The time trend and age-period-cohort effects on incidence of adenocarcinoma of the stomach in Connecticut from 1955-1989

BACKGROUND

Adenocarcinoma of the gastric cardia has been be increasing in Connecticut, and the risk factors responsible for the increasing incidence are unknown. This study examined the incidence pattern of adenocarcinoma of the gastric cardia and distal stomach in Connecticut during the past decades and identified components of birth cohort, period, and age as determinants of the observed time trends by regression modeling.

METHODS

This study was based on all histologically confirmed incident cases of gastric adenocarcinoma reported to the Connecticut Tumor Registry between 1955 and 1989. Stomach cancers were grouped into cancers of the gastric cardia, distal stomach, or unknown/unspecified subsite. Age-adjusted incidence rates were calculated by the direct method standardized to the 1970 United States population. A regression model was used to identify birth cohort, period, and age as determinants of the observed time trends.

RESULTS

The results indicated that the incidence rate of adenocarcinoma of the cardia is increasing, particularly in white males, whereas adenocarcinoma of the distal stomach is now decreasing in both sexes in Connecticut. Regression modeling suggests that the increase of adenocarcinoma of the cardia may be explained partly by a birth cohort phenomenon.

CONCLUSION

There is little information regarding the risk factors that might be responsible for the observed increasing trend for adenocarcinoma of the cardia, although smoking, alcohol intake, retinol intake, and hiatal hernia have been associated with an increased risk of adenocarcinoma of the cardia or gastric cancer. Considering the different epidemiologic features of adenocarcinoma of the cardia and distal stomach, future analytic studies should separate cancer of the gastric cardia and cancer of the distal stomach in searching for etiologic factors.

The time trend and age-period-cohort effects on incidence of adenocarcinoma of the stomach in Connecticut from 1955-1989

BACKGROUND

Adenocarcinoma of the gastric cardia has been be increasing in Connecticut, and the risk factors responsible for the increasing incidence are unknown. This study examined the incidence pattern of adenocarcinoma of the gastric cardia and distal stomach in Connecticut during the past decades and identified components of birth cohort, period, and age as determinants of the observed time trends by regression modeling.

METHODS

This study was based on all histologically confirmed incident cases of gastric adenocarcinoma reported to the Connecticut Tumor Registry between 1955 and 1989. Stomach cancers were grouped into cancers of the gastric cardia, distal stomach, or unknown/unspecified subsite. Age-adjusted incidence rates were calculated by the direct method standardized to the 1970 United States population. A regression model was used to identify birth cohort, period, and age as determinants of the observed time trends.

RESULTS

The results indicated that the incidence rate of adenocarcinoma of the cardia is increasing, particularly in white males, whereas adenocarcinoma of the distal stomach is now decreasing in both sexes in Connecticut. Regression modeling suggests that the increase of adenocarcinoma of the cardia may be explained partly by a birth cohort phenomenon.

CONCLUSION

There is little information regarding the risk factors that might be responsible for the observed increasing trend for adenocarcinoma of the cardia, although smoking, alcohol intake, retinol intake, and hiatal hernia have been associated with an increased risk of adenocarcinoma of the cardia or gastric cancer. Considering the different epidemiologic features of adenocarcinoma of the cardia and distal stomach, future analytic studies should separate cancer of the gastric cardia and cancer of the distal stomach in searching for etiologic factors.

