Renal AT1 receptor: computerized quantification in spontaneously hypertensive rats and DOCA-salt rats

To assess the involvement of angiotensin II (Ang II) in the regulation of blood pressure, we investigated the alterations of renal Ang II type 1 (AT1) receptors in two different models of hypertension; i.e., in spontaneously hypertensive rats (SHR) and deoxycorticosterone acetate (DOCA)-salt hypertensive rats by using the method for quantification of in vitro macro-autoradiography (ARG). In the SHR model, although the number of cortical AT1 receptors equaled that of Wistar Kyoto (WKY) rats at 4 and 12 weeks of age, the number of medullary AT1 receptors in the 4-week-old SHR animals was significantly lower than that in age-matched WKY rats, and increased by 12 weeks of age. The renal AT1 receptor number in DOCA-salt hypertensive rats was significantly higher than that in control rats. The amount of these receptors also increased with age in both DOCA-salt hypertensive rats and control rats. These findings indicate that the development of medullary AT1 receptors in early stages of hypertension in the SHR model differs from that in WKY rats or DOCA-salt hypertensive rats. This suggests that renal AT1 receptors may contribute to the hypertension seen in the SHR group. The renal AT1 receptors appear to be up-regulated in early stages of DOCA-salt-induced hypertension as well.

Renal AT1 receptor: autoradiographic localization and quantification in rat

To elucidate the precise localization of angiotensin II (Ang II) type 1 (AT1) receptors in the kidney, we utilized in vitro macro- and micro-autoradiography (ARG) of [3H]-Ang II bindings to the Wistar rat kidney in the presence of L-158,809, a specific non-peptide AT1 receptor antagonist. Besides, we estimated the density of renal AT1 receptors using the quantification of macro-ARG. The density of [3H]-Ang II binding to renal tissue was concentration-dependent in both renal cortex and medulla. Although the addition with 500 nM arginine vasopressin and 500 nM atrial natriuretic peptide had no effect on [3H]-Ang II, the total binding of [3H] Ang II completely displaced by the addition with 500 nM unlabeled Ang II or L-158,809. Macro-ARG revealed that the amount of both Ang II and AT1 receptors in the renal medulla greatly exceeded those in the renal cortex. In the medulla, the density of these receptors was not localized on the outer medulla but was confirmed mainly to the inner medulla, especially to the inner zone and longitudinal bands. Since the density and localization of AT1 receptors was consistent with that of total Ang II receptors, it appears that AT1 receptors comprise most of the Ang II receptors in the kidney. Micro-ARG revealed that Ang II receptors were mainly located in the glomerulus and proximal tubules of the renal cortex, as well as on the circumferences of vessels and the vasa recta of the renal medulla. The present study established a method for ARG of AT1 receptors in the kidney as well as a method for quantifying the macro-ARG.

Effect of continuous infusion of vasopressin on glomerular growth response in spontaneously hypertensive rats

Vasopressin (VP) is thought to play an important role in the pressor and proliferative responses of renal glomeruli. We have utilized the spontaneously hypertensive rat (SHR) model to determine if glomerular proliferation is induced by chronic infusion of exogenous VP. SHR were continuously infused with 0.1 ng/kg/min VP (H-VP group), 1.0 ng/kg/min (H-VP group), or vehicle alone (control group) for fifteen days using osmotic minipumps, and the histological alterations and level of expression of platelet-derived growth factor B-chain (PDGF-B) and transforming growth factor (TGF)-beta1 mRNA were determined. We observed no significant differences in systolic blood pressure, heart rate, serum electrolytes, protein and creatinine among the three groups of rats, but urine volume was found to be significantly decreased, and urine osmolality significantly increased, in the H-VP group. Kidney weight was significantly higher in the H-VP and L-VP groups than in the control group, and glomerular diameter was higher in the H-VP group. When we measured mesangial injury score and cellularity in the glomeruli of these animals, we observed VP dose-dependent proliferative changes. In the immunofluorescence study, although we did not find an obvious difference in depositions of collagen types III, IV and VI, alpha-smooth muscle actin and PDGF-B among the groups, the collagen type I and TGF-beta1 increased in several glomeruli in the H-VP group. Reverse transcription polymerase chain reaction (RT-PCR) revealed no significant differences in the glomerular levels of PDGF-B mRNA among the three groups of rats, but the level of expression of TGF-beta1 mRNA was significantly higher in the L-VP and H-VP groups than in the control group. These findings suggest that VP may contribute to glomerular proliferation, and that VP may exert its effects in part through the induction of TGF-beta1 expression. These results also raise the possibility that blockade of VP receptors may be useful in the treatment of some forms of glomerular disease.

