Antioxidant food supplements and obesity-related inflammation

The obesity prevalence is growing worldwide and largely responsible for the increased incidence of cardiovascular disease, the most common cause of death in the western world. Excessive food intake along with insufficient physical exercise is the basic impetus for this development. The obese state is commonly associated with an increase in leptin levels and chronic immune-mediated inflammation. Despite high leptin levels, the leptin response, normally associated with satiety and satiation, seems to be impaired and individuals continue to consume calorie-rich food. Antioxidant food additives such as sodium sulphite, sodium benzoate and curcumin were shown to suppress the leptin release in lipopolysaccharide- treated murine adipocytes. Based on this, we hypothesize that the insufficient leptin release, caused by excessive consumption of food additives, may lead to a reduced exposure of the central nervous system to leptin and ultimately propagate obesity. On the other hand, leptin has been shown to favor Th1-type activity, which ultimately decreases tryptophan levels. Tryptophan derivatives, serotonin and melatonin, induce satiety/satiation through several mechanisms. In this context, the antioxidant suppression of leptin release and Th1-type activity is beneficial to increase serotonin and melatonin levels. The molecules in the mechanism described in this review are highly integrated in the reward system, and have been implicated in the addiction behavior of obesity. Based on these facts, the involvement of antioxidant food supplements in the mechanisms of the reward-deficiency syndrome which perpetuates obesity will be discussed.

Microdissection and reverse painting reveals a microdeletion 6(q26qter) in a de novo r(6) chromosome

Ring chromosomes 6 are rare constitutional abnormalities with inconsistent phenotypic and clinical features. One of the reasons for this variability is the cytogenetically undetectable loss of chromosomal material from the telomeric segments at 6p or 6q. We have therefore used fluorescence in situ hybridization (FISH) to analyse a ring chromosome 6 that was detected in a newborn boy with dysmorphic features. Reverse painting of the microdissected ring chromosome onto normal metaphase spreads revealed a small deletion of the terminal region of the long arm, 6(q26qter). Moreover, the simple all-telomeric sequence (TTAGG)n was lost, whereas the p-specific subtelomeric sequence was still present. Our findings confirm that microdeletions occur during the formation of r(6) chromosomes and, therefore, are an important determinator of the associated phenotype.

Preferential fluorescent staining of heterochromatic regions in human chromosomes 9, 15, and the Y by D 287/170

The utility of a newly synthesized chemical variation of DAPI (4'-6-diamidino-2-phenyl-indole), D 287/170, for differential staining of constitutive heterochromatin in man is demonstrated. Direct staining of human chromosomes with D 287/170 results in brilliant fluorescence of the paracentromeric C-band of chromosome 9, of a proximal short-arm segment of chromosome 15, and of certain heterochromatic regions in the Y. Bright, but less conspicuous fluorescence is occasionally seen at the centromeres of other chromosomes. The staining differentiation obtained by D 287/170 is very distinct, and the intensity of the fluorescent light is unusually high. The new fluorochrome should prove particularly useful for detecting and analyzing human chromosome 9 heterochromatin at various stages of the cell cycle in normal and structurally altered chromosomes.

Comparative evaluation of three assay systems for automated determination of hemoglobin A1c

We evaluated three newly introduced systems for automated determinations of hemoglobin (Hb) A1c, which allow the processing of large amounts of samples in a routine clinical laboratory. We compared these methods--the Variant HPLC, the Hi-Auto A1c analyzer system, and the Roche immunoassay--with the Diamat HPLC system. All showed good precision and good concordance with the Diamat HPLC. The reference range for Hb A1c has to be determined by the laboratory for each assay system. Interference study showed no statistically significant influence of anemia, polycythemia, rheumatoid factor, or chronic hemodialysis, although individual Hb A1c values can be influenced by polycythemia (when measured with the Hi-Auto A1c analyzer) and by chronic hemodialysis (when measured with the Variant HPLC). HPLC was not suitable for measuring Hb A1c in the examined cases of hemoglobin variants; assaying fructosamine seems to be better for monitoring these patients.

