[Association between cord blood BPDE-DNA and neurodevelopment of children aged 0 and 2 years: A birth cohort study]

Objective: To explore the effects of mothers' exposure to polycyclic aromatic hydrocarbons during pregnancy on their children's neurobehavioral development. Methods: In November 2009 to April 2010, a total of 221 pairs of mother-newborn pairs were recruited from two cooperative hospitals in Taiyuan, and their children were followed up at age two. High performance liquid chromatography was used to determine the level of BPDE-DNA in cord blood leukocytes. The Neonatal behavioral neurological assessment (NBNA) was used to assess the neurodevelopment of newborns, and the Gesell Development Scale was used to measure neurodevelopmental indexes of 2-year-old children. NBNA includes behavior, active and passive tone, primitive reflexes and general assessment, with a total score of 40 points. The Gesell Developmental Schedules consisted of four sub-scales: motor development, adaptive behavior development, language development and personal-social behavior development. We used mean and standard deviation to describe continuous variables with normal distribution, median (interquartile range) to describe continuous variables with skewed distribution, and frequency and proportion to describe categorical variables. Restricted cubic spline models were applied to assess the dose-response relationships between maternal prenatal polycyclic aromatic hydrocarbons exposure and children's neurobehavioral development at two years old. Generalized linear models were applied to evaluate the effect of exposure to maternal prenatal polycyclic aromatic hydrocarbons exposure on children's neurobehavioral development at 0 and two years old. Results: The NBNA score was 38.0±0.8, and the scores of 2-year-old children's motor, adaptive, language and personal-social were 111.6±15.0, 110.5±14.6, 108.8±17.2 and 111.7±14.5, respectively. After adjusting for confounding factors, there is no dose-response association between the cord blood BPDE of pregnant women and neonatal NBNA scores, but there were dose-response associations between BPDE and scores of 2-year-old children's motor, adaptive, language and personal-social. A unit increase in cord blood ln (BPDE-DNA), the score of motor, adaptive, language and personal-social of 2-year-old children decreased on average by 4.54、6.29、8.41 and 7.02 points. Conclusion: Maternal exposure to polycyclic aromatic hydrocarbons during pregnancy is associated with decreased children's neurobehavioral development at two years old.

[Expert consensus on the treatment of oral and maxillofacial space infections]

Oral and maxillofacial space infections (OMSI) are common diseases of the facial region involving fascial spaces. Recently, OMSI shows trends of multi drug-resistance, severe symptoms, and increased mortality. OMSI treatment principles need to be updated to improve the cure rate. Based on the clinical experiences of Chinese experts and with the incorporation of international counterparts' expertise, the principles of preoperative checklist, interpretation of examination results, empirical medication principles, surgical treatment principles, postoperative drainage principles, prevention strategies of wisdom teeth pericoronitis-related OMSI, blood glucose management, physiotherapy principles, Ludwig's angina treatment and perioperative care were systematically summarized and an expert consensus on the diagnosis and treatment of OMSI was reached. The consensus aims to provide criteria for the diagnosis and treatment of OMSI in China so as to improve the level of OMSI treatment.

[A cohort study on the association between dietary patterns which benefit for normal kidney function and the cognitive performance in the Chinese elderly]

Objective: To explore the association between dietary pattern which benefit for normal kidney function and the risk of cognitive decline or impairment in the elderly. Methods: In 2015, subjects aged 60 and over from four counties in the Nutrition and Chronic Disease Family Cohort project, were followed up in 2017. Cognitive function was repeatedly assessed, using the Mini Mental State Evaluation (MMSE) scale. Dietary pattern that benefit for normal kidney function was extracted, using the reduced rank regression method and followed by logistic regression models to explore the associations between scores that showing the kidney function on dietary patterns and the risk of cognitive deterioration and impairment in two years among those who were with normal cognition in 2015. Results: Dietary pattern that benefit for normal kidney function, was characterized by high consumption of cereal, vegetables, legume and fruits but with less meat and soy products. Comparing with the group with lowest score quartile on this dietary pattern, the risk of cognitive deterioration in the highest quartile group was significantly low (P<0.01) in two years, with an odds ratio as 0.57 (95%CI: 0.37-0.85). Linear trend was also obviously visible (P=0.007) in this group. The ones at the highest quartile group among the normal cognition ones in 2015, the risk of cognitive impairment also significantly reduced (P<0.05) in two years time, with an odds ratio as 0.52 (95%CI: 0.29-0.93). Also, linear trend could obviously be seen (P=0.01). Conclusion: Dietary pattern that benefit for normal kidney function was both inversely associated with cognitive deterioration and impairment, in two years.

