On the design of a macro-micro parallel manipulator for cochlear microrobot operations.

BACKGROUND: The method of stem cell transfer to narrow cochlear canals in vivo to generate hair cells is still an unclear operation. Thus, the development of any possible method that will ensure the usage of medical microrobots in small cochlear workspaces is a challenging procedure. METHODS: The current study tries to introduce a macro-micro manipulator system composed of a 6-DoF industrial serial manipulator as a macro manipulator and a proposed 5-DoF parallel manipulator with dual end effectors as a micro manipulator carrying permanent magnets for tetherless microrobot actuation inside the cochlea. RESULTS: Throughout the study, structural synthesis and kinematic analysis of the proposed micro manipulator were introduced. A prototype of the manipulator was manufactured and its hardware verification procedures were carried out using motion capture cameras and surgical navigation registration methodologies. CONCLUSIONS: Following motion training, the assembled macro-micro manipulator was successfully utilised to actuate a microrobot placed inside a manufactured cochlea mockup model.

Molecular prevalence and subtyping of Blastocystis sp. isolates in stray cats of Izmir, Turkey: First report of "ST4 allele 42" in cats.

Blastocystis sp. is one of the most frequently detected intestinal parasites in humans and can inhabit a wide range of animals. Close contact with animals is one of the transmission factors of Blastocystis sp. infection in humans. In this study, we aimed to investigate the molecular prevalence and subtypes of Blastocystis sp. in stray cats living in Izmir, Turkey. The PCR target- ing the barcode region in the SSU rRNA gene was performed with DNA samples isolated from feces (n:465) to investigate the presence of Blastocystis sp. PCR positive samples were sequen- ced for subtyping analysis. Among the samples analyzed, Blastocystis sp. DNA was detected in 17 (3.65%) of them and sequence data were obtained from only seven isolates. Phylogenetic analysis showed that seven Blastocystis sp. isolates clustered with the reference Blastocystis ST4 isolates. Similarity rates were between 83.22% and 99.25%. In addition, Blastocystis database results confirmed that all of these were "allele 42" corresponding to ST4. As a result, the present study shows for the first time the presence of "ST4 allele 42", the prevalent subtype in humans, in stray cats in Izmir, Turkey. This finding supports the notion that stray cats can be a source of Blastocystis sp. infection in humans.

Risk factors associated with mortality in intensive care COVID-19 patients: the importance of chest CT score and intubation timing as risk factors

Background/aim: Coronavirus disease 2019 (COVID-19) is a disease with a high rate of progression to critical illness. However, the predictors of mortality in critically ill patients admitted to the intensive care unit (ICU) are not yet well understood. In this study, we aimed to investigate the risk factors associated with ICU mortality in our hospital. Materials and methods: In this single-centered retrospective study, we enrolled 86 critically ill adult patients with COVID-19 admitted to ICU of Dokuz Eylül University Hospital (Izmir, Turkey) between 18 March 2020 and 31 October 2020. Data on demographic information, preexisting comorbidities, treatments, the laboratory findings at ICU admission, and clinical outcomes were collected. The chest computerized tomography (CT) of the patients were evaluated specifically for COVID-19 and CT score was calculated. Data of the survivors and nonsurvivors were compared with survival analysis to identify risk factors of mortality in the ICU. Results: The mean age of the patients was 71.1 ± 14.1 years. The patients were predominantly male. The most common comorbidity in patients was hypertension. ICU mortality was 62.8%. Being over 60 years old, CT score > 15, acute physiology and chronic health evaluation (APACHE) II score ≥ 15, having dementia, treatment without favipiravir, base excess in blood gas analysis ≤ ­2.0, WBC > 10,000/mm3, D-dimer > 1.6 µg/mL, troponin > 24 ng/L, Na ≥ 145 mmol/L were considered to link with ICU mortality according to Kaplan­Meier curves (log-rank test, p < 0.05). The APACHE II score (HR: 1.055, 95% CI: 1.021­1.090) and chest CT score (HR: 2.411, 95% CI:1.193­4.875) were associated with ICU mortality in the cox proportional-hazard regression model adjusted for age, dementia, favipiravir treatment and troponin. Howewer, no difference was found between survivors and nonsurvivors in terms of intubation timing. Conclusions: COVID-19 patients have a high ICU admission and mortality rate. Studies in the ICU are also crucial in this respect. In our study, we investigated the ICU mortality risk factors of COVID-19 patients. We determined a predictive mortality model consisting of APACHE II score and chest CT score. It was thought that this feasible and practical model would assist in making clinical decisions.

Mortality and risk factor analysis for Candida blood stream infection: A three-year retrospective study.

BACKGROUND: The aim of this study was to evaluate the possible risk factors for mortality in adult patients with candidemia by investigating the causative agents, underlying conditions and predisposing factors. MATERIAL AND METHODS: The data including causative Candida species, predisposing factors, and underlying conditions of candidemia patients between the years 2015-2017 were collected and the impact of these factors on mortality was evaluated. Patients were divided into two groups as died (died patients within 30 days of the onset of candidemia) and survived and risk factors were evaluated for each group. RESULTS: We found 163 adult candidemia cases during the study period. Overall 30-day mortality was 40.5%. Candida parapsilosis was the most frequent causative agent (49.1%). C. parapsilosis candidemia was more common in the survived group compared with the died group (n: 49 (61.3%) vs. n: 31 (38.8%), P=0.888). Mortality rates were significantly higher in patients with dialysis (n: 27 (69.2%) vs. n: 12 (30.8%), P<0.00) and concurrent bacteremia (n: 20 (57.1%) vs. n: 15 (42.9%), P=0.024). Survival rates were significantly higher in patients with follow-up blood cultures (n: 75 (65.8%) vs. n: 39 (34.2%), P=0.013). The most important source of candidemia was catheter (49.7%), and C. parapsilosis was the most common causative agent (58%). The catheter was removed in 96.3% of these patients and the mortality rate was 38.5%. All of the patients received antifungal therapy and there was no significant difference between the effects of antifungals on mortality (n: 65 (39.9%) vs. 98 (60.1%), P=0.607). CONCLUSIONS: Dialysis and concurrent bacteremia are strong predictors of mortality in 30 days within patients with candidemia, whereas follow-up blood cultures have a protective role with lower mortality rates. In our study, the most important source of candidemia was catheter, and C. parapsilosis was the most common causative agent. The catheter was removed in almost all patients and the mortality rate was almost one third among these patients.

