Complex mechanisms underlying impaired activation of Cdk4 and Cdk2 in replicative senescence: roles of p16, p21, and cyclin D1

Numerous changes in gene expression are known to occur during replicative senescence, including changes in genes involved in the cell cycle control. In the present study, we have found a severe impairment in the activation of Cdk2 and Cdk4 in response to mitogens in senescent human fibroblasts and determined the molecular basis for this. Although Cdk4 protein was constitutively expressed in senescent cells at the same level as in early-passage young cells, it was found to be complexed with a distinct set of Cdk inhibitors. Cdk4 derived from early passage quiescent cells was effectively activated by incubation with cyclin D1 and Cdk-activating kinase (CAK) in vitro, whereas Cdk4 from senescent cells was not. Cdk2 protein was dramatically decreased in senescent cells and complexed primarily with cyclin D1 and p21. This cyclin D1-bound Cdk2 was not activated by CAK either in vivo or in vitro, implicating cyclin D1 as an inhibitor of Cdk2 activation. Thus, one of the underlying molecular events involved in replicative senescence is the impaired activation of Cdk4 and Cdk2 due to increased binding of p16 to Cdk4 and increased association of Cdk2 with cyclin D1 and p21.

[Outbreak of tuberculosis among middle aged employees in an office]

We experienced an outbreak of tuberculosis in a salesmen's office during the period from 1993 to 1997. The outbreak was detected retrospectively. In July, 1997, a 47-year-old man was diagnosed as pulmonary tuberculosis. As he worked with a 42-year-old man who was already registered in our health center, we suspected an outbreak and started a survey. Contact examinations were carried out for 9 employees of his office and 3 members of his friends. As the result of these examinations, one employee showed strongly positive tuberculin skin test, and was indicated isoniazid chemoprophylaxis. Furthermore, some contacts told us that seven cases of active tuberculosis and three cases of primary infection indicated chemoprophylaxis had occurred among employees and their family members. The index case was a 41-year-old man who was diagnosed as tuberculosis in January, 1993. The second case among employees had previous history of pulmonary tuberculosis. Almost the patients among the employees had a hard life suffering from debts, and had heavy alcohol use. These facts may partly explain the spread of tuberculosis in this office. As each case was registered at different health centers, we hadn't noticed the outbreak for 4 years. But it is true that insufficient approach of health centers to contacts caused a serious delay of detecting the outbreak. A thorough investigation for contacts and complete contact examinations are needed.

Occurrence of D-amino acids in a few archaea and dehydrogenase activities in hyperthermophile Pyrobaculum islandicum

The contents of D-enantiomers of serine, alanine, proline, glutamate (glutamine) and aspartate (asparagine) were examined in the membrane fractions, soluble proteins and free amino acids from some species of archaea, Pyrobaculum islandicum, Methanosarcina barkeri and Halobacterium salinarium. Around 2% (D/D+L) of D-aspartate was found in the membrane fractions. In the soluble proteins, the D-amino acid content was higher in P. islandicum than that in the other archaeal cells: the concentrations in P. islandicum were 3 and 4% for D-serine and D-aspartate, respectively. High concentrations of free D-amino acids were found in P. islandicum and H. salinarium; the concentrations of D-serine (12-13%), D-aspartate (4-7%) and D-proline (3-4%) were higher than those of D-alanine and D-glutamate. This result showed a resemblance between these archaea and not bacterial, but eukaryotic cells. The presence of D-amino acids was confirmed by their digestion with D-amino acid oxidase and D-aspartate oxidase. The occurrence of D-amino acids was also confirmed by the presence of activities catalyzing catabolism of D-amino acids in the P. islandicum homogenate, as measured by 2-oxo acid formation. The catalytic activities oxidizing D-alanine, D-aspartate and D-serine at 90 degrees C were considerably high. Under anaerobic conditions, dehydrogenase activities of the homogenate were 69, 84 and 30% of the above oxidase activities toward D-alanine, D-aspartate and D-serine, respectively. Comparable or higher dehydrogenase activities were also detected with these D-amino acids as substrate by the reduction of 2, 6-dichlorophenolindophenol. No D-amino acid oxidase activity was detected in the homogenates of M. barkeri and H. salinarium.

