[HLA and uveitis in leprosy]

In order to investigate the role of immunogenetic factors in the pathogenesis of uveitis in leprosy, human leukocyte antigens (HLA) were analyzed among leprotics with and without uveitis. The subjects were 85 Japanese leprosy patients, 44 with uveitis and 41 without uveitis. Controls were 138 healthy subjects. A modified two-stage complement dependent microcytotoxicity test was used for typing HLA-A, -B, -C, -DR and -DQ antigens. The occurrence of HLA-DR2 antigen was significantly increased in patients as a whole (69.4%), and in the patients with uveitis (79.5%) as compared with the control subjects (35.5%). The association with DR2 was even stronger in the patients with uveitis (odds ratio = 7.1, Pc < 0.000005) than in the patients as a whole (odds ratio = 4.1, Pc < 0.0001). On the other hand, HLA-DR53 antigen was significantly decreased in the patients as a whole (43.5%) and in the patients with uveitis (36.4%) as compared with the control subjects (69.6%). No significant difference in the distribution of HLA antigens was observed in the patients without uveitis. Our results suggest that HLA-DR2 contributes to the susceptibility to uveitis in Japanese leprosy patients.

[A phase II study of FK506 (tacrolimus) on refractory uveitis associated with Behçet's disease and allied conditions]

A multicenter open study was conducted to investigate optimum dose schedule of FK506 on refractory uveitis associated with Behçet's disease and allied conditions. Fifty-three patients (41 with Behçet's and 12 with allied conditions) were enrolled in this study. A daily oral dose of FK506 was initially 0.05, 0.1, 0.15 or 0.2 mg/kg, but adjusted in more than half patients during the study based on clinical conditions of patients and/or adverse effects of FK506. The improvement rate of initial daily dose as well as final improvement rate were evaluated in the study. The improvement rate of initial daily dose was increased dose-dependently; 37.5% with 0.05 mg/kg initial daily dose group, 60.0% with 0.1 mg/kg, 91.7% with 0.15 mg/kg and 78.6% with 0.2 mg/kg. The final improvement rate was 76.5%. In patients with Behçet's disease, ocular symptoms improved in 30 (75.0%) of 40 patients evaluable for efficacy and the frequency of ocular attacks was significantly reduced. In eight (66.7%) of 12 patients with Behçet's disease in whom cyclosporin treatment had been failed, their ocular symptoms improved by FK506. Main adverse reactions of FK506 were renal impairment (28.3%), neurologic symptoms (22.6%), gastrointestinal symptoms (20.8%), hypomagnesemia (28.3%), hyperkalemia (13.2%), and hyperglycemia (13.2%. Most of the adverse effects disappeared or ameliorated after FK506 dose reduction or withdrawal from FK506 therapy. It seems that the incidence of the adverse effects depends on the dosage of FK506. The lower dosage (0.05 and 0.1 mg/kg) caused a relatively small number of adverse effects, and the higher dosage (0.15 and 0.2 mg/kg) caused them more frequently. Through level is recommended to maintain between 15-25 ng/ml during early days of treatment based on the safety and efficacy. It is also recommended that a initial daily dose is 0.15 mg/kg on the basis of the efficacy and safety results, and then adjusted based on symptoms of patients and whole blood through level of FK506.

Correlation between tumor volume doubling time and histologic findings in gastric smooth muscle tumors: clinical implications of tumor volume doubling time

To assess the clinical implications of the tumor volume doubling time of gastric smooth muscle tumors based on a comparison with the histologic findings, seven tumors (four leiomyomas and three leiomyosarcomas) were followed up by consecutive upper gastrointestinal studies between March 1985 and December 1993. The patients were four men and three women with an average age of 58 years (range: 50-71 years). The observation period ranged from 6 to 51 months, with an average of 35 months. All tumors were surgically resected and the histologic diagnosis was confirmed. The following microscopic features were evaluated: 1) mitotic rate, 2) nuclear atypia, and 3) cellularity. Each tumor was also evaluated for the presence or absence of necrosis, hemorrhage, and degeneration. The doubling time ranged from 5 to 27 months with a mean of 16 months. There was a strong negative correlation between the mitotic rate and the doubling time (r = -0.935, P = 0.0019). The doubling time was also significantly related to nuclear atypia, but the number of tumors studied was so small that its reliability was questionable. The doubling time was not related to any other histologic findings. This study shows that the doubling time is useful for estimating the malignant potential of gastric smooth muscle tumors, and that tumors with a doubling time of 16 months or less should be considered as malignant.