[Effect of intervention programs regarding community "5+1" staged diabetes target management on patients with type 2 diabetes mellitus]

Objective: To analyze the effect of intervention programs and influencing factors regarding the community "5+1" staged diabetes target management on patients with type 2 diabetes mellitus (T2DM) and to provide evidence for improving the quality of life (QOL). Methods: A total of 12 community health service centers from Shanxi province, Jiangsu province, and Ningxia Hui autonomous region were selected as intervention group and control group, by stratified cluster sampling method. "5+1" model was used in intervention groups and basic public health services model was applied in control groups for this two-year follow-up. Data was collected through a questionnaire on demographic and disease-related information, while the QOL was measured with SF-36. Multiple linear regression and conducted by SAS 9.4. Results: A total of 2 467 subjects were included at baseline and 1 924 had completed a two-year-long management service. After intervention programs being implemented, the net effect of PCS score between the intervention and the control groups was 13.6, with the net effect of MCS score as 29.8. Results from the multiple linear regression showed that the main factors affecting PCS scores included age, type of medical insurance, baseline PCS score and regions of residency. Main factors related to MCS score included age, type of medical insurance, baseline MCS score, hypertension, and region of residency. Conclusion: Community "5+1" staged diabetes target management model presented favorable effect of improving the QOL on T2DM patients.

[Association between blood pressure related dietary patterns and identified cognitive performance in the elderly Chinese-a study by reduced rank regression method]

Objective: To study the association between blood pressure related dietary pattern and cognitive impairment in the elderly. Methods: In 2015, all participants who were aged ≥60 and participated in the Nutrition and Chronic disease family cohort were involved in the study. Information on demographic variables, lifestyle and health status was collected. Cognitive performance was assessed by the Mini Mental State Evaluation (MMSE) scale. Blood pressure, height and weight were measured by trained medical personnel and fasting venous blood samples were collected for testing on serum level of triglycerides and total cholesterol. Both SBP and DBP were used as response variables when dietary patterns were identified by reduced rank regression method. Logistic regression models were fit to explore the associations of scores on blood pressure-related dietary pattern and cognitive impairment. Results: Two blood related dietary patterns were identified. The first one was characterized by high consumption of vegetables and less meat, eggs and dessert (Pattern 1), while the second one was with high consumption of meat, soy products, wine and fried foods and less intake of dairy (Pattern 2). Data showed that the Pattern 1 was associated with the risk of cognitive impairment. Comparing with the lowest quartile of score of this dietary pattern, the risk of cognitive impairment in the highest quartile group showed a significant (P<0.01) increase, with OR=1.94 (1.21-3.11) and showing significant (P=0.002) linear trend. However, no significant association was observed (P>0.05) with cognitive impairment in the second dietary pattern. Conclusion: Blood pressure-related dietary pattern was positively associated with cognitive impairment.

Down-regulation of lncRNA MIR31HG correlated with aggressive clinicopathological features and unfavorable prognosis in esophageal squamous cell carcinoma

OBJECTIVE

Long non-coding RNA MIR31HG (MIR31HG) has been shown to affect numerous tumorigenesis. However, the function of MIR31HG in esophageal squamous cell carcinoma (ESCC) remains unclear. The aim of this study was to investigate whether the levels of MIR31HG could be served as a prognostic factor in patients with ESCC.

PATIENTS AND METHODS

MIR31HG expression was detected in 185 samples of surgically resected ESCC and matched normal tumor-adjacent tissues by qRT-PCR. The association between MIR31HG expression levels in tissue and characteristics was examined. Overall survival (OS) curves were conducted to compare MIR31HG level and clinical characteristics. Cox regression analysis was conducted to determine the prognostic value of MIR31HG.

