A human vitelline component in embryonal carcinoma of the testis

The correlation between increased serum alpha-fetoprotein (AFP) and a human vitelline component of 5 testicular embryonal carcinomas (1 was one histological type, 4 were more than one histological type) with no histological features specific for yolk sac tumor (YST) or endodermal sinus tumor (EST) was presented. In all 5 cases, distinct cells simulating the human yolk sac endodermal cell (HYSEC) with eosinophilic-granular or clear-vacuolated cytoplasm were found. These cells contained PAS positive, diastase resistant eosinophilic hyaline globules (EHG) which were positive for AFP. In the embryoid body, the same cells with positive AFP as the HYSEC were also seen. Electron microscopic investigation of these cells revealed basement membrane-like materials which were observed in organoid structure of YST. Positive AFP in these cells showed no binding to Concanavalin A (Con A), which was similar to AFP in YST. It was suggested that testicular embryonal carcinoma with higher serum AFP showing no histological features specific for YST had a vitelline component simulating the HYSEC and produced an increased serum AFP. Immunohistochemical staining for AFP of embryonal carcinoma with higher serum AFP is useful for detecting a human vitelline component and is important to guess the survival for the patient.     

Pineal malignant rhabdoid tumor with chondroid formation in an adult

A pineal tumour in a 27-year-old male is presented with the characteristic histological features of a pineal malignant rhabdoid tumor (MRT) with chondroid formation. Occasionally, tumor cells contained a single well-demarcated hyaline globular inclusion within the cytoplasm adjacent to the nucleus. The stroma of these tumors tends to be densely hyalinized and become chondroid. Immunohistochemical staining was positive for vimentin, epithelial membrane antigen, chromogranin A, synaptophysin, neuron-specific enolase, S-100 protein, and muscle actin. Despite surgery and radiochemotherapy, the tumor recurred in the pineal region and metastasized to the lower lobe of right lung. The patient died 2 years after the initial diagnosis. This is the second published case of central nervous system-MRT appearing in an adult. The clinical and pathological features of pineal MRT in this patient are presented.     

A HUMAN VITELLINE COMPONENT IN EMBRYONAL CARCINOMA OF THE TESTIS

The correlation between increased serum alpha-fetoprotein (AFP) and a human vitelline component of 5 testicular embryonal carcinomas (1 was one histological type, 4 were more than one histological type) with no histological features specific for yolk sac tumor (YST) or endodermal sinus tumor (EST) was presented. In all 5 cases, distinct cells simulating the human yolk sac endodermal cell (HYSEC) with eosinophilic-granular or clear-vacuolated cytoplasm were found. These cells contained PAS positive, diastase resistant eosinophilic hyaline globules (EHG) which were positive for AFP. In the embryoid body, the same cells with positive AFP as the HYSEC were also seen. Electron microscopic investigation of these cells revealed basement membrane-like materials which were observed in organoid structure of YST. Positive AFP in these cells showed no binding to Concanavalin A (Con A), which was similar to AFP in YST. It was suggested that testicular embryonal carcinoma with higher serum AFP showing no histological features specific for YST had a vitelline component simulating the HYSEC and produced an increased serum AFP. Immunohistochemical staining for AFP of embryonal carcinoma with higher serum AFP is useful for detecting a human vitelline component and is important to guess the survival for the patient.     

Mechanical properties of dilated human ascending aorta

Dilation of the ascending aorta, associated with Marfan Syndrome, bicuspid aortic valve, or advanced age, may lead to aortic dissection and rupture. Mathematical models can be used to assess the relative importance of increased wall stresses and decreased strength in these mechanical failures. To obtain needed inputs for such models, mechanical properties of dilated human ascending aorta were measured in vitro. Specimens for opening angle, biaxial elastic, and uniaxial circumferential strength tests were cut from excised tissue obtained from 54 patients (age 18–81 years) undergoing elective aortic graft replacement surgery. Opening angle was significantly greater in patients older than 50 years (262°±76°, n=21) compared to younger patients (202°±70°, n=13 All biaxial elastic specimens n=40 exhibited nonlinear stress-strain behavior. Rapid increases in circumferential and axial stresses occurred at lower strains in the older patient group than in the younger. Mean strength was significantly lower in older patients (1.35±0.37 MPa, n=14) than younger (2.04 ± 0.46 MPa, n=11, age <50 years). These changes in mechanical properties suggest that age may influence the risk of aortic dissection or rupture of dilated ascending aorta. © 2002 Biomedical Engineering Society. PAC2002: 8719Rr, 8719Hh     

