The hydration of Ras p21 in solution during GTP hydrolysis based on solution X-ray scattering profile

The small-angle X-ray scattering technique was used to characterize the structure in solution of wild type ras p21 as well as the oncogenic proteins mutated at residue 12, 59, or 61. In the presence of GDP, the radius of gyration, Rg, determined for wild type ras p21 was 16.89 +/- 0.01 A, while the wild type ras p21 bound to the GTP analogue GDPNHP (5'-guanyl imido diphosphate beta-gamma-imidoguanosine 5'-triphosphate) showed an Rg value of 17.46 +/- 0.01 A, which is 3.3% larger. The result shows that ras p21 expands upon GTP binding. The Rgs of mutated proteins were 17.04 +/- 0.01, 16.98 +/- 0.01, and 17.03 +/- 0.01 A for the Gly-12 to Val, Ala-59 to Thr, and Gln-61 to Leu mutants, respectively. The scattering profiles were analyzed by simulation of hydrated ras p21, based on the crystal atomic coordinates, and it was concluded that the ras p21 molecule incorporates 20% more bulk water upon GTP binding. The increase of bulk water is especially conspicuous around the interface between switch I (residues 32-40) and switch II (residues 60-66) regions. This suggests that hydration plays an important role in the interaction with GAP.

Polyhedral assembly of a membrane protein in its three-dimensional crystal

A novel ordered assemblage of bacteriorhodopsin, a transmembrane protein functioning as a light-driven proton pump, is found in its three-dimensional crystal. Atomic force microscope images of the crystal surface reveal that spherical protein clusters with a diameter of approximately 50 nm are hexagonally close-packed. Electron micrographs of mechanically disintegrated crystals show that the inside of the protein cluster is filled with the mother liquor. The crystal is made up of hollow protein clusters. When disintegrated crystals are illuminated in the presence of a lipophilic anion, a significant alkalization of the external medium occurs. This result indicates that the protein cluster contains native lipids and that the cytoplasmic side of the protein faces the external medium. X-ray diffraction patterns and the observed diameter of the spherical shell suggest that approximately 200 bacteriorhodopsin trimers are aligned on a polyhedral surface lattice. Another remarkable feature of the spherical assemblies of bacteriorhodopsin is that they fuse with each other at low ionic strength and occasionally form a tubular or doughnut-like structure. The concept of membrane protein polymorphism is introduced on the basis of these observations, and it is used to describe the dynamic structure of some other biological membranes.

Malignant duodenocolic fistula: report of a case and considerations for operative management

Malignant duodenocolic fistula is a rare complication of gastrointestinal malignancy. We present herein the case of a 34-year-old female in whom a large duodenocolic fistula was caused by advanced transverse colonic carcinoma. Right hemicolectomy combined with pancreaticoduodenectomy enabled en bloc resection of the tumor, and the patient has been free of disease for 1 year and 8 months postoperatively. A review of the international literature, including 33 cases reported in Japan, indicates that if the disease is curable, the treatment of choice is right hemicolectomy with pancreaticoduodenectomy, whereas if it is not curable but locally resectable, the best palliation appears to be right hemicolectomy with partial duodenectomy to include the fistulous tract. Dehiscence of the duodenal wound closure associated with partial duodenectomy can be prevented by using the mucosal or serosal patch techniques with intestinal loops. These therapeutic principles are also applicable for colonic carcinoma which massively involves the duodenum without fistula formation.

[An atypical multilocular cystic nephroma presenting recurrent lumbago]

A 54-year-old female suffered from repeated flank pain. A large, irregular cystic mass that compressed and distorted the left pelviocalyceal system was found. She underwent left nephrectomy. The cyst arose from the inner zone of the kidney. Although monolocular grossly, it was compatible with the multilocular cystic nephroma on the microscopic examination.

Neurotrophic action of gliostatin on cocultured neurons with glial cells

Gliostatin is a polypeptide factor (apparent M(r) = 100 k with a homodimeric structure comprising two 50 kDa subunits) acting on cortical neurons (neurotrophic action) as well as astrocytic cells (growth inhibition). Under the coculture system of cerebral cortical neurons and astrocytes from fetal rats (E15 or E16), the neurotrophic action of gliostatin was examined immunocytochemically. Immunostaining by an anti-neurofilament (NF) monoclonal antibody visualized a marked neurite-outgrowth and interconnecting bundles of neuritic processes induced by gliostatin in the coculture system. Neurons stimulated by gliostatin formed dense aggregates in clumps, while neurons in control coculture spread out. Gliostatin has also shown survival-promoting effects on neurons. Furthermore, it was shown that gliostatin induced the differentiation of protoplasmic astrocytes to fibrous astrocytes. These results further support our previous contention that gliostatin plays physiological roles on neuronal and glial development.

Disappearance of pulmonary metastases by OK-432 treatment in a case of hepatocellular carcinoma

We report here a case of hepatocellular carcinoma (HCC) with multiple lung metastases, which were disappeared by treatment of OK-432. The patient was a 65-year-old man and was diagnosed in 1986 with a small (17 x 11 mm) HCC in the anterior-superior segment of the liver. A part of the right hepatic lobe including the tumor was surgically removed, and transarterial injections of adriamycin (10 mg/week) and subcutaneous injections of OK-432 (10 KE/week) were given. Two and a half years later, recurrence of HCC in the liver and its invasion to vena cava inferior (IVC) were found. OK-432 administration was then stopped and percutaneous ethanol injection therapy (PEIT) was performed 10 times. Six months later, the PEIT was effective and the liver tumor with IVC invasion diminished. However, multiple lung metastases were visible on roentgenograms of the chest, and serum alphafetoprotein (AFP) concentration increased to 50,000 ng/ml. The OK-432 treatment resumed. After 6 months of OK-432 treatment, the multiple lung metastases were disappeared and the serum AFP level decreased to 100 ng/ml. At present, the patient is surviving without any sign of recurrence in either the liver or the lung. The clinical course of this case suggests that OK-432 might have effectively treated lung metastases of HCC, although the exact mechanisms are at present unclear.

