Resolution of experimental pneumothorax in rabbits by oxygen therapy.

The treatment of asymptomatic patients with small pneumothoraces (ie, less than 20% by volume) has included observation, tube thoracostomy, and operation. When observation is used, the anticipated expansion of the lung has been estimated to be 1.25% of the lung volume daily. This study was designed to evaluate the use of inhaled oxygen as a method to accelerate the resolution of a pneumothorax in a rabbit model. Experimental pneumothoraces were created in 23 white New Zealand rabbits. Group 1 (9 rabbits) were placed in a cage with room air and group 2 (11 rabbits) were placed in a cage with high oxygen concentration. Three rabbits died before completion of the study. Serial chest roentgenograms were performed until the pneumothoraces resolved. The majority of rabbits treated with oxygen had resolution of their pneumothoraces by 36 hours, whereas the majority of rabbits treated with room air did not show complete resolution before 48 hours. Biopsies showed no evidence of damage secondary to oxygen treatment. Oxygen treatment was found to be significantly better in the early resolution of pneumothoraces when compared with room air. This establishes an alternative treatment for some pneumothoraces that are small and asymptomatic.

Blast injury with particular reference to recent terrorist bombing incidents.

The aetiology of primary blast lung is discussed with reference to the biodynamics of blast injury, and the clinical and pathological features of the condition are described. An analysis of casualties from bomb blast incidents occurring in Northern Ireland leads to the following conclusions concerning the injuries found in persons exposed to explosions: (1) there is a predominance of head and neck trauma, including fractures, lacerations, burns, and eye and ear injuries; (2) fractures and traumatic amputations are common and often multiple; (3) penetrating trunk wounds carry a grave prognosis; and (4) primary blast lung is rare. A comparison of four bombing incidents in England in 1973 and 1974 shows how the type and severity of injury are related to the place in which the explosion occurs. The administrative and clinical aspects of the management of casualties resulting from terrorist bombing activities are discussed.

A comparison of the interferon gamma assay with the absorbed ELISA for the diagnosis of Johne's disease in cattle.

Two interferon gamma (IFN-gamma) assays, the IFN-gamma enzyme immunoassay (EIA) and the IFN-gamma bioassay and an absorbed ELISA were used to screen 6 cattle herds for Johne's disease. Each herd had a history of Johne's disease but the majority of infected animals did not show clinical signs. The disease status of the cattle, which were removed from the herds, was confirmed by bacteriological culture of faeces or histopathological examination and culture of tissues collected at necropsy. The sensitivities of the IFN-gamma assays and the absorbed ELISA were determined using test results from infected animals. The sensitivity of the IFN-gamma EIA in detecting subclinical (71.8 to 93.3%) and clinical animals (100%) was not significantly different. However, the IFN-gamma bioassay and the absorbed ELISA were more sensitive in detecting cattle with advanced infections (80%) than those that were subclinically affected (16.7 to 33.3%).

Construction budget: the financial manager as part of the planning team.

The financial manager can best fulfill his role and have the most beneficial effect on a facility planning project as an active member of the planning team from the onset of the project. In addition to representing a realistic financial planning perspective to the project's development, the financial manager can, very early in the process, begin to determine and refine various costs associated with facility planning and construction. The role is a vital and active one from the first planning meeting through development, financing, construction and activation.

Angiotensin converting enzyme inhibitors and quality of life: the European trial.

Two prospective multi-centre randomized trials were initiated to compare the relative efficacy and influence on quality of life of captopril, alone or in combination with hydrochlorothiazide, against either methyldopa, alone or in combination with hydrochlorothiazide, or oxprenolol in combination with chlorothalidone. The complaint rate, activity index and psychiatric morbidity were evaluated as indices of quality of life. Captopril was associated with a significantly (P less than 0.05) greater reduction in complaint rate compared with methyldopa and a tendency for less symptoms of depression compared with oxprenolol (P = 0.06), the latter drug being associated with an increase in depression scores. The trends in quality of life indices in the captopril-treated patients would suggest the need for double-blind placebo-controlled trials to investigate these apparent benefits.

Changes in corneal curvature and refractive error upon refitting with flatter hydrophilic contact lenses.

Eight subjects who wore hydroxy-ethylmethacrylate (HEMA) contact lenses showed a steepening in corneal curvature and an increase of minus in their post-wear refraction after three months of wear. After one year or more of wear, with the previously noted changes still present, these patients were fitted with a flatter series lenses which they wore for three months. Significant results are noted in corneal curvature and post-wear refractive error.

Clinical comparison of the (polymacon) spin-cast hydrogel contact lens to the (polymacon) lathe-cut hydrogel lenses.

