Notes on Ipomoea L. (Convolvulaceae) in Cuba and neighbouring islands with a checklist of species found in Cuba.

An updated checklist of species of Ipomoea L. found in Cuba is presented with analysis of the different elements represented. I. alterniflora Griseb. is defined broadly to include I. obtusata Griseb. and I. excisa Urb. and its differences from the little-known I. cubensis (House) Urb. are discussed. I. calophylla C. Wright ex Griseb. is reinstated as the correct name for the species generally known as I. lacteola House. I. praecox C. Wright is recognised as a distinct species from I. argentifolia A. Rich. and images are provided to help distinguish the two species. I. flavopurpurea Urb. and I. dajabonensis Alain are shown to be conspecific with I. longeramosa Choisy, whose disjunct distribution is mapped and discussed. The little-known I. montecristina Hadac is described and illustrated and the cited collections show it to be locally common in the Guantánamo region. I. microdonta J. R. I. Wood & Scotland is described as new from Camagüey in central Cuba. Eight species endemic to Cuba collected by Ekman and described by Urban in 1924 - 25 are evaluated but only two, I. balioclada Urb. and I. erosa Urb., are deemed to warrant recognition as distinct endemic species. The origin and typification of I. horsfalliae Hook. are discussed and an epitype designated. Cultivated plants named I. horsfalliae occur in many tropical countries including Cuba but their extreme variation suggests hybrid origin. Four species from Jamaica, I. rubella House, I. lineolata Urb., I. carmesina Proctor and the Jamaican plant called I. horsfalliae are treated as synonyms of a variable I. lineolata, which is endemic to the island. I. saxicola Proctor is treated as var. saxicola J. R. I. Wood & Scotland of I. ternata Jacq. I. cyanantha Griseb. is treated as a synonym of I. lindenii M. Martens & Galeotti. Lectotypes are designated for I. cyanantha, I. lindenii, I. praecox, I. punctata C. Wright, I. geranioides Meisn. and I. grisebachii Urb.

Genome-wide prediction of age at puberty and reproductive longevity in sows.

Traditional selection for sow reproductive longevity is ineffective due to low heritability and late expression of the trait. Incorporation of DNA markers into selection programs is potentially a more practical approach for improving sow lifetime productivity. Using a resource population of crossbred gilts, we explored pleiotropic sources of variation that influence age at puberty and reproductive longevity. Of the traits recorded before breeding, only age at puberty significantly affected the probability that females would produce a first parity litter. The genetic variance explained by 1-Mb windows of the sow genome, compared across traits, uncovered regions that influence both age at puberty and lifetime number of parities. Allelic variants of SNPs located on SSC5 (27-28 Mb), SSC8 (36-37 Mb) and SSC12 (1.2-2 Mb) exhibited additive effects and were associated with both early expression of puberty and a greater than average number of lifetime parities. Combined analysis of these SNPs showed that an increase in the number of favorable alleles had positive impact on reproductive longevity, increasing number of parities by up to 1.36. The region located on SSC5 harbors non-synonymous alleles in the arginine vasopressin receptor 1A (AVPR1A) gene, a G-protein-coupled receptor associated with social and reproductive behaviors in voles and humans and a candidate for the observed effects. This region is characterized by high levels of linkage disequilibrium in different lines and could be exploited in marker-assisted selection programs across populations to increase sow reproductive longevity.

Occurrence of microalbuminuria in young people with Type 1 diabetes: importance of age and diabetes duration.

