Efficiency and sensitivity optimization of a protocol to quantify indoor airborne SARS-CoV-2 levels.

BACKGROUND: Development of methodologies to quantify airborne micro-organisms is needed for the prevention and control of infections. It is difficult to conclude which is the most efficient and sensitive strategy to assess airborne SARS-CoV-2 RNA levels due to the disparity of results reported in clinical settings. AIM: To improve our previously reported protocol of measuring SARS-CoV-2 RNA levels, which was based on bioaerosol collection with a liquid impinger and RNA quantification with droplet digital polymerase chain reaction (ddPCR). METHODS: Air samples were collected in COVID-19 patient rooms to assess efficiency and/or sensitivity of different air samplers, liquid collection media, and reverse transcriptases (RT). FINDINGS: Mineral oil retains airborne RNA better than does hydrophilic media without impairing integrity. SARS-CoV-2 ORF1ab target was detected in 80% of the air samples using BioSampler with mineral oil. No significant differences in effectiveness were obtained with MD8 sampler equipped with gelatine membrane filters, but the SARS-CoV-2 copies/m3 air obtained with the latter were lower (28.4 ± 6.1 vs 9 ± 1.7). SuperScript II RT allows the detection of a single SARS-CoV-2 genome RNA molecule by ddPCR with high efficiency. This was the only RT that allowed the detection of SARS-CoV-2 N1 target in air samples. CONCLUSION: The collection efficiency and detection sensivity of a protocol to quantify SARS-CoV-2 RNA levels in indoor air has been improved in the present study. Such optimization is important to improve our understanding of the microbiological safety of indoor air.

STAT3 expression, activity and functional consequences of STAT3 inhibition in esophageal squamous cell carcinomas and Barrett's adenocarcinomas.

Signal transducer and activator of transcription 3 (STAT3) is altered in several epithelial cancers and represents a potential therapeutic target. Here, STAT3 expression, activity and cellular functions were examined in two main histotypes of esophageal carcinomas. In situ, immunohistochemistry for STAT3 and STAT3-Tyr705 phosphorylation (P-STAT3) in esophageal squamous cell carcinomas (ESCC, n=49) and Barrett's adenocarcinomas (BAC, n=61) revealed similar STAT3 expression in ESCCs and BACs (P=0.109), but preferentially activated P-STAT3 in ESCCs (P=0.013). In vitro, strong STAT3 activation was seen by epidermal growth factor (EGF) stimulation in OE21 (ESCC) cells, whereas OE33 (BAC) cells showed constitutive weak STAT3 activation. STAT3 knockdown significantly reduced cell proliferation of OE21 (P=0.0148) and OE33 (P=0.0243) cells. Importantly, STAT3 knockdown reduced cell migration of OE33 cells by 2.5-fold in two types of migration assays (P=0.073, P=0.015), but not in OE21 cells (P=0.1079, P=0.386). Investigation of transcriptome analysis of STAT3 knockdown revealed a reduced STAT3 level associated with significant downregulation of cell cycle genes in both OE21 (P<0.0001) and OE33 (P=0.01) cells. In contrast, genes promoting cell migration (CTHRC1) were markedly upregulated in OE21 cells, whereas a gene linked to tight-junction stabilization and restricted cell motility (SHROOM2) was downregulated in OE21 but upregulated in OE33 cells. This study shows frequent, but distinct, patterns of STAT3 expression and activation in ESCCs and BACs. STAT3 knockdown reduces cell proliferation in ESCC and BAC cells, inhibits migration of BAC cells and may support cell migration of ESCC cells. Thereby, novel STAT3-regulated genes involved in ESCC and BAC cell proliferation and cell migration were identified. Thus, STAT3 may be further exploited as a potential novel therapeutic target, however, by careful distinction between the two histotypes of esophageal cancers.

[Organization model for mass orthodontic prophylaxis in integrated pediatric institutions]. / Model na organizatsiia za masova ortodontska profilaktika v obedinenite detski zavedeniia.

