A protocol combining multiphoton microscopy and propidium iodide for deep 3D root meristem imaging in rice: application for the screening and identification of tissue-specific enhancer trap lines

BACKGROUND

The clear visualization of 3D organization at the cellular level in plant tissues is needed to fully understand plant development processes. Imaging tools allow the visualization of the main fluorophores and in vivo growth monitoring. Confocal microscopy coupled with the use of propidium iodide (PI) counter-staining is one of the most popular tools used to characterize the structure of root meristems in A. thaliana. However, such an approach is relatively ineffective in species with more complex and thicker root systems.

RESULTS

We adapted a PI counter-staining protocol to visualize the internal 3D architecture of rice root meristems using multiphoton microscopy. This protocol is simple and compatible with the main fluorophores (CFP, GFP and mCherry). The efficiency and applicability of this protocol were demonstrated by screening a population of 57 enhancer trap lines. We successfully characterized GFP expression in all of the lines and identified 5 lines with tissue-specific expression.

CONCLUSIONS

All of these resources are now available for the rice community and represent critical tools for future studies of root development.

Radiological study to evaluate the spreading of two volumes (10 vs. 20ml) of radiological contrast in the block of cutaneous branches of intercostal nerves in medial axillary line (BRILMA) in a porcine experimental model

OBJECTIVE

Interfascial blocks of the thoracic wall are being developed as an alternative to central blocks in breast surgery. However, there are few studies that have evaluated the anatomical extension of the local anaesthetic. The objective of this study was to analyse, using fluoroscopy, the spreading of two volumes (10 vs. 20ml) of radiological contrast in the serratus-intercostal plane block in an experimental pig model.

MATERIAL AND METHODS

Ten Large-White breed pigs were selected to have a bilateral ultrasound serratus-intercostal plane block performed, with the administering of 10ml and 20ml of iopamidol in the right and left hemithorax, respectively. The spreading of contrast was analysed by fluoroscopy. The Spearman test correlation was used to evaluate the relationship between the administered volume and radiological spreading. A value of P<.05 was considered significant.

RESULTS

Twenty anaesthetic blocks were performed, being able to analyse 18 of them. The administration of 10ml of contrast was associated with a mean spreading of 2.28±0.31 (95% CI; 2.01-2.54) intercostal spaces, while the administration of 20ml showed a spreading of 3±0.25 (95% CI; 2.81-3.18) intercostal spaces. There was a significant correlation between the injected volume and the spreading of the contrast (Spearman correlation coefficient of 0.81; P=.0001).

CONCLUSION

The results showed a spreading of volume subject to the serratus-intercostal plane block, although not maintaining a 1:1 ratio. Doubling the volume increased the blocked segments by 31%. These findings, if corroborated in the clinical practice, would allow a more precise adjustment in the anaesthetic volume administered.

Analysis of the temporal regression of the QRS widening induced by bupivacaine after Intralipid administration. Study in an experimental porcine model

OBJECTIVE

The principal mechanism of cardiac toxicity of bupivacaine relates to the blockade of myocardial sodium channels, which leads to an increase in the QRS duration. Recently, experimental studies suggest that lipid emulsion is effective in reversing bupivacaine cardiac toxicity. We aimed to evaluate the temporal evolution of the QRS widening induced by bupivacaine with the administration of Intralipid.

MATERIAL AND METHODS

Twelve pigs were anesthetized with intravenous sodium thiopental 5mg kg(-1) and sevoflurane 1 MAC (2.6%). Femoral artery and vein were canalized for invasive monitoring, analysis of blood gases and determination of bupivacaine levels. After instrumentation and monitoring, a bupivacaine bolus of 4-6 mg kg(-1) was administered in order to induce a 150% increase in QRS duration (defined as the toxic point). The pigs were randomized into two groups of six individuals. Intralipid group (IL) received 1.5 mL kg(-1)of IL over one minute, followed by an infusion of 0.25 mL kg min(-1). Control group (C) received the same volume of a saline solution. The electrocardiographic parameters were recorded, and blood samples were taken after bupivacaine and 1, 5, 10 and 30 minutes after Intralipid/saline administration.

