Reversed-phase liquid chromatographic purification and isolation of a radio-iodinated selective probe for mu opioid receptors in the brain

A Guard-PAK precolumn system was used for the reversed-phase liquid chromatography purification of a small, synthetic radiolabeled opioid peptide, FK 33-824 (D-Ala2, methyl-phe4, Met (O)ol5 enkephalin) (FK). This procedure involves trace enrichment of iodinated peptide onto the precolumn while iodination reagents are not retained. Radioactive contamination of high-performance liquid chromatography columns and injectors is thus avoided. Precolumn chromatography has sufficient resolving power to separate not only labeled from unlabeled peptide but also mono- from di-iodinated peptide. Purified 125I-labeled FK (estimated specific activity 85.9-153.7 Ci/mmol) showed high specific binding to mouse corpus striatum, neocortex, cingulate cortex, nucleus accumbens septi, diagonal band of Broca, nucleus medialis septi, area preopticus magnocellularis, and the nucleus of the caudate/putamen. Radioligand binding was inhibited by both antagonists (naloxone and naltrexone); and agonists D-Ala2, N-methyl-phe4, gly-ol5-enkephalin [DAGO]; FK; and beta-endorphin at all concentrations tested (1 x 10(-8) to 1 x 10(-4) M). Adrenocorticotropin hormone (ACTH) did not block ligand binding at any concentration tested. Distribution of mu opioid receptors was analyzed by light microscopic autoradiography. Sections incubated with 125I-labeled FK in the presence of agonists and antagonists demonstrated decreasing ligand binding with increasing doses of competitor. ACTH did not block ligand binding at any concentration tested. HPLC analyses of ligand which had been iodinated 1.5 half lives before the date of the experiment demonstrated a single peak similar to that of freshly iodinated ligand. Similar binding kinetics and autoradiographic labeling patterns were observed as compared to those obtained with freshly iodinated peptide.(ABSTRACT TRUNCATED AT 250 WORDS)

Morphometric assessment of the murine ovarian toxicity of 7,12-dimethylbenz(a)anthracene

7,12-Dimethylbenz(a)anthracene (DMBA) is a polycyclic aromatic hydrocarbon and a component of cigarette smoke that has been identified as a murine reproductive toxicant. The morphometric parameters of total ovarian volume, individual corpus luteum volumes, and total corpora lutea volume were measured in C57BL/6N mice treated with DMBA. Each group received single intraperitoneal injections of 0, 0.1, 1.0, or 10 mg/kg and were sacrificed at 1, 2, 3, or 4 weeks after treatment. DMBA produced a dose-dependent decrease in ovarian volume and number of corpora lutea in each ovary. The observed reduction in total corpora lutea volume did not fully account for the loss in total ovarian volume. This is consistent with previous descriptions of a toxic effect on all ovarian components including growing and resting follicles. Growing follicles that escaped the toxic effects of DMBA and achieved ovulation resulted in a corpus luteum that appeared histologically normal. Morphometric analysis of this animal model further defines the dynamic changes in the mouse ovary in response to DMBA.

Use of impression cytology to demonstrate a retrovirus in AIDS patients with cytomegalovirus retinitis

Utilizing transmission electron microscopy, the authors describe results obtained from cellulose acetate impressions of the bulbar conjunctiva in acquired immunodeficiency syndrome patients with cytomegalovirus (CMV) retinitis. Particles consistent with a retrovirus were isolated, but no CMV particles were demonstrated.

Immunoglobulin variable-region-like domains of diverse sequence within the major histocompatibility complex of the chicken

The highly polymorphic B-G antigens are considered to be part of the major histocompatibility complex (MHC) of the chicken, the B system of histocompatibility, because they are encoded in a family of genes tightly linked with the genes encoding MHC class I and class II antigens. To better understand these unusual MHC antigens, full-length B-G cDNA clones were isolated from B21 embryonic erythroid cell cDNA library, restriction-mapped, and sequenced. Five transcript types were identified. Analysis of the deduced amino acid sequences suggests that the B-G polypeptides are composed of single extracellular domains that resemble immunoglobulin domains of the variable-region (V) type, single membrane-spanning domains typical of integral membrane proteins, and long cytoplasmic tails. Sequence diversity among the five transcript types was found in all domains, notably including the B-G immunoglobulin V-like domains. The cytoplasmic tails of the B-G antigens are made up entirely of units of seven amino acid residues (heptads) that are typical of an alpha-helical coiled-coil conformation. The heptads vary in number and sequence between the different transcripts. The presence within B-G polypeptides of polymorphic immunoglobulin V-like domains warrants further investigations to determine the degree and nature of variability within this domain in these unusual MHC antigens.

