Building upon the foundational science curriculum with physiology-based grand rounds: a multi-institutional program evaluation

Introduction: Vertically integrating physiology into patient care has the potential to improve clinical reasoning. Clinical Physiology Grand Rounds (CPGR) is a case-based teaching method that brings together students from all years of medical school to focus on linking clinical presentations to core basic science concepts including anatomy, physiology, and pathophysiology. In this study, we describe the implementation of CPGR at two different institutions in the United States and assess student-reported outcomes.Methods: We survey students who participated in CPGR at Columbia University College of Physicians & Surgeons (P&S) and Medical University of South Carolina (MUSC). Subjects were queried across three domains: the benefits of attending, the impact of concept maps, and the impact of the mixed-learner environment.Results: Despite differences in session leadership and the underlying medical school curricula, conference attendees reported similar benefits at the two schools included in this study. Students overwhelmingly (92.9%) reported that remembering clinical presentations was easier when they understood the underlying physiology. They also reported gaining a true understanding of concepts that were previously memorized (87.5%). Both clinical (92.5%) and preclinical students (93.1%) valued the mixed-learner environment as a component of the conference.Discussion: By assuring a mixed-learner environment with near-peer interactions, using concept maps as a teaching tool, and rigorously linking clinical presentation and management to physiological concepts, we found that the key benefits of CPGR were replicable across different institutions, despite several local differences in how CPGR was implemented, led, and conducted.

Variation in COVID-19 Mortality Across 117 US Hospitals in High- and Low-Burden Settings

Some hospitals have faced a surge of patients with COVID-19, while others have not. We assessed whether COVID-19 burden (number of patients with COVID-19 admitted during April 2020 divided by hospital certified bed count) was associated with mortality in a large sample of US hospitals. Our study population included 14,226 patients with COVID-19 (median age 66 years, 45.2% women) at 117 hospitals, of whom 20.9% had died at 5 weeks of follow-up. At the hospital level, the observed mortality ranged from 0% to 44.4%. After adjustment for age, sex, and comorbidities, the adjusted odds ratio for in-hospital death in the highest quintile of burden was 1.46 (95% CI, 1.07-2.00) compared to all other quintiles. Still, there was large variability in outcomes, even among hospitals with a similar level of COVID-19 burden and after adjusting for age, sex, and comorbidities.

Persistent low-level viremia in HIV-1 elite controllers and relationship to immunologic parameters

BACKGROUND

Human immunodeficiency virus type 1 (HIV-1) elite controllers are able to control virus replication to levels below the limits of detection by commercial assays, but the actual level of viremia in these individuals is not well defined. Here, we quantify plasma HIV-1 RNA in elite controllers and correlate this with specific immunologic parameters.

METHODS

Plasma HIV-1 RNA levels were quantified in 90 elite controllers with use of a real time reverse-transcriptase polymerase chain reaction assay with a sensitivity of 0.2 copies/mL. HIV-1-specific immune responses and longitudinal CD4(+) T cell counts were examined.

RESULTS

The median plasma HIV-1 RNA level was 2 copies/mL (interquartile range, 0.2-14 copies/mL). A longitudinal analysis of 31 elite controllers demonstrated 2-5-fold fluctuations in viremia in the majority of individuals; 6 had persistent levels below 1 copy/mL. Viremia correlated directly with HIV-1-specific neutralizing antibodies and Western blot reactivity but not with CD8(+) T cell responses. Absolute CD4(+) T cell decrease was more common among individuals with detectable viremia (P = .04).

CONCLUSIONS

Low-level viremia is present in the majority of elite controllers and is associated with higher HIV-1-specific antibody responses. Absolute CD4(+) T cell loss is more common among viremic individuals, suggesting that even very low-level viremia has negative consequences over time.

Elite control of HIV infection: implications for vaccine design

BACKGROUND

'Elite controllers' are rare HIV-infected individuals who are able to spontaneously control HIV replication without medication, maintaining viral loads that are consistently below the limits of detection by currently available commercial assays.

