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There was no significant difference in the mitotic indices of the cultures maintained at different CO2 concentrations, i.e. 0 percent, 5 percent and 10 percent. However, considerable variation was recorded among different individuals.

A 36-yr-old black female presented with primary amenorrhea. The chromosomal constitution based on QFQ (Q bands by fluorescence using quinacrine) RFA (R bands by fluorescence using acridine orange), GTG (G band by Giemsa using trypsin), and CBG (C band by Giemsa using barium hydroxide) techniques was 46, XX, duplicated (9; q12), inverted (9; p12q12.1) in lymphocytes and skin fibroblasts. Both sex chromosomes were normal. Buccal smear revealed 22% Barr bodies. Duplication and inversion of secondary constriction regions of chromosome 9 may possibly be associated with abnormal clinical features.

Sequential QFQ, RFA, and NSG techniques have been demonstrated on the same metaphase to facilitate the maximum characterization of human chromosomes with respect to heteromorphic markers. This combination offers an opportunity to compare the results of the RFA and NSG techniques, which are of particular interest as they concern NOR activity. Furthermore, it is useful in studying abnormalities involving acrocentric chromosomes, somatic association, and the regulation of rRNA synthesis.

Eighty normal Caucasians were studied by CBG technique for estimation of size and inversion heteromorphisms of chromosomes 1, 9, and 16. Size heteromorphisms were classified into one of five sizes using 16p as a reference standard: very small, small, intermediate, large, and very large. Inversion heteromorphisms were also classified into 5 categories - eg, no inversion; partial inversion - minor; half inversion; partial inversion - major; and complete inversion. The frequencies of size heteromorphisms for chromosomes 1, 9, and 16 were 11.3%, 47.5%, and 7.5%, respectively. Thirty-four chromosomes were found to have inversions. Of these, 16 were in chromosome 1, and 18 were in chromosome 9. No inversions were found in chromosome 16. An increase in the size of the h region was more frequently associated with inversion, suggesting that there is a possible relationship between size and inversion. For example, there were 118 chromosomes that were classified as "intermediate" by size; 23 (19.5%) had inversions. In contrast, there were 225 that were "small" in size, and only 10 (4.4%) had inversions. There was no significant difference between males and females for size and position heteromorphisms.

A case of chronic myelogenous leukemia (CML) with complex chromosomal abnormalities is reported. Conventional staining techniques indicated incorrectly that the Ph1 chromosome was not present. These studies showed a 46,XY,-1,+C karyotype in all bone marrow cells. Employing RFA (R bands by fluorescence using acridine orange) technique it was clear that the part of the long arm of chromosome 1 (1q23 leads to qter) was missing the tip of the long arm chromosome 22 (band q22) was translocated to it. The missing long arm of chromosome 1 was translocated to the long arm of chromosome 9. Furthermore, there was a break at band 9q22 and the whole terminal part was lost. The value of RFA technique is discussed.

One hundred patients with Ph1-chromosome-positive chronic myelogenous leukemia (CML) with t(9;22) are included in the present investigation. The position of the Ph1 chromosome in relation to the normal as well as the abnormal chromosomes 9 was localized at metaphase in 1,000 bone-marrow cells. Our study suggests that the rearranged chromosomes, i.e., Ph1 and t(9;22), are closer together than their normal homologues. This impression is based on extensive statistical analysis. The intimate relationship may be due to the fact that they carry reciprocal genetic material responsible for a power of attraction between them. Alternatively, it is tempting to hypothesize that there may be a DNA sequence homology in the bands of chromosomes 9q and 22q involved in the reciprocal translocation perpetuating this relationship in subsequently generating cells during mitotic cell divisions. Furthermore, c-abl and bcr genes might play some role in maintaining the spatial relationship.

The constitutive heterochromatin of the Indian muntjac (Muntiacus muntjak) was examined following digestion with various restriction endonucleases (AluI, HaeIII, HinfI, and MboI), as well as by selective fluorescence staining with distamycin A plus 4'-6-diamidino-2-phenylindole. Distinct areas within the C-bands were found to have characteristic staining patterns which were more conspicuous in the sex chromosomes. Two dot-like structures resistant to AluI were found in the X and Y1 chromosomes in the same position as the nucleolus organizer regions.