Structural change of jack bean urease induced by addition of surfactants studied with synchrotron-radiation small-angle X-ray scattering

Both the quaternary and subunit structures of jack bean urease in solutions with ionic and nonionic surfactants have been studied by small-angle X-ray scattering using a synchrotron-radiation source. The effects of those surfactants on the enzyme activity of urease have also been investigated in the same kind of solvent systems as those used for the scattering experiments. The present results show that the quaternary structure of urease in solution is fairly elongate and that by the relatively minor binding of SDS (SDS/protein = 0.23/1) the native urease molecule is dissociated into six identical subunits with nearly spherical structures. In addition the enzyme activity of urease was mostly retained under every solvent condition investigated, indicating that the subunit found in the present scattering experiments is the fundamental monomeric unit for both the quaternary-structure formation and enzyme function of urease.

BU-4794F, a new beta-1,3-glucan synthase inhibitor

New beta-1,3-glucan synthase inhibitor (BU-4794F) was isolated from the culture broth of Gilmaniella sp. FA4459. Structural studies indicated that it was a novel member of the papulacandin group of antibiotics.

Morphological changes of Candida albicans induced by BMY-28864, a highly water-soluble pradimicin derivative

The time course of BMY-28864-dependent morphological changes in Candida albicans A9540 was studied by electron microscopy. Scanning electron microscopy revealed that BMY-28864 often induced cell surface deformations such as abnormal swelling and bulging around budding sites and bud scars. The cell membrane damage was visualized by freeze-fracturing technique as deep pit-like invaginations. Transmission electron microscopy with thin-sectioned specimens also demonstrated that BMY-28864 induced cell membrane invaginations together with cell membrane detachment from the cell wall, nuclear membrane fragmentation and mitochondrial aberration. Statistical sequence analysis of the prominent BMY-28864-dependent morphological changes of the yeast cells led to the conclusion that BMY-28864 first attacked the cell membrane and then caused disintegration of other intracytoplasmic organelles, resulting in the lethal effect.

Effect of dietary fat and cholesterol on dimethylbenz[a]-anthracene-induced mammary tumorigenesis in Sprague-Dawley rats

The effect of dietary fats and cholesterol on dimethylbenz[a]-anthracene-induced mammary tumorigenesis was studied in female Sprague-Dawley rats. When the dietary fat source (at the 5% level) was palm oil (saturated fat) or corn oil (unsaturated fat), dietary cholesterol at the 0.2% level increased the tumor number of rats fed corn oil, but not those fed palm oil. Perilla oil (rich in alpha-linolenic acid) reduced tumor development as compared with safflower oil (rich in linoleic acid), but again dietary cholesterol at the 0.5% level diminished the favorable effect of n-3 polyunsaturated fatty acid (PUFA). The adverse effect of cholesterol was also observed in the n-6 PUFA fat. The promotive effect of dietary cholesterol was not necessarily associated with the change in the production of prostaglandin E2 by the tumor tissue or in the immunopotentiation. These results at least stress that the contrasting effects of dietary fats should be carefully evaluated whether cholesterol is present simultaneously or not.

Carcinoma of the ampulla of Vater

A consecutive series of 36 Japanese patients with ampullary carcinoma who underwent a pancreatoduodenectomy at the Department of Surgery I, Kyushu University Hospital during the past 20 years were reviewed clinicopathologically to study prognostic factors. A univariate generalized Wilcoxon test showed that preoperative serum carcino-embryonic antigen (CEA) concentration, venous invasion, lymphatic permeation and perineural invasion were significant parameters. A multivariate Cox regression analysis showed that venous invasion was the only significant variable. In a sequential serum CEA follow up of 10 patients, an elevation of serum CEA levels was seen to correspond to the clinical development of a recurrence in six, while a high concentration of serum CEA was not evident despite the clinical manifestation of a recurrence in two, and serum CEA levels remained within the normal limits with no evidence of a recurrence in two others. According to the death certificates of 15 patients, where an exact site of metastasis was available, 11 died from liver metastasis, three from lung metastasis and one from peritoneal dissemination. These findings support the theory that a histologic invasion of the venous space is an independent prognostic factor and close attention should be paid to any signs of haematogenous metastasis, such as to the liver and lung, as well as to a serial serum CEA follow up.

Studies on the mode of antifungal action of pradimicin antibiotics. II. D-mannopyranoside-binding site and calcium-binding site

Based on the structure-activity relationship data of BMY-28864 and related pradimicin derivatives, the calcium salt-forming ability and the D-mannopyranoside-specific visible absorption maximum shift of BMY-28864 were analysed in the ternary complex formation of BMY-28864 with D-mannopyranoside and calcium. The free C-18 carboxyl group of BMY-28864 was proved to be the sole site for binding to calcium, while no hydroxyl groups of the aglycone were involved in calcium salt formation. The stereospecific D-mannopyranoside-recognizing ability of BMY-28864 was completely abolished by removal of the C-5 disaccharide moiety, and, more particularly, of the C-5 thomosamine moiety. Close relationship of these findings with the antifungal action was also supported by the in vitro antifungal assay and the potassium leakage induction test.

