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Biomedical subjects

P Bath

Publications and source records attributed to P Bath.

9 recordsLinked to original sources
PubMed1993

L-arginine infusion has no effect on systemic haemodynamics in normal volunteers, or systemic and pulmonary haemodynamics in patients with elevated pulmonary vascular resistance.

1. The evidence that the infusion of L-arginine, the precursor of endothelium-derived relaxing factor (EDRF)/nitric oxide (NO), may reduce systemic blood pressure, via the generation of intracellular cyclic guanosine-3,5-monophosphate(cGMP), in normotensive volunteers is controversial. In the first part of the study we investigated the effect of an L-arginine infusion on systemic blood pressure and plasma cGMP in healthy volunteers. 2. Patients with systemic sclerosis have widespread endothelial damage which, by reducing the release of NO, could contribute to the raised pulmonary vascular resistance (PVR) often found in this condition. We hypothesised that if there were a failure of NO synthesis this might be overcome by infusing L-arginine into the pulmonary artery, thereby lowering PVR. In the second part of the study we investigated the effect of L-arginine infusion on systemic and pulmonary haemodynamics, and on plasma cGMP levels in patients with pulmonary hypertension and systemic sclerosis. 3. L-arginine (500 mg kg-1) was infused over 30 min into five normotensive volunteers and five patients with systemic sclerosis and pulmonary hypertension. Blood pressure, heart rate and skin temperature were measured non-invasively in the volunteers and systemic and pulmonary haemodynamics recorded via radial artery cannulae and balloon-tipped, flow directed, pulmonary artery catheters in the patients with systemic sclerosis. 4. L-arginine had no significant effect on blood pressure, heart rate or skin temperature in the normotensive volunteers nor on systemic or pulmonary haemodynamics in the systemic sclerotic group. Cyclic-GMP levels did not significantly change in either group.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

[Endocapsular cataract surgery using the excimer laser at 308 nm].

We present our experience with in vitro endocapsular cataract surgery ("phakoablation") using the excimer laser at a wavelength of 308 nm. The ablation threshold for human lens nuclei (0.5 J/cm2) was found to be significantly lower compared to that for the capsule (1.5 J/cm2). A total energy of 215 J (mean value) is required for endocapsular ablation of human lens nuclei. For cataract surgery the laser pulses are coupled to a quartz fiber that is integrated into an irrigation/aspiration handpiece. Using the prototype we developed, endocapsular cataract surgery on autopsy eyes with opaque lenses could be performed within about 30 min without major damage to the capsule. Initial measurements of retinal UV exposure indicate that retinal damage might be expected only if the posterior lens capsule is ruptured. Thus endocapsular cataract surgery with the excimer laser seems to be feasible.

Cataract Extraction↗
PubMed1987

Corneal wound healing after excimer laser keratotomy in a human eye.

A pulsed excimer argon-fluorine laser was used to produce corneal incisions in vivo in a human cornea. Fourteen days after the laser surgery, the incisions were examined by light and transmission electron microscopy. There was good initial healing, with no inflammatory or immune reactions in the incisions.

Adult↗
PubMedDate not supplied

Stroke scoring systems.

Explore the source record for details and available documents.

Cerebral Hemorrhage↗
PubMedDate not supplied

The King's College Hospital Acute Stroke Unit.

The King's College Hospital (KCH) Acute Stroke Unit (ASU) was set up in January 1994 in order to provide acute management for patients admitted with stroke and to undertake biomedical research. Of 206 patients admitted to KCH with a stroke or suffering an in-hospital stroke, 141 (68%) patients were admitted to the ASU over its first 6 months of operation: 120 (85%) were from the Accident and Emergency Department and 21 (15%) from other wards. Management included resuscitation and medical stabilisation, investigation, prevention of stroke complications (including aspiration, venous thrombosis, and pressure sores), rehabilitation (physiotherapy, occupational therapy, speech and language therapy), nutrition (dietetics) and initiation of secondary prevention measures (aspirin or anticoagulation, blood pressure and lipid lowering, and carotid endarterectomy). All aspects of management are driven by agreed guidelines. Patients remain under the care of the admitting physician but specific stroke management and guidance is provided by two research doctors and the unit's nurses, therapists and dietician. The unit also facilitates research into stroke pathophysiology and acute therapeutic interventions. Our experience suggests that an ASU is relatively easy to set up and may contribute to improved care. Whether ASUs improve patient survival and functional outcome, and are cost-effective, requires further study.

Acute Disease↗