Explant of an infected, endo-trashed IVC filter in an immunosuppressed patient with chronically occluded iliocaval stents.

BACKGROUND: In the absence of a contiguous bowel perforation or intraabdominal source, infection of a retained vena cava filter in an occluded IVC has never been described. OBJECTIVE: To describe a case of an infected IVC filter in a chronically occluded iliocaval segment. METHODS: Here we present a case of an immunosuppressed 35-year-old female with chronically occluded iliocaval stents and an extensive staphylococcus hominis infection of a previously endo-trashed Bard Eclipse® filter. Particular attention is paid to supportive imaging in establishing the diagnosis and technical aspects of successful device explant and retroperitoneal debridement. RESULTS: At 6 months postoperatively, the patient was doing well without evidence of recurrent infection. Her lower extremity edema was controlled with compression alone. CONCLUSIONS: The main objective of this operation was source control with debridement of the infection and removal of the filter and as much of the iliac vein as safely possible. Superinfection of a previously placed iliocaval stents and inferior vena cava filter remains a concern in patients with retroperitoneal infection and chronic iliocaval occlusion. Operative explant and debridement can be safely performed in patients with favorable cardiopulmonary risk.

Complement activity and complement regulatory gene mutations are associated with thrombosis in APS and CAPS.

The antiphospholipid syndrome (APS) is characterized by thrombosis and/or pregnancy morbidity in the presence of antiphospholipid antibodies, including anti-ß2-glycoprotein-I (anti-ß2GPI), that are considered central to APS pathogenesis. Based on animal studies showing a role of complement in APS-related clinical events, we used the modified Ham (mHam) assay (complement-dependent cell killing) and cell-surface deposition of C5b-9 to test the hypothesis that complement activation is associated with thrombotic events in APS. A positive mHam (and corresponding C5b-9 deposition) were present in 85.7% of catastrophic APS (CAPS), 35.6% of APS (and 68.5% of samples collected within 1 year of thrombosis), and only 6.8% of systemic lupus erythematosus (SLE) sera. A positive mHam assay was associated with triple positivity (for lupus anticoagulant, anticardiolipin, and anti-ß2GPI antibodies) and recurrent thrombosis. Patient-derived anti-ß2GPI antibodies also induced C5b-9 deposition, which was blocked completely by an anti-C5 monoclonal antibody, but not by a factor D inhibitor, indicating that complement activation by anti-ß2GPI antibodies occurs primarily through the classical complement pathway. Finally, patients with CAPS have high rates of rare germline variants in complement regulatory genes (60%), compared with patients with APS (21.8%) or SLE (28.6%) or normal controls (23.3%), and have mutations at a rate similar to that of patients with atypical hemolytic uremic syndrome (51.5%). Taken together, our data suggest that anti-ß2GPI antibodies activate complement and contribute to thrombosis in APS, whereas patients with CAPS have underlying mutations in complement regulatory genes that serve as a "second hit," leading to uncontrolled complement activation and a more severe thrombotic phenotype.

Targeting viral dsRNA for antiviral prophylaxis.

Double-stranded (ds)RNA in the infected cells is a trait shared by most if not all viruses. While humans have developed variable immune responses, viruses have also developed countermeasures to defeat dsRNA-induced antiviral strategies. Thus, we proposed a broad antiviral strategy to antagonize the countermeasures of viruses and bypass the dsRNA-induced signals that are readily defeated by viruses. By rewiring the dsRNA-binding proteins in the dsRNA complex and reconnecting them to apoptosis signaling, we created several dsRNA-dependent caspase recruiters, termed dsCAREs, to bypass dsRNA-induced antiviral signals that would otherwise be targeted by viruses. Adenovirus and vesicular stomatitis virus, representing viruses of the dsDNA and negative-stranded RNA viral groups, were used to infect HEK293 cells. The dsCARE chimera was added in medium to evaluate its antiviral activity. The truncated dsCAREs were used as controls. We demonstrate that dsCARE suppresses viral infection starting at 0.1 µg/ml and reaches the peak at 2 µg/ml. The EC(50) was ∼0.2 µg/ml. However, it had an undetectable effect on uninfected cells. Further data show that both dsRNA binding and apoptosis activation of dsCARE are essential for its antiviral activity. We conclude that dsRNA is a practical virus-associated molecular pattern that can be targeted for broad and rapid antiviral prophylaxis.

Empowering Medical Students to Respond to Discriminatory Comments from Patients: A Just-in-Time Training Method.

