Striatal Isolated from Cyathus striatus Extracts Induces Apoptosis in Human Pancreatic Cancer Cells

The aim of the present study was to identify the structure of active compounds in Cyathus stratus that previously demonstrated anti-pancreatic cancer activity. The active compounds were purified from a crude extract by a series of RP-18 preparative chromatography using homemade octadecyl silica gel column. HPLC injection of the crude extract revealed a chromatogram with three main peaks with retention times (RT) 15.6, 18.2, and 22.5 min. Each fraction that exhibited promising activity in vitro was further separated using various available chromatographic techniques. The purified compound with the ultimate anti-cancer activity appeared at RT of 15.8 in the HPLC chromatogram with more than 90% purity. The main peak at the mass spectra appeared at m/z = 446.2304 with the calculated molecular formula of C25H34O7. One- and two-dimensional NMR analyses indicated that the structure of the active molecule (peak 15.8 min in HPLC) was identified as striatal C. Exposure of human pancreatic cancer cells to purified striatal C resulted in induction of apoptosis. Further studies are needed in order to develop a method for the synthesis of striatal in order to use it in clinical studies for treatment of cancer.

The Effect of Natural-Based Formulation (NBF) on the Response of RAW264.7 Macrophages to LPS as an In Vitro Model of Inflammation

Macrophages are some of the most important immune cells in the organism and are responsible for creating an inflammatory immune response in order to inhibit the passage of microscopic foreign bodies into the blood stream. Sometimes, their activation can be responsible for chronic inflammatory diseases such as asthma, tuberculosis, hepatitis, sinusitis, inflammatory bowel disease, and viral infections. Prolonged inflammation can damage the organs or may lead to death in serious conditions. In the present study, RAW264.7 macrophages were exposed to lipopolysaccharide (LPS; 20 ng/mL) and simultaneously treated with 20 µg/mL of natural-based formulation (NBF), mushroom–cannabidiol extract). Pro-inflammatory cytokines, chemokines, and other inflammatory markers were analyzed. The elevations in the presence of interleukin-6 (IL-6), cycloxygenase-2 (COX-2), C-C motif ligand-5 (CCL5), and nitrite response, following exposure to LPS, were completely inhibited by NBF administration. IL-1β and tumor necrosis factor alpha (TNF-α) release were inhibited by 3.9-fold and 1.5-fold, respectively. No toxic effect of NBF, as assessed by lactate dehydrogenase (LDH) release, was observed. Treatment of the cells with NBF significantly increased the mRNA levels of TLR2, and TLR4, but not NF-κB. Thus, it appears that the NBF possesses anti-inflammatory and immunomodulatory effects which can attenuate the release of pro-inflammatory markers. NBF may be a candidate for the treatment of acute and chronic inflammatory diseases and deserves further investigation.

Metabolomic Characterization of a cf. Neolyngbya Cyanobacterium from the South China Sea Reveals Wenchangamide A, a Lipopeptide with In Vitro Apoptotic Potential in Colon Cancer Cells

Metabolomics can be used to study complex mixtures of natural products, or secondary metabolites, for many different purposes. One productive application of metabolomics that has emerged in recent years is the guiding direction for isolating molecules with structural novelty through analysis of untargeted LC-MS/MS data. The metabolomics-driven investigation and bioassay-guided fractionation of a biomass assemblage from the South China Sea dominated by a marine filamentous cyanobacteria, cf. Neolyngbya sp., has led to the discovery of a natural product in this study, wenchangamide A (1). Wenchangamide A was found to concentration-dependently cause fast-onset apoptosis in HCT116 human colon cancer cells in vitro (24 h IC₅₀ = 38 μM). Untargeted metabolomics, by way of MS/MS molecular networking, was used further to generate a structural proposal for a new natural product analogue of 1, here coined wenchangamide B, which was present in the organic extract and bioactive sub-fractions of the biomass examined. The wenchangamides are of interest for anticancer drug discovery, and the characterization of these molecules will facilitate the future discovery of related natural products and development of synthetic analogues.

The REGγ inhibitor NIP30 increases sensitivity to chemotherapy in p53-deficient tumor cells

A major challenge in chemotherapy is chemotherapy resistance in cells lacking p53. Here we demonstrate that NIP30, an inhibitor of the oncogenic REGγ-proteasome, attenuates cancer cell growth and sensitizes p53-compromised cells to chemotherapeutic agents. NIP30 acts by binding to REGγ via an evolutionarily-conserved serine-rich domain with 4-serine phosphorylation. We find the cyclin-dependent phosphatase CDC25A is a key regulator for NIP30 phosphorylation and modulation of REGγ activity during the cell cycle or after DNA damage. We validate CDC25A-NIP30-REGγ mediated regulation of the REGγ target protein p21 in vivo using p53-/- and p53/REGγ double-deficient mice. Moreover, Phosphor-NIP30 mimetics significantly increase the growth inhibitory effect of chemotherapeutic agents in vitro and in vivo. Given that NIP30 is frequently mutated in the TCGA cancer database, our results provide insight into the regulatory pathway controlling the REGγ-proteasome in carcinogenesis and offer a novel approach to drug-resistant cancer therapy.

Inula Viscosa Extract Inhibits Growth of Colorectal Cancer Cells in vitro and in vivo Through Induction of Apoptosis

Colorectal cancer (CRC) is the second most common cancer in females and the third in males worldwide. Conventional therapy of CRC is limited by severe side effects and by the development of resistance. Therefore, additional therapies are needed in order to combat the problem of selectivity and drug resistance in CRC patients. Inula viscosa (IV) is a well-known medicinal perennial herb in traditional medicine. It is used for different therapeutic purposes, such as; topical anti-inflammatic, diuretic, hemostatic, antiseptic, antiphlogistic, and in the treatment of diabetes. Several studies attempted to reveal the anti-cancer activity of different extracts prepared by different organic solvents from different parts of the IV plant. The aim of the present study is to examine the potential beneficial effects of IV leaf aqueous extract on the growth of colon cancer cells in vitro and in vivo. The results indicated that exposure of colorectal cancer cells to IV extract, significantly reduced cell viability in a dose and time dependent manner. Moreover, treatment of cells with 300 μg/ml of IV extract induced apoptosis, as it was detected by Annexin V/FITC/PI, TUNEL assay, and the activation of caspases. In vivo studies revealed that treatment with 150 or 300 mg/kg IV extract inhibited tumor growth in mice transplanted with MC38 cells. Tumors' weight and volume were significantly (P < 0.001) reduced when compared to untreated-control group. Staining of the paraffin section of tumors revealed that IV treatment inhibited cell proliferation and induced apoptosis. Additionally, no side effects such as; weight loss, behavior changes, ruffled fur or changes in kidney, and liver functions were observed. These results may indicate that active doses of IV extract are not toxic. Further studies are needed in order to identify the structure of the active compounds. Results from this study may contribute to the development of new and efficient strategies for treatment of human colon cancer.

