Multichannel Electrochemical Detection System for Quantitative Monitoring of PCR Amplification.
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Journal Article↗
Biomedical subjects
M Moreno
Publications and source records attributed to M Moreno.
Molecular Epidemiology of Group A Rotavirus Causing Acute Diarrhea in Infants and Young Children in Rio de Janeiro, Brazil, 1997-1998.
During April, 1997, and February, 1998, an epidemiological survey of group A rotavirus strains causing acute diarrhea in infants and young children was conducted in Hospital Municipal Jesus (Rio de Janeiro, D.C.) Rotaviruses were detected in 18.6% of examined specimens. Among the rotavirus strains tested for dsRNA by PAGE, 70% belonged to the long pattern and 30% the short pattern. A long pattern classified as LD was the most common electropherotype among all of the types. This same pattern had been identified in the city 15 years ago. The most common short pattern was SA type and a few were SB types. The SB types were more common than SA types 15 years ago. Rotavirus infection was observed throughout the period studied, but peaks of infection occurred in May, June, and September. The long pattern was recorded continuously and in all ages studied (0-8 years old), but the short pattern ocurred only in young children (age range 0-11 months) and only in May and June of 1997. This data show epidemiologic differences in infection associated with long and short electropherotypes; the long electropherotypes appear to circulate continuously in the community, whereas the short electropherotype strains appear only in young children in an episodic fashion.
Journal Article↗
Acrosomal status of mouse spermatozoa in the oviductal isthmus.
The principal purpose of this study was to establish the acrosomal status of mouse spermatozoa stored in the isthmus of the oviduct after natural mating. Scanning electron microscopy of oviducts fixed about 6 hr before the estimated ovulation time showed numerous acrosome-intact spermatozoa attached to the mucosal surface of the oviduct, or trapped in the oviductal crypts. Nevertheless, an unambiguous assessment of the state of the acrosome requires transmission electron microscopy. Using this method, it was observed that the acrosome was intact in the 81% of spermatozoa attached to the mucosal surface but in only 31% of spermatozoa that were free in the lumen. Most of the free spermatozoa showed swelling or disruption of the acrosome. This result might indicate that the in vivo spermatozoon-oviductal mucosa interaction maintains the acrosome intact. Alternatively, it could mean that only ejaculated spermatozoa with a normal acrosome can establish such a mucosal relationship.
Acrosome↗
Novel defensin subfamily from spinach (Spinacia oleracea).
Antimicrobial peptides (So-D1-7) were isolated from a crude cell wall preparation from spinach leaves (Spinacia oleracea cv. Matador) and, judged from their amino acid sequences, six of them (So-D2-7) represented a novel structural subfamily of plant defensins (group IV). Group-IV defensins were also functionally distinct from those of groups I-III. They were active at concentrations < 20 microM against Gram-positive (Clavibacter michiganensis) and Gram-negative (Ralstonia solanacearum) bacterial pathogens, as well as against fungi, such as Fusarium culmorum, F. solani, Bipolaris maydis, and Colletotrichum lagenarium. Fungal inhibition occurred without hyphal branching. Group-IV defensins were preferentially distributed in the epidermal cell layer of leaves and in the subepidermal region of stems.
Amino Acid Sequence↗
Effect of 3,5-di-iodo-L-thyronine on the mitochondrial energy-transduction apparatus.
We examined the effect of a single injection of 3,5-di-iodo-L-thyronine (3,5-T2) (150 microg/100 g body weight) on the rat liver mitochondrial energy-transduction apparatus. We applied 'top-down' elasticity analysis, which allows identification of the site of action of an effector within a metabolic pathway. This kinetic approach considers oxidative phosphorylation as two blocks of reactions: those generating the mitochondrial inner-membrane potential (DeltaPsi; 'substrate oxidation') and those 'consuming' it ('proton leak' and 'phosphorylating system'). The results show that 1 h after the injection of 3,5-T2, state 4 (respiratory state in which there is no ATP synthesis and the exogenous ADP added has been exhausted) and state 3 (respiratory state in which ATP synthesis is at maximal rate) of mitochondrial respiration were significantly increased (by approx. 30%). 'Top-down' elasticity analysis revealed that these increases were due to the stimulation of reactions involved in substrate oxidation; neither 'proton leak' nor the 'phosphorylating system' was influenced by 3,5-T2. Using the same approach we divided the respiratory chain into two blocks of reactions: cytochrome c reducers and cytochrome c oxidizers. We found that both cytochrome c reducers and cytochrome c oxidizers are targets for 3,5-T2. The rapidity with which 3,5-T2 acts in stimulating the mitochondrial respiration rate suggests to us that di-iodo-L-thyronine may play an important role in the physiological conditions in which rapid energy utilization is required, such as cold exposure or overfeeding.