AIMS: To determine the occurrence of microalbuminuria in young people with Type 1 diabetes mellitus followed prospectively for 2 years and to relate the presence of persistent elevations in urinary albumin excretion (UAE) to age, diabetes duration, puberty and other factors. METHODS: During a 2 year period, random urine samples were obtained from 471 patients, aged 8-18 years (mean +/-sd 12.9 +/- 2.3 years) with Type 1 diabetes duration 5.6 +/- 3.0 years, as part of routine clinical care. Urine albumin and creatinine concentrations were measured in 1310 samples (median, 3 samples per patient) and the albumin:creatinine ratio was calculated (in micrograms albumin per milligram creatinine). Height, weight, blood pressure (BP), glycated haemoglobin (HbA(1c)), blood glucose monitoring frequency and Tanner staging were collected from patients' medical records. RESULTS: Twenty-three per cent of patients had one or more sample with elevated UAE (> or =20 microg/mg) and 9.3% had persistent elevations (> or =2 samples > or =20 microg/mg). Those with and without persistent microalbuminuria did not differ significantly in age, diabetes duration, z-score for body mass index, pubertal status or BP percentile. Ten per cent of children <13 years old and 9% of children > or =13 years old had persistent microalbuminuria. Persistent microalbuminuria was significantly associated with diabetes duration only in older children (duration 0.5-3 years, 4%; 4-6 years, 8%; > or =7 years, 14%; P = 0.02, trend test). Mean HbA(1c) over the 2 years was 8.7 +/- 1.2%. In a logistic regression model, mean HbA(1c) was the only significant predictor of persistent microalbuminuria (odds ratio 1.3, 95% confidence interval 1.0-1.6, P = 0.05). CONCLUSIONS: Microalbuminuria in older children with Type 1 diabetes is likely to be clinically significant. In younger children, it may reflect functional, reversible renal changes. Longitudinal analysis is needed to confirm the probable transient nature of microalbuminuria in young patients with Type 1 diabetes.

Estrogen response elements function as allosteric modulators of estrogen receptor conformation.

The estrogen receptor (ER) is a ligand-dependent transcription factor that regulates the expression of estrogen-responsive genes. ER-mediated transcriptional changes are brought about by interaction of the ER with the estrogen response element (ERE). In this study, we examined the interaction of the Xenopus laevis ER DNA binding domain (DBD) and the intact ER with the X. laevis vitellogenin A2 ERE and the human pS2 ERE. Using gel mobility shift, DNase I footprinting, and methylation interference assays, we demonstrated that the DBD bound only as a dimer to the A2 ERE. However, the DBD bound as a monomer to the consensus pS2 ERE half site at lower DBD concentrations and then as a homodimer to the consensus and imperfect pS2 ERE half site at higher DBD concentrations. Antibody supershift experiments carried out with partially purified, yeast-expressed full-length ER demonstrated that three ER-specific antibodies interacted differentially with A2 and pS2 ERE-bound ER, indicating that receptor epitopes were differentially exposed. Furthermore, partial digestion of the A2 and pS2 ERE-bound ER with chymotrypsin or trypsin produced distinct protease cleavage patterns. Taken together, these data provide evidence that differential interaction of the DBD with the A2 and pS2 EREs brings about global changes in ER conformation. The conformational changes in ER induced by individual ERE sequences could lead to association of the receptor with different transcription factors and assist in the differential modulation of estrogen-responsive genes in target cells.

Fine mapping of genetic susceptibility to polycystic ovary syndrome on chromosome 19p13.2 and tests for regulatory activity.

CONTEXT: Little is known about genes that contribute to polycystic ovary syndrome (PCOS). We previously found linkage and association of PCOS with the dinucleotide marker D19S884 in two independent sets of families; allele 8 of D19S884 confers increased risk. OBJECTIVE/DESIGN: The objectives of the study were: 1) use the transmission/disequilibrium test (TDT) to assess linkage and association between PCOS and D19S884 (and nearby markers) in a third set of families; and 2) test D19S884 and surrounding DNA sequence for in vitro regulatory activity in lymphoblastoid cell lines (LCLs) and granulosa cells. SETTING/SUBJECTS: We studied 98 new families with a PCOS proband, father, mother, and other available offspring. We analyzed data from these families separately and in combination with data obtained previously. INTERVENTIONS: Interventions were venipuncture. MAIN OUTCOME MEASURES: Measures were transmission frequencies and in vitro functional studies. RESULTS: The first result we found was that in the 98 new families, the TDT was significant for allele 8 of D19S884 (P = 0.043). In the total collection of 465 families, the TDT evidence is very strong (nominal P < 7 x 10(-5)). Results for all other genetic markers near D19S884 were nonsignificant after correction for multiple testing. The second result was that an approximately 800-bp fragment containing various alleles of D19S884 showed modest but reproducible promoter activity in LCLs. However, no allelic differences were detected. No activity of this fragment was detected in granulosa cells. CONCLUSIONS: This is the second independent confirmation of linkage and association of D19S884 with PCOS. We found in addition that some sequence in the region of D19S884 confers in vitro promoter activity in LCLs.

Calcium and colorectal epithelial cell proliferation: a preliminary randomized, double-blinded, placebo-controlled clinical trial.

