The Nongenotropic Synthetic Ligand 4-Estren-3α17β-diol Is a High-Affinity Genotropic Androgen Receptor Agonist

The nongenotropic ligand estren (Science 298:843-846, 2002) was evaluated for its transcriptional activity mediated by the human androgen receptor (AR). Our results show that estren can bind, translocate, transactivate, and regulate two known target genes of AR in androgen-responsive cell lines. Estren binds recombinant AR with 10-fold higher affinity than either estrogen receptor (ER)-alpha or ERbeta. Estren-bound AR can translocate AR to the nucleus and stimulate the androgen response element-luciferase reporter activity with an efficacy similar to that of androgen. Estren also increased the expression of prostate-specific antigen (PSA) in a dose-dependent manner in human LnCaP cells. Using chromatin immunoprecipitation analysis, we show that the estren-bound AR coimmunoprecipitates with a region of the PSA gene promoter. Therefore, cotreatment with an AR antagonist, bicalutamide, blocked the estren-induced increase in PSA expression. In contrast, phosphoinositol 3-kinase inhibitor wortmannin, or extracellular signal-regulated kinase inhibitor 1,4-diamino-2,3-dicyano-1,4-bis(2-aminophynyltio)butadiene (U0126), and ER antagonist ICI-182780 failed to block the effects of estren. In vivo analysis of estren's action on male-orchidectomized ICR mice revealed estren's AR agonist actions on the levator ani and seminal vesicle target tissues. Taken together, our results reveal the hitherto unidentified genotropic action of estren mediated by AR in androgen-responsive cells and tissues.

Pharmacologic issues in the critically ill

The pharmacotherapy of critically ill patients poses numerous challenges to the ICU team. Polypharmacy and alterations in drug disposition are common in the ICU; critically ill patients have limited physiologic reserve to deal with adverse drug events. Careful prescribing, based upon sound pharmacologic principles, decreases the potential for preventable adverse events and maximizes the opportunity for successful therapy. A systematic approach to reporting, analysis, and prevention of errors is a further step in our ultimate goal to provide optimal care for the vulnerable patients whom we support in our ICUs.

Osteoblast apoptosis and bone turnover

With the discoveries of different death mechanisms, an emerging definition of apoptosis is the process of cell death associated with caspase activation or caspase-mediated cell death. This definition accepts that caspases represent the final common mechanistic pathway in apoptosis. Apoptosis may be triggered either by activation events that target mitochondria or endoplasmic reticulum or by activation of cell surface "death receptors," for example, those in the tumor necrosis factor (TNF) superfamily. In the postnatal and adult skeleton, apoptosis is integral to physiological bone turnover, repair, and regeneration. The balance of osteoblast proliferation, differentiation, and apoptosis determines the size of the osteoblast population at any given time. Although apoptosis has been recorded in many studies of bone, the selective mechanisms invoked in the different models studied rarely have been identified. This review offers a broad overview of the current general concepts and controversies in apoptosis research and then considers specific examples of osteoblast apoptosis pertinent to skeletal development and to the regulation of bone turnover. In reviewing selected work on interdigital apoptosis in the developing skeleton, we discuss the putative roles of the bone morphogenetic proteins (BMPs), Msx2, RAR-gamma, and death inducer obliterator 1 (DIO-1). In reviewing factors regulating apoptosis in the postnatal skeleton, we discuss roles of cytokines, growth factors, members of the TNF pathway, and the extracellular matrix (ECM). Finally, the paradoxical effects of parathyroid hormone (PTH) on osteoblast apoptosis in vivo are considered in the perspective of a recent hypothesis speculating that this may be a key mechanism to explain the anabolic effects of the hormone. An improved understanding of the apoptotic pathways and their functional outcomes in bone turnover and fracture healing may facilitate development of more targeted therapeutics to control bone balance in patients with osteoporosis and other skeletal diseases.

Reactive and clonal thrombocytosis: proinflammatory and hematopoietic cytokines and acute phase proteins

BACKGROUND

We quantitated proinflammatory and thrombopoietic cytokines in reactive thrombocytosis (RT) and clonal thrombocytosis (CT) to identify a cytokine profile that might aid in the distinction of these two disorders.