Studies on the mode of antifungal action of pradimicin antibiotics. III. Spectrophotometric sequence analysis of the ternary complex formation of BMY-28864 with D-mannopyranoside and calcium

Sequence of reactions in the process of ternary complex formation of BMY-28864 with D-mannopyranoside and calcium was spectrophotometrically determined under more strict analytical conditions using metal-free preparations of sugars and the pradimicin derivative at a bandpass slit width of 1 nm. In the first phase of ternary complex formation, BMY-28864 stereospecifically recognized and bound to D-mannopyranoside in the absence of calcium, which was revealed by a visible absorption maximum shift of ca. 8 nm. Subsequently, the BMY-28864-D-mannopyranoside conjugate reacted with calcium to yield the ternary complex, which was detected by an additional visible absorption maximum shift of ca. 8 nm. When the three components were mixed at the same time, both phases simultaneously occurred to produce the ternary complex which was accompanied by a visible absorption maximum shift of 16 nm in total. Based on this two-phased reaction sequence, the mechanism of ternary complex formation of BMY-28864 with D-mannopyranoside and calcium was reexamined in details. Terminal D-mannopyranoside was confirmed to be essential as BMY-28864-specific sugar receptor by in vitro analysis and animal cell experiments. While calcium, strontium and cadmium behaved similar in the in vitro ternary complex formation, the yeast and animal cell experiments showed that only calcium played a dual role as a base in the ternary complex formation and as an effector in physiological disturbances leading to cell death.

Reversibility of hepatopulmonary syndrome evidenced by serial pulmonary perfusion scan

A patient with liver cirrhosis who exhibited marked hypoxemia is presented. An abnormal dilatation of intrapulmonary capillaries was evidenced by perfusion lung scan, contrast-enhanced echocardiography, and histological examinations of lungs. Serial perfusion lung scan disclosed that the radioisotope uptake by extrapulmonary organs was significantly increased and uptake by both lungs was significantly decreased during the state of severer hypoxemia. Shunt quantification method revealed that intrapulmonary right-to-left shunt ratio also paralleled the extent of hypoxemia. The pathophysiology of hepatopulmonary syndrome appeared to involve a reversible intrapulmonary vascular dilatation. The perfusion lung scan could semiquantitate the severity of intrapulmonary vascular dilatation and could offer the efficient method to follow their progress.

Studies on the mode of antifungal action of pradimicin antibiotics. I. Lectin-mimic binding of BMY-28864 to yeast mannan in the presence of calcium

BMY-28864 (BMS-181184), a water-soluble pradimicin derivative, specifically bound on the yeast cell surface in the presence of calcium, which was considered to be the initial step that triggered chain reactions leading to the fungicidal action. Close cause-effect relationships of the cell wall binding of BMY-28864 with its antifungal activity and potassium leakage induction were observed by Candida albicans and Saccharomyces cerevisiae in the presence and absence of calcium. Using mannan and methyl alpha-D-mannopyranoside as specific sugars, the mode of binding of BMY-28864 to sugar was examined in vitro in the presence of calcium. Quantitative component analysis revealed that the precipitate of BMY-28864 with methyl alpha-D-mannopyranoside and calcium was a ternary complex possessing a molar component ratio of 2.1:4.3:1.0. These findings altogether proved that BMY-28864, although not protein, recognized specific sugars such as mannose in the same manner as lectin, and that the ternary complex formation of BMY-28864 with specific sugar and calcium was the first step for expression of the selective antifungal action of the pradimicin.

Protective effect of eurystatins A and B, new prolyl endopeptidase inhibitors, on scopolamine-induced amnesia in rats

Eurystatins A and B, which are produced by Streptomyces eurythermus R353-21, potently inhibited Flavobacterium prolyl endopeptidase (PED) with IC50 values of 0.004 and 0.002 micrograms/ml, respectively, while no inhibition was observed against another 5 proteases, even at 100 micrograms/ml. The protective effect of eurystatins A and B against scopolamine (3 mg/kg, i.p.)-induced amnesia in rats was evaluated by the step-through one-trial passive avoidance method. When administered i.p. 30 min prior to the acquisition trial, both eurystatins A, at 2-8 mg/kg, and B, at 4-8 mg/kg, significantly protected rats from the amnesic effect of scopolamine without behavioral side effects.

[Analysis of factors influencing the recent decline in birth rate in Tokyo]

This study was undertaken in an attempt to find factors which affected the recent declining birth rate in Tokyo. Vital statistics of the female population, age 20-39, for the period of 1970 through 1985 for Tokyo were compared to national averages. Indices examined were birth rate, percentage of married women, birth rate for married women, and birth rate for married women by live birth order. Results thus obtained were as follows: 1. Birth rates for females aged 20-24 and 25-29 were largely dependent on percentages of married women rather than birth rates for married women both in Tokyo and in the nation as a whole, while the birth rates for females aged 30-34 and 35-39 were more dependent on birth rates for married women. 2. Percentages of married women aged 20-24 and 25-29 decreased during the observation period both in Tokyo and in the nation as a whole. 3. Birth rates for married women aged 30-34 and 35-39 dropped in the first 5 or 10 years of observation in both groups as a result of the reduction in high order live births. Thereafter, the decline changed to an upturn trend. 4. Yearly changes of birth rate, percentage of married women, birth rate for married women, birth rate for married women by live birth order, and birth rate of first child for married women appeared to have the same timing both in Tokyo and in Japan as a whole in each age category.(ABSTRACT TRUNCATED AT 250 WORDS)

