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PubMed1976

Regulation of behavioral events by thyrotropin releasing factor and cyclic AMP.

Like dibutyryl cyclic AMP, thyrotropin releasing factor (TRF) has potent antianesthetic properties, but only dibutyryl cyclic AMP shortens narcosis dose-relatedly. In contrast, only TRF reverses amobarbital-induced hypothermia (dose-relatedly). In naive rats, dibutyryl cyclic AMP (25-200 mug) induces convulsions while TRF (5-100 mug) produces intermittent hyperactivity and sedation but never convulsions. To determine whether behavioral events may be regulated in the central nervous system through an interaction of the two naturally occurring compounds, TRF (5-100 mug) and dibutyryl cyclic AMP (25-200 mug) were injected simultaneously into the lateral ventricle of the brain of naive rats or rats anesthetized with amobarbital (80 mg/kg). TRF (12.5-50 mug) and dibutyryl cyclic AMP (100-200 MUG) DID NOT SHORTEN NARCOSIS FURTHER THAN DIBUTYRYL CYCLIC AMP alone. Amobarbital protected against the lethal effects of the two compounds injected simultaneously. Long-lasting locomotor disorders and mortality rate increased with increasing doses of TRF (12.5-25 mug) and dibutyryl cyclic AMP (100-200 MUG) GIVEN TO NAIVE RATS. Results did not support the postulate that cyclic AMP is the second messenger of TRF.

Amobarbital↗
PubMed1993

Thermogenic response to feeding in severely burned patients: relation to resting metabolic rate.

Energy expenditure (EE) was measured one to five times by indirect calorimetry for 1 h after an overnight fast, and for 2 h after starting feeding in 19 severely burned patients (TBSA > 20 per cent) for a total of 36 tests. Twelve tube-fed volunteers served as controls. Thermogenic response to feeding (TRF) was calculated as the percentage of energy intake and hypermetabolism as the percentage of values obtained with the Harris-Benedict formula (%HB). Measured energy expenditure values were compared with values given by three predicting formulae. TRF was present in 10 out of the 33 measurements. Fasting EE was not different between the tests with and without TRF, but %HB was different between the two groups: 121.1 +/- 25.8 vs 157.8 +/- 32.0 per cent (tests with and without TRF, respectively (P < 0.01)). TRF was always absent when %HB was higher than 50. When TRF was present it was not statistically different from the control values. None of the three predicting formulae gave values within 10 per cent of the measured values in more than 25 per cent of the patients. We conclude that TRF is suppressed in burned patients with marked hypermetabolism, and that EE measured in the fed state reflects resting expenditure accurately in these patients. In addition, EE cannot be predicted from existing formulae.

Adult↗
PubMedDate not supplied

Biosynthesis of thyrotropin releasing factor: effect of RNase treatment.

In the present study the role of RNA in the vitro biosynthesis of thyrotropin releasing factor (TRF) was investigated. The biosynthesis of TRF was assessed by measuring the ability of a 1000 g supernatant fraction of newt brain origin to incorporate (3H)proline into (3H)TRF. It was found that measurable amounts of (3H)TRF are synthesized by newt brain homogenates, that preincubation of these homogenates with protease-free RNase completely abolishes (3H)TRF synthesis, while preincubation of homogenates with inactivated RNase allows for (3H)TRF synthesis to proceed. These studies suggest that the presence of intact RNA is mandatory for TRF biosynthesis by newt brain homogenates.

Animals↗
PubMed1987

Synergism and diurnal variations of human growth hormone-releasing factor (1-29)NH2 and thyrotropin-releasing factor on growth hormone release in dairy calves.

