A bacteriological study of hospital beds before and after disinfection with phenolic disinfectant

In hospitals, one of the ways to control microbial contamination is by disinfecting the furniture used by patients. This study's main objective was to evaluate the microbiological condition of hospital mattresses before and after such disinfection, in order to identify bacteria that are epidemiologically important in nosocomial infection, such as Staphylococcus aureus and Pseudomonas aeruginosa. RODAC plates with two different culture media were used to collect specimens. Patient beds were selected according to previously established criteria, and surface areas on the mattresses were chosen at random. From the total of 1,040 plate cultures from 52 mattresses, positive results were obtained from 500 of them (48.1%), 263 before disinfection and 237 after disinfection. Considering the selectivity of the culture media, the positivity rate was high. There were high prevalences of S. aureus both before and after mattress disinfection. The study results suggest that the usual disinfection procedures, instead of diminishing the number of microbes, merely displace them from one part of the mattress to another, and the number of microorganisms remains the same.

Inside-out vs. standard vein graft to repair a sensory nerve in rats

Nerve regeneration in a sensory nerve was obtained by the application of different techniques: inside-out vein graft (IOVG group) and standard vein graft (SVG group). These techniques provide a good microenvironment for axon regeneration in motor nerves, but their efficiency for regeneration of sensory nerves is controversial. The saphenous nervtce was sectioned and repaired by the inside-out and standard vein graft techniques in rats. After 4, 12, and 20 weeks the graft and the distal stump were observed under electron microscopy. In each studied period, the pattern, diameters, and thickness of the myelin sheaths of the regenerated axons were measured in the graft and distal stump. A comparative study about the regenerated nerve fibers by these two different techniques was performed. Regenerated nerve fibers were prominent in both vein grafts 4 weeks after the surgical procedures. On the other hand, in the distal stump, regenerated nerve fibers were observed only from 12 weeks. In both inside-out vein graft and standard vein graft statistical difference was not observed about the diameters and thickness of the myelinated fibers after 20 weeks. On the other hand, the inside-out group had greater regenerated axon number when compared to the standard group. There is a capillary invasion in both graft and distal stump, especially in the IOVG group. The regenerated axons follow these capillaries all the time like satellite microfascicles. After 20 weeks, the diameters of regenerated fibers repaired by the standard vein graft technique were closer to the normal fibers compared to the inside-out vein graft. On the other hand, the pattern of these regenerated axons was better in the IOVG group.

Morphometric analysis of the endometrial epithelium of rats (Rattus norvegicus albinus) submitted to chronic experimental alcoholism

The effects of alcohol ingestion on the epithelial layer of the uterine endometrium of rats submitted to experimental chronic alcoholism were observed by morphometric methods. Sixty adult rats (Rattus norvegicus albinus) of the same age (3 months) and weighing on average 228 g were divided into two groups. The control group received solid diet, rat chow, and tap water ad libitum. The experimental group received the same solid diet and was allowed to drink only sugar cane brandy dissolved in 30 degrees Gay Lussac (v/v). At the end of 90, 180 and 270 days of treatment, the animals at estro were anaesthetized with ethyl ether, weighed and sacrificed. The internal reproductive organs were dissected, weighed and fixed. The final mean body weights were similar in the control and alcoholic groups. The histological results showed intense atrophy of the lining epithelium of the endometrium of uterine horns in the alcoholic group. Morphometric analysis confirmed the endometrial epithelial atrophy, showing that the alcoholic group had small cytoplasmic and nuclear areas and small cytoplasmic and nuclear perimeter compared to the control group. Scanning electron microscopic images showed intense lipid droplets accumulation in the epithelial cells from alcoholic group. Therefore, we concluded that alcohol acts as a toxin on the epithelial layer of the rat endometrium.

