The role of allelic variation in estrogen receptor genes and major depression in the Nurses Health Study.

PURPOSE: The role of exogenous and endogenous sex hormones in the etiology of depression remains elusive, in part because sex hormone variation is often correlated with behaviors, life stage changes, and other factors that may influence depression. Estrogen receptor alpha (ESR1) and beta (ESR2) are known to regulate gene expression and estrogen response in areas of the brain associated with major depression and are unlikely to be correlated with exogenous factors that may influence depression. METHODS: We examined whether functional polymorphisms in these genes are associated with lifetime major depression and chronic major depression among a sample of women from the Nurses' Health Study II (N = 2527). DSM-IV depressive disorder symptoms were assessed by structured interview in 2007. Genotyping was performed on DNA extracted from blood using Taq-man. RESULTS: Women with the AA alleles of ESR2 RS4986938 had the higher prevalence of lifetime major depression than women with other allele frequencies (36.7 % for those with AA versus 28.5 % with GA and 29.1 % with GG, p = 0.02) and chronic major depression (14.7 % for those with AA versus 9.3 % with GA and 9.1 % with GG, p = 0.01). History of post-menopausal hormone (PMH) use modified the association of ESR1 polymorphism RS2234693 with any lifetime depression; specifically, those with the TT allele had the highest risk of lifetime depression among PMH users, and the lowest risk of depression among non-PMH users (p value for interaction = 0.02). Further, carriers of the AA alleles in ESR1 polymorphism RS9340799 had increased prevalence of lifetime major depression only among lifetime PMH users (p = 0.007). CONCLUSIONS: Our findings support the hypothesis that estrogen receptor polymorphisms influence risk for major depression; the role of estrogen receptors and other sex steroid-related genetic factors may provide unique insights into etiology.

Tumour-like presentations of anogenital herpes simplex in HIV-positive patients.

Genital and perianal ulcers seen in patients with HIV are commonly due to herpes simplex virus (HSV) infection. While it is well known that the characteristic presentation of HSV is a vesicular rash or crops of erosions, the clinical presentation of genital HSV infection in HIV is varied and can assume vegetative, hypertrophic, condyloma-like, nodular, ulcerative and tumour-like nodules or plaques. These unusual presentations often lead to a delayed diagnosis. We describe five immunocompromised HIV-positive patients with CD4 counts ranging from 114 to 326 cells/µL with unusual presentations of anogenital herpes.

Endobronchial stenting in the management of large airway pathology.

Endobronchial interventions including the deployment of endobronchial stents have a clear role in the management of central airway problems. The use of endobronchial stents has rapidly increased since the first airway stent was developed in the 1960s and with the subsequent manufacture of improved silicone and metallic stents. They provide effective relief for symptoms of intrinsic and extrinsic airway obstruction secondary to a wide range of pathologies including lung cancer, lymphoma, thyroid carcinoma and benign disease such as tracheal strictures and tracheobronchomalacia. Endobronchial stents can also seal defects within the airway including malignant broncho-oesophageal fistulae and posterior wall tracheal tears. They can be placed safely under conscious sedation at flexible bronchoscopy or under general anaesthetic at rigid bronchoscopy. Rigid bronchoscopy under general anaesthesia provided by a multidisciplinary team is safe with few contraindications. Complications of endobronchial stents include infection, granulation tissue formation and metallic stent fracture sometimes requiring removal, although serious life-threatening complications are very rare. Increasing numbers of patients are being referred to specialist centres for airway intervention. This article reviews the history of endobronchial stents, the different stents available, and the indications, outcomes and complications involved in deploying endobronchial stents.

SERCA2A overexpression decreases the incidence of aftercontractions in adult rabbit ventricular myocytes.