RESULTS

Bupivacaine (4.33±0.81 mg/kg in IL group and 4.66±1.15 mg/kg in C group) induced similar electrocardiographic changes in both groups; mean maximal percent increase in QRS interval was 184±62% in IL group, and 230±56% in control group (NS). Lipid administration reversed the QRS widening previously impaired by bupivacaine. After ten minutes of the administration of IL, the mean QRS interval decreased to 132±56% vs. 15±76% relative to the maximum widening induced by bupivacaine, in IL and C group, respectively.

CONCLUSION

Intralipid reversed the lengthening of QRS interval induced by the injection of bupivacaine. Time to normalization of electrocardiographic parameters can last more than 10 minutes. While the phenomena of cardiac toxicity persist, resuscitation measures and adequate monitoring should be continued until adequate heart conduction parameters are restored.

["CLAPSEN", a global approach to the rehabilitation of severe childhood malnutrition in Bolivia]

The "CLAPSEN" approach was developed at the Hospital Materno Infantil German Urquidi in Cochabamba, to provide a global response for the study and treatment of childhood malnutrition. "CLAPSEN" is short for Clinical, Laboratory, Anthropometry, Psychology, Sociology, Nursing (Enfermera in Spanish) and Nutritional care. Most of the malnourished children admitted to Cochabamba Hospital are from poor families, more than three quarters of whom have only recently arrived in the city. Acute malnutrition is just one of the manifestations of a generally unfavorable environment. Malnutrition should not be considered as a simple deficiency in energy, protein or micronutrients, but rather as a multi-deficiency syndrome, also involving a lack of basic health and social care. This study demonstrates that malnourished children display a considerable degree of psychological retardation and of immune system depression. After five weeks of rehabilitation, the children were considered to have recuperated physically, as assessed by anthropometry, but not psychologically, as assessed by the adapted Dewer Score, or immunologically, as shown by the size of the thymus or the extent of maturation of lymphocytes. This strategy was not designed as a long-term approach for treating malnutrition, but rather as a research project to characterize the children arriving at the hospital, to determine the reasons for their malnutrition and to identify strategies that could be implemented earlier by health centers of social services, to prevent deterioration in the condition of these children to severe malnutrition requiring hospital admission. We believe that, in this Latin American context, in which the rate of acute malnutrition is low, the hospital should continue to be involved in the treatment of severely malnourished children with associated diseases. The child's stay in hospital should be short and once the child has recovered clinically, he should be sent home. In light of the observed levels of social deprivation, psychosocial and immune deficits, there appears to be a need for continued support for the family, to ensure the full recovery of the child and to prevent relapses.

Immune recovery of malnourished children takes longer than nutritional recovery: implications for treatment and discharge

Protein-energy malnutrition decreases cellular immunity yet immune recovery has rarely been investigated during nutritional rehabilitation. Malnourished children from low income families of Cochabamba (Bolivia) were hospitalized for 2 months in the Center for Immune and Nutritional Rehabilitation (CRIN), of the German Urquidi Materno-Infantil Hospital. They received a special four-step diet. Nutritional status was determined by a daily clinical examination and weekly anthropometric measurements. Immune status was assessed by weekly ultrasonography of the thymus. The classical criterion for discharge (90 per cent of median reference weight for height) was reached after the first month, whereas a 2-month period was required for complete immunologic recovery. The children belonged to disadvantaged population groups with high exposure to disease. In such an environment, discharge based only on nutritional status after 1 month of treatment could explain frequent relapses because the children were still immunodepressed.

[Immuno-nutritional recovery of children with severe malnutrition]