[Video-polygraphic-EEG study in the full-term newborn with low birthweight for their gestational age]

Video-polygraphic-EEG studies were performed in the first 24 life-hours of 26 healthy full-term newborns without perinatal injuries. The neurological examination and cranial ultrasonography were normal. The newborns were divided into two groups: one, with full-term appropriate--birth weight 11 newborns (control group) and the other with full-term low-birth weight 15 newborns. Thirteen newborns of the second group had video-polygraphic-EEG study abnormalities. The most frequent abnormalities were found in 11 cases, as far as sleep architecture is concerned. Also, when compared with the control group, 8 cases of an excessive amount of startles and 2 cases of low behavior activities were found. The results demonstrate the usefulness of video-polygraphic-EEG study in the full-term newborns with intra-uterine growth retard. This examination was sensitive to detect behavior, sleep architecture and EEG standard differences in the low birth-weight newborns as to the control group.

Effects of uracil calculi on cell growth and apoptosis in the BBN-initiated Wistar rat urinary bladder mucosa

The different potential of initiated and non-initiated urinary bladder mucosa (UBM) to develop neoplasia was quantitatively evaluated in the male Wistar rat. Initiation of carcinogenesis was accomplished with N-butyl-N-(4-hydroxybutyl)-nitrosamine (BBN). Stimuli for cell proliferation and apoptosis were obtained by exposure followed by withdrawal of 3% Uracil in the diet. The proliferation index (PI) was estimated in UBM immunostained for the proliferating nuclear cell antigen (PCNA). The apoptotic index (AI) and the density of papillary/nodular hyperplasia (PNH) were estimated in hematoxilin-eosin stained sections. PNH was the main proliferative response to the mechanical irritation by uracil, irrespective of previous initiation with BBN. Uracil exposure induced higher PI and PNH density in the initiated rats. After uracil withdrawal, there was a significant increase of the AI in both uracil-treated groups, which correlated well to the respective PNH density. However, at the end of the experiment, PNH incidence and density were significantly higher in the BBN-initiated mucosa, which also presented 18% incidence of papillomas and 27% of carcinomas. Therefore, under prolonged uracil calculi trauma, the UBM of BBN-initiated Wistar rats gives rise to epithelial proliferative lesions that progress to neoplasia through acquired resistance to apoptosis.

[Evolution of the weight-height and weight-age relationship in children 3-6 years of age receiving preschool care in Sorocaba (SP), Brazil]

The nutritional status of Brazilians has improved over the last three decades. Still, little is known about the role played by nutritional assistance programs that public institutions and philanthropic organizations provide for low-income preschool children, who face greater nutritional risk. Therefore, we carried out a quasi-experimental study to evaluate the nutritional impact of the municipal preschool nutritional assistance program in the city of Sorocaba, São Paulo, Brazil. Over the course of a year, we performed quarterly measurements of weight and height on 444 children, whose ages ranged from 3 months to 6 years. In this population, 164 children were assisted by the preschool nutritional program (intervention group), and 280 children were not (nonintervention group). The children in the nonintervention group were identified by a special census for that purpose; they did not attend the preschool but lived nearby. After obtaining informed consent and carrying out a pretest, professionals and university students interviewed the mothers of the participating children, following standard techniques and conditions. Anthropometric measurements were done by teams of two interviewers, one of whom was a permanent member of the team, using equipment calibrated by the appropriate regional technical organization. The correspondence between the first measurement and subsequent measurements was evaluated by stratifying the population into three groups by z scores for weight-for-age and for weight-for-height, using U.S. National Center for Health Statistics reference curves. The z score groupings were established at the beginning of the study for three different age groups: younger than 24 months, 24-36 months, and older than 36 months. The two study groups (intervention and nonintervention) were similar sociodemographically, with the following exceptions: maternal employment (more of the mothers of children in the intervention group had jobs outside the home); age (children in the intervention group were significantly older); nutritional status (it was worse in the intervention group); and prevalence of hospital admittance (it was higher in the intervention group). After just the first three months of the study, 32% of the children in the intervention group had moved to a higher nutritional stratum, whereas only 13% of children in the nonintervention group had shown improved nutritional status. The difference in favor of the intervention group increased with the length of the intervention and was higher among older children. These results show that the preschool nutritional assistance program helped to improve the assisted children's nutritional status.

