The evolution of a faculty development program in an academic psychiatry department

Issues affecting faculty development in academic psychiatry departments have taken on a special urgency as a result of declining financial support from government sources and the emerging consequences of this country's fast-evolving health care system. Junior faculty need usable information on how to succeed in academia. Available information from the senior administration ("top-dawn") often lacks the immediacy and accessibility of grassroots ("bottom-up") strategies that more experienced junior colleagues have discovered. Over the past 2 years, the Department of Psychiatry at the University of Texas-Houston Health Science Center has focused attention on codifying these grassroots efforts and on integrating them with formal departmental initiatives. The authors describe how general recommendations formulated by departmental planning committees and a Continuous Quality Improvement Team on faculty development were developed into a formal, concrete program f or career development. (Academic Psychiatry 1997; 21:107-115).

Interspecific variation at the Y-linked RPS4Y locus in hominoids: implications for phylogeny

Within- and between-species variation in restriction endonuclease recognition sites was examined at the Y-linked RPS4Y locus of six hominoid species: human (Homo sapiens), gorilla (Gorilla gorilla), chimpanzee (Pan troglodytes), bonobo (Pan paniscus), orangutan (Pongo pygmaeus), and gibbon (Hylobates lar). RPS4Y is an expressed gene that maps to the non-recombining region of the Y chromosome. An approximately 1,490 base pair fragment of the RPS4Y gene, including all of intron 3, was amplified by PCR from DNA extracted from each of the six species. Forty-seven restriction sites were identified on the six-species composite map derived from double-digest restriction analyses of the amplified fragment. As expected, maximum parsimony analysis indicated that chimpanzee and bonobo are the two most closely related living hominoids. The same analysis suggested that the closest living relative of Homo is Gorilla, not Pan, although support for this relationship was relatively weak. These results disagree with recently published phylogenies based on analyses of mtDNA sequences (Horai et al. [1995] Proc. Natl. Acad. Sci. U.S.A. 88:7401-7404) and the Y-linked ZFY locus (Dorit et al. [1995] Science 268:1183-1185). A combined data set derived from three distinct Y-linked loci-RPS4Y, SRY, and ZFY-was also analyzed. The maximum parsimony topology for the combined data provided only weak support for a shared common ancestor for Homo and Pan subsequent to divergence from the Gorilla lineage. Taken together, the data from the Y chromosome do not provide unequivocal support for any single, dichotomously branching species tree linking Homo, Pan, and Gorilla.

A new DNA marker, U15557, is linked to protease inhibitor and adenylate kinase-1 in the laboratory opossum, Monodelphis domestica

A 323-bp DNA fragment (U15557) was isolated, cloned, and sequenced after polymerase chain reaction (PCR) amplification from Monodelphis domestica genomic DNA. A HindIII restriction fragment length polymorphism was identified in this species using the U15557 PCR, fragment as a hybridization probe. DNA samples exhibited either a 6.4 kb band, a 7.2 kb band, or both bands simultaneously. Behaviour of these two variants in family studies was consistent with codominant autosomal inheritance. Linkage between this marker and the loci encoding protease inhibitor (PI) and adenylate kinase 1 (AK1) was found in M. domestica.

Characterization of the DiFi rectal carcinoma cell line derived from a familial adenomatous polyposis patient

The DiFi human colorectal cancer cell line was recently established from a familial adenomatous polyposis patient with extracolonic features characteristic of the Gardner syndrome. These cells have now been propagated for 150 passages in standard culture media and vessels without feeder layers or collagen coatings. They retain features of colonic epithelial cells such as surface microvilli, secretory vesicles, and desmosomes. Cytosol of DiFi cells contains a high level (502 U/mg protein) of the mucin CA 19-9. In addition, DiFi cells produce carcinoembryonic antigen, and induce tumors in athymic mice. Cytoskeleton analysis of DiFi cells by fluorescence microscopy showed a pronounced disorganization of actin cable structure. The isozyme genetic signature of DiFi cells is unique (0.01 probability of finding the same genetic signature in a different cell line), differs from that of HeLa cells, and has expressional features seen in other colorectal cell lines. The DiFi cell karyotype is tetraploid, contains many marker chromosomes, and shows numerous episomal particles. Two copies of chromosome 18 were absent, and only a single normal chromosome 17 was found. This parallels detection of allelic losses from DiFi cell DNA at loci on chromosomes 17p and 18 using molecular (cDNA) probes. DiFi cells clearly express transcripts for the c-myc proto-oncogene, the c-myb proto-oncogene, and the p53 tumor suppressor gene. Transforming growth factor beta inhibits DiFi cell growth in soft agar and suppresses c-myc expression in these cells. The value of this cell line in the study of genetic alterations in colorectal cancer is discussed.

