Prognostic factors for survival of patients treated systemically for disseminated melanoma

PURPOSE

The current American Joint Commission on Cancer (AJCC) staging system distinguishes between soft tissue and visceral metastases in advanced (stage IV) melanoma. We sought to verify these staging criteria and to identify prognostic variables that could be used to evaluate the impact of systemic therapy on long-term survival during the prior decade.

PATIENTS AND METHODS

We conducted a retrospective study of patients with advanced cutaneous melanoma enrolled in clinical trials between 1979 and 1989 at The University of Texas M.D. Anderson Cancer Center. Pretreatment age, sex, number of organs with metastases, serum levels of lactate dehydrogenase (LDH) and albumin, and period of enrollment were analyzed using a Cox proportional hazards model of survival.

RESULTS

In univariate and multivariate analyses that involved 318 stage IV patients, normal serum levels of LDH and albumin, soft tissue and/or single visceral organ metastases (especially lung), female sex, and enrollment late in the decade were independent positive predictors for survival. In multivariate analyses, the current AJCC criteria did not significantly predict outcome. Systemic treatment response did not bias these results, and only 4% of patients had a complete response. Patients who lived more than 2 years (11%) had a mix of favorable prognostic characteristics and a high frequency of systemic or surgically induced complete response.

CONCLUSION

This study supports the use of stratification parameters that reflect the favorable prognostic impact of soft tissue or single visceral organ metastases and normal serum levels of LDH and albumin at time of enrollment in advanced melanoma trials. Improved survival over the prior decade probably reflects advances in diagnostic and palliative interventions.

Degradation of surfactant protein D by alveolar macrophages

Surfactant protein (SP) D is a pulmonary surfactant-associated protein that may function in lung host defense. SP-D is produced by alveolar type II cells and nonciliated bronchiolar epithelial (Clara) cells of the airway and is secreted into the air space. Here we investigated whether alveolar macrophages degraded SP-D in vitro. We also examined the effects of SP-A and lipids on SP-D metabolism. The results showed that alveolar macrophages bound and degraded SP-D in a time- and temperature-dependent fashion. After 100 min of incubation, the formation of trichloroacetic acid-soluble degradation products increased 4-fold in the medium and 30-fold in the cells. The degradation of SP-D was via a cell-associated process because SP-D was not degraded when incubated in medium previously conditioned by alveolar macrophages. Gel autoradiography of cell lysate samples after incubation with 125I-labeled SP-D demonstrated an increase in degradation products, further confirming the degradation of SP-D by alveolar macrophages. In addition, the degradation of SP-D was not affected by coincubation with SP-A or surfactant-like liposomes containing either phosphatidylglycerol or phosphatidylinositol. In conclusion, alveolar macrophages rapidly degrade SP-D and may play an important role in SP-D turnover and clearance.

Effect of retinol in preventing squamous cell skin cancer in moderate-risk subjects: a randomized, double-blind, controlled trial. Southwest Skin Cancer Prevention Study Group

We conducted a randomized, double-blind, controlled trial to examine the efficacy of retinol supplementation on the incidence of first new nonmelanoma skin cancer in moderate-risk subjects. A total of 2297 free-living subjects were enrolled; subjects resided in Arizona (median age, 63 years) and had a history of more than 10 actinic keratoses and at most 2 squamous cell carcinoma (SCC) or basal cell carcinoma (BCC) skin cancers. Subjects were randomly assigned to receive oral retinol (25,000 IU) or placebo supplementation daily for up to 5 years. The primary end points for the trial were time to first new SCC or BCC. During a median follow-up time of 3.8 years, we found that 526 subjects had a first new skin cancer. Comparing retinol-supplemented subjects with placebo-supplemented subjects showed a hazard ratio for first new SCC of 0.74 (95% confidence interval, 0.56-0.99; P = 0.04). The hazard ratio of first new BCC for the retinol-supplemented subjects compared with those receiving placebo was 1.06 (95% confidence interval, 0.86-1.32; P = 0.36). Potentially adverse symptoms that were judged to be associated with retinol were rare (approximately 1% higher in the retinol group than in the control group). Therefore, we concluded that daily supplementation with 25,000 IU of retinol was effective in preventing SCC, although it did not prevent BCC.

[Effect of Helicobacter pylori on gastric epithelial apoptosis]

To investigate the mechanisms by which Helicobacter pylori (Hp) induces gastric mucosal damage, gastric epithelial apoptotic index (AI) of normal gastric mucosa and Hp positive gastritis before and after anti-Hp treatment was studied with the method of terminal transferase mediated dUTP nick end labeling. The results showed that AI in Hp positive gastritis was higher than that in normal mucosa (P < 0.001). After the eradication of Hp, AI fell significantly to the normal level (P < 0.001). AI in persisting Hp positive gastritis had no statistically significant decrease after the anti-Hp treatment. There was no correlation between AI and the severity of gastritis. These results indicated that Hp could induce gastric epithelial apoptosis, which may be an important mechanism involved in gastric mucosal damage.

Trial of retinol and isotretinoin in skin cancer prevention: a randomized, double-blind, controlled trial. Southwest Skin Cancer Prevention Study Group

The objective of this study was to examine the effect of retinol and isotretinoin on the incidence of nonmelanoma skin cancer in high-risk subjects. A total of 525 participants with a history of at least four basal cell carcinomas (BCCs) and/or cutaneous squamous cell carcinomas (SCCs) were entered into a randomized, double-blind, placebo-controlled trial, performed in free-standing study clinics. Participants were randomly assigned to receive oral retinol (25,000 units), isotretinoin (5-10 mg), or placebo supplementation daily for 3 years. The time to first new occurrence of BCC or cutaneous SCC was used as the outcome measure. During the study period, 319 BCCs and 125 cutaneous SCCs were diagnosed clinically and pathologically. There were no differences between those who received retinol, isotretinoin, or the placebo, with regard to the time to first occurrence or to the total number of tumors noted. No beneficial effects were noted with regard to the prevention of nonmelanoma skin cancer with either retinol or isotretinoin.