Immunological characterization and localization of a Porphyromonas gingivalis BApNA-hydrolyzing protease possessing hemagglutinating activity

A monoclonal antibody (mAb-PC) was produced against a BA pNA-hydrolyzing protease possessing hemagglutinating activity (Pase-C) from Porphyromonas gingivalis. Other P. gingivalis BA pNA-hydrolyzing enzymes (Pase-B and Pase-S) did not react with this antibody. By ELISA or SDS-PAGE and Western immunoblotting analysis, mAb-PC recognized all P. gingivalis and P. endodontalis strains tested but did not recognize other members of the Porphyromonas genus nor other putative periodontopathogenic organisms. Pase-C, extracellular vesicles (ECV) and human strains of P. gingivalis showed two major immunoreactive bands (44 kDa and 40 kDa), whereas a different pattern was obtained with animal strains of P. gingivalis. Biotinylarginyl chloromethane, an irreversible inhibitor of trypsin-like proteases, did not affect the reactivity of Pase-C with mAb-PC on immunoblot. By reversed-phase electronmicroscopy following immunogold labeling, the antibody was shown to bind to the cell surface of P. gingivalis. mAb-PC inhibited the hemagglutinating activity of both P. gingivalis cells and ECV whereas a monoclonal antibody against LPS of P. gingivalis did not. These results suggest that Pase-C is located on the cell surface of P. gingivalis and may participate in erythrocyte binding.

Immunohistochemical localization of C-reactive protein-binding sites in human atherosclerotic aortic lesions by a modified streptavidin-biotin-staining method

One-step fluorescein-conjugated polyclonal antibody technique has shown that C-reactive protein (CRP) was located only extracellularly in human atherosclerotic lesions. In this report a more sensitive streptavidin-biotin technique was applied to detect the localization of CRP in human atherosclerotic lesions. Immunohistochemical staining with polyclonal and monoclonal anti-human CRP antibodies both produced a brown color extracellularly in the necrotic lesions, and intracellularly in CD68+ foam cells. The latter suggests an uptake of CRP-lipid complexes by macrophages. The staining is human CRP-specific because it was eliminated by preabsorption of the monoclonal antibody with pure human CRP, or by substitution of the primary antibody with non-immune rabbit serum. By overlaid CRP-binding study, a positive stain was observed on intimal smooth muscle cells and foam cells, suggesting that they have CRP-binding sites unless the CRP-binding activity was generated de novo through the fixation procedure. Accordingly, it is hypothesized that CRP may facilitate the uptake of lipids by macrophages accumulating in atherosclerotic lesions. Further, CRP might participate in cytolysis, which enlarges the necrotic area, and/or in phagocytosis that scavenges the necrotic tissue.

Functional Rescue of photoreceptors from the damaging effects of constant light by survival-promoting factors in the rat

PURPOSE

To investigate whether and how survival-promoting agents rescue photoreceptor cell function and morphology from constant light damage, the authors recorded electroretinographic (ERG) responses and examined light micrographs of retinas in those rats given intravitreal injection of midkine (MK) and basic fibroblast growth factor (bFGF) before constant exposure.

METHODS

Albino Sprague-Dawley rats were injected with MK, bFGF, or phosphate-buffered saline (PBS) 2 days before the onset of 1 week of constant light. ERG responses were recorded using white flash stimuli with the intensity range of 4 log units, followed by histologic examinations of retinas, including quantitative assessment of the outer nuclear layer thickness as an index of photoreceptor cell loss.