This article was migrated. The article was marked as recommended. Physicians in training may experience harassment and discrimination from supervisors, consultants, colleagues, or patients and families. Instances of discrimination towards students may impact students' self-esteem, self-efficacy, and ultimately performance. In this particular time, many institutions are looking to enhance their curriculum regarding bias. More tools are needed to help students feel empowered to respond professionally when they encounter challenging situations. This study was designed to assess the impact of a training intervention in addressing biased patient statements. The training was strategically placed prior to clinical interactions. The authors' intention was to present discriminatory statements by patients as one of the many difficult clinical situations that students are being trained to navigate. The authors developed a clinical rubric for decision-making in flowchart style to mimic the decision trees used in diagnostic or treatment decisions. They then created a workshop to help learners use the flowsheet. The workshop was delivered to third-year medical students as part of "Junior Bootcamp," a day-long session of events to orient students to the clinical experiences of the M3 year. The workshop was delivered in the summer of 2019. Respondents indicated that they were more likely to be able to appropriately respond to discriminatory comments after completing the workshop. They also felt that they were more likely to be able to engage in respectful dialogue with a patient and to debrief with a faculty member. Fewer participants felt that they were likely to use the flowchart. Findings indicate that the workshop was useful to participants. It may be especially useful to educators dealing with the COVID pandemic because it is scalable and easily delivered remotely. Further studies are needed to determine if introducing this topic in the clinical years of medical school leads to improved skill in addressing instances of bias that come from patients and families.

Significance of the amyloidogenic transthyretin Val 122 Ile allele in African Americans in the Arteriosclerosis Risk in Communities (ARIC) and Cardiovascular Health (CHS) Studies.

BACKGROUND: Many African Americans carry an amyloidogenic transthyretin mutation (TTR V122I), with a high risk for cardiac TTR amyloid deposition after the age of 65 years. We wished to determine the allele frequency and its clinical penetrance in community-dwelling African Americans. METHODS: Five thousand consenting African Americans, aged 41 to 93 years, in 2 community studies of cardiovascular risk (CHS and ARIC) were included in the study. The following were performed: genotyping of banked DNA for TTR V122I allele status and review of cardiovascular and demographic parameters in CHS and ARIC databases, with statistical comparisons of the frequency of congestive heart failure, survival, and occurrence of features of cardiac amyloidosis in carriers of the amyloidogenic allele and controls. RESULTS: One hundred nineteen (3.23%) of 3,712 ARIC and 17 (2.12%) of 805 CHS African Americans carried TTR V122I. After the age of 65 years (CHS), the frequencies of congestive heart failure (38% vs 15%, relative risk 2.62, P = .04) and mortality (76% vs 53%, relative risk 1.46, P = .08) were higher in V122I allele carriers than in age-, gender- and ethnically matched controls. In ARIC (all subjects <65 years old), there were no differences between carriers and noncarriers in mortality, frequency of congestive heart failure, or findings consistent with cardiac amyloidosis. CONCLUSIONS: Heterozygosity for the amyloidogenic TTR V122I mutation is relatively common in community-dwelling African Americans. Before the age of 65 years, the allele has no discernible impact on cardiac function or mortality. After the age of 70 years, carriers show a higher frequency of congestive failure and greater mortality with more echocardiographic evidence suggestive of cardiac amyloidosis, findings consistent with age-dependent clinical penetrance of this autosomal dominant gene.

Open-source system for millisecond-synchronized continuous video-EEG.

The causes of epilepsy are incompletely understood, and rodent models enable valuable mechanistic investigations. Synchronized video-electroencephalography (video-EEG) data is critical for clinical assessment of seizure events and is similarly important in basic research on epilepsy, but commercial packages offer limited flexibility and are costly. We've developed and here make freely available OpenVEEG, fully open-source software for millisecond-synchronized video-EEG. With only hardware costs, the system price is approximately one-fifth that of a commercial system with similar capabilities. It is straightforward to use, readily extensible, and records robustly on the time scale of weeks.

Chronic lymphocytic leukemia with prostate infiltration mediated by specific clonal membrane-bound IgM.