BACKGROUND: Colonic epithelial cell proliferation is increased in patients at high risk for colon cancer. Calcium administration has ameliorated the proliferative changes in rodents, and findings in small, uncontrolled clinical trials have suggested similar effects in humans. PURPOSE: This preliminary, double-blind, randomized clinical trial was designed 1) to investigate whether supplemental calcium will reduce colonic epithelial cell proliferation in patients with sporadic adenomas who consume a high-fat, Western-style diet; 2) to determine the sample size (number of scorable crypts per person) needed to achieve adequate statistical power; and 3) to evaluate the feasibility of full-scale clinical trials. METHODS: Twenty-one sporadic adenoma patients were treated daily with placebo or 1200 mg of supplemental calcium. To determine colonic epithelial cell proliferation, we used tritiated thymidine labeling of colon crypt epithelial cells in rectal biopsy specimens and calculated the percentage of labeled cells (labeling index [LI]). Two pathology technician "readers" independently scored each specimen, and inter-reader reliability was determined. Subjects remained on their usual diet during the study, and intake of calories, calcium, total fat, and vitamin D did not differ substantially among them. We calculated curves for statistical power to determine the number of scorable crypts needed per person for detection of a statistically significant difference (P < .05) of 1.0% in mean LI. RESULTS: The pooled baseline LI was 4.7%. In the calcium-treated group, the LI increased 0.6% (proportional increase, 12.8%); in the placebo-treated group, it decreased 0.5% (proportional decrease, 10.6%). The difference between change in the mean LI from baseline to 8 weeks' follow-up in the placebo group versus the calcium group was not statistically significant. The intraclass correlation coefficient for inter-reader reliability for the baseline LI was .66. Analyses indicated scoring eight crypts sufficient for estimates of the LI adequate for between-group comparisons, a level achieved in 81% of biopsy specimens. CONCLUSIONS: Calcium carbonate supplements delivering 1200 mg elemental calcium daily may not decrease colonic epithelial cell proliferation over an 8-week period in sporadic adenoma patients. In future trials measuring the LI, consideration should be given to ensuring adequate numbers of scorable crypts and to the impact of inadequate biopsy procedures, labeling failure, reader reliability, and participant withdrawal. Our findings support the feasibility of a full-scale clinical trial to further study the relationships among dietary calcium, colonic epithelial cell proliferation, and colorectal cancer.

Calcium and colorectal epithelial cell proliferation in sporadic adenoma patients: a randomized, double-blinded, placebo-controlled clinical trial.

BACKGROUND: The kinetics of colorectal epithelial cell proliferation is altered in patients at increased risk for colon cancer. Calcium administration ameliorates such proliferative changes in rodents. Findings in preliminary clinical trials have suggested similar effects in humans. PURPOSE: A randomized, double-blind, placebo-controlled, clinical trial was designed to determine whether calcium supplementation will reduce the colorectal epithelial cell proliferation rate and normalize the distribution of proliferating cells within colorectal crypts (i.e., shift the zone of proliferation from the entire crypt to the lower 60% of the crypt, which is thought to be the normal proliferative zone of the crypt) in patients with sporadic adenomas. METHODS: Sporadic adenoma patients (n = 193) were treated with placebo (n = 66), 1.0 g calcium (n = 64), or 2.0 g calcium (n = 63) daily for 6 months. Rectal mucosa biopsy specimens were obtained at base line and at 1-, 2-, and 6-month follow-up. Cell proliferation was measured by detection of S-phase-associated proliferating cell nuclear antigen by immunohistochemical methods. The cell proliferation rate, called labeling index (LI), was calculated as the proportion of labeled cells in the crypts. The deviation of the proliferative zone from the normal location in the lower 60% of the crypt was calculated as the proportion of labeled cells in the upper 40% of the crypt, called distributional index (phi h). The effects of calcium treatment on the LI and phi h were expressed as relative effects--(calcium follow-up/calcium base line)/(placebo follow-up/placebo base line). Calculations and inference testing of the relative effects were accomplished using a repeated-measures mixed model on log-transformed LI and phi h values. All statistical tests were two-sided. RESULTS: Scorable biopsy specimens were obtained on 170 patients at base line, 164 at 1 month, 161 at 2 months, and 163 at 6 months. The difference in the change in the LI between the combined calcium groups and the placebo group was insignificant, with a relative effect of calcium versus placebo of 0.97 (P = .87). However, for the phi h, the relative effect of calcium versus placebo was 0.50 (P = .05) in the combined calcium groups, 0.56 (P = .16) in the 1.0-g calcium group, and 0.44 (P = .05) in the 2.0-g calcium group. CONCLUSIONS: Calcium supplementation normalizes the distribution of proliferating cells without affecting the proliferation rate in the colorectal mucosa of sporadic adenoma patients. IMPLICATIONS: These results support further study of whether alterations in colon cell proliferative kinetics represent true intermediate steps in colon carcinogenesis that can be used to investigate the etiology and prevention of, and whether a higher calcium consumption can reduce the risk of, colon cancer.

