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Biomedical subjects

R Mazzoni

Publications and source records attributed to R Mazzoni.

At least 19 recordsLinked to original sources
PubMed2005

Reproductive biology of Astyanax janeiroensis (Osteichthyes, Characidae) from the Ubatiba river, Maricá, RJ, Brazil.

Aspects of the reproductive biology of Astyanax janeiroensis in the Ubatiba river in Maricá, RJ, Brazil were evaluated in order to ascertain whether the strategy adopted by the species is causally related to environmental variables. Specimens were collected on a monthly basis from October 1994 to September 1995, through electrofishing. The Sex ratio was not significantly different from the expected frequency of 1:1 (G = 1.29; p > 0.50); nonetheless, considering three standard length classes, significantly larger numbers of females were recorded for the higher SL class (G = 11.07; p < 0.01). Size at first maturation showed no significant differences between sexes. Length-weight ratio analyses showed negative allometry for males and isometry, for females. Length structure was significantly different between sexes, suggesting that females are larger than males (D = 0.027, p < 0.01). Reproductive specimens were recorded during nine months of the annual cycle. Seasonal variations of reproductive specimens belonging to two different standard length classes displayed an asynchronous behavior, with larger specimens having a longer reproductive period and smaller ones reproducing for fewer months during the annual cycle. High values of fecundity (F), varying from 3169 to 18714 oocytes, were recorded for fish of 9.1 and 10.2 cm lengths, respectively. The correlation between weight and number of oocytes/unit of weight was positive, indicating that larger specimens produced more eggs.

Animals↗
PubMed2003

Seasonal diet shift in a Tetragonopterinae (Osteichthyes, Characidae) from the Ubatiba River, RJ, Brazil.

In the present study, we describe feeding habits of Deuterodon sp. from the Ubatiba River and explore if diet changes according to a temporal cycle of dry and wet seasons. We observed that Deuterodon sp. fed on an extremely high diversity of items ranging from organic matter, sediment (sand plus quartz parts), algae, seeds and leaves to animal organisms, such as, crustaceans, oligochaets and several life stages of terrestrial and aquatic insects, indicating an omnivorous diet. An important shift in the use of feeding resources was also registered; animal and vegetal items had alternated importance between both seasons. Allochthonous vs. autochthonous items analysis showed predominance of allochthonous items during dry season while no significant differences were registered during wet season.

Animals↗
PubMed2002

Reproductive biology of a Characidiinae (Osteichthyes, Characidae) from the Ubatiba River, Maricá-RJ.

The Ubatiba river is a coastal stream subject to stochastic spates all over the year and, Characidium sp.n. is among the twenty-two species that compose its ichthyofauna. In this study we analyse some traits of its reproductive biology and discuss whether the adopted strategy has causal relationship with the environmental variables. Specimens were collected in the upper Ubatiba river. Samplings, were carried out monthly by electrofishing, between Oct./94 and Sep./95. Some differences between male and female strategies were observed. Females were significantly (p < 0.05) bigger than males; length--weight relationship was different (p < 0.05) between sexes with the onset of sexual maturity occuring at smaller sizes among males. Reproductive investment is high for both males and females but higher for males, maximum Gonadosomatic Index for females and males were 40.97% and 44.90%, respectively. Reproductive specimens were registered all over the year, suggesting continuous reproduction. High values of fecundity were also registered varying from 1342 to 5535 eggs for ripe females of 4.4 and 7.0 cm, respectively and an amount of 1105 oocytes per grams of fish. We suggest that differences in the reproductive strategy, between sexes, determine the observed patterns in the size structure; the absence of males in the higher SL classes could be a consequence of high mortality rates and/or reduction in the growth rates as a precocity consequence in the onset of reproduction and/or high reproductive investment. Relationship between continuous reproduction and environmental condition could be explained as an adaptation to maximise supervivency of the young fishes that is: guarantee the species maintenance in a stochastic environment.

Adaptation, Biological↗
PubMed2002

Distribution pattern of two fish species in a coastal stream in southeast Brazil.

Longitudinal distribution of Mimagoniates microlepis and Hoplias malabaricus was analyzed in a coastal stream system in Southeast Brazil. Six sites were sampled by electrofishing in seven months, from July 94 to July 95. Densities of M. microlepis, and H. malabaricus and its prey (Poecilia vivipara, Deuterodon sp. and Astyanax janeiroensis) were estimated by the Zippin method; environmental variables of: (i) kind of substratum; (ii) percentage of pools, runs, riffles, instream vegetation, and canopy were registered for each site in each sampling month. The relative importance of each biotic and abiotic variable was tested through simple correlation analyses. We verified that M. microlepis occurrence correlates with canopy; H. malabaricus is correlated with instream vegetation, pools, clay substratum, and P. vivipara densities; and P. vivipara correlates with pools and clay substratum. Our results suggest that environmental variables, and food and shelter availability are the main factors in determining M. microlepis and H. malabaricus distribution.