Complications and surgical interventions during 4 years of biliary extracorporeal shockwave lithotripsy

BACKGROUND/AIMS

Extracorporeal shockwave lithotripsy (ESWL) of renal concrements, a revolutionary therapeutic concept, was introduced into clinical routine in the early 1980s. In this study, complications and surgical interventions of biliary extracorporeal shockwave lithotripsy were investigated.

MATERIAL AND METHODS

Two hundred-eighty patients with gallbladder stones underwent extracorporeal shockwave lithotripsy during a 4 year (January 1990-December 1993) investigation period. Two hundred four patients were female, and 76 patients were male with a mean age of 48 years. All patients were symptomatic. Selection was carried out following the "Munich criteria" and the selection rate was 15.3% of all referred patients (n = 1831). One hundred eighty-eight patients had solitary stones, 92 patients presented with multiple stones (maximum 3 stones), with an average of 1.7 stones and a mean stone volume of 2.4 cm3 and stone diameter of 16.5 mm. Shockwave lithotripsy was performed with a second generation electrohydraulic lithotriptor with a mean of 2.1 sessions. Mean duration of one session was 50 min, 1331 discharges were applied on average with a mean power of 22.7 kV.

RESULTS

Analgesia, with Alfetanil (mean 2.3 mg), was necessary in 68% of all treatment sessions. Fragmentation could be achieved in 81% of the cases, stone clearance was observed in 172 cases (66.4%) out of 258 patients after 12 months. Twenty-two patients were treated in 1993 and are still under observance. Side effects such as colic after treatment were observed in 88 cases (31.4%). In seven cases, severe complications such as impaction of fragments in the papilla of Vater followed by serochemical pancreatitis were seen. An urgent endoscopic sphincterotomy was necessary in these 7 cases (2.5%). Within 4 weeks after shockwave treatment in 4 cases 1.4% emergency cholecystenomy had to be performed. Elective cholecystectomy was done in 16 patients (5.7%). There were no deaths observed during the investigation period.

CONCLUSION

Based on the results of our series, we do not recommend biliary ESWL in patients with stone volumes exceeding 14 cm3 (3cm), the high fragment volume after sufficient fragmentation by shockwaves indicates long term oral dissolution therapy. The probability of complications will be increased by the presence of larger fragments.

Sonographically-guided extracorporeal shockwave lithotripsy for pancreatic stones in patients with chronic pancreatitis

Over a 2 year period, 10 patients with pancreatic stones due to alcohol induced chronic pancreatitis (proven by endoscopic retrograde pancreatography) underwent extracorporeal shockwave lithotripsy. Prior to shockwave therapy, all patients underwent endoscopic sphincterotomy. Targeting of shockwave lithotripsy was exclusively performed under sonographic control. All patients were treated with a second generation electrohydraulic spark gap lithotriptor and fragmentation of concrements could be achieved in all cases. Complete duct clearance was confirmed in seven patients by endoscopic retrograde pancreatography in one session, with endoscopic fragment extraction by basket and/or balloon catheter. In three patients, balloon dilation of concomitant strictures located in the head of the pancreas was performed prior to fragment extraction. All stone-free patients showed no further symptoms over the follow-up period of 12 months. Three patients in whom complete extraction of fragments was not successful experienced minor symptoms over the 12 month follow-up period.

A simple scintigraphic method for continuous monitoring of gastric emptying

A new and simple scintigraphic method for the measurement of gastric emptying was developed and validated. The test meal consists of 200 g potato mash mixed with 0.5 g Dowex 2X8 particles (mesh 20-50) labelled with 37 MBq (1 mCi) technetium-99m. After ingestion of the meal, sequential dynamic 15-s anteroposterior exposures in the supine position are obtained for 90 min. A second recording sequence of 20 min is added after a 30-min interval. The results can be displayed as immediate cine-replay, as time-activity diagrams and/or as activity retention values. Complicated mathematical fittings are not necessary. The method lends itself equally to the testing of in- and outpatients.