Artificial Light at Night of Different Spectral Compositions Differentially Affects Tumor Growth in Mice: Interaction With Melatonin and Epigenetic Pathways

Lighting technology is rapidly advancing toward shorter wavelength illuminations that offer energy-efficient properties. Along with this advantage, the increased use of such illuminations also poses some health challenges, particularly breast cancer progression. Here, we evaluated the effects of artificial light at night (ALAN) of 4 different spectral compositions (500-595 nm) at 350 Lux on melatonin suppression by measuring its urine metabolite 6-sulfatoxymelatonin, global DNA methylation, tumor growth, metastases formation, and urinary corticosterone levels in 4T1 breast cancer cell-inoculated female BALB/c mice. The results revealed an inverse dose-dependent relationship between wavelength and melatonin suppression. Short wavelength increased tumor growth, promoted lung metastases formation, and advanced DNA hypomethylation, while long wavelength lessened these effects. Melatonin treatment counteracted these effects and resulted in reduced cancer burden. The wavelength suppression threshold for melatonin-induced tumor growth was 500 nm. These results suggest that short wavelength increases cancer burden by inducing aberrant DNA methylation mediated by the suppression of melatonin. Additionally, melatonin suppression and global DNA methylation are suggested as promising biomarkers for early diagnosis and therapy of breast cancer. Finally, ALAN may manifest other physiological responses such as stress responses that may challenge the survival fitness of the animal under natural environments.

Epigenetic modification in 4T1 mouse breast cancer model by artificial light at night and melatonin - the role of DNA-methyltransferase

Currently, one of the most disputed hypotheses regarding breast cancer (BC) development is exposure to short wavelength artificial light at night (ALAN) as multiple studies suggest a possible link between them. This link is suggested to be mediated by nocturnal melatonin suppression that plays an integral role in circadian regulations including cell division. The objective of the research was to evaluate effects of 1 × 30 min/midnight ALAN (134 µ Wcm^-2, 460 nm) with or without nocturnal melatonin supplement on tumor development and epigenetic responses in 4T1 tumor-bearing BALB/c mice. Mice were monitored for body mass (W_b) and tumor volume for 3 weeks and thereafter urine samples were collected at regular intervals for determining daily rhythms of 6-sulfatoxymelatonin (6-SMT). Finally, mice were sacrificed and the tumor, lungs, liver, and spleen were excised for analyzing the total activity of DNA methyltransferases (DNMT) and global DNA methylation (GDM) levels. Mice exposed to ALAN significantly reduced 6-SMT levels and increased W_b, tumor volume, and lung metastasis compared with controls. These effects were diminished by melatonin. The DNMT activity and GDM levels showed tissue-specific response. The enzymatic activity and GDM levels were lower in tumor and liver and higher in spleen and lungs under ALAN compared with controls. Our results suggest that ALAN disrupts the melatonin rhythm and potentially leading to increased BC burden by affecting DNMT activity and GDM levels. These data may also be applicable to early detection and management of BC by monitoring melatonin and GDM levels as early biomarker of ALAN circadian disruption.

Development of long-acting recombinant glycoprotein hormones by increasing the carbohydrate content

Therapeutic recombinant glycoproteins are important for both the biotechnological industry and clinical purposes. Given the rapid clearance of these proteins from the circulation, they have to be injected frequently to obtain optimal therapy. Several strategies have been developed to overcome this limitation, aiming to increase the half-life of such proteins in the circulation. These strategies included chemical attachment of polyethylene glycol, nanocapsulation, fusion to immunoglobulins or to albumin as protein carriers, or enrichment of the carbohydrate content. Here, we describe a strategy for increasing the half-life of recombinant proteins using gene fusion to increase the carbohydrate content of the protein backbone.

Pathogenic variants in glutamyl-tRNAGln amidotransferase subunits cause a lethal mitochondrial cardiomyopathy disorder

Mitochondrial protein synthesis requires charging a mitochondrial tRNA with its amino acid. Here, the authors describe pathogenic variants in the GatCAB protein complex genes required for the generation of glutaminyl-mt-tRNA^Gln, that impairs mitochondrial translation and presents with cardiomyopathy.

Mitochondrial protein synthesis requires charging mt-tRNAs with their cognate amino acids by mitochondrial aminoacyl-tRNA synthetases, with the exception of glutaminyl mt-tRNA (mt-tRNA^Gln). mt-tRNA^Gln is indirectly charged by a transamidation reaction involving the GatCAB aminoacyl-tRNA amidotransferase complex. Defects involving the mitochondrial protein synthesis machinery cause a broad spectrum of disorders, with often fatal outcome. Here, we describe nine patients from five families with genetic defects in a GatCAB complex subunit, including QRSL1, GATB, and GATC, each showing a lethal metabolic cardiomyopathy syndrome. Functional studies reveal combined respiratory chain enzyme deficiencies and mitochondrial dysfunction. Aminoacylation of mt-tRNA^Gln and mitochondrial protein translation are deficient in patients’ fibroblasts cultured in the absence of glutamine but restore in high glutamine. Lentiviral rescue experiments and modeling in S. cerevisiae homologs confirm pathogenicity. Our study completes a decade of investigations on mitochondrial aminoacylation disorders, starting with DARS2 and ending with the GatCAB complex.

Estrogen receptor and laminin genetic polymorphism among women with pelvic organ prolapse

OBJECTIVE

Laminin is a connective tissue component. The LAMC1 gene encodes for gamma-1 chain of laminin, which is associated with familial clustering of POP. The ERα gene which encodes for cellular estrogen receptor has also been associated with POP. The aim of this study was to evaluate a possible correlation between polymorphism in these genes and the risk for developing POP.

MATERIALS AND METHODS

Blood samples were drawn from 33 women with advanced POP (study group) and 33 women without POP (control group). DNA was extracted, and the presence of the rs10911193 C/T mutation in LAMC1 and of the rs2228480 G/A mutation in ERα was detected using the PCR technique.

RESULTS

26 samples were available for each group regarding ERα. 33 samples were available for each group, regarding LAMC1. The prevalence of homozygotes for the ERα rs2228480 G/A mutation was 19.2% and 0% among women with and without POP, respectively (OR 39.77, 95% CI 1.93-817.0, P = 0.00046). The prevalence of heterozygotes for this mutation was 83.3% and 11.5%, respectively (OR 19.2, 95% CI 4.15-88.6, P < 0.0001). The prevalence of homozygotes for the LAMC1 gene rs10911193 C/T mutation was 3.6% and 6.1% among women with and without POP (NS), while the respective for heterozygotes for this mutation was 21.4% and 33.3% (NS).