Long-term reversal of diabetes by the injection of immunoprotected islets

The intraperitoneal injection of insulin-producing islets immunoprotected by an alginate-poly(amino acid) membrane is a potential method of reversing diabetes without the need for lifelong immunosuppression. Previous attempts to demonstrate this technology in large animals have failed, preventing application in humans. We have determined that key factors responsible for these past failures include cytokine (interleukins 1 and 6 and tumor necrosis factor) stimulation by mannuronic acid monomers from alginate capsules with weak mechanical integrity, which results in fibroblast proliferation. With this insight, we formulated mechanically stable microcapsules by using alginate high in guluronic acid content and report prolonged reversal of diabetes in the spontaneous diabetic dog model by the intraperitoneal injection of encapsulated canine islet allografts. Euglycemia, independent of any exogenous insulin requirement, was noted for up to 172 days. Graft survival, evidenced by positive C-peptide release, was noted for as long as 726 days in a recipient receiving a single injection of immunoprotected islets. Histological evidence of viable islets retrieved from the peritoneal cavity 6 months posttransplant confirmed the biocompatibility and immunoprotective nature of this capsule formulation. The finding that intraperitoneal injection of alginate-immunoprotected islets, a minimally invasive surgical procedure, is effective in prolonged (> 1 year) maintenance of glycemic control, without the need for lifelong immunosuppression, may have significant implications for the future therapy of type I diabetes in humans.

An epidemiological survey of deformities and disabilities among 14,257 cases of leprosy in 11 counties

This study was planned and conducted in Yang Zhou Prefecture, covering 11 counties that were formerly areas with a high prevalence of leprosy. Out of 14,257 leprosy patients, 8122 (56.97%) cases with deformities and disabilities were found. The disability rate is much higher in patients with MB leprosy (81.15%) than in PB leprosy (53.04%). The statistical data and the type of deformities and disabilities are presented. The influences of various host factors and disease factor which cause disability and deformity are discussed.

cAMP inhibition of interleukin-1-induced interleukin-6 production by human lung fibroblasts

We characterized the effects of agents that alter intracellular adenosine 3',5'-cyclic monophosphate (cAMP) on the interleukin (IL)-6 production of human lung fibroblasts. Unstimulated fibroblasts did not produce significant amounts of IL-6. Recombinant (r) tumor necrosis factor (TNF) weakly stimulated, recombinant interleukin-1-alpha (rIL-1 alpha) strongly stimulated, and rIL-1 alpha and rTNF in combination synergistically augmented fibroblast IL-6 production. Prostaglandin (PG)E1, forskolin, dibutyryl cAMP (DBcAMP), 3-isobutyl-1-methylxanthine (IBMX), and cholera toxin did not cause a detectable alteration in the IL-6 production of unstimulated fibroblasts. However, these agents inhibited the IL-6 production of rIL-1 and rIL-1 plus rTNF-stimulated cells. These effects were dose dependent with a concentration of 2 x 10(-9) M PGE1, 5 x 10(-6) M forskolin, 5 x 10(-4) M DBcAMP, and 1 x 10(-3) M IBMX decreasing rIL-1 alpha (2.5 ng/ml)-induced IL-6 production by approximately 50%. The inhibitory effects of these agents, correlated with their ability to induce fibroblast cAMP accumulation, could not be explained by alterations in cell number or viability and were appreciable even when cAMP modifiers were added to fibroblast culture, 1 h after rIL-1. They were also at least partly specific for rIL-1, since these agents increased the IL-6 production of rTNF-stimulated cells. These cAMP-induced alterations in IL-6 production were associated with corresponding alterations in IL-6 mRNA accumulation. Nuclear run-on analysis demonstrated that the inhibitory effects of PGE1 were associated with a comparable decrease in IL-6 transcription. Agents that increase the levels of intracellular cAMP inhibit rIL-1-induced IL-6 by human lung fibroblasts.

A case-control study of oral cancer in Beijing, People's Republic of China. Associations with nutrient intakes, foods and food groups

A case-control study of oral cancer was conducted in Beijing, People's Republic of China to examine the association between dietary nutrient intake and risk of oral cancer, both in terms of estimated intake of nutrients and micro-nutrients, and in terms of specific foods and food groups. The study was hospital-based and controls were hospital in-patients matched for age and sex with the cases. The response rate for cases and controls was 100% and 404 case/control pairs were interviewed. The results suggest that increased protein and fat intake are related to a decreased risk of oral cancer. Carbohydrate intake, however, showed a moderate increased risk for oral cancer. Total carotene intake and carotene intake from fruits and vegetables are inversely associated with risk of oral cancer. A similar pattern was observed for dietary vitamin C intake. Dietary fibre derived from fruits and vegetables showed a strong negative association with oral cancer risk, but fibre derived from other sources did not exhibit any protective effect. At the level of foods and food groups, increased consumption of fresh meat, chicken and liver was significantly associated with a reduction in oral cancer risk: the tests for trend were all statistically significant at the P < 0.01 level. Consumption of common carp, hairtail, shrimp and lobster were also associated with decreased risk. Risk was found to increase with increasing consumption of millet and corn bread (P < 0.01) but to decrease with increasing consumption of rice (P < 0.01). Increased consumption of grapes, bananas, oranges, tangerines, peaches and pears were associated with reduced risk.(ABSTRACT TRUNCATED AT 250 WORDS)