METHODS

Serum levels of cytokines relevant to platelet biology--interleukins 3, 6, 11, and 1beta; thrombopoietin; tumor necrosis factor alpha; and C-reactive protein (CRP)--were measured by enzyme-linked immunosorbent assay in healthy subjects and in patients with CT and RT.

RESULTS

Interleukin-6 and CRP levels were higher in RT patients than in controls or CT patients. Interleukin 1beta levels were higher in the RT group than in the CT and control groups.

CONCLUSIONS

In RT, IL-6, IL-1beta, and CRP levels are elevated. In both RT and CT, IL-11 is elevated, but thrombopoietin levels are not.

Mechanism of action of estrogens and selective estrogen receptor modulators

Estrogen, one of several sex steroid hormones, mediates its actions through the estrogen receptor. The estrogen receptor (ER) has two subtypes, ER alpha and ER beta, each of which predominates in specific tissues and organs. Cofactor proteins interact with the ER to maximize ligand-dependent transactivation of target-gene promoters. The estrogen response element is the final step in estrogen-mediated gene regulation, and current research is focused on alternate response elements. The resulting biologic action can vary according to the specific type of ER, cofactor milieu, response element, and ligand. Selective estrogen receptor modulators (SERMs) exhibit tissue-specific estrogen agonist or antagonist activity. The SERM raloxifene, which binds to ER and targets a distinct DNA element, may distinguish agonist vs antagonist activity by ER subtype and has unique activity among other SERMs because of its molecular conformation. Phytoestrogens, a potential alternative to hormone replacement therapy and for cancer prevention, do not consistently mimic estrogen's activity. Different types of phytoestrogens have different potencies, and taking high-dose supplements after menopause may not emulate the apparent benefits of lifelong consumption of phytoestrogen-rich diets. In conclusion, the complexity of estrogen action--through different ER subtypes, with various cofactors, on alternate response element--is further enhanced by ligands with selective estrogen activity. Additional research is needed to elucidate these pathways and the resulting biological effects.

Bone anabolic effects of sonic/indian hedgehog are mediated by bmp-2/4-dependent pathways in the neonatal rat metatarsal model

A neonatal rat metatarsal organ culture model has been employed to study the anabolic effects of Sonic/Indian hedgehog and BMP-4. In this culture system, a significant increase in endochondral ossification is measured by an increase in length of mineralized bone, after daily treatment for 7 days with Sonic hedgehog protein (Shh-N). Previous evidence indicated that PTH related protein (PTHrP) is a critical target of hedgehog function in endochondral ossification. Using a PTHrP blocking antibody, it is shown that hedgehog mediates this activity via pathways other than through PTHrP. A dose-related increase in endochondral ossification is observed when metatarsals are treated with 25 ng/ml recombinant human bone morphogenetic protein 4 (BMP-4). However, this activity is not evident at higher doses of BMP-4 (200 ng/ml). High doses of BMP-4 resulted in increased expression of noggin messenger RNA and cotreatment of noggin and Shh-N resulted in reversal of the anabolic action of Shh-N. This observation suggests that BMP-4 signaling can influence the Shh-N mediated increase in endochondral ossification. Finally, we show that the Shh-N and BMP-4 mediated increase in endochondral ossification is reversed by treatment with antisense oligonucleotides targeted against Cbfa1. Thus, this report identifies Shh-N as an inducer of endochondral ossification that mediates its effect via BMP-4 and Cbfa1-dependent pathways.

Reproductive tract infection in women of reproductive age group in Sitapur/Shahjahanpur District of Uttar Pradesh

