Interactions between birth cohort and urbanization on gastric cancer mortality in Taiwan

Birth-cohort analysis is of particular importance for gastric cancer since migrant studies have indicated that early life experiences play a dominant role in the occurrence of the disease. However, none of the birth-cohort analyses conducted in various countries have provided information on variation in the birth-cohort phenomenon. To examine the interaction of birth cohort and urbanization, mortality data for gastric cancer between 1971 and 1990 in differentially urbanized areas in Taiwan were analysed. Traditional birth-cohort analysis and age-period-cohort (APC) analysis were employed in the study. The identification problem inherent in the APC analysis was circumvented by the 'individual record' method. Grading of the degree of urbanization of each township and district in Taiwan was based on an urbanization index derived from several demographic and socioeconomic variables. The birth-cohort effects diffused from urban to rural areas after fitting the APC model. In the older generations, born before 1910, the relative risks of gastric cancer were higher in urban areas than in rural ones, but in recent generations, i.e. those born after 1916-1922, the reverse was true. The age curves of gastric cancer mortality emerged as almost straight lines when plotted on a double logarithmic scale. Sex ratios increased with age up to age 60 and then remained constant. The spread of the birth-cohort effects suggested that dietary factors, e.g. dietary habits and food processing practices, in the early life of the population play an important role in the occurrence of gastric cancer.(ABSTRACT TRUNCATED AT 250 WORDS)

Risk of childhood leukemia in areas passed by high power lines

There has been an emerging concern about possible health risks posed by exposure to extremely low frequency electromagnetic fields (EMF). The incidence of childhood leukemia near high-power transmission lines has only rarely been investigated. A total of 67 cases of childhood leukemia (aged 0-14 years) were reported to the Cancer Registration Center in Taiwan between 1979 and 1988 from the five districts in the Taipei Metropolitan Area, where at least one elementary school campus is passed over by a high power transmission line (69-345 KV). The standardized incidence ratio (SIR) of childhood leukemia in the five districts was found to be significantly elevated (SIR = 1.49, 95% confidence interval: 1.16-1.91). Younger children seemed more susceptible to EMF exposure as indicated by the fact that children aged 0-4 years in two of the five districts showed significantly elevated SIRs compared to older ones. The unusually high SIRs for children of age 5-9 and 10-14 years in one of these districts (SIR = 4.38 and 3.68 respectively) deserves further investigation.

Age-period-cohort analysis of lung cancer mortality in Taiwan, 1966-1990

The specific aim of this study was to examine the effects of age, calender period of death, and birth cohort in lung cancer mortality in Taiwan over the period 1966-1990. A log-linear model modified from the method of Osmond and Gardner was used. Age is the most important predictor of lung cancer mortality according to the model. The oldest age group of 75-79 years old had a lung cancer mortality 185.3 and 79.2 times those for the youngest age group of 30-34 for males and females, respectively. There was also a significant cohort effect. The birth cohorts at the highest risk of lung cancer death were those born around 1931 for males and 1921 for females. A leveled off or declined trend of lung cancer mortality was observed for more recent cohorts. Parameters of the period factor showed an increasing lung cancer mortality from 1966 to 1990. In addition to the adverse effect of cigarette smoking, dietary and environmental factors should be taken into consideration in interpreting the results.

A yeast artificial chromosome contig linking the steroid sulfatase and Kallmann syndrome loci on the human X chromosome short arm

In this report we describe the construction of a yeast artificial chromosome (YAC) contig linking the steroid sulfatase (STS) and Kallmann syndrome (KAL) loci on Xp22.3. Four human YAC libraries were screened initially with sequences from DXS237 (GMGX9), DXS278 (S232B), and KAL and later with primers from exon 10 of the STS gene and the end fragment of a YAC clone YGX3 to fill the gaps. Fifteen clones were isolated and the sizes of their human inserts were determined by pulsed-field gel electrophoresis followed by Southern hybridization with labeled total human DNA. Overlaps between the YAC clones were evaluated using more than 20 DNA markers, including the screening probes, the end fragments, and the Alu-PCR products of the YAC clones. The extent of overlapping between the clones was further determined by long-range restriction mapping. In combination with our previously reported YAC contigs around STS and KAL, a total of 2 Mb of Xp22.3 have been isolated in YAC clones. These clones will facilitate the isolation of new genes and the characterization of deletions and translocations which occur at very high frequency in this region of the human X chromosome.

