Characterization and genomic analysis of the Lyme disease spirochete bacteriophage ϕBB-1.

Lyme disease is a tick-borne infection caused by the spirochete Borrelia (Borreliella) burgdorferi. Borrelia species have highly fragmented genomes composed of a linear chromosome and a constellation of linear and circular plasmids some of which are required throughout the enzootic cycle. Included in this plasmid repertoire by almost all Lyme disease spirochetes are the 32-kb circular plasmid cp32 prophages that are capable of lytic replication to produce infectious virions called ϕBB-1. While the B. burgdorferi genome contains evidence of horizontal transfer, the mechanisms of gene transfer between strains remain unclear. While we know that ϕBB-1 transduces cp32 and shuttle vector DNA during in vitro cultivation, the extent of ϕBB-1 DNA transfer is not clear. Herein, we use proteomics and long-read sequencing to further characterize ϕBB-1 virions. Our studies identified the cp32 pac region and revealed that ϕBB-1 packages linear cp32s via a headful mechanism with preferential packaging of plasmids containing the cp32 pac region. Additionally, we find ϕBB-1 packages fragments of the linear chromosome and full-length plasmids including lp54, cp26, and others. Furthermore, sequencing of ϕBB-1 packaged DNA allowed us to resolve the covalently closed hairpin telomeres for the linear B. burgdorferi chromosome and most linear plasmids in strain CA-11.2A. Collectively, our results shed light on the biology of the ubiquitous ϕBB-1 phage and further implicates ϕBB-1 in the generalized transduction of diverse genes and the maintenance of genetic diversity in Lyme disease spirochetes.

Simultaneous Hepatic and Visceral Resection: Preoperative Risk Stratification and Implications on Return to Intended Oncologic Therapy.

PURPOSE: Sequence of therapies for synchronous liver metastasis (LM) is complex, with data supporting individualized approaches, although no guiding tools are currently available. We assessed the impact of simultaneous hepatic and visceral resections (SHVR) on textbook outcome (TO) and return to intended oncologic therapy (RIOT), and provide risk-stratification tools to guide individualized decision making and counseling. METHODS: Patients with synchronous LM undergoing hepatectomy ± SHVR were included (2015-2021). Primary and secondary outcomes were TO and RIOT (days), respectively. Using multivariable modeling, a risk score for TO was developed. Decision tree analysis using recursive partitioning was performed for hierarchical risk stratification. The associations between SHVR, TO, and RIOT were examined. RESULTS: Among 533 patients identified, 124 underwent SHVR. TO overall was 71.7%; 79.2% in the non-SHVR group and 46.8% in the SHVR group (p < 0.001). SHVR was the strongest predictor of non-TO (right colon/small bowel: odds ratio [OR] 4.63, 95% confidence interval [CI] 2.65-8.08; left colon/rectum: OR 6.09, 95% CI 2.59-14.3; stomach/pancreas: OR 6.69, 95% CI 1.46-30.7; multivisceral: OR 10.9, 95% CI 3.03-39.5). A composite score was developed yielding three risk strata for TO (score 0-2: 89% vs. score 3-5: 67% vs. score ≥ 6: 37%; p < 0.001). Decision tree analysis was congruent, identifying SHVR as the most important determinant of TO. In patients with colorectal LM, SHVR was associated with delayed time to RIOT (p = 0.004); the risk-stratification tool for TO was equally predictive of RIOT (p < 0.01). CONCLUSIONS: SHVR is associated with reduced likelihood of TO and in turn delayed RIOT. As SHVR is increasingly performed in order to consolidate cancer care, patient selection considering these different outcomes is critical.

Predicting the Impact of Transforming the Medicaid Program on Health Centers' Revenues and Capacity to Serve Medically Underserved Communities.

