Genetic variations of HSD11B2 in hypertensive patients and in the general population, six rare missense/frameshift mutations.

Mutations in the gene encoding 11beta-hydroxysteroid dehydrogenase type 2, HSD11B2, cause a rare monogenic juvenile hypertensive syndrome called apparent mineralocorticoid excess (AME). In AME, defective HSD11B2 enzyme activity results in overstimulation of the mineralocorticoid receptor (MR) by cortisol, causing sodium retention, hypokalemia, and salt-dependent hypertension. Here, we have studied whether genetic variations in HDS11B2 are implicated in essential hypertension in Japanese hypertensives and the general population. By sequencing the entire coding region and the promoter region of HDS11B2 in 953 Japanese hypertensives, we identified five missense mutations in 11 patients (L14F, n = 5; R74H, n = 1; R147H, n = 3; T156I, n = 1; R335H, n = 1) and one novel frameshift mutation (4884Gdel, n = 1) in a heterozygous state, in addition to 19 genetic variations. All genetic variations identified were rare, with minor allele frequencies less than 0.005. Four of 12 patients with the missense/frameshift mutations showed renal failure. Four missense mutations, L14F, R74H, R147H, and R335H, were successfully genotyped in the general population, with a sample size of 3,655 individuals (2,175 normotensives and 1,480 hypertensives). Mutations L14F, R74H, R147H, and R335H were identified in hypertensives (n = 6, 8, 3, and 0, respectively) and normotensives (n = 8, 12, 5, and 0, respectively) with a similar frequency, suggesting that these missense mutations may not strongly affect the etiology of essential hypertension. Since the allele frequency of all of the genetic variations identified in this study was rare, an association study was not conducted. Taken together, our results indicate that missense mutations in HSD11B2 do not substantially contribute to essential hypertension in Japanese.     

Microvasculature of bone

The three dimensional vascular microarchitecture of mercox resin on the lateral surface of parietal bone in Wistar strain adult male rats (b. w. 260–350 g.) was studied in relation to bone formation by SEM observation of corrosion casts. The microarchitecture was a single layer of network composed of precapillary artery, capillary and postcapillary vein, which were serpigious, sometimes joined with the vein from the vascular foramen of bone. The meshes of this network, which were irregular and varied in size, existed apart from the bone surface. According to the report of Iwaku and Ozawa (1986), it was reported that the vascular microarchitecture of the bone surface was very changable during the process of bone remodeling and this network, which was shown on the flat bone surface in this study, was very similar to one in the resting phase and/or the period in which the bone formation further advanced. From these facts and the morphological features of the bone surface observed here by SEM, it is suggested that this vascular network was closely related with the resting stage and/or the period in which bone formation further advanced in bone remodeling.     

Microheterogeneity of regional myocardial blood flows in low-perfused rat hearts evaluated by double-tracer digital radiography.

Using (3)H- and (125)I-labeled desmethylimipramine (DMI) for regional flow tracers, we established a two-time measurement method for the spatial pattern of myocardial perfusion in cross-circulated rat hearts. Myocardial extractions and retentions of these tracers were confirmed to be satisfactory; however, the latter were less than 90% after 3 min at a perfusion rate of 2.9 ml/min/g, limiting the present application to a short-time perfusion measurement. Distributions of myocardial depositions were separated by subtraction digital radiography with 400-microm pixel resolution. Its feasibility was examined by regression analysis between local deposition densities of (3)H- and (125)I-DMI injected simultaneously. The slope, y-intercept, and correlation coefficient (r) of the regression line were 0.98+/-0.04, 0.02+/-0.04, and 0.95+/-0.03, respectively, indicating the validity of the present image subtraction technique. The spatial pattern of myocardial perfusion in response to flow reduction was evaluated by the injections of (3)H- and (125)I-DMI, respectively, before and after a nearly 70% flow reduction. A significant correlation between normalized density distributions of these tracers was found in both subepicardium (r=0.77+/-0.12) and subendocardium (r=0.73+/-0.20), indicating the stable pattern of myocardial perfusion. However, the coefficient of variation of tracer densities showed a decrease of subendocardial flow heterogeneity from 35+/-15% to 31+/-16%. Thus, flow differences between originally high- and low-flow regions in subendocardium were reduced on a relative basis during low perfusion.     

