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Biomedical subjects

A A Van den Berg

Publications and source records attributed to A A Van den Berg.

9 recordsLinked to original sources
PubMed1997

Determination of CTP synthetase activity in crude cell homogenates by a fast and sensitive non-radiochemical assay using anion-exchange high-performance liquid chromatography.

A non-radiochemical assay procedure for CTP synthetase was developed in which CTP is detected at 280 nm after separation with anion-exchange HPLC. A complete separation of all nucleoside triphosphates was achieved within 11 min and the minimum amount of CTP which could be accurately determined proved to be 5 pmol. Therefore, our assay procedure is ten-fold more sensitive compared to the frequently used radiochemical assays. The assay was linear with time and protein concentration, although at low protein concentration a lag phase was observed. An amount of 2 x 10(6) cells was already sufficient to determine the specific activity of CTP synthetase in HL-60 cells, lymphocytes and in lymphoblasts obtained from pediatric patients suffering from acute lymphoblastic leukemia.

Carbon-Nitrogen Ligases↗
PubMed1995

Rationalizing venepuncture pain: comparison of lignocaine injection, Butterfly (21 gauge and 23 gauge) and Venflon (20 gauge).

Two hundred and seventy-eight patients scheduled for all types of surgery and premedicated with diazepam and metoclopramide were randomly allocated to one of four groups to compare the relative pain of an injection of 0.25 ml of lignocaine 1% via a 25 gauge needle with the pain of the siting of a 21 gauge Butterfly (Abbott), 23 gauge Butterfly or a 20 gauge Venflon (Vigo Spectramed). The injection of lignocaine and insertion of the 23 gauge Butterfly were associated with the least complaints of pain and least observed responses to pain. The 21 gauge Butterfly and 20 gauge Venflon were associated with complaints of greater pain and more pain responses. We conclude that a pre-cannulation injection of lignocaine causes minimal discomfort and is the most appropriate means of reducing the discomfort of venous cannulation when not using skin penetrating analgesic creams.

Adolescent↗
PubMed1995

Comparison of total intravenous, balanced inhalational and combined intravenous-inhalational anaesthesia for tympanoplasty, septorhinoplasty and adenotonsillectomy.

Two hundred and thirty-five consecutive Saudi patients aged between two and fifty-three years undergoing elective tympanoplasty (n = 32), septorhinoplasty (n = 68) or adenotonsillectomy (n = 135) were studied. They were randomized to receive either a total intravenous anaesthetic (10 ears, 23 noses, 44 throats) consisting of propofol for induction of anaesthesia followed by a propofol infusion, a combined intravenous-inhalational anaesthetic (11 ears, 22 noses, 46 throats) consisting of the above with isoflurane in oxygen-enriched air, or a balanced inhalational anaesthetic (11 ears, 23 noses, 45 throats) consisting of thiopentone for induction of anaesthesia and oxygen in nitrous oxide with isoflurane for maintenance. During tympanoplasty, all three anaesthetic techniques produced stable heart rates and arterial pressures. During septorhinoplasty, blood pressure rose in patients who received total intravenous anaesthesia, while combined and balanced techniques produced haemodynamic stability. During adenotonsillectomy, total intravenous anaesthesia produced a rise in both heart rate and blood pressure, the combined technique produced a rise in heart rate alone while balanced anaesthesia produced haemodynamic stability. Postoperatively, vomiting, pain scores and analgesic requirements were similar following all three types of anaesthetic within each surgical site subgroup. Our findings support the choice of balanced inhalational anaesthesia for all three types of ENT surgery and, where cost and facilities permit, total intravenous anaesthesia for tympanoplasty and combined intravenous-inhalational anaesthesia for septorhinoplasty.

Adenoidectomy↗
PubMed1994

Clinical comparison of spontaneous respiration versus controlled ventilation general anaesthesia using isoflurane for intraocular surgery: intraoperative, recovery and postoperative effects.