Gender differences and the interpretation of genetic instability in Alzheimer's disease

The neuronal degeneration and death which characterize Alzheimer's disease (AD) may stem from a constitutive genetic instability related to DNA repair deficits. To test this hypothesis, we treated peripheral blood lymphocytes from persons with AD, age-matched controls, and young controls with two drugs that induce chromosome breakage. Bleomycin, a radiomimetic antineoplastic drug, causes single- and double-stranded DNA breaks through the generation of activated oxygen radicals. Methyl methane-sulfonate (MMS) is a monofunctional alkylating agent that binds covalently to DNA. Cells were grown in culture for 72 h, with drug treatments for 4 h (bleomycin) or 24 h (MMS) prior to harvest. Fifty cells per subject per drug were scored for chromosome breakage. Breakage rates for both drugs in AD women were significantly higher than those in age-matched control women. This was not the case in men, due to the very high induced breakage rates seen in the age-matched normal control men. Because the induced breakage rates in AD women and AD men are equivalent, it seems likely that an independent factor may be contributing to genetic instability in the normal control men. Our findings indicate that the interpretation of the response of AD lymphocyte chromosomes to DNA-damaging chemicals can be strongly confounded by the effects of gender ratio in the control population sampled. These findings have important implications for the design of future studies of Alzheimer's disease, as well as for the assessment of health risks in unaffected elderly populations.

Mitosis-arresting effects of cigarette smoke condensate on human lymphoid cell lines

Whole-smoke condensates from the University of Kentucky reference cigarettes induced partial mitotic arrest in 4 human lymphoid cell lines. Treatment of cells for 3 h with 100 and 200 micrograms of cigarette-smoke condensate/ml of culture medium increased the frequency of metaphases and decreased the proportion of anaphases in the treated cell populations. Cytoskeletal studies using antitubulin immunofluorescence techniques and transmission electron microscopic studies demonstrated that in early stages of mitosis the formation of aster and the separation of centrosomes in condensate-treated cells were comparable to those of untreated control cells, but the poleward migration of centrosomes was inhibited. Arrested metaphases revealed two centrosomes surrounded by aggregated chromosomes in the center of each cell but the structure of the centrioles, microtubules and the kinetochores appeared normal. The results demonstrate the presence of antimitotic compounds in the tobacco-smoke condensate.

Cytogenetic characterization of 20 lymphoblastoid lines derived from human individuals differing in bleomycin sensitivity

Forty lymphoblastoid (lymphoid) lines were established from 42 volunteer blood donors, including healthy individuals and patients with head and neck carcinomas. Each peripheral blood sample was split into two portions, one for the establishment of a lymphoid line and the other for short-term culture, which was used to estimate bleomycin sensitivity by cytogenetic procedures. Twenty lymphoid lines were selected at random to compare bleomycin sensitivity with data obtained from short-term lymphocyte cultures. In each set, bleomycin sensitivity of lymphoid cells was similar to that of the lymphocytes. The lymphoid lines, which can be propagated for an unlimited supply of relatively homogeneous cellular material, will be useful for a variety of future investigations.