Loss during aging of beta-endorphinergic neurons in the hypothalamus of female C57BL/6J mice

Beta-endorphin (B-EP) content is often reduced in hypothalami of aging rodents. The objective of this study was to determine whether reduced B-EP content is associated with a reduced number of B-EP immunoreactive neurons. Serial coronal sections extending from the caudal hypothalamus through the retrochiasmatic area were examined by quantitative light microscopy in mature (5-6 month) and senescent (24-28 month) mice that had been ovariectomized 1 week earlier and injected with colchicine 24-48 h before sacrifice. Old mice were acyclic. As expected, B-EP immunoreactive cell bodies were restricted to the region of the arcuate nucleus. There was a 35% loss of B-EP immunopositive neurons in old, macroscopically disease-free animals. By contrast, some old animals with pituitary tumors had no loss of B-EP neurons. These results suggest that a subpopulation of B-EP neurons either die or stop synthesizing detectable concentrations of B-EP in aged mice. The basis for the absence of reduced B-EP neurons in some mice with pituitary tumors is unclear, but this observation underscores the importance of distinguishing age-related changes associated with diseases of aging from those that are independent of such diseases.

Liposome-entrapped calcitonin and parathyroid hormone are orally effective in rats

We have demonstrated that liposomally entrapped calcitonin (CT) and parathyroid hormone (PTH) can be orally effective in regulating blood calcium. Liposomal CT produced hypocalcemia and liposomal PTH produced hypercalcemia upon oral administration to rats. Specific liposomal formulations were necessary to affect the appropriate decrease and increase in blood calcium concentration. Future extension of these studies may lead to clinically valuable forms of liposomal-peptide preparations.

Comparison of endometrial biopsy and urinary pregnanediol glucuronide concentration in the diagnosis of luteal phase defect

To determine if pregnanediol glucuronide (PG) excretion is useful in luteal phase assessment, we compared daily first morning urinary PG concentrations during the luteal phase in nine normal and nine deficient cycles. Total luteal pregnanediol excretion (44.1 +/- 11.3 versus 64.0 +/- 11.6 area units +/- SEM) was not different. However, significantly less pregnanediol was excreted by the abnormal group during the 1st 5 days of the luteal phase (12.7 +/- 1.2 versus 18.0 +/- 1.7 area units +/- SEM, respectively). Thus, delayed PG excretion may be characteristic of luteal phase defect and measurement of urinary PG may be useful only if daily samples during the early luteal phase are obtained.

Factors influencing the enhanced hypocalcemic action of liposome-entrapped calcitonin

The mechanism whereby liposomal entrapment enhances the hypocalcemic effect of calcitonin (CT) was evaluated in the rat. Phosphatidylcholine (PC) and PC plus cholesterol (PCC) preparations of large multilammelar vesicles (MLV) and small unilammelar vesicles (SUV) were used to entrap human calcitonin (hCT). The effect of each of these preparations was assessed by measuring plasma calcium after their parenteral administration. Changes in calcium were compared with plasma concentrations of liposomal hCT (L-hCT) and free hCT (F-CT). The plasma form of hCT was also evaluated by gel filtration chromatography. Most of the liposomal preparations had a greater hypocalcemic effect than unencapsulated hCT. Following I.V. administration, the MLV-hCT preparations had the greatest hypocalcemic effect. Thus, to enhance the hypocalcemic effect of hCT, large vesicular size is important for I.V. administration and the absence of cholesterol in the liposome is important for I.M. administration. In general, the greatest hypocalcemic effect was achieved by those liposomal preparations that resulted in the most sustained increase of L-hCT and F-hCT in plasma. Thus, liposomal entrapment enhances the hypocalcemic effect of hCT by prolonging the presence of the peptide in the peripheral circulation.

