A comparative study for determining Covid-19 risk levels by unsupervised machine learning methods

The restrictions have been preferred by governments to reduce the spread of Covid-19 and to protect people's health according to regional risk levels. The risk levels of locations are determined due to threshold values ​​based on the number of cases per 100,000 people without environmental variables. The purpose of our study is to apply unsupervised machine learning techniques to determine the cities with similar risk levels by using the number of cases and environmental parameters. Hierarchical, partitional, soft, and gray relational clustering algorithms were applied to different datasets created with weekly the number of cases, population densities, average ages, and air pollution levels. Comparisons of the clustering algorithms were performed by using internal validation indexes, and the most successful method was identified. In the study, it was revealed that the most successful method in clustering based on the number of cases is Gray Relational Clustering. The results show that using the environmental variables for restrictions requires more clusters than 4 for healthier decisions and Gray Relational Clustering gives stable results, unlike other algorithms.

First Report of Onion yellow dwarf virus and Leek yellow stripe virus in Garlic in Turkey

Garlic (Allium sativum L.) is one of the most important Allium spp. plants that are widely cultivated throughout the world. A significant reduction in yield and quality due to virus infection is now a serious economic problem (1). In many cases, garlic plants are infected with a variety of viruses, but elimination of these viruses is difficult because this crop is propagated through bulbs. Potyviruses, carlaviruses, and allexiviruses have been detected in diseased garlic. Onion yellow dwarf virus (OYDV) and Leek Yellow Stripe Virus (LYSV), genus Potyvirus, family Potyviridae, are two important viral pathogens of garlic. Virus diseases of garlic are widespread in the world, causing serious damage to yields and quality of the crop. The East Mediterranean Region produces 14% of the garlic production of Turkey (110,000 t). A survey was done in garlic fields in Adana, Mersin, Kahramanmaras, Hatay, and Gaziantep provinces of Turkey where virus-like symptoms were noted in samples collected during the 2007-2008 growing season. Leaf and bulb samples were taken from 202 plants with leaf yellow stripe, mosaic, enations, and deformation or dwarfism symptoms. ELISA was performed with antibodies from Agdia (Elkhart, IN). Results indicated that 57 samples (28.2%) were infected with OYDV and 43 samples (21.2%) were infected with LYSV. In addition, 23 samples were determined to be infected by both viruses. All ELISA-positive samples and 10 ELISA-negative samples were analyzed by reverse transcription-PCR with primers 1OYDV-G (5' TTA CAT TCT AAT ACC AAG CA 3') and 2OYDV-G (5' GCA GGA GAT GGG GAG GAC GC 3') for the detection of OYDV and primers 1LYSV (5' TCA CTG CAT ATG CGC ACC AT 3') and 2LYSV (5' GCA CCA TAC AGT GAA TTG AG 3') for the detection of LYSV. These primers were previously reported to be specific for the coat protein genes of OYDV and LYSV, respectively (2). Products of the expected size (774 bp for OYDV and 1,020 bp for LYSV) were amplified only from the ELISA-positive samples of the respective viruses, confirming infections by OYDV and LYSV. To our knowledge, this is the first report of OYDV and LYSV in garlic in Turkey. References: (1) L. Bos et al. Neth. J. Plant Pathol. 84:185, 1978. (2) T. V. M. Fajardo et al. Fitopatol. Bras. 26:619, 2001.

Influence of atropine therapy on fenthion-induced pancreatitis

OBJECTIVE

We searched the influence of dose and timing of atropine therapy in fenthion-induced pancreatitis model.

METHODS

All rats were intoxicated with fenthion except the control group. Two milligrams of atropine was administered for 24 hours in a high dose atropine group while a low dose atropine group received 100 micrograms of atropine for 24 hours. One group received 2 milligrams of atropine in the first four hours of intoxication while the other group received 2 milligrams of atropine in the last four hours before sacrifice. All rats were sacrificed 24 hours after intoxication. Pseudo-cholinesterase and lipase concentrations and histopathological markers of pancreatitis were studied.

RESULTS

None of the models in this study completely prevented pancreatitis, however high dose atropine that is administered for 24 hours or the first four hours after intoxication prevented severe pancreatitis.

CONCLUSION

Atropine administration influence on fenthion-induced pancreatitis should be studied for other organophosphates in animals and humans.

Oral administration of avocado soybean unsaponifiables (ASU) reduces ischemic damage in the rat hippocampus

BACKGROUND

The beneficial effects of avocado/soybean unsaponifiables (ASU) are known as an antiarthritic agent. This experimental study presents the effects of ASU on oxidant/antioxidant systems and the number of apoptotic neurons of hippocampal formation after ischemia and reperfusion.