A splicing mutation of the tyrosinase gene causes yellow oculocutaneous albinism in a Japanese patient with a pigmented phenotype

BACKGROUND

Yellow oculocutaneous albinism (OCA) that is caused by tyrosinase gene mutations shows two characteristics: extreme hypopigmentation at birth and the eventual development of yellow or blond hair.

OBJECTIVE

We studied a Japanese girl who had brown hair, a lighter skin color than her unaffected family and brown eyes at 9 months of age.

METHODS

We performed direct sequencing analyses of the tyrosinase gene in her genomic DNA.

RESULTS

The patient was a compound heterozygote for the +DeltaC310 mutation (known to result in absent melanogenic activity) and a second t-->a transition at the 3' end of intron 2.

CONCLUSION

The t-->a transition has previously been reported as a splicing mutation in other Caucasian patients with a typical yellow OCA phenotype. However, this patient showed much more pigmentation than that reported in Caucasians. Therefore, we estimate that the mild phenotype results from her genetic pigment background.

Possible involvement of IL-12 expression by Epstein-Barr virus in Sjögren syndrome

AIM

To determine the correlation between interleukin 12 (IL-12) expression and Epstein-Barr virus (EBV) in Sjögren syndrome.

METHODS

Indirect immunohistochemical technique, enzyme linked immunosorbent assay (ELISA), and immunoblot analysis were used to investigate IL-12 expression by EBV activation, using 13 surgical specimens and four B cell lines.

RESULTS

Marked expression of IL-12 was found in the epithelial cells and the infiltrating B cells of salivary gland tissues from patients with Sjögren syndrome (six of 10 cases), but not in those from normal individuals (none of three cases). A striking topographic correlation between IL-12 and EBV was found. In addition, levels of IL-12 production by B cell lines were clearly enhanced by EBV activation in vitro.

CONCLUSIONS

IL-12 expression closely reflects the intracellular event of EBV activation in Sjögren syndrome, and may contribute to the T helper cell type 1 (Th1) cytokine overexpression seen in this disease.

Construction and characterization of histidine-tagged haloalkane dehalogenase (LinB) of a new substrate class from a gamma-hexachlorocyclohexane-degrading bacterium, Sphingomonas paucimobilis UT26

The linB gene product (LinB), which is involved in the degradation of gamma-hexachlorocyclohexane in Sphingomonas paucimobilis UT26, is a member of haloalkane dehalogenases with a broad range of substrate specificity. Elucidation of the factors determining its substrate specificity is of interest. Aiming to facilitate purification of recombinant LinB protein for site-directed mutagenesis analysis, a 6-histidyl tail was added to the C-terminus of LinB. The His-tagged LinB was specifically bound with Ni-NTA resin in the buffer containing 10 mM imidazole. After elution with 500 mM imidazole, quantitative recovery of protein occurred. The steady-state kinetic parameters of the His-tagged LinB for four substrates were in good agreement with that of wild-type recombinant LinB. Although the His-tagged LinB expressed in an average of 80% of the activity of the wild type LinB for 10 different substrates, the decrease was very similar for different substrates with the standard deviation of 5.5%. The small activity reduction is independent of the substrate shape, size, or number of substituents, indicating that the His-tagged LinB can be used for further mutagenesis studies. To confirm the suitability of this system for mutagenesis studies, two mutant proteins with substitution in putative halide binding residues (W109 and F151) were constructed, purified, and tested for activity. As expected, complete loss in activity of W109L and sustained activity of F151W were observed.

