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Biomedical subjects

A J Schneider

Publications and source records attributed to A J Schneider.

At least 19 recordsLinked to original sources
PubMed2006

[First abdominal access in gynecological laparoscopy: which method to utilize?].

The choice of the technique to enter the peritoneal cavity, during a laparoscopy, depends on a lot of variables which hinder a standardized method and, actually, it appears impossible to show, with certainty, the best method to choose for the first abdominal access in gynecological laparoscopy. The preference for one or another technique depends on the operator experience, school and speciality of the surgeon, laparoscopical upgrading and the work environment; many surgical techniques are not yet used due the limits and fears of some surgeons to change the preference in first access approaching and for the lack of operating versatility by a method or another one. A review of the scientific literature, underlines that the major problems during the first laparoscopical abdominal access are two, vascular and intestinal and their percentage is variable. In this paper we describe the large range of methods for open and closed laparoscopy and for direct access, that permit to perform a first abdominal laparoscopical access, and their major possible problems.

Abdominal Wall↗
PubMed2004

[Pregnant, addicted prostitutes: compulsory admission is sometimes necessary in the interests of the child].

Three drug-addicted prostitutes, who were 37, 27 and 25 weeks pregnant respectively, were admitted to a psychiatric department under court order. After the birth, the children were placed in foster families. The mothers withdrew from further treatment. In Rotterdam, The Netherlands, there is a city network made up of doctors and social workers; in the case of addicted pregnant prostitutes they advise the Child Protection Agency of the Ministry of Justice about the care of the child after its birth. The combination of heavy addiction and prostitution in a pregnancy without any prenatal care can be considered a psychiatric disorder. Consequently, an addicted woman can be compulsorily admitted because of the threat she forms to her unborn child. In these cases the mother's right to self-determination must be limited in the interest of the child.

Adult↗
PubMed2000

Effect of the mechanical ventilatory cycle on thermodilution right ventricular volumes and cardiac output.

The purpose of this study was to evaluate right ventricular (RV) loading and cardiac output changes, by using the thermodilution technique, during the mechanical ventilatory cycle. Fifteen critically ill patients on mechanical ventilation, with 5 cmH(2)O of positive end-expiratory pressure, mean respiratory frequency of 18 breaths/min, and mean tidal volume of 708 ml, were studied with help of a rapid-response thermistor RV ejection fraction pulmonary artery catheter, allowing 5-ml room-temperature 5% isotonic dextrose thermodilution measurements of cardiac index (CI), stroke volume (SV) index, RV ejection fraction (RVEF), RV end-diastolic volume (RVEDV), and RV end-systolic volume (RVESV) indexes at 10% intervals of the mechanical ventilatory cycle. The ventilatory modulation of CI and RV volumes varied from patient to patient, and the interindividual variability was greater for the latter variables. Within patients also, RV volumes were modulated more by the ventilatory cycle than CI and SV index. Around a mean value of 3.95 +/- 1.18 l. min(-1). m(-2) (= 100%), CI varied from 87.3 +/- 5.2 (minimum) to 114.3 +/- 5.1% (maximum), and RVESV index varied between 61.5 +/- 17.8 and 149.3 +/- 34.1% of mean 55.1 +/- 17.9 ml/m(2) during the ventilatory cycle. The variations in the cycle exceeded the measurement error even though the latter was greater for RVEF and volumes than for CI and SV index. For mean values, there was an inspiratory decrease in RVEF and increase in RVESV, whereas a rise in RVEDV largely prevented a fall in SV index. We conclude that cyclic RV afterloading necessitates multiple thermodilution measurements equally spaced in the ventilatory cycle for reliable assessment of RV performance during mechanical ventilation of patients.

Aged↗
PubMed1999

[Syphilis in addicted pregnant women: better care through more awareness and contract between organizations involved].