The purpose of this study was to compare the clinical acceptability of polymacon spin-cast to polymacon lathe-cut hydrophilic contact lenses. Ten patients successfully wearing polymacon spin-cast lenses were studied. Each patient had one eye refitted with polymacon lathe-cut lenses. Comparison of the two types of lenses was then made. Objective evaluation included centration, movement, visual acuity, and over-refraction. Subjective criteria were based on patient comfort and stability and quality of vision. Results indicate that lathe-cut lenses can be just as clinically satisfactory as the spincast ones.

Variation in refractive error and corneal curvature after wearing hydrophilic contact lenses.

Twenty-eight eyes of people who have successfully worn hydrophilic contact lenses were monitored during a period after removal of their contact lenses. The results are compared to similar studies of wearers of non-flexible contact lens. While both curvature and refractive changes in a number of eyes stabilized at about one week, others did not stabilize until three weeks or more.

Softcon: an extended wear study.

Forty-eight subjects were fitted with a new design Softcon lens to determine the acceptability of the lens for extended wear. The subjects were monitored for periods of up to two years of extended wear. Periodic measurements or observations were made of visual acuity, keratometry, biomicroscopy, and refraction. The results showed that there was a high degree of acceptability of the lens, with less than three percent of the subjects manifesting significant changes in measurements or observations.

Efficacy of captopril and hydrochlorothiazide administered once a day.

One hundred and ten mild and moderately hypertensive patients were treated with a fixed combination of captopril 50 mg and hydrochlorothiazide 25 mg (Capozide 50) once daily for 12 months. Eighty four patients were treated initially with Capozide 50 12 hourly for 3 months before receiving Capozide 50 o.d.; the other 26 patients received Capozide 50 as initial treatment immediately after the placebo run-in period. Blood pressures were measured 24 hours after ingestion of the drug. Capozide 50 once daily induced statistically significant reductions in supine blood pressure and these beneficial effects were sustained throughout the duration of the trial. In patients receiving Capozide 50 as initial therapy, a gradual hypotensive effect was seen. No clinically significant changes in biochemical or haematological variables were recorded although a small but statistically significant rise in uric acid was noted. This latter effect was attributed to the thiazide component of the combination. The efficacy and safety profile of this once-a-day compound makes it an ideal therapeutic agent for the management of mild and moderate hypertension.

Casualties from terrorist bombings.

The physical factors responsible for injury following an explosion in a room or building are: direct exposure to overpressure; blast-induced whole body displacement; impact of blast-energized debris; burns from flash and hot gases. The patterns of injury seen in the casualties from four terrorist bombings are described to illustrate the types and severity of particular wounds. The most common fatal injury is brain damage; 'blast lung' is uncommon in civilian terrorist bombings; flash burns, fractures, serious soft-tissue damage, and eardrum injuries are seen in people close to the bomb, who usually require hospital admission; many others taken to hospital can be treated for injury by debris and released. The environment and its internal structure and the position of the occupants of the space can influence the type and severity of injuries.

Eighteen-month clinical experience with extended wear silicone contact lenses on 400 patients.

Four hundred patients wearing silicone elastomer contact lenses for extended wear were monitored over an 18-month period. Safety and efficacy were evaluated as related to corneal physiology and lens performance. These lenses proved to be reasonably durable and the lens material and design characteristics did not interfere with ocular physiology but permitted good visual acuity and comfort. The authors' clinical experiences, when compared with other reports of extended-wear lens designs and materials, indicate that this silicone elastomer lens provides superior performance characteristics.

Resolution of experimental pneumothorax in rabbits by graded oxygen therapy.

BACKGROUND: Small pneumothoraces have been treated by observation and tube thoracostomy in asymptomatic patients. Using a rabbit model, we demonstrated previously that inspired oxygen at 60% FiO2 hastened the time to resolution of complete pneumothoraces compared with room air. The present study was designed to evaluate the use of lower levels of inspired oxygen and to establish a dose-response curve for the treatment of experimental pneumothoraces. METHODS: Forty New Zealand White rabbits were divided randomly into four groups: room air (21%) and 30, 40, and 50% FiO2. Experimental pneumothoraces were created in the rabbits, and the animals were placed in cages with the designated level of inspired oxygen. Serial chest radiographs were performed until the pneumothoraces resolved. RESULTS: Pneumothoraces treated with room air resolved in 61.65 +/- 12.30 hours. Those treated with 30% FiO2 resolved in 42.90 +/- 5.97 hours, with 40% FiO2 in 35.80 +/- 4.26 hours, and with 50% FiO2 in 33.80 +/- 4.66 hours. CONCLUSION: These results show a statistically significant (p < 0.01) dose-dependent improvement in the resolution of pneumothoraces with increasing levels of inspired oxygen. Supplemental oxygen therapy may be used to facilitate the resolution of small, uncomplicated pneumothoraces.