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Biomedical subjects

B Just

Publications and source records attributed to B Just.

18 recordsLinked to original sources
PubMed1999

Riluzole series. Synthesis and in vivo "antiglutamate" activity of 6-substituted-2-benzothiazolamines and 3-substituted-2-imino-benzothiazolines.

Two series of analogues of riluzole, a blocker of excitatory amino acid mediated neurotransmission, have been synthesized: monosubstituted 2-benzothiazolamines and 3-substituted derivatives. Of all the compounds prepared in the first series, only 2-benzothiazolamines bearing alkyl, polyfluoroalkyl, or polyfluoroalkoxy substituents in the 6-position showed potent anticonvulsant activity against administration of glutamic acid in rats. The most active compounds displaying in vivo "antiglutamate" activity were the 6-OCF(3) (riluzole), 6-OCF(2)CF(3), 6-CF(3), and 6-CF(2)CF(3) substituted derivatives with ED(50) values between 2.5 and 3.2 mg/kg i.p. Among the second series of variously substituted benzothiazolines, compounds as active as riluzole or up to 3 times more potent were identified in two series: benzothiazolines bearing a beta-dialkylaminoethyl moiety and compounds with an alkylthioalkyl chain and their corresponding sulfoxides and sulfones. The most potent derivatives were 2-imino-3-(2-methylthio)- and 2-imino-3-(2-methylsulfinyl)-ethyl-6-trifluoromethoxybenzothiazolines (61 and 64, ED(50) = 1.0 and 1.1 mg/kg i.p., respectively). In addition, intraperitoneal administration of some of the best benzothiazolines protected mice from mortality produced by hypobaric hypoxia.

Animals↗
PubMed1995

Effect of neostigmine at different levels of mivacurium-induced neuromuscular blockade.

The effectiveness of neostigmine 40 micrograms/kg for antagonism of two different levels of neuromuscular blockade, induced by a bolus dose of mivacurium 0.15 mg/kg, was studied in 45 patients. The patients were anaesthetized with thiopentone, fentanyl, nitrous oxide in oxygen, and enflurane. Neostigmine was administered at either 10% recovery of the twitch height (TH10) at the adductor pollicis muscle (n = 14) or upon reappearance of the first response at the orbicularis oculi muscle (OO1) after train-of-four (TOF) stimulation (n = 16), the latter representing a deeper degree of neuromuscular blockade. Fifteen of the 45 patients did not receive neostigmine (control group). Neostigmine administration at OO1 rather than at TH10 at the adductor pollicis muscle caused reversal of neuromuscular blockade to occur 8 min earlier and shortened the time to reach 25% recovery of the twitch height (TH25) at the adductor pollicis muscle by about 5 min, compared with the control group. However, the time needed to reach a T4/T1 ratio > or = 0.8 was similar in both the early and late neostigmine administration groups, being 9 min faster than in the control group. It can be concluded that there is no advantage in administering neostigmine at profound neuromuscular blockade to achieve clinically adequate recovery (T4/T1 ratio > or = 0.8). However, the time between injection of mivacurium and TH25 may be shortened by using neostigmine at profound neuromuscular blockade, a procedure which may be useful in case of unpredictably difficult intubation, since diaphragmatic movements usually reappear at TH25.

Adolescent↗
PubMed1994

Glutamine metabolism in healthy adult men: response to enteral and intravenous feeding.

To assess the effect of feeding on glutamine kinetics, six healthy men received 4-h intravenous infusions of L-[2-15N]glutamine and L-[1-13C]leucine on 3 separate days: 1) in the postabsorptive state, 2) over the course of an 8-h nasogastric infusion of a small peptide-based nutrient mixture, and 3) during an 8-h isonitrogenous, isoenergetic intravenous infusion (1.5 g amino acid.kg-1.d-1; 130 kJ.kg-1.d-1, or 31 kcal.kg-1.d-1; 58% carbohydrate and 42% fat). Regardless of the route, nutrition increased leucine appearance rate (Ra) and oxidation, stimulated protein synthesis, and improved leucine balance; apparent rates of protein breakdown decreased during enteral nutrition only. Glutamine Ra increased 16.8% (NS) and 26.2% (P < 0.01) with parenteral and enteral feeding, respectively, over postabsorptive values. The present findings are consistent with a major role of glutamine in interorgan nitrogen transport in the fed state and further suggest that increased availability of precursors may stimulate glutamine synthesis de novo, and enteral infusion of peptide-bound amino acids may be an effective route to provide free glutamine to the rest of the body.

Adult↗
PubMed1993

Prevention of intraoperative hypothermia by preoperative skin-surface warming.