CARE India with its UP Office has initiated demand generation and acceptability of services for reproductive health and birth spacing services at community level in two districts in the state of Uttar Pradesh. A total of 3,49,000 women of reproductive age will benefit from participation in program activities over the next five years. Out of total surveyed population of 3662, 798 women of reproductive age group were identified of whom 272 were found to be symptomatically positive in relation of STDs/RTIs giving the overall prevalence rate of 34%. Clinical as well as the microbiological examination was carried out on 193 of these 272 women in field conditions. Those found clinically and/or microbiologically positive were provided treatment and preventive advice. Total of 150 (77.7%) women were diagnosed on the basis of symptoms (syndromic approach) and 151 (78.2%) were diagnosed on the basis of clinical examinations. However, 137 (70.9%) were confirmed microbiologically positive. A large extent was found in the age group of 15 to 24 years. Confirmed cases were comparatively less among nulliparous women (63.6%) than multipara (73.2%) cases. 64.1% women were having watery discharge while 29.1% were having complaint of curd discharge. The discharge was offensive in only 1.9% cases while 4.9% reported mixed discharge. 54.4% women complaining of vaginal discharge were suffering from PID. The discharge were either bacterial alone (26.1%) or bacterial mixed with candidiasis (16.5%) or trichomoniasis (8.7%). Compared to syndromic approach, an improvement in the sensitivity (81.8%) and predictive accuracy (74.1%) was noted when cases were detected with the help of clinical examination.

Relative prevalence of hepatitis B viral markers and hepatitis C virus antibodies (anti HCV) in Madurai, south India

(1) The positivity of HBsAg was 4% (75/1819) whereas anti HCV was present only in 0.75% (27/3574) of blood donors. (2) 5.3% (4/75) of hospital staff had HBsAg alone in their blood samples. One doctor, one Staff nurse, one Lascar and one Sanitary worker were positive for HBsAg. None of them were positive for anti HBcIgm and anti-HCV. (3) 29% (31/115) of suspected hepatitis cases were positive for any one of the viral markers or both. 21% (15/72) of males and 14% (6/43) of females were positive for HBsAg. Whereas only 4% (3/72) of males and 2% (1/43) of females were positive for anti HCW. Both HBsAg and anti HCV were found in 8% (6/72) of males only. The age group predominantly, i.e. in 29 out of 31 cases found positive for HBsAg and/or anti HCV, was above 15 years. Two remaining HBsAg positive cases belonged to the 5 to 14 years age group. 71% (84/115) of suspected hepatitis cases were negative for both HBsAg and anti HCV.

Neutrophils in induced sputum arise from central airways

A high neutrophil count is often found in induced sputum compared to bronchoalveolar lavage fluid (BALF). This study investigated whether such a high neutrophil count may be a response to inhaled hypertonic saline or that the airway compartment sampled by induced sputum has a higher concentration of neutrophils than BALF. Saliva and induced sputum samples were taken at 10 and 20 min following inhalation of 3% hypertonic saline from an ultrasonic nebulizer in 12 healthy nonsmoking subjects. Four days later the 12 subjects underwent bronchoscopy (six following inhalation with 3% saline). Tracheal, proximal bronchial secretions, bronchial washings and BALF samples were obtained. The neutrophil count (% total leukocytes) increased significantly in saliva at 10 and 20 min post nebulization with 3% saline, although there was no change in neutrophils in induced sputum at 10 and 20 min. There was no significant difference in neutrophil count in the subjects who inhaled 3% saline as compared to those who did not, in secretions from the trachea, proximal bronchi, bronchial washings and BALF. Neutrophil counts were significantly higher in the trachea, proximal bronchi and bronchial washings as compared to BALF (p<0.001). It is concluded that neutrophil counts in healthy subjects increase from the peripheral towards the proximal airways, in the absence of hypertonic saline-induced changes. This suggests that the relatively high neutrophil count in induced sputum arises from the proximal airways and is not a response to inhaled hypertonic saline during the procedure.

First fatty acylated dipeptides to affect muscarinic receptor ligand binding

Fatty acylated dipeptides homologous to Gi alpha N-termini affect ligand binding to muscarinic acetylcholine receptors. Myristylglycine-serine containing dipeptides decrease antagonist binding at both M1 and M2 muscarinic receptors. Palmitate on the serine analogous to native palmitoylated cysteine affords dipeptide which selectively decreases the number of high affinity agonist binding sites at M2 but not M1 receptor.

