A re-evaluation of the prolactin-releasing activity of growth hormone-releasing hormone in acromegaly in vivo

In 1985, Losa et al reported that an i.v. bolus injection of GH-releasing hormone (GHRH) was able to paradoxically stimulate PRL secretion in more than half of their acromegalic patients. However, this observation was not generally accepted since several other investigators have concluded that such an anomalous PRL response to GHRH was an extremely rare phenomenon in acromegaly. Therefore, in this study we examined a large number (51 patients) of active acromegalics in order to obtain more reliable data on the incidence of the paradoxical PRL response to GHRH in this disorder. Each patient underwent i.v. bolus injections of GHRH (100 micrograms) and thyrotropin-releasing hormone (TRH, 500 micrograms) on separate days, and plasma levels of GH and PRL were measured. The plasma PRL response to GHRH was considered positive (a paradoxical increase) when an increase over baseline of at least 50% occurred. We found that only 6 patients (12%) showed a positive PRL response to GHRH. These PRL-responders to GHRH had higher GH responses to this peptide than PRL-non-responders to GHRH. Although PRL-responders and non-responders to GHRH had a similar PRL responsiveness to TRH, the GH response to TRH was lower in PRL-responders to GHRH than PRL-non-responders to this peptide. In addition, PRL-non-responders to GHRH had lower basal GH and higher basal PRL levels than PRL-responders to GHRH.(ABSTRACT TRUNCATED AT 250 WORDS)

[5-FU concentrations in the blood and tumor tissue after 5'-DFUR or UFT administration in the patients with uterine cervical cancer]

In order to verify the antitumor activity of fluorinated pyrimidine drugs, we conducted an investigation of the clinical pharmacology with two drugs, 5'-DFUR and UFT. Total 21 cases of cervical cancer were alloted randomly into 5'-DFUR group (daily dose 800 mg for 3 days) consisting of 11 patients and UFT group (daily dose 600 mg for 3 days) consisting of 10 patients, the unchanged substances (5'-DFUR in the 5'-DFUR group and tegafur concentrations in the UFT group) and 5-FU concentrations in serum and tissues were measured 6 hours after administration of the drugs. The 5'-DFUR concentration in the 5'-DFUR group was not detected in serum and less than a detectable limit for all of cancerous tissues, normal cervical tissues, and lymph nodes. The tegafur concentrations in the UFT treated group was 13.8 +/- 7.0 micrograms/ml for serum, 10.4 +/- 6.4 micrograms/g for cancerous tissues, 14.1 +/- 7.3 micrograms/g for normal cervical tissues, and 4.5 +/- 4.2 micrograms/g for lymph nodes. The 5-FU concentrations in the 5'-DFUR treated group were 0.018 +/- 0.046 micrograms/g for cancerous tissues, but less than a detectable limit for serum and normal cervical tissues. On the other hand, in the UFT group, 0.271 +/- 0.247 micrograms/g for a cancerous tissue, 0.035 +/- 0.018 micrograms/ml for serum, 0.125 +/- 0.073 micrograms/g for normal cervical tissues, showing significantly high values (p < 0.01, p < 0.001, and p < 0.01, respectively) compared to those in the 5'-DFUR treated group. These results suggest that UFT is a promising drug for the treatment of cancer of the uterine cervix.

Clinical significance of the growth hormone response to vasoactive intestinal peptide and gonadotropin-releasing hormone in acromegaly

GH-secreting pituitary adenomas causing acromegaly can be classified into at least two types, i.e. the lactotroph-like adenoma and somatotroph-like adenoma. From a functional point of view, the lactotroph-like adenoma is characterized by positive GH responses to TRH and bromocriptine (Br) with a GH increase or decrease, respectively, whereas the somatotroph-like adenoma is characterized by a high GH response to GHRH and a low GH response to TRH and Br. In this study, we examined whether the loading of vasoactive intestinal peptide (VIP) and GnRH, another hypothalamic hormone capable of stimulating GH secretion in acromegaly, have a pathophysiological significance as TRH, GHRH, and Br tests. In 52 patients with active acromegaly, we performed iv bolus injections of TRH (500 micrograms), GHRH (100 micrograms), VIP (100 micrograms), and GnRH (100 micrograms), and a peroral administration of Br (2.5 mg), in order to compare the GH responses to these loads. There was a significant correlation that the higher was the GH response after TRH the greater was the GH decrease after Br. Although statistically insignificant, there was a trend (0.05 < p < 0.1) that the higher was the GH response after GHRH the smaller was the GH decrease after Br. In addition, as novel findings, we observed that the GH responses to GHRH, VIP, and GnRH were in significant positive correlations to each other, and that the higher were the GH responses after VIP and GnRH the smaller was the GH decrease after Br. In agreement with this, we also found that a simultaneous GH responsivity to VIP and/or GnRH in TRH-responsive acromegalics significantly enhanced the GH response to GHRH and lowered the Br responsiveness compared to the data of pure TRH-responders. From these results, we hypothesize that the positive GH responsiveness to VIP and GnRH, like that to GHRH, may be a feature of the somatotroph-like pituitary adenoma causing acromegaly. The present results appear to be of some help in understanding the basis of the great variabilities in the GH responses to various dynamic testings in acromegaly.

