Gas production in human ingesting a soybean flour derived from beans naturally low in oligosaccharides.

BACKGROUND: Ingestion of soy products may cause excessive intestinal gas. This gas results from colonic bacterial fermentation of the indigestible oligosaccharides raffinose and stachyose, which are present in high concentrations in legumes. OBJECTIVE: The objective of the study was to compare gas production and gaseous symptoms in healthy volunteers after ingestion of 34 and 80 g soy flour made from either conventional soybeans or soybeans naturally low in indigestible oligosaccharides. DESIGN: In a double-blind, randomized, crossover protocol, breath hydrogen (an indicator of carbohydrate malabsorption), flatus frequency, and abdominal symptoms were assessed after subjects ingested the soy products and after 2 control meals (rice or lactose-hydrolyzed milk). RESULTS: The sum of breath-hydrogen concentrations for 8 h was significantly greater (P < 0.005) after 34 g conventional soy (60.4+/-9.4 ppm) than after low-oligosaccharide soy (34.3+/-8.1 ppm). Greater differences were observed with 80-g doses: 157.9+/-19.4 ppm after conventional soy and 50.8+/-6.8 ppm after low-oligosaccharide soy (P < 0.001). Flatus frequency (7.5+/-1.9 times/12 h) was significantly greater (P = 0.039) after ingestion of 80 g conventional soy than after the control, rice meal (3.2+/-0.8 times/12 h), whereas flatus frequency after the low-oligosaccharide soy meal (3.9+/-0.7 times/12 h) was comparable with that after the rice meal. There were no significant differences in the severity of other abdominal symptoms. CONCLUSION: Soy flour derived from low-oligosaccharide soybeans resulted in less gas production than that derived from conventional soybeans.

Are some motives more linked to suicide proneness than others?

This research examines the importance of assessing motivations that crisis patients attribute for considering a suicide attempt. For 251 consecutive patients attending a crisis unit, suicide attempters and ideators indicated agreement with each of 14 reasons for attempting suicide. Principal components analysis of these agreement ratings yielded two factor scales of motives: Extrapunitive/Manipulative Reasons and Internal Perturbations. Scores for internal perturbations correlated significantly with patients' wishes to die, clinicians' ratings of patients' suicidal desire and preparation for suicide, and clinicians' overall evaluation of patients' suicidal risk. Associations between internal perturbations and these suicide measures were nonredundant with hopelessness. It is concluded that evaluating a suicidal person's internal reasons for attempting suicide has unique assessment value.

Fructan Accumulation and Sucrose Metabolism in Transgenic Maize Endosperm Expressing a Bacillus amyloliquefaciens SacB Gene.

Over 40,000 species of plants accumulate fructan, [beta]-2-1- and [beta]-2-6-linked polymers of fructose as a storage reserve. Due to their high fructose content, several commercial applications for fructans have been proposed. However, plants that accumulate these polymers are not agronomically suited for large-scale cultivation or processing. This study describes the transformation of a Bacillus amyloliquefaciens SacB gene into maize (Zea mays L.) callus by particle bombardment. Tissue-specific expression and targeting of the SacB protein to endosperm vacuoles resulted in stable accumulation of high-molecular-weight fructan in mature seeds. Accumulation of fructan in the vacuole had no detectable effect on kernel development or germination. Fructan levels were found to be approximately 9-fold higher in sh2 mutants compared to wild-type maize kernels. In contrast to vacuole-targeted expression, starch synthesis and endosperm development in mature seeds containing a cytosolically expressed SacB gene were severely affected. The data demonstrate that hexose resulting from cytosolic SacB activity was not utilized for starch synthesis. Transgenic seeds containing a chimeric SacB gene provide further evidence that the dominant pathway for starch synthesis in maize endosperm is through uridine diphosphoglucose catalyzed by the enzyme sucrose synthase.

Pathological fracture after prophylactic reconstruction nailing of the femur. The need for distal locking.

Reconstruction nails have become the treatment of choice for established or impending subtrochanteric fractures of the femur and distal locking is said not to be indicated if the isthmus is intact. We report a case where distal locking was not performed and a proximal fracture subsequently occurred. We believe that distal locking should always be carried out in impending subtrochanteric fractures which are treated by nailing.

Assessing outcome following calcaneal fracture: a rational scoring system.