An epidemiological survey of deformities and disabilities among 14257 leprosy patients in 11 counties

This study was planned and conducted in 11 counties in Yangzhou Prefecture, which had formerly had a high prevalence of leprosy. Out of 14257 leprosy patients, 8122 (56.97%) with permanent deformities and disabilities were found. The disability rate was much higher among patients with multibacillary (MB) leprosy (81.15%) than among those with paucibacillary (PB) leprosy (53.04%). The statistical data involving the patients and the types of deformities and disabilities are presented in this paper, and the influences of various host factors and disease factors are discussed.

Time trends of non-Hodgkin's lymphoma: are they real? What do they mean?

Factors that need to be considered in the analysis of time trends in disease incidence are age, year of diagnosis, and birth cohort. When these are included in a log-linear model, a nonidentifiability problem arises from the linear dependence among these three time factors so that only specified functions of the parameters can be unambiguously determined. One of these invariant functions is the drift or the sum of the period and cohort trend. Non-Hodgkin's lymphoma incidence rates from Connecticut for the period 1935-1989 were analyzed for males and females. In addition to an age effect, both period and cohort significantly improved the fit of the model. The estimated drift shows that there has been a 10.3% increase in risk every 5 years since 1965 for females and 9.2% for males. It is unlikely that a trend of this magnitude can be attributed entirely to data artifact.

Early markers of pancreas transplant rejection

To compare the predictive value of urinary amylase (UA), urinary insulin (UI), and urinary prostaglandin (PGE2), whole pancreas isografts or allografts from (ACI rat donors, RT1a) with bladder drainage of exocrine secretions were performed in Lewis rats (RT1(1)) with streptozotocin-induced diabetes. UA, UI, PGE2 and plasma glucose levels were measured daily. Euglycemia was restored on Postoperative Day 1 in all the recipients of isografts (N = 6) and was maintained for over a year. UI concentrations and PGE2 outputs were stable, with low levels ranging between 0.3 +/- 0.2 to 7 +/- 2 ng/ml and 56 +/- 15 to 164 +/- 48 ng/24 hr, respectively, while UA levels were significantly elevated compared to normal controls (> 1,000 U/ml vs 29 +/- 16 U/ml). In the allograft group (N = 12), rejection occurred on Days 7 through 9, with a mean graft survival time of 8.1 +/- 0.1 days. UA dropped from a post-transplant peak of 2,422 +/- 353 U/ml on Postoperative Day 4 to below 1,380 +/- 256 U/ml 3 days before rejection (Day -3). UI increased to 83 +/- 16 ng/ml (P < 0.05) on Day -6 and reached a post-transplant peak of 140 +/- 24 ng/ml on Day -5, while PGE2 output rose from a pretransplant level of 18 +/- 2 to 92 +/- 25 ng/24 hr on Postoperative Day 1, followed by a significant elevation on Day 4 (-4).(ABSTRACT TRUNCATED AT 250 WORDS)

Time trend and age-period-cohort effects on incidence of esophageal cancer in Connecticut, 1935-89

