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Biomedical subjects

J Barr

Publications and source records attributed to J Barr.

At least 37 records · Page 2Linked to original sources
PubMed2001

Heliox use in the treatment of acute hyperammonemia.

The objective of this study was to evaluate a new method for the treatment of acute hyperammonemia with a helium-oxygen mixture (heliox). We conducted a prospective, randomized, controlled study of male Sprague-Dawley rats. Experimental hyperammonemia was induced by 7 days of a high-ammonia diet. Subsequently, the animals were randomly divided into two groups: the study group treated with heliox breathing for 24 hours and a control group breathing room air for 24 hours. A prospective, randomized, controlled laboratory animal study was conducted at an animal research facility. The baseline plasma ammonia level was 9.49 +/- 10.96 micromol/L. After 7 days of a high-ammonia diet, the plasma ammonia level rose to 31.53 +/- 8.86 micromol/L. There was a significant statistical difference between the plasma ammonia level following 24 hours of heliox therapy (23.14 +/- 13.97 micromol/L) and the ammonia level in the control group (42.31 +/- 24.25 micromol/L) (P < .05). Heliox breathing was found to be an efficient treatment modality for decreasing plasma ammonia levels in an animal model. Further studies are required to evaluate its potential application in the treatment of patients with hyperammonemia.

Administration, Inhalation↗
PubMed2000

Comparison of intranasal midazolam with intravenous diazepam for treating febrile seizures in children: prospective randomised study.

OBJECTIVE: To compare the safety and efficacy of midazolam given intranasally with diazepam given intravenously in the treatment of children with prolonged febrile seizures. DESIGN: Prospective randomised study. SETTING: Paediatric emergency department in a general hospital. SUBJECTS: 47 children aged six months to five years with prolonged febrile seizure (at least 10 minutes) during a 12 month period. INTERVENTIONS: Intranasal midazolam (0.2 mg/kg) and intravenous diazepam (0.3 mg/kg). MAIN OUTCOME MEASURES: Time from arrival at hospital to starting treatment and cessation of seizures. RESULTS: Intranasal midazolam and intravenous diazepam were equally effective. Overall, 23 of 26 seizures were controlled with midazolam and 24 out of 26 with diazepam. The mean time from arrival at hospital to starting treatment was significantly shorter in the midazolam group (3.5 (SD 1.8) minutes, 95% confidence interval 3.3 to 3.7) than the diazepam group (5.5 (2.0), 5.3 to 5.7). The mean time to control of seizures was significantly sooner (6.1 (3.6), 6.3 to 6.7) in the midazolam group than the diazepam group (8.0 (0.5), 7. 9 to 8.3). No significant side effects were observed in either group. CONCLUSION: Seizures were controlled more quickly with intravenous diazepam than with intranasal midazolam, although midazolam was as safe and effective as diazepam. The overall time to cessation of seizures after arrival at hospital was faster with intranasal midazolam than with intravenous diazepam. The intranasal route can possibly be used not only in medical centres but in general practice and, with appropriate instructions, by families of children with recurrent febrile seizures at home.

Administration, Intranasal↗
PubMed2000

Development of a poly(ortho ester) prototype with a latent acid in the polymer backbone for 5-fluorouracil delivery.

A study has been carried out to determine whether the latest family of poly(ortho esters) can be converted into a practical delivery system. This polymer differs from the previously described polymers in that it incorporates a short segment of a latent acid in the polymer backbone. The following issues were specifically addressed: (a) can the erosion and drug release be reproducibly controlled to yield the desired drug release kinetics and erosion rates? (b) Is the polymer stable during radiation sterilization, on storage and on fabrication? (c) Can the polymer be prepared reproducibly at the desired molecular weights and molecular weight distribution? (d) Is the polymer safe for its intended application and does the in vivo erosion proceed to completion? (e) Can the polymer be easily fabricated into desired configurations? Studies have shown that if the synthesis is carefully controlled, the desired molecular weights can be reproducibly prepared, that the polymer is reasonably stable after irradiation at 24 kGy and during storage at room temperature under anhydrous conditions, and that it can be safely thermally fabricated at temperatures in the neighborhood of 120 degrees C. When polymer devices were implanted intraperitoneally in rats the polymer eroded to completion without any overt toxicity as determined by the measured parameters.

