The effect of prophylactic penicillin treatment on the course of arthritis episodes in patients with Behçet's disease. A randomized clinical trial

Objective. Because exposure to streptococcal antigens might be a major disease activity—provoking factor in Behçet's disease, this study was undertaken to evaluate the effectiveness of benzathine penicillin in the prophylaxis of recurrent arthritis episodes during the course of this disease. Methods. A prospective, randomized study design was used to allocate patients to receive colchicine alone or colchicine plus benzathine penicillin for 24 months. Results. The duration, severity, and pattern of arthritis episodes were found to be similar in the 2 treatment groups, but the number of arthritis episodes was significantly reduced, and the duration of episode-free time significantly prolonged, in the penicillin group compared with the colchicine-alone group. Conclusion. Penicillin treatment was demonstrated to offer adjunctive benefits in the prevention of arthritis episodes which are not obtainable with colchicine monotherapy. This finding could provide additional evidence for antigen triggering in the pathogenesis of Behçet's disease.     

Recommendations for Hepatitis B Immunoglobulin and Antiviral Prophylaxis Against Hepatitis B Recurrence After Liver Transplantation

The combination of hepatitis B immunoglobulin and potent nucleos(t)ide analogs after liver transplantation is considered as the standard of care for prophylaxis against hepatitis B virus recurrence. However, the recommended doses, route of administration, and duration of HBIG administration remain unclear. Moreover, hepatitis B immunoglobulin-free prophylaxis with potent nucleos(t)ide analogs has shown promising disease outcomes in preventing hepatitis B virus recurrence. The current recommendations, produced by the Turkish Association for the Study of the Liver, Acute Liver Failure and Liver Transplantation Special Interest Group, suggest a reduced need for hepatitis B immunoglobulin administration with effective long-term suppression of hepatitis B virus replication using potent nucleos(t)ide analogs after liver transplantation.     

A proposed unified interphase nucleus chromosome structure: Preliminary preponderance of evidence

Cryoelectron tomography of the cell nucleus using scanning transmission electron microscopy and deconvolution processing technology has highlighted a large-scale, 100- to 300-nm interphase chromosome structure, which is present throughout the nucleus. This study further documents and analyzes these chromosome structures. The paper is divided into four parts: 1) evidence (preliminary) for a unified interphase chromosome structure; 2) a proposed unified interphase chromosome architecture; 3) organization as chromosome territories (e.g., fitting the 46 human chromosomes into a 10-μm-diameter nucleus); and 4) structure unification into a polytene chromosome architecture and lampbrush chromosomes. Finally, the paper concludes with a living light microscopy cell study showing that the G1 nucleus contains very similar structures throughout. The main finding is that this chromosome structure appears to coil the 11-nm nucleosome fiber into a defined hollow structure, analogous to a Slinky helical spring [https://en.wikipedia.org/wiki/Slinky; motif used in Bowerman et al., eLife 10, e65587 (2021)]. This Slinky architecture can be used to build chromosome territories, extended to the polytene chromosome structure, as well as to the structure of lampbrush chromosomes.

