Emergence of novel coronavirus and progress toward treatment and vaccine

In late December 2019, a group of patients was observed with pneumonia‐like symptoms that were linked with a wet market in Wuhan, China. The patients were found to have a novel coronavirus genetically related to a bat coronavirus that was termed SARS‐CoV‐2. The virus gradually spread worldwide and was declared a pandemic by WHO. Scientists have started trials on potential preventive and treatment options. Currently, there is no specific approved treatment for SARS‐CoV‐2, and various clinical trials are underway to explore better treatments. Some previously approved antiviral and other drugs have shown some in vitro activity. Here we summarize the fight against this novel coronavirus with particular focus on the different treatment options and clinical trials exploring treatment as well as work done toward development of vaccines.     

Activation of caspase-3 pathway by expression of sGalphai2 protein in BHK cells

Treatment with dopamine and other dopamine D2 receptor agonists has been shown to induce cell death through activation of caspase-3 pathway. However, initial step that leads to the activation of caspase-3 in D2 receptor-mediated apoptotic pathway remains unclear. Recently, it was shown that a spliced variant of Galphai2 protein (sGalphai2) forms intracellular complex with D2 receptors by protein-protein interaction and that D2 drugs treatment causes the liberation of sGalphai2 protein from complex. Now, we show that the unbound form of sGalphai2 protein is able to activate caspase-3 pathway in baby hamster kidney (BHK) cells. Expression of sGalphai2 protein in BHK cells led to the production of active form of caspase-3 and activation of p38 mitogen-activated protein kinase (p38 MAPK) and extracellular regulated kinase 1/2 (ERK1/2). Co-expression of sGalphai2 with either D2 short (D2S) or D2 long (D2L) isoforms of dopamine D2 receptors blocked the activation of caspase-3 pathway. Thus, our results demonstrate that high level of unbound sGalphai2 protein can affect the cell survival and engagement of this protein with D2 receptors can block this process. It is suggested that this process may be a crucial step in the initiation of D2 receptor-mediated cellular apoptosis through this pathway.     

Pemphigus Vulgaris Autoantibody Response is Linked to HLA-DQB10503 in Pakistani Patients

ABSTRACT: Pemphigus vulgaris (PV) is an autoimmune disease of the skin and mucous membranes characterized by an autoantibody response against an epidermal cadherin. We performed high resolution HLA class II typing in 19 patients with PV from Rawalpindi, Pakistan and 19 non-Jewish European PV patients from Boston by sequence-specific oligonucleotide probe hybridization. The results were compared with two separate ethnically matched control populations. We found that PV patients from Pakistan had significantly increased frequencies of DRB1*1404 ( p = 0.01), DQA1*0101 ( p = 0.02), and DQB1*0503 ( p = 0.01). Among the patients of non-Jewish European ancestry, DRB1*1401 ( p < 10⁻⁶), DQA1*0101 ( p < 10⁻⁵) and DQB1*0503 ( p < 10⁻⁶), were increased in PV patients. Formal linkage analysis between the major histocompatibility complex and the PV antibody was performed in 67 relatives of the 19 Pakistani patients. The results showed strong evidence for linkage of HLA-DRB1*1404, DQA1*0101, DQB1*0503, with the presence of PV antibody in relatives’ families with a significant logarithm of the odds score of 6.06. Based on the three dimensional structure of class II molecules, we propose that HLA-DQA1*0101 and DQB1*0503, encode a negatively charged P9 peptide binding pocket of the DQ molecule and are significantly associated with susceptibility to PV in non-Jewish populations.     