Sixteen male Holstein calves averaging 168 kg body weight (BW) were used to determine the effects of human growth hormone-releasing factor (1-29)NH2 (hGRF (1-29)NH2; .22 micrograms/kg BW), thyrotropin-releasing factor (TRF; .165 micrograms/kg BW) or hGRF (1-29)NH2 plus TRF (.22 and .165 micrograms/kg BW, respectively) on growth hormone (GH) release in animals exposed to 16 hr of light (L): 8 hr of dark (D) (lights on at 0100 hr) and hGRF plus TRF (.22 and .165 micrograms/kg BW, respectively) in animals exposed to 8L:16D (lights on at 0900 hr). For each treatment, times of iv injection were 0400, 1000, 1600 and 2200 hr. In animals exposed to 16L:8D, average GH peaks reached after hGRF (1-29)NH2 or TRF injections were 49.7 and 32.0 ng/ml while the area under the GH response curve (AUC) were 1247 and 1019 ng/ml.min, respectively. There was no significant effect of times of injection on GH release following the separate injection of hGRF(1-29)NH2 or TRF. In animals exposed to 16L:8D, GH peaks and AUC after hGRF plus TRF injections were 226.4, 189.2 and 116.8 ng/ml, and 4340, 3660 and 2415 ng/ml.min at 0400, 1000 and 1600 hr (lights on), respectively but only 42.3 ng/ml and 1692 ng/ml.min at 2200 hr (lights off). In animals exposed to 8L:16D, GH levels and AUC after hGRF plus TRF injections reached 177.5 and 180.5 ng/ml, and 2759 and 3704 ng/ml.min at 1000 and 1600 hr (lights on) but only 84.0 and 72.7 ng/ml, and 1544 and 1501 ng/ml.min at 0400 and 2200 hr (lights off), respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed2006

The impact of folate status and folic acid supplementation on the micronucleus frequency in human erythrocytes.

Folic acid has a well-documented stabilising effect on chromosomes. A correlation between folate status and chromosome stability in humans has been reported in studies that were restricted to certain subpopulations, e.g., folate-deficient persons. The goal of the present investigation was to clarify if there also is a correlation between folate status and chromosome stability among individuals without any folate deficiency. The method used here is the recently developed flow cytometry-based micronucleus assay in human transferrin-positive reticulocytes (MN-Trf-Ret). In a blood sample, separation of the very young reticulocytes from the mature erythrocytes makes this micronucleus assay possible. This investigation comprises three studies (cross-sectional, giving baseline data), two of which are connected to an intervention study. In the three cross-sectional studies (total number of subjects, 99) the frequency of MN-Trf-Ret (fMN-Trf-Ret) was measured and compared with the serum folate status. In two of the studies also serum homocysteine and Vitamin B12 were measured and compared with the baseline fMN-Trf-Ret. Combining the results from the three cross-sectional studies, a negative correlation between folate status and fMN-Trf-Ret was obtained (p<0.05). The goal of the intervention studies was to clarify if different nutritional supplementations had any effect on the fMN-Trf-Ret and the cell proliferation (percentage polychromatic erythrocytes, PCE). Each of the two studies involved two groups, one placebo and one supplemented group. In one of the studies the supplementation was folic acid, 1000 microg/day during 1 week (n=30, both sexes); in the other intervention study, folic acid (800 microg/day), B12 (20 microg/day) and B6 (4 mg/day) were taken during 1 week (n=29, both sexes). No significant difference in %PCE or fMN-Trf-Ret between the two groups was found in either of the two intervention studies.

Adult↗
PubMed2003

The role of c-Myc on granulocyte colony-stimulating factor-dependent neutrophilic proliferation and differentiation of HL-60 cells.

