Non-isotopic, two-step free thyroxine immunoassay: a better measure of free thyroxine than analogue radioimmunoassay

Plasma or serum free thyroxine (T4) was measured by a novel non-isotopic, two-step immunoassay in 373 consecutive patients attending a thyroid clinic, in whom thyroid status was categorized according to clinical findings, supported by routine thyroid function tests. The 95% confidence limit of free T4 in the euthyroid patients (n = 112) was 7-20 pmol/L. Free T4 concentrations within the reference range were found in six of 40 patients with primary hypothyroidism and nine of 182 patients with overt thyrotoxicosis, six of whom had T3 toxicosis. Serum or plasma free T4 measured by the two-step method showed improved diagnostic specificity over an analogue RIA in selected groups of euthyroid patients in whom abnormal binding of analogue T4 can affect the validity of the result. Free T4 results found by analogue RIA and the two-step method in 58 patients who were receiving thyroxine replacement therapy were similar. The between-assay precision of the two-step method was poor ranging from a coefficient of variation of 9.7% to 19.3% over a free T4 concentration range of 5.0 to 46.0 pmol/L. We conclude that the two-step methodology offers diagnostic advantages for a laboratory which receives specimens from such patients for exclusion of thyroid disease but that improved assay precision is required before it could be used in a routine situation.

Purification and characterization of an NAD(+)-dependent dehydrogenase that catalyzes the oxidation of thromboxane B2 at C-11 from porcine liver. Development and application of 11-dehydro-thromboxane B2 radioimmunoassay to enzyme assay

11-Dehydro-thromboxane B2 has been identified as a major metabolite of infused as well as endogenous thromboxane B2 in mammalian plasma and urine. This metabolite is derived from thromboxane B2 by enzymatic oxidation at C-11 catalyzed by 11-hydroxythromboxane B2 dehydrogenase. A radioimmunoassay for 11-dehydro-thromboxane B2 has been developed and used for enzyme assay, purification and characterization. Antibodies were generated against 11-dehydro-thromboxane B2 conjugated to bovine thyroglobulin. Labeled marker was prepared by radioiodinating 11-dehydro-thromboxane B2-tyrosine methyl ester conjugate. A sensitive radioimmunoassay capable of detecting 10 pg of 11-dehydro-thromboxane B2 per assay tube was developed. The antibodies showed minimal crossreaction with thromboxane B2 (0.03%), prostaglandin D2 (2.76%) and other eicosanoids (less than 0.03%). The enzyme activity was determined by assaying NAD(+)-dependent formation of immunoreactive 11-dehydro-thromboxane B2 from thromboxane B2. The enzyme was found to be enriched in liver although significant activity was also detected in gastrointestinal tract and kidney in pig. The enzyme was purified from porcine liver cytosol to apparent homogeneity using conventional and affinity chromatography. The purified enzyme exhibited coenzyme specificity for NAD+ and used thromboxane B2 as a substrate. The enzyme also catalyzes NADH-dependent reduction of 11-dehydro-thromboxane B2 to thromboxane B2 indicating the reversibility of the enzyme catalyzed reaction. The apparent Km values for thromboxane B2, 11-dehydro-thromboxane B2 and NAD+ are 8.1, 8.0 and 23 microM, respectively. Subunit Mr was shown to be 55,000, whereas the native enzyme Mr was found to be 110,000 indicating that the enzyme is a dimer. The enzyme is sensitive to sulfhydryl inhibitions suggesting cysteine residues are essential to enzyme activity. The availability of a homogeneous enzyme preparation should allow further studies on the substrate specificity and the structure and function of the enzyme.

Cytochemical studies of responses of corticotropes and thyrotropes to cold and novel environment stress

Cold stress stimulates the release of both ACTH and TSH from the pituitary. More striking changes in ACTH content have been seen in the intermediate lobe after cold stress. Therefore, this study was designed to test responses of individual anterior lobe corticotropes to cold exposure. Male rats were exposed to either 30 min of cold (+3-5 C), 30 min of a novel, temperate environment (+24 C) or were unstressed (+24 C). Pituitaries were fixed and embedded in preparation for immunolabeling for ACTH or TSH-beta at the light (semithin sections) and electron microscopic levels. The semithin sections were used to measure areas of corticotropes and thyrotropes with Bioquant image analysis equipment. Separate groups of pituitaries were dissociated and the cells were cultured for 2 or 15 h. Then the cells were stimulated for 5-10 min with biotinylated analogs of corticotropin-releasing hormone (bio-CRH) or arginine vasopressin (bio-AVP) to detect the target cells cytochemically. A third group of dissociated cells were fixed for immunolabeling for ACTH, 16K fragment of pro-opiomelanocortin, beta-endorphin, or TSH-beta. Cold exposure resulted in a 1-4-fold increase in the levels of serum ACTH over that of unstressed rats. This was correlated with a 40% increase in the percentage of cells that contained 16K fragment and a 30-40% increase in percentages of cells storing ACTH or beta-endorphin. Cold stress also increased the percentage of cells that bound bio-CRH or bio-AVP by 45%. Analyses of semithin sections showed that areas of corticotropes increased by 21% following cold stress. The number of rows of immunolabeled (ACTH) secretion granules also increased in corticotropes from cold-stressed rats. Exposure to a novel environment for 30 min resulted in no significant increase in serum ACTH over that of unstressed rats. There was, however, a 20% increase in percentages of cells that stored 16K fragment, beta-endorphin, or target cells that bound bio-CRH. However, the corticotropes were not significantly larger. Many of the cells exhibited reduced numbers of immunolabeled secretory granules. Other corticotropes resembled those from cold-stressed rats. When TSH cells were studied, their percentages increased from 8 +/- 3% to 15.8 +/- 4% and their areas increased by 22% following exposure to cold. After exposure to a novel environment, percentages of cells that stored TSH-beta increased to 11 +/- 2%, however, no changes in areas of TSH cells were measured. These studies demonstrated that the anterior lobe corticotrope is clearly activated by exposure to both cold and novel environment.(ABSTRACT TRUNCATED AT 400 WORDS)