K. Davia, E. Bernobich, H. K. Ranu, F. del Monte, C. M. N. Terracciano, K. T. MacLeod, D. L. Adamson, B. Chaudhri, R. J. Hajjar and S. E. Harding. SERCA2a Overexpression Decreases the Incidence of Aftercontractions in Adult Rabbit Ventricular Myocytes. Journal of Molecular and Cellular Cardiology (2001) 33, 1005-1015. Slow relaxation and poor contractile response to increasing stimulation frequency in failing human heart have been strongly linked to a decrease in the activity of the sarcoplasmic reticulum (SR) Ca(2+)-ATPase (SERCA2a). Restoration of SERCA2a levels using gene transfer has beneficial effects on contractile function but, like beta -adrenoceptor stimulation, could potentially produce excess SR Ca(2+), arrhythmias and cell death. We have examined the effects of SERCA2a overexpression in adult rabbit cardiac myocytes, and compared changes in relaxation with those following beta -adrenoceptor stimulation. Myocytes were infected with an adenovirus carrying both SERCA2a and green fluorescent protein (GFP) for positive identification of infected cells. Myocyte survival was significantly enhanced in the infected cultures. There was a reduction in both time-to-peak contraction and time-to-50% relaxation (R50) 48 h after infection. Time-to-90% relaxation (R90) was particularly improved (non-infected 516+/-41 ms, AD.SERCA2a-GFP 230+/-23 ms, n=7 preparations, P<0.001). There was also a decreased incidence of aftercontractions in Ad.SERCA2a-GFP infected myocytes (21+/-5%v 41+/-4% in controls, P<0.01). This contrasts with beta -adrenoceptor stimulation, which reduced R50 but prolonged R90 by 158+/-76 ms (P<0.02, n=16). At higher stimulation frequencies (2-3 Hz) contraction amplitude and SR calcium content were increased and diastolic contracture was reduced following SERCA2a overexpression. Overall, increasing levels of SERCA2a resulted in an improvement in systolic and diastolic function and a reduction in cell death and arrhythmic aftercontractions. SERCA2a overexpression therefore lacks the detrimental effects associated with some other inotropic interventions.

The effect of Gi-protein inactivation on basal, and beta(1)- and beta(2)AR-stimulated contraction of myocytes from transgenic mice overexpressing the beta(2)-adrenoceptor.

The atria and ventricles of transgenic mice (TGbeta(2)) with cardiac overexpression of the human beta(2)-adrenoceptor (beta(2)AR) were initially reported to show maximum contractility in the absence of beta-AR stimulation. However, we have previously observed a different phenotype in these mice, with myocytes showing normal contractility but reduced betaAR responses. We have investigated the roles of cyclic AMP and Gi in basal and betaAR function in these myocytes. ICI 118,551 at inverse agonist concentrations decreased contraction by 32%. However, the cyclic AMP antagonist Rp-cAMPS had no effect on contraction in TGbeta(2) myocytes, indicating that there was no tonic influence of raised cyclic AMP. These findings cannot be explained by the proposed model for inverse agonism, where the activated receptor (R*) raises cyclic AMP levels and so increases contraction in the absence of agonist. After pertussis toxin (PTX) pretreatment to produce inactivation of Gi, the basal contraction in 1 mM Ca(2+) was increased in TGbeta(2) mice (7.82+/-0.47%, n=23) compared to LM mice (3.60+/-0.59%, n=11) (P<0.001). The contraction amplitude of myocytes to the maximal concentration of isoprenaline was also increased significantly by PTX in TGbeta(2) mice (9.40+/-1.22%, n=8) and was no longer reduced compared to LM mice (8.93+/-1.50%, n=11). Both beta(1)- and beta(2)AR subtypes were affected both by the original desensitization and by the resensitization with PTX. PTX treatment has therefore restored the original phenotype, with high basal contractility and little further effect of isoprenaline. We suggest that both beta-AR desensitization and lack of increased basal contraction in ventricular myocytes from our colony of TGbeta(2) mice were due to increased activity of PTX-sensitive G-proteins.

Glycogen synthase kinase-3beta is a negative regulator of cardiomyocyte hypertrophy.

Hypertrophy is a basic cellular response to a variety of stressors and growth factors, and has been best characterized in myocytes. Pathologic hypertrophy of cardiac myocytes leads to heart failure, a major cause of death and disability in the developed world. Several cytosolic signaling pathways have been identified that transduce prohypertrophic signals, but to date, little work has focused on signaling pathways that might negatively regulate hypertrophy. Herein, we report that glycogen synthase kinase-3beta (GSK-3beta), a protein kinase previously implicated in processes as diverse as development and tumorigenesis, is inactivated by hypertrophic stimuli via a phosphoinositide 3-kinase-dependent protein kinase that phosphorylates GSK-3beta on ser 9. Using adenovirus-mediated gene transfer of GSK-3beta containing a ser 9 to alanine mutation, which prevents inactivation by hypertrophic stimuli, we demonstrate that inactivation of GSK-3beta is required for cardiomyocytes to undergo hypertrophy. Furthermore, our data suggest that GSK-3beta regulates the hypertrophic response, at least in part, by modulating the nuclear/cytoplasmic partitioning of a member of the nuclear factor of activated T cells family of transcription factors. The identification of GSK-3beta as a transducer of antihypertrophic signals suggests that novel therapeutic strategies to treat hypertrophic diseases of the heart could be designed that target components of the GSK-3 pathway.

