An anatomical study of the entry point in the greater trochanter for intramedullary nailing

Malpositioning of the trochanteric entry point during the introduction of an intramedullary nail may cause iatrogenic fracture or malreduction. Although the optimal point of insertion in the coronal plane has been well described, positioning in the sagittal plane is poorly defined. The paired femora from 374 cadavers were placed both in the anatomical position and in internal rotation to neutralise femoral anteversion. A marker was placed at the apparent apex of the greater trochanter, and the lateral and anterior offsets from the axis of the femoral shaft were measured on anteroposterior and lateral photographs. Greater trochanteric morphology and trochanteric overhang were graded. The mean anterior offset of the apex of the trochanter relative to the axis of the femoral shaft was 5.1 mm (sd 4.0) and 4.6 mm (sd 4.2) for the anatomical and neutralised positions, respectively. The mean lateral offset of the apex was 7.1 mm (sd 4.6) and 6.4 mm (sd 4.6), respectively. Placement of the entry position at the apex of the greater trochanter in the anteroposterior view does not reliably centre an intramedullary nail in the sagittal plane. Based on our findings, the site of insertion should be about 5 mm posterior to the apex of the trochanter to allow for its anterior offset.

Characterization of reproductive, metabolic, and endocrine features of polycystic ovary syndrome in female hyperandrogenic mouse models

Polycystic ovary syndrome (PCOS) affects 5-10% of women of reproductive age, causing a range of reproductive, metabolic and endocrine defects including anovulation, infertility, hyperandrogenism, obesity, hyperinsulinism, and an increased risk of type 2 diabetes and cardiovascular disease. Hyperandrogenism is the most consistent feature of PCOS, but its etiology remains unknown, and ethical and logistic constraints limit definitive experimentation in humans to determine mechanisms involved. In this study, we provide the first comprehensive characterization of reproductive, endocrine, and metabolic PCOS traits in 4 distinct murine models of hyperandrogenism, comprising prenatal dihydrotestosterone (DHT, potent nonaromatizable androgen) treatment during days 16-18 of gestation, or long-term treatment (90 days from 21 days of age) with DHT, dehydroepiandrosterone (DHEA), or letrozole (aromatase inhibitor). Prenatal DHT-treated mature mice exhibited irregular estrous cycles, oligo-ovulation, reduced preantral follicle health, hepatic steatosis, and adipocyte hypertrophy, but lacked overall changes in body-fat composition. Long-term DHT treatment induced polycystic ovaries displaying unhealthy antral follicles (degenerate oocyte and/or > 10% pyknotic granulosa cells), as well as anovulation and acyclicity in mature (16-week-old) females. Long-term DHT also increased body and fat pad weights and induced adipocyte hypertrophy and hypercholesterolemia. Long-term letrozole-treated mice exhibited absent or irregular cycles, oligo-ovulation, polycystic ovaries containing hemorrhagic cysts atypical of PCOS, and displayed no metabolic features of PCOS. Long-term dehydroepiandrosterone treatment produced no PCOS features in mature mice. Our findings reveal that long-term DHT treatment replicated a breadth of ovarian, endocrine, and metabolic features of human PCOS and provides the best mouse model for experimental studies of PCOS pathogenesis.

Estimated risk of cancer transmission from organ donor to graft recipient in a national transplantation registry

BACKGROUND

Transplanted organs carry the risk of inadvertent donor cancer transmission. Some cancers in organ donors have been classified as being associated with a high or unacceptable risk, but the evidence for such recommendations is scanty.

METHODS

The risk of cancer transmission from donors characterized as high or unacceptable risk was studied by analysing transplant and cancer registry data. Donors and recipients from England (1990-2008) were identified from the UK Transplant Registry. Cancer details were obtained from cancer registries and classified using guidelines from the Council of Europe and Organ Procurement and Transplantation Network/United Network for Organ Sharing.

RESULTS

Of 17,639 donors, 202 (1.1 per cent) had a history of cancer, including 61 donors with cancers classed as having an unacceptable/high risk of transmission. No cancer transmission was noted in 133 recipients of organs from these 61 donors. At 10 years after transplantation, the additional survival benefit gained by transplanting organs from donors with unacceptable/high-risk cancer was 944 (95 per cent confidence interval (c.i.) 851 to 1037) life-years, with a mean survival of 7.1 (95 per cent c.i. 6.4 to 7.8) years per recipient.

