Patients view of the anaesthetist in a developing country

OBJECTIVE

The objective of this study was to assess patients regarding their knowledge and perception of the anaesthetists' role in patient care in a developing country.

SETTING

The audit was conducted at the Aga Khan University Hospital, Karachi.

METHODS

Two hundred surgical and 102 medical out-patients were included in the audit prospectively who filled a detailed questionnaire.

RESULTS

Fifty-six percent of the patients knew that anaesthetists were medically qualified but only 20% and 27% had an idea about their role in the intraoperative and immediate postoperative period. 14.6% were aware of the anaesthetists role outside the operating room. No difference was observed between the two groups of patients except that a higher percentage of surgical patients were interested in having more information regarding anaesthesia and wanted to choose their anaesthetist if the need arose. Gender difference was observed in answer to two questions only. A higher percentage of males know the role of anaesthetist in the recovery room whereas a greater number of females who had surgery before remembered their anaesthetist postoperatively.

CONCLUSION

The results of this audit show a poor perception of the anaesthetists role both inside and outside the operating room. Although public knowledge surveys have been carried out in developed countries there is a pressing need to repeat these in developing countries since the image as perceived by public may have a direct bearing on the recruitment of young doctors into an already shortage specialty in these less affluent countries.

Decrease in Ca-ATPase activity in aged synaptosomal membranes is not associated with changes in fatty acyl chain dynamics

We have examined lipid peroxidation (LPO) and fatty acid acyl chain dynamics in synaptosomal membranes isolated from aged rat (Fischer 344 x Brown Norway F1 hybrids) brains, correlating these results with measurements of enzymatic activity of the synaptic plasma membrane Ca2(+)-ATPase (PMCA). Calcium-dependent ATPase activity in these membranes exhibits progressive decreases with a maximal loss of activity with age of approximately 35%. The sensitivity of this membrane-bound ion transporter to the lipid composition of the surrounding membrane, as well as the high abundance of oxidatively sensitive polyunsaturated fatty acyl chains in synaptosomal membranes, suggests that this age-related loss in catalytic turnover may result from LPO-mediated protein modification and/or changes in the physical structure of the bilayer. However, high-performance liquid chromatography analysis of 2,4-dinitrophenylhydrazone derivatives reveals no significant age-related increases in the content of reactive aldehydes (malondialdehyde, formaldehyde, acetaldehyde or acetone) which comprise breakdown products of lipid peroxidation. Electron paramagnetic resonance measurements employing 5- and 12-stearic acid spin labels with the nitroxide reporter groups at two depths in the bilayer were used to assess the fatty acyl chain dynamics (fluidity) of synaptosomal membranes. The resulting spectra demonstrate anisotropic lipid dynamics of two populations of lipids, i.e. lipids in direct association with membrane proteins (boundary lipids) and bulk lipids that do not directly associate with proteins. The nanosecond dynamics of both lipid populations is unaltered with age indicating that any compositional changes occurring with age are insufficient to result in alterations in bilayer fluidity relevant to PMCA activity. Thus, the observed age-related decline in PMCA activity may be explained by direct modification of membrane protein.

Sensitivity of the synaptic membrane Na+/Ca2+ exchanger and the expressed NCX1 isoform to reactive oxygen species

Two plasma membrane proteins, the Na+/Ca2+ exchanger (NCX) and the Ca2+-ATPase, are major regulators of free intraneuronal Ca2+ levels as they are responsible for extrusion of Ca2+ from the intracellular to the extracellular medium. Because disruption of cellular Ca2+ regulation plays a role in damage occurring under conditions of oxidative stress, studies were conducted to assess the sensitivity of the NCX to reactive oxygen species (ROS). Exchanger activity in brain synaptic plasma membranes and in transfected CHO-K1 cells was inhibited following brief exposure to the peroxyl radical generating azo initiator 2,2'-azobis(2-amidinopropane)dihydrochloride (AAPH) and to peroxynitrite. Incubation with hydrogen peroxide did not alter NCX activity, even at 800 microM concentration. In CHO-K1 cells transiently transfected with the NCX1 isoform of the exchanger, AAPH treatment decreased the maximal transport capacity (Vmax), whereas the K(act) remained unchanged. Peroxynitrite led to an increase in K(act) with no change in Vmax. Loss of activity following exposure to either AAPH or peroxynitrite was associated with the formation of high molecular weight aggregates of NCX, and AAPH also caused fragmentation of the exchanger protein. These findings suggest that the NCX is sensitive to biologically relevant ROS and could be involved in the loss of Ca2+ homeostasis observed under oxidative stress.