[A case of foreign-body granuloma treated with steroid hormone]

A 68-year-old woman was admitted to Nagasaki University Hospital complaining of gait disturbance. She had suffered from hemifacial spasm since the age of 56 and had undergone neurovascular decompression for the spasm in another hospital five years before admission. At surgery, the vertebral and posterior inferior cerebellar arteries had been separated from the facial nerve with cotton string and attached to the clivus with alpha-cyanoacrylate monomer. Although the hemifacial spasm had improved postoperatively, the patient had suffered from gait disturbance and headache for two months after surgery, and hearing disturbance and hemifacial palsy on the same side as the hemifacial spasm for seven months after surgery. At the time of the present admission, contrast-enhanced CT scan revealed a mass at the left cerebello-pontine angle. In the T1-weighted inversion recovery sequence of MRI, the mass showed a slightly lower intensity than that of surrounding tissues. In the T2-weighted spin echo sequence of MRI, it showed a heterogenously low intensity with some high intensity spots. We diagnosed this mass as a foreign-body granuloma and treated it with dexamethasone injected intramuscularly. Edema decreased around the granuloma, and her gait disturbance improved markedly. But the hearing disturbance and hemifacial palsy did not improve at all, indicating that these two symptoms might not be caused only by brain edema but also by direct damage due to granuloma or inflammation. We thought that the steroid hormone elicited good results in the treatment of inoperable foreign-body granuloma.

Suppressive effect of sesamin against 7,12-dimethylbenz[a]-anthracene induced rat mammary carcinogenesis

The effects of dietary supplementation of sesamin on 7,12-dimethylbenz[a]anthracene (DMBA)-induced mammary carcinogenesis in female Sprague-Dawley rats were studied. Experimental diets containing 0.2% sesamin (an equiweight mixture of sesamin and episesamin) or 0.2% alpha-tocopheryl acetate were given to rats starting 1 week before intragastric administration of DMBA (10 mg/rat). Sesamin significantly (p less than 0.05) reduced the cumulative number of palpable mammary cancers by 36% at 12 weeks post-DMBA administration compared with animals on a control diet. Alpha-tocopheryl acetate inhibited both the incidence and the cumulative number of mammary tumors by 20% and 45%, respectively. Concentrations of lipid peroxides in plasma, liver and tumors were all decreased in both sesamin and alpha-tocopheryl acetate groups. The activity of peripheral blood mononuclear cells (PBMC) increased in rats fed sesamin (140 to 150% of the control and alpha-tocopheryl acetate groups). Fatty acid compositions of plasma, liver and tumor phosphatidylcholine showed a decreased tendency of the metabolism of linoleic acid to arachidonic acid and hence of the plasma concentration of prostaglandin E2 in the sesamin group. The inhibitory effect of sesamin on DMBA-induced mammary carcinogenesis may be ascribed, at least in part, to immunopotentiation and increased antioxidative activity.

X-ray scattering study of the shape of the DNA region in nucleosome core particle with synchrotron radiation

The structure of the DNA region in rat thymus nucleosome core particle has been studied by synchrotron X-ray scattering analysis and the contrast-variation technique has been applied to determine the contribution of the DNA to the total scatterings. Small-angle contrast-matching measurements show that the entire core particle and isolated histone octamers are contrast-matched by solvents containing 64 and 54% (w/w) sucrose, respectively. At a contrast of 54% sucrose, where the scattering of the DNA dominates, the scattering data extending to higher angle of about 0.05 A-1 have been collected from relatively concentrated solutions (10 mg/ml) of core particles and interpreted on the basis of the regular helical model for the DNA region. The model calculations show that the shape of the DNA around the histone core is approximately by 1.8 turns of regular helix of 42 A radius and 28 A pitch. These values for helical parameters of our model are in good agreement with those of the structure of DNA in crystallized nucleosome cores shown by earlier diffraction studies.

[Gram-positive cocci in the urinary tract. Do they influence the postoperative course of transurethral prostatectomy?]

The influence of gram-positive cocci on the postoperative course of transurethral prostatectomy was analysed on 463 patients. The half of isolated cocci was Enterococcus, followed by S. epidermidis and S. aureus. The rates of postoperative urinary infection by gram-negative bacilli were nearly the same for patients with preoperative gram-positive cocci infection and those without any of bacteria (3/79 vs. 9/310). Patients who developed new infection with gram-negative bacilli had fever, in contrast to patients with new gram-positive cocci infection. Gram-positive cocci prolonged the postoperative pyuria but not so long as gram-negative bacilli. All these findings suggest that infection caused by gram-positive cocci is not so severe as that caused by gram-negative bacilli.