CONCLUSIONS

Polymorphism in the ERα gene is associated with an increased risk for advanced POP. However, polymorphism in the LAMC1 gene does not seem to be associated with such risk.

The Shaggy Ink Cap Medicinal Mushroom, Coprinus comatus (Higher Basidiomycetes) Extract Induces Apoptosis in Ovarian Cancer Cells via Extrinsic and Intrinsic Apoptotic Pathways

In a previous study, ethyl acetate extract of Coprinus comatus was found to reduce viability of human ovarian cancer cells. The objective of the current research was to clarify the mechanism of action of this extract. Ovarian cancer cells (ES-2) were subjected to ethyl acetate extract of C. comatus for different concentrations or exposure times. Cell cycle analysis and annexin V staining were performed using an automated flow cytometer. DNA fragmentation was detected using the TUNEL assay. Western blot analysis was performed for the assessment of activation of caspases -3, -8, and -9. Results revealed that treatment of ES-2 cells with ethyl acetate extract of C. comatus (100 μg/ml medium), for 48 h or for 72 h resulted in an increased number of cells at the sub-G1 phase of the cell cycle. These treatments also resulted in an increased number of apoptotic cells (positively stained by annexin and positively labeled by TUNEL), in comparison to the control. Reduced levels of procaspases -3, -8, and-9 were also detected in treated cells. In conclusion, ethyl acetate extract of C. comatus induces apoptosis in ovarian cancer cells (ES-2), via both extrinsic and intrinsic pathways. Meanwhile, more investigations are needed to demonstrate weather the apoptotic effect on ovarian cancer cells is accomplished by one active compound, or combined activities of different compounds that exist in the extract.

Endothelial nitric oxide synthase polymorphism and prognosis in systolic heart failure patients

BACKGROUND

The endothelial nitric oxide synthase (eNOS) gene single nucleotide polymorphism G894T is associated with thrombotic vascular diseases. However, its functional significance is controversial and data are scarce concerning its influence in heart failure (HF).

METHODS

We studied 215 patients with chronic systolic HF. DNA was analyzed for eNOS gene G894T polymorphism using PCR and DNA sequencing. Evaluation of clinical characteristics and analysis of factors associated with 2-year mortality were performed for the homozygous G-allele G894T variant (GG), relative to the TT and GT variants.

RESULTS

The genotype distributions of eNOS G894T alleles were: GG 135 patients (63%) and TT/GT 80 (37%). Two-year mortality was significantly higher in the GG variant (48%) than the combined TT/GT group (32%). The usage of nitrates was associated with increased 2-year mortality (HR 2.0, 95% CI 1.28-3.17; p = 0.003), which was most significant in the GG group treated with nitrates (73.5%) in comparison to the TT/GT group not treated with nitrates (34%); HR 2.75, 95% CI 1.57-4.79, P < 0.001.

CONCLUSIONS

Homozygosity for the G allele of the eNOS G894T polymorphism was associated with worse survival in systolic HF patients, especially in those treated with nitrates. ENOS polymorphism may result in different mechanistic interactions in HF than in thrombotic vascular diseases, suggesting that overexpression of NO may be associated with deleterious effects in systolic HF.

Patents on enhancing the potency and longevity of highly valuable protein hormones

One major issue regarding the clinical use of many peptides is their short half-life span in the body, due to the rapid clearance from the circulation. Thus, at the clinical level, there is a need for a regime of frequent injections of the peptides into the patients to overcome this low stability factor. The major strategies for overcoming this problem by pharmaceutical companies are based on chemical techniques and using specific peptidase inhibitors or cocktails. For this purpose, the cassette gene contains the sequence of the carboxyl-terminal peptide (CTP) of human chorionic gonadotropin β subunit which was ligated to the coding sequence of follitropin (FSH), erythropoietin (EPO), growth hormone (GH) and thus to increase the longevity and bioactivity of these proteins in vivo. Interestingly, FSH-CTP and GH-CTP were found to be not immunogenic in humans. FSH-CTP was approved by The European Commission. In addition, GH-CTP is not toxic and it passed successfully clinical trials Phase II in adults. Thus, using this technology seems to be promising in designing long acting peptides. Development of long acting peptides will diminish the cost of these drugs and perhaps reduce the number of injections in the clinical protocols. The article also summarizes some relevant patents.

Benzene-poly-carboxylic acids complex with Cis-diammineplatinum (II) dichloride (BP-C1), a novel anticancer agent, induces apoptosis in human breast cancer cells through caspase activation

e12029

Background: Breast cancer is the most frequent malignancy in women in western countries and despite progress in the treatment options surgery, radiation, chemotherapy and hormonal therapy it is still the leading cause of cancer death. BP-C1 is a novel anti-cancer complex of benzol-polycarbonic acids with ammonium-platinum salt developed by Meabco ltd, Denmark. Methods: In the present study, the effect of BP-C1 on growth of human breast cancer cells, MCF7 and T47D, was studied. Cells were exposed to different doses of BP-C1, 100-1000 µg/ml, and cell viability, toxicity (LDH release), cell cycle, apoptosis, caspase activation and gene expression were examined. Results: No toxicity was observed. Exposure of the cells to BP-C1 for 48h, significantly (P<0.001) reduced cell viability by approxematly 90% with IC50 of 400 µg/ml. In cell cycle studies cells were accumulated in sub-G1 phase, which may indicate induction of apoptosis. Annexin 5 assay demonstrated that BP-C1 induces apoptosis of MCF-7 and T47D cell by 65% and 34%, respectively, after 48h of treatment. Detection of caspases by western blot analysis revealed that BP-C1 activates caspase 8 and caspase 9. Moreover, gene expression experiments following BP-C1 treatment and using the Applied Biosystems TaqMan Array Plates indicated that BP-C1 caused an increase in the the expression of pro-apoptotic genes; CASP8AP2, TNFRSF21, RELB, NFKB2, BIRC8 and FADD when compared to the expression level of the House keeping genes, HPRT1 and GAPDH. On the other hand, lower levels of mRNA transcripts of the inhibitory apoptotic genes; BCL2L2 and XIAP were detected. Conclusions: These results may indicate that BP-C1 reduced cell viability of human cancer cells by a unigue induction of apoptosis through activation of the extrinsic (death receptors) and the intrinsic (mitochondrion) apoptotic pathways. These findings may lead to the development of new therapeutic strategies for treatment of cancer using BP-C1 or analogs.