Inhibitory action of lansoprazole and its analogs against Helicobacter pylori: inhibition of growth is not related to inhibition of urease

The proton pump inhibitors omeprazole and lansoprazole and its acid-activated derivative AG-2000, which are potent and specific inhibitors of urease of Helicobacter pylori (K. Nagata, H. Satoh, T. Iwahi, T. Shimoyama, and T. Tamura, Antimicrob. Agents Chemother. 37:769-774, 1993), inhibited the growth of H. pylori. The growth was inhibited not only in urease-positive clinical isolates but also in their urease-negative derivatives which had no urease polypeptides. AG-1789, a derivative of lansoprazole with no inhibitory activity against H. pylori urease, also inhibited the growth of both strains even more strongly than the urease inhibitors lansoprazole and AG-2000. Furthermore, the antibacterial activity of omeprazole and lansoprazole was not affected by glutathione or dithiothreitol, which completely abolished the inhibitory activity of lansoprazole against H. pylori urease. These results indicated that the inhibitory action of these compounds against the growth of H. pylori was independent from the inhibitory action against urease.

Effects of luteinizing hormone and follicle-stimulating hormone on the progesterone receptor induction in chicken granulosa cells in vivo

Progesterone receptor (PR) is increased in the granulosa cells prior to ovulation. In order to investigate the factors that induce PR in granulosa cells, we examined whether the PR is induced in granulosa cells by the injection of chickens with ovine luteinizing hormone (oLH) or porcine follicle-stimulating hormone (pFSH) by Western blot analysis. In the oLH-stimulated birds, PR of 79 kDa and 110 kDa were recognized in the granulosa cells of the largest follicle, whereas a PR of 110 kDa was observed in those of the smaller follicles (the second and third largest follicles). No immunoreaction product was observed in the granulosa cells of both the largest and the smaller follicles in pFSH-stimulated birds. In the control birds that were injected with saline, no immunoprecipitate was recognized in the granulosa cells of the largest or smaller follicles. These results suggest that LH may be involved in the induction of PR in the granulosa cells prior to ovulation.

The influence of ageing on cisplatin pharmacokinetics in lung cancer patients with normal organ function

This study was performed to identify any relationship between age and cisplatin (CDDP) pharmacokinetics in lung cancer patients. CDDP was given at a dose of 80 mg/m2 by 1-h intravenous infusion to 23 lung cancer patients. All patients had normal renal, hepatic, and bone marrow functions. We measured ultrafilterable platinum (U-Pt) and total plasma platinum (T-Pt) using atomic absorption spectrometry. There was significant correlation between the age of the patients and U-Pt pharmacokinetic parameters such as the area under the plasma concentration versus time curve (AUC), total clearance (Cl), and peak plasma concentration (Cmax) as well as the AUC of T-Pt (P < 0.05). We performed univariate regression analysis to examine the influence of factors aside from age on the AUC of U-Pt and T-Pt. Creatinine and GPT levels were significantly related to the AUC of U-Pt, and creatinine clearance and creatinine concentrations were significantly related to the AUC of T-Pt. Therefore, stepwise multiple-regression models for the AUC of U-Pt and T-Pt were developed to assess an age effect. Age was consistently an independent and significant predictor of the AUC of U-Pt and T-Pt.

