Biomedical subjects

C J Chang

Publications and source records attributed to C J Chang.

At least 145 records · Page 8Linked to original sources

PubMed1996

Major depressive disorder in Taiwan defined by the Chinese diagnostic Interview Schedule.

The lifetime prevalence rate of major depressive disorder (MDD), as defined by the Chinese Diagnostic Interview Schedule, is 1.14% in Taiwan. This is significantly lower than the lifetime prevalence rates reported in Western studies and similar to other studies in the Chinese population using similar methods for assessing cases of MDD. Epidemiological data from 136 MDD cases were analyzed to provide possible explanations for this difference in lifetime prevalence rates. The low rate of broken families in Chinese culture, low comorbidity rate, and older age of onset of MDD may suggest a reality of low lifetime prevalence rates of MDD in Taiwan.

Adult↗

PubMed1996

Q-switched ruby laser treatment of oculodermal melanosis (nevus of Ota).

The Q-switched ruby laser at 694 nm, a wavelength well absorbed by melanin relative to other optically absorbing structures in skin, causes highly selective destruction of pigment-laden cells. In addition, the 20- to 40-ns pulse duration produced by this laser approximates the thermal relaxation time for the melanosomes, thereby confining the energy to the target. The Q-switched ruby laser was used to treat 47 patients (11 males and 36 females) with nevus of Ota during the period December 1991 to 1994. The involved facial area ranged from 3 x 3 cm2 to 20 x 20 cm2. The energy fluence used varied from 8 to 10 J/cm2, and the number of treatments ranged from 1 to 8 (mean 3.4). The results were graded on the basis of cleaning and fading as follows: poor (0 to 25 percent), fair (26 to 50 percent), good (51 to 75 percent), and excellent (76 to 100 percent). The mean follow-up period was 15 months. Poor and/or fair results were found in 8 patients who received one treatment and 7 patients who had two treatments. Good results were seen in 1 patient who had two treatments, 7 patients who received three treatments, and 3 patients who had four treatments. Twenty-one patients had excellent results after three or more treatments of the whole lesion. In conclusion, this laser system produces clinically significant fading of nevus of Ota in patients without complications such as hypertrophic scarring or permanent changes in the normal skin pigmentation.

Adolescent↗

PubMed1996

Genomic diversity and differentiation among phytoplasma strains in 16S rRNA groups I (aster yellows and related phytoplasmas) and III (X-disease and related phytoplasmas).

Conserved gene sequences, including 16S rRNA and ribosomal protein gene sequences, were used to evaluate genetic variations in phytoplasma strains belonging to 16S rRNA groups I (aster yellows and related phytoplasmas) and III (X-disease and related phytoplasmas). We used PCR to amplify the sequences of the 16S ribosomal DNA and a segment of the ribosomal protein gene operon (encoding the 3' region of rps19, all of rp122, and rps3) from diverse phytoplasma group I and III strains. Additional chromosomal gene sequences of group I strains were also amplified. The PCR products amplified from members of each group of phytoplasmas were compared by performing restriction fragment length polymorphism (RFLP) analyses. On the basis of the RFLP patterns observed and similarity coefficients derived from combined RFLP analyses, the phytoplasma strains belonging to groups I and III were placed in distinct 16S rRNA, ribosomal protein, and 16S rRNA-ribosomal protein subgroups. Analyses of two or more conserved gene sequences revealed that members of the two groups were more diverse than previously thought. Subgroup differentiation on the basis of our combined analyses of 16S rRNA and ribosomal protein gene sequences seemed to adequately reflect the levels of chromosomal homology determined by DNA-DNA hybridization assays. On the basis of unique RFLP profiles, we identified new, previously unclassified group I phytoplasma strains, including the organisms that are associated with Ipomoea obscura witches'-broom [subgroup 16SrI-F(rr-rp)], maize bushy stunt [subgroup 16SrI-I(rr-rp)], and Mexican periwinkle virescence [subgroup 16SrI-J(rr-rp)], and new, previously unclassified group III phytoplasma strains, including the organism that is associated with pecan bunch [subgroup 16SrIII-H(rr-rp)]. On the basis of the results of our analyses of 16S rRNA and ribosomal protein conserved gene sequences, we recognized 9 group I subgroups and eight group III subgroups. We propose that phytoplasma strains belonging to each group I and III subgroup should be distinguished taxonomically at a level equivalent to the subspecies level.