G(i)-dependent suppression of beta(1)-adrenoceptor effects in ventricular myocytes from NE-treated guinea pigs.

It has been suggested that there is a preferential coupling in heart muscle between the inhibitory G protein (G(i)) and the beta(2)-subtype of the beta-adrenergic receptor (beta-AR), since pertussis toxin (which inactivates G(i)) reveals latent beta(2)-ARs in rat and mouse myocytes. We have previously shown that guinea pigs treated with norepinephrine (NE) for 7 days have myocytes that are desensitized to beta-AR-agonist stimulation, and that pertussis toxin restores these responses. The purpose of the present investigation was to determine whether pertussis toxin specifically upregulated beta(2)-ARs in myocytes from NE-treated guinea pigs. The sole beta-AR subtype in control guinea pig myocytes was confirmed as beta(1)-AR by radioligand binding, single-cell autoradiography, and concentration-response curves to isoproterenol in contracting myocytes. In contrast, a minor pool of beta(2)-ARs was observed in rat myocytes by use of the same methods. NE treatment decreased the maximum isoproterenol response (relative to high Ca(2+)) from 0.89 +/- 0.06 to 0.58 +/- 0.08 (n = 7, P < 0.01) and the pD(2) (-log EC(50)) from 8.8 +/- 0.2 to 7.5 +/- 0.2 (n = 7, P < 0.01). Pertussis toxin treatment increased the isoproterenol-to-Ca(2+) ratio to 0.88 +/- 0.04 (n = 6, P < 0.05) and the pD(2) to 8.6 +/- 0.3 (P < 0.01). This was not mediated by increases in either number or function of beta(2)-ARs. G(i) is therefore able to modulate beta(1)-AR responses in guinea pig myocytes.

Functional alterations in adult rat myocytes after overexpression of phospholamban with use of adenovirus.

An increased phospholamban (PLB)-to-sarco(endo)plasmic reticulum Ca(2+)-ATPase (SERCA) ratio has been suggested to contribute to the slowing of relaxation in failing human ventricle. We have used an adenoviral vector carrying the sequence for PLB to increase this ratio in isolated adult rat ventricular myocytes, and we have examined the functional consequences. With use of adenoviral vectors, the PLB content of adult rat myocytes was increased 2.73-fold, with SERCA2a levels unchanged. Maximum contraction amplitude of PLB-overexpressing myocytes was decreased to 6.9 +/- 0.3% shortening compared with 11.2 +/- 0.8% for 24-h controls (Con; P < 0.001, 5 preparations, 103 myocytes). Maximum rates of shortening and relengthening were also significantly decreased. Ca(2+) transient amplitudes were slightly depressed, and time to 50% decay of the transients was significantly increased: 237 +/- 18 (n = 14 myocytes) and 432 +/- 32 ms in Con and PLB (n = 15) myocytes, respectively (P < 0.001). The amount of Ca(2+) in the sarcoplasmic reticulum stores was reduced by 21% (P < 0.05). Relaxation was significantly slower in PLB than in Con myocytes when the Na(+)/Ca(2+) exchanger was blocked but not when sarcoplasmic reticulum Ca(2+) uptake was inhibited. Adenovirus infection with Ad.RSV.PLB was therefore able to produce functional changes in adult cardiac myocytes within 24 h, consistent with overexpression of PLB and similar to those seen in failing human heart.

Bioengineering in the Millennium, National Institute of Health Symposium, Bioengineering: Building the Future of Biology and Medicine.

