Flow Cytometric and Immunohistochemical Correlations in High Incidence Human Solid Tumors

475 patients with carcinoma at different sites (141 colon-rectum; 102 breast; 50 stomach; 48 kidney; 46 head and neck; 41 bladder; 47 other sites) submitted to surgery have been analyzed after histopathological staging and grading, by flow cytometry (monoparametric DNA content analysis) and immunohistochemistry (p53, c-erbB-2, and PCNA expression). In breast cancer patients the presence of receptors for estrogen (ER) and progesterone (PGR) has also been determined. Flow cytometry-derived parameters were DNA ploidy, fraction of cells in S-phase (SPF), and DNA content heterogeneity (multiclonal stem cell lines with different DNA index and/or more than one subpopulations with different ploidy levels in different samples from the same tumor). Correlations of the results obtained by the different techniques have been attempted by the non-parametric Spearman's rank correlation approach. Significant associations (P «0.05) were found between the histopathological, immunohistochemical and flow cytometric parameters considered in some anatomical regions, such as stomach (p53 vs DNA content aneuploidy and vs heterogeneity), colon-rectum (TNM vs p53 and vs heterogeneity), bladder (grading vs DNA content aneuploidy and vs heterogeneity). Tumor heterogeneity proved to be dependent on the number of tumor samples taken. The results of this preliminary assessment will subsequently be compared with the data obtained from a currently ongoing follow-up survey.

Non-linear association between androgen receptor CAG and GGN repeat lengths and reproductive parameters in fertile European and Inuit men

Recently the dogma that there is an inverse linear association between androgen receptor (AR) CAG and GGN polymorphisms and receptor activity has been challenged. We analysed the pattern of association between 21 male reproductive phenotypes and AR CAG/GGN repeat lengths in 557 proven-fertile men. A linear association was only found between sperm DNA fragmentation index (DFI) and CAG length, and between inhibin B and GGN length. Men with longer CAG then the reference (22-24), had higher oestradiol levels, whereas men with shorter CAG stretches had a higher DFI and a higher proportion of Fas-positive germ cells. Subjects with either short or long CAG had increased seminal levels of prostate-specific antigen and neutral α-glucosidase activity. Compared to men with the median GGN length of 23, those with shorter GGN repeats had higher levels of inhibin B, higher proportions of normal and progressive sperm, and a higher fraction of Fas-positive sperm, while men with longer GGN had higher oestradiol levels. These data indicate that at least for some markers of male reproductive function the association with CAG or GGN repeat length is curvilinear.

Relationships between sperm DNA fragmentation, sperm apoptotic markers and serum levels of CB-153 and p,p′-DDE in European and Inuit populations

Persistent organochlorine pollutants (POPs) are suspected to interfere with hormone activity and the normal homeostasis of spermatogenesis. We investigated the relationships between sperm DNA fragmentation, apoptotic markers identified on ejaculated spermatozoa and POP levels in the blood of 652 adult males (200 Inuits from Greenland, 166 Swedish, 134 Polish and 152 Ukrainian). Serum levels of 2, 2′, 4, 4′, 5, 5′-hexachlorobiphenyl (CB-153), as a proxy of the total POP burden, and of 1,1-dichloro-2,2-bis(p-chlorophenyl)-ethylene (p,p′-DDE), as a proxy of the total DDT exposure were determined. Sperm DNA fragmentation was measured by using the TUNEL assay, whereas immunofluorescence methods were utilized for detecting pro-apoptotic (Fas) and anti-apoptotic (Bcl-xL) markers. Both TUNEL assay and apoptotic markers were statistically differed across the four populations. No correlation between neither sperm DNA fragmentation nor apoptotic sperm parameters and the large variations in POPs exposure was observed for the separate study groups. However, considering the European populations taken together, we showed that both %TUNEL positivity and Bcl-xL were related to CB-153 serum levels, whereas our study failed to demonstrate any relations between DDE and %TUNEL positivity and apoptotic sperm biomarkers (Fas and Bcl-xL) in any region or overall regions. These results suggest that CB-153 and related chemicals might alter sperm DNA integrity and Bcl-xL levels in European adult males, but not in the highly exposed Inuit men. Additional issues (genetic background, lifestyle habits and characterization of total xeno-hormonal activities) need to be investigated in order to fully assess the population variations observed.

Cryopreservation and Sperm DNA Integrity

Cryopreservation of sperm is an extremely important issue in the field of male infertility as freezing can have detrimental effects on a variety of sperm functions, some of them not accessible to the traditional semen quality analysis. In this study, chromatin structure variations in human spermatozoa in semen were studied with the sperm chromatin structure assay (SCSA), both before and after cryopreservation. Samples were divided into two aliquots: the first was analysed without further treatment, while the second was stored in liquid nitrogen at -196 degrees C using standard cryopreservation techniques. The fresh and thawed aliquots were also assessed by light and fluorescence microscopy (after Acridine Orange staining, AO), and computer-assisted semen analysis (CASA) of motility. Overall sperm quality was found to deteriorate after cryopreservation. When thawed spermatozoa were subjected to an extra swim-up round, a general improvement in nuclear maturity was seen in post-rise spermatozoa.

Exposure to PCB and p, p′-DDE in European and Inuit populations: impact on human sperm chromatin integrity

BACKGROUND

Persistent organochlorine pollutants (POP), such as polychlorinated biphenyls (PCB) and dichlorodiphenyldichloroethylene (p, p'-DDE), are widely found in the environment and considered potential endocrine-disrupting compounds (EDC). Their impact on male fertility is still unknown.