Three women, aged 21, 20 and 30 years, were cocaine users and pregnant. There had been no prenatal monitoring until they reported with uterine contractions. Blood of the first two women was then tested; serology revealed active syphilis infections: their children had died in utero. The blood of the third woman had been tested as part of a street project; it revealed an active syphilitic infection but she could not be found for treatment. After delivery, the child showed withdrawal symptoms. The first and third women and the child of the third woman were treated with benzylpenicillin. The system for screening and treating drug-addicted pregnant women should be intensified.

Adult↗
PubMed1999

Three distinct D-amino acid substitutions confer potent antiangiogenic activity on an inactive peptide derived from a thrombospondin-1 type 1 repeat.

Mal II, a 19-residue peptide derived from the second type 1 properdin-like repeat of the antiangiogenic protein thrombospondin-1 (TSP-1), was inactive in angiogenesis assays. Yet the substitution of any one of three L-amino acids by their D-enantiomers conferred on this peptide a potent antiangiogenic activity approaching that of the intact 450-kDa TSP-1. Substituted peptides inhibited the migration of capillary endothelial cells with an ED50 of 8.5 nM for the D-Ile-15 substitution, 10 nM for the D-Ser-4 substitution, and 0.75 nM for the D-Ser-5 substitution. A peptide with D-Ile at position 15 could be shortened to its last seven amino acids with little loss in activity. Like whole TSP-1, the Mal II D-Ile derivative inhibited a broad range of angiogenic inducers, was selective for endothelial cells, and required CD36 receptor binding for activity. A variety of end modifications further improved peptide potency. An ethylamide-capped heptapeptide was also active systemically in that when injected i.p. it rendered mice unable to mount a corneal angiogenic response, suggesting the potential usefulness of such peptides as antiangiogenic therapeutics.

Acetylation↗
PubMed1995

"Helper:" A critical events prompter for unexpected emergencies.

OBJECTIVE: The medical practitioner is faced with an increasing list of protocols and algorithms related to patient care. These recommendations are often difficult to recall, particularly in stressful emergency situations. Using advanced cardiac life support (ACLS) protocols, we built a computer-based system to exhibit precompiled response plans for medical emergencies. To validate the usefulness of this prompting device, we tested application of two of the nine ACLS algorithms, pulseless ventricular fibrillation/ventricular tachycardia (Vfib/Vtach) and bradycardia, in a simulated operating room (OR) environment. METHODS: The system utilized the software authoring system IconAuthor (Aimtec Inc., Nashua, NH) and a touch-screen monitor (DiamondScan, Microtouch, Methuen, MA). Prior to testing our system, all 39 subjects were given time to familiarize themselves with its operation. Subsequently, all subjects were videotaped while managing a standard simulated anesthetic. During the anesthetic, the subjects were presented with two emergency scenarios, not viewed during the familiarization period. The electrocardiographic (EKG) signals for normal sinus rhythm, ventricular fibrillation, and second-degree heart block were presented. By random selection, the prompter was available to half of the subjects for help with arrhythmia management (experimental group), while to half it was not (control group). RESULTS: A total of 39 subjects completed the exercise. Use of the prompter enabled significantly more subjects to administer correct drugs and dosages during ventricular fibrillation. The correct lidocaine dose was chosen more often by the experimental group than by the control (p = 0.015); similarly MgSO4 was appropriately ordered more often in the experimental group (p = 0.003). During second-degree heart block, atropine was correctly followed with a dopamine infusion (p = 0.004), and epinephrine infusion was ordered for refractory bradycardia (p = 0.002) more often in the experimental than the control group. CONCLUSIONS: These data demonstrate the value of a prompting device at the anesthesia workstation. We foresee the use of such prompters in many areas of medicine.

Algorithms↗
PubMed1995

Transient increase in interleukin-8 and pulmonary microvascular permeability following aortic surgery.