Sensitivity to genotoxic effects of bleomycin in humans: possible relationship to environmental carcinogenesis

Responses to the genotoxic effect of bleomycin in lymphocytes of blood cultures, expressed as the average number of chromatid breaks per cell (b/c), varied from less than 0.20 to more than 2.00 in 335 normal individuals. More than 11% of the subjects tested showed a b/c rate above 1.00 and more than 22% showed a b/c rate above 0.80. These individuals are considered sensitive to this radiomimetic drug. The distributional profile of bleomycin responses of the control individuals appears to be representative of the normal human population. In patients with cancers of the colon (83), upper aerodigestive tract (head/neck) (77), and lung (71), the frequencies of subjects in the hypersensitive class were found to be between 40 and 50%, and the response profiles were distinctly different from those of the control population. On the other hand, in a group of elderly cigarette smokers, who exhibited no symptoms of lung cancer, the bleomycin sensitivity profile was significantly skewed toward the more resistant stratum, with only one hypersensitive case among 56 individuals tested (1.78%). The sensitivity profile of patients with breast cancer (82) was similar to that of the control population. Our data suggest that: (1) mutagen sensitivity may play an important role in carcinogenesis of organs and tissues that have direct contact with the external environment (respiratory, digestive, and integumentary systems); (2) it appears to have no significant influence on carcinogenesis of tissues that are not directly exposed to the environment (e.g., breast, brain); and (3) it also has little impact on carcinogenesis in individuals with a hereditary predisposition to cancer (e.g., retinoblastoma, Gardner's syndrome). Development of more effective and precise test systems for carcinogen sensitivity is highly desirable for identification of persons at risk.

Kinetochore size variation in mammalian chromosomes: an image analysis study with evolutionary implications

The kinetochore, a proteinaceous plate that is the site for attachment of spindle microtubules to the metaphase chromosome, can be visualized using anti-kinetochore indirect immunofluorescence. We have used computer-assisted image analysis to measure the variation of kinetochore surface areas, as reflected by immunofluorescence areas, in cell lines derived from rat kangaroo, Chinese hamster and common rat, to determine if our size estimates correlate well with those obtained using measurements from electron micrographs. In addition, we used male and female human fibroblast cell lines, as well as a transformed human female cell line as well as a transformed human female cell line (HeLa), to examine kinetochore size variation among cells, between sexes, and between cell lines. We found that our system gave reproducible estimates of kinetochore size, and that these sizes correlated very well (r = 0.95) with the electron micrograph measurements. In examining variation within humans, we observed measurable differences between cell lines. Despite this difference, all the human lines had size distributions that were leptokurtotic and positively skewed. The fact that very few chromosomes exhibited areas smaller than the mode gives support to the idea that mammalian chromosomes may require a specific, minimum amount of kinetochore material in order to maintain stable attachment to the mitotic spindle. On the other hand, the positive skewness seems to indicate that larger kinetochores, possibly the result of events such as Robertsonian fusions, are fully functional. The retention of this plasticity may allow the chromosomes to maintain an evolutionary adaptability that might otherwise be lost.

Nuclear and manchette development in spermatids of normal and azh/azh mutant mice

Germinal cells or nuclei with attached cytoskeletal elements were prepared from the testes and epididymides of normal mice and mice homozygous for the recessive azh mutation, which results in abnormal sperm heads. To make observations, we utilized phase-contrast microscopy, immunofluorescence microscopy with antitubulin antibodies, and a direct-view stereo electron microscope system developed by A. Cole. Sperm nuclei, tails, manchettes, and other cytoskeletal structures were studied at various stages of development. The tail architectures were similar in the normal and mutant forms, but the shape of the heads at the attachment regions were markedly different. Normal sperm nuclei were very flat, whereas the posterior regions of mutant nuclei were tapered cylinders. The manchette, an organized microtubular structure that girdles the posterior region of the spermatid nucleus, differed in size and configuration between normal and mutant forms. In normal midstage spermatids, the manchette microtubules extended outward at a 45 degree angle from the long axis of the flattened head, whereas in mutant spermatids, the microtubules formed tapered cylinders around the long axis of the caudal part of the nucleus. Radical differences in head shapes between normal and mutant sperm could be related, in part, to the manner in which manchettes formed and matured on the spermatids.

A technique for simultaneous antikinetochore immunofluorescence staining and Q-banding in chromosomes from human lymphocytes

Antikinetochore immunofluorescence staining has been used in several studies to determine whether a second kinetochore is present, active, or both, in multicentric chromosomes. All of these studies have used tissue culture cells, and contended with the problem of obtaining well spread, banded metaphase chromosomes without affecting the kinetochore staining. We have adapted hypotonic, centrifugation and chromosome staining techniques to obtain simultaneous Q-banding and bright kinetochore staining of chromosomes from human lymphocytes.