METHODS

To explore the hypothesis that POP is associated with altered sperm chromatin integrity, a cross-sectional study involving 707 adult males (193 Inuits from Greenland, 178 Swedish fishermen, 141 men from Warsaw, Poland, and 195 men from Kharkiv, Ukraine) was carried out. Serum levels of 2,2',4,4',5,5'-hexachlorobiphenyl (CB-153), as a proxy of the total PCB burden, and of p,p'-DDE were determined. Sperm chromatin structure assay (SCSA) was used to assess sperm DNA/chromatin integrity.

RESULTS

We found a strong and monotonically increasing DNA fragmentation index with increasing serum levels of CB-153 among European but not Inuit men, reaching a 60% higher average level in the highest exposure group. No significant associations were found between SCSA-derived parameters and p, p'-DDE serum concentrations.

CONCLUSION

These results suggest that human dietary PCB exposure might have a negative impact on the sperm chromatin integrity of adult males but additional issues, including differences in the genetic background and lifestyle habits, still need to be elucidated.

Full-term pregnancies achieved with ICSI despite high levels of sperm chromatin damage

BACKGROUND

Sperm DNA integrity is essential for the accurate transmission of genetic information. The clinical significance of this assessment lies in its association with not only natural conception rates, but also the success of assisted reproduction technology (ART). It has been reported that sperm chromatin structure assay (SCSA) identified thresholds for negative pregnancy outcome after ART when the DNA fragmentation index (DFI), previously known as COMPalphat, was >30%.

METHODS

In a prospective clinical study, we examined 34 male infertile patients, the husbands of women undergoing conventional IVF or ICSI. SCSA and ART were carried out on semen aliquots taken from the same ejaculate. Fertilization rate, embryo quality and pregnancy rates were correlated to SCSA parameters, DFI and highly DNA stainable (HDS) cells.

RESULTS

No differences were seen in SCSA parameter values between patients initiating pregnancies and not doing so in either ICSI or conventional IVF. Pregnancies and normal delivery were obtained even with high levels of DFI.

CONCLUSIONS

There is still controversy over whether analytical techniques currently in use are able to identify the level of damage to spermatozoa. Large-scale studies should be conducted in different clinical settings to determine the effects of sperm DNA damage on the outcome of ART.

Evaluation of DNA damage in different stages of mouse spermatogenesis after testicular X irradiation

To evaluate whether DNA alterations in mature spermatozoa could stem from DNA damage induced in immature germ cells, testis cells and spermatozoa were analyzed by the comet assay and by the sperm chromatin structure assay 14, 45 and 100 days after in vivo X irradiation of the testes. These times were selected, according to the mouse seminiferous epithelium cycle, to follow the DNA damage induced in different germ cell compartments. The cytotoxic action was assessed by DNA flow cytometric analysis of testicular cells. A dose-dependent increase of DNA damage in testis cells was observed 14 days after irradiation, whereas mature sperm cells were not affected. On the other hand, an increase in DNA strand breaks was seen in spermatozoa 45 days after treatment. DNA damage returned to the control levels 100 days after irradiation. The methods used to evaluate DNA damage gave comparable results, emphasizing the correlation between DNA fragmentation and susceptibility of sperm chromatin to denaturation. Both techniques showed the high radiosensitivity of differentiating spermatogonia. The overall results showed that DNA damage induced in pre-meiotic germ cells is detectable in primary spermatocytes and is still present in mature spermatozoa.

Cytogenetic biomonitoring carried out in a village (Dolon) adjacent to the Semipalatinsk nuclear weapon test site

The Semipalatinsk region (Kazakhstan Republic) has been affected by extensive radioactive contamination due to more than 450 nuclear tests of which almost 100 were exploded in the atmosphere. The present results refer to cytogenetic assessments in a study cohort of the population of Dolon, a settlement located on the NE boundary of the nuclear weapon test site, which was exposed to elevated doses of ionising radiation primarily due to the first Soviet nuclear test in 1949. Conventional cytogenetic analyses were carried out on 21 blood samples from individuals (more than 50 years old) living in Dolon since the very beginning of nuclear testing. A matched control group included 20 individuals living in non-contaminated areas. Higher frequencies of chromosome aberrations were found in the Dolon cohort compared to the control group, even though they remain within the range of the background levels reported for large normal human population studies on elderly individuals.

Flow cytometric DNA ploidy, p53, PCNA, and c-erbB-2 protein expressions as predictors of survival in surgically resected gastric cancer patients

In order to determine retrospectively the impact of some cytometric and immunohistochemical parameters on the overall survival of gastric cancer patients treated with surgery alone, paraffin-embedded tumor samples from 137 gastric carcinoma patients undergoing curative resection from 1987-1993 were analyzed by flow cytometry (FCM) and immunohistochemistry (p53, c-erbB-2, and PCNA expression). FCM-derived parameters were DNA ploidy and fraction of S-phase cells (SPF). Multiple regression analysis was applied to determine the prognostic significance of the conventional clinicopathologic findings together with the flow cytometric and immunohistochemical parameters on overall survival. When all parameters were entered simultaneously into the Cox regression model, stage and DNA ploidy (DNA index >1.35) clearly emerged as the only independent prognostic factors. When the stages were analysed separately, the independent prognostic factors resulted DNA ploidy in early stages (I-II) and grading in stage IIIA tumors. For stage IIIB tumors, no independent prognostic factor was found. These results indicate that the DNA ploidy pattern is a valuable predictor of survival in curatively resected gastric cancer patients, especially when less advanced tumors are taken into consideration.

