VACTERL-H associated with central hypothyroidism: a case report

The VACTERL-H syndrome is a rare combination of vertebral anomalies, anal atresia, congenital heart defects, tracheo-esophageal fistula, abnormalities of kidneys and limb anomalies together with hydrocephalus. This condition is recognized as a hereditary entity with poor prognosis. We present a newborn weighing 3400 g, born by cesarean section to a 27 years old mother who had had an irregular antenatal follow-up. The patient had severe hydrocephalus, proximal esophageal atresia and distal tracheoesophageal fistula, gastric outlet obstruction, imperforated anus and recto-urethral fistula, patent ductus arterious, a bifid scrotum, a vertebral defect, sacral dimple and central hypothyroidism. The patient had no limb defects. The association of central hypothyroidism and VACTERL-H has previously not been reported.     

Effects of seed nickel reserves or externally supplied nickel on the growth,nitrogen metabolites and nitrogen use efficiency of urea- or nitrate-fed soybean

Background and aims

Nickel (Ni) has a critical role in the urea metabolism of plants. This study investigated the impact of seed Ni content along with external Ni supply on the growth, various nitrogen (N) metabolites and N use efficiency (NUE) of soybean plants.

Methods

Soybean plants raised from Ni-poor or Ni-rich seeds were grown in nutrient solution with or without external Ni supply and fed with either urea or nitrate as the sole N source. The changes in growth, leaf chlorophyll levels, Ni and N concentrations of different plant parts, tissue accumulation of various N metabolites and N uptake of soybean as well as NUE and its components were examined.

Results

Nickel starvation reduced the shoot biomass of urea-fed plants by 25 % and the leaf chlorophyll levels by up to 35 %, but nitrate-fed plants were unaffected. Visual toxicity symptoms were not observed in urea-fed plants. Under urea supply, Ni-deficient plants had lower levels of total N, protein and free amino acids in various organs. Root uptake of urea was severely depressed in Ni-deprived plants. Availability of Ni did not have any effect on the NUE of nitrate-fed plants, whereas its deficiency reduced the NUE of urea-fed plants by 30 %. The growth and N nutritional status of urea-fed soybean were significantly improved by high seed Ni reserves as well as external Ni supply.

Conclusion

Adequate Ni supply is required for maximizing the growth, root uptake of urea and NUE of urea-fed plants. Seed Ni reserves contribute significantly to the Ni and thus N nutritional status of soybean.     

Investigation of the association between ATP2B4 and ATP5B genes with colorectal cancer

Colorectal cancer (CRC) develops as a multi-step process which results from gradual accumulation of mutations in proto-oncogenes, tumor suppressor, and DNA repair genes. Mortality rate of CRC is very high. Therefore, development of alternative diagnostic methods which can be used in the early diagnosis is crucial. ATP2B4 gene encodes one of the four isoforms of p-type ATPase PMCA enzyme and bears critical importance in maintaining the balance of intracellular calcium homeostasis by providing the export of calcium ions out of the cell. ATP5B encodes a subunit of the mitochondrial ATP synthase which is an f-type ATPase. In this study, the relationship between ATP2B4 and ATP5B genes and CRC regarding gene expression was investigated. Study groups were constructed from a number of 50 patients (25 males, 25 females) with the mean age of 55.68 ± 9.4 and the gene expression levels in the healthy and cancerous tissues of the patients were compared by using semi-quantitative PCR and Real-Time PCR methods. As a result, in patients with rectum tumors, there was a significant relationship between ATP2B4 gene expression and the tumor location and in patients younger than 45 years, ATP5B gene expressions were detected significantly higher in tumor tissues by using RT-PCR. However, no significant relationship was detected in terms of expression differences of ATP2B4 and ATP5B genes between cancerous and healthy tissues of the CRC patients. ATP2B4 and ATP5B genes might have indirect associations in CRC pathogenesis and the investigation of their interactions with DNA repair and other related genes may help in understanding of CRC formation.     

Amifostine, a radioprotectant agent, protects rat brain tissue lipids against ionizing radiation induced damage: an FTIR microspectroscopic imaging study

The ABC proteins are a family of membrane transporters that mediates the extrusion from cells of a wide variety of structurally unrelated substrates. The current review focuses on the role of these efflux pumps located in the intestine on the low oral bioavailability of trans-resveratrol. The enterocytes hold in the apical membrane three transporters, namely, P-glycoprotein (P-gp), multidrug resistance associated protein 2 (MRP2) and breast cancer resistance protein (BCRP), whereas the basolateral membrane contains multidrug resistance associated protein 3 (MRP3). The use of different specific inhibitors of these transporters as well as knockout mice enabled us to conclude that MRP2 and BCRP are involved in the extrusion of trans-resveratrol glucuronide and sulfate to the intestinal lumen without the participation of P-gp. The role of these transporters as a bottleneck in the absorption of trans-resveratrol cannot be undervalued affecting not only the bioavailability of its glucuronide and sulfate but also their distribution in the different organs.     

