Pituitary somatotroph adenoma producing growth hormone (GH)-releasing hormone (GHRH) with an elevated plasma GHRH concentration: a model case for autocrine and paracrine regulation of GH secretion by GHRH

An acromegalic patient with a pituitary somatotroph adenoma associated with an extremely elevated plasma GHRH concentration is presented. The preoperatively high concentration of plasma GHRH returned to the normal level after successful removal of the adenoma. GHRH production and GHRH gene expression were confirmed in the adenoma by studies including immunohistochemistry and in situ hybridization. Expression of GHRH receptor messenger ribonucleic acid was verified by in situ hybridization. Immunohistochemical double staining for GH and GHRH revealed their colocalization in single adenoma cells. These findings confirmed the autocrine or paracrine regulation of GH production by endogenous GHRH from the adenoma cells. GHRH synthesis in the pituitary gland has recently been demonstrated, however, there have been no previous reports of a GHRH-producing pituitary somatotroph adenoma associated with an elevated plasma GHRH concentration. The existence of this GHRH-producing adenoma suggests a possible role of locally generated GHRH in the progression of somatotroph adenomas, i.e. the monoclonally established somatotroph adenomas develop further under the influence of locally produced GHRH. The demonstration of GHRH production by this somatotroph adenoma is of importance in clarifying the autocrine or paracrine regulation of GH production and the progression of human somatotroph adenomas.

DNA mismatch repair deficiency in curatively resected sextuple primary cancers in different organs: a molecular case report

A male patient synchronously or metachronously underwent six curative resections after diagnoses of cancers in the rectum, urinary bladder, stomach, colon, liver and lung. Five cancers, excluding early colon cancer, were analyzed for instability in seven microsatellite markers and in transforming growth factor beta type II receptor, insulin-like growth factor II receptor and BAX. All analyzed cancers had replication errors and instability in at least one target gene. These results suggest that abnormal DNA mismatch repair system plays a major role in the occurrence of multiple primary cancers in this case.

Cutting edge: an inducible sialidase regulates the hyaluronic acid binding ability of CD44-bearing human monocytes

Previous studies established that variable degrees and types of glycosylation can account for differences in the ability of CD44 to function as a receptor for hyaluronic acid. We have now used neuraminidase treatment to conclude that sialylation negatively regulates CD44 on the human monocytic cell line THP-1 and peripheral blood monocytes. Both of these cell types displayed increased receptor activity after overnight culture with LPS. Of particular interest, the sialidase inhibitor 2-deoxy-2, 3-dehydro-N-acetylneuraminic acid completely blocked the LPS induced recognition of hyaluronic acid by THP-1 cells. Furthermore, acquisition of this characteristic paralleled induction of one type of sialidase activity. Monocytes may be capable of enzymaticly remodeling cell surface CD44, altering their ability to interact with the extracellular matrix.

Enterochromaffin-like cells, a cellular source of uroguanylin in rat stomach

Uroguanylin is an endogenous peptide ligand for guanylyl cyclase-C, an apical membrane receptor predominantly located in the gastrointestinal epithelium. It regulates intestinal and renal fluid and electrolyte transport through the second messenger, cyclic GMP. Uroguanylin messenger RNA and the peptide are present in rat stomach, but the cellular source has not been identified. We separated gastric mucosal cells by size into seven fractions (F1-F7) and enriched endocrine cells into F1-F3 using counterflow elutriation. Uroguanylin messenger RNA and peptide were found in F1-F3 by Northern blot analysis and an RIA specific for rat uroguanylin. Uroguanylin-producing cells were identified as endocrine cells by immunocytochemical methods using antisera for uroguanylin, prouroguanylin, and chromogranin A, as well as by in situ hybridization cytochemistry. Double-staining showed that uroguanylin and histamine are colocalized in enterochromaffin-like (ECL) cells that release histamine, leading to the stimulation of gastric acid secretion from parietal cells. Uroguanylin is synthesized in ECL cells. These findings should contribute to elucidating the physiological functions of ECL cells and the cyclic GMP-mediated gastric ion transport mechanism.