Mediation of Sonic hedgehog-induced expression of COUP-TFII by a protein phosphatase

A Sonic hedgehog (Shh) response element was identified in the chicken ovalbumin upstream promoter-transcription factor II (COUP-TFII) promoter that binds to a factor distinct from Gli, a gene known to mediate Shh signaling. Although this binding activity is specifically stimulated by Shh-N (amino-terminal signaling domain), it can also be unmasked with protein phosphatase treatment in the mouse cell line P19, and induction by Shh-N can be blocked by phosphatase inhibitors. Thus, Shh-N signaling may result in dephosphorylation of a target factor that is required for activation of COUP-TFII-, Islet1-, and Gli response element-dependent gene expression. This finding identifies another step in the Shh-N signaling pathway.

Identification of a novel sonic hedgehog response element in the chicken ovalbumin upstream promoter-transcription factor II promoter

Sonic hedgehog (Shh) is a secreted morphogen that regulates dorso-ventral patterning within the neural tube during embryonic development. It is well established that Shh can induce motor-neuron differentiation that coincides with the appearance of specific motor-neuron markers including chicken ovalbumin upstream promoter-transcription factor II (COUP-TFII) and Isl1. However, the mechanism of Shh-induced signaling pathway in vertebrates is not clearly defined. In this report we have identified COUP-TFII as a target gene for Shh. In addition we have used a 1.6-kb region of the COUP-TFII promoter to identify a target element that mediates the Shh-induced activity. Extensive deletions introduced within this region have further enabled us to identify a novel sonic hedgehog response element (ShhRE) in the COUP-TFII promoter. Point mutations introduced within the ShhRE reveal some key nucleotides that are essential for protein(s)-binding activity. Finally, the ShhRE is capable of functioning as a true enhancer element and can mediate Shh-induced transactivation of reporter gene via a heterologous promoter.

Identification of a novel sonic hedgehog response element in the chicken ovalbumin upstream promoter-transcription factor II promoter

Sonic hedgehog (Shh) is a secreted morphogen that regulates dorso-ventral patterning within the neural tube during embryonic development. It is well established that Shh can induce motor-neuron differentiation that coincides with the appearance of specific motor-neuron markers including chicken ovalbumin upstream promoter-transcription factor II (COUP-TFII) and Isl1. However, the mechanism of Shh-induced signaling pathway in vertebrates is not clearly defined. In this report we have identified COUP-TFII as a target gene for Shh. In addition we have used a 1.6-kb region of the COUP-TFII promoter to identify a target element that mediates the Shh-induced activity. Extensive deletions introduced within this region have further enabled us to identify a novel sonic hedgehog response element (ShhRE) in the COUP-TFII promoter. Point mutations introduced within the ShhRE reveal some key nucleotides that are essential for protein(s)-binding activity. Finally, the ShhRE is capable of functioning as a true enhancer element and can mediate Shh-induced transactivation of reporter gene via a heterologous promoter.

Orbital floor reconstruction with autogenous mandibular symphyseal bone grafts

PURPOSE

This article shows the usefulness of the mandibular symphysis as a source of bone graft for the reconstruction of the orbital floor.

PATIENTS AND METHODS

A retrospective study was conducted on 16 patients who had isolated blowout fractures (n = 10) or orbital floor defects (n = 6) reconstructed with mandibular symphyseal bone grafts. Symphyseal bone grafts were used when the defects were less than 2 cm in diameter. Patients were examined at recall visits for any evidence of unsuccessful reconstruction by checking extraocular movements, and evidence of diplopia or enophthalmous.

RESULTS

During a mean follow-up of 12 months (range, 9 to 36 months), patients had no postoperative complaints. There were no instances of infection at the surgical sites, and none of the grafts were extruded or lost. There was good restoration of the orbital floor, with no clinical evidence of enophthalmous or diplopia. Extraocular movements were intact in all patients.

CONCLUSION

The mandibular symphysis is a readily available source of autogenous bone that can be harvested with minimal morbidity. Its contour is suitable for use in orbital floor reconstruction. It merits consideration when autogenous bone grafts are considered for orbital floor defects less than 2 cm in diameter.

