Defining blood gas analysis stability limits across five sample types.

Accurate reporting of blood gas samples is dependent upon following proper preanalytical sample handling requirements though there is variation for sample acceptability criteria across institutions. We examined five common sample types (arterial, venous, umbilical arterial, umbilical venous and capillary) stored at either room temperature or on crushed ice in a time series (0, 15, 30, 45, 60, 90, 180, 240 min) and applied local regulatory and/or institutional allowable performance limits to determine the need for cold preservation and/or maximum stability time for pH, pO2, pCO2, glucose, lactate, sodium, potassium, chloride, and ionized calcium where applicable in each sample type. Although changes in sample pO2 and/or lactate values were responsible, in part or in whole, for surpassing the allowable limits in nearly all sample types analyzed, this was not uniformly observed across sample types within the typical time limits that are referenced in literature. Furthermore, we demonstrated that cold preservation may not ubiquitously provide longer stability for blood gas specimens and this is dependent on the sample type and analyte in question. Nevertheless, these results demonstrate the known instability of pO2 and lactate and suggest that it may be possible to simplify the monitoring of preanalytical conditions by first evaluating pO2 and lactate in patient blood gas samples if applicable.

Design of a simple radio frequency circuit for implementing the open-ended coaxial probe method for permittivity measurement.

The development of electromagnetic (EM)-based therapeutic and diagnostic tools, as well as safety assessment of EM interactions with the human body, requires adequate measurement of the complex permittivity of different biological tissues. Such measurement techniques must be low-cost, readily available, and easy to implement. In this study, a simple circuit with basic radio frequency electronics was used to implement the open-ended coaxial probe method for permittivity measurement, as opposed to the widely used vector network analyzers. The non-ideal behavior of the circuit due to spurious reflections and ohmic losses was accounted for by a scattering matrix (SM) that relates the measured reflection coefficient to the true reflection coefficient at the probe tip. Parameters of SM were obtained using three calibration standards, and the circuit was used to measure the complex permittivity of a standard, tissue-equivalent, American Society of Testing Materials (ASTM) polymer gel. A more intuitive approach to circuit analysis is also introduced. For both methods, the dielectric constant and electrical conductivity of the gel were found to agree with the recommended uncertainties of the ASTM standard and validate the utility of the circuit at the test frequency.

Assessment of the Safety and Efficacy of Pre-emptive Use of Extended-release Buprenorphine for Mouse Laparotomy.

Buprenorphine is commonly used to control postoperative pain in rodents. Short-acting formulations of buprenorphine (bup-HCl) require frequent handling and restraint of animals for appropriate dosing, which can be stressful and confound research outcomes. Ethiqa XR (bup-ER) is an FDA-indexed extended-release buprenorphine formulation that is an alternative to bup-HCl in mice and rats. In the current study, we first evaluated the pharmacokinetics of bup-ER in male C57BL/6J mice by sampling blood at 10 time points, ranging from 30 min to 72 h after administration (n = 3 mice per time point). Average plasma concentrations fell below therapeutic levels at 48 h after administration. We also evaluated the safety of bup-ER when administered prior to surgery in combination with common anesthetics and the efficacy of bup-ER in mouse laparotomy. Anesthetic safety was studied by measuring respiratory rate, rectal temperature, and recovery time in groups of mice (n = 8) given bup-HCl, bup-ER, or saline in combination with isoflurane or ketamine-xylazine anesthesia. No differences were seen between analgesic treatment groups with either of the general anesthetics. To evaluate efficacy, mice (n = 10) were randomly allocated to receive either bup-ER (3.25 mg/kg) once presurgically, bup-HCl (0.1 mg/kg) presurgically and then every 8 h, or saline once before surgery. Mice underwent a sham laparotomy and were assessed for pain based on changes in weight, cageside ethogram, nesting consolidation test, rearing frequency, and nociception to von Frey testing at 6, 12, 24, 48, and 72 h after surgery. Cageside ethogram, rearing frequency, and von Frey testing showed significant differences between bup-ER-treated mice and saline controls in the early postoperative period. No significant effects between treatment groups were seen in daily weights or nesting consolidation scores. This study demonstrates that bup-ER can be safely administered before surgery and provides analgesia for up to 48 h after administration based on pharmacokinetic and behavioral data.