Lesões na dança: estudo transversal híbrido em academias da cidade de Bauru-SP

As atividades físicas praticadas pelos bailarinos predispõem-nos à ocorrência de inúmeros agravos. A busca por informações sobre as lesões dessa modalidade permitiu constatar, em nosso meio, escassez de investigações sobre o assunto. Nesse sentido, o objetivo desta pesquisa foi apontar as principais lesões da dança, visando descrever sua distribuição e caracterização a partir de nossa realidade, bem como sugerir medidas preventivas para os agravos de maior ocorrência. Para tanto, realizou-se estudo com 122 bailarinas na faixa etária de 8 a 30 anos, alocadas nas academias de dança da cidade de Bauru. Em sua maioria, eram membros do corpo de baile (42%) ou estudantes (45%), com 3 a 11 anos de prática (73%), alunas de balé clássico (84%) e jazz (66%) e participavam de 4 a 8 aulas semanais (70%), com duração de 60 a 120 minutos (89%). O procedimento para coleta de dados foi o inquérito de morbidade referida para obtenção de informações sobre os agravos ocorridos no período de um ano. A apresentação dos resultados deu-se sob a forma de estatística descritiva, com distribuições de freqüência absoluta, relativa, corrigida e razão de lesões. Em termos analíticos foram utilizados testes não paramétricos de Wilcoxon, Spearman e Kruskal-Wallis, para p < 0,05. Os resultados apontaram 53,27% das respondentes com freqüências entre 1 e 6 lesões agudas, que aumentam com a idade, concentram-se no plano tegumentar (79,46%) e estão associadas a variáveis como a idade em que começou a dançar e com o uso de sapatilha de ponta; 97,48% são agravos de membros inferiores, com predominância de calos (47,03%) e bolhas (28,56%) nos pés. O balé clássico foi o estilo responsável pela maior parte das lesões; as mais experientes e as estudantes foram as mais afetadas e o uso da sapatilha de ponta implicou risco elevado para ocorrência dos agravos observados nos pés.

Effects of protein-calorie restriction on mechanical function of hypertrophied cardiac muscle

OBJECTIVE

To assess the effect of food restriction (FR) on hypertrophied cardiac muscle in spontaneously hypertensive rats (SHR).

METHODS

Isolated papillary muscle preparations of the left ventricle (LV) of 60-day-old SHR and of normotensive Wistar-Kyoto (WKY) rats were studied. The rats were fed either an unrestricted diet or FR diet (50% of the intake of the control diet) for 30 days. The mechanical function of the muscles was evaluated through monitoring isometric and isotonic contractions.

RESULTS

FR caused: 1) reduction in the body weight and LV weight of SHR and WKY rats; 2) increase in the time to peak shortening and the time to peak developed tension (DT) in the hypertrophied myocardium of the SHR; 3) diverging changes in the mechanical function of the normal cardiac muscles of WKY rats with reduction in maximum velocity of isotonic shortening and of the time for DT to decrease 50% of its maximum value, and increase of the resting tension and of the rate of tension decline.

CONCLUSION

Short-term FR causes prolongation of the contraction time of hypertrophied muscles and paradoxal changes in mechanical performance of normal cardiac fibers, with worsening of the shortening indices and of the resting tension, and improvement of the isometric relaxation.

End-to-side neurorrhaphy with and without perineurium

OBJECTIVE

We compared end-to-side neurorraphy with and without the perineural sheath.

METHOD

Twenty rats were used. The peroneal nerve was sectioned and the distal end was sutured to the lateral face of the tibial nerve. We removed the perineural sheath only on the right side, but not on the left side. The proximal end of the peroneal nerve was curved back approximately at a 100 degrees angle and implanted into the adductor muscle. Six months later, the 14 surviving animals were submitted to electrophysiological tests, sacrificed, and the nerves and muscles were taken for histological exams.

