VACTERL with hydrocephalus and branchial arch defects: prenatal, clinical, and autopsy findings in two brothers.

VACTERL association is defined as a combination of vertebral, anal, cardiac, tracheoesophageal, renal and limb anomalies, in particular radial defects. In recent years hydrocephalus was observed in patients with apparent VACTERL association. This particular condition was recognized as a hereditary entity with poor prognosis. Both autosomal recessive and X-linked forms were described. Here we report prenatal, clinical and autopsy findings in 2 brothers with this syndrome, who had, in addition, branchial arch anomalies. The recurrence in this family suggests X-linked inheritance. Branchial arch defects have so far not been described as part of the VACTERL+H syndrome. This observation further supports that a variety of brain anomalies including hydrocephalus associated with VACTERL anomalies represents separate entities with a considerable recurrence risk. The use of the term VACTERL "association" for these conditions is misleading and is discouraged.

Demonstration that the galactosyl and arabinosyl residues in the cell-wall arabinogalactan of Mycobacterium leprae and Mycobacterium tuberculosis are furanoid.

By a complex process involving methylation, partial hydrolysis with acid, reduction with sodium borodeuteride, ethylation, further hydrolysis and reduction, and subsequent capillary gas-liquid chromatography-mass spectrometry of the derived alditol acetates, it was established that the arabinogalactans of Mycobacterium leprae and Mycobacterium tuberculosis contain arabinofuranyosyl and galactofuranosyl residues exclusively. Thus, the covalently bound, highly immunogenic arabinogalactan of mycobacteria, and presumably of other actinomycetes, is highly unusual, in that all of the glycosyl residues are in the furanoid form. Furthermore, by establishing that the galactofuranosyl residues are either 5-, 6-, or 5,6-linked, their linkage pattern was established, and the literature is corrected on this point.

Heat Stress Responses in Cultured Plant Cells : Heat Tolerance Induced by Heat Shock versus Elevated Growing Temperature.

Using cultured pear (Pyrus communis cv Bartlett) cells, heat tolerance induced by heat shock was compared to that developed during growth at high temperature. After growth at 22 degrees C, cells exposed to 38 degrees C for 20 minutes (heat shock) showed maximum increased tolerance within 6 hours. Cells grown at 30 degrees C developed maximum heat tolerance after 5 to 6 days; this maximum was well below that induced by heat shock. Heat shock-induced tolerance was fully retained at 22 degrees C for 2 days and was only partly lost after 4 days. However, pear cells acclimated at 30 degrees C lost all acquired heat tolerance 1 to 2 days after transfer to 22 degrees C. In addition, cells which had been heat-acclimated by growth at 30 degrees C showed an additional increase in heat tolerance in response to 39 degrees C heat shock. The most striking difference between heat shock and high growth temperature effects on heat tolerance was revealed when tolerance was determined using viability tests based on different cell functions. Growth at 30 degrees C produced a general hardening, i.e. increased heat tolerance was observed with all three viability tests. In contrast, significantly increased tolerance of heat-shocked cells was observed only with the culture regrowth test. The two types of treatment evoke different mechanisms of heat acclimation.

Characteristics of tomato cell wall degradation in vitro: implications for the study of fruit-softening enzymes.

The in vitro degradation of green tomato (Lycopersicon esculentum L.) cell walls by an extract of ripe fruits was characterized. The susceptibility of isolated walls to enzymolysis varied considerably among the different cultivars tested. Wall solubilization in vitro appeared to be nearly as extensive as that which accompanies fruit ripening. The solubilized material was primarily polyuronide; smaller amounts of neutral sugar were released. Gel filtration chromatography indicated that an endopolygalacturonase was the only enzyme in the citrate extract able to hydrolyze isolated cell walls. However, this polygalacturonase in vitro did not lead to the substantial (40-60%) decrease in wall galactose which was observed in situ. This difference between in vitro and in situ wall modification is discussed in terms of the possible involvement of other wall hydrolases in fruit softening.

Glycosidases in Cell Wall-degrading Extracts of Ripening Tomato Fruits.

Enzyme preparations were obtained from cell wall debris of tomato (Lycopersicon esculentum L. cv. Tropic) fruits at various stages of ripeness and were assayed for glycosidase and polysaccharidase activities. In addition to polygalacturonase (mol wt 40,000), ripening fruits contain beta-galactosidase (mol wt 63,000) and beta-1, 3-glucanase (mol wt 12,000). The beta-glycosidases, unlike polygalacturonase, are active in extracts of green fruits. Placental tissue shows very low polygalacturonase but increasing beta-galactosidase and beta-1, 3-glucanase activities as ripening proceeds. A large change in the susceptibility of the walls to hydrolase action occurs before the stage in which the greatest polygalacturonase activity occurs. The possibility that the beta-glycosidases contribute to the wall modifications that lead to fruit softening is discussed.

