HLA-Bw52 in Takayasu disease

Takayasu disease is characterized by a pulseless condition which most often occurs in young females from Asian or South American areas. The cause of this disease remains obscure. Recently we encountered monozygotic, Japanese identical twin sisters, both of whom were diagnosed as having Takayasu disease. A genetically related factor was considered and HLA analysis was carried out. A population study on HLA typing analyses of 65 patients with Takayasu disease revealed a high frequency of HLA-B5 as compared with 128 healthy Japanese (chi2 :17.0, P less than 10(-4)). Subgroups of B5, Bw51 and Bw52 were successively studied in 82 patients with this disease. Bw51 antigen was found in 12.2% of patients with Takayasu disease and in 19.5% of 128 healthy Japanese. Contrarily, Bw52 antigen was confirmed in 43.9% of patients, a statistically significant frequency with the level of 26.5 in the chi2 test (cP less than 3 x 10(-4)) when compared with 12.5% in normal Japanese. Thus a genetically related factor in the pathogenesis of Takayasu disease has to be considered.

HL-A antigens in Takayasu's disease

Takayasu's disease is characterized by a "pulseless" condition which most often occurs in young females from Asian or South American areas. The cause of this disease remains obscure. Recently, we encountered monozygotic, Japanese, identical twin sisters, both of whom were diagnosed as having Takayasu's disease. The parents, two sisters, and one brother are healthy. HL-A typing analyses revealed that one haplotype found in the father had passed only to these twins. Such observations led us to search HL-A typing in Takayasu's disease to determine the possible participation of genetic factors in the pathogenesis of this morbid condition. Ten families, including that of our own patient, have been reported in the literature in Japan, as family cases of Takayasu's disease. HL-A typings in A and B locus analyzed in all family members of six families in attempts to find a common haplotype composed of A9, A10, B5, or BW40 in patients with Takayasu's disease, were confirmed statistically (chi 2 = 7.8, 0.01 less than p less than 0.05). In a population study, HL-A typing analyses of 65 patients with Takayasu's disease also revealed a high frequency of HL-A A10 and HL-A B5 with the level of 15.3 and 17.0 in the chi 2-test (p less than 10(-4)), as compared with the frequency in 128 healthy Japanese. These data strongly suggest that a genetic-related factor has to be given serious consideration.

Ultrastructural characteristics of occluded perforating arteries in stroke-prone spontaneously hypertensive rats

We studied ultrastructurally cerebral perforating arteries in 60 stroke-prone spontaneously hypertensive rats (SHRSP), which were sequentially killed at 4-52 weeks of age before showing symptoms of stroke. Another 24 SHRSP were killed soon after they showed symptoms of cerebral infarction. The initial vascular lesions observed in the asymptomatic group included focal cytoplasmic necrosis in the outer layers of the media. This change progressed to widespread medial necrosis with time. In the infarction group, numerous monocytes were seen adhering to the endothelium of the arteries having advanced medial damage. Following the adherence of monocytes to the endothelium, large amounts of plasma components were visible in the arterial wall. The accumulation of the plasma components (especially fibrin) thickened the wall, narrowed the lumen, and resulted in occlusion. These results suggest that monocytes may affect the endothelium, perhaps disturbing the so-called blood-brain barrier to proteins. The monocytes may therefore be closely related to the occurrence of arterial occlusion with resultant cerebral infarction.

Human airway trypsin-like protease stimulates human bronchial fibroblast proliferation in a protease-activated receptor-2-dependent pathway

Human airway trypsin-like protease (HAT) was isolated from airway secretions and localized to bronchial epithelial cells by immunohistochemistry. In the present study, we examined whether HAT could stimulate DNA synthesis and proliferation of primary human bronchial fibroblasts (HBF). HAT significantly stimulated the proliferation of HBF by 20–55%, a level similar to that of the mitogenic activity of lung mast cell tryptase (MCT). HAT also stimulated the incorporation of [3H]thymidine in HBF, and this HAT-induced DNA synthesis was abolished by leupeptin. Protease-activated receptor-2 (PAR-2) mRNA was expressed and localized to the cell surface in HBF. PAR-2 activating peptide (AP) also enhanced DNA synthesis, and both HAT and PAR-2 AP induced receptor internalization, similar to the response to trypsin. Pretreatment of HBF with anti-PAR-2 antibody significantly suppressed both HAT and PAR-2 AP-induced DNA synthesis. In addition, HAT and PAR-2 AP induced intracellular Ca2+mobilization in HBF. The HAT-induced increase in Ca2+was desensitized by pretreatment with trypsin or PAR-2 AP. U0126, a specific MAPK inhibitor, completely inhibited HAT-induced DNA synthesis as well as HAT-induced phosphorylation of MAPK. The effect of HAT and MCT together was additive, whereas the effect of HAT and insulin together on HBF DNA synthesis was synergistic. These results indicate that HAT stimulates fibroblast proliferation in bronchial airways through a PAR-2-dependent MEK-MAPK mediated pathway and that HAT is linked to airway processes involving fibroblasts.

