A new compound heterozygous mutation in the 11 beta-hydroxysteroid dehydrogenase type 2 gene in a case of apparent mineralocorticoid excess

Apparent mineralocorticoid excess (AME) characterized by early-onset hypertension and hypokalemia is due to congenital deficiency of 11 beta-hydroxysteroid dehydrogenase (11 beta HSD). Two isoforms of human 11 beta HSD are known, and the type 2 isoform (11 beta HSD2) has been recently shown to be responsible for AME. In this study we have analyzed the 11 beta HSD2 gene of a Japanese patient with AME. PCR amplification and subsequent nucleotide sequencing of the 11 beta HSD2 gene from the patient and his family members revealed that the patient has a compound heterozygous mutation of this gene. In 1 allele, an undescribed single nucleotide transition in codon 208 in exon 3 resulted in a substitution of arginine to histidine (CGC to CAC: R208H). In the other allele, a deletion of 3 nucleotides in codons 337-338 in exon 5 resulted in a substitution of arginine to histidine and a deletion of tyrosine residue (CGCTAT to CAT: R337H, delta Y338), which has been previously shown to abolish 11 beta HSD2 enzyme activity. A chloramphenicol acetyltransferase assay-based expression study involving the mineralocorticoid receptor indicated that the novel R208H mutation eliminates the enzymatic activity of 11 beta HSD2. From the genetic analysis of 50 healthy subjects, the novel R208H mutation was unlikely to be due to polymorphism. Together, these results indicate that this patient is a compound heterozygote for the mutation in the 11 beta HSD2 gene (R208H and R337H, delta Y338) and that these mutations inactivate the 11 beta HSD2 function and give rise to clinically manifest AME.

Magnetic resonance imaging in diagnosis of right coronary arteriovenous fistula--a case report

We describe a patient with a right coronary arteriovenous fistula in whom magnetic resonance imaging (MRI) was useful in establishing the diagnosis. In a 36-year-old woman, T1 spin echo MRI demonstrated a massively dilated coronary arteriovenous fistula connecting the right coronary artery to the right atrium. The cine field echo technique showed a continuous shunt flow within the fistula as documented by the flow void throughout the cardiac cycle. These findings were confirmed by cardiac catheterization. We conclude that MRI is useful not only in detecting a coronary arteriovenous fistula but also in identifying its origin and the drainage site.

[Familial male-limited precocious puberty]

Familial male-limited precocious puberty (FMPP) is a gonadotropin-independent disorder that is inherited in an autosomal dominant, male-limited pattern. Affected males generally exhibit signs of puberty by the age of 4 years. Testosterone production and Leydig cell hyperplasia occur autonomously in context of prepubertal levels of luteinizing hormone (LH). The LH receptor is a member of the family of G-protein-coupled receptors. Thus far, eleven constitutively activating mutations of the LH receptor gene, which result in high basal cyclic AMP levels, have been identified in pedigree with FMPP and in sporadic cases. It has been suggested that some of the mutations have effects on the Gq coupling and phospholipase-C activation in addition to their effects on Gs coupling and activation of adenylate cyclase.

Serum protein determination by high-performance gel-permeation chromatography

A general high-performance gel-permeation chromatography (HPGPC) method was developed to determine protein in human serum with improved sensitivity and speed. The optimum UV wavelength for protein detection was found to be 210 nm, by comparing the protein values obtained by varying the UV wavelength of the HPLC detection system with the protein values obtained from spectrophotometric protein assays, i.e., the bicinchoninic acid (BCA) method and the biuret method. The analysis time was less than 1 min. Since this HPGPC serum protein assay method is simple and rapid, it is expected to be particularly well adapted for use in clinical laboratories.

Platelet activating factor causes hyperconstriction at the inflammatory coronary lesions in pigs in vivo

BACKGROUND

Although platelet activating factor (PAF) is an important vasoactive substance released from activated leukocytes, platelets and endothelial cells, little is known about its effect at the inflammatory coronary lesions in vivo.

OBJECTIVE

To examine the coronary vasomotor responses to PAF at the inflammatory lesions in our swine model with interleukin-1 beta (IL-1 beta) in vivo.