Erythrocyte deformation in simulated weightless human and rabbits

Effect and mechanism of simulated weightlessness (SWL) in humans and rabbits erythrocyte deformation were studied. Erythrocyte deformation and membrane fluidity in humans and rabbits, and erythrocyte morphology and hemorreology indices in control and HDT rabbits were measured. The results were a decrease in erythrocyte deformation and membrane fluidity in humans and rabbits during SWL, a significant increase in abnormal erythrocyte, blood viscosity, hematocrit, fibrinogen, and red blood cell aggregation index in HDT rabbits. These results show that the changes in erythrocyte shape, increase of erythrocyte internal viscosity and changes in erythrocyte visco-elasticity may be causing the decrease of erythrocyte deformation in SWL humans and rabbits.

[Experimental study on supraeruption of the unopposed miniature pig molars]

Supraeruption of the molars in the absence of antagonist molars or without occlusal contacts was observed in a miniature pig. Tetracycline was used to label the new regenerated cementum and alveolar bone associated with the supraeruption. The results showed that the molar through root canal treatment migrated the same level as the molars with pulp, which means that the hydrodynamic and hydrostatic forces arising from the blood in pulp vessels look doubtful. Cementum and alveolar bone deposition was seen around the apical, cervical regions and under the furcation area. The thickness of the deposition layers was almost the same as the supraerupted volume from the model measurement.

[Primary study on the sensitivity of cytokinesis blocked micronucleus assay in CHL cells]

Studies were performed to determine the cytochalasin B induced binucleated cell percentage influenced by clastogens and aneuploidgens and to compare the efficacy of cytokinesis blocked binucleated cells for scoring micronuclei with that of the conventional mononucleated method following the treatment with mitomycin C, methyl methanesulforate, colchicin and chloral hydrate. The results showed that mitomycin C decreased the binucleated cell percentage induced by cytochalasin B, whereas colchicin increased the frequencies of binucleated cells. The frequencies of micronuclei in binucleated cells were not significantly higher than those in the conventional mononucleated cells. The results suggest that cytokinesis blocked method is not more sensitive than the conventional method for scoring micronuclei. The factors that may influence the cytokinesis blocked micronucleus assay have been discussed.

Effects of simulated weightlessness on erythrocyte deformability in rats

In order to investigate the mechanism of space anemia, the erythrocyte deformability membrane fluidity and cell shape in 7, 15, 30 day tail-suspended rats were observed. The results were: (1) erythrocyte deformability (DImax and IDI) in suspended rats was significantly lower than that in the control on the 7th day (P<0.05), and had a further decrease on the 15th day (P<0.01), but a recovery was found on the 30th day (P<0.05). (2) membrane fluidity in suspended rats was markedly lower than that in the control group on the 15th and 30th day, degrees of fluorescence polarization was increased (P<0.01), but there was no change on the 7th day. (3) percentage of erythrocytes with abnormal shape in suspended rats was higher than that in the control group during the whole experimental period. The results indicate that the changes of rheological and morphological properties of red cell were induced by simulated weightlessness (SWL), which may be an important cause of space anemia.

Methylator resistance mediated by mismatch repair deficiency in a glioblastoma multiforme xenograft

A methylator-resistant human glioblastoma multiforme xenograft, D-245 MG (PR), in athymic nude mice was established by serially treating the parent xenograft D-245 MG with procarbazine. D-245 MG xenografts were sensitive to procarbazine, temozolomide, N-methyl-N-nitrosourea, 1,3-bis(2-chloroethyl)-1-nitrosourea, 9-aminocamptothecin, topotecan, CPT-11, cyclophosphamide, and busulfan. D-245 MG (PR) xenografts were resistant to procarbazine, temozolomide, N-methyl-N-nitrosourea, and busulfan, but they were sensitive to the other agents. Both D-245 MG and D-245 MG (PR) xenografts displayed no O6-alkylguanine-DNA alkyltransferase activity, and their levels of glutathione and glutathione-S-transferase were similar. D-245 MG xenografts expressed the human mismatch repair proteins hMSH2 and hMLH1, whereas D-245 MG (PR) expressed hMLH1 but not hMSH2.

Age and gender differences in the self-esteem of Chinese children

A Chinese version of the Self-Description Questionnaire 1 (SDQ-1; Marsh, 1988) was used to investigate age and gender differences in a sample of 303 male and 296 female 10-year-old children and 116 male and 116 female 13-year-old children attending typical Beijing public schools. Significant Age x Gender interaction effects were found on all 8 SDQ-1 scales. Main effects for age were found on the Physical Abilities, Reading, and School subscales and for gender on the same three subscales plus Peer Relations. Further analysis indicated that the older girls tended to report significantly lower self-esteem than both the younger girls and older boys in the areas of physical abilities, reading, mathematics, and general self-concept. The boys reported more positive self-perceptions on most nonacademic self-scales, but both the older boys and older girls reported less favorable self-esteem than their younger peers on the scales for reading and school in general.