Six existing clinical scoring systems for assessing outcome after calcaneal fracture are reviewed. All were applied to a diverse group of 75 patients who had sustained this injury. Stepwise multiple regression analysis was used to identify the most relevant variables within these systems. Based on this, a simplified and rational outcome scoring system was devised. This system was then tested on a further group of 41 patients and shown to comply well with the characteristics required of an objective outcome score.

Early experiences with the AO calcaneal fracture plate.

We describe our early experiences using the new AO plate for open reduction and internal fixation of displaced intra-articular fractures of the calcaneum. An overview of our operative technique based on 22 cases is given. The relative merits of the new plate are discussed and we conclude that the plate is a useful device for dealing with this complex injury.

The use of the axial CT scan in intra-articular fractures of the calcaneum.

The axial CT scan has become part of our routine management of os calcis fractures. This investigation helps distinguish between tongue and joint depression type fractures, gives important information regarding the fracture pattern in the anterior calcaneum and the degree of comminution of the sustentaculum tali and the subtalar joints. The scan is also useful in determining direction of movement of the body fragment.

Fractures of the calcaneum: the anterolateral fragment.

Our previous reports on the pathological anatomy and operative treatment of intra-articular fractures of the calcaneum failed to take account of the fracture pattern anterior to the posterior facet of the subtalar joint. We have reviewed our experience of 63 operative cases and have studied fractures with axial and coronal CT scans reconstructed onto plastic model bones. A constant anterolateral fragment exists, which is displaced by an extended lateral approach to the fracture. If it is unrecognised and unreduced, union in a displaced position may limit hindfoot eversion and disrupt the calcaneocuboid joint. We describe techniques for reduction and fixation of the fragment.

Heel pad thickness following calcaneal fractures: ultrasound findings.

Ultrasound measurements of heel pad thickness in 21 patients who had suffered unilateral fractures of the calcaneum were taken. Body weight was also recorded. Contrary to previous assertions in the literature, heel pad thinning was not found to occur and in fact a significant increase in heel pad thickness on the affected side was noted.

Diurnal changes in maize leaf photosynthesis : I. Carbon exchange rate, assimilate export rate, and enzyme activities.

Diurnal changes in photosynthetic parameters and enzyme activities were characterized in greenhouse grown maize plants (Zea mays L. cv Pioneer 3184). Rates of net photosynthesis and assimilate export were highest at midday, coincident with maximum irradiance. During the day, assimilate export accounted for about 80% of net carbon fixation, and the maximum export rate (35 milligrams CH(2)O per square decimeter per hour) was substantially higher than the relatively constant rate maintained through the night (5 milligrams CH(2)O per square decimeter per hour). Activities of sucrose phosphate synthase and NADP-malate dehydrogenase showed pronounced diurnal fluctuations; maximum enzyme activities were generally coincident with highest light intensity. Reciprocal light/dark transfers of plants throughout the diurnal cycle revealed that both enzymes were deactivated by 30 minutes of darkness during the day, and they could both be substantially activated by 30 minutes of illumination at night. During 24 hours of extended darkness, sucrose phosphate synthase activity declined progressively to an almost undetectable level, but was activated after 1.5 hours of illumination. Thus, the diurnal fluctuation in maize sucrose phosphate synthase can be explained by some form of light modulation of enzyme activity and is not due to an endogenous rhythm in activity. No diurnal fluctuations were observed in the activities of NADP-malic enzyme or fructose 6-phosphate-2-kinase. Phosphoenolpyruvate carboxylase was activated by light to some extent (about 50%) when activity was measured under suboptimal conditions in vitro. The results suggested that the rates of sucrose formation and assimilate export were closely aligned with the rate of carbon fixation and the activation state of sucrose phosphate synthase.

Diurnal Changes in Maize Leaf Photosynthesis : II. Levels of Metabolic Intermediates of Sucrose Synthesis and the Regulatory Metabolite Fructose 2,6-Bisphosphate.

Diurnal changes in the regulatory metabolite, fructose-2,6-bisphosphate (F26BP), and key metabolic intermediates of sucrose biosynthesis were studied in maize (Zea mays L. cv Pioneer 3184) during a day-night cycle. Whole leaf concentrations of dihydroxyacetonephosphate (DHAP) and fructose 1,6-bisphosphate changed markedly during the photoperiod. DHAP concentration was correlated positively with the rate of sucrose formation in vivo (assimilate export plus sucrose accumulation) and extractable activity of sucrose phosphate synthase (SPS). The changes closely followed net photosynthetic rate, which tracked irradiance. The other metabolic intermediates measured (glucose 6-phosphate, fructose 6-phosphate, and UDP-glucose) were either relatively constant over the 24 hour period or changed in a different pattern. Diurnal changes in leaf F26BP concentrations were pronounced, and fundamentally different than the pattern reported with other species. F26BP concentration decreased at the beginning of the day and remained low and constant; a 3- to 4-fold increase occurred with darkness, and slowly declined thereafter. In general, leaf F26BP concentration was negatively correlated with net photosynthetic rate, and also leaf DHAP concentration. Consequently, co-ordination of the regulation of cytosolic fructose 1,6-bisphosphatase and SPS was apparent. The results support the postulate that in maize leaves the activation state of SPS may be dependent on availability of DHAP and possibly other metabolites.

