An alternative method for measuring total respiratory resistance during quiet breathing: a feasibility and validation study.

OBJECTIVE: Determining the respiratory system's mechanical properties with minimal patient effort has been an important field of investigation addressing patients unable to perform pulmonary function testing and in light of the preventive measures due to the recent pandemic. The current study aimed to present an alternative method for total respiratory resistance measurement during tidal breathing, compare it with airway resistance (Raw), measured by body plethysmography, and validate the procedure in three groups of subjects with normal, constrictive and obstructive respiratory patterns in spirometry. PATIENTS AND METHODS: We developed an alternative method of assessing total respiratory resistance during quiet breathing. After manufacturing the appropriate hardware apparatus, we applied a steady extrinsic resistance (ΔR) for 100-200 m/s during tidal breathing. Α theoretical mathematical model allowed measurement of total respiratory resistance (Rtot) during inspiration (Rin) and expiration (Rex). To validate the method, 15 individuals were enrolled and assigned to the normal, obstructive and restrictive groups based on their spirometry patterns. All groups participated in two sets of measurements, the plethysmographic and novel method. Finally, respiratory resistance measurements were compared between groups and methods. RESULTS: The method was successfully developed, and Rtot measurements were recorded in five normal subjects and in five obstructive and restrictive subjects. Mean Rin and mean Rex were 4.99 cm H2O/L/sec and 4.42 cm H2O/L/sec in the healthy, 4.87 cm H2O/L/sec, and 6.63 cm H2O/L/sec in the obstructive and 5.97 cm H2O/L/sec and 4.12 cm H2O/L/sec in the restrictive group, respectively. Rex was notably higher than Rin in the obstructive group and was positively correlated with Raw (p<0.005, r=0.47). CONCLUSIONS: This method provides the theoretical background for a plausible alternative tool for accessing a mechanical parameter of the respiratory system, which is easy to perform and requires only passive patient cooperation while enabling rough differentiation between obstructive and restrictive disorders. The model's feasibility potential in a real-life setting was studied in a small sample, and additional implementation and validation of the method in a larger population are guaranteed.

The effect of revascularization procedures on healing of mixed arterial and venous leg ulcers.

AIM: The optimal management of venous leg ulcers in patients with concomitant peripheral artery disease (PAD) remains unclear. The aim of the present study was to evaluate the effectiveness of revascularization procedures in healing of the ulcers of mixed etiology. METHODS: During a 6-year period a total of 20 patients with evidence of chronic venous insufficiency, impaired arterial perfusion (ABI<0.75) and active leg ulcer were treated. Patients with moderate PAD (0.5

Sir Robert Carswell (1793-1857): coining the term "melanoma".

Melanoma is a neoplastic disorder produced by malignant transformation of the normal melanocyte, accounting for 4% of all skin malignancies. This malignancy was described since antiquity as a "fatal black tumour". In the 19th century, the distinguished pathologist Sir Robert Carswell coined first the term melanoma, provided its pathological description and depicted the lesion in his famous work Pathological Anatomy: Illustrations of the elementary forms of disease.

Clovis Vincent (1879-1947): founder of French neurosurgery and promoter of oncologic neurosurgery.

The eminent neurologist Clovis Vincent decided to become neurosurgeon at an advanced age. His is considered the founder of French neurosurgery and the Europe's first neurosurgeon. He was mainly interested in pituitary tumors and his work on oncologic neurosurgery remains valuable.

Dexamethasone plus octreotide regimen increases anticancer effects of docetaxel on TRAMP-C1 prostate cancer model.

AIM: The aim of this study was to evaluate whether the neoadjuvant use of the dexamethasone (DEX) plus octreotide (OCT) regimen can improve the direct anticancer effects of docetaxel (DOC) in the TRAMP-C1 prostate cancer model. MATERIALS AND METHODS: TRAMP-C1 cells were first characterized for the expression of SSTR1-5 and then were inoculated onto the femur of C57Bl mice. Investigation protocols employed TRAMP-C1 cell proliferation and invasion assays, analysis of radiographic images of the bone lesions and overall survival of the diseased animals. RESULTS: The triple combination treatment scheme showed significant anticancer effects, in both proliferation and invasion assays, compared to any single agent treatment scheme. DOC treatment following the neoadjuvant administration of DEX plus OCT regimen improved significantly the anticancer effects both on the grading of the bone lesions and on the overall survival of the diseased animals. CONCLUSION: Our data suggest that the neoadjuvant administration of DEX plus OCT regimen can improve the anticancer effects of DOC on the TRAMP-C1 model.

Septic and other complications resulting from biliary stones placed in the abdominal cavity. Experimental study in rabbits.

BACKGROUND: The aim of this experimental study is to assess the consequences of biliary stones placed in the abdominal cavity of rabbits. METHODS: The animals were allocated to five groups. In group A a nonsterile gallstone was used. In group B animals with a nonsterile gallstone received preoperative chemoprophylaxis. In group C a sterile stone was placed in the abdomen. Group D served as control. In group E were animals with a nonsterile stone who had a prolonged follow-up period. Parameters studied postoperatively were temperature, white blood cell count, abscess formation, sepsis, peritonitis, adhesion formation, intestinal obstruction, and histological changes of the omentum enveloping the gallstones. RESULTS: There was no statistically significant difference among the five groups concerning morbidity, mortality, or histological findings. CONCLUSIONS: The prevalence of septic complications was higher among the four groups that received gallstones compared to the control group and thus an adverse effect of gallstone implantation can be suggested.

Calcium dobesilate and transmembrane potential in canine cardiac cells. A preliminary study.

The electropharmacological effects of calcium 2,5-dihydroxybenzene sulfonate (calcium dobesilate, Doxium) were studied by means of intracellular microelectrode technique in order to measure the changes in action potentials (A.ps.) in dog isolated cardiac Purkinje fibers and the adjacent ventricular tissue superfused with Tyrode's solution. The addition of 25 mmol/l of calcium dobesilate to the superfusate suppressed automaticity in spontaneously functioning preparation. The frequency of the action potentials was decreased and their duration increased with elevation and prolongation of their plateau phase. These effects were produced in both Purkinje and adjacent ventricular fibers and they were reversed by washing out with Tyrode's solution. Addition of calcium (25 mmol/l) restored automaticity in preparation in which spontaneous activity had been previously arrested by tetrodotoxin (10(-4) mol/l). Calcium dobesilate-induced action potentials were slow i.e. with low dV/dtmax and were abolished by verapamil (10(-5) mol/l). Calcium dobesilate increased the contractile force in both normally working and tetrodotoxin-arrested preparations. These findings suggest that calcium dobesilate acts on the myocardial cell by promoting transmembrane calcium influx during the plateau phase through activation of the slow inward calcium current.