The 894G Allele of the Endothelial Nitric Oxide Synthase 3 (eNOS) is Associated with Atrial Fibrillation in Chronic Systolic Heart Failure

BACKGROUND

Atrial fibrillation (AF) in patients with heart failure signals poor prognosis. The endothelial nitric oxide synthase (eNOS) enzyme is a key player in the counterregulation of oxidative stress, which is related in part to AF pathogenesis. The purpose of this study was to investigate a possible clinical association in heart failure patients between the presence of exon 7 G894T eNOS polymorphism, known to result in the Glu298Asp protein variant, and the occurrence of AF.

METHODS

We analyzed the DNA of 344 patients with chronic systolic heart failure for exon 7 G894T eNOS polymorphism, using PCR. Odds ratios for AF were calculated for the homo- and heterozygous G-allele G894T variants relative to the TT variant.

RESULTS

Of the 344 patients, 204 (59%) were homozygous for the G allele, 122 (36%) were heterozygous (GT), and 18 (5%) were homozygous for the T allele. AF episodes were documented in 73 patients (36%) with the GG genotype, in 35 (29%) with GT, and in 2 (11%) with TT. The odds ratio for AF, based on the presence of at least one G allele in the eNOS 894 gene, was 3.96 (95% confidence interval, 1.17‒13.56, p=0.04). Having two G alleles increased the odds ratio to 4.5 (95% confidence interval, 1.0‒20.0, p=0.02).

CONCLUSION

Patients with systolic heart failure demonstrate strong correlation between AF and the presence of a G allele in the exon 7 G894T eNOS genotype. These findings support the importance of eNOS polymorphism in the pathogenesis of AF in heart failure patients.

The effect of culture liquid ethyl acetate mycelium extracts of medicinal mushrooms on the viability of human pancreatic cancer cells

Pancreatic cancer, one of the deadliest of all solid malignancies, is one of the leading causes of cancer death worldwide, with 232,000 new cases and 213,000 deaths reported each year. These unfortunate statistics reflect the advanced stage at which most patients with pancreatic cancer are diagnosed and the paucity of effective chemotherapeutic regimens. Fungal metabolites have been gaining scientific interest because of their medicinal properties. In the present study, 31 different mushroom extracts of 12 medicinal mushroom species were screened for their effect on the viability of human pancreatic adenocarcinoma cells. Extraction procedures were executed with organic solvents--ethanol (EAL), ethyl acetate (EAC), and chloroform (CHL). In some cases, culture liquid (CL) extraction was also performed. All extracts were diluted to a concentration of 50 mg/mL dimethyl sulfoxide. Extract effects on cell viability were examined in human pancreatic adenocarcinoma cells HPAF-II (well differentiated) and PL5 (porrly differentiated), using XTT assay and crystal violet assay (CV). Furthermore, extract effects on LDH leakage were also studied in order to exclude necrotic damage of the extract. The screening phase revealed that among the total 31 extracts examined with various treatment doses (50-500 μg/mL) administered for 72 h, the CL extract of the mushroom Cyathus striatus exhibited the most prominent decrease in cell viability. Moreover, exposure of cells to lower concentrations then the above (1, 2.5, 5, 7.5, 10, 15, 20, and 50 μg/mL) for 24, 48, and 72 h showed a significant decrease in cell viability. Crystal violet results support these findings, and LDH levels measured suggest the lack of a necrotic effect of the extract. Our results indicate that C. striatus CL extract inhibits the viability of human pancreatic adenocarcinoma cells; HPAF-II and PL45. Growth inhibition can be achieved in low concentrations of the extract and a short exposure period. This effect can be mediated through apoptosis induction and/or cell cycle arrest; therefore, additional experiments are needed in order to elucidate the extract mechanism of action. These findings may lead to the development of new therapeutic strategies for the treatment of pancreatic cancer.

Conversion of TSH heterodimer to a single polypeptide chain increases bioactivity and longevity

TSH is a dimeric glycoprotein hormone composed of a common α-subunit noncovalently linked to a hormone-specific β-subunit. Previously, the TSH heterodimer was successfully converted to an active single-chain hormone by genetically fusing α and β genes with [TSHβ- carboxyl-terminal peptide (CTP)-α] or without (TSHβ-α) the CTP of human chorionic gonadotropin β-subunit as a linker. In the present study, TSH variants were expressed in Chinese hamster ovarian cells. The results indicated that TSHβ-α single chain has the highest binding affinity to TSH receptor and the highest in vitro bioactivity. With regard to the in vivo bioactivity, all TSH variants increased the levels of T(4) in circulation after 2 and 4 h of treatment. However, the level of T(4) after treatment with TSH-wild type was significantly decreased after 6 and 8 h, compared with the levels after treatment with the other TSH variants. TSHβ-α and TSHβ-CTP-α single chains exhibited almost the same bioactivity after 8 h of treatment. Evaluating the half-life of TSH variants, TSHβ-CTP-α single chain revealed the longest half-life in circulation, whereas TSH-wild type exhibited the shortest serum half-life. These findings indicate that TSH single-chain variants with or without CTP as a linker may display conformational structures that increase binding affinity and serum half-life, thereby, suggesting novel attitudes for engineering and constructing superagonists of TSH, which may be used for treating different conditions of defected thyroid gland activity. Other prominent potential clinical use of these variants is in a diagnostic test for metastasis and recurrence of thyroid cancer.

Photoperiodicity and increasing salinity as environmental cues for reproduction in desert adapted rodents

Understanding the ways environmental signals, regulate reproduction and reproductive behavior of desert adapted rodents is a major gap in our knowledge. In this study, we assessed the roles of photoperiod and diet salinity, as signals for reproduction. We challenged desert adapted common spiny mice, Acomys cahirinus, males and females with osmotic stress, by gradually increasing salinity in their water source - from 0.9% to 5% NaCl under short and long days (SD and LD, respectively). Photoperiodicity affected testosterone levels, as under LD-acclimation, levels were significantly (p<0.05) higher than under SD-acclimation. Salinity treatment (ST) significantly reduced SD-acclimated male body mass (W(b)) and testis mass (p<0.005; normalized to W(b)). ST-LD-females significantly (p<0.005) decreased progesterone levels and the numbers of estrous cycles. A reduction in white adipose tissue (WAT) to an undetectable level was noted in ST-mice of both sexes under both photoperiod regimes. Receptors for vasopressin (VP) and aldosterone were revealed on testes of all male groups and on WAT in control groups. Our results suggest that photoperiod serves as an initial signal while water availability, expressed by increased salinity in the water source, is an ultimate cue for regulation of reproduction, in both sexes of desert-adapted A. cahirinus. We assume that environmental changes also affect behavior, as water seeking behavior by selecting food items, or locomotor activity may change in extreme environment, and thus indirectly affect reproduction and reproductive behavior. The existence of VP and aldosterone receptors in the gonads and WAT suggests the involvement of osmoregulatory hormones in reproductive control of desert adapted rodents.