Widespread distribution of orexin in rat brain and its regulation upon fasting

Orexins A and B, novel hypothalamic peptides encoded by a single mRNA transcript, stimulate food intake. Two antisera specific for the individual rat orexins were prepared and sensitive RIAs developed. Orexin-A and -B are abundant in the rat hypothalamus, medulla-pons, and midbrain-thalamus, and moderately abundant in the cerebral cortex. No orexins were found in the adipose tissues or visceral organs studied. The major endogenous molecule of orexin-A is a 33-amino-acid peptide, and that of orexin-B a 28-amino-acid peptide. After a 48 h fast, the orexin-A and -B contents of the lateral hypothalamus exhibited a trend to increase, but the contents of other brain tissues significantly decreased as compared with the fed control rats. No circadian variations in the orexin contents were found in the brain. The extensive and abundant distribution of orexins in the brain and changes in their contents upon fasting suggest that they serve as neuromodulators and/or neurotransmitters that regulate feeding behavior through interaction with diverse neural networks.

Detection of a new TIGR gene mutation in a Japanese family with primary open angle glaucoma

PURPOSE

To describe a new mutation of the trabecular meshwork-inducible glucocorticoid response protein (TIGR) gene in a Japanese patient with familial primary open angle glaucoma (POAG).

METHODS

Standard ocular examinations were performed on the 44-year-old patient, his sister, and mother. DNA sequencing was used to identify the mutation. We also developed a DNA diagnostic method for detecting this missense mutation by polymerase chain reaction-induced mutation restriction analysis (PCR-IMRA).

RESULTS

The patient, father, and sister had been diagnosed as having POAG. The patient and his sister had a Thr448Pro mutation (C-->A transition at the nucleotide number 1419) in exon 3. This mutation has not been reported before.

CONCLUSIONS

Gene analysis is promising for an early diagnosis among the family members of familial POAG patients and will contribute to early therapy before an occurrence of irreversible visual impairment.

Down regulation of the prepro-orexin gene expression in genetically obese mice

The gene expression of prepro-orexin, the precursor of orexin-A and orexin-B which are hypothalamic pepetides that are associated with feeding behavior, were examined in control (C57B1/6J) and obese (ob/ob and db/db) mice using in situ hybridization histochemistry. Orexins are identical with hypocretins that have been identified by directional tag PCR subtractive hybridization method. In situ hybridization histochemistry revealed that the expression of the prepro-orexin gene was significantly decreased in ob/ob and db/db mice compared with control mice. The gene expression of neuropeptide Y (NPY), a potent feeding stimulant, is known to be increased in ob/ob and db/db mice. The expression of the NPY gene in the arcuate nucleus was increased remarkably in ob/ob and db/db mice compared to that of control mice. An immunohistochemical study showed that orexin-A and orexin-B immunoreactive neurons exhibited in the lateral and posterior hypothalamic areas and the perifornical nucleus were distributed similarly in control, ob/ob and db/db mice. These results suggest that the regulatory mechanism of orexins/hypocretins may be different from that of NPY in genetically obese mice.

[A study of human beta-defensin-1 and human beta-defensin-2 in airway mucosal defense]

Human beta-defensin-1 (hBD-1) and human beta-defensin-2 (hBD-2) are new members of the defensin family. In this study, we investigated their gene expressions in the respiratory epithelial surface of the human lung and their bactericidal activities against Escherichia coli. Both hBD-1 and hBD-2 gene transcripts were detected in human lung tissue and cellular component of bronchoalveolar lavage fluid by reverse transcription-polymerase chain reaction. Synthetic hBD-1 and hBD-2 had dose-dependent bactericidal activities against E. coli. The concentration for the 50% colony reduction of hBD-2 was 0.46 nmol/ml, that for HNP-1 2.15 nmol/ml, and hBD-1 99.3 nmol/ml under conditions nearly the same as in human bronchial airway surface liquid. We prepared an antiserum against hBD-2 and established a highly sensitive radioimmunoassay and quantified plasma hBD-2 concentrations in normal subjects and patients with pneumonia. The plasma concentration of hBD-2 in normal individuals was 8.3 +/- 0.9 fmol/ml (mean +/- SE). The mean hBD-2 plasma concentration for the 12 patients with bacterial pneumonia in the acute stage was 34.2 +/- 3.4 fmol/ml, significantly higher than normal individuals, and returned to the normal range after recovery. The presence of hBD-1 and hBD-2 in the airway tract and their bactericidal activity suggest that they function in innate airway mucosal defense.