RESULTS

On the right side, the muscles that had positive response needed an average of 258.89 mV (+/- 92.31) of electric stimulus and on the left side 298.34 mV (+/- 139.32). The average weight of the tibial cranial muscles of the right side was 0.47 g (0.18) and for the left side 0.45 g (0.15). The distal end of the peroneal nerve showed averages of 310.29 (+/- 191.34) nerve fibers on the right side and 287.71 (+/- 183.60) on the left side. The tibial nerve above the neurorraphy showed averages of 939.46 (+/- 223.51) nerve fibers on the right side and 959.46 (+/- 327.48) on the left side. The tibial nerve below the neurorraphy showed averages of 935.17 (+/- 298.65) nerve fibers on the right side and 755.31 (+/- 323.26) on the left side. The average areas of the right tibial cranial muscles were 0.0162 m2 (+/- 0.008), after 230 magnification, and 0.0152 m2 (0.0064) for the left tibial cranial muscles. The histological features of the tibial cranial muscles, taking normal as 100%, were 78.21 (+/- 20.75) on the right side and 82.14 (+/- 15.89) on the left side. The statistical analysis (Student's t test) did not reveal any difference (p > 0.05) among right and left sides for all variables.

CONCLUSION

The authors concluded that the two neurorraphies (with and without perineurium) did not show any difference regarding morphological and electrophysiological features studied.

Effect of management practices on screw-worm among sheep in São Paulo State, Brazil

The screw-worm Cochliomyia hominivorax (Coquerel), whose larvae develop in wild and domestic animals as well as in man, is one of the major causes of myiasis in Brazil. Sheep raising is expanding in the state of São Paulo, where information about the infestation of screw-worm is necessary for appropriate control measures. The present data were obtained from questionnaires sent to all sheep breeders belonging to Associacão Paulista de Criadores de Ovinos--ASPACO (São Paulo State Association of Sheep Breeders). Response reliability was tested by random visits paid to 10.6% of the respondents. The results show that screw-worm is the most frequent ectoparasite in the flocks and is responsible for the greatest economic losses. Its occurrence is strongly associated with flock size, reaching 100% in flocks consisting of more than 500 animals. Infestation is higher in spring and summer and lowest in the fall. The number of cases increases in the presence of some management practices such as tail amputation. Furthermore, several other associations between the indicators surveyed were also found to be significant. The data obtained will permit the elaboration of strategies for the control of this parasitosis.

Estrous behavior and the estrus-to-ovulation interval in Nelore cattle (Bos indicus) with natural estrus or estrus induced with prostaglandin F2 alpha or norgestomet and estradiol valerate

Estrous behavior and the estrus-to-ovulation interval are essential for estimating the best time to artificially inseminate cattle. Because these parameters are not well characterized in the Nelore breed (Bos indicus), the main purpose of the this study was to determine the estrus-to-ovulation interval in Nelore heifers and cows with natural estrus or with estrus induced by treatments with PGF2 alpha or norgestomet and estradiol valerate (NEV). The cows and heifers were observed continuously (24 h a day) to determine the onset of estrus and to study estrous behavior in the cows. Ten hours after the start of estrus the ovaries were scanned every 2 h by ultrasonography to monitor the dominant follicle until ovulation. Blood samples were collected periodically to determine progesterone levels by RIA. Administration of PGF2 alpha (2 injections, 11 days apart) did not induce estrus in most Nelore females in spite of the presence of functional CL, indicated by progesterone concentrations above 6.0 ng/ml in 25 of 28 animals. Treatment with NEV induced high sexual receptivity in cows (10/11), but only 66% ovulated. Cows with natural or induced estrus exhibited behavioral estrus of 10.9 +/- 1.4 h, and ovulation occurred 26.6 +/- 0.44 h (n = 26) after the onset of estrus. In most of the cows (53.8%) estrus began at night (between 1801 and 600 h), and 34.6% it started and finished during the night. It is concluded that in Nelore females ovulation occurs approximately 26 h after the onset of estrus. Additionally, estrous behavior is shorter than in European breeds, and there is a high incidence of estrus at night, which makes it difficult to detect and, consequently, impairs Al in Nelore cattle. The observation that a high percentage of Nelore females with an active CL did not respond to usual dosages of PGF2 alpha warrants further investigation.