In vitro mitochondrial effects of PK 11195, a synthetic translocator protein 18 kDa (TSPO) ligand, in human osteoblast-like cells

The role of the TSPO in metabolism of human osteoblasts is unknown. We hypothesized that human osteoblast metabolism may be modulated by the TSPO. Therefore we evaluated the presence of TSPO in human osteoblast-like cells and the effect of its synthetic ligand PK 11195 on these cells. The presence of TSPO was determined by [(3)H]PK 11195 binding using Scatchard analysis: Bmax 7682 fmol/mg, Kd 9.24 nM. PK 11195 did not affect significantly cell proliferation, cell death, cellular viability, maturation, [(18)F]-FDG incorporation and hexokinase 2 gene expression or protein levels. PK 11195 exerted a suppressive effect on VDAC1 and caused an increase in TSPO gene expression or protein levels. In parallel there was an increase in mitochondrial mass, mitochondrial ATP content and a reduction in ΔΨm collapse. Thus, it appears that PK11195 (10(-5) M) stimulates mitochondrial activity in human osteoblast-like cells without affecting glycolytic activity and cell death.

Designing a long-acting human growth hormone (hGH) by fusing the carboxyl-terminal peptide of human chorionic gonadotropin beta-subunit to the coding sequence of hGH

Chimeric genes were constructed by fusing of human GH (hGH) cDNA to one, two, or three cassettes of the carboxyl-terminal peptide (CTP) of human chorionic gonadotropin (hCG)-beta-subunit. hGH variant genes were inserted into the pCI-DHFR plasmid, transfected into DG44 cells, and stable clones were selected. Bioactivity and pharmacokinetic studies were performed in hypophysectomized Sprague Dawley derived male rats. The results indicated that sc injections of GH-wild-type (WT), Biotropin (commercial), GH-CTP, or CTP-GH (0.6 mg/kg) once every 5 d for 11 d (total dose of 1.2 mg/kg) resulted in an increased weight gain by 4, 4.9, 5.1, and 7 g, respectively. Treatment with CTP-GH-CTP-CTP (GH-LA) or CTP-GH-CTP (0.6 mg/kg) once every 5 d for 11 d or with Biotropin (0.12 mg/kg) daily for 11 d (total dose 1.2 mg/kg) resulted in a dramatic increase in weight gain of 16.5, 16.8, and 17 g, respectively. Repeated injections with different doses of GH-LA, 0.6, 1.8 mg/kg every 4 d or daily injection of 0.12 mg/kg of Biotropin increased the weight gain by 16, 28, and 18 gr, respectively. In addition, the cumulative serum levels of IGF-I after injection of GH-LA was significantly higher than that detected after injection of Biotropin. Pharmacokinetic studies indicated that the half-life, mean residence time, area under the curve, time of maximal plasma concentration, and maximal plasma concentration of GH-LA are dramatically increased compared with Biotropin. This may suggest that the mechanism of GH metabolic clearance is affected by the presence of CTP. These data establish a rationale for using this chimera as a long-acting GH analog.

Effect of increased dietary salinity on the reproductive status and energy intake of xeric and mesic populations of the spiny mouse, Acomys

The possible role of increased dietary salinity as a proximate regulator of reproduction in xeric population of golden spiny mice (Acomys russatus) and mesic population of common spiny mice (A. cahirinus) was tested. In the wild, as the dry season progresses, evaporative water loss in the vegetation increases. This leads to increase in particle concentration of plant tissues. Thus, species consuming a plant diet are exposed to increased dietary salinity. Both male and female individuals of A. russatus were subjected to gradually increasing dietary salinity (0.9%, 2.5%, 3.5%, and 5%) while those of A. cahirinus only up to 3.5% for a total period of 8 and 6 weeks, respectively. Urine osmolarity showed a significant increase under 3.5% and 5% salinity in A. russatus and 2.5% and 3.5% in A. cahirinus. Testis mass and spermatogenesis were significantly reduced while uterine mass and vaginal estrus cycles were not affected in A. russatus. None of the parameters was significantly affected in A. cahirinus. Increase in salinity also significantly reduced body mass in A. russatus but not in A. cahirinus. Mass-specific daily digestible energy intake was not significantly affected by increased salinity in both species. Recovery individuals regained body mass quickly and surpassed initial values after four weeks. However, testis mass and spermatogenesis did not show recovery. The results suggest that increase in dietary salinity could be used as a proximate signal to regulate reproduction in A. russatus by halting it in males, as the dry season progresses while such role in the mesic population of A. cahirinus is unlikely.

Development of a long-acting erythropoietin by fusing the carboxyl-terminal peptide of human chorionic gonadotropin beta-subunit to the coding sequence of human erythropoietin

Human erythropoietin (EPO) is a glycoprotein hormone secreted from the kidney and controls red blood cell production. EPO has a wide clinical use in the treatment of anemia associated with renal disease, certain chronic diseases, and anemia related to chemotherapy and radiotherapy. One major issue regarding the clinical use of EPO is its relatively short half-life due to its clearance by glomerular filtration. Thus, the therapeutic protocol used in the treatment of patient-required frequent injections of EPO. To address this issue, we constructed a chimeric gene that contains the sequence of the carboxyl-terminal peptide (CTP) of human chorionic gonadotropin-beta subunit bearing four O-linked oligosaccharide recognition sites and the coding sequence of human EPO cDNA. Fusing the CTP to the carboxyl-terminal of EPO did not affect secretion, receptor binding affinity, or in vitro bioactivity. However, both in vivo potency and half-life of EPO-CTP were significantly enhanced. A single injection dose (660 IU/kg) of EPO wild-type administered once a week had no significant effect on haematocrit levels. However, EPO-CTP administered as 660 IU/kg once a week was effective as well as the same total dose of EPO wild-type administered as 220 IU/kg three times a week. This may emphasize the importance of sustained blood levels rather than total dose of administration for in vivo bioactivity. These data established the rationale for using this chimera as a long-acting EPO analog. The therapeutic efficacy of EPO-CTP analog needs to be established in higher animals and human clinical trials.

