[Lack of association between alcoholism and alleles in the delta-aminolevulinic acid dehydratase (ALAD) gene]

delta-Aminolevulinic acid dehydratase (ALAD) is the second enzyme in the heme biosynthetic pathway and catalyzes two molecules of delta-aminolevulinate (ALA), which is a potent agonist for GABA autoreceptors. ALAD has two common alleles and thus consists of three distinct isozymes, designated 1-1, 1-2, and 2-2. It has been shown recently that ALAD1 allele is associated with alcoholic liver injury. This association was ascribed to possible differences among isozymes in sensitivity to oxidized glutathione (GSSG), and this sensitivity is increased in erythrocytes of alcoholic patients. In the present study we measured erythrocyte ALAD activity from subjects with different ALAD genotype and found ALAD-1 is most sensitive to GSSG. We then investigated allele frequencies of ALAD in alcoholics (n = 126) and healthy controls (n = 115). For the control group, the frequencies were 0.94 (ALAD1) and 0.06 (ALAD2) and for the overall alcoholic group, 0.91 (ALAD1) and 0.09 (ALAD2). There were no significant differences in allele frequencies at the ALAD locus between the two groups. Subtyping the alcoholics according to the presence or absence of delirium tremens, hallucinosis, withdrawal seizure or liver cirrhosis failed to show statistically significant differences in the allele frequencies. We conclude that our data do not support the evidence of an allelic association between the ALAD1 and alcoholism.

Induction of vascular endothelial growth factor expression by prostaglandin E2 and E1 in osteoblasts

PGE1 and PGE2 are potent stimulators of bone formation. Osteogenesis is strongly dependent on angiogenesis. Vascular endothelial growth factor (VEFG), a secreted endothelial cell-specific mitogen, has been implicated in physiological and pathological angiogenesis. The aim of this study was to examine the possible role of VEGF in PG stimulation of bone formation. We found that in rat calvaria-derived osteoblast-enriched cells and in the osteoblastic RCT-3 cell line PGE2 and E1 increased VEGF mRNA and protein levels. The increased expression of VEGF mRNA produced by PGE2 was rapid (maximal at 1 h), transient (declined by 3 h), potentiated by cycloheximide, and abolished by actinomycin D. PGE2 had no effect on VEGF mRNA stability, suggesting transcriptional regulation of VEGF expression by PGF2. Rp-cAMP, a cAMP antagonist, suppressed VEGF mRNA induced by PGE2, indicating cAMP mediation. The upregulation of VEGF expression by PGE2 in the preosteoblastic RCT-1 cells was potentiated by treatment with retinoic acid, which induces the differentiation of these cells. The upregulation of VEGF mRNA by PGE2 was inhibited by dexamethasone treatment. In addition, Northern blot analysis showed that VEGF mRNA is expressed in adult rat tibia. In summary, we documented, for the first time, the expression of VEGF in osteoblasts and in bone tissue. Stimulation of VEGF expression by PGs and its suppression by glucocorticoids, which, respectively, stimulate and suppress bone formation, strongly implicate the involvement of VEGF in bone metabolism.

[A case of hypogamma-globulinemia with thymoma (Good's syndrome) follow-up for 8 years]

A 58-year-old woman, who had a past history of left upper lobectomy with thoracoplasty for pulmonary tuberculosis and resection of thyroid cancer, was diagnosed as having a mediastinal tumor by chest X-ray examination. It was found to be a malignant thymoma (spindle cell type) after resection. The level of serum gammaglobulin, which had been low before resection, progressively decreased. Afterward, she frequently suffered from airway infections which resulted in severe bronchiecatsis. She died due to respiratory failure 8 years later. In the early stage, though the percentage of pan T cells in peripheral blood lymphocyte subsets was normal, CD4 T cells decreased and CD8 T cells increased. A decrease in helper T cells and an increase in cytotoxic T cells were especially marked. In the late stage, all T cells subsets decreased. In particular, naive T (CD45RA* CD3+ T) cells decreased markedly. However, the percentage of B cells remained normal and that of NK cells was elevated. From the findings of lymphocyte subsets and lymphocyte reactivity to PHA stimulation, it is suggested that T cell dysfunction caused hypogrammaglobulinemia in this case.

