Microsatellite instability and loss of heterozygosity in chromosomes 9 and 16 in human breast epithelial cells transformed by chemical carcinogens

Microsatellite instability (MSI) and loss of heterozygosity (LOH) in chromosomes 9 and 16 have been reported in human breast cancers. In order to determine whether changes in these chromosomes play a role in the initiation and progression of this disease, we performed microsatellite polymorphism analyses in human breast epithelial cells (HBEC) transformed by chemical carcinogens, an in vitro system that recapitulates various stages of neoplastic transformation. In this experimental system we studied the mortal HBEC MCF-10M, immortal MCF-10F cells, derived from MCF-10M cells, and clones derived from MCF-10F cells treated with benzo[a]pyrene (B[a]P) (BP1 and BP1E) and 7,12-dimethylbenz[a]anthracene (DMBA) (D3 and D3-1). The four clones of transformed cells were injected into severe combined immunodeficient (SCID) mice. Only BP1-E cells induced the formation of tumors, designated BP1E-Tp cells. These cells originated six additional tumors, designated BP1E-Tf no. 1 through Tf no. 6. Microsatellite analyses were carried out using five markers for chromosome 9 and 20 for chromosome 16. There was no evidence of MSI or LOH in clones BP1 and BP1E when compared with the MCF-10M and MCF-10F cells, whereas BP1E-Tp cells and Bp1E-Tf no. 1-Tf no. 6 tumors exhibited MSI at loci p23 and p21, and LOH at p21-22 of chromosome 9. They also exhibited MSI and LOH at multiple loci of both the short and long arms of chromosome 16, i.e. p13.13, p13.3, p12, q12.1, q12.2, q23 and q24, to which putative tumor suppressor genes have been localized. Clones D3 and D3-1 exhibited no genomic changes in chromosome 9, but did show MSI at locus q12.1 of chromosome 16 using marker D16S285. Although the cells treated with DMBA expressed early phenotypes of neoplastic transformation, they were not tumorigenic, and also manifested fewer changes than the tumorigenic BP1E-Tp cells and the tumors BP1E-Tf. The changes in chromosomes 9 and 16 observed in these latter ones indicated an association with the expression of tumorigenesis, which represents a late event in the progression of the neoplastic transformation of HBEC. Of interest was the observation that HBEC transformed by chemical carcinogens in vitro express genomic changes similar to those found in spontaneous breast carcinomas.

Adult attention-deficit hyperactivity disorder: assessment guidelines based on clinical presentation to a specialty clinic

Of 143 adults presenting for attention-deficit hyperactivity disorder (ADHD) evaluation, 46 (32%) clearly met diagnostic criteria, 46 (32%) clearly did not meet diagnostic criteria, and another 51 (36%) with current ADHD-like features did not meet criteria due to either a lack of childhood history and/or complicating severe psychiatric or substance abuse comorbidity. The three groups were similar in demographics, psychiatric diagnosis, psychiatric symptom severity, and functional impairment. Compared with the group not meeting ADHD criteria, patients with ADHD had more frequent histories of learning disability in childhood, poorer reading scores on the Wide-Range Achievement Test (WRAT), poorer scores on the Continuous Performance Test (CPT), and higher scores on the Wender-Utah Rating Scale (WURS) for ADHD. Patients in the ambiguous ADHD category had higher rates of current substance abuse than the other two groups. While this group resembled the non-ADHD group in having a low incidence of learning disability and normal reading scores, their poor performance on the CPT and high scores on the WURS more closely resembled those of ADHD patients. These findings suggest that there are a few rating scales, testing instruments, and lifetime history characteristics that help to clarify the difficult diagnostic distinction between adult patients who do and do not have ADHD.

