Cybernetic Approach to Health Assessment

The exploration of orbital space served as a prerequisite for the creation of a new direction of medical science in relation to the very extreme conditions of life of spacecraft crews. Space medicine, relying on the most modern research methods and approaches, thanks to the development of new medical devices and the use of unique data analysis algorithms, has made a significant contribution to the development of telemedicine, medical cybernetics, and prenosological principles for assessing the state of human health. The review reflects the main stages in the development of medical cybernetics and prenosological diagnostics based on the assessment of the regulatory components of the cardiovascular system. Discussed the aspects of the application of the method of mathematical analysis of the heart rhythm in relation to the assessment and forecast of the working capacity of cosmonauts, at the simulating model of microgravity and confinement. Shown the useful methodically apply for the healthcare of manufacture teams at the plants, passenger bus driver’s employments. As the part of appliance of the new advance tools of children and adolescents public health during the educating process at schools. The created system for analyzing the current functional state of human health and mathematical models that make it possible to predict its negative changes make it possible to predetermine the vector of development of medicine in the future. The foundations of knowledge gained over the period of more than 70 years of scientific activity of Professor R.M. Bavsky are reflected in promising areas of cardiology research using computer technologies - such as Cardiometry technologies.

413 Fat Grafting as a Therapeutic Treatment for Frey's Syndrome: A Comprehensive Review of the Literature and Recommendations for Management

Aim

With the reported incidence of Frey's syndrome as high as 59%, the significant morbidity experienced by patients post parotidectomy has resulted in a range of treatment options being proposed with variable outcomes. The lack of consensus has resulted in patients being offered a wide range of treatments with varying success. While fat grafting remains a treatment for contour deformity correction, there is emerging evidence to suggest its effectiveness as a treatment for Frey's syndrome, warranting further investigation. This systematic review aims to evaluate the efficacy of fat grafting as a treatment for Frey's syndrome post parotidectomy.

Method

A systematic review was conducted as per PRISMA guidelines, with all articles from MEDLINE, Embase, Web of Science, Ovid, Scopus, and Cochrane screened by two independent reviewers using discreet inclusion and exclusion criteria followed by in depth full-text reviews.

Results

116 papers were screened with 16 meeting the inclusion criteria (13.8%) totalling 785 patients, with multiple outcome measures for assessing Frey's syndrome. Fat grafting was shown to significantly reduce the incidence of Frey's syndrome in patients having undergone both superficial and total parotidectomies, with 15 studies (93.8%) finding a significant reduction in its incidence post treatment.

Conclusions

With low donor site morbidity, biocompatibility, ease of use, low cost to perform and high patient satisfaction, the systematic review of the evidence supports the use of fat grafting post parotidectomy as an effective treatment for Frey's syndrome. Further research to determine the long-term outcome would inform its suitability as a first line treatment.

386 A Comparison of Academic Output of Welsh Plastic Surgery Trainees Pre- and Mid-COVID-19 Pandemic

Aim

The COVID-19 pandemic has affected doctors worldwide, with 1.5 million surgeries being postponed or cancelled in England and Wales during 2020. Surgeons in competitive specialties requiring active research portfolios may have used this time to strengthen their academic work. This cross-sectional study provides insight into the academic output of Welsh plastic surgery trainees during the COVID-19 pandemic, which could be used to highlight contributing factors to benefit future training.

Method

A cross-sectional study was distributed to all Welsh burns and plastic surgery trainees from specialty trainee levels 3–8. Data was obtained comparing publications achieved, abstracts submitted, and projects undertaken pre-pandemic, March 1^st to 31^st August 2019 and mid-pandemic, March 1^st to 31^st August 2020.

Results

Of the 12 Welsh plastic surgery trainees, 75% participated in this survey, with representation from all years of training. Mid-pandemic, an average of 3 publications were achieved per trainee when compared with 1.4 pre-pandemic. 78% submitted abstracts during both periods, increasing from 1.5 to 2.44 mid-pandemic. Although the average number of projects undertaken pre- and mid-pandemic was 3.2 and 3.1 respectively, the number of trainees undertaking projects increased by 22% to 100%. Most commonly, this was attributed to an increase in capacity.

Conclusions

Our study demonstrated that overall, academic output increased significantly during the COVID-19 pandemic. Unsurprisingly, this sudden decrease in surgical activity led to trainees in this highly competitive specialty employing their time towards research. Further studies investigating the factors enabling trainees to increase their academic productivity would be beneficial as routine surgical activity resumes.

Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

Formation Constants and Conformational Analysis of Carbamates in Aqueous Solutions of 2-Methylpiperidine and CO2 from 283 to 313 K by NMR Spectroscopy

Quantitative ¹³C nuclear magnetic resonance (NMR) spectroscopy was used to investigate the speciation in (2-methylpiperidine + H₂O + CO₂) systems at 283.2-313.2 K. The carbamate of 2-methylpiperidine(2-methylpiperidine- N-carboxylate) was shown for the first time to be a stable species in aqueous solutions. The spectroscopic results were used to obtain temperature-dependant formation constants for the carbamate using a simplified model for the activity coefficients from which the standard molar enthalpy of reaction was estimated. The results were incorporated into a self-consistent chemical equilibrium model, which includes vapor-liquid equilibria and all aqueous species, including the formation of carbamate. The predominant conformation of the sterically hindered carbamate, which was determined using two-dimensional exchange spectroscopy NMR, has the methyl group in the axial orientation and is in agreement with the density functional theory quantum chemical calculations.