Primary amino acid sequence of alpha-trichosanthin and molecular models for abrin A-chain and alpha-trichosanthin

Ricin A-chain, abrin A-chain, and alpha-trichosanthin are members of a larger group of proteins called ribosome-inactivating proteins. These proteins all function to catalytically inactivate eukaryotic 60 S ribosomal subunits leading to rapid shutdown of protein synthesis. They are homologous in sequence and are probably evolutionarily related. We have determined the complete primary amino acid sequence of alpha-trichosanthin and have found it to be homologous, as expected, to that of abrin A-chain and ricin A-chain. A crystal structure for ricin, which includes ricin A-chain and ricin B-chain, has been determined from x-ray diffraction data. Based on the sequence homologies of these proteins, we fit the primary sequences of abrin A-chain and alpha-trichosanthin to the backbone structure for ricin A-chain and have generated energy-minimized molecular models for them. These models should prove useful in studying the structural-functional relationships of these proteins in particular and of the class in general.

Immunologic reactivity against Borrelia burgdorferi in patients with motor neuron disease

Of 19 unselected patients with the diagnosis of amyotrophic lateral sclerosis (ALS) living in Suffolk County, New York (an area of high Lyme disease prevalence), 9 had serologic evidence of exposure to Borrelia burgdorferi; 4 of 38 matched controls were seropositive. Eight of 9 seropositive patients were male (8 of 12 male patients vs 2 of 24 controls). Rates of seropositivity were lower among patients with ALS from nonendemic areas. All patients had typical ALS; none had typical Lyme disease. Cerebrospinal fluid was examined in 24 ALS patients--3 (all with severe bulbar involvement) appeared to have intrathecal synthesis of anti-B burgdorferi antibody. Following therapy with antibiotics, 3 patients with predominantly lower motor neuron abnormalities appeared to improve, 3 with severe bulbar dysfunction deteriorated rapidly, and all others appeared unaffected. There appears to be a statistically significant association between ALS and immunoreactivity to B burgdorferi, at least among men living in hyperendemic areas.

A glutathione conjugate of hepoxilin A3: formation and action in the rat central nervous system

Incubation of (8R)- and (8S)-[1-14C]hepoxilin A3 [where hepoxilin A3 is 8-hydroxy-11,12-epoxyeicosa-(5Z,9E,14Z)-trienoic acid] and glutathione with homogenates of rat brain hippocampus resulted in a product that was identified as the (8R) and (8S) diastereomers of 11-glutathionyl hepoxilin A3 by reversed-phase high performance liquid chromatographic comparison with the authentic standard made by total synthesis. Identity was further confirmed by cleavage of the isolated product with gamma-glutamyltranspeptidase to yield the corresponding cysteinylglycinyl conjugate that was identical by reversed-phase high performance liquid chromatographic analysis with the enzymic cleavage product derived from the synthetic glutathionyl conjugate. The glutathionyl and cysteinylglycinyl conjugate are referred to as hepoxilin A3-C and hepoxilin A3-D, respectively, by analogy with the established leukotriene nomenclature. Formation of hepoxilin A3-C was greatly enhanced with a concomitant decrease in formation of the epoxide hydrolase product, trioxilin A3, when the epoxide hydrolase inhibitor trichloropropene oxide was added to the incubation mixture demonstrating the presence of a dual metabolic pathway in this tissue involving hepoxilin epoxide hydrolase and glutathione S-transferase processes. Hepoxilin A3-C was tested using intracellular electrophysiological techniques on hippocampal CA1 neurons and found to be active at concentrations as low as 16 nM in causing membrane hyperpolarization, enhanced amplitude and duration of the post-spike train afterhyperpolarization, a marked increase in the inhibitory postsynaptic potential, and a decrease in the spike threshold. These findings suggest that these products in the hepoxilin pathway of arachidonic acid metabolism formed by the rat brain may function as neuromodulators.

The dose dependent effect of cyclic AMP on ribonucleotide reductase in mitogen stimulated mononuclear cells

Cyclic adenosine monophosphate arrests proliferating T lymphocytes in the G1 phase of the cell cycle. Here we demonstrate that exogenous and endogenous elevations in cyclic AMP concentration result in diminished mitogen stimulation, cell cycle arrest, and decreased ribonucleotide reductase messenger RNA concentrations in peripheral blood mononuclear cells. At lower concentrations (less than 1mM) of dibutyryl cyclic AMP that do not generate cell cycle arrest there is inhibition of ribonucleotide reductase activity without decreased messenger RNA concentration for the M2 subunit of ribonucleotide reductase. However, at higher concentrations of dibutyryl cyclic AMP there is G1 cell cycle arrest and reduced M2 specific messenger RNA concentration. Thus, cyclic AMP inhibition of lymphocyte activation may occur by different mechanisms that are dose dependent.

Secretor status and infection in patients with Graves' disease

We have demonstrated that the inability to secrete the water soluble glycoprotein form of the ABO blood group antigens into saliva is significantly more common in patients with Graves' disease than control subjects (40% vs 27%: P less than 0.025) but not among those with Hashimoto's thyroiditis or spontaneous primary atrophic hypothyroidism. Non-secretion is associated with increased susceptibility to infection and to asymptomatic carriage of some microorganisms. Although Yersinia enterocolitica has been found to express antigen cross reactive with the TSH receptor, we did not find an increased prevalence of Yersinia species in the faeces of 107 patients with Graves' disease. The isolation rate (less than 1%) was similar to that observed in the local population with diarrhoeal illness. Salivary IgA levels determined by whole cell ELISA with Y. enterocolitica 03 were not elevated in the majority of specimens examined. The results suggest that in contrast to reports from Scandinavia, there is no strong evidence that yersiniae play a role in the pathogenesis of Graves' disease among patients in South east Scotland. Non-secretors are significantly over represented among patients with several other autoimmune diseases; however, with the exception of antitubulin antibodies, non-secretors with Graves' disease did not have more antibodies to other human antigens than secretor patients.

