Effects of successful parathyroidectomy on neuropsychological and cognitive status in patients with asymptomatic primary hyperparathyroidism

PURPOSE

Besides typical clinical symptoms, primary hyperparathyroidism (pHPT) is associated with impaired quality of life and cognitive status. The aim of this study was to evaluate the quality of life and cognitive impairment in patients with pHPT, before and after parathyroidectomy.

METHODS

We conducted a panel study, which included asymptomatic pHPT patients scheduled for parathyroidectomy. Besides demographic and clinical data, patients' quality of life and cognitive capacity were recorded before, 1 month, and 6 months following parathyroidectomy using the Short Form 36 questionnaire (RAND-36), Beck Depression Inventory (BDI), Depression Anxiety Stress Scales (DASS), Mini-Mental State Examination (MMSE), and Symptom Check List 90-revised version (SCL90R).

RESULTS

During a 2-year follow-up, 101 patients entered the study (88 women), with an average age of 60.7 years. The Global score of RAND-36 test ameliorated by almost 50% 6 months after parathyroidectomy. The most sustained subscores of the RAND-36 test were role functioning/physical and health change, with an improvement of more than 125%. According to the BDI, DASS depression subscore, and SCL90R depression subscore, the extent of depressive symptoms reduction was approximately 60% 6 months postoperatively. The level of anxiety was reduced by 62.4%, measured by both the DASS and SCL90R anxiety subscores. The stress level was almost halved according to the DASS stress subscore (from 10.7 to 5.6 points). The results of the MMSE test showed a significant improvement postoperatively, for 1.2 points (4.4%). A worse preoperative score of each tool was related to the higher magnitude of improvement 6 months after parathyroidectomy.

CONCLUSION

A considerable number of pHPT patients, even without other typical symptoms, show signs of impaired quality of life and neurocognitive status preoperatively. After a successful parathyroidectomy, there is an improvement in quality of life, declined levels of depression, anxiety, and stress, as well as amelioration of cognitive status. Patients with more impaired quality of life and pronounced neurocognitive symptoms may expect more benefits from the surgery.

Child Neurology: Bartonella henselae Neuroretinitis in 2 Patients

Neuroretinitis due to Bartonella henselae infection is a rare cause of vision loss in children. Two pediatric cases of acute unilateral vision loss accompanied by edema of the optic nerve on fundoscopic examination are presented. Severe causes of vision loss were excluded. During the course of the disease, macular stellate exudates emerged on control fundoscopic examinations and diagnosis of neuroretinitis was made. A causative agent was confirmed by serologic examination, as high titers of IgM and IgG antibodies to Bartonella henselae were detected. Both patients significantly recovered after oral antibiotic treatment.

The usefulness of visual evoked potentials in the assessment of the pediatric multiple sclerosis

BACKGROUND

To evaluate the significance of visual evoked potentials (VEP) in the early diagnosis of optic neuritis (ON) and detecting clinically silent lesions in pediatric multiple sclerosis (PedMS). This study represents one of the largest series of PedMS which evaluated characteristics of VEP in PedMS patients.

METHODS

This was a retrospective study on 52 PedMS patients, aged 7-17 years. VEP analysis were done for all patients, after the first attack of disease and were compared to control subjects according to the pattern-reversal VEP findings.

RESULTS

The mean age of patients was 15.65 ± 1.89 years with male to female ratio of 16 (30.8%): 36 (69.2%). All of the patients had a relapsing-remitting course of the disease. ON was discovered on the initial attack in 18 (34.6%) patients, while 30 (57.7%) patients had ON in the second attack. Pathological VEP findings were present in 40 (76.9%) patients, of which 22 (42.3%) PedMS patients had clinically silent lesions. Prolonged latency of P100 waves in the PedMS group was statistically significant when compared to control subjects. The amplitude N1P1 showed a correlation with residual visual deficit.

CONCLUSION

Our results show that ON is a common initial manifestation of PedMS in the Serbian PedMS population. The prolonged P100 latency is the main indicator of ON. VEP is an objective, fast and accessible diagnostic method for detecting clinical and subclinical lesions. Thus, VEP deserves evaluation to be considered as an additional criterion for PedMS diagnosis.

Redox metabolism correlates with cellular turnover and clinical phenotype of papillary thyroid carcinoma and colloid goiter

INTRODUCTION

Papillary thyroid carcinoma (PTC) and colloid goiter (CG) represent the most common thyroid malignant and benign diseases, respectively. Oxidative stress is considered to have an important role in the pathogenesis of both diseases, but without sufficient and comprehensive data. The aim was to evaluate the redox profile, its influence on cell survival of PTC, comparing it with CG as a control and its relation with demographic, pathological and clinical parameters.

