History Dependence in a Chemical Reaction Network Enables Dynamic Switching.

This work describes an enzymatic autocatalytic network capable of dynamic switching under out-of-equilibrium conditions. The network, wherein a molecular fuel (trypsinogen) and an inhibitor (soybean trypsin inhibitor) compete for a catalyst (trypsin), is kept from reaching equilibria using a continuous flow stirred tank reactor. A so-called 'linear inhibition sweep' is developed (i.e., a molecular analogue of linear sweep voltammetry) to intentionally perturb the competition between autocatalysis and inhibition, and used to demonstrate that a simple molecular system, comprising only three components, is already capable of a variety of essential neuromorphic behaviors (hysteresis, synchronization, resonance, and adaptation). This research provides the first steps in the development of a strategy that uses the principles in systems chemistry to transform chemical reaction networks into platforms capable of neural network computing.

Governing factors for preparation of silver nanoparticles using droplet-based microfluidic device.

Droplet-based microfluidic devices are now more than ever used for the synthesis of nanoparticles with low polydispersity and well-defined properties suitable for various industrial applications. Very small reaction volumes (microlitre to femtolitre) and short diffusion lengths, provide superior mixing efficiency and heat transport. Both play the dominant role in case of ultra-fast chemical reactions triggered upon reactant mixing, e.g. preparation of colloidal silver by reduction of silver salt. The high sensitivity of these systems to process variables makes otherwise more straightforward batch-wise production prone to suffer from inconsistency and poor reproducibility, which has an adverse effect on the reliability of production and further particle utilisation. This work presents a rigorous description of microfluidic droplet formation, reactant mixing, and nanoparticle synthesis using CFD simulations and experimental methods. The reaction mixture inside of droplets was homogenized in less than 40 milliseconds, which has been confirmed by simulations. Silver nanoparticles produced by droplet-based microfluidic chip showed superior to batch-wise preparation in terms of both particle uniformity and polydispersity.

Concomitant infection of the tricuspid valve and right ventricle free wall after chest tube insertion in a young patient without predisposing diseases.

Infective endocarditis (IE) is one of the most dreaded complications of healthcare-associated bloodstream infection. It is an important and potentially lethal complication of medical care and there is incidence evidence of it in this population. We describe a case of concomitant infection of the tricuspid valve and right ventricle free wall after chest tube insertion for spontaneous pneumothorax in a young patient without predisposing diseases.

In vitro motility changes in Roux limb after Roux-en-Y reconstruction.

BACKGROUND: The aim of this study is to compare the motility of Roux limb with that of normal segment. MATERIALS AND METHODS: Rats were divided into 3 equal groups as control, Roux-en-Y (Group A) and Roux-en-Y with vagotomy (Group B). Only midline incision and manipulations were applied in control group. Following distal gastrectomy, Roux-en-Y reconstruction was applied in Group A, while vagotomy Roux-en-Y gastrojejunostomy was applied in Group B. Rats were sacrificed 1 month later by cervical dislocations under anesthesia. The obtained jejunal segments were cut into four equal parts. The bath was 37 °C warm while 95 % O2 and 5 % CO2 gases were supplied in 10 ml bicarbonate Krebs' solution. RESULTS: KCl responses were similar in all three groups. Acetylcholine contraction responses in the vagotomy and non-vagotomy Roux-en-Y groups was higher than in those in control group significantly (p < 0.05). This response in vagotomy Roux-en-Y group was also higher than that in non-vagotomy group (p < 0.05). The induced electrical field stimulation contraction response in the vagotomy + Roux-en-Y group was lower than those in control group and non-vagotomy group (p < 0.05). CONCLUSIONS: These results show that muscarinic receptor density and/or function may increase after vagotomy and non-vagotomy group operation, and vagotomy may contribute to this increase. The decrease in electrical signal response in vagotomy Roux-en-Y group may depend on the decrease in acetylcholine oscillation from the cholinergic nerve ending (Tab. 1, Fig. 5, Ref. 25).

Relationship between uric acid albumin ratio and peripheral artery disease complexity.

