Chromosome banding in amphibia. IV. Differentiation of GC- and AT-rich chromosome regions in Anura

The chromosomes of 26 species of Anura from variously highly envolved groups were analysed with the fluorescent GC-specific antibiotics mithramycin and chromomycin A3 as well as with the AT-specific quinacrine. The mithramycin- and chromomycin A3-stainings generally resulted in a pattern of the constitutive heterochromatin opposite to the one obtained with quinacrine stain. The weaker a heterochromatic region fluoresces with quinacrine, the stronger is the intensity of the fluorescence achieved with mithramycin and chromomycin A3. Some of the telomeric and interstitial heterochromatic regions, however, exhibit no enhanced fluorescence with any of the fluorochromes. The nucleolar constrictions of the nucleolus organizer regions (NORs) displayed the brightest mithramycin- and chromomycin A3-fluorescence in the karyotypes and interphase nuclei of all species examined. The contrast of the brightly fluorescing GC-rich heterochromatin and of the NORs is considerably enhanced, when the non-fluorescent AT-specific oligopeptide distamycin A is employed as a counterstain. No banding patterns were observed with the fluorochromes in the euchromatic regions of the metaphase chromosomes; this attributed to the strong spiralization of the anuran chromosomes. A cytochemical classification of the various chromatin types in the anuran chromosomes is discussed on the basis of the differential labelings found on the constitutive heterochromatin by means of the fluorochromes.

Demonstration of a heritable fragile site in human chromosome 16 with distamycin A

Fragile sites are induced in chromosome 16 (band q22) of lymphocytes from some individuals, when the lymphocyte cultures are treated with the oligopeptide antibiotic distamycin A. These induced fragile sites are inherited in a Mendelian fashion; there are interfamilial differences in their appearance. The interactions between distamycin A and chromosomal DNA and the possible composition of the DNA at the induced fragile sites are discussed.

Insulin-dependent diabetes and HLA

The study of a hundred and fifteen unrelated insulin-dependent diabetes and eight families with at least two insulin-dependent diabetes members made it possible to confirm the higher frequency of HLA-B8 and B18 (p less than 0.001) among patients, producing a RR of 2.24 and 2.47 respectively. The increased B15 frequency did not achieve statistical significance. B18 whose gametic association (delta = 0.0438) was significant only in diabetic patients was often related to Aw19-2 (Aw30 + Aw31). The B8/B18 genotype gave a relative risk (RR = 4.98) which was significantly higher than that of B8, B18 and B15 heterozygotes (1.50, 1.24 and 1.39 respectively). Pairs of diabetic siblings were more frequently HLA identical than would be expected by chance, and distribution of the pairs of affected sibs into the three categories, identical, semi-identical and different, was closer to the recessive model than to the dominant one. The fact that the B8/B18 individuals had a RR slightly higher than the B8 and B18 homozygotes and distinctly higher than the heterozygotes for only one of these genes, favours the hypothesis of two dominant genes, giving the appearance of recessivity. The gene associated with B18 in Southern Europe seems to play the same part as that of the gene associated with B15 in Northern Europe.

On the arrangement of chromosomes in the elongated sperm nuclei of Anura (Amphibia)

The position of specific constitutive heterochromatic chromosome regions within the elongated sperm nuclei of eight species of Anura was examined with Q- and C-banding. These species differ widely with regard to the number, size and position of the brightly fluorescing heterochromatic regions. The empirical frequency distributions determined for the heterochromatic regions relative to the longitudinal axis of the sperm nuclei were compared with random frequency distributions calculated on the basis of two spatial models. None of the specifically stained heterochromatic regions occupy any definite preferential position within the sperm nuclei. In two instances, a specific sequence of the heterochromatic regions within the sperm nuclei could be excluded. The type of chromosomal arrangement within the elongated sperm nuclei of Anura is discussed on the basis of the distribution patterns obtained.