Hostility, social support, and perceptions of work

The aim of this study was to determine whether hostility and perceived availability of social support are related to perceptions of the work environment. The W.W. Cook and D.M. Medley (1954) Hostility (Ho) scale; the Interpersonal Support Evaluation List (S. Cohen, R. Mermelstein, T. Kamarck, & H. Hoberman, 1985); and measures of collegiality, time pressure, and job dissatisfaction were completed by 204 attorneys (159 men and 45 women). After controlling for age, gender, and other job characteristics, high Ho scores were related to lower perceived supportive collegiality at work. Low perceived availability of social support was related to greater job dissatisfaction. Neither hostility nor social support was associated with perceptions of time pressure at work. These findings suggest that hostility and availability of social support may be an important pathway linking certain job characteristics to cardiovascular disease and other illnesses.

Are aluminium potroom workers at increased risk of neurological disorders?

OBJECTIVE

To determine whether long term potroom workers in an aluminium smelter are at increased risk of neurological disorders.

METHODS

Cross sectional study of 63 current and former aluminium potroom workers first employed before 1970 and with at least 10 years of service. A group of 37 cast house and carbon plant workers with similar durations of employment and starting dates in the same smelter were used as controls. The prevalence of neurological symptoms was ascertained by questionnaire. Objective tests of tremor in both upper and lower limbs, postural stability, reaction time, and vocabulary were conducted. All subjects were examined by a neurologist.

RESULTS

No significant differences in age, race, or education were found between the two groups. Although the potroom group had higher prevalences for all but one of the neurological symptoms, only three odds ratios (ORs) were significantly increased; for incoordination (OR 10.6), difficulty buttoning (OR 6.2), and depression (OR 6.2). Tests of arm or hand and leg tremor in both the visible and non-visible frequencies did not show any significant differences between the two groups. Testing of postural stability showed no definitive pattern of neurologically meaningful differences between the groups. There were no significant differences between the two groups in reaction time, vocabulary score, or clinical neurological assessment.

CONCLUSIONS

The objective measures of neurological function provided little support for the finding of increased neurological symptom prevalences in the potroom workers, although increased symptoms may be an indicator of early, subtle neurological changes. The results provide no firm basis for concluding that neurological effects among long term potroom workers are related to the working environment, in particular aluminium exposure, in potrooms. These findings should be treated with caution due to the low participation of former workers and the possibility of information bias in the potroom group.

Hostility, social support, and perceptions of work

The aim of this study was to determine whether hostility and perceived availability of social support are related to perceptions of the work environment. The W.W. Cook and D.M. Medley (1954) Hostility (Ho) scale; the Interpersonal Support Evaluation List (S. Cohen, R. Mermelstein, T. Kamarck, & H. Hoberman, 1985); and measures of collegiality, time pressure, and job dissatisfaction were completed by 204 attorneys (159 men and 45 women). After controlling for age, gender, and other job characteristics, high Ho scores were related to lower perceived supportive collegiality at work. Low perceived availability of social support was related to greater job dissatisfaction. Neither hostility nor social support was associated with perceptions of time pressure at work. These findings suggest that hostility and availability of social support may be an important pathway linking certain job characteristics to cardiovascular disease and other illnesses.

The relationship of patient-administered outcome assessments to quality of life and physician ratings: validity of the BASIS-32

The reliability and validity of a patient-administered version of the Behavior and Symptom Identification Scale (BASIS-32) was compared to the original interviewer-administered version. The construct validity of BASIS-32 subscales was assessed by examining their relationship with functional and satisfaction quality of life and physician ratings of functional and clinical status. A total of 361 acute psychiatric inpatients were given a self-administered BASIS-32, nurse-administered Lehman's Quality of Life Interview (QOLI), and Psychiatrist Assessment Form at admission and discharge. The original factor structure, internal consistency reliability, discriminant validity, and sensitivity to change were replicated. The patient-administered BASIS-32 is equally as reliable and valid as the interview. Construct validity analyses revealed that functional and satisfaction QOLI indices were moderately related to the BASIS-32 in the hypothesized directions. All satisfaction scales were associated with significantly less severity. Physician ratings were only mildly related to the subscales. The BASIS-32 used in outcome assessments with inpatients provides important and unique perspectives on functional and clinical status that are not tapped by clinician-rated assessments.