Localization of the multiple endocrine neoplasia type I (MEN1) gene based on tumor loss of heterozygosity analysis

Multiple endocrine neoplasia type I (MEN1) is an inherited syndrome that results in parathyroid, anterior pituitary, and pancreatic and duodenal endocrine tumors as well as foregut carcinoids in affected patients. The gene responsible for the disease has been linked to chromosome 11q13. We analyzed loss of heterozygosity (LOH) in 188 tumors from 81 patients in an attempt to further define the location of the MEN1 gene. Both tumors from MEN1 patients and corresponding sporadic tumors were analyzed. Tumor types included parathyroid, gastrinoma, pancreatic endocrine, pituitary, and lung carcinoid. Six tumors (three MEN1 and three sporadic tumors) were identified that provided important LOH boundaries. Four tumors (two parathyroid tumors, one gastrinoma, and one lung carcinoid tumor) showed allelic loss that placed the MEN1 gene distal to marker PYGM. Two tumors (one gastrinoma and one parathyroid tumor) showed an LOH boundary that placed the gene proximal to D11S449, one of which further moved the telomeric boundary to D11S4936. Taken together, the present data suggest that the MEN1 gene lies between PYGM and D11S4936, a region of approximately 300 kb on chromosome 11q13.

[The effect of heterogeneous scleral transplantation on hypotony after filtration surgery of glaucoma with mitomycin C]

OBJECTIVE

The study was designed to observe the effect of heterogeneous scleral transplantation in treatment of hypotony after filtration surgery of glaucoma with mitomycin C.

METHOD

7 patients (8 eyes) with hypotony after filtration surgery of glaucoma with mitomycin C were treated by heterogeneous scleral transplantation.

RESULTS

The post-operative follow-up periods ranged from 3 to 19 months (mean 7.75 +/- 5.37 months). Postoperatively, the visual acuity was increased in 5 eyes, and the intraocular pressure was increased to normal level in all eight eyes.

CONCLUSION

Heterogeneous scleral transplantation has therapeutic effects in the treatment of hypotonic eyes after filtration surgery of glaucoma.

Loss of heterozygosity at 11q13: analysis of pituitary tumors, lung carcinoids, lipomas, and other uncommon tumors in subjects with familial multiple endocrine neoplasia type 1

Loss of heterozygosity (LOH) for polymorphic markers flanking the multiple endocrine neoplasia type 1 (MEN-1) gene in parathyroid and pancreatic islet tumors from subjects with familial MEN-1 (FMEN-1) has been well documented and has led to the hypothesis that the MEN-1 gene functions as a tumor suppressor. To assess the role of the MEN-1 gene in the pathogenesis of tumors less commonly associated with MEN-1, we employed a large number of highly informative polymorphic markers closely linked to the MEN-1 gene to study a series of 13 such tumors from subjects with FMEN-1 for LOH at 11q13. We were able to identify LOH for 1 or more 11q13 markers in 2 of 3 pituitary tumors, 3 lung carcinoids, and 1 of 2 lipomas. In every case studied, the allele lost represented the normal allele inherited from the unaffected parent. No LOH was detected in 3 skin angiofibromas, an esophageal leiomyoma, or a renal angiomyolipoma despite the presence of at least 2 informative markers for each tumor. Our results suggest that, like that for parathyroid and pancreatic islet tumors, the pathogenesis of pituitary tumors, lung carcinoids, and lipomas occurring in subjects with FMEN-1 probably involves loss of the normal tumor suppressor function of the MEN-1 gene. Our inability to detect 11q13 LOH in skin angiofibromas, leiomyoma, and angiomyolipoma from subjects with FMEN-1 is consistent with the possibility that these neoplasms arose independently by a mechanism unrelated to the MEN-1 gene, but a role for the MEN-1 gene in the pathogenesis of these tumors cannot be definitively excluded until the gene itself is identified and evaluated for small intragenic deletions or point mutations in such tumors.

Cross-cultural consensus in personality judgments

Building on recent research demonstrating consensus and accuracy in interpersonal perception based on minimal information, the present studies examined American and Chinese participants' within- and cross-cultural judgments. In Study 1, the authors used the zero-acquaintance paradigm in the People's Republic of China and found consensus on all personality dimensions. In Study 2, Chinese and American participants judged each other on the basis of photographs, and consensus was found among Americans' judgments of Chinese and Chinese participants' judgments of Americans. Further, by correlating target effects based on within-culture zero-acquaintance judgments and cross-cultural photographic judgments, the authors found agreement in the judgments of individuals by members of their own culture and the other culture for both Chinese and Americans.

Positional cloning of the gene for multiple endocrine neoplasia-type 1

Multiple endocrine neoplasia-type 1 (MEN1) is an autosomal dominant familial cancer syndrome characterized by tumors in parathyroids, enteropancreatic endocrine tissues, and the anterior pituitary. DNA sequencing from a previously identified minimal interval on chromosome 11q13 identified several candidate genes, one of which contained 12 different frameshift, nonsense, missense, and in-frame deletion mutations in 14 probands from 15 families. The MEN1 gene contains 10 exons and encodes a ubiquitously expressed 2.8-kilobase transcript. The predicted 610-amino acid protein product, termed menin, exhibits no apparent similarities to any previously known proteins. The identification of MEN1 will enable improved understanding of the mechanism of endocrine tumorigenesis and should facilitate early diagnosis.

Cross-cultural consensus in personality judgments

Building on recent research demonstrating consensus and accuracy in interpersonal perception based on minimal information, the present studies examined American and Chinese participants' within- and cross-cultural judgments. In Study 1, the authors used the zero-acquaintance paradigm in the People's Republic of China and found consensus on all personality dimensions. In Study 2, Chinese and American participants judged each other on the basis of photographs, and consensus was found among Americans' judgments of Chinese and Chinese participants' judgments of Americans. Further, by correlating target effects based on within-culture zero-acquaintance judgments and cross-cultural photographic judgments, the authors found agreement in the judgments of individuals by members of their own culture and the other culture for both Chinese and Americans.