This symposium identified the major challenges in biomedical research that will benefit from bioengineering applications. Attention was focused on the important role that bioengineers will play in future advances in biomedical research. There was considerable discussion about how to integrate bioengineering with biological research in meeting the challenges of the twenty-first century. Symposium presenters showcased the accomplishments of NIH-funded bioengineering researches and increased the visibility of bioengineering to NIH leaders, staff and members of the intramural and extramural research community. Recommendations were also made for future NIH-funded research projects. Attention was also placed on how basic bioengineering research can lead to commercialization of new health care technology and therefore maintain the Nation's leadership in this important area. New products, from biotechnology and novel devices for diagnosis and treatment, are marketed through interactions between universities, medical centers, small start-up firms, and larger, more established companies. In the United States the gross revenue of the bioengineering private sector industry involved in the manufacture of health care products already exceeds $40 billion. More than 750 persons attended this bioengineering symposium. Over 110 scientific posters and exhibits relating to biology and medicine were presented. They provided a forum for showcasing NIH-funded bioengineering projects and fostered future collaboration among academic investigators, industry and members of the small business community. The role of bioengineering in the 21st century has already been highlighted by the author as far as research, education and space age technologies are concerned. The contributions of Pugwash bioengineer, Maciej Natecz, a member of the Polish Academy of Sciences, was recognized by the Conference Planning Committee. He was honoured for his work in nuclear disarmament.

Bioengineering in the millennium.

This symposium identified the major challenges in biomedical research that will benefit from bioengineering applications. Attention was focused on the important role that bioengineers will play in future advances in biomedical research. There was considerable discussion about how to integrate bioengineering with biological research in meeting the challenges of the twenty-first century. Symposium presenters showcased the accomplishments of NIH-funded bioengineering researches and increased the visibility of bioengineering to NIH leaders, staff, and members of the intramural and extramural research community. Recommendations were also made for future NIH-funded research projects. Attention was also placed on how basic bioengineering research can lead to commercialization of new health care technology and therefore maintain the nation's leadership in this important area. New products, from biotechnology and novel devices for diagnosis and treatment, are marketed through interactions between universities, medical centers, small start-up firms, and larger, more established companies. In the United States the gross revenue of the bioengineering private sector industry involved in the manufacture of health care products already exceeds $40 billion. More then 750 persons attended this bioengineering symposium. Over 110 scientific posters and exhibits relating to biology and medicine were presented. They provided a forum for showcasing NIH-funded bioengineering projects and fostered future collaboration among academic investigators, industry, and members of the small business community. The contributions of Pugwash bioengineer, Maciej Natecz, a member of the Polish Academy of Sciences, was recognized by the Conference Planning Committee. He was honored for his work in nuclear disarmament. Indian medical scientists should note that this symposium provided a framework for the development of technology in biomedical sciences during the Twenty-First Century. Major concentrations in interdisciplinary research should occur at all of the premier research institutions in India.

The role of cAMP in the frequency-dependent changes in contraction of guinea-pig cardiomyocytes.

OBJECTIVES: beta-Receptor desensitisation, low basal cAMP, and a negative force-frequency relationship are characteristic changes in human heart failure. Isolated cardiomyocytes from noradrenaline-treated guinea pigs also show these features. We tested the hypothesis that low basal cAMP underlies the loss of contractile response to increasing stimulation frequency in this model. METHODS: Isolated cardiomyocytes were obtained from noradrenaline-treated (NA) and sham-operated (SHAM) guinea pigs. They were stimulated from 0.1-2 Hz and contraction amplitude was monitored with a video edge-detection system. RESULTS: NA cells had less positive amplitude-frequency responses (AFR) compared to SHAMs at 2 mM (P = 0.002, n = 17), or midrange Ca2+ concentrations (EC40-EC60) (P < 0.001, n = 13). When the cAMP agonist, 8-CPT-cAMP (CPT, 10 microM) or high Ca2+ (above EC75) was added to NA cells the AFR was normalised to that of SHAM myocytes (NA vs. SHAM P = ns). In control experiments the cAMP antagonists, Rp-cAMPS (Rpc) and Rp-8-CPT-cAMPS (Rp8, 100 microM), blocked the positive inotropic effects of CPT at 0.5 Hz (control pD2 = 4.36 +/- 0.06, Rp8 pD2 = 3.68 +/- 0.08, P < 0.0001), n = 6 paired). Rpc (100 microM) completely but reversibly blocked the effect of maximal isoprenaline in control experiments (P < 0.0001). Neither antagonist reduced the AFR compared to time-matched controls (P = ns, n = 6). Blockade of SERCA2a with thapsigargin resulted in a significant reduction in the AFR (ANOVA P < 0.0001). CONCLUSIONS: The results are consistent with sarcoplasmic reticulum (SR) function being a more important determinant of the amplitude-frequency relationship than tonic levels of cAMP under basal conditions. Reversal of AFR depression by CPT may result from stimulation of SR Ca2+ uptake.