Mitochondrial permeability transition pore induction is linked to formation of the complex of ATPase C-subunit, polyhydroxybutyrate and inorganic polyphosphate.

Mitochondrial permeability transition pore (mPTP) opening allows free movement of ions and small molecules leading to mitochondrial membrane depolarization and ATP depletion that triggers cell death. A multi-protein complex of the mitochondrial ATP synthase has an essential role in mPTP. However, the molecular identity of the central 'pore' part of mPTP complex is not known. A highly purified fraction of mammalian mitochondria containing C-subunit of ATPase (C-subunit), calcium, inorganic polyphosphate (polyP) and polyhydroxybutyrate (PHB) forms ion channels with properties that resemble the native mPTP. We demonstrate here that amount of this channel-forming complex dramatically increases in intact mitochondria during mPTP activation. This increase is inhibited by both Cyclosporine A, an inhibitor of mPTP and Ruthenium Red, an inhibitor of the Mitochondrial Calcium Uniporter. Similar increases in the amount of complex formation occurs in areas of mouse brain damaged by ischemia-reperfusion injury. These findings suggest that calcium-induced mPTP is associated with de novo assembly of a channel comprising C-subunit, polyP and PHB.

An ex vivo co-culture model system to evaluate stromal-epithelial interactions in breast cancer.

Breast cancer is the most commonly diagnosed cancer among women worldwide. High breast cancer incidence and mortality rates, especially in obese patients, emphasize the need for a better biological understanding of this disease. Previous studies provide substantial evidence for a vital role of the local extracellular environment in multiple steps of tumor progression, including proliferation and invasion. Current evidence supports the role of adipocytes as an endocrine organ, which produces steroid hormones, pro-inflammatory cytokines and adipokines, such as leptin. To further define the role of the mammary microenvironment on tumorigenesis, we have developed an adipose-tumor epithelial cell co-culture system designed to reproduce the in vivo mammary environment. We validate this model through use of coherent anti-Stokes Raman scattering (CARS) microscopy, a label-free vibrational imaging technique. CARS analysis demonstrates the sustained viability of the adipocytes, and that mammary cancer cell morphology parallels that of tumors in vivo. Also, characterized was the influence of mammary adipose tissue on tumor cell growth and migration. Adipose tissue co-cultured with mammary tumor epithelial cells, in the absence of any serum or supplemental growth factors, resulted in substantial increases in growth and migration of tumor cells. In conclusion, this novel co-culture system provides an ideal model to study epithelial-stromal interactions in the mammary gland. Understanding the relationship between adipose tissue, the most abundant and least studied component of the breast stroma and tumor epithelial cells is critical to clarifying the influence of obesity on the development, progression and prognosis of breast cancer.

The 15° face-changing acetabular component for treatment of osteoarthritis secondary to developmental dysplasia of the hip.

We report the use of a 15° face-changing cementless acetabular component in patients undergoing total hip replacement for osteoarthritis secondary to developmental dysplasia of the hip. The rationale behind its design and the surgical technique used for its implantation are described. It is distinctly different from a standard cementless hemispherical component as it is designed to position the bearing surface at the optimal angle of inclination, that is, < 45°, while maximising the cover of the component by host bone.

Obesity prevention in the family day care setting: impact of the Romp & Chomp intervention on opportunities for children's physical activity and healthy eating.