Age-related decrease in brain synaptic membrane Ca2+-ATPase in F344/BNF1 rats

We used Fisher 344/Brown Norway hybrid rats (F344/BNF1) to determine whether previously reported decreases in brain synaptic plasma membrane (SPM) Ca2+-ATPase activity in inbred F344 rats also occurred in the hybrids. Plasma membrane Ca2+-ATPase (PMCA) activity in SPMs from F344/BNF1 rat brains showed a progressive age-dependent decrease in Vmax from 60.9 +/- 3.7 nmol Pi/mg/min (n = 6) in 5-month rats to 32.4 +/- 3.6 nmol Pi/mg/min (n = 6) in 34-month animals, with no change in K (act) for Ca2+. Immunoreactive PMCA in SPMs also decreased by approximately 20% at 34 months, and the calmodulin (CaM) bound to membranes following extraction with EDTA also declined progressively with age. The effectiveness of CaM in stimulating PMCA activity was significantly lower when CaM was purified from the brains of old vs. young F344 rats and when CaM from 5-month rats was oxidized in vitro. These results indicate: 1) that PMCA activity in SPMs from longer lived F344/BNF1 hybrids also decreases with age; 2) that part of the reduction in PMCA activity is due to loss of PMCA from the membranes; and 3) that age-related structural changes in CaM may decrease its interaction with proteins in SPMs.

Orthotopic heart transplantation in a transgenic pig-to-primate model

BACKGROUND

Previous studies demonstrated that hearts from transgenic pigs expressing human decay-accelerating factor (hDAF) were not hyperacutely rejected when transplanted heterotopically into the abdomen of cynomolgus monkeys. This study examines orthotopic transplantation of hDAF transgenic pig hearts into baboon recipients.

METHODS

Orthotopic xenogeneic heart transplantation was performed using piglets, transgenic for hDAF, as donors. Ten baboons were used as recipients and were immunosuppressed with a combination of cyclophosphamide, cyclosporine, and steroids.

RESULTS

Five grafts failed within 18 hr without any histological signs of hyperacute rejection. Pulmonary artery thrombosis induced by a size mismatch was observed in two of these animals. The other three recipients died because of failure to produce even a low cardiac output and/or dysrhythmia. The remaining five animals survived between four and nine days. One animal died of bronchopneumonia on day 4. Three xenografts stopped beating on day 5 due to acute vascular rejection. The longest survivor was killed on day 9 with a beating, histologically normal xenograft, because of pancytopenia.

CONCLUSIONS

The results reported here demonstrate that hDAF transgenic pig hearts are not hyperacutely rejected when transplanted into baboon recipients. Orthotopically transplanted transgenic pig hearts are capable of maintaining cardiac output in baboons. An optimum immunosuppressive regimen is the subject of ongoing research.

Life-supporting pig-to-primate renal xenotransplantation using genetically modified donors

BACKGROUND

In order to circumvent the complement-mediated hyperacute rejection of discordant xenografts, a colony of pigs transgenic for the human regulator of complement activity, human decay-accelerating factor (hDAF), has been produced.

METHODS

Seven kidneys from hDAF transgenic pigs and six kidneys from nontransgenic control pigs were transplanted into cynomolgus monkeys; both native kidneys were removed during the same operation. The recipient animals were immunosuppressed with cyclosporine, steroids, and cyclophosphamide.

RESULTS

In the transgenic group, the median survival time was 13 days (range, 6-35 days); the median survival time in the control group was 6.5 days (range, 0.3-30 days). There were no cases of hyperacute rejection in the transgenic group, and the two longest-surviving kidneys in this group showed no evidence of rejection on histological examination. In contrast, all control kidneys underwent antibody-mediated rejection, one demonstrating hyperacute rejection and the others acute vascular rejection.

