Photodegradation of 2,4-D (dichlorophenoxyacetic acid) with Rh/TiO2; comparative study with other noble metals (Ru, Pt, and Au).

In this work the effect of noble metal on the photodegradation of 2,4-dichlorophenoxyacetic acid herbicide using TiO2 as support was studied. The metals and concentration were: Rh, Ru, Pt and Au and 1, 0.98, 1.89, and 1.91 wt% respectively. Rhodium was taken as reference for this experiment. The samples were characterized by X-Ray Diffraction (XRD), UV-vis absorption spectra, N2 physisorption (BET Specific Surface Area), High Annular Angle Analysis Darkfield (HAADF) and Transmission Electron Microscopy Scanning (STEM), H2 chemisorption, optical emission spectroscopy with inductive coupling plasma analysis (ICP-OES), solid fluorescence, X-ray Photoelectron Spectroscopy (XPS) and OH quantification. The presence of the anatase crystalline phase was mostly confirmed in all samples. The band gap decreased with the presence of metal (from 3.24 to 2.92 eV). The specific area was a function of the metal particle size. The metal particle diameter showed the following sequence Pt > Ru > Au > Rh. By XPS, TiO2 does not manifest changes in oxidation states, but when impregnated with metals, only Pt shows the highest abundance of any oxidized state (Pt2+). The presence of metal reveals less electron-hole recombination compared with titanium oxide. The results of photocatalytic activity showed that Pt and Rh are the two metals with the highest mineralization (99.0 and 98.3%, respectively).

Pituitary adenylyl cyclase-activating polypeptide stimulates DNA synthesis but delays maturation of oligodendrocyte progenitors.

The neuropeptide pituitary adenylyl cyclase-activating peptide (PACAP) and one of its receptors (PAC(1)) are expressed in embryonic neural tube, where they appear to regulate neurogenesis and patterning. We now show that PAC(1) gene expression is also present in neonatal rats in the ventricular and subventricular zones and in the optic chiasm, areas that are rich in oligodendrocyte (OL) progenitors (OLP). Because actions of PACAP on OLP have not been reported, we examined the effects of PACAP on the proliferation of purified OLP in culture and on myelinogenesis in cerebellar slices. Northern analyses on total RNA from purified glial cell subtypes revealed an abundant 7 kb hybridizing transcript in OLP, which was confirmed to correspond to the PAC(1) receptor by reverse transcription-PCR. The presence of this receptor was also corroborated by radioligand binding and cAMP assay. In cultured OL, receptor density decreased during maturation but was partially counterbalanced by the appearance of sites that bound both PACAP and the related peptide vasoactive intestinal peptide. PACAP increased DNA synthesis in OLP cultures almost twofold and increased the bromodeoxyuridine-labeling index in O4-positive OLP. PACAP treatment also resulted in decreased sulfate incorporation into sulfatide in cultures of differentiating OL. The PACAP effect on sulfatide synthesis was fully reproduced in a cerebellar explant model. These findings indicate that PACAP may act at two stages during OL development to (1) stimulate proliferation and (2) delay maturation and/or myelinogenesis.

In vitro injury model for oligodendrocytes: development, injury, and recovery.

In this study we investigated the effects of severe hypothermia (cryoinjury) on oligodendrocyte (OL) cell marker expression and morphological features. We used a chemically defined cell culture medium, glial development medium (GDM), which favored the optimal expression of the OL phenotype in CG4 cells. Experiments using CG4 cells cultured in 2% serum or in GDM were conducted in parallel. After severe hypothermia, cells were reanimated at 37 degrees C and 4.5% CO(2) and cultured in either GDM or in medium supplemented with 2% serum. In either medium, around 70% of the total number of cells detached within 2 to 4 hours following reanimation. Oligodendroglial markers such as A2B5, O4, Tf, ferritin, tubulin, and MBP were examined by double and triple immunofluorescence. All of these markers except MBP re-appeared at different times during the recovery period for up to 48 hours. Glial fibrillary acidic protein (GFAP) and heat shock protein 60 (HSP-60) were used as injury markers. The presence of serum induced HSP-60 expression, while GDM did not. All CG4 cells expressed HSP-60 in response to hypothermia independently of the cell culture medium used. Cryoinjury induced a spectrum of morphological changes in CG4 cells. The expression of OL specific markers was also influenced by hypothermia. Moreover both, serum and cryoinjury induced the expression of HSP-60 that colocalized with OL and myelin markers. The expression of GFAP by injured cells but not by normal cells corroborated the state of injury of CG4 cells.

