A comparison of sub-Tenon's with peribulbar anaesthesia in patients undergoing sequential bilateral cataract surgery.

The aim of this study was to compare efficacy and particularly patient preference of sub-Tenon's anaesthesia with peribulbar anaesthesia in patients undergoing sequential, bilateral, cataract surgery. Fifty patients were randomised to either sub-Tenon's or peribulbar anaesthesia for their first operation and the alternative technique for their subsequent operation. Intra-ocular pressure was measured, globe and lid akinesia were scored, patients completed a visual rating score of injection and operative pain and their preference for anaesthesia was assessed. Intra-ocular pressure rose significantly following peribulbar injection (p = 0.02) but was comparable at 5 min. There was no significant difference in lid or globe movement. Injection and operative pain scores were low and comparable. Both methods provided similar anaesthesia and akinesia. The majority (86%) chose the method they received first irrespective of whether it was sub-Tenon's or peribulbar, but 10% of patients preferred sub-Tenon's, disliking the facial numbness from peribulbar anaesthesia.

DNA polymerases delta and epsilon are required for chromosomal replication in Saccharomyces cerevisiae.

Three DNA polymerases, alpha, delta, and epsilon are required for viability in Saccharomyces cerevisiae. We have investigated whether DNA polymerases epsilon and delta are required for DNA replication. Two temperature-sensitive mutations in the POL2 gene, encoding DNA polymerase epsilon, have been identified by using the plasmid shuffle technique. Alkaline sucrose gradient analysis of DNA synthesis products in the mutant strains shows that no chromosomal-size DNA is formed after shift of an asynchronous culture to the nonpermissive temperature. The only DNA synthesis observed is a reduced quantity of short DNA fragments. The DNA profiles of replication intermediates from these mutants are similar to those observed with DNA synthesized in mutants deficient in DNA polymerase alpha under the same conditions. The finding that DNA replication stops upon shift to the nonpermissive temperature in both DNA polymerase alpha- and DNA polymerase epsilon- deficient strains shows that both DNA polymerases are involved in elongation. By contrast, previous studies on pol3 mutants, deficient in DNA polymerase delta, suggested that there was considerable residual DNA synthesis at the nonpermissive temperature. We have reinvestigated the nature of DNA synthesis in pol3 mutants. We find that pol3 strains are defective in the synthesis of chromosomal-size DNA at the restrictive temperature after release from a hydroxyurea block. These results demonstrate that yeast DNA polymerase delta is also required at the replication fork.

DNA polymerases required for repair of UV-induced damage in Saccharomyces cerevisiae.

The ability of yeast DNA polymerase mutant strains to carry out repair synthesis after UV irradiation was studied by analysis of postirradiation molecular weight changes in cellular DNA. Neither DNA polymerase alpha, delta, epsilon, nor Rev3 single mutants evidenced a defect in repair. A mutant defective in all four of these DNA polymerases, however, showed accumulation of single-strand breaks, indicating defective repair. Pairwise combination of polymerase mutations revealed a repair defect only in DNA polymerase delta and epsilon double mutants. The extent of repair in the double mutant was no greater than that in the quadruple mutant, suggesting that DNA polymerases alpha and Rev3p play very minor, if any, roles. Taken together, the data suggest that DNA polymerases delta and epsilon are both potentially able to perform repair synthesis and that in the absence of one, the other can efficiently substitute. Thus, two of the DNA polymerases involved in DNA replication are also involved in DNA repair, adding to the accumulating evidence that the two processes are coupled.

A yeast replicative helicase, Dna2 helicase, interacts with yeast FEN-1 nuclease in carrying out its essential function.

We have recently described a new helicase, the Dna2 helicase, that is essential for yeast DNA replication. We now show that the yeast FEN-1 (yFEN-1) nuclease interacts genetically and biochemically with Dna2 helicase. FEN-1 is implicated in DNA replication and repair in yeast, and the mammalian homolog of yFEN-1 (DNase IV, FEN-1, or MF1) participates in Okazaki fragment maturation. Overproduction of yFEN-1, encoded by RAD27/RTH1, suppresses the temperature-sensitive growth of dna2-1 mutants. Overproduction of Dna2 suppresses the rad27/rth1 delta temperature-sensitive growth defect. dna2-1 rad27/rth1 delta double mutants are inviable, indicating that the mutations are synthetically lethal. The genetic interactions are likely due to direct physical interaction between the two proteins, since both epitope-tagged yFEN-1 and endogenous yFEN-1 coimmunopurify with tagged Dna2. The simplest interpretation of these data is that one of the roles of Dna2 helicase is associated with processing of Okazaki fragments.