Aortic surgery results in ischemia/reperfusion of the lower body. This may liberate inflammatory mediators that activate neutrophils, and may result in lung microvascular changes with increased permeability and respiratory failure. We studied circulating inflammatory mediators and the pulmonary leak index (PLI) of 67Ga, a measure of transvascular transferrin transport and permeability, in patients scheduled for elective aortic and peripheral vascular surgery, before and after surgery. Aortic surgery patients in Groups 1 (n = 10) and 2 (n = 7) were studied before and at a median of 2.5 and 21.0 h after surgery, respectively. A control Group 3 (n = 6) was studied before and at a median of 2.9 h after peripheral vascular surgery. The PLI (median) increased from a median of 9.1 (range, 6.6 to 14.7) before to a median of 23.4 (range, 18.7 to 86.4) x 10(-3)/min after surgery in Group 1 but not in the other groups (p < 0.001). The postoperative increase in circulating neutrophils and elastase-alpha 1-antitrypsin, a marker of neutrophil activation, was similar among the groups. Plasma levels of activated complement 3a and tumor necrosis factor (TNF-alpha) did not change in any of the groups. In contrast, plasma levels of interleukin-8 (IL-8) increased in Group 1 from < 3 (range, < 3 to 37) before to 324 (range, 36 to 868) pg/ml after surgery, but did not change in the other groups (p < 0.005). The decrease in plasma levels of angiotensin converting enzyme (ACE) was greater in Group 1 than in the other groups (p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1994

Acute effect of ibopamine and isosorbide mononitrate on blood volume distribution in congestive heart failure.

In order to compare ibopamine (IBO), a dopamine congener, with isosorbide mononitrate (ISMN) and to study their interaction in effects on the capacitance vasculature in congestive heart failure (CHF), a prospective, randomized, placebo-controlled, double-blind clinical trial was performed in 32 patients with New York Heart Association class II-IV CHF, randomly assigned to receive single oral doses of placebo, 200 mg IBO, 20 mg ISMN, or both IBO and ISMN. After labelling of red cells with 99mTc, changes in regional radioactivity, indicative of changes in blood volume, were recorded using a gamma-camera before and at 30, 60 and 120 min after drug administration. At 30 and 60 min, arterial systolic and pulse pressures were higher with IBO than with ISMN and placebo (for pulse pressure by mean 13.7 mmHg, 95% confidence interval 4.5-23.0 mmHg, at 30 min), probably reflecting an IBO-induced rise in stroke volume at unchanged heart rate and mean arterial pressure. IBO did not change regional radioactivity except for a transient increase of 4.4% (0.5-7.6%) in the thorax at 30 min. This was attenuated by concomitant ISMN treatment since, starting at 30 min, the drug increased radioactivity in the legs, compared with patients not receiving the drug, by 8.0% (95% confidence interval 0.2-15.8%), leading to a fall in thoracic and left ventricular radioactivity at 30 min of 3.4% (0.3-7.0%) and 6.4% (0.8-11.9%), respectively, and a fall of 5.5% (0.5-10.5%) in hepatic radioactivity at 60 min.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1993

Prevalence and prediction of multiple organ system failure and mortality in acute pancreatitis.

We studied the prevalence of multiple organ system failure (MOSF), the relations between age, pre-existing chronic conditions, local complications, systemic infection, organ system failure, and mortality in patients with acute pancreatitis. During the study period, 267 consecutive patients were admitted to a tertiary hospital with acute pancreatitis. Multivariate analyses were used to identify factors predictive of MOSF occurrence and mortality. Using a previously developed MOSF scoring system at our center, MOSF (> or = 2 organ systems) was found to occur in 63 (24%) of the patients. Cardiovascular, pulmonary, renal, and hepatic failure predominated. Advanced age (> 55 yr) and chronic disease were related to local complications and systemic infection (both, P < .001). Local complications and systemic infection occurred in 68% and 75% of patients, respectively. In multiple logistic regression, advanced age, chronic disease, local complications, and systemic infection independently contributed to the development of MOSF. Overall mortality was 19%. MOSF accounted for 96% of deaths; mortality increased from 1% to 79% in patients without and with MOSF, respectively. In multiple logistic regression, advanced age, chronic disease, local complications, failure of the cardiovascular, renal, hepatic, gastrointestinal, and neurological systems independently contributed to mortality prediction. Advanced age and prior chronic disease may reflect diminished physiological reserve and predispose to local complications, systemic infection, and MOSF. Although local complications and systemic infection are important predisposing factors for MOSF, a host-dependent response to unknown specific or nonspecific factors may have a role in the pathogenesis of the syndrome in 25% of patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1993

Transvascular transport of 67Ga in the lungs after cardiopulmonary bypass surgery.

