Hyperbranching induced by cold-shock or snow-flake mutation in Neurospora crassa is prevented by addition of exogenous calcium

Hyphal tip growth is a highly polarized process of cell extension, which may be affected by chemical and physical stress. Neurospora crassa exposed to cold-shock lost its polarized growth and dichotomous branches were detected. These effects were not observed in the presence of 500 mM Ca2+. We compared here the morphological pattern of a snow-flake mutant (sn) and the wild-type (wt) exposed to 4 degrees C. Hyphal morphology, nuclei, actin and microtubule distribution were analyzed. No effects on sn hyphal morphology were detected at 4 degrees C. Exogenous Ca2+ converted sn to an essentially wt appearance. The results presented here suggest that sn mutation and cold-shock treatment have affected Ca2+ influx since addition of this cation to sn (30 degrees C) and to wt (4 degrees C) maintained polarized growth and normal nuclear and microtubules distribution.     

Langerhans cell histiocytosis immunohistochemical expression of fascin,a dendritic cell marker

Langerhans cell histiocytosis (LCH) is a clonal disorder believed to be derivedfrom cells of the dendritic system. Fascin, a 55-kd actin-bundling protein, represents a highly selective marker for dendritic cells of lymphoid tissues and peripheral blood and is involved in the formation of dendritic processes in maturing epidermal Langerhans cells. Since lesional cells of LCH may represent Langerhans cells arrested at an early stage of activation, immunohistochemical expression offascin in epidermal Langerhans cells and in the lesional cells of 34 cases of LCH was evaluated in paraffin sections using an immunoalkaline phosphatase technique. Though epidermal Langerhans cells were nonreactive for fascin, lesional cells in all LCH cases exhibited immunoreactivityforfascin, CD1a, and S-100 protein. Variation in staining intensity was observed in some cases, possibly reflecting differences in cell maturation or activation. Involved tissues included bone, soft tissue, lymph node, thyroid, orbit, and extradural cranial tissue. Immunoreactivity of lesional cells of LCH for fascin supports their derivation from cells of the dendritic system and represents another alteration in the phenotype of Langerhans cells that is associated with maturation, migration, culture, or clonal expansion.     

Characterization of Non-Hodgkin''s Lymphomas Using Multiple Cell Markers: Immunologic, Morphologic, and Cytochemical Studies of 72 Cases

Tissues from 72 cases (87 specimens) of various non-Hodgkin's lymphomas were analyzed for cell markers using multiple techniques. Cell suspensions were evaluated for E, EAC, and IgGEA rosette forming cells; Fc receptor cells; and surface immunoglobulin bearing cells. Cryostat section studies topographically defined EAC binding cells. Cytochemical determinations and immunoperoxidase methods for detection of intracellular immunoglobulin and lysozyme complemented other techniques in evaluating infiltrates containing large neoplastic cells. B-cell malignancies comprised 58 cases (80%) of this series and included well and moderately well differentiated lymphocytic lymphomas (10/10); nodular (23/23) and diffuse (10/18) poorly differentiated lymphocytic lymphomas; and lymphomas of mixed lymphocytic-“histiocytic” (3/3), “undifferentiated” (3/3), and “histiocytic” (9/13) types. Nodular lymphomas were characterized as B-cell neoplasms but also revealed a prominent population of T lymphocytes (39 ± 12%). Alkaline phosphatase activity, a cytochemical marker for lymphoid cells of follicular cuffs, was most consistently observed in B-cell lymphomas of moderately well differentiated lymphocytic type (4/6 cases). In some diffuse lymphomas, cryostat section studies (EAC rosettes) suggested a pre-existing nodular proliferation. One unusual B-cell lymphoma of large cell type exhibited IgGEA rosette formation and a strong receptor for the Fc portion of IgG. Ten lymphomas (14%) were of T-cell type and were represented by cases of diffuse poorly differentiated lymphocytic lymphoma (5/18, including 3 lymphoblastic lymphomas), Sézary syndrome (1), mycosis fungoides (1), and a cytologically distinctive large cell (“histiocytic”) lymphoma (3/13). Acid phosphatase activity was a consistent marker for the T-cell malignancies, some of which also revealed α-naphthyl butyrate esterase activity. No true histiocytic lymphomas were detected. Three cases of diffuse poorly differentiated lymphocytic lymphoma and one “histiocytic” lymphoma were null.     

Sequential synthesis and secretion of pectinases by Penicillium frequentans

Penicillium frequentans synthesized eleven polygalacturonases and three pectinesterases when grown in the presence of pectin, sodium polypectate or monogalacturonic acid. When glucose was the sole carbohydrate source in the medium two of these polygalacturonases and one pectinesterase were produced. The enzymes produced under any of these conditions degraded pectic substrates to monogalacturonic acid, suggesting that this monosaccharide or its metabolites should induce the pectinolytic complex. All pectinesterases and most of the extracellular polygalacturonases were synthesized after the 2nd hour of incubation. The pectinases produced by Penicillium frequentans were not secreted at the same time but after 5 hours of incubation all of them could be detected outside the cell those detected only inside the cell were probably membrane-associated or unglycosylated forms of the extracellular pectinases.     