METHODS

Under aseptic conditions, the proximal segment of the porcine left coronary artery was dissected and wrapped with cotton mesh absorbing IL-1 beta. Two weeks after the operation, coronary vasomotion in response to intracoronary administration of 0.3 and 1 microgram/kg PAF, 1, 3, and 10 micrograms/kg serotonin, 1, 3 and 10 micrograms/kg histamine, and 5 and 50 micrograms/kg prostaglandin F2 alpha was examined by coronary arteriography.

RESULTS

At the IL-1 beta-treated site, PAF, serotonin and histamine, but not prostaglandin F2 alpha, caused hyperconstriction (n = 8). A synergy of the vasoconstricting effects of PAF and serotonin was also noted (n = 6). Administration of TCV-309, a selective PAF receptor antagonist, abolished the hyperconstrictive responses to PAF but not those to other agonists (n = 6). The PAF-induced coronary hyperconstrictions were significantly inhibited by administrations of the protein kinase C inhibitors staurosporine and sphingosine, but not by administrations of ryanodine, thapsigargin, or indomethacin (n = 4 each).

CONCLUSIONS

These results indicate that PAF causes hyperconstriction at the inflammatory coronary lesions in vivo by itself as well as in a synergistic manner with serotonin and that the PAF-induced hyperconstrictions are substantially mediated by a protein kinase C-dependent pathway in vivo.

Homozygous Q258X mutation in the steroidogenic acute regulatory gene in a Japanese patient with congenital lipoid adrenal hyperplasia

Congenital lipoid adrenal hyperplasia (CLAH) is an autosomal recessive disorder characterized by impaired synthesis of all adrenal and gonadal steroid hormones. It has recently been reported that mutations in the steroidogenic acute regulatory protein (StAR) gene cause CLAH. We analyzed the nucleotide sequences of exon 7 of the StAR gene in a Japanese CLAH patient with a karyotype of 47,XYY, and her parents. The patient was homozygous for a nonsense mutation Q258X, which changed codon 258 (CAG) encoding Gln to the stop codon TAG, and the her parents were heterozygous for the Q258X mutation. Since the Q258X mutation destroys a MvaI site normally present in the StAR gene sequence, we confirmed the Q258X mutation by means of the restriction endonuclease MvaI digestion of the PCR products. Endocrinological examinations of the parents revealed normal responses of adrenal steroid hormones to exogenous adrenocorticotropin administration, confirming the failure to detect the heterozygous carriers of CLAH by hormonal evaluation.

Urinary biotinidase and alanine excretion in patients with insulin-dependent diabetes mellitus

Twenty-four-hour urine specimens from 21 juvenile insulin-dependent diabetics and 10 healthy controls were compared with respect to biotinidase activity and alanine content. Urinary biotinidase activity was analysed by a newly developed high-performance liquid chromatography (HPLC) method. It was found that the excretion of biotinidase in urine was elevated in diabetics (7.02 mU/d; p < 0.005) as compared with controls (not detectable). Alanine excretion was also found to increase (p < 0.01) in diabetics. Biotinidase excretion in diabetics was correlated with alanine excretion (rS = 0.667; p < 0.01), but not with protein, albumin or N-acetyl-beta-glucosaminidase excretion. The simultaneous elevation of urinary biotinidase and alanine excretion in juvenile diabetics suggests that changes in kidney metabolism arise in the early stages of diabetes.

Prognostic factors and a predictive model of follicular lymphoma: a 25-year study at a single institution in Japan

The incidence of follicular lymphoma in Japan is far lower than that in western countries, and no large-scale clinicopathologic studies on this neoplasm have been conducted in Japan. We reviewed histopathological specimens from 118 of 135 patients who had been diagnosed as having follicular lymphoma between 1968 and 1993. Prognostic factors influencing survival were analyzed using univariate and multivariate analyses. Factors that were independently significant upon multivariate analysis were incorporated into a predictive model. Ninety-three patients (78.8%) had a confirmed diagnosis of follicular lymphoma. Twenty-one of the remaining 25 patients were categorized as having other lymphoma subtypes, and four patients showed indefinite findings or those suggesting diseases other than lymphoma. Major characteristics of the 93 patients with follicular lymphoma were a median age of 53 years (20-85); 59 males (63%) and 34 females (37%); small cleaved cell type in 33 (35%), mixed cell type in 41 (44%) and large cell type in 19 (20%); stage I/II in 41 (44%) and stage III/IV in 50 (54%). Overall survival was 71% at 5 years, 58% at 10 years, and 43% at 15 years with a median survival of 13.3 years. Multivariate analysis revealed that two variables, age (>60) (P=0.001) and the serum LDH level (>1 x normal value) (P=0.026), were unfavorably significant prognostic factors influencing survival. The predictive model using these two variables identified three risk groups with estimated five-year survival rates of 88.5%, 56.8%, and 31.5%. Age and serum LDH were significant predictors of survival in Japanese patients with follicular lymphoma. Our predictive model may provide a basis for future therapeutic trials against follicular lymphoma in Japan.