RESULTS

ERG responses were barely detectable in uninjected eyes after 1 week of constant light. On the other hand, distinct responses were recordable in eyes injected intravitreally with MK and bFGF, and the degree of ERG rescue in terms of the amplitude of b-wave was approximately 40% to 60% compared with normal eyes. Intravitreally injected PBS showed slight, but noticeable, preservation of ERG responses as well. Histologic examination revealed that MK and bFGF protected photoreceptors from light damage. A good correlation was found between anatomic rescue of photoreceptors as assessed by outer nuclear layer thickness and the functional rescue as defined by the magnitude of ERG responses.

CONCLUSIONS

Functional and anatomic rescue of photoreceptors in albino rats from constant light damage is achieved by prior intravitreal injection of MK and bFGF.

[Intra-bile duct growth of hepatocellular carcinoma: value of biliary dilatation on CT]

In order to evaluate the usefulness of CT in demonstrating biliary invasion by hepatocellular carcinoma, 191 surgically proved cases were studied. Among 191 CT scans performed before surgery, six (3%) showed biliary dilatation. Pathological biliary invasion was found in eight cases (4%). Of these eight cases, four cases (50%) showed biliary dilatation on CT. In six cases with biliary dilatation on CT, pathological biliary invasion was revealed in four cases (67%). In two cases, the large (> or = 6cm) encapsulated tumors located in the hepatic hilum dilated the intrahepatic bile duct without intraductal tumor growth. We concluded that biliary dilatation on CT cannot be a sign of biliary invasion by hepatocellular carcinoma.

Radiosynthesis, rodent biodistribution, and metabolism of 1-deoxy-1-[18F]fluoro-D-fructose

Fluorine-18 labeled analog of D-fructose, 1-deoxy-1-[18F]fluoro-D- fructose (1-[18F]FDFrc), was synthesized by nucleophilic substitution of [18F]fluoride ion and the effect of the fluorine substitution on its in vivo metabolism was investigated. The tissue distributions of 1-[18F]FDFrc in rats and tumor bearing mice showed initial high uptake and subsequent rapid washout of the radioactivity in the principal sites of D-fructose metabolism (kidneys, liver and small intestine). The uptakes in the brain and tumor (fibrosarcoma) were the lowest and moderate, respectively, but tended to increase with time. The in vivo metabolic studies of 1-[18F]FDFrc and nonradioactive 1-FDFrc in mouse brain and tumor showed that the fluorinated analog remained unmetabolized in these tissues, indicating that the substitution of fluorine at the C-1 position produces a nonmetabolizable analog of D-fructose. Thus, 1-[18F]FDFrc had no features of a metabolic trapping tracer without showing any appreciable organ or tumor specific localization.

Postcontrast 3D-TOF-MR angiography of intracranial venous angiomas

The clinical value of three-dimensional time-of-flight magnetic resonance angiography (3D-TOF-MRA) was assessed in 15 patients with intracranial venous angiomas (VAs), by comparing results thereof with those of postcontrast T1-weighted MR images (MRIs). All 15 VAs were identified both on the postcontrast MRIs and MRAs. The MRAs surpassed the MRIs in imaging entire structures, including the draining veins of the supratentorial VAs. For the infratentorial VAs, the MRAs and the MRIs were of equal value. Although the addition of MRA to the MRI procedure incurs more time and expense, the complete structure of the VA can thereby be identified three-dimensionally on MRA. Conventional angiography is apparently not required for the confirmation of a VA. Thus, it is concluded that MRA is very useful for diagnosing VAs.