Cloning and sequencing of a novel meta-cleavage dioxygenase gene whose product is involved in degradation of gamma-hexachlorocyclohexane in Sphingomonas paucimobilis

Sphingomonas (formerly Pseudomonas) paucimobilis UT26 utilizes gamma-hexachlorocyclohexane (gamma-HCH), a halogenated organic insecticide, as a sole source of carbon and energy. In a previous study, we showed that gamma-HCH is degraded to chlorohydroquinone (CHQ) and then to hydroquinone (HQ), although the rate of reaction from CHQ to HQ was slow (K. Miyauchi, S. K. Suh, Y. Nagata, and M. Takagi, J. Bacteriol. 180:1354-1359, 1998). In this study, we cloned and characterized a gene, designated linE, which is located upstream of linD and is directly involved in the degradation of CHQ. The LinE protein consists of 321 amino acids, and all of the amino acids which are reported to be essential for the activity of meta-cleavage dioxygenases are conserved in LinE. Escherichia coli overproducing LinE could convert both CHQ and HQ, producing gamma-hydroxymuconic semialdehyde and maleylacetate, respectively, with consumption of O(2) but could not convert catechol, which is one of the major substrates for meta-cleavage dioxygenases. LinE seems to be resistant to the acylchloride, which is the ring cleavage product of CHQ and which seems to react with water to be converted to maleylacetate. These results indicated that LinE is a novel type of meta-cleavage dioxygenase, designated (chloro)hydroquinone 1, 2-dioxygenase, which cleaves aromatic rings with two hydroxyl groups at para positions preferably. This study represents a direct demonstration of a new type of ring cleavage pathway for aromatic compounds, the hydroquinone pathway.

The stabilization mechanism of mutant-type p53 by impaired ubiquitination: the loss of wild-type p53 function and the hsp90 association

Mutant-type p53 (mt p53) is largely accumulated in cancer cells due to its increased stability. To elucidate the mechanism of mt p53 stabilization, we analysed the turnover of p53 mutated at codon 248 whose alteration is most frequently found in human cancers. Proteasome inhibition induced the accumulation of ubiquitinated mt p53, indicating that the ubiquitinated forms were essentially unstable and degraded by the proteasome. The presence of a small amount of the ubiquitinated mt p53 relative to the abundant non-ubiquitinated form suggested that the mt p53 ubiquitination was a rate-limiting process in the slow turnover. Two phenomena destabilizing mt p53 via the ubiquitin-proteasome degradation were proved to be independent. First, the coexpression of wild-type p53 (wt p53) promoted mt p53 destabilization as feedback regulation. Second, geldanamycin also induced mt p53 destabilization through the dissociation of the protein from hsp90 but not through the restoration of wt p53 function. Neither the mutant-specific conformation nor the N-terminal phosphorylation seemed to contribute directly to the mt p53 stabilization. Further, a two-dimensional gel electrophoresis revealed that most of the post-translationally modified mt p53 was equally subjected to ubiquitination and subsequent proteasomal degradation. These findings are evidence that mt p53 stabilization depends on the impaired ubiquitination due to both the loss of wt p53 function and the hsp90 association.

Crystal structure of chitosanase from Bacillus circulans MH-K1 at 1.6-A resolution and its substrate recognition mechanism

Chitosanase from Bacillus circulans MH-K1 is a 29-kDa extracellular protein composed of 259 amino acids. The crystal structure of chitosanase from B. circulans MH-K1 has been determined by multiwavelength anomalous diffraction method and refined to crystallographic R = 19.2% (R(free) = 23.5%) for the diffraction data at 1.6-A resolution collected by synchrotron radiation. The enzyme has two globular upper and lower domains, which generate the active site cleft for the substrate binding. The overall molecular folding is similar to chitosanase from Streptomyces sp. N174, although there is only 20% identity at the amino acid sequence level between both chitosanases. However, there are three regions in which the topology is remarkably different. In addition, the disulfide bridge between Cys(50) and Cys(124) joins the beta1 strand and the alpha7 helix, which is not conserved among other chitosanases. The orientation of two backbone helices, which connect the two domains, is also different and is responsible for the differences in size and shape of the active site cleft in these two chitosanases. This structural difference in the active site cleft is the reason why the enzymes specifically recognize different substrates and catalyze different types of chitosan degradation.