Integrated regulation in response to simulated weightlessness

To investigate physiological effects of tail suspension, Ca2+ concentration, immune factors, erythrocyte rheological properties, and growth hormone were determined in rats suspended for 15 and 30 d. The results showed that inhibitory changes of both local factors (proteins secreted by bone cell, Ca(2+)-ATPase in sarcoplasmic reticium) and integrated regulative factors (immune factor, growth hormone) were observed simultaneously with the decrease of bone mineral content, calcium transportation in skeletal muscles as well as erythrocyte deformability. It suggests that both local and integrated regulative processes are functioning in response to the effects of weightlessness.

Allelic deletions on chromosome 11q13 in multiple tumors from individual MEN1 patients

Familial multiple endocrine neoplasia type 1 is an autosomal dominant hereditary disorder characterized by multiple parathyroid, pancreatic, duodenal, and pituitary tumors. The parathyroid tumors may arise as diffuse areas of hyperplasia, whereas the pancreatic and duodenal tumors usually form as discrete nodules. Except for a single report, tumor loss of heterozygosity (LOH) mapping of the putative MEN1 suppressor gene on chromosome 11q13 in the past has been restricted by analysis of a single tumor from individual patients and somatic cellular contamination. For this reason, it has not been possible to analyze the clonality of the emerging MEN1 neoplasms. Furthermore, it has been previously unknown whether the LOH pattern varies between individual MEN1 tumors in a given patient or among tumors of different histological origins within unrelated patients. To address these previous limitations, the present study introduces a refinement in microdissection in which endothelial cells are stained and selectively excluded. Tissue microdissection was applied to study LOH patterns on chromosome 11q13 using 8 polymorphic DNA markers in 44 different MEN1 tumors from parathyroid, pancreas, and duodenum in nine unrelated patients. In addition, X-chromosome inactivation clonal analysis was applied to 16 individual microdissected regions from seven parathyroid glands in three female patients. The LOH rates of parathyroid lesions (100%) and endocrine tumors of the pancreas (83%) were strikingly different from the LOH rate of gastrinomas (21%), suggesting that the mechanism that drives LOH may be influenced by the tissue context. Moreover, combined LOH and X-chromosome inactivation scoring of the same microdissected region revealed that parathyroid MEN1 neoplasms can consist of more than one clone. In this study, the centromeric boundary of the putative MEN1 gene was PYGM. Analysis of differential LOH patterns in multiple microdissected tumors in the same patient constitutes a novel approach to suppressor gene mapping.

The rate and pattern of alcohol consumption among Chinese adolescents

OBJECTIVE

To assess the prevalence and pattern of alcohol consumption and its relation to participation in other social activities and problem behaviors among adolescents residing in the People's Republic of China.

METHODS

Data were collected from a sample of 1,040 students in 6th, 8th, and 10th grades from five public schools in Beijing, China by using a self-administered questionnaire. Chi-square statistics and two-way ANOVA were used to assess the gender and grade difference in lifetime alcohol use of various alcoholic beverages. The age-adjusted and grade-adjusted odds ratio was used to assess the association between alcohol use and selected social activities and problem behaviors.

RESULTS

Approximately 70% of the study sample reported prior alcohol consumption. The rate of drinking among males was significantly higher than among females (78% vs. 61%, p < .00001), and the rates among both genders increased with advancing grade (54%, 72%, and 84%, respectively, p < .001). Beer was the most commonly consumed alcoholic beverage. The results also suggested a progression from beer to wine and/or liquor. Drinking behavior was positively associated with participation in unstructured social activities and other problem behaviors.

CONCLUSIONS

Alcohol use was prevalent among adolescents residing in China. The findings underscore the need for and importance of intervention efforts targeting alcohol consumption among early adolescents in China.

Evidence for physical and functional association between EMB-5 and LIN-12 in Caenorhabditis elegans

The Caenorhabditis elegans LIN-12 and GLP-1 proteins are members of the LIN-12/Notch family of receptors for intercellular signals that specify cell fate. Evidence presented here suggests that the intracellular domains of LIN-12 and GLP-1 interact with the C. elegans EMB-5 protein and that the emb-5 gene functions in the same pathway as the lin-12 and glp-1 genes. EMB-5 is similar in sequence to a yeast protein that controls chromatin structure. Hence, a direct consequence of LIN-12 or GLP-1 activation may be an alteration of chromatin structure that produces changes in transcriptional activity.

Expression of C-reactive protein by alveolar macrophages

C-reactive protein (CRP) is well characterized as one of the serum acute phase proteins, the levels of which increase dramatically after infection. CRP has been shown to be involved in multiple immunoregulatory functions. For example, it activates the classical complement cascade, opsonizes bacteria for phagocytosis, and stimulates phagocytic cells. Although CRP is predominantly produced and secreted by hepatocytes, other cells including subsets of lymphocytes, Kupffer cells, and blood monocytes have been shown to synthesize this protein as well. We hypothesized that CRP may be produced in the lung, and therefore it could function directly in pulmonary host defense. Western blot analysis showed that CRP was present in the lung tissue, lung lavage, and alveolar macrophages. This result was further confirmed by immunohistochemical staining of lung sections that showed the localization of CRP in alveolar macrophages. The CRP mRNA was detected subsequently by reverse-transcriptase PCR (RT-PCR), and a single amplified product was obtained from alveolar macrophages as well as from whole lung tissue. Both were the same size as the amplified product obtained from liver mRNA. Furthermore, in situ hybridization with CRP riboprobe demonstrated specific staining of alveolar macrophages both in lung sections and isolated cells. In addition, in situ hybridization showed that CRP mRNA levels in isolated alveolar macrophages were up-regulated by in vitro LPS stimulation. In summary, these results indicate that CRP is produced by alveolar macrophages, and suggest that CRP may be involved in the pulmonary immune response.