Negative predictive value of preoperative computed tomography in determining pathologic local invasion, nodal disease, and abdominal metastases in gastric cancer

BACKGROUND

Before undergoing curative-intent resection of gastric adenocarcinoma (ga), most patients undergo abdominal computed tomography (ct) imaging to determine contraindications to resection (local invasion, distant metastases). However, the ability to detect contraindications is variable, and the literature is limited to single-institution studies. We sought to assess, on a population level, the clinical relevance of preoperative ct in evaluating the resectability of ga tumours in patients undergoing surgery.

METHODS

In a provincial cancer registry, 2414 patients with ga diagnosed during 2005-2008 at 116 institutions were identified, and a primary chart review of radiology, operative, and pathology reports was performed for all patients. Preoperative abdominal ct reports were compared with intraoperative findings and final pathology reports (reference standard) to determine the negative predictive value (npv) of ct in assessing local invasion, nodal involvement, and intra-abdominal metastases.

RESULTS

Among patients undergoing gastrectomy, the npv of ct imaging in detecting local invasion was 86.9% (n = 536). For nodal metastasis, the npv of ct was 43.3% (n = 450). Among patients undergoing surgical exploration, the npv of ct for intra-abdominal metastases was 52.3% (n = 407).

CONCLUSIONS

Preoperative abdominal ct imaging reported as negative is most accurate in determining local invasion and least accurate in nodal assessment. The poor npv of ct should be taken into account when selecting patients for staging laparoscopy.

Combined heart and kidney transplantation provides an excellent survival and decreases risk of cardiac cellular rejection and coronary allograft vasculopathy

BACKGROUND

We analyzed the results of combined heart-kidney transplantation (CHKTx) over a 10-year period.

METHODS

Between September 1996 and May 2007 at Mayo Clinic, 12 patients (age 52 ± 12.2 years) underwent CHKTx as a simultaneous procedure in 10 recipients and as a staged procedure in two recipients with unstable hemodynamics after heart transplantation.

RESULTS

There was no operative mortality. Patient survival rates for the CHKTx recipients at 1 and 3 months and 6 years were 91%, 83%, and 83% and did not differ from isolated heart transplantation (IHTx) recipients (97%, 95%, and 79%, P = 0.61). The freedom from cardiac allograft rejection (≥ grade 2) at 3 months was 73% for CHKTx and had not changed during further follow-up; for IHTx, freedom from rejection at 3 months and 1 and 6 years was 61%, 56%, and 42% (P = .08). Heart and renal allograft survival was 100% with and left ventricular ejection fraction 66% ± 8.4% and glomerular filtration rate 61 ± 25 at last follow-up. There were no signs of cardiac allograft vasculopathy in the CHKTx recipients.

CONCLUSION

CHKTx yields favorable long-term outcome, with a low incidence of cardiac rejection and vasculopathy. Simultaneous CHKTx appears feasible, if hemodynamics is satisfactory. This approach expands the selection criteria for transplantation in patients with coexisting end-stage cardiac and renal disease.

Rational approaches to the design of cationic gemini surfactants for gene delivery

We report a new class of amphiphilic gemini surfactants as vehicles for gene delivery into cells, and the beginnings of a systematic structure-activity study. Preliminary results suggest that combining gemini surfactants with dioleoylphosphatidylethanolamine (DOPE) should allow the preparation of liposomes of various sizes and lipid compositions. Control of such colloidal changes could be as significant as the changes in the molecular composition of the gemini surfactants in delivering optimum gene expression in animal models.

Intracranial arteriovenous malformations: real-time auto-triggered elliptic centric-ordered 3D gadolinium-enhanced MR angiography--initial assessment

Auto-triggered elliptic centric-ordered three-dimensional (3D) gadolinium-enhanced magnetic resonance (MR) angiography was compared with 3D multiple overlapping thin-slab acquisition time-of-flight (TOF) MR angiography in the evaluation of intracranial arteriovenous malformations (AVMs) in 10 patients. Intraarterial digital subtraction angiography (DSA) was the reference standard. Gadolinium-enhanced MR angiograms were found to be equivalent to DSA images in AVM component depiction in 70%--90% of cases and were consistently superior to TOF MR angiograms.

Withdrawal of peripheral vasodilators in primary care

AIMS

To investigate the use of peripheral vasodilators in selected practices in primary care and to observe the effect of withdrawing therapy in a sample of patients.

METHODS

Patients receiving repeat prescriptions for peripheral vasodilators, identified from two practices in Grampian, were interviewed prior to and following withdrawal of therapy.