Endosperm and pericarp involvement in the supercooling of imbibed lettuce seeds.

Fully hydrated lettuce (Lactuca sativa L.) seeds showed dual freezing exotherms (-9 and -18 degrees C), even after 10 hours imbibition. Only the -9 degrees C exotherm was observed in seeds imbibed for 20 hours, but without external nucleation, all water in the embryo supercooled. Results indicate that the endosperm acts as a barrier to ice propagation. Other experiments suggest that the pericarp may also protect the embryo under certain freezing conditions.

Degradation of Cell Wall Polysaccharides during Tomato Fruit Ripening.

Changes in neutral sugar, uronic acid, and protein content of tomato (Lycopersicon esculentum Mill) cell walls during ripening were characterized. The only components to decline in amount were galactose, arabinose, and galacturonic acid. Isolated cell walls of ripening fruit contained a water-soluble polyuronide, possibly a product of in vivo polygalacturonase action. This polyuronide and the one obtained by incubating walls from mature green fruit with tomato polygalacturonase contained relatively much less neutral sugar than did intact cell walls. The ripening-related decline in galactose and arabinose content appeared to be separate from polyuronide solubilization. In the rin mutant, the postharvest loss of these neutral sugars occurred in the absence of polygalacturonase and polyuronide solubilization. The enzyme(s) responsible for the removal of galactose and arabinose was not identified; a tomato cell wall polysaccharide containing galactose and arabinose (6:1) was not hydrolyzed by tomato beta-galactosidase.

Heat stress responses in cultured plant cells : development and comparison of viability tests.

The response of suspension-cultured pear (Pyrus communis cv Bartlett) cells to heat stress was studied using three viability tests: regrowth (culture growth during 10 days after stress); triphenyltetrazolium chloride reduction; and electrolyte leakage. Critical (50% injury) temperatures for a 20-minute exposure were 42 degrees , 52 degrees , and 56 degrees C, respectively, for these viability tests. Electrolyte leakage had the lowest temperature coefficient. Heat stress inhibition of triphenyltetrazolium chloride reducing capacity was much greater if the viability test was conducted 3 days, rather than immediately, after the stress treatment. Consistent with a major role for indirect metabolic strain in heat injury, treatment with 3.6 micromolar cycloheximide and heat stress (20 minutes at 43 degrees C) affected culture regrowth similarly. We conclude that the measurements of direct response are not adequate substitutes for regrowth tests in assessing heat injury to cultured plant cells.

Heat stress responses in cultured plant cells : effect of culture handling and age.

The pipetting of pear (Pyrus communis cv Bartlett) suspension cultures was followed by a substantial but transient decrease in heat sensitivity. During a culture cycle, pear cells were most sensitive to heat at day 3, which coincided with the period of most active cell division. To minimize serious artifacts, the influence of culture handling and age on parameters such as heat sensitivity must be standardized.

Loss of tomato cell wall galactan may involve reduced rate of synthesis.

Changes in the galactose content of the noncellulosic polysaccharides of tomato (Mill) fruit cell walls were analyzed under various conditions. On the plant, galactan decreased gradually during fruit growth. As normal fruits ripened, the loss of galactan increased sharply; this was not observed in attached rin fruits beyond the fully mature stage. The ability to produce new wall galactan in vitro was retained in mature fruit tissue but declined with ripening. Normal tomatoes ripening on the plant showed a transient increase in galactan content at the climacteric. It is suggested that the decline in wall galactan is partly due to reduced synthesis in senescing, normal fruits and in detached rin tomatoes.

Cell Wall and Extensin mRNA Changes during Cold Acclimation of Pea Seedlings.

During exposure to 2 degrees C, pea (Pisum sativum) seedlings cold acclimated to a killing temperature of -6 degrees C. Associated with this increase in freezing resistance was an increase in the weight of cell walls and changes in wall composition. Arabinosyl content increased by 100%, while other cell wall glycosyl residues and cellulose increased by about 20%. The cell wall hydroxyproline content increased by 80%. Arabinose and hydroxyproline are both major components of the structural cell wall glycoprotein, extensin. The increase in these components indicates that the level of extensin in the cell wall increases during cold acclimation. Northern blot analysis, using the pDC5A1 genomic clone as a probe, revealed a more than three-fold increase in total extensin mRNA during exposure to cold temperature. Specific extensin transcripts of 6.0, 4.5, 3.5, 2.6, 2.3, 1.8, and 1.5 kilobases were identified. Those at 6.0, 2.6, and 1.5 kilobases were especially promoted by low temperature treatment. The rise in extensin during cold acclimation may be regulated, at least in part, at the gene level. The possible structural role of this protein in freezing protection is discussed.

Relationships among cold hardiness, root growth potential and bud dormancy in three conifers.