We have previously suggested that phosphatidylinositol 3-kinase (PI3K)/p70 S6 kinase (p70 S6K) plays an important role in the regulation of neutrophilic differentiation of HL-60 cells on the basis of analysis of transferrin receptor (Trf-R)-positive (Trf-R(+)) and -negative (Trf-R(-)) cells that appear after treatment with dimethyl sulfoxide (DMSO). In the present study, we analyzed the downstream events of p70 S6K in differentiation and proliferation of both cell types, with a particular focus on c-Myc. Similar to p70 S6K, we found that the expression of c-Myc in Trf-R(+) cells is also higher than that in Trf-R(-) cells. Wortmannin, a specific inhibitor of PI3K, partially inhibited G-CSF-induced p70 S6K activity, c-Myc expression, and G-CSF-dependent proliferation, whereas rapamycin, an inhibitor of p70 S6K, completely inhibited p70 S6K activity, c-Myc expression, and G-CSF-dependent proliferation, indicating that the extent of c-Myc inhibition by these inhibitors correlates with a reduction in proliferation, and that c-Myc is downstream from PI3K/p70 S6K. We also determined phosphorylation of the 4E-binding protein 1 (4E-BP1), which is regulated downstream of the mammalian target of rapamycin. The addition of G-CSF failed to enhance the phosphorylation state of 4E-BP1 of HL-60 cells 2 days after DMSO differentiation. An antisense oligonucleotide for c-myc inhibited both G-CSF-dependent enhancement of c-Myc expression and proliferation in Trf-R(+) cells, but did not enhance the differentiation in terms of O(2)(-)-generating ability or fMLP-R expression. In contrast, antisense oligonucleotide for c-myc promoted fMLP-R on non-treated HL-60 cells. We therefore conclude that the PI3K/p70 S6K/c-Myc cascade plays an important role in neutrophilic proliferation in HL-60 cells. Unlike that of rapamycin, however, the antisense oligonucleotide for c-myc could not promote differentiation of Trf-R(+) cells cultured with G-CSF, indicating that another target downstream of p70 S6K may control the differentiation of HL-60 cells in terms of the signal transduction of G-CSF.

Adaptor Proteins, Signal Transducing↗
PubMed1997

Efficacy of topically applied tocopherols and tocotrienols in protection of murine skin from oxidative damage induced by UV-irradiation.

To assess the efficacy of various forms of vitamin E in protection of skin from UV-light-induced oxidative stress, vitamin E (tocotrienol-rich fraction of palm oil, TRF) was applied to mouse skin and the contents of antioxidants before and after exposure to UV-light were measured. Four polypropylene plastic rings (1 cm2) were glued onto the animals' backs, and 20 microliters 5% TRF in polyethylene glycol-400 (PEG) was applied to the skin circumscribed by two rings and 20 microliters PEG to the other two rings. After 2 h, the skin was washed and half of the sites were exposed to UV-irradiation (2.8 mW/cm2 for 29 mi: 3 MED). TRF treatment (n = 19 mice) increased mouse skin alpha-tocopherol 28 +/- 16-fold, alpha-tocotrienol 80 +/- 50-fold, gamma-tocopherol 130 +/- 108-fold, and gamma-tocotrienol 51 +/- 36-fold. A significantly higher percentage of alpha-tocopherol was present in the skin as compared with that in the applied TRF. After UV-irradiation, all vitamin E forms decreased significantly (p < .01), while a larger proportion of the vitamin E remained in PEG-treated (approximately 80%) compared with TRF-treated (approximately 40%) skin. Nonetheless, vitamin E concentrations in irradiated TRF-treated skin were significantly higher than in the nonirradiated PEG-treated (control) skin (p < .01). Thus, UV-irradiation of skin destroys its antioxidants: however, prior application of TRF to mouse skin results in preservation of vitamin E.

Absorption↗
PubMed2001

T-cell mean telomere lengths changes in treatment naïve HIV-infected patients randomized to G-CSF or placebo simultaneously with initiation of HAART.

The effect of highly active antiretroviral therapy (HAART) and granulocyte colony stimulating factor (G-CSF) on mean telomere restriction fragment (TRF) length of peripheral blood mononuclear cells (PBMC) was examined in 11 treatment naïve human immunodeficiency virus (HIV)-infected individuals with a CD4+ T-cell count < 350 cells/mm3. Patients were randomized to HAART combined with G-CSF thrice weekly for 12 weeks (n = 6) or placebo (n = 5). An increase in the mean TRF lengths was observed in PBMC of patients on HAART after 24 weeks of treatment mainly owing to increased mean CD8+ T-cell TRF lengths. However, in the group of patients on HAART combined with G-CSF no changes of PBMC mean TRF length was observed during treatment or during 12 weeks of follow-up. The mean CD4+ T-cell TRF length did not change in any of the two groups. These results confirm that HAART induces mainly the lengthening of the mean CD8+ T-cell TRF length. However, G-CSF given simultaneously with HAART induces an inhibition of the expected lengthening in mean TRF length. These results do therefore not support the use of adjuvant G-CSF treatment simultaneously when initiating HAART and should further be evaluated before use in non-neutropenic HIV-infected patients.