[Carcinoma of the gastric remnant fed by the accessory left gastric artery--a case report]

A 65-year-old female, who had undergone partial gastrectomy with Billroth II reconstruction for duodenal ulcer 22 years ago, visited our hospital with a complaint of anorexia. Roentgenogram and endoscopic examination revealed a protruding lesion on the posterior wall of the gastric remnant. An endoscopic biopsy specimen was histologically regarded as carcinoma. Proper hepatic arteriography revealed an accessory left gastric artery arising from the left hepatic artery, which was a main feeder to the tumor. Total gastrectomy with lymph node dissection and splenectomy were performed. Histology of the tumor was poorly differentiated adenocarcinoma located in the submucosal layer. To our knowledge, there is no report about the carcinoma of the gastric remnant fed by the accessory left gastric artery.

[In situ hybridization study of human papillomavirus from the penile cancer]

The histochemical detection of human papillomavirus (HPV) was performed using the technique of in situ hybridization from the formalin fixed paraffin embedded specimens of penile carcinoma and condylomata+ acuminata . One of 19 penile cancer cases (5.3%) revealed the positive staining on the nuclei of the tumors for HPV type 16/18. However, the positive nuclei were scattered and localized in small part of the tumor which showed no koilocytosis. On the contrary, 11 of 12 condyloma acuminata cases (91.7%) showed positive staining on the nuclei of the tumors for HPV type 6/11, also 5 of the 11 cases (45.5%) revealed cross reaction for other type of HPV. The HPV types 6/11, 16/18 and 31/33/35 may be unrelated to the pathogenesis of the Japanese penile carcinoma. However, further study is necessary to evaluate that the number of HPV-DNA copy in our cases is too small, or the other type of HPV is responsibility.

Usefulness and limitations of methotrexate, vinblastine, doxorubicin and cisplatin for the treatment of advanced urothelial cancer

Methotrexate, vinblastine, doxorubicin and cisplatin were used to treat 66 patients with advanced urothelial cancer. Of these 66 patients 58 could be evaluated for response. A total of 84 sites was evaluated in these patients. Response rates were 73% in the bladder, 67% in the renal pelvis, 50% in the ureter, 60% in the lung, 68% in the lymph nodes, 14% in the liver and 25% in the bone. Ten patients (17%) had a complete response and 23 (40%) had a partial response, with an over-all response rate of 57% (the 95% confidence limits are 44 to 69%). The mean durations of response were 10.1 months for complete response patients and 6.2 months for partial response patients. The most prominent toxicity was severe myelosuppression that resulted in 2 septic deaths. While this chemotherapy regimen provided an excellent over-all response rate, the matters of concern were the short duration of response and low effectiveness in the liver and bone.

Dynamic mechanism of the self-assembly process of tobacco mosaic virus protein studied by rapid temperature-jump small-angle X-ray scattering using synchrotron radiation

The self-assembly process of tobacco mosaic virus protein (TMVP) was observed by rapid temperature-jump time-resolved solution X-ray small-angle scattering using synchrotron radiation. The temperature-jump device used for the X-ray measurements is rapid enough to cope with even the fastest-assembling process of TMVP, and accumulates data of reasonable signal-to-noise ratios with a minimum total counting time of 7.5 seconds. The measurements suggested that the 20 S disk of TMVP polymerized to stacked disks (short rods). The time to complete stacking varied from approximately 25 seconds to approximately 1200 seconds, depending on the solution condition and magnitude of the temperature gap. Higher protein concentration, ionic strength and temperature favoured faster association. The results were analysed in terms of a set of kinetic equations that describe the two-stage aggregation of TMVP with an equilibrium constant K1, and two rate constants k+2 and k-2 for association and dissociation of disks, respectively. The consistency of the analysis suggests that the TMVP assembly proceeds in two steps of: (1) the aggregation of A-proteins into double-layered disks; and (2) the stacking of double-layered disks. The kinetic analysis indicated that the stacking belongs to the lowest range of protein-protein interaction system.

Isolation of a possible archetypal JC virus DNA sequence from nonimmunocompromised individuals

We molecularly cloned JC polyomavirus DNAs from urine samples of eight nonimmunosuppressed patients and two healthy individuals. The cloned viral DNAs all contained an archetypal regulatory sequence from which various regulatory sequences of JC polyomavirus isolates derived from patients with progressive multifocal leukoencephalopathy could have evolved by deletion and amplification.

Structural change of troponin C molecule and its domains upon Ca2+ binding in the presence of Mg2+ ions measured by a solution X-ray scattering technique

A small-angle X-ray scattering study on troponin C showed that two domains of the molecule move closer to each other and the molecule shrinks along its long axis upon Ca2+ binding in the absence of Mg2+ ions (Fujisawa, T., Ueki, T., & Iida S. (1988) J. Biochem. 105, 377-383). When Mg2+ ions bind to troponin-C, the radius of gyration changes from 27.8 to 24.3 A and the average radius of gyration of the two domains is estimated to be 15.1 A. These radii indicate that the distance between the centers of the two domains is 38.1 A. Such a change is analogous to the previous result for troponin C with two Ca2+ ions bound at the high-affinity sites. Thus, the structural behavior of troponin C molecule is essentially the same when Ca2+/Mg2+ ions bind to its high-affinity sites. On the other hand, the effect of Ca2+ binding to the low-affinity sites in the presence of Mg2+ ions is quite different from the previous result. The binding of Ca2+ ions causes a dimerization of troponin C molecules with an apparent constant of 511 M-1. Such a characteristic behavior, implying the occurrence of a surface property change, may be related to the physiological role of troponin C molecule in the muscle. The scattering experiments on the tryptic fragments of troponin C also had interesting and important results: the C-domain shrinks, with the radius of gyration changing from 17.0 to 14.9 A while the N-domain swells from 13.9 to 15.0 A upon Ca2+ binding. Such an opposite change is consistent with the results of circular dichroism and spectroscopic studies of the domains.