DNA polymerase I is required for premeiotic DNA replication and sporulation but not for X-ray repair in Saccharomyces cerevisiae.

We have used a set of seven temperature-sensitive mutants in the DNA polymerase I gene of Saccharomyces cerevisiae to investigate the role of DNA polymerase I in various aspects of DNA synthesis in vivo. Previously, we showed that DNA polymerase I is required for mitotic DNA replication. Here we extend our studies to several stages of meiosis and repair of X-ray-induced damage. We find that sporulation is blocked in all of the DNA polymerase temperature-sensitive mutants and that premeiotic DNA replication does not occur. Commitment to meiotic recombination is only 2% of wild-type levels. Thus, DNA polymerase I is essential for these steps. However, repair of X-ray-induced single-strand breaks is not defective in the DNA polymerase temperature-sensitive mutants, and DNA polymerase I is therefore not essential for repair of such lesions. These results suggest that DNA polymerase II or III or both, the two other nuclear yeast DNA polymerases for which roles have not yet been established, carry out repair in the absence of DNA polymerase I, but that DNA polymerase II and III cannot compensate for loss of DNA polymerase I in meiotic replication and recombination. These results do not, however, rule out essential roles for DNA polymerase II or III or both in addition to that for DNA polymerase I.

Compliance of NHS dental practice websites in Wales before and after the introduction of the GDC document 'Principles of ethical advertising'.

Objectives To evaluate the compliance of NHS dental practice websites in Wales, UK, with the 2012 GDC document Principles of ethical advertising, before its introduction (2011) and again after its introduction (2014).Methods All practices in Wales with an NHS contract and dental practice website were identified. The content of the website was evaluated to determine if it complied with the principles outlined in the 2012 GDC document Principles of Ethical Advertising.Results Twenty-five percent of the 446 practices sampled in 2011 had a website, compared to 44% of the 436 practices sampled in 2014. The principles best complied with were; displaying the name, geographic address, and telephone number of the practice (100% for both years). None of the websites compared the qualifications or skills of its practitioners to others, therefore 100% complied with this principle. Displaying team members' professional qualification and the country from which this is obtained was fairly well represented; 92% and 61% respectively in 2014; an improvement from only 50% and 49% respectively in 2011. Principles worst complied with were displaying the GDC's address (3% 2011; 9% 2014) or link to the GDC website (11% 2011; 7% 2014) and details of the practice complaints procedure (1% 2011; 5% 2014). Overall, no practice complied with all of the compulsory principles.Conclusion In both 2011 and 2014 no practice website was compliant with all the principles outlined in the 2012 GDC document Principles of ethical advertising. Reflecting results from previous studies, this study showed that compliance is slowly improving, yet over 4 years after the introduction of the mandatory principles, it remains that no practice website is 100% compliant.

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.

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.

Treatment of somatization in primary care.

A large proportion of patients present to primary care with chronic, stress-related symptoms having no organic cause. Biomedical treatment of these patients is usually ineffective and expensive. A 6-week behavioral medicine intervention designed to provide adjunctive treatment to primary care was evaluated in a randomized, controlled study. Thirty-eight individuals receiving treatment and 44 waiting for treatment completed the SCL-90-R at times corresponding to 1 week before (time 1) and 1 week after the course (time 2). The treatment group was then followed up at 6 months. After correction for initial levels, the treatment group reported significantly less somatization, anxiety, and depression than did the wait-list group at time 2. Within the treatment group, decreases in somatization, anxiety, and depression were statistically significant and were maintained 6 months later. Within the wait-list group, distress remained unchanged. A review of relevant literature reveals that a general behavioral medicine course such as the one studied here has an important adjunctive role in primary care, since 1) subsyndromal psychological distress is common in primary care; 2) physicians are reluctant to address psychosocial issues; 3) negative mood is associated with poor health; 4) negative mood is associated with high, inappropriate medical utilization; and 5) negative mood is associated with help-seeking behavior.

Short-term effect of a 75 g oral glucose load on glycohaemoglobin levels.

Two hundred and twenty-three subjects out of a total of 347 with various degrees of glucose tolerance were recalled after a screening survey for diabetes. They were a randomly selected sample of people over the age of 40 and they underwent a formal 75 g glucose tolerance test in order to assess the effect of a glucose load on glycohaemoglobin levels measured by four different assay methods. Oral glucose loading was found to affect glycohaemoglobin levels only when these were measured by an agar-gel electrophoretic method that did not remove the labile aldimine-linked Schiff base fraction. The increase in glycohaemoglobin during the glucose tolerance test as estimated by this method was proportional to the 2 h blood glucose level. Glycohaemoglobin levels measured by agar-gel electrophoresis with elimination of the Schiff base, by affinity chromatography and by iso-electric focussing, were not affected by a 75 g oral glucose load. We conclude that blood samples for glycohaemoglobin assay may be collected at any time of the day, without regard to the subject's previous food intake, provided an assay method is used that removed the aldimine-linked labile fraction.