Pharmacological activity of the C-terminal and N-terminal domains of secretory leukoprotease inhibitor in vitro

1. In order to characterize the physiological functions of the domain structure of secretory leukoprotease inhibitor (SLPI), the biological capacities of half-length SLPIs, (Ser1-Pro54)SLPI and (Asn55-Ala107)SLPI, were investigated and compared with those of full-length SLPI. 2. The activities of these inhibitors against several serine proteases were determined using synthetic chromogenic substrates. The inhibitory capacity of the C-terminal domain, (Asn55-Ala107)SLPI, was as strong as that of full-length SLPI against human neutrophil elastase (NE), cathepsin G and chymotrypsin. It possessed less trypsin inhibitory activity than intact SLPI. For the N-terminal domain of SLPI, (Ser1-Pro54)SLPI, no inhibitory activity could be detected against the serine proteases tested in this study. 3. The inhibitory activity of (Asn55-Ala107)SLPI against the proteolysis of the natural substrates elastin and collagen by NE was comparable with that of full-SLPI (elastin, IC50 = 907 +/- 31 nM for SLPI, 767 +/- 33 nM for (Asn55-Ala107)SLPI; collagen, IC50 = 862 +/- 36 nM for SLPI, 727 +/- 47 nM for (Asn55-Ala107)SLPI). 4. The binding affinities of full- and half-length SLPIs for heparin were measured by affinity column chromatography. Full-length SLPI showed high affinity for heparin while the binding capacities of both half-length SLPIs were lower. (Concentration of NaCl for elution, 0.45 M for SLPI, 0.24 M for (Ser1-Pro54)SLPI, 0.27 M for (Asn55-Ala107)SLPI). 5. The effects of full-SLPI and (Asn55-Ala107)SLPI on blood coagulation were measured using the activated partial thromboplastin time (APTT). Full-length SLPI prolonged clotting time dose dependently(1.25, 2.5 and 5.0 microM), whereas (Asn55-AlalO7)SLPI had no effect even at the highest concentration.6. In conclusion, the C-terminal domain of SLPI is a promising candidate for the treatment of inflammatory diseases in which participation of neutrophil proteases has been suggested.

[HLA-DR2 alleles and uveitis in leprosy]

In order to investigate the role of immunogenetic factors in the pathogenesis of uveitis in leprosy, HLA antigens were analyzed between the leprotics with and without uveitis. Sixty-five Japanese leprosy patients comprised 32 with uveitis and 33 without uveitis. Controls consisted of 138 healthy subjects. A lymphocyte cytotoxicity test was used for typing HLA-A, -B, -C, -DR and -DQ antigens. HLA-DR2 genotyping was performed by the polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) and PCR-restriction fragment length polymorphism (RFLP) methods. The frequency of HLA-DR2 antigen was significantly increased in the patients with uveitis as compared with the control subjects (Pc < 0.0005), whereas HLA-DR53 antigen was significantly decreased (Pc < 0.05). At the genomic level the frequency of HLA-DRB1*1501 was significantly increased in the patients with uveitis and without uveitis as compared with that in the controls. The association with DRB1*1501 was even stronger in patients with uveitis (odds ratio = 7.1, Pc < 0.000005) than in the patients without uveitis (odds ratio = 4.1, Pc < 0.005). Our results suggest that HLA-DRB1*1501 contribute to the susceptibility to uveitis in the Japanese with leprosy.

[A comparison of the cerebrovascular responses to CO2 and Diamox in patients with unilateral occlusive cerebral arteries: a H2(15)O PET study]

We studied the relationship between the cerebrovascular responses to CO2 and Diamox in patients with chronic cerebrovascular diseases. The subjects consisted of 11 patients with unilateral occlusive or highly stenotic carotid artery. The cerebral blood flow was measured at the resting state, during the inhalation of 5% CO2, at both 5 and 20 min after Diamox i.v. (1 g). The rCBF ratios (occlusive/non-occlusive side) during the inhalation of CO2 and 20 min after Diamox i.v. closely correlated with each other. However, the ratio at 5 min after Diamox i.v. was slightly lower than that during the inhalation of CO2. The percent increases of rCBF also showed a significant correlation between 5% CO2 inhalation and 20 min after Diamox i.v. However, the rCBF decreased inversely at 5 min after Diamox i.v. in some regions on the occlusive side, which indicates the presence of a so-called "steal phenomenon". The percent increases in the rCBF after 1 g Diamox i.v. were more or equal to those during the inhalation of 5% CO2. The CO2 and Diamox were thus considered to be equally useful in the evaluation of the perfusion reserve capacity. However, these various characteristics as described above should be considered in the clinical practice.

