive care unit under surgical management.

RESULTS

Twenty-eight children had computed tomography (CT) or operatively proven lacerations of the spleen, 25 had lacerations of the liver, 18 had lacerations of the kidney, 7 had lacerations of the pancreas, and 11 had two or more solid organ injuries. Three of the 28 children with injured spleens required laparotomy (two splenectomy, one splenorrhaphy). Two of the 25 children with liver injuries required laparotomy (one suturing, one partial resection). One of the 18 children with kidney injuries required laparotomy (nephrectomy), and 3 of the 7 children with pancreas injuries required laparotomy (two resection, one pseudocyst). There were three deaths after laparotomy (two head, one chest/abdominal). There were no deaths in the children managed nonoperatively, and there were no immediate or long-range complications.

CONCLUSIONS

Comparison of the authors' data with the National Pediatric Trauma Registry shows similar results. The authors believe that nonoperative management of solid organ injuries under careful surgical observation in a pediatric intensive care unit is safe and appropriate.

Bringing parents into school clinics: parent attitudes toward school clinics and contraception

Prior to implementing a change in school clinic policy to allow dispensing of contraceptives, parents of school-based clinic (SBC) enrollees were surveyed regarding attitudes toward clinic quality of care, desired services, and contraceptive distribution. Telephone interviews were conducted with a systematic sample of 262 parents who normally are in charge of the adolescent's health care. Parental opinion was felt to be crucial in shaping Baltimore SBC contraception policy. Parents overwhelmingly endorsed current clinic services including family planning for sexually active teens, annual physicals, and drug and alcohol counseling. Most parents rated the SBC as excellent (25%) or very good (36%), although a substantial minority found it difficult to rate the clinics (27%, "don't know"). Parents with prior verbal contact (45%) were more likely to rate the clinic as excellent (35% versus 16%) and less likely to respond "don't know" (13% versus 38%, p less than 0.001). Parent attitudes toward contraception was context specific: 63% endorsed and 27-30% opposed prescribing and dispensing. If a boy (or girl) was already having sex, 76% (or 75%) of parents supported and 14% (or 17%) opposed providing birth control pills or condoms. With parental permission, 93% supported contraception and only 3% were opposed. No differences were found by age, race, gender, or grade of student. Prior verbal communication with the clinic did not affect parent attitudes toward contraception. Consideration of parent attitudes was critical to changing SBC contraceptive dispensing policy in Baltimore. Contraceptive distribution, after counseling and necessary medical care, was initiated in September 1990. The parent and community response has been very supportive.