Reversibility of pulmonary telangiectasia in liver cirrhosis evidenced by serial dynamic pulmonary perfusion imaging

Pulmonary perfusion imaging with Tc-99m MAA revealed significant uptake in the lungs, brain, spleen, and both kidneys of a 48-year-old woman with liver cirrhosis and pulmonary telangiectasia associated with marked hypoxemia and cyanosis. Dynamic pulmonary perfusion imaging revealed a gradual reduction after peak uptake in both lungs. Several weeks after albumin replacement, the hypoxia and dyspnea disappeared with no change in hepatocellular function. At that time, dynamic pulmonary perfusion imaging revealed a plateau-like time-activity curve of uptake in the lungs, as compared with the findings obtained during the state of severe hypoxemia. These observations suggest that pulmonary telangiectasia in a patient with liver cirrhosis may be due to functional vasodilatation. Serial dynamic pulmonary perfusion imaging indicates the passage of the MAA particles through the widened lumen of the pulmonary alveolar capillaries.

Calcium-induced shape change of calmodulin with mastoparan studied by solution X-ray scattering

Solution x-ray scattering using synchrotron radiation as an x-ray source was used to analyze the Ca2+-dependent shape change of pig brain calmodulin in detail. The radius of gyration of calmodulin at 10 mg/ml was increased by 0.9 A. The increase was nearly completed when 2.5 mol of Ca2+/mol of calmodulin was added, whereas the radius of gyration of calmodulin with mastoparan decreased by about 3 A with an increasing Ca2+ concentration up to 4 mol of Ca2+/mol of calmodulin. At a moderate angle of region, both scattering profiles from calmodulin with or without Ca2+ displayed clear humps at s = 0.03 A-1 which are characteristic of a dumbbell structure. However, in the presence of mastoparan, the hump in the scattering profile became obscure and later disappeared with the third and fourth Ca2+ binding to calmodulin. These findings are attributable to the Ca2+-induced shape change of calmodulin with mastoparan from a dumbbell structure to a non-dumbbell structure in which the distance between the two lobes of calmodulin become closer by a bend in the central helix.

Circular dichroic study of conformational changes in ovalbumin induced by modification of sulfhydryl groups and disulfide reduction

Sulfhydryl groups of ovalbumin were chemically modified under denaturing conditions in the absence and presence of dithiothreitol, and effects on the secondary structure of the protein were investigated by circular dichroic (CD) measurements. The contents of alpha-helix, beta-structure, and "random coil" (unordered, nonrepetitive structure) were estimated by simulation of the CD spectra and using the parameters established by Chen et al. The principal findings were these: (1) Modification of the four free sulfhydryl groups [with 5,5'-dithiobis(2-nitrobenzoic acid), iodoacetate, or iodoacetamide] caused ovalbumin molecule to unfold partially and to undergo primarily helix-to-beta structure transition. (2) Cleavage of the disulfide bond did not lead to a further conformational change in the sulfhydryl-modified ovalbumin. (3) The remaining helical structure existed in a destabilized state with increased chain flexibility, as the modified protein was very susceptible to denaturation by guanidine and urea. (4) Further evidence for increased chain flexibility was provided by the finding that sodium dodecyl sulfate (SDS) induced helix formation in the sulfhydryl-modified, but not native, ovalbumin. And (5), since both nonreduced and reduced proteins, with their sulfhydryl groups blocked, displayed similar transitions in solutions of guanidine, urea, and SDS suggested that the single disulfide bond did not physically constrain the ovalbumin molecule.

[M-VAC chemotherapy for patients with lymph node metastases and/or locally advanced bladder carcinoma]

Sixteen patients with lymph nodes metastases and/or locally advanced bladder carcinoma were treated with a combination chemotherapy regimen consisting of methotrexate, vinblastine, adriamycin, and cisplatin (M-VAC) from November 1986 through September 1988. There were 14 men and 2 women. The median age was 61.9 years, with a range from 43 to 81 years. Complete response (CR) was observed in 6 of 16 patients (38%), partial response (PR) was confirmed in 5 of 16 patients (31%), and overall response rate was 69%. Median duration of response was 10.3 and 5.2 months in CR and PR patients, respectively. The myelosuppression with this regimen was tolerable. This study demonstrates that the M-VAC regimen is effective in the invasive bladder carcinoma with or without lymph nodes metastases. However, the duration of response is relatively short, and the true long-term benefits of this regimen remain to be determined.

[Bladder carcinoma in situ which harbored human papilloma virus. A case report]

Last year, we reported that human papilloma virus type 16 genome (HPV 16 genome) was detected in a case (S.Y.) of bladder carcinoma in situ (bladder CIS) (Cancer Res., 1988). Since then, a number of bladder tumors other than CIS were searched for HPV genome. However, no HPV genome was detected in the bladder tumors. From the results, we consider that HPV may not have a relation with all types of bladder tumor but with only a part of it. In the current report, the case (S.Y.) is presented more precisely than before, in particular on the characteristic bladder lesion. The patient was a 40-year-old female with immunodeficiency and anemia who was referred from a hospital with a complaint of asymptomatic pyuria. Cystoscopic examination revealed a bladder tumor, well-demarcated, white and velvety lesion with slight elevation. On November 25, 1987, she underwent total cystectomy, resection of the anterior vaginal wall and of a part of vulval skin, and ileal conduit formation. Postoperative course was stormy because of bleeding from the wounds and thrombophlebitis in the right femoral vein. In spite of the episodes, she eventually recovered and was discharged 2 months later. However she was readmitted 9 months later due to severe anemia which was ascribed to acute myelogenous leukemia. She is now on cancer chemotherapy for leukemia.