Takayasu's disease in twin sisters. Possible genetic factors

Takayasu's disease is well-known for its characteristic clinical features and its elusive etiology. Recently, we encountered twin Japanese sisters, both of whom were diagnosed as having Takayasu's disease. The parents, two sisters, and one brother are healthy. Family history revealed the parents are first cousins. Analyses of serveral blood types and HLA typing were performed on all members of the family, and it was confirmed that these twins are monozygotic. Moreover, HLA typing analyses revealed that one haplotype found in the father was passed only to these twins. The history of consanguinity of the parents, the occurrence in twins, and the results of HLA typing suggest a genetic factor in the etiology of Takayasu's disease.

Effects of K-shell X-ray absorption of intracellular phosphorus on yeast cells

The effects of K-shell absorption of phosphorus atoms on yeast cells were investigated using synchrotron X-rays that were tuned to the resonance absorption peak (2153 eV). Three types of cellular effect (cell inactivation, induction of gene conversion at the trp-5 locus, and cell membrane impairment (changes in the permeability] were measured. It was demonstrated that the enhancement factor was 1.4 at the resonance peak regarding both lethality and the induction of gene conversion in reference of off-peak irradiation (2146 and 2160 eV). No difference was found between the two off-peak irradiation energies. No cell membrane impairment was detected, irrespective of the X-ray photon energies employed within the fluence range tested. These results strongly suggest that K-shell X-ray absorption in the resonance mode by cellular phosphorus atoms causes significantly more cellular effects than the off-resonance mode of absorption, probably via some specific changes induced in the phosphates of the DNA strand. Calculations using the number of phosphorus atoms in a defined size of the trp locus (2127 base pairs) on the DNA and the absorption cross-section of the resonance mode of phosphorus showed that gene conversion is inducible at a rate of 0.13 per X-ray photon absorption per locus. These results are discussed regarding the modes of K-shell photoabsorption.

Single- and double-strand breaks in pBR322 plasmid DNA by monochromatic X-rays on and off the K-absorption peak of phosphorus

Using a synchrotron irradiation system pBR322 plasmid DNA was irradiated under vacuum by monochromatic X-rays having five specific photon energies (2.147, 2.153, 2.159, 2.168 and 2.199 keV) both on and off the K-absorption peak (2.153 keV) of phosphorus. The single- and double-strand breaks (ssb and dsb) were measured as conversions of the closed circular form of DNA (form I) to open circular (form II) and linear (form III) forms respectively. Exposures to induce one strand break per molecule were lowest at the peak (2.153 keV), and highest at 2.147 keV; the ratios were 2.7 for ssb and 3.0 for dsb. The exposures for dsb were 21-26 times higher than those for ssb. When the exposures were converted to absorbed doses in grays the absorbed doses per ssb were almost independent of photon energy. This result indicates that a certain absorbed dose was necessary to induce a ssb, regardless of whether photons were absorbed by the K-shell of phosphorus or by other shells, or by other atoms. However, the absorbed dose per dsb at 2.147 keV was 1.17 times higher than that averaged over four X-ray energies above 2-153 keV, indicating that the K-shell absorption, and the subsequent Auger event, efficiently induce dsb. The results are also discussed concerning the number of photo-absorptions of the constituent atoms per DNA strand break.

Induction of chromosome aberrations in human lymphocytes by monochromatic X-rays of quantum energy between 4.8 and 14.6 keV

The induction of chromosome aberrations was studied in human peripheral blood lymphocytes irradiated in vitro with synchrotron-produced monochromatic soft X-rays of quantum energy in a range between 4.8 and 14.6 keV. These X-rays were more effective in producing chromosome aberrations (dicentrics and rings) than 60Co gamma-rays. The efficiency increased with increasing LET of the photoelectrons and their associated Auger electrons, reaching a maximum at a track average LET (L delta = 100, T) of around 4 keV/microns, and tended to decrease or become rather refractory with further increase of LET. This unique LET dependency was consistent with the dual nature of chromosome aberration formation, and interpreted as a reflection of a limited range of photoelectrons as compared with the size and intranuclear geometry of the elemental chromatin fibres as vehicles of damage interaction.