Isolation, characterization and biological activities of novel triprenyl phenols as pancreatic cholesterol esterase inhibitors produced by Stachybotrys sp. F-1839

Ten triprenyl phenol metabolites were isolated as inhibitors of pancreatic cholesterol esterase from cultures of Stachybotrys sp. F-1839 by solvent extraction and column chromatographies. Combination of spectroscopic analyses revealed that two of these compounds are K-76 (1) and stachybotrydial (2), and that the remaining eight are new congeners (designated F1839-A (3), -B (4), -C (5), -D (6), -E (7), -F (8), -I (9) and -J (10). These compounds inhibited pancreatic cholesterol esterase by 50% at 6 x 10(-5) to 1.1 x 10(-1) M. Inhibition of the enzyme by compound 2, the most potent one among these compounds, was time-dependent and irreversible. When administered to normal rats, 2, at a single oral dose of 100 mg/kg, reduced [14C]cholesterol absorption by 50-60%. In cholesterol-fed mice, dietary supplementation of 2 (0.1%) for 14 days resulted in a 20% reduction in serum total cholesterol level without causing significant change in the high density lipoprotein cholesterol level.

[Endothelin-1 and intraocular inflammation in pigmented rabbit eyes]

We assessed the role of endothelin-1 (ET-1) in the development of anterior chamber inflammation in pigmented rabbit eyes. After the injection of ET-1 (10(-13), 10(-11), 10(-9) or 10(-7) M) into the anterior chamber, aqueous protein concentration increased significantly in a dose-dependent fashion, with a peak at 1 to 2 hours after treatment, and it returned to the normal level 8 hours after the injection. Pupillary diameter was significantly reduced when 10(-9) M or 10(-7) M ET-1 solution was injected. These effects were blocked by pretreatment with anti-prostaglandin agents, i.e., topical indomethacin or venous diclofenac sodium. In the endotoxin-induced experimental uveitis model, ET-1 concentration in the aqueous humor was significantly higher than that of normal controls as well as the plasma ET-1 level. These results suggest that ET-1 is an important mediator in the ocular inflammatory reactions through the arachidonic acid cascade.

The structures of the human calcium channel alpha 1 subunit (CACNL1A2) and beta subunit (CACNLB3) genes

Calcium influx in pancreatic beta-cells is regulated mainly by L-type voltage-dependent calcium channels (VDCCs) and triggers insulin secretion. The alpha 1 subunit (CACN4) and the beta subunit (beta 3) of VDCCs, both of which are expressed in pancreatic islets, are major components for the VDCC activity, and so they may play a critical role in the regulation of insulin secretion. We have determined the structures of the human CACN4 (CACNL1A2) and the human beta 3 (CACNLB3) genes. The CACNL1A2 gene spans more than 155 kb and has 49 exons. Most of the positions interrupted by introns are well conserved between the CACNL1A2 gene and the previously reported L-type VDCC alpha 1 subunit, CACNL1A1, gene. On the other hand, the CACNLB3 gene distributes in approximately 8 kb and comprises 13 exons, most of which are located together within approximately 5 kb. Comparisons of the genomic sequences of CACNL1A2 with the previously reported cDNA sequences indicate that there are a number of polymorphisms in the human CACNL1A2 gene. In addition, the PCR-SSCP procedure of exon 1 of CACNL1A2 revealed a change from 7 to 8 ATG trinucleotide repeats in a patient with non-insulin-dependent diabetes mellitus (NIDDM), resulting in an addition of methionine at the amino-terminus of CACN4. The determination of the structures of the human CACNL1A2 and CACNLB3 genes should facilitate study of the role of these genes in the development of NIDDM and also other genetic diseases such as long QT syndrome.