Animals↗
3,5-Diiodo-L-thyronine and 3,5,3'-triiodo-L-thyronine both improve the cold tolerance of hypothyroid rats, but possibly via different mechanisms.
The effects of 3,5-diiodo-L-thyronine (3,5-T2, 2.5-10 microg/100 g BW) on cold tolerance, energy expenditure and oxidative capacity of four metabolically very active tissues (brown adipose tissue, skeletal muscle, liver and heart) were determined in hypothyroid, cold-exposed rats. Hypothyroid rats survived cold for only 3-4 days. 3,5-T2 improved survival dose dependently; with 10 microg/100 g BW the rats survived 3 weeks (limit of observation). This effect was paralleled by an increased energy expenditure of the whole animal for the entire 3 weeks. Similar effects were observed in hypothyroid rats treated with 3,3',5-triiodo-L-thyronine (T3). 3,5-T2 stimulated the specific oxidative capacity (expressed as cytochrome oxidase activity per milligram protein) of all four tissues dose dependently. When the oxidative capacity was expressed as total activity (cytochrome oxidase activity times organ weight), the percentage increases were of the same order. T3 exerted similar effects, but the changes in total activity were much greater than in specific activity, indicating an effect on the tissue trophism. The effect of 3,5-T2 on cold tolerance thus mimics the effect of T3, but via different cellular mechanisms. T3 seems to act primarily on the trophism of the tissues, while 3,5-T2 may act directly on mitochondria without an effect on tissue trophism.
Adaptation, Physiological↗
Role of transesophageal echocardiography in the assessment of patients with blunt chest trauma: correlation of echocardiographic findings with the electrocardiogram and creatine kinase monoclonal antibody measurements.
OBJECTIVES: This study was designed to evaluate the usefulness of transesophogeal echocardiography (TEE) for detecting cardiac damage after blunt chest trauma (BCT). BACKGROUND: Multiple methods have been used to detect cardiac damage after a BCT, but none has been demonstrated to be sensitive, specific, and feasible enough. METHODS: This multicenter prospective trial was designed to evaluate the usefulness of TEE in the assessment of patients with BCT and to compare the TEE findings with those provided by the electrocardiogram (ECG) and cardiac isoenzymes assay. One hundred seventeen consecutive patients with a significant BCT were enrolled. A TEE was performed in each patient. Serial ECGs and plasma profiles of creatine kinase (CK) and CK-monoclonal antibody (MB) were obtained. RESULTS: Sixty-six (56%) patients had pathologic findings in the TEE attributed to the BCT (group A). In the remaining 51 (44%) patients the TEE was normal (group B). An abnormal ECG was more frequent in group A (59% vs 24%; p < 0.001), and the serum CK-MB peak level was also higher in group A (174 +/- 30 U/L vs 93 +/- 21 U/L; p = 0.05). Relative to pathologic TEE findings, the sensitivity and specificity of an abnormal ECG were 59% and 73% and of high CK-MB with CK-MB/CK > 5% were 64% and 52%, respectively. CONCLUSIONS: We conclude that TEE can be routinely and safely performed for diagnosing cardiac injuries after a BCT and plays an important role in the evaluation and treatment of these patients. EGG and CK-MB assay are not good methods for detecting cardiac damage in this setting.
Adolescent↗
Predictive factors of oxygen desaturation during upper gastrointestinal endoscopy in nonsedated patients.
BACKGROUND: Hypoxemia can occur during upper gastrointestinal endoscopy with or without pharmacologic sedation. We investigated possible predictive factors of severe oxygen desaturation (SaO2 < 90%) in nonsedated patients undergoing endoscopy. METHODS: A total of 481 patients who underwent upper gastrointestinal endoscopy without sedation were monitored with continuous pulse oximetry. Multivariate logistic regression analysis was used to identify factors related to the patient, the examination, and the monitoring data that would predict severe desaturation. RESULTS: Mild desaturation (SaO2 between 90% and 94%) was found in 23.7% of the patients, and severe desaturation (SaO2 < 90%) was found in 6.4%. The variables found to predict severe desaturation were basal SaO2 < 95% (odds ratio 67.7), respiratory disease (odds ratio 30.5), more than one attempt needed for intubation (odds ratio 39.4), emergency procedure (odds ratio 14.9), and American Society of Anesthesiologists score of III or IV (odds ratio 3.9). CONCLUSIONS: The predictive variables analyzed in this study can be used to identify patients who are at increased risk for desaturation. Such patients require very close monitoring (pulse oximetry at a minimum). Endoscopists and assistants should be especially alert to the possibility of respiratory depression in these patients.