Thyrotropin-releasing hormone (TRH) precursor processing. Characterization of mature TRH and non-TRH peptides synthesized by transfected mammalian cells

Prepro-thyrotropin-releasing hormone (TRH) contains five TRH progenitor sequences and at least six other potential peptides (Lechan, R. M., Wu, P., Jackson, I. M. D., Wolf, H., Cooperman, S., Mandel, G., and Goodman, R. H. (1986a) Science 231, 159-161). Previous studies using radioimmunoassays developed against discrete regions of prepro-TRH have demonstrated that several of the potential peptides are present in rat brain and pancreas (Wu, P., Lechan, R. M., and Jackson, I. M. D. (1987) Endocrinology 121, 108-115; Wu, P. and Jackson, I. M. D. (1988a) Brain Res. 456, 22-28; Wu, P., and Jackson, I. M. D. (1988b) Regul. Pept. 22, 347-360). However, the low level of peptides present in intact tissues has made isolation of the peptides difficult. CA77 cells, a medullary thyroid carcinoma cell line, also express prepro-TRH and display processing similar to that found in tissues. However, peptide content in this tumor cell line is enhanced only 3-fold compared with normal tissues (Sevarino, K. A., Wu, P., Jackson, I. M. D., Roos, B. A., Mandel, G., and Goodman, R. H. (1988) J. Biol. Chem. 263, 620-623). To achieve higher levels of expression for facilitating peptide sequencing studies and to see if alternate processing of prepro-TRH could be detected in different cell types, we transfected into 3T3, GH4, AtT20, and RIN 5F cells a cDNA vector under control of the cytomegalovirus immediate-early promoter. 3T3 and GH4 cells failed to process prepro-TRH beyond cleavage of the signal sequence. Both AtT20 and RIN 5F cells efficiently cleaved the precursor at dibasic sites to generate mature TRH and the non-TRH peptides previously identified in vivo. Peptide content was up to 30 times greater than in hypothalamic extracts and 10 times greater than in CA77 cells. Secretion experiments with transfected AtT20 cells demonstrated that both mature TRH and the non-TRH peptides were secreted via a regulated secretory pathway similar to that utilized by endogenously synthesized peptides. We isolated several of the non-TRH peptides synthesized by transfected AtT20 cells and characterized these peptides by sequential Edman degradation. These studies identified the signal sequence cleavage site and determined that the non-TRH peptides are generated by cleavage at the dibasic sites flanking the five TRH progenitor sequences. Further, we determined that processing occurs at the Arg51-Arg52 site located in the amino-terminal portion of the precursor, the only dibasic site not flanking a TRH progenitor sequence.

Effects of chloroquine on the torsional dynamics and rigidities of linear and supercoiled DNAs at low ionic strength

The magnitude and uniformity of the torsion elastic constant (alpha) of linear and supercoiled pBR322 DNAs are measured in 3 mM Tris as a function of added chloroquine/basepair ratio (chl/bp) by studying the fluorescence polarization anisotropy of intercalated ethidium dye. The time-resolved FPA is measured using a picosecond dye-laser for excitation and time-correlated single-photon counting detection. For both linear and supercoiled DNAs, alpha remains uniform except at the very highest chl/bp ratio examined. For the linear DNA, alpha decreases from 5.0 x 10(-12) dyne-cm at chl/bp = 0 to about 3.5 x 10(-12) dyne-cm at chl/bp = 0.5, and remains at that value up to chl/bp = 5, whereupon it increases back up to its original value. For the supercoiled DNA, alpha remains constant at about 5.2 x 10(-12) dyne-cm from chl/bp = 0 up to chl/bp = 5, whereupon it increases in parallel with the linear DNA. The effect of chloroquine on the secondary structure, torsion constant, and torsional dynamics evidently differs substantially between linear and supercoiled DNAs, even under conditions where the supercoiled DNA is completely relaxed and both DNAs bind the same amount of dye. This strongly contradicts any notion that the local structures of linear and relaxed supercoiled DNA/dye complexes with the same binding ratio are identical. The increase in apparent alpha at chl/bp = 5 for both DNAs may be due to stacking of the chloroquine in the major groove and consequent stiffening of the filament.

[Diagnosis and treatment of solitary tuberculosis of the spleen]

Solitary tuberculosis of spleen is a rare case in abdominal organ tuberculosis, three cases were reported and we discussed the nomination diagnosis, classification, treatment and some important points that surgeons should notice during the operation. It is suggested that according to the pathological classification we classified solitary tuberculosis of spleen into miliary, caseous and calcified type. This would help us to determine the stage and the treatment of the disease, we also emphasize that B-scan is important to the diagnosis of the disease and splenectomy is preferable in treating solitary tuberculosis of caseous type of spleen.

Illusory conjunctions in the perception of Chinese characters

A Chinese compound character consists of a radical component and a stem component. When compound characters were presented briefly, Ss often reported seeing illusory recombinations of radicals and stems. A series of 5 experiments suggested that the probability of seeing illusory characters is not under the direct influence of lexicality, pronounceability, or character frequency, but depends on 2 factors: (1) familiarity defined in terms of unit frequency, i.e., the frequency of occurrence of a unit either by itself or as part of a larger unit, and (2) the context-dependent perceptual distinctiveness of the components of a given character. It is suggested that the seemingly unreliable lexicality effect obtained in English studies may be reduced to a familiarity effect, and that what McClelland and Mozer (1986) referred to as the surround-similarity effect may be better characterized as an effect of perceptual distinctiveness.

Glucose utilization of ischemic hippocampal slices

Hippocampal brain slices that were 1000 mu thick were prepared from Sprague-Dawley rats and studied using in vitro glucose utilization under well-oxygenated conditions or after a 15 min anoxic insult produced with a nitrogen atmosphere. Autoradiography reveals that glucose utilization is increased in CA1 and CA3 stratum radiatum of 1000 mu slices, even with full oxygenation, compared to the same regions in 540 mu slices. Following anoxia, there is an initial addition increase in stratum oriens of CA1 and CA3 glucose utilization that is followed by a decline in glucose utilization in all slice regions within an hour of the insult. Because increased glucose utilization is apparent at the slice surfaces as well as at the interior, it is suggested that thick brain slices are a model of brain ischemia, not just hypoxia.