Origin of the nitrogen atom of pyridoxine in Saccharomyces cerevisiae

The origin of the nitrogen atom of pyridoxine was studied in Saccharomyces cerevisiae. The 15N atom of 15NH4Cl added to the growth medium as the nitrogen source was incorporated efficiently into the nitrogen atom of pyridoxine. The competitive effects of 14N-amino acids on the incorporation of 15NH4Cl were examined. Incorporation of 15N into pyridoxine was inhibited by glutamine. The label of L-[amide-15N]glutamine was incorporated effectively into pyridoxine in S. cerevisiae. On the other hand, the label from L-[amide-15N]glutamine was not incorporated into pyridoxine in Escherichia coli. These findings suggest that the biosynthetic pathway of pyridoxine in S. cerevisiae differs from that in E. coli.

Hepatocellular carcinoma with pyrexia: report of a case

Reported here is a case of an unusual type of hepatocellular carcinoma (HCC). Since this patient with liver mass exhibited continuous pyrexia, an inflammatory pseudotumor or abscess was strongly suspected. Two-phased incremental CT, MR with and without Gd-DTPA administration, and angiography demonstrated peripheral enhancement of the hepatic mass. Histologically, the tumor proved to be HCC with sarcomatoid degeneration. When one encounters a patient with a mass clinically and radiologically mimicking an inflammatory pseudotumor or an abscess, poorly differentiated HCC with sarcomatoid degeneration should be suspected.

A morphologic study of lung secretory leukoprotease inhibitor in pneumonia

The present study was undertaken to determine the localization of cells laden with secretory leukoprotease inhibitor (SLPI) in bronchial/bronchiolar epithelium (B/Br-E) by histochemical techniques to see whether SLPI production occurs in conjunction with pathologic bronchopneumonia. Ten lung were obtained at autopsy from patients between 63 and 100 yr of age, including six with pathologic pneumonia and four without pneumonia. SLPI-laden cells in the B/Br-E corresponded mostly to goblet cells with apparent hyperplasia. A morphometric study performed on the B/Br-E indicated that the percentage of SLPI-laden cells was significantly correlated with the percentage of mucus-containing cells (r = 0.72, p < 0.001). This trend was similar in the bronchi (r = 0.60, p < 0.05) and in the bronchioles (r = 0.90, p < 0.01). The increased percentage of mucus and SLPI-laden cells in the B/Br-E was closely correlated with acute inflammatory changes in the adjacent alveoli, particularly in bronchi rather than in bronchioles. From these observations we conclude that the number of SLPI-laden cells in the airways increases in correlation with goblet cell hyperplasia. In addition, these morphologic changes are associated with the existence of acute inflammatory cell infiltration in the alveolar area.

Proteolytic fragmentation with high specificity of mouse immunoglobulin G. Mapping of proteolytic cleavage sites in the hinge region

We report the results of fragmentation of mouse IgG by clostripain, lysyl endopeptidase, metalloendopeptidase, and V8 protease that have a narrower substrate specificity than papain and pepsin. A panel of mouse monoclonal switch variant antibodies with IgG1, IgG2a, and IgG2b subclasses were examined. Cleavage sites by these proteases were mapped on the hinge region of each of the IgG subclasses. It was demonstrated that lysyl endopeptidase can cleave the core hinge portion of IgG2a and IgG2b without perturbing the inter-chain disulfide bridges. Digestion products were successfully isolated by a combined use of protein A affinity chromatography and HPLC techniques. This is a first successful attempt of obtaining the F(ab')2 fragment of IgG2b by proteolytic digestion.

HLA-DR8 and acute anterior uveitis in ankylosing spondylitis

OBJECTIVE

To identify possible factors in the development of acute anterior uveitis (AUU) in patients with ankylosing spondylitis (AS).

METHODS

We investigated HLA antigens serologically, and HLA-DRB1*08 alleles by polymerase chain reaction-restriction fragment length polymorphism, in 42 Japanese AS patients with and without AAU.

RESULTS

Thirty-six of the AS patients (85.7%) had HLA-B27. Thirteen (65%) of the 20 patients with AAU had HLA-DR8, whereas only 1 (4.5%) of the 22 patients without AAU had DR8. The difference was statistically significant (Pcorr < 0.001).