RESULTS

Of the 35 patients, review of the continued need for therapy was documented in the medical notes of only one patient. Treatment was successfully withdrawn from 17 patients, generating considerable savings.

CONCLUSIONS

Review of peripheral vasodilators merits further attention in larger numbers of patients.

Bone loss and fracture after lung transplantation

BACKGROUND

Osteoporosis is very common in patients with end-stage pulmonary disease. However, there are few prospective data on fracture incidence after lung transplantation.

METHODS

We prospectively evaluated changes in bone mass, fracture incidence, and biochemical indices of bone and mineral metabolism in 30 patients who completed 1 year of observation after lung transplantation. All received calcium, vitamin D, and therapy with one or more agents that inhibit bone resorption, initiated shortly after transplantation.

RESULTS

Before transplantation, only 20% of the patients had normal lumbar spine (LS) and femoral neck bone mineral density (BMD). After transplantation, 15 patients (50%) sustained significant bone loss at either the LS (-8.6+/-1.0%) or the femoral neck (-11.3+/-2.2%). Eleven (37%) patients (10 women) sustained a total of 54 atraumatic fractures. Pretransplantation LS BMD and T scores were significantly lower in those who sustained fractures (-2.809+/-0.32 versus -1.569+/-0.29; P<0.01). Fracture patients were more likely to have had pretransplantation glucocorticoid therapy (chi-square 5.687; P<0.02). The duration of pretransplantation glucocorticoid therapy was also longer in fracture patients (4.9+/-0.8 versus 1.3+/-0.4 years; P<0.001). Biochemical markers of bone resorption were significantly higher in patients who sustained bone loss and/or fractures.

CONCLUSIONS

We conclude that fractures are a significant problem in the first year after lung transplantation, even in patients who receive therapy to prevent bone loss. Women with low pretransplantation BMD and a history of pretransplantation glucocorticoid therapy are at greatest risk.

Declination angle and its role in selecting surgical telescopes

BACKGROUND

Clinicians usually expect manufacturers to provide properly adjusted surgical telescope products. However, to ensure optimal selection and adjustment, the clinician must understand certain contributing factors, particularly the optical declination angle.

METHODS

The authors have developed a simple, stepwise approach for determining a clinician's optimal working posture and declination angle. This information is then applied to each specific surgical telescope to assist the clinician in ascertaining whether the telescopes comply, or can be made to comply, with the individual needs of the clinician.

RESULTS

After the optimal working posture and declination angle have been identified and defined, any surgical magnification system can be evaluated for suitability and proper adjustment.

CONCLUSIONS

Declination angle is a key feature in the selection and adjustment of surgical telescope systems, permitting telescopes to be adjusted to meet the clinician's needs instead of forcing the clinician to make compromises to fit the telescopes.

CLINICAL IMPLICATIONS

Properly selected and well-adjusted surgical telescopes can enhance dental operating postures and positions, resulting in sound clinical ergonomics. Poor selection and adjustment can result in poor postures and positions.

Why children with inflammatory bowel disease are diagnosed at a younger age than their affected parent

BACKGROUND

Genetic anticipation has been proposed to explain observed age differences at diagnosis of Crohn's disease in affected parents and offspring.

AIMS

To compare affected parent-child pairs with Crohn's disease and ulcerative colitis with a control group of non-familial patients with inflammatory bowel disease (IBD) in order to quantify whether ascertainment bias could account for this effect.

METHODS

137 affected parent-child pairs from 96 families and 214 patients with sporadic IBD were studied. Age at onset of symptoms and diagnosis were ascertained by interview and disease confirmed from clinical records.

RESULTS

Of the 137 affected parent-child pairs, 50 had Crohn's disease only, 51 had ulcerative colitis only, and in 36, one had Crohn's disease and the other ulcerative colitis. The median age of parents at diagnosis was 17.5 years older, 16 years older, and 18 years older in the Crohn's disease, ulcerative colitis, and mixed disease families respectively (p<0.001 in each case). These observed age differences were compatible with those predicted from the regression lines of years of birth against age at diagnosis for the non-familial IBD patients. No evidence was found for an effect of parental sex on age at diagnosis or disease extent in offspring.

CONCLUSIONS

There was no evidence of genetic anticipation or genomic imprinting of age at diagnosis in this sample of IBD families. Ascertainment bias is responsible for the age differences at diagnosis between affected parents and children.

Salvage by volume reduction of chronic allograft rejection in emphysema

BACKGROUND

We hypothesized that native lung volume reduction surgery (LVRS) would improve respiratory function in patients who had previously undergone single lung transplantation for emphysema and who were disabled by obliterative bronchiolitis.

METHODS

Seven single lung transplant recipients who had advanced bronchiolitis obliterans syndrome (BOS grade 3b), absence of active infection, and suitable anatomy underwent native LVRS. Mean time from lung transplantation to LVRS was 39 +/- 17 months.