Expression of C-reactive protein by alveolar macrophages

C-reactive protein (CRP) is well characterized as one of the serum acute phase proteins, the levels of which increase dramatically after infection. CRP has been shown to be involved in multiple immunoregulatory functions. For example, it activates the classical complement cascade, opsonizes bacteria for phagocytosis, and stimulates phagocytic cells. Although CRP is predominantly produced and secreted by hepatocytes, other cells including subsets of lymphocytes, Kupffer cells, and blood monocytes have been shown to synthesize this protein as well. We hypothesized that CRP may be produced in the lung, and therefore it could function directly in pulmonary host defense. Western blot analysis showed that CRP was present in the lung tissue, lung lavage, and alveolar macrophages. This result was further confirmed by immunohistochemical staining of lung sections that showed the localization of CRP in alveolar macrophages. The CRP mRNA was detected subsequently by reverse-transcriptase PCR (RT-PCR), and a single amplified product was obtained from alveolar macrophages as well as from whole lung tissue. Both were the same size as the amplified product obtained from liver mRNA. Furthermore, in situ hybridization with CRP riboprobe demonstrated specific staining of alveolar macrophages both in lung sections and isolated cells. In addition, in situ hybridization showed that CRP mRNA levels in isolated alveolar macrophages were up-regulated by in vitro LPS stimulation. In summary, these results indicate that CRP is produced by alveolar macrophages, and suggest that CRP may be involved in the pulmonary immune response.

Analysis of impact of rigid projectiles on compound targets

We developed a model to simulate a person, with and without protective armor, being subjected to an impact of a high speed, rigid projectile. The complex nature of the head and chest are simulated in our layered, spaced, various thickness targets made of different materials. A rigid projectile-target interaction model is described. Target resistance force was obtained from a generalized Poncelet equation. Good agreement between observed and computed penetration phenomena was obtained.

Screening of candidate oncogenes in human thyrotroph tumors: absence of activating mutations of the G alpha q, G alpha 11, G alpha s, or thyrotropin-releasing hormone receptor genes

Activating mutations encoding substitutions at positions Arg201 and Gln227 of the alpha-subunit of the stimulatory G protein. G10 have been found in about 40% of pituitary somatotroph tumors. Although the etiology of thyrotroph adenomas is unknown, their autonomous behavior and blunted response to stimulatory hypothalamic hormone superficially resemble those of somatotroph tumors. We hypothesized that a subset of thyrotroph tumors might be caused by dominant somatic mutations that lead to inappropriate activation of the Gq/phospholipase C beta/Ca2+/protein kinase C. pathway normally triggered by occupancy of the TRH receptor (TRHR). We, therefore, screened samples from nine thyrotroph tumors for the presence of activating mutations of the alpha q, alpha 11, and TRHR genes. Fragments of alpha q and alpha 11 complementary DNA encompassing residues (Arg183 and Gln209) that correspond to Arg201 and Gln227 of alpha q were amplified and sequenced. Temperature gradient gel electrophoresis was used to screen for heterozygous mutations in the TRHR coding sequence as well as for known alpha s mutations. No mutations were detected. We conclude that mutations in these regions of the alpha q, alpha 11, alpha s, and TRHR genes occur infrequently, if at all, in human thyrotroph tumors. Alternative mechanisms underlying thyrotroph tumorigenesis, including changes in the expression levels of G protein alpha-subunits or TRHR, dysregulation of downstream components, inappropriate activation of other stimulatory pathways, or loss of inhibitory inputs, remain to be explored.

Fears in American, Australian, Chinese, and Nigerian children and adolescents: a cross-cultural study

The fears of childhood and adolescence may differ from one cultural context to another. We explored this possibility in 1200 American, Australian, Chinese, and Nigerian children and adolescents between 7 and 17 years of age. Responses to a standard fear survey schedule revealed significant differences in the number, content, pattern, and level of fears. Nigerian children and adolescents endorsed fears at higher levels than American, Australian, or Chinese youth who did not differ from one another. However, differences in the pattern and content of fears for boys and girls of different ages were noted across the countries. Results were interpreted within a cultural context, which suggested that cultures which favor inhibition, compliance, and obedience serve to increase levels of fear. Alternative interpretations are offered and limitations of cross-cultural research are explored.

A structural basis for a phosphoramide mustard-induced DNA interstrand cross-link at 5'-d(GAC)

Phosphoramide mustard-induced DNA interstrand cross-links were studied both in vitro and by computer simulation. The local determinants for the formation of phosphoramide mustard-induced DNA interstrand cross-links were defined by using different pairs of synthetic oligonucleotide duplexes, each of which contained a single potentially cross-linkable site. Phosphoramide mustard was found to cross-link dG to dG at a 5'-d(GAC)-3'. The structural basis for the formation of this 1,3 cross-link was studied by molecular dynamics and quantum chemistry. Molecular dynamics indicated that the geometrical proximity of the binding sites also favored a 1,3 dG-to-dG linkage over a 1,2 dG-to-dG linkage in a 5'-d(GCC)-3' sequence. While the enthalpies of 1,2 and 1,3 mustard cross-linked DNA were found to be very close, a 1,3 structure was more flexible and may therefore be in a considerably higher entropic state.