Chronic lymphocytic leukemia (CLL) is characterized by an accumulation of monoclonal B lymphocytes in the hematopoietic organs. Rarely, CLL cells accumulate in a single atypical site. The mechanism underlying this unusual distribution of CLL cells has not been studied previously. We obtained peripheral blood from five patients having early stage CLL with heavy prostate infiltration. These patients' circulating CLL cells bound strongly in vitro to cultured prostate cell lines PC3, LNCaP, and DU145 and to short-term cultures of fresh prostate cells but not to colon, breast, or bladder cells. CLL cells from patients without prostate infiltration did not bind in vitro to any cell line. Peripheral blood CLL cells from one patient with CLL with heavy prostate infiltration were fused with a mouse-human heteromyeloma line to make hybridomas expressing the same monoclonal IgM as the patient's CLL cells. The hybridoma cells bound specifically to prostate cells. IgM secreted by the hybridoma blocked binding of the patient's CLL cells to prostate cells. Flow cytometry and immunohistochemistry demonstrated that the secreted IgM bound specifically to prostate cells. These results indicate that CLL with atypical prostate infiltration can be mediated by specific surface-bound IgM against an antigen expressed specifically by prostate cells and suggest that a similar mechanism might also apply to cases of CLL with atypical infiltration into other organs.

Hypertension and Chronic Kidney Disease in Primary Care.

INTRODUCTION: TBL enables a group of learners to engage in independent preparation through prereadings, check their knowledge with readiness assessments, and both share and build on their personal experience with each topic through robust small-group discussions. This TBL exercise uses case-based questions to enable learners to make a treatment plan for challenging cases of hypertension and to manage chronic kidney disease (CKD) in the primary care setting. METHODS: This module serves as part of a series of team-based learning (TBL) modules in an internal medicine residency ambulatory medicine curriculum. The modules are delivered during the didactic half-days of the ambulatory week of our 3 + 1 block schedule. This particular module takes approximately 90 minutes to deliver and is intended to be moderated by an experienced primary care clinician. RESULTS: Learners who participated in this TBL felt that it increased their knowledge about hypertension and CKD; they gave it an average rating of 4.67/5 (n = 30). DISCUSSION: TBL has been heavily utilized in undergraduate medical education, and we have adapted the method to use it with small groups of resident physicians. It may also be suitable for other learners who will be responsible for the treatment of hypertension and CKD in the primary care setting (e.g., family medicine residents, advanced practice nurses, and physician assistants).

The prevalence and distribution of the amyloidogenic transthyretin (TTR) V122I allele in Africa.

BACKGROUND: Transthyretin (TTR) pV142I (rs76992529-A) is one of the 113 variants in the human TTR gene associated with systemic amyloidosis. It results from a G to A transition at a CG dinucleotide in the codon for amino acid 122 of the mature protein (TTR V122I). The allele frequency is 0.0173 in African Americans. METHODS: PCR-based assays to genotype 2767 DNA samples obtained from participants in genetic studies from various African populations supplemented with sequencing data from 529 samples within the 1000 Genomes Project. RESULTS: The rs76992529-A variant allele was most prevalent (allele frequency 0.0253) in the contiguous West African countries of Sierra Leone, Guinea, Ivory Coast, Burkina Faso, Ghana, and Nigeria. In other African countries, the mean allele frequency was 0.011. CONCLUSIONS: Our data are consistent with a small number of founder carriers of the amyloidogenic TTR V122I (p.Val142Ile) allele in southern West Africa, with no apparent advantage or disadvantage of an allele carrying newborn reaching adulthood. In U.S. African Americans, the allele represents a significant risk for congestive heart failure late in life. If clinical penetrance is similar in African countries with high allele frequencies, then cardiac amyloidosis could also represent a significant cause of heart disease in the elderly in those populations.

Prevalence of the amyloidogenic transthyretin (TTR) V122I allele in 14 333 African-Americans.

BACKGROUND: Transthyretin (TTR) V122I (rs76992529) is one of 111 variants caused by point mutations in the coding sequence of the human TTR gene that are associated with systemic amyloidosis. It results from a G to A transition at a CG dinucleotide in codon 142(122 of the mature protein) of the gene and has been described almost exclusively in people of African descent. Several series have reported allele frequencies from 0.015 to 0.020 in African-Americans. OBJECTIVE: To define more accurately the frequency of the TTR V122I variant allele in the African-American population. METHODS: DNA isolated from blood spots from 1688 New York State African-American newborns was genotyped for the TTR V122I allele. We also compiled new data from the Jackson Heart Study and previously unpublished data from the Dallas Heart Study, plus data from a San Diego "wellness study", providing 15 650 additional allelotypes to those already reported. RESULTS: Among the New York newborns, the TTR V122I allele was present in 65/3376 alleles (allele prevalence 0.0193). The combined available data from all the non-selected African-American cohorts showed the TTR variant allele to be present in 451/26 062 alleles (allele prevalence of 0.0173), slightly but not significantly lower than our previously published estimates. CONCLUSIONS: The allele prevalence for TTR V122I in African-Americans is 0.0173. Of African-Americans under age 65, 3.43% carry at least one copy of the variant amyloidogenic allele.