RESULTS

Mean FEV1 rose from 684 +/- 164 ml before LVRS to 949 +/- 219 ml at 3 months after LVRS, an increment of 40% (p = .002). Mean 6-minute walk rose from 781 +/- 526 ft before LVRS to 887 +/- 539 ft at 3 months after LVRS (p = .031), and mean dyspnea index declined from 3.1 +/- 1.1 before LVRS to 1.6 +/- 0.5 at 3 months after LVRS (p = .010). Mean native lung volume declined from 2956 +/- 648 ml before LVRS to 2541 +/- 621 ml at 3 months after LVRS, but the change was not statistically significant (p = .12). Mean transplant lung volume was little changed before and after LVRS (2099 +/- 411 ml and 1931 +/- 607 ml, respectively, p = NS). There was also a trend toward increased ventilation and perfusion of the native lung and reduction in ventilation and perfusion of the transplant lung, but these changes did not achieve statistical significance. By six months after LVRS, three patients died (two as a consequence respiratory failure), and survivors began to show evidence of deteriorating spirometry.

CONCLUSIONS

LVRS is capable of salvaging respiratory function in chronic allograft rejection in emphysema by reducing native lung hyperinflation. These benefits, however, appear to be limited in magnitude and duration by the severity of the underlying allograft dysfunction.

Immunohistochemical localization of calmodulin-dependent cyclic phosphodiesterase in the human brain

The amplification of cyclic nucleotide 'second messenger' signals within neurons is controlled by phosphodiesterases which are responsible for their degradation. Calmodulin-dependent phosphodiesterase (CaMPDE) is an abundant enzyme in brain which carries out this function. For the first time, we have localized CaMPDE in the normal human brain at various ages, using a mononoclonal antibody designated A6. This antibody was generated using standard techniques, purified, and applied to tissue sections. Autopsy specimens of human brain with no neuropathological abnormalities were selected representing a range of pre- and postnatal ages. Sections of various brain regions were evaluated for immunoreactivity, graded as nil, equivocal, or definite. We demonstrated definite CaMPDE immunohistochemical staining in neocortex, especially in neurons in layers 2 and 5. There was definite neuronal immunoreactivity in the hippocampus, and in the subiculum. The striatum had definite patchy neuronal staining. Definite terminal staining in the globus pallidus externa and substantia nigra pars reticulata outlined resident neurons, interpreted as axonal terminal staining. Cerebellar Purkinje cells showed definite immunoreactivity. In the developing brain, definite immunohistochemical staining was seen in the cerebellar external granular layer. The expression of CaMPDE in specific subsets of neurons suggests they may correlate with cells having dopaminergic innervation and/or high levels of neuronal integration.

Preliminary experience with mycophenolate mofetil used after lung transplantation

This study reports our preliminary experience with mycophenolate mofetil (MMF)-based immune suppression after lung transplantation. Thirteen patients (group 1) received MMF as primary therapy immediately after transplantation. Use of MMF was associated with a linearized rate of 0.85 episodes of acute rejection per 100 patient days during the first 3 months after transplantation, as compared with rates of 1.49 and 1.38, observed in two groups of historical control subjects (p = .094 and p = .053, respectively). Rejection rates after the first 3 months were not lower than in historical control subjects. Nine additional patients were switched from azathioprine to MMF because of recurrent episodes of high-grade acute rejection (group 2). In this group, the linearized rate of acute rejection episodes declined significantly (p = .004) after initiation of MMF therapy. These data suggest a potential role for MMF in reducing the rate of acute rejection episodes after lung transplantation.

Bone mass and vitamin D deficiency in adults with advanced cystic fibrosis lung disease

Osteoporosis and fractures are increasingly recognized in children and adults with cystic fibrosis. To investigate the prevalence and pathogenesis of osteoporosis and low bone mass in adults with advanced pulmonary disease due to cystic fibrosis, we examined the relationships between bone mineral density (BMD), anthropomorphic variables, pulmonary status, glucocorticoid therapy, and vitamin D concentrations. BMD of the lumbar spine, hip, and proximal radius was measured by dual energy X-ray absorptiometry in 30 white adults (16 women), age 30 +/- 2 yr (mean +/- SEM). Compared with a normal control population, the patients had significantly reduced BMD at the lumbar spine (17 +/- 3%), total hip and femoral neck (24 +/- 3% and 20 +/- 4%, respectively). The radius was significantly less demineralized (4 +/- 2%; p <= 0.003) than the other sites. Moreover, only 21% of patients with cystic fibrosis had normal BMD (T score > -1.0) at the lumbar spine, 23% at the hip sites, and 39% at the radius. Age, weight, and body mass index (BMI) were most strongly correlated with bone mass, whereas glucocorticoid therapy and pulmonary function were not predictive. Despite oral vitamin D (400 to 800 IU daily), the mean serum 25-hydroxyvitamin D (25-OHD) concentration was at the low end of the normal range (16 +/- 2 ng/ml; normal 10 to 52 ng/ml); 8 of 20 patients (40%) had frankly low (<= 10 ng/ml) levels. BMD was significantly lower in patients with low 25-OHD concentrations at the lumbar spine (0.774 +/- 0.02 versus 0.913 +/- 0.04 g/cm2; p = 0.01) and total hip (0.648 +/- 0.04 versus 0.811 +/- 0.04 g/cm2; p = 0.01). Vertebral fractures were present in 19% of subjects and 41% had a confirmed history of previous fracture. In summary, osteoporosis, low bone mass, and fractures are common in adults with advanced cystic fibrosis lung disease. Despite oral supplements, vitamin D deficiency is also common and is associated with more severe demineralization at the lumbar spine and hip. We conclude that the widespread practice of oral supplementation with 400 to 800 units of vitamin D is ineffective in maintaining normal vitamin D stores in many patients with cystic fibrosis. To ensure adequacy of vitamin D stores, measurement of serum 25-OHD should be included in the routine management of patients with cystic fibrosis.