Molecular cloning of human G alpha q cDNA and chromosomal localization of the G alpha q gene (GNAQ) and a processed pseudogene

G alpha q is the alpha subunit of one of the heterotrimeric GTP-binding proteins that mediates stimulation of phospholipase C beta. We report the isolation and characterization of cDNA clones from a frontal cortex cDNA library encoding human G alpha q. The encoded protein is 359 amino acids long and is identical in all but one amino acid residue to mouse G alpha q. Analysis of human genomic DNA reveals an intronless sequence with strong homology to human G alpha q cDNA. In comparison to G alpha q cDNA, this genomic DNA sequence includes several small deletions and insertions that alter the reading frame, multiple single base changes, and a premature termination codon in the open reading frame, hallmarks of a processed pseudogene. Probes derived from human G alpha q cDNA sequence map to both chromosomes 2 and 9 in high-stringency genomic blot analyses of DNA from a panel of human-rodent hybrid cell lines. PCR primers that selectively amplify the pseudogene sequence generate a product only when DNA containing human chromosome 2 is used as the template, indicating that the authentic G alpha q gene (GNAQ) is located on chromosome 9. Regional localization by FISH analysis places GNAQ at 9q21 and the pseudogene at 2q14.3-q21.

Only children and children with siblings in the People's Republic of China: levels of fear, anxiety, and depression

In 1979, China implemented its one-child-per-family policy in order to control its burgeoning population. Subsequently, concern has been raised about the policy and its potentially negative effects on children. In the present study, we examined these presumed effects on 202 adolescents born before the policy went into effect, 290 preadolescents born during the period in which the policy was being implemented, and 239 children who were born after the policy went into effect. Measures of fear, anxiety, and depression were obtained. Contrary to our hypotheses, based on concerns raised by the one-child policy, children with siblings reported significantly higher levels of fear, anxiety, and depression than only children, regardless of when they were born. For depression, this effect was qualified by a sibling status x age interaction. Children with siblings born after the policy went into effect, or during its implementation, reported higher levels of depression than did only children; however, only children and children with siblings born before the policy went into effect did not differ significantly from one another. Sociocultural factors associated with these findings are explored.

Mutational studies of human DNA polymerase alpha. Lysine 950 in the third most conserved region of alpha-like DNA polymerases is involved in binding the deoxynucleoside triphosphate

The function of a lysine residue, Lys950, of human DNA polymerase alpha located in the third most conserved region and conserved in all of the alpha-like polymerases was analyzed by site-directed mutagenesis. Lys950 was mutagenized to Arg, Ala, or Asn. The mutant enzymes were expressed in insect cells infected with recombinant baculoviruses and purified to near homogeneity. The mutant enzymes had specific activities ranging from 8 to 22% of the wild type. All three Lys950 mutants utilized Mn2+ as metal activator more effectively than the wild type enzyme and showed an increase in Km values for deoxynucleoside triphosphate but not k(cat) values in reactions with either Mg2+ or Mn2+ as the metal activator. Although mutation of the Lys950 residue caused an increase in Km values for deoxynucleoside triphosphates, mutations of Lys950 to Arg, Ala, or Asn did not alter the mutant enzymes' misinsertion efficiency in reactions with Mg2+ as a metal activator as compared with that of the wild type, suggesting that the base of the incoming deoxynucleoside triphosphate is not the structural feature interacting with the Lys950 side chain. In reaction with Mn2+ as a metal activator, all three Lys950 mutants had an improved fidelity for deoxynucleotide misinsertion compared to wild type. Inhibition studies of the three Lys950 mutant derivatives with an inhibitor, structural analogs of deoxynucleoside triphosphate, and pyrophosphate suggest that the deoxyribose sugar and beta-,gamma-phosphate groups are not the structural feature recognized by the Lys950 side chain.(ABSTRACT TRUNCATED AT 250 WORDS)

Interaction of herpes simplex virus 1 origin-binding protein with DNA polymerase alpha

The herpes simplex virus 1 (HSV-1) genome encodes seven polypeptides that are required for its replication. These include a heterodimeric DNA polymerase, a single-strand-DNA-binding protein, a heterotrimeric helicase/primase, and a protein (UL9 protein) that binds specifically to an HSV-1 origin of replication (oris). We demonstrate here that UL9 protein interacts specifically with the 180-kDa catalytic subunit of the cellular DNA polymerase alpha-primase. This interaction can be detected by immunoprecipitation with antibodies directed against either of these proteins, by gel mobility shift of an oris-UL9 protein complex, and by stimulation of DNA polymerase activity by the UL9 protein. These findings suggest that enzymes required for cellular DNA replication also participate in HSV-1 DNA replication.

Perceptions of fear in other children and adolescents: the role of gender and friendship status

Gender differences in fear were examined in 693 Chinese children and adolescents. Subjects were asked to rate their own fears, the fears of their best friends, and the fears of "other" classmates using the Fear Survey Schedule for Children--Revised (Ollendick, 1983). Consistent with previous investigations in Western and Eastern countries, girls rated themselves as more fearful than boys. In addition, both girls and boys rated their best friends as similar in number, content, and intensity of fears. However, girls rated their classmates as less fearful than themselves or their best friends, while boys rated their classmates as more fearful then themselves or their best friends. Findings are discussed in terms of gender role expectations and similarity-attraction hypotheses.

The stability and prediction of fears in Chinese children and adolescents: a one-year follow-up

The stability in number, level, content, and pattern of fears over a one-year period was examined in Chinese children and adolescents aged 7-17. In addition, perceptions of fear in friends and parents as well as perceptions of the controllability and modifiability of fears were explored as predictors of subsequent fear level. Evidence for moderate stability of fears was obtained. However, stability was qualified by age and sex interaction effects. A developmental-cultural hypothesis was put forth to account for those findings. Hierarchical regression analyses revealed that perceptions of fears in friends and parents, along with perceptions of the controllability and modifiability of fears, were predictive of fear level at follow-up. Limitations of the study are noted.