1,10-Phenanthroline increases nuclear accumulation of insulin in response to inhibiting insulin degradation but has a biphasic effect on insulin's ability to increase mRNA levels

Previous reports demonstrated that insulin is translocated through the cytoplasm to the nucleus of H35 hepatoma cells and suggested that nuclear insulin may be involved in stimulating transcription of immediate-early genes. In a recent study, inhibition of insulin-degrading enzyme with 1,10-phenanthroline, a Zn2+ chelator, caused a significant increase in the nuclear accumulation of insulin. The present study characterized the effects of 1,10-phenanthroline and its nonchelating isomer, 1,7-phenanthroline, on insulin degradation, nuclear accumulation, and stimulation of immediate-early gene expression. 1,10- but not 1,7-phenanthroline inhibited insulin degradation and increased nuclear accumulation of insulin in a dose-dependent manner. 1,7-phenanthroline caused a dose-dependent decrease in the expression of insulin-stimulated immediate-early genes, but had no significant effect on alpha-tubulin mRNA levels. In the presence of insulin, Northern analysis revealed that 1,10-phenanthroline at all concentrations tested increased alpha-tubulin mRNA levels, but had a biphasic effect on insulin-stimulated immediate-early gene expression. At low concentrations (5-200 microM), 1,10-phenanthroline increased the expression of insulin-stimulated g33, c-fos, and Egr-1 mRNA. At concentrations greater than 1 mM, insulin-stimulated immediate-early gene expression was decreased similar to the effect seen with 1,7-phenanthroline. Nuclear run-on analysis demonstrated that high concentrations of 1,10-phenanthroline decreased insulin-stimulated immediate-early gene transcription but had no effect on transcription of alpha-tubulin. However, low concentrations of 1,10-phenanthroline did not increase transcription of any genes.(ABSTRACT TRUNCATED AT 250 WORDS)

New naphthacenecarboxamide antibiotics, TAN-1518 A and B, have inhibitory activity against mammalian DNA topoisomerase I

New naphthacenecarboxamide antibiotics, TAN-1518 A and B, were isolated from a culture broth of Streptomyces sp. AL-16012. Their structures were elucidated from their reactions and from spectroscopic analyses. The relaxation of supercoiled pBR322 DNA by calf thymus DNA topoisomerase I was inhibited by these metabolites as potently as by camptothecin. However, the decatenation of kinetoplast DNA by calf thymus DNA topoisomerase II was little affected by these agents. The major metabolite, TAN-1518 A, strongly suppressed the growth of various murine and human tumor cells, inducing apoptosis. Unlike camptothecin, TAN-1518 A did not stimulate cleavable complex formation in the nuclei of CHO-K1 cells and had weak activity in intercalating into DNA strands. This metabolite arrested the growth of human tumor cell lines in G1 phase of the cell cycle. These results suggest that TAN-1518 A and B are novel antitumor agents targeting topoisomerase I.

Influence of arotinolol hydrochloride on heart rate spectrum in hypertensive subjects

Influence of arotinolol hydrochloride and atenolol on the balance between the sympathetic and parasympathetic nervous systems was evaluated in 8 hypertensive subjects by spectral analysis of heart rate (HR) and systemic blood pressure (BP). Before and after administration of either arotinolol (n = 7) or atenolol (n = 7) for 2 weeks, BP was continuously and non-invasively monitored by a finger-cuff manometry (Finapres). A time series of instantaneous HR was constructed from the BP signal. A time series of mean BP was also constructed. Spectral analysis was performed by the use of an autoregressive algorithm on these time series (approximately 180 sec). Each spectrum was subdivided into low-(0.05-0.15 Hz, LF) and high-frequency (0.15-0.4 Hz, HF) components, and each component was divided by the sum of the two for normalization. As a measure of the balance between the sympathetic and parasympathetic nervous systems, the ratio of LF to HF (LF/HF) was evaluated. Arotinolol increased fractional HF in the HR spectrum from 0.45 +/- 0.12 to 0.73 +/- 0.08 (p < 0.01) and decreased fractional LF from 0.55 +/- 0.12 to 0.27 +/- 0.08 (p < 0.01); consequently, it decreased LF/HF from 1.4 +/- 0.5 to 0.4 +/- 0.2 (p < 0.01). Atenolol had similar effects on these parameters. Neither of these beta-adrenergic blockades produced a discernible decrease in LF/HF in the BP spectrum. In conclusion, these beta-adrenergic blockades decreased LF/HF in the HR spectrum in hypertensive subjects, which suggests that they improved the balance between the sympathetic and parasympathetic nervous systems.