PcpA, which is involved in the degradation of pentachlorophenol in Sphingomonas chlorophenolica ATCC39723, is a novel type of ring-cleavage dioxygenase

The pentachlorophenol (PCP) mineralizing bacterium Sphingomonas chlorophenolica ATCC39723 degrades PCP via 2,6-dichlorohydroquinone (2,6-DCHQ). The pathway converting PCP to 2,6-DCHQ has been established previously; however, the pathway beyond 2,6-DCHQ is not clear, although it has been suggested that a PcpA plays a role in 2, 6-DCHQ conversion. In this study, PcpA expressed in Escherichia coli was purified to homogeneity and shown to have novel ring-cleavage dioxygenase activity in conjunction with hydroquinone derivatives, and converting 2,6-DCHQ to 2-chloromaleylacetate.

A case of sarcoidosis involving the tongue

Sarcoidosis is a systemic granulomatous disorder which commonly affects the skin. Involvement of the tongue is rare; a review of the previous literature over the last 30 years revealed only six cases of sarcoidosis affecting the tongue. We studied a case of sarcoidosis involving the tongue in a 32-year-old Japanese woman with characteristic clinical and pathological findings. She visited our department with a complaint of a tongue lesion of which she had been aware for a month. A diagnosis of sarcoidosis was made for the lesion by clinical and pathological examinations. Oral involvement by sarcoidosis is rare, however this disorder should be considered as a possible cause of intraoral granulomatous lesions.

Complete analysis of genes and enzymes for gamma-hexachlorocyclohexane degradation in Sphingomonas paucimobilis UT26

gamma-Hexachlorocyclohexane (gamma-HCH; also called BHC or lindane) is one of the highly chlorinated pesticides which can cause serious environmental problems. Sphingomonas paucimobilis UT26 degrades gamma-HCH under aerobic conditions. The unique degradation pathway of gamma-HCH in UT26 is revealed. In the upstream pathway, gamma-HCH is transformed to 2,5-dichlorohydroquinone (2,5-DCHQ) by two different dehalogenases (LinA and LinB) and one dehydrogenase (LinC) which are expressed constitutively. In the downstream pathway, 2,5-DCHQ is reductively dehalogenated, and then ring-cleaved by enzymes (LinD and LinE, respectively) whose expressions are regulated. We have cloned and sequenced five structural genes (linA, linB, linC, linD, and linE) directly involved in this degradation pathway. The linD and linE genes form an operon, and its expression is positively regulated by the LysR-type transcriptional regulator (LinR). The genes linA, linB, and linC are constitutively expressed, and are present separately from each other in the UT26 genome. Cell fractionation analysis, Western blotting, and immuno electron microscopy revealed that LinA and LinB are localized in the periplasmic space of UT26.

The contribution of menopause to changes in body-fat distribution

OBJECTIVE

To investigate whether menopause contributes to changes in body-fat distribution, irrespective of aging or obesity.

METHODS

The subjects were 545 premenopausal (aged 16-55 years; mean +/- standard deviation, 37.7 +/- 9.1 years) and 219 postmenopausal (aged 45-65 years, 58.0 +/- 5.0 years) women. Baseline characteristics included age, body mass index (BMI), and menopausal status (premenopause or postmenopause). The ratio of trunk fat to leg fat (trunk-leg ratio) was estimated by dual-energy X-ray absorptiometry. The trunk-leg ratio and baseline characteristics were compared between the 2 groups. In all subjects (n = 764), possible correlations between the trunk-leg ratio and the baseline characteristics were determined using univariate and multivariate analysis. In postmenopausal women, the relationship of the trunk-leg ratio to YSM or age after adjusting for BMI was investigated.

RESULTS

The trunk-leg ratio and BMI were significantly higher in postmenopausal women than in premenopausal women. In all subjects, age and BMI were positively correlated with the trunk-leg ratio (r = 0.445 and 0.587, respectively, p < 0.0001). Menopause was also positively correlated with the trunk-leg ratio on univariate regression analysis (standardized regression coefficient = 0.369, p < 0.0001). On multiple regression analysis, age, BMI, and menopause were independently correlated with the trunk-leg ratio (p < 0.05). In postmenopausal women, age and YSM were positively correlated with the trunk-leg ratio, independent of the BMI (p < 0.01).

CONCLUSIONS

Menopause contributes to a change in body-fat distribution, irrespective of aging or obesity.