Cushing's syndrome due to unilateral adrenocortical hyperplasia

A 49-year-old woman with Cushing's syndrome due to unilateral adrenal hyperplasia is presented. She had developed obesity and menopause for 2 years, but no hypertension or hypertrichosis was observed. Although plasma adrenocorticotropin and serum cortisol levels were within normal ranges, the circadian rhythm has completely disappeared. Free thyroxine and triiodothyronine levels were decreased. Adrenocorticotropin did not respond to corticotropin-releasing hormone, and urinary excretion of 17-hydroxycorticosteroids was not suppressed by dexamethasone. Abdominal computed tomography and 131I-Adosterol scintigraphy demonstrated a unilateral functioning mass in the left adrenal gland. The resected left adrenal mass was pathologically diagnosed as the rare condition of adrenocortical nodular hyperplasia.

Manifestation of primary hyperthyroidism after pituitary adenomectomy: a case report

We report a 47-year-old Japanese man who presented with visual disturbance due to a pituitary tumor with suprasellar extension. The patient had mild secondary hypothyroidism preoperatively, and was started on administration of levothyroxine sodium immediately before transsphenoidal surgery. After the operation, levothyroxine sodium was continued for several months. Pathological examination of the surgical specimen, together with endocrinological investigation revealed that the suprasellar tumor was a FSH-producing pituitary adenoma. Since 3 months after the operation, he has developed muscle weakness and finger tremor. He was found to be thyrotoxicosis, and levothyroxine sodium was discontinued. Seven weeks after levothyroxine sodium was discontinued, thyrotoxicosis continued, with a positive thyrotropin binding inhibitory immunoglobulin (TBII) and a high diffuse 123I-uptake by the thyroid. He was started on thiamazole 30 mg/day. Although his thyroid dysfunction improved within 2 months, hyperthyroidism worsened repeatedly on attempts to discontinue thiamazole, and he required continuous treatment at 2.5 mg/day. Patients with occult autoimmune thyroiditis rarely progress to thyrotoxicosis after operations on other endocrine organs such as the adrenal or parathyroid gland. In patients with pituitary adenoma, thyroid function and thyroid-associated autoantibodies should be investigated pre- and post-operatively.

IDDM accompanied by a growth hormone-producing pituitary adenoma. A case report

CASE HISTORY

A 30-year-old Japanese man who presented with recurrent ketoacidosis caused by IDDM was found to have increased secretion of growth hormone (GH). On initial cranial magnetic resonance imaging (MRI), no pituitary lesion was detected; however, a pituitary microadenoma was found 2 years later during a repeat MRI. In spite of the hypersecretion of GH, serum IGF-I was dramatically suppressed. Transsphenoidal surgery was performed to resect the pituitary tumor that was histologically an acidophilic pituitary adenoma. Although the GH excess rapidly improved postoperatively, the IGF-I level remained low. Subsequent insulin therapy initiated 1 year after the operation elevated the serum IGF-I level to within the normal range.

DISCUSSION

The first case of coexistent IDDM and a GH-producing pituitary adenoma suggests that patients with uncontrolled IDDM may develop GH hypersecretion. Furthermore, the low IGF-I levels may be closely associated with the GH excess and with the development or progression of GH-secreting pituitary adenomas.