[M-VAC (methotrexate, vinblastine, adriamycin and cisplatin) chemotherapy in advanced renal pelvic and ureteral carcinoma]

Seventeen patients with advanced renal pelvic and ureteral carcinoma receiving M-VAC chemotherapy were evaluated. There were 10 men and 7 women ranging in age from forty-two to seventy-eight years with a mean of sixty-six years. The primary sites of carcinoma were renal pelvis in 4 patients, ureter in 12, renal pelvis and ureter in 1. Fifteen patients had transitional cell carcinoma, one patient had transitional cell carcinoma mixed with squamous cell carcinoma and the histology of one patient was not identified. The median number of treatment cycles was 2.6, ranging from 1 to 6. Significant remissions following the treatment were observed in 5 of 8 primary lesions, 6 of 11 lymph nodes, 2 of 3 lung lesions and 2 of 5 bone lesions, respectively. However, the responses were not seen in 4 liver lesions. Two patients achieved a complete response (CR), 7 had a partial response (PR), 6 had stabilization of their disease, 2 had progressed, and the overall response rate was 52.9%. Two CR patients remain free of disease. Relapse or recurrence was seen in 4 of the 7 patients who achieved PR, and the median duration of response was 6.4 months. While the myelosuppression with this regimen was tolerable, the decreases of white blood cell and platelets count were significant in patients who had undergone prior irradiation. These results indicate that the M-VAC regimen is effective in patients with advanced upper urothelial malignancy. Further, a short response and a poor effectiveness in the metastases of liver and bone remain to be overcome.

Synchrotron X-ray scattering study of chromatin condensation induced by monovalent salt: analysis of the small-angle scattering data

Small-angle X-ray scattering experiments were carried out on rat thymus chromatin in "native" and "H1-depleted" states at various NaCl concentrations using synchrotron radiation. From the analysis of cross-sectional Guinier plots, the radius of gyration of the cross section (Rc) and the mass per unit length (Mc) of native chromatin were evaluated. In the absence of NaCl, the cross section of chromatin filament has a radius of gyration of 3.44 nm, suggesting the structure corresponding to the "10 nm" filament. With increasing NaCl concentration, the Rc value increases steeply to 6.74 nm at 5 mM NaCl and then gradually to 8.82 nm at 50 mM NaCl, whereas the Mc value, which is determined relative to that of tobacco mosaic virus (TMV), increases steadily from 1.58 nucleosomes per 10 nm in the absence of NaCl to 7.66 nucleosomes per 10 nm at 50 mM NaCl. However, since calibration with TMV tends to overestimate the Mc value, the actual Mc values may be less than those values. Above about 40 mM NaCl, aggregation of chromatin is suggested. Similar analysis of H1-depleted chromatin confirmed that H1-depleted chromatin takes a more disordered structure than native chromatin at low ionic strength and does not undergo a definite structure change upon further addition of NaCl.

Binding of both Ca2+ and mastoparan to calmodulin induces a large change in the tertiary structure

The technique of small-angle X-ray scattering has been employed to examine the solution conformation of calmodulin and its complexes with Ca2+ alone, and with both Ca2+ and mastoparan. The radius of gyration decreased by 3.1 +/- 0.3 A upon binding of both 4 mol Ca2+/mol of protein and 1 mol mastoparan/mol of protein to form the ternary complex. A smaller increase was found for the separate binding of 4 mol Ca2+/mol of protein in the absence of mastoparan (0.6 +/- 0.3 A). The analyses of pair distance distribution function showed that the maximal pair distance in calmodulin complex with both Ca2+ and mastoparan decreased by 20-30% in comparison with calmodulin or its complex with Ca2+, and a shoulder near 40 A, which characterizes the dumbbell-shaped molecule of calmodulin, disappeared. These results indicate that the two globular domains of the calmodulin complex with Ca2+ and mastoparan come close together by 8.0-9.5 A on average, if the size and the overall shape of the globular domains are the same in Ca2+-calmodulin-mastoparan complex as in calmodulin or Ca2+-calmodulin complex.

Circular dichroic study of conformational changes in ovalbumin

By simulation of the circular dichroic spectra (Greenfield and Fasman (1969] and using reference spectra of Chen et al. (1974), native ovalbumin was estimated to contain 33% alpha-helix, 5% beta-structure, and 62% random coil. Ovalbumin resisted conformational changes in solutions of urea and of SDS. However, guanidine induced transition, starting at about 2 M and completing at about 4.5 M. At concentrations exceeding 4.5 M guanidine, ovalbumin existed as 6-7% alpha-helical, 12-13% beta-structure, and 80-81% random coil. Ovalbumin after denaturation in 6 M guanidine or in 8 M urea (incubated at 4 degrees C for 24 hr) did not recover the native conformation but acquired a new conformation in each case, with a somewhat destabilized helical structure.