Two different types of dehalogenases, LinA and LinB, involved in gamma-hexachlorocyclohexane degradation in Sphingomonas paucimobilis UT26 are localized in the periplasmic space without molecular processing

gamma-Hexachlorocyclohexane (gamma-HCH) is one of several highly chlorinated insecticides that cause serious environmental problems. The cellular proteins of a gamma-HCH-degrading bacterium, Sphingomonas paucimobilis UT26, were fractionated into periplasmic, cytosolic, and membrane fractions after osmotic shock. Most of two different types of dehalogenase, LinA (gamma-hexachlorocyclohexane dehydrochlorinase) and LinB (1,3,4,6-tetrachloro-1,4-cyclohexadiene halidohydrolase), that are involved in the early steps of gamma-HCH degradation in UT26 was detected in the periplasmic fraction and had not undertaken molecular processing. Furthermore, immunoelectron microscopy clearly showed that LinA and LinB are periplasmic proteins. LinA and LinB both lack a typical signal sequence for export, so they may be secreted into the periplasmic space via a hitherto unknown mechanism.

Serum androgen levels and muscle mass in women with polycystic ovary syndrome

OBJECTIVE

To relate serum androgen levels and muscle size in women with polycystic ovary syndrome (PCOS).

METHODS

Forty-eight women with PCOS were studied. Baseline characteristics included age, height, weight, and hirsutism. Total-body lean mass was measured by wholebody scanning with dual-energy x-ray absorptiometry, and the lean mass index (total-body lean mass/height2, kg/m2) was calculated. Trunk-leg fat mass ratio (trunk-leg fat ratio) was assessed by dual-energy x-ray absorptiometry. Serum testosterone, dehydroepiandrosterone sulfate, and androstenedione levels were measured by radioimmunoassay. Subjects were arbitrarily divided into two groups according to lean mass index (lean mass index at least 14 kg/m2, n = 24; or less than 14 kg/m2, n = 24). Baseline characteristics and serum androgen levels were compared between the groups. In all subjects, lean mass index was correlated with age, height, trunk-leg fat ratio, and serum androgen levels.

RESULTS

Although trunk-leg fat ratio, serum testosterone and androstenedione levels, and the prevalence of hirsutism were significantly higher in women with a lean mass index at least 14 kg/m2, age and height did not differ significantly between the groups. Trunk-leg fat ratio and serum testosterone and androstenedione levels correlated significantly with lean mass index (r = .68, .75, and .54, respectively). Hirsutism also correlated with lean mass index (standardized regression coefficient = .49; P<.05).

CONCLUSION

Muscle size in women with PCOS correlated positively with serum androgen levels and upper body-fat distribution, independent of height.

Pharmacokinetics of exogenous gonadotropin and ovarian response in in vitro fertilization

OBJECTIVE

To assess the diffusion of gonadotropin into the follicular fluid (FF) and its relation to the results achieved in a human IVF-ET program.

DESIGN

Retrospective pharmacokinetic study.

SETTING

Fukuoka University Hospital, Japan.

PATIENT(S)

Eighty-seven infertile patients underwent 137 cycles of IVF-ET.

INTERVENTION(S)

Serum and FF were collected at the time of oocyte recovery. The hCG ratio (between follicular hCG and serum hCG concentrations, measured by time-resolved fluoroimmunoassay) was evaluated as an index of the diffusion of exogenous gonadotropin.

MAIN OUTCOME MEASURE(S)

Relation between hCG ratio and the results and outcome of the IVF-ET program.

RESULT(S)

The hCG ratio decreased with the total dosage of hMG and increased with the serum E2 level, the number of oocytes recovered, and the number of oocytes fertilized. Patients with a poor response showed a low hCG ratio, which was associated with a complete lack of fertilization. The mean hCG ratio in the pregnant cycles was significantly higher than that in the nonpregnant cycles. An hCG ratio > 0.46 was seen in all pregnant cycles.

CONCLUSION(S)

The diffusion of exogenous gonadotropin into the FF may be an important predictor of IVF outcome.