Longitudinal assessment of quality of life in acute psychiatric inpatients: reliability and validity

This study examined the reliability, validity, and responsiveness of Lehman's Quality of Life Interview (QOLI) as an outcome measure on 981 acutely ill psychiatric inpatients assessed longitudinally at admission and discharge. Patients were stratified into five diagnostic (DX) (depressed bipolar, depressed unipolar, schizophrenia, mania, and other diagnoses) and two substance use disorder (SA) strata (with and without concurrent substance abuse/dependence) based on DSM-III-R criteria. There was good replication of the factor structure, excellent internal consistency, overall and within DX and SA groups. Intercorrelations showed that the functional and satisfaction indices measure unique aspects of the quality of life. The construct consistency of the QOLI was dependent upon psychiatric diagnosis and life domain. Intercorrelations of functional and satisfaction indices for patients with depression were greater than for manic patients. We demonstrated strong consistency of construct validity for family and social relation domains, but not safety or leisure activities. Construct validity was shown to hold longitudinally. Analyses of DX and SA group differences on satisfaction and functional indices of the 8 life domains supported discriminative validity: Depressed patients reported the most dissatisfaction, followed by schizophrenic patients, and manic patients reported the greatest satisfaction in most life domains. Patients with concurrent substance abuse generally reported less satisfaction and lower quality of life than patients without a dual diagnosis. Examination of longitudinal changes in satisfaction indicated the QOLI is responsive to changes in global life, leisure activities, living situation, and social relations from hospital admission to discharge (an average of 2 weeks). This study supports the use of the QOLI as an outcome measure to assess quality of life in acutely ill hospitalized psychiatric patients.

Tamoxifen down-regulates CD36 messenger RNA levels in normal and neoplastic human breast tissues

Tamoxifen (TAM) exerts a long-term suppressive effect on human breast cancer cell proliferation. To determine whether the effects of TAM are mediated by specific gene activation or repression, normal and tumoral human breast tissues obtained before and during TAM treatment were analyzed by differential display technique. Total RNA for differential display analysis was obtained from breast tissues from two women with the diagnosis of estrogen receptor-positive stage II (T2N1M0) infiltrating ductal carcinoma, made by incisional biopsy, followed by modified radical mastectomy performed after a 30-day treatment with TAM (20 mg/day). One 202-bp cDNA band, AP5-1, was present in normal and tumoral biopsy samples, but was absent in breast tissue obtained during TAM treatment, and was confirmed by Northern hybridization, which showed a 2.7-kb band in both patients. The differentially expressed cDNA fragment showed 99% homology to Homo sapiens CD36 gene, a glycoprotein that acts as a receptor for the extracellular matrix proteins thrombospondin-1, collagen types I and IV, and oxidized low-density lipoprotein. These results indicate that the down-regulation of CD36 induced by TAM might represent alternative or additional mechanisms of action of this drug affecting the functions of thrombospondin-1, which is involved in hematogenous tumor spread, invasion and angiogenesis, and oxidized low-density lipoprotein, playing a role in inhibition of arteriosclerosis. The multiple functions affected by the down-regulation of CD36 by TAM warrant the need for additional studies.

A profile of medically serious suicide attempts

BACKGROUND

This study identified factors associated with medically serious suicide attempts (requiring medical hospitalization).

METHOD

Demographic information, current psychiatric mental state, suicide attempt and psychiatric history characteristics, and DSM-IV diagnoses were compared between 65 patients hospitalized for a medically serious suicide attempt (MSSA) and 32 patients seen in the emergency room for suicide attempt but not medically hospitalized (NMSSA).