A simplified R banding technic is described which provides excellent delineation of major regions, easy identification of all chromosomes, and an accurate comparison of homologue lengths. The technic is simple, requiring only an initial incubation in buffer at 85 degrees C followed by acridine orange staining. The best presentation of the R banded chromosomes was obtained by printing in black and white from color transparency film. Variations in the length of the short arms of the acrocentric chromosomes are clearly and consistently defined. Satellites are not demarcated and appear as part of the short arm. Consistent banding was obtained, and the technic is suitable for use in routine clinical cytogenetic work.

The CML patients with so called masked Ph1-chromosome have been reviewed. Although the importance of c-sis and c-abl oncogenes is gaining popularity yet their role in the genesis of CML remain obscure. Patients with masked Ph1-chromosomes where chromosome 9 is not involved in the translocation(s) will provide a clue to the role of c-abl and/or c-sis in oncogenesis.

'Home made brew' (illicit liquor) is often consumed in rural areas of India. Forty-six such alcohol samples were collected from different areas to assess total acidity, pH and ethanol content. The mean ethanol content was 16.47% (v/v) (range 1.11-36.88%). Total acidity ranged between 0.56 and 10.88 with the mean of 2.85 g of sodium hydroxide/l. The mean pH was 4.20 (range 2.70-9.41).

The replication profiles of terminal segments of short arms (p) of human X and Y chromosomes are analyzed with RBA-technique at high resolution. Both the terminal regions present yellow green fluorescence showing the early and synchronous replication pattern during S-phase of the cell cycle. This clearly demonstrates the identical nature and functional homology between the two regions which contribute to end pairing seen in meiotic prophase I.

A possible cause of non-disjunction of chromosome 21 in Down Syndromes has been cytogenetically evaluated by examining the parents by Ag-staining technique. In all the cases studied so far, the contributing parents have active ribosomal cistrons on both chromosomes 21 i.e. both chromosomes are stained positively by silver staining. These results show that the active NORs might play an essential role in meiotic non-disjunction. Furthermore, the preliminary results demonstrate that the acrocentric associations of homologous and non-homologous nature involving chromosome 21 are the most frequent in the contributing parent which may further indicate the role of multiple cellular factors affecting the associations in promoting the nondisjunction in addition to active NORs. The possible mechanisms regarding the non-disjunction of chromosome 21 have been described.

The recent addition of restriction endonucleases in obtaining selective bands in the human genome has added a new dimension to molecular genetics. However, a considerable discrepancy exists in banding patterns produced by AluI in chromosomes 19 and 20, by MboI in chromosomes 4, 5, 8, 21 and 22 and by RsaI in chromosomes 12, 21 and 22. The principal causes of these differences are highlighted.

The extent of length heteromorphisms of the human Y chromosomes was measured in 50 patients with chronic myelogenous leukemia and was compared with 50 normal controls. No significant difference (p greater than 0.05) in the size of the Y chromosome was noted between these two groups. These findings differ from an earlier investigation, where a longer heterochromatic segment of Y chromosome was noted in malignant tumors and it was stressed that constitutive heterochromatin plays a role in susceptibility of cancer. Present investigation, however, suggests that this is not the case in patients with chronic myelogenous leukemia.

A 28-year-old normal East Indian was found to have a pericentric inversion of the Y chromosome. After reviewing the literature, it was concluded that an inverted Y chromosome does not impede the production of normal sperm and does not predispose to non-disjunction of other chromosomes in the progeny. Thus, the earlier concept of nondisjunction was rejected, and it is suggested that aberrant cases with aneuploidy and an inverted Y are fortuitous. The pericentric inverted Y is inherited from generation to generation and has no clinical significance. The prevalence of males with pericentric Y inversion in the general population is approximately 1 per 1000. It is suggested that a pericentric inversion of the Y chromosome is a rare chromosomal heteromorphism and should be called type III.