OBJECTIVE: Uric acid to albumin ratio (UAR) reflects inflammatory activity and its predictive value has been shown in various diseases. In this study, we sought to evaluate the value of uric acid to albumin ratio in patients with peripheral arterial disease (PAD). PATIENTS AND METHODS: Two hundred forty-three PAD patients were divided into TransAtlantic Inter-Society Consensus-II (TASC-II) A-B and TASC-II C-D groups, according to their TASC-II classification. Biochemical variables of the patients were recorded, and the UAR of each patient was calculated. RESULTS: Patients who had TASC-II A-B disease were younger than the patients who had TASC-II C-D disease (60.7±8.71 vs. 63.28±8.8 years, p=0.024). Quade ANCOVA results showed that patients with TASC-II C-D disease had higher values of UAR when age was used as a covariate (t=-5.045, p<0.001). Lymphocyte count was significantly lower, and UAR was significantly higher in patients with TASC-II C-D disease (p=0.035 and p<0.001, respectively). UAR and lymphocyte count showed a significant positive correlation and a negative correlation with the TASC-II class of the disease (r=0.403, and r=-0.299, p<0.001 for both). A UAR of 1.54 predicted TASC-II C-D disease with a sensitivity and specificity of 57.9% and 78.8%, respectively. UAR predicted severe PAD with an OR of 3.723. CONCLUSIONS: UAR was a better tool for predicting TASC-II C-D disease compared to uric acid and albumin levels. UAR is an easily calculable parameter that can be used in clinical practice.

Successful percutaneous closure in patients with difficult atrial septal defects: case series and review of literature.

Atrial septal defect is a common form of congenital heart disease. Percutenous closure is an important treatment option for these patients. In this case series, we intend to share the percutaneous closure of the difficult types of secundum atrial septal defects.

COVID-19 illness and treatment decrease bone mineral density of surviving hospitalized patients.

OBJECTIVE: The number patients surviving COVID-19 hospitalization is steadily increasing. Follow-up management for these patients relies on an understanding of the long-term effects of COVID-19. Specifically, there are insufficient data about the lasting effects of COVID-19 on bone health. We aim in this study to evaluate whether COVID-19 illness and treatment adversely affect the bone health of surviving patients. PATIENTS AND METHODS: We assessed the bone mineral density (BMD) of hospitalized COVID-19 patients at diagnosis and at follow-up visits. Using the chest computed tomography (CT) scans of patients that were obtained for clinical management at diagnosis and follow-up visits, BMD was retrospectively measured by quantitative CT. The effect of COVID-19 severity markers and treatment-related factors on BMD were also assessed. RESULTS: BMD decreased by a mean of 8.6% (± 10.5%) from diagnosis to follow-up. The follow-up visits occurred at a mean of 81 (± 48) days after hospital discharge. The BMD decrease was significantly greater than expected for age-related annual BMD loss. The osteoporosis ratio increased two-fold after hospitalization for COVID-19 because of this substantial bone loss. On multivariable linear regression, only severity of COVID-19 pneumonia on initial chest CT and total steroid dose were predictive of change in BMD after COVID-19 hospitalization. CONCLUSIONS: Secondary osteoporosis may occur as a post-acute sequela of COVID-19. Therefore, the bone health status of patients surviving COVID-19 hospitalization should be monitored closely at follow-up visits, to facilitate the prevention and early treatment of osteoporosis complications.

Influence of channel height on mixing efficiency and synthesis of iron oxide nanoparticles using droplet-based microfluidics.

Microfluidic devices, allowing superior control over the spatial and temporal distribution of chemical substances and high process reproducibility, are nowadays essential in various research areas and industrial fields where the traditional "macroscopic" approach was no longer able to keep up with the increasing demands of high-end applications. In the present work, internal mixing of droplets formed by a flow-focusing X-junction at constant flow rates of both phases for three different channel heights (i.e. 20, 40 and 60 µm) was investigated and characterised. Both experimental methods and 3D CFD simulations were employed in order to resolve governing factors having an impact on internal mixing and homogenization time of model tracers inside of droplet reactors. Additionally, the influence of channel height on internal mixing was experimentally studied for continuous preparation of iron oxide nanoparticles by co-precipitation reaction. Since the initial nucleation phase is strongly affected by mixing and spatial distribution of all reactants, the final particle size and particle size distribution (PSD) can be used as direct indicators of mixing performance. It has been demonstrated that the smallest 20 µm channels provided narrower PSD and smaller particle mean size compared to higher channels.