STUDY OBJECTIVE: To examine the effect of cardiac surgery with cardiopulmonary bypass (CPB) on pulmonary vascular permeability. DESIGN: A prospective, serial study. SETTING: Department of nuclear medicine and intensive care units of a university hospital. PATIENTS: Twelve consecutive patients were studied, before and immediately after elective cardiac surgery using CPB (group 1), and 4 consecutive, artificially ventilated patients with acute cardiogenic pulmonary edema (group 2). MEASUREMENTS AND RESULTS: The kinetics in blood and over both lungs were measured, using two mobile probes at the bedside, of intravenously injected 67Ga, assumed to bind to circulating transferrin, and in vitro 99mTc-labeled red blood cells to account for pulmonary blood volume. From data recorded in time (1 h), a pulmonary leak index (PLI), the time constant of transport of 67Ga from the intravascular to the extravascular space of the lung, was calculated and values for both lungs were averaged. In group 1, the PLI (.10(-3).min-1, mean +/- SD) was 8.2 +/- 3.7 before and 17.0 +/- 13.5 after CPB surgery (p < 0.01) and changes directly related to the duration of CPB. In four patients with a CPB duration > or = 120 min, the PLI, 31.1 +/- 16.3.10(-3).min-1, exceeded 2 SD plus mean preoperative PLI. Changes in PLI tended to relate inversely to changes in arterial WBC, which, in turn, inversely related to CPB duration. The PaO2/FIO2 ratio decreased and tended to relate inversely to PLI after surgery. No patient developed alveolar pulmonary edema on chest radiograph. In group 2, the PLI was 11.1 +/- 3.1.10(-3).min-1 (NS from group 1 preoperative PLI). CONCLUSIONS: Cardiopulmonary bypass induces a pulmonary vascular leak, as assessed by 67Ga kinetics using a bedside detection technique, in some cardiac surgery patients with prolonged CPB. This leak may reflect pulmonary vascular injury and increased permeability, following activation of leukocytes by CPB and subsequent pulmonary sequestration, rather than increased filtration through pressure factors. It may contribute to impaired gas exchange, even in the absence of manifest alveolar edema of the lungs, after surgery.

Acute Disease↗
PubMed1991

Total body blood volume redistribution in porcine E. coli septic shock: effect of volume loading, dobutamine, and norepinephrine.

The purpose of the present study was to determine the effect of volume loading alone (CONTR) vs. volume loading in combination with dobutamine (DOBU) or norepinephrine (NOR) on total body blood volume distribution in septic shock. After instrumentation, injection of in vitro labelled 99mTc red blood cells, and baseline measurements, anesthetized, ventilated pigs (n = 21) received 3-4.10(8).kg-1 live E. coli bacteria intravenously. Images of thorax, abdomen, and hindlimb were obtained by using a gamma camera simultaneously with hemodynamic measurements. E. coli infusion resulted in a decrease in arterial pressure, ventricular filling pressures, and cardiac output with a concomitant increase in pulmonary arterial pressure. Blood volume was redistributed from the heart, lungs, spleen, abdomen, and leg to the liver. After randomization, the CONTR group (I, n = 5) was subjected to volume loading, and treatment groups (each n = 8) received volume loading in combination with DOBU (group II, 5-10 micrograms/kg/min) or NOR (group III, 0.25-0.50 micrograms/kg/min). As compared to volume loading alone, DOBU and NOR increased cardiac output but only NOR restored arterial pressure. Volume loading increased blood volume in all regions studied; however, it was unequally distributed amongst organs with a preference for the liver. Neither DOBU nor NOR influenced the partitioning of the infused volume between organs. However, NOR prevented pooling of blood in the leg.

Animals↗