Postganglionic sympathetic nerve discharges can contain both central and pulse-related oscillations simultaneously in rabbits

We examined whether modulation of sympathetic nerve discharges (SND) by changes in carotid sinus pressure (CSP) is influenced by the pattern of the rhythm of central sympathetic neurons and whether the rhythm of the sympathetic nerve derived from central sympathetic neurons and that from the inputs from baroreceptors can coexist in postganglionic renal SND. In alpha-chloralose-anesthetized rabbits with aortic denervation and vagotomy, firing of central sympathetic neurons was at first left spontaneous and then driven artificially at 3 Hz by peroneal nerve stimulation. Under these conditions, renal SND were recorded and compared while CSP was altered at low frequencies. When central sympathetic neurons were firing spontaneously and low frequency oscillation was applied to CSP, two kinds of oscillation were noted in SND; first oscillation at the same frequency as that of central sympathetic neurons, and second oscillation of CSP changes. Power spectra of SND also showed two peaks at these two oscillations. When central sympathetic neurons regularly discharged at 3 Hz by electrical stimulation and CSP was kept constant, the power spectra of SND had a discrete single peak at 3 Hz. When a regular oscillation was applied to CSP at 1 Hz, the amplitude of central sympathetic outflow at 3 Hz was modulated at 1 Hz without disturbance of the frequency of the central 3 Hz rhythm. In other words, two apparently different rhythms coexisted in SND. In the power spectra, two discrete peaks were noted at the frequency of CSP changes and at the central sympathetic oscillation. When SND were averaged by CSP-triggered summation during spontaneous or artificial 3 Hz central firing, it was revealed that the shape of these two averaged SND were completely same in spite of obviously different central firing patterns. Nadir of SND occurred about 400 ms after the peak of CSP during changes in CSP at several frequencies in these two conditions. Thus, these results indicated two points; (1) CSP changes modulate the amplitude of SND in the same manner irrespective of the frequency or pattern of discharge of central sympathetic neurons; (2) both of frequency components of SND induced by oscillatory changes in central sympathetic neurons and oscillatory inhibitory input from baroreceptors can coexist even if their frequencies were different.

Crystallization and preliminary X-ray diffraction studies of curculin. A new type of sweet protein having taste-modifying action

A taste-modifying protein, curculin, has been crystallized by the vapor diffusion method using polyethylene glycol 400 as a precipitant. The crystals belong to orthorhombic space group P2(1)2(1)2(1) with unit cell dimensions: a = 105 A, b = 271 A, c = 48.7 A. The crystals diffract X-rays to at least a resolution of 3.0 A and are suitable for X-ray crystallographic studies.

Cytotoxic T cell response and expression of the target antigen in HTLV-I infection

The cytotoxic T cell response of peripheral blood mononuclear cells (PBMC) to in vitro stimulation with human T cell leukemia virus type I (HTLV-I) was compared among HTLV-I-infected individuals with various clinical conditions. Induction of HTLV-I-specific cytotoxic T lymphocytes (CTL) was observed in 57% of asymptomatic HTLV-I carriers, 86% of patients with HTLV-I associated myelopathy/tropical spastic paraparesis (HAM/TSP) or other HTLV-I-related inflammatory diseases, and 18% of adult T cell leukemia (ATL) patients. HTLV-I p40tax, one of the major CTL target antigens, has an epitope strongly associated with HLA-A2. HTLV-I p40tax-specific CTL were frequently induced from HLA-A2-positive donors with HTLV-I-related inflammatory diseases regardless of neurological symptoms, but not from all the HLA-A2-positive HTLV-I-infected individuals tested. Leukemic cells of an ATL patient with HLA-A2, whose PBMC did not show an HTLV-I-specific CTL response, could be lyzed by p40tax-specific CTL derived from an HAM/TSP patient. This indicates that i) the presence of a certain HLA presenting CTL epitopes is not the sole determinant of the individual CTL response to HTLV-I, ii) HTLV-I-specific CTL act as potential effectors of anti-tumor surveillance in vivo. The role of HTLV-I-specific CTL, however, may be limited by another in vivo mechanism suppressing the expression of HTLV-I antigens. This suppression, presumably mediated by a plasma factor and commonly observed in HTLV-I-infected individuals, could be one reason for the persistence of HTLV-I-infection.