The prognostic importance of tumor size in malignant gliomas: a computed tomographic scan study by the Brain Tumor Cooperative Group.

The prognostic importance of tumor size was studied in 510 patients with malignant glioma (80% with glioblastoma multiforme) in the Valid Study Group of Study 80-01 of the Brain Tumor Study Group (now the Brain Tumor Cooperative Group [BTCG]). The endpoint was length of survival from randomization, which occurred within 3 weeks of definitive surgery. Following randomization, patients were scheduled to receive radiotherapy (RT) (6,020 cGy) during a 7-week period, along with continuing courses of chemotherapy. Computed tomographic (CT) scan information was available for 124 patients preoperatively, 300 patients postoperatively (preradiation), and 218 patients 9 weeks post-RT (+/- 3 weeks). Tumor size was determined as area (length x width) on the contrast-enhanced scan and survival was compared by log rank statistics. Preoperative tumor area was unrelated to survival (P = .48), but postoperative area was significantly prognostic (P less than .0001); the smaller the residual tumor, the longer the patient lived. Patients with a 75% or greater resection, as determined by measuring the difference between the preoperative and the postoperative scans, tended to have better survival, but the difference was not significant (P = .16). The post-RT area was strongly related to survival (P less than .00001). The percent change in area between the pre- and post-RT scans was also prognostic. Tumor size was of prognostic importance independent of the other known prognostic variables: age, Karnofsky performance score, and whether the tumor was glioblastoma or anaplastic astrocytoma. We conclude that the amount of tumor remaining after surgery is an important baseline variable at the start of RT, and that the tumor size 9 weeks following RT is also prognostic. Surgical resection is most important when it leaves the least amount of residual tumor.

Allosteric modulation of estrogen receptor conformation by different estrogen response elements.

Estrogen-regulated gene expression is dependent on interaction of the estrogen receptor (ER) with the estrogen response element (ERE). We assessed the ability of the ER to activate transcription of reporter plasmids containing either the consensus vitellogenin A2 ERE or the imperfect pS2, vitellogenin B1, or oxytocin (OT) ERE. The A2 ERE was the most potent activator of transcription. The OT ERE was significantly more effective in activating transcription than either the pS2 or B1 ERE. In deoxyribonuclease I (DNase I) footprinting experiments, MCF-7 proteins protected A2 and OT EREs more effectively than the pS2 and B1 EREs. Limited protease digestion of the A2, pS2, B1, or OT ERE-bound receptor with V8 protease or proteinase K produced distinct cleavage products demonstrating that individual ERE sequences induce specific changes in ER conformation. Receptor interaction domains of glucocorticoid receptor interacting protein 1 and steroid receptor coactivator 1 bound effectively to the A2, pS2, B1, and OT ERE-bound receptor and significantly stabilized the receptor-DNA interaction. Similar levels of the full-length p160 protein amplified in breast cancer 1 were recruited from HeLa nuclear extracts by the A2, pS2, B1, and OT ERE-bound receptors. In contrast, significantly less transcriptional intermediary factor 2 was recruited by the B1 ERE-bound receptor than by the A2 ERE-bound receptor. These studies suggest that allosteric modulation of ER conformation by individual ERE sequences influences the recruitment of specific coactivator proteins and leads to differential expression of genes containing divergent ERE sequences.

The high mobility group protein 1 enhances binding of the estrogen receptor DNA binding domain to the estrogen response element.