Vimentin serves as a phosphate sink during the apparent activation of protein kinases by okadaic acid in mammalian cells

The vimentin contents of four mammalian cell lines originating from rat and human tissues were determined by immunoblotting and scanning densitometry. On per cell volume basis, vimentin content in 9L, KD, and HeLa cells was found to be 206.6, 151.6, and 19.1 ng/microliters, respectively. A431 cells were devoid of vimentin. Protein phosphorylation was augmented by treatment of 600 nM okadaic acid for 1 h in these cells. During the apparent activation of protein kinases, vimentin became hyperphosphorylated and the phosphorylation level of other nonvimentin phosphoproteins was relatively little affected in 9L and KD cells. In contrast, cytokeratins and other nonvimentin proteins were heavily phosphorylated in OA-treated HeLa and A431 cells. Regression analysis indicated that the relative increase in phosphorylation level of nonvimentin phosphoproteins was inversely correlated to the contents of vimentin in the four cell lines [r2 = -0.985]. These observations strongly suggest that vimentin acts as a phosphate sink by which the effects of "excess kinase activity" inflicted by phosphatases inhibition was attenuated.

Herpes simplex virus type 1 and pseudorabies virus bind to a common saturable receptor on Vero cells that is not heparan sulfate

Herpes simplex virus type 1 (HSV-1) and pseudorabies virus (PRV) infect different natural hosts but are very similar in structure, replicative cycle, and entry into cultured cells. We determined whether HSV-1 and PRV use the same cellular components during entry into Vero cells, which are highly susceptible to each virus but are not from native hosts for either. UV-inactivated virions of either HSV-1 or PRV could saturate cell surfaces to block infection of challenge HSV-1 or PRV. In the presence of saturating levels for infection of either virus, radiolabeled virus bound well and in a heparin-sensitive manner. This result shows that heparan sulfate proteoglycans on Vero cells are not the limiting cellular component. To identify the virus component required for blocking, we used an HSV-1 null mutant virus lacking gB, gD, or gH as blocking virus. Virions lacking gB were able to block infection of challenge virus to the same level as did virus containing gB. In contrast, virions lacking gD lost all and most of the ability to block infection of HSV-1 and PRV, respectively. HSV-1 lacking gH and PRV lacking gp50 also were less competent in blocking infection of challenge virus. We conclude that HSV-1 and PRV bind to a common receptor for infection of Vero cells. Although both viruses bind a heparin-like cell component on many cells, including Vero cells, they also attach to a different and limited cell surface component that is bound at least by HSV-1 gD and possibly gH and to some degree by PRV gp50 but not gB. These results clearly demonstrate binding of both HSV-1 and PRV to a common cell receptor that is not heparan sulfate and demonstrate that several types of attachment occur for both viruses during infectious entry.

Diagnostic yield of colorectal neoplasia with colonoscopy for abdominal pain, change in bowel habits, and rectal bleeding

OBJECTIVES

To assess the clinical yield of colonoscoping in patients who present with rectal bleeding, persistent abdominal pain, or change in bowel habits in the absence of bleeding.

DESIGN

A prospective study of colonoscopy patients.

SETTING

Three colonoscopy practices in New York City between April 1986 and November 1989.

PATIENTS

Eight hundred sixty-one patients with rectal bleeding, 113 patients with abdominal pain, 154 with change in bowel habits, and 44 patients with both abdominal pain and bowel change.

MAIN RESULTS

Of 861 patients with rectal bleeding, 293 (33.6%) had colonic neoplasia (8.6% cancer and 25% adenomatous polyps). In patients who had colonoscopy because of abdominal pain (n = 113), change in bowel habits (n = 154), or both abdominal pain and bowel change (n = 44), respectively 25 (22.1%), 42 (27.3%), and 10 (22.7%) had colonic neoplasms. If one looks at significant neoplasia (cancer or adenomas > 1 cm), then the findings in rectal bleeders were 14.5%, whereas the abdominal pain, change in bowel habits, and both groups had 7.1%, 7.1%, and 13.6%, respectively. Patients with rectal bleeding were more likely to have multiple adenomas than those with nonbleeding symptoms (p < 0.05).

CONCLUSIONS

Patients with persistent nonbleeding GI symptoms, including abdominal pain and change in bowel habits, have almost as high a yield of colorectal neoplasia as those with rectal bleeding.

Induction of vimentin modification and vimentin-HSP72 association by withangulatin A in 9L rat brain tumor cells

Withangulatin A induced cell rounding up and the morphological alteration resulted from the reorganization of all of the major cytoskeletal components, i.e., vimentin, tubulin, and actin, as revealed by immunofluorescence techniques. When the withangulatin A-treated cells changed to a round-up morphology, vimentin intermediate filaments were found to be collapsed and clustered around the nucleus. The alteration was accompanied by characteristic changes of vimentin molecules, including augmentation of phosphorylation, retardation of electrophoretic mobility, and decrease in detergent extractability. The levels of vimentin phosphorylation were augmented by 2.5- and 1.8-fold in cells incubated with 50 microM withangulatin A for 1 and 3 h, respectively. The electrophoretic mobility of vimentin was partially retarded in cells treated with withangulatin A for 1 h at 10 microM and a completely upshift mobility was observed after 5 h treatment at 50 microM. In addition, vimentin molecules became less extractable by nonident P-40 after the cells were treated with withangulatin A and this effect was dose dependent. The decrease in solubility of vimentin was accompanied by the redistribution of HSP72 into the detergent nonextractable fraction and these two events were well correlated. Our results suggest that withangulatin A induced the modification of vimentin, which resulted in the alteration of cell morphology and redistribution of intracellular HSP72, an event that may play an important role in the induction of heat-shock response.