The rate of force generation by the myocardium is not influenced by afterload

The influence of afterload on the rate of force generation by the myocardium was investigated using two types of preparations: the in situ dog heart (dP/dt) and isolated papillary muscle of rats (dT/dt). Thirteen anesthetized, mechanically ventilated and thoracotomized dogs were submitted to pharmacological autonomic blockade (3.0 mg/kg oxprenolol plus 0.5 mg/kg atropine). A reservoir connected to the left atrium permitted the control of left ventricular end-diastolic pressure (LVEDP). A mechanical constriction of the descending thoracic aorta allowed to increase the systolic pressure in two steps of 20 mmHg (conditions H1 and H2) above control values (condition C). After arterial pressure elevations (systolic pressure C: 119 +/- 8.1; H1: 142 +/- 7.9; H2: 166 +/- 7.7 mmHg; P < 0.01), there were no significant differences in heart rate (C: 125 +/- 13.9; H1: 125 +/- 13.5; H2: 123 +/- 14.1 bpm; P > 0.05) or LVEDP (C: 6.2 +/- 2.48; H1: 6.3 +/- 2.43; H2: 6.1 +/- 2.51 mmHg; P > 0.05). The values of dP/dt did not change after each elevation of arterial pressure (C: 3,068 +/- 1,057; H1: 3,112 +/- 996; H2: 3,086 +/- 980 mmHg/s; P > 0.05). In isolated rat papillary muscle, an afterload corresponding to 50% and 75% of the maximal developed tension did not alter the values of the maximum rate of tension development (100%: 78 +/- 13; 75%: 80 +/- 13; 50%: 79 +/- 11 g mm-2 s-1, P > 0.05). The results show that the rise in afterload per se does not cause changes in dP/dt or dT/dt.

A morphometric ultrastructural study of the seminal vesicle of rats submitted to experimental chronic alcoholism

The effects of chronic alcohol ingestion on the secretory epithelium of the seminal vesicle were studied in rats (Rattus norvegicus). Male adult albino Wistar rats were divided into two groups: alcoholic and control. Tips of the seminal vesicle were removed and prepared for light and electron microscopy. Ultrastructural observations on the epithelial cells of the seminal vesicle showed reduced epithelial cell size, decreased apical secretory vacuoles, irregularly shaped nuclei with deep infoldings, increased lipid droplets and dense bodies, a small number of microvilli covering the cell surface, and signs of degeneration. In addition to the hormonal effects, alcohol may act on the secretory epithelium of the seminal vesicle.

[Arterial dysfunction as a possible mechanism of cardiac injury in type II diabetic patients. A Doppler-echocardiographic study]

PURPOSE

To evaluate the left ventricular structure and function and the arterial stiffness in type II diabetic patients.

METHODS

Thirteen diabetic patients, men and women (age 55 +/- 8 years) were included in the study. None of the patients had any other clinical disorders. Doppler-echocardiography and non-invasive monitoring of arterial blood pressure were performed. All the results were compared to an age and sex matched control group (n = 12).

RESULTS

There were no differences between the groups for diastolic blood pressure, dimensions of cardiac chambers and ventricular systolic and diastolic function indexes. Diabetic patients had increased left ventricular mass index (101 +/- 10 vs 80 +/- 14 g/m2; p < 0.001) and increased arterial stiffness (0.86 +/- 0.26 vs 0.69 +/- 0.19 mmHg/mL; p < 0.05), when compared to control group.

CONCLUSION

Diabetes mellitus is associated to increased systemic arterial stiffness and this may contribute to the adverse effects of diabetes on left ventricular morphology.

Ultrastructural and morphometric aspects of ageing in the retinal capillaries of rats

Age-related morphological, ultrastructural and morphometric changes in the capillaries of the superficial and deep plexuses of the rat retina were studied in animals aged from 3 to 15 months. Our results suggest that age-related morphological alterations start occurring in the retina of rats at about 12 months of age. Increased glycogen deposits, pinocytotic vesicles, residual bodies and cell debris were observed in both the endothelial and pericytic cells of 12- and 15-month-old animals. In addition, heterogeneous osmiophilic accumulations, electron-transparent spaces were observed in the basement membrane as well as projections of the basement membrane towards the neighboring cells. Morphometric examination of the two vascular plexuses studied did not show differences in the area of the endothelial or pericytic cells, basement membrane or vascular lumen between rats of different ages.