We have examined the ability of the high-mobility group protein 1 (HMG1) to alter binding of the estrogen receptor DNA-binding domain (DBD) to the estrogen response element (ERE). HMG1 dramatically enhanced binding of purified, bacterially expressed DBD to the consensus vitellogenin A2 ERE in a dose-dependent manner. The ability of HMG1 to stabilize the DBD-ERE complex resulted in part from a decrease in the dissociation rate of the DBD from the ERE. Antibody supershift experiments demonstrated that HMG1 was also capable of forming a ternary complex with the ERE-bound DBD in the presence of HMG1-specific antibody. HMG1 did not substantially affect DBD-ERE contacts as assessed by methylation interference assays, nor did it alter the ability of the DBD to induce distortion in ERE-containing DNA fragments. Because HMG1 dramatically enhanced estrogen receptor DBD binding to the ERE, and the DBD is the most highly conserved region among the nuclear receptor superfamily members, HMG1 may function to enhance binding of other nuclear receptors to their respective response elements and act in concert with coactivator proteins to regulate expression of hormone-responsive genes.

A polymorphism in myostatin influences puberty but not fertility in beef heifers, whereas µ-calpain affects first calf birth weight.

The use of genetic markers to aid in selection decisions to improve carcass and growth characteristics is of great interest to the beef industry. However, it is important to examine potential antagonistic interactions with fertility in cows before widespread application of marker-assisted selection. The objective of the current experiment was to examine the influence of 2 commercially available markers currently in use for improving carcass traits, the myostatin (MSTN) F94L and µ-calpain (CAPN1) 316 and 4751 polymorphisms, on heifer development and reproductive performance. In Exp. 1, beef heifers (n = 146) were evaluated for growth and reproductive traits over a 3-yr period to determine if these polymorphisms influenced reproductive performance. In Exp. 2, heifers representing the 2 homozygous genotypes for the MSTN F94L polymorphism were slaughtered on d 4 of the estrous cycle and reproductive tracts were collected for morphological examination. In Exp. 1, there was a tendency (P = 0.06) for birth BW to be affected by MSTN with the Leu allele increasing birth BW in an additive fashion. Additionally, MSTN significantly affected the proportion of pubertal heifers by the start of the breeding season (P < 0.05) with the Leu allele additively decreasing the proportion pubertal; however, this did not result in a delay in conception or a decrease in pregnancy rates during the first breeding season (P > 0.15). The GT haplotype of CAPN1, which was previously associated with decreased meat tenderness, was associated with an additive decrease in birth BW of the first calf born to these heifers (P < 0.05). In Exp. 2, there were no differences between the MSTN genotypes for gross or histological morphology of the anterior pituitary, uterus, or ovaries (P > 0.05). From these results, we concluded that the MSTN F94L and CAPN1 polymorphisms can be used to improve carcass traits without compromising fertility in beef heifers. The influence of these markers on cow performance and herd life remains to be determined. While the delay in puberty associated with the MSTN F94L polymorphism did not negatively impact reproductive performance in heifers, caution should be used when combining this marker with other markers for growth or carcass traits until the potential interactions are more clearly understood.

The biochemical basis for increased testosterone production in theca cells propagated from patients with polycystic ovary syndrome.

Ovarian theca cells propagated from patients with polycystic ovary syndrome (PCOS) convert steroid precursors into T more efficiently than normal theca cells. To identify the basis for increased T production by PCOS theca cells, we examined type I-V 17 beta-hydroxysteroid dehydrogenase (17 beta HSD) isoform expression in long-term cultures of theca and granulosa cells isolated from normal and PCOS ovaries. RT-PCR analysis demonstrated that theca cells express type V 17 beta HSD a member of the aldo-keto reductase (AKR) superfamily (17 beta HSDV, AKR1C3), whereas expression of type I, II, and IV 17 beta HSD, which are members of the short-chain dehydrogenase/reductase superfamily, was limited to granulosa cells. Type III 17 beta HSD, the testicular isoform, was not detected in either granulosa or theca cells. Northern and real-time PCR analyses demonstrated that 17 beta HSDV transcripts were not significantly increased in PCOS theca cells compared with normal theca cells. RT-PCR analysis revealed that theca cells also express another AKR, 20 alpha HSD (AKR1C1). Both basal and forskolin-stimulated 20 alpha HSD mRNA levels were increased in PCOS theca cells compared with normal theca cells. However, 17 beta HSD enzyme activity per theca cell was not significantly increased in PCOS, suggesting that neither AKR1C3 nor AKR1C1 contributes to the formation of T in this condition. In contrast, 17 alpha-hydroxylase/C17,20 lyase and 3 beta HSD enzyme activities were elevated in PCOS theca cells, driving increased production of T precursors. These findings indicate that 1) increased T production in PCOS theca cells does not result from dysregulation of "androgenic" 17 beta HSD activity or altered expression of AKRs that may express 17 beta HSD activity; and 2) increased synthesis of T precursors is the primary factor driving enhanced T secretion in PCOS.