Lung cancer after radiation therapy for breast cancer

BACKGROUND

Radiation, including radiation therapy (RT) for a variety of conditions, is known to be a lung carcinogen.

METHODS

Data from the Surveillance, Epidemiology, and End Results program of the National Cancer Institute for 1973-1986 were utilized to investigate whether RT for breast cancer affects the risk of subsequent lung cancer. The relative risk was calculated by comparing the incidence rate in patients with irradiated breast cancer with that in those with nonirradiated breast cancer.

RESULTS

It was found that the risk of lung cancer overall was increased in women who underwent irradiation compared with those who were not irradiated 10 years after the initial breast cancer diagnosis with a relative risk of 2.0 (95% confidence interval, 1.0-4.3). In addition, the risk of lung cancer was in the ipsilateral lung compared with the contralateral lung for irradiated women. This increase was observed after 10 years for lung cancer overall and for the three major histologic subgroups (small cell, squamous cell, and adenocarcinoma). Specific information on RT doses and treatment plans and cigarette smoking were not available.

CONCLUSIONS

It was concluded that RT for breast cancer may increase the risk of lung cancer after a latency period of 10 years.

Cigarettes, alcohol, coffee, and caffeine as risk factors for colorectal adenomatous polyps

The possible association of colorectal adenomatous polyps, a precursor lesion for colorectal cancer, with cigarette smoking, alcohol consumption, and coffee and caffeine consumption was investigated in a case-control study. Between April 1986 and March 1988, 271 cases of patients with pathologically confirmed incident colorectal adenomatous polyps and 457 control subjects were collected from three colonoscopy practices in New York City. Information on exposure was obtained by structured interviews. After adjustment of age, statistically significant odds ratios (highest-lowest quartile) were found for cigarette smoking in males (2.2; 95% confidence interval (CI), 1.2 to 3.8) and coffee consumption in females (2.0%; 95% CI, 1.0 to 3.9). No significant associations were obtained for cigarette smoking in females, for coffee consumption in males, or for alcohol or caffeine consumption. After adjustments for alcohol, coffee, and caffeine consumption, the association of adenomas with cigarette smoking remained in males and significant associations were also observed in subcategory analysis for both left-side and right-side adenomatous polyps. Adjustment for cigarette smoking eliminated the association between colorectal adenomatous polyps and coffee consumption in females. Cigarette smoking appears to be a significant risk factor for colorectal adenomatous polyps in males.

Plasminogen activation activity of urokinase determined via a cascade enzymatic reaction system

A method for determining the plasminogen activation rate by urokinase via a cascade enzymatic reaction system is presented. A procedure of parameter estimation has been proposed for the determination of the activity of urokinase and the kinetic constants. Urokinase from urine has been successfully assayed through use of a plasminogen concentration lower than its saturating level. The methodology presented in this work may be adopted for the analysis of other cascade enzymatic reaction systems.

Enhanced phosphorylation of a 65 kDa protein is associated with rapid induction of stress proteins in 9L rat brain tumor cells

Induction of heat-shock proteins and glucose-regulated proteins in 9L rat brain tumor cells can be differentially elicited by sodium arsenite, cadmium chloride, zinc chloride, copper sulfate, sodium fluoride, and L-azetidine-2-carboxylic acid. The kinds of stress protein induced by the above chemicals varied considerably, mainly determined by the nature and the concentration of the chemicals, as well as the treatment protocols. In addition, at the concentrations where stress proteins can be induced, the above chemicals were able to suppress general protein synthesis and were cytotoxic. Enhanced phosphorylation of a protein with an apparent molecular weight of 65 kDa was detected during the induction of stress proteins except in azetidine treatments during which uptake of phosphate by the cells was impaired after prolonged incubation. The phosphate moiety on the 65 kDa phosphoprotein appeared to be alkaline-stable and two-dimensional gel electrophoresis revealed that the phosphoprotein resolved into four isoforms with isoelectric points ranging from 5.1 to 5.6. Enhanced phosphorylation of the same protein was also detected in heat-shocked and withangulatin A-treated 9L cells in which stress proteins were induced. It is suggested that this phosphoprotein may be a common target for heat stress response-stimulated phosphorylation and important in the further metabolic responses of the cell to stress.

Dietary risk factors for the incidence and recurrence of colorectal adenomatous polyps. A case-control study

OBJECTIVE

To investigate the association of dietary factors with the incidence and recurrence of colorectal adenomatous polyps.

DESIGN

Two case-control studies.

SETTING

Three university-based colonoscopy practices in New York City.