A macro approach to the explanation of physician distribution in Canada

Physician distribution is influenced by complex factors. It is generally argued that the probability of physician increase will be greater in areas that have more to offer in the way of social and economic advantages, This study examines the effects of selected demographic, socioeconomic, and environmental factors (e.g., population size, percent university educated, and hospital bed/population ratio) on the spatial distribution of physicians, using data for "active" civilian physicians obtained from Health and Welfare Canada. The findings indicate that the variable "percentage university educated" is the most important factor influencing physician distribution, once demographic and environmental factors are controlled. The higher the educational level of the population, the higher the physician/population ratio and the higher the proportion of children under age 5, the lower the physician/population ratio. Findings provide evidence of a concentration of physicians in high-status areas. A pattern of larger relative dispersion was also observed for physician/population ratios across areas for suburban dwellers.

Chicken ovalbumin upstream promoter-transcription factors and their regulation

COUP-TFs are orphan members of the steroid/thyroid hormone receptor superfamily. COUP-TF homologues have been cloned in several species, from Drosophila to man. The vertebrate COUP-TFs can be classified into four subgroups according to sequence homology in their ligand-binding domain. COUP-TFs bind to AGGTCA direct repeats or palindromes with various spacings. These include the response elements of several other members of the superfamily, the vitamin D receptor, the thyroid hormone receptor, the retinoic acid receptor, the retinoid X receptor, the peroxisome proliferation activated regulator, and the hepatocyte nuclear factor-4. COUP-TF response elements have been identified in the promoters of many genes and COUP-TFs have been shown to act as negative regulators both in vitro and in vivo. They can compete with the above mentioned receptors for binding to the common response elements. The ratio of COUP-TF and the other positive regulator determines the transcriptional state of the particular gene in any given moment. COUP-TFs are expressed in the developing central nervous system of mouse and zebra-fish. In addition, they are also expressed in many organs during mouse organogenesis. The expression pattern and profile of COUP-TFs favor the hypothesis that they are involved in development and differentiation. The expression of COUP-TFs are also highly regulated. P19 embryonal carcinoma cells have been used as a model system to study COUP-TF regulation. COUP-TFs are up-regulated in retinoic acid (RA) treated P19 cells. Transient transfection assay showed that mouse COUP-TFII promoter directly responded to RA treatment, suggesting that COUP-TF expression is directly regulated by RA signaling pathway.

Molecular mechanism of inhibition of estrogen-induced cathepsin D gene expression by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in MCF-7 cells

17 beta-Estradiol (E2) induces cathepsin D mRNA levels and intracellular levels of immunoreactive protein in MCF-7 human breast cancer cells. 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) alone does not affect cathepsin D gene expression in this cell line; however, in cells cotreated with TCDD and E2, TCDD inhibited E2-induced cathepsin D mRNA levels, the rate of gene transcription, and levels of immunoreactive protein. The inhibitory responses were observed within 30 to 120 min after the cells were treated with TCDD. TCDD also inhibited E2-induced secreted alkaline phosphatase activity in aryl hydrocarbon (Ah)-responsive MCF-7 and wild-type mouse Hepa 1c1c7 cells cotransfected with the human estrogen receptor (hER) and the pBC12/S1/pac plasmid, which contains the 5' promoter region (-296/+57) of the cathepsin D gene and an alkaline phosphatase reporter gene. The E2-responsive ER/Sp1 sequence (-199 to -165) in the cathepsin D 5' region contains an imperfect GTGCGTG (-175/-181) xenobiotic responsive element (XRE); the role of this sequence in Ah responsiveness was investigated in gel electrophoretic mobility shift assays and with plasmid constructs containing a wild-type ER/Sp1 oligonucleotide or a mutant ER/Sp1-"XRE" oligonucleotide containing two C-->A mutations in the XRE sequence (antisense strand). In plasmid constructs which contained a chloramphenicol acetyltransferase reporter gene and the wild-type ER/Sp1 promoter sequence, E2-induced chloramphenicol acetyltransferase activity and mRNA levels were inhibited by TCDD whereas no inhibition was observed with the mutant ER/Sp1-"XRE" plasmids. Electrophoretic mobility shift assays showed that the nuclear or transformed cytosolic Ah receptor complex blocked formation of the ER-Sp1 complex with the wild-type but not the ER/Sp1 mutant oligonucleotide. Moreover, incubation of the wild-type bromodeoxyuridine-substituted ER/Sp1 oligonucleotide with the nuclear Ah receptor complex gave a specifically bound cross-linked 200-kDa band. These data demonstrate that Ah receptor-mediated inhibition of E2-induced cathepsin D gene expression is due to disruption of the ER-Sp1 complex by targeted interaction with an overlapping XRE.