Partial trisomy for the long arm of chromosome 7 due to familial balanced translocation

A partial trisomy for the distal segment of the long arm of chromosome 7 (bands q32 replaced by qter) was observed in a severely retarded child with somatic and CNS anomalies. The phenotypically normal father and paternal grandmother had a balanced reciprocal translocation between the long arm of a chromosome 2 and the long arm of a chromosome 7: 46,XX-XY,t(2;7) (q37;q32). The clinical features of the child at birth and at the ages of 5 months and 2 years are compared with those previously reported in cases of partial trisomy 7q.

[Congenital cystic dilatation of the intrahepatic bile ducts. Caroli's disease and its complications]

Two cases with congenital dilatations of the intrahepatic bile ducts are reported. The clinical, diagnostic and therapeutic aspects and possible complications of this rare disease are discussed. The well-known frequent occurrence of cholangiocarcinoma in Caroli's disease is illustrated by one of our patients. Because of the limited therapeutic possibilities, the prognosis of this illness remains unfavourable.

Seventh allele of the HLA-C series (Cve)

Serum VE reacting with 29.8% of French individuals seemed to define the seventh allele of the HLA-C series as shown by serologic and genetic investigations. The gene frequency of Cve is 0.163.

Pattern of activity of nucleolus organizers during spermatogenesis in mammals as analyzed by silver-staining

Silver-staining in the nuclei and chromosomes of spermatogenesis of four species of mammals (Man, Mus musculus, Rattus norvegicus, and Cavia cobaya) was investigated qualitatively and quantitatively. These species show a very similar pattern of activity of the nucleolus organizer regions (NORs) during the various stages of spermatogenesis. Silver precipitates are detectable in growing spermatogonia and up until the pachytene stage of meiotic prophase. During the meiotic metaphases I and II and during interkinesis silver-stainability disappears completely. A resumpton of silver-stainability occurs in round spermatids indicating a postmeiotic reactivation of NORs. This process does not persist beyond the early elongation phase. The quantitative determination of the silver-covered areas in relation to the total nuclear areas reveals minor differences between the species investigated with regard to the times and extents of maximum activation. The known localizations of the NORs in the karyotypes of the species investigated was confirmed using metaphase-preparations derived from somatic tissues.

A double-blind trial of synthetic salmon calcitonin in the treatment of acute pancreatitis

A multicenter randomized double-blind trial on the use of synthetic salmon calcitonin (SCT) was carried out in 94 patients with acute pancreatitis. In addition to strict standard treatment--without aprotinin, atropine, or antacids--50 patients received daily 3 x 20 micrograms = 300 MRCU SCT intravenously and 44 patients received placebo for 6 days. Mortality rate was not influenced, overall mortality being 5.3%. The number of patients without pain and with normalized serum amylase on a given day was significantly higher in the group treated with SCT. Other parameters such as doses of analgesics, leukocyte count, and normalization of seven defined clinical and laboratory criteria within 6 days showed a positive trend without reaching significance.

Demonstration of Y/autosomal translocations using distamycin A

The condensation of the brightly fluorescing Y-heterochromatin is prevented by cultivating leukocytes in a medium containing distamycin A. This technique provides a reliable method for the identification of those Y/autosomal translocations in which Y heterochromatin is involved. A case of a familiar Y/22 translocation and the distamycin A technique are described.

[Combination of cystic dilatation of the hepatic, common, and intrahepatic bile ducts (author's transl)]

Common duct cysts are a rare entity. The combination of cystic alterations of the entire bile duct system is less known. Etiology, classification, and Roentgen signs are described in a case presentation with common duct cyst and marked ectasia of the intrahepatic bile ducts.

Cystic fibrosis and HLA

In 94 children suffering from cystic fibrosis, no abnormal frequencies of HLA markers of the A and B locus were observed in comparison with the distribution of these antigens in control series. Furthermore, the HLA genotypes of seven pairs of diseased sibs are incompatible with the hypothesis of a closed linkage between CF--an autosomal recessive transmitted disease--and HLA.