Effects of OPC-21268, a vasopressin V1-receptor antagonist, on expression of growth factors from glomeruli in spontaneously hypertensive rats

To assess the chronic in vivo effects of OPC-21268, a vasopressin-V1 receptor antagonist, on renal injury, we investigated the mRNA expressions of platelet-derived growth factor (PDGF) B-chain, transforming growth factor (TGF)-beta1 and proliferating cell nuclear antigen (PCNA) in the glomeruli of spontaneously hypertensive rats (SHR) treated with OPC-21268 for 3 weeks. SHR aged 10 weeks were given 2% NaCl in drinking water for 3 weeks. The OPC group was fed a 0.5% OPC-21268-containing diet for 3 weeks and the control group was given a normal diet. There were no significant changes in the time course of systolic blood pressure, heart rate, urine volume, or urinary sodium, protein and N-acetyl-beta-glucosaminidase (NAG) excretion between the two groups. Serum electrolytes, protein and creatinine levels also did not differ between the groups. The mRNA expressions of PDGF B-chain, TGF-beta1 and PCNA in the glomerulus were examined using reverse transcriptase-polymerase chain reaction (RT-PCR) methods. The mRNA expressions of PDGF B-chain and PCNA among these were significantly suppressed in the OPC group. No significant differences in renal histology including the organ weights were found between the two groups; however, the glomerular size tended to be enlarged in the OPC group. These findings suggest that chronic V1-receptor blockade directly inhibits the glomerular proliferative injury of salt-loaded SHR at the established hypertension stage.

Papillary eccrine adenoma: immunohistochemical studies of keratin expression

Despite various studies, there are serious disagreements about the cellular differentiation of papillary eccrine adenoma. In the present study, 2 specimens of papillary eccrine adenoma were analyzed by immunohistochemical techniques, using a panel of monoclonal antibodies against keratins, to elucidate its differentiation. Histopathologically, the tumor was composed of multiple tubular structures lined by two or more layers of epithelial cells. The luminal cells of the tubules were flattened or cuboidal. The former were noted in large dilated tubules. The latter were usually observed in small-to-moderate-sized tubules, and formed intraluminal papillary projections in some tubules. Immunohistochemically, there were two kinds of cuboidal cells in the luminal layers of the tubules. Most of the large dilated tubules and some of the small-to-moderate-sized tubules expressed immunophenotypes similar to those of the eccrine dermal duct. The other tubular structures, including the small tubules resembling those of syringoma, expressed immunophenotypes similar to those of the transitional portions between the dermal ducts and the secretory segments of eccrine glands. From the above comparative studies, papillary eccrine adenoma is considered to differentiate towards the dermal duct and the transitional portions between the dermal ducts and the secretory segments of eccrine glands.

Isolation of a cDNA encoding a tyrosine kinase expressed in murine skin

Tyrosine phosphorylation is widely recognized as playing an important role in cell differentiation, proliferation and carcinogenesis. We used the polymerase chain reaction (PCR) method to identify protein tyrosine kinases that were expressed in the skin. Mixed oligonucleotide probes were used to amplify and screen neonatal murine skin mRNA for clones encoding amino acid contiguities, the conservation of which is characteristic of the protein tyrosine kinase family. When the PCR products were sequenced, a novel clone encoding protein tyrosine kinase, PTK70, was identified. A full-length cDNA was isolated from a mouse thymus cDNA library. The nucleotide and deduced amino acid sequence showed that it featured src-homology (SH) 2 domain, SH3 domain and kinase domain like other src family protein tyrosine kinases, but lacked the N-terminal myristylation site and C-terminal tyrosine residue. Although the mRNA of PTK70 was detected in various tissues ubiquitously, the degree of its expression differed among tissues. Murine skin is one in which PTK70 was expressed strongly, with its expression being much stronger in the epidermis and in the cell line derived from murine keratinocytes than in those from melanoma or fibroblast cell lines. These evidences suggest that PTK70 may be involved in proliferation or differentiation of keratinocytes in the skin.