BACKGROUND: The Romp & Chomp intervention reduced the prevalence of overweight/obesity in pre-school children in Geelong, Victoria, Australia through an intervention promoting healthy eating and active play in early childhood settings. This study aims to determine if the intervention successfully created more health promoting family day care (FDC) environments. METHODS: The evaluation had a cross-sectional, quasi-experimental design with the intervention FDC service in Geelong and a comparison sample from 17 FDC services across Victoria. A 45-item questionnaire capturing nutrition- and physical activity-related aspects of the policy, socio-cultural and physical environments of the FDC service was completed by FDC care providers (in 2008) in the intervention (n= 28) and comparison (n= 223) samples. RESULTS: Select results showed intervention children spent less time in screen-based activities (P= 0.03), organized active play (P < 0.001) and free inside play (P= 0.03) than comparison children. There were more rules related to healthy eating (P < 0.001), more care provider practices that supported children's positive meal experiences (P < 0.001), fewer unhealthy food items allowed (P= 0.05), higher odds of staff being trained in nutrition (P= 0.04) and physical activity (P < 0.001), lower odds of having set minimum times for outside (P < 0.001) and organized (P= 0.01) active play, and of rewarding children with food (P < 0.001). CONCLUSIONS: Romp & Chomp improved the FDC service to one that discourages sedentary behaviours and promotes opportunities for children to eat nutritious foods. Ongoing investment to increase children's physical activity within the setting and improving the capacity and health literacy of care providers is required to extend and sustain the improvements.

Using semi-automated image processing and desktop systems to incorporate actual patient volumetric data in immersive surgical planning and viewing systems for multiple patients.

This paper describes how patient specific volumetric data are managed from image acquisition through final processing for the purposes of creating a 3D VR rendering of user selected and manipulated 3D models. The system described here allows for the development of quick, inexpensive, and clinician manipulated patient-specific models. The utility of this process is demonstrated by being able to move VRML models to desktop or immersive environments for both pre-operative planning and patient-specific surgical and anatomical training.

The colon cancer burden of genetically defined hereditary nonpolyposis colon cancer.

BACKGROUND & AIMS: Estimates of the frequency of hereditary nonpolyposis colon cancer (HNPCC) based on clinical criteria have varied widely. Recent studies of germline mismatch repair gene mutations have suggested that HNPCC accounts for close to 3% of all colon cancer, but this estimate may have been inflated by inclusion of founder effects peculiar to Finland. We therefore determined by genetic criteria the colon cancer burden associated with HNPCC in a population-based study of 1066 individuals from Utah and California. METHODS: The coding regions of mismatch repair genes hMSH2 and hMLH1 were sequenced from the germline of those individuals whose tumors exhibited microsatellite instability. RESULTS: Microsatellite instability was present in 16% (171/1066) of tumors. Pathogenic germline mismatch repair gene mutations were identified in 7 individuals, and missense amino acid changes of uncertain significance were identified in another 6 individuals. After adjusting for the availability of sufficient germline DNA for sequencing, the 7 clearly pathogenic mutations accounted for 0.86% of colon cancer at the population level. Individuals with these mutations were significantly younger, more likely to have a family history of colon and endometrial cancer, and more likely to have first-degree relatives with a young-age onset of colon cancer than individuals with unstable tumors but without germline mutations (P < 0.01). CONCLUSIONS: We conclude that genetically defined HNPCC accounts for a very small percentage of colon cancer at the population level, a percentage less than that estimated by most previous clinical studies.

Inverse relationship between microsatellite instability and K-ras and p53 gene alterations in colon cancer.

Some studies have shown an inverse relationship between microsatellite instability in colon cancer and mutations in p53 and K-ras, whereas others have not. We therefore evaluated these features in a population-based sample of 496 individuals with colon cancer. Microsatellite instability was determined by a panel of 10 tetranucleotide repeats, the Bethesda consensus panel of mono- and dinucleotide repeats, and coding mononucleotide repeats in transforming growth factor-beta receptor type II, hMSH3, BAX, hMSH6, and insulin-like growth factor receptor type II. Mutations in codons 12 and 13 in K-ras were evaluated by sequencing. p53 overexpression (as detected by immunohistochemistry) was used as an indicator of p53 mutation; this was evaluated in 275 of the tumors. K-ras mutations were present in 33.2% of tumors, p53 overexpression in 51.5%, and microsatellite instability (as determined by the Bethesda consensus panel) in 12.5%. K-ras mutations were significantly less common in unstable tumors than stable tumors (11.8% versus 36.9%, P: < 0.001). p53 overexpression was significantly less common in unstable tumors than stable tumors (20.0% versus 55.7%, P: < 0.001). These inverse relationships between microsatellite instability and ras gene mutations and p53 overexpression were shown to be independent of tumor site in logistic regression analyses. All other measures of instability also showed statistically significant inverse relationships independent of tumor site with alterations in ras and p53, and instability results determined by the panel of 10 tetranucleotide repeats were highly significantly related to those determined by the Bethesda consensus panel. Coding mononucleotide repeat mutations were significantly more common in unstable tumors than stable tumors (85.7% versus 1.0%, P: < 0.001). We conclude that there is an inverse relationship between microsatellite instability and mutations in p53 and K-ras, and that the molecular profile of colon cancers with microsatellite instability is characterized by relatively infrequent mutations in K-ras and p53 and relatively frequent mutations in coding mononucleotide repeats.