Chlorinated hydrocarbons: estrogens and antiestrogens

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) and related compounds bind to the intracellular aryl hydrocarbon (Ah) receptor and induce a diverse spectrum of biochemical and toxic responses. Ah receptor agonists also modulate several endocrine pathways, and research in several laboratories has shown that TCDD and related compounds inhibit estrogen (E2)-induced responses in the rodent mammary and uterus and in human breast cancer cell lines. The mechanisms of interaction between the TCDD- and E2-induced signaling pathways are complex and some of the inhibitory effects may be related to 5'-flanking inhibitory-dioxin responsive elements (i-DREs) in target genes. The antiestrogenic and antitumorigenic activity of Ah receptor agonists has been used to prepare a series of relatively non-toxic alkyl polychlorinated dibenzofurans which have clinical potential for treatment of mammary cancer.

Correlation between Laboratory and Road Rubber Wear Tests

The wear resistance ranking of three rubber compounds A, G and K measured in the laboratory at medium to high slip on sharp silicon carbide (SiC) grinding wheels was similar to that determined by road tests at Pecos, Texas. The wear resistance ranking of the three compounds changed on blunt alumina grinding wheels compared to wear resistance rankings on sharp SiC grinding wheels. The change was most probably due to a change of mechanism from mainly cutting on sharp surfaces to predominantly fatigue on blunt surfaces. For these three compounds a change in the ambient temperature from 23 to 75°C during laboratory testing had no effect on the wear resistance ranking. The wear of the rubber compounds on the abrasive grinding wheels and during road tests followed Zapp's relation in which the wear is proportional to the ratio of dynamic modulus to rupture energy.

Isolation, characterization, and chromosomal localization of mouse and human COUP-TF I and II genes

Chicken ovalbumin upstream promoter transcription factors (COUP-TFs) are orphan members of the steroid/thyroid hormone receptor superfamily. COUP-TF homologues have been cloned in many species, from Drosophila to human. The protein sequences of COUP-TFs are highly homologous across species, suggesting functional conservation. Two COUP-TF genes have been cloned from human, and their genomic organizations have been characterized. To determine whether the genomic organization is conserved between human and mouse, we isolated two mouse COUP-TF genes (I and II) and characterized their genomic structures. Both genes have relatively simple structures that are similar to those of their human counterparts. In addition, we mapped mouse COUP-TF I to the distal region of chromosome 13 and COUP-TF II to the central region of chromosome 7. Furthermore, we mapped human COUP-TF I to 5q14 of chromosome 5 and COUP-TF II to 15q26 of chromosome 15. The results demonstrate that COUP-TF genes are located in chromosomal regions that are syntenic between mouse and human.

Effect of housing tenure on fertility

"This article used the 1984 Canadian Fertility Survey data to examine the effects of housing tenure and a number of sociodemographic and economic factors (e.g., education, religion, income) on both completed fertility and selected parity progression. Results showed a statistically significant positive effect of housing tenure on completed fertility.... Age at marriage, education, religiosity, nativity, and region of residence were highly associated with completed fertility. Housing tenure effects on the parity progression were similar in pattern, although statistically significant effect occurred only in the progression from two to three children. Furthermore, religious attendance was found to increase the likelihood of higher order births among Canadian women."

An ecological model of child maltreatment in a Canadian province

The rate at which children are maltreated is one of the most sensitive measures of demographic, social, and economic conditions. Although the consequences of maltreatment and the effectiveness of treatment programs in reducing the incidence have been extensively studied, little attention has been given to identifying spatial variations in maltreatment in terms of characteristics of areas, especially demographic, social or economical. Maltreatment may differ markedly in terms of an area's socio-demographic and economic makeup and this phenomenon needs to be studied in a structural context. This study employs an ecological perspective to predict variations in the rate of maltreatment (including neglect and abuse) among children aged 0 to 19 years in Alberta, Canada in 1986. Several hypotheses are tested in a multivariate framework and the implications of the findings in assessing the effectiveness of intervention strategies are briefly discussed.