Interpretation of low-level Plasmodium infection rates determined by ELISA for anophelines (Diptera: Culicidae) from Egyptian oases

Plasmodium infection rates determined by enzyme-linked immunosorbent assay (ELISA) were compared for Anopheles sergentii (Theobald) and An. multicolor Cambouliu in Siwa Oasis, Egypt, an area with low-level Plasmodium vivax transmission, and in Bahariya and Farafra, two other Egyptian oases which appear to be free of malaria. Initial testing indicated that 4.4% (23 of 518) and 0.8% (4 of 518) of the An. sergentii were positive for P. vivax and P. falciparum, respectively, and that 1.4% (1 of 71) of the An. multicolor were positive for P. falciparum. However, after two confirmational tests, only 1.2% (6 of 518) of the An. sergentii remained consistently positive for P. vivax. Initial ELISA absorbance was not a useful predictor of potential false positive reactions in the P. vivax assay. Paradoxically, the six ELISA-positive An. sergentii were from the two malaria-free oases. This study raises the question of whether ELISA-positive reactions for anopheline vector species provides unequivocal evidence for transmission in areas of low malaria endemicity.     

Pakistan’s Response to COVID-19: Overcoming National and International Hypes to Fight the Pandemic

The COVID-19 outbreak started as pneumonia in December 2019 in Wuhan, China. The subsequent pandemic was declared as the sixth public health emergency of international concern on January 30, 2020, by the World Health Organization. Pakistan could be a potential hotspot for COVID-19 owing to its high population of 204.65 million and its struggling health care and economic systems. Pakistan was able to tackle the challenge with relatively mild repercussions. The present analysis has been conducted to highlight the situation of the disease in Pakistan in 2020 and the measures taken by various stakeholders coupled with support from the community to abate the risk of catastrophic spread of the virus.     

An Overview of the Treatment Options Used for the Management of COVID-19 in Pakistan: Retrospective Observational Study

BackgroundSince the first reports of COVID-19 infection, the foremost requirement has been to identify a treatment regimen that not only fights the causative agent but also controls the associated complications of the infection. Due to the time-consuming process of drug discovery, physicians have used readily available drugs and therapies for treatment of infections to minimize the death toll.ObjectiveThe aim of this study is to provide a snapshot analysis of the major drugs used in a cohort of 1562 Pakistani patients during the period from May to July 2020, when the first wave of COVID-19 peaked in Pakistan.MethodsA retrospective observational study was performed to provide an overview of the major drugs used in a cohort of 1562 patients with COVID-19 admitted to the four major tertiary-care hospitals in the Rawalpindi-Islamabad region of Pakistan during the peak of the first wave of COVID-19 in the country (May-July 2020).ResultsAntibiotics were the most common choice out of all the therapies employed, and they were used as first line of treatment for COVID-19. Azithromycin was the most prescribed drug for treatment. No monthly trend was observed in the choice of antibiotics, and these drugs appeared to be a random but favored choice throughout the months of the study. It was also noted that even antibiotics used for multidrug resistant infections were prescribed irrespective of the severity or progression of the infection. The results of the analysis are alarming, as this approach may lead to antibiotic resistance and complications in immunocompromised patients with COVID-19. A total of 1562 patients (1064 male, 68.1%, and 498 female, 31.9%) with a mean age of 47.35 years (SD 17.03) were included in the study. The highest frequency of patient hospitalizations occurred in June (846/1562, 54.2%).ConclusionsGuidelines for a targeted treatment regime are needed to control related complications and to limit the misuse of antibiotics in the management of COVID-19.     

Is anticoagulation with bivalirudin comparable to heparin for pediatric extracorporeal life support? Results from a high‐volume center

There is a paucity of data regarding the use of direct thrombin inhibitors such as bivalirudin for children on extracorporeal life support (ECLS). We sought to compare the outcomes of children on ECLS anticoagulated with bivalirudin versus heparin. Patients transitioned from heparin to bivalirudin were treated as a separate group. A single‐institution, retrospective review of all consecutive children (neonate to 18 years) placed on ECLS in the cardiac or pediatric intensive care units was performed (June 2018‐December 2019). Data collected included demographics, anticoagulation strategy, number of circuit interventions, blood product use on ECLS, survival to decannulation, and survival to discharge. Fifty‐four children were placed on ECLS for a total of 56 runs. Demographics and venovenous versus venoarterial ECLS were similar. The bivalirudin group had longer median duration of support compared to the heparin group––11.0 days [IQR 6.2, 23.1] versus 3.3 days [2.1, 6.2], P < .001. Patients switched from heparin to bivalirudin had a similar duration of support (10.3 days [8.3, 18.3]) as those on bilvalirudin alone. However, there was no difference in red blood cell, fresh frozen plasma, or platelet transfusions. There was no difference in the number of circuit interventions, survival to decannulation or discharge. The freedom to first circuit intervention was longer with bivalirudin compared to heparin. Our data suggest that even with longer pediatric ECLS runs on bivalirudin, there were no differences in the outcomes between the heparin and bivalirudin groups, with longer freedom from first circuit intervention with bivalirudin. While this is the largest reported series comparing children on ECLS anticoagulated with heparin versus bivalirudin, larger studies are needed to determine the optimal anticoagulation strategy for this diverse and complicated group of children.