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Biomedical subjects

M Budd

Publications and source records attributed to M Budd.

12 recordsLinked to original sources
PubMed1997

Comparison of Ho:YAG versus Nd:YAG thoracoscopic laser treatment of pulmonary bullae in a rabbit model.

OBJECTIVE: To determine the relative efficacy and morbidity of Ho:YAG versus Nd:YAG laser treatment of bullous lung disease in an animal model. SUMMARY BACKGROUND DATA: Laser coagulation procedures for treatment of emphysematous pulmonary bullae and heterogeneous emphysema continue to evolve. The role of lasers in lung volume reduction surgery remains controversial due to issues of relative efficacy and morbidity. The Nd:YAG laser is most commonly used for these procedures. We hypothesized that the shallower penetration of the Ho:YAG laser may be better suited for laser bullae coagulation and emphysema lung volume reduction with increased efficacy and reduced lung injury. METHODS: Thirty New Zealand White rabbits (15 normal rabbits; 15 with bullous lung disease) were evaluated with Ho:YAG compared to Nd:YAG laser exposures. Bullae were coagulated by either Ho:YAG or Nd:YAG treatment. In all animals (bullous-induced and normals), unaffected lung tissue in the upper lobes and contralateral lungs were treated with 5 spot exposures of Nd:YAG and Ho:YAG, each to assess depth of lung injury. Animals were sacrificed at Days 0, 7, and 21 and their lungs were examined histologically. RESULTS: Ho:YAG and Nd:YAG exposures caused equivalent lung injury to normal lung tissue. In the acute phase, parenchymal necrosis depth was similar for both Ho:YAG and Nd:YAG (850 +/- 273 microns vs. 900 +/- 270 microns respectively, p = 0.7). By Day 7, lung necrosis depth was 925 +/- 133 microns Ho:YAG vs. 1225 +/- 235 microns Nd:YAG (p = 0.33), and lung fibrosis depth was 300 +/- 134 microns Ho:YAG vs. 558 +/- 127 microns Nd:YAG (p = 0.11). By Day 21, pulmonary parenchymal necrosis was not seen. Pleural fibrosis depth was maximal at Day 21, reaching 250 +/- 102 microns for Ho:YAG vs. 300 +/- 156 microns Nd:YAG (P = 0.88). Pleural necrosis depth was 67 +/- 42 microns Ho:YAG vs 48 +/- 34 microns Nd:YAG (p = 0.42) on Day 7 and resolved by Day 21. During surgical coagulation procedures, the Ho:YAG laser was dramatically more efficient in coagulating bullae. The Ho:YAG laser required less exposure at equivalent power and resulted in immediate desiccation of bullae, in sharp contrast to the Nd:YAG laser. CONCLUSIONS: Because the Ho:YAG was more effective and did not result in more acute lung injury than the standard Nd:YAG laser in this study, Ho:YAG lasers may have improved potential for laser treatment of bullae or lung volume reduction surgery (LVRS) compared to Nd:YAG lasers.

Animals↗
PubMed1992

Organising a continence advisory service.

Modern surgical techniques have greatly improved the treatment of incontinence, but there remains a large number of patients for whom conservative management will be necessary. This paper reports the appointment of a continence adviser 10 years ago, and describes the subsequent development of a District Continence Advisory Service. Experience has shown that this appointment is essential, not only in terms of facilitating the service, but also as a means of ensuring cost efficiency.

Community Health Nursing↗
PubMed1990

A study of the effectiveness of two group behavioral medicine interventions for patients with psychosomatic complaints.

This randomized, prospective study investigated the effectiveness of two group behavioral medicine interventions for primary care patients experiencing physical symptoms with a psychosocial component (eg, palpitations, gastrointestinal disturbances, headaches, malaise, sleep disorders). The subjects were 80 volunteers at a health maintenance organization (HMO) in the greater Boston area. Both interventions focused on the mind/body relationship and used didactic material, relaxation-response training, awareness training, and cognitive restructuring. The two behavioral medicine intervention groups were compared with a group that focused exclusively on information about stress management and its relation to illness. Measures of visits to the HMO and of distress from physical and psychological symptoms were obtained before the interventions and again 6 months afterward. At the 6-month follow-up, patients in the behavioral medicine groups showed significantly greater reductions in visits to the HMO and in discomfort from physical and psychological symptoms than did the patients in the information group. The results suggest that when the relationship among thoughts and behaviors and symptoms of patients with psychosomatic dysfunction is actively addressed, the patients' discomfort level and the cost of medical care can be reduced.

Adaptation, Psychological↗
PubMed1990

The caffeine breath test and caffeine urinary metabolite ratios in the Michigan cohort exposed to polybrominated biphenyls: a preliminary study.