Antiretroviral Therapy, Highly Active↗
PubMed2001

Alterations of telomerase activity and terminal restriction fragment in gastric cancer and its premalignant lesions.

AIMS: In order to explore the role of alterations of telomerase activity and terminal restriction fragment (TRF) length in the development and progression of gastric cancer. METHODS: Telomerase activity was detected in 176 specimens of gastric mucosa obtained through an operation or endoscopical biopsy by using the telomeric repeat amplification protocol (TRAP) assay. Meanwhile, the mean length of TRF was measured with the use of a Southern blot in part of those samples. RESULTS: Telomerase activity was detected in 14 of 57 (24.6%) chronic atrophy gastritis patients, six of 18 (33.3%) intestinal metaplasia patients, three of eight (37.5%) dysplasia patients and 60 of 65 (92.3%) gastric cancer patients, respectively. Normal gastric mucosa revealed no telomerase activity. No association was found between telomerase activity and any clinicopathological parameters. The mean TRF length was decreased gradually with age in normal mucosa and in gastric cancer tissue. Regression analysis demonstrated that the reduction rate in these tissues was 41 +/- 12 base pairs/year. Among 35 gastric cancers, TRF length was shown to be shorter in 20 cases (57.1%), similar in 12 cases (34.3%) and elongated in three cases (7.6%), compared to the corresponding adjacent tissues. The mean TRF length tended to decrease as the mucosa underwent chronic atrophy gastritis, intestinal metaplasia, dysplasia and into gastric cancer. The mean TRF length in gastric cancer was not statistically correlated with clinicopathological parameters and telomerase activity. CONCLUSIONS: Our results suggest that telomerase is expressed during the early stage of gastric carcinogenesis, and that the clinical significance of TRF length appears to be limited in gastric cancer.

Adult↗
PubMed1983

Induction of a B-lymphocyte receptor for a T cell-replacing factor by the crosslinking of surface IgD.

The observation that anti-immunoglobulin antibodies and T cell-replacing factor (TRF) have a synergistic effect on the stimulation of B lymphocytes to differentiate into antibody-secreting cells suggested to us the possibility that the crosslinking of B-cell surface immunoglobulin by antigen or anti-immunoglobulin antibody might induce the expression of a B-cell receptor for TRF. In order to test this possibility we studied whether spleen cells from mice injected with 400-800 micrograms of anti-IgD antibody 1-3 days before sacrifice had an enhanced capacity to adsorb TRF activity from a partially purified culture supernatant of concanavalin A-stimulated mouse spleen cells. We found that spleen cells from euthymic or congenitally athymic mice injected 24-30 hr prior to sacrifice with either affinity-purified goat anti-mouse IgD antibody or a monoclonal allospecific anti-IgD antibody had greater than 100 times the TRF adsorptive capacity of spleen cells from control mice. In contrast, spleen cells from anti-IgD treated DBA/2Ha mice, which have been shown to have an immune defect associated with the lack of a TRF receptor, were unable to adsorb TRF activity from concanavalin A-stimulated helper supernatants. This suggests that the crosslinking of B-cell surface immunoglobulin may induce B lymphocytes to express a receptor or receptors for TRF and thus enhance B-cell responsiveness to this helper factor.

Animals↗
PubMed1996

Structure, subnuclear distribution, and nuclear matrix association of the mammalian telomeric complex.