Hb Graz or alpha 2 beta 2(2)(NA2)His-->Leu; a new beta chain variant observed in four families from southern Austria

Two abnormal hemoglobins were accidentally detected by cation exchange high performance liquid chromatography with the Diamat system of Bio-Rad Laboratories; the variants eluted together with the fast-moving Hb A1c. Structural analysis of isolated beta chains and sequence analysis of amplified DNA identified a new variant, i.e. Hb Graz that has a His-->Leu replacement at position 2 of the beta chain, in four healthy, apparently unrelated, adults. The second variant was identical to Hb Sherwood Forest or alpha 2 beta 2(104)(G6)Arg-->Thr; it is believed that this may be the second observation of this abnormal hemoglobin.

[The diagnostic potential of amniocentesis in the first 12 weeks of pregnancy]

Prenatal diagnosis of chromosomal and biochemical defects is accepted as a routine in high-risk patients. To eliminate the disadvantages of traditional amniocentesis (late diagnosis) and of chorion villus sampling (placentar mosaics, higher fetal loss rate) we evaluated the facts on amniocentesis during the first 12 weeks of pregnancy. 42 samples were analysed. 21 amniotic fluid samples were from pregnancies before the 13th week of gestation, 21 further punctures were performed between the 13th to 15th week and served as comparative figures. Of 21 samples, diagnosis was possible in 16 cases. Four cultures did not show any growth of cells; in one case, amniotic fluid could not be aspirated. In the comparison group chromosomal diagnosis could be done in every case. An average of 12.3 ml of amniotic fluid were taken. Chromosomal disorders found, included a translocation in chromosome 13/14 as well as a trisomy of chromosome 18. Biochemical defects such as Gaucher's disease and Niemann-Pick disease were excluded. 30 pregnancies without pathological symptoms were seen (mean birth weight 3200 g, mean duration of pregnancy 39 weeks). One case of abortion following amniocentesis was found in the 16th week of gestation. One case of premature delivery occurred in the 34th week and the pregnancy of a 40-year old women was complicated by EPH gestosis while 9 pregnancies were terminated by interruption following the patients' wish. Because chromosomal diagnosis could not be performed in five of 21 cases, amniocentesis during the 13th week of gestation cannot be recommended as a routine method. Early amniocentesis, however, is an alternative to the traditional amniocentesis at the 16th week of gestation.

Abortion risk in chorionic villus sampling. Evaluation in elective termination of pregnancy

100 patients were examined to evaluate the risk of abortion of chorionic villus sampling. In the 8th-10th week of pregnancy a catheter with a mandrin was introduced into the chorion frondosum under ultrasound guidance. The mandrin was then removed and trophoblast tissue obtained by aspiration. The patients agreed to postpone elective termination of pregnancy for 2 weeks. Another ultrasound was performed before suction curettage. With increasing experience, the abortion rate dropped to 4%, whereas the rate of successful biopsies and analyses rose to more than 90%. Based on these results, chorionic villi sampling was made available at the 1st Department of Obstetrics and Gynecology, University of Vienna, as an alternative method to amniocentesis. Out of 38 biopsies, 25 karyotypes were normal, two biopsies revealed pathological results (trisomy 21, 22), 11 samples showed no results (insufficient tissue or no mitoses). One patient had a spontaneous abortion (trisomy 22) and one an abortion due to infection. Chorionic villus sampling could replace amniocentesis because chromosomal anomalies may be detected already in the 1st trimester of pregnancy.

[Value of chorionic biopsy in routine clinical diagnosis]

To test the advantages and risks of chorionic villi sampling, a method still new in prenatal diagnosis, 100 patients were examined. Most of the biopsies were taken in the 8th week of pregnancy. A soft catheter with a flexible mandrin was introduced transcervically to the chorion frondosum guided by ultrasound. The mandrin was then removed and trophoblastic tissue obtained by aspiration. The risk of abortion within 10-14 days after biopsy could be reduced to 4%. In the last series of chorionic villi samplings 92% of these could be evaluated cytogenetically. The use of quinacrine fluorescence technique showed that female mitoses were never found in male tissue. Because of the relatively low risk of abortion and the high diagnostic accuracy achieved in a very short period of time chorionic villi sampling can be considered as an alternative to amniocentesis.