Base Sequence↗

PubMed1996

Transcriptional induction of the alpha-1 acid glycoprotein (AGP) gene by synergistic interaction of two alternative activator forms of AGP/enhancer-binding protein (C/EBP beta) and NF-kappaB or Nopp140.

Alpha-1 acid glycoprotein/enhancer-binding protein (AGP/EBP) (C/EBPbeta), a member of the C/EBP family, is one of the key transcription factors responsible for the induction of a wide array of genes, some of which are expressed during the acute-phase response. Both activator and repressor were shown to be encoded by the intronless agp/ebp or its rat and human homologs, which contain a common bZIP domain at their C-terminal regions. Expression of the AGP gene (agp) is regulated by AGP/EBP in liver during the acute-phase response. However, the molecular mechanism for this regulation is poorly understood. The experiments reported here demonstrate that two activator forms of AGP/EBP, one of which has an additional 21 amino acids at its N-terminal region, are expressed in liver as well as in a number of cell lines. We have also demonstrated that NF-kappaB and a phosphoprotein of 140 kDa, Nopp140, interact with different AGP/EBP activators synergistically, which results in induction of the agp gene in an AGP/EBP-binding-motif-dependent manner. Furthermore, extracellular stimuli that are known to be NF-kappaB inducers can selectively activate the agp gene by cooperating with one of the two activator forms of AGP/EBP. The physiological significance of differential regulation for the function of two activator forms of AGP/EBP through selective interaction with different transcription factors is discussed.

Alternative Splicing↗

PubMed1996

Disturbances in the distribution of neurotransmitters in the rat retina after ischemia.

PURPOSE: Disturbances in neurotransmitter distribution have been observed in cerebral ischemia in the pathophysiologic process of excitotoxicity. The goal of this study was to examine the effect of pressure-induced retinal ischemia on the distribution of the retinal neurotransmitters glutamate and gamma-aminobutyric acid (GABA) within the rat retina. METHODS: Animals were subjected to increased intraocular pressure of 110 mm Hg for 45 min using an intracameral hydrostatic pressure device. The distribution of glutamate and GABA immunoreactivity (IR) was determined at 0, 2, 4, 8 and 24 hrs after reperfusion by immunogold with silver intensification. RESULTS: Three phases of neurotransmitter immunoreactivity patterns were discernible following retinal ischemia. Immediately following reperfusion (Phase I), a shift of GABA-IR from inner retinal neurons to the Mueller cells and their processes was noted. In contrast, despite marked decreases in neuronal glutamate-IR, a less pronounced shift of glutamate-IR to the Muller cells was simultaneously noted. This shift of neurotransmitter IR to the Mueller cells was transient with the gradual reappearance of IR within the inner retinal neurons noted 2-8 hrs after reperfusion (Phase II). Phase III began at 8 hrs after reperfusion with progressive loss of GABA-IR noted in the inner retina; by 24 hrs, secondary loss of inner retinal glutamate-IR was evident with corresponding dropout and pyknosis of inner retinal neurons apparent. CONCLUSIONS: The distribution of glutamate-IR and GABA-IR was significantly altered following retinal ischemia. The alteration noted in Phase I suggested that the regulation of glutamate by Mueller cells was disrupted by this ischemic insult leading to glutamate excitotoxicity, and delayed neuronal cell degeneration as evidenced by the subsequent loss of inner retinal immunoreactivity in Phase III.

Animals↗

PubMed1996

A comparison of continuous versus intermittent light exposure on apoptosis.