A Clinical Study for the Durability of Oxygenators on Cardiopulmonary Support

Abstract: Cardiopulmonary support (CPS) requires durability of the oxygenator. The life span of the oxygenator is affected by various clinical factors, including patient condition, perfusion condition, and equipment usage. Predictors for the durability of oxygenators were evaluated clinically in this study. Thirty-two patients, who had undergone CPS during the last 3 years in our institute were assigned to this study. Fifty oxygenators had been used (Capiox SX in 19, CB Maxima in 23, and AL-6000 in 8). Significant predictors for the durability of oxygenators were evaluated by nonparametric survival analysis and proportional hazards regression analysis. Univariate regression analysis revealed 6 significant predictors for the life span of oxygenators. These were the oxygenator type, type of centrifugal pump, acidosis with blood pH less than 7.35, base excess less than -5, blood glutamic-oxaloacetic transaminase (GOT) levels greater than 1,000 IU, and blood lactate dehydrogenase (LDH) levels greater than 3,000 IU. After multivariate analysis, there remained only 2 significant predictors. An oxygenator used with a noncoated CPS system (Capiox SX with Capiox EBS) proved to have a significantly shorter life span than one used with a heparin-coated system (CB Maxima or AL-6000 with CB BP-80) (hazards ratio, 3.588, p = 0.0065). Patient conditions, which revealed acidosis with less than -5 of base excess, significantly shortened the life of the oxygenator (hazards ratio, 3.595, p = 0.0188).     

Human T-Cell Leukemia Virus-1-positive Cell Line Established from a Patient with Small Cell Lung Cancer

A stable cell line, KHM-3S, was established from a patient with small cell lung cancer (SCLC), who had a high serum level of soluble interleukin 2 receptors (sIL2-R) and was seropositive for human T cell leukemia virus (HTLV)-l. KHM-3S cells were positive for IL2-R (Tac) and NKH-1, but negative for other lymphocytic markers such as OKT 11, OKT 4, OKT 8, T cell receptor (WT 31), B 1, and B 4. Moreover, the KHM-3S cells were negative for leukocyte common antigen and strongly positive for neuron-specific enolase (NSE). Secretion of sIL2-R and NSE by the KHM-3S line was detected by an enzyme-linked immunosorbent assay. Rearrangement of the T cell receptor gene and monoclonal HTLV-1 integration were found by Southern blot analysis of KHM-3S DNA. However, Northern blot analysis showed no T cell receptor mRNA. KHM-3S may be useful for studies on the role of HTLV-1 in carcinogenesis and IL2-R expression in SCLC.     

A study on the development of a filing system for funduscopic images with a personal computer for Twin AMHTS

A filing system for ocular fundscopic image data was developed by using a personal computer for the Twin AMHTS. The development of the system was tried as one of the data transfer system including image data between two similar AMHTSs named the Twin AMHTS through the information network system. The filing system is capable of storing 26782 data of ophthalmoscopic pictures with a data compression mode by using a magneto-optical disk (MOD) whose storage capacity of both sides is 616 MB. It takes no long time for retrieval and display of the image data in the filing system. Good quality of compression and decompression obtained and reproducibility of the ocular fundus picture is favorable regardless of normal or abnormal cases. As a result, it is suggested that the developed system has practical utility although it requires more improvement.     

INTRA- AND INTERINDIVIDUAL VARIATION IN THE PHARMACOKINETICS OF TACROLIMUS (FK506) IN KIDNEY TRANSPLANT RECIPIENTS—IMPORTANCE OF TROUGH LEVEL AS A PRACTICAL INDICATOR