Coordinate control of sucrose formation in soybean leaves by sucrose-phosphate synthase and fructose-2,6-bisphosphate.

Net photosynthesis (CER), assimilate-export rate, sucrose-phosphate-synthase (EC 2.4.1.14) activity, fructose-2,6-bisphosphate content, and 6-phosphofructo-2-kinase (EC 2.7.1.105) activity were monitored in leaves of soybean (Glycine max (L.) Merr.) plants during a 12:12 h day-night cycle, and in plants transferred, at regular intervals throughout the diurnal cycle, to an illuminated chamber for 3 h. In the control plants, assimilate-export rate decreased progressively during the day whereas in transferred plants, a strongly rhythmic fluctuation in both CER and export rate was observed over the 24-h test period. Two maxima during the 24-h period for both processes were observed: one when plants were transferred during the middle of the normal light period, and a second when plants were transferred during the middle of the normal dark period. Overall, the results indicated that export rate was correlated positively with photosynthetic rate and sucrose-phosphate-synthase activity, and correlated negatively with fructose-2,6-bisphosphate levels, and that coarse control and fine control of the sucrose-formation pathway are coordinated during the diurnal cycle. Diurnal changes in sucrose-phosphate-synthase activity were not associated with changes in regulatory properties (phosphate inhibition) or substrate affinities. The biochemical basis for the diurnal rhythm in sucrose-phosphate-synthase activity in the soybean leaf thus appears to involve changes in the amount of the enzyme or a post-translational modification that affects only the maximum velocity.

Resolution of two molecular forms of sucrose-phosphate synthase from maize, soybean and spinach leaves.

Two forms of sucrose-phosphate synthase (EC 2.4.1.14) were resolved from leaves of three species, maize (Zea mays L. cv. Pioneer 3184), soybean (Glycine max (L.) Merr., cv. Ransom) and spinach (Spinacia oleracea L. cv. Resistoflay) by hydroxyapatite Ultrogel chromatography, using a 75-mM (designated peak 1) and 250-mM (peak 2) K-phosphate discontinuous-gradient elution. Rechromatography of the two forms showed that they were not readily interconvertible. The distribution of activity between the two forms differed among species and changed during purification of the enzyme. Recovery of peak-1 activity was specifically lowered when maize leaf extracts were prepared in the absence of magnesium, indicating that the two forms may differ in stability. In addition, the forms of the enzyme from maize differed in the extent of glucose-6-phosphate activation. These results provide evidence for the existence of multiple forms of sucrose-phosphate synthase in leaves of different species and that the forms differ in regulatory properties.

Changes in Nonstructural Carbohydrates in Different Parts of Soybean (Glycine max [L.] Merr.) Plants during a Light/Dark Cycle and in Extended Darkness.

Diurnal patterns of nonstructural carbohydrate (starch, sucrose, and hexose sugars) concentration were characterized in different parts (leaves, petioles, stems, and roots) of vegetative soybean (Glycine max [L.] Merr.) plants. Pronounced changes in all carbohydrate pools were observed in all plant parts during the normal photosynthetic period; however, starch accumulation within leaves accounted for more than 80% of the nonstructural carbohydrate accumulated by the plant during the light period. Efficiency of utilization of starch and sucrose during the normal dark period differed among organs, with leaves being most efficient in mobilizing starch reserves and roots being most efficient in utilizing sucrose reserves. The vast majority (about 85%) of the whole plant carbohydrate reserves present at the end of the photosynthetic period were utilized during the normal dark period. Sink leaf expansion ceased in plants transferred to extended darkness and the cessation in leaf expansion corresponded with carbohydrate depletion in the subtending source leaf and the remainder of the plant. Collectively, the results indicated that under the conditions employed, leaves are the whole plant's primary source of carbon at night as well as during the day.