GLQ223: an inhibitor of human immunodeficiency virus replication in acutely and chronically infected cells of lymphocyte and mononuclear phagocyte lineage

GLQ223 is a highly purified, formulated preparation of trichosanthin, a 26-kDa plant-derived ribosome-inactivating protein with potent inhibitory activity against human immunodeficiency virus (HIV) in vitro. The compound produced concentration-dependent inhibition of HIV replication in acutely infected cultures of T-lymphoblastoid cells (VB cell line). Treatment with GLQ223 selectively reduced levels of detectable viral proteins compared to total cellular protein synthesis and produced a selective decrease in levels of viral RNA relative to total cellular RNA in acutely infected cells. Substantial inhibition of viral replication was observed at concentrations of GLQ223 that showed little inhibition of parallel uninfected cultures. Selective anti-HIV activity was also observed in cultures of primary monocyte/macrophages chronically infected with HIV in vitro. When freshly drawn blood samples from HIV-infected patients were treated with a single 3-hr exposure to GLQ223. HIV replication was blocked for at least 5 days in subsequently cultured monocyte/macrophages, without further treatment. The anti-HIV activity of GLQ223 in both acutely and chronically infected cells and its activity in cells of both lymphoid and mononuclear phagocytic lineage make it an interesting candidate as a potential therapeutic agent in HIV infection and AIDS.

Illusory conjunctions in the perception of Chinese characters

A Chinese compound character consists of a radical component and a stem component. When compound characters were presented briefly, Ss often reported seeing illusory recombinations of radicals and stems. A series of 5 experiments suggested that the probability of seeing illusory characters is not under the direct influence of lexicality, pronounceability, or character frequency, but depends on 2 factors: (1) familiarity defined in terms of unit frequency, i.e., the frequency of occurrence of a unit either by itself or as part of a larger unit, and (2) the context-dependent perceptual distinctiveness of the components of a given character. It is suggested that the seemingly unreliable lexicality effect obtained in English studies may be reduced to a familiarity effect, and that what McClelland and Mozer (1986) referred to as the surround-similarity effect may be better characterized as an effect of perceptual distinctiveness.

Adrenal autotransplantation with attached blood vessels for treatment of Cushing's disease

A case of Cushing's disease was treated successfully by staged total adrenalectomy, left adrenal autotransplantation with the attached blood vessels and pituitary irradiation. In the first stage the left adrenal gland was removed with its attached blood vessels intact, and adrenal autotransplantation then was performed. An end-to-end anastomosis was made between the adrenal central vein and the right inferior epigastric artery. The anastomosis between the right saphenous vein and the adrenal middle artery was accomplished by intussuscepting the artery into the vein followed by suturing. The second stage operation was total right adrenalectomy. Steroid replacement therapy was stopped 7 days postoperatively and all laboratory studies were normal. Two months after total right adrenalectomy the patient had a sensation of facial fullness. Plasma cortisol and 24-hour urinary 17-hydroxycorticosteroid levels were elevated. Part of the graft was excised with the patient under local anesthesia. The symptoms disappeared and the laboratory studies returned to normal. Pituitary irradiation was administered as supplementary treatment of Cushing's disease. This method for the treatment of Cushing's disease has proved feasible. The inguinal region is the optimal site for adrenal autotransplantation.

The inhibitory effect of gossypol on human sperm motility: relationship with time, temperature and concentration

The inhibitory effect of gossypol acetic acid on human sperm motility was studied with a transmembrane migration method. Gossypol decreased sperm motility after it had been incubated with semen for more than 15 min. However, when sperm motility was evaluated immediately after semen had been mixed with gossypol, no inhibitory effect could be found. We consider that the sperm immobilizing potency of gossypol is much less than our previously studied sperm immobilizing agents. It is unlikely that gossypol can be developed as a vaginal spermicide. The importance of time course in the pharmacological study of sperm motility is emphasized in this study.

Partial purification and characterization of a novel growth hormone-releasing factor (GRF) from teleost brain related to the rat hypothalamic peptide

A growth hormone-releasing factor (GRF)-like molecule has been partially purified and characterized from acid extracts of codfish (Gadhus morhua) brain using immunoaffinity and gel chromatography, followed by HPLC. This material has a mol.wt. which is similar to known mammalian forms of GRF but is immunologically and/or chromatographically distinct from previously described GRF peptides. However, it is related to rat(r) GRF(1-43) since it causes marked displacement in the rGRF RIA. Codfish GRF is a highly specific and potent hypophysiotropic factor as shown by its ability to stimulate the release of GH, but no other hormone, from rat anterior pituitary cells in vitro. These findings suggest that, phylogenetically, GRF is an ancient molecule with its biologic activity and certain immunoreactive domain(s) conserved, at least, from teleost to mammal.

Triiodothyronine exerts direct cell-specific regulation of thyrotropin-releasing hormone gene expression in the hypothalamic paraventricular nucleus

Thyroid hormone administered systemically exerts negative feedback control of biosynthesis of the TRH pro-hormone in the hypothalamic paraventricular nucleus (PVN), the origin of neurons that regulate anterior pituitary TSH secretion, but not in any other group of TRH-synthesizing neurons in the brain. To determine whether this response is mediated by direct effects on PVN neurons, we studied the effect of unilateral stereotaxic implants of L-T3 into the anterior hypothalamus on the concentration of pro-TRH mRNA and pro-TRH in the PVN of hypothyroid rats. Because hypothalamic-pituitary-thyroid function is also regulated by central catecholamines, we also determined the effect of unilateral ablation of ascending catecholaminergic fibers to one side of the PVN by stereotaxic injection of 6-hydroxydopamine or transection of ascending catecholaminergic pathways. T3-implanted hypothyroid animals showed a marked reduction in pro-TRH mRNA and immunoreactive pro-TRH in medial parvocellular neurons of the PVN on the same side as the implant, but not in contralateral PVN neurons or TRH-synthesizing neurons in other hypothalamic regions. In contrast, hypothyroid animals implanted with pellets of hormonally inactive 3,5-diiodo-L-thyronine showed intense symmetric hybridization and immunoreaction product in both wings of the PVN. Despite marked unilateral reduction in the catecholamine innervation to the PVN, no reduction in pro-TRH mRNA or immunoreactive pro-TRH was observed in the PVN on the affected side compared to that on the unaffected side. These studies demonstrate that negative feedback regulation of thyroid hormone occurs directly on TRH neurons and is restricted only to those in the PVN tuberoinfundibular system.