Gestational thyrotoxicosis manifesting as wernicke encephalopathy: a case report

The thyroid gland is physiologically stimulated in normal early pregnancy. This stimulated thyroid function is occasionally termed "gestational transient thyrotoxicosis". The cause of this thyrotoxicosis has been clarified to closely it associate with human chorionic gonadotropin (hCG). We encountered a pregnant patient with hyperemesis and thyrotoxicosis, who manifested symptoms of Wernicke encephalopathy. Although her serum hCG concentration transiently increased in accordance with the thyrotoxicosis, it was within normal limits for the gestational week. Both the thyrotoxicosis and a catabolic state due to the hyperemesis were thought to have induced a vitamin B1 deficiency, causing the Wernicke encephalopathy. This case suggests that pregnant patients with hyperemesis should undergo careful endocrinological and neurological evaluations.

Eosinophil-colony stimulating activity in blister fluid of bullous pemphigoid

We examined eosinophil-colony stimulating activity in blister fluid or serum obtained from patients with bullous pemphigoid using the methylcellulose semi-solid hematopoietic stem cell culture system, and demonstrated that the blister fluid of patients with bullous pemphigoid generated strong eosinophil-colony stimulating activity. This evidence suggests that eosinophil-colony stimulating activity in blister fluid probably influences the induction of eosinophilia in bullous pemphigoid.

Peripheral blood neutrophil rheology measured by micropore filtration reflects Behçet's disease activity well

Activated neutrophils take a long time to pass through a narrow lumen like a micropore, and are supposed to play a deteriorating effect on microcirculation. Although the activation of neutrophils has been demonstrated in Behçet's disease, nobody analyzes the clinical activity of the disease by means of the rheological measure of neutrophils activity. Using a micropore (pore diameter 5 microns) filtration technique, we measured the filtration time of peripheral blood neutrophils, as a rheological measure of their activity, in order to determine the clinical activity of Behçet's disease. Twenty-one patients with Behçet's disease and 14 healthy control individuals were enrolled in the study. Symptoms and signs exhibited in the patients led us to distinguish the Behçet's disease into inactive and active cases. The latter were further differentiated into cases with absent symptoms and with present symptoms. Neutrophil filtration times were 11.5 +/- 4.8 s in the active cases with present symptoms, which were significantly (P < 0.05) larger than those (7.4 +/- 1.9 s) in the active cases with absent symptoms. The latter filtration times were further significantly (P < 0.001) larger than values (3.7 +/- 1.3 s) in the inactive cases and also those (4.8 +/- 1.2 s) in control subjects. Furthermore, increases in the filtration time obtained immediately after the exposure of cells to the chemotactic peptide formyl-methionyl-leucyl-phenylalanine (FMLP: 10 nM) were significantly (P < 0.01) larger in the active cases with present symptoms than those in the active cases with absent symptoms. The latter were also larger, but not significantly, than those in the inactive cases, and were significantly (P < 0.01) larger than those in control subjects. The present results demonstrate that the micropore filtration method reflects well the rheological activity of neutrophils as well as the clinical status of Behçet's disease. This method is much better than the measurement of O2 production to differentiate between active cases with absent symptoms and inactive patients or even control individuals. Furthermore, it is more sensitive and useful than laboratory data like the CRP value or the number of peripheral blood neutrophils.

DNA-ploidy abnormalities are a reflection of the metastatic potential of malignant melanoma. Microfluorometric DNA analysis

Using DAPI (4',6-diamidino-2-phenylindole)-DNA microfluorometry, we examined the nuclear DNA-ploidy abnormalities of 15 primary malignant melanomas and their 20 corresponding metastases. They all presented the aneuploid DNA histographic pattern. When the DNA index value was calculated as the reflection of DNA-ploidy abnormalities, it was found to be significantly higher in the metastases (2.07 +/- 0.50) than in the primary tumors (1.76 +/- 0.50) (p < 0.01). Sixteen (80%) of the metastatic tumors had a higher DNA index value than their primary tumors, whereas the remaining four (20%) had a lower value. The difference in the DNA index values between the primary and metastatic tumors did not correlate to any other conventional prognostic variables (e.g. histologic type, level, and thickness). When we added 15 non-metastatic melanomas to the above 15 primary melanomas and evaluated the predictors for metastasis using multivariate stepwise logistic regression analysis, the DNA index value of the primary melanomas was found to be the most reliable risk factor. These results suggest that primary melanoma cell populations, having high DNA index values, are usually responsible for subsequent metastasis, and that hence, DNA-ploidy abnormalities of primary melanomas are likely to provide useful information for patient potential with regard to metastasis.

