Efeito da vitamina C sobre o hematócrito e glicemia de alevinos de tilápia-do-nilo (Oreochromis niloticus) em transporte simulado / Effect of vitamin C over the haematocrit and glycemia of nile tilapia (Oreochromis niloticus) alevins in simulated transport

Avaliou-se o efeito do ascorbato sobre o hematócrito e glicemia em alevinos de tilápia nilótica (Oreochromis niloticus) submetidos à simulação de práticas relacionadas ao transporte. Foram utilizadas três dietas experimentais com diferentes níveis de vitamina C (16, 500 e 1000mg de vitamina C/kg), fornecidas durante os 14 dias anteriores à simulação do transporte que se estendeu por 14 horas. O tratamento que continha 16mg de vitamina C/kg foi o que apresentou a glicemia mais elevada logo após a simulação, 108,5mg/dl imediatamente após a simulação e 91mg/dl 12 horas após a simulação. A concentração de 1000mg de vitamina C/kg foi a mais eficiente no controle do aumento da glicemia, 94,6mg/dl imediatamente após a simulação e 74,4mg/dl 12 horas após a simulação. Para a concentração de 500mg de vitamina C/kg foram observados os níveis de 91,4mg/dl imediatamente após a simulação e 103,8mg/dl 12 horas após a simulação. Os valores do hematócrito não apresentaram variação significativa (P>0,05). A suplementação com 1000mg de vitamina C/kg por 14 dias anteriores ao transporte pode ser utilizada de forma profilática em alevinos de tilápia nilótica para amenizar o aumento da glicemia relacionado ao estresse

The effects of ascorbate on the haematocrit and blood glucose level were evaluated in Nile tilapia alevins (Oreochromis niloticus) submitted to a transport simulation. Three experimental diets with different levels of vitamin C (16, 500 and 1000mg/kg) were given for 14 days before the simulation of the transport. The treatment containing 16mg of vitamin C showed the highest level of glucose after the simulation (108.5mg/dl immediately after the transport and 91mg/dl 12 hours after the transport). The vitamin C concentration of 1000mg/kg was the most efficient treatment to control glycemia increases (94.6mg/dl immediately after the simulation and 74.4mg/dl 12 hour after simulation). In the 500mg/kg treatment, the glucose level was 91.4mg/dl immediately after the simulation and 103.8mg/dl 12 hours after the simulation. The haematocrit values did not show any significative variation (P<0.05). The supplementation with 1000mg/kg of vitamin C for a 14 days period can be used in a prophylactic way to soften glycemia increases in Nile tilapia alevins submitted to transport stress

Do urinary mononuclear cells reflect disease activity in lupus nephritis?

Glomerular inflammation is associated with urinary mononuclear cells (UMC) in a number of diseases including IgA nephropathy and glomerulonephritis. We examined UMC from children with lupus nephritis for a number of years to characterize the types of mononuclear cells found in urine and to determine if they were associated with active lupus nephritis. Detailed analysis of UMC by cell counts and by flow cytometry showed that monocytes were the clearly dominant cell type. Evaluation of the smaller number of lymphocytes found in the urine of patients with active lupus nephritis demonstrated a strong predominance of CD8+ lymphocytes, in contrast to the normal CD4+/CD8+ ratio that is found in peripheral blood. The degree of proteinuria strongly correlated with the presence of UMC. The UMC counts decreased as their clinical condition improved as indicated by lower indices of flare. These observations suggest that UMC may be a valuable tool in detecting and monitoring disease activity in patients with severe lupus nephritis. More importantly, this study indicated that both monocytes and cytotoxic CD8+ T cells may play a role in pathogenesis of lupus nephritis.

Injury reduction and bounce characteristics of safety baseballs and acceptability by youth leagues.

The only reasonable way to reduce the potential for ball-related youth baseball injuries sustained by the defensive players (the majority of ball-related injuries) is to make the ball less injurious. The American Academy of Pediatrics' 1994 statement on youth baseball injuries in this regard reads, "Consideration should be given to utilizing low-impact NOCSAE-approved baseballs and softballs for children 5 to 14 years of age, if these balls demonstrate satisfactory playing characteristics and reduce injury risk. A variety of studies should be undertaken to determine the efficacy of low-impact balls in reducing serious impact injuries." The purpose of this study, in accordance with this AAP policy, is to investigate the following: A) injury reduction potential of softer baseballs, B) their bounce characteristics, and C) their acceptability by youth leagues. Six simple injury models were studied, baseball bounce characteristics were analyzed, and attitudes of safety baseballs among statewide Little League district presidents were surveyed. Injury models demonstrated less injury potential with safety baseballs compared to that with standard hard baseballs. Safety baseballs bounced higher after vertical drops and slow throws, but during fast throws (with the greatest injury potential), the bounce heights were similar for all ball types. Of 27 survey cards sent out, 13 were returned. While 9 respondents indicated that they were already using safety baseballs for the younger players, none of the 13 respondents indicated that they were planning to expand the use of safety baseballs in their leagues. In conclusion, safety baseballs are less injurious in these models. The bounce characteristics of safety baseballs are satisfactory. Youth baseball league officials are not very willing to expand the use of safety baseballs. We recommend using safety baseballs as a standard for all youth baseball leagues because these balls are safer.