Mismatches at the HLA-DR and HLA-B loci are risk factors for acute rejection after lung transplantation

Early high-grade acute rejections (pathologic grade A2 or A3) in recipients of lung allografts are a major risk factor for the subsequent development of obliterative bronchiolitis (OB). We analyzed the risk factors for high-grade acute rejections in 152 recipients of single (100) or bilateral (52) lung allografts transplanted at our institution between 1990 and 1996. Using Kaplan-Meier product limit estimate analysis, there was a 50% probability of grade A2 or A3 rejection by 1 yr after transplant. By univariate analysis, the only significant predictor of early high-grade rejections was the presence of one or more mismatches at the HLA-DR locus (p = 0.038). This association was confirmed using the Cox proportional hazards model for multivariable analysis, with HLA-DR locus mismatch being the only risk factor identified for high-grade rejection (p = 0.036). Using repeated rejection analysis, recipients with one or more matches at the HLA-DR locus had a lower cumulative rate of grade A2 or A3 rejections during the first year compared with recipients with no matches at the HLA-DR locus (0.73 versus 1.32). In addition, recipients with one or more HLA-B locus matches had a lower cumulative rate of grade A2 or A3 rejections in the first year than did recipients with no matches at the HLA-B locus (0.59 versus 1.30). These results indicate that mismatches between donors and recipients at the HLA-DR and HLA-B loci are important risk factors for early high-grade rejections after lung transplantation. Immunosuppressive protocols that are more effective in preventing recipient T-cell activation by donor alloantigens are likely to reduce the rate of high-grade acute rejections in recipients of lung transplants, and may directly impact on the time to onset of OB.

Experience of non-fatal overdose among heroin users in Adelaide, Australia: circumstances and risk perceptions

AIMS

To ascertain the prevalence and risk factors for non-fatal overdose among heroin users to assist in the development of an effective intervention.

DESIGN

Cross-sectional design.

SETTING

Community setting, principally metropolitan Adelaide.

PARTICIPANTS

Current heroin users (used heroin in the previous six months).

MEASUREMENTS

A structured questionnaire including the Severity of Dependence Scale.

FINDING

Of 218 current South Australian heroin users interviewed in 1996, 48% had experienced at least one non-fatal overdose their life-time (median: two overdoses), and 11% had overdosed in the previous 6 months. At some time, 70% had been present at someone else's overdose (median: three overdoses). At the time of their own most recent overdose, 52% had been using central nervous system depressants in addition to heroin, principally benzodiazepines (33%) and/or alcohol (22%). The majority of overdoses occurred in a private home (81%) and in the presence of other people (88%). Unrealistic optimism regarding the risk of overdose was evident across the sample. Despite almost half the sample reporting having had an overdose, and the belief expressed by respondents that on average about 50% of regular heroin users would overdose during their life-time 73% had, during the previous 6 months, "rarely" or "never" worried about possibly overdosing. Optimism regarding the possibility of future overdose was reduced in those with recent experience of overdose in comparison to the rest of the sample. A targeted intervention aimed at the reduction of overdose among heroin users is outlined.

Reduction in tuberculin skin-test conversions among medical house staff associated with improved tuberculosis infection control practices

OBJECTIVE

To assess the efficacy of an infection control program as measured by tuberculin skin-test (TST) conversion rates in medical house staff.

DESIGN

Observational study.

SETTING

University-based hospital in New York City serving a large indigent population.

PARTICIPANTS

Medical house staff.

INTERVENTIONS

TST conversions were measured every 6 months in medical house staff from June 1992 to June 1994. Compliance with the isolation policy was measured by identifying room locations 24 hours after admission of patients who had Mycobacterium tuberculosis recovered from respiratory specimens.

RESULTS

The TST conversion rate decreased from 5.8 to 0, 2.3, and 0 per 100 person years of exposure in successive 6-month periods. The estimated annual TST conversion rate among interns fell from 7 per 100 person years in June 1992 to 0 per 100 person years in June 1993 and 0 per 100 person years in June 1994 (P < .029). The proportion of patients with pulmonary tuberculosis who were isolated in negative-pressure rooms increased from 38% to 75% over the study period (P < .01).