RESULTS

The levels of MIR31HG were decreased in the ESCC tissues from patients with ESCC compared with the control (p < 0.01). In malignant cases, lower expression MIR31HG levels were significantly associated with poor differentiation (p < 0.001), advanced lymph node metastasis (p = 0.006), positive distant metastasis (p = 0.005) and TNM stage (p = 0.004). Kaplan-Meier analysis indicated that patients presenting with reduced MIR31HG expression exhibited poorer OS (p = 0.0002). Univariate and multivariate analysis suggested that MIR31HG expression was an independent prognostic marker for survival in patients with ESCC.

CONCLUSIONS

We observed that down-regulated MIR31HG in ESCC patients was associated with malignant clinical characteristics. MIR31HG might be considered as a potential prognostic indicator and a potential target for therapeutic targets in ESCC.

[Validity, reliability, and acceptability of the scale of knowledge, attitude, and behavior of lifestyle intervention in a diabetes high-risk population]

OBJECTIVE

To evaluate the validity, reliability, and acceptability of the scale of knowledge, attitude, and behavior of lifestyle intervention in a diabetes high-risk population (HILKAB), and provide scientific evidence for its usage.

METHODS

By convenient sampling, we selected 406 individuals at high risk for diabetes for survey using the HILKAB. Pearson correlation coefficient, factor analysis, independent sampling, and t-test for high- and low-score groups were used to evaluate the content validity, construct validity, and discriminant validity of the scale. Reliability of the scale was evaluated by internal consistency, which included Cronbach's α coefficient, θ coefficient, Ω coefficient, and split-half reliability. Scale acceptability was evaluated by acceptance rate and completion time of the survey.

RESULTS

In this study, 366 questionnaires (90.1%) was qnalified and the completion time was (8.62±2.79) minutes. Scores for knowledge, attitude, and behavior were 10.60±3.73, 26.56±3.58, 17.09±9.74, respectively. The scale had good face validity and content validity. The correlation coefficient of items and the dimension to which they belong was between 0.25 and 0.97, and the correlation coefficient of three dimensions and the entire scale was between 0.64 and 0.91, all with P<0.001. Factor analysis of the scale extracted eight common factors. The cumulative variance contribution rate was 65.23%, thereby reaching the 50% approved standard. Of 30 items there were 29 items with factor loadings ≥0.40, indicating the scale had good construct validity. For the high-score group, scores for knowledge, attitude, and behavior dimensions were 13.89±2.55, 29.56± 2.46, 28.05 ± 2.93, respectively, which were higher than those for the low-score group (7.67 ± 2.78, 23.89 ± 3.35, 6.25 ± 3.13); t-values were 55.14, 119.40, 95.29, respectively, with P<0.001. The scale consisted of three dimensions: knowledge, attitude, and behavior. The Cronbach's α coefficient was between 0.84 and 0.92, the θ coefficient was between 0.85 and 0.96, the Ω coefficient was between 0.90 and 0.94, and the split-half reliability was between 0.77 and 0.95, reaching the 0.70 standard letter.

CONCLUSION

The validity, reliability, and acceptability of the HILKAB scale were satisfactory for use in a population at high risk of diabetes.

Molecular genetic and epigenetic analysis of NCX2/SLC8A2 at 19q13.3 in human gliomas

AIM

Loss of heterozygosity at 19q13.3 is a common genetic change in human gliomas, indicating yet unknown glial-specific tumour suppressor genes in this chromosome region. NCX2/SLC8A2 located on chromosome 19q13.32 encodes a Na(+)/Ca(2+) exchanger, which contributes to intracellular Ca(2+) homeostasis. Its expression is restricted to brain, and it is present neither in other normal tissues nor in gliomas at any significant level. The aim of this study was to investigate if NCX2 might be a tumour suppressor gene involved in glioma.

METHODS

We performed a systematic analysis of NCX2 in 42 human gliomas using microsatellite analysis for evaluation of loss of heterozygosity at 19q, DNA sequencing and DNA methylation analysis.