A case of idiopathic intracranial hypertension related with vesicoureteral reflux.

Pseudotumor cerebri is idiopathic intracranial hypertension. The etiology of this syndrome has not been fully clarified. Excess cerebrospinal fluid production, scarcity of cerebrospinal fluid absorption, intracranial venous pressure elevation, increased intracranial blood volume are all thought to be responsible. The symptoms of the disease may be ordered according to prevalence as follows: headache due to increased intracranial pressure, blurred vision and diplopia. A thirteen-year-old female patient was brought in with complaints of headache, double and blurred vision. Systemic arterial hypertension (140/70 mmHg) was determined. Vesicoureteral reflux was detected as the hypertension etiology. In this article a rare pseudotumor cerebri case is presented secondary to vesicoureteral reflux which caused hypertension.

Randomized comparative study of burr-hole craniostomy versus twist drill craniostomy; surgical management of unilateral hemispheric chronic subdural hematomas.

OBJECTIVE: Although there is a tendency to minimize the surgical procedures for chronic subdural hematomas, there is no agreement on the optimal treatment. In the literature there is only one published result of a randomized study comparing twist drill craniostomy with burr-hole craniostomy. We aimed to compare twist drill craniostomy with burr-hole craniostomy for the treatment of unilateral hemispheric chronic subdural hematomas in adults. MATERIAL AND METHODS: The study was planned as a prospective, randomized, controlled investigation. Between November 2002 and April 2006, 70 patients (54 male and 16 female) with unilateral hemispheric chronic subdural hematomas were operated. 32 patients underwent burr-hole craniostomy and 38 patients were treated by twist drill craniostomy. After discharge, the patients were followed up at 1, 3 and 6 months after operation. Mortality, morbidity, surgical complications requiring reoperation, duration of hospitalization, recurrence, total number of reoperations, and cure rates were compared. RESULTS: Two patients died and one patient developed 6th nerve paresis in the inpatient period. There were three recurrences (two in the burr-hole craniostomy group, one in the twist drill craniostomy group) and in one patient from the burr-hole craniostomy group a chronic subdural hematoma developed on the contralateral side postoperatively. There was no significant difference clinically and radiologically between the two groups at any time period. CONCLUSION: Both surgical methods seem effective for the treatment of unilateral chronic subdural hematomas.

Is there a way to avoid surgical complications of twist drill craniostomy for evacuation of a chronic subdural hematoma?

BACKGROUND: Although twist drill craniostomy for evacuation of a chronic subdural hematoma is a rapid and minimally invasive procedure, it carries the risk of complications because it is a 'blind' technique. Our aim was to analyse the complications in a series of patients treated by this technique in order to identify methods of avoidance by modifications in the surgical technique. METHOD: Thirty-nine patients with a chronic subdural hematoma underwent twist drill craniostomy between November 2002 and December 2005 in our clinic. When a surgical complication happened we modified our surgical technique to see if this avoided it in future patients. FINDINGS: Surgical complications happened in 7 patients (17.9%) including inadequate drainage, brain penetration, acute epidural hematoma and catheter folding. After preventive modifications these complications did not recur. CONCLUSIONS: Modifications in the technique of twist drill craniostomy are described in this paper which may minimise the occurrence of surgical complications.

Chernobyl radioactivity on the Black Sea coast of Turkey.

After the Chernobyl reactor accident, Eastern Black Sea coast was one of the heavily contaminated regions of Turkey. Clouds loaded with radioactive isotopes arrived the region on May 1986 and emptied their contents with the heavy rains that are frequently seen in the region. In order to asses the current level of contamination, several different samples, moss, lichen, litter, surface soil and soil cores were collected on August 1994. Samples were brought to the laboratory and their moisture, pH and organic matter contents were determined. Gamma-ray spectra of the samples were collected with a HpGe detector. (137)Cs was the major isotope observed. Activity of most litter samples were below 1000 Bq/kg, while most of the moss samples had activities below 5000 Bq/kg, there were a few with higher (137)Cs activities. Surface soil samples generally had activities less than 2000 Bq/kg and depth profiles of cesium activities in the soil cores showed regional variations.

Determination of selenium in human diets by radiochemical neutron activation analysis.

A post-irradiation radiochemical separation technique was tested for the determination of selenium levels in diet samples, collected by using a duplicate portion technique, from both rural and urban population groups in Turkey. The technique involved sample irradiation, acid digestion, selective distillation, precipitation and filtration steps. During the separations it was possible to determine the yield of each sample using a stable selenium carrier. An average chemical yield of 71 +/- 3% was obtained for the radiochemical neutron activation analysis. For samples from urban and rural regions, the average selenium concentrations obtained were 0.14 +/- 0.04 and 0.07 +/- 0.02 mg kg-1, respectively. It was also possible to determine daily dietary selenium intakes, which were found to be 81 +/- 41 micrograms and 23 +/- 11 micrograms for the urban and rural groups, respectively. Although daily selenium intakes were found for a small number of subjects in this study, the separation technique developed can be used for determination of the selenium status in larger population groups.