The inferior supernumerary renal arteries: A classification into three types

Among cases that had multiple renal arteries on one side, an inferior supernumerary renal artery was found in 24/270 cases (ca. 9%) on the right and in 19/270 cases (ca. 7%) on the left, together with the usual renal artery. We have noticed that there are correlations between their levels of origin from the aorta and their positional relation to the ureter and the inferior vena cava (IVC). An inferior supernumerary renal artery (InfRA) of lower origin passes in front of the IVC and behind the ureter. An InfRA of middle origin passes in front of both the IVC and the ureter. An InfRA of upper origin passes behind the IVC and in front of the ureter or renal pelvis. In addition there was a tendency for the lower origin type to have an ureteric branch, while the middle and upper origin types had a gonadal branch. These findings suggest that different derivations lead to the inferior supernumerary renal arteries.     

Mechanisms responsible for delayed and immediate hemolytic transfusion reactions in a patient with anti-E + Jk(b)+ Di(b) and anti-HLA alloantibodies

Immediate hemolytic transfusion reactions (IHTR) occurred in the course of delayed hemolytic transfusion reactions (DHTR). An 84-year-old man had received a blood transfusion 20 years ago. Progressive anemia developed, because of continuous bleeding from a bladder tumor. He was transfused with concentrated red blood cells (CRC) which were Rh-E antigen negative, because he had anti-E antibodies (day 0). He received CRC on day 3, and underwent resection of bladder tumor on day 6. Although crossmatch-compatible CRCs were prepared for the operation, those were not required and were kept in a refrigerator in the ward. On day 9, when a CRC kept in the ward was transfused, he suddenly had a IHTR. In order to analyze a mechanism of IHTR, the anti-Jk(b) and anti-Di(b) antibodies, anti-HLA antibodies and the concentrations of inflammatory cytokines were measured in serum samples. The anti-Jk(b) and anti-Di(b) antibodies increased prior to IHTR experienced on day 9. The concentrations of IL-6 and IL-1beta increased from day 2, while the concentration of IL-8 increased from day 7. The anti-HLA class I antibody could be detected 2 days before IHTR. Thus, the anti-Jk(b) and anti-Di(b) antibodies induced the production of inflammatory cytokines and symptoms of DHTR and IHTR. The anti-HLA class I antibody could be produced in spite of using the filer for removing leukocytes, and may take part in the induction of IHTR. Further, blood products should be transfused soon after completing a crossmatch test in patients with anti-RBC alloantibodies.     

The loss of subtypic determinants in alleles, d/y or w/r, on hepatitis B surface antigen

Hepatitis B surface antigen possesses the group-specific determinant called a and one or another member from each of two pairs of allelic determinants, d and y as well as w and r, thereby creating the four major subtypes, adw, adr, ayw and ayr. In the sequence of major surface antigen polypeptides made of 226 amino acid residues, lysine or arginine at amino acid position 122 specifies d or y determinant, and lysine or arginine at position 160 specifies w or r determinant, respectively. By means of site-directed mutagenesis and expression of mutant genes in cultured cells, the mechanism for the loss of subtypic determinants on surface antigens was investigated at the molecular level. A rare sample of surface antigen of subtype ad, devoid of w or r determinant, had asparagine at position 160. When it was converted to lysine, the surface antigen of subtype adw was obtained. Two samples of surface antigen were subtyped as ar. They lacked d determinant, despite having lysine at position 122 which usually specified it. They differed from all reported sequences of surface antigen in amino acid 144 or 145. They displayed d determinant when amino acid 144 was converted from glutamic acid to aspartic acid, or when amino acid 145 was changed from alanine to glycine. These results indicate that the key amino acid residue at position 122 or 160 is indispensable for the expression of subtypic determinants and that some distant residues are also crucially involved in conforming them.     