OBJECTIVE

To examine studies of elite controllers that may elucidate mechanisms of HIV immune control useful in designing a vaccine.

METHODS

Recent literature on HIV controllers and studies that have evaluated aspects of viral and host immunology that correlate with viral control are examined.

RESULTS/CONCLUSIONS

Although many elements of innate and adaptive immunity are associated with control of HIV infection, the specific mechanism(s) by which elite controllers achieve control remain undefined. Ongoing studies of elite controllers, including those examining host genetic polymorphisms, should facilitate the definition of an effective HIV-specific immune response and guide vaccine design.

HLA-associated alterations in replication capacity of chimeric NL4-3 viruses carrying gag-protease from elite controllers of human immunodeficiency virus type 1

Human immunodeficiency virus type 1 (HIV-1)-infected persons who maintain plasma viral loads of <50 copies RNA/ml without treatment have been termed elite controllers (EC). Factors contributing to durable control of HIV in EC are unknown, but an HLA-dependent mechanism is suggested by overrepresentation of "protective" class I alleles, such as B*27, B*51, and B*57. Here we investigated the relative replication capacity of viruses (VRC) obtained from EC (n = 54) compared to those from chronic progressors (CP; n = 41) by constructing chimeric viruses using patient-derived gag-protease sequences amplified from plasma HIV RNA and inserted into an NL4-3 backbone. The chimeric viruses generated from EC displayed lower VRC than did viruses from CP (P < 0.0001). HLA-B*57 was associated with lower VRC (P = 0.0002) than were other alleles in both EC and CP groups. Chimeric viruses from B*57(+) EC (n = 18) demonstrated lower VRC than did viruses from B*57(+) CP (n = 8, P = 0.0245). Differences in VRC between EC and CP were also observed for viruses obtained from individuals expressing no described "protective" alleles (P = 0.0065). Intriguingly, two common HLA alleles, A*02 and B*07, were associated with higher VRC (P = 0.0140 and 0.0097, respectively), and there was no difference in VRC between EC and CP sharing these common HLA alleles. These findings indicate that cytotoxic T-lymphocyte (CTL) selection pressure on gag-protease alters VRC, and HIV-specific CTLs inducing escape mutations with fitness costs in this region may be important for strict viremia control in EC of HIV.

Revising expectations from rapid HIV tests in the emergency department

BACKGROUND

Expanded HIV screening efforts in the United States have increased the use of rapid HIV tests in emergency departments. The reported sensitivity and specificity of rapid HIV tests exceed 99%.

OBJECTIVE

To assess whether a reactive rapid oral HIV test result correctly identifies adults with HIV infection in the emergency department.

DESIGN

Diagnostic test performance assessment within the framework of a randomized, clinical trial.

SETTING

Brigham and Women's Hospital emergency department (Boston, Massachusetts) from 7 February to 1 October 2007.

PATIENTS

849 adults with valid rapid oral HIV test results.

INTERVENTION

Rapid HIV testing with the OraQuick ADVANCE Rapid HIV-1/2 Antibody Test (OraSure Technologies, Bethlehem, Pennsylvania). Patients with reactive rapid test results were offered enzyme-linked immunoassay, Western blot, and plasma HIV-1 RNA testing for confirmation.

MEASUREMENTS

Specificity and positive likelihood ratio.

RESULTS

39 patients had reactive results (4.6% [95% CI, 3.2% to 6.0%]). On confirmation, 5 patients were HIV-infected (prevalence, 0.6% [CI, 0.1% to 1.1%]) and 26 were non-HIV-infected (8 patients declined confirmation). The estimated rapid test specificity was 96.9% (CI, 95.7% to 98.1%). Sensitivity analyses of the true HIV status of unconfirmed cases and test sensitivity resulted in a positive likelihood ratio of 8 to 32. Western blot alone as a confirmation test provided conclusive HIV status in only 50.0% (CI, 30.8% to 69.2%) of patients at first follow-up. The addition of HIV-1 RNA testing to the confirmation protocol improved this rate to 96.2% (CI, 88.8% to 100.0%).