Fluorescence supravital stain of human sperm: correlation with sperm motility measured by a transmembrane migration method

We developed a supravital stain of human sperm with fluorescent dyes. Either Hoechst 33,258 or fluorescein isothiocyanate could be used, the former stained sperm head while the later stained the whole sperm. Sperm vitality assessed with any of these two fluorescent dyes correlated well with that determined by eosin-nigrosin counterstain. When sperm vitality was compared with sperm motility measured with a transmembrane migration method, we found that many vital sperm were immotile because sperm vitality was higher than sperm motility in tested samples.

Neurons containing a N-terminal sequence of the TRH-prohormone (preproTRH53-74) are present in a unique location of the midbrain periaqueductal gray of the rat

Using an antiserum (no. 373) raised against a tyrosinated analog of preproTRH53-74 [( Tyr1]preproTRH53-74 or pYT 22), we have demonstrated the presence of a discrete population of immunoreactive neurons in the midbrain periaqueductal gray (PAG). Relative to the distribution of serotonin, somatostatin, peptide histidine isoleucine (PHI), methionine enkephalin, substance P and neurotensin-containing neuronal perikarya in the PAG, neurons containing immunoreactive pYT 22 occupied a unique location in the ventrolateral PAG. In contrast, terminal fields containing these neuroactive substances with the exception of PHI, were seen in abundance in the region of the ventrolateral PAG neurons. These studies indicate that a non-TRH sequence contained within the N-terminal portion of the TRH prohormone are expressed in a distinct group of neurons in the ventrolateral PAG. The location of these neurons in the PAG in a region richly innervated by nerve terminals containing analgesia-mediating substances, suggests a possible role for proTRH-derived peptides in the modulation of nociception.

Identification, characterization and localization of thyrotropin-releasing hormone precursor peptides in perinatal rat pancreas

The sequence of rat hypothalamic prepro TRH, deduced from its complementary DNA, contains five TRH progenitor sequences and six cryptic sequences separated by paired basic amino acid residues. We have utilised antisera against two synthetic peptides corresponding to sequences within proTRH, [Tyr53] preproTRH (53-74), part of the amino terminal leader sequence of proTRH and [Cys 74,83] preproTRH-(75-82), representing a TRH progenitor sequence flanked by cysteine residues (pCC10) in radioimmunoassays (RIA) to identify and chromatographically characterize proTRH derived peptides in extracts of rat perinatal pancreas and to localize these peptides immunohistochemically. Two forms of immunoreactive pYT22 (ipYT22) were observed, similar in size to ipYT22 seen in extracts of adult rat brain. By RIA immunoreactive pCC10 was detectable in neonatal but not fetal pancreas. However, immunohistochemical double staining of both fetal and neonatal rat pancreas colocalized both ipYT22 and ipCC10 with immunoreactive insulin in the B-cell of the developing Islets of Langerhans. These findings indicate that the B-cell of the perinatal pancreas synthesizes TRH from a prohormone encoded by a mRNA similar to that present in adult rat hypothalamus.

Thick brain slices model the ischemic penumbra

Hypothalamic brain slices, varying in thickness from 400 mu to 1,000 mu, were assessed by studying 2-deoxyglucose (2DG) metabolism, lactate accumulation, inulin spaces, and morphology at the light and ultrastructural levels. Evidence of increased glycolytic flux due to anaerobic metabolism is found at thickness greater than 600 mu in association with a progressive increase in the inulin-exclusion space. The metabolic profiles, as a function of depth into the slices, reveal that 700-mu slices function in a manner similar to 540-mu slices at the surfaces, but with a core of increased 2DG phosphorylation at the slice center. In contrast, the 1,000-mu slices show significant reduction of 2DG and increases in 2DG6P relative to the 540-mu slices at the slice surface as well as in the slice interior, suggesting impaired transport of 2DG into cells and spread of ischemic injury from the slice interior to the slice surface. Despite these metabolic changes, only minor morphologic changes of ischemic injury were found at the center of thicker slices, and in vitro glucose utilization of 1000-mu slices remained constant for up to 15 h. These three slice thicknesses should provide a useful model for studying the neurochemistry and neuropharmacology of the ischemic penumbra.

Post-translational processing of thyrotropin-releasing hormone precursor in rat brain: identification of 3 novel peptides derived from proTRH

The sequence of rat hypothalamic pro-thyrotropin releasing hormone, deduced by sequencing of cDNA, in addition to 5 TRH progenitor sequences contains leader, trailer and 4 intervening sequences separated by paired basic amino acid sequences. We have developed radioimmunoassays to synthetic peptides corresponding to portions of these cryptic proTRH sequences and have used these assays to identify and partially characterize proTRH peptides, distinct from TRH, in extracts of rat brain. Two of these peptides correspond closely in size to one intervening sequence and the carboxy-terminal sequence of proTRH. Three other peptides correspond to the intact amino-terminal leader sequence and two peptides formed by a further cleavage of the leader sequence at an internal paired basic amino acid sequence.

Replantation of the testis: report of a case

To our knowledge there has been no report to date of successful testis replantation after complete traumatic severance of the funiculus within the scrotum. We report a case in which both funiculi were cut completely (one of which was severed 0.8 cm. proximal to the upper pole of the testis, and the other just at the junction of the funiculus and the testis). We successfully rejoined the testis with the funicular stump to the proximal cut end of the right side using a microsurgical technique. The total ischemia period of the replanted testis was 6 hours. The penis was erect 4 days postoperatively and blood testosterone level was within the normal range. At testicular biopsy 120 days postoperatively the germ cells could be seen in various stages of development and the appearance of the Leydig cells was normal.