Glucose-repressed cells of the yeast Pichia ohmeri IGC 2879 transported glucose by facilitated diffusion. Derepression led to the formation of a glucose/proton symport and the simultaneous reduction of the facilitated diffusion capacity by about 70%. Cycloheximide prevented this interconversion indicating its dependence on de novo protein synthesis (proteosynthetic interconversion). In buffer with 2% glucose the glucose/proton symport suffered irreversible inactivation while the facilitated diffusion system was simultaneously restored. This reverse interconversion process did not require de novo protein synthesis as indicated by its lack of sensitivity to cycloheximide (degradative interconversion). Thus the glucose/proton symport system appeared to consist of about 70% of the facilitated diffusion proteins turned silent through association with additional protein(s) the latter being sensitive to glucose-induced repression and glucose-induced inactivation.

A new chromosomal abnormality is being presented in a patient with acute myelomonocytic leukemia (AMMoL). The cytogenetic findings in this case can be described as 43, XY, t(12;17) (q12;p13), del (4) (q31), -5,-7. This patient developed a treatment-associated leukemia. The possible causal and clinical implications in such patients with unusual cytogenetic findings are stressed. In addition, basic biological as well as public health implications are discussed which are based on particular cytogenetic abnormalities.

The heteromorphisms of C-band regions of human chromosomes are evaluated by means of restriction endonucleases AluI, DdeI, MboI, and RsaI. Every chromosome exhibits heteromorphic markers of the C-band regions except chromosome 8. Each enzyme was found to be highly characteristic in its staining profile, a result that clearly suggests the diversity of heterochromatin. The inherent C-band-region heterochromatin variability that is revealed by these enzymes provides a valuable tool in identifying markers as compared with other previously described techniques.

The cytological map of human Y chromosome is investigated at high resolution using Q-banding technique. There was no segmentation of the short arm which is in disagreement with current International Nomenclature. Also, the band q11.22 was not seen in the long arm using different individuals with variable size of Y chromosome. Furthermore, the length variation of nonfluorescent segment is also noted which was not suggested by the nomenclature.

Eighty normal American blacks were studied by the CBG technique (C-bands by barium hydroxide using Giemsa) for estimation of size and inversion heteromorphism of chromosomes 1, 9, and 16, and the data were compared to those of whites using subjectively defined criteria. Size and inversion heteromorphisms were classified into 5 levels. The frequencies of size hetromorphisms of chromosomes 1 and 16 were 10.63% and 6.88%, respectively, which are not significantly different from those of a normal population of whites. A higher incidence of size heteromorphisms for chromosome 9 was noted in whites (47.5% vs 30%). The frequencies of inversion heteromorphism of chromosomes 1, 9, and 16 were 17.5%, 21.9%, and 0.0%, respectively. Overall, 61 chromosomes were found to have an inversion. Of these, 28 were in chromosome 1, and 33 were in chromosome 9. A higher incidence of inversion heteromorphisms of chromosomes 1 and 9 was noted in American blacks, while no inversions were found in chromosome 16 in either population. A significant association of increased size of the h region with inversion (r = 0.99 P less than 0.01) is demonstrated, ie, enlarged h regions have a higher frequency of inversions.

The variable morphology of nucleolar organizer regions (NORs) of human acrocentric chromosome 13 was studied in detail by the N-banding technique. It was demonstrated that NOR may become further segmented and several hypotheses have been proposed for structural variability. The polymorphic nature of NORs may have an important significance in human evolution.

We suggest that the short arms of human chromosome 15 (15p) exhibit intensity heteromorphisms by DA/DAPI technique. A method for classification of variable intensities is proposed. The different intensities can be classified into at least five classes. They are: negative, pale, medium, intense, and brilliant. Therefore we suggest that 15p is not always positive by DA/DAPI technique. The present findings reveal that the heteromorphism on 15p is far greater than previously thought.

The first cases of congenital adrenal hyperplasia III with variable clinical manifestations in female monozygotic twins are presented. Twin "A" revealed severe hypertrophy of the clitoris, labial fusion and a visible introitus. However, twin "B" manifested moderate clitoral hypertrophy, a visible introitus and no labial fusion. Neither infant had palpable gonads.