The effect of distal arterial anatomy on the success of popliteal aneurysm repair

The success of bypass grafting for popliteal aneurysms may be compromised by the natural history of these lesions. During a 9-year period 35 patients had repair of 48 popliteal aneurysms. Elective repair was performed in 26 limbs and the remaining 22 limbs required urgent or emergent treatment after aneurysm thrombosis (16) or embolic digital ischemia (six). Retrospective review of preoperative and intraoperative arteriograms and CT or ultrasound scans was done to define the relationship of distal runoff anatomy to initial symptoms and long-term grafting success during a mean follow-up of 48 months. Only five of 48 limbs (10%) had three continuous tibial vessels and a patent pedal arch. Twenty-six limbs (55%) had one or no named calf vessels and 11 limbs had incomplete pedal arches. When thrombosis or symptomatic embolism occurred, the anatomy was significantly worse; 15 of 22 such limbs (68%) had one or no patent tibial vessels and seven had incomplete pedal arches. Nineteen of 28 aneurysms examined by CT or ultrasound scanning showed intraluminal thrombus. Eight of 13 patent aneurysms with intraluminal thrombus had one or no patent tibial vessels. The 5-year graft patency rate was 74% for the entire study group. Bypass for repair of asymptomatic aneurysms had a patency rate of 91% at 5 years vs 54% for symptomatic patients (p less than 0.05). Patients with popliteal aneurysms often have advanced tibial disease that appears worse in those with symptoms. The occurrence of a patent popliteal aneurysm with intraluminal thrombus and advanced runoff disease suggests that chronic microembolism may be an etiologic factor in the tibial disease observed.(ABSTRACT TRUNCATED AT 250 WORDS)     

Outcome of long-term ribavirin therapy for recurrent hepatitis C after liver transplantation.

Ribavirin therapy was initiated at a median of 181 days after liver transplantation in 18 patients with persistent elevation of alanine aminotransferase values and biopsy-proven hepatitis, and continued for 23 months (12-44 months). All patients had a prompt biochemical response, with alanine aminotransferase decreasing by 69%; complete normalization occurred in 5 (28%). Serum hepatitis C virus RNA levels did not change during therapy. Liver biopsies obtained after 17 months (9-38 months) of therapy showed no improvement in necroinflammation. However, worsening of fibrosis occurred in 12 patients; and cirrhosis developed in 5 patients (28%), with 3 patients progressing to graft failure. Biopsies from 27 untreated patients who did not fulfill treatment criteria (median follow-up, 38 months) and 4 patients who received 3 months of ribavirin (44 months) showed cirrhosis in 11 and 75%, respectively. Patient and graft survival rates for treated and untreated patients were similar. Although ribavirin improves alanine aminotransferase, it does not prevent the development or progression of fibrosis in patients with recurrent hepatitis C virus.     

Resource conservation as a strategy for community psychology

Conservation of resources (COR) theory (Hobfoll, 1988, 1989) was applied to social intervention and research. COR theory depicts resource loss as disproportionately weighted in comparison to resource gain. COR theory further posits that to prevent resource loss or establish resources, other resources must be invested. Resources contribute to further resource gain, whereas lack of resources contributes to ongoing resource loss. Consequently, people, groups, or organizations that are endowed with strong personal or social resource reserves should better resist the deleterious effects of stress and withstand everyday challenges. One of the basic principles of the theory—that loss is disproportionately weighted compared to gain—was tested in two samples and strongly supported. Implications of the model for intervention were discussed.     

Transmission and Progression to Disease of Mycobacterium tuberculosis Phylogenetic Lineages in The Netherlands

The aim of this study was to determine if mycobacterial lineages affect infection risk, clustering, and disease progression among Mycobacterium tuberculosis cases in The Netherlands. Multivariate negative binomial regression models adjusted for patient-related factors and stratified by patient ethnicity were used to determine the association between phylogenetic lineages and infectivity (mean number of positive contacts around each patient) and clustering (as defined by number of secondary cases within 2 years after diagnosis of an index case sharing the same fingerprint) indices. An estimate of progression to disease by each risk factor was calculated as a bootstrapped risk ratio of the clustering index by the infectivity index. Compared to the Euro-American reference, Mycobacterium africanum showed significantly lower infectivity and clustering indices in the foreign-born population, while Mycobacterium bovis showed significantly lower infectivity and clustering indices in the native population. Significantly lower infectivity was also observed for the East African Indian lineage in the foreign-born population. Smear positivity was a significant risk factor for increased infectivity and increased clustering. Estimates of progression to disease were significantly associated with age, sputum-smear status, and behavioral risk factors, such as alcohol and intravenous drug abuse, but not with phylogenetic lineages. In conclusion, we found evidence of a bacteriological factor influencing indicators of a strain''s transmissibility, namely, a decreased ability to infect and a lower clustering index in ancient phylogenetic lineages compared to their modern counterparts. Confirmation of these findings via follow-up studies using tuberculin skin test conversion data should have important implications on M. tuberculosis control efforts.     