Expression of retinoblastoma and cyclin D1 in gastric carcinoma.

Abnormal regulation of the cell cycle is a feature of many neoplasms. The role of cell cycle regulators in oncogenesis has been investigated in many human tumors. Alteration of the retinoblastoma (pRb) and cyclin D1 disrupt the Rb pathway and occur in many carcinomas. However the expression of the Rb and cyclin D1 in intestinal type gastric carcinoma is unclear. The purpose of this study was to investigate the expression of Rb and cyclinD1 in resected gastric carcinoma, their adjacent nonneoplastic mucosa and normal gastric mucosa, and finally to provide insights into the role of the Rb and cyclin D1 in gastric carcinogenesis. We investigated Rb and cyclin D1 expression in 43 patients (32 men, 11 women; mean age: 64) with primary gastric adenocarcinoma and compared the results with adjacent nonneoplastic mucosa. Adjacent nonneoplastic mucosa consisted of atrophy, dysplasia, intestinal metaplasia and gastritis. Expression of Rb was detected in 30 (69.7%) of gastric carcinoma, 18 (41.8%) of the adjacent nonneoplastic mucosa. Expression of cyclinD1 protein was detected in 31 (72%) of gastric carcinoma, 24 (55.8%) of adjacent nonneoplastic mucosa. Expression of Rb and cyclinD1 was not detected in normal gastric mucosa. The positive rate of Rb and cyclin D1 expression in gastric carcinoma was significantly higher than that adjacent nonneoplastic mucosa (p<0.05). There were significant trends for increased expression of Rb and cyclinD1 from nonneoplastic mucosa including atrophy, dyplasia, intestinal metaplasia and gastritis to carcinoma. These results suggested that positive expression of pRb and cyclinD1 might be an early event in gastric carcinoma and it tend to begin at precursor lesions and maintain throughout the progression of infiltration. Key words: Retinoblastoma, cyclin D1, gastric carcinoma, dysplasia, atrophy, intestinal metaplasia.

Effect of nitric oxide/cyclic guanosine mono-phosphate pathway on gallbladder relaxant response in bile duct-ligated guinea pigs.

BACKGROUND/AIMS: Common bile duct ligation (CBDL) in the guinea pig is a well-defined model of acalculous cholecystitis. Nitric oxide (NO) mediates smooth muscle relaxation by stimulating the activity of soluble guanylate cyclase. The aim of this study was to determine whether the NO/cyclic guanosine monophosphate pathway plays a role in gallbladder relaxant response after CBDL. METHODS: Relaxant response of gallbladder muscle strips from CBDL and sham-operated guinea pigs was studied in vitro. Animals were treated with saline, aminoguanidine or an aminoguanidine + L-arginine combination in vivo. Concentration-response curves of papaverine, diethylamine/NO, YC-1, sildenafil and amrinone were obtained and relaxations in each group were calculated as the percent of the contractions induced by carbachol (10(-6) M). RESULTS: There was a significant decrease in the gallbladder muscle relaxant responses to these substances in CBDL and aminoguanidine groups compared with sham surgical controls. The decreased relaxant response was reversed by aminoguanidine + L-arginine but not by aminoguanidine alone. CONCLUSION: Decreased relaxant responses might be due to the reduced guanylate cyclase enzyme activity, but further studies are required.

Cartilage tissue engineering on macroporous scaffolds using human tooth germ stem cells.