X-ray crystallographic structure of a complex between a synthetic protease of human immunodeficiency virus 1 and a substrate-based hydroxyethylamine inhibitor

The structure of a crystal complex of the chemically synthesized protease of human immunodeficiency virus 1 with a heptapeptide-derived inhibitor bound in the active site has been determined. The sequence of the inhibitor JG-365 is Ac-Ser-Leu-Asn-Phe-psi[CH(OH)CH2N]-Pro-Ile-Val-OMe; the Ki is 0.24 nM. The hydroxyethylamine moiety, in place of the normal scissile bond of the substrate, is believed to mimic a tetrahedral reaction intermediate. The structure of the complex has been refined to an R factor of 0.146 at 2.4-A resolution by using restrained least squares with rms deviations in bond lengths of 0.02 A and bond angles of 4. The bound inhibitor diastereomer has the S configuration at the hydroxyethylamine chiral carbon, and the hydroxyl group is positioned between the active site aspartate carboxyl groups within hydrogen bonding distance. Comparison of this structure with a reduced peptide bond inhibitor-protease complex indicates that these contacts confer the exceptional binding strength of JG-365.

Loss of LH-RH neurons in the rostral forebrain of old female C57BL/6J mice

This study reports the quantitative immunohistochemical distribution of luteinizing hormone-releasing hormone (LH-RH) neurons within the rostral forebrain of young (5-6 month) and old (26-28 month) C57BL/6J mouse. Old mice demonstrated a significant (18%) loss of LH-RH-containing neurons (p less than 0.001, ANOVA). The most striking losses involved the preoptic area (24%) and more rostral regions (26%). The presence of pituitary or mesenteric tumors in older mice did not affect the density of LH-RH neurons. These observations indicate that LH-RH neurons comprise part of the neuronal population previously reported to be reduced in the preoptic area of older mice (4).

Recurrent allergic vulvovaginitis: treatment with Candida albicans allergen immunotherapy

Recurrent vaginal candidiasis is a difficult problem for many women who do not respond to the usual antifungal agents. Normally these women have recurrent disease for many years before they are referred for evaluation of local vaginal hypersensitivity. We evaluated 18 women with recurrent vulvovaginal candidiasis that was unresponsive to all other modalities of therapy and who were skin-test positive to Candida albicans with a positive prick test or intradermal skin test. Three patients had late-phase skin test reactions only. Of the 18 study participants, 16 responded with significant improvement in the mean incidence of episodes of vaginitis per year from 17.2 +/- 2.0 to 4.3 +/- 1.8 (p less than 0.0004). Overall, there was approximately 79% improvement in these patients. More than half the women were also atopic but were not first seen with these allergic symptoms. These data suggest that certain women who have chronic vaginal candidiasis may have a local hypersensitivity response to Candida that may improve with allergy immunotherapy with C. albicans extract. A double-blind, placebo-controlled trial in a homogeneous group of women with standardized extract is needed to establish this as a recommended form of therapy in this subgroup of patients.

Antigens similar to major histocompatibility complex B-G are expressed in the intestinal epithelium in the chicken

A monoclonal antibody directed against the erythrocytic B-G antigens of the major histocompatibility complex (MHC) of the chicken, an antiserum raised against purified erythrocytic B-G protein, and a cDNA probe from the B-G subregion were used to look for evidence of the expression of B-G genes in tissues other than blood. Evidence has been found in northern hybridizations, in immunoblots, and in immunolabeled cryosections for the presence of B-G-like antigens in the duodenal and caecal epithelia. Additional B-G-like molecules may be expressed in the liver as well. The B-G-like molecules in these tissues appear larger and somewhat more heterogeneous than the B-G antigens expressed on erythrocytes. Further characterization of these newly recognized B-G-like molecules may help to define a function for the enigmatic B-G antigens of the MHC. al. 1977; Miller et al. 1982, 1984; Salomonsen et al. 1987; Kline et al. 1988), and in the multiplicity of B-G restriction fragment patterns found in genomic DNA from different haplotypes (Goto et al. 1988; Miller et al. 1988; Chaussé et al. 1989). The B-G antigens have contributed, together with the B-F (class I) and B-L (class II) antigens, to the definition of over 27 B system haplotypes in experimental flocks (Briles et al. 1982). Yet the function of the B-G antigens remains entirely unknown. No mammalian counterparts have been identified, although the possibility remains that there may be similar antigens among the blood group systems of mammals. In an effort to define a function of the B-G antigens, a recently cloned B-G sequence (Miller et al. 1988; Goto et al. 1988) and antibodies to the B-G polypeptides (Miller et al. 1982, 1984) were used to examine other tissues for evidence of B-G expression.

