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The staining pattern of anti-actin sera on various cells smeared on glass was compared to the relative amount of cellular actin estimated by SDS-polyacrylamide-gel electrophoresis with subsequent scanning of the gel. Although the cells showed a varying stainability the actin content was fairly constant. Thus, the staining differences reflected changes in the organization of cellular actin rather than actual differences in the amount of actin. [ABSTRACT FROM AUTHOR]

Thirty sera reacting by IFL. technique in titres⩾ 100 with smooth muscle fibres of rat stomach, rat renal glomeruli, and with the membrane region of thyroid cells were randomly chosen among sera .sent in for routine testing of tissue antibodies. All sera but one were found to be derived from patients with chronic active hepatitis. The smooth muscle and other relevant cell staining were abolished after absorption of sera with actin, prepared from rabbit skeletal muscle and found to be homogeneous by SDS gel-electrophoresis and by electron microscopy. The actin antibodies were purified by precipitation of sera with K-actin and elution of the precipitates at acid pH. The purified antibodies stained all tissues in the same way as the original sera. In double immunudirtusion tests all thirty .sera gave precipitation with actin. Thus, it was concluded that these broad-reacting SMA are directed against actin. The finding of high-titred S.MA is of diagnostic value and supports the clinical diagnosis of active chronic hepatitis. In addition, anti-actin antibodies eluted from buman sera are a suitable tool for studying actin-containing cellular structures. [ABSTRACT FROM AUTHOR]

The importance of the dependence on single amino acids in the V3 region of HIV-1 gp120 was evaluated for virus neutralization and antibody-dependent cellular cytotoxicity (ADCC). Synthetic overlapping 15-mer peptides and a set of omission peptides covering amino acids 301-317 were used. Sera from 29 HIV-1-infected individuals at different stages of disease were tested for neutralization, ADCC and specific IgG reactivity. Six HIV-1 neutralizing monoclonal antibodies (mAb) acted as controls. All mAb reacted with a region (amino acids 304-318) of gp120, previously shown to induce neutralizing antibodies. The amino acids essential for reactivity were identified to be within the sequence GPGR (amino acids 312-315). The importance of this region for occurrence of neutralizing antibodies in infected humans was investigated using the same set of peptides. Out of 29 individuals, 21 were found to have neutralizing antibodies in titres between 100 and 1000. Among the neutralization-positive sera, 17/21 (81%) reacted with amino acids 304-318, compared with only one of eight sera (13%) negative in neutralization. When any of the four amino acids G, P, G or R were deleted, the seroreactivity decreased considerably. The conserved sequence GPGR was therefore considered to be the most important for neutralization in this region in human sera as well. Thus, the conserved sequence GPGR in the V3 region of gp120 is critical for virus neutralization by human HIV-1-specific antibodies. [ABSTRACT FROM AUTHOR]

To define the amino acids involved in IgG subclass reactivity to two overlapping HIV-1 gp41 (E34/32; amino acid positions 582-613) peptides, sera from 18 HIV-infected individuals were studied. Peptides mimicking E34 but with single amino acid deletions or glycine substitutions were used to define the amino add residues necessary for antibody binding. Two dominating immunogenic epitopes, containing highly hydrophilic amino acids, were found on the original peptide. Further analysis was undertaken with two corresponding omission sets of dodecapeptides representing halves of the complete E34 plus a terminal cystein peptide. The subclass reactivities usually differed between the patients with regard to the epitopes with which the different IgG subclasses reacted and also to the importance of different amino acids in antibody binding. The 600 glycine and the 601 lysine were involved in the binding of all IgG1,2 and 4 and most IgG3. The development of E34/32-reactive IgM and IgG subclasses showed different patterns in four patients with primary HIV infections, contradicting the existence of a general pattern for the development of IgG subclasses to this peptide. The findings suggest that different progenitor clones are selected for synthesis of the different subclasses. [ABSTRACT FROM AUTHOR]