A model is proposed for the organization of mass orthodontic prophylaxis in the integrated pediatric institutions (IPI), covering the following more important activities: I. Follow-up care of the organized pediatric groups in the crêches and nurseries with a view to orthodontic prophylaxis. II. Analysis of the data from the prophylactic examinations, written down in special cards, worked out by the authors. According to the needs of the children they are distributed in four follow-up groups. III. Mass orthodontic prophylaxis. The more important measures of primary and secondary mass orthodontic prophylaxis are established and grouped respectively. IV. Visual-educational materials. V. Colour film of the model. The proposed model is admitted to illustrate and convincingly present the possibilities of the mass prophylaxis in IPI and, in parallel, it could serve as a programme for mass orthodontic prophylaxis.

[Intravenous pulsed therapy with prednisolone hemisuccinate in severe forms of systemic lupus erythematosus]. / Intravenozna pulsova terapiia s prednizolon khemisuktsinat pri tezhki formi na sistemen lupus erythematosus.

The intravenous pulsed treatment with prednisone hemisuccinate of severe forms of systemic lupus erythematosus influences favorably the basic clinical manifestations of the disease--polyarthritis, fever, vasculitis, myocarditis, sialoadenitis. Prednisolone is as efficient as methylprednisolone in the pulsed treatment of patients with systemic lupus erythematosus.

[Renal onset of multiple myeloma]. / Bubrechno nachalo na multipleniia mielom.

67 patients with multiple myeloma with different duration and stage were studied. In 12 patients (17.91%) the onset of the disease was manifested by renal symptoms which were mistaken for primary renal disease. This group of patients was compared with the patients with usual onset of the disease by clinical, paraclinical and immunologic parameters. 75% of the patients with renal onset were in the III stage of the disease when the correct diagnosis was made. A tendency toward normal proteinuria (80.6 +/- 12.04 g/l), stable azotemia (creatinine 497.83 +/- 313.96 mmol/l), significant and non-selective proteinuria, positive correlation with light-chain secretion (r = +0.77) and lack of therapeutic response in 41.66% of the patients were found. Suggestions about the frequency, characteristics, diagnostic problems, therapeutic responses and the unfavourable prognosis of multiple myeloma with renal onset are put forward.

[Case report on the diagnosis and therapy of hairy-cell leukemia]. / Kum diagnostikata i terapiiata na kosmatokletuchnata levkoza s opisanie na edin sluchai.

A survey was performed of that rare hematological disease with a diagnostic therapeutic purpose. A case is reported with hairy-cell leukemia diagnosed while living, with the description of the clinical signs, morphological, cytochemical and immunohematological characteristics of hairy-cell leukemia. The diagnosis was confirmed by trephine biopsy, electron microscopy and pathomorphological study on the spleen. Good results are reported from splenectomy after 2-year observation.

[Venous treatment with streptase in acute myocardial infarct and unstable stenocardia (a new method)]. / Venozno lechenie sus streptaza pri ostur miokarden infarkt i nestabilna stenokardiia (nov metod).

Streptokinase treatment was carried out in the intensive care unit of III Internal Clinic, the Higher Medical Institute--Plovdiv, on 54 patients, 51 of them with acute myocardial infarction (AMI) and 3 with intermediary coronary syndrome, making use of the preparations streptase (GFR) and avelysin (GDR). A control group of 35 patients with AMI was used. The treatment was initiated with stream administration of heparin 10,000 U and urbazon 20 mg, whereafter streptokinase 1,250,000 U per 1 h was included on that background. The results were determined according to ECG in 30 leads, recorded by 2, 4, 6, 12 and 24 h, according to creatine-phosphokinase activity and the outcome of the disease. The treatment was uninterrupted up to 24 h with the determination of the individual fibrinolytic activity. Normalization of S-T segment was established by 4 h with restoration of ECG in 10 patients, and in the rest--maintaining QS or QR forms. Re-perfusion arrhythmias were observed in 66.67% and data about re-thrombosis--in 13.61%. Lethality was 5.89%. The method is emphasized to be a reliable means for the treatment of AMI.

[Diabetes mellitus and myocardial infarct]. / Zakharen diabet i miokarden infarkt.