Background: Tacrolimus (FK506) is currently used as the primary immunosuppressant in clinical kidney transplantation in some centers. The purpose of this study was to evaluate the pharmacokinetics of this drug and to see if trough level, which has been used widely in therapeutic drug monitoring, can be used as an appropriate substitute for other pharmacokinetic measurement tests. Methods: The blood concentration-time curve was studied in 10 kidney transplant recipients on 26 Occasions after oral dosage of 2 to 18 mg every 12 hours. Whole blood concentration was measured by two-step irnmunoabsorption assay. Methylprednisolone was used as a concomitant immuno-suppressive drug. Results: The blood concentration-time curves showed remarkable interindividual variation. lntraindividual variation was also found, but the degree of variation was slight compared with interindividual variation. On 17 occasions of measurement in one patient, the dose was significantly correlated with trough (r = 0.684). C_max (r = 0.838) and AUC_0–12 (r = 0.817). In nine patients on nine occasions, however, the dose was not significantly correlated with trough (r = 0.351), C_max (r = 0.270) or AUC_0–12 (r = 0.355). t_max ranged from one to four hours (mean + SD; 2.8 + 1.3) and fluctuated in both intra- and interindividual measurements. In spite of a wide variation in the blood concentration-time-curve patterns, a highly significant linear relationship between trough and C_max or AUC_0–12 was observed in both intraindividual (C_max, r = 0.876; AUC_0–12, r = 0.926) and interindividual (C_max, f = 0.943; AUC_0–12, r = 984) measurements. Concluslons: We conclude that trough level is a practical acceptable indicator of the blood levels of tacrolimus, and can be used to monitor blood concentration.     

The effects of nucleotides and potassium channel openers on the SUR2A/Kir6.2 complex K+ channel expressed in a mammalian cell line, HEK293T cells

 The effects of potassium channel opening drugs and intracellular nucleotides on the ATP-sensitive K+ (K_ATP) channel composed of SUR2A and Kir6.2 in HEK293T cells were examined using the patch-clamp technique. The SUR2A/Kir6.2 channel was activated effectively by pinacidil, marginally by nicorandil but not by diazoxide. The pinacidil-activated channel currents were inhibited by glibenclamide with a K _i value of 160 nM. Upon formation of inside-out (I-O) patches, spontaneous openings of the channels appeared, which were inhibited by intracellular ATP (ATP_i) equipotently in the presence and in the absence of intracellular Mg²⁺ (Mg²⁺ _i). The channel activity ran-down gradually in I-O patches. The run-down channels could be reactivated by ATP_i only in the presence of Mg²⁺ _i. Uridine 5’-diphosphate (UDP) antagonized the ATP_i-mediated inhibition of the channel activity before run-down. After run-down, UDP activated the channel without antagonizing ATP_i-mediated channel inhibition. Thus, the SUR2A/Kir6.2 reproduced the major properties of the native cardiac K_ATP channel well in terms of nucleotide regulation and pharmacology, and therefore can be a useful tool with which to elucidate the molecular mechanisms characterizing the K_ATP channel. Received: 24 October 1997 / Received after revision and accepted: 4 December 1997     

Immunohistological analysis in the distribution of cells in the fetal porcine adenohypophysis

Adenohypophyses of porcine fetuses from 25 to 110 days of gestation were studied by immunohistochemical staining to ascertain the ontogeny of specific cell types and their spatial distribution in the pars distalis. No hormonecontaining cells were found before 30 days of gestation. ACTH cells were observed first at 40 days, while GH and LH cells appeared first at 60 days. PRL cells were initially detected at 105 days. ACTH immunoreactive cells were also observed in the pars intermedia at 40 days. Blood capillaries were interposed between cell cords of the pars distalis after 40 days of gestation. ACTH cells were evenly distribution in all areas of the pars distalis except the rostal area (sex zone). GH cells were densely distributed in lateral wings of the pars distalis and immediately anterior to Rathke's lumen. PRL cells resembled GH cells in their distribution pattern, but PRL cells were fewer in number. LH cells were scattered in the sex zone of the pars distalis from 60 to 80 days of gestation. After 90 days, they became scattered throughout the pars distalis but were more numerous in the sex zone than in other areas. The inductive elements of adenohypophysial cells from Rathke's pouch epithelia are discussed. We hypothesize that cell cords of specific areas facing Rathke's lumen may differentiate into specific cell types of the pars distalis during fetal life. © 1992 Wiley-Liss, Inc.