Aging and long-term ovariectomy alter the cytoarchitecture of the hypothalamic-preoptic area of the C57BL/6J mouse

Long-term ovariectomy attenuates several neuroendocrine-dependent changes in reproductive function of aging female rodents, but the sites affected and underlying mechanisms are not known. This study was designed to identify effects of aging on hypothalamic-preoptic neurocytoarchitecture and to determine whether long-term ovariectomy attenuated any of those changes. Coronal sections from midportions of the preoptic area (POA), suprachiasmatic nucleus (SCN) and arcuate nucleus (ARC) were examined by quantitative light microscopy in young (5 month) and old (18-20 months) intact mice and in old mice which had been ovariectomized at 6 months of age. Neuronal density in old intact mice decreased in both ARC and POA (30%; p less than 0.05), but no significant decrease occurred in SCN. Total perikaryal area decreased only in ARC (10%; p less than 0.05), while area of perikaryal nuclei did not change in any region. Area of nucleoli increased (13%; p less than 0.005) in all three regions of old intact and old ovariectomized mice. Neither density nor size of glia changed with age. Density of blood vessels increased strikingly in ARC (150%; p less than 0.05), and in POA (30%; p less than 0.05), but not significantly in SCN of old mice. Long-term ovariectomy did not prevent any of these changes; indeed, it promoted the decline of neuronal density in SCN (40%; p less than 0.05) and neuronal area (15%; p less than 0.05) in POA. Reductions in neuronal density were not explained by expansion of the SCN or peri-ARC or peri-POA regions.(ABSTRACT TRUNCATED AT 250 WORDS)

Short term effects of glucocorticoids upon hippocampal ultrastructure

This study evaluated hippocampal cytoarchitecture in male Sprague-Dawley (225-250 g) rats treated with corticosterone (CORT) and in unhandled, unstressed rats. CORT-treated animals received 20 mg/kg CORT in sesame oil/day x 3 days; each dose produces levels in the upper physiologic range, similar to those produced by major stressors. Using quantitative electron microscopy, sections from regions Ca3b, Ca1, and dentate gyrus were examined. Surface density and surface area of Golgi and the number of Golgi-stacks increased following CORT-treatment (p less than 0.05, ANOVA). Paralleling these changes surface area of rough endoplasmic reticulum and number of cisternae also increased in neuronal perikarya (p less than 0.001, p less than 0.003 respectively). In contrast, surface densities of mitochondria, multivesicular bodies, and lysosomes were unaffected by CORT treatment. These data suggest that both pyramidal and granule cells of hippocampus are subject to short term effects of high physiological levels of CORT, and that these effects may involve stimulation of protein biosynthesis.

In vitro fertilization: an overview

The advanced reproductive technologies are an acceptably safe but invasive method to treat infertility. The decision to proceed with IVF/ET should be based on 1) a complete infertility investigation, 2) an understanding by the couple of the emotional, physical and financial aspects of the process and 3) an understanding by physicians of the real advantages and disadvantages of the procedures.

A high-fat diet increases calcitonin secretion in the rat

We have studied the effects of diet-induced obesity on thyroidal calcitonin, plasma calcitonin, calcium and phosphorus in rats. Twelve 9-week-old female rats were randomly divided into two groups. One group was fed a low-fat diet while the other was fed a high-fat diet. Both diets had 0.76% Ca, 0.56% P and 2.2 U/g vitamin D; however, the high-fat diet had hydrogenated vegetable oil added at 405 g/kg. All rats were pair-fed and consumed 11 g/day per rat for 27 weeks at which time the rats were fasted overnight and exsanguinated. The rats on the high-fat diet weighted 406 +/- 21 g (mean +/- SEM) versus 292 +/- 13 g for controls and had higher levels of serum calcitonin (104 +/- 12 versus 57 +/- 9 pg/ml). The obese rats also had increased thyroidal calcitonin by radioimmunoassay and increased thyroidal C-cells by immunohistology. The increased calcitonin levels occurred without a concomitant increase in calcium levels. These data indicate that a high-fat diet in rats stimulates C-cell growth and calcitonin secretion.