Evaluation of EDTA and fish skin extract in primary culture of fish liver cells

The isolation, primary culture and attachment of liver cells to the substratum from a tropical catfish (Heteropneustes fossilis) using ethylenediaminetetraacetic acid (EDTA) as isolating agent of liver cells and skin extract (SE) from fish as attachment substrate for the primary culture of liver cells has been standardised. A suitable temperature for such cultures has also been determined. Attachment efficiency of the liver cells in culture and their intracellular lactate dehydrogenase (LDH) activity have been taken as parameters for characterization of the primary culture. Disaggregation of liver cells with EDTA is very potent to isolate substantial rumber of cells from the liver of H. fossilis. An ideal concentration of EDTA for liver cell isolation has been standardized. Matrix prepared from carp and catfish skin at different pH (2.0, 4.0, 6.0 and 8.0) were also evaluated for liver cell culture by considering the attachment efficiency of the cells over the substratum as well as retention of intracellular LDH enzyme after 48 hours of seeding. Matrix of carp skin was compared with that of catfish as suitable substrate for primary culture of fish liver cells. It has been found that the SE prepared at pH 4.0, both from carp and catfish skin, performed better than those at other pHs. At the same time, the matrix of carp skin was found to be better than that of catfish skin. Cultures were incubated separately at 17 and 23 °C in air atmosphere. Incubation temperature at 23 °C was found to be more suitable than that at 17 °C. The percent of detached/unattached cells showed only marginal variation between two temperatures but LDH-activity recorded drastic reduction (between 50 to 75%) depending upon the pH of the matrix during preparation. Our finding establishes despensibility of enzyme (collagenase/trypsin) for cell isolation in catfish. Our studies also exhibit that carp skin extract performs better than catfish skin extract in terms of attachment efficiency as well as intracellular LDH activity. This study indicates that no species/generic barrier exists in matrix between catfish and carp.     

Thymosin alpha 1: A comprehensive review of the literature

Thymosin alpha 1 is a peptide naturally occurring in the thymus that has long been recognized for modifying, enhancing, and restoring immune function. Thymosin alpha 1 has been utilized in the treatment of immunocompromised states and malignancies, as an enhancer of vaccine response, and as a means of curbing morbidity and mortality in sepsis and numerous infections. Studies have postulated that thymosin alpha 1 could help improve the outcome in severely ill corona virus disease 2019 patients by repairing damage caused by overactivation of lymphocytic immunity and how thymosin alpha 1 could prevent the excessive activation of T cells. In this review, we discuss key literature on the background knowledge and current clinical uses of thymosin alpha 1. Considering the known biochemical properties including antibacterial and antiviral properties, time-honored applications, and the new promising findings regarding the use of thymosin, we believe that thymosin alpha 1 deserves further investigation into its antiviral properties and possible repurposing as a treatment against severe acute respiratory syndrome coronavirus-2.     

Anatomy and White Matter Connections of the Superior Frontal Gyrus

The superior frontal gyrus (SFG) is an important region implicated in a variety of tasks including motor movement, working memory, resting-state, and cognitive control. A detailed understanding of the subcortical white matter of the SFG could improve postoperative morbidity related to surgery around this gyrus. Through DSI-based fiber tractography validated by gross anatomical dissection, we characterized the fiber tracts of the SFG based on their relationships to other well-known neuroanatomic structures. Diffusion imaging from the Human Connectome Project from 10 healthy adult subjects was used for fiber tractography. We evaluated the SFG as a whole based on its connectivity with other regions. All tracts were mapped in both hemispheres, and a lateralization index was calculated based on resultant tract volumes. Ten cadaveric dissections were then performed using a modified Klingler technique to delineate the location of major tracts integrated within the SFG. We identified four major SFG connections: the frontal aslant tract connecting to the inferior frontal gyrus; the inferior fronto-occipital fasciculus connecting to the cuneus, lingual gyrus, and superior parietal lobule; the cingulum connecting to the precuneus and parahippocampal gyrus/uncus; and a callosal fiber bundle connecting the SFG bilaterally. The functional networks of the SFG involve a complex series of white matter tracts integrated within the gyrus, including the FAT, IFOF, cingulum, and callosal fibers. Postsurgical outcomes related to this region may be better understood in the context of the fiber-bundle anatomy highlighted in this study. Clin. Anat. 33:823–832, 2020. © 2019 Wiley Periodicals, Inc.     

Spatial distribution of human arachnoid trabeculae

Traumatic brain injury (TBI) is a common injury modality affecting a diverse patient population. Axonal injury occurs when the brain experiences excessive deformation as a result of head impact. Previous studies have shown that the arachnoid trabeculae (AT) in the subarachnoid space significantly influence the magnitude and distribution of brain deformation during impact. However, the quantity and spatial distribution of cranial AT in humans is unknown. Quantification of these microstructural features will improve understanding of force transfer during TBI, and may be a valuable dataset for microneurosurgical procedures. In this study, we quantify the spatial distribution of cranial AT in seven post-mortem human subjects. Optical coherence tomography (OCT) was used to conduct in situ imaging of AT microstructure across the surface of the human brain. OCT images were segmented to quantify the relative amounts of trabecular structures through a volume fraction (VF) measurement. The average VF for each brain ranged from 22.0% to 29.2%. Across all brains, there was a positive spatial correlation, with VF significantly greater by 12% near the superior aspect of the brain (p < .005), and significantly greater by 5%−10% in the frontal lobes (p < .005). These findings suggest that the distribution of AT between the brain and skull is heterogeneous, region-dependent, and likely contributes to brain deformation patterns. This study is the first to image and quantify human AT across the cerebrum and identify region-dependencies. Incorporation of this spatial heterogeneity may improve the accuracy of computational models of human TBI and enhance understanding of brain dynamics.     