Acids↗
PubMed2000

Cation metabolism during propofol sedation with and without EDTA in patients with impaired renal function.

OBJECTIVE: To compare the effects of propofol with and without disodium edetate (EDTA) on cation metabolism in intensive care unit (ICU) patients with renal insufficiency who received propofol or propofol plus EDTA (propofol EDTA) for sedation and mechanical ventilation. DESIGN: Double-blind, randomised, multicentre study. SETTING: Medical and surgical ICUs from 5 hospitals. PATIENTS: Thirty-nine ICU patients with acute and chronic renal impairment expected to require at least 24 hours of continuous sedation and respiratory failure necessitating mechanical ventilation. INTERVENTIONS: Propofol or propofol EDTA administered for sedation by continuous intravenous infusion. MEASUREMENTS AND RESULTS: The depth of sedation, as measured by the Modified Ramsay Sedation Scale, was similar in the 2 groups, when adjusted for dosing differences. The amount of propofol required to maintain adequate sedation was decreased in both groups compared to propofol requirements in ICU patients with normal renal function. EDTA levels were elevated at baseline in both groups. In the propofol EDTA group, the EDTA levels increased further by 20 % but decreased to below baseline EDTA levels at 48 hours after sedation. In the propofol group, EDTA levels decreased during sedation and remained below baseline levels at 48 hours after sedation. PATIENTS in both groups were hypocalcaemic and hyperphosphataemic at baseline with low levels of 1,25-dihydroxyvitamin D and elevated parathyroid hormone (PTH) levels. Other than a slight difference in ionised serum calcium levels at 4 h after the start of sedation, there were no significant differences observed in serum calcium levels between the two groups. There were no significant differences in 1,25-dihydroxyvitamin D or PTH levels over time between the two groups. There was no significant effect on renal function in either group. CONCLUSIONS: The results of this study suggest that adding EDTA to propofol does not adversely affect cation homeostasis or renal function when used for sedation of ICU patients with renal insufficiency. Although EDTA levels increased over time from baseline levels in patients with renal insufficiency who receive propofol EDTA, this increase does not appear to be clinically significant, and EDTA levels return to below baseline levels within 48 hours of discontinuing the propofol EDTA infusion. The efficacy of propofol with and without EDTA also appears comparable in these patients.

Adolescent↗
PubMed2000

Intranasal midazolam as a treatment of autonomic crisis in patients with familial dysautonomia.

To evaluate the efficacy and safety of intranasal midazolam in the treatment of autonomic crises in children with familial dysautonomia, intranasal midazolam was administered at the hospital to six patients during nine episodes of autonomic crisis. Treatment was successful in seven of nine episodes of autonomic crisis in five of six patients, with a mean interval to response of 9.25 +/- 1.25 minutes. The parents of five patients in whom the treatment was successful were instructed to use midazolam at home. At home, 16 additional episodes were treated by the parents, with successful control achieved in 14 (87%). The mean interval to response was 12.8 +/- 2 minutes. No significant side effects were observed at the hospital or at home after intranasal administration of midazolam. Midazolam, given intranasally, is effective and safe in the management of autonomic crises in patients with familial dysautonomia, either in the hospital or at home by the parents after appropriate instruction.

Acute Disease↗
PubMed2000

Poly(ortho esters) - their development and some recent applications.

Poly(ortho esters) have been under development since the early 1970s and four families of such polymers have been described. Of most interest are poly(ortho ester) III and poly(ortho ester) IV. Poly(ortho ester) III is a semisolid material that has been shown to be highly biocompatible and is currently being investigated as an adjunct to glaucoma filtering surgery and other ocular applications. However, the polymerization is difficult to control and is not readily scaled up. Poly(ortho ester) IV can be easily prepared in a highly reproducible manner, is very stable provided moisture is rigorously excluded and has also been shown to be highly biocompatible. It is currently under development for a variety of applications, such as ocular delivery, protein release, post-operative pain treatment and post-operative cancer treatment.

Animals↗
PubMed2000

The number of CD34+ cells mobilized into the peripheral blood can predict the quality of subsequent collections.