Antithrombotic agents: from RGD to peptide mimetics

This review covers the recent advances in the development of highly potent inhibitors of platelet aggregation as potential therapeutic drugs for thrombosis related to cardiovascular and cerebrovascular diseases. The discovery of RGD sequence-directed cell surface receptors (the integrins) has led to extensive research in the development of small RGD containing peptides and their mimetics as antithrombotic agents. These agents work by inhibiting platelet aggregation through competitive blocking of fibrinogen to the platelet surface receptor, GPIIb/IIIa. The pharmacophoric nature of the aspartic acid and arginine side chains of the RGD unit has allowed the development of strategies for rational design, largely based on assumed bioactive RGD conformations and lead optimization. Applications of such strategies, from RGD peptides to peptide hybrids and then to non-peptide mimetics, are described. Also discussed is the important issue of specificity toward GPIIb/IIIa, keeping in view that the RGD unit is a key recognition signal for a variety of cell surface receptors.

The czc operon of Alcaligenes eutrophus CH34: from resistance mechanism to the removal of heavy metals

The plasmid-borne czc operon ensures for resistance to Cd2+, Zn2+ and Co2+ ions through a tricomponent export pathway and is associated to various conjugative plasmids of A. eutrophus strains isolated from metal-contaminated industrial areas. The czc region of pMOL30 was reassessed especially for the segments located upstream and downstream the structural genes czc CBA. In cultures grown with high concentrations of heavy metals, czc-mediated efflux of cations is followed by a process of metal bioprecipitation. These observations led to the development of bioreactors designed for the removal of heavy metals from polluted effluents.

Repair analysis of 4-hydroperoxycyclophosphamide-induced DNA interstrand crosslinking in the c-myc gene in 4-hydroperoxycyclophosphamide-sensitive and -resistant medulloblastoma cell lines

Cyclophosphamide is one of the most active agents in the treatment of medulloblastoma. However, development of resistance to this alkylator frequently occurs and is the harbinger of tumor progression and death. In order to understand the biochemical basis of this resistance, we generated a panel of medulloblastoma cell lines in our laboratory that were resistant to 4-hydroperoxycyclophosphamide (4-HC). Previously, we have shown that elevated levels of aldehyde dehydrogenase and glutathione mediate cellular resistance to 4-HC. The present study was conducted to identify the third unknown mechanism mediating the resistance of cell line D283 Med (4-HCR) to 4-HC, testing the hypothesis that this resistance is mediated by an increased repair of DNA interstrand crosslinks (ICLs). The doses of 4-HC that produced a one- and two-log cell kill of D283 Med cells were 25 and 50 microM, respectively, compared with values of 125 and 165 microM in D283 Med (4-HCR), the resistant cell line. The formation and disappearance of 4-HC-induced DNA ICLs at the c-myc gene were subsequently studied by DNA denaturing/renaturing gel electrophoresis and Southern blot analysis. 4-HC-induced DNA ICLs in the c-myc gene exhibited a dose-dependent relationship. The percentage of the c-myc gene that was crosslinked was approximately 1-3% at a dose of 100 microM. More than 50% of the DNA crosslinking in D283 Med (4-HCR) cells was removed by 6 h after drug treatment, whereas, in D283 Med cells, more than 90% of the DNA crosslinking was still present at 6 h. These findings suggest that the increased repair of DNA ICLs in D283 Med (4-HCR) may contribute significantly to its resistance to 4-HC.

Treatment of adolescent myopia by pressure plaster of semen impatientis on otoacupoints

295 cases (424 eyes) of adolescent myopia were treated by pressure plaster of Semen Impatientis on otoacupoints with a cure rate of 44.3% and a total effective rate of 98.5%. 36 random cases (69 eyes) were compared with the same number of similar control cases. Findings were that the therapeutic effects of the pressure plaster group excelled significantly those of the control group.

The sss gene product, which affects pyoverdin production in Pseudomonas aeruginosa 7NSK2, is a site-specific recombinase

Pyoverdin production by Pseudomonas aeruginosa strain 7NSK2 was induced by Zn(II) in the presence of iron. A mutant was isolated in which Zn(II) no longer induced pyoverdin production. The sss gene which was inactivated in this mutant was cloned and sequenced. Its protein sequence showed 50% identity to the XerC protein of Escherichia coli, which is a member of the lambda integrase family of site-specific recombinases. An open reading frame was found upstream of sss whose protein sequence showed strong identity to DapF, the diaminopimelate epimerase. In E. coli, xerC is part of a multicistronic unit that also contains dapF. The sss gene of P. aeruginosa could restore site-specific recombination at cer in an E. coli xerC mutant and the E. coli xerC gene could complement a genomic sss mutation in P. aeruginosa.

Characterization of the activating region of Escherichia coli catabolite gene activator protein (CAP). I. Saturation and alanine-scanning mutagenesis

It has been proposed that the surface loop consisting of amino acid residues 152 to 166 of the catabolite gene activator protein (CAP) of Escherichia coli makes direct protein-protein contact with RNA polymerase at the lac promoter. In this work, we have used targeted saturation mutagenesis of codons 152 to 166 of the gene encoding CAP, followed by a screen, to isolate more than 200 independent mutants of CAP defective in transcription activation but not defective in DNA binding. All isolated single-substitution mutants map to just eight amino acid residues; 156, 157, 158, 159, 160, 162, 163 and 164. We propose that these residues define the full extent of the epitope on CAP for the proposed CAP-RNA polymerase interaction. In addition, we have constructed alanine substitutions at each position from residue 152 to 166 of CAP, and we have analyzed the effects on transcription activation at the lac promoter and on DNA binding. Alanine substitution of Thr158 results in an approximately eightfold specific defect in transcription activation. In contrast, alanine substitution of no other residue tested results in a more than twofold specific defect in transcription activation. We conclude that, for Thr158, side-chain atoms beyond C beta are essential for transcription activation at the lac promoter, and we propose that Thr158 OH7 gamma makes direct contact with RNA polymerase in the ternary complex of lac promoter, CAP and RNA polymerase. We conclude further that for no residue other than Thr158 are side-chain atoms beyond C beta essential for transcription activation at the lac promoter.