Adult↗
Effect of 3,5-diiodo-L-thyronine on thyroid stimulating hormone and growth hormone serum levels in hypothyroid rats.
We have investigated the biological effects of physiological doses of 3,5-diiodo-L-thyronine (3,5-T2) and 3,3'-diiodo-L-thyronine (3,3'-T2) (at doses from 2.5 to 10 microg/100 g BW) on serum TSH and GH levels in rats made hypothyroid by propylthiouracil and iopanoic acid administration. In such animals deiodinase activities were inhibited and thyroid hormones serum levels strongly reduced. The effects of T2s were compared with those elicited by 3,5,3'-triiodo-L-thyronine (T3) (2.5 microg/100 g BW).The serum TSH level was much greater in hypothyroid rats than in euthyroid ones. T3 administration suppressed TSH by 88% compared to control (i.e, the level in hypothyroid rats); it thus reached a value not significantly different from that seen in the euthyroid rats. 3,5-T2 produced a similar effect, suppressing the TSH level by about 75% compared to control; it thus reached values not significantly different from those of the euthyroid and T3-treated rats. By contrast, 3,3'-T2 had no effect on TSH, whatever the dose. The serum GH level was much lower in hypothyroid rats than in euthyroid ones. T3 administration increased the GH level by about 5-fold, restoring it to the value seen in euthyroid rats. 3,5-T2-treated hypothyroid rats, at all the doses used (from 2.5 to 10 microg/100 g BW), showed increased serum GH levels: at a dose of 10 microg/100 g BW the level reached a value about 5-fold higher than that in hypothyroid rats. This value was not significantly different from those of euthyroid and T3-treated rats. 3,3'-T2 did not affect GH levels whatever the dose. Thus, 3,5-T2 (but not 3,3'-T2) seems to mimic the effects of T3 on serum TSH and GH levels in rats.
Animals↗
Influence of hepatitis C virus infection on FK 506 blood levels in renal transplant patients.
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Adult↗
Monitoring of tacrolimus as rescue therapy in pediatric liver transplantation.
The introduction of tacrolimus as rescue therapy represents a significant advance in the prevention of late graft failure and second liver transplantation. The authors report the blood level monitoring of tacrolimus as a rescue therapy in 21 children who underwent liver transplantation, and they report the dose-concentration relationship in the presence or absence of hepatitis C virus (HCV) in these patients. This was a retrospective study conducted from May 1993 to January 1997. Indication for the conversion from cyclosporine (CsA) to tacrolimus were acute rejection (62%), chronic rejection (33%), and CsA toxicity (5%). Mean daily dose in the first month was 0.32 mg/kg, whereas at the end of the follow-up period it was 0.14 mg/kg. Tacrolimus mean whole blood concentration levels were between 7.1 ng/ml and 9.4 ng/ml, without significant differences over time. Mean daily doses in HCV+ and HCV- patients were 0.08 and 0.24 mg/kg, respectively (p < 0.01), and mean concentrations were 8.3 and 8.4 ng/ml (NS). HCV+ children required a mean dose three times lower than the dose used in HCV- children to obtain the same tacrolimus trough blood level. Therefore, doses in HCV+ children must be decreased to achieve levels within the therapeutic range.
Adolescent↗
Squamous cell carcinoma and infection in a solitary hepatic cyst.
Solitary benign non-parasitic hepatic cysts (SBNHC) are rare congenital cystic abnormalities. Complications of SBNHC include infection, perforation, spontaneous haemorrhage, torsion and neoplastic degeneration. Squamous cell carcinoma is an exceedingly rare entity, which usually arises from metaplastic and subsequent neoplastic transformation of pre-existing cyst of the liver. We report a new case of squamous cell carcinoma of the liver in a non-parasitic solitary hepatic cyst infected by aerobic mixed flora at the time of diagnosis.
Aged↗
Resistance in plants transformed with the P1 or P3 gene of tobacco vein mottling potyvirus.
Tobacco plants were transformed with genes encoding the tobacco vein mottling potyvirus (TVMV) P1 or P3 protein. When compared with vector-transformed or P1 transgenic lines, seedlings of P3 transgenic lines (except a low expressor line) developed poorly, suggesting a detrimental effect of P3 on the plant. All P1 and P3 transgenic lines were protected against the homologous TVMV strain and showed variable proportions of two resistance phenotypes: asymptomatic plants or symptomatic plants that recovered from infection. The resistance was effective against a high inoculum dose but had a narrow spectrum. The heterologous strain TVMV-S was able to overcome resistance in most P1 lines but did not break the resistance of most P3 lines. No line showed resistance to another potyvirus (potato virus Y) or to potato virus X. These features and the low levels of transgene expression in resistant plants suggest that protection in P1 and P3 lines is RNA-mediated. In contrast with most reports on virus-activated gene silencing, some P3 lines with the predominant 'recovery' phenotype showed silencing of the transgene that was activated at a certain developmental stage of the plant independently of virus infection.