Greenhouse-cultured, container-grown ponderosa pine (Pinus ponderosa var. scopulorum Engelm.), interior Douglas-fir (Pseudotsuga menziesii var. glauca (Beissn.) Franco) and Engelmann spruce (Picea engelmannii (Parry) Engelm.) were cold acclimated and deacclimated in growth chambers over 19 weeks. Stem cold hardiness, total new root length at 14 days and days to bud break were measured weekly. Relationships among cold hardiness, root growth potential (RGP) and bud dormancy suggest that cold hardiness, which can be measured quickly, could provide a useful basis for estimating the two other parameters. During cold acclimation, there was a lag period in which stem cold hardiness remained at -15 degrees C and RGP was at a minimum, in all three species. Douglas-fir and Engelmann spruce buds remained fully dormant during this lag period. Ponderosa pine buds had no chilling requirement for the loss of dormancy, and reached quiescence during the lag period. Immediately following the lag period, as stem cold hardiness progressed to -22 degrees C, RGP increased to a high plateau in all three species, and Douglas-fir and Engelmann spruce buds approached quiescence. Cold deacclimation and bud development began immediately on exposure to warm, long days, but RGP remained high until stem cold hardiness returned to approximately -15 degrees C. At bud break, cold hardiness and RGP were at the minimum.

Comparison of three cold hardiness tests for conifer seedlings.

Greenhouse-cultured, container-grown ponderosa pine (Pinus ponderosa var. scopulorum Engelm.), interior Douglas-fir (Pseudotsuga menziesii var. glauca (Beissn.) Franco), and Engelmann spruce (Picea engelmannii (Parry) Engelm.) were cold acclimated and deacclimated in growth chambers over 19 weeks. Cold hardiness was measured weekly by a whole-plant freeze test and by two quick tissue tests: freeze-induced electrolyte leakage of needles, and differential thermal analysis of buds. The whole-plant freeze test provided results in 7 days, and indicated differences in cold hardiness among stems, buds, and needles. Although the whole-plant freeze test could accurately measure cold hardiness, it was not precise, and it required destructive sampling. Results from freeze-induced electrolyte leakage and differential thermal analysis were available in 2 days and 1 hour, respectively. The freeze-induced electrolyte leakage test was a precise, sensitive and objective predictor of changes or differences in tissue cold hardiness. To determine actual cold hardiness, results could be calibrated to the response of the same tissue in the whole-plant freeze test. The speed and objectivity of differential thermal analysis made this test useful for rapid, general assessment of cold hardiness status, but calibration was difficult, and precision varied.

[The von Hippel-Lindau syndrome. Its differential diagnosis from cystic kidneys in adulthood]. / Das v. Hippel-Lindau-Syndrom. Differentialdiagnose von Zystennieren im Erwachsenenalter.

A 51-year-old patient with severe back pain had undergone resection of a benign cerebellar tumour when aged 15 years. In addition, polycystic kidney disease was diagnosed 24 years ago, bilateral phaeochromocytoma 2 years ago, and for 4 months before the present admission he had been on haemodialysis. The family history indicated autosomal dominant inheritance of the polycystic renal disease. His general condition was found to have deteriorated, he had pain on pressure over the upper thoracic and lower lumbar vertebrae, and the kidneys were enlarged on palpation. There were increased concentrations of calcium (3.01 mmol/l), parathormone (2.0 ng/l), carcinoembryonic antigen (13.5 micrograms/l) and TPA (69 U/l). Computed tomography demonstrated cystic and solid parts of much enlarged kidneys. Biopsy revealed a poorly differentiated clear-cell renal carcinoma. Further information concerning the previously removed brain tumour showed this to have been an haemangioblastoma of the cerebellar tonsils indicating the diagnosis of v. Hippel-Lindau disease. Nine other family members had been affected, but none had the full-blown picture of the disease. The patient died 3 weeks later from the rapidly advancing tumour. Autopsy showed the bilateral renal carcinoma, bilateral phaeochromocytoma and metastases to the sternum, femurs, vertebrae and liver.

Body fat distribution of overweight females with a history of weight cycling.

Weight cycling may cause a redistribution of body fat to the upper body fat compartments. We investigated the distribution of subcutaneous adipose tissue (SAT) in 30 overweight women with a history of weight-cycling and age-matched controls (167 normal weight and 97 overweight subjects). Measurements of SAT were performed using an optical device, the Lipometer. The SAT topography describes the thicknesses of SAT layers at 15 anatomically well-defined body sites from neck to calf. The overweight women with a history of weight cycling had significantly thicker SAT layers on the upper body compared to the overweight controls, but even thinner SAT layers on their legs than the normal weight women. An android fat pattern was attributed to overweight females and, even more pronounced, to the weight cyclers. The majority of normal weight women showed a gynoid fat pattern. Using stepwise discriminant analysis, 89.0% of all weight cyclers and overweight controls could be classified correctly into the two groups. These findings show the importance of normal weight maintenance as a health-promoting factor.