PURPOSE: We recently found that continuous light exposure at a moderate intensity triggered apoptosis of photoreceptor cells. Since intermittent light exposure is known to cause more severe retinal damage than is continuous light exposure, we sought to determine if intermittent light exposure also triggered apoptosis of photoreceptor cells. METHODS: Lewis albino rats were reared, for 2 weeks, in cyclic light and dark adapted for 24 hr before light exposure. Rats were exposed to intermittent light or continuous light for 6 or 9 hr, respectively. Light-exposed rats were killed by lethal injection at three timepoints: immediately after light exposure, after 6 hr of dark recovery following light exposure and after 24 hr of dark recovery following light exposure. Retinal damage after light exposure was evaluated by morphology, morphometry, the terminal transferase-mediated biotin dUTP nick end labeling (TUNEL) technique for identification of nicked/cleaved nuclear DNA and agarose gel electrophoresis of retinal DNA. RESULTS: Evaluation of morphology confirmed that intermittent light exposure caused more photoreceptor cell damage than did continuous light exposure of the same duration and intensity. The TUNEL technique showed that photoreceptor nuclei contained nicked or cleaved DNA after either intermittent or continuous light exposure, although more TUNEL-positive nuclei were observed after intermittent exposure. Agarose gel electrophoresis of retinal DNA showed internucleosomal DNA fragmentation, which is associated with apoptosis in samples from intermittent light exposure. CONCLUSIONS: These data demonstrated that intermittent light exposure triggered apoptosis in more photoreceptor cells than did continuous light exposure of the same intensity and duration.

Animals↗

PubMed1996

Analysis of outpatient referral failures.

BACKGROUND: The purpose of this study was to measure the rate at which outpatient referrals failed to be completed, and to analyze predisposing factors for referral failure in the family practice of a medical center. METHODS: Structured questionnaires were completed by referring physicians whenever a referral was initiated during a 4-month period. On the 60th day after referral, an investigator contacted the referred patients by telephone and also reviewed their charts. RESULTS: During the 4-month period, 604 referrals (2.28%) were made from 26,476 encounters at the study clinic. Sixty-four patients (10.6%) failed to complete the referral processes within a 60-day period. The most frequent reasons for referral failure were administrative factors, ie, too long a wait (59.4%), and the patient's belief that the referral was not necessary (23.4%). The physician's or patients's opinion of referral necessity, the level of experience of the referring physician, and the method of contact with the consultant all had significant influence on the referral failure rate. CONCLUSIONS: Improving administrative efficiency, enhancing communication between physicians and between physicians and patients, assessing the willingness of patients to follow through on a referral, and the method used to initiate the referral by the physician may reduce the referral failure rate.

Adolescent↗

PubMed1996

Hypercholesterolemia in undiagnosed non-insulin-dependent diabetes in southern Taiwan.

The purpose of this study was to investigate the prevalence of hypercholesterolemia among subjects having diabetes and glucose intolerance, according to the guidelines of the National Cholesterol Education Program (Adult Treatment Panel II, ATP II). This survey consisted of 2090 subjects (856 men, 1234 women) aged 30 years or more from the Sun-Ming district of Kaohsiung city. Glucose tolerance status was ascertained for both medical history and a 75-g oral glucose tolerance test according to World Health Organization criteria. Frequency of elevated total cholesterol in female subjects with abnormal glucose tolerance is significantly greater than in those with normal glucose tolerance (NGT). However, only male subjects with undiagnosed NIDDM (UDDM) had a statistically higher rate of hypercholesterolemia than those with NGT. Of UDDM individuals, 68% have total cholesterol level between 200 and 239 mg/dl and two or more risk factors for heart disease or evidence of coronary heart disease or total cholesterol > or = 240 mg/dl or high-density lipoprotein (HDL) cholesterol < or = 35 mg/dl. Such individuals should have their low-density lipoprotein (LDL) cholesterol measured. Using the ATP II, LDL cholesterol levels warranting dietary treatment for hypercholesterolemia would be expected in 76% of UDDM. Due to the high prevalence of coronary heart disease in diabetic patients, investigation of blood lipid levels and coronary heart disease risk factors should be routine in these patients, and treatment strategies should include management of lipid disorders and the many other risk factors. A high frequency of dyslipidemia was found among UDDM group in our study. Early detection of undiagnosed diabetic patients is also very important in decreasing the prevalence of coronary heart disease.