Fifty novel sequence-tagged sites (STSs) on human chromosome 11q13.4-->q25 identified from microclones generated by microdissection

Fifty sequence-tagged sites (STSs) from human chromosome region, 11q13.4-->q25 were identified in microdissection-generated microclones. From a total of 124 single-copy microclones obtained from regions 11q14-->q22 and 11q23-->q25, 59 were sequenced, and a PCR primer pair was designed for each of them. Fifty of the 59 clones were mapped to regions ranging from 11q13.4 to 11q25 by means of PCR on a somatic hybrid cell panel with various deletions of the long arm of human chromosome 11. These STSs will contribute to the construction of physical cosmid/YAC maps representing the chromosome regions. They are also useful for analysis of chromosome aberrations, such as translocations, inversions or marker chromosomes.

A pharmacokinetic and pharmacodynamic analysis of CPT-11 and its active metabolite SN-38

In the present study, an attempt was made to determine the precise pharmacokinetics of 7-ethyl-10-[4-(1-piperidino)-1-piperidino]carbonyloxycamptothecin (CPT-11) and its active metabolite, 7-ethyl-10-hydroxycamptothecin (SN-38). The relationship between pharmacokinetic parameters and pharmacodynamic effects was also investigated to elucidate the cause of interpatient variation in side effects. Thirty-six patients entered the study. CPT-11, 100 mg/m2, was administered by IV infusion over 90 min weekly for four consecutive weeks. The major dose-limiting toxicities were leukopenia and diarrhea. There was a positive correlation between the area under the concentration-time curve (AUC) of CPT-11 and percent decrease of WBC (r = 0.559). On the other hand, episodes of diarrhea had a better correlation with the AUC of SN-38 (r = 0.606) than that of CPT-11 (r = 0.408). Multivariate analysis revealed that the AUC of SN-38, AUC of CPT-11 and indocyanine green retention test were significant variables for the incidence of diarrhea and that both performance status and AUC of CPT-11 were significant variables for percent decrease of WBC. The large interpatient variability of the degree of leukopenia and diarrhea is due to a great plasma pharmacokinetic variation in CPT-11 or SN-38. The AUCs of CPT-11 and SN-38 obtained from the first administration of CPT-11 correlate with toxicities, but it is impossible to predict severe side effects before the administration of CPT-11 at the present time.

Effect of atrial and ventricular activation interval on hemodynamics during atrioventricular and ventriculoatrial pacing: determination from pressure-volume loops in dogs

To determine the effect of relative timing of atrial and ventricular activation on hemodynamic indices, we evaluated pressure-volume loops during pacing at 160 beats/min with various atrioventricular intervals in dogs. End-systolic pressure, end-diastolic volume, and stroke volume were reduced during pacing at atrioventricular intervals of 0 ms, compared with 80 ms. These changes were more significant during pacing at atrioventricular intervals of -50 and -100 ms than at 0 ms. During tachycardia, the abnormal timing of atrial contraction leads to unfavorable hemodynamic change and the degree of the changes are determined by the ventriculoatrial activation interval.

Influence of tyrosine residues Y705 and Y807 on the transforming potency of the v-fms oncogene product of feline sarcoma virus

Cell transformation is characterized by overt changes in growth control and cell morphology. To study the role of tyrosine residues Y705 and Y807 of v-Fms of the McDonough strain of feline sarcoma virus in cell transformation we replaced them individually with phenylalanine residues. Cells expressing the mutant genes showed mitogenic properties similar to wild-type v-Fms transformed cells. However, the morphology of cells expressing the Y807F mutant remained the same as nontransformed cells. Four phosphoproteins of 190, 120, 55 and 50 kDa were detected in cells expressing the wild-type but were absent in cells expressing the mutant Y807F-v-fms gene.

Chronic lymphocytic leukemia associated with nephrotic syndrome and dermatomyositis

Several types of autoimmune complications of chronic lymphocytic leukemia (CLL) have been previously reported. However, the tendency to develop autoantibodies is usually restricted to the hematopoietic system. We report a 68-year-old man who had developed dermatomyositis after ten years of chemotherapy for CLL. He also had secondary nephrotic syndrome at the onset of CLL. Subsequently, the patient died of perforation of the small intestine. The association of both nephrotic syndrome and dermatomyositis with CLL is very rare. We discuss the possibility of a casual relation.

The mutual sparing effects of selenium and vitamin E in animal nutrition may be further explained by the discovery that mammalian thioredoxin reductase is a selenoenzyme

The recent discovery that mammalian thioredoxin reductase is a selenoprotein furnishes an additional explanation of the mutual sparing roles of selenium and vitamin E in cellular antioxidant systems. Thioredoxin reductases isolated from human lung adenocarcinoma cells, human Jurkat T-cells and HeLa cells contain selenocysteine which is located in a C-terminal tripeptide, -Cys-SeCys-Gly.