A field biochemical epidemiology study was conducted using the Michigan cohort consisting of 51 rural residents exposed to polybrominated biphenyls (PBB). The study had three major objectives: a) to determine the serum half-life of the major PBB congener, hexabromobiphenyl (HBB), in the human, b) to determine if the PBB-exposed subjects had elevated cytochrome P-450I function as determined by the caffeine breath test (CBT) and the caffeine urinary metabolite ratio (CMR), and c) to determine the applicability of the CBT and CMR in field studies. PBB serum levels were detected in 36 of the 51 PBB-exposed subjects. The serum half-life of HBB was determined by comparing the current serum HBB values to the subject's previous serum values obtained 5 to 8 years earlier. The median HBB half-life was 12 years (range 4-97 years). The CBT and CMR were elevated in the subjects exposed to PBBs as compared to the values obtained from urban nonsmokers and were similar to those found in adults who smoke. A gender effect was seen in the PBB-exposed subjects, the median CBT and CMR values of the females being lower than the values of males. There was a correlation between the CBT and the HBB serum values (r2 = 0.2, p = 0.01) but not between CMR and HBB serum values. The CBT and CMR were easily conducted in the field and appear to be useful metabolic probes of cytochrome P-450I activity in human environmental toxicology.

Adult↗
PubMed1987

Temperature-sensitive mutations in the yeast DNA polymerase I gene.

Seven mutations that yield thermolabile DNA polymerases have been isolated in the DNA polymerase I gene, POL1, of Saccharomyces cerevisiae. Strains carrying the mutant genes are temperature sensitive for growth. The pol1 mutants were identified by a method that has general applicability for identification of both temperature-sensitive and null mutations. A plasmid containing a mutagenized pol1 gene was transformed into a strain in which the only functional copy of the POL1 gene was carried on an unstable plasmid. The genes conferring temperature-sensitive growth were detected after elimination of the unstable plasmid containing the wild-type gene. DNA polymerase I isolated from each of the mutants is defective at both 23 degrees C and 36 degrees C. DNA synthesis is deficient in vivo at 36 degrees C in all the mutants, while RNA synthesis is normal in all but one of the mutants. The terminal phenotype of pol1 temperature-sensitive mutants is dumbbell-shaped cells in which the nucleus has migrated to, but apparently not entered, the isthmus separating the mother and the daughter. The POL1 gene is located on chromosome XIV approximately 2 centimorgans away from met4.

DNA Polymerase I↗
PubMed1986

Yeast DNA replication.

We have explored various strategies for exploiting the yeast genetic and biochemical system for understanding DNA replication. Because of the long time that has intervened between the isolation of random replication mutants of yeast and the identification of the gene products affected, an alternative approach to elucidating the molecular basis of replication has been needed. One such alternative involves purifying replication proteins, isolating the genes encoding them, and constructing the appropriate mutant from the cloned gene. We have applied this "reverse genetics" strategy to three different replication activities: DNA polymerases, single-stranded DNA binding proteins, and proteins that bind to autonomously replicating sequence (ARS) elements.

DNA Polymerase I↗
PubMed1984

The effect of cycloheximide on repair in a temperature conditional radiation-sensitive mutant of Saccharomyces cerevisiae.

Previous results [M. Budd and R. K. Mortimer, Mutat. Res. 103, 19-24 (1982)] have shown that rad54-3 strains are temperature conditional for double-strand break repair. At the temperature where survival is high, 23 degrees C, rad54-3 strains are able to repair X-ray-induced double-strand breaks, while at the temperature where survival is low, 36 degrees C, these strains are unable to repair rad54-3 strains provide a system to study the effects of drugs that block protein synthesis such as cycloheximide on repair of X-ray damage. Repair of X-ray damage is studied by irradiating rad54-3 cells, incubating them at the permissive temperature, 23 degrees C, for 5 hr, shifting the cells to the restrictive temperature, 36 degrees C, and assaying for colony-forming ability. Comparing the survival of these cells with those which had been continuously incubated at the restrictive temperature after irradiation shows the extent of repair. Addition of cycloheximide at the time of irradiation causes an inhibition of repair. If cycloheximide is added a short time after irradiation, an enhanced recovery is observed compared with the addition of the drug at the time of irradiation. One explanation for the enhanced recovery is an increased synthesis of repair enzymes after irradiation.

Cell Survival↗
PubMedDate not supplied

An animal model for lung volume reduction therapy of pulmonary emphysema.