LIMITATION

Test sensitivity cannot be assessed because nonreactive OraQuick test results were not confirmed.

CONCLUSION

Although patients with a reactive oral OraQuick HIV screening test in the emergency department had an 8- to 32-fold increased odds of HIV infection compared with the pretest odds, the specificity of the test was lower than anticipated.

Combined N- and C-terminal truncation of human apolipoprotein A-I yields a folded, functional central domain

A combined N- and C-terminal truncation variant of human apolipoprotein A-I (apoA-I) was designed, expressed in Escherichia coli, isolated, and characterized. Hydrodynamic experiments yielded a weight average molecular weight of 34000, indicating apoA-I-(44-186) exists in solution predominantly as a dimer. An axial ratio of 4.2 was calculated for the dimer based on sedimentation velocity experiments. Far-UV circular dichroism spectroscopy of apoA-I-(44-186) in buffer indicated the presence of 65% alpha-helix secondary structure. Guanidine hydrochloride denaturation experiments yielded a transition midpoint of 0.5 M for apoA-I-(44-186). ApoA-I-(44-186) induced solubilization of dimyristoylphosphatidylcholine vesicles at a rate comparable to that of full-length apoA-I, displayed lipoprotein binding ability, and was an acceptor of ABCA1-mediated cholesterol efflux from cultured macrophages. Fluorescence quenching studies with KI indicate that the three Trp residues in apoA-I-(44-186) are shielded from the aqueous environment. Taken together, the data indicate that lipid-free apoA-I-(44-186) adopts a folded conformation in solution that possesses lipid binding capability. The central region of apoA-I appears to adopt a globular amphipathic alpha-helix bundle organization that is stabilized by intramolecular and/or intermolecular helix-helix interactions. Lipid association likely results in a conformational adaptation wherein helix-helix contacts are substituted for helix-lipid interactions.

Superior vena cava syndrome and tracheal obstruction due to multinodular goiter

Tracheal obstruction and superior vena cava (SVC) syndrome are rare complications of retrosternal goiter. These two conditions present a difficult diagnostic and therapeutic challenge. Malignancy is the most common cause of SVC syndrome. Determining whether SVC syndrome is due to a benign or malignant process is imperative before instituting treatment, but this determination may be difficult. We present a case of a patient presenting with upper airway obstruction and SVC syndrome with a large mediastinal mass. The mass was determined to be a multinodular goiter. The patient was managed by surgical removal of the goiter with complete resolution of symptoms. This case illustrates the need for careful preoperative evaluation and the importance of establishing a histologic diagnosis prior to initiating treatment for SVC syndrome.

The treatment of papillary and follicular carcinoma of the thyroid

The treatment of patients with differentiated carcinoma of the thyroid is a controversial subject. This article discusses the authors' approach in the clinical practice. A description of the various types of papillary and follicular carcinoma is presented. Diagnostic tests, biologic behavior, and management are reviewed.

Synchronous unilateral parotid neoplasms of different histologic types

Synchronous parotid neoplasms are rare. Unilateral, synchronous neoplasms of two separate and histologically distinct types are extremely unusual. Our review of the literature revealed 31 previously reported cases. We add two additional cases found in 291 parotid neoplasms seen in our institutions over the last 10 years; both including a pleomorphic adenoma and a Warthin's tumor. This combination was found in 15 of 33 cases, while Warthin's tumors were found in association with another tumor in 24 of 33 reported cases (82%).

Pleomorphic adenoma manifesting as aural polyp. Report of a case

We report the sixth known case of a pleomorphic adenoma of the external auditory canal. It manifested as an aural polyp, and the diagnosis was made only after microscopic pathologic examination. Complete removal was accomplished after a total parotidectomy (with preservation of the facial nerve) provided access to the parapharyngeal space surrounding the internal carotid artery, where it is postulated that the tumor originated. A thorough knowledge of the developmental anatomy of this area greatly enhances operative success.