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Biomedical subjects

S A Garcia

Publications and source records attributed to S A Garcia.

At least 19 recordsLinked to original sources
PubMed2003

Use of photoplethysmography to determine gastrointestinal perfusion pressure: an experimental canine model.

OBJECTIVES: To develop an experimental model to assess the parietal perfusion pressure (PPP) of the digestive tract using photoplethysmography. MATERIALS AND METHODS: Twenty-two mongrel dogs were used. Progressive external compression was applied to the intestinal wall and the PPP was assessed with photoplethysmography. The study group was divided into two groups. In group 1 PPP was measured at the levels of the stomach, duodenum, jejunum and transverse colon. In group 2 PPP was measured after temporary occlusion of the truncal and marginal circulation of the jejunum to provide further variables. RESULTS: The PPP decreased significantly for each successive distal section. Correlation coefficients and indices for PPP and mean arterial pressures were statistically significant (p < 0.005). Truncal occlusion provoked a drop in PPP whereas marginal occlusion scarcely modified the basal results. CONCLUSIONS: Photoplethysmography, through measurements of the residual arterial wave amplitude, is a valid method of determining quantitatively the PPP of the digestive tract and could be useful in a clinical environment.

Animals↗
PubMed2001

Hippocampal injections of amyloid beta-peptide 1-40 impair subsequent one-trial/day reward learning.

The injection of amyloid beta-peptide (Abeta) into rat CNS has been reported to induce cellular neuropathology. The present study investigated whether multiple intrahippocampal injections of Abeta 1-40 would impair one-trial/day reward learning 14 days later. Twenty-four male Sprague-Dawley rats, 3-4 months old, were injected with either Abeta 1-40 or distilled water into seven hippocampal sites bilaterally. Ten rats received 3 nmol Abeta 1-40 in 2 microl of distilled water per injection site, while 14 rats received distilled water alone. Following a 9-day recovery period, rats were gradually food deprived to 82% of their initial body weight. Fourteen days after the intrahippocampal injection, all rats received an initial training trial and three subsequent daily retention trials. Rats receiving Abeta 1-40 were significantly impaired on the second retention trial in terms of accuracy (number of unbaited alleys entered) and on the second and third retention trials in terms of speed (reciprocal of latency to reward). Histological analysis showed that Abeta 1-40 injections produced significant neuronal loss and gliosis. Abeta 1-40 immunoreactivity persisted locally at the injection site and in macrophages 2 weeks following the hippocampal injections. These effects appear to be sequence-specific; rats receiving Abeta 1-42 with a scrambled peptide sequence did not differ significantly from rats receiving distilled water alone in retention of the learning task or degree of histological damage.

Alzheimer Disease↗
PubMed1999

Primary socialization theory: comments on racism, sexism, generational neglect, abuse, and abandonment.

This article asks whether primary socialization theory adequately deals with the most distressed and disadvantaged members of society, whether for most of them the family, school, and peers are the primary sources of socialization. Children who are subjected to the effects of racism, sexism, physical and mental abuse, inferior dangerous schools, and abandonment to foster care from birth may find other sources of primary socialization which can be either negative and positive. "Nihilism" and "anomie" are used to describe such children's position in their societies, and the article asks if those without benefit of the three primary sources of socialization can find ways to create new and positive norms, or whether they are doomed to lives of hopelessness and deviance. [Translations are provided in the International Abstracts Section of this issue.]

Child↗
PubMed1994

Elevation of cord blood TSH concentration in newborn infants of mothers exposed to acute povidone iodine during delivery.

The thyroid function in full term newborn infants of 30 pregnant women given topical germicide providine-iodine (PVPI) during delivery was evaluated. For comparison 12 full term newborn infants of pregnant women using clorhexidine hydrochloride as germicide in selective cesarean section were designed as control. The two pregnant groups had similar median age (27.5 yr in PVPI group, range: 19-42 yr and 28.5 yr in control group, 19-40 yr) and gestational age (39 weeks, 38-42 weeks and 39.5 weeks, 38-42 weeks). Birth weight (3365 g, 2500-3860 g and 3265 g, 2850-4000 g) and the apgar score (9, 9-10 and 9, 8-10) of newborn were similar in both groups. Umbilical cord blood samples were taken after immediate clamping and serum total T3, total T4, free T4 and TSH concentrations were assayed by an immunofluorimetric method. T3, T4 and free T4 concentrations in the cord blood were not different in PVPI newborn infants (median values: 0.92 nmol/L, 135 nmol/L, and 15.9 pmol/L), in comparison to control newborns (0.97 mmol/L, 140.9 nmol/L and 17.3 pmol/L). In contrast, cord blood TSH concentration in newborn infants of PVPI pregnant women (median value: 6.47 mIU/L) was significantly higher (p < 0.01) than in control newborn infants (4.8 mIU/L). In PVPI exposed group 14 out of 30 newborn infants had TSH concentration above the upper value (6.7 mIU/L) observed in the control groups (X2 = 8.4, p < 0.01). These data suggest that fetal thyroid is susceptible even to acute iodine overload and support the recommendation that PVPI should be avoided during pregnancy.

Adult↗
PubMed1993

Maternal drug abuse: laws and ethics as agents of just balances and therapeutic interventions.