RESULTS

Except for three known intragenic single nucleotide polymorphisms, rs12459087, rs7259674 and rs8104926, no NCX2 sequence variations were detected in any of the tumour samples. Furthermore, a CpG island in the 5' promoter region of NCX2 was unmethylated. Interestingly, the CpG sites of three gene-body CpG islands located in exon 2, intron 2-3 and exon 3 and of a 5' CpG-rich area relevant to so-called CpG island shore of NCX2 were methylated in all eight glioma samples and in three established glioma cell lines tested. Surprisingly, NCX2 could be activated by addition of the DNA methylation inhibitor 5-aza-2'-deoxycytidine to glioma cell lines in which NCX2 was completely silent.

CONCLUSION

Results indicate that DNA methylation may play a key role in the transcriptional silencing of NCX2.

Planning for intracavitary anti-EGFR radionuclide therapy of gliomas. Literature review and data on EGFR expression

Targeting with radionuclide labelled substances that bind specifically to the epidermal growth factor receptor, EGFR, is considered for intracavitary therapy of EGFR-positive glioblastoma multiforme, GBM. Relevant literature is reviewed and examples of EGFR expression in GBM are given. The therapeutical efforts made so far using intracavitary anti-tenascin radionuclide therapy of GBM have given limited effects, probably due to low radiation doses to the migrating glioma cells in the brain. Low radiation doses might be due to limited penetration of the targeting agents or heterogeneity in the expression of the target structure. In this article we focus on the possibilities to target EGFR on the tumour cells instead of an extracellular matrix component. There seems to be a lack of knowledge on the degree of intratumoral variation of EGFR expression in GBM, although the expression seemed rather homogeneous over large areas in most of the examples (n=16) presented from our laboratory. The observed homogeneity was surprising considering the genomic instability and heterogeneity that generally characterises highly malignant tumours. However, overexpression of EGFR is, at least in primary GBMs, one of the steps in the development of malignancy, and tumour cells that lose or downregulate EGFR will probably be outgrown in an expanding tumour cell population. Thus, loss of EGFR expression might not be the critical factor for successful intracavitary radionuclide therapy. Instead, it is likely that the penetration properties of the targeting agents are critical, and detailed studies on this are urgent.

Genetic alterations in tp53 in recurrent urothelial cancer: a longitudinal study

PURPOSE

Because bladder cancer has a recurrence rate that can be as high as 90% at 2 years, we sought to clarify whether these metachronous tumors are polyclonal or monoclonal in origin. We have examined the genetic alterations of the TP53 gene in a cohort of patients with urothelial cancer who underwent multiple biopsies at different times and sites because of tumor recurrence and/or progression. We postulated that if tumor cells at different points in the natural history of the disease contain an identical mutation in the TP53 gene, this pattern could provide evidence for the monoclonality of the recurrent bladder tumors.

EXPERIMENTAL DESIGN

Fifty-three biopsy specimens from 13 patients at different times and sites were selected for this study. Microdissection was used to ensure the purity of tumor cells. DNA extraction, PCR, and direct sequencing of exons 5 through 8 of the TP53 gene were conducted following protocols optimized in our laboratory.

RESULTS

We found that specimens from seven patients carried tumor-specific TP53 mutations. The number of lesions in these patients ranged from two to seven, extending from 2 to 4 years. All of the seven patients displayed identical mutations in the different microdissected tumors.

CONCLUSIONS

On the basis of these data, it appears that the recurrent bladder tumors originate from the same clone.

Recovering DNA and optimizing PCR conditions from microdissected formalin-fixed and paraffin-embedded materials

Microdissection is a powerful technique in molecular pathology and genetic investigations. To detect genetic alterations such as gene mutation or deletion from tumor specimen, the purity of target cells is extremely critical. Unwanted cell contamination will dramatically dilute the detectable level of the abnormality. The major obstacle in clinical research is to obtain sufficient and qualified DNA from a small amount of formalin-fixed and paraffin-embedded materials. We have successfully modified our previous protocols and overcome the difficulties of recovery of DNA. After these modifications, almost every single formalin-fixed and paraffin-embedded specimen has been successfully amplified in the required DNA region.