Background: The current national burden of emergency general surgery (EGS) illnesses and the extent of surgeon involvement in the care of these patients remain largely unknown. To inform needs assessments, research, and education, we sought to: (1) translate previously developed International Classification of Diseases (ICD), 9th Revision, Clinical Modification (ICD-9-CM) diagnosis codes representing EGS conditions to ICD 10th Revision, CM (ICD-10-CM) codes and (2) determine the national burden of and assess surgeon involvement across EGS conditions., Methods: We converted ICD-9-CM codes to candidate ICD-10-CM codes using General Equivalence Mappings then iteratively refined the code list. We used National Inpatient Sample 2016 to 2017 data to develop a national estimate of the burden of EGS disease. To evaluate surgeon involvement, using Wisconsin Hospital Association discharge data (January 1, 2016 to June 30, 2018), we selected adult urgent/emergent encounters with an EGS condition as the principal diagnosis. Surgeon involvement was defined as a surgeon being either the attending provider or procedural physician., Results: Four hundred and eighty-five ICD-9-CM codes mapped to 1,696 ICD-10-CM codes. The final list contained 985 ICD-10-CM codes. Nationally, there were 2,977,843 adult patient encounters with an ICD-10-CM EGS diagnosis. Of 94,903 EGS patients in the Wisconsin Hospital Association data set, most encounters were inpatient as compared with observation (75,878 [80.0%] vs. 19,025 [20.0%]). There were 57,780 patients (60.9%) that underwent any procedure. Among all Wisconsin EGS patients, most had no surgeon involvement (64.9% [n = 61,616]). Of the seven most common EGS diagnoses, surgeon involvement was highest for appendicitis (96.0%) and biliary tract disease (77.1%). For the other five most common conditions (skin/soft tissue infections, gastrointestinal hemorrhage, intestinal obstruction/ileus, pancreatitis, diverticular disease), surgeons were involved in roughly 20% of patient care episodes., Conclusion: Surgeon involvement for EGS conditions ranges from highly likely (appendicitis) to relatively unlikely (skin/soft tissue infections). The wide range in surgeon involvement underscores the importance of multidisciplinary collaboration in the care of EGS patients., Level of Evidence: Prognostic/epidemiological, Level III., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Background: Emergency general surgery (EGS) encompasses a heterogeneous population of acutely ill patients, and standardized methods for determining disease severity are essential for comparative effectiveness research and quality improvement initiatives. The American Association for the Surgery of Trauma (AAST) has developed a grading system for the anatomic severity of 16 EGS conditions; however, little is known regarding how well these AAST EGS grades can be approximated by diagnosis codes in administrative databases., Methods: We identified adults admitted for 16 common EGS conditions in the 2012 to 2017q3 National Inpatient Sample. Disease severity strata were assigned using International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) and International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM) diagnosis codes based on AAST EGS anatomic severity grades. We evaluated whether assigned EGS severity (multiple strata or dichotomized into less versus more complex) were associated with in-hospital mortality, complications, length of stay, discharge disposition, and costs. Analyses were adjusted for age, sex, comorbidities, hospital traits, geography, and year., Results: We identified 10,886,822 EGS admissions. The number of anatomic severity strata derived from ICD-9/10-CM codes varied by EGS condition and by year. Four conditions mapped to four strata across all years. Two conditions mapped to four strata with ICD-9-CM codes but only two or three strata with ICD-10-CM codes. Others mapped to three or fewer strata. When dichotomized into less versus more complex disease, patients with more complex disease had worse outcomes across all 16 conditions. The addition of multiple strata beyond a binary measure of complex disease, however, showed inconsistent results., Conclusion: Classification of common EGS conditions according to anatomic severity is feasible with International Classification of Diseases codes. No condition mapped to five distinct severity grades, and the relationship between increasing grade and outcomes was not consistent across conditions. However, a standardized measure of severity, even if just dichotomized into less versus more complex, can inform ongoing efforts aimed at optimizing outcomes for EGS patients across the nation., Level of Evidence: Prognostic, level III., (Copyright © 2020 American Association for the Surgery of Trauma.)