Requirement of activation of JNK and p38 for environmental stress-induced erythroid differentiation and apoptosis and of inhibition of ERK for apoptosis

C-Jun amino terminal kinase/stress-activated protein kinases (JNK/SAPK) and p38 subgroups of mitogen-activated protein kinases have been suggested to play a critical role in apoptosis, cell growth, and/or differentiation. We found that a short exposure of SKT6 cells, which respond to erythropoietin (Epo) and induce erythroid differentiation, to osmotic or heat shock induced transient activation of JNK/SAPK and p38 and inactivation of ERK and resulted in erythroid differentiation without Epo, whereas long exposure of the cells to these stresses induced prolonged activation/inactivation of the same kinases and caused apoptosis. Inhibition of JNK/SAPK and p38 resulted in inhibition of stress-induced erythroid differentiation and apoptosis. Inhibition of ERK had no effect on stress-induced erythroid differentiation, but stimulated apoptosis. Activation of p38 and/or JNK/SAPK for a short time caused erythroid differentiation without Epo, although its prolonged activation induced apoptosis. Activation of ERK suppressed stress-induced apoptosis. These results indicate that short cellular stresses, inducing transient activation of JNK/SAPK and p38, lead to cell differentiation rather than apoptosis. Furthermore, activation of JNK/SAPK and p38 is required for both cell differentiation and apoptosis, and the duration of their activation may determine the cell fate, cell differentiation, and apoptosis. In contrast, inactivation of ERK is required for stress-induced apoptosis but not cell differentiation.

Apoptosis in placentas from human T-lymphotropic virus type I-seropositive pregnant women: a possible defense mechanism against transmission from mother to fetus

OBJECTIVE

The mechanism by which the placenta serves as the barrier against mother-to-fetus transmission of microorganisms remains to be elucidated. Programmed cell death, apoptosis, is considered a cellular defense mechanism against infection. The hypothesis of this study is that apoptosis of human T-lymphotropic virus type I (HTLV-I)-infected placental villous cells is involved in the defense mechanism against mother-to-fetus transmission of HTLV-I.

METHODS

Apoptosis was compared in term placentas from eight HTLV-I-seropositive pregnant women and eight HTLV-I-seronegative pregnant women by the terminal deoxynucleotidyl transferase-mediated deoxyuridine nick end-labeling method. In addition, an in vitro cocultivation with an HTLV-I-infected lymphocyte cell line (MT-2 cells) was performed to examine whether placental villous cells were infected with HTLV-I and apoptosis was induced.

RESULTS

The incidence of apoptosis-positive cells (nuclei) in placentas from the HTLV-I-seropositive pregnant women was higher than in the HTLV-I-seronegative pregnant women (P < .02). Cocultivation with MT-2 cells showed that trophoblast cells were able to be infected with HTLV-I and that apoptosis was induced in the placental villous cells.

CONCLUSION

HTLV-I infection induces apoptosis in the placenta. We speculate that apoptosis may be involved in the defense mechanism of the placenta against mother-to-fetus transmission of HTLV-I.

External beam radiation therapy with or without high-dose-rate intraluminal brachytherapy for patients with superficial esophageal carcinoma

BACKGROUND

Clinical results of external beam radiation therapy (RT) with or without intraluminal brachytherapy (IBT) for patients with superficial esophageal carcinoma were evaluated retrospectively.

METHODS

Between 1985 and 1996, 21 patients with superficial esophageal squamous cell carcinoma were treated by external beam RT, with or without high dose rate IBT, with curative intent. There were 18 males and 3 females; their median age was 67 years (range, 51-85 years). Eight patients were treated by external beam RT alone (60-69 gray [Gy]), whereas the remaining 13 patients were treated by IBT after external beam RT. Most patients in the IBT group received 2 or 3 fractions of IBT of 4 Gy after external beam RT of 50-56 Gy.