BACKGROUND: Intraoperative hypothermia initially results from internal redistribution of heat facilitated by anesthesia-induced vasodilation. Preinduction skin-surface warming minimizes postinduction hypothermia in anesthetized volunteers. However, its efficacy might be reduced in surgical situations, because of multiple sources of heat loss. METHODS: Intraoperative core and mean skin temperatures were measured during total hip arthroplasty in 16 patients, randomly assigned to be covered preoperatively with a warming blanket for > or = 90 min (prewarmed group) or not covered (unwarmed group). RESULTS: During the first hour of anesthesia, core temperature decreased more than twice as much in the unwarmed group (-0.7 +/- 0.1 degree C; mean +/- SE) than in the prewarmed patients (-0.3 +/- 0.1 degree C). At the end of surgery, core temperature was 36.3 +/- 0.1 degree C in the prewarmed group and 35.2 +/- 0.2 degree C in the unwarmed group. During recovery, seven patients obviously shivered in the unwarmed group and none in the prewarmed group. CONCLUSIONS: Preanesthetic skin-surface warming reduces the initial postinduction hypothermia in surgical patients, preventing intraoperative hypothermia and postoperative shivering even for procedures lasting 3 h or longer.

Aged↗
PubMed1993

Leg warming minimizes core hypothermia during abdominal surgery.

The efficacy of leg skin warming in preventing hypothermia and shivering was evaluated in two separate prospective, randomized trials in patients undergoing abdominal surgery. In the first trial, 22 patients were randomized to receive no hypothermia prevention (control group) or active warming with an electric warming blanket (electric blanket group). In the second trial 33 patients were randomized to receive no hypothermia prevention (control group) or forced-air warming (Bair Hugger group) or forced-air warming with insulation of the air blanket from the environment (insulated Bair Hugger group). The core and skin temperatures were measured and changes in body heat content calculated. In the first trial, core temperature was 34.6 +/- 0.3 degrees C at the end of surgery in the control group vs 36.4 +/- 0.1 degrees C in the electric warming blanket group (P < 0.001). Shivering occurred in nine control patients and in one warmed patient (P < 0.05). In the second trial, core temperature was 35.1 +/- 0.2 degrees C at the end of surgery in the control group, 36.3 +/- 0.1 degrees C in the Bair Hugger group (P < 0.01) and 37.1 +/- 0.1 degrees C in the insulated Bair Hugger group (P < 0.01 versus control; P < 0.05 versus Bair Hugger). Shivering occurred in one patient of each warmed group and in seven of the control group (P < 0.05). Skin-surface warming limited to the legs provides sufficient heat (ranging 34 to 43 watts) to counterbalance heat losses during abdominal surgery.

Abdomen↗
PubMed1992

Oxygen uptake during recovery following naloxone. Relationship with intraoperative heat loss.

The increased metabolic and respiratory demand during naloxone recovery from opioid-based anesthesia could be related to the return of thermoregulation in hypothermic patients and thus be avoided by preventing intraoperative hypothermia. In this study, we measured O2 uptake (VO2) during naloxone-induced recovery in two groups of patients to determine the effect of intraoperative heat loss on postoperative VO2 changes. In seven patients, intraoperative hypothermia was prevented (normothermic group), whereas hypothermia was allowed to develop in seven other patients (hypothermic group). Core and skin temperatures were measured throughout the study to calculate changes in body heat content. Before naloxone antagonism of fentanyl-supplemented anesthesia, core temperature (mean +/- SEM) was 36.8 +/- 0.1 degrees C in the normothermic group and 34.2 +/- 0.2 degrees C in the hypothermic group (P less than 0.001). After titrated administration of naloxone during recovery, VO2 and minute ventilation (VE) increased in the hypothermic group, by 114 +/- 37% and 97 +/- 52% respectively (P less than 0.05), with a three-fold increase in four patients. In the normothermic group, VO2 increased significantly less (25 +/- 5%), without any significant change in VE. The change in VO2 and VE was significantly greater in patients who were hypothermic. VO2 was integrated throughout the recovery period to calculate recovery energy expenditure. Recovery energy expenditure and intraoperative heat loss were highly correlated (r = 0.88; P less than 0.01). This study demonstrates that the metabolic and respiratory stresses associated with naloxone-induced recovery from opioid-based anesthesia depend on the intraoperative heat loss and can therefore be reduced by preventing intraoperative hypothermia.

Anesthesia Recovery Period↗
PubMed1991

Glutamine metabolism after small intestinal resection in humans.

Glutamine and leucine kinetics were measured using stable isotopes in five enterectomized patients (residual small bowel, 80 +/- 25 cm [mean +/- SE]) who were in a near normal nutritional status at distance from surgery. While parameters of leucine metabolism were normal, rates of whole body glutamine utilization were reduced by 20% in the patients. The data suggest that the small intestine plays a prominent role in glutamine utilization in vivo in humans.

Adult↗
PubMed1991

Oral nutrition in patients receiving home cyclic parenteral nutrition: pattern of substrate utilization.