CONCLUSION

Strict implementation of present guidelines is likely to result in overestimation of cancer transmission risk in some donors. Organs from some donors with cancers defined as unacceptable/high risk can be used safely.

Study of Venturi Scrubber Efficiency for Pesticide Industry

A venturi scrubber is designed to effectively use the energy from the inlet gas stream to atomize the liquid being used to scrub the gas stream. This type of technology is a part of the group of air pollution controls. The air pollution generated from the industry is now become serious problem for the environment, which affect the living and non living thing on the Earth. Among all the air pollution monitoring equipment venturi scrubber found to suitable for prevention of air pollution by pesticide. It was found that scrubber shows 99.1 % efficiency.

Study of Venturi Scrubber Efficiency for Pesticide Industry

A venturi scrubber is designed to effectively use the energy from the inlet gas stream to atomize the liquid being used to scrub the gas stream. This type of technology is a part of the group of air pollution controls. The air pollution generated from the industry is now become serious problem for the environment, which affect the living and non living thing on the Earth. Among all the air pollution monitoring equipment venturi scrubber found to suitable for prevention of air pollution by pesticide. It was found that scrubber shows 99.1 % efficiency.

Human α1β3γ2L gamma-aminobutyric acid type A receptors: High-level production and purification in a functional state

Gamma-aminobutyric acid type A receptors (GABA(A)Rs) are the most important inhibitory chloride ion channels in the central nervous system and are major targets for a wide variety of drugs. The subunit compositions of GABA(A)Rs determine their function and pharmacological profile. GABAA Rs are heteropentamers of subunits, and (α1)2 (β3)2 (γ2L)1 is a common subtype. Biochemical and biophysical studies of GABA(A)Rs require larger quantities of receptors of defined subunit composition than are currently available. We previously reported high-level production of active human α1β3 GABA(A)R using tetracycline-inducible stable HEK293 cells. Here we extend the strategy to receptors containing three different subunits. We constructed a stable tetracycline-inducible HEK293-TetR cell line expressing human (N)-FLAG-α1β3γ2L-(C)-(GGS)3 GK-1D4 GABA(A)R. These cells achieved expression levels of 70-90 pmol [(3)H]muscimol binding sites/15-cm plate at a specific activity of 15-30 pmol/mg of membrane protein. Incorporation of the γ2 subunit was confirmed by the ratio of [(3)H]flunitrazepam to [(3)H]muscimol binding sites and sensitivity of GABA-induced currents to benzodiazepines and zinc. The α1β3γ2L GABA(A)Rs were solubilized in dodecyl-D-maltoside, purified by anti-FLAG affinity chromatography and reconstituted in CHAPS/asolectin at an overall yield of ∼ 30%. Typical purifications yielded 1.0-1.5 nmoles of [(3)H]muscimol binding sites/60 plates. Receptors with similar properties could be purified by 1D4 affinity chromatography with lower overall yield. The composition of the purified, reconstituted receptors was confirmed by ligand binding, Western blot, and proteomics. Allosteric interactions between etomidate and [(3)H]muscimol binding were maintained in the purified state.

Cysteine substitutions define etomidate binding and gating linkages in the α-M1 domain of γ-aminobutyric acid type A (GABAA) receptors

Etomidate is a potent general anesthetic that acts as an allosteric co-agonist at GABAA receptors. Photoreactive etomidate derivatives labeled αMet-236 in transmembrane domain M1, which structural models locate in the β+/α- subunit interface. Other nearby residues may also contribute to etomidate binding and/or transduction through rearrangement of the site. In human α1β2γ2L GABAA receptors, we applied the substituted cysteine accessibility method to α1-M1 domain residues extending from α1Gln-229 to α1Gln-242. We used electrophysiology to characterize each mutant's sensitivity to GABA and etomidate. We also measured rates of sulfhydryl modification by p-chloromercuribenzenesulfonate (pCMBS) with and without GABA and tested if etomidate blocks modification of pCMBS-accessible cysteines. Cys substitutions in the outer α1-M1 domain impaired GABA activation and variably affected etomidate sensitivity. In seven of eight residues where pCMBS modification was evident, rates of modification were accelerated by GABA co-application, indicating that channel activation increases water and/or pCMBS access. Etomidate reduced the rate of modification for cysteine substitutions at α1Met-236, α1Leu-232 and α1Thr-237. We infer that these residues, predicted to face β2-M3 or M2 domains, contribute to etomidate binding. Thus, etomidate interacts with a short segment of the outer α1-M1 helix within a subdomain that undergoes significant structural rearrangement during channel gating. Our results are consistent with in silico docking calculations in a homology model that orient the long axis of etomidate approximately orthogonal to the transmembrane axis.