Mammalian telomeres are composed of long arrays of TTAGGG repeats complexed with the TTAGGG repeat binding factor, TRF. Biochemical and ultrastructural data presented here show that the telomeric DNA and TRF colocalize in individual, condensed structures in the nuclear matrix. Telomeric TTAGGG repeats were found to carry an array of nuclear matrix attachment sites occurring at a frequency of at least one per kb. The nuclear matrix association of the telomeric arrays extended over large domains of up to 20-30 kb, encompassing the entire length of most mammalian telomeres. TRF protein and telomeric DNA cofractionated in nuclear matrix preparations and colocalized in discrete, condensed sites throughout the nuclear volume. FISH analysis indicated that TRF is an integral component of the telomeric complex and that the presence of TRF on telomeric DNA correlates with the compact configuration of telomeres and their association with the nuclear matrix. Biochemical fractionation of TRF and telomeric DNA did not reveal an interaction with the nuclear lamina. Furthermore, ultrastructural analysis indicated that the mammalian telomeric complex occupied sites throughout the nuclear volume, arguing against a role for the nuclear envelope in telomere function during interphase. These results are consistent with the view that mammalian telomeres form nuclear matrix-associated, TRF-containing higher order complexes at dispersed sites throughout the nuclear volume.

Adenocarcinoma↗
PubMed1983

T cell-replacing factor for glucocorticosteroid-induced immunoglobulin production. A unique steroid-dependent cytokine.

Glucocorticosteroids (GCS) added to otherwise unstimulated cultures of human peripheral blood mononuclear cells (PBMC) induce the synthesis and secretion of all classes of immunoglobulin. The magnitude of this response is similar to that seen with other polyclonal B cell activators such as pokeweed mitogen (PWM), and like that of PWM, the steroid effect is dependent on both T cells and monocytes. To determine the cellular target for GCS in these cultures, separated populations of T cells and non-T cells were preincubated with steroids and then recombined. No immunoglobulin was produced in any of these preincubation experiments. As a different approach to this question, supernatants were collected from various cell populations following stimulation with PWM, concanavalin A (Con A), phytohemagglutinin (PHA), alloantigens, or GCS. These supernatants were tested for their effects on GCS-induced Ig production by B cells. Supernatants from 3-d cultures of unstimulated, as well as GCS-treated, PBMC contained a T cell-replacing factor that permitted T-depleted PBMC to produce Ig upon steroid stimulation. This supernatant factor (TRF-S) could be produced in the absence of steroid stimulation, but both the factor and GCS were necessary for the induction of Ig synthesis. Production of the TRF-S required the presence of both T cells and adherent cells in culture and was found in the highest concentrations at 3-4 d of culture. Supernatants from cultures stimulated with PWM, PHA, Con A, and alloantigens did not contain detectable TRF-S activity, and TRF-S was unable to replace helper T cells for PWM-induced Ig production. TRF-S required the presence of adherent cells in the T cell-depleted responder population for its action. Further, it was effective in inducing Ig production along with GCS in the presence of a sufficient concentration of cyclosporin A to block all T cell helper activity for primary responses of PBMC to PWM or GCS. TRF-S was inactivated by trypsin treatment, heating to 56 degrees C, freezing, lyophilization, and storage at 4 degrees C for greater than 3 wk. Its molecular weight is probably 10,000 daltons or more, since TRF-S activity is not rapidly dialyzable. These experiments indicate that GCS-induced Ig production by human B cells does not require the presence of intact T cells in the cultures and therefore the steroids are not exerting their influence directly on T suppressor or T helper cells. Furthermore, they demonstrate a previously unrecognized cytokine that induces the differentiation of human B cells to Ig production in the presence of GCS.

B-Lymphocytes↗
PubMed2004

Suppression of diethylnitrosamine and 2-acetylaminofluorene-induced hepatocarcinogenesis in rats by tocotrienol-rich fraction isolated from rice bran oil.