Memory T-Cell Responses to Vibrio cholerae O1 Infection

Vibrio cholerae O1 can cause diarrheal disease that may be life-threatening without treatment. Natural infection results in long-lasting protective immunity, but the role of T cells in this immune response has not been well characterized. In contrast, robust B-cell responses to V. cholerae infection have been observed. In particular, memory B-cell responses to T-cell-dependent antigens persist for at least 1 year, whereas responses to lipopolysaccharide, a T-cell-independent antigen, wane more rapidly after infection. We hypothesize that protective immunity is mediated by anamnestic responses of memory B cells in the gut-associated lymphoid tissue, and T-cell responses may be required to generate and maintain durable memory B-cell responses. In this study, we examined B- and T-cell responses in patients with severe V. cholerae infection. Using the flow cytometric assay of the specific cell-mediated immune response in activated whole blood, we measured antigen-specific T-cell responses using V. cholerae antigens, including the toxin-coregulated pilus (TcpA), a V. cholerae membrane preparation, and the V. cholerae cytolysin/hemolysin (VCC) protein. Our results show that memory T-cell responses develop by day 7 after infection, a time prior to and concurrent with the development of B-cell responses. This suggests that T-cell responses to V. cholerae antigens may be important for the generation and stability of memory B-cell responses. The T-cell proliferative response to VCC was of a higher magnitude than responses observed to other V. cholerae antigens.Vibrio cholerae is a gram-negative bacterium that can cause a severe, acute secretory diarrhea. Serological differentiation of V. cholerae strains is based on the O-side chain of the lipopolysaccharide (LPS) component of the outer membrane. Of the more than 200 serogroups of V. cholerae identified, only the O1 and O139 serogroups can cause epidemic cholera (44). These pathogens are noninvasive and colonize the mucosal surface of the small intestine (44).Natural infection with V. cholerae is known to provide protection against subsequent disease, but the mechanism of this protective immunity is not fully characterized. The vibriocidal antibody is a complement-dependent bactericidal antibody that is associated with protection from infection. However, no known threshold level of the vibriocidal antibody confers complete protection from V. cholerae infection, and some individuals with low serum vibriocidal antibody titers are still protected. This suggests that the vibriocidal titer may be a surrogate marker (16, 45). Elevated serum immunoglobulin A (IgA) antibody levels specific for the B subunit of cholera toxin (CTB), the major structural subunit of a type IV pilus (TcpA), and LPS are also associated with protective immunity in areas where cholera is endemic (19). However, after natural infection, the serum levels of these antibodies wane more rapidly than protective immunity (19). Patients with cholera develop memory B-cell responses of both the IgG and the IgA isotype to at least two V. cholerae protein antigens, CTB and TcpA. These responses are detectable for at least 1 year after infection and persist even after V. cholerae antigen-specific antibody-secreting cells and serum antibody titers have returned to baseline (18). B-cell memory responses also develop for the T-cell independent antigen LPS, but these responses wane more rapidly than memory B-cell responses to protein antigens, suggesting that durable memory B-cell responses to some V. cholerae antigens may be T-cell dependent (18).We have recently demonstrated that cholera patients mount a primed T-cell response in the mucosa after V. cholerae O1 infection (6). We hypothesize that protection from cholera may be mediated by memory B cells capable of an anamnestic response in the gut mucosa and that these memory B cells may depend on stimulation provided by memory T cells for their development and maintenance. T cells may contribute to the activation of B cells during V. cholerae infection by secreting stimulatory cytokines and direct contact with B cells in lymph nodes. Therefore, T cells may have an important role in protective immunity to V. cholerae infection.We characterized the memory T-cell responses to V. cholerae antigens following natural V. cholerae infection and compared these with serological responses to the same antigens. Previously, our group has studied various V. cholerae antigens, including mannose-sensitive hemagglutinin, TcpA, CTB, and LPS (22, 33, 37). We also included in the present study responses to a novel antigen, V. cholerae cytolysin/hemolysin (VCC) (31, 32). The hly gene that encodes the VCC protein is widespread across both pathogenic and environmental strains of V. cholerae, suggesting that VCC may impart an advantage to the organism (42). Although the precise role of VCC in V. cholerae infection is unknown, VCC is the primary virulence factor in V. cholerae infection with non-O1, non-O139 strains that do not produce cholera toxin (12, 46). The immune response to VCC is not well understood; however, recent studies suggest that VCC may promote a Th2 response in V. cholerae infection (2). In addition, the cytolytic activity of VCC may generate epithelial destruction that allows other V. cholerae antigens to penetrate the mucosa and promote the inflammatory response observed in V. cholerae infection (35, 39).     