Primary nodal marginal zone B-cell lymphoma arising from more than one clonal neoplastic population.

Primary nodal marginal zone B-cell lymphoma is an uncommon monoclonal B-cell lymphoproliferative disorder. We report a case of a 79-year-old woman who presented with generalized lymphadenopathy. Histologic and immunohistochemical examinations of biopsy sections from an axillary lymph node were consistent with nodal marginal zone B-cell lymphoma. Flow cytometry analysis showed 2 distinct clonal B-cell populations expressing lambda or kappa light chain restriction. Subsequently, genomic deoxyribonucleic acid (DNA) isolated from a paraffin-embedded lymph node section was analyzed for the presence of gene rearrangements. Polymerase chain reaction (PCR) analysis of immunoglobulin heavy chain genes revealed 3 rearranged DNA bands, confirming the presence of more than one clonal B-cell population. These immunophenotypic and genotypic findings have not been previously described in association with this type of lymphoma. To our knowledge, this represents the first reported case of biclonal nodal marginal zone B-cell lymphoma.

Anosognosia and asomatognosia during intracarotid amobarbital inactivation.

BACKGROUND: Anosognosia (i.e., denial of hemiparesis) and asomatognosia (i.e., inability to recognize the affected limb as one's own) occur more frequently with right cerebral lesions. However, the incidence, relative recovery, and underlying mechanisms remain unclear. METHODS: Anosognosia and asomatognosia were examined in 62 patients undergoing the intracarotid amobarbital procedure as part of their preoperative evaluation for epilepsy surgery. Additional questions were asked in the last 32 patients studied. RESULTS: During inactivation of the non-language-dominant cerebral hemisphere, 88% of the 62 patients were unaware of their paralysis, and 82% could not recognize their own hand at some point. Only 3% did not exhibit anosognosia or asomatognosia. In general, asomatognosia resolved earlier than anosognosia. When patients could not recognize their hand, they uniformly thought that it was someone else's hand. Dissociations in awareness were seen in the second series of 32 patients. Although 23 patients (72%) thought that both arms were in the air, 31% pointed to the correct position of the paralyzed arm on the table. Despite the inability of 24 of 32 patients (75%) to recognize their own hand, 21% of these patients were aware that their arm was weak, and 38% had correctly located their paralyzed arm on the angiography table. CONCLUSIONS: Anosognosia and asomatognosia are both common during acute dysfunction of the non-language-dominant cerebral hemisphere. Dissociations of perception of location, weakness, and ownership of the affected limb are frequent, as are misperceptions of location and body part identity. The dissociations suggest that multiple mechanisms are involved.

The roles of clinical assessment, human chorionic gonadotropin assays, and ultrasonography in medical abortion practice.

The clinical assessment of patients who request early medical abortion includes confirmation of the diagnosis of pregnancy and estimation of gestational age. Accurate gestational dating is essential, because the efficacies of medical abortion regimens decline as pregnancy advances. Whereas medical abortion researchers in the United States have relied on routine ultrasonography for gestational dating, abortion providers experienced with mifepristone and prostaglandin regimens outside the United States have reported high efficacy and safety primarily with clinical dating parameters. Diligent follow-up of patients allows clinicians to confirm that complete abortion has occurred without complications. In cases of uncertain outcome or suspected ectopic pregnancy, transvaginal ultrasonography and beta-human chorionic gonadotropin assays can assist in prompt diagnosis and management. As medical abortion with mifepristone and misoprostol becomes more prevalent in the United States, studies will be needed to further evaluate the effects of these modalities on medical abortion outcomes.

