Toxicity assessment of hydroxyapatite nanoparticles in rat liver cell model in vitro

Hydroxyapatite nanoparticles (HAP NPs) are widely used for preparations of biomedical and biotechnological fields such as drug delivery, gene therapy, and molecular imaging. However, the current toxicological knowledge about HAP NPs is relatively limited. The present study was designed to investigate the toxicity potentials of various concentrations (0–1000 µg cm−2) of HAP NPs in cultured primary rat hepatocytes. Cell viability was detected by 3-(4,5-dimethyl-thiazol-2-yl) 2,5-diphenyltetrazolium bromide (MTT) assay and lactate dehydrogenase (LDH) release, while total antioxidant capacity (TAC) and total oxidative stress (TOS) levels were determined to evaluate the oxidative injury. The DNA damage was also analyzed via scoring liver micronuclei rates and determining 8-oxo-2-deoxyguanosine (8-OH-dG) levels. The results of MTT and LDH assays showed that the higher concentrations of dispersed HAP NPs (300, 500, and 1000 µg cm−2) decreased cell viability. Also, HAP NPs increased TOS (500 and 1000 µg cm−2) levels and decreased TAC (300, 500, and 1000 µg cm−2) levels in cultured hepatocytes. On the basis of increasing doses, the NPs as depending on dose caused significant increases of the number of micronucleated hepatocytes and 8-OH-dG levels as compared to control culture. Furthermore, the highest concentration of HAP NPs (1000 µg cm−2) exhibited cytotoxic activity. Based on these results, HAP NPs have a dose-dependent toxic effect in rat hepatocytes. Further extensive research in this field is promising and reasonable.

Metabolic impact of partial volume correction of [18F]FDG PET-CT oncological studies on the assessment of tumor response to treatment

AIM

The aim of this work is to evaluate the metabolic impact of Partial Volume Correction (PVC) on the measurement of the Standard Uptake Value (SUV) from [18F]FDG PET-CT oncological studies for treatment monitoring purpose.

METHODS

Twenty-nine breast cancer patients with bone lesions (42 lesions in total) underwent [18F]FDG PET-CT studies after surgical resection of breast cancer primitives, and before (PET-II) chemotherapy and hormone treatment. PVC of bone lesion uptake was performed on the two [18F]FDG PET-CT studies, using a method based on Recovery Coefficients (RC) and on an automatic measurement of lesion metabolic volume. Body-weight average SUV was calculated for each lesion, with and without PVC. The accuracy, reproducibility, clinical feasibility and the metabolic impact on treatment response of the considered PVC method was evaluated.

RESULTS

The PVC method was found clinically feasible in bone lesions, with an accuracy of 93% for lesion sphere-equivalent diameter >1 cm. Applying PVC, average SUV values increased, from 7% up to 154% considering both PET-I and PET-II studies, proving the need of the correction. As main finding, PVC modified the therapy response classification in 6 cases according to EORTC 1999 classification and in 5 cases according to PERCIST 1.0 classification.

CONCLUSION

PVC has an important metabolic impact on the assessment of tumor response to treatment by [18F]FDG PET-CT oncological studies.

Zingiberene attenuates hydrogen peroxide-induced toxicity in neuronal cells

In this experimental design, we explored the neuroprotective potential of zingiberene (ZGB), a monocyclic sesquiterpene, in hydrogen peroxide (H2O2)-induced toxicity in newborn rat cerebral cortex cell cultures for the first time. The rats were exposed to H2O2 for 6 h to determine the oxidative stress levels. To evaluate cell viability, both 3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide and lactate dehydrogenase assays were carried out. Total antioxidant capacity (TAC) and total oxidative stress (TOS) parameters were used to evaluate oxidative changes. Besides determining 8-hydroxy-2-deoxyguanosine (8-OH-dG) levels in vitro, single-cell gel electrophoresis was also performed to measure the resistance of neuronal DNA to H2O2- exposed rats. Our results showed that survival and TAC levels of the cells decreased, while TOS, 8-OH-dG levels and the mean values of the total scores of cells showing DNA damage increased in the H2O2 alone-treated cultures. But pretreatment of ZGB suppressed the cytotoxicity, genotoxicity and oxidative stress that were increased by H2O2. Based on these observations, it is suggested that the sesquiterpene ZGB can be used as a novel and natural potential therapeutic in counteracting oxidative damages in the field of neurodegenerative disorders.