METHODS

Eighteen rats were divided into three equal groups: group I rats were used as controls; group II rats were fed with standard diet and group III rats were fed with standard diet plus ASU pills for 10 days. One day after electrocauterization of bilateral vertebral arteries for groups II and III, bilateral common carotid arteries were occluded for 30 min and then reperfused for 30 min. After these procedures, rats of all groups were sacrificed. The levels of malondialdehyde (MDA) and nitric oxide (NO) and activities of superoxide dismutase (SOD) and catalase (CAT) were measured in the left hippocampus. The number of apoptotic neurons was counted by Tunel method in histological samples of right hippocampus.

RESULTS

MDA and NO levels increased in group II compared with group I rats (p = 0.002, p = 0.015). In group III, MDA and NO levels decreased as compared to group II (p = 0.041, p = 0.002). SOD and CAT activities increased in group III as compared to group II rats (p = 0.002, p = 0.002). The number of apoptotic neurons was lower in group III as compared to group II rats.

CONCLUSIONS

The present findings suggest that ASU could decrease oxidative stress and apoptotic changes in ischemic rat hippocampus. Dietary supplementation of ASU may be beneficial to prevent or ameliorate ischemic cerebral vascular disease.

Influence of Different Atropine Therapy Strategies on Fenthion-Induced Organ Dysfunction in Rats

We studied the influence of dose and timing of atropine therapy on fenthion-induced organ dysfunction. Thirty-six rats were randomized into six groups. All rats in the five groups except the control group were intoxicated with fenthion. The high-dose atropine group received 2 mg/kg of atropine, whereas the low-dose group received 100 microg/kg of atropine every hour for 24 hr. One group received 2 mg/kg of atropine in the first 4 hr of intoxication while the other group received 2 mg/kg of atropine in the last 4 hr before killed, which for all rats was 24 hr after intoxication. Pseudocholinesterase and aspartate aminotransferase and alanine aminotransferase levels and histopathological markers of lung, brain and liver were studied. None of our atropine therapy strategies in this study totally prevented harm on the three organs. Although the high dose of atropine administered for 24 hr had the least harmful markers for lung, it also had the most harmful markers for brain and liver. We did not succeed in finding a unique therapy strategy in our models beneficial for all studied organs in fenthion intoxication in rats. Atropine administration strategy should be oriented for the most affected organ pathology in fenthion intoxication.

Prevalence of sleep apnoea in patients undergoing operation

Obstructive sleep apnoea (OSA) is defined as episodes of obstructive apnoeas and hypopnoeas during sleep with daytime somnolence. The gold standard in diagnostic tool patients with these symptoms is polisomnography. The goals of this study were to determine the frequency of OSA symptoms and the prevalence of OSA in patients undergoing operation. Patients were asked questions pertaining to symptoms of sleep apnoea. The patients who had two major symptoms or one major and two minor symptoms were invited to undergo a sleep study. Patients were diagnosed as OSA when they had apnoea-hypopnoea index higher than five. Forty-one patients with two major or one major and two minor symptoms of 433 patients were referred to the sleep laboratory. The most frequent major symptom was snoring, and the most frequent minor symptom was morning tiredness. In this connection, 18 (43.9%) patients accepted to be studied in the sleep laboratory (14 with two major, 4 with one major and two minor symptoms). Obstructive sleep apnoea was finally diagnosed in 14 patients or 3.2% of the initial entire population. Thirteen of them had two major symptoms, and only one of the 14 had one major and two minor symptoms. Six of the OSA patients were women. High percentage of OSA focus attention on anaesthesiology concerns of OSA. The exact management of each sleep apnoea patient with regard to intubation, extubation and pain control requires judgement and is a function of many anaesthesia, medical and surgical considerations. Therefore, we suggest that all patients should be asked for OSA symptoms, and patients with two major OSA symptoms must be evaluated with polisomnography.

The protective effect of fish n-3 fatty acids on cerebral ischemia in rat hippocampus

Reactive oxygen species (ROS) have been implicated in the pathogenesis of cerebral injury after ischemia-reperfusion (I/R). Fish n-3 essential fatty acids (EFA), contain eicosapentaenoic acids (EPA) and docosahexoenoic acids (DHA), exhibit antioxidant properties. DHA is an important component of brain membrane phospholipids and is necessary for the continuity of neuronal functions. EPA prevents platelet aggregation and inhibits the conversion of arachidonic acid into thromboxane A(2) and prostaglandins. They have been suggested to be protective agents against neurological and neuropsychiatric disorders. In this study, the neuroprotective effects of fish n-3 EFA on oxidant-antioxidant systems and number of apoptotic neurons of the hippocampal formation (HF) subjected to cerebral I/R injury was investigated in Sprague-Dawley rats. Six rats were used as control (Group I). Cerebral ischemia was produced by occlusion of both the common carotid arteries combined with hypotension for 45 min, followed by reperfusion for 30 min, in rats either on a standard diet (Group II) or a standard diet plus fish n-3 EFA (Marincap((R)), 0.4 g/kg/day, by gavage) for 14 days (Group III). At the end of procedures, the rats were sacrificed and their brains were removed immediately. The levels of malonedialdehyde (MDA) and nitric oxide (NO) and activities of superoxide dismutase (SOD) and catalase (CAT) were measured in left HF. In addition, the number of apoptotic neurons was counted by terminal transferase dUTP nick end labelling (TUNEL) assay in histological samples of the right HF. We found that SOD activities and MDA levels increased in Group III rats compared with Group II rats. On the other hand, CAT activities and NO levels were found to be decreased in Group III rats compared with Group II rats. Additionally, the number of apoptotic neurons was lower in Group III in comparison with Group II rats. The present findings suggest that fish n-3 EFA could decrease the oxidative status and apoptotic changes in ischemic rat hippocampal formation. Dietary supplementation of n-3 EFA may be beneficial to preserve or ameliorate ischemic cerebral vascular disease.