Construction of 700 human/mouse A9 monochromosomal hybrids and analysis of imprinted genes on human chromosome 6.

As an in vitro assay system for the identification of human imprinted genes, a library of human/mouse A9 monochromosomal hybrids containing a single, intact bsr-tagged human chromosome of known parental origin, derived from normal human fibroblasts, has been previously generated by microcell-mediated chromosome transfer (MMCT). To supplement this assay system, we constructed additional 700 A9 monochromosomal hybrids, using a pSTneo or pPGKneo selection marker. To validate the A9 hybrids, we screened them with chromosome-specific polymorphic markers, and identified the hybrids containing either human chromosome 6, 7, 14, 18, or 21 of known parental origin. Matching paternal and maternal chromosome pairs of A9 hybrids were identified for chromosomes 6, 7, 14, and 18. The paternal-specific expression of ZAC (zinc finger protein, which regulates apoptosis and cell cycle arrest) and HYMAI (hydatidiform mole-associated and imprinted transcript), and the maternal-specific methylation of a CpG island within an imprinted domain on human chromosome 6q24, were maintained in A9 hybrids. For an example, we profiled the expression of expressed sequence tags (ESTs) and the methylation of CpG islands in the 300-kb imprinted domain around 6q24, which may be associated with cancers and transient neonatal diabetes mellitus (TNDM). Thus, the 700 A9 hybrids should be useful for various aspects of imprinting studies.

Dispensing home nebulizers for acute wheezing from the hospital is cost-effective.

The objective was to investigate the use characteristics of home nebulizers and to measure the benefit gained from dispensing home nebulizers (compared with their cost) to patients from the hospital. During the study period, August 28,1996 to May 17,1997, a sample of 232 of the 291 entries from a log of home nebulizers dispensed by the hospital respiratory care department were surveyed over the telephone. Of the 232 study subjects under the age of 21, a telephone interview of a guardian or supervising adult was completed in 106 subjects (46%) a mean of 43 weeks after the home nebulizer was prescribed (47% of the cohort received their home nebulizers from the inpatient service and another 47% were discharged with home nebulizers from the emergency department (ED)). An average of 3.6 estimated additional ED visits and 5.4 office/clinic visits for each patient were prevented by the home nebulizer. The benefit (savings from reduced ED and office visits alone) to cost ratio estimates range from $855:$90 to $1710:$90 or more. The overwhelming majority of the patients felt that the home nebulizer was a good idea, it was easy to use, they had no problems with the nebulizer and they received adequate training for home nebulizer use. Home nebulizers are a cost-effective means of providing home nebulized albuterol for selected outpatients. Hospital inpatient units and EDs which have the ability to dispense a home nebulizer, have an additional therapeutic option available for selected patients who may benefit from it. Medical insurance companies should fully support (ie, pay for) home nebulizers because it is cost effective. If there is any concern about the reliability of the patient to follow-up with their primary physician, the patient's primary physician should be contacted to discuss the feasibility of discharging the patient with a home nebulizer.

Telomerase activity and microsatellite instability in colorectal cancer and adenoma.

In order to examine their roles in carcinogenesis or in progression of colorectal carcinoma, we investigated telomerase activity and microsatellite instability in 67 non-familial colorectal cancers and in 18 adenomas. The incidence of detectable telomerase activity increased from 22% of normal colorectal mucosas adjacent to carcinoma, and 33% of adenomas, to 75% of carcinomas. On the other hand, the incidence of detectable microsatellite instability in carcinomas (30%) was almost the same as in adenomas (22%). No significant correlation was detected in the incidence of telomerase activity and microsatellite instability in carcinomas or in adenomas. Moreover, the incidence of telomerase activity and microsatellite instability did not increase during the progression of carcinomas. These results indicate that telomerase activity and microsatellite instability are independent events in colorectal carcinogenesis, and that telomerase activity and microsatellite instability are not correlated with the progression of colorectal carcinoma. However, in 13 multiple cancers, the incidence of telomerase activity (92%) and the incidence of microsatellite instability (54%) was higher than that of telomerase activity (70%) and that of microsatellite instability (24%) in 54 sporadic cancers. Moreover, the incidence of telomerase activity and that of microsatellite instability in adenomas with carcinomas (45% and 36% respectively) was higher than that of telomerase activity and microsatellite instability in adenomas without carcinomas (14% and 0% respectively). These results indicate that telomerase activity and microsatellite instability may play an important role in multicentric carcinogenesis in colorectal carcinoma.