[Effect of Momordica charantia L. in mice infected with Plasmodium berghei]

According to the World Health Organization malaria is one of the major public health problems in Brazil and all over developing countries, where 80% of the population use traditional medicine to solve their primary medical problems. Both treatment and control of this parasitosis have become difficult, because of parasite strains that are resistant to conventional drugs, such as chloroquine. That makes the search for new antimalarial drugs not only important but urgent. We aimed therefore at evaluating the effects of Momordica charantia L. (Cucurbitaceae) in mice infected with Plasmodium berghei. We used aquose and ethanotic extracts in a dose of 1000 mg/kg of body weight, orally, for five consecutive days (i.e. from day 2 to day 6 postinfection). We then followed up the parasitaemia during the course of infection. Although the population use this plant as an antimalarial, in our experimental conditions, M. charantia extracts have not shown such activity.

Control of parasitic infections among school children in the peri-urban area of Botucatu, São Paulo, Brazil

The prevalence of intestinal parasitosis was investigated in a primary school located in Rubião Júnior, a peri-urban district of Botucatu, São Paulo state, Brazil, in order to assess the effect of treatment and practical measures of prophylaxis in the control of parasitic infections among 7-to-18-year-old school children of a low socio-economic status. The first series of parasitological examinations included 219 school children, of which 123 (56.1%) were found to be infected with one or more parasite species. Eighty-four children carrying pathogenic parasites were submitted to various anti-parasitic treatment schedules. We re-evaluated 75 (89%) students after 4 to 6 months post-chemotherapy. The results indicate that the combination of treatment with prophylactic measures has been successful in the control of parasitic infections, since reinfection rates were generally low (< or = 5.3%), except for Giardia lamblia infections (18.6%), and a marked reduction on the prevalence rates was observed with a significant percentage of cure (> or = 73.1%) in children infected with most parasite species. The reasons for the apparent failure in the control of infections caused by Hymenolepis nana and Strongyloides stercoralis are discussed.

[Anthropometric evolution during hospitalization of severe malnourished children with persistent diarrhea receiving standardized nutritional support]

In order to estimate the nutritional rehabilitation (NR) during admission of malnourished children with persistent diarrhea (PD) receiving standardized nutritional support (NS), we prospectively evaluated the weight, height, head circumference and arm measurements (AM) of 20 children, 19 below 1 year, admitted to the ward with weigh/age -2.89 to -5.21 standard deviation. Four infants comprised the death group (DG) and 16 survived (SG). The SG was separated, according to initial weight behavior, into weight gain (WG) or weight loss (WL). Compared to SG at admission, DG only had lower AM and more metabolic-infectious alterations (p<05). The survivors presented NR but this was evident for WL only when considering the minimum weight. DG received less calories than SG and weight loss during the pre-death period was higher than for WL (p<05). It was concluded that very altered AM, severe metabolic-infectious insults, low caloric input and high weight loss velocity are associated to bad prognosis; severely malnourished infants with PD began NR during hospitalization while receiving adequate NS, but minimum weight must be considered for this evaluation; AM must be obtained at admission, due to its prognostic value, and adequate NS as well as anthropometric follow-up during the hospital stay are essential.

Ultrastructural study of the coagulating gland of Wistar rats submitted to experimental chronic alcohol ingestion

Morphological changes of coagulating gland of Wistar rats submitted to the experimental chronic alcoholism were noted. Ultrastructurally, it was observed reduction of the granular endoplasmic reticulum cisternae and nuclei with basal position and irregular shape. The epithelial cells presented pycnotic nuclei and the mitochondrial cristae disappeared, characteristic of cellular degeneration.