Bombesin, somatostatin and neurotensin-like immunoreactivity in bronchial carcinoma.

Bombesin, a regulatory peptide found in adult lung and in higher concentration during development in the foetal lung, has potent biological actions which include the ability to stimulate the release of a number of hormones. Radioimmunoassay of extracts of tumour, lung and plasma from patients with bronchial carcinoma revealed very high tissue bombesin concentrations in two oat cell carcinomas, with lower levels in two out of six adenocarcinomas exceeding the concentrations found in normal lung. The oat cell carcinomas also contained significant amounts of somatostatin and in one case neurotensin. Neurotensin was further detected in two out of seven squamous tumours and three adenocarcinomas. Secretion of regulatory peptides by bronchial carcinomas may account for some of their ill-understood non-metastatic clinical manifestations.

Calcium and colorectal epithelial cell proliferation in ulcerative colitis.

In persons at higher risk for colon cancer (e.g., those with sporadic adenoma or ulcerative colitis), compared to those at lower risk, colonic epithelial cell proliferation kinetics are altered. We have shown previously that calcium supplementation appears to normalize the distribution of proliferating cells without affecting the proliferation rate in the colorectal mucosa of sporadic adenoma patients. In a pilot randomized, double-blind, placebo-controlled, clinical trial conducted concurrently with our previously published sporadic adenoma trial, we tested whether calcium supplementation can also modulate cell proliferation kinetics in patients with ulcerative colitis. Ulcerative colitis patients (n = 31) were randomized to placebo or 2.0 g of supplemental calcium daily. Colorectal epithelial cell proliferation was determined by immunohistochemical detection of proliferating cell nuclear antigen labeling of cells in "nonprep" rectal biopsies taken at randomization and after 2 months treatment. All biopsies were scored by one reviewer. Differences in mean follow-up minus baseline labeling index (LI; the proportion of colon crypt epithelial cells that were labeled) and in the phi(h) (proportion of labeled cells that were in the upper 40% of the crypts) were compared with analysis of covariance. Pill-taking adherence was 97%. Biopsy-scoring reliability was high (r = 0.89). The pooled baseline LI and phi(h) were 6.3% and 5.6%, respectively. The LI in the calcium group decreased by 0.5% (proportionately, 3%) more than in the placebo group (P = 0.91). Similarly, the phi(h) in the calcium group decreased by 0.3% (proportionately, 10%) more than in the placebo group (P = 0.85). This pilot study does not suggest that 2.0 g of calcium as calcium carbonate daily can substantially normalize either the rate or distribution of proliferating cells over a 2-month period in the colon crypts of patients with ulcerative colitis; a more definitive answer to the question of whether calcium may be effective would require a study with a larger sample size and/or other study design modifications.

Methodological findings and considerations in measuring colorectal epithelial cell proliferation in humans.