A major deletion in the cucumber mitochondrial genome sorts with the MSC phenotype

The cucumber mitochondrial genome is unique because of its large size, paternal transmission, and the existence of a paternally transmitted mosaic (MSC) phenotype spontaneously appearing after independent tissue culture experiments. Transmission studies eliminated paternal imprinting as the genetic basis for the MSC phenotype. We identified a 13 kb region (JLV5-DEL) in the wild-type mitochondrial genome that was absent from three MSC lines. This deleted region was paternally transmitted with the MSC phenotype through the F3 and test-cross generations. Southern hybridizations and PCR amplifications using primers within the JLV5 region revealed that rare wild-type sorters possessed the wild-type region. MSC plants possess the wild-type region at levels (approximately 0.002) below detection by standard PCR reactions and Southern hybridizations, using genomic DNA. Sequence analysis of the wild-type contig revealed no homologies to mitochondrial genes and no open reading frames within JLV5-DEL. PCR amplifications across JLV5-DEL using MSC mtDNA revealed that the loss of this region was not a simple deletion and may be associated with a rearrangement. Because no genic regions were identified within the wild-type JLV5 region, the specific lesion conditioning the MSC phenotype may be associated with the putative rearrangement or another mutation that occurred during tissue culture or exists substoichiometrically in the parental line and is transmitted together with JLV5 within the same mitochondrion.     

Efficacy of immunotherapy with combination of cryotherapy and topical imiquimod for treatment of Kaposi sarcoma

Multiple treatment modalities for Kaposi sarcoma (KS) have been reported, including chemotherapy, radiation therapy, surgical excision, electrochemotherapy, and cryotherapy. Common topical treatments include timolol, imiquimod, and alitretinoin. We searched our institutional database for patients with ICD-9 or 10 codes for KS seen by a dermatologist with experience in KS management from July 1, 2004 to January 1, 2022. We screened patient charts to include patients who received combination therapy of cryotherapy followed by topical imiquimod three times a week for 2 months (n = 9). Patients were followed in the clinic every 3 months. Time to resolution was assessed by photographic evidence of resolution as determined by a dermatologist and corroborated with clinical documentation in patient charts. Median age (IQR) at KS diagnosis was 58 (27.5) years. All patients were male (n = 9, 100%). Majority were white (n = 7, 78%) and non-Hispanic (n = 8, 89%). Five (56%) had classic KS, one (11%) had HIV-associated KS, and three (33%) were HIV-negative men who have sex with men. Median time to resolution was 30.5 weeks, with a median of two treatments. In our study, 93% (n = 42/45) of lesions and 89% (n = 8/9) of patients experienced complete resolution during a median (range) duration of follow-up of 58 (13–209) weeks. Side effects were limited to pain during cryotherapy, occasional blister formation after cryotherapy, and mild inflammation due to imiquimod. No infections were observed. Combination therapy of cryotherapy and topical imiquimod may be an efficacious and comparatively low-risk treatment for limited, cutaneous KS.     

Exploration of High- and Low-Frequency Options for Subperception Spinal Cord Stimulation Using Neural Dosing Parameter Relationships: The HALO Study

ObjectivesSubperception spinal cord stimulation (SCS) is described mostly utilizing waveforms that require high energy. However, the necessity of these waveforms for effective subperception has not been established. We aimed to explore whether effective subperception pain relief can be achieved using frequencies below 1 kHz.Materials and MethodsThirty chronic pain patients implanted with SCS were enrolled as part of a multicenter, real-world, consecutive, observational case series. An effective stimulation location was determined using a novel electric field shape designed to preferentially modulate dorsal horn elements. Subsequently, programs at lower frequencies (600, 400, 200, 100, 50, and 10 Hz) were provided with pulse-width and amplitude adjusted to optimize response.ResultsAll tested frequencies (1 kHz down to 10 Hz) provided effective subperception relief, yielding a mean of 66–72% reduction in back, leg, and overall pain. It was found that to maintain analgesia, as frequency was decreased, the electrical or “neural” dose had to be adjusted according to parameter relationships described herein. With the reduction of frequency, we observed a net reduction of charge-per-second, which enabled energy savings of 74% (200 Hz) and 97% (10 Hz) relative to 1 kHz. Furthermore, pain reduction was sustained out to one year, with 85% of patients reporting a preference for frequencies of 400 Hz or below.ConclusionsWe have derived an electric field configuration and, along with previous learnings in the kHz range, a set of neural dosing parameter relationships (10–10,000 Hz), which enable the expansion of effective subperception SCS to low frequency and achieve major energy savings.