Geographic structure of chloroplast DNA polymorphisms in European oaks

Chloroplast DNA polymorphisms have been detected by the conventional Southern-blotting hybridization method in four species of European oaks (Quercus petraea, Q. robur, Q. pubescens and Q. pyrenaica). Three polymorphisms, shared by at least three of these species, can be scored directly in ethidium bromidestained gels and were used in a broad survey of the level of differentiation of the oak species and of their pattern of genetic structure in western Europe. The highly significant geographic variation and the high genetic differentiation (Gst=0.895, SGst=0.025) indicate a low level of cytoplasmic gene flow. We conclude that cytoplasmic genomes are well suited for the reconstruction of past migrational routes of such a complex of species.

Maturation of maritime pine (Pinus pinaster Ait.) seedlings after exposure to a period of continuous light

Nine half-sib families of maritime pine (Pinus pinaster Ait.) of known adult performance were grown in continuous light at either 25 degrees C or 25/20 degrees C for 18 weeks. They were then exposed to a dormancy induction period followed by a dormancy release period and then grown for a further 9 weeks in a 16-h photoperiod at a day/night temperature of 25/20 degrees C. Seedlings exhibited great diversity in morphology at the end of the first growth period. The number of morphogenetic cycles varied between one and three and the form of the apical meristem ranged from a typical rosette to an adult-like bud. The type of seedling obtained at the end of the first growth period strongly influenced later growth, independently of the temperature regime. Maturity was proportional to the number of morphogenetic cycles achieved during the first growth period and was characterized by short growth duration, small primary needles and a high degree of fixed growth. The state of the apical meristem that underwent the dormancy period had less influence on the rate of maturation than the number of morphogenetic cycles. The time course of maturation was endogenously controlled and varied among traits. Conspicuous morphological differences were not associated with changes in the relationship between growth components at the phenotypic level. However, there seemed to be a shift in the genetic correlations between growth components after first budset.

Baculovirus gene ME53, which contains a putative zinc finger motif, is one of the major early-transcribed genes

We have been investigating the first viral genes to be transcribed in Spodoptera frugiperda cells after the infection with Autographa california nuclear polyhedrosis virus in order to identify regulatory proteins required for the activation of early and/or late gene transcription. By screening a cDNA library from polyadenylated RNA transcribed at 1 h postinfection, we identified a gene which is designated ME53. This newly identified gene is located upstream of the late p74 gene and forms a divergent promoter unit with the immediate-early gene IE0. The determination of the nucleotide sequence of ME53 has revealed an open reading frame encoding a gene product of 53 kDa. Furthermore, the sequence data suggest a putative DNA binding motif, a zinc finger, whose functional significance has yet to be shown. Transcription of ME53 does not require previous viral protein synthesis, and during infection, the level of promoter activity seems to be independent of trans-acting viral factors, as suggested by transient expression studies.

Predictions of age-age correlations of total height based on serial correlations between height increments in Maritime pine (Pinus pinaster Ait.)

Successive annual height increments (AHIs) are considered to be elements of a time series. Empirical data in Maritime pine (Pinus pinaster Ait.) show that genetic correlations between successive AHIs (serial correlation) decrease when the lag between corresponding growing seasons increases. When separated by more than 13 years AHIs are no longer genetically correlated. It is shown that age-age correlations between total heights depend on three components: the serial correlation structure between AHIs, the genetic coefficient of variation of AHIs, and the phenotypic growth curve of AHIs. Age-age correlations are computed in various combinations of the three components. Serial correlation structure and the genetic coefficient of variation had the more pronounced effect on age-age correlations. The genetic correlation between height at age 10 and height at age 50 varies between 0.764 and -0.136 according to the different combinations. Results obtained by simulations are comparable to those issued from previous empirical methods. mplications on early selection procedures and on optimal selection age are discussed.

Prevalence of lactose malabsorption among patients with functional bowel disorders

To investigate the prevalence of lactose malabsorption among patients with functional gastrointestinal disturbances we prospectively evaluated all patients referred to a gastrointestinal outpatient clinic over a period of 18 months. All patients had a breath hydrogen test following oral lactose in addition to the standard diagnostic procedures. In 37 of the total of 64 patients no organic cause of the gastrointestinal complaints was found. In 9 of these 37 patients (24%) the breath hydrogen test indicated lactose malabsorption. Three to 6 month later most of the patients with lactose malabsorption showed a significant reduction of gastrointestinal complaints after they had maintained a lactose-poor diet. In comparison, patients with functional disturbances but without lactose malabsorption reported nor or only minor improvement of symptoms; most of these patients had consulted another physician since the last visit in the clinic.

Vanadium induced impairment of haem synthesis

Biochemical and haematological profiles of workers exposed to vanadium were compared with those of non-exposed age matched subjects. A significantly positive and dose related correlation between serum vanadium and zinc protoporphyrin (ZPP) was observed. Normal lead concentrations excluded this heavy metal as a possible cause. Inhibition of the reduction of Fe to Fe++ by vanadium is discussed as the possible cause of interference of vanadium with haem synthesis. Iron and iron binding capacity were found to be significantly lower and ferritin significantly higher in the population exposed to vanadium. Strong inter-individual variations do not allow an explanation of this interference with iron metabolism.

[Temporomandibular ankylosis in Gabon (apropos of 13 case reports)]

The authors report on 13 cases of temporomandibular ankylosis observed in Gabon. Based on an epidemiologic and etio-pathogenic study, they dwell on the existing therapy of this affection, i.e. broad osteotomy with silicone interposition followed by mechanotherapy prolonged in time. Prophylaxis is discussed in the framework of Primary Health Care.

[Clinical aspects of sudden deafness]

Sudden deafness is a disease of multifactorial genesis. The cause remains as ever unknown. In addition to the vascular theory, the possibility of a perilymphatic fistula due to rupture of the oval or the round window membranes has gained more significance. Therefore the treatment of sudden deafness should begin as soon as possible. We treat such patients with infusions of Dextran 40. BVK and Complamin in increasing amounts, in addition to stella-ganglion block. It is not justifiable, for legal reasons to withhold treatment, and therapy should begin immediately.