A case of recessive X-linked ichthyosis: scale-specific abnormalities of lipid composition may explain the pathogenesis of the skin manifestation

We analyzed the lipid content of the scales, red blood cells, and plasma from a recessive X-linked icthyosis patient. The patient's scales accumulated cholesterol sulfate, had decreased levels of free sterols, sterol esters and sphingolipids, and lacked phospholipids. Although the accumulation of cholesterol sulfate was found in the patient's red blood cells and plasma as well as in the scales, other lipid composition abnormalities were specific for scales. Such scale-specific abnormal lipid composition may explain the pathogenesis of generalized hyperkeratosis and abnormal scaling of the disease.

A case of primary hyperparathyroidism accompanying multiple myeloma

We report a case of 77-year-old woman who presented with lumbago and hypercalcemia. Multiple myeloma (MM) was first diagnosed by serum protein electrophoresis and bone marrow aspiration, but intact parathyroid hormone (intactPTH) was also found to be high in the presence of persistent hypercalcemia with anorexia and nausea. After lowering serum calcium with bisphosphonate administration, parathyroidectomy was performed. Upon histologic examination, the tumor was determined to be parathyroidal chief-cell hyperplasia and the patient was treated with melphalan and prednisolone. The relationship between MM and primary hyperparathyroidism (I degree HPT) remains unknown. Although the co-existence of MM and I degree HPT was reported in 12 reports from various parts of the world, there was only 1 report in Japan. The present case is an example of successful treatment for a complicated disorder, and suggests that patients suffering from bone pain or hypercalcemia need to be examined both endocrinologically and hematologically.

Interleukin-1 and lipopolysaccharide enhance intercellular adhesion molecule-1 expression in cell lines of human squamous cell carcinoma

We show that in two cell lines of human squamous cell carcinoma (SCC) which slightly express intercellular adhesion molecule-1 (ICAM-1), the expression is enhanced not only by interferon-gamma (IFN-gamma) and tumor necrosis factor-alpha (TNF-alpha) but also by interleukin-1 (IL-1) and lipopolysaccharide (LPS). This expression is totally dependent on the increase of ICAM-1 mRNA. This evidence contrasts with previously reported findings indicating that, in human cultured keratinocytes, ICAM-1 expression is induced by IFN-gamma and TNF-alpha, and not by either IL-1 or LPS. This result suggests that various cytokines or agents easily enhance ICAM-1 expression in SCC cell lines, and may explain the clinical finding that ICAM-1 expression increases according to the progression of malignant tumors.

Leiomyoblastoma and leiomyomatosis of the small intestine in a case of von Recklinghausen's disease

A 70-year-old patient with von Recklinghausen's neurofibromatosis 1 (NF1) developed a stomach ulcer and underwent a total gasterectomy. During the laparotomy, a leiomyoblastoma and multiple leiomyomas, which were histologically diagnosed as such later, were found in the small intestine and resected. It is quite possible that the association of gastrointestinal leiomyomas and NF1 is more than coincidental. It is thus important to take this complication into account in clinical treatment of patients with NF1.