PATIENTS

For the incidence study, 286 patients with pathologically confirmed incident adenomatous polyps (162 men and 124 women) were compared with 480 controls (210 men and 270 women) with no current or previous neoplasia. For the recurrence study, 186 patients with recurrent polyps (130 men and 56 women) were compared with 330 controls (187 men and 143 women). These patients had a history of polyps but no current neoplasia.

MEASUREMENTS

Structured interviews using the Block food frequency questionnaire were conducted on all participants and were compared over quartiles of crude nutrient intake of total and saturated fat; fiber; protein; carbohydrates; carotene; vitamins A, C, and E; and various food groups. Data were adjusted for age, Quetelet index, and caloric intake by multiple logistic regression for men and women separately.

RESULTS

For incident polyps, elevated adjusted odds ratios (high to low quartile) for women were found for saturated fat (odds ratio, 2.3; 95% CI, 0.9 to 5.8) and the ratio of red meat to chicken and fish intake (odds ratio, 1.9; CI, 1.0 to 3.6). Protective associations were observed for fish and chicken (odds ratio, 0.6; CI, 0.3 to 1.2) and vitamin A intake (odds ratio, 0.4; CI, 0.2 to 0.9). Among women, recurrent polyps showed an association with total dietary fat (odds ratio, 4.4; CI, 1.0 to 19.5), saturated fat (odds ratio, 3.8; CI, 1.0 to 14.9; P = 0.15 for the trend), and total fiber (odds ratio, 0.2; CI, 0.1 to 0.5; P = 0.01) and a borderline association with carbohydrates (odds ratio, 0.3; CI, 0.1 to 1.3; P = 0.10). No consistent relations were observed for men, although increased caloric intake increased the risk for incidence and recurrence in both men and women.

CONCLUSIONS

These findings are consistent with previously described relations between diet and the incidence of colon cancer and suggest that, at least in women, dietary modification may be warranted in patients diagnosed with polyps.

Okadaic acid as an inducer of the 78-kDa glucose-regulated protein in 9L rat brain tumor cells

Okadaic acid (OA), a potent inhibitor of protein phosphatases 1 and 2A, has been widely used as a tool for unravelling the regulation of cellular metabolic processes involving protein phosphorylation/dephosphorylation. It has recently been found that OA can induce reversible hyperphosphorylation of vimentin and reorganization of intermediate filaments [Lee et al., J. Cell. Biochem. 49: 378-393, 1992]. We report here that OA specifically induced the synthesis of a 78-kDa protein, which was identified as the 78-kDa glucose-regulated protein (GRP78) by two-dimensional sodium dodecylsulfate-polyacrylamide gel electrophoresis and peptide mapping. The induction of GRP78 by OA was dose-dependent and reversible. For 7 h treatments, GRP78 synthesis was initially enhanced under 50 nM OA and became the highest (about 6-fold) under 200 nM OA. Meanwhile, under 200 nM OA, GRP78 synthesis was initially enhanced after 4 h and reached its maximal level (about 8-fold) after 15 h of treatment. Subsequently, upon removal of OA, the level of OA-induced GRP78 was reduced to basal level after 12 h of recovery. Induction of GRP78 synthesis by OA was abolished in cells pretreated with actinomycin D and cycloheximide, indicating that it was regulated at the transcriptional level and its induction required de novo protein synthesis. Furthermore, OA suppressed protein glycosylation, and the result lent support to the hypothesis that suppression of protein glycosylation may correlate with induction of GRP78 synthesis.

Mortality trends of pancreatic cancer: an affluent type of cancer in Taiwan

Interest in the increasing trends in pancreatic cancer mortality in Taiwan has recently emerged. The mortality data for pancreatic cancer in Taiwan from 1971 to 1988 for both sexes are presented to cast some light on the etiology of this ominous and yet little-known disease. A steeply increasing trend was found between 1975 and 1984 for both sexes; it dropped in 1985-86 and climbed again in 1987-88. The urban excess risks persisted in our study period of 18 years. Further study is mandatory to elucidate the etiological implications of dietary and other lifestyle changes on the magnitude of these rising secular trends and urban-rural gradients, particularly in the elderly, as well as the puzzling finding of cross-sectional drops in mortalities between 1985 and 1986. It is speculated that the drop may be associated with an economic recession that occurred in Taiwan between 1980 and 1981.

Hepatitis C and B viruses in hepatitis B surface antigen-negative hepatocellular carcinoma

The relative role of hepatitis C virus and hepatitis B virus in hepatitis B surface antigen-negative hepatocellular carcinoma was evaluated by polymerase chain reaction in 31 patients from Taiwan. Twenty-one were positive for antibody to hepatitis C virus (group 1) and 10 were negative (group 2). Of the group 1 patients, hepatitis C viral RNA was detected in the serum by polymerase chain reaction in 16 and in the liver tissue in 17, whereas hepatitis B viral DNA was found in the liver tissue in only 4, and none were found in the serum. In group 2 patients, hepatitis C viral RNA was detected in the serum of 1 and in the liver tissue of another. In contrast, hepatitis B viral DNA was found in the serum of 4 patients and in the liver tissues of 5. It was concluded that hepatitis C virus plays an important role in hepatocarcinogenesis in hepatitis B surface antigen-negative patients in Taiwan, especially in those who had antibody to hepatitis C virus; in those without antibody to hepatitis C virus, hepatitis B virus might still be associated with the development of hepatocellular carcinoma in a significant proportion of such patients.