Orexins, orexigenic hypothalamic peptides, interact with autonomic, neuroendocrine and neuroregulatory systems

We determined the immunohistochemical distributions of orexin-A and orexin-B, hypothalamic peptides that function in the regulation of feeding behavior and energy homeostasis. Orexin-A and -B neurons were restricted to the lateral and posterior hypothalamus, whereas both orexin-A and -B nerve fibers projected widely into the olfactory bulb, cerebral cortex, thalamus, hypothalamus, and brainstem. Dense populations of orexin-containing fibers were present in the paraventricular thalamic nucleus, central gray, raphe nuclei, and locus coeruleus. Moderate numbers of these fibers were found in the olfactory bulb, insular, infralimbic and prelimbic cortex, amygdala, ventral, and dorsolateral parts of the suprachiasmatic nucleus, paraventricular nucleus except the lateral magnocellular division, arcuate nucleus, supramammillary nucleus, nucleus of the solitary tract, and dorsal motor nucleus of the vagus. Small numbers of orexin fibers were present in the perirhinal, motor and sensory cortex, hippocampus, and supraoptic nucleus, and a very small number in the lateral magnocellular division of the paraventricular nucleus. Intracerebroventricular injections of orexins induced c-fos expression in the paraventricular thalamic nucleus, locus coeruleus, arcuate nucleus, central gray, raphe nuclei, nucleus of the solitary tract, dorsal motor nucleus of the vagus, suprachiasmatic nucleus, supraoptic nucleus, and paraventricular nucleus except the lateral magnocellular division. The unique neuronal distribution of orexins and their functional activation of neural circuits suggest specific complex roles of the peptides in autonomic and neuroendocrine control.

Activation of lymphocytes and increased interleukin-5 levels in bronchoalveolar lavage fluid in acute eosinophilic pneumonia

Acute eosinophilic pneumonia (AEP) is a recently described illness and the number of case reports has increased during the last few years. However, the role of interleukin (IL)-5 and activated lymphocytes in the pathogenesis or activity of AEP is still not clear. The clinical features, lymphocyte surface analysis and IL-5 concentrations in bronchoalveolar lavage fluid (BALF) and peripheral blood (PB) of a young female patient with AEP are described before and at 2 weeks, 4 weeks and 6 months after a 3-day course of i.v. methylprednisolone. Serum and BALF concentrations of IL-5 before treatment were 5,200 and 8,400 pg x mL(-1), respectively. Activated CD4 lymphocytes bearing CD25 and human leukocyte antigen (HLA)-DR in BALF were higher than in PB. Treatment caused a rapid fall in these cells and levels of IL-5 in BALF returned to normal levels in parallel with clinical improvement. There was no evidence of recurrence after cessation of steroid therapy. In contrast, eosinophilia in BALF persisted for 4 weeks after steroid therapy in spite of normalization of the chest radiograph and arterial blood gases. The number of CD8+CD11b- (suppressor/cytotoxic) T-cells subsequently increased while the number of CD8+CD11b+ cells decreased. These results suggest that activated CD4 cells and interleukin-5 elevation contribute to the development of acute eosinophilic pneumonia rather than persistent eosinophilia in the lung and that a short course of steroid therapy may effectively control acute eosinophilic pneumonia.

123I-MIBG myocardial scintigraphy in diabetic patients: relationship with 201Tl uptake and cardiac autonomic function

PURPOSE

To investigate the influence of diabetic myocardial damage (suspected myocardial damage; SMD) diagnosed by 201Tl-SPECT and diabetic cardiac autonomic neuropathy (AN) on myocardial MIBG uptake in patients with non-insulin-dependent diabetes mellitus (NIDDM).