Policy Points Recent federal proposals to use block grants or per capita caps to fund Medicaid would likely lead to cuts in Medicaid funding for health centers, which are an important source of care for Medicaid enrollees. Recent Medicaid §1115 waivers are seeking to change state-level enrollment and eligibility requirements in ways that are expected to adversely affect health center revenues. Proposed Medicaid funding cuts are expected to lead to reductions in service capacity across all health centers over the long term. State policymakers should understand the likely impacts of proposed Medicaid program changes on health centers in their states and allocate funding to help offset lost federal financing. CONTEXT: In 2017, Congress considered implementing block grants or per capita caps to significantly reduce federal financing of the Medicaid program. Medicaid plays a key role in supporting health centers in their provision of care to patients with Medicaid coverage. Consequently, changes to the program could have serious implications for health centers and their ability to fulfill their mission. METHODS: We used a mixed-methods approach to (a) test a model simulating the effect of block grants and per capita caps on health centers' total revenues and general service capacity, and (b) augment model assumptions by using information collected from official Medicaid documents and interviews with health center leadership staff. Data came from the Uniform Data Systems (UDS), state- and county-level population projections, structured analyses of waiver documents, and interviews with health center leaders in seven states with approved or pending Medicaid §1115 waivers. FINDINGS: By 2024, in states where Medicaid coverage was expanded under the Affordable Care Act, block grant funding for Medicaid would decrease total health center revenues for the expansion population by 92%, and by 58% for traditional enrollees. In nonexpansion states, block grants would decrease health center revenues for traditional Medicaid enrollees by 38%. In expansion states, a per capita cap would, by 2024, decrease health center revenues for the expansion population by 78%, and for traditional Medicaid enrollees by 3%. The per capita cap would reduce health center revenues for traditional Medicaid enrollees in nonexpansion states by 2%. Eliminating the Medicaid expansion population would not fully compensate for health center revenue deficits in expansion states. Health center executives in all sample states expressed significant uncertainty around federal plans to reduce Medicaid funding as well as the financial implications of §1115 waiver requirements. Many interviewees anticipate cutting back on services and/or staff as a result. CONCLUSIONS: Both block grants and per capita caps would have a detrimental effect on health centers. Although health center leaders anticipate a reduction in services and/or staff, the uncertainty around federal and state proposals hinders health centers from making concrete strategic plans. States should prioritize communicating changes to health centers in a timely manner and be prepared to set aside dedicated funding to address anticipated shortfalls.

Characterization and genomic analysis of the Lyme disease spirochete bacteriophage ϕBB-1.

Lyme disease is a tick-borne infection caused by the spirochete Borrelia (Borreliella) burgdorferi. Borrelia species have highly fragmented genomes composed of a linear chromosome and a constellation of linear and circular plasmids some of which are required throughout the enzootic cycle. Included in this plasmid repertoire by almost all Lyme disease spirochetes are the 32-kb circular plasmid cp32 prophages that are capable of lytic replication to produce infectious virions called ϕBB-1. While the B. burgdorferi genome contains evidence of horizontal transfer, the mechanisms of gene transfer between strains remain unclear. While we know that ϕBB-1 transduces cp32 and shuttle vector DNA during in vitro cultivation, the extent of ϕBB-1 DNA transfer is not clear. Herein, we use proteomics and long-read sequencing to further characterize ϕBB-1 virions. Our studies identified the cp32 pac region and revealed that ϕBB-1 packages linear cp32s via a headful mechanism with preferentially packaging of plasmids containing the cp32 pac region. Additionally, we find ϕBB-1 packages fragments of the linear chromosome and full-length plasmids including lp54, cp26, and others. Furthermore, sequencing of ϕBB-1 packaged DNA allowed us to resolve the covalently closed hairpin telomeres for the linear B. burgdorferi chromosome and most linear plasmids in strain CA-11.2A. Collectively, our results shed light on the biology of the ubiquitous ϕBB-1 phage and further implicates ϕBB-1 in the generalized transduction of diverse genes and the maintenance of genetic diversity in Lyme disease spirochetes.

Clockwise Anterior-to-Posterior-Double Isolation (CAP-DI) Approach for Portal Lymphadenectomy in Biliary Tract Cancer: Technique, Yield, and Outcomes.