Sperm chromatin damage impairs human fertility. The Danish First Pregnancy Planner Study Team

OBJECTIVE

To examine the relationship between sperm chromatin defects, evaluated by the flow cytometric (FCM) sperm chromatin structure assay (SCSA), and the probability of a pregnancy in a menstrual cycle (fecundability).

DESIGN

Follow-up study.

SETTING

The Section of Toxicology and Biomedical Sciences, ENEA Casaccia, Rome, Italy, and the Department of Occupational Medicine, Aarhus University Hospital, Aarhus, Denmark.

PATIENT(S)

Two hundred fifteen Danish first pregnancy planners with no previous knowledge of their fertility capability.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Semen samples were collected at enrollment to measure semen volume, sperm concentration, motility, and morphology (by microscopy), as well as chromatin susceptibility to in situ, acid-induced partial denaturation by the FCM SCSA. Time to pregnancy was evaluated during a 2-year follow-up period. Demographic, medical, reproductive, occupational, and lifestyle data were collected by questionnaire. Fecundability was correlated with SCSA-derived parameters.

RESULT(S)

Fecundability declines as a function of the percentage of sperm with abnormal chromatin and becomes small when aberrant cells are >40%.

CONCLUSION(S)

Optimal sperm chromatin packaging seems necessary for full expression of the male fertility potential. The SCSA emerged as a predictor of the probability to conceive in this population-based study.

Human semen quality in relation to dietary pesticide exposure and organic diet

The objective of the study was to corroborate or refute the hypothesis that farmers having a high intake of organic grown commodities have a high semen quality due to their expected lower level of dietary pesticides intake. Food frequency data and semen were collected from 256 farmers (171 traditional farmers and 85 organic farmers, overall participation rate: 32%) who were selected from central registers. Each farmer delivered one semen sample before the spraying season started. The farmers were divided into three groups where the commodities from organic production contributed no (N, 0%), medium (M, 1-49%), or a high (H, 50-100%) proportion of the fruit and vegetables consumed. Farmers having a high relative intake of organically grown fruit and vegetables also had a high relative consumption of organically produced meat, milk, and bread, and differences were observed comparing the actual mean intake of single commodities, such as rice, potato, and pork meat. The current individual dietary intake of 40 pesticides was estimated using food frequencies and generalized serving size data in combination with data on pesticide concentrations in food commodities as obtained from the National Danish Food Monitoring Program. The estimated pesticide intake was significantly lower among farmers of group H, but for all three groups of farmers the average dietary intake of 40 pesticides was at or below 1% of the acceptable daily intake (ADI) except for the dithiocarbamates (max = 0.21 microg/kg day = 2.2% ADI), methidathion, (max = 0.01 microg/kg day = 1.4% ADI), and 2-phenylphenol (max = 0.21 microg/kg day = 1.1% ADI). The median sperm concentration for the three groups of farmers was not significantly different (p = 0.40, median sperm concentration was N = 62, M = 44, and H = 75 million/ml). The group of men without organic food intake had a significant lower proportion of morphologically normal spermatozoa, but in relation to 14 other semen parameters no significant differences were found between the groups. Intake of 40 individual pesticides was correlated with four semen parameters (concentration, percentage dead spermatozoa, percentage normal sperm heads, and motility [VCL]). Five significant correlations (p value 0.01) were found among the 160 comparisons in relation to percentage dead spermatozoa: azinphos-methyl, carbaryl, chlorfenson, fenitrothion, and tetradifon. For all of them a lower percentage of dead spermatozoa were found in the groups with a high dietary intake of the specific pesticide. In contrast, for all pesticides evaluated only minor differences were found between the groups when considering spermatozoa concentration, morphology, and motility. In conclusion, the estimated dietary intake of 40 pesticides did not entail a risk of impaired semen quality, but precautions should be taken when generalizing this negative result to populations with a higher dietary exposure level or an intake of other groups of pesticides.

Semen quality and sex hormones among organic and traditional Danish farmers. ASCLEPIOS Study Group

OBJECTIVES

To confirm or refute the hypothesis that organic farmers have higher sperm concentrations than traditional farmers.

METHODS

Traditional and organic farmers were selected randomly from central registers, and 171 traditional farmers and 85 organic farmers delivered one semen sample before the start of the spraying season. The participation rate was 28.8% among traditional farmers and 42.9% among organic farmers.

RESULTS

The median sperm concentration for traditional and organic farmers was 58 million/ml and 64 million/ml, respectively. After adjustment for several confounders, sperm concentration, total count, proportion of non-vital spermatozoa, sperm chromatin structure, and motility variables did not differ significantly between the two groups. The traditional farmers had a significantly lower proportion of normal spermatozoa, but this result was not confirmed in a second sample. Organic farmers had slightly higher inhibin B concentration and testosterone/sex hormone binding globulin ratio.

CONCLUSION

Despite slight differences in concentrations of reproductive hormones, no significant differences in conventional measures of semen quality were found between organic and traditional farmers.