[Comparative neuromuscular inhibitory effects of volatile anesthetics]

Neuromuscular inhibitory effects of three volatile anesthetics were compared using muscular compound action potential (CAP) which was elicited from gastrocnemius muscle by sciatic nerve stimulation in cats. The amplitude of CAP evoked by 0.1 Hz single stimulation and eight repetitive stimulation (RS8) with frequencies ranged from 2 to 100 Hz were recorded as control values. After obtaining the control values, 0.5, 1, 1.5 and 2 MAC of halothane (n = 5), isoflurane (n = 7) or sevoflurane (n = 10) were administered respectively for 30 minutes and the single CAP amplitude and the responses evoked by RS8 were observed. Only after the inhalation of sevoflurane 2MAC, mean single CAP amplitude was depressed significantly to 82.6% of control. Under halothane and isoflurane anesthesia, the depression of single CAP amplitude was not observed at any concentration. Additionally, the most prominent fading responses were observed in sevoflurane-inhaled cats when the results obtained by 100Hz-RS8 were compared under 2MAC of three different anesthetic agents. Our results suggest that sevoflurane has the most potent neuromuscular inhibitory effect through both post- and presynaptic inhibitory mechanisms.

High-performance liquid chromatographic determination of lipoamidase (lipoyl-X hydrolase) activity with a novel substrate, lipoyl-6-aminoquinoline

An HPLC lipoamidase (lipoyl-X hydrolase) assay method has been developed, which uses a novel fluorescent substrate, lipoyl-6-aminoquinoline (LAQ). LAQ is synthesized from lipoic acid and 6-aminoquinoline (AQ) through lipoyl chloride as an intermediate and is conveniently purified by washing with chloroform-methanol. Mechanistic studies on the time-course, the dependence on enzyme and substrate concentrations were performed by using LAQ and a model enzyme (milk lipoamidase). Moreover, this method was successfully applied to the direct determination of the lipoamidase (LAQ hydrolase) activity in samples of human liver, milk, stools and porcine serum. Using this novel synthetic lipoyl substrate, we demonstrated that LAQ hydrolase was present in some specific tissues; LAQ hydrolase was solely present in the grey matter and not in the white matter in the human cerebrum. Furthermore, LAQ hydrolase activity was shown to increase in human liver cancer. Thus, this enzyme assay method is expected to be applicable to the tissue distribution study and also to the basic research on human diseases such as cancer.

Serum levels of cytokines in patients with untreated primary lung cancer

To evaluate the relationships between serum endogenous cytokine levels and their clinical implications in cancer patients, we measured the serum levels of endogenous granulocyte colony-stimulating factor (G-CSF), granulocyte-macrophage colony-stimulating factor (GM-CSF), macrophage colony-stimulating factor (M-CSF), and interleukin 6 (IL-6) in patients with untreated primary lung cancer. The serum G-CSF level was measured using a chemiluminescent ELISA, and the other cytokine levels were measured using ELISA. Fifty healthy adults and 183 patients with primary lung cancer were studied. The mean M-CSF level in the lung cancer patients (1106.4 units/ml) was significantly higher than that in the healthy adults (836 units/ml, P = 0.0001). In patients with large cell carcinoma, endogenous G-CSF, M-CSF, and IL-6 levels were significantly higher than those in patients with carcinomas of other cell types (P < 0.05). Univariate analysis showed that survival of 159 non-small cell lung cancer patients with high (more than cutoff level) G-CSF, M-CSF, and IL-6 levels was significantly poorer than that of patients with low levels (Wilcoxon's test, P = 0.018, P < 0. 0001, and P < 0.0001, respectively). Survival of patients with high levels of two or more cytokines was poorer than that of those with high levels of one cytokine or normal cytokine levels (P < 0.0001). Multivariate analysis using Cox's proportional hazards model showed that high M-CSF and C-reactive protein levels correlated significantly with poor survival (P = 0.037 and 0.037, respectively). Our preliminary data suggest that high M-CSF levels in non-small cell lung cancer may be of poor prognostic value.