Multipoint determination of pressure-volume curves in human intervertebral discs.

To gain further insight into the biomechanics of the human intervertebral disc and to determine a potential mechanism for causation and relief of symptoms related to a herniated disc, the pressure-volume relation was determined within the nucleus pulposus. Pressure was measured continuously within the nucleus pulposus in 17 intact lumbar discs from human cadavers by means of a miniature strain gauge at the tip of a size 4 French (1.3 mm) catheter inserted into the nucleus pulposus. The volume of the nucleus pulposus was increased at the slow, continuous rate of 0.034 ml/min by the pump regulated infusion of saline coloured with methylene blue. In 12 unloaded discs, nucleus pulposus pressure rose in a linear fashion (linear r = 0.96) from an initial mean pressure of 174 (SD 81) kPa. The mean rate of pressure rise was 327 (SD 109) kPa/ml volume increase. The peak pressure measured was 550 kPa; this was slightly higher than the capability of the transducer. Similar linear relations were obtained during infusion of saline into five vertically loaded discs fixed at the deformation produced by a 9.1 kg weight. The data define the pressure-volume relation within the disc and show that the nucleus pulposus, surrounded by the relatively inelastic annulus and the solid vertebral end plates, has the properties of a tight hydraulic space in which a large pressure rise will regularly result from a small increase in volume. Presumably the opposite is also true. The data may provide a biomechanical basis for the physiological variation in symptoms related to the disc, and for any benefits obtained from interventions designed to remove disc tissue.

Percutaneous laser disc decompression. A new therapeutic modality.

The authors present a new advance in the treatment of herniated disc disease using percutaneous Nd:YAG laser to vaporize a small portion of nucleus pulposus, thereby decompressing the disc. In vitro and in vivo animal data are presented. Three hundred seventy-seven magnetic resonance imaging or computed tomography scan-documented, herniated, nonsequestered lumbar intervertebral discs with corresponding clinical findings in 333 patients were so treated in an outpatient setting. The longest follow-up was 62 months, with a mean of 26 months. According to the Macnab criteria, there was a good to fair response in 261 patients (78.4%), and a poor response in 72 (21.6%); 166 patients experienced relief of pain during the procedure. One-third of repeat magnetic resonance imaging scans at 4-6 months postlaser treatment showed modest to moderate decrease of disc herniation.

Spectrophotometric analysis of cortical bone.

An attempt was made to study the structural behavior of a crystal in bone composite material of rats and rabbits. A Fourier transform infrared (FTIR) spectrophotometer and computer were used to monitor the infrared spectra of five bone samples each from the rats and rabbits. The spectra indicate the absorption band in the region of 500 to 700 cm(-1), with a wider bandwidth in the samples of rats as compared to rabbits. The spectra indicate that (1) the amorphous crystalline behavior of bone crystal is animal specific: (2) bone surface resorption is greater in amorphous bone; (3) cortical thickness may be affected by the bone's molecular structure; and (4) the mineral deposits on the collagen matrix are mediated through a biophysical mechanism that follows a crystallographical arrangement in the protein lattice.

Effects of radiotherapy on the mechanical properties of human skin.

A portable apparatus that measures the elastic properties of human skin in vivo was used in a study involving 34 female patients being treated for carcinoma of the breast. Two skin areas were stretched: one at a site on the breast in the irradiated area and the other at a site on the nonirradiated contralateral breast. The mechanical tests on the skin were carried out before radiotherapy and then monthly after the treatment had ceased. It was found that the clinical and biological response of skin to radiation, particularly in fractionated treatments, depends on both the dose and the time. In particular, a three fractions a week treatment regime is preferable to five fractions a week.

On the classification of equine force traces.

Evidence indicating that comparison of a particular animal trace with a population average is an insufficient test of the health of a limb is presented. The methodology involves representing each of three recorded force components (vertical, lateral, and transverse) as a Fourier-Legendre series; the coefficients in the series represent the trace. A history for the horse is built by accumulating the coefficients (along with pertinent experimental data such as date, sex, weight, height, and in the case of race horses the date of last race) over a long duration. Then, on each subsequent recording, the trace is first compared with the animal's history to identify the occurrence of injury or pathology. If the limb is found to be normal, the trace is added to the history. Otherwise, it is recommended that the animal be further examined by a veterinarian. Preliminary results indicate that an animal trace needs to be compared with a history of traces for the same animal to identify alterations in the locomotive behavior of the limb.