Trends in mortality from diabetes mellitus in Taiwan, 1960-1988

The increasing trends of mortality from diabetes mellitus in Taiwan are becoming a public health concern. The age-adjusted death rate for diabetes was 3.7 per 100,000 population in 1960, which increased to 23.2 per 100,000 in 1988, a 6.3-fold increase over the past 30 years. The mortality data for diabetes in Taiwan from 1960 to 1988 for both sexes are presented and analysed using an age-period-cohort model in order to gain a better understanding of the possible determinants of the time trends of this disease. Steeply increasing trends which are particularly prominent in the elderly are found in the periods studied. Females and urban dwellers demonstrated greater risks for developing the disease. Significant cohort effects were found which peaked in the birth-cohort 1910-1917. This declined thereafter for females but has levelled since then for males. Further study is necessary to assess the aetiological implications of diet and urbanization on time trends of diabetes.

Induction of HSP70 is associated with vincristine resistance in heat-shocked 9L rat brain tumour cells

The most prominent cellular changes in heat-shock response are induction of HSPs synthesis and reorganisation of cytoskeleton. Vincristine was used as a tool to evaluate the integrity of microtubules in 9L rat brain tumour cells recovering from heat-shock treatment. Cells treated at 45 degrees C for 15 min and recovered under normal growing condition became resistant to vincristine-inflicted cytotoxicity and microtubule destruction. Among all HSPs, the level of HSP70 and the degree of vincristine resistance are best correlated. HSP70 and tubulin were found to be associated with each other as they were co-immunoprecipitated by either anti-HSP70 or anti-beta-tubulin monoclonal antibody. The current studies establish for the first time that HSP70 can complex with tubulin in cells and this association may stabilise the organisation of microtubules thus protect the heat-treated cells from vincristine damage. These findings are noteworthy in combining hyperthermia and chemotherapy in the management of malignant diseases.

NSR1 is required for pre-rRNA processing and for the proper maintenance of steady-state levels of ribosomal subunits

NSR1 is a yeast nuclear localization sequence-binding protein showing striking similarity in its domain structure to nucleolin. Cells lacking NSR1 are viable but have a severe growth defect. We show here that NSR1, like nucleolin, is involved in ribosome biogenesis. The nsr1 mutant is deficient in pre-rRNA processing such that the initial 35S pre-rRNA processing is blocked and 20S pre-rRNA is nearly absent. The reduced amount of 20S pre-rRNA leads to a shortage of 18S rRNA and is reflected in a change in the distribution of 60S and 40S ribosomal subunits; there is no free pool of 40S subunits, and the free pool of 60S subunits is greatly increased in size. The lack of free 40S subunits or the improper assembly of these subunits causes the nsr1 mutant to show sensitivity to the antibiotic paromomycin, which affects protein translation, at concentrations that do not affect the growth of the wild-type strain. Our data support the idea that NSR1 is involved in the proper assembly of pre-rRNA particles, possibly by bringing rRNA and ribosomal proteins together by virtue of its nuclear localization sequence-binding domain and multiple RNA recognition motifs. Alternatively, NSR1 may also act to regulate the nuclear entry of ribosomal proteins required for proper assembly of pre-rRNA particles.

Herpes simplex virus type 1 entry through a cascade of virus-cell interactions requires different roles of gD and gH in penetration

We examined the entry process of herpes simplex virus type 1 (HSV-1) by using infectious virus and previously characterized noninfectious viruses that can bind to cells but cannot penetrate as a result of inactivation of essential viral glycoprotein D (gD) or H (gH). After contact of infectious virus with the cell plasma membrane, discernible changes of the envelope and tegument could be seen by electron microscopy. Noninfectious virions were arrested at distinct steps in interactions with cells. Viruses inactivated by anti-gD neutralizing antibodies attached to cells but were arrested prior to initiation of a visible fusion bridge between the virus and cell. As judged from its increased sensitivity to elution, virus lacking gD was less stably bound to cells than was virus containing gD. Moreover, soluble gD could substantially reduce virus attachment when added to cells prior to or with the addition of virus. Virus inactivated by anti-gH neutralizing antibodies attached and could form a fusion bridge but did not show expansion of the fusion bridge or extensive rearrangement of the envelope and tegument. We propose a model for infectious entry of HSV-1 by a series of interactions between the virion envelope and the cell plasma membrane that trigger virion disassembly, membrane fusion, and capsid penetration. In this entry process, gD mediates a stable attachment that is likely required for penetration, and gH seems to participate in fusion initiation or expansion.