Stapled lung volume reduction surgery (LVRS) has recently been described for treatment of emphysema. Many questions arise regarding physiologic mechanisms of response from surgical treatment of emphysema. The objective of this study was to develop an animal model for the study of lung volume reduction surgery in diffuse heterogeneous emphysema. We hypothesized that elastic recoil would increase, static respiratory system compliance would decrease, and expiratory flows would increase after lung volume reduction surgery in animals with emphysema. In the study, emphysema was induced in 31 New Zealand White rabbits (3-5 kg) with endotracheally aerosalized porcine elastase (10,000-12,000 U). Lateral thoracotomies were performed 4-6 weeks postinduction under general anesthesia and mechanical ventilatory support. Stapled volume reduction was performed on the right lower lobe using a standard multirow pediatric stapler (U.S. Surgical). Pulmonary function tests were performed at baseline (preinduction), before stapling LVRS (postemphysema induction), immediately post stapling LVRS, and 1 week poststapling. Static respiratory system compliance, flow, conductance and forced expiratory flows, and peak flows at 20 and 40 cm3 of exhaled volume were analyzed. Animals were sacrificed 1 week poststapling, and bilateral lungs were harvested for histopathology. Diffuse but heterogeneous pulmonary emphysema was seen in these animals treated with high-dose aerosolized elastase. Static compliance increased, while expiratory flows and conductance decreased after induction of emphysema. Immediately post stapled volume reduction therapy, animals had decreased static compliance. By 1 week following surgery, animals showed increased forced expiratory flows and decreased expiratory resistance, although compliance was similar to preoperative levels. In conclusion, we describe initial results in an animal model of obstructive emphysema suitable for the study of lung volume reduction surgery. Changes in pulmonary function indicate that unilateral lower lobe LVRS increases airway conductance in the rabbits. Findings from LVRS studies in animal models such as this may help explain clinical improvement following LVRS in humans.

Animals↗
PubMedDate not supplied

Effect of lung volume reduction surgery in a rabbit model of bullous lung disease.

Clinical use of staple lung volume reduction surgery (LVRS) has proliferated for treatment of emphysema despite limited data regarding efficacy or optimal techniques. Recent studies in animal models of obstructive lung disease describe the decrease in lung compliance and increase in airway support as mechanisms of an improvement in pulmonary functions analogous to human data. We describe contrasting results in an animal model of bullous lung disease with a mixed but predominantly restrictive pattern of lung disease. Mixed restrictive and bullous lung disease was induced in 17 New Zealand white rabbits with i.v. Sephadex beads and endotracheally instilled carrageenan. Unilateral stapled lung volume reduction surgery was performed at 5 weeks postinduction of emphysema on the right lower lobe by lateral thoracotomy using a pediatric stapler. Static trans-pleural pressures were measured at 60, 40, and 20 cm3 inflation at preinduction (baseline), pre- and postoperatively, and 1 week postoperatively in anesthetized animals. Lungs were then harvested en bloc and examined histopathologically. The effects of volume reduction surgery on static lung compliance, lung conductance, and forced expiratory flows (FEF) were assessed. Five weeks after induction of lung disease, the animals had no significant change in static compliance and forced expiratory volume in 0.5 s (FEV0.5) or lung conductance compared to baseline. Immediately following LVRS, the animals showed a significant decrease in static compliance, FEV0.5, and conductance. One week postoperatively, compliance increased to approximately baseline levels along with a slight increase in FEFs and conductance toward preoperative levels. Histology examination revealed restrictive and bullous lung disease. Thus, we have demonstrated the feasibility of using an animal model for evaluation of volume reduction therapy for restrictive-obstructive lung disease. Physiologically, this model showed decrease conductance and decreased forced expiratory flows following lung volume reduction despite increased recoil. This is in contrast to increased conductance and flows seen in humans with severe emphysema following surgery and suggests that current criteria excluding patients with a significant restrictive component to their lung disease from LVRS surgery may be justified.

Animals↗
PubMedDate not supplied

Computer-based data entry for nurses in the ICU.

Efforts are being made to improve the efficiency and quality of care in intensive care units (ICUs) at Latter Day Saints Hospital. The ICUs have been computerized, and the collection, storage, and presentation of patients' data have been improved. Nurses use computers for entering clinical data and plans for nursing care, and the effects of these changes on the work patterns of nurses in the ICU have been evaluated. Contrary to our expectation, our studies showed a decrease in the proportion of time that nurses spent in direct patient care (from 49.1% to 43.2%) and an increase in the proportion they spent entering clinical data (from 18.2% to 24.2%) after computerization. These changes, however, were attributed to a decrease in the severity of patients' illnesses, rather than the availability of the computer. There was no measurable difference in the proportion of time spent at other nursing activities.

Data Interpretation, Statistical↗