A prospective randomized study was undertaken on elderly patients undergoing intraocular, predominantly cataract, surgery to compare the intraoperative, recovery and postoperative features associated with general anaesthesia employing either the spontaneous (SV) or controlled ventilation (IPPV) techniques of respiration using isoflurane, nitrous oxide and a constant FiO2 of 0.33. SV patients received isoflurane 0.97% (mean). IPPV patients were intubated with atracurium alone, and received isoflurane 0.60% (mean). Heart rates were lower intraoperatively with IPPV, and blood pressures were lower with SV. Intraocular pressure measurement identified three subgroups of patients within each respiratory group: a large subgroup (70% of SV, 64% of IPPV patients) with a high-normal initial mean intraocular pressure which fell intraoperatively; a small subgroup (25% of SV, 24% of IPPV patients) with a low normal initial mean intraocular pressure which rose intraoperatively; and a small subgroup (5% of SV and 11% of IPPV patients) in whom the intraocular pressure remained unchanged. A satisfactory operative field was reported by surgeons in 87% of SV and in 86% of IPPV patients. SV patients had a lower mean end-operative SaO2 than IPPV patients (SV 95.0%; IPPV 96.7%), and were extubated sooner at the end of anaesthesia. In the recovery ward the times to awakening, vomiting incidences, analgesic usages and recovery times were similar, and patients were similarly restful. Postoperatively, the incidences of vomiting, headache, fever, sore throat and myalgia were similar, but SV patients required more analgesia for headache. We conclude that both technique properly performed are similarly satisfactory for cataract surgery in elderly patients.

Aged↗
PubMed1987

Vomiting after ophthalmic surgery. Effects of intra-operative antiemetics and postoperative oral fluid restriction.

The usefulness of intra-operative antiemetics and postoperative oral fluid restriction in the prevention of vomiting following anaesthesia for ophthalmic surgery, was studied in 200 patients. They were allocated into four groups of 50 and given either saline (as control), droperidol, metoclopramide or prochlorperazine. Oral intake was restricted postoperatively in half of the patients of each group. Anaesthesia comprised morphine and atropine premedication and a halothane, nitrous oxide and oxygen spontaneous breathing technique. No significant beneficial effects resulted from intra-operative antiemetics; vomiting incidences of 26% after saline and droperidol, 28% after metoclopramide and 14% after prochlorperazine were observed. Younger patients and females vomited most frequently. Restriction of oral fluids did not decrease the incidence of vomiting but demonstrated that approximately half of those patients who vomit do so with their first postoperative oral intake. Vomiting was observed more frequently after non intra-ocular surgery than after intra-ocular surgery (37% cf. 16%, p less than 0.01) and postoperative analgesics were required by more non intra-ocular patients than by intra-ocular patients (25% cf. 5%, p less than 0.001). Squint patients vomited most frequently (48%) and most frequently required postoperative analgesia (35%).

Adult↗
PubMed1985

The anesthetic technician's essential services--a training guide.

The development of sophisticated medical services in the Middle East has resulted in the need for training programmes for staff in all disciplines of health care. Operating Department Assistants (ODAs/Anesthetic Technicians) are essential operating theatre personnel, forming an integral part of the operating theatre team. This paper is designed as a teaching guide for Anesthetic Technicians in training. It lists in point form the essential services that should be provided in each of the seven identifiably different work periods in the Anesthetic Technician's working day.

Allied Health Personnel↗
PubMedDate not supplied

A fast and novel assay of CTP synthetase. Evidence for hysteretic properties of the mammalian enzyme.

A novel assay of CTP synthetase was developed which allows the processing of large numbers of samples. The amount of glutamate produced by CTP synthetase was determined with glutamate dehydrogenase and the NAD analogue acetyl-pyridine-adenine dinucleotide was used to shift the initial unfavourable equilibrium towards the formation of a-ketoglutarate. The amount of glutamate determined with the assay was comparable to that of CTP. The assay proved to be linear with time up to 90 min and protein concentrations up to 520 micrograms/ml. However, at low protein concentrations as well as at early time points a lag phase was observed. This hysteretic phenomenon of CTP synthetase may be due to the association-dissociation equilibrium that exists between the various polymerisation states of the enzyme.

Animals↗