Evidence that action potential generation is not the exclusive determinant to trigger spontaneous myogenic contraction of guinea-pig urinary bladder smooth muscle

Urinary bladder smooth muscle (UBSM) exhibits spontaneous contraction. This spontaneous mechanical activity is myogenic and can be closely related to the UBSM cell action potential to facilitate Ca2+ influx through voltage-gated Ca2+ channels. In the present study, to know whether this membrane electrical event is the exclusive mechanism to trigger spontaneous smooth muscle contraction, we compared the inhibitory effects of Ca2+ channel blockers on the spontaneous action potential and mechanical activity in the isolated guinea-pig UBSM. Both action potential and rhythmic contraction were generated spontaneously in the presence of atropine (1 microM), phentolamine (1 microM), propranolol (1 microM), suramin (10 microM) and tetrodotoxin (1 microM), which suggest that both phenomena were myogenic in origin. Nisoldipine (100 nM) and diltiazem (10 microM) completely eliminated the generation of action potential whereas its frequency was dramatically increased by a dihydropyridine Ca2+ agonist, BayK 8644 (1 microM). In contrast to disappearance of action potential in the presence of Ca2+ channel blockers, spontaneous contraction of UBSM was inhibited only partly by nisoldipine or diltiazem and most of the mechanical components persisted in these channel blockers. These results indicate that spontaneous action potential in UBSM cell is generated through the activation of L-type voltage-gated Ca2+ channels. The subsequent elevation of intracellular Ca2+ concentrations during a burst of action potentials can be partly responsible for the induction of UBSM mechanical activity. In addition, the present study provides evidence that UBSM spontaneous mechanical activity is also attributable to the mechanism(s) other than the generation of Ca2+ spike.     

Calcitonin inhibits proton extrusion in resorbing rat osteoclasts via protein kinase A

Although calcitonin is well known to be a potent inhibitor of bone resorption, it remains unknown how it regulates osteoclastic H(+) transport. In this study, we examined the effects of calcitonin on H(+) extrusion in cultured rat resorbing osteoclasts using an intracellular pH (pHi) indicator, BCECF [2'7'-bis-(2-carboxyethyl)- 5-carboxyfluorescein]. Resorbing osteoclasts were identified by their formation of resorbing pits on calcium phosphate-coated quartz coverslips. Both basal pHi and H(+) extrusion activity were significantly higher compared to non-resorbing osteoclasts. Two types of H(+)-extruding systems were identified by pharmacological and immunocytochemical means: a bafilomycin-A(1)-sensitive and an amiloride-sensitive system [H(+) extrusion mediated by a vacuolar type proton pump (V-ATPase) and by a Na(+)/H(+) exchanger (NHE), respectively]. Calcitonin inhibited both H(+) extrusion activities in a dose-dependent manner and this action was mimicked by protein kinase A (PKA) activators, but not by protein kinase C (PKC) activators. Pretreatment with PKA inhibitors completely suppressed calcitonin-induced inhibition, whereas neither PKC inhibitors nor calcium chelators suppressed it. These results indicate that calcitonin inhibits H(+) extrusion generated by V-ATPase and NHE via PKA activation. These inhibitory mechanisms of H(+) transport by calcitonin are important for the regulation of bone resorption.     

Mevalonic acidemia: First case of Japan

Summary Mevalonic acidemia is a rare metabolic disorder due to mevalonate kinase deficiency which affects the biosynthesis of cholesterol and nonsterol isoprenes. We report the first case of Japan. The clinical course is characterized by intrauterine growth retardation, postnatal growth failure, intractable diarrhea, liver dysfunctions and death at three months of age. Dysmorphic features including triangular face, protrusion of forehead, hypertelorism, low set ears and micrognathism were noted. High mevalonic acid level was found by GC/MS.