Drop-in, drop-out allele-specific PCR: a highly sensitive, single-tube method.

Allelotyping large numbers of samples by allele-specific polymerase chain reaction (PCR) can be problematic if the DNA samples to be tested are of highly variable concentration. On the one hand, analysis of dilute DNA samples often requires nested PCR to produce a product of sufficient yield to be detectable on ethidium bromide-stained agarose gels. Such two-step assays require additional reagents, are labor-intensive, and have a higher risk of contamination. On the other hand, the specificity of allele-specific PCR assays can be lost at high input DNA concentrations. Large population-based genetic studies using DNA from varied sources would benefit from one-tube assays that could detect mutations in samples over a wide range of concentration. We describe a one-tube nested allele-specific PCR-based assay, in which the input DNA concentration has little effect on the assay's yield or specificity. An assay using this method is highly sensitive and specific, and was used to type several thousand DNA samples, obtained from various sources, for a G to A transition at human transthyretin codon 122. Similar assays could be readily adapted to any high-throughput allelotype assay where input DNA is of highly variable concentration.

The Cell Wall Teichuronic Acid Synthetase (TUAS) Is an Enzyme Complex Located in the Cytoplasmic Membrane of Micrococcus luteus.

The cell wall teichuronic acid (TUA) of Micrococcus luteus is a long-chain polysaccharide composed of disaccharide repeating units [-4-ß-D-ManNAcAp-(1→6)α-D-Glcp-1-](n), which is covalently anchored to the peptidoglycan on the inner cell wall and extended to the outer surface of the cell envelope. An enzyme complex responsible for the TUA chain biosynthesis was purified and characterized. The 440 kDa enzyme complex, named teichuronic acid synthetase (TUAS), is an octomer composed of two kinds of glycosyltransferases, Glucosyltransferase, and ManNAcA-transferase, which is capable of catalyzing the transfer of disaccharide glycosyl residues containing both glucose and the N-acetylmannosaminuronic acid residues. TUAS displays hydrophobic properties and is found primarily associated with the cytoplasmic membrane. The purified TUAS contains carotinoids and lipids. TUAS activity is diminished by phospholipase digestion. We propose that TUAS serves as a multitasking polysaccharide assembling station on the bacterial membrane.

Sentinel lymph node mapping and molecular staging in nonsmall cell lung carcinoma.

BACKGROUND: Lymph node (LN) involvement predicts recurrence in patients who have undergone resection of apparently localized nonsmall cell lung carcinoma (NSCLC). Standard detection methods for LN disease have a low sensitivity, and many patients with apparent N0 disease status develop recurrent disease. Molecular techniques can improve the detection of micrometastases, whereas sentinel lymph node (SLN) mapping can indicate which LN may contain micrometastases. These methods, although potentially complementary, have not, to the authors' knowledge, been used together previously. METHODS: The authors used SLN mapping and molecular staging to improve the detection of LN micrometastases in patients with NSCLC. Reverse transcriptase-polymerase chain reaction (RT-PCR) analysis for cytokeratin-7 (CK7), expressed both in normal lung and in malignant lung, was used to identify tumor-derived material in LN. RESULTS: SLN mapping was performed in 13 patients, with 1-3 SLNs identified in each patient, and sufficient RNA for RT-PCR was obtained in 12 of these 13 patients. Eleven of 12 tumors expressed CK7. Overall, 32 LNs were positive for CK7, including 13 of 21 SLNs. Ten of 11 patients with evaluable SLNs had at least 1 CK7-positive SLN. Routine pathology showed Stage I disease in eight patients, T3N0 disease in one patient, and LN-positive disease in two patients. Of the nine patients with N0 disease according to routine pathology that was evaluable by RT-PCR, eight patients were upstaged by this technique. All patients with positive LN status by routine pathology who were evaluable by RT-PCR analysis had positive RT-PCR results. CONCLUSIONS: LN micrometastases were common in resected NSCLC, including patients with N0 disease according to routine pathology. SLN mapping was useful for identifying disease-containing LNs. This approach may be useful for stratifying histologically N0 patients into higher risk and lower risk groups.