The purpose of this study was to examine the incidence pattern of esophageal cancer in Connecticut (USA) during the past decades, and to identify components of birth cohort, period, and and age as determinants of the observed time trends by regression modelling. This study is based on all of the esophageal cancer cases reported to the Connecticut Tumor Registry between 1935 and 1989. A total of 6,310 incident cases were included. Results indicate that among males, the overall age-adjusted incidence rate of esophageal cancer increased after 1935 and peaked between 1955 and 1959. Since then, incidence rates have been relatively stable. Among females, the overall esophageal cancer rate has not changed markedly since 1935. Analysis by histologic type indicates that the incidence rate of squamous cell carcinoma has been declining in this population; adenocarcinoma, however, showed a continuous increase. A fivefold increase among males and a threefold increase among females were observed for adenocarcinoma of the esophagus between 1970 and 1989. If cancers of the esophagus and gastric cardia are considered together, the incidence rate of adenocarcinoma exceeds that of squamous cell carcinoma among males during 1985-89. The observed increasing trend for adenocarcinoma of the esophagus is mainly from cancers arising in the lower third of the esophagus and primarily among Whites, especially White males. The results from regression modeling indicate that both period and birth cohort may have contributed to the observed increasing trend, and adenocarcinoma of the esophagus is likely to increase continuously in this population in the coming years.

Epidemiology of non-Hodgkin lymphoma in Connecticut. 1935-1988

BACKGROUND

During the past decades, there have been reports of increases in the incidence and mortality rates due to non-Hodgkin lymphoma (NHL) in many parts of the world. The risk factors responsible for the increasing incidence are largely unknown. This study provided an overview of the incidence pattern of NHL in Connecticut and generated hypotheses for additional investigation.

METHODS

This study was based on all the NHL cases reported to the Connecticut Tumor Registry (CTR) between 1935 and 1988. Crude, age-adjusted, and age-specific incidence rates of NHL were calculated for each sex. Age-adjusted incidence rates were calculated by the direct method standardized to the 1970 United States standard million population. The data are presented by calendar year and cohort year of birth to examine the secular trends and birth cohort effects. Racial information was not coded before 1957 and is of uncertain validity until the early 1970s; therefore, racial analysis was restricted to 1970-1988. Analyses by histologic subtypes and by anatomic sites were restricted to the last 3 decades (1960-1988) because more accurate classification systems were used during this time.

RESULTS

A total of 11,326 newly diagnosed cases of NHL were included in the study. Of them, 5866 (52%) were diagnosed in men and 5460 (48%) were diagnosed in women. The study results indicated that the incidence rate of NHL has been increasing during the past decades for men and women, whites and blacks, nodular NHL and diffuse NHL, disease originating from lymph nodes and disease originating from other sites, and in all age groups, especially the older age groups. Birth cohort examination did not show any indication of a decline or levelling off in incidence rates among recent birth cohorts. Age-specific incidence rates in both sexes suggested that the rates increase with age, with a sharp increase beginning at 50 years of age and peaking at 80 years of age. Men had a 30% higher incidence rate than women, and whites had approximately 1.5 times the age-adjusted incidence rate of blacks.

CONCLUSIONS

The results indicated that the incidence rate of NHL has been increasing in Connecticut during the past decades and is likely to continue to rise in the coming years. Analytical epidemiologic studies are needed to examine the risk factors that might account for the increase in NHL.

Recent advances in epidemiology of head and neck cancer

Cancer of the oral cavity is an important contributor to the overall international cancer burden, especially in the developing countries. Smoking cessation, moderation of alcohol consumption, and increased consumption of fruits, and probably vegetables, have been identified by epidemiologic studies as three actions that could lead to the prevention of approximately three fourths of cases in Western countries. Similar effects could be brought about in developing countries through cessation of cigarette smoking and, where appropriate, betel quid chewing and increased consumption of fruits and vegetables. Since this disease is increasing in frequency in many countries, it is important to implement these health education messages. A similar situation holds true for larynx cancer. Clearly many head and neck cancers are preventable and it is worth repeating that prevention should become an epidemiologic priority. There are exciting prospects of effective chemoprevention opportunities in head and neck cancer, with a number of compounds having activity. Further developments in this important area are awaited.