Clinical significance of the parental origin of the X chromosome in turner syndrome

CONTEXT

The phenotype in Turner syndrome (TS) is variable, even in patients with a supposedly nonmosaic karyotype. Previous work suggested that there were X-linked parent-of-origin effects on the phenotype.

HYPOTHESIS

The TS phenotype is influenced by the parental origin of the missed X chromosome.

DESIGN

This was a multicenter prospective study of TS patients and both their parents, determining parental origin of the X-chromosome, and characterizing the clinical phenotype.

PATIENTS AND METHODS

Eighty-three TS patients and their parents were studied. Inclusion criteria were TS with karyotype 45,X or 46Xi(Xq). Four highly polymorphic microsatellite markers on the X-chromosome DMD49, DYSII, DXS1283, and the androgen receptor gene and three Y chromosome markers, SRY, DYZ1, and DYZ3.

OUTCOME MEASURES

The study determined the correlation between the parental origin of the X chromosome and the unique phenotypic traits of TS including congenital malformations, anthropometry and growth pattern, skeletal defects, endocrine traits, education, and vocation.

RESULTS

Eighty-three percent of 45,X retained their maternal X (X(m)), whereas 64% 46Xi(Xq) retained their paternal X (X(p), P < 0.001). Kidney malformations were exclusively found in X(m) patients (P = 0.030). The X(m) group had lower total and low-density lipoprotein cholesterol (P < 0.003), and higher body mass index sd score (P = 0.030) that was not maintained after GH treatment. Response to GH therapy was comparable. Ocular abnormalities were more common in the paternal X group (P = 0.017), who also had higher academic achievement.

CONCLUSIONS

The parental origin of the missing short arm of the X chromosome has an impact on overweight, kidney, eye, and lipids, which suggests a potential effect of an as-yet-undetermined X chromosome gene imprinting.

The role of O-linked and N-linked oligosaccharides on the structure-function of glycoprotein hormones: development of agonists and antagonists

Thyrotropin (TSH) and the gonadotropins; follitropin (FSH), lutropin (LH) and human chorionic gonadotropin (hCG) are a family of heterodimeric glycoprotein hormones. These hormones composed of two noncovalently linked subunits; a common alpha and a hormone specific beta subunits. Assembly of the subunits is vital to the function of these hormones. However, genetic fusion of the alpha and beta subunits of hFSH, hCG and hTSH resulted in active polypeptides. The glycoprotein hormone subunits contain one (TSH and LH) or two (alpha, FSHbeta and hCGbeta) asparagine-linked (N-linked) oligosaccharides. CGbeta subunit is distinguished among the beta subunits because of the presence of a carboxyl-terminal peptide (CTP) bearing four O-linked oligosaccharide chains. To examine the role of the oligosaccharide chains on the structure-function of glycoprotein hormones, chemical, enzymatic and site-directed mutagenesis were used. The results indicated that O-linked oligosaccharides play a minor role in receptor binding and signal transduction of the glycoprotein hormones. In contrast, the O-linked oligosaccharides are critical for in vivo half-life and bioactivity. Ligation of the CTP bearing four O-linked oligosaccharide sites to different proteins, resulted in enhancing the in vivo bioactivity and half-life of the proteins. The N-linked oligosaccharide chains have a minor role in receptor binding of glycoprotein hormones, but they are critical for bioactivity. Moreover, glycoprotein hormones lacking N-linked oligosaccharides behave as antagonists. In conclusion, the O-linked oligosaccharides are not important for in vitro bioactivity or receptor binding, but they play an important role in the in vivo bioactivity and half-life of the glycoprotein hormones. Addition of the O-linked oligosaccharide chains to the backbone of glycoprotein hormones could be an interesting strategy for designing long acting agonists of glycoprotein hormones. On the other hand, the N-linked oligosaccharides are not important for receptor binding, but they are critical for bioactivity of glycoprotein hormones. Deletion of the N-linked oligosaccharides resulted in the development of glycoprotein hormone antagonists. In the case of hTSH, development of an antagonist may offer a novel therapeutic strategy in the treatment of thyrotoxicosis caused by Graves' disease and TSH secreting pituitary adenoma.

Paternal isodisomy of chromosome 7 with cystic fibrosis and overgrowth

We have diagnosed a boy with cystic fibrosis (CF) due to paternal UPD presenting with overweight and developmental delay, not typical features to CF patients. Two previously reported patients with paternal UPD(7) did not present overgrowth. The discrepancy between the phenotype of this boy and the other two patients raises the question of imprinted genes or homozygotization of a disease-causing gene in paternal UPD7.

Arsenic Trioxide inhibits the growth of human ovarian carcinoma cell line

OBJECTIVE

To determine whether Arsenic Trioxide may be an effective treatment of human ovarian carcinoma, we examined if it induced apoptosis in human ovarian cancer cell line.

METHODS

The human ovarian cell line SKOV3 was exposed to different concentrations of As2O3: 0 (control), 0.1 microM, 1 microM, 5 microM and 10 microM. The effect on cells proliferation and apoptotic parameters was examined.

RESULTS

The most effective inhibitory Arsenic Trioxide concentrations were 5 microM and 10 microM, causing growth inhibition of 79% and 83%, respectively. The maximum inhibitory effect of Arsenic Trioxide on cellular proliferation was seen after 48 h. No morphological or molecular features of apoptosis have been observed. At the same time, there were no typical changes of cellular necrosis.

CONCLUSIONS

The exact mechanism by which Arsenic Trioxide inhibits the growth of ovarian cancer cells is probably not by apoptosis. However, since As2O3 has been shown to inhibit ovarian cancer cellular growth, it should be further elucidated as a possible chemotherapeutic agent of ovarian cancer.

Differences in the characteristics of families with BRCA1 and BRCA2 mutations in Israel

Three specific mutations in the BRCA1 (185delAG, 5382insC) and BRCA2 (6174delT) genes have been reported to be of high prevalence in the Jewish Ashkenazi population. We studied the differences in phenotype of families carrying these mutations. All consecutive families found by the CHS Familial Cancer Service to carry one of the three 'Jewish' mutations of the BRCA1/BRCA2 genes were evaluated for phenotypic characteristics. Chi-squared and Student's t-test statistics were employed to study differences in a variety of clinical and demographic parameters. A total of 111 families with 1499 family members were included. Among them 454 cases of cancer (297 in breast/ovary) were reported. Ovarian cancer, but not breast cancer, was detected at a significantly younger age among carriers of 185delT compared with other mutation carriers. In families with 185delAG, 5382insC and 6174delT mutations, breast cancer was found in 20.2, 39.4 and 24.1% of all identified women (born between 1900 and 1975), correspondingly. The corresponding figures for ovarian cancer were 13.9, 6.8 and 4.9%. Families carrying the 5382insC mutation had the highest probability of expressing bilateral breast cancer (38.9% of families, 15.4% of women with cancer, 6.1% of all women in family) and metachronous breast and ovary tumours (22.2, 9.8 and 4.5% correspondingly). Other tumours were reported in 7.9, 9.1 and 12.0% of women and 9.5, 12.9 and 15.8% of men in families with 185delAG, 5382insC, 6174delT, correspondingly. Marked phenotypic differences were found between families carrying different BRCA mutations warranting mutation-specific counselling to families seeking risk-reduction advice. 5382insC emerged as a most aggressive mutation.