Gene localisation of the PGM1 enzyme system and the Duffy blood groups on chromosome No. 1 by means of a new fragile site at 1p31

During routine paternity testing an apparent maternal exclusion was suggested by the PGM1 enzyme system (mother PGM1 1, child PGM1 2) and by the Duffy system (mother Fy(a-b+), child Fy(a+b-]. To clarify these findings chromosomal analyses and anthropological investigations were carried out. The possibility that the child had been mistakenly identified after birth could be eliminated. Chromosome analysis of the child showed a fragile site on one chromosome No. 1 at 1p31, a position supposed to carry the PGM1 and the Duffy loci. Although the father of the child is unknown, paternal origin of the fragile site is unlikely on account of the coincidence of the structural aberration with the missing expression of the maternal PGM1 and Duffy alleles thought to be located at the chromosome region involved. Thus localisation of the PGM1 and Duffy loci on 1p31 seems to have been achieved in an unusual way. The two loci appear to be closely linked.

Malignant histiocytosis with unusual features. Disseminated intravascular coagulation with severe hyperfibrinolysis, acute polyneuroradiculitis Guillain-Barré, and a unique chromosome abnormality

The case of a 25-year-old man with the characteristic features of malignant histiocytosis (proliferation of abnormal histiocytic cells with erythrophagocytosis, hepatosplenomegaly, increased serum acid phosphatase, hypercalcemia, and bone pain) is reported. Chromosome studies revealed a near tetraploid karyotype with a pair of marker chromosomes. A few hours after initiation of chemotherapy with cyclophosphamide, Adriamycin (doxorubicin), vincristine, and prednisolone (CHOP regimen), the patient developed an acute ascending paralysis. Cerebrospinal fluid (CSF) findings were consistent with a diagnosis of Guillain-Barré Syndrome. On the next day, disseminated intravascular coagulation (DIC) with severe hyperfibrinolysis occurred. After intensive chemotherapy, complete remission could be achieved.

[New staining methods for chromosome analysis (author's transl)]

The new fluorescent dye D 287/170 selectively stains human heterochromatin in chromosomes 9, 15 and Y. By using the DA-DAPI method the secondary constrictions of chromosomes 1 and 16 are additionally brilliantly stained. Various AT-specific dyes, such as quinacrine mustard or DAPI, show different staining behaviour in these heterochromatic segments. The most likely cause for these diverse results may be found not only in differences in DNA base frequency, but also in base sequence binding of fluorochrome to DNA. The D 287/170 method may prove useful in a variety of investigations such as, for instance, chromosome studies in malignant cells, hybridomas, evolutionary studies and in patients with problematic chromosome aberrations.

Chromosome abnormalities in 150 couples with multiple spontaneous abortions

One hundred fifty consecutive couples with recurrent abortions with or without fetal deaths, malformations, or healthy infants were evaluated cytogenetically with a G-band method. Seven couples (4.7%) showed a chromosome aberration in one partner (5 translocations, 1 inversion, and 1 gonosomal mosaicism). Of the couples with a pure abortion history, 2.9% had a chromosomal abnormality. A high incidence of chromosomal rearrangements in the groups of couples with abortions plus fetal deaths or malformations was found. In contrast to other reports, a high incidence of cytogenetic abnormalities was also found in couples with abortions and healthy infants. Chromosome analysis is advocated as a primary tool in the evaluation of couples with repetitive fetal wastage.

Differential fluorescent staining of porcine heterochromatin by chromomycin A3/distamycin A/DAPI and D 287/170

R banding of porcine chromosomes by chromomycin A3 plus distamycin A and DAPI (DA-DAPI) revealed two distinct types of heterochromatin: The GC-rich centromeric heterochromatin of the biarmed autosomes (Nos. 1-12) and of the X chromosome exhibited bright chromomycin A3 fluorescence, while the heterochromatin of the acrocentric chromosomes (Nos. 13-18) stained brightly by DA-DAPI. The latter also fluoresced brightly when stained by D 287/170. In addition, significant fluorescent polymorphism was observed among both acrocentric and metacentric chromosomes.