The mycoplasma-related inhibitor of HIV-1 reverse transcriptase has a DNase activity and is present in the particle-free supernatants of contaminated cultures

Drastic inhibition of the human immunodeficiency virus (HIV) reverse transcriptase (RT) by mycoplasma has been noted in many laboratories causing confusion in data interpretation. The mycoplasma-related inhibitor of HIV-1 RT was identified as a soluble protein in the particle-free supernatant of a contaminated culture. Gel filtration studies revealed the molecular mass of this protein to be about 70 kDa. This RT-inhibitor contained a DNase with strong activity on both linear and circular DNAs. Addition of this inhibitor after completion of reverse transcription still reduced the final outcome of the RT assay significantly, implying that the inhibitory mechanism occurred mainly by its DNase activity. Treatment of the culture with an antimycoplasma drug cured the mycoplasma contamination, removed the RT-inhibitor and abolished the DNase activity.

Reproductive toxicity studies of the new cognition-enhancing agent nefiracetam in rats and rabbits

The reproductive toxicity of nefiracetam (N-(2,6-dimethylphenyl)-2-(2-oxo-1-pyrrolidinyl) acetamide, DM-9384, CAS 77191-36-7) was investigated in rats and rabbits. Nefiracetam was administered orally for 9 weeks or more until successful copulation to male rats at doses of up to 480 mg/kg/d. Female rats were treated with nefiracetam at the same doses for more than 2 weeks prior to and in the early stages of pregnancy. No adverse effects on fertility were noted at any dose level. Nefiracetam elicited no evidence of teratogenicity when administered during the fetal organogenesis period to pregnant rats at doses of up to 1000 mg/kg/d, or to pregnant rabbits at doses of up to 270 mg/kg/d. Rat fetuses in the 1000 mg/kg group exhibited decreased body weights, delayed ossification and an increased incidence of skeletal variations such as cervical ribs and shortening of the 13th ribs. Decreased body weight gain and decreased food intake were also noted in rat dams of the 1000 mg/kg group. Nefiracetam showed no adverse effects on postnatal development, behavior or reproductive performance of rat offspring, except for decreased body weight gain in the 1000 mg/kg group. Rabbit fetuses in the 270 mg/kg group exhibited increased skeletal variations, mainly presence of the 13th ribs. Decreased body weight gain and decreased food intake were also noted in rabbit dams of the 270 mg/kg group. In a perinatal and postnatal toxicity study in rats using doses of up to 500 mg/kg, decreased food intakes were noted in dams of the 500 mg/kg group.(ABSTRACT TRUNCATED AT 250 WORDS)

Age-dependent decreases in fibrinolytic enzyme activities in serum of healthy subjects

We investigated the age-dependency of serum levels of 9 kinds of proteases. The results showed that the enzymatic activities corresponding to urokinase, plasmin, and thrombin, all involved in blood clotting and fibrinolysis, were inversely correlated with age. This suggests that there is some similarity between the normal process of aging and the pathologic process of Alzheimer's disease. Compared with our previous data on Alzheimer patients, the present results indicate that some derangement in the aging process is involved in the pathogenetic mechanisms of Alzheimer's disease.

Polymorphism of pentanucleotide repeats in the 5' flanking region of glutathione S-transferase (GST) pi gene

The upstream sequence of the glutathione S-transferase pi gene contains pentanucleotide (ATAAA) repeats. Analysis of the region using polymerase chain reaction indicated that the repeat sequence was polymorphic and segregation of the polymorphic alleles was codominant heredity. Heterozygosity of the new VNTR was 0.818 in healthy Japanese and 0.794 in American whites. Allelic frequencies among healthy controls and alcoholics as well as other diseases were not significantly different.