Androgen receptor function during undernutrition

Hypothalamo-pituitary inhibition of reproductive function during undernutrition is well known, however, the physiological mechanisms leading to suppression of gonadotrophin secretion are not clear. A variety of studies have indicated that testicular negative feedback on LH secretion is enhanced during food restriction. To evaluate directly the suppression by endogenous androgens on hypothalamic GnRH pulse generator activity during food restriction and examine the mechanism underlying the increased testicular steroidal feedback, we examined (1) circulating bioactive LH (bLH) levels in response to selective cerebral androgen blockade by intraventricular administration of an androgen receptor antagonist (hydroxyflutamide, SCH 16423) and (2) the binding capacity and affinity of androgen receptors in medio-basal hypothalamus, pituitary and prostate during undernutrition of intact mature male rats. Hydroxyflutamide (20 micrograms in 10 microliters vehicle), but not vehicle alone, markedly increased bLH levels in both food restricted and ad-lib fed rats. However, the faster (geometric mean 11.4 vs 27.7 min) and greater (47.2 vs 21.9 ng/ml) increase in bLH level in food restricted compared with ad-lib fed controls demonstrates an enhanced sensitivity to blockade of androgenic negative feedback during undernutrition. Food restriction increased androgen receptor binding capacity in pituitary (3.36 vs 0.77 fmol/mg protein) but not in medio-basal hypothalamus or prostate while binding affinity was unchanged by undernutrition in all 3 tissues. These studies reveal that undernutrition both enhances tonic, androgen receptor-mediated feedback suppression of GnRH secretion and increases in pituitary (but not hypothalamic) androgen receptor numbers to cause inhibition of LH secretion.

Effect of undernutrition on pulsatile luteinizing hormone (LH) secretion in castrate and intact male rats using an ultrasensitive immunofluorometric LH assay

The recent development of an ultrasensitive immunofluorometric rat LH assay makes possible evaluation of pulsatile LH secretion in intact male rats under physiological conditions of minimal volume blood sampling without requiring orchidectomy. Specifically, we applied this assay to determine the effect of macronutrient restriction on pulsatile LH secretion in the presence or absence of testes. In testes-intact rats, halving of food intake for 7 days while maintaining micronutrient supply caused a reduction of mean, maximal, and basal LH levels and LH pulse amplitude (all P < 0.05) compared with those in ad libitum fed controls. The loss of body weight was positively correlated with decreases in mean LH level, pulse amplitude, and area under the curve (all P < 0.009). In contrast, the same food restriction in castrated rats caused an increase in pulse length and area under the curve and a decrease in pulse frequency, but did not change mean, maximal, and basal LH levels or LH pulse amplitude compared to castrated ad libitum fed controls (all P < 0.02). The observed positive correlations between body weight and the LH secretion parameters in intact rats were absent or reversed in castrated rats. This study demonstrates qualitatively different effects of macronutrient restriction on pulsatile LH secretion in castrated and intact rats, indicating that it is not necessary valid to extrapolate consequences of undernutrition on LH secretion from castrate to intact male rats. We conclude that undernutrition-induced inhibition of LH secretion involves both an indirect suppression of LH secretion via amplification of endogenous testicular negative feedback as well as more direct suppression of GnRH release.

Plasmids for heavy metal resistance in Alcaligenes eutrophus CH34: mechanisms and applications

Alcaligenes eutrophus CH34 is the main representative of a group of strongly related strains (mostly facultative chemolithotrophs) that are well adapted to environments containing high levels of heavy metals. It harbors the megaplasmids pMOL28 and pMOL30 which carry resistance determinants to Co2+, Ni2+, CrO(4)2-, Hg2+, Tl+, Cd2+, Cu2+ and Zn2+. Among the best characterized determinants are the cnr operon (resistance to Co, Ni) on pMOL28 and the czc operon on pMOL30 (resistance to Co, Cd and Zn). Although the two systems reveal a significant degree of amino acid similarity in the structural genes, the regulation of the operons is different. The resistance mechanism in both cases is based on efflux. The efflux mechanism leads to a pH increase outside of the cytoplasmic membrane. Metals are sequestered from the external medium through the bioprecipitation of metal carbonates formed in the saturated zone around the cell. This latter phenomenon can be exploited in bioreactors designed to remove metals from effluents. The bacteria are immobilized on composite membranes in a continuous tubular membrane reactor (CTMR). The effluent continuously circulates through the intertubular space, while the external surface of the tubes is in contact with the growth medium. Metal crystals are eventually removed by the effluent stream and collected on a glass bead column. The system has been applied to effluents containing Cd, Zn, Co, Ni and Cu. By introducing catabolic plasmids involved in the aerobic degradation of PCBs and 2,4-D into metal-resistant A. eutrophus strains, the application range was widened to include effluents polluted with both organic and inorganic substances. Biosensors have been developed which are based on the fusion of genes induced by metals to a reporter system, the lux operon of Vibrio fischeri. Bacterial luciferases produce light through the oxidation of fatty aldehydes. The gene fusions are useful both for the study of regulatory genes and for the determination of heavy metal concentrations in the environment.