Nuclear chromatin variations in human spermatozoa undergoing swim-up and cryopreservation evaluated by the flow cytometric sperm chromatin structure assay

The sperm chromatin structure assay (SCSA) is a flow cytometric (FCM) technique which exploits the metachromatic properties of Acridine Orange to monitor the susceptibility of sperm chromatin DNA to in-situ acid denaturation. SCSA was used to study the chromatin structure variations of human spermatozoa in semen, both before and after swim-up and after cryopreservation. Semen samples were provided by 19 healthy normozoospermic subjects attending pre-marriage checks. Each sample was divided into three aliquots: the first aliquot was evaluated without further treatment, the second underwent swim-up, and the third was stored according to standard cryopreservation techniques in liquid nitrogen at -196 degrees C. Samples were also analysed by light and fluorescence microscopy (after Acridine Orange staining to evaluate the number of green fluorescent sperm heads), and by computer-assisted semen analysis. The results showed that post-rise spermatozoa represent a subpopulation characterized by a general improvement of the morphological (reduction of the percentage of abnormal forms and heads, increase of the green head sperm percentage) and kinetic parameters. This subpopulation also exhibited improved chromatin structure properties, confirming that these cells have the best structural and functional characteristics, indicative of optimal fertilizing ability. On the other hand, overall sperm quality deteriorates after cryopreservation. When thawed spermatozoa underwent an additional swim-up round, a general improvement of nuclear maturity was seen in the post-rise spermatozoa.

Motor and perceptual-motor competence in children with Down syndrome: variation in performance with age

The aim of this study was to determine whether perceptual-motor competence in school-age children with Down syndrome was generally delayed or varied as a function of type of action. Twenty-two children with Down syndrome (13 males, 9 females), aged between 4.5 and 14 years were assessed on two standardized tests, the Movement Assessment Battery for Children (Movement ABC), a test of motor competence assessing gross and fine motor coordination, and on the Developmental Test of Visual-Motor Integration, a test focusing on shape copying. In order to obtain a profile of each child's performance on the different items contained in the Movement ABC, the test was used in its extended form. This involves testing any child who failed an item appropriate for his/her level, at progressively lower levels until a base-line measure was obtained. All the children obtained scores below the 5th percentile for their age on both tests. However, superimposed on this delay, we found distinct variation as a function of task. Whereas some aspects of gross motor function showed age development with delayed but regular acquisitions, all the aspects of fine motor skills assessed were more severely impaired and showed little development with age. Accuracy and timing of tasks requiring bimanual coordination were most impaired in our sample while balance and ball skills showed more variability. These results suggest that intervention in the motor domain should be varied according to each child's particular profile of performance.

A longitudinal study of semen quality in pesticide spraying Danish farmers. The ASCLEPIOS Study Group

It was hypothesized that occupational exposure to pesticides during a spraying season causes changes in semen quality that might be detected in a longitudinal study. We analyzed the within-person changes in semen quality and reproductive hormones across a spraying season in groups of farmers using and not using pesticides. A total of 248 men collected two semen samples (participation rate: 32%). The median sperm concentration declined significantly from the first to the second sample in both groups, but there was no statistical difference in the decline between the two groups, unadjusted or adjusted. Only minor changes were found in sperm morphology, vitality, motility, sperm chromatin denaturation (SCSA), and reproductive hormones, and the differences in changes between the two groups were nonsignificant, or, in the opposite direction to the expected. There was no relation between the changes in sperm parameters in relation to pesticide exposure variables. In conclusion, use of pesticides by Danish farmers is not a likely cause of short-term effects on semen quality and reproductive hormones.

The applicability of the flow cytometric sperm chromatin structure assay in epidemiological studies. Asclepios

The impact of demographic, lifestyle, and seminal factors on the sperm chromatin structure assay (SCSA) parameters was evaluated in a population of 277 healthy Danish men. This cohort was established within the framework of a European Concerted Action on occupational hazards to male reproductive capability in order to examine the possible reproductive effects of exposure to styrene or pesticides. The SCSA measures the susceptibility of sperm DNA to in-situ acid-induced denaturation, by multiparameter flow cytometric analysis after staining with the DNA-specific fluorescent dye acridine orange. The green versus red bivariate cytogram patterns were quite variable among donors, showing a wide heterogeneity of sperm DNA denaturability. Nevertheless, in those cases where we had the possibility to measure two semen samples from the same donor, the cytogram pattern remained stable over time (0.64 < r < 0.78). Analysis of variance demonstrated that the SCSA results can be influenced by the age of the donor (P < 0.0001), smoking habits (P < 0.05), the presence of leukocytes and immature germ forms in the ejaculate (P < 0.0001), and the duration of sexual abstinence (P < 0.0001). Furthermore, the relationship between the SCSA data and sperm concentration, morphology, and vitality was weak (-0.22 < r < -0.46). Therefore, the SCSA provides independent and complementary measurements of semen quality and is thus a useful tool for epidemiological studies, but the effects of some confounders should be accounted for in the survey design and analysis.