Among the many pressing legal, psychosocial, and ethical issues surrounding perinatal chemical dependence is one of achieving balances between far-reaching rights claimed for the unborn and for children, and those claimed by their mothers. In an attempt to achieve balances that are just and promote positive consequences, policies and laws have evolved that have pitted disparate individuals and groups against each other, most obviously mothers against their fetuses and children. Some such policies have had negative consequences such as the further weakening of already at-risk families and the erosion of doctor/patient trust. This article asserts that ethical concepts and legal tenets must be combined to develop new paradigms designed to minimize conflict and to achieve just and therapeutic balances between the rights and needs of those involved.

Child↗
PubMed1992

Drug abuse in America: medical and socio-legal dilemmas.

This article's first section describes some medico-legal issues that have been most influential in shaping responses to drug abuse in America. The next section presents a number of approaches to combating substance abuse within the criminal justice and civil systems, and discusses their rationale, effectiveness and problems. The article concludes by raising socio-political dilemmas that face America regarding the control of drug use, and asks to what extent these dilemmas are the product of ill-conceived theory and practice.

Criminal Law↗
PubMed1985

Effects of diet composition on the metabolic and heart rate responses to cold water exposure in men.

The reaction to immersion in cold water (22 degrees C) was studied in ten healthy male volunteers successively receiving balanced (C), hypercarbohydrate (HC), hyperprotein (HP), and hyperlipid (HL) normocaloric diets with a three week equilibration period on each diet. Oxygen consumption (ml min-1 m-2) increased from 149 to 224 during C, from 160 to 196 during HL, from 154 to 178 during HP, and from 166 to 187 during HL. Only the first two differences were significant. Pulmonary ventilation (ml min-1 m-2) increased from 4.08 to 6.24 during C, from 4.01 to 5.48 during HC, from 3.41 to 3.83 during HP, and from 3.77 to 5.48 during HL. The difference was statistically significant only for C. Heart rate (beats/min) decreased from 73 to 64 during C, from 74 to 61 during HC, from 73 to 60 during HP and from 72 to 64 during HL. The differences were statistically significant for all diets except HL. Oral temperature decreased in all groups (range 0.4 to 1.6 degrees C). Respiratory rate changes were not statistically significant. The calorigenic reaction to cold water immersion was demonstrable for all groups but more efficient in subjects receiving either balanced or HC diets, suggesting that HP and HL diets reduce cold adaptation.

Adult↗
PubMed1979

Student voluntarism in transition.

The university student volunteer as a social change agent is in a period of transition. There is no returning to the idealism and activism of the 1960s if this and future generations of students continue to see self-preservation and individual advancement as their only viable option here in America. In view of the changing nature of today's students, the conventional definitions of volunteers, such as Shultz's (1972) altruist, average, and pseudo-volunteer, must be reconsidered. Does the acceptance of minimal pay or demand for academic credit preclude one's being a true altruist? Further, is altruism a necessary or sufficient condition of voluntarism? While we must attempt to answer these questions, the purpose here was to suggest viable first steps in reviving and enhancing student voluntarism. Some of the most salient points are: (1) Student volunteers provide critically needed services to the community, (2) Students are increasingly demanding tangible personal and educational gains for services through voluntarism, (3) Faculty support is vital to student voluntarism and they should be encouraged to actively design their classes to integrate classroom theory and practice through volunteering, and (4) The community agencies served should be active participants in the faculty, student, agency triad, and not merely passive recipients of services. The future of student voluntarism must be viewed in the larger context of changes occurring in the society-at-large, such as cynicism, mistrust of authority figures and leaders, and a move away from altruism and toward symbiosis and/or individualism. There is widespread disillusionment with "band-aid" approaches to solving enormous social problems, i.e., trying to help the few while some of society's most fundamental structures guarantee the perpetuation of poverty, crime, and general anomie. The rekindling of the ideology of cooperative altruism will take ingenuity and tireless effort. Meanwhile, if community psychology and related disciplines are to continue to utilize student volunteers, programs must be oriented toward new trends in student and faculty values and interests, and evolving community needs.

Altruism↗
PubMedDate not supplied

Herpes simplex virus type 2 infection in pregnancy: asymptomatic viral excretion at delivery and seroepidemiologic survey of two socioeconomically distinct populations in São Paulo, Brazil.

The objective of the present study was to estimate the prevalence of herpes simplex virus type 2 (HSV 2) antibodies in child bearing women of 2 Brazilian populations with different socioeconomic status and to determine the risk of neonatal HSV exposure by means of maternal cultures at the onset of labor. The study was conducted at 2 hospitals: A, serving very low income patients and B, serving middle socioeconomic class. 173 participants from group A and 127 from B answered a questionnaire which showed that the patients had similar ages (27.7 and 26.8 years, respectively) but differed with regard to socioeconomic status, age at first intercourse (18.6 vs 20.6 years), number of sex partners (1.5 vs 1.2) and previous sexually transmitted diseases (15% vs. 1.5%). History of genital herpes was given by 11% of group A participants and by a similar number, 7%, of patients from group B. In addition, 200 serum samples from population A and 455 from B were tested by ELISA for anti HSV antibodies and 92% and 86%, respectively, were found to be positive. Sixty seropositive samples from group A and 90 from B were further analyzed by Western blot, which showed the presence of type 2 specific antibodies in 46% and 36%, respectively, suggesting an overall HSV 2 prevalence of 42% in group A and 31% in B. Cervical specimens were obtained for culture from 299 asymptomatic patients of population A and 313 of B. HSV was isolated from one specimen in each group, indicating a 0.3% incidence of asymptomatic viral excretion in both populations.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