Screening for PIT1 abnormality by PCR direct sequencing method

PIT1 abnormality is defined as a genetic abnormality in the PIT1 gene, which encodes a pituitary specific transcription factor Pit-1/GHF-1.PIT1 abnormality has been reported in several patients displaying either complete or incomplete deficiency of thyrotropin (TSH), growth hormone (GH), and prolactin (PRL) in either familial or sporadic cases. To see if there are abnormalities in the PIT1 gene in patients with incomplete TSH, GH, and PRL deficiency, we utilized a PCR direct sequencing method to determine the Pit-1/GHF-1 coding sequence. A total of 15 patients, 1 patient from a family with TSH and GH deficiency, 3 patients with TSH, GH, and PRL deficiency, and 11 patients treated with both human GH (hGH) and thyroid hormone were studied. In one patient of combined pituitary hormone deficiency, the Arg-271-Trp mutation was detected. Since both of the parents did not harbor this mutation, it is a de novo germ line mutation. No mutation was detected in the other patients, showing that PIT1 abnormality is not a frequent cause of GH deficiency.

Plasma clearance, tissue uptake and expression of pituitary peptide 23/pancreatitis-associated protein in the rat

The secretion of peptide 23 by rat pituitary cells is stimulated by growth hormone-releasing hormone and inhibited by somatostatin. Recent cloning of the cognate cDNA for peptide 23 revealed that it is identical to pancreatitis-associated protein (PAP). In the present study, the clearance and tissue uptake of recombinant peptide 23/PAP in normal adult male rats was assessed. The plasma half-life of recombinant peptide 23/PAP was 4.8 +/- 1.4 (S.D.) min. Maximal accumulation of radio-labelled peptide 23/PAP was observed in the kidney, stomach, small intestine and pancreas whereas negligible uptake was seen in the liver, lung or heart. Peptide 23/PAP was detected in a variety of tissue extracts using a radioimmunoassay. Extracts of ileum contained the highest concentrations of peptide 23/PAP. In situ hybridization analysis showed that peptide 23/PAP mRNA was highly expressed in the columnar epithelial cells of ileum, jejunum and duodenum. These observations demonstrate that peptide 23/PAP, a protein previously thought to be of pituitary origin, is widely expressed in the gastrointestinal tract and that it is rapidly removed from the circulation by the kidney and by tissues which express peptide 23/PAP.

Transesophageal echocardiographically detected atherosclerotic aortic debris in a patient with systemic embolism following coronary angiography

Transesophageal echocardiography (TEE) has enabled detection of the cardiac source of systemic emboli. We report the case of a patient who manifested systemic, multiple embolization in the kidney, skin, and upper gastrointestinal tract following coronary angiography. TEE allowed visualization of the atherosclerotic debris in the thoracic aorta. The clinical picture of the patient was consistent with that of cholesterol embolism. We recommend that patients with extensive atherosclerotic disease should undergo TEE before cardiac catheterization or other invasive procedures involving the aorta are carried out.

Age-related changes in peptide-23/pancreatitis-associated protein and pancreatic stone protein/reg gene expression in the rat and regulation by growth hormone-releasing hormone