Reversible hyperphosphorylation and reorganization of vimentin intermediate filaments by okadaic acid in 9L rat brain tumor cells

Okadaic acid (OA), a protein phosphatase inhibitor, was found to induce hyperphosphorylation and reorganization of vimentin intermediate filaments in 9L rat brain tumor cells. The process was dose dependent. Vimentin phosphorylation was initially enhanced by 400 nM OA in 30 min and reached maximal level (about 26-fold) when cells were treated with 400 nM OA for 90 min. Upon removal of OA, dephosphorylation of the hyperphosphorylated vimentin was observed and the levels of phosphorylation returned to that of the controls after the cells recovered under normal growing conditions for 11 h. The phosphorylation and dephosphorylation of vimentin induced by OA concomitantly resulted in reversible reorganization of vimentin filaments and alteration of cell morphology. Cells rounded up as they were entering mitosis in the presence of OA and returned to normal appearance after 11 h of recovery. Immuno-staining with anti-vimentin antibody revealed that vimentin filaments were disassembled and clustered around the nucleus when the cells were treated with OA but subsequently returned to the filamentous states when OA was removed. Two-dimensional electrophoresis analysis further revealed that hyperphosphorylation of vimentin generated at least seven isoforms having different isoelectric points. Furthermore, the enhanced vimentin phosphorylation was accompanied by changes in the detergent-solubility of the protein. In untreated cells, the detergent-soluble and -insoluble vimentins were of equal amounts but the solubility could be increased when vimentins were hyperphosphorylated in the presence of OA. Taken together, the results indicated that OA could be involved in reversible hyperphosphorylation and reorganization of vimentin intermediate filaments, which may play an important role in the structure-function regulation of cytoskeleton in the cell.

Structure of a protected C3-C10 subunit of erythromycin and its C8 epimer

(1) (2S,3R,4R,6R)-3,4-O-Carbonyl-7,7-dimethylenedithio-2,4,6-trimet hylnonane-1,3,4-triol, C15H26O4S2, M(r) = 334.49, triclinic, P1, a = 6.460 (2), b = 8.917 (3), c = 15.616 (5) A, alpha = 83.60 (3), beta = 83.41 (2), gamma = 89.52 (2) degrees, V = 888.0 (5) A3, Z = 2, Dx = 1.25 g cm-3, mu = 2.980 cm-1, lambda (Mo K alpha) = 0.7107 A, F(000) = 360, T = 298 K, R = 0.0465 for 1832 reflections [Fo greater than or equal to 4 sigma (Fo)]. (2) (2S,3R,4R,6S)-3,4-O-Carbonyl-7,7-dimethylenedithio-2,4,6-trimet hylnonane-1,3,4-triol, C15H26O4S2, M(r) = 334.49, monoclinic, P21, a = 8.1849 (8), b = 8.9456 (14), c = 12.0258 (14) A, beta = 100.878 (8) degrees, V = 864.7 (2) A3, Z = 2, Dx = 1.28 g cm-3, mu = 3.060 cm-1, lambda (Mo K alpha) = 0.7107 A, F(000) = 360, T = 298 K, R = 0.0569 for 2001 reflections [Fo greater than or equal to 4 sigma (Fo)]. The two diastereomers differ in configuration at C6. For (1) there are two unique molecules in the unit cell. These two molecules differ in conformation by a rotation about the bond C7-C8. The molecules are hydrogen bonded into infinite chains along b. The hydroxyl O atom of molecule (2), O10', acts as both a donor and an acceptor in hydrogen-bonding interactions with the carbonyl O atom, O14, and the hydroxyl H atom, H10, of molecule (1).(ABSTRACT TRUNCATED AT 250 WORDS)

Acupuncture in the treatment of renal colic

A prospective randomized study was performed to compare the effect of acupuncture and intramuscular Avafortan injection in the treatment of renal colic. Our results showed that acupuncture is as effective in relieving renal colic as Avafortan but it had a more rapid analgesic onset (3.14 +/- 2.88 minutes versus 15.44 +/- 7.55 minutes, p less than 0.05). Of the patients in the Avafortan group 7 (43.8%) had side effects, including skin rash in 3, tachycardia in 2, drowsiness in 1 and facial flush in 1. No side effects were noted in the acupuncture group. During 2 hours of observation acupuncture and Avafortan seemed to be ineffective in promoting stone passage. However, patients receiving Avafortan treatment were more likely to have paralytic ileus. In summary, acupuncture can be a good alternative for the treatment of renal colic.