Transfection of wild-type CFTR into cystic fibrosis lymphocytes restores chloride conductance at G1 of the cell cycle

We complemented the Cl- conductance defect in cystic fibrosis lymphocytes by transfection with wild-type cDNA for the cystic fibrosis transmembrane conductance regulator (CFTR). Stable transfectants were selected and subjected to molecular and functional analyses. We detected expression of endogenous CFTR mRNA in several CF and non-CF lymphoid cell lines by PCR. Expression from cDNA in the transfectants was demonstrated by amplifying vector-specific sequences. Both fluorescence and patch-clamp assays showed that transfectants expressing wild-type CFTR acquired properties previously associated with Cl- conductance (GCl) regulation in non-CF lymphocytes: (i) GCl was elevated in the G1 phase of the cell cycle, (ii) cells fixed at G1 increase GCl in response to increased cellular cAMP or Ca2+, (iii) agonist-induced increases in GCl were lost as the cells progressed to the S phase of the cell cycle. The cell cycle and agonist dependent regulation of GCl was not observed in CF lymphocytes transfected with CFTR cDNA containing stop codons in all reading frames at exon 6. Our findings indicate that lymphocytes express functional CFTR since wild-type CFTR corrects the defects in Cl- conductance regulation found in CF lymphocytes. Evaluation of the mechanism of this novel, CFTR-mediated regulation of GCl during cell cycling should provide further insights into the function of CFTR.

A mathematical model of proliferation and aging of cells in culture

A mathematical model is presented which describes the proliferative senescence of cells in culture. The model is based on the DNA damage hypothesis of cellular aging and is able to account for both the limited and unlimited in vitro proliferative potential of normal and transformed cells. It is predicted that the destiny of a cell population is determined by two counteracting factors: the proliferation rate of the dividable cells and the gene damage accumulation rate. The formation of an immortal cell line requires high rate of proliferation and/or low rate of gene damage accumulation. The related computer simulations on a number of proliferative properties of cell culture produces results in agreement, in the general properties, with experimental observations.

Activities of serum enzymes in patients with viral hepatitis B, posthepatitic cirrhosis and hepatocellular carcinoma

Using spectrophotometric method, we studied the activities of serum alpha-L-fucosidase, N-acetyl-beta-D-glucosaminidase and alpha-D-mannosidase in 94 patients, of whom 32 had acute hepatitis, 4 subacute fulminant hepatitis, 27 chronic active hepatitis, 22 posthepatitic cirrhosis and 9 hepatocellular carcinoma. In comparison with normal controls, the activities of the three glycosidases in the patients were significantly increased. The degree of the elevation of alpha-L-fucosidase activity correlated to the clinical phases and the course of acute infection of hepatitis B virus (HBV). The levels of glycosidase activities could reflect to a certain degree the pathological variations of the liver. Monitoring the levels of glycosidase activities, especially alpha-L-fucosidase, would be helpful in the diagnosis and medical care of viral hepatitis and hepatocellular carcinoma.

[Identification of plant morphology of herba Plantaginis in China]

This paper deals with the identification of plant morphology of 18 Herba Plantaginis produced in China, of which 6 species are reported for the first time in China. Keys and diagrams for the identification are given.

Ionomycin releases calcium from the sarcoplasmic reticulum and activates Na+/Ca2+ exchange in vascular smooth muscle cells

Ionomycin (1 microM) produced a large spike in cytosolic free Ca2+ [( Ca2+]i). The ionophore had no effect on [Ca2+]i if the sarcoplasmic reticulum had previously been Ca2+ depleted by stimulating neurohormone receptors. Ionomycin markedly increased 45Ca2+ efflux and decreased total cell Ca2+ by 60 to 70% in 1 min. Replacing extracellular Na+ [( Na+]o) with choline or N-methyl-D-glucamine strongly inhibited the effects of ionomycin on 45Ca2+ efflux and total Ca2+. Ionomycin caused similar peak increases in [Ca2+]i in the presence and absence of [Na+]o, but the exponential fall from the peak was faster in the presence of [Na+]o. Dimethylbenzamil, a potent blocker of Na+/Ca2+ exchange in these cells, strongly inhibited the effects of ionomycin on 45Ca2+ efflux and total cell Ca2+. We conclude that the increase in cytosolic free Ca2+ produced by ionomycin may be sufficient to activate the plasma membrane Na+/Ca2+ exchanger which removes Ca2+ from the cytosol and helps restore basal [Ca2+]i.