Gene Expression Regulation, Plant↗
Inhibition of human immunodeficiency virus type 1 infection in SCID-hu Thy/Liv mice by the G-quartet-forming oligonucleotide, ISIS 5320.
Viral replication was inhibited in a dose-dependent manner after administration of the phosphorothioate oligonucleotide TTGGGGTT (ISIS 5320) to human immunodeficiency virus type 1 (HIV-1)-infected SCID-hu Thy/Liv mice. Potent in vivo antiviral activity was observed against the T-cell-tropic molecular clone NL4-3; the agent was found to have weak activity against one primary HIV-1 isolate, and the agent was inactive against a second primary isolate.
Acquired Immunodeficiency Syndrome↗
Aggregation of Rotavirus Particles and Improvement of the Detection of Rotavirus RNA by Polycrylamide Gel Electrophoresis After Treatment With Tween-80.
Treatment of feces rotavirus-positive with Tween-80 at 0.25% enhances by a factor of 4-fold the viral detection of rotavirus RNA by polyacrylamide gel electrophoresis (PAGE) after silver impregnation. By use of electron microscopy 35% of the rotavirus particles in untreated feces are aggregated, but after Tween-80 treatment, the percentage aggregated is decreased significantly to approximately 6%. Disaggregation of virus particles by Tween-80 can amplify the range of rotavirus RNA detection in feces.
Journal Article↗
[Changes in therapeutic attitude based on transesophageal echocardiography in cardiac surgery].
Transesophageal echocardiography is a monitoring system that is changing the practice of cardiovascular anesthesia and surgery by providing real time images of cardiovascular anatomy and pathophysiology. Our hospital's anesthesiology and postoperative intensive care departments, in particular the cardiac anesthesia team, initiated a joint project in June 1993 with the echocardiography laboratory team to incorporate this surgical monitoring system. Here we report the wealth of information we obtained and describe the possibility of modifying a therapeutic approach based on the images visualized, even when conventional monitoring gives contradictory information. Two illustrative case reports are included.
Anesthesia, General↗
How the thyroid controls metabolism in the rat: different roles for triiodothyronine and diiodothyronines.
1. Although the first evidence of a relationship between the thyroid and metabolism was reported in 1895, the mechanism by which thyroid hormones influence resting metabolic rate in whole animals is still poorly understood. This paper reports an attempt to test whether diiodothyronines (T2s) and triiodothyronine (T3) have different roles in the control of resting metabolism (RM). 2. Changes in resting metabolic rate were measured in hypothyroid rats treated acutely (25 micrograms (100 g body weight)-1) either with one of the T2s or with T3. Injection of T3 induced an increase of about 35% in RM that started 25-30 h after the injection and lasted until 5-6 days after the injection, the maximal value being observed at 50-75 h. The injection of T2s evoked a temporally different pattern of response. The increases in RM started 6-12 h after the injection, had almost disappeared after 48 h, and the maximal stimulation was observed at 28-30 h. 3. When actinomycin D (an inhibitor of protein synthesis) and T3 were given together, the stimulation of RM was almost completely abolished. The simultaneous injection of actinomycin D and either of the T2s, on the other hand, did not cause any attenuation of the stimulation seen with the T2s alone. 4. Following chronic treatment (3 weeks) with either T3 or T2s there was a stimulation of organ growth only after the administration of T3. 5. Chronic administration of either T2s or T3 to hypothyroid rats significantly enhanced the oxidative capacity of each of the tissues considered. In the case of T2s the stimulation was almost the same whether it was expressed as an increase in specific activity or total tissue activity. In the case of T3 the increases were, in the main, secondary to the hypertrophic or hyperplastic effect. 6. These results indicate that T2s and T3 exert different effects on RM. The effects of T2s are rapid and possibly mediated by their direct interaction with mitochondria. Those of T3 are slower and more prolonged, and at least partly attributable to a modulation of the cellularity of tissues that are metabolically very active.
Adipose Tissue, Brown↗
Induction of UCP2 mRNA by thyroid hormones in rat heart.
The possible regulation of the expression of uncoupling protein-2 (UCP2) mRNA by thyroid hormones in different tissues was examined in rats. Triiodothyronine (T3) was found to produce an organ-specific enhancement of UCP2 expression in rat tissues. The effect of T3 was markedly observed in heart, whereas a moderate effect was seen in skeletal muscle and no effect in kidney or liver. These results suggest that UCP2 is a protein that may be involved in the nuclear-mediated effect of T3 on resting metabolic rate in the rat.
Animals↗