Patient-reporting improves estimates of postoperative complication rates: a prospective cohort study in gynaecological oncology

Background:

Most studies use hospital data to calculate postoperative complication rates (PCRs). We report on improving PCR estimates through use of patient-reporting.

Methods:

A prospective cohort study of major surgery performed at 10 UK gynaecological cancer centres was undertaken. Hospitals entered the data contemporaneously into an online database. Patients were sent follow-up letters to capture postoperative complications. Grade II–V (Clavien–Dindo classification) patient-reported postoperative complications were verified from hospital records. Postoperative complication rate was defined as the proportion of surgeries with a Grade II–V postoperative complication.

Results:

Patient replies were received for 1462 (68%) of 2152 surgeries undertaken between April 2010 and February 2012. Overall, 452 Grade II–V (402 II, 50 III–V) complications were reported in 379 of the 1462 surgeries. This included 172 surgeries with 200 hospital-reported complications and 231 with 280 patient-reported complications. All (100% concordance) 36 Grade III–V and 158 of 280 (56.4% concordance) Grade II patient-reported complications were verified on hospital case-note review. The PCR using hospital-reported data was 11.8% (172 out of 1462; 95% CI 11–14), patient-reported was 15.8% (231 out of 1462; 95% CI 14–17.8), hospital and verified patient-reported was 19.4% (283 out of 1462; 95% CI 17.4–21.4) and all data were 25.9% (379 out of 1462; 95% CI 24–28). After excluding Grade II complications, the hospital and patient verified Grade III–V PCR was 3.3% (48 out of 1462; 95% CI 2.5–4.3).

Conclusion:

This is the first prospective study of postoperative complications we are aware of in gynaecological oncology to include the patient-reported data. Patient-reporting is invaluable for obtaining complete information on postoperative complications. Primary care case-note review is likely to improve verification rates of patient-reported Grade II complications.

State-dependent etomidate occupancy of its allosteric agonist sites measured in a cysteine-substituted GABAA receptor

A central axiom of ligand-receptor theory is that agonists bind more tightly to active than to inactive receptors. However, measuring agonist affinity in inactive receptors is confounded by concomitant activation. We identified a cysteine substituted mutant γ-aminobutyric acid type A (GABAA) receptor with unique characteristics allowing the determination of allosteric agonist site occupancy in both inactive and active receptors. Etomidate, the allosteric agonist, is an anesthetic that activates or modulates α1β2γ2L GABAA receptors via transmembrane sites near β2M286 residues in M3 domains. Voltage-clamp electrophysiology studies of α1β2M286Cγ2L receptors show that GABA is an efficacious agonist and that etomidate modulates GABA-activated activity, but direct etomidate agonism is absent. Quantitative analysis of mutant activity using an established Monod-Wyman-Changeux (MWC) allosteric model indicates that the intrinsic efficacy of etomidate, defined as its relative affinity for active versus inactive receptors, is lower than in wild-type receptors. Para-chloromercuribenzene sulfonate covalently modifies β2M286C side-chain sulfhydryls, irreversibly altering GABA-induced currents. Etomidate concentration dependently reduces the apparent rate of β2M286C-pCMBS bond formation, tracked electrophysiologically. High etomidate concentrations completely protect the β2M286C suflhydryl from covalent modification, suggesting close steric interactions. The 50% protective etomidate concentration (PC50) is 14 μM in inactive receptors and 1.1 to 2.2 μM during GABA-activation, experimentally demonstrating that activated receptors bind etomidate more avidly than do inactive receptors. The experimental PC50 values are remarkably close to, and therefore validate, MWC model predictions for etomidate dissociation constants in both inactive and active receptors. Our results support MWC models as valid frameworks for understanding the agonism, coagonism, and modulation of ligand-gated ion channels.