Derivatization and purification of bisecting tyrosinamide-oligosaccharides from ovotransferrin

The major N-linked oligosaccharides from ovotransferrin were purified on a large scale. The oligosaccharides were released from 5 g of the glycoprotein using N-glycosidase F and isolated from a mixed bed ion exchange column. Reducing-oligosaccharides were reacted with ammonium bicarbonate to form a reducing-end glycosylamine which coupled with the N-hydroxysuccinimidyl ester of Boc-tyrosine, resulting in tyrosinamide-oligosaccharides. Resolution of tyrosinamide-oligosaccharides on reverse-phase (RP)-HPLC necessitated the removal of Boc by treatment with trifloroacetic acid. Two major tyrosinamide-oligosaccharides were isolated from preparative RP-HPLC and were characterized by 500 MHz proton NMR and FAB-MS. These were a biantennary and triantennary oligosaccharide, each possessing a bisecting GlcNAc residue extending from the central core Man residue. Thus, ovotransferrin represents an abundant glycoprotein source from which to prepare multi-micromole quantities of bisecting complex oligosaccharides which may find utility in exploring the ligand specificity of mammalian lectins or may be used as synthons to prepare novel glycoconjugates.

Genetic heterogeneity of Helicobacter pylori by pulse-field gel electrophoresis and re-evaluation of DNA homology

PURPOSE

The genetic heterogeneity of Helicobacter pylori isolates was re-evaluated by using pulse-field gel electrophoresis to examine macrorestriction patterns and by studying DNA homology.

MATERIALS AND METHODS

Twenty H. pylori isolates, two closely related species, H. mustelae and H. felis, and Campylobacter spp. were used. Notl-digested macrorestriction patterns were examined by pulse-field gel electrophoresis. DNA homology was examined by the S1 nuclease method, using [3H]-labeled DNA from H. pylori NCTC11637 and two H. pylori isolates for reference.

RESULT

Intergenus DNA homology between H. pylori and Campylobacters was 50-60%. Interspecies homology between H. pylori and H. mustelae or H. felis was around 60%. Intraspecies homology among H. pylori isolates was above 80%, except for a few that exhibited 70-80% homology. These findings indicate that all H. pylori isolates were homogeneous and belonged to the same species. Notl pulse-field gel electrophoresis patterns of H. pylori isolates differed markedly at the individual strain level. There was no specific relationship to any deviation from DNA homology, and the differences were observed within rather homogeneous members of the species.

CONCLUSION

The polymorphism in the Notl pulse-field gel electrophoresis patterns of H. pylori isolates differed markedly among strains, even though these isolates displayed species homogeneity, with DNA homology of 70-100%.

Isolation and characterization of alpha-type HC3 and beta-type HC5 subunit genes of human proteasomes

Eukaryotic proteasomes from an evolutionarily conserved multi-gene family and are thought to have originated from a common ancestral gene and diverged into alpha-type and beta-type subgroups. To understand the molecular basis of the proteasome genes, we isolated and characterized two human proteasome genes econding the alpha-type HC3 and beta-type HC5 subunit. The functional genes for HC3 and HC5 are similar in being approximately 15 kb in length, but differ in having exon numbers of 9 and 6, respectively. Analyses of about 2.5 to 3.0 kb of the 5'-flanking regions of these two genes revealed the absence of TATA and CAAT promoter elements. However, two or three GC boxes were found. By analysis of the transcriptional regulatory activities in the 5'-flanking regions of the two genes, these GC boxes were found to function coordinately as promoters of the two genes. Interestingly, the HC3 gene possesses an additional silencer element in the 5'-upstream region near the first exon. This element is also able to repress the promoter activities of other genes, such as the HC5 and the type 1 glucose transporter genes, irrespective of whether it has a sense or antisense orientation, indicating that it acts as a general transcriptional silencer. The HC5 gene does not have this silence element, and its promoter activity is five to ten times that of HC3. These results show that the human proteasomal HC3 and HC5 genes differ not only in their genomic structures, such as their numbers of exons and their exon-intron organizations, but also in the mechanisms regulating their transcription, suggesting that they diverged at an early stage of evolution.