CV 205-502 treatment of hyperprolactinemia

CV 205-502 is a nonergot oral dopamine agonist with specific D2 activity, which has a prolonged suppressive effect on serum PRL and may have fewer side-effects than other dopamine agonists. We treated 26 hyperprolactinemic women with this compound given as a single bedtime (hs) dose for up to 12 weeks. All had gonadal dysfunction, either amenorrhea or oligomenorrhea, and 15 had galactorrhea. The initial and subsequent doses were administered in a randomized fashion; the initial dose ranged from 0.01-0.05 mg, and the dose at 12 weeks ranged from 0.03-0.09 mg. The women were evaluated every 2 weeks, and the dose was increased by 0.02 mg every 4 weeks if the serum PRL level was greater than 20 micrograms/L. Of the 26 women initially enrolled, 24 completed 12 weeks of therapy, and 2 discontinued therapy because of side-effects. Thirteen women (54%) had return of menses, and 12 (80%) had either a decrease in or disappearance of galactorrhea. Serum PRL concentrations decreased to a variable degree in all patients; 13 (54%) achieved a normal serum PRL level (less than or equal to 20 micrograms/L). The mean (+/- SE) pretreatment serum PRL concentration was 129 +/- 34, and it was 29.9 +/- 5.9 micrograms/L after 12 weeks of treatment (P = 0.005). The mean (+/- SE) percent reduction in serum PRL was 66.5 +/- 5.0% (median, 78.0%). A dose response was not demonstrated (r = -0.08; P = 0.70) among the 6 dose groups during the last 4 weeks of therapy. In 5 women, serum PRL levels, measured frequently for 24 h after treatment remained low. Side-effects after the initiation of therapy included nausea, headache, and morning fatigue in 10 women. These symptoms caused 2 women to discontinue therapy; they subsided in the other women. An optimal dose was not determined and will probably need to be determined by titration in each patient. CV 205-502, given once daily, appears to be a safe and effective alternative to other dopamine agonists in the treatment of hyperprolactinemia.

Transformation of human progesterone receptor in the presence of the progestin (R5020) and the antiprogestin (RU486)

We have examined and compared the binding characteristics and transformation in vitro of human uterine cytosolic progesterone receptor (PR) bound to either the progestin agonist, R5020 or the antiprogestin, RU486. Incubation of cytosol with 5-20 nM [3H]R5020 and [3H]RU486 yielded macromolecular complexes that sedimented in the 4S and 8S regions in 10-35% glycerol gradients. The 8S peaks of radioactivity due to macromolecular-bound [3H]R5020 or [3H]RU486 could be eliminated by a preincubation of the uterine cytosol with 1-2 microM progesterone or RU486. The [3H]R5020 binding in the 4S peak was not competable with either steroid. In contrast, the binding of [3H]RU486 in the 4S peak could be abolished by a pretreatment of uterine cytosol with excess RU486, but not progesterone. Selective fractionation of the cytosol with ammonium sulfate, in the presence of sodium molybdate, eliminated the non-specific 4S [3H]R5020 binder. The thermal (23 degrees C) transformation of the [3H]RU486-receptor complex, as a function of the loss of the area under the 8S peak, appeared to be comparable to that achieved with [3H]R5020-receptor complex. The 8S [3H]RU486 peak was reduced by only 46% compared to the [3H]R5020 peak, which was reduced by 60%. These results demonstrate that in human uterine cytosol, R5020 and RU486 bind in a specific and saturable manner to an 8S PR, which is susceptible to thermal 8S to 4S transformation. In addition, [3H]R5020 also interacts with a nonsaturable 4S macromolecule, whereas the 4S [3H]RU486 binder is saturable and specific for RU486. The above observations indicate the heterogeneity of the steroid binding components present in the human uterine cytosol, and suggest that caution should be taken when interpreting data which shows the presence of different molecular forms of the steroid receptors.

Genotyping chickens for the B-G subregion of the major histocompatibility complex using restriction fragment length polymorphisms

Chicken B-G-subregion cDNA probes were used to analyze restriction fragment length polymorphisms (RFLP) of the B-G subregion of the chicken major histocompatibility complex. Genomic DNA from chickens representing 17 of the 27 standard B haplotypes were digested with restriction endonucleases and analyzed in Southern hybridizations with two cDNA clones from the B-G subregion. Each B-G genotype was found to produce a unique pattern of restriction fragments in these Southern hybridizations. With 15 of the 17 genotypes examined, the different genotypes could be readily distinguished in hybridizations produced with DNA digested with a single restriction enzyme, PVU II. The two additional genotypes produced nearly identical patterns in PVU II preparations and with three additional enzymes as well, but were readily distinguishable in Eco RI digestions. For many of the haplotypes, samples from several individuals in different flocks were examined. In every instance, genotyping by RFLP pattern was found to confirm the B-G allele assigned serologically.