The association of breast cancer and colorectal cancer in men. An analysis of surveillance, epidemiology, and end results program data

There is a known increased risk for the co-occurrence of both breast cancer and colorectal cancer in the same women, presumably as a result of either shared reproductive hormonal or environmental risk factors. Using data from the Surveillance, Epidemiology, and End Results Program of the National Cancer Institute, the authors investigated whether there is a similar relationship between breast cancer, colorectal cancer, and prostate cancer in men. The observed-expected ratio was not significantly elevated for either colorectal cancer after breast cancer or for breast cancer after colorectal cancer in men. There was an increased incidence of prostate cancer after colorectal cancer, but this relationship was not present in the opposite direction and is believed to result from detection bias. There was an increased incidence of breast and colorectal cancer in women. These results suggest that the observed breast and colorectal cancer relationship in women may be a result of shared reproductive hormonal factors.

Induction of heat-shock response and alterations of protein phosphorylation by a novel topoisomerase II inhibitor, withangulatin A, in 9L rat brain tumor cells

Withangulatin A is a newly identified in vitro topoisomerase II inhibitor isolated from the Chinese antitumor herb Physalis angulata. In vivo, it was found to be cytotoxic, capable of suppressing general protein synthesis and of inducing the synthesis of a small set of proteins including those generated by heat-shock treatment. The 70 kDa protein generated by withangulatin A was unequivocally identified as the heat-shock protein 70 (HSP70) since both proteins migrated to the same position on two-dimensional polyacrylamide gels, could be recognized by a monoclonal antibody to human HSP70, and exhibited identical peptide maps. The induction of protein synthesis by withangulatin A was regulated at the transcriptional level since it was aborted in cells pre-treated with actinomycin D. However, the initiation of this process did not require de novo protein synthesis since it was not affected by cycloheximide. Other cellular effect of withangulatin A was alterations of protein phosphorylation including an enhancement of phosphorylation of a 65 kDa protein which was also detected in the heat-shocked cells. Moreover, this process was observed within 7.5 min after the initial heat treatment which is much faster than the onset of HSP synthesis. Therefore, increased phosphorylation of the 65 kDa protein may represent one of the earliest signals generated by both heat-shock and withangluatin A and may be involved in the upstream regulation of heat-shock response in cells.

Fluorescent tetradecanoylphorbol acetate: a novel probe of phorbol ester binding domains

Protein kinase C (PKC) has a prominent role in signal transduction of many bioactive substances. We synthesized the fluorescent derivative, phorbol-13-acetate-12-N-methyl-N-4-(N,N'-di(2-hydroxyethyl)amino)-7-n itr obenz-2-oxa-1,3-diazole-aminododecanoate (N-C12-Ac(13)) of 12-O-tetradecanoylphorbol-13-acetate (TPA) to monitor the location of phorbol ester binding sites and evaluate its potential use as a probe of PKC in viable cells. The excitation maximum wavelength of N-C12-Ac(13) is close to 488 nm, facilitating its use in argon-ion laser flow and imaging cytometry. When incubated with 100 nM N-C12-Ac(13) at 25 degrees C, P3HR-1 Burkitt lymphoma cells accumulated the dye rapidly, reaching maximum fluorescence within 25 min, 20-fold above autofluorescence. Addition of unlabeled TPA significantly decreased the fluorescence of N-C12-Ac(13) stained cells in a dose-dependent manner indicating specific displacement of the bound fluoroprobe. Competitive displacement of [3H]-phorbol-12,13-dibutyrate ([3H]-PBu2) from rat brain cytosol with N-C12-Ac(13) gave an apparent dissociation constant (Kd) of 11 nM. N-C12-Ac(13) possessed biological activity similar to TPA. Like TPA (final concentration 65 nM) N-C12-Ac(13), at a lower concentration (51 nM), induced expression of Epstein-Barr viral glycoprotein in P3HR-1 cells, differentiation of promyelocytic HL60 cells, and caused predicted changes in the mitotic cycle of histiocytic DD cells. Microspectrofluorometric images of single cells labeled with N-C12-Ac(13) showed bright fluorescence localized intracellularly and dim fluorescence in the nuclear region, consistent with dye binding mainly to cytoplasmic structures and/or organelles and being mostly excluded from the nucleus. Because of the high level of non-specific binding of N-C12-Ac(13), this probe is not ideal for visualizing PKC in intact cells, but would be a valuable fluoroprobe to investigate the kinetic properties of purified PKC. Also, knowledge gained from these studies allows us to predict structures of fluorescent phorbols likely to have less non-specific binding and, consequently, be potentially useful for monitoring PKC in viable cells.

