Topical N-Acetylcysteine Improves Wound Healing Comparable to Dexpanthenol: An Experimental Study

In this study, we aimed to compare the effects of dexpanthenol and N-acetylcysteine on wound healing. The wound healing process is a multifaceted sequence of activities associated with tissue restoration process. A number of investigations and clinical studies have been performed to determine new approaches for the improvement of wound healing. A total of 30 rats were divided into 3 equal groups. A linear 2-cm incision was made in the rats'' skin. No treatment was administered in the first (control) group. Dexpanthenol cream was administered to the rats in the second group and 3% N-acetylcysteine cream was administered to the rats in the third group. The wound areas of all of the rats were measured on certain days. On the 21st day, all wounds were excised and histologically evaluated. The epithelialization and granulation rates between the groups were revealed to be similar in microscopic evaluations. Although the fibrosis was remarkable in the control group as compared with the other groups, it was similar in N-acetylcysteine and dexpanthenol groups. Angiogenesis rate was remarkable in the N-acetylcysteine group compared with the others. In multiple-comparison analysis, Dexpanthenol and N-acetylcysteine groups had similar results in terms of wound healing rates (P < 0.05), which were both higher than in the control group (P > 0.05). The efficacy of N-acetylcysteine in wound healing is comparable to dexpanthenol, and both substances can be used to improve wound healing.Key words: N-acetylcysteine, Dexpanthenol, Wound healingWound healing is a multifaceted sequence of activities associated with the tissue restoration process.¹ This activity takes place in 4 main steps: inflammation, proliferation, matrix deposition, and remodeling.^2,3 Moreover, there are many factors that might have harmful effects on the wound healing process. In this regard, there have been numerous analyses and clinical studies aiming to find new methods for the improvement of wound healing processes.⁴Dexpanthenol is the biologically-active alcohol of pantothenic acid, which leads to an elevation in the amount of coenzyme A in the cell. Dexpanthenol is extensively used in topical form, since it can easily penetrate the skin even at large local concentrations. When used in formulations, dexpanthenol is most effective for the stimulation of epithelialization, granulation, and the mitigation of itching.⁵N-acetylcysteine (NAC) is a prodrug that supplies bioavailable cysteine for glutathione replenishment and prevents oxidative damage as well as inflammation. It also leads to glutathione (GSH) formation in the body. Besides fostering angiogenesis, it is used to scavenge free radicals. NAC has a number of functions in the stages of repair process, including cell proliferation, migration, and scratch wound healing. Moreover, NAC has also been reported to promote wound healing in diabetic rats.⁶In this study, we aimed to compare the effects of dexpanthenol, a molecule that is widely used to improve wound healing, and NAC, a molecule that reduces oxidative stress and inflammation, on wound healing.     

Exercise testing induces fatal thromboembolism from mechanical mitral valve

Thromboembolism is still one of the most important complications of prosthetic heart valves. Embolism to a major coronary branch is rare, but acute proximal occlusions can be fatal, even when the coronary arteries are otherwise normal and intervention is rapid. We report a fatal complication of an exercise test in a patient who had a St. Jude bileaflet mitral valve. After an exercise test, a 42-year-old woman with a mechanical prosthetic valve had a severe hemodynamic collapse with acute ST segment changes. Coronary angiography showed a totally occluded left main coronary artery with TIMI grade 0 to 1 flow. Rapid injection of contrast material and the passage of a floppy guidewire through the thrombus restored a TIMI grade 3 flow. Angiography showed no coronary atherosclerostic involvement. Despite successful coronary reperfusion, intra-aortic balloon counterpulsation, and intensive medication, the patient died. This case demonstrates that exercise testing should be applied with great caution in patients with prosthetic valves, and only after a careful evaluation of valve function. We recommend transesophageal echocardiography prior to exercise testing in these patients.     

Whole-body vibration-induced muscular reflex: Is it a stretch-induced reflex?

[Purpose] Whole-body vibration (WBV) can induce reflex responses in muscles. A number of studies have reported that the physiological mechanisms underlying this type of reflex activity can be explained by reference to a stretch-induced reflex. Thus, the primary objective of this study was to test whether the WBV-induced muscular reflex (WBV-IMR) can be explained as a stretch-induced reflex. [Subjects and Methods] The present study assessed 20 healthy males using surface electrodes placed on their right soleus muscle. The latency of the tendon reflex (T-reflex) as a stretch-induced reflex was compared with the reflex latency of the WBV-IMR. In addition, simulations were performed at 25, 30, 35, 40, 45, and 50 Hz to determine the stretch frequency of the muscle during WBV. [Results] WBV-IMR latency (40.5 ± 0.8 ms; 95% confidence interval [CI]: 39.0–41.9 ms) was significantly longer than T-reflex latency (34.6 ± 0.5 ms; 95% CI: 33.6–35.5 ms) and the mean difference was 6.2 ms (95% CI of the difference: 4.7–7.7 ms). The simulations performed in the present study demonstrated that the frequency of the stretch signal would be twice the frequency of the vibration. [Conclusion] These findings do not support the notion that WBV-IMR can be explained by reference to a stretch-induced reflex.Key words: Skeletal muscle function, Gravitational physiology, Tonic vibration reflex     