SUBJECTS AND METHODS

Eighty-seven diabetic patients divided into four subgroups: 23 with SMD (+) AN (+); 19 with SMD (+) AN (-); 27 with SMD (-) AN (+); 18 with SMD (-) AN (-), and 10 controls were studied. Both planar and SPECT images were taken at 30 minutes (early) and 3 hours (delayed) after 123I-MIBG injection. The heart to mediastinum uptake ratio (H/M) and washout ratio of 123I-MIBG (WR) were obtained from both planar images. On SPECT images, the total uptake score (TUS) was obtained by the 5 point score method by dividing the myocardium into 20 segments on visual analysis. Similarly, the difference between the 201Tl image and the 123I-MIBG image in TUS was taken as the difference in the total uptake score (delta TUS) representing cardiac sympathetic denervation without SMD.

RESULTS

On both early and delayed planar images, the mean H/M value in the subgroups of diabetic patients was significantly lower in the SMD (+) AN (+) group than in the control group, but among those subgroups, there was statistically significant difference between the SMD (+) AN (+) and SMD (-) AN (-) groups only on the delayed images. Regarding the WR value, there was no statistically significant difference among subjects. On SPECT image analysis, the diabetic subgroup with AN or SMD had statistically significant lower values for TUS than those of the control group. Among diabetics, there was a statistically significant differences between SMD [+] AN [+] and SMD [-] AN [-] on both early and delayed images. Similarly, the SMD [+] AN [-] group also had significantly lower values than those of SMD [-] AN [-] on early images. Regarding delta TUS, there was a statistically significant differences between AN [+] subgroups and controls. Similarly, the mean value for delta TUS was much higher in AN [+] subgroups than in AN [-] subgroups with or without SMD in diabetes mellitus.

CONCLUSION

123I-MIBG myocardial uptake is affected by both SMD and cardiac autonomic neuropathy. Based on the finding that delta TUS was much higher in AN [+] subgroups and there was no statistically significant difference between SMD [+] AN [+] and SMD [-] AN [+] subgroups, a decrease in myocardial 123I-MIBG uptake might progress independently of SMD.

Tissue distribution, cellular source, and structural analysis of rat immunoreactive uroguanylin

Uroguanylin, a member of the guanylin peptide family, acts on guanylyl cyclase C (GC-C) to regulate intestinal and renal fluid and electrolyte transport through the second messenger, cGMP. Using an antiserum raised against synthetic rat uroguanylin, we established an RIA and identified three endogenous molecular forms in the intestine and kidney: a 15-amino acid uroguanylin, an 18-amino acid uroguanylin that is a monobasic processing product, and a 9.4-kDa prouroguanylin. Prouroguanylin is the major molecular form in these two tissues, whereas only 15-amino-acid uroguanylin is present in the urine. Rat uroguanylin is most abundant in the proximal small intestine, its content decreasing toward the colon. Uroguanylin is present immunohistochemically in the endocrine cells in the intestine and stomach, B cells in the pancreatic islets, and tubular epithelial cells in the kidney. Uroguanylin has a widespread tissue distribution and is located in cells that function in an endocrine, paracrine, and/or luminocrine (luminal secretion) fashion. Uroguanylin may have physiological functions other than the regulation of fluid and electrolyte transport in the intestine and kidney.

[Factors that influence the serum of atrial natriuretic peptide and brain natriuretic peptide concentrations--is there a specific marker for senile patients?]