Long-term functional outcome of suprasellar germinomas: usefulness and limitations of radiotherapy

We investigated the long-term functional outcome of patients with suprasellar germinoma after radiotherapy to determine the usefulness and limitations of radiotherapy for these tumors. From among 54 cases of intracranial germ cell tumor at Kitasato University Hospital, 12 patients with suprasellar germinoma who were treated with radiotherapy but not chemotherapy retrospectively investigated for mental, hormonal and visual functions. The follow-up period ranged from 63 to 262 months (mean, 161.1 months). The mortality rate was zero and there was no recurrence of tumors. However, three patients treated with local irradiation alone showed metastasis to the ventricles or spinal cord. With regard to mental function, 50% of the patients showed remarkably low mental function after radiotherapy. With regard to pituitary hormonal function, deficiency of ADH, GH, ACTH, and TSH was documented in 75%, 41.7%, 16.7% and 8.3% of the patients, respectively, before radiotherapy. Prolactin was elevated in 50% of the patients. After radiotherapy, 91.7% needed hormone replacement. With regard to visual function, most patients showed an improvement or no change after radiotherapy. In conclusion, radiotherapy for suprasellar germinomas gave long-time survival. However, such radiotherapy may cause mental and pituitary hormonal dysfunction. Our results show that while radiotherapy is useful for treating suprasellar germinomas, its dose have some limitations.

Organic anion transport study in mutant rats with autosomal recessive conjugated hyperbilirubinemia

The EHBR is a mutant rat strain with congenital conjugated hyperbilirubinemia bred from a Sprague-Dawley rat. Transport of conjugated bilirubin, indocyanine green, and tetrabromosulfophtalein from liver to bile is severely impaired in these rats. Serum bilirubin amounts to 6.0 +/- 0.05 mg/dl (n = 4) in adult rats, with 97% conjugates. The bile flow is reduced to about 65% of the control group, whereas total bile acid in 10-min bile samples is similar. Liver histology of 10 week-old rats revealed neither intracellular pigmentation nor architectural abnormalities.

Increased transendothelial channel transport of cerebral capillary endothelium in stroke-prone SHR

Permeability of brain capillaries of stroke-prone spontaneously hypertensive rats (SHRSP) was studied using labelling (horseradish peroxidase) and cytochemical techniques at the cellular level. In the cerebral capillary endothelium the tracer molecules were quickly transported by abundant transendothelial channels which directly connected the capillary lumen to the subendothelial space. Transendothelial channels are abundant and should be postulated as structural formations engaged in the increased transport of proteins across the capillary endothelium. Ultracytochemical studies revealed that the channels, bounded by indistinct delimiting membranes, initially had no acid phosphatase activity. With the passage of time, however, the channels showed acid phosphatase activity and were lined with distinct membranes. These observations suggested that the lysosomes might fuse with the transendothelial channels and might play an important part in the transport of macromolecules.

Electrophysiological properties of isolated rat liver cells

The electrophysiological properties of isolated rat liver cells were studied using the patch clamp method in whole-cell configuration. The membrane potential in isolated hepatocytes was -42 +/- 7 mV (n = 20). The input resistance (Rin) and the time constant (tau m) were 51 +/- 17 M (the range of 34 to 180 M omega) (n = 20) and 4.2 +/- 1.0 msec (the range of 3 to 16.5 ms) (n = 20). Assuming that the specific membrane capacitance is 1 microF/cm2, the membrane resistance and membrane capacitance were 42. +/- 9.0 K omega cm2 and 87 +/- 27 pF. These values indicate that isolated rat hepatocytes are not abnormally permeable or leaky. The current-voltage relationship was linear with no rectification. The depolarizing pulse from the resting potential did not induce fast or slow inward currents even when norepinephrine or high Ca2 (3.6 mM) were applied. This indicates that there is no voltage-sensitive Ca2+ channel in the isolated hepatocytes.

Bystander cell killing in normal human fibroblasts is induced by synchrotron X-ray microbeams

Abstract The radiation-induced bystander response is defined as a response in cells that have not been directly targeted by radiation but that are in the neighborhood of cells that have been directly exposed. In the work described here, it is shown that bystander cell killing of normal human fibroblast WI-38 cells was induced by synchrotron microbeam X radiation. Cell nuclei in confluent WI-38 cells were irradiated with the microbeam. All of the cells on the dish were harvested and plated 24 h after irradiation. It was found that the bystander cell killing effect showed a parabolic relationship to the radiation dose when five cells were irradiated. At doses above 1.9 Gy, the surviving fraction increased to approximately 1.0. This suggests that induction of bystander cell killing may require some type of activity in the targeted cells, because the dose resulting in 37% cell survival was about 2.0 Gy. Bystander cell killing was suppressed by a pretreatment with aminoguanidine [an inhibitor of inducible nitric oxide (NO) synthase] or carboxy-PTIO (a scavenger of NO). These results suggest that NO is the chief initiator/mediator of bystander cell killing induced by X-ray microbeams.