CONCLUSION

Development of a multifaceted infection control program can decrease the risk of nosocomial tuberculosis infection in medical house staff.

Osteoporosis in lung transplantation candidates with end-stage pulmonary disease

PURPOSE

Fractures, a common complication of cardiac and liver transplantation, have not been reported in association with lung transplantation. However, many patients with end-stage pulmonary disease have multiple risk factors for osteoporosis, and several studies have suggested that osteoporosis before transplantation may increase the risk of fracture after transplantation. Therefore, we evaluated a group of patients with end-stage pulmonary disease who were awaiting lung transplantation to determine the prevalence of osteoporosis.

METHODS

Seventy patients (aged 18-70 years) were evaluated consecutively with bone densitometry by dual-energy x-ray absorptiometry. The patients were predominantly Caucasian (96%). Bone mass was expressed as bone mineral density (BMD; g/cm2), as the number of standard deviations (SD) below peak bone mass (T score), and as bone mineral apparent density (BMAD; g/cm3), a measurement that minimizes the effects of bone size on BMD. Spine radiographs were obtained in a subset of 50 consecutive patients to detect vertebral compression fractures. Vitamin D status was assessed with serum concentrations of 25-hydroxyvitamin D. The patients were sorted into groups by pulmonary diagnosis: chronic obstructive pulmonary disease (COPD; n = 28); cystic fibrosis (n = 11); idiopathic pulmonary fibrosis; and other lung diseases (Other; n = 31).

RESULTS

In the group as a whole, osteoporosis (T score below -2.5) was present in 30% of the patients at the lumbar spine and 49% at the femoral neck. Osteopenia (T score between -1 and -2.5) was present in an additional 35% at the lumbar spine and 31% at the femoral neck. The average femoral neck T score of patients with COPD and cystic fibrosis fell into the osteoporotic range (-2.7 +/- 0.3 and -2.6 +/- 0.3, respectively), significantly (P < 0.01) below that of the patients in the Other category (-1.5 +/- 0.3). The average lumbar spine T score fell into the osteopenic range in all three groups. Low BMAD in patients with cystic fibrosis confirmed that their low BMD was not due to their smaller body size. The prevalence rate of vertebral fractures was 29% in patients with COPD and 25% in those with cystic fibrosis. Vitamin D deficiency (25-hydroxyvitamin D levels < or = 10 ng/ml) was present in 36% of patients with cystic fibrosis and 20% with COPD and Other lung diseases. Lumbar spine BMD tended to be lower in cystic fibrosis patients with vitamin D deficiency. Patients with exposure to glucocorticoids (n = 46) had significantly more vertebral fractures (P < 0.05) and duration of exposure correlated negatively with lumbar spine BMD (r = -0.398; P = 0.008). COPD and Other patients not on glucocorticoids had mild lumbar spine osteopenia (0.972 +/- 0.06 g/cm2; T = -1.2 +/- 0.6). Very few of the patients on glucocorticoids were on any regimen to prevent osteoporosis.

CONCLUSIONS

Osteoporosis and vitamin D deficiency are extremely common in patients with end-stage pulmonary disease. Only 34% of patients had normal lumbar spine BMD and only 22% had normal BMD at the hip. Patients with cystic fibrosis and glucocorticoid-treated patients with COPD were most severely affected. Therapies to prevent bone loss and treat established osteoporosis are uncommonly utilized in glucocorticoid-treated patients with end-stage pulmonary disease. Candidates for lung transplantation should be evaluated for osteoporosis and vitamin D deficiency at the time of acceptance to the transplant waiting list.

Immunologic monitoring in lung allograft recipients

To identify patients with increased risk of chronic lung allograft rejection, we assessed the utility of an in vitro biopsy-derived lymphocyte growth assay and serum anti-HLA antibody screening as a complement to currently available methods of monitoring lung allograft recipients. Lymphocyte growth assay was performed on bronchoscopic fragments of tissue cultured in medium with rIL-2. Seventy-nine biopsies from 31 lung transplant recipients were tested by lymphocyte growth assay, and results were correlated with histopathology findings. Positive lymphocyte growth was found in 12/26 (46%) episodes of acute rejection, 5/44 biopsies without rejection (11%), and 0/9 episodes of bronchitis. Positive lymphocyte growth was seen in 7/16 (44%) grade A1 rejections and in 5/10 (50%) grade A2 rejections, as opposed to only 5/44 (11%) grade A0 (no rejection) biopsies (P < 0.01 for both A1 and A2 with respect to A0). Actuarial probability of remaining free from obliterative bronchiolitis (OB)* tended to be higher in patients who did not exhibit lymphocyte growth in biopsies. Sequential samples of sera obtained at the time of the biopsy were screened for lymphocytotoxic anti-HLA antibodies. Twenty-two of 44 recipients (50%) developed anti-HLA antibodies during the first postoperative year, exhibiting greater than 10% reactivity to an HLA reference panel of lymphocytes in four or more consecutive serum samples. Actuarial survival of lung allograft recipients with anti-HLA antibodies (n = 22) was lower than in those without anti-HLA antibodies (n = 22; P = 0.03). Of the 22 antibody producers, 7/12 died as a consequence of OB. Of the 22 non-antibody-producers, 1/2 deaths occurred as a consequence of OB. Anti-HLA antibodies were present in 9/11 instances of OB (82% sensitivity) and in 13/33 patients without OB (61% specificity; P = 0.03). These data indicate that lung transplant recipients with positive lymphocyte growth and anti-HLA antibodies are at an increased risk of chronic allograft rejection.