Molecular cloning of a novel protein-tyrosine phosphatase containing a membrane-binding domain and GLGF repeats

A full-length cDNA encoding a novel cytosolic protein-tyrosine phosphatase (PTP), PTP-BAS, was cloned from human basophils. Due to in-frame deletions in the coding region, PTP-BAS exists in three isoforms: 7,455 bp (2,485 aa) for type 1, 7,398 bp (2,466 aa) for type 2 and 6,882 bp (2,294 aa) for type 3. All three isoforms contain a single PTP catalytic domain at the carboxyl termini as well as two distinct structural sequences. Amino terminal sequences of 300 amino acids are homologous to membrane-binding domains of cytoskeleton-associated proteins. Three 90 amino acid internal repetitive sequences are homologous to the GLGF repeats found in guanylate kinase proteins. PTP-BAS was expressed in various human tissues, especially highly in the kidney and lung. Interestingly, the BAS mRNA level in the fetal brain was remarkably high.

Family characteristics and offspring growth in various countries. I. Frequency of various family types in Bulgaria, Japan, Korea, Mexico and Poland

9936 families were analyzed from Bulgaria, Japan, Korea, Mexico, and Poland. A factor analysis revealed four factors: culture (F1), income (F2), genetics (F3), and family and apartment size (F4). Family types we coded as 1 if below the median and 2 if above the median. The most frequent types were represented by 1122, 2221, and 2211 (frequency 8.7-8.0%), and the least frequent by 1221 and 2111 (frequency 4.2-4.3%). Some similarity with respect to family types were found between populations: from Polish regions with heavy industry and seaside regions; from Polish towns under industrialization and from Mexico; from the Polish medium-size town of Lublin and Bulgarian towns; from Polish villages; from Polish mountain areas and north-eastern towns; from Korea; from Japan; from Polish cities.

An unusual presentation of spontaneous pneumoperitoneum secondary to the rupture of a gas-containing pyogenic liver abscess: report of a case

We describe a rare case of spontaneous pneumoperitoneum secondary to the rupture of a gas-containing pyogenic liver abscess in a 59-year-old man. The patient was diagnosed as having a hollow viscus perforation based on a sudden onset of acute abdominal pain along with radiological evidence of bilateral subphrenic feee air (pneumoperitoneum), and underwent an emergency laparotomy. Contrary to expectations, the surgery revealed no perforations of the hollow viscus, but instead a ruptured liver abscess at the dome of the right hepatic lobe was identified associated with suppurative peritonitis. To the best of our knowledge, such a case of spontaneous pneumoperitoneum secondary to the rupture of a gas-containing liver abscess is extremely rare.

Exposure of p19 matrix protein of human T-cell leukemia virus type I (HTLV-I) on the surface of MOLT-4#8 cells after virus adsorption

The p19 matrix (MA) protein of human T-cell leukemia virus type I (HTLV-I) was exposed on the surface of MOLT-4#8 cells in the very early step of the virus infection. Transfer of the virus-binding MOLT-4#8 cells from 4 degrees C to 37 degrees C resulted in increased detection of the viral gp46 and p19 MA protein on the cells, which was, however, inhibited by 4 degrees C or cytochalasin B treatment. These data showed that increased temperature and fluidity of the cell membrane were required for the increased detection of gp46 and p19 after viral adsorption. On the other hand, exposure of the p19 MA protein was not observed on the virus-treated U937 cells although gp46 was detected. This was not due to inefficient binding of the HTLV-I to the U937 cells, since the methanol-fixed cells were p19 MA protein-positive. MOLT-4#8 cells induced marked cell fusion when co-cultured with MT-2 cells, but U937 cells induced no fusion. All of these results indicated that these two cell lines differed in the property of plasma membrane in terms of degradation of HTLV-I envelope after viral adsorption. Uncoating of the HTLV-I might occur on the plasma membrane, especially on MOLT-4#8 cells.