Lumbar spinal subdural hematoma following craniotomy--case report

A 52-year-old female complained of lumbago and weakness in the lower extremities 6 days after craniotomy for clipping an aneurysm. Neurological examination revealed symptoms consistent with lumbosacral cauda equina compression. The symptoms affecting the lower extremities spontaneously disappeared within 3 days. Magnetic resonance (MR) imaging 10 days after the operation demonstrated a lumbar spinal subdural hematoma (SSH). She had no risk factor for bleeding at this site, the symptoms appeared after she began to walk, and MR imaging suggested the SSH was subacute. Therefore, the SSH was probably due to downward movement of blood from the cranial subdural space under the influence of gravity. SSH as a complication of cranial surgery is rare, but should be considered if a patient develops symptoms consistent with a lumbar SSH after craniotomy.

Thallium-201 stress scintigraphy in Takayasu arteritis

Thirty-eight women with Takayasu arteritis were studied using thallium-201 stress myocardial scintigraphy to assess the prevalence and pathophysiology of the perfusion abnormality. Twenty (53%) had abnormal scintigraphic findings (group A). Abnormal scans were divided into 3 groups: permanent defects in 6, reversible defects in 7 and slow washout in 7. The remaining 18 patients had normal scintigrams (group N). Group A had a tendency to be older and to have a high prevalence of complicated significant aortic regurgitation. Interventricular thickness plus left ventricular posterior wall thickness (26 +/- 7 vs 17 +/- 2 mm, p less than 0.01) and left ventricular mass (267 +/- 121 vs 133 +/- 39 g, p less than 0.01) were all greater in group A on echocardiography. The mean value of the central aortic pressure in systole was 170 +/- 15 mm Hg in the 7 catheterized patients in group A. Coronary ostial stenoses were present in 2 group A patients who showed reversible defects on scintigrams. These data indicate that the abnormal perfusion detected by imaging in patients with Takayasu arteritis was responsible for a decrease in coronary reserve or myocardial damage, or both, due to long-standing systemic hypertension or aortic regurgitation. Coronary artery disease should be considered if a reversible defect is present.

Hereditary factors in Takayasu's disease

In an attempt to provide support for the genetic link theory as related to the etiology of Takayasu's disease, we analyzed simultaneously A, B, and D loci of HLA antigens in 75 Japanese patients with the disease. Serving as control were 128 healthy Japanese. A statistically significant high frequency of BW52 and DHO was confirmed with the levels being 25.6 and 10.4, respectively, in the chi 2 test. A haplotype of A9-BW52-DHO was frequently evident in these patients as compared to the controls, and here also the statistical difference was significant. There appears to be a closer relationship of the gene to BW52 than to DHO. A survey of the homozygote of BW52 revealed 6 of 75 patients with BW52; however, statistically speaking, this rate did not differ from the expected one. Thus, our analysis of HLA illustrates the genetic factors involved in Takayasu's disease. The genes are located between the B and D loci and are closer to BW52 than DHO and these genes have a dominant character.

A low molecular weight binding protein for organic anions (Z protein) from human hepatic cytosol: purification and quantitation

Human Z protein from liver was purified to homogeneity. The protein has a molecular weight of 11,000 an an isoelectric point of pH 5.8. Circular dichroism spectra of Z protein-bilirubin (unconjugated and diglucuronide) complexes revealed two ellipticity extrema, a negative peak at 460 nm, and a positive peak at 410 nm. Human serum albumin had a higher affinity for bilirubin than did Z protein. Fluorescence studies showed the approximate association constants of this protein and bilirubin, bromosulfophthalein, and indocyanine green were 10(6) M-1, 10(5) M-1, and 10(6) M-1, respectively. Immunofluorescence studies revealed that Z protein was localized in the cytoplasm of hepatocytes, proximal tubular epithelium, and epithelial cells of the small intestine. Radioimmunoassay studies were done to assess the amount of Z protein in controls and in various liver diseases. The highest concentrations of Z protein were found in the liver, kidney, heart muscle, and small intestine, in that order. In cases of acute and chronic hepatitis, hepatic Z protein concentrations were generally decreased, whereas serum Z protein concentrations were increased. In contrast, both serum and hepatic Z protein concentrations were decreased in cases of constitutional hyperbilirubinemia.