Dietary iron and the integrity of the developing rat brain: a study with the artificially-reared rat pup.

Inadequate iron nutrition is thought to affect many aspects of brain development. Iron is a component of enzyme systems in DNA synthesis, the respiratory chain, neurotransmitter and lipid metabolism. The iron content of the striatum increases post-natally, with neuronal differentiation, myelin lipid and receptor formation: Seventy percent of the iron in the brain is associated with myelin. In an attempt to dissociate the global effects of under-and/or malnutrition and to produce exclusively an iron deficiency, we have used the gastrostomy-reared rat pup fed milk substitutes which vary only in their iron content. To ensure the pups did not have adequate iron reserves at birth, dams were fed a meal diet of low iron content (3 ppm) throughout gestation. The pups were then artificially reared on milk with (43 ppm), and without added iron (2.5 ppm) from 6 up to 21 days after birth. At 21 days of age, body weights of iron deficient pups were about 90% those of control animals. At 21 days of age, the pups were weaned, then fed standard laboratory rat chow. Brain was examined at 42 days of age (for young adults) and up to 6 months of age (180 days as mature adults). Morphometric analysis of sagittal sections of the cerebellum at 21 and 63 days of age revealed a deficit in white matter formation in pups fed low-iron at 21 days of age when compared to controls. This deficit was partially recouped by age 63 days. By contrast, animals fed milk supplemented with iron showed greater definition in white matter formation than controls at 21 days of age; indicative of precocious maturation of the white matter tracts. Our findings indicate that iron deficiency, without under/mal-nutrition and other variables, does not result in extensive growth deficits in body and brain weight. However, the iron status profoundly influences the development of myelination in that the process is delayed in iron deficiency.

Nasal zygomycosis and pulmonary aspergillosis in an American bison.

Concomitant nasal zygomycosis and pulmonary aspergillosis was diagnosed in a 3-mo-old female American bison calf (Bison bison) in Pennsylvania (USA). Etiologic diagnosis was made by immunohistochemistry using a panel of monoclonal antibodies and heterologously absorbed polyclonal antibodies. In the lungs fungal infection was accompanied by hemorrhage, fibrin exudation, and infiltration with neutrophils. Fungi were observed to penetrate apparently normal epithelial lining of the nasal turbinates, and there was hemorrhage, edema, and invasion of blood vessels in the submucosa. In vessels fungi were typically associated with thrombosis. The calf may have been infected due to a high level of exposure to mouldy feed and litter in the environment in combination with a collapse of it's natural defence mechanisms.

Isolation of Mycoplasma mycoides, mycoides (LC variant), from two naturally aborted caprine fetuses.

Described in this study are 2 cases of caprine abortion associated with the LC type of Mycoplasma mycoides , subsp. mycoides . This mycoplasma and Mycoplasma mycoides , subsp. capri had been previously reported in adult goats in this herd. The abortion took place in the latter part of gestation. Samples from heart blood, lung and pleural exudate were collected for the isolation of mycoplasmas and other bacterials in both fetuses. Two strains of Mycoplasma mycoides , subsp. mycoides (LC variant) were isolated. The only gross lesion of the internal organs in the aborted fetuses was congestion of the lungs. Microscopic lesions were encountered in the lungs, and these were characterized by patchy to diffuse pneumonia. Exfoliated cells, many alveolar macrophages, scattered neutrophils and lymphocytes were seen in the lumen of the terminal airways and alveolar spaces. This report appears to be the first isolation of Mycoplasma mycoides , subsp. mycoides (LC variant) from aborted caprine fetuses.

[The effect of the early administration of progesterone on egg recovery, fertilization and pregnancy in an institutional fertilization in vitro program]. / Efecto de la administración temprana de progesterona sobre la tasa de captura ovular, fertilización y embarazo en un programa institucional de fertilización in vitro.

39 patients which underwent an IVF-ET procedure at the INPer were divided in two groups. To one of them, progesterone was administered since the day of oocyte retrieval (group I), whereas the other group received progesterone 48 hours before hCG administration (group II). There were no statistical differences between the groups in the parameters analysed before the oocyte retrieval. There were statistical differences between the groups in progesterone levels in the day of oocyte retrieval in favour of group II, and in fertilization rate and transfer rate for group I. There were no valuable differences between the groups in pregnancy rate.