To evaluate factors that influence of atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) levels in elderly people, we measured those levels in 54 men and 148 women (84.4 +/- 0.5 years old), and looked for associations of ANP and BNP with clinical factors and echocardiographic variables [left ventricular mass index and atrial to-early peak transmitral velocity ratio (A/E)]. ANP and BNP levels were 1.6 and 6.5 times higher than average. Sex was not a significant factor. We also looked for a link between cardiac rhythms and levels of ANP and BNP. Patients with atrial fibrillation had significantly higher levels of ANP and BNP than did patients with sinus rhythm. ANP and BNP levels were abnormally high in patients with left ventricular hypertrophy (LVH). We could measured A/E in 161 of 202 subjects; 154 of 157 subjects with normal LV systolic function had A/E > 1 which indicates abnormally low in LV diastolic function. Moreover, abnormally high LV diastolic stress might have been present, because 124 of 202 subjects had aortic regurgitation. We divided the patients into two groups: those 65 to 75 years old, and those over 75 years old. The older patients had significantly higher levels of ANP and BNP even without LVH and without a difference in renal function. Furthermore, the older patients had significantly higher levels of BNP even without LVH, with normal renal function, with sinus rhythm, with normal LV systolic function, and in NYHA Class I or II. These data indicate that ANP and BNP levels in people with senility may be associated with the cardiac rhythm and with abnormally low renal function, myocardial hypertrophy, abnormally high cardiac volume, and abnormally low diastolic function.

Pulmonary Nocardia otitidiscaviarum infection in a patient with chronic respiratory infection

We report a case of pulmonary Nocardia (N.) otitidiscaviarum infection in a 76-year-old man with chronic respiratory infection. The patient responded poorly to intravenous imipenem and oral minocycline, but later improved after treatment with trimethoprim-sulfamethoxazole. Pulmonary infection with N. otitidiscaviarum should be considered in the differential diagnosis of chronic respiratory infections. Further studies are needed to evaluate the correlation between species and drug susceptibility.

Identification of human beta-defensin-2 in respiratory tract and plasma and its increase in bacterial pneumonia

Human beta-defensin-2 (hBD-2), a novel antimicrobial peptide, was originally isolated from human skin. We found that synthetic hBD-2 has high bactericidal activity against Escherichia coli under conditions nearly the same as in human bronchial airway surface liquid. We prepared an antiserum against hBD-2 and established a highly sensitive radioimmunoassay (RIA). Reverse-phase high-performance liquid chromatography coupled with the RIA showed that hBD-2 in patients with human lung, bronchoalveolar lavage flid, and plasma. The plasma concentration of hBD-2 in patients with bacterial pneumonia was 32.1 +/- 3.7 fmol/ml (mean +/- SE), 3.9-fold that of normal individuals. By reverse transcription-polymerase chain reaction, the hBD-2 gene transcript was detected in the respiratory epithelial surface of human lung. Human beta-defensin-2 seems to function in airway mucosal defense. Our findings provide a clue to elucidate its pathophysiological significance in respiratory infection.

Severe chronic active Epstein-Barr virus infection accompanied by virus-associated hemophagocytic syndrome, cerebellar ataxia and encephalitis

We present a rare case of chronic active Epstein-Barr virus (EBV) infection showing various clinical outcomes. A 26-year-old man was admitted to our hospital due to persistent fever and dyspnea. Serologic response of the patient to EBV indicated chronic active infection. He showed pleuritis, parotitis, chronic hepatic dysfunction, disseminated intravascular coagulation, virus associated hemophaghocytic syndrome, acute rhabdomyolysis, acute renal failure, acute cerebellar ataxia, encephalitis and multiple brain abscesses. None of acyclovir, gancyclovir, prednisolone or interleukin-2 was effectual to abolish those abnormalities. This is the first report of transient cerebellar ataxia which aggravated to panencephalitis associated with chronic EBV infection.

Therapeutic effects of aldose reductase inhibitor on experimental diabetic neuropathy through synthesis/secretion of nerve growth factor

We investigated alterations in nerve growth factor (NGF) and ciliary neurotrophic factor (CNTF) contents during treatment with epalrestat, an aldose reductase inhibitor (ARI), on streptozotocin (STZ)-induced diabetic neuropathy in rats. Diabetic rats showed a statistically significant reduction in H-wave-related sensory nerve conduction velocity (HSNCV) and in NGF content in sciatic nerves during the experiment of 8 weeks. No reduction in the CNTF content in sciatic nerves was seen in the diabetic rats. The epalrestat treatment, which started 4 weeks after STZ injection, resulted in a significantly greater NGF content and faster HSNCV than those in untreated diabetic rats. But no statistically significant alterations of motor nerve conduction velocity (MNCV) or CNTF content were seen during the treatment. ARI showed the stimulating effect for NGF synthesis/secretion in rat Schwann cell culture in vitro. These findings suggest that decreased levels of NGF in diabetic sciatic nerves may be involved in the pathogenesis of diabetic neuropathy in these rats and further show that epalrestat treatment can be useful for the treatment of diabetic neuropathy through NGF-induction in Schwann cells and/or inhibition of the polyol pathway.