Effect of molecular structure on the performance of triarylmethane dyes as therapeutic agents for photochemical purging of autologous bone marrow grafts from residual tumor cells.

Extensively conjugated cationic molecules with appropriate structural features naturally accumulate into the mitochondria of living cells, a phenomenon typically more prominent in tumor than in normal cells. Because a variety of tumor cells also retain pertinent cationic structures for longer periods of time compared with normal cells, mitochondrial targeting has been proposed as a selective therapeutic strategy of relevance for both chemotherapy and photochemotherapy of neoplastic diseases. Here we report that the triarylmethane dye crystal violet stains cell mitochondria with efficiency and selectivity, and is a promising candidate for photochemotherapy applications. Crystal violet exhibits pronounced phototoxicity toward L1210 leukemia cells but comparatively small toxic effects toward normal hematopoietic cells (murine granulocyte-macrophage progenitors, CFU-GM). On the basis of a comparative examination of chemical, photochemical, and phototoxic properties of crystal violet and other triarylmethane dyes, we have identified interdependencies between molecular structure, and selective phototoxicity toward tumor cells. These structure-activity relationships represent useful guidelines for the development of novel purging protocols to promote selective elimination of residual tumor cells from autologous bone marrow grafts with minimum toxicity to normal hematopoietic stem cells.

Cerebral lateralization: relationship of language and ideomotor praxis.

OBJECTIVE: To determine the relationship of language lateralization and hand preference to praxis performance following left and right hemispheric amobarbital-induced inactivations. BACKGROUND: Patients who are aphasic from left cerebral dysfunction also frequently exhibit ideomotor apraxia in which they make temporal, spatial, and postural errors of learned skilled movements. However, hemispheric lateralization of the systems mediating ideomotor praxis in patients with atypical cerebral language dominance (i.e., bilateral or right hemispheric language function) remains uncertain. METHODS: Subjects included 90 patients with intractable seizures who were undergoing the intracarotid amobarbital procedure (IAP) as part of their preoperative evaluation for epilepsy surgery. Hand preference was determined by the Benton Handedness Questionnaire. Praxis was assessed by the subject's performance when pantomiming the use of four pictured tools. RESULTS: During left IAP, patients with typical language dominance made more ideomotor apraxic errors than did patients with atypical language dominance. During right IAP, patients with atypical language dominance made more ideomotor apraxic errors than did patients with typical language dominance. Overall, patients with atypical language dominance made fewer ideomotor apraxic errors than did patients with typical language dominance. These relationships were present irrespective of hand preference. CONCLUSIONS: Language dominance is more closely associated with the laterality of temporal and spatial movement representations (i.e., ideomotor praxis dominance) than is hand preference. Patients with atypical language dominance exhibit more bilateral cerebral distribution of both language and praxis function.

Tyrosine kinase-independent inhibition of cyclic-AMP phosphodiesterase by genistein and tyrphostin 51.

The phosphodiesterase activity in the HT4.7 neural cell line was pharmacologically characterized, and phosphodiesterase isozyme 4 (PDE4) was found to be the predominant isozyme. The Km for cAMP was 1-2 microM, indicative of a "low Km" phosphodiesterase, and the activity was inhibited by PDE4-selective inhibitors rolipram and Ro20-1724, but not PDE3- or PDE2-selective inhibitors. Calcium, calmodulin, and cGMP, regulators of PDE1, PDE2, and PDE3, had no effect on cAMP hydrolysis. The protein tyrosine kinase inhibitor, genistein, inhibited HT4.7 cAMP phosphodiesterase activity by 85-95% with an IC50 of 4 microM; whereas daidzein, an inactive structural analog of genistein, had little effect on phosphodiesterase activity. This is a common pharmacological criterion used to implicate the regulation by a tyrosine kinase. However, genistein still inhibited phosphodiesterase activity with a mixed pattern of inhibition even when ion-exchange chromatography was used to partially purify phosphodiesterase away from the tyrosine kinase activity. Moreover, tyrphostin 51, another tyrosine kinase inhibitor, was found to also inhibit partially purified phosphodiesterase activity noncompetitively. These data suggest that HT4.7 phosphodiesterase activity is dominated by PDE4 and can be regulated by genistein and tyrphostin 51 by a tyrosine kinase-independent mechanism.