The anticancer efficacy of tocotrienol-rich fraction (TRF) was evaluated during diethylnitrosamine (DEN)/2-acetylaminofluorene (AAF)-induced hepatocarcinogenesis in male Sprague-Dawley rats. TRF treatment was carried out for 6 months, and was started 2 weeks before initiation phase of hepatocarcinogenesis. Morphological examination of the livers from DEN/AAF rats showed numerous off-white patches and few small nodules, which were significantly reduced by TRF treatment. Cytotoxic damage by DEN/AAF was estimated by alkaline phosphatase (ALP) release into the plasma from the cell membranes. DEN/AAF caused a twofold increase in the activity of ALP in plasma as compared with normal control rats, and this increase was prevented significantly by TRF treatment. We observed an increase of 79% in liver ALP activity in DEN/AAF rats, which was further increased by another 48% after the administration of TRF. Hepatic activity of glutathione S-transferase (GST) was also increased (3.5-fold) during the induction of hepatic carcinogenesis. Lipid peroxidation and low-density lipoprotein (LDL) oxidation increased threefold following initiation by DEN/AAF as compared with normal control rats. However, TRF treatment to DEN/AAF-treated rats substantially decreased (62-66%) the above parameters and thus limited the action of DEN/AAF. We conclude that long-term intake of TRF could reduce cancer risk by preventing hepatic lipid peroxidation and protein oxidation damage due to its antioxidant actions.

2-Acetylaminofluorene↗
PubMed2001

Phylogenetic specificity and reproducibility and new method for analysis of terminal restriction fragment profiles of 16S rRNA genes from bacterial communities.

Terminal restriction fragment (TRF) analysis of 16S rRNA genes is an increasingly popular method for rapid comparison of microbial communities, but analysis of the data is still in a developmental stage. We assessed the phylogenetic resolution and reproducibility of TRF profiles in order to evaluate the limitations of the method, and we developed an essential analysis technique to improve the interpretation of TRF data. The theoretical phylogenetic resolution of TRF profiles was determined based on the specificity of TRFs predicted from 3,908 16S rRNA gene sequences. With sequences from the Proteobacteria or gram-positive division, as much as 73% of the TRFs were phylogenetically specific (representing strains from at most two genera). However, the fraction decreased when sequences from the two divisions were combined. The data show that phylogenetic inference will be most effective if TRF profiles represent only a single bacterial division or smaller group. The analytical precision of the TRF method was assessed by comparing nine replicate profiles of a single soil DNA sample. Despite meticulous care in producing the replicates, numerous small, irreproducible peaks were observed. As many as 85% of the 169 distinct TRFs found among the profiles were irreproducible (i.e., not present in all nine replicates). Substantial variation also occurred in the height of synonymous peaks. To make comparisons of microbial communities more reliable, we developed an analytical procedure that reduces variation and extracts a reproducible subset of data from replicate TRF profiles. The procedure can also be used with other DNA fingerprinting techniques for microbial communities or microbial genomes.

Ecosystem↗
PubMed1992

A mammalian factor that binds telomeric TTAGGG repeats in vitro.

We have identified a DNA-binding activity with specificity for the TTAGGG repeat arrays found at mammalian telomeres. This factor, called TTAGGG repeat factor (TRF), is present in nuclear extracts of human, mouse, and monkey cells. TRF from HeLa cells was characterized in detail by electrophoretic mobility shift assays. It binds double-stranded TTAGGG repeats in linear and circular DNAs. Single-stranded repeats are not recognized. The optimal site for TRF appears to contain more than six contiguous TTAGGG repeats. Tandem arrays of TAGGG, TTTAGGG, TTTTAGGG, TTGGGG, and TTAGGC repeats do not bind TRF well, indicating that TRF preferentially recognizes the telomeric repeat sequence present at mammalian chromosome ends. The apparent molecular mass of this factor, based on recovery of TRF from sodium dodecyl sulfate-polyacrylamide gels, is approximately 50 kDa. We suggest that TRF binds along the length of mammalian telomeres.

Animals↗
PubMed2004

Symptoms defined by parents' and teachers' ratings in attention-deficit hyperactivity disorder: changes with age.