Peptide-23 is a 16-kilodalton protein secreted by rat pituitary cells that was first identified because it was regulated by GRF and somatostatin in a similar fashion to GH. Cloning of peptide-23 complementary DNA revealed that it is identical to pancreatitis-associated protein (PAP) and a member of the c-lectin gene family. We examined the expression of peptide-23/PAP and a structurally related protein, pancreatic stone protein (PSP/reg), in the rat gastrointestinal tract. Here we report age-related changes in the expression and GRF regulation of peptide-23. Both peptide-23/PAP messenger RNA (mRNA) and PSP/reg mRNA were virtually undetectable in the small intestine of newborn and 1- and 2-week-old rats. A dramatic increase in the expression of both genes was seen at the time of weaning in the third week postpartum. The abundance of both of these mRNA decreases after 3 and 6 months of age. Peptide-23/PAP mRNA is most abundant in the ileum, whereas PSP/reg is maximally expressed in the pancreas and duodenum. Human GRF analog pellets were implanted sc into adult male rats for 2 weeks to study the chronic effects of GRF on the expression of these genes. Both peptide-23/PAP and PSP/reg mRNA levels in duodenum and jejunum were increased in these rats compared with levels in control rats. However, no increase in peptide-23/PAP mRNA in response to GRF treatment was seen in the ileum, where the level of expression of this gene is very high, and GRF had no effect on peptide-23/PSP expression in the heart, pituitary, or hypothalamus, where expression is normally undetectable. In situ hybridization was used to localize peptide-23/PSP in the small intestine and pancreas of GRF-treated rats. An increase in peptide-23/PAP mRNA was restricted to acinar cells close to islets, whereas little expression was seen in acinar cells distant from islets, suggesting that either peptide-23/PAP may have some paracrine action on the islets, or alternatively, an islet-derived factor may function as a paracrine modulator of peptide-23/PAP expression. These data demonstrate that GRF modulates peptide-23/PAP expression in the gastrointestinal tract in a similar fashion to that previously reported for pituitary cells in primary culture.

Molecular cloning and expression of peptide 23, a growth hormone-releasing hormone-inducible pituitary protein

Peptide 23 is a newly identified protein secreted by rat pituitary cells in primary culture. Although the secretion of this protein is stimulated by GH-releasing hormone and inhibited by somatostatin, the N-terminal amino acid sequence of peptide 23 shows no homology to rat GH. Using the polymerase chain reaction technique, we cloned and sequenced the peptide 23 complementary DNA (cDNA). By means of the mixed oligonucleotide-primed amplification of cDNA technique, primers corresponding to the NH2-amino acid sequence of peptide 23 were used to amplify, clone, and sequence a 74-basepair cDNA of peptide 23. This polymerase chain reaction product was then used as a primer to amplify the complete peptide 23 cDNA by means of the rapid amplification of cDNA ends procedure. The cDNA of peptide 23 obtained by the rapid amplification of cDNA ends procedure contained 777 nucleotides and encoded a 175-amino acid protein with a 26-amino acid putative signal peptide. The calculated mol wt of the mature protein (16,613 daltons) was in good agreement with that estimated by polyacrylamide gel electrophoresis (16 kilodaltons). Northern blot analysis revealed a major messenger RNA species of about 0.9 kilobase and a minor species of about 1.7 kilobases in cultured rat anterior pituitary cells. In rats, peptide 23 was most abundant in the pancreas and gastrointestinal tract. A GenBank sequence search revealed complete sequence identity between peptide 23 cDNA and pancreatitis-associated protein cDNA, an approximately 73% homology with human hepatocellular carcinoma cDNA from human hepatocellular carcinoma, 64% homology with bovine pancreatic thread protein cDNA, and 55% homology with rat and human reg cDNAs, which have been reported to be expressed in regenerating pancreatic islets. Therefore, peptide 23 is identical to pancreatitis-associated protein and a member of the C-type lectin supergene family.

Expression of pituitary peptide 23 in the rat uterus: regulation by estradiol

Peptide 23 was first identified in pituitary cell conditioned medium as a secreted protein which was regulated in a similar fashion to growth hormone. It was subsequently found to be a member of the C-type lectin gene superfamily and identical to pancreatis associated protein (PAP). It is widely expressed in the gastrointestinal tract. Our present study demonstrates that peptide 23 gene is also expressed in the uterus. Peptide 23/PAP mRNA was at highest levels during estrus and was not detectable in the immature rat uterus. A single injection of 17 beta-estradiol resulted in a transient induction of peptide 23/PAP mRNA in ovariectomized rats whereas a sustained induction was seen with diethylstilbestrol implants. In situ hybridization localized peptide 23/PAP mRNA to the luminal epithelial cells. During gestation, peptide 23/PAP mRNA was detected only in the uterine samples from day 12 to 18 of pregnancy with maximal expression on day 12. Peptide 23 expression was confined to the uterus itself and not expressed in either the decidua or the fetal tissues. PSP/reg, another closely related member of the C-lectin gene family was not expressed in any of these uterine tissues. These results indicate that estrogen may act as a physiological regulator of peptide 23 in the uterus and suggests that this protein may have some role in estrogen action.