Laparoscopic salpingotomy for tubal pregnancy: comparison of linear salpingotomy with and without suturing

BACKGROUND: The study was carried out to clarify the incidence of post-operative tubal adhesions, patency rate and pregnancy outcome after laparoscopic salpingotomy with and without suturing for tubal pregnancy. METHODS: From May 1996 to December 2002, a total of 97 cases of tubal pregnancy were treated in our centre by laparoscopic conservative surgery. The successful salpingotomy cases were randomly assigned to undergo salpingotomy without suturing (group I; n = 43) or with suturing (group II; n = 32). We compared these patients and assessed their surgical and pregnancy outcome by second look laparoscopy (SLL) 3 months after the first operation. RESULTS: Seventy-five cases (77%) were treated successfully by salpingotomy at initial laparoscopic surgery, and the remaining 22 cases were unsuccessful because of bleeding or complete tubal damage. Pelvic findings were assessed at SLL in 21 of 43 cases (49%) in group I and 17 of 32 (53%) in group II. There were no significant differences in gestational age, ectopic site, tubal diameter, tubal condition, intraperitoneal haemorrhage and pre-operative HCG levels between the two groups. Only the operation time was longer in group II than in group I (91 +/- 15 versus 69 +/- 15 min, P < 0.05). The tubal patency rate of the treated side was 90% (19/21) in group I and 94% (16/17) in group II. Also the peritubal adhesions were observed in 33% (7/21) in group I and 29% (5/17) in group II, and were mostly comprised of filmy adhesions. A tubal fistula occurred in two cases in each group. Pregnancy rate was 79% (15/19) in group I and 92% (12/13) in group II, and this did not reveal any significant difference of cumulative pregnancy rate between the groups. CONCLUSION: We recommend laparoscopic linear salpingotomy as a useful method in the management of cases with tubal pregnancy who desire future pregnancy. This preliminary study emphasizes that the procedure involving suturing has no additional benefit over the non-suturing technique during salpingotomy.     

Salsola pollen as a predominant cause of respiratory allergies in Kuwait.

BACKGROUND: Respiratory allergies are common in Kuwait, and the role of certain allergens has been previously documented. OBJECTIVE: To evaluate the results of skin prick tests to a range of allergens that were considered relevant to the vegetation surveys and aerobiological studies performed in Kuwait. METHOD: New patients attending our center during August 2002 to February 2003 with asthma or allergic rhinitis underwent skin prick tests to a battery of allergens. RESULTS: A total of 451 patients aged 5 to 60 years (mean age, 29.5 years) were tested. Of these patients, 403 (89.4%) had a positive test result to at least one allergen and were considered allergic. A total of 76.7% of the allergic patients had a positive reaction to Salsola pollen, with a mean wheal diameter of 8.25 mm (median, 8 mm). Chenopodium album was positive in 57.6% and Bermuda grass was positive in 38.2% of the allergic cases. Indoor allergens seemed to play a lesser role than pollens: Dermatophagoides pteronyssinus was positive in only 37.5%, and American and German cockroaches were positive in 33.2% and 22.3%, respectively. All the allergens other than Salsola elicited a mean wheal diameter of less than 6.25 mm (median, < or = 6 mm). CONCLUSIONS: Indoor allergens seem to play a lesser role in respiratory allergies in Kuwait. Most allergic patients become sensitized to pollens; the strongest and most frequent reaction is from Salsola pollen. Salsola imbricata is found growing extensively in most areas of the country, flowering mainly in autumn, when the most common pollen is of the Chenopod-Amaranth type and when most patients with seasonal allergic rhinitis become symptomatic.