The pattern of sensitivity of yeast dna2 mutants to DNA damaging agents suggests a role in DSB and postreplication repair pathways.

The Saccharomyces cerevisiae DNA2 gene encodes a DNA-stimulated ATPase and DNA helicase/nuclease essential for DNA replication. In characterizing dna2 mutants, we have found that Dna2p also participates in DNA repair or in damage avoidance mechanisms. dna2 mutants are sensitive to X rays, although they are less sensitive than rad52 mutants. The X-ray sensitivity of dna2 mutants is suppressed by overexpression of a 5' to 3' exonuclease, the yeast FEN-1 structure-specific nuclease, encoded by the RAD27 gene, which also suppresses the growth defect of dna2-ts mutants. SGS1 encodes a helicase with similar properties to Dna2 protein. Although sgs1Delta mutants are resistant to X rays, dna2-2 sgs1Delta double mutants are more sensitive to X rays than the dna2-2 mutant. Temperature sensitive dna2 mutants are only slightly sensitive to UV light, show normal levels of spontaneous and UV induced mutagenesis, and have only a 2.5-fold elevated level of dinucleotide tract instability compared to wildtype. However, dna2Delta strains kept alive by overproduction of RAD27 are highly sensitive to UV light. These phenotypes, in addition to the epistasis analysis reported, allow us to propose that Dna2 is involved in postreplication and DSB repair pathways.

Effects of pneumoperitoneum on intraoperative pulmonary mechanics and gas exchange during laparoscopic gastric bypass.

BACKGROUND: Hypercarbia and elevated intraabdominal pressure resulting from carbon dioxide (CO2) pneumoperitoneum can adversely affect respiratory mechanics. This study examined the changes in mechanical ventilation, CO2 homeostasis, and pulmonary gas exchange in morbidly obese patients undergoing a laparoscopic or open gastric bypass (GBP) procedure. METHODS: In this study, 58 patients with a body mass index (BMI) of 40 to 60 kg/m2 were randomly allocated to laparoscopic ( n = 31) or open ( n = 27) GBP. Minute ventilation was adjusted to maintain a low normal arterial partial pressure of CO2 (PaCO2), low normal end-tidal partial pressure of CO2 (ETCO2), and low airway pressure. Respiratory compliance, ETCO2, peak inspiratory pressure (PIP), total exhaled CO2 per minute (VCO2), and pulse oximetry (SO2) were measured at 30-min intervals. The acid-base balance was determined by arterial blood gas analysis at 1-h intervals. The pulmonary gas exchange was evaluated by calculation of the alveolar dead space-to-tidal volume ratio (V(Dalv)/V(T)) and alveolar-arterial oxygen gradient (PAO2-PaO2). RESULTS: The two groups were similar in age, gender, and BMI. As compared with open GBP, laparoscopic GBP resulted in higher ETCO2, PIP, and VCO2, and a lower respiratory compliance. Arterial blood gas analysis demonstrated higher PaCO2 and lower pH during laparoscopic GBP than during open GBP ( p < 0.05). The V(Dalv)/V(T) ratio and PAO2-PaO2 gradient did not change significantly during laparoscopic GBP. Intraoperative oxygen desaturation (SO2 < 90%) did not develop in any of the patients in either group. CONCLUSIONS: Laparoscopic GBP alters intraoperative pulmonary mechanics and acid-base balance but does not significantly affect pulmonary oxygen exchange. Changes in pulmonary mechanics are well tolerated in morbidly obese patients when proper ventilator adjustments are maintained.

Pharmaceutical and clinical analysis by tandem mass spectrometry.

Tandem mass spectrometry (MS/MS) is a promising technique for trace determination of compounds in complex mixtures. The application of triple-quadrupole MS/MS to clinical and pharmacological studies has been investigated with major emphasis on rapid screening and determination of drugs and biomolecules in physiological fluids and tissues. These techniques have been applied to a range of problems, including the determination of chlorinated compounds in humans, subpicogram analysis of neurochemicals and the detection of illegal drugs in racing animals. A new technique for determining the structures of all the metabolites of a particular drug has also been developed. It is possible to identify in a single sample all molecular ions which contain substructures characteristic of the parent drug. The structure of each metabolite can then be determined by obtaining the MS/MS spectrum of the molecular ion.

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.

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.

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.