Size variation in kinetochores of human chromosomes

Aneuploidy, the loss or gain of chromosomes from cells, is likely in many cases to involve the kinetochore, the site of attachment of spindle microtubules. We analyzed human fibroblast cells with antikinetochore-antibody indirect immunofluorescence, and noted an apparent heterogeneity in the sizes of kinetochores among different chromosomes. The Y chromosome in particular always showed minute kinetochores, an observation which was quantified and substantiated using computer-assisted image analysis. This finding, combined with literature reports about in vivo and in vitro involvement of the Y chromosome in aneuploidy, was used to frame a novel hypothesis about the generation of chromosome imbalance.

Mitotic inhibition and aneuploidy induction by naturally occurring and synthetic estrogens in Chinese hamster cells in vitro

We used a predominantly diploid Chinese hamster cell line to test a number of naturally occurring and synthetic estrogens for their ability to arrest cells at metaphase, their potential for allowing anaphase recovery, and their capability of inducing aneuploid progeny. The chemicals employed included diethylstilbestrol, dienestrol, hexestrol, beta-estradiol, ethynylestradiol and estriol. We also tested progesterone, estrone and testosterone in this regard. Only estrogens and their synthetic analogs caused mitotic arrest and aneuploidy, while progesterone, estrone and testosterone did not cause mitotic disturbances. Among the estrogens, DES was the most effective arrestant on a comparative molar basis, whereas dienestrol was most potent over a wide range of concentrations. Estriol was the least potent as an arrestant but was an effective inducer of aneuploidy. The addition of a metabolic activator (S9) did not alter the ability of DES to arrest mitosis. Following the removal of the drugs, cells were able to quickly reorganize a spindle apparatus and enter anaphase. Diethylstilbestrol, dienestrol, hexestrol, beta-estradiol, ethynylestradiol and estriol caused significant increase in aneuploidy within a narrow range of high concentrations in recovering cell populations. Aneuploidy was induced in a non-random manner. Immunofluorescence studies with anti-tubulin antibody indicate that estrogens may have a mechanism of mitotic arrest similar to that of colchicine and colcemid, viz inhibiting the polymerization of tubulin to form microtubules. These data suggest that the interaction between estrogens and microtubules may mediate the induction of aneuploidy in somatic cells. Aneuploidy induction by DES and similar compounds may be related to their carcinogenic potential.

Differential mutagen susceptibility in cultured lymphocytes of normal individuals and cancer patients

When cultured human lymphocytes were treated with a radiomimetic chemical bleomycin, metaphase chromosomes from different individuals exhibited a wide spectrum of responses in terms of number of chromatid lesions. This variability is interpreted as the result of capability for DNA repair. Among 100 healthy, normal individuals tested, nearly 60% showed a mean breaks per cell rate in the range of 0.20-0.60, whereas, only 12% showed breaks per cell rates above 1.00. On the other hand, among 75 cancer patients, 60% showed breaks per cell rates above 1.00. It is believed that differential responses to a mutagen have genetic implications. Individuals with DNA repair deficiencies may be more susceptible to carcinogens and, therefore, are more susceptible to neoplastic induction.

Fluorescence microscopy with antisera against specific cellular structure: double photography method for cell identification in populations of multiple cell types

Immunofluorescent staining techniques using antitubulin antibody have been difficult to apply to meiotic tissue (testis) because of the large number of cell types present. Such techniques customarily use a fluorescent dye to counterstain nuclei, and this counterstain is hard to distinguish because of the fluorescence of the antitubulin. By counterstaining with dilute hematoxylin, we can photograph the same field using UV and then conventional illumination. This double photography allows us to identify precisely the many types of cells present, and it will be a useful tool for reexamining the staging of spermatogenesis.

Antitubulin immunofluorescence studies of spermatogenesis in the mouse

Immunofluorescence staining techniques, using antibodies against tubulin molecules, have been successfully used with somatic tissue culture cells. Their application to gametogenesis, however, has been more difficult, largely due to the presence of many different cell types in such a preparation. We have circumvented this problem by counterstaining with dilute hematoxylin, a biological stain that shows excellent cellular morphology without affecting the fluorescence of the antibody. We can then photograph the same field, using either ultraviolet light or conventional bright-field microscopy. Using this approach, we have examined the entire progression of murine spermatogenesis, from spermatogonial cells through mature spermatozoa. This technique has been especially valuable in the visualization of the manchette, and has allowed a reassessment of the staging of spermatid development. In the future, the antibody/hematoxylin double-staining approach will allow a more informative examination of the effects of tubulin-active mitotic poisons on mammalian germline cells.