The data from the case histories of 106 patients with myocardial infarction (MI) and diabetes mellitus (DM) from the intensive care unit of III Internal Clinic of the Medical Faculty of the Higher Medical Institute "I. P. Pavlov"-- Plovdiv are interpreted as well as of the same number of patients with myocardial infarction without diabetes mellitus. The authors found a higher percentage of painless forms of myocardial infarction in diabetics, no matter the duration, form and severity of the diabetes. The patients with DM and MI have a slowed down rehabilitation and reverse ECG dynamics. The complications in both groups observed do not differ. Myocardial rupture is significantly more frequent among the females from both groups. High leukocytosis, with shifting to the left, accelerated ESR, high SGOT and LDH activity and hypercoagulemia as well as their slowed down restoration should be admitted--a constellation with an unfavourable prognostic sign, requiring a cautious treatment and a slower rehabilitation.

[Minkowski-Chauffard disease in 1 family]. / Morbus Minkowski-Chauffard s opisanie na edna familiia.

A check up of literature has been made concerning the congenital microspherocytic hemolytic anemia, reporting of some new data about the pathogenesis of the disease. One family is described with CMHA--one father and his two daughters, the two children of his first daughter and the only child of the second daughter, hence confirming the familial character of the disease. All patients have been splenectomized. After the splenectomy they are practically healthy, without hemolytic crises, supporting the statement that splenectomy is the treatment of choice in CMHA therapy.

[Changes in the polymorphism of the blood serum alkaline phosphatase in chickens undergoing subacute lindane treatment]. / Promeni v polimorfizma na alkalnata fosfataza v kruvna plazma na kokoshki pri subakutno tretirane s lindan.

Investigated were a total of 123 birds of the White Leghorn breed and 50 birds of the White Plymouth Rock breed. Preliminary studies were carried out on the LD50 amount of lindane (151 mg/kg body mass) with 6 groups of chickens. The birds were divided into 4 subgroups for each breed. The first subgroup was a control one and was not given lindane, and the remaining subgroups were offered the following amounts of lindane in the course of 5 successive days: II - 1/20 LD50 (7.6 mg/kg daily); III - 1/10 LD50 (15.1 mg/kg); and IV - 1/5 LD50 (30.2 mg/kg). Each single one of the test birds was treated individually by means of a rubber tube and a syringe with a pure substance of lindane dissolved in oil. The polymorphism of alkaline phosphatase in the blood plasms of chickens was determined through horizontal electrophoresis in starch gel after the method of Gahne [14]. It was found that at subacute treatment of the birds a drop off was observed of the S1 fraction, and, as a result, the frequence of the homozygotic alkaline-phosphatase phenotypes FF and SS rose, while that of FS1 and SS1 dropped. Subacute treatment with part of the birds led to the appearance of an additional fraction F1, which accompanied the SS, SS1, and SS2 phenotypes only. The changes that took place as a result of the subacute treatment were only phenotypic ones as the F1 and S1 fractions had no hereditary character.

[Resistance of different breeds of laying poultry to Marek's disease virus]. / Ustoichivost na razlichni linii ptitsi iaitsenosno napravlenie kum virusa na bolestta na Marek.

Investigated were a total of 447 two-day-old chicks of lines 5-A, ia-73' ll and lS of the Leghorn breed divided into 2 groups: controls--99 males and females, and test ones--348 infected at the age of 2 days via intraabdominal injection with 0.4 cm3 heparinized blood each, containing 5000 PFU per dose of the Marek's disease virus (CT-1 isolate). Both linear and sexual variations were found in the resistance of the birds. Most resistant proved to be the 5-A chicks of both sexes, and most susceptible--those of the lS line. No essential differences were observed in the response of the initial lines of broiler birds and the lines of laying birds raised in this country at the intraabdominal infection with the same virus. It was established that the birds of lines 5-A and 6-E of the Canadian Leghorn breed were close in terms of resistance with the birds of lines 66 and 77 of the Cornish breed, while those of the Leghorn lines ll and lS were resembling by resistance the birds of lines 88 and 89 of the White Plymouth Rock broilers which were more susceptible to Marek's disease. It is stated that the cockerels and poults of the ia-73 synthetic line, newly developed in this country, show essentially varying resistance most probably associated with insufficient consolidation.