RESULTS

Those with MSSAs had a higher rate of substance-induced mood disorder (but not substance abuse or dependence), while those with NMSSA had more attempts, more years since first attempt, and a higher rate of sexual and physical abuse, traumatic life events, borderline personality disorder, and bipolar disorder.

CONCLUSION

Substance-induced mood disorder is an important diagnosis in the evaluation of suicidal patients. The vulnerability of mood effects caused by substance abuse may lead to a more serious suicide attempt despite less extensive psychiatric problems. The most important early psychiatric intervention may be the immediate recognition and aggressive treatment of an individual's affective and substance use disorders.

Weight changes in caregivers of Alzheimer's care recipients: psychobehavioral predictors

Relationships of changes in body mass index (BMI) were examined with changes in psychobehavioral variables in spouse caregivers of individuals with Alzheimer's disease (n = 81) and matched spouses of controls (n = 86). Men caregivers had significantly greater BMI and obesity than men controls at both times. Over 15-18 months, women caregivers gained significantly more weight than did women controls. A trend for greater obesity occurred in women caregivers than in women controls at follow-up. Although weight gain was not related to psychobehavioral variables in controls, in men caregivers decreased perceived control and increased fat intake explained significant variance in weight gain. In women caregivers, increased anger control and increased calories explained weight gain. Such caregivers may be at risk for health problems.

Variations in plasma lipid concentration during examination stress

The effect of psychological stress on plasma lipids was studied in 40 law students (20 men and 20 women). Plasma cholesterol, triglyceride, and apolipoprotein concentrations were examined at the beginning of the quarter and during the week before final examinations. Cortisol, blood pressure, and heart rate, and self-reports of stress and workload were also measured to verify that examinations were associated with increased stress levels. Perceived stress, perceived workload, and cortisol increased before examinations. Low density lipoprotein cholesterol (LDL-C) increased 5.8 +/- 13.9 mg/dL, and apolipoprotein B (apo B) increased 2.9 +/- 4.0 mg/dL. High density lipoprotein cholesterol decreased in women only. These changes were not due to changes in dietary intake or indexes of plasma volume. However, changes in cortisol and changes in LDL-C and apo B were associated, suggesting a neuroendocrine component to the effects. These results suggest that episodic, stressful situations may lead to potentially atherogenic changes in lipid and lipoprotein concentrations.

Mammary gland neoplasia in long-term rodent studies

Breast cancer, the most frequent spontaneous malignancy diagnosed in women in the western world, is continuously increasing in incidence in industrialized nations. Although breast cancer develops in women as the result of a combination of external and endogenous factors such as exposure to ionizing radiation, diet, socioeconomic status, and endocrinologic, familial, or genetic factors, no specific etiologic agent(s) or the mechanisms responsible of the disease has been identified as yet. Thus, experimental models that exhibit the same complex interactions are needed for testing various mechanisms and for assessing the carcinogenic potential of given chemicals. Rodent mammary carcinomas represent such a model to a great extent because, in these species, mammary cancer is a multistep complex process that can be induced by either chemicals, radiation, viruses, or genetic factors. Long-term studies in rodent models have been particularly useful for dissecting the initiation, promotion, and progression steps of carcinogenesis. The susceptibility of the rodent mammary gland to develop neoplasms has made this organ a unique target for testing the carcinogenic potential of specific genotoxic chemicals and environmental agents. Mammary tumors induced by indirect- or direct-acting carcinogens such as 7, 12-dimethlbenz(a)anthracene or N-methyl-N-nitrosourea are, in general, hormone dependent adenocarcinomas whose incidence, number of tumors per animal, tumor latency, and tumor type are influenced by the age, reproductive history, and endocarinologic milieu of the host at the time of carcinogen exposure. Rodent models are informative in the absence of human data. They have provided valuable information on the dose and route of administration to be used and optimal host conditions for eliciting maximal tumorigenic response. Studies of the influence of normal gland development on the pathogenesis of chemically induced mammary carcinomas have clarified the role of differentiation in cancer initiation. Comparative studies with the development of the human breast and the pathogenesis of breast cancer have contributed to validate rodent-to-human extrapolations. However, it has not been definitively established what type of information is necessary for human risk assessment, whether currently toxicity testing methodologies are sufficient for fulfilling those needs, or whether treatment-induced tumorigenic responses in rodents are predictive of potential human risk. An alternative to the traditional bioassays are mechanism-based toxicology and molecular and cellular approaches, combined with comparative in vitro systems. These approaches might allow the rapid screen of chemicals for setting priorities for further studies to determine the dose-response relationship for chemical effects at low doses, to assess effects other than mutagenesis and/or tumorigenesis, or to establish qualitative and quantitative relationships of biomarkers to toxic effects. Until there is enough information on the predictive value of mechanism-based toxicology for risk assessment, this approach should be used in conjunction with and validated by the traditional in vivo long-term bioassays.