The main objective was to study cartilage regeneration through differentiation of human tooth germ stem cells (HTGSCs) into chondrocytes on different three-dimensional (3D) scaffolds (PCL, PLLA and PCL-PLLA). Scaffold topographies were studied by scanning electron microscopy and it was found that the scaffolds had interconnected macroporous structures. HTGSCs were isolated from impacted third molar tooth germs of young adult patients and grown for 3 weeks on the scaffolds in chondrogenic differentiation medium. Cell proliferation on the scaffolds was determined by MTS assay and it was observed that all scaffolds supported cell proliferation. Immunostaining was carried out for morphological and differentiation analyses. Immunohistochemical analyses revealed that the cells attached onto the scaffolds and deposited cartilage-specific extracellular matrix (ECM). Real-time PCR was performed to determine the expression levels of cartilage-specific genes. After 21 days of incubation in cartilage differentiation medium, expression of collagen type II increased only in the cells seeded onto PCL-PLLA blend scaffolds. Similarly, aggrecan expression was the highest on PCL-PLLA scaffolds after 3 weeks. These results suggest that all the scaffolds, and especially PCL-PLLA, were suitable for chondrogenic differentiation of HTGSCs. Copyright © 2015 John Wiley & Sons, Ltd.

Evaluation of serum vitamin D levels in patients with X syndrome.

OBJECTIVE: Cardiac X syndrome is defined in patients with normal coronary angiogram who has typical chest pain and objective myocardial ischemia evidence. Recent studies have evaluated the association between vitamin D deficiency (vit D def) and cardiovascular diseases. Our aim of this study was to compare serum vit D levels in patients with syndrome X and controls. PATIENTS AND METHODS: We included 66 patients (49 women, 17 men) with syndrome X and 47 (30 women, 17 men) healthy controls. All of the patients' demographic features, laboratory analysis and medications are recorded. Vit D is measured quantitatively by paramagnetic particle chemiluminescence method. RESULTS: Mean age of the syndrome X group was higher than controls (56 ± 9.2 vs. 49 ± 9.6 years p < 0.001). Body mass index was higher in the patient group than controls (31.2 ± 5.6 vs. 29.1 ± 4.7 kg/m2 p: 0.011). Vit D levels were significantly lower in the syndrome X group than controls (6 ± 5.2 vs. 11.9 ± 7 ng/ml, p < 0.001). Parathormone levels were significantly higher in the syndrome X group than the control group (38.3 ± 23.4 vs. 28 ± 17.2 pg/ml, p: 0.014). hsCRP levels were higher in the syndrome X group than controls (3.1 ± 5.4 vs. 1.8 ± 2.4 mg/L, p: 0.042). CONCLUSIONS: Our study demonstrated significantly lower vit D levels in patients with CSX. This finding is correlated with previous studies showing an inverse correlation with lower serum vit D levels and different types of cardiovascular diseases. Vit D def may be a risk factor for syndrome X. Vit D def related increased inflammation may lead to the development of endothelial dysfunction and microvascular angina.

Comparison of early postoperative function of liver and renal allografts with radionuclide imaging.

OBJECTIVES: Radionuclide imaging is a valuable tool during the early posttransplantation period for evaluating the functional status of renal and liver allografts. The aim of this study was to compare the early postoperative function of renal and liver allografts with serial radionuclide imaging. METHODS: Twenty-two renal and 22 liver allograft recipients were evaluated with serial radionuclide imaging. All grafts were from living related donors. For renal scintigraphy, recipients were injected with Tc-99m DTPA, and imaging was performed on postoperative days 3 and 7. Liver allograft recipients were evaluated with Tc-99m mebrofenin hepatobiliary scintigraphy within the first postoperative week and as required thereafter. The following parameters were computed for each scintigraphy: uptake, time to excretion of the radiopharmaceutical (T(ex)), and retention of radioactivity at the end of the study. RESULTS: Among 22 renal transplant recipients, 19 (86%) had normal uptake and T(ex) values on day 7 posttransplantation. Nine (41%) renal grafts exhibited retention. Among 22 liver transplant recipients, 7 (32%) had normal findings on the first hepatobiliary scan. All except eight liver grafts (64%) had a delay in T(ex), and 15 (68%) had parenchymal retention on the first scan, with improvement of function observed on serial scintigraphies obtained during follow-up. Decreases in uptake were seen less frequently and correlated with a prolonged postoperative hospital stay. CONCLUSION: Renal transplant recipients are more likely than liver allograft recipients to have a normal scintigraphy in the early posttransplantation period. Retention of radioactivity at the end of the study was the most frequently observed abnormality for both renal and liver allografts. Most liver transplant recipients exhibited a delay in excretion, and parenchymal retention, of radioactivity on the first evaluation, with subsequent improvement on follow-up serial scintigraphy studies.