A recent publication introduced iterative deconvolution for scanning transmission electron microscopy (TEM) tomograms of cryopreserved cellular structures (ref. 1 and references therein). Micron-thick areas of the vitrified cells were accessible without prior cryosectioning or lamella preparation. The deconvolution computation simplified interpretation of the tomograms by substantially filling the missing wedges of information that result from incomplete tilts. The effect was a substantial improvement in resolution along the depth (Z) direction. This technology made it possible to assess a tomogram from an area of the nucleus intact, in which large-scale interphase chromosome structures were noted (1).Here, the chromosome structures observed in these nuclear tomograms are further documented and analyzed. This paper is divided into four parts. The first part presents the evidence, preliminary but compelling, for a unified interphase chromosome structure. The second part presents the proposed unified interphase chromosome architecture. The third part shows that this interphase chromosome structure could be further organized as chromosome territories: for example, by fitting the 46 human chromosomes into a 10-μm-diameter nucleus. The fourth part unifies this structure into a polytene chromosome architecture and lampbrush chromosomes. The paper concludes with a living light microscopy cell study showing that the G1 nucleus has very similar structures throughout this organelle.The interphase nucleus encloses the genomic DNA, as well as the machinery for regulation of gene expression, RNA synthesis, and DNA replication (2). DNA is packaged into chromatin, the in vivo structure of which remains unclear. While mitotic chromosomes are highly condensed, interphase chromosomes decondense but remain in distinct territories with little overlap. Interphase chromatin is organized in a number of ways, including immutable gene-rich and -poor domains in the primary sequence and expression-promoting or -suppressing regions that may vary during the cell cycle or reflect cell differentiation (2). A classic distinction is drawn between euchromatin and heterochromatin, with the former more “open” and prone to expression, while the latter is more “closed” and prone to silencing (but see ref. 3). However, different methods, such as fluorescence and electron microscopy (EM), or posttranslational histone modifications, are sensitive to different parameters and do not necessarily agree in their identification.The predominant model to describe the path of the DNA strand in the interphase nucleus is the constrained random walk (4) or fractal globule (5, 6). At prophase, the dispersed polymers must recondense without entangling. During mitosis, the space-filling interphase chromatin condenses into a compact micrometer-sized structure. The degree of order in these structures remains undefined.The double-stranded DNA polymer itself, which in isolation appears as a semiflexible, right-hand helix 2 nm in diameter, winds tightly around core histones to form nucleosomes. Each nucleosome has a DNA footprint of 146 base pairs and a geometric diameter of ∼11 nm (7–9). Nucleosomes appear as beads on a string, but the density and spacing of nucleosomes along the DNA sequence may be highly variable (10). In the next stage, the nucleosomes are supposed to coil up into a 30-nm filament, possibly as a tight solenoid or alternatively with a zig-zag structure (11, 12). Today, the 30-nm filament is largely considered an artifact (13, 14). It has been observed in vitro, in isolated or ruptured nuclei, and in cases of deliberate manipulation of divalent cation concentration, but not in intact nuclei (13–15).Current insights into chromatin structure arise primarily from methods based on sequencing. With a number of significant variations, chromatin is cross-linked, cleaved, captured, and sequenced in order to determine which sequences lie in close proximity (5, 16). These methods have revealed a genetic structure of chromosome territories at the largest scale, active and inactive compartments at the multimega base level, followed by topologically associated domains (also known as TADs) whose regulation is controlled concomitantly even if they appear to be distant in sequence (16, 17). An overall, three-dimensional (3D) spatial map of the genome can be generated from the proximity constraints. Extension of the methods to analysis of individual cells revealed a strong heterogeneity, however, making it difficult to connect proximity data to local structure.Microscopy offers the most direct observations of structure, but specimen preparation may be disruptive. Classic EM requires fixation, followed by solvent-based dehydration and impregnation with a hardening polymer. Heavy metal salts are added to generate image contrast based on electron scattering; the indirect nature makes it difficult to interpret apparent density in terms of molecular composition (18). This limitation was circumvented by electron spectroscopic imaging, which distinguishes protein from nucleic acid on the basis of nitrogen and phosphorus concentrations (19). A recent advance used a DNA-binding dye to induce a localized polymerization of diaminobenzidine, which in turn binds an osmium stain (15). A modest density difference between euchromatin and heterochromatin was found, but no evidence was seen for long-range order (15). Fluorescence microscopy has made great advances with the introduction of superresolution methods. The combination with in situ hybridization permits even a degree of sequencing in situ. Still, long exposures and biochemical manipulations require strong cross-linking, which necessarily influences local structure. Cryoelectron tomography offers the most direct and pristine view of cellular structure, including chromatin, but conventional TEM requires thin sectioning or lamella fabrication using the focused ion beam microscope.Cryoscanning transmission electron tomography is a new addition to the toolkit of cellular imaging techniques. The most obvious advantages in relation to conventional defocus phase-contrast TEM are the ability to accommodate thicker specimens and the quantitative contrast based on electron scattering cross-sections. As implemented for cellular tomography, it provides: 1) a unipolar optical transfer function with the specimen in focus, 2) a long depth of field, and most importantly, 3) strong contrast for low spatial frequencies (20). We have recently demonstrated the application of cryoscanning transmission electron tomography in combination with 3D iterative deconvolution processing to whole-cell tomography and obtained a view of the cell nucleus that revealed unexpected large-scale structures (1).Data Considerations and Their Complexity.The primary data for this paper have considerably different attributes, such as the close-spaced 3D pixels with subtle gray level differences and textures, requiring new ways to display its details and architecture. This is a common problem for various imaging technologies (e.g., cellular cryoelectron tomography and MRI). The usual methods to visualize 3D data, such as moving up and down in the Z-dimension through two-dimensional (2D) slices, do not adequately show 3D relationships. Therefore, we propose the extensive use of stereo with extensions to circumvent this problem. Evidence for the chromosome structure is presented primarily in 3D stereo movies of various kinds (Movie S1 and rocking angular stereo pairs A to C′ presented in Movies S2–S8). Visualization guidance and challenges for the stereo movies are also discussed in depth in SI Appendix.     