Adult↗

PubMed1996

Photic injury triggers apoptosis of photoreceptor cells.

Apoptosis, a highly regulated and energy-dependent process of cell death, plays an important part in normal tissue development. Its role in pathological conditions may vary. Earlier morphologic studies suggest that apoptosis may be an important mechanism in light-induced photoreceptor degeneration. In this study, we determined if photic exposure triggers apoptosis in photoreceptor cells in an established model of photoreceptor degeneration by light exposure. Twenty eight Lewis albino rats were divided into seven groups of 4 animals each: one group served as the unexposed control; and the other groups were exposed continuously to green fluorescent light (320 foot-candles) for 3, 6, 9, 12, 18 or 24 hours, respectively and killed for histopathological examination, biochemical isolation of retinal DNA; and in situ analysis of nicked nuclear DNA by terminal transferase biotin-dUTP nick end labeling (TUNEL). Histopathological study revealed morphological changes comparable to previous reports on photic injury. Electrophoretic analysis of DNA showed internucleosomal DNA cleavage as early as 12 hours of light exposure. The fluorescent intensity of DNA fragments, which were monomers and multimers of 180-200 base pairs, increased with the duration of light exposure. TUNEL technique, which localized DNA cleavage to the photoreceptor cell nuclei as early as 6 hours of light exposure, showed that the number of TUNEL positive nuclei increased with light exposure, and revealed more DNA degradation in the superior quadrant. Our findings confirmed earlier morphologic observations that photic exposure triggers apoptosis of photoreceptor cells.

Animals↗

PubMed1996

Experimentally-induced prostatic hyperplasia in young beagles: a model to evaluate the chemotherapeutic effects of gossypol.

This study investigated the effect of gossypol on hyperplastic canine prostates induced with long-term administration of androgen and estrogen. Twelve 16-week-old male beagle dogs were divided evenly (n = 3) into 4 treatment groups: (1) CONTROL: vehicle only; (2) Gossypol-Treated: 20 mg/kg gossypol acetic acid; (3) Steroid-Induced: 4 mg/kg testosterone and 40 micrograms/kg estradiol-17 beta; (4) Gossypol-Treated and Steroid-Induced: 4 mg/kg testosterone, 40 micrograms/kg estradiol-17 beta and 20 mg/kg gossypol. The subjects received treatments every other day for 1 month. The beagles treated with steroids developed an acute enlargement (approximately 10-fold) of the prostate as compared to control. The prostatic acini were underdeveloped and characterized by simple squamous to low cuboidal epithelium in the control subjects while acini in steroid-induced subjects were characterized by simple tall columnar epithelium. The subjects treated with gossypol had prostates histologically similar to controls with the exception of loosened periurethral connective tissue. Serum testosterone and estradiol-17 beta levels imply that gossypol can reduce steroid hormonal levels. Mean serum testosterone levels in gossypol-treated subjects were reduced approximately 50% from controls. Serum biochemistry profiles indicate that steroid and/or gossypol treatments were not toxic at the doses and duration used in this study. These observations imply that gossypol and steroid hormones can interact to alter prostate development and gossypol metabolism and/or clearance.

5-alpha Reductase Inhibitors↗

PubMed1996

Laser treatment of complicated head and neck hemangiomas in infancy.