A clinicopthologic study of a rare clinical entity mimicking breast carcinoma: idiopathic granulomatous mastitis.

Idiopathic granulomatous mastitis (IGM) is a rare chronic inflammatory lesion of the breast clinically simulating carcinoma. The purpose of this report is to review the clinicopathological features of this clinical entity in a series of 18 cases diagnosed in our institute. The notes of patients and the slides of the biopsy specimens of 18 cases with IGM were reviewed. Special stains for organisms and immunohistochemistry for T and B markers using the primary antibody was done. The diagnosis of IGM was made according to the criteria of Kessler and Wolloch. All but two patients were of reproductive age and all were parous. The main clinical finding was a unilateral, firm, discrete mass. All patients underwent excisional biopsy and recurrence was seen in three patients. In two of these patients who had recurrences, the prolactin level was high and reexcision combined with antiprolactinemic therapy was performed. The third patient was treated by reexcision and oral prednisone. There was granulomatous inflammation, centered mainly on breast lobules in all patients. T cell domination was observed. Exclusion of the other causes of a granulomatous lesion is necessary to make the diagnosis of IGM. The treatment of choice is unclear. Because of the clinical concern of malignancy, fine-needle aspiration cytology or core biopsy can be useful in some cases. To differentiate it from other granulomatous lesions, incisional biopsy or surgical excision of the lesion is necessary. In patients with delayed wound healing or recurrence after excisional biopsy, or those patients who have had an incisional biopsy only, if prolactin level is normal, reexcision and oral prednisone usage may be curative. In patients with a high prolactin level who have recurrence, medical treatment to control prolactin level may be useful in the management of these women.

Direct trocar insertion versus Veress needle insertion in laparoscopic cholecystectomy.

BACKGROUND: Direct insertion of the trocar is an alternative method to Veress needle insertion for the creation of pneumoperitoneum. The safety of direct disposable shielded trocar insertion for the creation of pneumoperitoneum was assessed by comparing with Veress needle insertion during laparoscopic cholecystectomy (LC). METHODS: One thousand five hundred patients undergoing LC with pneumoperitoneum were included in this study. In 470 patients the Veress needle insertion technique was used, and in 1,030 patients direct trocar insertion technique was used. Patients having indications for open trocar insertion were excluded from the study. RESULTS: Complication rate was significantly higher in the Veress needle group (14% versus 0.9%; P <0.01), and the two major complications, gastric perforation and iliac artery laceration, were also encountered in this group. CONCLUSIONS: Our results suggest that with a lower complication rate, direct insertion of the disposable trocar is a safe alternative to Veress needle insertion technique for the creation of pneumoperitoneum. Such an approach has further advantages such as less cost/instrumentation and rapid creation of pneumoperitoneum.

Acceleration of hepatobiliary dynamics in liver transplant donors.

This study compared hepatobiliary scintigraphy findings in livers before and after liver graft donation to examine whether there is a change in hepatobiliary dynamics. Nine donors underwent hepatobiliary scintigraphy with intravenous injection of Tc-99m mebrofenin 1 day before and during the first week after left liver lobectomy. Five donors also underwent additional scintigraphy more than 1 year postsurgery. Images were acquired every second for the first minute, and then every minute for the next 40 minutes. Hepatic arterial perfusion index and portal perfusion index(PPI) were calculated from the images acquired during the first minute. For the function phase the computed parameters included: hepatic extraction efficiency, (HEE), time to appearance of activity in the intrahepatic biliary channels, and in the intestine, time to half maximal activity, and activity retained in the liver parenchyma at 40 minutes. Time to appearance of intrahepatic biliary channels and of intestinal activity was shorter among scintigraphies obtained within 1 week postsurgery compared to the preoperative values. Early after the operation HEE increased and PPI decreased significantly. Visual inspection of the scintigraphy scan obtained in all donors, within the first week postsurgery revealed hypertrophy of the right liver lobe. None of the patients showed progression of right lobe activity to the left side, even among scans obtained more than 1 year after donation. Reduced time to activity in the biliary channels and intestine and increased HEE suggest acceleration of hepatobiliary dynamics.