Semirigid thoracoscopy in the diagnosis of pleural effusion: first four cases in Turkey

Medical thoracoscopy is a valuable tool in the management and investigation of pleural diseases. It has advantages when compared to conventional closed pleural biopsy and video-assisted thoracoscopic surgery. However, the use of this technique is limited in Turkey. The present report is about the first experience with semi-rigid thoracoscope that was implemented in our country. Four patients underwent medical thoracoscopy in September 2009 with the new device. All patients were referred due to non-diagnostic closed pleural biopsy. The use of the device was simple and fabulous views were obtained. All biopsy specimens of the 4 patients were histologically adequate. Definite diagnosis was enabled in 3 of the 4 patients when clinical features and CT findings combined with thoracoscopic specimens. The design is similar to the fiberoptic bronchoscope, respiratory physicians can easily adapt to its use. It is also compatible with most video operating systems and light sources used in endoscopy suites. The convenient use and compatibility with most endoscopic systems are raising the importance of the device. However, biopsy size from semirigid thoracoscope might cause diagnostic difficulty when compared to rigid thoracoscope.     

Long-term results of the application of solvent-dehydrated bone xenograft and duramater xenograft for the healing of oroantral osseous defects: a pilot experimental study

Abstract –  The aim of this study was to investigate the long-term effects of the use of human cadaveric solvent-dehydrated bone graft and duramater as a barrier membrane for the treatment of oroantral communication. Standard oroantral osseous defects were created in five minipigs. Subjects received cancellous bone graft in the form of block or microchips, duramater or a combination of bone and membrane. Uneventful healing was achieved in all of the subjects, clinically including the control site which did not receive any material. The operated bone segments were evaluated both by radiological and histological examinations after 6 months. Radiological evaluation was carried out using bone density analysis software and histological evaluation made by light microscopy. Radiological and histological results revealed that bone grafting of oroantral osseous defects improved the bone quality. However, application of duramater did not change this activity, both alone or combined with bone grafts. Within the limits of this experimental study, although solvent-dehydrated bone grafts were found superior and could be applied for the healing of osseous oroantral defects, resorbable membranes did not contribute to this process.     

The importance of cyclin D1 and Ki67 expression on the biological behavior of pancreatic adenocarcinomas

The aim of this study was to evaluate the role of cyclin D1 and Ki67 proteins involved in cell-cycle control as a prognostic factor in pancreatic carcinomas. We examined formalin-fixed, paraffin-embedded material from 59 pancreatic adenocarcinomas, for which appropriate clinical and prognostic data were available. The standard streptavidin biotin immunoperoxidase method was used for immunostaining with cyclin D1 and Ki67. The extent of positive nuclear and cytoplasmic cyclin D1 staining was graded semiquantitatively. Ki67 reactivity was quantified and expressed as the percentage of stained nuclei. Staining with cyclin D1 and Ki67 was compared with histopathological prognostic features, and their relation with survival was also tested statistically. Patients whose tumors were cyclin D1-positive showed perineural invasion significantly more frequently than did patients with cyclin D1-negative tumors at the immunohistochemical level. In addition, tumors with lymphatic vessel invasion and without showed a significant difference in terms of cytoplasmic cyclin D1 staining. Ki67 indices were statistically different in stage groups. There was a significant and direct correlation between Ki67 index and nuclear cyclin D1 staining scores. No relation with survival was found. Our results suggest that cell-cycle proteins do not directly affect the prognosis of patients with pancreatic adenocarcinoma. Conversely, cyclin D1-positive tumors tend to have perineural invasion more frequently. In addition, lymph vessel invasion is another factor related to cyclin D1 reactivity of the cells. Ki67 indices differ statistically in stage groups.     

Immunohistochemical detection of pS2 protein and heat shock protein-70 in pancreatic adenocarcinomas. Relationship with disease extent and patient survival