Investigation of the genetic markers associated with alcoholic liver diseases

Polymorphic alleles of three genes (GSTMl, CYP1A1 and ApoB) were analysed in the context of the relationship between alcohol and liver diseases. DNAs were prepared from whole blood samples of 84 male controls, 71 male patients with alcoholic liver diseases. PCR and related techniques were used for detection of these polymorphic loci. The frequency of GSTMl gene deletion was significantly higher in the patients with alcoholic liver diseases than in controls (P < 0.05), whereas the frequencies of the genotypes (A, AB, B) in the individuals with GSTMl gene were not statistically different between both groups. In addition, the frequency of GYP1A1*A was found to be significantly higher in alcoholic liver diseases than in controls (P < 0.01). Gene frequencies of ApoB were not different between the two groups. These data suggest that GSTM1 gene deletion and CYP1A1*A gene increase the risk for alcoholic liver diseases.

Relationship between antigens and IgG subclasses in bullous pemphigoid

Bullous pemphigoid (BP) is an autoimmune blistering disease characterized in part by the presence of tissue-bound and circulating antibodies (mostly of IgG) to the basement membrane zone (BMZ). We previously reported that IgG subclasses of BP antibodies were IgG1, IgG2 and IgG4, and that only BP IgG1 fixed complements. In this study, we examined whether BP IgG sub-classes bound to the same epitope of BP antigen or a different epitope. In an inhibition immunofluorescence studies, the complement fixing capability of IgG1 was inhibited by the pretreatment with IgG4 and partially inhibited by IgG2. On immunoblot analysis, IgG1 and IgG4 were bound to the same MW of BP antigen. In enzyme-linked immunosorbent assay (ELISA), the binding capability of IgG subclass fractions from patients with BP to synthetic peptide P1-2, exceeding normal IgG subclass fractions was seen in five IgG1, one IgG2 and two IgG4, from eight BP patients. The binding capability of IgG subclass fractions from the patients with BP to P1-1, exceeding the normal IgG fractions was seen in two IgG1, three IgG2 and one IgG4 from ten BP patients. On inhibition ELISA, the binding activity to P1-2 of IgG4 was partially inhibited by the pretreatment of IgG1 and IgG2. These findings suggest that BP IgG1, IgG2 and IgG4 could bind to the same epitope though considerable variation occurred between patients.

Anti-human IgE monoclonal antibodies recognizing epitopes related to the binding sites of high and low affinity IgE receptors

Anti-human IgE monoclonal antibodies (mAbs) were produced and eight clones recognizing epitopes on native IgE were selected. Epitopes were mapped by a competitive inhibition enzyme-linked immunosorbent assay, Western blotting and a multi-pin peptide technology. Four sites (one each in the C epsilon 1, C epsilon 2, C epsilon 2/C epsilon 3 junction and C epsilon 3) were recognized by the mAbs. The relationship between the four epitopes and the binding sites of high and low affinity IgE receptors (Fc epsilon RI and Fc epsilon RII, respectively) was studied using a monovalent Fab fragment of each mAb as a binding inhibitor. The IgE-Fc epsilon RII binding was clearly inhibited by the mAb recognizing the C epsilon 2/C epsilon 3 junction, suggesting that Fc epsilon RII binds to a rather limited area around the C epsilon 2/C epsilon 3 junction. The IgE-Fc epsilon RI binding, on the other hand, was scarcely inhibited by any single mAb. However, the binding was inhibited when the epitope in C epsilon 2 was blocked simultaneously with that at the C epsilon 2/C epsilon 3 junction or with that in C epsilon 3, indicating that these three distinct epitopes are related to the Fc epsilon RI binding sites. When these three epitopes were shown in the stereograph of human IgE, the Fc epsilon RI binding area was spread largely on the groove side between C epsilon 2 and C epsilon 3 domains. These results suggest that Fc epsilon RI acquires the high affinity through multiple bindings.