Structural change of the troponin C molecule upon Ca2+ binding measured in solution by the X-ray scattering technique

The small-angle X-ray scattering technique was used to characterize the overall structural change as well as the state of aggregation of troponin C upon binding various amount of Ca2+ ions: in the Ca2+-free state and at pCa 6.5 and 4.0. Under these conditions, the forward scattering intensities of troponin C are not much different from each other: i.e., they coincide within 4%. From these intensities, the Ca2+-facilitated dimerization of troponin C was not verified, and no appreciable aggregation of troponin C molecules was detected below pCa 4.0. Thus, the small-angle X-ray scattering profiles from troponin C solutions were analyzed assuming a monomeric molecule. The radii of gyration of troponin C were 27.8 +/- 0.3 A, 23.8 +/- 0.2 A, and 22.6 +/- 0.1 A for the Ca2+-free state and at pCa 6.5 and 4.0, respectively. The maximum dimension of the molecule decreases from 111 to 98 A with increasing Ca2+ concentration. These results indicate that the troponin C molecule shrinks remarkably as Ca2+ ions bind to the high affinity sites of the molecule. Ca2+ binding to the low affinity sites, on the other hand, leads to a less pronounced change. Following the interpretation of scattering from the dumbbell-shaped structure (Fujisawa, T., Ueki, T., Inoko, Y., & Kataoka, M. [1987] J. Appl. Cryst. 20, 349-355), the two domains of the molecule move closer to each other. The distance between the centers of the two domains decreases from 46 to 35 A.(ABSTRACT TRUNCATED AT 250 WORDS)

Circular dichroic study of the conformational stability of sulfhydryl-blocked bovine serum albumin

1. The blockage of the single sulfhydryl-group of bovine serum albumin does not alter the secondary structure, although the alpha-helical structure is destabilized since lower concentrations of guanidine and of urea unfold the protein. 2. What happens to the previously helical structure depends upon the reagent used to block the sulfhydryl-group. Bovine serum albumin derivatized with 5,5'-dithiobis-(2-nitrobenzoic acid) and iodoacetate preferentially acquire the beta-structure in high concentrations of guanidine and urea, whereas iodoacetamide-derivatized bovine serum albumin acquires primarily the random coil structure. 3. Part of the helical structure is also lost in 5-6 mM sodium dodecyl sulfate; thionitrobenzoate-bovine serum albumin shows an increase in the random coil, whereas the two alkylated proteins display the increase both in beta-structure and random coil. 4. Carboxymethylation or carboxamidomethylation of fully reduced bovine serum albumin results in a drastic change in the secondary structure of the protein with a substantial decrease in alpha-helix and a corresponding increase in both beta-structure and random coil. These extensively alkylated proteins also display differences in denaturation profiles in solutions of guanidine and urea.

Presence of human papillomavirus type 16 genome in bladder carcinoma in situ of a patient with mild immunodeficiency

Using blot hybridization, we analyzed 10 bladder tumors (1 transitional cell carcinoma in situ, 1 adenocarcinoma, and 8 papillary tumors) for the presence of human papillomavirus (HPV) DNA. We detected HPV 16 DNA in a transitional cell carcinoma in situ, whereas no HPV DNA was found in the other bladder tumors. The patient, a 40-year-old female, who harbored HPV 16 DNA in the bladder tumor, had mild immunodeficiency and recently suffered from the bladder tumor, common warts on the right hand, Bowen's disease of the vulva, and severe dysplasia of the vaginal wall. From each of these lesions, we detected the DNA of HPV 16 or an unclassified HPV. HPV DNAs existed in nonintegrated form in all lesions examined. To our knowledge, this is the first case in which a bladder tumor was shown to harbor HPV DNA. However, HPV does not seem to be regularly present in bladder tumor, because we could not detect HPV DNA from the most common bladder tumor, i.e., papillary tumor. Our demonstration of HPV 16 DNA in a transitional cell carcinoma in situ of the bladder suggests that HPV may be associated with some of the bladder tumors of this type.

Temperature dependence of the structure of aggregates of tobacco mosaic virus protein at pH 7.2. Static synchrotron small-angle X-ray scattering

The small-angle X-ray scattering (SAXS) method using a synchrotron radiation source was applied to the study of the self-aggregation process of tobacco mosaic virus protein (TMVP) at a concentration of 5.0 or 12.0 mg ml-1 in 50 mM or 100 mM-phosphate buffer (ionic strengths approx. 0.1 and 0.2, respectively) at pH 7.2 in the temperature region of 4.8 to 25.0 degrees C. This paper presents the results of static measurements of SAXS. Sedimentation velocity experiments were performed simultaneously under the same conditions. These results are qualitatively parallel to those of the SAXS measurements, although the size of stacked disks derived from the SAXS measurements is larger than that derived from the sedimentation experiments, suggesting a change in the equilibrium conditions in the centrifugal field. Qualitative analysis of the SAXS data with model simulation calculations implies that the aggregation of TMVP consists of two steps: (1) the aggregation of A-protein comprising a few subunits to form double-layered disks; and (2) the random polymerization of double-layered disks by disk-stacking. Increase in temperature, ionic strength or protein concentration induced TMVP to polymerize to form a double-layered disk or a quadruple-layered short rod with consumption of A-proteins, accompanied by a small number of multi-layered short rods. The SAXS results indicate that the A-protein and the multilayered short rods are polydisperse with respect to size and shape, i.e. the mixture of A-protein, double-layered disks and multi-layered short rods coexists in the equilibrium state without pressure-induced partial dissociation of TMPV as observed during normal ultracentrifugation, and even under solution conditions in which the formation of double-layered disks or higher-order aggregates is favored.