Biosynthesis of thyrotropin-releasing hormone by a rat medullary thyroid carcinoma cell line

Prepro-thyrotropin-releasing hormone (TRH) messenger RNA was detected in the rat medullary thyroid carcinoma cell line CA77. The RNA of 1.6 kilobases comigrated with that found in rat hypothalamus. Using three radioimmunoassays specific for pro-TRH-derived peptides, we demonstrated that CA77 cells synthesize high levels of immunoreactive TRH and all of the other pro-TRH-derived peptides identified in hypothalamic tissue. The relative levels of the pro-TRH-derived peptides also indicate that CA77 cells process the TRH precursor in a manner similar to hypothalamic tissue. CA77 cells provide a promising model system for further studies of prepro-TRH gene regulation and post-translational maturation.

Circulating catecholamines and glucagon in infants of strictly controlled diabetic mothers

Previous studies have demonstrated impaired perinatal adaptation of glucose homeostasis with inappropriately low levels of catecholamines and glucagon in newborn infants born to diabetic mothers. To investigate whether these neonatal changes are related to maternal metabolic control, we sequentially measured plasma glucose, catecholamines and glucagon in the neonatal period in 10 infants born to well-controlled mothers with class B diabetes mellitus after uncomplicated pregnancies. Good glycemic control in the mothers resulted in appropriate counterregulatory hormone responses in the neonatal period, similar to those described in infants born to normal mothers. The significant rise in plasma epinephrine and glucagon paralleled the establishment of euglycemia, further suggesting that these hormones are important for perinatal adaptation of glucose homeostasis.

Immunocytochemical distribution in rat brain of putative peptides derived from thyrotropin-releasing hormone prohormone

Processing of the TRH prohormone (Pro-TRH), a protein of approximately 26,000 mol wt, could yield 5 copies of TRH, as well as extended forms of TRH and several other non-TRH peptides. To determine whether some of these peptides are formed and transported by axons in the rat brain, we used antiserum to synthetic peptides corresponding to portions of pro-TRH. These included the N-tyrosyl analogs [Tyr0]prepro-TRH-(25-50) (pYE27) and [Tyr1]prepro-TRH-(53-74) (pYT22) contained within the N-terminal flanking region of the prohormone, the N-tyrosyl analog [Tyr0]prepro-TRH-(165-186) (pYS23), expanding the fourth progenitor sequence of TRH in the midportion of the prohormone, and the synthetic peptide pAC12 corresponding to the first 12 amino acids of the C-terminal flanking region or prepro-TRH-(208-219). All antisera showed staining in neuronal perikarya and processes in all regions of the brain previously demonstrated to immunostain for TRH, including dense innervation of the external zone of the median eminence. In addition, these antisera immunostained regions of the brain not previously immunopositive for TRH. Not all regions reactive with antiserum to [Tyr0]prepro-TRH-(25-50) were also recognized by anti-pYT, -pYS, and -pAC. These studies confirm the presence of the deduced non-TRH sequences within the TRH precursor and their formation and transport in vivo in the central nervous system. The presence of immunoreactivity in regions of the brain that do not contain TRH and the variability of immunostaining of the different antisera in some of these regions suggest regional preferential processing of pro-TRH to other peptides that may be biologically active.

GRF immunoreactive neurons in the paraventricular nucleus of the rat: an immunohistochemical study with monoclonal and polyclonal antibodies

Our study demonstrates a complex GRF neuronal system within the rat hypothalamus. Using both high affinity polyclonal and high specificity monoclonal antibodies to rat (r) GRF, we have substantiated evidence for immunoreactive GRF (GRF-i) perikarya in the parvocellular portion of the paraventricular nucleus. Other hypothalamic areas containing rGRF-positive perikarya include the lateral arcuate nucleus, lateral hypothalamus, perifornical area and dorsomedial nucleus. GRF-i neuronal terminals were seen in the external zone of the median eminence, more rostrally in the periventricular nucleus, and near the suprachiasmatic nucleus and more caudally in the dorsomedial nucleus and ventral premammillary nucleus.

Characterization of LH-RH immunoreactivity in mammalian pituitary neural lobe by HPLC

High performance liquid chromatography was used to characterize luteinizing hormone-releasing hormone (LH-RH) immunoreactivity that was previously identified immunocytochemically in the pituitary neural lobes of bats, ferrets and humans. Extracts of bat posterior lobe and hypothalamus, ferret posterior lobe and hypothalamus and human neurohypophysis were partially purified with C-18 Bond-Elut cartridges. Samples were chromatographed using a C-18 reverse phase HPLC column, and LH-RH-immunoreactive moieties were separated by gradient elution (TFA/acetonitrile solvent system). For bats and ferrets, the major peak of neural lobe LH-RH immunoreactivity eluted with a retention time identical to that of hypothalamic LH-RH. Synthetic mammalian standard added to bat and ferret hypothalamic extracts coeluted as a single peak with the predominant form of LH-RH immunoreactivity present in those tissues. In humans, the peak of LH-RH immunoreactivity in neural lobe extracts coeluted with synthetic standard. These results provide strong evidence that the LH-RH-immunoreactive fibers which terminate within the neural lobe contain authentic LH-RH. Additional minor peaks of LH-RH immunoreactivity were observed in posterior lobe and hypothalamic extracts of both bats and ferrets. Comparisons of posterior lobe content of LH-RH immunoreactivity across species verify that the neural lobe projection is a major component of the LH-RH system in bats, whereas it is represented only minimally in the laboratory rat.