A retrospective study of 73 patients treated for symptomatic hemangiomas of head and neck from May 1981 to April 1994 was conducted. Fifty-three females and 20 males ranging in age from 1 day of life to 11 years with the average age being 19 months were reviewed in the University of California, Irvine Medical Center. All patients were referred by pediatricians or family practitioners for evaluation and possible laser treatment. The lesions reported were particular troublesome because of obstruction of orifice(s), repeated ulceration, bleeding, subsequent pain or life threatening. Various lasers have been used for these patients including: CO2 laser [10], Argon laser/with intralesional steroid injection [33/14], Nd YAG laser [21], KTP laser [1] and Flashlamp-pumped pulsed dye laser (FPPDL)[8]. All treated lesions healed in 7 to 21 days (mean, 12 days). Complications associated with laser treatment, such as postoperative bleeding and infection were not seen. The symptoms were totally relieved from 7 days to 24 months (mean, 9 months). Combined with reconstructive surgery, the texture changes (7 patients) after laser treatment were corrected successfully. The outcome was graded by reduction in volume, improvement of color and texture of hemangioma as follow: Grade 1 - Poor (0-25%); Grade II - Fair (26-50%); Grade III - Good (51-75%); Grade IV - Excellent (76-100%). The final results of the patients are similar to what may be expected after spontaneous involution of a complicated hemangioma. In summary, complicated hemangiomas of head and neck in infancy have significant morbidity that can be efficiently avoided with the use of laser therapy.

Child↗

PubMed1996

Major burns in pregnancy.

From June 1986 to May 1991, there were 1,931 patients to be treated for burns in Linkou Burn Unit, at the Chang Gung Memorial Hospital. Seven patients, aged 24 to 32 years, were pregnant and had burns greater than 10% of total body surface area (TBSA). The severity of the dermal injuries was diagnosed as partial or full thickness. Patient's gestational ages ranged from 8 to 38 weeks. Five patients had normal deliveries at term; one patient had intrauterine fetal death 7 weeks after the burn injury, and one patient had premature labor at gestational age of 33 weeks. Termination of the pregnancy was never done in our series. Active medical treatment together with conservative wound care should be the standard in each trimester of pregnancy.

Abortion, Spontaneous↗

PubMed1996

Community-based study on the relationship between physical activity and hypertension.

In order to investigate the prevalence and risk factors for hypertension, and the association between reported physical activity and newly-diagnosed hypertension in Taiwan, 1,103 subjects randomly sampled from 6,725 residents, aged over 20 years from Nanhwa Township, Tainan County, Taiwan, were examined. Questionnaire interviews as well as blood pressure and anthropometric measurements were completed for 479 participants (adjusted response rate, 71.1%) in 1994. The prevalence of hypertension age-sex-standardized to the population of Taiwan in 1992 was 17.8% for adults aged over 20 years and 33.3% for those aged over 40 according to the Fifth Report of the Joint National Committee on Detection, Evaluation and Treatment of High Blood Pressure (systolic > or = 140 and/or diastolic > or = 90 mmHg), and 11.3% and 22.0%, according to the World Health Organization (systolic > or = 160 and/or diastolic > or = 95 mmHg). Education level, socioeconomic status, history of heart disease and diabetes, family history of hypertension, body mass index, waist-to-hip ratio and physical activity level were all correlated with newly-diagnosed hypertension prevalence after adjustment for age and sex. In a multiple logistic regression model, physical activity, especially low sports activity, was an independent risk factor for hypertension after adjustment for age, sex, body mass index, waist-to-hip ratio and family history of hypertension.

Adult↗

PubMed1995

Persistent genital human papillomavirus infection as a risk factor for persistent cervical dysplasia.