Cathepsins D, B, and L in transformed human breast epithelial cells

To investigate the regulation of lysosomal enzymes during carcinogenesis, we measured cathepsins (Cats) D, B, and L in MCF-10F, which is a human breast epithelial cell line, and cells evolved after treatment with carcinogen and transfected with c-Ha-ras oncogene. The clones used in this study, MCF-10FTras, D3, D3-1, and D3-1Tras, expressed no estrogen receptors and gradually increased invasive potential, while oncogene-transfected lines were also tumorigenic in SCID mice [16, 19]. Cats D, B, and L were determined in the cells and in cell media using enzyme-linked immunosorbent assay (ELISA), specific enzyme activity measurements, and immunocytochemistry. The major intra- and extracellular lysosomal proteinase in these cells was Cat D (30-180 pm/mg), followed by Cat B (2-10 pm/mg) and Cat L (1-5 pm/mg). An inverse relationship between intracellular Cat D levels and invasive potential of carcinogen-treated and c-Ha-ras oncogene-transfected cell lines was observed. No significant changes in extracellular concentration of Cat D precursor in this series of cell lines was observed. Intracellular levels of Cats B and L were unchanged or slightly lower in carcinogen-treated D3 and D3-1 cells, as well as in MCF-10FTras. On the other hand, in D3-1Tras cell line, evolving from c-Ha-ras transfected D3-1 line, 3.5 fold and 4.4 fold increases in Cat B and Cat L, respectively, but a 2 fold decrease in Cat D, were observed compared to the parental cell line. Immunocytochemical staining showed a granular, polarized perinuclear and cytoplasmic staining of cathepsins in all cell lines. Cysteine proteinases stained more frequently and more intensely in D3-1Tras compared to other lines, confirming the immunochemical assays. We hypothesize that several molecular events, caused by a carcinogen and an oncogene such as c-Ha-ras, are needed to increase Cat B and Cat L, but not Cat D, expression. Therefore, the cysteine and aspartic lysosomal proteinases are differentially expressed in the breast cell lines with more invasive phenotype.

Weight changes in caregivers of Alzheimer's care recipients: psychobehavioral predictors

Relationships of changes in body mass index (BMI) were examined with changes in psychobehavioral variables in spouse caregivers of individuals with Alzheimer's disease (n = 81) and matched spouses of controls (n = 86). Men caregivers had significantly greater BMI and obesity than men controls at both times. Over 15-18 months, women caregivers gained significantly more weight than did women controls. A trend for greater obesity occurred in women caregivers than in women controls at follow-up. Although weight gain was not related to psychobehavioral variables in controls, in men caregivers decreased perceived control and increased fat intake explained significant variance in weight gain. In women caregivers, increased anger control and increased calories explained weight gain. Such caregivers may be at risk for health problems.