[Polymorphisms of the human chromosome no. 15 (author's transl)]

The short arm of the human chromosome No. 15 is composed of various heterochromatic regions. By using silver staining, mithramycin, Da-DAPI and quinacrine mustard fluorescence staining at least 5 different regions may be differentiated. All these components show independent heteromorphisms allowing easy individual identification of a given chromosome No. 15. These features may be useful for studies on heredity including affiliation cases.

[Cytogenetic findings in habitual abortion. Chromosomal analysis in 123 couples (author's transl)]

From the 1st of April 1974 till the 30th of September 1979 a consecutive series of 123 couples with a history of recurrent abortion was studied cytogenetically with modern banding techniques. 8 chromosomal aberrations were detected (6.5%); 3 women were found to be balanced reciprocal translocation carriers; the karyotype of 3 women and one man showed a pericentric inversion, one women was found to be a mosaic for 46 XX/45 X0. It is concluded from the results of this report that cytogenetic evaluation is indicated in cases of habitual abortion. The expected rate of chromosomal aberrations is especially high in couples with a mixed history of abortions, intrauterine fetal deaths and malformations. In case a chromosomal aberration is detected the patients have to be counselled individually according to the type of anomaly.

Effects of counterstaining with DNA binding drugs on fluorescent banding patterns of human and mammalian chromosomes

Pairs of fluorescent A-T specific dyes and nonfluorescent agents with similar or complementary base pair binding specificity were used to analyse the extent to which banding patterns in human chromosomes obtained by fluorescent staining can be modified by counterstaining. By testing a variety of different combinations of drugs, essentially three types of alterations were observed. Enhanced contrast of specific heterochromatic regions was obtained with pentamidine, or netropsin, in conjunction with the fluorescent stains Hoechst 33258, DAPI or DIPI, the resulting banding patterns being similar to that reported for distamycin A plus DAPI (DA-DAPI banding [21]. Uniform quenching of Hoechst 33258, DAPI or DIPI fluorescence was induced by counterstaining with stilbamidine or berenil. The combination of echinomycin with DAPI resulted in an improved contrast of DAPI banding on chromosome arms and pale fluorescence on major autosomal C band regions. In addition, a subdivision of the heterochromatic part of the Y chromosome may be discerned by this latter technique.

[Amniocentesis for antenatal diagnosis. A report on an initial series of 180 cases (author's transl)]

The results are presented of amniocentesis for diagnostic genetic purposes in 180 patients. A diagnosis was obtainable in 170 cases (94%). Genetic abnormalities were detected in 11 cases; one patient miscarried 3 days after amniocentesis. Antenatal diagnosis of certain genetic disorders can be considered a routine method nowadays and should be offered to any woman at risk. It therefore seems necessary to supply the practitioners with the relevant information on this topic.

[Amniocentesis for antenatal diagnosis. A report on an initial series of 180 cases (author's transl)]

The results are presented of amniocentesis for diagnostic genetic purposes in 180 patients. A diagnosis was obtainable in 170 cases (94%). Genetic abnormalities were detected in 11 cases; one patient miscarried 3 days after amniocentesis. Antenatal diagnosis of certain genetic disorders can be considered a routine method nowadays and should be offered to any woman at risk. It therefore seems necessary to supply the practitioners with the relevant information on this topic.

Antenatal diagnosis of a de novo reciprocal translocation 46,XX,t(3;7)(q21;q11)

A de novo reciprocal translocation 46,XX,t(3;7)(q21;q11), detected at amniocentesis performed because of advanced maternal age, is presented. Both parents showed a normal karyotype. The girl was delivered and has shown no phenotypic abnormality in the first year after birth. Problems encountered with the prediction of the fetal outcome in balanced structural rearrangements are discussed.