Reproductive toxicity of 1,3-butadiene in the mouse: cytogenetic analysis of chromosome aberrations in first-cleavage embryos and flow cytometric evaluation of spermatogonial cell killing

Reproductive effects of 1,3 butadiene inhalation have been evaluated in male mice by reduction of post-meiotic germ cells, alteration of sperm chromatin structure and transmission of chromosome aberrations to one-cell embryos. Animals were exposed for 5 consecutive days for 6 h per day to butadiene concentrations of 130, 500 or 1300 ppm. The testicular fraction of post-meiotic germ cells was measured by flow cytometric analysis on the basis of their DNA content. Round spermatids were discriminated from mature, elongated spermatids by their different degree of chromatin condensation. Butadiene-induced cytotoxic effects on differentiating spermatogonia were shown by a concentration-dependent decrease of round spermatids occurring 21 days after chemical exposure, confirmed by a similar decrease of elongated spermatids measured in testes sampled 7 days later. Statistically significant effects were seen already at 130 ppm. An incomplete repopulation of the elongated spermatid compartment observed 35 days after exposure to 1300 ppm suggested that, at the highest concentration tested, butadiene toxicity extended to stem cells. Alterations of sperm chromatin were revealed by its increased sensitivity to acidic denaturation in situ. The percentage of abnormal sperm was significantly increased after butadiene exposure of differentiating spermatogonia and spermatocytes. This suggested the induction of persistent effects interfering with chromatin remodelling during spermiogenesis. Chromosome-type structural aberrations were significantly elevated in first-cleavage embryos conceived by males mated during the first and second week after the end of exposure. The lowest effective tested concentration was 500 ppm, the same reported for dominant lethal induction under identical exposure conditions. As in the dominant lethal assay, the effect of this dose was confined to exposed sperm, while both sperm and late spermatids were affected by the inhalation of 1300 ppm. A quantitative comparison between the effects induced by intraperitoneal injections of diepoxybutane or butadiene inhalations suggested that other reactive intermediates, in addition to diepoxybutane, might contribute to mediate butadiene-induced reproductive toxicity.

Diepoxybutane cytotoxicity on mouse germ cells is enhanced by in vivo glutathione depletion: a flow cytometric approach

Diepoxybutane is one of the key metabolites of butadiene, a compound of high environmental and occupational concern. The effects of diepoxybutane on mouse reproductive cells have been previously characterized by flow cytometry demonstrating a specific, dose-dependent cytotoxicity for differentiating spermatogonia. It is known that butadiene epoxides, deriving from butadiene bioactivation by cytochrome P450-monooxygenase systems, can be enzymatically conjugated to glutathione by glutathione S-transferases. In this paper, we tested the hypothesis whether a pretreatment with phorone, a well-known intracellular glutathione depleter, would enhance the germ cell cytotoxicity of diepoxybutane. Results were consistent with an active role played in vivo by the glutathione-detoxifying system, as diepoxybutane cytotoxicity was increased after chemically induced reduction of glutathione concentration.

Quality control study of the Italian Group of Cytometry on flow cytometry DNA content measurements: II. Factors affecting inter- and intralaboratory variability

A multicentric national quality control study has been organized under the auspices of the Italian Group of Cytometry to find a possible influence of some procedural steps in DNA flow cytometry measurements on DNA index (DI) values and to identify the main parameters affecting the interlaboratory variability. To 40 participating laboratories we provided suspensions containing unknown mixture of different cell types: an homogeneous thymocyte population used to check instrument linearity; one mixture composed of two cell types characterized by DI = 1.00 and 1.10; and another composed of three different cell types with relative DIs of 1.00, 1.26, and 1.62, respectively. Possible effects due to staining protocols were studied, allowing the participants to stain cellular DNA according to the procedure routinely adopted in each laboratory, in addition to a standardized procedure with a fixed PI solution. As far as the influence of instrument linearity on DI values is concerned, we did not find any correlation with the DI variability observed, even if the use of a standardized staining protocol could lead to a sensible gain in interlaboratory DI reproducibility. Twenty-five of 40 (65%) laboratories were able to discriminate the near-diploid subpopulation, and a coefficient of variation of less than 4% was the minimum condition necessary to recognize the DI = 1.1 population. In samples containing two aneuploid subpopulations, 25 of 35 (71.4%) laboratories showed a high reproducibility with the standard staining protocol and 22 of 38 (57.9%) with the free staining protocol. However, a sensible improvement in interlaboratory reproducibility emerged with respect to the previous trial.

Visual outcome in children with congenital hemiplegia: correlation with MRI findings

Fourteen children with congenital hemiplegia were studied with a detailed assessment of various aspects of vision (linear acuity, stereopsis, visual fields) and MRI. The aim of this study was to evaluate the effect of a congenital lesion on visual function. The results showed a very high incidence (78%) of children who had abnormal results on at least one of the visual tests. Visual abnormalities were not correlated with the clinical severity of hemiplegia or with a specific pattern of lesion on MRI. Similarly no constant association could be found between visual structures (optic radiations and primary visual cortex) and visual function. Finally, our results would suggest that all the children with congenital hemiplegia need to be investigated irrespective of the clinical severity or of the type or the extent of the lesion. This would help to identify children with minor visual abnormalities which can affect everyday life performance.