Gastroparesis after lung transplantation. Potential role in postoperative respiratory complications

BACKGROUND

We observed an unexpectedly high incidence of postoperative gastroparesis among lung and heart-lung transplant recipients.

PURPOSE

To identify the incidence of GI complications and to describe the clinical profiles of patients who developed symptomatic gastroparesis after lung transplantation.

PATIENTS AND METHODS

Retrospective study of GI symptoms and complications identified during 3 years of follow-up of 38 adult lung and heart-lung transplant recipients.

RESULTS

Sixteen of 38 patients (42%) reported one or more GI complaint and received a specific GI diagnosis. Nine of 38 patients (24%) complained of early satiety, epigastric fullness, anorexia, nausea, or vomiting. Gastroparesis was suspected when endoscopic evaluation revealed undigested food in the stomach after overnight fast and symptoms could not be attributed to peptide disease or cytomegalovirus gastritis. Delayed gastric emptying was confirmed by gastric scintigraphy. Mean gastric empty (t1/2) was 263 +/- 115 min (normal < 95 min). Gastroparesis occurred in 4 of 13 right lung, 2 of 12 left lung, 1 of 9 bilateral single lung, and 2 of 4 heart-lung recipients (p = NS). Patients responded partially to metoclopramide or cisapride, with the exception of two patients who required placement of jejunal feeding tubes secondary to severe symptoms. In long-term follow-up, symptoms resolved in all patients and treatment with medications or mechanical intervention was successfully discontinued. Four of nine patients (44%) suffering from gastroparesis developed obliterative bronchiolitis (OB). Food particles were discovered in the BAL fluid of two such symptomatic patients. In contrast, only 6 of 29 (21%) nonsymptomatic patients developed OB (p = 0.16).

CONCLUSION

Symptomatic gastroparesis is a frequent complication of lung or heart-lung transplantation that may promote microaspiration into the lung allograft.

Twenty-four hour ambulatory monitoring of tremor, sweating, skin temperature and locomotor activity in the alcohol withdrawal syndrome

An ambulatory monitor has been used to determine the characteristic patterns of tremor, sweating, skin temperature and locomotor activity in subjects undergoing alcohol withdrawal. Twenty-four hour records were obtained from six male subjects who had been consuming an average of 345 g of alcohol per day prior to cessation and from a group of age-matched controls. Consistent with earlier research and clinical observation, tremor, sweating and locomotor activity were elevated in withdrawal subjects. Sweating was greatest in the period from approximately 00.00 h to 06.00 h, as was skin temperature. Tremor and activity levels decreased during this period, but were considerably higher in withdrawal subjects. The data suggest that 24-h monitoring of alcohol withdrawal using objective methods provides a more sensitive assessment technique than the standard clinical approaches. The technique may be of value in other dysautonomic states.

Pharmacokinetics and metabolism of diltiazem in healthy males and females following a single oral dose

Plasma concentrations and urinary excretion of DTZ and its metabolites were determined in 20 healthy volunteers (10 males and 10 females) after they had each been given a single oral 90 mg dose of DTZ. DTZ and six of its metabolites which included N-monodesmethyl DTZ (MA), deacetyl DTZ (M1), deacetyl N-monodesmethyl DTZ (M2), deacetyl O-desmethyl DTZ (M4) and deacetyl DTZ N-oxide (M1NO) and deacetyl N,O-didesmethyl DTZ (M6), were determined by a sensitive and specific HPLC assay. The major metabolites measurable in the plasma of all the volunteers were MA, M1, and M2. The terminal half-lives (t1/2) of M1 and M2 were considerably longer than those of DTZ and MA. Less than 5% of the dose was excreted as unchanged DTZ in the urine over the 24 h period. The major urinary metabolite was MA, followed by M6, M2, and then M1. Except for the urinary excretion of M4 there were no statistically significant differences in any of the pharmacokinetic parameters between the males and the females. The mean 24 h urinary recovery of M4 was higher in the males than in the females (P < 0.05). However there were large inter-individual variations in the plasma concentrations and urinary excretion of DTZ and its metabolites with some parameters differing by more than 20-fold. In addition, O-desmethyl DTZ (Mx) and N,O-didesmethyl DTZ (MB) were identified as two other major urinary metabolites.