Identification of a novel splicing mutation and 1-bp deletion in the 17alpha-hydroxylase gene of Japanese patients with 17alpha-hydroxylase deficiency

We report studies of two unrelated Japanese patients with 17alpha-hydroxylase deficiency caused by mutations of the 17alpha-hydroxylase (CYP17) gene. We amplified all eight exons of the CYP17 gene, including the exon-intron boundaries, by the polymerase chain reaction and determined their nucleotide sequences. Patient 1 had novel, compound heterozygous mutations of the CYP17 gene. One mutant allele had a guanine to thymine transversion at position +5 in the splice donor site of intron 2. This splice-site mutation caused exon 2 skipping, as shown by in vitro minigene expression analysis of an allelic construct, resulting in a frameshift and introducing a premature stop codon (TAG) 60 bp downstream from the exon 1-3 boundary. The other allele had a missense mutation of His (CAC) to Leu (CTC) at codon 373 in exon 6. These two mutations abolished the 17alpha-hydroxylase and 17,20-lyase activities. Restriction fragment length polymorphism (RFLP) analysis with a mismatch oligonucleotide showed that the patient's mother and brother carried the splice-site mutation, but not the missense mutation. Patient 2 was homozygous for a novel 1-bp deletion (cytosine) at codon 131 in exon 2. This 1-bp deletion produces a frameshift in translation and introduces a premature stop codon (TAG) proximal to the highly conserved heme iron-binding cysteine at codon 442 in microsomal cytochrome P450 steroid 17alpha-hydroxylase (P450c17). RFLP analysis showed that the mother was heterozygous for the mutation.

[Severe bronchorrhea accompanying alveolar cell carcinoma: treatment with clarithromycin and inhaled beclomethasone]

We report the efficacy of oral clarithromycin and inhaled beclomethasone against severe bronchorrhea in a patient with alveolar cell carcinoma. A 54-year-old man produced about 500 to 900 ml of clear and egg-white-like sputum each day. Anti-cancer chemotherapy and erythromycin therapy did not reduce the volume of sputum. After administration of clarithromycin and inhaled beclomethasone, sputum volume decreased to about 300 nl each day and the patient's ability to perform daily activities improved. Two months later, clarithromycin was stopped and the patient was treated with inhaled beclomethasone alone. Sputum volume did not increase for 6 months, although the chestroentgenographic findings gradually worsened. Then the sputum volume gradually increased. Five months after the sputum volume began to increase, he was producing about 2 liters of sputum each day and died of respiratory failure. Although the levels of CA 19-9, SLX, and CEA in serum were all within the normal range, the sputum contained high levels of CA 19-9 (1,133,620 U/ml), SLX (3,000 U/ml), and CEA (283 ng/ml). In patients with bronchorrhea, measurement of tumor markers in sputum may be useful for the diagnosis of alveolar cell carcinoma.

[Idiopathic interstitial pneumonia exacerbated by alveolar hemorrhage]

A 60-year-old man, in who idiopathic interstitial pneumonia (IIP) was diagnosed in 1990, was admitted to our hospital in March 1995 with exertional dyspnea, hemosputum and fever. On chest X ray, new infiltrates in the bilateral middle lung fields were seen, in addition to reticulonodular shadows in the bilateral lower lung fields, which had been noted in 1990. Intubation was reformed because of hypoxemia, and bronchoalveolar lavage (BAL) was performed in right B6. The BAL fluid was bloody, and a diagnosis of alveolar hemorrhage was made based on the presence of many hemosiderin-laden macrophages in the fluid. After pulse therapy with methylprednisolone, the hypoxemia and chest X ray findings improved, and he was extubated. Alveolar hemorrhage may be one possible complication leading to an exacerbation of IIP.