Tissue-specific transcriptional profiling of iron-deficient and cadmium-stressed rice using laser capture microdissection.

Several metals are essential nutrients for plants. However, they become toxic at high levels and deleteriously affect crop yield and quality. We recently reported the spatial gene expression profiles of iron (Fe)-deficient and cadmium (Cd)-stressed rice using laser microdissection and microarray analysis. The roots of Fe-deficient and Cd-stressed rice were separated into the vascular bundle (VB), cortex (Cor), and epidermis plus exodermis (EP). In addition, vascular bundles from new and old leaves at the lowest node, which are important for metal distribution, were analyzed separately (newDC and oldDC, respectively). Genes expressed in a tissue-specific manner in the VB, Cor, EP, newDC, and oldDC formed large clusters. The genes upregulated in all of the VB, Cor, and EP by Fe deficiency formed a substantial cluster that was smaller than the tissue-specific clusters. Significant numbers of genes expressed in newDC or oldDC were also expressed in VB in roots, suggesting that vascular bundles in the lowest nodes and roots have a partially common function. The expression patterns of transporter families involved in metal homeostasis were investigated, and members of each family were either expressed differentially in each tissue or showed different responses to Fe deficiency. One potassium transporter gene, OsHAK22, was upregulated by Fe deficiency in VB, Cor, and EP, suggesting that OsHAK22 is involved in potassium transport associated with mugineic acids secretion.

Toxic trace metals in the mentally ill patients.

Serum Cadmium and lead were measured in 61 in- and out-patients of the Mental Health Unit of a University Teaching Hospital. Diagnosis using the ICD-10 Criteria divided the patients into 21 Depressives, 20 Manic-depressive and 20 Schizophrenics. Twenty "healthy" individuals matched for age and sex were used as controls. The measurements of cadmium and lead were done on admission and at 3 and 7 weeks after the relevant treatment had been given. Serum zinc was also measured because of the interaction between zinc and these toxic metals. Measurement was with the Atomic Absorption Spectrophotometer. Results showed that cadmium was raised in depressives (p < 0.02) and reduced in mania patients (p < 0.01). Lead was increased in depressives (p < 0.01) and schizophrenics (p < 0.05) but not in mania patients. Serum zinc was reduced in all mental patients. Serum levels of the toxic metals of the mental patients tended to move towards the values of the control group with treatment.

The concentration levels of Cd, Pb, Hg, Cu, Zn and Se in blood of the population in the Czech Republic.

Knowledge of normal levels of concentrations of trace elements (Cd, Pb, Hg, Cu, Zn, and Se) in the population serves, among others, in design of regulations concerning health protection, determination of exposure limits and prevention of diseases caused by deficiency of trace elements. Concentrations of the named elements in whole blood of the Czech population were determined by means of atomic absorption spectrometry. The blood was collected during 1996-1998 from 1,216 blood donors (896 males and 320 females, average age 33 years) and 758 children (397 boys and 361 girls, average age 9.9 years). Mineralisation in a microwave digestion system was used in sample preparation. The accuracy of results was checked by means of the Control material Seronorm Whole Blood 404107 and Seronorm Serum 704121, Nycomed. Values of concentrations of the trace elements in blood found for adult (medians) were 0.7 microgram Cd.l-1, 800 micrograms Cu.l-1, 0.78 microgram Hg.l-1, 41 micrograms Pb.l-1, 76 micrograms Se.l-1, and 5,800 micrograms Zn.l-1, respectively. Statistically significant differences between men and women have been found in the concentrations of Cu, Hg, Pb, and Zn. In the juvenile population following medians of concentrations have been found: 0.15 microgram Cd.l-1, 1,047 micrograms Cu.l-1, 0.46 microgram Hg.l-1, 34 micrograms Pb.l-1, 69 micrograms Se.l-1, and 8,180 micrograms Zn.l-1. Statistically significant differences between boys and girls were found only in Pb and Zn concentrations. Concentrations of the studied elements correspond to the published values concerning population not exposed professionally.

The effects of a low level of dietary cadmium on blood pressure, '24Na, '42K, andwater retention in growing rats.

The effects of 5 pg Cd per millilter of drinking water on body weight gain, food intake, systolic blood pressure, '24Na, '42K; and water retention and freference for NaCl solution in male and female rats were studied. After 205 days, Cd had no significant effect on weight gain, food intake, water intake, or feed efficiency. The'24Na retention of the Cd-fed male and female rats was greater at 161 days than in the control animals and was significantly greater (P less than 0.05) in the Cd-treated females than in the control females at 294 days. In vivo retention of '42K was significantly greater in the Cd-treated males than in the control males at 189 days, butthe oppisite was true of the Cd-treated females in comparison with female control animals. There were no significant differences between treatments in '42K retention after 330 days. No significant differences were found between treatments in systolic blood pressure. Water retention was significantly greater in the Cd-treated males and females than in the control animals after 320 days. Preference for 0.20 M NaCl was significantly greater in the Cd-fed males than in the control males at 277 days. Possible mechanisms which might explain the sodium retention in thhe Cd-fed rat are discussed.