Hypersensitivity myocarditis in heart transplant candidates

Hypersensitivity myocarditis is a rare event; however, routine histologic examination of all (193) explanted hearts for heart transplantation in our institutions revealed hypersensitivity myocarditis in 15 patients (7%). This is a previously unreported finding in heart transplant recipients. None of the cases was detected clinically, although all manifested peripheral eosinophilia at some point during the 2 weeks before transplantation. Only one patient exhibited a skin rash interpreted as allergic. The severity of the interstitial infiltrate varied from grade I to grade IV (semiquantitative). This group of pretransplantation patients was receiving a multiplicity of drugs, some of which could have potentially triggered the hypersensitivity myocarditis, although in only one case was a definite association between a hypersensitivity reaction and a drug made. The unusually high rate (10.3% for the Emory cases) of drug-induced myocarditis in this group of patients, contrasted with the general autopsy population, probably reflects that these patients received more vigorous than usual drug treatment, particularly antibiotics, to sustain them until a suitable donor was found.

Getting the "feel" of it: the non-visual component of dimensional accuracy during operative tooth preparation

The purpose of this study was to determine what portion of a dentist's dimensional accuracy in the use of the high-speed rotary handpiece for operative tooth preparation can be attributed to visual control during the preparation. Dental students in a performance simulation laboratory recorded an 87.5 per cent handpiece control accuracy during a maxillary occlusal preparation, using normal intraoral mirror vision. When visual contact was eliminated during preparation, the accuracy declined only 13 per cent, to 74.5 per cent. The results of this study lend support to the development and use of dental clinical simulations and approaches which encourage proprioceptive and other non-visual skills, in addition to visual skills, during preclinical and clinical dental education.

Sexual function and mental distress status of patients with end-stage renal disease on hemodialysis

There were changes in the sexual functioning of the patient with ESRD after starting hemodialysis. This was marked by decrease in the sex urge, the frequency of intercourse, and the level of satisfaction. The majority of the male patients reported some amount of morning erection, indicating reasons other than physiologic reasons for their sexual dysfunction. The level of mental distress was very low, and younger patients may suffer from a higher level of mental stress. Intervention through individual counseling and sex therapy may be beneficial to most of these patients.

High-performance liquid chromatographic assay of diltiazem and six of its metabolites in plasma: application to a pharmacokinetic study in healthy volunteers

A sensitive and specific reversed-phase high-performance liquid chromatographic assay for simultaneous determination of plasma concentrations of diltiazem and six of its metabolites known to occur in humans is reported. Using 2 mL of plasma, the lower limit of quantitation of the assay was less than 10 ng/mL of diltiazem and each of the metabolites, with coefficients of variation of less than 10%. The assay was successfully applied to determine the kinetics of diltiazem and its major metabolites in four healthy volunteers after each received a single 90-mg oral dose of diltiazem. In addition to the previously reported two major metabolites in humans, deacetyl diltiazem (M1) and N-monodemethyl diltiazem (MA), another previously unreported major metabolite, deacetyl N-monodemethyl diltiazem (M2), was present at comparable concentrations to M1 and MA in all four volunteers. In addition, another metabolite, deacetyl diltiazem N-oxide (M1-NO), which was previously found most abundant in urine, was also estimated in the plasma of two volunteers. Two other known human metabolites, deacetyl O-demethyl diltiazem (M4) and deacetyl N,O-didimethyl diltiazem (M6), were not detected in any of the four study subjects. The average maximum plasma concentrations of M1, M2, MA, and M1-NO were 10, 15, 26, and 13%, respectively, of the mean maximum diltiazem concentrations.

Isometric exercise in the denervated heart: a Doppler echocardiographic study

The haemodynamic responses to isometric exercise of eight recipients of orthotopic heart transplants and eight healthy controls were studied. Each performed sustained exercise at 30% of maximal voluntary contraction for three minutes on a handgrip dynamometer. Cardiac output was measured by combined Doppler and cross sectional echocardiography before exercise and every 30 seconds during and after exercise. In the controls cardiac output and blood pressure increased significantly owing to an increase in heart rate with no change in stroke volume. In the transplant group cardiac output, heart rate, and stroke volume remained unchanged throughout exercise. In contrast with its response to dynamic exercise the denervated human heart is unable to increase cardiac output during isometric exercise. The pressor response that occurs is mediated via an increase in peripheral vascular resistance.

Twenty-eight cases of human heart-lung transplantation

Between March, 1981, and August, 1985, twenty-eight heart-lung transplant operations were done in 27 patients at a single institution. 8 patients died in the perioperative period and adhesions related to previous thoracic surgery proved to be a major risk factor for postoperative haemorrhage. Obliterative bronchiolitis developed in half of the 20 long-term survivors, a mean of 11.2 months (range 2-35 months) after surgery: 4 of these patients died, 3 are functionally limited, 2 were successfully treated with corticosteroids, and the remaining patient was successfully retransplanted. The other 10 long-term survivors returned to a normal life with essentially normal pulmonary function measured at a mean of 22.6 months (range 4-42 months) after transplantation. All the surviving patients have evidence of renal impairment related to cyclosporin nephrotoxicity. The results indicate that, although heart-lung transplantation is compatible with essentially normal long-term pulmonary function, the procedure should not yet be regarded as a routine clinical intervention.