The methodological issues for measuring colorectal epithelial cell proliferation, an intermediate end point for studies of colon neoplasia, in epidemiological studies are deceptively numerous and complex, with few methodological data available. Accordingly, during our experience with measuring colorectal epithelial cell proliferation from nearly 500 participants attending over 1300 study visits over a 6-year period, we recorded data on a variety of measurement variations. Methods investigated included rectal biopsy technique, general histological and labeling procedures [including the tritiated thymidine, 5-bromodeoxyuridine (BrdUrd), and the proliferating cell nuclear antigen (PCNA) immunohistochemical techniques used to label S-phase cells in colonic crypts in rectal biopsy specimens], biopsy scoring procedures, and summary scoring methods. Findings include that the PCNA technique was the simplest, most economical, and least time-consuming. The BrdUrd labeling failure rate was 15% versus < 1% for PCNA. The percentage of labeled cells (labeling index) was highest using PCNA in biopsies processed without prior incubation, intermediate using PCNA in biopsies processed with prior incubation as for BrdUrd, and lowest using BrdUrd. The percentage of labeled cells that were in the upper 40% of the crypt (phi h) was higher using BrdUrd than PCNA; visit-to-visit correlations were higher using PCNA (r = 0.51 versus 0.35), and visit-to-visit variability was lower and between-person variability was higher using PCNA. Intra- and inter-rater reliabilities for the techniques were comparable (PCNA intra-rater r = 0.93, inter-rater r = 0.92). The PCNA technique, compared to the BrdUrd technique, is more feasible and reliable, provides a more accurate estimate of the labeling index, and cell proliferation measures determined with PCNA have statistical properties that are generally more favorable for detecting differences in clinical trials. Thus, the PCNA technique may be preferable to techniques requiring incubation of biopsies. Other methodological findings lead us to recommend that, for larger studies measuring colorectal epithelial cell proliferation on outpatient rectal biopsies, biopsies should be taken 10 cm above the anus using a flexible, preferably jumbo cup, endoscopic forceps through a rigid sigmoidoscope, and histological sections should be 3 microns thick taken 50 microns apart.

Colorectal epithelial cell proliferative kinetics and risk factors for colon cancer in sporadic adenoma patients.

Colorectal epithelial cell proliferative kinetics are altered in patients at increased risk for colon cancer: proliferation rates [labeling index (LI)] are higher and there is a shift of the proliferative zone from one confined to the lower 60% of the colonic crypt to one that includes the entire crypt (higher phi(h)). To assess factors associated with LI and phi(h), we performed a cross-sectional analysis using baseline rectal mucosal biopsies from sporadic adenoma patients participating in a chemoprevention trial. Biopsies (taken without preparatory cleansing) were taken 10 cm above the level of the anus, and proliferation was assessed by detection of endogenous S-phase-associated proliferating cell nuclear antigen by immunohistochemical methods. High-quality, scorable biopsies were obtained for 115 patients, and using analysis of covariance and multiple linear regression, the LI and phi(h) were evaluated in relation to diet and other lifestyle factors, demographics, anthropometrics, family history of colon cancer, and polyp history. Statistically significant findings included the following: (a) The LI for those in the upper versus the lowest tertile of vegetable and fruit consumption was, proportionately, 35% lower (3.4% versus 5.3%; P < 0.001); for vitamin supplement users versus nonusers, it was 36% lower (3.3 versus 5.2%; P < 0.001); for recurrent versus incident polyp patients, it was 36% higher (6.2 versus 4.0%; P < 0.001); and for those with rectal polyps only versus those with colon polyps only, it was 28% higher (6.0 versus 4.3%; P = 0.05); and (b) the phi(h) for those in the upper versus the lowest tertile of sucrose consumption was, proportionately, 48% higher (7.1% versus 3.7%; P = 0.01). These results indicate that (a) colorectal epithelial cell proliferation rates are higher in recurrent adenoma patients than in incident adenoma patients and in patients with rectal adenomas only versus those with colon adenomas only, but they are lower in patients with higher intakes of vegetables and fruit and in those who take vitamin/mineral supplements, and (b) the distribution of proliferating cells is shifted toward more inclusion of the upper 40% of the crypt in patients with higher intakes of sucrose. The pattern of positive, negative, and null associations of potential risk factors with cell proliferation is similar to that commonly found with colonic neoplasms.

Interaction of estrogen receptors alpha and beta with estrogen response elements.

To understand how estrogen-responsive genes are regulated, we compared the abilities of estrogen receptors (ERs) alpha and beta to bind to and activate transcription through the consensus vitellogenin A2 ERE and the imperfect pS2, vitellogenin B1, and oxytocin (OT) EREs. Transient transfection experiments demonstrated that ERalpha and ERbeta induced the highest levels of transcription with the A2 ERE, intermediate levels of transcription with the OT ERE, and low levels of transcription with the pS2 and B1 EREs. ERalpha and ERbeta had higher affinities for the A2 ERE than for any of the three imperfect EREs but similar affinities for the pS2, B1, and OT EREs in gel mobility shift assays. ERalpha had a higher affinity and was a more potent activator of transcription than ERbeta. Interestingly, protease sensitivity assays demonstrated that A2, pS2, B1, and OT EREs induced distinct changes in ERalpha and ERbeta conformation thereby providing different functional surfaces for interaction with regulatory proteins involved in control of estrogen-responsive genes.