Thyroid hormone regulates TRH biosynthesis in the paraventricular nucleus of the rat hypothalamus

Thyroid hormone is important in the regulation of synthesis and secretion of thyroid-stimulating hormone (TSH) in the anterior pituitary, but its role in the control of hypothalamic thyrotropin-releasing hormone (TRH) is controversial. To determine whether thyroid hormone regulates the function of TRH in the hypothalamic tuberoinfundibular system, a study was made of the effect of hypothyroidism on thyrotropin-releasing hormone messenger RNA (proTRH mRNA) and TRH prohormone in the rat paraventricular nucleus. Extracts of rat hypothalamic paraventricular nucleus were examined by quantitative Northern blot analysis, and coronal sections of rat brain were examined by in situ hybridization histochemistry and immunocytochemistry. A nearly twofold increase in proTRH mRNA was observed in hypothyroid animals; this increase could be obliterated by levothyroxine treatment, suggesting an inverse relation between circulating thyroid hormone and proTRH mRNA. In situ hybridization showed that this response occurred exclusively in medial parvocellular neurons of the paraventricular nucleus. A simultaneous increase in proTRH mRNA and immunoreactive TRH prohormone in this region suggests that hypothyroidism induces both transcription and translation of the TRH prohormone in the paraventricular nucleus.

The spermicidal potency of Coca-Cola and Pepsi-Cola

The inhibitory effect of Old Coke, caffeine-free New Coke, New Coke, Diet Coke and Pepsi-Cola on human sperm motility was studied with a trans-membrane migration method. None of them could decrease sperm motility to less than 70% of control within one hour. A previous study which claimed a marked variation of spermicidal potencies among different formulations of Coca-Cola could not be confirmed. Even if cola has a spermicidal effect, its potency is relatively weak as compared with other well-known spermicidal agents.

Identification and characterization of thyrotropin-releasing hormone precursor peptides in rat brain

The sequence of rat hypothalamic pro-TRH, deduced by sequencing of cDNA, contains five copies of the TRH progenitor sequence Gln-His-Pro-Gly flanked by paired basic amino acid sequences. The TRH prohormone also contains leader and trailer sequences and four intervening sequences. We have developed two RIAs against synthetic peptides corresponding to sequences within the deduced pro-TRH sequence and have used these assays to identify and partially characterize four pro-TRH-derived peptides distinct from TRH in extracts of rat brain tissue. Two of these peptides contain incompletely processed TRH sequences; the other two peptides are probably derived from the N-terminal leader sequence. The presence of these authentic pro-TRH-derived peptides indicates that pro-TRH may give rise to a family of peptides other than TRH, some of which may be of biological significance.

Localization of thyrotropin-releasing hormone prohormone messenger ribonucleic acid in rat brain in situ hybridization

We studied the distribution of pro- TRH mRNA in rat brain by in situ hybridization histochemistry using radiolabeled single stranded cRNA probes to confirm the hypothesis that the TRH precursor is distributed beyond regions that contain immunoreactive TRH. All regions of the central nervous system previously recognized to contain TRH showed hybridization. Hypophysiotropic neurons in the medial parvocellular division of the paraventricular nucleus showed more intense hybridization than anterior parvocellular division cells, suggesting regional differences in expression. In addition, regions not previously recognized to contain TRH in neuronal perikarya by immunocytochemistry showed specific hybridization for pro-TRH mRNA. These include cells in the olfactory bulbs, dorsal motor nucleus of the vagus, ventrolateral periaqueductal gray, reticular nucleus of the thalamus, and anterior commissural nucleus. Only a single hybridizing band was observed on Northern blots of RNA extracts of the periaqueductal gray and reticular nucleus, identical to that seen in extracts of the paraventricular nucleus. The appearance of pro-TRH mRNA in neurons not previously recognized to contain TRH but which contain the prohormone suggests that non-TRH peptides within the TRH precursor may be preferentially expressed in certain regions of the brain.

Bioequivalence and pharmacokinetic profile of promethazine hydrochloride suppositories in humans

A bioequivalence study of promethazine hydrochloride (10-[2-(dimethylamino)propyl]-phenothiazine monohydrochloride) was conducted in 20 male human subjects with the purpose of comparing, under blind condition, the human serum levels of promethazine in three different formulations. The formulations tested were a 50-mg promethazine hydrochloride polyethylene glycol suppository, a 50-mg promethazine hydrochloride cocoa butter-white wax suppository, and a 50-mg oral dose of promethazine hydrochloride syrup. Each subject received single doses of each of the three formulations on each of three different days on a crossover basis. From the measured serum levels, estimates of the bioavailability parameters (area under the serum concentration versus time curve, time-to-peak serum concentration, and peak serum concentration) were obtained by least-squares digital computer fitting. Also, a one-compartment pharmacokinetic open model with two consecutive first-order input steps is proposed. Statistical analysis of the results was performed by using a linear multiple regression approach for the analysis of variance. No significant differences between the syrup and the polyethylene glycol suppositories were obtained (p greater than 0.05) for the above three bioavailability parameters. However, the polyethylene glycol suppositories provided statistically higher peak serum concentration, shorter time-to-peak serum concentration, and larger area under the serum concentration versus time curve than the cocoa butter-white wax suppositories.

Hypophysiotrophic thyrotropin releasing hormone (TRH) synthesizing neurons. Ultrastructure, adrenergic innervation and putative transmitter action