Gender difference in sleep profile of severely obese patients with obstructive sleep apnea (OSA)

OBJECTIVES

Few papers addressed the gender difference in the polisomnographic features of obstructive sleep apnea (OSA). In this paper we investigated the sleep architecture and the nocturnal respiratory pattern in a group of severely obese women with OSA compared with a group of men with OSA matched by age and weight.

DESIGN

A cross-sectional study.

SETTING

Primary-care setting.

SUBJECTS, MAIN OUTCOME MEASURES

Anthropometric parameters, respiratory function data and a full night polisomnography were evaluated in a group of 45 obese subjects, 20 females and 25 males, with a previous diagnosis of OSA.

RESULTS

The group of the severely obese women with OSA presented greater disturbances of the sleep architecture than the group of the men does (wake time after sleep onset 92.6+/-52.4 vs 58.2+/-45.2 min, P<0.05; total wake time 104.8+/-51.4 vs 67.8+/-47.4, P<0.05; number of awakenings 15.5+/-3.6 vs 10.2+/-6.215, P<0.001; OSA that occurred almost exclusively during REM sleep (REM OSA) 35% vs 4%, P<0.05) and a reduced sleep efficiency (69.6+/-15.9 vs 80.3+/-14.0%, P<0.05).

CONCLUSIONS

Severely obese women with OSA, even with milder OSA, present greater disturbances of the sleep architecture with a more severe sleep disruption and more frequently REM OSA in comparison with men matched by age and weight.

Preference for fixed or automatic CPAP in patients with obstructive sleep apnea syndrome

BACKGROUND

The aims of this study were to compare compliance to treatment with fixed CPAP and with autoCPAP, subjective preference for type of CPAP treatment, and factors associated to preference for autoCPAP in patients with OSAS.

PATIENTS AND METHODS

Twenty-two subjects were studied in a randomized, single blind cross-over fashion. They were treated for one month by fixed CPAP (Elite Sullivan V, ResMed, Sydney, Australia) and one month by autoCPAP (Autoset T, ResMed, Sydney, Australia).

RESULTS

Four subjects who stated a preference for fixed CPAP and four who expressed no preference were pooled together; fourteen preferred autoCPAP. Compliance to treatment using the two machines did not differ in the first group (3.8 (1.9) vs. 3.8 (1.5)h/day, fixed vs autoCPAP), but was higher with autoCPAP in the second group (4.8 (1.8) vs 5.5 (1.5)h/day, P<0.05). Baseline apnea/hypopnea index (AHI) was high in both groups, but was higher in the second group P<0.02. First treatment was always fixed CPAP in patients who preferred fixed CPAP, while it was either in the other subjects.

CONCLUSIONS

Compliance to autoCPAP differs among OSAS patients. As long as factors predicting higher compliance to autoCPAP are not found, a trial with autoCPAP in patients poorly compliant to fixed CPAP may be warranted.

A new simple laparoscopic-extracorporeal technique for the repair of a Morgagni diaphragmatic hernia

We used a new technique to treat a right-sided Morgagni hernia in a symptomatic adult with a transverse colon that was herniated in the chest. Three trocars were required. The herniated viscera were easily reduced in the abdomen, and the diaphragmatic border that was mobilized from the liver showed the elliptical diaphragmatic defect (9 x 5 cm); however, the hernial sac was not resected. Four transversal 1-cm cutaneous incisions were made just below the costal arch. Using a Reverdin needle holder, we introduced eight ligatures under laparoscopic control through the abdominal wall and through the free diaphragmatic border. Each suture was then held by the grasper and freed from the Reverdin. After the Reverdin was extracted and reintroduced more caudally, the intraabdominal suture was placed into it and finally extracted again. Before knotting, all the sutures were pulled together to achieve perfect closure of the defect. A suction drain was placed in the hernial sac. The duration of the procedure was 12 min. The patient was discharged on the 5th postoperative day. A review of 20 other patients treated via a video-assisted approach is also included here. We found this original technique to be extremely simple, rapid, and effective. It can also be performed by surgeons who are not specially trained in intracorporeal suturing and knotting and can probably also be used for the repair of other types of diaphragmatic defects. The use of laparoscopy and magnification allows the surgeon to achieve a better point of control for simpler solutions.