Experimentally induced mammary tumors in rats

Among the multiple experimental animal models employed for analyzing the various aspects of mammary carcinogenesis, the induction of mammary tumors in rats by chemical carcinogens is one of the models most utilized. Experimentally-induced mammary tumors in rodents have proven to constitute useful tools for the study of the pathogenesis of cancer and of the molecular mechanisms involved in the initiation and progression of the neoplastic process. In vivo experimental animal models provide information not available in human populations; they are adequate for hazard identification, dose-response modeling, exposure assessment, and risk characterization, the four required steps for quantifying the estimated risk of cancer development associated with toxic chemical exposure. Using the DMBA rat mammary model, we have been able to demonstrate that the carcinogen acts on the intermediate cell of the terminal end bud (TEB), and that this structure is the one that evolves to intraductal proliferation, carcinoma in situ, and invasive carcinoma. There are several factors that regulate the susceptibility of the TEB; some of them are: a) topographic location of the mammary gland, b) age of the animal, and c) reproductive history. The understanding of the mechanisms that modulate tumorigenesis will further our knowledge and understanding in the prevention of the disease, as a result of the development of strategies for stopping the progression of the initiated cells.

Insect immunity: early events in the encapsulation process of parasitoid (Leptopilina boulardi) eggs in resistant and susceptible strains of Drosophila

Eggs of an immune suppressive strain (= virulent) of the parasitoid Leptopilina boulardi are encapsulated neither in resistant nor in susceptible strains of Drosophila melanogaster but are encapsulated in Drosophila yakuba. Eggs of a nonimmune suppressive strain (= avirulent) of the same parasitoid are encapsulated in a resistant strain of D. melanogaster and in D. yakuba but are not encapsulated in a susceptible strain of D. melanogaster. Egg chorion in the 2 parasitoid strains showed the same morphology and the same modifications after egg laying whatever the host strain. When a capsule is built, a small dotted dense layer was first spread on the chorion, followed by accumulation layers of cells (plasmatocytes and lamellocytes) and lastly necrosis of the inner haemocytes. The encapsulated eggs darken only at the time of necrosis of haemocytes. In susceptible hosts, neither the tiny dense layer nor haemocyte accumulation occurred. We concluded that (1) this tiny dense layer was present before the deposition of the first haemocytes, (2) inhibition of deposition of this dense layer was the initial event of the induced immunosuppression, (3) haemocytes other than lamellocytes were engaged in capsule formation, (4) the immunosuppressive factors did not target only the lamellocytes but also the plasmatocytes, (5) darkening of the encapsulated eggs was due to cell necrosis rather than to extracellular melanin deposition.

Influence of lobular development on breast epithelial-cell proliferation and steroid-hormone receptor content

The development of the breast evolves through progressive formation of lobular structures. Lobules type 1 (Lob 1) are the most undifferentiated ones; they evolve to lobules type 2 (Lob 2), and those to type 3 (Lob 3), in response to mainly ovarian hormones. Although estradiol and progesterone act by binding to their specific receptors, their content in these structures and how they correlate with proliferative activity are not known. Normal breast tissues obtained from 40 reduction mammoplasties performed for cosmetic reasons in women free of mammary pathology were processed for light microscopy. Paraffin sections were immunoreacted with antibodies against estrogen receptor (ER), progesterone receptor (PgR), and proliferating cell nuclear antigen (PCNA). The number of cells positively labeled with each one of the three antibodies was quantitated in Lob 1, 2 and 3, and expressed as a percentage of the total number of cells. ER were positive in Lob 1 (21%) and Lob 2 (10%), but negative in Lob 3. PgR were positive in Lob 1 (66%) and 2 (68%), decreasing in Lob 3 (31%). The highest percentage of PCNA positive cells were found in Lob 1 (40%), decreasing in Lob 2 (33%) and Lob 3 (11%). These results indicate that the normal breast epithelium contains ER and PgR, but the former is at higher levels in Lob 1, which also expresses greater proliferative activity as demonstrated with PCNA.