Our sigmoid colon volvulus experience and benefits of colonoscope in detortion process.

BACKGROUND/AIMS: The sigmoid colon is the most frequent site for a volvulus. In this report, we review our experience with sigmoid colon volvulus. METHODOLOGY: We present our experience of 81 cases of sigmoid volvulus admitted to our department. RESULTS: Preoperative endoscopic volvulus detortion was attempted in all patients, and in 39 of them the procedure was successful. The success rate of endoscopic detortion for sigmoid colon volvulus with a flexible colonoscope (60%) was higher than with a rigid rectosigmoidoscope (42%). In 19 of these 39 non-operatively devolvulated patients, sigmoid resection with primary anastomosis was performed within 7-10 days after reduction, but 20 patients did not accept the elective operation after a non-operative treatment. Among the 61 patients undergoing urgent or elective operation for sigmoid volvulus, there were 17 laparotomies with only detortion, 19 resections with elective anastomosis, 6 resections with primary anastomosis, and 19 resections with a Hartmann's pouch. There were 9 deaths (21%) among 42 patients who underwent an emergency operation, and one (5.2%) among the 19 patients who had elective surgery died because of a cerebral embolus. CONCLUSIONS: Initial therapy with endoscopy affords decompression and an adequate preparation of patients for surgical resection, and a flexible colonoscope has notable advantages over rigid instruments for the detortion process.

Primary hydatid cyst of vastus lateralis muscle.

Musculoskeletal system is rarely involved by hydatid cyst,the larval form of Echinococcus Granulosus. A 37-year old man was diagnosed as having a cystic mass within his left thigh musculature. Preoperative computerized tomography suggested an unusual location of echinococcus although serology could not confirm the diagnosis. During surgery, a white coloured cyst within left vastus lateralis muscle was enucleated. Pathological examination after removal of the mass revealed hydatid cyst of vastus lateralis muscle. This case emphasizes that hydatidosis should be included in differential diagnosis of any soft tissue mass especially in regions where it is endemic.

Barium stone impaction in parkinsonism.

Autonomic symptoms such as orthostatic hypotension, abnormal sweating and constipation occur frequently in Parkinson's disease. In our case, barium meal used for upper gastrointestinal study caused barium stone formation and a paralytic-ileus-like syndrome. Therefore, attention should be paid while using barium meal for diagnostic purpose in Parkinsonism.

Validation of breast cancer nomograms for predicting the non-sentinel lymph node metastases after a positive sentinel lymph node biopsy in a multi-center study.

OBJECTIVE: In the study, our aim was to evaluate the predictability of four different nomograms on non-sentinel lymph node metastases (NSLNM) in breast cancer (BC) patients with positive sentinel lymph node (SLN) biopsy in a multi-center study. METHODS: We identified 607 patients who had a positive SLN biopsy and completion axillary lymph node dissection (CALND) at seven different BC treatment centers in Turkey. The BC nomograms developed by the Memorial Sloan Kettering Cancer Center (MSKCC), Tenon Hospital, Cambridge University, and Stanford University were used to calculate the probability of NSLNM. Area under (AUC) Receiver Operating Characteristics Curve (ROC) was calculated for each nomogram and values greater than 0.70 were accepted as demonstrating good discrimination. RESULTS: Two hundred and eighty-seven patients (287) of 607 patients (47.2%) had a positive axillary NSLNM. The AUC values were 0.705, 0.711, 0.730, and 0.582 for the MSKCC, Cambridge, Stanford, and Tenon models, respectively. On the multivariate analysis; overall metastasis size (OMS), lymphovascular invasion (LVI), and proportion of positive SLN to total SLN were found statistically significant. We created a formula to predict the NSLNM in our patient population and the AUC value of this formula was 0.8023. CONCLUSIONS: The MSKCC, Cambridge, and Stanford nomograms were good discriminators of NSLNM in SLN positive BC patients in this study. A newly created formula in this study needs to be validated in prospective studies in different patient populations. A nomogram to predict NSLNM in patients with positive SLN biopsy developed at one institution should be used with caution.