Bleomycin-induced chromosome damage in lymphocytes of medullary thyroid carcinoma patients and their family members

Lymphocyte cultures were treated with bleomycin to see if individuals who exhibit a high rate of spontaneous chromosome breakage also show an exaggerated response to clastogenic agents. For our experimental group, we used patients with medullary thyroid carcinoma and their immediate family members. Lymphocytes from these individuals tend to show high rates of spontaneous chromosome breakage. The average bleomycin-induced breakage rate in this group was significantly higher than that found in the normal controls. In the control group, the distribution of breakage rates was bimodal, with mean values of 0.68 breaks per cell in one group, and 1.84 breaks/cell in the other. The high rate of induced breakage shown by phenotypically normal subjects may mean that these individuals have a potential sensitivity to mutagen exposure.

Restitution of chromatid and isochromatid breaks induced in the G2 phase by actinomycin D

Although actinomycin D (AMD) appears to cause chromatid breakage, it has been suggested that it merely weakens the chromosomal proteins, causing breaks to occur during the stress of fixation. To determine if this was true, we examined lymphocytes treated with AMD (3.5 micrograms/ml) for 90 min prior to harvesting for evidence of DNA repair. Besides single chromatid breaks, we observed a high frequency of chromatid exchange figures (translocations, inversions, rings) and closed isochromatid breaks, indicating that a type of DNA repair leading to chromosome aberration had occurred prior to cell fixation. Therefore, at least some of the breaks observed after AMD treatment in G2 represented true DNA damage and were not merely artifacts of fixation.

The nonpolar egg wax lipids of the cattle tick, Boophilus microplus (canestrini)

About 40% of the lipids of the egg wax of Boophilus microplus are nonpolar and comprise hydrocarbons (10%) and wax esters (90%). The hydrocarbon fraction is 87% unbranched alkanes, the major components being n-nonadecane (10.8%), n-eicosane (12.1%), and n-heneicosane (9.8%). This fraction also contains 2,4,6-cholestatriene (4.6%). The majority of the acids are branched (77%) the major components being 12-methyl-tetradecanoic (16.3%) and branched hexadecanoic acids (28%). The major alcohols are n26:0 (20.4%), n28:0 (47.3%) and n36:0 (18.2%). A steroid possibly 2,4,6-cholestatrien-25-ol (5.6%), is also present.

The accumulation and utilization of food reserves by the adult female cattle tick, Boophilus microplus (Canestrini)

Changes in water content and cuticle weight during adult parasitic life of B. microplus, and the manner in which water and dry matter are utilized for egg production, suggest that capacity for cuticle growth, and thus for distension, determines water content in relation to body weight, and this in turn fecundity of the female. Figures for Australian B. microplus are compared with those for this species in Japan, where higher average engorged weight, cuticle weight, percentage water content, and numbers of eggs laid have been reported.

The Production of Cuticle Wax by Engorged Females of the Cattle Tick, Boophilus Microplus (Canestrini)

Weight of cuticle wax produced by the engorged female cattle tick, Boophihis microplus (Canestrini), and loss of body weight during egg production, have been measured at intervals between dropping from the host and completion of egg laying.

2. Wax increased in weight from 20 to 63 µg. per tick between 6 and 222 hr. after dropping. This increase took place in two stages, with the steepest increase between 6 and 54 hr. and a smaller increase between 78 and 150 hr.

3. Body weight fell by 71% between 6 and 222 hr. The rate of loss was highest during early egg production, reaching its peak on the fourth day after dropping.

4. The most rapid increase in weight of cuticle wax took place before the onset of oviposition. During peak egg production the increase was slight. During the decline of egg production cuticle wax increased slowly in weight.

5. The possible physiological function of the increased wax secretion, and its relation to general metabolic activity, are discussed.