BACKGROUND: Cervical dysplasia, also referred to as squamous intraepithelial lesion (SIL) in cytology or cervical intraepithelial neoplasia in histopathology, is thought to have the potential to advance in progressive stages to cervical cancer. However, not all cases of SIL progress, and most of the mild lesions spontaneously regress. Factors that govern regression, persistence, and progression of SIL are poorly understood. PURPOSE: Our analysis sought to identify factors that determined persistence or regression of SIL. METHODS: Seventy subjects with histopathologically confirmed cervical dysplasia were followed at 3-month intervals for 15 months. At each visit, the cervix was evaluated by Pap smear and colposcopy, and exfoliated cervicovaginal cells were analyzed for human papillomavirus (HPV) DNA. For each subject, data from every two consecutive visits were grouped as a pair. Persistent SIL was considered present if a lesion was detected at a visit (t) as well as at the next visit (t + 1) and absent if a lesion was detected at visit t but not at visit t + 1. A statistical model for time-dependent data correlated persistent SIL with various risk factors. RESULTS: Age, ethnicity, education, sexual behavior, smoking, and the use of oral contraceptives did not correlate with persistent SIL. The risk of persistent SIL was associated with continual HPV infection in visits t and t + 1 (HPV positive by Southern blot analysis: odds ratio [OR] = 3.91, and 95% confidence interval [CI] = 1.58-9.65; HPV positive by polymerase chain reaction [PCR]: OR = 2.42, and 95% CI = 1.03-5.67) and a persistent high viral load (OR = 4.07, and 95% CI = 1.35-12.30). When typed by PCR, individuals with type-specific persistent infection in visits t and t + 1, and particularly those with a continual high viral load (OR = 4.97; 95% CI = 1.45-17.02), had the highest risk for persistent SIL compared with those with a low level of type-specific persistent infection or non-type-specific persistent infection. The presence of persistent HPV infection in visits t-1 (the preceding time interval) was also predictive of persistent SIL in visits t and t + 1, although the strength of association was weaker, suggesting that persistent HPV and SIL occur synchronously. CONCLUSION: HPV infection and its associated cervical lesions tend to occur concurrently, and type-specific persistent HPV infection, particularly with a high viral load, produces chronic cervical dysplasia. IMPLICATIONS: The natural history of genital HPV infection directly influences the prognosis of cervical dysplasia as measured by persistence of the lesion. Testing for HPV infection may be valuable in the clinical management of women with cervical dysplasia.

Adult↗

PubMed1995

Suppressed transformation and induced differentiation of HER-2/neu-overexpressing breast cancer cells by emodin.

The amplification and overexpression of the HER-2/neu proto-oncogene, which encodes the tyrosine kinase receptor p185neu, have been observed frequently in tumors from human breast cancer patients and are correlated with poor prognosis. To explore the potential of chemotherapy directed at the tyrosine kinase of p185neu, we have found that emodin (3-methyl-1,6,8-trihydroxyanthraquinone), a tyrosine kinase inhibitor, suppresses autophosphorylation and transphosphorylation activities of HER-2/neu tyrosine kinase, resulting in tyrosine hypophosphorylation of p185neu in HER-2/neu-overexpressing breast cancer cells. Emodin, at a 40-microM concentration, which repressed tyrosine kinase of p185neu, efficiently inhibited both anchorage-dependent and anchorage-independent growth of HER-2/neu-overexpressing breast cancer cells. However, the inhibition was much less effective for those cells expressing basal levels of p185neu under the same conditions. Emodin also induced differentiation of HER-2/neu-overexpressing breast cancer cells by exhibiting a morphological maturation property of large lacy nuclei surrounded by sizable flat cytoplasm and by showing a measurable production of large lipid droplets, which is a marker of mature breast cells. Therefore, our results indicate that emodin inhibits HER-2/neu tyrosine kinase activity and preferentially suppresses growth and induces differentiation of HER-2/neu-overexpressing cancer cells. These results may have chemotherapeutic implications for using emodin to target HER-2/neu-overexpressing cancer cells.

Breast Neoplasms↗

PubMed1995

The effects of apolipoprotein E polymorphism on the distribution of lipids and lipoproteins in the Chinese population.

The effects of apolipoprotein E (apo E) polymorphism on the distribution of serum levels of total cholesterol (TC), triglyceride (TG), high density lipoprotein cholesterol (HDL-C) and low density lipoprotein cholesterol (LDL-C) were studied in 546 unrelated Chinese in Taiwan. By isoelectric focusing and immunoblotting, three common alleles were demonstrated. The frequencies of the epsilon 2, epsilon 3 and epsilon 4 alleles were 0.076, 0.875 and 0.049, respectively. The relative frequency of the epsilon 3 allele was higher than that in Caucasians, whereas the frequency of epsilon 4 was lower in the Chinese population. Individuals with apo E4/4 phenotype had the highest serum TC and LDL-C concentrations, while the lowest levels were associated with apo E2/2 phenotype. There was a trend for individuals carrying the epsilon 2 allele to have a higher HDL-C level. No relationship between apo E phenotype and TG level was observed in this study. These data indicated that a given apo E allele acted in a relatively similar way in determining individual differences between Chinese and Caucasian populations in serum lipid and lipoprotein.