CONCLUSION

This study demonstrates that (i) a kidney from an hDAF transgenic pig can support the life of a primate for up to 35 days (and also shows the basic physiological compatibility between the pig and nonhuman primate); (ii) nontransgenic kidneys are not routinely hyperacutely rejected; and (iii) the presence of hDAF on the kidney confers some protection against acute vascular rejection. Improved immunosuppression and immunological monitoring may enable extended survival.

Images in clinical medicine. Stab wounds to the heart: a useful radiological sign

Images

Comparison of nalbuphine and buprenorphine in total intravenous anaesthesia

Nalbuphine (0.3 mg.kg-1) and buprenorphine (2.5 micrograms.kg-1) were compared as part of a total intravenous anaesthesia regimen using a propofol infusion in 60 patients undergoing laparoscopic cholecystectomy in a randomised double-blind study. Changes in haemodynamic variables greater than 20% from the baseline were noted. No difference was observed in blood pressure but the heart rate was significantly lower in the buprenorphine group. Intra-operative bradycardia (heart rate < 60 beat.min-1) occurred more often in the buprenorphine group. Recovery was fast and comparable with both drugs and no patient reported awareness. Quality of analgesia was similar in both groups. Both drugs provide suitable analgesic supplementation to total intravenous anaesthesia.

Detection of autoantibodies to nuclear antigens by EIA and IF techniques

The detection of antibodies to certain nuclear components has considerable importance in the diagnosis and management of patients with autoimmune diseases. In this study, antibodies to nuclear antigens in 250 positive and negative patient specimens were detected by immunofluorescence (IF) and enzyme immunoassay (EIA). Specimens were tested by three different EIA assays for autoantibodies to SS-A, SS-B, Scl-70 Sm, RNP, Jo-1, ENA, Histone, ss-DNA and ds-DNA and one IF assay for Antinuclear Antibodies (ANA). The majority of positive specimens were also confirmed positive by Western Blot. Ninety-seven percent of IF-ANA positive specimens assayed positive by EIA-ENA assay and only 6% of ENA negative specimens tested positive in IF-ANA assay indicating that EIA-ENA assay is as reliable as IF-ANA for screening patient specimens. Forty-five percent of EIA Jo-1 positive specimens showed negative IF-ANA results indicating that IF-ANA assay is not a reliable method for detection of antibodies to Jo-1. This may be due to the fact that specimens with low titer and sera which are positive for a limited number of specific nuclear antigen(s) cannot produce visible or clear fluorescence patterns and therefore are reported negative by IF-ANA. Our data shows that both methods are reliable for screening purposes, however EIA has greater specificity over IF because the presence or absence of antibody to a specific antigen can be better assessed. Overall, due to higher reproducibility, low cost, antigen specificity, and the nature of EIA, we recommend microtiter-based EIA assays for detection of antibodies to nuclear antigens.

Eliminating access to anonymous HIV antibody testing in North Carolina: effects on HIV testing and partner notification

Anonymous HIV testing may attract persons who might otherwise not be tested but may hinder partner notification. We evaluated the effects on North Carolina's HIV testing and partner notification programs of policy changes that eliminated and later restored anonymous testing in 82 counties. We used an interrupted time-series design to compare counties eliminating with counties retaining anonymous testing. We analyzed HIV testing and partner notification data from before, during, and after elimination of anonymous testing. After elimination of anonymous testing in 82 counties, the mean monthly level of testing (+/- SE) increased by 45%, or 548 (+/- 123) tests per month, while in 18 counties that retained anonymous testing, there was a 63% increase, or 802 (+/- 162) tests per month (p > .05). Among men of all races, testing increased by 16%, or 155 (+/- 35) tests per month, in counties that eliminated anonymous testing; and by 51%, or 305 (+/- 42) tests per month (p < .05), in counties that retained anonymous testing. After elimination of anonymous testing, both county types experienced similar increases in the rate of partners notified. However, partner notification was more successful if the index patient was tested confidentially; 2.7 times as many partners per index patient were notified and counseled. There was no effect on testing or on partner notification rates following restoration of anonymous testing. Substantial community opposition to eliminating anonymous testing was encountered. The policy change appeared to result in a slight decrease in testing among men and a slight increase in partners notified. Programs considering the elimination of anonymous testing should weigh these potential gains and losses, as well as the impact on relationships between the public health and advocacy communities