Intradermo-reação cervical para diagnóstico de infecções por Eurytrema sp em bovinos

Foram realizadas intradermo-reações (IDR) cervicais em 101 bovinos, machos e fêmeas, que receberam, simultaneamente e ao acaso, em sete áreas adjacentes, 0,1 ml de salina e igual volume de um extrato antigênico de Eurytrema sp, nas seguintes concentrações de proteína: 25ng/ml, 50|jg/ml, 100pg/ml, 250pg/ml, 500[jg/ml e 1 mg/ml. Feitas todas as injeções intradérmicas e, ao final de 30min, com auxílio de uma régua milimetrada, de cada pápula produzida foram medidos os dois diâmetros maiores, extraídas as médias (diâmetros inicial, D,e final, D) e calculada a diferença Di - D,. No dia seguinte acompanhava-se o abate de cada animal a fim de se verificar, por meio de exames macroscópicos dos respectivos pâncreas, se eram ou não parasitados por Eurytrema sp. Concluiu-se, então, que o extrato salino bruto do trematódeo, utilizado como antígeno, deverá conter, no momento de sua utilização, concentração de proteínas equivalente a 250pg/ml e, respectivamente, serem consideradas positivas e negativas as IDR que apresentarem Di - D, > 2,5mm e Di - D* < 2,5mm.

[Influence of afterload on the rate of variation of developed pressure (dT/dt). Study in isolated cardiac muscle]

PURPOSE

To evaluate the effects of afterload on peak rate of tension rise (dT/dt) in the isolated muscle.

METHODS

Left ventricular papillary muscles from Wistar rats were studied in isometric and isotonic afterloaded contractions. Muscles were analised in Krebs-Henseleit solution with calcium concentration of 2.52mM at 28 degrees C. The resting muscle length (preload) was maintained constant. The peak isometric developed tension (DT) and dT/dt were measured during increases of afterload (25, 50, 75 and 100% from DT).

RESULTS

A rise in afterload corresponding to 50, 75 and 100% of DT, did not cause an increase in dT/dt values (p > 0.05). The dT/dt value decreased (p < 0.05) when afterload was changed from 75% to 25% of DT.

CONCLUSION

The data suggest that an increase in the afterload from 50% of the DT did not promote changes in the dT/dt.

Alterações pancreáticas em bovinos naturalmente infectados por Eurytrema sp e sua associação com a carga parasitária e o número de ovos por grama de fezes (OPG)

Foram examinados, ao microscópio óptico, fragmentos de 41 pâncreas de bovinos naturalmente infectados por Eurytrema sp e as lesões encontradas foram classificadas em quatro graus, de acordo com sua extensão desde o epitélio dos ductos. Em seguida, tomando-se os valores das cargas parasitárias (CP) e o número de ovos por grama de fezes (OPG) dos animais, em cada grau de lesão estabelecido, comprovou-se que os valores do OPG e, principalmente, da CP podem ser utilizados para caracterizar, de maneira satisfatória, a extensão das lesões pancreáticas.

Comparative mechanical study of isolated papillary muscle from Wistar-Kyoto and Wistar rats

Isolated papillary muscles have often been used in myocardial mechanical function studies. The objective of the present study was to compare the mechanical function of papillary muscle isolated from left ventricle between Wistar (W) and Wistar-Kyoto (WKY) rats of different ages (1, 3, 6 and 12 months), in order to examine whether there is a difference in intrinsic mechanical properties of muscle between the two rat strains. Muscles were perfused with Krebs-Henseleit solution at 28 degrees C and studied isometrically and isotonically at a stimulation rate of 0.2 Hz. The W and WKY showed statistically significant differences during both isometric and isotonic contractions. During isometric contraction, (1) the peak developed tension (DT) and +dT/dt were lower in WKY rats in the 1 mo groups, (2) the resting tension (RT) was greater in WKY at 3, 6 and 12 mo, (3) time to peak tension (TPT) was greater in WKY at 3 and 12 mo, (4) time for tension to fall from peak to 50% of peak tension (RT 1/2) was greater in WKY at 3 mo and (5)-dT/dt was lower in WKY at 1 and 3 mo. During isotonic contraction, (1) the peak shortening (PS) and--dL/dt were lower in WKY at 12 mo, (2) the time to peak shortening (TPS) was greater in WKY at 3 and 12 mo; (3) +dL/dt was lower in WKY at 3, 6, and 12 mo and (4) the relative variation of length (Lmax-PS)/Lmax was greater in WKY at 6 and 12 mo. These data showed a difference in mechanical behaviour of the papillary muscle between Wistar and Wistar-Kyoto rats of different age.