Effect of regional myocardial perfusion abnormalities on regional myocardial early diastolic function in patients with hypertrophic cardiomyopathy

Nonuniform hypertrophy of the left ventricle is an important factor in regional diastolic dysfunction in patients with hypertrophic cardiomyopathy (HCM). However, the effect of myocardial perfusion abnormalities on regional diastolic dysfunction has not been established in patients with HCM. We investigated the relationship between regional myocardial perfusion abnormalities and regional early diastolic function in 31 patients with HCM and 8 control patients. Short-axis images of the left ventricle recorded by cine magnetic resonance imaging were divided into ten blocks. The time-to-peak-wall-thickness-thinning rate (TPWR) and the wall thickness were measured in each block. Of the 310 blocks from the patients with HCM, 242 (78%) showed normal thallium-201 uptake (group 1), 40 (13%) showed slightly decreased uptake (group 2), and 28 (9%) showed markedly decreased uptake (group 3). There was no difference in the regional wall thickness among the three groups. The TPWR was longer in patients with HCM than in control patients. It was significantly longer in group 3 (190+/-45ms) than in group 1 (167+/-36 ms) and group 2 (160+/-31 ms). (P < 0.01). The linear regression slope of the relationship between the TPWR and the regional wall thickness was significantly steeper in group 3 than in groups 1 and 2 (P < 0.05). In conclusion, abnormalities in regional myocardial perfusion, in addition to regional hypertrophy, contributed to the regional early diastolic dysfunction in patients with HCM.

In vitro macro- and microautoradiographic localization of V1 and V2 receptors in the rat kidney using OPC-21268 and OPC-31260

To elucidate the precise localization of vasopressin (VP) V1 and V2 receptors in the kidney, we utilized in vitro macroautoradiography (macro-ARG) and microautoradiography (micro-ARG) of these receptors in Wistar rat kidneys. This was done by using OPC-21268 and OPC-31260, two newly developed selective V1 (OPC-21268) and V2 (OPC-31260) receptor antagonists. For macro-ARG, 10-microm kidney sections were incubated with Tris-HCl buffer containing [3H]-VP with or without unlabeled ligand (VP, OPC-21268, or OPC-31260) at 20 degrees C for 40 min. These sections were then loaded into X-ray cassettes with Hyperfilm-[3H] and exposed in the dark for 2 months. The autoradiograms were quantitatively analyzed by using the research analysis system RAS 1,000; the V1 and V2 receptors were quantitated by subtracting the nonspecific binding (incubated with OPC-21268 and OPC-31260, respectively) from the total binding. To assess a more precise localization of the V1 and V2 receptors, we also investigated the micro-ARG of the renal V1 and V2 receptors by dipping the kidney section slides used for macro-ARG into a photographic emulsion and observing the receptors under light microscopy. [3H]-VP binding to the rat kidney was completely displaced by unlabeled excess VP, but not by unlabeled angiotensin II, indicating that [3H]-VP binding was specific for VP receptors. Computerized quantification showed that V2 receptors, visualized by OPC-31260, were the predominant type of VP receptor in the kidney. Conversely, V1 receptors, visualized by OPC-21268, were fewer in number. V1 receptors were partly localized to the glomerulus, cortical vessels, interstitial cells, and the medullary vessels. The V2 receptors localized to the collecting ducts and medullary tubules. Our findings indicated that renal V1 and V2 receptors can be detected by in vitro macro- and micro-ARG by using OPC-21268 and OPC-31260.

Normotensive bilateral pheochromocytoma with Lindau disease: case report

A 46-year-old man was found to have numerous cerebellar hemangioblastomas on magnetic resonance imaging (MRI). He denied any symptoms and had no history of hypertension, but his family history was remarkable for a father who died of renal cell carcinoma. Computed tomography (CT) of the abdomen revealed bilateral adrenal pheochromocytomas with significant enhancement in the regions where 131I-metaiodobenzylguanidine (MIBG) had noticeably accumulated. Endocrinological examinations demonstrated high plasma and urine catecholamine concentrations which were very responsive to metoclopramide and glucagon loading tests, without a significant change in blood pressure. After resection of bilateral pheochromocytomas, he underwent an operation for the cerebellar tumors. Since pheochromocytomas associated with Lindau or von Hippel-Lindau (VHL) disease have a tendency to multiple occurrence in normotensive patients, we suggest that patients with a family history involving VHL lesions should undergo cranial MRI, abdominal CT, MIBG scintigraphy and endocrinological examinations.