A field trial of wheat-based oral rehydration solution among Afghan refugee children

A total of 326 Afghan children aged between 6 months and 5 years with uncomplicated nondysenteric diarrhea for the previous 24 h to 5 days were treated at home by their mothers with either wheat-salt solution (WSS) or World Health Organization recommended glucose-oral rehydration salts (G-ORS). For 7 consecutive days the children were examined in the household and the mothers interviewed to assess the progress, feeding practices, and perception of treatment efficacy. Children treated with WSS recovered significantly earlier; the mean duration on treatment was 4.0 days (SD 1.7 days) on WSS compared to 6.4 days (SD 1.7 days) on G-ORS. By the second day of treatment, significantly more mothers using WSS (56%) reported that their children had formed stools versus 11% of their G-ORS counterparts; the mean stool frequency after 2 days was also significantly reduced; 3 stools day-1 (SD 2.1) on WSS versus 5 (SD 2.9) on G-ORS. The cereal-based solution was not confused with normal food and led to better feeding patterns. By day 2, 74% of the mothers using WSS had resumed their normal feeding frequencies as opposed to 33% of G-ORS mothers. On recovery the WSS group had gained significantly more weight; the WSS group gained 169 g (SD 142 g) while the G-ORS group lost 150 g (SD 174g). This study suggests by subjective and objective measures that WSS could be considered as an effective home fluid for the first-line treatment of diarrhea.

Studies on the differential morphological alterations in human and goat erythrocytes against ATP depletion and Ca(2+)-induced stresses

Erythrocyte membranes obtained from goat exhibited Ca2+/calmodulin-insensitive (Ca(2+)-Mg2+)-ATPase activity and the activity levels were significantly lower as compared to those obtained from human erythrocyte membranes. Although Ca2+/ionophore A23187 -treatment enhanced the intracellular Ca2+ levels in both the freshly collected human and goat erythrocytes, negligible loss of ATP was noticed in goat erythrocytes under such conditions. Also, fluoride, a known metabolic inhibitor, caused a lesser ATP depletion in goat erythrocytes compared to that of human. Goat erythrocytes showed remarkable rigidity to shape change and unlike human erythrocytes, did not undergo echinocytic formation as a result of metabolic depletion and Ca2+/ionophore A23187-treatments. These studies suggest the participation of (Ca(2+)-Mg2+)-ATPase -independent mechanism(s) for Ca(2+)-extrusion.

Protection by lazaroids of the erythrocyte (Ca2+, Mg2+)-ATPase against iron-induced inhibition

The calmodulin-stimulated (Ca2+, Mg2+)-ATPase (calmodulin-ATPase) of the erythrocyte membrane is susceptible to oxidative stress induced by heme and non-heme iron. There is a time-and concentration-dependent inhibition of the calmodulin-ATPase activity when the erythrocyte membranes are treated with either iron or hemin. In the present study, the calmodulin-ATPase has been used as a model system to evaluate the protective effects of a vitamin E analog (U83836E) and two 21-aminosteroids (U74500A and U74389G) against calmodulin-ATPase inhibition induced by iron and hemin. The drugs, lazaroids from Upjohn, can significantly protect the enzyme against iron-induced inhibition and also causes a decrease in the formation of thiobarbituric acid reactive species, with an IC50 of 0.4 microM for the drug U83836E and 4 microM for the drug U74500A. The 21-aminosteroid U74389G does not restore iron-inhibited calmodulin-ATPase activity under similar conditions. At higher concentrations (> 100 microM) all three drugs inhibit the calmodulin-ATPase activity. None of the drugs tested can restore hemin-inhibited calmodulin-ATPase activity.