PBPC were mobilized using a variety of chemotherapy regimens plus G-CSF in a group of 126 consecutive patients. Data are presented that show a close correlation between the number of CD34+ cells mobilized into the peripheral blood (PB) and the number of CD34+ cells subsequently collected by leukapheresis (R = 0.904). On the basis of this correlation, a regression formula was calculated that could give an estimate of the total number of CD34+ cells likely to be collected by leukapheresis from a given number of CD34+ cells per microliter PB. An easy-to-read table has been compiled to show how this type of analysis can be applied to predict the likely dose of CD34+ cells that will be obtained by leukapheresis over a wide range of patient weights.

Antigens, CD34↗
PubMed2000

Peritoneal ventilation with oxygen improves outcome after hemorrhagic shock in rats.

OBJECTIVE: In experimental pulmonary consolidation with hypoxemia in rabbits, peritoneal ventilation (PV) with 100% oxygen (PV-O2) improved PaO2. We hypothesized that PV-O2 could improve outcome after hemorrhagic shock (HS) with normal lungs, by mitigating dysoxia of the abdominal viscera. DESIGN: Randomized, controlled, laboratory animal study. SETTING: University animal research facility. SUBJECTIVE: Male Sprague-Dawley rats. INTERVENTIONS: Thirty rats under light anesthesia (N2O/oxygen plus halothane) and spontaneous breathing underwent blood withdrawal of 3 mL/100 g over 15 mins. After volume-controlled HS phase 1 of 60 mins, resuscitation phase 2 of 60 mins included infusion of shed blood and, if necessary, additional lactated Ringer's solution intravenously to control normotension from 60 to 120 mins. This was followed by observation phase 3 for 7 days. We randomized three groups of ten rats each: group I received PV-O2, starting at 15 mins of HS at a rate of 40 inflations/min, and a peritoneal "tidal volume" of 6 mL, until the end of phase 2. Group II received the same PV with room air (PV-Air). Control group III was treated without PV. MEASUREMENTS AND MAIN RESULTS: During the second half of HS phase 1, mean arterial pressures were higher in the PV-O2 group I compared with the PV-Air group II and control group III (p < .05). All 30 rats survived the 120 mins of phases 1 and 2. Survival to 7 days was achieved by ten of ten rats in PV-O2 group I; by nine of ten in PV-Air group II; and by five of ten in control group III (p < .05 vs. group I; NS vs. group II). Survival times of <7 days were 5 days in the one death of group II and ranged between 6 hrs and 4 days in the five deaths of group III. In 7-day survivors, neurologic deficit scores (0% to 10% = normal, 100% = death) were normal, ranging between zero and 8%. Necropsies of rats that died during phase 3 showed multiple areas of necrosis of the gut, some with perforations. Necropsies in the five survivors to 7 days of group III showed marked macroscopic and microscopic changes (scattered areas of necrosis of stomach and intestine, adhesions, and pale areas in the liver). These changes were absent or less severe in the nine survivors of group II. Viscera appeared normal in all ten rats of PV-O2 group I. CONCLUSIONS: Peritoneal ventilation with oxygen during and after severe hemorrhagic shock in rats seems to decrease morbidity and mortality by helping preserve viability of abdominal viscera.

Animals↗
PubMed2000

Talismans and amulets in the Pediatric Intensive Care Unit: legendary powers in contemporary medicine.

BACKGROUND: For centuries talismans and amulets have been used in many cultures for their legendary healing powers. METHODS: We asked the parents of every child (Jews and Arabs) admitted to the Pediatric Intensive Care Unit over a 2 month period to complete a questionnaire, which included demographic data on the patient and the family, the use of talismans or other folk medicine practices, and the perception of the effects of these practices on the patient's well-being. A different questionnaire was completed by the ICU staff members on their attitude toward the use of amulets. RESULTS: Thirty percent of the families used amulets and talismans in the ICU, irrespective of the socioeconomic status of the family or the severity of the patient's illness. Amulets and talismans were used significantly more by religious Jews, by families with a higher parental educational level, and where the hospitalized child was very young. The estimated frequency of amulet use by the children's families, as perceived by the staff, was significantly higher than actual use reported by the parents. In Jewish families the actual use of amulets was found to be 30% compared to the 60% rate estimated by the medical staff; while in Moslem families the actual use was zero compared to the staff's estimation of about 36%. Of the 19 staff members, 14 reported that the use of amulets seemed to reduce the parents' anxiety, while 2 claimed that amulet use sometimes interfered with the staff's ability to carry out medical treatment. CONCLUSIONS: The use of talismans in a technologically advanced western society is more frequent than may have been thought. Medical and paramedical personnel dealing with very ill patients should be aware of the emotional and psychological implications of such beliefs and practices on patients and their families.