In developing countries, more than 12 million children die each year from the combined effects of malnutrition and infection. Malnourished children have impaired cellular immunity and are particularly sensitive to opportunistic infections. However, immune recovery has rarely been investigated during nutritional rehabilitation. Indeed, mortality remains high during renutrition, and relapses are frequent. We established a center in Cochabamba, Bolivia, specifically to save these children by treating both clinical and nutritional problems and restoring immune function. The CRIN (center for immuno-nutritional recovery) admits children with severe malnutrition from the Cochabamba suburban area. They are from low income families, in crowded living conditions with poor sanitation and are weaned early. Nutritional diagnosis was based on weight-for-height, arm to head circumference ratio and clinical examination for edema, loss of subcutaneous tissue and diminished muscle mass. The children were examined daily, and first treated for respiratory and intestinal infections. Sociological and psychological aspects were also included in our holistic approach to treating severe malnutrition. Children received a four-stage diet lasting 2 months. During the initial phase (1 week) they were given an oil-sugar-milk based diet, with half lactose concentration, seven times a day. This supplied 1.5 to 2.5 g of protein and 120 to 150 kcal/kg of body weight, according to the PEM pattern. Protein and energy intake was then slowly increased during the transition phase (1 week). During the next, 'calorific-protein bombing' phase (6 weeks) 5 g of protein and 200 kcal/kg of body weight were given daily, such that there was sufficient energy for protein accumulation. During the last, discharge phase (1 week), the protein and energy contents were slowly decreased. Weight, height, arm and head circumferences, and triceps skin-fold thickness were measured weekly by standardized methods. Thymus size was assessed weekly by mediastinal ultrasound scanning with a portable scanner (ALOKA SSD-210 DXII, Tokyo) using a 5 MHz linear pediatric probe. Lymphocyte subpopulations in peripheral blood were investigated monthly using monoclonal antibodies. Compared to controls, the malnourished group had severe involution of the thymus, a significantly higher proportion of circulating immature T lymphocytes and a lower proportion of mature T lymphocytes. The two month longitudinal study showed that normal anthropometric values (90% NCHS weight for height) were recovered after one month of rehabilitation. However, immune recovery (thymic area of 350 nm2) required two months. This may explain the frequent relapses among malnourished children discharged after one month on the basis of 'apparent nutritional health'. Such children may remain immunodepressed, and should therefore be considered as high risk children. To test an immunostimulatory treatment, we designed a historical cohort study of malnourished children who received 2 mg of zinc per day. The children were matched for age, sex, anthropometric criteria and nutritional status with malnourished control children (treated previously with zinc). Anthropometric recovery was obtained in both groups in one month. Children receiving zinc attained immunological recovery within one month, whereas children not receiving zinc took two months. Thus zinc hastened immunological recovery concomitant with nutritional recovery such that the duration of hospitalization could be halved: after one month of this immuno-nutritional treatment, malnourished children appear to be sufficiently healthy to face their pathogenic home environment.

In vitro lymphocyte-differentiating effects of thymulin (Zn-FTS) on lymphocyte subpopulations of severely malnourished children

This work investigates how thymic dysfunction contributes to the depression of cell-mediated immunity in protein-energy malnutrition (PEM). In Bolivian children hospitalized for severe PEM, the size of the thymus was measured by echography, and the lymphocyte subpopulations were detected by using monoclonal antibodies. These data were compared with those obtained from healthy control subjects. Regardless of the clinical form of PEM, our results show a high degree of T lymphocyte immaturity in severely malnourished children, which correlates with a severe involution of the thymus. Before in vitro incubation with thymulin, this significant increase in the percentage of circulating immature T lymphocytes was concomitant with a decrease in mature T lymphocytes and a slight increase in cytotoxic T subpopulations. After in vitro incubation with thymulin, immature T lymphocytes decreased and mature T lymphocytes increased.

[Acquired immunodeficiency syndrome in childhood. Report of 3 cases and review of the literature]

Three infants with the acquired immunodeficiency syndrome (AIDS) are reported. Two cases belong to infants died with AIDS; one of them have as infection source multiple transfusions of blood during the neonatal period and the other case was an haemophilic children transfused several times with commercial factor VIII. The third case belong to an infant, four months old, with AIDS-related complex, born of mother intravenous drug abuser. The authors comments some characteristics about pediatric AIDS and the present problems.

[N.B.T.-test in diagnosis of paediatric bacterial meningitis (author's transl)]

Usefulness of N.B.T.-test (absolute values and percentages) has been tested in the diagnosis of "acute meningitis" in pediatric age. A total of 210 children of different ages have been divided in 3 groups: group A, consisting of 105 children with bacterial meningitis. Group B, 36 children with viral meningitis and group C formed by 69 health children. Differences between groups A and B were statistically significant (p less than 0.001) on both percentage and absolute values, while they were non-significant (p less than 0.001) on both percentage and absolute values, while they were non-significant between B and C groups. On serial controls of N.B.T. test percentage value during follow-up of the disease, a progressive normalization was observed which authors think had value for evaluation of the efficacy of the treatment as well as for prognostic significance. Results were tabulated on the normogram of Feign et al., with significant areas for each group.