Genetic instability in the 9q22.3 region is a late event in the development of squamous cell carcinoma

Squamous cell carcinoma (SCC) of the skin represents a group of neoplasms which is associated with exposure to UV light. Recently, we obtained data suggesting that invasive skin cancer and its precursors derive from one original neoplastic clone. Here, the analysis were extended by loss of heterozygosity (LOH) analysis in the chromosome 9q22.3 region. A total of 85 samples, taken from twenty-two sections of sun-exposed sites, corresponding to normal epidermis, morphological normal cells with positive immuno-staining for the p53 protein (p53 patches), dysplasias, cancer in situ (CIS) and squamous cell carcinomas (SCC) of the skin were analysed. Overall, about 70% of p53 patches had mutations in the p53 gene but not LOH in the p53 gene or 9q22.3 region. Approximately 70% of the dysplasias showed p53 mutations of which about 40% had LOH in the p53 region but not in the 9q22.3 region. In contrast, about 65% of SCC and CIS displayed LOH in the 9q22.3 region, as well as frequent (80%) mutations and/or LOH in the p53 gene. These findings strongly suggest that alterations in the p53 gene is an early event in the progression towards SCC, whereas malignant development involves LOH and alterations in at least one (or several) tumor suppressor genes located in chromosome 9q22.3.

Clones of normal keratinocytes and a variety of simultaneously present epidermal neoplastic lesions contain a multitude of p53 gene mutations in a xeroderma pigmentosum patient

A patient with xeroderma pigmentosum group C was extensively examined for mutations in the p53 gene in normal skin exposed to varying degrees of sunlight and in excisional biopsies of basal cell cancer, squamous cell cancer, and squamous cell dysplasia. Seventy-three samples were analyzed by microdissection of small cell clusters, followed by PCR and direct DNA sequencing. In skin taken from areas that most likely had never been exposed to the sun, no mutations were found. However, in skin exposed to the sun, we observed a multitude of mutations in the p53 gene. UV light-induced mutations were found in all types of lesions, as well as in clusters of morphologically normal epidermal cells. Twenty-nine distinct mutations were found in exons 5-8, all missense or nonsense, of which 27 (93%) were UV-specific C --> T or CC --> TT transitions at dipyrimidine sites of the nontranscribed strand. Two types of normal skin areas containing p53 mutations were observed: areas that stain strongly with p53 antibody (p53 patches) and those that do not stain. Because no silent or intron mutations were found in these cell clusters, the alterations in the p53 gene of morphologically normal cells are likely to have resulted in a selective growth advantage. The poor correlation between mutations and morphological phenotypes demonstrates that p53 mutations alone do not determine the phenotypes observed.

Molecular pathology in basal cell cancer with p53 as a genetic marker

Human basal cell cancer (BCC) has unique growth characteristics with virtual inability to metastasize. We investigated clonality and genetic progression using p53 mutations as marker. Sampling was done through microdissection of frozen immunohistochemically stained 16 microm slices of tumors. From 11 BCC tumors 78 samples were analysed. Direct DNA sequencing of exons 5-8 was performed, haplotypes were determined after cloning of p53 exons and loss of heterozygosity (LOH) ascertained by microsatellite analysis. All tumors had p53 mutations and in a majority both p53 alleles were affected, commonly through missense mutations. Microdissection of small parts (50-100 cells) of individual tumors showed BCC to be composed of a dominant cell clone and prone to genetic progression with appearance of subclones with a second and even third p53 mutation. Samples from normal immunohistochemically negative epidermis always showed wild type sequence, except for a case of previously unknown germline p53 mutation. Our analysis also included p53 immunoreactive patches i.e. morphologically normal epidermis with a compact pattern of p53 immunoreactivity. Mutations within those were never the same as in the adjacent BCC. This detailed study of only one gene thus uncovered a remarkable heterogeneity within a tumor category famous for its benign clinical behavior.

