A family with a satellited Yq chromosome

Summary A large pedigree with a satellited Yq chromosome is described, Q, C, and NOR banding were performed. Family C proband suffers from a Klinefelter syndrome.     

Retinoblastoma,gross internal malformations,and deletion 13q14→q31

Summary A male patient with an interstitial deletion 13q14q31 is described. Our necropsy findings included a left retinoblastoma and several gross internal malformations. In this paper we reaffirm that band 13q14 is involved in cases of retinoblastoma and we propose, after studying accompanying cases of total or partial long arm trisomies 13, that the loss of specific 13q bands, from 13q14 to 13q31 is responsible for the congenital defects we are describing.     

Familial reciprocal translocation t(9;13)(p11;p12) investigated by silver staining and in situ hybridisation

Summary A maternal de novo reciprocal translocation between the short arms of chromosomes 9 and 13 is reported. Using C-, Q- or G-banding, it was not possible to determine the precise breakpoint on 13, but a combination of silver staining and in situ hybridisation was used to do so on the two chromosomes, and it was demonstrated that the break on chromosome 13 had occurred within the NOR.     

Growth and cell wall changes in rice coleoptiles

A fractionation of non-cellulosic sugars of Oryza sativa L. coleoptile cell walls was carried out and the composition of each fraction was studied during coleoptile growth.Percentages of fractions extracted with boiling water and with oxalate (pectic substances) were almost constant throughout development. An increase in the K II hemicellulosic fraction (extracted with 24% KOH) content, and a decrease in the K I hemicellulosic fraction (extracted with 10% KOH) were detected, when coleoptile growth finished.The percentage of glucose content in the K I hemicellulosic fraction was highest in young coleoptiles and lowest in old ones. Furthermore, a highly significant linear relationship between amounts of glucose and growth rate was obtained, while a inverse relationship between the amount of xylose and arabinose and growth rate was attained.Abreviations GLC gas liquid chromatography - IAA indole-3-acetic-acid - TFA trifluoroacetic acid - T_o minimum stress-relaxation time     

Could life have evolved in cometary nuclei?

Hoyle and Wickramasinghe have recently suggested that life may have originated in cometary nuclei rather than directly on Earth. Even though comets are known to contain substantial amounts of organic compounds which may have contributed to the formation of biochemical molecules on the primitive Earth, it is doubtful that the process of chemical evolution has proceeded in comets beyond the stage that has occurred in carbonaceous chondrites. Some of the arguments which do not favor the occurrence of biopoesis in comets are:

1. A large layer of cometary ices is ablated from the nucleus' surface each time the comet passes through perihelion, so that essentially most of the organic products on the surface would be sublimed, blown off or polymerized.
2. Because of the low temperatures of the cometary ices, polymers formed on one perihelion passage would not migrate deep enough into the nucleus to be preserved before they would be ablated away by the next perihelion passage.
3. In the absence of atmosphere, and discrete liquid and solid surfaces, it is difficult to visualize the synthesis of key life molecules, such as oligopeptides, oligonucleotides and phospholipids by condensation and dehydration reactions as is presumed to have occurred in the evaporating ponds of the primitive Earth.
4. Observations suggest that cometary nuclei have a rather weak structure. Hence, the low central pressures in comets combined with the high vapor pressures of cometary ices at the melting point of water ice, suggest that a liquid core is not a tenable structure. Yet, even if a cometary nucleus is compact enough to hold a liquid core and a transient liquid water environment was provided by the decay of²⁶Al, the continuous irradiation in water of most of the biologically relevant polymers would have hydrolyzed and degraded them.
5. Needless to say that the effects of radiation on self-replicating systems would also have caused the demise of any life forms which may have appeared under any circumstances.
6. Concerning viruses, the high specificity of host-parasite relationships and their coevolutionary lines of descent, rule out a cometary origin for them.

In summary, the view that life originated in comets is untenable in the light of all the available evidence.     

Energy metabolism in relation to oxygen partial pressure in human skeletal muscle during exercise.

1. The intramuscular oxygen partial pressure (pO2) in human gastrocnemius muscle was monitored during exercise and compared with metabolite concentrations reflecting the energy and the redox state in the tissue. Ten normal subjects and ten patients with peripheral vascular occlusive disease were investigated. 2. In normal subjects the pO2 at the end of exercise was related to the intensity of the exercise, expressed as effect (J/s) per contraction. 3. In both patients and normal subject the pO2 was related to the [ATP]/[ADP] ratio, the [lactate/[pyruvate] ratio and the phosphocreatine concentration in the muscle tissue at rest and during exercise. 4. At each pO2 value, a lower [lactate/[pyruvate] ratio was found in the muscle tissue of the patients compared with that of normal subjects. This was interpreted as a beneficial effect of the higher oxidative-enzyme capacity in the muscle of the patients. 5. The results show the importance of pO2 for the regulation of the energy and the redox state of the tissue. During exercise the changes induced in pO2 and thus the energy state will stimulate the respiratory rate. This might be an important link in triggering the oxidative-enzyme capacity in response to physical training as well as in peripheral vascular occlusive disease.     

Distribution of intermediate filaments in amphibian oxyntic cells

Summary Intermediate filaments of toad oxyntic cells were isolated and analysed by SDS-PAGE. The major proteins of the residue were identified as actin and a 51,000 dalton polypeptide. Immunological crossreactivity between toad oxyntic cell intermediate filament components and anti-prekeratin, was shown by double immunodiffusion tests and indirect immunofluorescence. The immunofluorescent decoration of oxyntic cells and the electron microscope images are coincident in locating the intermediate filaments mainly at the cortical and perinuclear basal zones. Furthermore, the cortical zone appears especially rich in prekeratin-like material at its adluminal third. This results in a cup-like structure that encloses the cell portion occupied by the tubulovesicular system, which does not contain intermediate filaments. The translocation of membranes occurring during the secretory cycle of the oxyntic cell, has been attributed to a system of contractile proteins. The disposition of the prekeratin-like material suggests a role for intermediate filaments in the generation of movement, produced by actin and myosin interaction, by providing a fixed plane for the anchoring of actin microfilaments.