CONCLUSION

Our data suggest that HLA-B27 is strongly associated with AS in Japanese patients and that HLA-DR8 is important for the development of AAU in Japanese patients with AS.

Cloning and functional characterization of a novel ATP-sensitive potassium channel ubiquitously expressed in rat tissues, including pancreatic islets, pituitary, skeletal muscle, and heart

ATP-sensitive K+ (KATP) channels play a crucial role in coupling metabolic energy to the membrane potential of cells. We have isolated a cDNA encoding a novel member (uKATP-1) of the inward rectifier K+ channel family from a rat pancreatic islet cDNA library. Rat uKATP-1 is a 424-amino acid residue protein (M(r) = 47,960). Electrophysiological studies of uKATP-1 expressed in Xenopus laevis oocytes show that uKATP-1 is a weak rectifier and is blocked with Ba2+ ions. Single-channel patch clamp study of clonal human kidney epithelial cells (HEK293) transfected with uKATP-1 cDNA reveals that uKATP-1 closes in response to 1 mM ATP and has a single channel conductance of 70 +/- 2 picosiemens (n = 6), indicating that uKATP-1 is an ATP-sensitive inward rectifier K+ channel. In addition, uKATP-1 is activated by the KATP channel opener, diazoxide. RNA blot analysis shows that uKATP-1 mRNA is expressed ubiquitously in rat tissues, including pancreatic islets, pituitary, skeletal muscle, and heart, suggesting that uKATP-1 may play a physiological role as a link between the metabolic state and membrane K+ permeability of cells in almost every normal tissue. Since uKATP-1 shares only 43-46% amino acid identity with members of previously reported inward rectifier K+ channel subfamilies, including ROMK1, IRK1, GIRK1, and cKATP-1, uKATP-1 is not an isoform of these subfamilies and, therefore, represents a new subfamily of the inward rectifier K+ channel family having two transmembrane segments.

Comparative thermodynamic analyses of the Fv, Fab* and Fab fragments of anti-dansyl mouse monoclonal antibody

In order to investigate the role of the constant domains on the antigen-binding property of the variable domains, we have carried out a comparative thermodynamic study of the anti-dansyl Fv, Fab* and Fab fragments that possess the identical amino acid sequence of the variable domains. The thermodynamic analyses have shown that binding constants, enthalpy changes and entropy changes are similar for the three antigen-binding fragments, whereas the thermal stability of Fab is much higher than that of Fv and Fab*. We have concluded that (i) the variable domains of the three antigen-binding fragments possess identical intrinsic capability for antigen binding and (ii) the two constant domains serve to improve the stability of the variable domains.

[Clinical usefulness of urinary anti HIV antibody test--a large scale study from 11 institutes in Japan]

An enzyme immuno assay kit has been developed to detect anti-HIV antibody in urine. In order to examine the clinical utility of the kit, 1333 urine samples were assayed. These samples consisted of 233 urine samples from HIV infected patients, 472 samples from HIV uninfected patients including 203 samples from patients with urogenital diseases, and 628 samples from normal subjects. Anti-HIV antibodies were detected in all the urine samples from HIV infected patients, and the diagnostic sensitivity for HIV infection was 100% with no false negative cases. A variety of anti-HIV antibody titers were found in the urine samples from HIV infected patients. However, no significant differences were found in the distribution patterns of urinary anti-HIV antibody titers among AC, ARC and AIDS patients. False positives were determined in only five samples in 628 healthy subjects (0.8%), one in 19 patients with hepatitis (5.3%), one in 45 patients with hemophilia (2.2%) and two in 105 pregnant women (1.9%). The antibody titers of all the false positive samples in these groups were less than the cut-off index multiplied by two. However, relatively high positive rates were demonstrated in the samples from urogenital diseases (11.8%), diabetes mellitus (20.0%) and auto-immune diseases (7.3%). False positive results were found to be directly correlated to the protein concentration of urinary protein, especially the immunoglobulin concentration in urine. The assay system was also evaluated by various reproducibility tests performed by different operators at different laboratories. The test results were satisfactory.(ABSTRACT TRUNCATED AT 250 WORDS)