Structure and variability of human chromosomes analyzed by recent techniques

Besides the AT-specific fluorochromes, GC-specific fluorescent antibiotics are now available for chromosomal analysis. Chromosomal bands represent large accumulation of DNA sequences with similar AT:GC ratio. These uniform differences from the mean AT:GC ratio in the bands can be explained only by at least partial repetition of short DNA sequences in these regions. By comparison of various staining techniques more information also on the constitutive heterochromatin in man becomes available. The human NOR region exhibits a complex organization when studied by various base-specific fluorochromes and silver staining. The DNA-specific fluorochromes are also useful tools in cytophotometric DNA measurements.

The nature of the Ag-staining of nucleolus organizer regions. Electron- and light-microscopic studies on human cells in interphase, mitosis, and meiosis

Electron micrographs reveal that the Ag-stainable substance is located on the outside of NOR's or around them but not in the chromosomes themselves. In association figures, the Ag-positive material lies between the acrocentric chromosomes. Light-microscopic studies show that the Ag stainability of the nucleolus in interphase is correlated with the function of the NOR, as seen from inactive and activated lymphocytes. Much more Ag-positive material is seen in prophase than in meta- and anaphase. It starts to increase again in late telophase. In male meiosis the NOR's remain Ag-positive until pachytene. First and second metaphase figures are negative. Experiments using RNase, TCA, and trypsin indicate that the Ag-stainable substance is an acidic protein. The precipitation of Ag granules in interphase nuclei seen in the electron microscope is greatest over the fibrillar component of the nucleolus. The most likely interpretation is that the Ag-stainable material is a component of ribonucleic protein accumulating around active NOR's. In mitosis some of this material remains at the NOR's. In first meiosis it is completely removed before diakinesis.

Frequency of Ag-stained nucleolus organizer regions in the acrocentric chromosomes of man

The Ag-stainability of the nucleolus organizer region (NOR) was studied in the acrocentric chromosomes identified by Q-banding of cultured lymphocytes in 51 karyotypically normal persons (31 males and 20 females). A consistent pattern of Ag-positive NORs was found in each individual. Ninety percent of individuals have a model number of 8--10 Ag-positive NORs per cell. The frequency of Ag-positive NORs is similar in all five acrocentrics. A statistically nonsignificant lower frequency is found in chromosome 22. Ag-negative NORs on both homologues were found in four cases. The observed frequency distribution of individuals with homozygous NOR-positive, heterozygous, and homozygous negative acrocentric chromosomes was in accordance with the Hardy-Weinberg law in all five pairs of the acrocentric chromosomes as well as in total. No sex difference was observed on our material.

Mithramycin and DIPI: a pair of fluorochromes specific for GC-and AT-rich DNA respectively

The AT specificity of the fluorochromes DIPI and DAPI and the GC specificity of mithramycin are evidenced by observations in human, mouse, and bovine chromosomes. DIPI and DAPI produce a pattern similar to Hoechst 33258 in all three species, whereas mithramycin results in a reverse pattern. The AT-rich centromeric heterochromatin in mouse is brilliantly stained by DIPI or DAPI and remains nearly invisible after mithramycin staining. In the GC-rich centromeric heterochromatin of cattle the opposite behavior is observed.

DIPI and DAPI: fluorescence banding with only negliglible fading

DIPI and DAPI produce distinct fluorescent bands in human chromosomes similar to quinacrine banding patterns. Additionally, the AT rich secondary constrictions in the chromosomes Nos. 1, 9 and 16 are brightly fluorescent. On the other hand the brilliantly fluorescent regions after staining with quinacrine mustard in the chromosomes Nos. 3 and 4, satellites and some other regions in the acrocentric chromosomes are less striking. The distal part of the Y, however, is clearly discernible. Thus DIPI and DAPI seem to be strictly AT specific fluorochromes like Hoechst 33258. In interphase nuclei the Y chromosome can be identified. However, quinacrines are superior for Y-body analysis in buccal, hair cell and sperm smears. BrdU labeled chromatids show reduced fluorescence intensity. The difference, however, is less apparent than after staining with Hoechst 33 258. DAPI and especially DIPI are highly resistant to UV-irradiation; there is almost no fading within 30 min when using DIPI. Moreover, fluorescence intensity is stronger than in quinicrines. When photographing, exposure times may be reduced to about one quarter compared to quinacrine mustard.