Benign clonal keratinocyte patches with p53 mutations show no genetic link to synchronous squamous cell precancer or cancer in human skin

Ultraviolet light, which is the major etiology of human skin cancer, will cause mutations in the p53 gene. We and others have found that such mutations occur in more than one-half of non-melanoma squamous cell cancer and precancer. Immunostaining for p53 has disclosed a characteristic compact pattern not only in cancer/precancer but also in areas of microscopically normal epidermis termed p53 patches. By microdissection, sequence analysis of the p53 gene, and analysis of loss of heterozygosity (LOH) at the site of this gene, we have now extended previous data to ascertain whether these p53 patches are precursors of simultaneously present squamous cell cancer or its morphologically recognized precancerous stages (dysplasia, carcinoma in situ). In none of 11 instances with co-existence of a p53 patch with dysplasia or in situ or invasive cancer were the mutations identical. We conclude that p53 patches, estimated to be approximately 100,000 times as common as dysplasia, have a very small or even no precancerous potential. Their common presence demonstrates that human epidermis contains a large number of p53 mutations apparently without detrimental effect. The only result of the mutation may be a clandestine benign clonal keratinocyte proliferation. The importance of p53 mutations for such benign cell multiplication on one band and malignant transformation on the other is unclear. Although the spectrum, type, and multiplicity of mutations were similar in both types of proliferative responses, there was a clear difference with respect to LOH. No LOH was found in 17 p53 patches. By contrast 11 of 30 precancers/cancers had LOH.

Two distinct p53 immunohistochemical patterns in human squamous-cell skin cancer, precursors and normal epidermis

Specimens of squamous-cell neoplasms (81 invasive cancers, 36 in situ cancers, 70 dysplasias, 5 keratoacanthomas, 19 papillomas) and normal skin were immunostained with p53 antibody. Nuclear accumulation of p53 was visualized as following 2 distinct patterns: dispersed or compact. The former is interpreted as a reversible reaction to sunlight, whereas the latter, after microdissection and sequencing of DNA, has been shown to reflect clonal multiplication of keratinocytes with mutated p53. The dispersed pattern was diffusely distributed and usually only involved a small proportion of epidermal cells. The compact pattern was characterized as a contiguous area of homogeneously stained cells sharply demarcated from its surroundings. It involved patches of normal epidermis or large areas of dysplastic or malignant squamous epithelium. Immature cells were always stained, whereas immunoreactivity was variably present in differentiating keratinocytes. Dispersed patterns occurred in 94.7% of strongly UV-exposed skin (mainly face) and to a lesser extent in less exposed parts of the body. It showed no correlation to the age of the individual. About two-thirds of biopsies from individuals over age 50 displayed compact patterns in sun-exposed, otherwise normal, epidermis. About 65% of pre-malignant and malignant squamous-cell neoplasms had a compact pattern. The presence of p53 immunoreactivity as a compact pattern supports the idea that mutations of the p53 gene are early events in the sequence from dysplasia to invasive squamous-cell cancer of the skin. Also, even in the absence of cellular atypia, patches of epidermal cells can accumulate p53 in a way that is indistinguishable from that of cancer and pre-cancer.

Human epidermal cancer and accompanying precursors have identical p53 mutations different from p53 mutations in adjacent areas of clonally expanded non-neoplastic keratinocytes

Microdissection of biopsies with sequencing of exons 4-8 of the p53 gene permitted precise morphological identification of correlation between mutations and/or loss of heterozygosity, immunoreactivty of p53 and type of squamous neoplasia. Seventy-two specimens from ten lesions of sun-exposed sites including normal epidermis were analysed. Irrespective of p53 immunoreactivity and morphological grade dysplasia, in situ or invasive cancer, in each case, carried the identical mutation indicating that invasive skin cancer and its precursors derive from the same original neoplastic clone. Additionally, morphologically normal epidermis showed some sharply demarcated immunoreactive areas. These never had the same p53 mutation as that of the adjacent tumor, indicating that their mutations were separate events and ruling them out as common precursors of cancer. Non-immunoreactive normal epidermis did not show p53 mutations. Our findings indicate that a large fraction of keratinocytes in sun-exposed human skin carry mutations of p53 and suggest that at least two options exist for such cells (i) innocuous clonal expansion with preserved morphology and normal differentiation or (ii) malignant transformation with the p53 mutation as an early event. Suggestive evidence existed that the p53 mutations were qualitatively different in the two respective groups of lesions.