Detection and location of amphiregulin and Cripto-1 expression in the developing postnatal mouse mammary gland.

Amphiregulin (Ar) and Cripto-1 (Cr-1) are growth promoting peptides that share amino acid sequence homology with epidermal growth factor (EGF). The present study examined Ar and Cr-1 mRNA and protein expression during various stages of C57BL/6 mouse mammary morphogenesis. Reverse transcription-polymerase chain reaction (RT-PCR) was used to detect transcripts for Ar and Cr-1 at all stages of mammary development. Immunocytochemical (ICC) localization demonstrated that in virgin 4-week to mature 12-week-old mouse fourth inguinal mammary gland, Ar and Cr-1 are expressed in the stromal cells, luminal epithelial cells, and myoepithelial cells of the branching ducts. Ar, and to lesser extent Cr-1, were also found in the epithelial cap cells and in the luminal epithelial cells of the advancing terminal end bud (TEB) from virgin 4-week and 6-week-old mice. Western blot analysis demonstrated that both Ar (28 and 26 kDa) and Cr-1 (90, 67, 56, and 21 kDa) proteins are expressed in virgin, 13.5 day midpregnant and in the 14 day lactating mammary gland. In addition, Ar and Cr-1 are associated with developing alveolar structures as determined by ICC. These results imply that together with EGF and transforming growth factor alpha (TGF alpha), Ar and Cr-1 may play salient roles as modifiers in the morphogenesis and differentiation of the mammary gland.

V-sis induces Egr-1 expression by a pathway mediated by c-Ha-Ras.

The early growth response gene, Egr-1, is up-regulated transiently by mitogens and many other stimuli in all cells tested. Using NIH3T3 cells conditionally expressing v-sis from a metallothionein promoter, we show that the addition of Zn2+ stimulates the production of PDGF-B (v-sis) and elicits the expression of Egr-1 in a dose-dependent and time-regulated manner. The signal is likely independent of protein kinase C, but depends on tyrosine kinase and other kinase activities and is mediated by c-Ha-Ras since the presence of dominant-negative mutants of Ras and Raf abrogates the induction of Egr-1 expression by Zn2+. Transiently activated Ras expression in NIH3T3 cells also stimulates the transient expression of Egr-1, but cells that constitutively express Ras do not have elevated levels of Egr-1. Transient assays also demonstrated that Zn2+ or activated Ras expression stimulate the activity of a 950 bp Egr-1 promoter-reporter gene construct and this is abrogated in the presence of mutant Ras and Raf. The accumulated data show that Egr-1 gene expression is regulated by multiple mechanisms, as would be needed for putative roles in cell proliferation, in suppression of transformation and in differentiation.

Suppression of v-sis-dependent transformation by the transcription factor, Egr-1.

The transcription factor Egr-1, stimulates the activity of a number of genes and inhibits other genes, by binding to the sequence GCGGGGGCG in 5' enhancer regions. However, the functions of Egr-1 are obscure in spite of its rather ubiquitous expression. Egr-1 may play a role in proliferation in mitogen-stimulated cells but its expression is also correlated with the differentiated state in teratocarcinoma cells. The constitutive expression of Egr-1 appears to have little effect on the growth rate of normal immortalized cell-lines. We show that in NIH3T3 cells that are conditionally transformed by the expression of v-six, the presence of Egr-1 is inhibitory to the production of transformed colonies (foci) and to growth in soft agar. In addition, the first appearance of tumors in nu/nu mice is delayed in tumorigenicity tests with cells that over-express Egr-1 and tumor growth is suppressed compared to control cells. We used a series of fragments of Egr-1 cloned into expression vectors to show that not only full length, but also truncated Egr-1 fragments inhibit colony formation. Using deletion mutants, we observed that this inhibitory activity is dependent on the presence of the DNA-binding 'zinc-finger' region. Wilm's tumor protein, WT1, (known to be a tumor suppressor gene) that exhibits the same DNA binding activity is also inhibitory. In contrast, colony formation is stimulated by an Egr-1 antisense RNA-expressing plasmid, since colonies grow rapidly and the colony-forming frequency is higher than in the presence of v-sis alone. We conclude that proteins containing the Egr-1 'zinc-finger' domain can bind to the regulatory regions of one or more genes that are required for the transformation of fibroblasts by v-sis thus inhibiting transformation. One function for Egr-1 implied by these results is the restraint of transformed growth in mitogen-stimulated cells.

Ethnic differences in the recurrence of adenomatous polyps after colonoscopic polypectomy.

A retrospective study was done of polyp recurrence rates following an initial clearing colonoscopy for adenomatous polyps. The intent of the study was to identify risk factors that would predict a greater risk for recurrence in Hawaii's ethnically diverse population. When the initial exam detected multiple polyps, a higher recurrence rate was found in Caucasian patients.