Flow cytometric assessment of trophosphamide toxicity on mouse spermatogenesis

The effects of trophosphamide on mouse reproductive cells have been investigated by flow cytometric analysis of testicular cell populations and alterations of sperm chromatin structure. Mice were treated with single intraperitoneal injections of TP, the doses ranging between 50 and 150 mg/kg, and were killed after 7, 14, 21, 28, 35, or 49 days. Dose-dependent reductions of tetraploid cells, round spermatids, and elongated spermatids were detected at 7, 21, and 28 days, respectively, reflecting cytotoxic damage to the differentiating spermatogonia compartment. The dose necessary to reduce the number of differentiating spermatogonia to half the control value was approximately 70 mg/kg. Stem cells were not affected by this treatment, and the normal spermatogenic process was restored after 7 weeks. In addition, cauda epididymal sperm were analyzed by the sperm chromatin structure assay, a flow cytometric measurement of the susceptibility of the sperm nuclear DNA to in situ acid denaturation; a statistically significant increase of sperm with altered chromatin structure was detected after a TP treatment of 150 mg/kg. Together with previous findings published in the literature, where the same doses induced heritable genetic damage, this study demonstrates a marked adverse cytotoxic effect of TP on the male reproductive integrity. All this information should be taken into consideration when TP is used in chemotherapeutic regimens.

Flow cytometric and histological assessment of 1,2:3,4-diepoxybutane toxicity on mouse spermatogenesis

The effects of diepoxybutane (DEB) on mouse reproductive cells have been investigated by flow cytometric and histological description of testicular cell populations and alterations of sperm chromatin packaging. Mice were treated with single intraperitoneal injections of DEB, with doses ranging between 8.5 and 78 mg/kg (100-900 microM), and were killed after 7, 14, 21, 28 or 35 d. Dose-dependent reductions of tetraploid cells, round spermatids, and elongated spermatids were detected at 7, 21, and 28 d, respectively, reflecting cytotoxic damage on the differentiating spermatogonia compartment. The dose necessary to reduce the number of differentiating spermatogonia to half the control value was estimated equal to 650 microM or 55 mg/kg. Stem cells were not affected by this treatment. Histological section of seminiferous tubules showed depletion of spermatids and reduction of the secondary spermatocyte layers. In addition, a high although not statistically significant frequency of sperm with altered chromatin packaging was detected after DEB treatment. DEB is one of the key metabolites of butadiene, which is a compound of high environmental and occupational concern. These results contribute to the assessment of the reproductive health impact of butadiene in humans.

Mechanisms and evolution of the brain damage in neonatal post-hemorrhagic hydrocephalus

There are three main mechanisms of poor outcome in children with post-hemorrhagic hydrocephalus: (1) brain injuries due to ventricular dilatation, (2) shunt-related complications, and (3) primary cerebral hypoxic-ischemic and hemorrhagic lesions. The authors give a short up-to-date report, focusing mainly on the third mechanism, with reference to personal studies.

Mouse testis cell sorting according to DNA and mitochondrial changes during spermatogenesis

Flow cytometry can measure variations in DNA content and chromatin structure as well as dramatic changes in the mitochondria of germ cells during maturation from spermatogonia to elongated spermatids. Using 10-N nonyl acridine orange (NAO), an inner mitochondrial membrane dye, it is easy to follow mitochondria rearrangements. Mouse testis cells stained with the DNA fluorescent probe propidium iodide (PI) and analyzed by flow cytometry can be discriminated on the basis of their ploidy levels into five main regions corresponding to elongated spermatids, round spermatids, diploid, S-phase, and tetraploid cells. The simultaneous use of PI and NAO demonstrated the presence of cells having low and high mitochondrial content in the haploid, diploid, and tetraploid compartments. Eleven sorting windows were selected from the bivariate analysis (PI/NAO) and the corresponding cells were identified by microscopic observation. Cells were also discriminated by two parameter analysis of DNA content vs. cell diameter. The definition of seven different regions allowed us to determine NAO or rhodamine 123 (Rh 123) uptakes in each compartment. We observed that the ratio (Rh 123/NAO) dramatically changed according to the progression of cell differentiation which occurs during spermatogenesis.

Acrylamide-induced chromosomal damage in male mouse germ cells detected by cytogenetic analysis of one-cell zygotes

Within a project coordinated by the Commission of the European Communities for the detection of germ cell mutagens, the cytogenetic analysis of first-cleavage metaphases was carried out to detect chromosomal damage induced by acrylamide (AA) in meiotic and postmeiotic stages of mouse spermatogenesis. Male mice were intraperitoneally injected with single acute doses of 75 or 125 mg/kg or treated with five daily injections of 50 mg/kg and mated either 7 or 28 days after the end of treatment. Chromosomal aberrations were scored in C-banded metaphases prepared from one-cell zygotes by a mass harvest technique. AA treatment of late spermatids-spermatozoa resulted in significant increases of structural aberrations at all doses tested. The data could be fitted to a curvilinear regression and a doubling dose of 23 mg/kg was calculated. The large majority of observed aberrations were of the chromosome type, including dicentrics, rings and translocations, in agreement with a mechanism of chromosomal damage mediated through the alkylation of DNA-associated protamines. Even though the frequency of aberrations 28 days after treatment was not significantly higher than the control value, the presence of multiple rearrangements in two cells suggested that AA might also have a minor effect on spermatocytes. The results of the cytogenetic analysis of first cleavage metaphases agreed well both qualitatively and quantitatively with the outcome of dominant lethal and heritable translocation assays. AA-induced cytotoxicity was monitored by flow cytometric DNA content analysis of testicular cells. By this method, a dose-dependent depletion of mature spermatids after treatment of spermatogonia and a toxic effect upon primary spermatocytes were detected.