Outcomes of suction curettage and mifepristone abortion in the United States. A prospective comparison study.

A prospective, nonconcurrent cohort analysis of 178 mifepristone/misoprostol and 199 suction curettage abortion subjects, ages > or = 18 years, with intrauterine pregnancies < or = 63 days estimated gestational age, was conducted to compare the outcomes of suction curettage abortion to those of medical abortion. The medical abortion subjects received 600 mg of mifeprisone orally, followed by 400 micrograms of oral misoprostol 2 days later. Surgical abortion subjects underwent electronic vacuum aspiration. All subjects were followed for 2 weeks or until the absence of clinical bleeding. Outcome measures included a successful abortion (complete abortion without a surgical intervention), duration of bleeding, and morbidity. Overall, 18.3% medical and 4.7% surgical patients failed their primary procedure and received an unanticipated suction curettage (RR 3.93, 95% CI 1.87, 8.29). Four mifepristone subjects required curettage for acute bleeding, nine to manage ongoing pregnancy, and five for incomplete abortion. Fourteen mifepristone and eight surgical subjects required curettage for persistent bleeding. The median time delay for therapeutic curettage was significantly longer in the medical abortion group (35 versus 8 days; Mann-Whitney U = 17.0, p = 0.008). Medical subjects experienced significantly longer bleeding (mean difference = 9.6 days, 95% CI 6.8, 12.4). No significant change in hemoglobin occurred in either group. Mifepristone patients reported significantly greater pain (77.1% vs 10.5%; RR 7.4, 95% CI 4.7, 11.5), and nausea or vomiting (68.6% vs 0.6%; RR 117.9, 95% CI 16.7, 834.7). Women receiving mifepristone/misoprostol are more likely to require an unplanned surgical intervention than women who undergo suction curettage. They experience more discomfort with their procedure and in the follow-up interval, bleed for a longer period, and remain at risk for surgical completion curettage for several weeks.

PIP: A prospective, nonconcurrent cohort analysis was conducted to compare the outcomes of suction curettage abortion to those of medical abortion in the US. The study included 178 mifepristone/misoprostol and 199 curettage abortion subjects, ages 18 years or older, with intrauterine pregnancies of 63 or fewer days. Medical abortion subjects received 600 mg of mifepristone orally, followed by 400 mcg of oral misoprostol 2 days later. Surgical abortion subjects underwent electronic vacuum aspiration. Results showed that 18.3% of medical and 4.7% of surgical patients failed their primary procedure and received an unanticipated suction curettage. Medical subjects experienced significantly longer bleeding; however, no significant change in hemoglobin occurred in either group. While, mifepristone patients reported significantly greater pain, nausea or vomiting. Thus, women receiving mifepristone/misoprostol are more likely to require an unplanned surgical intervention than women who undergo curretage. Medical abortion patients have more discomfort, they bleed longer, and remain at risk for surgical completion curettage for several weeks.

Effect of low-dose oral contraceptives on androgenic markers and acne.

Oral contraceptives (OC) suppress excess androgen production; however, different progestins in combination with low-dose estrogens produce divergent effects on sex hormone-binding globulin (SHBG) and testosterone that may influence clinical outcomes. This multicenter, open-label, randomized study compared biochemical androgen profiles and clinical outcomes associated with two OC containing the same amounts of ethinyl estradiol (EE, 20 micrograms) but different progestins, levonorgestrel (LNG, 100 micrograms), and norethindrone acetate (NETA, 1000 micrograms). Fifty-eight healthy women (18-28 years old) received three cycles of treatment with LNG/EE (n = 30) or NETA/EE (n = 28). The results showed that LNG reduced androgen levels in three compartments--adrenal, ovarian, and peripheral. NETA reduced only adrenal and peripheral androgens. Despite a 2.2-fold greater relative increase in SHBG with NETA than LNG, bioavailable testosterone (T) was reduced by the same amount with LNG and NETA. Both treatments improved acne and were well tolerated. Low-dose OC (EE, 20 micrograms) are effective in reducing circulating androgens and acne lesions without causing weight gain. Although LNG and NETA affected secondary markers differently, both OC formulations produced an equivalent decrease in bioavailable.