[Correlation between estradiol concentrations and follicular measurements vs. oocyte maturity in three different ovarian stimulation schedules]. / Correlación de las concentraciones de estradiol y diámetro folicular con la madurez del ovocito en tres distintos esquemas de estimulación ovárica.

The responses to different ovarian stimulation schedules were studied in women which underwent in programs of assisted fertilization. The follicular development and seric estradiol with the number and quality of the retrieved oocytes. Were correlated 49 patients and divided in 3 groups according to ovarian stimulation schedule were analyzed. The stimulation was followed day by day with seric estradiol and ultrasound follicular measurement. With the three schedules were retrieved 205 oocytes, being mature 179, immature 9 and 17 atretic, there was no significant difference between the different schedules.

[Anthropometry at birth of the child of a mother with a change in glucose metabolism]. / Antropometría al nacimiento del hijo de madre con alteración en el metabolismo de la glucosa.

The study compares 156 newborns whose mothers had an endocrinological diagnosis of various glucose metabolism disorders, and a control group of 42 newborn whose mothers had no glucose metabolism disorder. The entire sample including the control group had 98 males and 100 females. The study group with 156 newborns was divided into 4 groups, depending on the degree of the mother's disorder. In group 1, the baby's mothers suffered diabetes mellitus type 1; group 2, diabetes type 2; group 3, gestational diabetes; and group 4, pregnancy disorders of glucose. We observed that there were no differences among the groups in the weight/height ratio. Nevertheless there was great variability in the correlation between height and weight among the study groups. Multiplex box and whisker plots conform that intergroup dispersions in the weight height ratio was greater for the experimental group than for the control group. The pattern results was similar for the weight-head circumference ratio. We concluded that adequate control of glucose metabolism disorder during pregnancy results in product with normal growth indices.

[The evolutionary anthropometric profile of the child of a mother with a change in glucose metabolism]. / Perfil antropométrico evolutivo del hijo de madre con alteración en el metabolismo de la glucosa.

There is not sufficient information about the follow up of children belonging to mothers with some degree of glucose metabolism disorder. At The National Institute of Perinatology were studied 151 newborn. The babies were divided into four groups. The group 1 consisting of babies born from mothers with diabetes mellitus type I; group 2 of babies born from mothers with diabetes mellitus type II; group 3 including babies from mother with gestational diabetes and group 4 babies from mothers who presented alteration in glucose metabolism during pregnancy. After the evaluation of the somatic indicator we found an harmonic behavior in group 3 in weight, height and head circumference again. The most important finding was the low correlation in anthropometry at birth and one year of age. Finally we conclude that a strict control on the follow-up of the somatic growth of children, must be achieved because the hypertrophy during the first year of age depends on sociocultural and economic patterns.

Neuroleptanalgesia in acute myocardial infarction.

Neuroleptanalgesia describes a state of sedated analgesia produced by the administration of the tranquilizer, droperidol, and the potent narcotic, fentanyl, in combination. This combination of drugs was administered intravenously to effect neuroleptanalgesia in the early treatment of eight patients with acute anterior transmural myocardial infarction. Criteria for inclusion in the study were (1) persistent ischemic pain, (2) ST segment elevation of 0.3 or more mV in at least two standard precordial leads, (3) a heart rate of 80 or more beats per minute, (4) a mean arterial pressure of 75 or more mm Hg, and (5) a cardiac index of 2.0 L/min/m(2). Within 30 minutes of the administration of the drugs, all patients were relieved of pain and emotional stress. The sum of ST segment elevation from leads V(1) through V(6) (sigmaST(6)) and the average ST elevation over the precordium (ST) decreased significantly by 57% and 56%, respectively. At the same time, there was a significant reduction in heart rate (from 112 +/- 17 to 86 +/- 8 beats per minute), mean arterial pressure (from 100 +/- 7 to 82 +/- 4 mm Hg), and pulmonary arterial wedge pressure (from 17 +/- 7 to 12 +/- 2 mm Hg). The cardiac index increased from 2.25 +/- 0.22 to 2.40 +/- 0.07 L/min/m(2). Two hours later the hemodynamic parameters had returned to control levels, but the beneficial effect on myocardial injury persisted. Thus neuroleptanalgesia in the early hours of myocardial infarction can reduce preload, afterload, oxygen demand, and eventually the infarct size without depressing myocardial function.