Beneficial Effects of Supplemental Nitric Oxide Donor Given during Reperfusion Period in Reperfusion-Induced Lung Injury

BACKGROUND

Reperfusion injury is a perplexing cause of early graft failure after lung transplantation and today we know that reperfusion may be more harmful to tissues than the preceding ischemia. We hypothesized that administration of the nitric oxide donor nitroglycerin (NTG) during flush perfusion and reperfusion periods would ameliorate reperfusion-induced lung injury.

METHODS

Using an IN SITU normothermic ischemic lung rabbit model, three groups were studied (n = 7/group): (1) NTG given during flush perfusion (ischemia group); (2) NTG given in the flush perfusion and the reperfusion period (reperfusion group); and (3) no NTG (control group). All groups were flushed with low potassium dextran glucose solution. Blood gas analysis, tissue nitrite (nitric oxide metabolite) level analysis, bronchoalveolar lavage (BAL) fluid examination and morphological examinations were performed.

RESULTS

Compared with the ischemia group, the reperfusion group had significantly improved arterial oxygenation (318 +/- 31.4 mmHg vs. 180 +/- 14.7 mmHg, P < 0.05), decreased BAL fluid neutrophil percentage (21 +/- 1.9 % vs. 30 +/- 5.6 %, P < 0.05), increased tissue nitrite level (32.55 +/- 4.12 nmol/g vs. 27.81 +/- 1.05 nmol/g, P < 0.05), and decreased tissue histopathological lesion scores (0.42 +/- 0.53 vs. 1.14 +/- 0.37, P < 0.05).

CONCLUSIONS

This study suggests that nitric oxide donors supplemented during flush perfusion and reperfusion have more beneficial effects on lung functions against reperfusion injury than any other treatment modalities during IN SITU normothermic ischemic lung model.

Effect of lung ischemia–reperfusion on oxidative stress parameters of remote tissues

OBJECTIVE

Ischemia-reperfusion injury induces a systemic inflammatory response and production of reactive oxygen species, which potentially can be more detrimental than its local effects. Although the lung injury that is formed by the effects of ischemia-reperfusion injury on remote organs has been previously studied, no previous study that investigated the effects of pulmonary ischemia-reperfusion injury on remote organs has been considered. We hypothesized that the lung ischemia-reperfusion injury may cause the spread of inflammation to remote organs such as liver and heart.

METHODS

Thirty New Zealand white rabbits were subjected to either sham operation or lung ischemia-reperfusion injury in various periods of time (60 min ischemia-60 min reperfusion and 120 min ischemia-60 min reperfusion, respectively). Pulmonary, myocardial and hepatic myeloperoxidase, protein sulfhydryl, thiobarbituric acid-reactive substances, and protein carbonyl levels were evaluated to show pulmonary, hepatic, and myocardial responses to lung ischemia-reperfusion injury.

RESULTS

Reperfusion after 60 min of lung ischemia led to increased myeloperoxidase and protein carbonyl levels and decreased protein sulfhydryl groups in pulmonary tissue, increased myeloperoxidase and decreased protein sulfhydryl groups in hepatic tissue, and increased myeloperoxidase, thiobarbituric acid-reactive substances and protein carbonyl levels in myocardial tissue. Reperfusion after 120 min of lung ischemia led to increased thiobarbituric acid-reactive substance levels in pulmonary tissue, increased protein carbonyl and thiobarbituric acid-reactive substance levels in hepatic tissue, and decreased protein sulfhydryl groups in myocardial tissue.

CONCLUSIONS

The data of the present study suggests that pulmonary ischemia-reperfusion induces liver and heart injury characterized by activated neutrophil sequestration and release of significant amounts of reactive oxygen species. The remote organ injury has to be kept in mind when performing a lung intervention or surgery and care should be taken to protect other organs remote from ischemia-reperfusion site.