Hypercapnia in obstructive sleep apnoea syndrome

BACKGROUND

The reports on the prevalence of hypercapnia in Obstructive Sleep Apnoea Syndrome (OSAS) are conflicting. We studied the prevalence of hypercapnia in a population of OSAS patients referred to a Department of Respiratory Medicine and the mechanism of the respiratory failure in OSAS associated with Obesity Hypoventilation Syndrome (OHS) or with Chronic Obstructive Pulmonary Disease (COPD) (Overlap syndrome).

METHODS

We studied 219 consecutive OSAS patients during a period of 3 years. We recorded age and anthropomorphic data and performed polysomnography and pulmonary function tests. In relation to the value of PaCO(2), the patients were divided in hypercapnic (PaCO(2)>45 mmHg) patients and normocapnic patients. They were also divided into three groups in relation to the presence of "simple" or "pure" OSAS, to the presence of OSAS associated with COPD, to the presence of OSAS associated with OHS.

RESULTS

Seventeen per cent of the patients were hypercapnic. They were significantly heavier, had more severe lung function test abnormalities and more severe nocturnal oxyhemoglobin desaturations than the normocapnic ones, while Forced Expiratory Volume in one second as a percentage of Forced Vital Capacity (FEV1/FVC %) and Apnoea/Hypopnoea Index (AHI) were similar. OHS patients (13%) were significantly younger and heavier, had lower PaO(2) and higher PaCO(2) than "simple" OSAS patients (77%) and Overlap patients (10%) and had more severe restrictive defect. There was no difference in terms of AHI among the three groups, but nocturnal oxyhemoglobin desaturations were more severe in OHS group. In OHS group hypercapnia was correlated to FVC% of predicted and FEV1% of predicted and to the mean nocturnal oxyhemoglobin saturation; in Overlap patients PaCO(2) was correlated to Forced Expiratory Flow rate at low Vital Capacity.

CONCLUSION

Seventeen per cent of OSAS patients referred to a Department of Respiratory Medicine were hypercapnic. Hypercapnia in OHS patients correlates to the restrictive ventilatory defect whereas in Overlap patients it seems to correlate to peripheral airways obstruction. The distinction between patients with "simple" or "pure" OSAS and patients affected by OSAS associated with OHS or COPD could be important not only for clinical and prognostic implications, but also for the consequences in terms of ventilatory treatment.

Sleep related O2 desaturation in COPD patients with normoxaemia and mild hypoxyaemia

It is unknown whether daytime features predict oxygenation during sleep in COPD patients with normoxaemia or mild hypoxaemia. In this study our purpose was to evaluate by a pulse oxymeter, nocturnal desaturation in 33 COPD with PaO2 > 60 mmHg and to examine some daytime parameters as possible predictors of nocturnal hypoxaemia. A significant nocturnal desaturation has been defined by spending > or = 30% of total sleep-time with a TSTSaO2 < 90% > 30. According to this criterion we classified our patients in Desaturators (D) and Non Desaturators (ND). Our results showed that 39% of our patients were D and 61% ND. Among anthropometric and respiratory functional data we found that daytime SaO2B (r = 0.74 p < 0.001) daytime PaO2 (r = 0.47 p < 0.01) and daytime PaCO2 (r = 0.45 p < 0.05) were significantly correlated with the nocturnal oxygen desaturation and can predict the presence of sleep related hypoxaemia. In conclusion, our study confirms that a relatively high percentage of COPD patients with normoxaemia or borderline hypoxaemia exhibits significant nocturnal hypoxaemia. Further studies will suggest whether sleep related hypoxaemia deserves nocturnal oxygen therapy.

Rapid separation of gonadotropin-releasing hormone molecular forms by isocratic high-performance liquid chromatography on an ion-exchange column

The purpose of the present work was to develop a chromatographic system for the separation of five molecular forms of the gonadotropin-releasing hormone (GnRH); mammalian GnRH (mGnRH) (LHRH), salmon GnRH (sGnRH), chicken I GnRH (cIGnRH), chicken II GnRH (cIIGnRH) and lamprey GnRH I (IGnRH-I). By using an ion-exchange HPLC column and isocratic elution, it was possible to separate properly the five peptides in approximately 20 min. The utility of the system in determining the GnRHs forms present in the brain of two species of vertebrates was examined.