Ultraviolet light induces expression of p53 and p21 in human skin: effect of sunscreen and constitutive p21 expression in skin appendages

It has been suggested that p53 plays an important role in skin carcinogenesis. The p21 molecule acts as a downstream effector of wild-type p53 by enacting cell cycle arrest. We studied p53 and p21 expression in sun-exposed skin. Healthy volunteers were exposed to ultraviolet irradiation (UVA + UVB) in normal, previously non-sun-exposed skin, and skin biopsies were taken. Immunohistochemically detectable p53 and p21 were quantified, and the pattern of distribution was recorded. p53 was induced in epidermal cells 4 h after irradiation and returned to nearly normal levels after 120 h. Suprabasal cells showed a peak at 4 h, whereas basal cells peaked later, at 48 h. In epidermis, the expression of p21 was induced with a pattern that mirrored that of p53. In addition, p21 was induced in mesenchymal cells of the upper dermis, where there was no p53, suggesting an alternative pathway for p21 induction. Topical sunscreen and pigmentation (skin type 5) nearly eliminated UV-induced expression of p53 and p21. In contrast to the complete absence of p53 in skin never exposed to UV radiation, p21 reactivity was found in sharply demarcated areas of anagen hair follicles and sebaceous glands, as well as in scattered epidermal cells. The prevalence and distribution suggest a physiologic role of p21 in stopping the cell cycle in terminally differentiating skin epithelium. Archival skin material from the vicinity of skin lesions with variable sun exposure were also stained for p53. There was an increased "disperse" reactive staining pattern in skin samples excised in the summer as compared with less sunny seasons. Intensely stained p53 foci were detected as "compact bands" in morphologically normal epidermis, predominantly in sun-exposed areas of the skin, suggesting the existence of clonal proliferation of p53 mutated keratinocytes. These data show that p53 and p21 play a role in the human skin response to UV exposure and that p21 is implicated in the homeostasis of differentiating skin appendages.

Ischemia-induced transplant arteriosclerosis in the rat

The effect of cold graft ischemia time on the development of transplant arteriosclerosis was investigated. Aorta grafts from DA or PVG rats were stored in a cold perfusion solution for 1, 4, or 24 hours before being orthotopically transplanted to PVG recipients. After observation times ranging from 2 to 8 weeks, the grafts were examined for various cell populations. Regional changes in the intima and media layers were measured by using an image analysis system. The arteriosclerosis-like changes seen in syngeneic grafts with the longest ischemia time could be almost as prominent as those seen in the allogeneic transplants. The magnitude of the regional intima changes in the syngeneic group correlated well with the ischemia time and in the allogeneic group with the observation time. The cell composition found in the intima and media of the allogeneic vessels consisted of macrophages, T-lymphocytes, MHC class II-expressing cells, and smooth muscle cells, whereas the syngeneic grafts contained almost exclusively smooth muscle cells and macrophages. We therefore conclude that the damage due to prolonged cold ischemia time is sufficient to cause pronounced graft arteriosclerosis. The pathophysiological mechanism leading to ischemia-induced arteriosclerosis is different from the one seen in the allogeneic situation.

Constitutive and inducible expression of PDGF in the human basophilic cell line, KU 812

The human basophilic cell line KU 812, that also has some mast cell characteristics, was found to express the PDGF-A gene and secrete PDGF-A like activity. After treatment with IL-6+ TNF-alpha, the PDGF-A mRNA expression increased as did cytoplasmic immunostaining with anti-PDGF antibodies. Secretion of PDGF-A was visualized by immunoprecipitation. An augmentation of non-secreted PDGF-like activity after IL-6+ TNF-alpha treatment was not accompanied by induction of the long splice variant of the PDGF-A-chain mRNA. Treatment with TPA caused an increase in PDGF-A expression and in addition, an induction of PDGF-B transcripts were seen. Staining of cytospin preparations with anti-PDGF antibodies visualized a substantial increase in immunostaining of the TPA treated cells and both intracellular and secreted PDGF-AA-like activity was substantially increased as compared to untreated control cultures. There was a concomitant induction of exon 6 specific mRNA, corresponding to a cellular retention signal after TPA treatment. Our results show that PDGF can be produced by a cell line of the basophilic/mast cell lineage, i.e. cells involved in allergic disorders and inflammation.