The neuropeptide thyrotropin releasing hormone (TRH) is capable of influencing both neuronal mechanisms in the brain and the activity of the pituitary-thyroid endocrine axis. By the use of immunocytochemical techniques, first the ultrastructural features of TRH-immunoreactive (IR) perikarya and neuronal processes were studied, and then the relationship between TRH-IR neuronal elements and dopamine-beta-hydroxylase (DBH) or phenylethanolamine-N-methyltransferase (PNMT)-IR catecholaminergic axons was analyzed in the parvocellular subnuclei of the hypothalamic paraventricular nucleus (PVN). In control animals, only TRH-IR axons were detected and some of them seemed to follow the contour of immunonegative neurons. Colchicine treatment resulted in the appearance of TRH-IR material in parvocellular neurons of the PVN. At the ultrastructural level, immunolabel was associated with rough endoplasmic reticulum, free ribosomes and neurosecretory granules. Non-labelled axons formed synaptic specializations with both dendrites and perikarya of the TRH-synthesizing neurons. TRH-IR axons located in the parvocellular units of the PVN exhibited numerous intensely labelled dense-core and fewer small electron lucent vesicles. These axons were frequently observed to terminate on parvocellular neurons, forming both bouton- and en passant-type connections. The simultaneous light microscopic localization of DBH or PNMT-IR axons and TRH-synthesizing neurons demonstrated that catecholaminergic fibers established contacts with the dendrites and cell bodies of TRH-IR neurons. Ultrastructural analysis revealed the formation of asymmetric axo-somatic and axo-dendritic synaptic specializations between PNMT-immunopositive, adrenergic axons and TRH-IR neurons in the periventricular and medial parvocellular subnuclei of the PVN. These morphological data indicate that the hypophysiotrophic, thyrotropin releasing hormone synthesizing neurons of the PVN are directly influenced by the central epinephrine system and that TRH may act as a neurotransmitter or neuromodulator upon other paraventricular neurons.

Purification and characterization of luteinizing hormone-releasing hormone from codfish brain

We have purified luteinizing hormone-releasing hormone (LH-RH) from codfish brain and have demonstrated its identity with salmon LH-RH (sLH-RH). An antiserum raised against sLH-RH was used in a specific radioimmunoassay (RIA) to monitor purification and to manufacture an immunoaffinity chromatography column for the initial purification step. The cross-reactivity of the sLH-RH RIA with mammalian LH-RH was 0.1%. Acid extracts of codfish brains were sequentially purified by immunoaffinity chromatography, gel-filtration chromatography, and three steps of reverse-phase HPLC. The purified material and synthetic sLH-RH coeluted on reverse-phase HPLC and exhibited similar biological activity in a dispersed pituitary cell bioassay. Furthermore, the amino acid composition of the purified material was identical to salmon LH-RH. These results suggest that there is structural conservation of LH-RH between these species of teleost fish.

Immunolocalization of the thyrotropin-releasing hormone prohormone in the rat central nervous system

The distribution of immunoreactive TRH prohormone in the rat central nervous system was studied by immunocytochemistry using an antiserum raised against a synthetic decapeptide hypothesized to represent a portion of the mammalian TRH precursor protein. Reaction product was identified in several regions of the brain in a distribution typical of that previously described for the tripeptide. In contrast to TRH, however, immunoreactive pro-TRH was largely confined to neuronal perikarya and only rarely seen in axons or axon terminals. In addition, immunoreactive pro-TRH was present in portions of the telencephalon and brainstem where TRH has not previously been described in neurons by immunocytochemistry. These studies indicate that in most regions of the brain the TRH prohormone is rapidly processed within the cell soma and not during axonal transport, and raise the possibility that in certain regions of the brain processing of the prohormone may be to non-TRH peptides, which may be of biological importance.

Effect of phosphatidylcholine, lysophosphatidylcholine, arachidonic acid and docosahexaenoic acid on the motility of human sperm

Lysophosphatidylcholine, arachidonic acid and docosahexaenoic acid were found to have a concentration-dependent inhibitory effect on the motility of human sperm, whilst phosphatidylcholine had no effect. Seminal plasma attenuated the sperm-immobilizing potencies of these lipids. Because all of the three inhibitors of motility are hydrolytic products of phosphatidylcholine, and the catalytic enzyme, phospholipase A2, is known to be calcium dependent, it is suggested that calcium might inhibit sperm motility by activating phospholipase A2 which in turn releases lysophosphatidylcholine and free fatty acids.

Thyrotropin-releasing hormone precursor: characterization in rat brain

To characterize the precursor of mammalian thyrotropin-releasing hormone (TRH), a rat hypothalamic lambda gt11 library was screened with an antiserum directed against a synthetic peptide representing a portion of the rat TRH prohormone. The nucleotide sequence of the immunopositive complementary DNA encoded a protein with a molecular weight of 29,247. This protein contained five copies of the sequence Gln-His-Pro-Gly flanked by paired basic amino acids and could therefore generate five TRH molecules. In addition, potential cleavage sites in the TRH precursor could produce other non-TRH peptides, which may be secreted. In situ hybridization to rat brain sections demonstrated that the pre-proTRH complementary DNA detected neurons concentrated in the parvocellular division of the paraventricular nucleus, the same location as cells detected by immunohistochemistry. These findings indicate that mammalian TRH arises by posttranslational processing of a larger precursor protein. The ability of the TRH prohormone to generate multiple copies of the bioactive peptide may be an important mechanism in the amplification of hormone production.

Thyrotropin-releasing hormone release from rat pancreas is stimulated by serotonin but inhibited by carbachol

Immunoreactive TRH (IR-TRH) has been found in the mammalian pancreas, with several studies documenting high concentrations in the late fetal/early neonatal period. As the factors regulating pancreatic TRH synthesis and release have not been fully explored, we developed a monolayer culture system of dissociated fetal/neonatal rat pancreatic cells to study the release of TRH from the mammalian pancreas. IR-TRH was detected in the culture medium and the IR material appeared authentic based on parallelism with synthetic TRH in RIA and retention time on HPLC. Potassium-induced depolarization (60 mM KCl) resulted in a 170% increase in TRH release compared to that by the Krebs-Ringer bicarbonate control (P less than 0.05). Serotonin stimulated TRH release, with the maximal effect seen with 10(-6) M (130% increase compared to control; P less than 0.05). Carbachol resulted in a dose-dependent inhibition of TRH release (57% inhibition of release at 10(-8) M; P less than 0.01 compared to control). There was no effect on release with norepinephrine, epinephrine, dopamine, gamma-aminobutyric acid, or histamine. We conclude the following. 1) Authentic TRH is secreted by fetal/neonatal rat pancreatic cells in culture. 2) The secretion of TRH is stimulated by potassium-induced depolarization in a calcium-dependent manner, suggesting a classic neurosecretory process of release. 3) The secretion of pancreatic TRH may be under specific neurotransmitter control, with serotonin stimulating and acetylcholine inhibiting release of the tripeptide.