Human thyrotropin (TSH) variants designed by site-directed mutagenesis block TSH activity in vitro and in vivo

TSH is a heterodimeric glycoprotein hormone synthesized in the pituitary and composed of a specific beta-subunit and a common alpha-subunit shared with FSH, LH, and human chorionic gonadotropin. The heterodimer was previously converted into a biologically active single chain protein by genetic fusion of the genes coding to both subunits in the presence of the carboxy-terminal sequence of human (h) chorionic gonadotropin-beta subunit as a linker [hTSHbeta-carboxyl-terminal peptide (CTP)-alpha]. N-linked carbohydrate-free single-chain TSH variants were constructed by site-directed mutagenesis and overlapping PCR: one devoid of both N-linked oligosaccharide chains on the alpha-subunit (hTSHbeta-CTP-alpha(deg)) and the other lacking also the oligosaccharides on the beta-subunit (hTSHbeta(deg)-CTP-alpha(deg)). These variants were expressed in Chinese hamster ovary cells and secreted into the culture media. We have previously reported that the variants block the activities of hTSH and thyroid-stimulating immunoglobulins in cultured human thyroid follicles. In the present study, binding affinity of hTSH variants to hTSH receptor and the localization of the antagonistic effect were examined. Moreover, the effect of these variants on TSH activity was tested in vivo. The results of the present study indicate that the hTSH variants bind to the hTSH receptor with high affinity. Experiments using forskolin also indicated that the N-linked carbohydrate-free TSH single-chain variants inhibit TSH activity at the receptor-binding site and not at a postreceptor level. Moreover, the variants significantly inhibited (about 50%) TSH activity with respect to thyroid hormone secretion in vivo in mice. These variants may offer a novel therapeutic strategy in treating hyperthyroidism.

Identification of two mutations for ataxia telangiectasia among the Druze community

Ataxia telangiectasia (AT) is a rare autosomal recessive disease characterized by progressive cerebellar ataxia, immunodeficiency, susceptibility to lymphoreticular malignancies and cancer predisposition, hypersensitivity to ionic radiation and chromosomal instability. In this study, we report a founder effect of AT with two different mutations: 1339 C > T and 6672 del GG together with 6677 del TACG, found in four Israeli Druze clans originating from three different Druze centers in the Middle East (Lebanon, Syria and Jordan). The 1339 C > T mutation, which results in a stop codon at position 447 of the ATM protein, was observed in two unrelated clans originating from Lebanon and Jordan. The 6672 del GG/6677 del TACG mutation was observed in two unrelated clans originating from Syria and Lebanon. In the present study, simple and fast detection assays were developed for both mutations. The ability to identify AT carriers routinely provides a unique opportunity for prenatal diagnosis, genetic counseling as well as marriage guidance in the Druze community.

Evaluation of the spectral transmittance of UV-absorbing disposable contact lenses

PURPOSE

Increasing evidence suggesting deleterious effects of ultraviolet radiation (UVR) on the eye has prompted manufacturers to develop UV-absorbing disposable contact lenses. The spectral transmittances of a sample of these lenses were measured in order to determine if they provide adequate protection from UVR.

METHODS

Four types of UV-absorbing disposable lenses were studied (Acuvue [Vistakon, Jacksonville, FL], Precision UV [Wesley-Jessen, Des Plaines, IL], Specialty Sport [Specialty UltraVision, Sunnyvale, CA], and Surevue [Vistakon]). For comparison, a lens without UV-absorbing properties (Acuvue), a conventional soft lens (Permaflex UV [Cooper Vision, San Jose, CA]) and an RGP lens (Boston ES [Polymer Technology, Rochester, NY]) were also evaluated. The tested lens was placed in a silica wet cell filled with saline. Spectral transmittance was measured over the 200-800 nm waveband.

RESULTS

Each disposable lens exhibited a transmittance window in the 240-320 nm waveband. Computing indices of protection factor and safe exposure duration allowed for the assessment of the level of protection afforded by each lens. Among disposable lenses studied, the Surevue performed best with a transmittance of less than 1% in the waveband 280-348 nm and the longest safe exposure duration, while the Specialty Sport had the highesttransmittance of UVB (290-315 nm).

CONCLUSION

All UV-absorbing lenses studied provided a better level of protection from UVR exposure than lenses without UV absorber. These results will help the eyecare practitioner in prescribing the most appropriate UV-blocking lens for each patient.

DNA global hypomethylation in EBV-transformed interphase nuclei

In tumors, DNA is often globally hypomethylated compared to DNA extracted from normal tissues. This observation is usually made after extraction and exhaustive digestion of DNA followed by analysis of nucleosides by chromatography or digestion with restriction enzymes, gel analysis, and hybridization. This approach provides an average value which does not give information on the various cell subpopulations included in heterogeneous samples. Therefore an immunochemical technique was set up with the aim of demonstrating, in a population of mixed cells, the possibility of detecting the presence of individual nuclei containing hypomethylated DNA, on a cell-by-cell basis. Monoclonal antibodies to 5-methylcytidine were used to label cells grown in vitro. Under appropriate fixation and permeabilization conditions, interphase nuclei were labeled. Quantitative differences in the labeling were detected between Epstein-Barr virus-transformed cells and normal peripheral blood monocytes by flow cytometry analysis. Similar differences were observed by fluorescence microscopy. Both results were confirmed by Southern transfer and hybridization of DNA fragments generated by restriction enzyme digestion. This observation, which is in accordance with the occurrence of global DNA hypomethylation in tumors as established by chromatography, opens the field for the analysis of fresh tumor samples by flow cytometry and microscopy.

