Publications
Department of Medicine faculty members published more than 3,600 peer-reviewed articles in 2024.
2015
IMPORTANCE
With an aging population, preoperative assessment of the frail older adult requires evaluation beyond simply accounting for chronic diseases. Impaired cognition is a recognized characteristic of the frail older adult.
OBJECTIVE
To examine the effect of preoperative impaired sensorium (IS) on general surgical outcomes.
DESIGN, SETTING, AND PARTICIPANTS
Retrospective cohort study using data between January 2005 and December 2010 at academic and community hospitals participating in the American College of Surgeons National Surgical Quality Improvement Program. Patients undergoing nonemergent general surgical operations were studied. Multivariable logistic regression involving 45 preoperative patient-level risk factors and comorbidities was used to calculate the conditional probability of having IS. Patients having and not having preoperative IS were matched on their propensity scores using a 1:1 greedy matching technique. Propensity score matching resulted in almost all (n = 1765) patients with IS uniquely matching to a patient without IS, resulting in a cohort size of 3530. Complication rates between patients with and without IS were compared.
MAIN OUTCOMES AND MEASURES
Rates of postoperative complications and death following nonemergent general surgical operations.
RESULTS
In total, 294 037 patients were studied, of whom 1771 (0.6%) had preoperative IS. Patients with IS were older and had more significant preoperative risk factors and comorbidities. As a result, unadjusted analysis found that 22 of 23 postoperative complications were significantly more likely to occur in patients with IS. Within the matched cohort, rates of postoperative pneumonia, ventilator dependence, progressive renal insufficiency, urinary tract infection, stroke, venous thromboembolism, and postoperative death continued to be significantly (P < .05) elevated in patients with IS.
CONCLUSIONS AND RELEVANCE
Impaired sensorium significantly increases postoperative morbidity and mortality independent of other preoperative risk factors and comorbidities following nonemergent general surgical operations. Incorporation of impaired cognitive function into routine preoperative risk assessment and decision making could be an important addition to traditional risk assessment strategies.
View on PubMed2015
BACKGROUND
The poorly healing perineal wound is a significant complication of abdominoperineal resection. The authors examined criteria for immediate flap coverage of the perineum and long-term cross-sectional surgical outcomes.
METHODS
Patients who underwent abdominoperineal resection or pelvic exenteration for anorectal cancer were retrospectively analyzed. Demographic characteristics, premorbid and oncologic data, surgical treatment, reconstruction method, and recovery were recorded. Outcomes of successful wound healing, surgical complications necessitating intervention (admission or return to the operating room), and progression to chronic wounds were assessed.
RESULTS
The authors identified 214 patients who underwent this procedure from 1995 to 2013. Forty-seven patients received pedicled flaps and had higher rates of recurrence and reoperation, active smoking, Crohn disease, human immunodeficiency virus, and anal cancers, and had higher American Joint Committee on Cancer tumor stages. Thirty-day complication rates were equivalent in the two groups. There were no complete flap losses or reconstructive failures. Perineal wound complication rates were marginally but not significantly higher in the flap group (55 percent versus 41 percent; p = 0.088). Infectious complications, readmissions for antibiotics, and operative revision were more frequent in the flap cohort. A larger proportion of the primary closure cohort developed chronic draining perineal wounds (23.3 versus 8.5 percent; p = 0.025).
CONCLUSIONS
Immediate flap coverage of the perineum was less likely to progress to a chronic draining wound, but had higher local infectious complication rates. The authors attribute this to increased comorbidity in the selected patient population, reflecting the surgical decision making in approaching these high-risk closures and ascertainment bias in diagnosis of infectious complications with multidisciplinary examination.
CLINICAL QUESTION/LEVEL OF EVIDENCE
Risk, III.