Isolation of rat TATA factor as an active 75kDa protein complex

A general transcription factor TFIID was purified from rat liver by a sequential column chromatography including organomercurial Sepharose and Sephacryl S-200 chromatographies, which were developed with an acidic buffer (pH5.5). Analyses by SDS-polyacrylamide gel electrophoresis, assay of eluants after renaturation, and immunoblotting showed that isolated TATA factor is an active 75kDa protein complex which contains 36kDa TATA-binding protein.

Myasthenia gravis associated with Addison's disease

Idiopathic Addison's disease developed in a 52-year-old female with a 15-year history of myasthenia gravis. The association of myasthenia gravis with other autoimmune diseases is well known, however an association with Addison's disease is rare. It was speculated that the development of Addison's disease in this patient might have been due to common immunological abnormalities underlying these two diseases. We report this case and briefly discuss the pathogenetic mechanism of this association.

Accelerated exon skipping of IRF-1 mRNA in human myelodysplasia/leukemia; a possible mechanism of tumor suppressor inactivation

The transcription factor IRF-1 has been shown to function as a tumor suppressor. Here we report that a significant proportion of the IRF-1 mRNA detected in normal human hematopoietic cells and cultured cell lines lacks exon 2 (containing the AUG initiation codon) and 3 as a result of exon skipping. Surprisingly, when we examined the bone marrow and peripheral mononuclear cells from patients with myelodysplastic syndrome (MDS) or leukemia secondary to MDS, we could still detect the exon-skipped form but little or none of the intact IRF-1 mRNA. This appears to be the result of accelerated exon skipping since we could find no mutations within the exons and splicing junctions from these patients. The exon-skipped form of IRF-1 lacking exons 2 and 3 displayed neither DNA binding nor tumor suppressive activities. Thus this accelerated exon skipping may cause the inactivation of IRF-1 and thereby contribute to the development of human hematopoietic malignancies.

Changes in muscle oxygenation during weight-lifting exercise

The quantitative analysis of haemoglobin oxygenation of contracting human muscle during weight-lifting exercise was studied noninvasively and directly using near-infrared spectroscopy. This method was developed as a three-wavelength method which confirmed the volume changes in oxygenated haemoglobin (oxy-Hb), deoxygenated haemoglobin (deoxy-Hb) and blood volume (total-Hb; Oxy-Hb+deoxy-Hb). Nine healthy adult men with various levels of training experience took part in the study. Ten repetition maximum (10 RM) one-arm curl exercise was performed by all the subjects. Results showed that at the beginning of the 10-RM exercise, rapid increases of deoxy-Hb and decreases of oxy-Hb were observed. In addition, total-Hb gradually increased during exercise. These results corresponded to the condition of arm blood flow experimentally restricted using a tourniquet in contact with the shoulder joint, and they showed the restriction of venous blood flow and an anoxic state occurring in the dynamically contracted muscle. In three sets of lifting exercise with short rest periods, these tendencies were accelerated in each set, while total-Hb volume did not return to the resting state after the third set for more than 90 s. These results would suggest that a training regimen emphasizing a moderately high load and a high number of repetitions, and a serial set with short rest periods such as usually performed by body builders, caused a relatively long-term anoxic state in the muscle.

Influence of efonidipine hydrochloride, calcium antagonist on the epithelium of prostates in spontaneously hypertensive rats

The hypertensive effect on the development of the prostatic abnormality in spontaneously hypertensive rats (SHRs) was examined using Efonidipine hydrochloride, a calcium antagonist. The control SHRs were given a high sodium and potassium diet (SP-diet) alone, and the treated SHRs were given a SP-diet with 0.15% Efonidipine hydrochloride from 8 to 28 weeks of age. The systolic blood pressure (SBP) in the control SHRs increased with age, while the elevation of SBP was significantly prevented in the treated SHRs. Light-microscopically, the prostatic lesion was observed both in the control and treated SHRs. The glandular lumen was narrowed with papillary protrusions, and the epithelium was composed of tall columnar epithelial cells. However, hypertension-induced complications in kidneys and hearts were not observed in the treated SHRs. These results suggested that the prostatic abnormality of SHRs might not be the consequent lesions upon hypertension.

Clival chordoma in early childhood without bone involvement

Intracranial chordomas are rare in childhood. Only 15 cases have been reported in children less than 6 years old. Bone destruction and calcification have been stated to be characteristics of this tumor. We present the case of a 5-year-old boy with clival chordoma without bone involvement.