Relationship between cytosolic free Ca2+ and Na+-Ca2+ exchange in aortic muscle cells

We examined the relationship between extracellular Na+ ([Na+]o) and cytosolic free Ca2+ ([Ca2+]i) in primary and passaged cultures of aortic muscle cells. Removing [Na+]o increased [Ca2+]i by approximately 10-fold in cells that were Na+ loaded. Decreasing [Na+]o from 140 to 32 mM caused the half-maximal increase in [Ca2+]i. [Ca2+]i exhibited a sigmoidal dependence on [Na+]o. Mg2+, a competitive inhibitor of Na2+-Ca2+ antiport in these cells, antagonized the increase in [Ca2+]i produced by lowering [Na+]o. High K+ decreased the potency of Mg2+ 6.5-fold as previously reported for Na+ gradient-dependent 45Ca2+ influx. In contrast to the Na+-loaded cells, removing [Na+]o caused no detectable change in [Ca2+]i in cells with normal Na+ even though the calculated electrochemical driving force for Na+-Ca2+ exchange was large enough to almost maximally increase [Ca2+]i in the Na+-loaded cells. We conclude that Na+-Ca2+ antiport activity is latent in the unstimulated cell at basal intracellular Na+ and Ca2+.

Effect of cholesterol on the branched-chain amino acid transport system of Streptococcus cremoris

The effect of cholesterol on the activity of the branched-chain amino acid transport system of Streptococcus cremoris was studied in membrane vesicles of S. cremoris fused with liposomes made of egg yolk phosphatidylcholine, soybean phosphatidylethanolamine, and various amounts of cholesterol. Cholesterol reduced both counterflow and proton motive force-driven leucine transport. Kinetic analysis of proton motive force-driven leucine uptake revealed that the Vmax decreased with an increasing cholesterol/phospholipid ratio while the Kt remained unchanged. The leucine transport activity decreased with the membrane fluidity, as determined by steady-state fluorescence polarization of 1,6-diphenyl-1,3,5-hexatriene incorporated into the fused membranes, suggesting that the membrane fluidity controls the activity of the branched-chain amino acid carrier.

Lipid requirement of the branched-chain amino acid transport system of Streptococcus cremoris

The role of the membrane lipid composition on the transport protein of branched-chain amino acids of the homofermentative lactic acid bacterium Streptococcus cremoris has been investigated. The major membrane lipid species identified in S. cremoris were acidic phospholipids (phosphatidylglycerol and cardiolipin), glycolipids, and glycerophosphoglycolipids. Phosphatidylethanolamine (PE) was completely absent. Protonmotive force-driven and counterflow transport of leucine was assayed in fused membranes of S. cremoris membrane vesicles and liposomes composed of different lipids obtained by the freeze/thaw-sonication technique. High transport activities were observed with natural S. cremoris and Escherichia coli lipids, as well as with mixtures of phosphatidylcholine (PC) with PE or phosphatidylserine. High transport activities were also observed with mixtures of PC with monogalactosyl diglyceride, digalactosyl diglyceride, or a neutral glycolipid fraction isolated from S. cremoris. PC or mixtures of PC with phosphatidylglycerol, phosphatidic acid, or cardiolipin showed low activities. In mixtures of PC and methylated derivatives of PE, both counterflow and protonmotive force-driven transport activities decreased with increasing degree of methylation of PE. The decreased transport activity in membranes containing PC could be restored by refusion with PE-containing liposomes. These results demonstrate that both aminophospholipids and glycolipids can be activators of the leucine transport system from S. cremoris. It is proposed that aminophospholipids in Gram-negative bacteria and glycolipids in Gram-positive bacteria have similar functions with respect to solute transport.