Optimal control strategy of SEIR endemic model with continuous age‐structure in the exposed and infectious classes

In this paper, we consider an endemic Susceptible‐Exposed‐Infectious‐Recovered model with continuous age‐structure for exposed and infectious classes. This work is appropriate for those infectious diseases that have exposed period such as tuberculosis and herpes virus infection. Key result is the existence of an optimal control problem. To control the spread of the disease, we use an objective functional with a suitable control and present an optimal control problem. Finally, we present some simulations that support our theoretical findings and show the effectiveness of the model.     

Avascular necrosis of the capitate

Although a large portion of the capitate is supplied by a single nutrient vessel, avascular necrosis of the capitatum is a rare condition. Its etiology is not clear, but a number of factors are linked to its pathogenesis including: repetitive trauma, dorsal instability of the carpus, Gaucher disease, systemic lupus erythematosus, gout, and steroid use. A 24-year-old woman presented with right wrist pain of 12 months duration. She reported no major trauma and reported that her pain had begun during the third month of her pregnancy. She had a history of hyperemesis gravidarum treated with 2 to 4 mg/daily of prednisone during her pregnancy for 6 weeks. She had 70° extension and 45° flexion of her wrist. Radiographs showed a hypodense area at the capitate head and midcarpal joint arthritis. Magnetic resonance imaging demonstrated avascular necrosis of the capitate and midcarpal collapse at the lunocapitate joint. Lunocapitate fusion with a partial scaphoidectomy was performed. At final follow-up 28 months postoperatively, she had 60° of volar flexion, and 50° of dorsiflexion. She was pain free in the majority of her activities of daily living. A small dose of steroid use during pregnancy, even in a short period of time, is a potential risk for avascular necrosis of the capitate and patients with a gradual onset of wrist pain during pregnancy may need to be investigated further if symptoms are not resolved with basic nonoperative measures within a reasonable time frame.     

Induction chemotherapy with triweekly docetaxel and cisplatin followed by concomitant chemoradiotherapy with or without surgery in stage III non-small-cell lung cancer: a phase II study

Background

The main goal of this study was to evaluate the feasibility and effectivity of triweekly docetaxel/cisplatin followed by weekly docetaxel/cisplatin concomitantly with radiotherapy with or without surgery in locally advanced non–small-cell lung cancer (NSCLC) patients.

Materials and Methods

Thirty five patients with locally advanced NSCLC were enrolled. Combination chemotherapy with triweekly docetaxel/cisplatin (75 mg/m²) was administered as induction regimen. After induction chemotherapy, patients were evaluated for surgery if their disease subsequently downstaged. Six cycles of weekly docetaxel/cisplatin (20 mg/m²) concurrently with radiotherapy up to a 60 Gy were administered after induction chemotherapy with or without surgery. Response, toxicity, time-to-progression and overall survival were evaluated.

Results

Twelve patients with stage IIIA-N2 and 23 patients with stage IIIB-T4N0-2 were evaluated (median age, 54 years). After 94 cycles of induction chemotherapy, partial response was achieved in 20 patients, 9 patients had stable disease and six had progressive disease. After overall treatment, 6 patients achieved complete response, 19 patients had partial response, 8 patients had progressive disease, and 2 patients had stable disease. Two patients experienced grade 3-4 pulmonary toxicity and 1 patient experienced grade 3 esophageal toxicity. Six patients underwent surgery. Median overall survival for all patients was 15 months and time-to-progression was 13 months with a median follow-up of 22 months.

Conclusion

Triweekly docetaxel plus cisplatin followed by weekly docetaxel plus cisplatin concomitantly with radiotherapy is effective and feasible and seems to be an alternative option for patients who have locally advanced NSCLC. Surgery may provide additional benefit for patients whose disease adequately downstaged after induction chemotherapy.     

Effect of a niobium-containing titanium alloy on osteoblast behavior in culture

Background: The chemistry of titanium is a key factor in determining implant–tissue interactions. Reports that a vanadium-based titanium alloy (Ti–6Al–4V) exhibits some cytotoxicity led to a search for an alternative.
Aim: The aim of the present study was to investigate the behavior of human osteoblast-like cells (Saos-2) cultured on Ti–6Al–4V or Ti–6Al–7Nb disks with a rough or a machined surface.
Results: In all four groups, the cells proliferated rapidly between days 1 and 3, and then plateaued. On day 1 of culture, the highest proliferation rate was of cells cultured on disks containing Nb with a machined surface. On day 7, there was no significant difference in cell density on all the tested surfaces. Alkaline phosphatase (ALP) activity was lower on the machined surfaces, regardless of the material used, suggesting that cells on rough surfaces exhibit a more mature phenotype. On day 3, cells cultured on rough disks made of Ti–6Al–7Nb showed the highest ALP activity; the lowest activity was observed on the machined Ti–6Al–4V surface. The highest level of osteocalcin (day 7) was found in the cells cultured on rough Ti–6Al–7Nb disks. Also, higher levels of transforming growth factor (TGFβ) were noted for cells cultured on the rough Ti–6Al–7Nb disks, suggesting that the Nb-containing alloy supports more rapid maturation of the osteoblast.
Conclusions: The results of the present study suggest that according to our cell culture preclinical model, Ti–6Al–7Nb may replace the Ti–6Al–4V alloy as an implant material.     

Resting regional cerebral perfusion in recent posttraumatic stress disorder.

BACKGROUND: Brain imaging research in posttraumatic stress disorder has been largely performed on patients with chronic disease, often heavily medicated, with current or past alcohol and substance abuse. Additionally, virtually only activation brain imaging paradigms have been done in posttraumatic stress disorder, whereas in other mental disorders both resting and activation studies have been performed. METHODS: Twenty-eight (11 posttraumatic stress disorder) trauma survivors underwent resting state hexamethylpropyleneamineoxime single photon emission computed tomography and magnetic resonance imaging 6 months after trauma. Eleven nontraumatized subjects served as healthy controls. RESULTS: Regional cerebral blood flow in the cerebellum was higher in posttraumatic stress disorder than in both control groups. Regional cerebral blood flow in right precentral, superior temporal, and fusiform gyri in posttraumatic stress disorder was higher than in healthy controls. Cerebellar and extrastriate regional cerebral blood flow were positively correlated with continuous measures of depression and posttraumatic stress disorder. Cortisol level in posttraumatic stress disorder was negatively correlated with medial temporal lobe perfusion. Anterior cingulate perfusion and cortisol level were positively correlated in posttraumatic stress disorder and negatively correlated in trauma survivors without posttraumatic stress disorder. CONCLUSIONS: Recent posttraumatic stress disorder is accompanied by elevated regional cerebral blood flow, particularly in the cerebellum. This warrants attention because the cerebellum is often used as a reference region in regional cerebral blood flow studies. The inverse correlation between plasma cortisol and medial temporal lobe perfusion may herald hippocampal damage.