PIP: Oral contraceptives (OCs) suppress excess androgen production; however, different progestins in combination with low-dose estrogens produce divergent effects on sex hormone-binding globulin (SHBG) and testosterone that may influence clinical outcomes. This multicenter, open-label, randomized study compared biochemical androgen profiles and clinical outcomes associated with 2 OCs containing the same amounts of ethinyl estradiol (EE, 20 mcg) but different progestins, levonorgestrel (LNG, 100 mcg), and norethindrone acetate (NETA, 1000 mcg). 58 healthy women aged 18-28 years received 3 cycles of treatment with LNG/EE (n = 30) or NETA/EE (n = 28). The results showed that LNG reduced androgen levels in 3 compartments-adrenal, ovarian, and peripheral. NETA reduced only adrenal and peripheral androgens. Despite a 2.2-fold greater relative increase in SHBG with NETA than LNG, bioavailable testosterone (T) was reduced by the same amount with LNG and NETA. Both treatments improved acne and were well tolerated. Low-dose OC (EE, 20 mcg) are effective in reducing circulating androgens and acne lesions without causing weight gain. Although LNG and NETA affected secondary markers differently, both OC formulations produced an equivalent decrease in bioavailable T.

The use of bupropion hydrochloride for smoking cessation therapy.

All healthcare providers have an obligation to promote smoking cessation to their patients who smoke. While patients are advised to stop smoking, the use of specific smoking cessation strategies is rarely addressed by primary care providers. This article discusses smoking cessation for two specifically vulnerable groups: women and African-Americans. Both groups have been identified as having increased rates of nicotine metabolism and may be less likely to respond effectively to nicotine replacement for smoking cessation. Increased nicotine metabolism results in greatest difficulty with successful smoking cessation and creates an increased vulnerability to a wide range of cardiovascular and respiratory health problems associated with smoking. Nicotine replacement therapy for smoking cessation has been the most common treatment available; however, many patients have not been successful with that method, and a majority (75%) of smokers who attempt to stop smoking return to smoking. The use of bupropion hydrochloride (Zyban) as a nonnicotine replacement therapy for smoking cessation is discussed. Relapses in smoking cessation are due to nicotine craving and the attempt to alleviate symptoms of nicotine withdrawal. Bupropion hydrochloride, an oral antidepressant, is believed to work by elimination of nicotine cravings and to decrease the physiologic and psychologic symptoms associated with nicotine withdrawal. Patients who have not been successful in smoking cessation may benefit from bupropion hydrochloride therapy in conjunction with counseling and behavior modification.

Positive and negative discrimination of estrogen receptor agonists and antagonists using site-specific DNA recombinase fusion proteins.

Activation of the estrogen receptor (ER) by hormone involves at least two steps. First, hormone binding initially relieves repression, a property imposed on ER in cis by its ligand-binding domain (EBD). Subsequently, the derepressed ER binds specific genomic sites and regulates transcription. In addition to the natural hormone, ER binds a broad range of ligands that evoke a spectrum of responses ranging from full ER activation by agonists to partial activation and inhibition by partial or complete antagonists. How these different ligands evoke different ER responses remains unclear. To address this issue, we have developed a nontranscriptional assay for ER ligand responsiveness based on Flp recombinase/human EBD protein chimeras. These fusion proteins transduce the transient event of ligand binding into a permanent DNA change in a human cell line system. A fusion protein including ER D, E, and F domains was activated by all the ER ligands tested, demonstrating that both agonists and antagonists serve to relieve initial repression, and that differences between them lie downstream in the activation pathway. Mutant variants of the Flp-ER protein that distinguish between agonists and antagonists, and a mutant EBD that selectively lost the ability to respond to 17beta,-estradiol but not to other ligands, were also identified. Thus, agonists and antagonists can be functionally distinguished in a nontranscriptional assay.