Autosomal recessive congenital cerebellar atrophy. A clinical and neuropsychological study

Congenital cerebellar atrophy associated with a non-progressive cerebellar syndrome and mild cognitive retardation is described in seven cases, four of them familial. Their occurrence is consistent with an autosomal recessive inheritance. Clinical and neuroimaging data seem to exclude supratentorial changes. Even though it is not possible to definitely rule out a possible role of the forebrain in determining the mental defect, the neuropsychological study supplies arguments stressing the relationship between cerebellar defect and cognitive development.

Flow cytometric analysis for reproductive biology

Flow cytometric studies of spermatogenesis have been advanced by the need for: i) rapid, sensitive, objective and multiparameter measurements of reproductive effects due to environmental, occupational, and therapeutic exposure to toxicants; and ii) assessment of fertility potential of human and animal sperm. As a consequence, various flow cytometric techniques are already available to identify germ cell subpopulations undergoing both proliferative and maturative processes in normal and perturbed conditions. Significant improvements have been introduced in order to investigate the spermatogenic complex differentiation pathway and the apparent uniformity of mature sperm. Flow cytometry (FCM) has been applied to the measurement of both testis and sperm cells in a variety of species, including man. End points considered in toxicology studies are: altered testicular germ cell ratios, DNA and RNA content, increase of the coefficient of variation, induction of diploid elongated spermatids and diploid sperm, altered nuclear morphology, sperm cell viability, mitochondrial function and sperm chromatin structure. Precise DNA content measurements allow accurate analysis to determine the proportion of X- and Y-chromosome bearing sperm and sorting of these subpopulations for gender preselection. FCM technology has reached a maturation level that allows its inclusion in the list of available and routine methods for reproductive studies in human and animal populations.

Quality control study of the Italian group of cytometry on flow cytometry cellular DNA content measurements

A quality control study on DNA flow cytometry, extended to 43 national laboratories, has been carried out by the Italian Group of Cytometry, using defined fixed suspensions of cultured human leukemia K562 cells and human blood lymphocytes. The participating laboratories were allowed to follow their own staining and measurement protocols. Aliquots of cellular suspension had to be measured three times on the same day and two other times on different days. A large heterogeneity of procedures emerged among participants. The average of mean DNA index laboratory values, from 36 laboratories who sent evaluable data, was 1.68, with a range from 1.49 to 1.97. The coefficients of variation ranged from 2.35 to 9.39% and from 2.79 to 8.5% for diploid and aneuploid peaks, respectively. Statistical analysis of the results showed quite good intralaboratory reproducibility, but statistically significant differences were observed among laboratories, for both DNA indices and coefficients of variation. These differences appear to be consistent. For standardization, it is essential that efforts should be made to identify the main sources of variation and to control them.

Evaluation of 2-methoxyacetic acid toxicity on mouse germ cells by flow cytometry

Flow cytometric (FCM) DNA content measurements were carried out on testicular monocellular suspensions obtained from mice exposed per os to a single dose of 50, 100, 300, 600, and 900 mg/kg body weight (b.w.) of 2-methoxyacetic acid (MAA) in order to investigate its cytotoxic action on germ cells. The effects of MAA were evaluated 2, 7, 14, 28, and 45 d after treatment in terms of altered cell type ratios in FCM fluorescence distribution histograms. Testis weight and histological tissue sections were also analyzed. MAA induced marked changes in the relative percentages of tetraploid and haploid cells, indicating the occurrence of cytotoxic damage on primary spermatocytes. Multiparameter FCM analysis showed that, besides its action on nucleic acid synthesis, MAA can also affect the cellular energy metabolism reflected in an altered mitochondrial mass distribution on round spermatids surviving the MAA treatment. This study demonstrates that rapid and unique FCM procedures can be usefully applied in reproductive toxicology.

Effects of L-acetylcarnitine (LAC) on the post-injury recovery of mouse spermatogenesis monitored by flow cytometry. 2. Recovery after hyperthermic treatment

It has been demonstrated that L-acetylcarnitine (LAC) can enhance the recovery of spermatogonial cells after X-ray damage. In the present work, the effects of LAC on the recovery processes of mouse spermatogenesis after local acute hyperthermia (42 degrees C, 1 hour) was investigated. LAC was administered i.p. (100 mg/kg body weight) every other day for four weeks after heat treatment. At intervals of 8, 14, 21, 28, 35, 40, 45, and 60 days after hyperthermic treatment, testes were weighed and their DNA content analysed by flow cytometry; the round spermatid fraction was found to be higher at 45 days in the LAC-treated animals than in controls (P less than 0.01). Correspondingly, at the same experimental point, the animals without LAC administration showed a lower testicular weight (P less than 0.05). Combined with histological analysis, these results suggest a more rapid recovery of normal spermatogenesis after physical insult with LAC treatment.

Comparison of gaussian and t-distribution densities for modeling fluorescence dispersion in flow cytometric DNA histograms

In this paper, we have analyzed, on an experimental basis, the behaviour of the standardized t-distribution with three degrees of freedom versus the gaussian model, when employed for describing the fluorescence dispersion effect in flow cytometric DNA measurements. The comparison has been performed by employing two different objective criteria based on a computer analysis for fitting DNA histograms and on a parameter related to the peak distribution shape. The results indicate that, when the peak variance is not particularly small, the two models are substantially equivalent. In the case of experimental data with very sharp peaks, the t-distribution performs better than the gaussian density.