The pyrrole etomidate analog carboetomidate potently inhibits human 5-HT3A receptor function: comparisons with etomidate and potential implications for emetogenesis

BACKGROUND

5-Hydroxytryptamine type 3 (5-HT(3)) receptors are excitatory ion channels belonging to the cys-loop family of ligand-gated ion channels. They are involved in nausea and vomiting and their antagonists are used clinically as antiemetic drugs. We previously reported the development of a novel pyrrole analog of etomidate, (R)-ethyl 1-(1-phenylethyl)-1H-pyrrole-2-carboxylate (carboetomidate), which retains etomidate's desirable anesthetic and hemodynamic properties, but lacks its potent inhibitory effect on adrenocorticotropic hormone-stimulated steroid synthesis. Also in contrast to etomidate, carboetomidate potently inhibits nicotinic acetylcholine receptors. Because nicotinic acetylcholine and 5-HT(3) receptors are highly homologous, we hypothesized that carboetomidate might also potently inhibit 5-HT(3) receptors with potentially important implications for the drug's emetogenic activity. In the current studies, we investigated and compared modulation of 5-HT(3A) receptors by carboetomidate and etomidate.

METHODS

5-HT(3) receptors were heterologously expressed in human embryonic kidney cells. Drugs were applied with a multichannel superfusion pipette coupled to piezoelectric elements, and currents were recorded from cells in either the whole-cell or excised outside-out patch configuration of patch-clamp recordings.

RESULTS

Carboetomidate and etomidate inhibited integrated 5-HT(3A) receptor-mediated currents with respective half-inhibitory concentrations of 1.9 μM (95% confidence interval [CI] = 1.4-2.7 μM) and 25 μM (95% CI = 17-37 μM). These values may be compared with respective hypnotic concentrations of 5.4 and 2.3 µM. This inhibition reflected hypnotic effects on peak current amplitudes and desensitization rates. Half-inhibitory concentrations for reducing peak current amplitudes were 34 μM (95% CI = 24-48 µM) for carboetomidate and 171 μM (95% CI = 128-228 µM) for etomidate. Half-inhibitory concentrations for reducing the desensitization time constant were 3.5 μM (95% CI = 2.4-5.1 µM) for carboetomidate and 36 μM (95% CI = 21-59 µM) for etomidate.

CONCLUSIONS

In contrast to etomidate, carboetomidate inhibits 5-HT(3A) receptor-mediated currents at hypnotic concentrations. This inhibition is primarily the result of enhancing the rate of desensitization. Because carboetomidate potently inhibits 5-HT(3A) receptors, it may be less emetogenic than etomidate.

Health advantage for black women: patterns in pre-menstrual dysphoric disorder

BACKGROUND

Pre-menstrual dysphoric disorder (PMDD) is commonly studied in white women; consequently, it is unclear whether the prevalence of PMDD varies by race. Although a substantial proportion of black women report symptoms of PMDD, the Biocultural Model of Women's Health and research on other psychiatric disorders suggest that black women may be less likely than white women to experience PMDD in their lifetimes.

METHOD

Multivariate multinomial logistic regression modeling was used with a sample of 2590 English-speaking, pre-menopausal American women (aged 18-40 years) who participated in the Collaborative Psychiatric Epidemiology Surveys in 2001-2003. The sample consisted of 1672 black women and 918 white women. The measure of PMDD yields a provisional diagnosis of PMDD consistent with DSM-IV criteria.

RESULTS

Black women were significantly less likely than white women to experience PMDD [odds ratio (OR) 0.44, 95% confidence interval (CI) 0.25-0.79] and pre-menstrual symptoms (OR 0.64, 95% CI 0.47-0.88) in their lifetimes, independently of marital status, employment status, educational attainment, smoking status, body mass index, history of oral contraceptive use, current age, income, history of past-month mood disorder, and a measure of social desirability. The prevalence of PMDD was 2.9% among black women and 4.4% among white women.

CONCLUSIONS

This study showed for the first time that black women were less likely than white women to experience PMDD and pre-menstrual symptoms, independently of relevant biological, social-contextual and psychological risk factors. This suggests that PMDD may be an exception to the usual direction of racial disparities in health. Further research is needed to determine the mechanisms that explain this health advantage.