High Epstein-Barr virus serum load and elevated titers of anti-ZEBRA antibodies in patients with EBV-harboring tumor cells of Hodgkin's disease

Hodgkin's disease is commonly associated with EBV latent infection. The incidence of EBV reactivation (active infection or EBV infection with replicative cycle) was evaluated in a series of 30 patients with untreated Hodgkin's disease (except for one case with chronic lymphocytic leukemia) by quantitation of EBV DNA and titration of anti-ZEBRA antibodies in serum samples. DNA was detected in serum (>2.5 x 10(2) genomes/ml) in 15 of 30 patients and was more frequent in Hodgkin's disease with EBV-positive Reed-Sternberg cells (10/12) than in EBV-negative cases (5/18), (P< 0.01). Of interest was the demonstration that viremia correlated well with increased titers of anti-ZEBRA IgG and/or standard serological profiles of EBV reactivation (12/15), (P < 0.05). However the lack of EBV replicative cycle in Reed-Sternberg cells (negative for ZEBRA antigen and early antigen BHLF1) suggests that the viral replication occurs in a nonneoplastic cell compartment rather than in tumor cells. The measurement of EBV DNA loads and the titration of anti-ZEBRA antibodies shed new lights on the link between activation of EBV replication and Hodgkin's disease: these serological markers together with the determination of the EBV status of the tumor suggest that replication of the viral genome occurs with a decreased efficiency of the immune system, thus allowing progression of the tumor.

In situ amplification of the Epstein-Barr virus genome in cell suspensions

Epstein-Barr virus (EBV) is distributed widely throughout the world. Apart from a association with two geographically-restricted malignancies (Burkitt's lymphoma and nasopharyngeal carcinoma), EBV is thought to be implicated in the etiology of B-cell lymphoma in immunocompromised individuals. In these patients, monitoring the viral load in serum can provide useful information on the timing of the instigation of antiviral therapy, i.e. as soon as a rise is detected. PCR technology, owing to its high sensitivity, is used frequently in such situations. In order to gain further insight into the nature of the peripheral blood cells carrying the viral genome on a cell-by-cell basis, an in situ amplification technique was developed as a model using two cell lines growing in suspension, with the aim of distinguishing between EBV-positive and EBV-negative cells. Preliminary experiments were undertaken subsequently on clinical samples from patients with infectious mononucleosis and patients with lymphoma indicating that this technique might be useful clinically.

Characterization of the O-glycosylation sites in the chorionic gonadotropin beta subunit in vivo using site-directed mutagenesis and gene transfer

Human chorionic gonadotropin (CG) is a member of a family of glycoprotein hormones which are heterodimers containing two nonidentical subunits: a common alpha and a hormone-specific beta subunit. One of the distinguishing features of the CGbeta subunit is the presence of four serine acceptors clustered within the last 25 amino acids. We previously demonstrated that this carboxyl-terminal region is important for maintaining its biologic half-life, and when the sequence was genetically fused to either the common alpha or follitropin beta subunits, O-glycosylation was observed. Because this carboxyl-terminal sequence is located at the end of the subunit, we considered this region a convenient in vivo model for studying O-linked glycosylation in domains containing multiple serine recognition sites. A CGbeta gene was engineered in which the N-linked sites were inactivated to eliminate background from those carbohydrate groups. Using this construct, we made a series of truncation and amino acid substitutions of acceptor serines, and these mutants were transfected into Chinese hamster ovary cells. O-Glycosylation was determined by [3H]glucosamine incorporation and glycanase sensitivity of the products on SDS-polyacrylamide gels. We show that the O-linked sites comprise independent repetitive regions in which each acceptor serine has a recognition signal bounded by the next carboxy acceptor serine within four to five amino acids. It is also apparent that recognition of one site is not dependent on the glycosylation of another acceptor. Amino acid mutations in the acceptor regions demonstrated the importance of proline as a necessary feature for O-linked recognition in the CGbeta sequence.

Polymerase chain reaction products containing 5-methyldeoxycytidine: a microplate immunoquantitation method

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Modulation of peripheral benzodiazepine receptors in female rat genital organs by various gonadal steroids

Peripheral benzodiazepine receptors (PBR) in the ovary, oviduct, uterus, and kidney of immature rats were studied under short- and long-term treatment with testosterone (T), progesterone (P4), and diethylstilbestrol (DES). A significant increase in PBR specific binding was observed after 4 days' treatment with T in the ovary (1.6-fold), oviduct (2.0-fold), and uterus (1.4-fold) compared with intact rats. Four days' treatment with P4 increased PBR specific binding in the ovary (1.5-fold), but no changes were detected in the oviduct or uterus. In contrast, PBR specific binding was significantly reduced by 10 days' treatment with T or P4: 40 and 12%, respectively, in the ovary and 35 and 40%, respectively, in the oviduct. Ten days' treatment with T reduced PBR specific binding in the uterus by 25%, but the same interval of treatment with P4 did not alter specific binding in the uterus. Four or 10 days' treatment with DES significantly increased PBR specific binding in the ovary (1.5-fold), oviduct (2.4-fold), and uterus (1.9-fold). Scatchard analysis revealed that the changes in the PBR specific binding were due to a change in PBR density values rather than PBR affinity values. No change in PBR specific binding was found in the kidney following any of these treatments. Taken together, it is suggested that PBR density in the ovary is altered by exogenously administered steroids that usually are biosynthesized in the ovary. Additionally, the altered PBR density in the oviduct and uterus via the various steroids employed may imply that changes occurring in ovarian steroidogenesis should affect PBR density in these organs.

Hippocampal gamma-aminobutyric acid and benzodiazepine receptors after early phenobarbital exposure

Mice were exposed to phenobarbital (PhB) prenatally (PreB offspring) by feeding their mothers 3 g/kg PhB in milled food on gestation days 9-18, or neonatally by directly injecting pups of intact mothers with daily dose of 50 mg PhB on postnatal days 2-21 (NeoB offspring). At age 22 or 50 days, the offspring were tested for gamma-aminobutyric acid (GABA) up take in the hippocampus and in the rest of the brain. In addition, [3H]muscimol and [3H]flunitrazepam binding in the hippocampus and cortex were measured in the offspring at age 22 and 50 days. Long-term decrease in GABA uptake was found in the NeoB group. A 23% decrease was found in 22-day-old mice (P < 0.001) and a 22% decrease in 50-day-old mice (P < 0.05). In addition, there was a 22% decrease in GABA uptake in the brain of 22-day-old PreB mice (P < 0.05). An increase of 52% in [3H]muscimol binding (P < 0.001) and 45% (P < 0.001) in [3H]flunitrazepam binding were measured in the hippocampus in the 22-day-old NeoB mice; no differences were found in affinity. The differences were short-term and could no longer be detected at age 50 days. No differences were found in the cortex; unlike NeoB, PreB mice did not differ from controls. The results suggest upregulation of the GABAergic system in early PhB exposed mice.