Effects of L-acetylcarnitine (LAC) on the post-injury recovery of mouse spermatogenesis monitored by flow cytometry. 1. Recovery after X-irradiation

L-acetylcarnitine plays a key role in sperm metabolism and in the whole spermatogenetic process. In the present work, the influence of L-acetylcarnitine, administered i.p. (100 mg/kg body weight), on the recovery processes of mouse spermatogenesis after local acute irradiation with 10 Gy X-rays has been investigated. The effects were monitored 28, 35, 40, 45, 50, 55, and 60 days after irradiation by flow cytometric analysis of cellular DNA content. In the LAC-treated animals, the fraction of tetraploid cells is higher at 28 (p less than 0.05) and 45 days (p less than 0.02). Corresponding with the timing of the stages of murine spermatogenesis, the round spermatid fraction is higher at 45 days (p less than 0.1) and the elongated spermatid fraction is higher at 50 days (p less than 0.1) after irradiation. In addition, the LAC-treated animals show a faster recovery throughout the maturation process, from tetraploid to round and elongated spermatids. These results indicate that the presence of exogenous LAC could enhance the recovery of spermatogonial cells.

Cytotoxic effects of benzene on mouse germ cells determined by flow cytometry

Flow cytometric (FCM) DNA content measurements were performed on testicular monocellular suspensions obtained from mice exposed per os to 0, 1, 2, 4, 6, and 7 ml/kg body weight of benzene in order to investigate its cytotoxic action on germ cells. The effects of benzene were measured 7, 14, 21, 28, and 70 d after treatment. Benzene had no effect on testis weight, but FCM analysis showed the relative percentages of some cell subpopulations (tetraploid and haploid cells) to be different from the control pattern, indicating the occurrence of some cytotoxic damage to differentiating spermatogonia. These data demonstrate that spermatogenesis is sensitive to benzene single exposures as evidenced by an altered cell ratio of testicular cell types.

Automatic analysis of flow cytometric DNA histograms from irradiated mouse male germ cells

An automatic procedure for recovering the DNA content distribution of mouse irradiated testis cells from flow cytometric histograms is presented. First, a suitable mathematical model is developed, to represent the pattern of DNA content and fluorescence distribution in the sample. Then a parameter estimation procedure, based on the maximum likelihood approach, is constructed by means of an optimization technique. This procedure has been applied to a set of DNA histograms relative to different doses of 0.4-MeV neutrons and to different time intervals after irradiation. In each case, a good agreement between the measured histograms and the corresponding fits has been obtained. The results indicate that the proposed method for the quantitative analysis of germ cell DNA histograms can be usefully applied to the study of the cytotoxic and mutagenic action of agents of toxicological interest such as ionizing radiations.

Flow cytometric analysis of the effects of 0.4 MeV fission neutrons on mouse spermatogenesis

(C57Bl/Cne X C3H/Cne)F1 male mice were irradiated with single acute doses of 0.4 MeV neutrons ranging from 0.05 to 2 Gy, and testis cell suspensions were prepared for cytometric analysis of the DNA content 2-70 days after irradiation. Various cell subpopulations could be identified in the control histogram including mature and immature spermatids, diploid spermatogonia and spermatocytes, tetraploid cells and cells in the S-phase. Variations in the relative proportions of different cell types were detected at each dose and time, reflecting lethal damage induced on specific spermatogenetic stages. The reduction of the number of elongated spermatids 28 days after irradiation was shown to be a particularly sensitive parameter for the cytometrical assessment of the radiosensitivity of differentiating gonia. A D0 value of 0.13 Gy was calculated and compared with data obtained after X-irradiation, using the same experimental protocol. In the latter case a biphasic curve was obtained over the dose range from 0.25 to 10 Gy, possibly reflecting the existence of some cell population heterogeneity. RBE values were estimated at different neutron doses relative to the radiosensitive component of the X-ray curve, and ranged from 3.3 to 4, in agreement with data in the literature. Genotoxic effects were monitored 7 days after irradiation by a dose-dependent increase of the coefficient of variation (CV) values of the round spermatid peak, reflecting the induction of numerical and structural chromosome aberrations, and 14 or 21 days after irradiation by the detection of diploid elongated spermatids, probably arising from a radiation-induced complete failure of the first or second meiotic division.

Considerations in the design of possible cell cycle effective drugs

Antineoplastic agents are known to induce differential cytotoxic and cytostatic effects throughout the cell cycle. Many drugs have greater toxicity for cycling cells and act selectively at one or more phases of the cycle and may cause partial synchrony of surviving cells. However, these observations have been generally carried out on in vitro systems only and present a variety of complexities and pitfalls. Furthermore, human tumours are often characterized by a relatively low fraction of proliferating cells and present a large cellular heterogeneity as far as their cytogenetic, cytokinetic, and clonogenic features and their responses to drugs are concerned. Therefore, resistance to chemotherapy is due to various factors characterizing, in some instances, each individual tumour. In spite of the advent of technological advances such as flow cytometry, it is still difficult to design kinetic-orientated therapies especially for the treatment of solid tumours. Consequently, it is also difficult to design protocols based on cell cycle effective drugs. The possibility remains, at least for the moment, to stratify tumours according to their cellular heterogeneity. Different protocols could then be assigned to classes of tumours. Such an approach could be completed by further advances in the cellular monitoring of individual tumours.