Background: Portal lymphadenectomy (PLND) is the current standard for oncologic resection of biliary tract cancers (BTCs). However, published data show it is performed infrequently and often yields less than the recommended 6 lymph nodes. We sought to identify yield and outcomes using a Clockwise Anterior-to-Posterior technique with Double Isolation of critical structures (CAP-DI) for PLND. Methods: Consecutive patients undergoing complete PLND for BTCs using CAP-DI technique were identified (2015−2021). Lymph node (LN) yield and predictors of LN count were examined. Secondary outcomes included intraoperative and postoperative outcomes, which were compared to patients having hepatectomy without PLND. Results: In total, 534 patients were included; 71 with complete PLND (36 gallbladder cancers, 24 intrahepatic cholangiocarcinomas, 11 perihilar cholangiocarcinomas) and 463 in the control group. The median PLND yield was 5 (IQR 3−8; range 0−17) and 46% had at least 6 nodes retrieved. Older age was associated with lower likelihood of ≥6 node PLND yield (p = 0.032), which remained significant in bivariate analyses with other covariates (p < 0.05). After adjustment for operative factors, performance of complete PLND was independently associated with longer operative time (+46.4 min, p = 0.001), but no differences were observed in intraoperative or postoperative outcomes compared to the control group (p > 0.05). Conclusions: Yield following PLND frequently falls below the recommended minimum threshold of 6 nodes despite a standardized stepwise approach to complete clearance. Older age may be weakly associated with lower PLND yield. While all efforts should be made for complete node retrieval, failure to obtain 6 nodes may be an unrealistic metric of surgical quality.

Collagen XI regulates the acquisition of collagen fibril structure, organization and functional properties in tendon.

Collagen XI is a fibril-forming collagen that regulates collagen fibrillogenesis. Collagen XI is normally associated with collagen II-containing tissues such as cartilage, but it also is expressed broadly during development in collagen I-containing tissues, including tendons. The goals of this study are to define the roles of collagen XI in regulation of tendon fibrillar structure and the relationship to function. A conditional Col11a1-null mouse model was created to permit the spatial and temporal manipulation of Col11a1 expression. We hypothesize that collagen XI functions to regulate fibril assembly, organization and, therefore, tendon function. Previous work using cho mice with ablated Col11a1 alleles supported roles for collagen XI in tendon fibril assembly. Homozygous cho/cho mice have a perinatal lethal phenotype that limited the studies. To circumvent this, a conditional Col11a1flox/flox mouse model was created where exon 3 was flanked with loxP sites. Breeding with Scleraxis-Cre (Scx-Cre) mice yielded a tendon-specific Col11a1-null mouse line, Col11a1Δten/Δten. Col11a1flox/flox mice had no phenotype compared to wild type C57BL/6 mice and other control mice, e.g., Col11a1flox/flox and Scx-Cre. Col11a1flox/flox mice expressed Col11a1 mRNA at levels comparable to wild type and Scx-Cre mice. In contrast, in Col11a1Δten/Δten mice, Col11a1 mRNA expression decreased to baseline in flexor digitorum longus tendons (FDL). Collagen XI protein expression was absent in Col11a1Δten/Δten FDLs, and at ~50% in Col11a1+/Δten compared to controls. Phenotypically, Col11a1Δten/Δten mice had significantly decreased body weights (p < 0.001), grip strengths (p < 0.001), and with age developed gait impairment becoming hypomobile. In the absence of Col11a1, the tendon collagen fibrillar matrix was abnormal when analyzed using transmission electron microscopy. Reducing Col11a1 and, therefore collagen XI content, resulted in abnormal fibril structure, loss of normal fibril diameter control with a significant shift to small diameters and disrupted parallel alignment of fibrils. These alterations in matrix structure were observed in developing (day 4), maturing (day 30) and mature (day 60) mice. Altering the time of knockdown using inducible I-Col11a1-/- mice indicated that the primary regulatory foci for collagen XI was in development. In mature Col11a1Δten/Δten FDLs a significant decrease in the biomechanical properties was observed. The decrease in maximum stress and modulus suggest that fundamental differences in the material properties in the absence of Col11a1 expression underlie the mechanical deficiencies. These data demonstrate an essential role for collagen XI in regulation of tendon fibril assembly and organization occurring primarily during development.