Frequency and significance of immunoglobulin M antibody to hepatitis B core antigen in corticosteroid-treated severe chronic active hepatitis B.

To assess the frequency and significance of immunoglobulin M (IgM) antibody to hepatitis B core antigen (anti-HBc) in corticosteroid-treated severe chronic active hepatitis B, we tested 96 serum samples from 16 patients who were seropositive for hepatitis B surface antigen (HBsAg) (group 1) and 8 HBsAg-negative, anti-HBc-positive patients (group 2) by enzyme-linked immunoassay. Samples obtained in the presence and absence of disease activity before, during, and after long-term corticosteroid therapy (mean duration, 42 +/- 7 months) were evaluated. Seropositivity for IgM antibody was demonstrated in 12 group 1 patients, including 9 tested before corticosteroid therapy; no group 2 patients were seropositive. Seropositivity was more common in serum samples obtained during active than during inactive disease (51% versus 22%; P less than 0.05) and more frequent in serum samples that contained hepatitis B e antigen (46% versus 11%; P less than 0.02) and hepatitis B virus deoxyribonucleic acid (50% versus 24%; P less than 0.05) than in those without these markers. In some patients, seropositivity persisted or recurred intermittently during corticosteroid therapy for up to 57 months. We conclude that seropositivity for IgM antibody can be demonstrated frequently by enzyme-linked immunoassay in corticosteroid-treated patients with severe disease. Seropositivity reflects active virus replication, and it is commonly associated with inflammatory activity. The duration of seropositivity may be protracted during long-term corticosteroid therapy.

Long-term versus short-term treatment with recombinant interferon alfa-2a in patients with chronic hepatitis B: a prospective, randomized treatment trial.

We conducted a prospective, randomized trial to study the efficacy and tolerance of long-term versus short-term treatment with recombinant interferon alfa-2a in patients with chronic hepatitis B. Ten patients were randomly assigned to a 6-month interferon regimen, and 10 patients were assigned to a 3-week interferon trial. Eleven patients (five assigned to long-term treatment and six to short-term treatment) did not complete interferon therapy: eight had either severe thrombocytopenia or neutropenia; one had pronounced fatigue in relationship to administration of interferon; one had spontaneous bacterial peritonitis and sepsis and died; and one had a massive fatal variceal hemorrhage during interferon therapy. Most of the serious hematologic complications occurred in patients with cirrhosis and hypersplenism. In one patient, seroconversion to hepatitis B virus DNA negativity occurred before the onset of treatment. Four of the five patients able to complete the 6-month interferon regimen and only one of four patients able to complete the 3-week trial had seroconversion to hepatitis B virus DNA negativity. Thus, we conclude that the therapeutic response was better among patients who were able to complete a 6-month interferon trial. In patients with cirrhosis and hypersplenism, development of either severe thrombocytopenia or leukopenia associated with interferon therapy precluded completion of treatment.

Review article: one-week clarithromycin triple therapy regimens for eradication of Helicobacter pylori.

BACKGROUND: One-week triple therapies have been endorsed as the treatment regimens of choice for eradication of Helicobacter pylori infection. Those that include clarithromycin appear to be the most effective. AIM: To review reports of triple therapies that include clarithromycin. METHODS: Reports were identified from the literature to May 1998. The variation between study designs prevents a formal meta-analysis. A measure of the relative efficacies of regimens has, however, been gained by comparison and by pooling of intention-to-treat eradication rates. RESULTS: One hundred and ninety-two studies were identified which included 264 treatment arms of a 1-week triple therapy composed of clarithromycin with amoxycillin or a nitroimidazole (metronidazole or tinidazole), and either ranitidine bismuth citrate or a proton pump inhibitor (omeprazole, lansoprazole or pantoprazole). From reports of these studies, an intention-to-treat H. pylori eradication rate could be determined from 210 treatment arms of 151 studies. CONCLUSIONS: There is little to choose between the efficacies of 1-week clarithromycin-based triple therapy eradication regimens. However, those comprising clarithromycin, a nitroimidazole and either ranitidine bismuth citrate or a high dose of omeprazole are, in general, the most effective. Against antibiotic-resistant strains of H. pylori, regimens including ranitidine bismuth citrate may be more effective than those including a proton pump inhibitor.