We investigated pS2 and HSP-70 protein expression in 36 pancreatic adenocarcinomas for their effect on disease extent and patient outcome. The cases were reviewed, histologically diagnosed, typed, graded, and staged. Lymphatic vessel, blood vessel and perineural invasion as well as lymph node, resection margin and adjacent organ involvements were re-evaluated. The standard streptavidin biotin immunperoxidase method was used for immunostaining with pS2 and HSP-70 antibodies. Cytoplasmic staining with both antibodies was scored semiquantitatively. The scores were compared with histopathological prognostic parameters using statistical methods. Standard prognostic parameters and staining scores were tested by survival analysis in terms of their effect on survival. All the tumors showed a positive cytoplasmic reaction with HSP-70 antibody. Seventy-seven percent of the tumors showed positive cytoplasmic staining with pS2 antibody (22.2% +, 13.9% ++ and 41.7% +++). There was a statistically significant difference between HSP-70 staining scores with N status and final stages of the tumors (Chi-square, p = 0.03 and p = 0.026, respectively), while neither direct nor inverse correlation was detected for both parameters. PS2 staining scores showed no statistically significant relationship with tumor grade T, M status, perineural invasion, lymph and blood vessel invasion. In tumors with extensive staining with pS2, tumor stage tended to be low (Chi square, p = 0.024, Kendall Tau-b, r: -0.336, p = 0.036). There was a statistically significant difference and inverse correlation between tumors with extensive pS2 staining and tumors with less intense staining in terms of lymph node metastasis (Chi-square, p = 0.041, Kendall Tau: p = 0.024, r = -0,373). In the R0 resection group, in univariate analysis, we found that with higher scores of HSP-70 staining, the prognosis of the patient tended to improve. (Cox regression, p = 0.013). In multivariate analysis, HSP-70 expression was found to be an independent prognostic factor. We found no relationship between pS2 staining and patient survival.     

Effects of whole blood, crystalloid, and colloid resuscitation of hemorrhagic shock on renal damage in rats: an ultrastructural study

Purpose:

The aim of this study was to determine the effects of whole blood, crystalloid, and colloid treatment on histopathologic damage of kidney induced by hemorrhagic shock in rats.

Methods:

Fifty-six male Sprague Dawley rats were divided into 8 groups. The carotid artery was cannulated, and systolic arterial pressure (SAP), diastolic arterial pressure (DAP), heart rate (HR), and rectal temperature (RT) were observed during the procedure. The jugular vein also was cannulated, and the SAP was decreased by aspiration of 75% of blood through the jugular vein in the control (nonresuscitated) and study (resuscitated) groups, whereas blood was not diminished in the sham group. The hemorrhagic shock was permitted to last 45 minutes; then, the study group rats were resuscitated with heparinized shed autologous whole blood (WB), normal saline (NS), Lactated Ringer’s solution (LR), hydroxyethyl starch 6% (HES6), hydroxyethyl starch 10% (HES10), or dextran 40 (D40). Histopathologic evaluation was performed under light and electron microscope.

Results:

The RT, SAP, and DAP decreased, and HR increased significantly in the control and study groups during the shock period compared with those of sham group. After volume resuscitation, these parameters changed to preshock levels. Electron and light microscopic examinations of kidneys showed severe proximal tubular degeneration with moderate glomerular damage in the control group; moderate proximal tubular degeneration with mild glomerular damage in the NS, LR, HES6, and HES10 groups; and mild proximal tubular degeneration with no evidence of glomerular damage in the WB and D-40 groups.

Conclusions:

The characteristic ultrastructural features of hemorrhagic shock appear to be severe tubular degeneration and mild to moderate changes in glomeruli. Resuscitation of hemorrhagic shock with whole blood or dextran 40 solution appears to be most favorable therapy in preventing ultrastructural renal damage in rats.     

Invasive staging of superior mediastinum in non-small cell lung cancer patients with specific indications

This prospective study was done between February 2001 and December 2002 on 84 non-small cell lung cancer patients who were apparently operable. We selectively performed mediastinoscopy to 46 patients (54.76%, group 1) with the following indications: clinical T4 tumor, high operative risk, radiologically enlarged mediastinal lymph nodes, clinical T3 tumors with central location, radiologically identified mediastinal lymph nodes of any size with adeno or large cell carcinoma histology. Other 38 patients (45.23%, group 2) underwent thoracotomy without mediastinoscopy. Sensitivity, specificity, negative predictive value and positive predictive value of the indications were calculated. Cost analysis was done in the 84 patients and the results were compared with alternative mediastinal staging strategies (vs. routine, and vs. selectively to patients with radiologically positive mediastinal lymph nodes) if they had been applied to our population. Group 1 had higher selectivity to differentiate N2 patients (p=0.02). Sensitivity, specificity, negative predictive value and positive predictive value of indications were calculated as: 0.85, 0.54, 0.92 and 0.36, respectively. Our approach was most economical in terms of total cost per patient and money spent unnecessarily per patient. Mediastinal evaluation in operable lung cancer patients should decrease the number of surgical procedures, N2 disease found at thoracotomy and cost.