Psychiatric diagnoses and sexual victimization in women with chronic pelvic pain

The authors evaluated 100 women scheduled for diagnostic laparoscopy (50 for chronic pain, 50 for tubal ligation or infertility evaluation) using structured psychiatric, family history, and sexual trauma interviews. Laparoscopy reports were blindly rated by a gynecologist. Compared with the nonpain group, the women with chronic pelvic pain had significantly higher current and lifetime rates of psychiatric disorders, as well as childhood and adult sexual victimization. They reported significantly higher mean numbers of somatization symptoms, but no significant differences in objective laparoscopic findings. Psychiatric disorders and sexual victimization are common in women with chronic pelvic pain and should be considered in the evaluation and treatment of these patients.

Chronic neurologic sequelae to cholinesterase inhibition among agricultural pesticide applicators

To test the hypothesis that chronic neurologic sequelae are associated with cholinesterase depression short of frank organophosphate poisoning, we compared 45 male subjects who had a history of moderate cholinesterase inhibition with 90 male subjects who had neither past cholinesterase inhibition nor current pesticide exposure. Cholinesterase-inhibited subjects were defined as having had a history of (a) red blood cell cholinesterase at 70% or less of baseline or (b) plasma cholinesterase at 60% or less of baseline absent symptoms of frank poisoning. In the subject comparison evaluation, only 1 of 27 neurologic tests (i.e., serial digit performance) was significant statistically, but it was opposite of the direction hypothesized. In a companion study for which the same battery of neurologic tests and the same subjects were used, neurologic sequelae were related to high exposures among subjects who sought treatment for organophosphate poisoning. The data in the current study, in which the subjects experienced lower exposures short of frank poisoning, provide some evidence that preventing acute organophosphate poisoning also prevents neurologic sequelae.

The 13q- syndrome: the molecular definition of a critical deletion region in band 13q32

Patients with interstitial deletions of the long arm of chromosome 13 may have widely varying phenotypes. From cytogenetic analysis, we have postulated that there is a discrete region in 13q32 where deletion leads to a syndrome of severe malformations, including digital and brain anomalies. To test this hypothesis at the molecular level, we have studied the deletions in 17 patients; 5 had severe malformations, while the remaining 12 had only minor malformations. Our results indicate that the deletions in the severely affected patients all involve an overlapping region in q32, while the deletions in the mildly affected patients include some, but not all, of this overlapping region. Our findings are consistent with the hypothesis that the severely malformed 13q- phenotype results from the deletion of a critical region in 13q32. This region is presently defined as lying between D13S136 and D13S147 and is on the order of 1 Mb in size.

Identification of 4-(N,N-dipropylamino)benzaldehyde as a potent, reversible inhibitor of mouse and human class I aldehyde dehydrogenase

As the physiologic roles for the different classes of aldehyde dehydrogenase (ALDH) enzymes are elucidated, the identification of specific, reversible inhibitors becomes of great pharmacologic interest. Previous structure-function studies identified dialkylamino substituted benzaldehyde compounds as a novel class of reversible inhibitors of class I ALDH. To examine further structural requirements for inhibition, we tested a series of 4-(N,N-dialkylamino)benzaldehyde analogs as inhibitors of propanal oxidation by mouse liver and human erythrocyte class I ALDH. 4-(N,N-dipropylamino)benzaldehyde (DPAB) was identified as the most potent, reversible inhibitor of propanal oxidation by class I ALDH in spectrophotometric enzyme assays. In kinetic studies, DPAB showed mixed-type inhibition with respect to the aldehyde substrates propanal, phenylacetaldehyde, benzaldehyde, and aldophosphamide. DPAB exhibited uncompetitive inhibition with respect to the cofactor NAD. Inhibition constants (Ki) for DPAB, estimated from Dixon plots, were 10 nM (propanal) and 77 nM (phenylacetaldehyde) for mouse ALDH and 3 nM (propanal) and 70 nM (phenylacetaldehyde) for human ALDH. These Ki values are 100-fold lower than those reported for class I specific inhibitors. At low (< 1 microM) DPAB concentrations, inhibition of propanal and aldophosphamide oxidation was > 75%, whereas inhibition of benzaldehyde (32%) and phenylacetaldehyde (19%) oxidation was reduced markedly. These results indicate that DPAB exhibits potent, reversible inhibition of mouse and human class I ALDH. The degree of inhibition was highly dependent on the structure of the aldehyde substrate.