Body position and obstructive sleep apnea syndrome

In adults, influence of body position on the occurrence of respiratory events during sleep is recognized, and increased numbers of respiratory events occur when the supine position is assumed.1-4 In 1985, Orr et al. showed that body position did not influence respiratory events during sleep in children.5 Recently, Fernandes do Prado et al. showed that children had a lower obstructive apnea hypopnea index (AHI) in supine position.6 Results of these two studies are different from others performed on adults. Moreover, upper airway abnormalities were not considered in these studies.The aim of the present study was to evaluate the effect of body position on obstructive respiratory events in children with different upper airway findings.     

Scintigraphic evaluation of gallbladder motor functions in H pylori positive and negative patients in the stomach with dyspepsia

AIM：To evaluate the relationship between gallbladder （GB） motor function and H pylori infection in the stomach.
METHODS： All cases （86） underwent the 14C urea breath test （UBT）. ^14C-UBT was found as positive in 58 and negative in 28 dyspeptic patients. ^14C- UBT was accepted as a gold standard test. Clo test and histopathologic examination were compared with the results of ^14C-UBT in cases who tolerated upper gastrointestinal endoscopy procedure. Cholescintigraphy with ^99mTc-mebrofenin was used to determine the parameters of GB motor function （GB filling and emptying time, half of the emptying time, ejection fraction at 30th and 60th min） in all patients.
RESULTS： We found the sensitivity and specificity as 88% and 86% for Clo test and as 89% and 80% for histologic evaluation, respectively. The parameters of GB function were not significantly different in H pylori positive and negative patients. The GB emptying was normal in both groups. Minimum GB filling time was 30 min in 34 of 86 cases （39.5%）, filling was not observed in 2 cases. The GB ultrasonography （USG） results were normal for all cases and bile composition abnormality was not determined.
CONCLUSION： Our study showed that ^14C-UBT is highly reliable method to detect the presence of H pylori. The presence of H pylori infection does not directly affect the GB function.     

Evaluation of corpus callosum morphometry in patients with mesial temporal lobe epilepsy with hippocampal sclerosis

Purpose

The purpose of the study was to evaluate the effects of mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS) on corpus callosum (CC) morphometry in large and pathologically proven MTLE-HS patients.

Methods

We measured certain CC dimensions in 103 patients and 33 healthy controls using in vivo magnetic resonance imaging. In particular, we compared the two groups in relation to the clinical (localization of the HS, duration of epilepsy, frequency of seizures and length of seizures) and demographical (age, gender, handedness) features. Students’ t test, two-way ANOVA and Spearman test were used for statistical analysis.

Results

There was no significant difference between CC morphometry with respect to age and handedness among patients. The differences between the genders, however, were significant favouring longer diameters in males. We found significant decrease in the dimensions of the genu, body, isthmus and splenium of the CC in the MTLE-HS group, but there was no reduction in the size of the rostrum.

Conclusions

This general reduction in the size of the CC except for the rostrum was thought to be the result of cortical atrophy secondary to the disease. Concerning the preserved rostral part of the CC, it was thought that the fibers of the frontal lobe pass through different pathways than the tracts in the rostrum.     

Angiotensin II inhibits uptake of transferrin-bound iron but not non-transferrin-bound iron by cultured astrocytes

The existence of all components of the renin–angiotensin system (RAS) and the iron metabolism system, and the recent findings on the functions of angiotensin II (ANGII) in peripheral iron metabolism imply that ANGII might play a role in iron homeostasis by regulating expression of iron transport proteins in the brain. Here, we investigated effects of ANGII on uptake and release of iron as well as expression of cell iron transport proteins in cultured astrocytes. We demonstrated that ANGII could significantly inhibit transferrin-bound iron (Tf-Fe) uptake and iron release as well as the expression of transferrin receptor 1 (TfR1) and the iron exporter ferroportin 1 (Fpn1) in cultured astrocytes. This indicated that the inhibitory role of ANGII on Tf-Fe uptake and iron release is mediated by its negative effect on the expression of TfR1 and Fpn1. We also provided evidence that ANGII had no effect on divalent metal transporter 1 (DMT1) expression as well as non-transferrin-bound iron (NTBI) uptake in the cells. Our findings showed that ANGII has a role to affect expression of iron transport proteins in astrocytes in vitro and also suggested that ANGII might have a physiological function in brain iron homeostasis.