View on PubMed2015
2015
The application of recently developed sensitive, specific, culture-independent tools for identification of microbes is transforming concepts of microbial ecology, including concepts of the relationships between the vast complex populations of microbes associated with ourselves and with states of health and disease. Although most work initially focused on the community of microbes (microbiome) in the gastrointestinal tract and its relationship to gastrointestinal disease, interest has expanded to include study of the relationships of the airway microbiome to asthma and its phenotypes and to the relationships between the gastrointestinal microbiome, development of immune function, and predisposition to allergic sensitization and asthma. Here we provide our perspective on the findings of studies of differences in the airway microbiome between asthmatic patients and healthy subjects and of studies of relationships between environmental microbiota, gut microbiota, immune function, and asthma development. In addition, we provide our perspective on how these findings suggest the broad outline of a rationale for approaches involving directed manipulation of the gut and airway microbiome for the treatment and prevention of allergic asthma.
View on PubMed2014
Beta-lactam antibiotics target penicillin-binding proteins including several enzyme classes essential for bacterial cell-wall homeostasis. To better understand the functional and inhibitor-binding specificities of penicillin-binding proteins from the pathogen, Mycobacterium tuberculosis, we carried out structural and phylogenetic analysis of two predicted D,D-carboxypeptidases, Rv2911 and Rv3330. Optimization of Rv2911 for crystallization using directed evolution and the GFP folding reporter method yielded a soluble quadruple mutant. Structures of optimized Rv2911 bound to phenylmethylsulfonyl fluoride and Rv3330 bound to meropenem show that, in contrast to the nonspecific inhibitor, meropenem forms an extended interaction with the enzyme along a conserved surface. Phylogenetic analysis shows that Rv2911 and Rv3330 belong to different clades that emerged in Actinobacteria and are not represented in model organisms such as Escherichia coli and Bacillus subtilis. Clade-specific adaptations allow these enzymes to fulfill distinct physiological roles despite strict conservation of core catalytic residues. The characteristic differences include potential protein-protein interaction surfaces and specificity-determining residues surrounding the catalytic site. Overall, these structural insights lay the groundwork to develop improved beta-lactam therapeutics for tuberculosis.
View on PubMed2014
2014
2014
2014
BACKGROUND
Few data exist on the use of text messaging as a tool to promote retention in HIV care and virologic suppression at the clinic level in the United States. We describe the protocol for a study designed to investigate whether a text messaging intervention that supports healthy behaviors, encourages consistent engagement with care, and promotes antiretroviral persistence can improve retention in care and virologic suppression among patients in an urban safety-net HIV clinic in San Francisco.
METHODS/DESIGN
Connect4Care (C4C) is a single-site, randomized year-long study of text message appointment reminders vs. text message appointment reminders plus thrice-weekly supportive, informational, and motivational text messages. Eligible consenting patients are allocated 1:1 to the two arms within strata defined by HIV diagnosis within the past 12 months (i.e. "newly diagnosed") vs. earlier. Study participants must receive primary care at the San Francisco General Hospital HIV clinic, speak English, possess a cell phone and be willing to send/receive up to 25 text messages per month, a have viral load >200 copies/μL, and be either new to the clinic or have a history of poor retention. The primary efficacy outcome is virologic suppression at 12 months and the key secondary outcome, which will also be examined as a mediator of the primary outcome, is retention in HIV care, as operationalized by kept and missed primary care visits. Process outcomes include text message response rate and percent of time in study without cell phone service. Generalized estimating equation log-binomial models will be used for intent to treat, per protocol, and mediation analyses. An assessment of the cost and cost-effectiveness of the intervention is planned along with a qualitative evaluation of the intervention.
DISCUSSION
Findings from this study will provide valuable information about the use of behavioral-theory based text messaging to promote retention in HIV care and virologic suppression, further elucidate the challenges of using texting technology with marginalized urban populations, and help guide the development of new mobile health strategies to improve HIV care cascade outcomes.
TRIAL REGISTRATION
NCT01917994.
View on PubMed