Adolescent↗
PubMed1999

Visual evoked potentials in the diagnosis of headache before 5 years of age.

UNLABELLED: Headache is a common complaint in children. Diagnosis of the type of headache and therapeutic approach is predominantly clinical based on a detailed history and physical examination. These data are often not available or informative in young children with headache, leading clinicians to look for diagnostic studies. We reviewed our experience with 53 children under the age of 5 years with headache. Of these, 42 (75%) children underwent neuro-imaging studies including CT scan (32 cases), MRI (10 cases), or both studies (6 cases). All were within normal limits except for two cases with a small arachnoid cyst and cerebellar hypoplasia respectively which were not directly related to the headache. Visual evoked potentials were performed in all children. There were no significant differences between the mean latencies of N(1)P(100) and N(2) of the children with clinically diagnosed migraine, however, the P(100)-N(2) amplitudes of children with migraine were significantly larger compared to those of children without migraine. Even in young children with headache, neuro-imaging studies have a very limited diagnostic value. Visual evoked potentials may also be used in this age group as a diagnostic tool, particularly when clinical symptoms are either unavailable or not characteristic. CONCLUSION: The diagnosis of migraine in young children remains clinical, based on history obtained from children and parents; however, visual evoked potentials may support the diagnosis in this age group.

Age Distribution↗
PubMed1999

Indoor survey of moulds and prevalence of mould atopy in Israel.

BACKGROUND: Moulds are ubiquitous indoor as well as outdoor allergens and therefore potential candidates for indoor environmental control measures. However, very few studies have been performed to examine the significance of indoor moulds in allergic diseases and the effectiveness of measures to reduce the quantity of indoor moulds has not been established. OBJECTIVE: To determine the significance and the contribution of moulds to allergic manifestations. METHODS: Prevalence of allergic rhinitis and asthma in 395 members of a rural community were examined by questionnaire and examination of medical files. The atopic status in general and allergy to moulds was determined by skin-prick tests (SPTs) to a panel of aeroallergens including Aspergillus, Penicillium, Alternaria and Cladosporium. A study of indoor mould levels was performed by placing SDA plates in 59 houses. The type of fungi and the number of colonies from each species were recorded. RESULTS: Forty-two subjects, comprising 10.9% of the study group had positive SPT to moulds, 61.9% of those were classified as symptomatic. When taking into account individuals with a borderline positive SPT to moulds, an additional 23 had positive results. Of the 65 mould-positive subjects, 48% were symptomatic and of the 13 who were allergic to moulds alone, only two had allergic symptoms. Viable moulds were recovered from all 59 houses examined. The most common isolated genus was Aspergillus, followed by Penicillium, Alternaria and Cladosporium. Aspergillus was also the most abundant mould in houses. There was no significant correlation between the abundance of moulds, positive SPT to that mould and symptomatology. CONCLUSIONS: Viable moulds are common in houses in temperate climates. Allergy to moulds itself has a low predictive value to development of allergic symptoms, but allergy to moulds in otherwise atopic subjects increases the risk of symptomatic allergic disease.

Adolescent↗
PubMed1999

Long term neurological outcome of herpes encephalitis.

Twenty eight children with herpes simplex encephalitis were followed up for a mean of 5.5 years. Two children died and 26 survived, of whom 16 were left with no neurological sequelae and 10 had persistent neurological sequelae. Mean (SD) Glasgow coma score was significantly lower in the patients with neurological sequelae (7.7 (1.5)) and the patients who died (4.5 (0.7)), compared with the patients without neurological sequelae (11 (1.7)).

Acyclovir↗