High-level expression and purification of Cys-loop ligand-gated ion channels in a tetracycline-inducible stable mammalian cell line: GABAA and serotonin receptors

The human neuronal Cys-loop ligand-gated ion channel superfamily of ion channels are important determinants of human behavior and the target of many drugs. It is essential for their structural characterization to achieve high-level expression in a functional state. The aim of this work was to establish stable mammalian cell lines that enable high-level heterologous production of pure receptors in a state that supports agonist-induced allosteric conformational changes. In a tetracycline-inducible stable human embryonic kidney cells (HEK293S) cell line, GABA(A) receptors containing α1 and β3 subunits could be expressed with specific activities of 29-34 pmol/mg corresponding to 140-170 pmol/plate, the highest expression level reported so far. Comparable figures for serotonin (5-HT(3A)) receptors were 49-63 pmol/mg and 245-315 pmol/plate. The expression of 10 nmol of either receptor in suspension in a bioreactor required 0.3-3.0 L. Both receptor constructs had a FLAG epitope inserted at the N-terminus and could be purified in one step after solubilization using ANTI-FLAG affinity chromatography with yields of 30-40%. Purified receptors were functional. Binding of the agonist [(3)H]muscimol to the purified GABA(A)R was enhanced allosterically by the general anesthetic etomidate, and purified 5-hydroxytryptamine-3A receptor supported serotonin-stimulated cation flux when reconstituted into lipid vesicles.

Possible suppression of fetal erythropoiesis by the Kell blood group antibody anti-Kp(a)

Antibodies to antigens in the Kell blood group system are usually immunoglobulin G, and, notoriously, anti-K, anti-k, and anti-Kp(a) can cause severe hemolytic transfusion reactions, as well as severe hemolytic disease of the fetus and newborn (HDFN). It has been shown that the titer of anti-K does not correlate with the severity of HDFN because, in addition to immune destruction of red blood cells (RBCs), anti-K causes suppression of erythropoiesis in the fetus, which can result in severe anemia. We report a case involving anti-Kp(a) in which one twin was anemic and the other was not. Standard hemagglutination and polymerase chain reaction (PCR)-based tests were used. At delivery, anti-Kp(a) was identified in serum from the mother and twin A, and in the eluate prepared from the baby’s RBCs. PCR-based assays showed twin A (boy) was KEL*841T/C (KEL*03/KEL*04), which is predicted to encode Kp(a+b+). Twin B (girl) was KEL*841C/C (KEL*04/KEL*04), which is predicted to encode Kp(a–b+). We describe the first reported case of probable suppression of erythropoiesis attributable to anti-Kp(a). One twin born to a woman whose serum contained anti-Kp(a) experienced HDFN while the other did not. Based on DNA analysis, the predicted blood type of the affected twin was Kp(a+b+) and that of the unaffected twin was Kp(a–b+). The laboratory findings and clinical course of the affected twin were consistent with suppression of erythropoiesis in addition to immune RBC destruction.

p-Trifluoromethyldiazirinyl-etomidate: a potent photoreactive general anesthetic derivative of etomidate that is selective for ligand-gated cationic ion channels

We synthesized the R- and S-enantiomers of ethyl 1-(1-(4-(3-((trifluoromethyl)-3H-diazirin-3-yl)phenyl)ethyl)-1H-imidazole-5-carboxylate (trifluoromethyldiazirinyl-etomidate), or TFD-etomidate, a novel photoactivable derivative of the stereoselective general anesthetic etomidate (R-(2-ethyl 1-(phenylethyl)-1H-imidazole-5-carboxylate)). Anesthetic potency was similar to etomidate's, but stereoselectivity was reversed and attenuated. Relative to etomidate, TFD-etomidate was a more potent inhibitor of the excitatory receptors, nAChR (nicotinic acetylcholine receptor) ((alpha1)(2)beta1delta1gamma1) and 5-HT(3A)R (serotonin type 3A receptor), causing significant inhibition at anesthetic concentrations. S- but not R-TFD-etomidate enhanced currents elicited from inhibitory alpha1beta2gamma2L GABA(A)Rs by low concentrations of GABA, but with a lower efficacy than R-etomidate, and site-directed mutagenesis suggests they act at different sites. [(3)H]TFD-etomidate photolabeled the alpha-subunit of the nAChR in a manner allosterically regulated by agonists and noncompetitive inhibitors. TFD-etomidate's novel pharmacology is unlike that of etomidate derivatives with photoactivable groups in the ester position, which behave like etomidate, suggesting that it will further enhance our understanding of anesthetic mechanisms.