RESULTS

All of the 21 tumors showed complete regression at the end of RT. Local recurrence was noted in 4 patients in the group that received external beam RT alone and in 2 patients in the IBT group. Salvage therapy was successful for 4 patients. Local control probability and cause specific survival probability for the IBT group were significantly higher than those for the group that received external beam RT alone (P < 0.05 for both). The 3-year local control and cause specific survival rates for the IBT group were 85% and 100%, respectively, whereas those for the external beam RT group were 45% and 67%, respectively. Transient esophageal ulcers were noted in two patients in the IBT group.

CONCLUSIONS

External beam RT and IBT is a safe and effective treatment modality for patients with superficial esophageal carcinoma.

Stimulation of steroidogenic acute regulatory protein (StAR) gene expression by D-aspartate in rat Leydig cells

D-aspartate and human chorionic gonadotropin act synergistically to increase testosterone production in purified rat Leydig cells, and D-aspartate stimulates testosterone synthesis even in the absence of human chorionic gonadotropin stimulation. In addition, D-aspartate enhances steady-state cellular mRNA and protein levels of steroidogenic acute regulatory protein, which is a key regulatory factor in gonadal and adrenal steroidogenesis. D-aspartate therefore appears to increase testosterone production in rat Leydig cells by stimulating steroidogenic acute regulatory protein gene expression. To our knowledge, this is the first report demonstrating a direct effect of D-aspartate on gene expression in mammalian cells.

Angiographic changes in uterine cervical cancer during the course of transarterial infusion chemotherapy

PURPOSE

To assess the correlation between angiographic findings, tumor stage, tumor size, histological type, and the effect of transcatheter arterial infusion (TAI) chemotherapy in patients with uterine cervical cancer.

MATERIALS AND METHODS

Thirty-three patients with untreated cervical cancer underwent two cycles of TAI. Changes in angiographic findings and other clinical and imaging data were assessed using the X2 test, multivariate analysis, and the two-sample t-test.

RESULTS

The group with parametric involvement included more patients with hypervascular tumors (21/24) than the group with no parametric involvement (0/5) (p < 0.001). Multivariate analysis revealed no correlation between initial tumor size, histology, or angiographic pattern and the effect of TAI.

CONCLUSION

The angiographic patterns seen in cervical cancer correlated with tumor stage. However, neither angiographic findings nor other clinical features predicted the effect of TAI.

Effects of a water-soluble prodrug of vitamin E on doxorubicin-induced toxicity in mice

Effects of the administration of a water-soluble prodrug of vitamin E on doxorubicine (DXR)-induced lethal and oxidative toxicity in mice were studied. The prodrug used was d-alpha-tocopheryl N,N-dimethylaminoacetate hydrochloride (TDMA). It was intravenously administered to animals 2 h prior to an intraperitoneal administration of DXR (15 mg/kg). The single preadministration of the prodrug (10-50 mg/kg equivalent for d-alpha-tocopherol) delayed the DXR-induced death and the ameliorative effect was TDMA-dose dependent. The extent of total lipid peroxidation of the heart and liver was assessed by 2-thiobarbituric acid reactant substance levels. DXR significantly accelerated lipid peroxidation in the liver but not in the heart. The elevation of liver lipid peroxide was significantly suppressed to a normal range by a single preadministration of TDMA (50 mg/kg equivalent for d-alpha-tocopherol). TDMA did not significantly affect the antitumor activity of DXR in mice inoculated with L1210 leukemia cells.

Crystallization and preliminary X-ray diffraction analysis of haloalkane dehalogenase LinB from Sphingomonas paucimobilis UT26

Haloalkane hydrolytic dehalogenase LinB from Sphingomonas paucimobilis UT26, an enzyme which releases chloride or bromide anion from n-halogenated alkanes and has a broad range of substrate specificity, was crystallized using the hanging-drop vapour-diffusion method at 278 K. The best crystals were obtained by microseeding with a precipitant containing 18-20%(w/v) PEG 6000, 0.2 M calcium acetate and 0.1 M Tris-HCl pH 8.9. The crystals diffract to at least 1.60 A using synchrotron X-ray under cryogenic (100 K) conditions. They belong to the orthorhombic space group P21212 with unit-cell parameters a = 50.29, b = 71.70, c = 72.73 A. The asymmetric unit contains one molecule of the enzyme.