OBJECTIVE: To determine whether Child Behavior Checklist/4-18 (CBCL) and Teacher Report Form (TRF) scores of children and adolescents with a first-time diagnosis of attention-deficit hyperactivity disorder (ADHD) are different and whether there is a similar difference in normal control subjects. METHOD: We analyzed the CBCL and TRF scores of 146 patients (124 boys and 22 girls, aged 6 to 18 years; mean age 11.0 years, SD 3.6). We analyzed the same scores for 274 age and sex-matched control subjects recruited from a nationally representative sample. RESULTS: Subjects with ADHD had significantly higher CBCL and TRF scores than control subjects. Age was significantly correlated with scores on the CBCL and TRF subscales Social Withdrawal, Somatic Complaints, and Internalization Problems; with scores on the CBCL subscale Attention Problems; and with scores on the TRF subscale Anxiety-Depression. In the group with ADHD, age was negatively correlated with scores on the CBCL and TRF subscale Externalizing Problems and with scores on the TRF subscale Aggressive Behavior. In the control group, the only significant correlation was between age and the CBCL subscale Somatic Complaints score. CONCLUSIONS: These results indicate that underdiagnosis of ADHD in childhood may cause the emergence of greater internalization problems in adolescence.

Adolescent↗
PubMed1989

Thyrotropin-releasing factor-induced adrenocorticotropin secretion is mediated by corticotropin-releasing factor.

TSH-releasing factor (TRF), administered into the lateral cerebroventricle of adult male rats, elevated plasma concentrations of ACTH, epinephrine, and norepinephrine. TRF given iv was devoid of these activities. The CRF receptor antagonist, alpha-helical CRF9-41 (CRF9-41) given iv suppressed the TRF-induced increase in ACTH, but did not alter TRF-induced changes in plasma catecholamines. Intravenous administration of CRF antiserum totally blocked TRF-induced elevation of plasma ACTH concentrations. CRF receptor antagonists administered icv attenuated CRF-induced, but not TRF-induced elevation of plasma concentrations of ACTH, epinephrine, and norepinephrine. It is concluded from these results that TRF acts within the central nervous system to stimulate ACTH release through a CRF-dependent mechanism.

Adrenocorticotropic Hormone↗
PubMed2004

Rapid method for beta2-transferrin in cerebrospinal fluid leakage using an automated immunofixation electrophoresis system.

BACKGROUND: Beta(2)-transferrin (beta-2 trf) is a desialated isoform of transferrin found only in cerebrospinal fluid (CSF), ocular fluids, and perilymph. In aural, nasal, and wound drainages, this protein is an important marker of CSF leakage. Immunofixation electrophoresis (IFE) on agarose gels is a widely accepted qualitative technique for detection of small amounts of beta-2 trf, but disadvantages include lengthy transfer immunoblotting techniques or the requirement of at least 2 mL of sample. METHODS: Using eight applications of unconcentrated sample on high-resolution agarose gels with an automated electrophoresis system (Helena SPIFE 3000), we developed a rapid method for beta-2 trf. Evaluation studies included reproducibility of migration distance (mm), limit of detection, specificity, and concordance of results compared with those reported by a reference laboratory. Neuraminidase-treated serum was the source of beta-2 trf for our sensitivity and specificity studies. Transferrin was measured by rate nephelometry. RESULTS: The 2.5-h procedure demonstrated reproducible migration (CV <2.5%) on five lots of gels. Detection of beta-2 trf at 0.002 g/L in an unconcentrated sample was attributed to reproducible application, quality of the anti-trf antiserum, and a sensitive acid violet stain. Our beta-2 trf findings (two negative and five positive) in seven available clinical samples agreed with the reference laboratory results. In 12 months after its inception, this test was ordered 48 times vs 13 in the previous year when testing was sent out. CONCLUSION: This method provides physicians with a rapid, reliable aid in the diagnosis of suspected CSF leakage, as described in a case report.

Adult↗