Structure of a fully protected seco-erythronolide B acid derivative

(3S,4R,5S,6R,7R,9R,10S,11S,12S,13S,- 14R)-14-Benzyloxymethoxy-10,12-O-carbonyl-4-N- imidazolylcarbonyl-6,7-O-isopropylidene-3,5,7,9,11,- 13-hexamethylhexadec-1-ene-4,6,7,10,12,14-hexol, C38H56N2O9, Mr = 684.87, monoclinic, P2(1), a = 8.7302 (12), b = 15.597 (2), c = 14.463 (2) A, beta = 104.797 (10) degrees, V = 1904.1 (4) A3, Z = 2, Dx (198 K) = 1.19 g cm-3, mu = 0.7893 cm-1, Mo K alpha radiation, lambda = 0.7107 A, F(000) = 740, T = 198 K, R = 0.0301 for 3141 reflections [Fo greater than or equal to 4 sigma (Fo)]. The crystal structure was undertaken to determine the stereochemistry of the title compound. The molecule is folded on itself in such a way that the portion of the molecule from the phenyl ring at C44 and extending to C28 forms nearly a single turn of a right-handed screw. Large deviations from ideality for several Csp3-Csp3 bond angles are observed that are presumably due to intramolecular steric effects. The largest deviations are: C3-C4-C5 117.8 (2), C5-C6-C7 121.2 (2), C7-C8-C9 115.3 (2), C9-C10-C11 116.2 (2), C11-C12-C13 117.2 (2), C14-C15-C16 115.5 (3) degrees.

The NSR1 gene encodes a protein that specifically binds nuclear localization sequences and has two RNA recognition motifs

We previously identified a protein (p67) in the yeast, Saccharomyces cerevisiae, that specifically recognizes nuclear localization sequences. We report here the partial purification of p67, and the isolation, sequencing, and disruption of the gene (NSR1) encoding this protein. p67 was purified using an affinity column conjugated with a peptide containing the histone H2B nuclear localization sequence from yeast. Using antibodies against p67 we have cloned the gene for this protein. The protein encoded by the NSR1 gene recognizes the wild-type H2B nuclear localization sequence, but does not recognize a mutant H2B sequence that is incompetent for nuclear localization in vivo. Interestingly, the NSR1 protein has two RNA recognition motifs, as well as an acidic NH2 terminus containing a series of serine clusters, and a basic COOH terminus containing arg-gly repeats. We have confirmed the nuclear localization of p67 by immunofluorescence and found that a restricted portion of the nucleus is highlighted. We have also shown that NSR1 (p67) is required for normal cell growth.

Obesity and colorectal adenomatous polyps

Obesity has been investigated as a risk factor for various malignancies, including colon cancer. A case-control study was conducted on patients in three colonoscopy practices in New York City to determine possible risk factors for colorectal adenomatous polyps, a known precursor lesion for most cases of colorectal cancer. Among 301 case subjects with incidence adenomatous polyps (174 men and 127 women) and 506 control subjects (223 men and 283 women), an increased risk was observed with increasing body mass index in women (odds ratio 2.1, 95% confidence interval 1.1-4.0; for highest versus lowest quartile, linear trend P = .02). A nonsignificant trend was observed for men. The increased risk seen in women is consistent with prior observations regarding reproductive hormonal and dietary risk factors for colorectal cancer.

Age-period-cohort analysis of pancreatic cancer mortality in Taiwan, 1971-1986

Interest has recently emerged about the increasing trend of pancreatic cancer mortality in Taiwan, particularly in the elderly. The mortality data of pancreatic cancer over the period 1971-1986 for males and females aged 40-84 in Taiwan were analysed using a log-linear Poisson model to examine the effects of age, calendar period of death, and birth cohort. This age-period-cohort model provides a summary guide for the reading and interpretation of cancer mortality trends. Age is the strongest factor in predicting pancreatic cancer mortality according to the models; the oldest age group 80-84 years old has 14.5 times the risk of the youngest age group 40-44. The cohort effect is also of particular interest because the generation at greatest risk for pancreatic cancer in both sexes, is the one born between 1917 and 1926, and a declining trend is observed thereafter for more recent cohorts. Parameters of the period factor show no observable trend before 1975, followed by a significantly increasing risk in the subsequent time period. However, the drop of pancreatic cancer mortality over all age groups between 1985-86 is puzzling and a further study to monitor the secular trends in the following years is warranted.

Experimental study of the effect of prostaglandin administration on tooth movement--with particular emphasis on the relationship to the method of PGE1 administration

Recently, the mechanism of action of prostaglandins in promoting bone resorption has received wide attention. Prostaglandins are used in orthodontics to shorten the period of tooth movement. PGE1 was administered locally (5 micrograms/kg every 12 hours) and systemically (7.5 ng/kg/min) to rats to study the difference in the efficacy of the two methods of administration in accelerating bone resorption. The Waldo method was used on 72 Wistar rats (8 weeks old) for 5 days to induce mesial movement of the first molar. The body weight of the rats was measured every 12 hours from the start of the experiment. Tissues were examined in the mesial surface of the mesial root and in the interradicular septum between the linguomesial root and the linguodistal root of the upper first molar. The pressure side of the mesial surface of the mesial root was studied, as well as the pressure side of the interradicular septum. The results showed that decrease in body weight during the experiment was more prominent in the local administration group than in the systemic administration group. In both the group receiving PGE1 through local administration and the group receiving PGE1 through systemic administration, the numbers of osteoclasts and Howship's lacunae were markedly increased over those in the control groups. Moreover, compared with local administration, systemic administration of PGE1 had a more marked effect on bone resorption.