Generation and characterization of a human immunodeficiency virus type 1 (HIV-1) mutant resistant to an HIV-1 protease inhibitor

A synthetic peptide, RPI 312, that specifically inhibits the protease of the human immunodeficiency virus type 1 (HIV-1) showed a potent inhibition on virus production, maturation, and infectivity. Treatment with this agent prevented the cleavage of Gag protein at the site between p17 and p24 in HIV-1 chronically infected MOLT-4 cells as well as in the released virus. Passage of HIV-1 in the presence of gradually increasing concentrations of this protease inhibitor resulted in emergence of a variant that could evade the drug effects. In the resistant variant the maturation of Gag proteins appeared normal, but its infectivity was reduced compared with that of the parent virus. The nucleotides coding the amino acids at and around the cleavage site between Gag proteins p17 and p24 were not changed. One point mutation (A-->G) at site 2082 of the pol gene that resulted in one amino acid change at site 84 of the protease from isoleucine to valine (I-84-->V) could be detected in the resistant variant. An HIV-1 infectious DNA clone with the I-84-->V mutation also showed reduced sensitivity to this protease inhibitor. The findings that the resistant variant had lower infectivity and was still affected by higher doses of the drug support the speculation that resistance to protease inhibitors may not be as problematic as other drug resistance.

Retraction induced brain edema

A local cerebral retraction apparatus which simulates cerebral retraction was devised in an effort to clarify the relationship among the retraction pressure, somatosensory evoked potential (SEP) and cerebral blood flow (CBF) by measuring these parameters both simultaneously and chronologically. Twenty seven cats were divided into three groups according to the retraction pressure (10,30 and 50 mmHg, respectively). Each group underwent 30 minutes' retraction. At a retraction pressure of 10 mmHg, the reduction rate of CBF was low and the recovery of SEP was excellent. With an excessive pressure of 50 mmHg, both SEP and CBF reduced to 60% of the control value during the retraction and the recovery of SEP was extremely poor. Marked hyperemia of the brain surface was seen immediately after the release of retraction in more than 50% of the animals. At 30 mmHg, the recovery of SEP was moderately disturbed but, nevertheless, with a satisfactory value of more than 60% of the control. When the N1 component of SEP was abolished, the residual CBF showed approximately 60% of the control value, which seemed relatively high as compared to cases where cerebral artery were occluded. Extravasation of Evans blue which is an indication of vasogenic brain edema due to disruption of the blood-brain barrier, occurred extensively in the cerebral cortex involving a deep-lying white matter and an increase of the retraction pressure, corresponding to a poor recovery of neuronal function.

Augmentation of host defense mechanisms against tumor by sperabillin polymers, new basic peptidyl biopolymers, in mice

Sperabillin polymers, which have been shown recently to have antitumor activity, are new basic peptidyl polymers composed of a pseudo-peptide antibiotic, sperabillin A. The polymers, HP-2 (MW 9990), AP-2 (MW 20,100) and AB-2 (MW 35,000), were found to potently activate murine peritoneal macrophages. The phagocytosis-dependent respiratory burst and Fc gamma receptor expression of peritoneal macrophages from C57BL/6 mice were enhanced after in vitro cultivation with these polymers. When HP-2, a representative of these polymers, was intraperitoneally injected into mice, the number of peritoneal exudate cells increased and phagocytosis-dependent respiratory burst and class II (I-A) antigen expression of peritoneal macrophages were augmented. These macrophages showed strong inhibitory activity against the growth of murine tumor cell lines such as EL4 lymphoma and B16 melanoma. Nitrogen oxide, tumor necrosis factor (TNF) and interleukin 1 (IL-1) might be required for this inhibitory activity. Moreover, in mice treated with HP-2, splenocyte counts also increased and non-specific killer activity of the splenocytes was augmented. These results indicate that sperabillin polymers are new macrophage activators.

Crystallization and preliminary X-ray studies on pseudoazurin from Achromobacter cycloclastes IAM1013

New crystals of a blue copper protein, pseudoazurin from denitrifier Achromobacter cycloclastes IAM1013, have been obtained by means of vapor diffusion with ammonium sulfate as a precipitant at pH 6.0 and 4 degrees C. The crystals belong to the orthorhombic system, space group P2(1)2(1)2(1), with unit cell dimensions of a = 56.69(2), b = 61.53(2), and c = 30.20(1) A. The asymmetric unit includes one molecule of pseudoazurin with a Vm value of 2.04 A3/Da. The crystals are so stable against X-ray irradiation that a complete data set up to 1.54 A has been collected using a single native crystal. Solution of the structure was performed by means of the Patterson search techniques, and the current crystallographic R-factor is 17.5% at 3.0 A resolution. Refinement at higher resolution is in progress.