[Catamneses of YY carriers in prison]

Among the 700 inmates of a big Austrian prison 5 cases of XYY caryotype were detected by means of the Quinacrinfluorescence method and subsequent lymphocyte culture. Keeping in mind that, if at all, only a small amount of criminal behavior may be explained by chromosomal factors three hypotheses about possible links between the XYY abnormality and criminal behavior are discussed in this paper. 1. the connection is a spurious one, as both criminal behavior and the XYY caryotype are more frequent in a working class population without being necessarily linked causally. 2. criminal behavior may be a consequence of the bodily abnormalities connected with the XYY abnormality. 3. the XYY type may contribute to criminal behaviour by acting upon neuro-endocrinological structures.

A photometric method for quantifying the polymorphisms in human acrocentric chromosomes

Photometric measurements on photomicrographs of quinacrine mustard--stained metaphase chromosomes, processed by a reverse developing procedure provide quantitative data on the polymorphisms of human acrocentric chromosomes. The method described is intended for population studies. The method is easily reproducible, allowing comparisons of data obtained by different laboratories.

[Translocation (13; 18) (q22; p 11) and prenatal diagnosis (author's transl)]

A balanced translocation (13; 18) (q 22; p 11) was diagnosed in two generations. Out of 10 pregnancies in these two translocation carriers, mother and daughter, only two phenotypically normal childern were born. One of these, namely the daughter, showed balanced translocation, whilst a normal karyotype was diagnosed prenatally in the second case. The other eight pregnancies ended either in spontaneous abortions, in intrauterine death or in lethal malformations. In the present translocation the formation of unbalanced gametes seems to be enhanced.

8-methoxypsoralen and UVA promote sister-chromatid exchanges

8-Methoxypsoralen (8-MOP) and long-wave UV light (UVA 365 nm) are now being use to treat vitiligo and psoriasis. Cultured human lymphocytes exposed to these agents in vitro show an increased infrequency of sister chromatid exchanges, related to 8-MOP-DNA photoadducts. Although these data raise questions regarding the biologic consequences of this therapeutic regimen, it is unknown whether 8-MOP and UVA cause mutations or extracutaneous somatic cell recombinants in vivo. Exchanges may represent cellular repair of DNA damage.

Increased sister chromatid exchange events in the human late replicating X

Human female blood cultures were labeled with BrdU for detecting sister chromatid exchanges (SCEs) by the Hoechst 33258 fluorescence technique. Late labeling with 3H-thymidine and autoradiography allowed the identification of the late replicating X. The mean number of SCEs in the cells was 13. The isopycnotic X showed an exchange frequency according to its relative length in the karyotype; in the late replicating X a doubled number of SCE events was observed.

Origin of the extra chromosome no. 21 in Down's syndrome

Eighteen of 38 examined families with children with Down's syndrome showed polymorphisms of chromosome 21 elucidating the origin of the extra chromosome 21. Maternal origin was found in 10 cases and paternal origin in 8 cases. In both sexes errors occurred both in the first and in the second meiotic division.

5-methylcytosine in heterochromatic regions of chromosomes in Bovidae

The centromeric regions of cattle, goat and sheep chromosomes bind anti-5-MeC as revealed by immunofluorescence technique, indicating concentration of 5-MeC at these heterochromatic regions. The centromere of the submetacentric X of cattle remains nearly unstained and so do the centromeres of the acrocentric X chromosomes in goat and sheep. The short arm of the cattle Y exhibits strong anti-5-MeC binding whereas the tiny Y chromosomes of goat and sheep contain no brightly fluorescent material.

[New methods in cytogenetic diagnosis (author's transl)]

Several different methods for identifying human chromosomes were developed over the past years. These methods include fluorescence techniques using quinacrine mustard, acridine orange or Hoechst 33 258 and special methods using Giemsa staining. Studies on replication of chromosomes were greatly improved by using BUdR labelling.