Patients receiving cyclic home parenteral nutrition (PN) often have a significant oral caloric intake. This study describes the metabolic use of fuels, as assessed by indirect calorimetry, in eight stable, ambulatory, noncancerous, adult patients receiving glucose-based PN with (PN + oral) or without (PN only) a self-selected oral intake. Patients' weight was 91 +/- 2% (mean +/- SE) of ideal body weight, and fat mass was 22 +/- 5 and 31 +/- 2% of actual body weight in males and females, respectively. Under the PN-only regimen, providing 104 +/- 5% of predicted basal energy expenditure (BEE), patients were in equilibrium for energy and nitrogen balances. Oral supplementation (absorbed oral intake 80 +/- 5% of BEE) was associated with positive energy and nitrogen balances but also with nearly continuous net fat synthesis. We conclude that the glucose-based PN + mixed oral regimen enables the patients to face the increased energy requirements of everyday ambulatory life but is not associated with an optimal body composition in long-term PN patients.

Administration, Oral↗
PubMed1990

Comparison of substrate utilization by indirect calorimetry during cyclic and continuous total parenteral nutrition.

Five male adult home patients were studied in a randomized order under continuous (24 h/d) and nocturnal cyclic (15 h/d) isocaloric, isonitrogenous total parenteral nutrition (TPN). They received 2626 +/- 265 total kcal/d as 60% dextrose and 40% lipids; the 3-h lipid infusion was followed by the dextrose amino acid infusion on both regimens. Substrate oxidation was measured by indirect calorimetry during four periods on the fourth day of each regimen. During cyclic TPN net lipogenesis occurred with a nonproteic respiratory quotient (npRQ) greater than 1 during dextrose amino acid infusion followed by net lipolysis with an npRQ less than 1 during the nonnourishing phase. In contrast, during continuous TPN net lipogenesis persisted with an npRQ greater than 1 over the 21 h of dextrose amino acid infusion. During the 3-h lipid infusion, fat oxidation was observed during both regimens but was more pronounced during cyclic TPN (p less than 0.05). As a consequence, 24-h lipid oxidation was higher and 24-h dextrose utilization lower during cyclic vs continuous TPN (p less than 0.05). These results suggest that cyclic TPN when alternating between substrate storage and oxidation, mimics the physiological pattern of oral feeding.

Adult↗
PubMed1990

Clinical reliability of measured and calculated oxygen parameters in surgical patients: influence of hyperventilation.

The acid-base and oxygen status were assessed in patients undergoing abdominal surgery. We determined the measured and calculated parameters described by Siggaard-Andersen in arterial and mixed venous blood before, during and after a controlled hyperventilation. In these dynamic conditions, the mixed venous calculated p50 showed the most interesting variations. Derived values in arterial blood were unreliable since: 1) fitting to hyperbolic tangent function is not possible when SaO2 greater than 0.98; 2) in these patients, the arterio-venous difference in CtO2 is different from 2.3 mmol/L. The acute changes in calculated p50 are in agreement with the effect of hyperventilation on oxygen status.

Abdomen↗
PubMedDate not supplied

A comprehensive school-based clinic: university and community partnership.

PURPOSE: To describe the evolution and current status of a university and community partnership engaged in operating an urban elementary school-based clinic (SBC) POPULATION: The children at the school who are eligible to receive care at the SBC include 500 elementary students and 200 adolescents who attend a magnet junior high school housed in the same building. The vast majority of the children attending the school are from families whose incomes are below the national poverty level. Eighty-five percent of the children are black. Fifteen percent are Hispanic, non-white. CONCLUSIONS: A variety of services and programs are offered to the children and their families for the promotion of health and the prevention of mental disorders. Service, education, and research occur simultaneously to achieve the multiple goals of the partners and participants. PRACTICE IMPLICATIONS: Advanced practice nurses can provide quality health and mental health care services for school-age children and their families through SBCs. Institutional partnerships, capitalizing on each other's strengths, can expand the availability of SBC offerings.

Adolescent↗
PubMedDate not supplied

Use of a ventilated canopy for assessment of [13C]leucine oxidation in patients receiving total parenteral nutrition.

Rates of oxidation of infused 13C-labeled substrates are calculated from CO2 production and 13C enrichment in breath CO2. Breath sampling through a mouthpiece is not appropriate in severely ill patients; the authors therefore validated the use of direct air sampling from the ventilated canopy of an indirect calorimeter for measuring the oxidation of 13C-labeled substrates. Infusions of H13CO3Na or L-[1-13C]leucine were performed in four healthy postabsorptive adults and six malnourished patients receiving total parenteral nutrition (TPN). At each sampling point, air was collected from the canopy to compare with breath air sampled through a mouthpiece and 13CO2 enrichment determined by isotope ratio mass spectrometry. Despite five-fold dilution of expired air by room air within the canopy (a dilution required to maintain safe CO2 levels in inspired air): (1) Breath 13CO2 enrichment was accurately predicted using samples from the canopy, with a correction taking into account the measured CO2 fractions in canopy and room air; (2) the precision in isotopic determination was similar with both methods (SD/mean of 12 determinations = 2.5 +/- 1.0% vs 3.0 +/- 1.0%). These data demonstrate that the use of a ventilated canopy allows for combined assessment of energy expenditure and rates of oxidation of 13C-labeled substrates even in sick, debilitated patients receiving total parenteral nutrition.

Adult↗