Adolescent↗

PubMed1995

Apoptotic photoreceptor cell death after traumatic retinal detachment in humans.

OBJECTIVE: To determine the mechanism of photoreceptor cell death after traumatic retinal detachment in humans. DESIGN: Clinical records from 1975 to 1993 of 75 patients, whose eyes were enucleated after traumatic retinal detachment, were reviewed for age, sex, previous ocular or systemic medical history, interval from initial trauma to enucleation, visual acuity, and types of trauma. The patients were divided into five groups of 15 cases each, based on the interval from initial trauma to enucleation. The retinal tissue was examined for two markers of apoptosis: (1) nicked nuclear DNA in situ by the terminal deoxynucleotidyl transferase-mediated biotinylated deoxyuridine triphosphate nick end labeling (TUNEL) technique and (2) apoptotic bodies by light and electron microscopy. RESULTS: Of the 75 cases of ruptured globe and traumatic retinal detachment that were evaluated, 19 eyes (25.3%) showed TUNEL-positive labeling of photoreceptor cells. Nicked nuclear DNA was detected in photoreceptor cells of detached retinas as early as 8 hours after trauma. The detached retinas in seven of 15 eyes enucleated within 2 days after ocular trauma showed TUNEL-positive photoreceptor nuclei. The number of cases showing TUNEL-positive photoreceptor nuclei decreased as the interval between initial trauma and enucleation increased. The TUNEL-positive photoreceptor cells could still be seen in the detached retinas of two eyes enucleated 22 days after trauma. Light microscopy disclosed condensation and fragmentation of photoreceptor nuclei in the detached retinas. Electron microscopy showed structures resembling apoptotic bodies phagocytosed by neighboring cells in the TUNEL-positive retinas. CONCLUSIONS: Apoptosis is an important mechanism of photoreceptor cell degeneration in the early stage after traumatic retinal detachment in humans.

Adolescent↗

PubMed1995

Antiproliferative activity of gossypol and gossypolone on human breast cancer cells.

Gossypol is a polyphenolic aldehyde occurring naturally in cottonseed that produces antisteroidogenic activity in vivo, has been extensively investigated as a male contraceptive agent, and has demonstrated anticancer activity. Gossypolone, the major metabolite of gossypol, also prossesses antisteroidogenic activity but has not been examined for its anticancer properties. The objectives of these investigations are to compare the effects of gossypolone with those of gossypol on cell proliferation of hormone-dependent and hormone-independent human breast carcinoma cells, i.e., MCF-7, MCF-7 Adr and MDA-MB-231 cells. Gossypol and gossypolone were examined at concentrations up to 10 microM, and cellular DNA synthesis was monitored by 3H-thymidine incorporation. Gossypol and gossypolone produced dose-dependent suppression of DNA synthesis in all of the human breast cell lines examined. Gossypol produced potent antiproliferative activity in MCF-7 cells at doses as low as 30 nM. Co-incubation of MCF-7 cells with gossypol (5 microM) and estradiol (10 nM) did not alter the effects of gossypl. Treatment of human breast cancer cells with 2.5 microM of gossypol resulted in alterations in cell shape and attachment to the surface of the culture dishes. At gossypol doses of 10 microM, pericytoplasmic globuation and cytoplasmic swelling were observed in the majority of breast cancer cells. These changes in cellular morphology indicate a loss of ability of the cells to maintain normal cell membrane permeability, resulting in subsequent disorganization and loss of cytoplasmic organelles. Gossypolone is less potent than gossypol in producing these effects in the human breast cancer cell lines, whereas it possesses equipotent antisteroidogenic and antireproductive activities with gossypol. These investigations suggest that gossypol and gossypol analogs may have therapeutic potential for human breast cancer.

Antineoplastic Agents↗