To gain insights into the composition of the B cell repertoire, we have investigated VH gene family expression associated with individual light chains. For this purpose, we have examined the use of 12 VH gene families in a large collection of hybridomas expressing one of the four lambda light chains [lambda 1 (V1J1), lambda 2 (V2J2 and V x J2) and lambda 3 (V1J3)]. Our results show that the distribution of the VH families is very different from one lambda subtype to another. This suggests that a few substitutions between VL regions are sufficient to generate very different associated repertoires by strong selection mechanisms. Moreover, we assume that the global VH expression pattern is not random but rather composed of many preferential VH/VL associations. 相似文献
Serial cytogenetic studies have been performed in four patients with myelodysplastic syndromes. In all four a 5q- alteration was present, but with a different pattern of presentation. One patient presented 5q- as the only alteration since diagnosis; two patients acquired this alteration during the course of the disease; and the fourth showed a 5q- plus other alterations since the first cytogenetic study. Likewise, three of the four patients showed a clone with trisomy 8 and without 5q-. According to these observations and others from the literature with similar cytogenetic behavior, we have analyzed the following points: 5q- as a primary event and as the only alteration, 5q- as a secondary event, 5q- plus other alterations, and presence of cytogenetically different clones. Analysis of these points suggests that the 5q- alteration can represent an early mutation conferring a slow capacity of expansion to the affected clones, with the possibility of cytogenetic evolution during the progression of the disease (about 30% of the patients). Likewise, the association of trisomy 8 clones with 5q- clones can be a nonrandom event. 相似文献
African trypanosomes are unable to synthesize purines and depend upon purine nucleoside and nucleobase transporters to salvage these compounds from their hosts. To understand the crucial role of purine salvage in the survival of these parasites, a central objective is to identify and characterize all of the purine permeases that mediate uptake of these essential nutrients. We have cloned and functionally expressed in a purine nucleobase transport deficient strain of Saccharomyces cerevisiae a novel nucleobase transporter gene, TbNT8.1, from Trypanosoma brucei. The permease encoded by this gene mediates the uptake of hypoxanthine, adenine, guanine, and xanthine with Kms in the low micromolar range. The TbNT8.1 protein is a member of the equilibrative nucleoside transporter (ENT) family of permeases that occur in organisms as diverse as protozoa and mammals. TbNT8.1 is distinct from other ENT permeases that have been identified in trypanosomes in utilizing multiple purine nucleobases, rather than purine nucleosides, as substrates and is hence the first bona fide nucleobase permease identified in these parasites. Furthermore, unlike the mRNAs for other purine transporters, TbNT8.1 mRNA is significantly more abundant in insect stage procyclic forms than in mammalian stage bloodstream forms, and the TbNT8.1 permease thus may represent a major route for purine nucleobase uptake in procyclic trypanosomes. 相似文献
The DSM-III diagnostic criteria for schizophreniform disorder, mainly based on duration of symptoms, are insufficient to furnish a good treatment strategy. In recent literature, schizophreniform disorder has been grouped either with the schizophrenias or with the affective disorders. Scandinavian researchers have described two other groups of psychotic disorders that resemble schizophreniform disorder. These are the reactive psychosis and the cycloid psychosis. They were found to be different from the schizophrenias and the affective disorders. "Good prognosis" schizophrenia, which has been extensively studied and reported in the literature, is clinically very similar to schizophreniform disorder. The relatively consistent data collected in patients with good prognosis schizophrenia may provide the basis for the additional diagnostic criteria needed in DSM-III schizophreniform disorder. 相似文献
Severe nasal Prototheca cutis infection was diagnosed postmortem for an immunocompetent cat with respiratory signs. Pathologic examination and whole-genome sequencing identified this species of algae, and susceptibility testing determined antimicrobial resistance patterns. P. cutis infection should be a differential diagnosis for soft tissue infections of mammals. 相似文献
Background: Skeletal muscle lacerations are a relatively common injury. Compared with nonrepaired lacerations, surgically repaired muscle lacerations regenerate faster, develop less scar tissue, have a higher return to baseline strength, and have lower incidence of hematomas. Despite the benefits of repair, the optimal repair technique is still unknown. The purpose of this study was to examine the biomechanical properties of common muscle repair techniques to determine the optimal repair. Methods: Forty-two fusiform porcine muscle specimens were dissected and used for this study. Three suture techniques were used for comparative analysis: Figure-eight, Mason Allen, and Perimeter. Each muscle was transected and then repaired using one of the 3 techniques. Fourteen muscle-tendon specimens were prepared for each group and tested for tensile failure using a material testing system. Biomechanical properties, including peak failure point and stiffness, were compared for differences between the suture groups by 1-way analysis of variance. The average time per repair technique was also recorded. Results: The Perimeter technique showed a statistically significant higher peak failure point than the Mason Allen technique (P = .03). Both the Figure-eight (P = .047) and Perimeter techniques (P < .001) were significantly stiffer than the Mason Allen technique. The repair time was comparable across all 3 techniques. Conclusions: The Figure-eight and Perimeter repairs were found to be similar in peak failure point and stiffness, whereas the Mason Allen technique showed significantly lower stiffness and peak failure point. The Figure-eight was the quickest repair to perform. The Figure-eight technique may be strongly considered for muscle laceration repairs due to its simplicity and efficiency. 相似文献
Current guidelines recommend deferring liver transplantation (LT) in patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection until clinical improvement occurs and two PCR tests collected at least 24 hours apart are negative. We report a case of an 18-year-old, previously healthy African-American woman diagnosed with COVID-19, who presents with acute liver failure (ALF) requiring urgent LT in the context of SARS-CoV-2 polymerase chain reaction (PCR) positivity. The patient was thought to have acute Wilsonian crisis on the basis of hemolytic anemia, alkaline phosphatase:bilirubin ratio <4, AST:ALT ratio >2.2, elevated serum copper, and low uric acid, although an unusual presentation of COVID-19 causing ALF could not be excluded. After meeting criteria for status 1a listing, the patient underwent successful LT, despite ongoing SARS-CoV-2 PCR positivity. Remdesivir was given immediately posttransplant, and mycophenolate mofetil was withheld initially and the SARS-CoV-2 PCR test eventually became negative. Three months following transplantation, the patient has made a near-complete recovery. This case highlights that COVID-19 with SARS-CoV-2 PCR positivity may not be an absolute contraindication for transplantation in ALF. Criteria for patient selection and timing of LT amid the COVID-19 pandemic need to be validated in future studies. 相似文献
Community health workers (CHWs) serve as the linkage between community and providers and are stakeholders for bridging services to the public. However, integration of CHWs into health care organizations is often lacking. This study explored macrosystem level barriers faced by CHWs and their ability to do their jobs effectively. Using qualitative interviews from CHWs (n?=?28) in Nebraska, we used an abductive approach to derive the following themes: (1) CHWs and client macrosystem barriers, (2) CHW workforce supports, and (3) macrosystem solutions for CHW workforce sustainability. Study results also found various macrosystem barriers affecting CHW workforces including immigration policies, insurance policies, funding sources, supervisor support, and obstacles for health seeking of clients. Moreover, through the lens of CHWs, results revealed the need to provide and advocate for solutions that prioritize the needs of CHWs as they continue to fill a crucial gap in community healthcare systems.