Role of magnesium in carbon partitioning and alleviating photooxidative damage

Magnesium (Mg) deficiency exerts a major influence on the partitioning of dry matter and carbohydrates between shoots and roots. One of the very early reactions of plants to Mg deficiency stress is the marked increase in the shoot-to-root dry weight ratio, which is associated with a massive accumulation of carbohydrates in source leaves, especially of sucrose and starch. These higher concentrations of carbohydrates in Mg-deficient leaves together with the accompanying increase in shoot-to-root dry weight ratio are indicative of a severe impairment in phloem export of photoassimilates from source leaves. Studies with common bean and sugar beet plants have shown that Mg plays a fundamental role in phloem loading of sucrose. At a very early stage of Mg deficiency, phloem export of sucrose is severely impaired, an effect that occurs before any noticeable changes in shoot growth, Chl concentration or photosynthetic activity. These findings suggest that accumulation of carbohydrates in Mg-deficient leaves is caused directly by Mg deficiency stress and not as a consequence of reduced sink activity. The role of Mg in the phloem-loading process seems to be specific; resupplying Mg for 12 or 24 h to Mg-deficient plants resulted in a very rapid recovery of sucrose export. It appears that the massive accumulation of carbohydrates and related impairment in photosynthetic CO2 fixation in Mg-deficient leaves cause an over-reduction in the photosynthetic electron transport chain that potentiates the generation of highly reactive O2 species (ROS). Plants respond to Mg deficiency stress by marked increases in antioxidative capacity of leaves, especially under high light intensity, suggesting that ROS generation is stimulated by Mg deficiency in chloroplasts. Accordingly, it has been found that Mg-deficient plants are very susceptible to high light intensity. Exposure of Mg-deficient plants to high light intensity rapidly induced leaf chlorosis and necrosis, an outcome that was effectively delayed by partial shading of the leaf blade, although the Mg concentrations in different parts of the leaf blade were unaffected by shading. The results indicate that photooxidative damage contributes to development of leaf chlorosis under Mg deficiency, suggesting that plants under high-light conditions have a higher physiological requirement for Mg. Maintenance of a high Mg nutritional status of plants is, thus, essential in the avoidance of ROS generation, which occurs at the expense of inhibited phloem export of sugars and impairment of CO2 fixation, particularly under high-light conditions.     

Glyphosate-induced impairment of plant growth and micronutrient status in glyphosate-resistant soybean (Glycine max L.)

This investigation demonstrated potential detrimental side effects of glyphosate on plant growth and micronutrient (Mn, Zn) status of a glyphosate-resistant (GR) soybean variety (Glycine max cv. Valiosa), which were found to be highly dependent on the selected growth conditions. In hydroponic experiments with sufficient Mn supply [0.5 μM], the GR cv. Valiosa produced similar plant biomass, root length and number of lateral roots in the control treatment without glyphosate as compared to its non-GR parental line cv. Conquista. However, this was associated with 50% lower Mn shoot concentrations in cv. Conquista, suggesting a higher Mn demand of the transgenic cv. Valiosa under the selected growth conditions. Glyphosate application significantly inhibited root biomass production, root elongation, and lateral root formation of the GR line, associated with a 50% reduction of Mn shoot concentrations. Interestingly, no comparable effects were detectable at low Mn supply [0.1 μM]. This may indicate Mn-dependent differences in the intracellular transformation of glyphosate to the toxic metabolite aminomethylphosphonic acid (AMPA) in the two isolines. In soil culture experiments conducted on a calcareous loess sub-soil of a Luvisol (pH 7.6) and a highly weathered Arenosol (pH 4.5), shoot biomass production and Zn leaf concentrations of the GR-variety were affected by glyphosate applications on the Arenosol but not on the calcareous Loess sub-soil. Analysis of micronutrient levels in high and low molecular weight (LMW) fractions (80% ethanol extracts) of young leaves revealed no indications for internal immobilization of micronutrients (Mn, Zn, Fe) by excessive complexation with glyphosate in the LMW phase.     