Sexual behavior, sexually transmitted diseases, and risk of cervical cancer

To explore sexually transmitted diseases and sexual behavior as risk factors for cervical cancer, we analyzed data from a population-based case-control study of breast and cervical cancer in Costa Rica. Data from 415 cases of cervical carcinoma in situ, 149 cases of invasive cervical cancer, and 764 controls were included in the analysis. Multivariate analysis showed that lifetime number of sex partners, first intercourse before age 15 years, number of livebirths, herpes simplex virus type 2 seropositivity, and serologic evidence of previous chlamydial infection were predictors of carcinoma in situ. Serologic evidence of previous syphilis was not associated with carcinoma in situ. Predictors for invasive cervical cancer included lifetime number of sex partners, first intercourse before age 15 years, number of livebirths, serologic evidence of previous syphilis, herpes simplex type 2 infection, and chlamydial infection. Cigarette smoking, socioeconomic status, self-reported history of sexually transmitted diseases, and douching were not associated with either carcinoma in situ or invasive cervical cancer.

Heme as an optical probe for studying the interactions between calmodulin and the Ca(2+)-ATPase of the human erythrocyte membrane

The heme group was used as an optical probe to study the interactions between calmodulin and its targets: the peptide melittin and the enzyme Ca(2+)-ATPase. As already reported, melittin when present in Tris buffer binds hemin-CN which quenches the tryptophan fluorescence. Addition of calmodulin restores the fluorescence significantly accompanied by a blue shift. We show here that the recovery of fluorescence is very slow and takes about 120 min to become constant. In a hydrophobic buffer, the fluorescence spectrum of melittin is already shifted with a peak at 335 nm and intensity almost 2-fold relative to a similar concentration of melittin in Tris buffer. The quenching of tryptophan fluorescence is lesser in this buffer and further addition of calmodulin fails to restore the fluorescence. This indicates the absence of binding of calmodulin to melittin in hydrophobic conditions. Under similar conditions of hydrophobicity, hemin-CN quenches about 35% of the tryptophan fluorescence of the Ca(2+)-ATPase. The subsequent addition of calmodulin restores about half of the quenched fluorescence. The interaction of calmodulin with the Ca(2+)-ATPase even under hydrophobic conditions suggests its high specificity for the enzyme which may be expected for a physiological target.

Quantitative studies on the effect of prostacyclin on freshly isolated rat osteoclasts in culture

Prostaglandins exert marked but transient inhibitory effects on bone resorption. The present study examines the effects of prostacyclin (0.15 to 25 microM) on the morphology of freshly disaggregated rat osteoclasts. An area descriptor, rho, represented changes in total cell spread area, and a motility descriptor, mu, represented overall changes in cell motility. The application of prostacyclin intercepted the trend of an increasing cell spread area with time and produced a transient reduction of rho, an R effect. Its magnitude depended upon concentration and was marked at 25 microM prostacyclin. The subsequent recovery (+0.8/min) of rho at this concentration resembled the persistent spreading seen in the absence of the agonist. There was also a sustained decrease in mu to approximately 60% of its pretreatment value (a Q effect) following the application of 25 microM prostacyclin. The extracellular application of 20 mM [Ca2+] produced a similarly transient cell retraction preceded by a rise of cytosolic [Ca2+], but without a corresponding decrease in mu. In contrast, prostacyclin did not elevate cytosolic [Ca2+], suggesting the triggering of an alternative transduction pathway. A fully reversible retraction together with incomplete quiescence may explain the transience characteristic of the antiresorptive action of prostacyclin.

Modulation of the osteoclast Ca2+ receptor by extracellular protons: possible linkage between Ca2+ sensing and extracellular acidification

We report a sensitivity of the osteoclast cell surface Ca2+ receptor to extracellular protons. Freshly isolated rat osteoclasts were exposed to the known agonists of the Ca2+ receptor, Ca2+ and Ni2+, in extracellular solutions set at different pH values. Decreasing the extracellular pH from 7.8 to 4.0 units markedly potentiated the cytosolic Ca2+ signals elicited in response to Ca2+ receptor activation by either Ni2+ (50 microM, 500 microM or 5 mM) or Ca2+ (5 mM). Each response consisted of a rapid and usually transient elevation of cytosolic [Ca2+]. Maximal cytosolic [Ca2+] responses were obtained at pH values of 6.6 (for 5 mM-[Ni2+]) and 4.0 units (for 5 mM-[Ca2+]). Finally, the effects of extracellular pH persisted in Ca(2+)-free, EGTA-containing solutions, suggesting a modulation of intracellular Ca2+ release.