Genome scanning using endogenous LTR-like elements for rapid DNA-fingerprinting of breast-cancer and transformed human breast epithelial-cells

In the present work genomic DNAs from nine primary breast cancers and transformed human breast epithelial cell lines obtained by treatment of MCF 10F, a spontaneously immortalized human breast epithelial cell line, with benzo(a)pyrene (BP) or 7,12 dimethyl benz(a)anthracene (DMBA), were used for genomic scanning. The treatment of MCF 10F with BP gave rise to different clones designated BP1 and BP1E, the latter being a tumorigenic cell line. Treatment with DMBA gave rise to D3 and D3-1 clones. The clones D3-1 and BP1 have been transfected with the plasmid pH06T1 containing the mutated c-Ha-ras oncogene resulting in the D3-1Tras and BP1T-ras cell lines, that are highly tumorigenic in SCID mice. Genomic DNA are separately hybridized to two different probes representing different families of human endogenous retrovirus like sequences (RTLV-H and HERV-K LTR). The technique of genomic scanning allows the mapping of each tumor or cell line and comparison with its counterpart obtained from the adjacent normal tissue of the same patient or with the untreated MCF 10F cells. DNA changes such as deletions, amplifications and/or rearrangements were detected in 5 of the tumor pairs studied. We have identified genomic alterations that involved amplification of a 10 kb band in the transformed cell lines. The cell lines D3-1Tras and BP1T-ras show, in addition, the presence of a second band of 4.5 kb in size. A third band of 500 bp size was found in clones D3-1 and BP1E that have a more aggressive behavior in vitro than their precursors D3 and BP1 cells respectively. In conclusion the present report indicates that genomic scanning detects DNA aberrations in primary primary tumors and in human breast epithelial cells transformed with chemical carcinogens and/or oncogene transfection that are not present in their normal counterpart. These results further indicate that detection of endogenous retrovirus elements may help in genome mapping and can be a useful tool for detecting genomic changes in the preliminary screening of DNA extracted from primary breast cancer and transformed cells.

Life events as correlates of burden in spouse caregivers of persons with Alzheimer's disease

The first goal of this study was to examine the occurrence and appraised distress of 20 stressful life events in 175 spouse caregivers (mean age = 68.6) of persons with Alzheimer's disease and 92 age- and gender-matched controls (mean age = 68.5). The second goal was to determine whether, in the caregivers, life stressors were related to burden after controlling for caregiver age, gender, satisfaction with social supports, and care-recipient cognitive and activities of daily living functioning. Caregivers and controls had similar occurrences and appraisals for all but 3 events, which occurred more frequently in caregivers (i.e., "changes in your spouse's health," "changes in your relationship with your spouse," and "changes in the way you friends and family treat you (social relations)"). Only "changes in finances" was appraised as more distressing by caregivers. Six events explained burden in the regressions: "victim of crime," "age discrimination," "serious family arguments (not including spouse)," "change in caregiver's health," "trouble with Medicaid/Medicare or Social Security," and "move to retirement home (associated with less burden)." Age discrimination was related to burden only for the caregivers of the most impaired care recipients. Also, caregivers who experienced health problems and who had been victims of crimes were the most burdened. Caregivers are not immune to problems experienced by older adults, and these problems may exacerbate caregiver burden. Clinicians should consider the overall context of a caregiver's life when evaluating burden.