Cytogenetic analysis of buccal cells from shoe-workers and pathology and anatomy laboratory workers exposed to n-hexane, toluene, methyl ethyl ketone and formaldehyde.

People employed in the shoe manufacture and repair industry are at an increased risk for cancer, the strongest evidence being for nasal cancer and leukaemia. A possible causal role for formaldehyde is likely for cancer of the buccal cavity and nasopharynx. Exfoliated buccal cells are good source of tissue for monitoring human exposure to inhaled and ingested occupational and environmental genotoxicants. To assess the cytogenetic damage related to occupational exposure to airborne chemicals during shoe-making and the processes in pathology and anatomy laboratories, the micronuclei (MN) count per 3000 cells was measured in buccal smears from shoe-workers (group I, n = 22) exposed to mainly n-hexane, toluene and methyl ethyl ketone (MEK) and from anatomy and pathology staff (group II, n = 28) exposed to formaldehyde (FA). Eighteen male university staff were used as controls. The mean time-weighted average (TWA) concentrations of n-hexane, toluene and MEK in 10 small shoe workshops were 58.07 p.p.m., 26.62 p.p.m. and 11.39 p.p.m., respectively. The measured air concentrations of FA in the breathing zone of the anatomy and pathology laboratory workers were between 2 and 4 p.p.m. Levels of 2,5-hexadione (2,5-HD) and hippuric acid (HA), metabolic markers of n-hexane and toluene exposure, respectively, were significantly higher in the urine of workers in group I than in control subjects (p < 0.001 and p < 0.01, respectively). The mean (+/- SD) MN (0/00) [corrected] frequencies in buccal mucosa cells from workers in group I, group II and controls were 0.62 +/- 0.45%, 0.71 +/- 0.56% and 0.33 +/- 0.30%, respectively (p < 0.05 and p < 0.05 compared with controls for group I and group II, respectively). The effects of smoking, age and duration of exposure on the frequency of micronucleated buccal cells from workers in all three groups studied were also evaluated. Overall, the results suggest that occupational exposure to organic solvents, mainly n-hexane, toluene, MEK and FA, may cause cytogenetic damage in buccal cells and that use of exfoliated buccal cells seems to be appropriate to measure exposure to organic solvents.     

Short-term effects of boron, germanium and high light intensity on membrane permeability in boron deficient leaves of sunflower

With the ultimate purpose of clarifying the mechanism for aluminium (Al) toxicity and for Al tolerance, we tried to isolate cDNAs whose expression is induced by Al treatment and phosphate (P_i) starvation. We performed P_i starvation and Al treatment (two-step treatment) on suspension-cultured cells of Nicotiana tabacum L. cv. Samsun and then constructed a cDNA library using poly(A)⁺-RNA derived from the treated cells. Four independent cDNA clones (pAL 111, 139, 141 and 142) were isolated from the library by differential screening. Northern blot hybridization analysis indicated that the expression of these clones was induced by P_i starvation. Furthermore, we found that pAL 111 and pAL 142 are also induced by Al treatment. The complete cDNA sequencing of these 4 clones was determined. The results indicated that pAL111 is identical to the parA gene of N. tabacum, which is described as an auxin-regulated gene and that pAL142 is highly homologous to the parB gene of N. tabacum whose product has glutathione S-transferase (GST, EC 2.5.1.18) activity. Furthermore, we found a cysteine-rich domain in the amino acid sequence of pAL139. No DNA and deduced amino acid sequences homologous to the pAL141 were found.     

Effect of withdrawal of phosphorus on nitrate assimilation and PEP carboxylase activity in tomato

Tomato plants (Lycopersicon esculentum) grown in a complete nutrient solution for 8 days were transferred to a P-free solution of pH 6.0. Within 2 days of transfer the rate of alkalinization of the nutrient solution declined and by 4 days the solution had become acid. Nitrate transferred from roots to leaves was depressed over this period, and the rate of nitrate reductase activity in the leaves (the main site of assimilation of nitrate in tomato) had declined by 60% within 5 days of transfer. The activity of PEP carboxylase in the leaves of the P-deficient plants increased after 3 days, eventually becoming 3 times greater than in the leaves of plants adequately supplied with P. The PEP carboxylase activity in the roots of the P-deficient plants increased within 2 days, becoming 4 times greater after 8 days' growth. These results are discussed in relation to mechanisms for enhancement of P acquisition and maintenance of cation and anion uptake during P-deficiency.