Animals↗
PubMed2000

Electrofishing as a sampling technique for coastal stream fish populations and communities in the Southeast of Brazil.

Electrofishing adequacy was tested as a technique to obtain quantitative data of coastal stream fish populations and communities in the Southeast of Brazil. Seven field trips, between July/94 and July/95, were done in 5 localities of the Ubatiba fluvial system (Maricá, RJ). Seventeen species, among the 22 collected, had their numbers estimated through the Zipping method, the model used to test the sampling methodology. At each field trip, three removals with electrofishing were done in each locality and, according to the number of obtained species at each locality/field trip, we analysed 315 cases. Nineteen cases, among 315, showed failure condition. Estimates were significant (p < 0.01) in 96% of the studied cases. Non-significant cases were obtained for rare species due to over and randomly efficient electrofishing in 63.3% and 36.4% of the cases, respectively. No correlation was found between catchability and the estimated number of individuals and/or environmental characteristics. High values for sampling efficiency (> 85%) were found for all estimates. An experimental analyses were done for one locality and, the comparison between the estimates for 3 and 6 successive removals showed a mean error and a standard deviation of 5.5% and 2.1% respectively. Therefore, it can be concluded that electrofishing was an efficient method for quantitative data analysis of fish populations and communities in the Ubatiba fluvial system.

Journal Article↗
PubMed1999

Failure of acupuncture in the treatment of obesity: a pilot study.

Acupuncture has been anecdotally reported to induce weight loss in obese patients. This pilot study examines its efficacy in a randomised, placebo-controlled clinical trial. Forty (33 F, 7 M) obese (BMI > 30 kg/m2) outpatients were randomised to either placebo or acupuncture (12 weekly sessions of minimal acupuncture and somatic moxibustion-acupuncture associated with auriculopuncture respectively). BMI, eating attitudes (BES), anxiety (STAI), depression (BDI), and obesity-related quality of life (ORWELL 97) were measured at the beginning and end of the treatment. Six (30%) patients in the treatment group and 12 (60%) in the placebo group dropped out. Intention-to-treat analysis did not show any significant effect of acupuncture on BMI and obesity-related quality of life; eating attitudes improved in both groups, possibly because of the placebo effect. A significant improvement in anxiety and depression was only observed in the acupuncture group. In conclusion, acupuncture does not promote weight loss and is not recommendable in the treatment of obesity. It may, however, improve the psychological status of obese patients.

Acupuncture Therapy↗
PubMed1987

Marketing, take two.

Explore the source record for details and available documents.

Economic Competition↗
PubMed1986

[Bone mineral measurement in the newborn infant].

In order to achieve parameters to evaluate mineralization of premature infants, bone mineral content at the midshaft of the radius was measured in 173 normal newborns. Data were correlated with the following factors: gestational age, postnatal age, sex and weight at birth. In spite of the wide range of variation of individual values, there was a statistically significant correlation between gestational age, sex and BMC.

Bone and Bones↗
PubMed1985

Esophagogastroplasty and its radiological approach.

Sixty-six patients with tumor of the distal esophagus and/or the gastric fundus were admitted for intrathoracic esophagogastroplasty. Surgical mortality was 6% (4 of 66 cases). There were 3 early and 7 late complications among the 62 remaining patients. The authors suggest that radiological examinations of patients after esophagogastroplasty should include an early examination on the 7th-10th day after surgery with water-soluble contrast medium for detection of early complications and double-contrast studies before dismissal, at later check-ups and whenever clinical symptoms of late complications are developing.

Adenocarcinoma↗
PubMed1983

[Pharmaco-radiodiagnosis of the digestive tract].

A brief account of the subject from the chronological standpoint is followed by a classification of the drugs most often used in radiological examination of the digestive tract into two groups according to their effects on individual viscera, namely excitomotor and hypotonising drugs. The indications and contraindications for each drug are explained, and the most common methods for the pharmacoradiological investigation of each organ are indicated. It is felt that this form of examination leads to an earlier radiological diagnosis and one more consonant with the real anatomical and pathological situation.

Depression, Chemical↗
PubMed1982

[Thermography in the follow-up of bone and soft tissue tumors].

Thermography was used for the follow-up of 16 cases of bone tumors and of 16 cases of soft tissue tumors, after conservative treatments (surgery and/or radio- and chemio-therapy). The hyperthermia, which corresponds to the primary tumor, underwent a marked reduction during the first six months after the treatment. The thermographic picture appeared normal at the first follow-up of 12/16 bone tumors and of 9/16 soft tissue tumors. The presence of local recurrencies, at 12 months distance or more, corresponded to a new hyperthermic spot and to the increase of local vascularity. Thermography is proposed as a simple and harmless procedure for the follow-up of bone and soft tissue tumors after conservative treatments.

Adolescent↗