MATERIAL AND METHODS

We evaluated for the first time the PTC and CG tissue profile of advanced oxidation protein products (AOPP) and total thiols as parameters of redox metabolism and deoxyribonuclease I (DNase I) and deoxyribonuclease II (DNase II) activity as biomarkers of cell turnover and apoptosis. Tissue levels of biochemical parameters were quantified in PTC and CG tissue using spectrophotometric methods. Study parameters were evaluated in light of different demographic, clinical and pathological features of PTC and CG.

RESULTS

Papillary thyroid carcinoma tissue is characterized by increased antioxidant activity and a normal prooxidation level. Biochemical parameters show numerous correlations with demographic and clinical characteristics of PTC and CG patients. DNase I and II activities are dependent upon the AOPP concentration in PTC tissue. The size of CG can be predicted with combined use of AOPP, DNase I and DNase II. AOPP is the most powerful predictor of PTC capsular invasion, multicentric intrathyroid dissemination and lymph node metastasis phenotype.

CONCLUSIONS

Evaluated parameters can be used for assessment of tumor redox and survival status and the clinical course of PTC and CG.

Evaluation of Genetic Damage in Persons Occupationally Exposed to Antineoplastic Drugs in Serbian Hospitals

INTRODUCTION

Although useful in the treatment of malignant cells, antineoplastic drugs (ANPDs) as chemical genotoxic agents, can interfere with normal cell physiology causing genetic damage and unfavourable health effects, especially in occupationally exposed persons. The Cytokinesis-block Micronucleus (CBMN) Cytome assay has been widely used in human biomonitoring studies as a reliable biomarker of chemical genotoxic exposure.

OBJECTIVES

Our comprehensive research was conducted in order to evaluate micronuclei as a marker for preventive medical screening purposes for persons occupationally exposed to ANPDs.

METHODS

Using the CBMN Cytome test, peripheral blood lymphocytes of 201 control and 222 exposed subjects were screened for genetic damage.

RESULTS

Age and gender influenced micronucleus (MN) frequency, but smoking habit did not. The mean micronuclei frequencies and other parameters of the CBMN Cytome test [numbers of binuclear lymphocytes with one (MN1) or two (MN2) micronuclei] were significantly higher in the group of exposed persons. Positive correlation between duration of occupational exposure and MN frequency was revealed.

CONCLUSIONS

The results of our study performed on a large sample confirmed the capacity of the CBMN Cytome assay to serve as a reliable biomarker of long-term ANPD exposure.

Ionizing radiation-induced genotoxic and oxidative damage in peripheral lymphocytes and plasma of healthy donors

Biological dosimetry of ionizing radiation (IR) exposure relies on validated cytogenetic tests measuring the frequencies of micronuclei (MN) and dicentric chromosomes (DC). IR also causes oxidative damage of biomolecules, including DNA. We evaluated IR-induced genotoxic and oxidative damage in a carefully defined cohort of healthy donors, reducing confounding factors as much as possible. Frequencies of MN and DC (peripheral blood lymphocyte cultures) and oxidative stress parameters (plasma) were quantified. We observed dose dependence of both cytogenetic and biochemical endpoints, independent of age, sex, and smoking habits. Oxidative stress parameters, especially oxidative stress index, malondialdehyde, advanced oxidation protein products, and catalase, may be used confidently to assess IR-induced damage, if cytogenetic results are unavailable.

Oxidative Stress Profile in Genetically Confirmed Cases of Leber's Hereditary Optic Neuropathy

The mechanisms of the complex pathophysiology of Leber's hereditary optic neuropathy (LHON) are still insufficiently clarified. The role of oxidative stress as an etiological factor has been proposed and demonstrated in vitro, but without conclusive data that rely on clinical samples. The aim of the study was to evaluate and characterize the existence of oxidative stress in the plasma of LHON patients and healthy individuals. Whole mitochondrial genome sequencing has been performed in order to identify primary LHON mutations. For the assessment of oxidative stress, the following biomarkers were determined in plasma: total oxidant status (TOS), total antioxidant status (TAS), and oxidative stress index (OSI), while oxidative damage of cellular proteins was estimated by quantifying advanced oxidation protein products (AOPP). All three primary LHON mutations (m.3460G > A, m.11778G > A and m.14484 T > C) were identified as a genetic cause of the disease, where the most prevalent one was m.11778G > A. LHON patients have a highly significant increase of TOS and a marked decrease of TAS levels, which suggests the existence of substantial oxidative stress. OSI is high in LHON patients, which definitely implies the presence of redox imbalance. Elevated level of AOPP in LHON patients refers to the significant deleterious effects of oxidative stress on cellular proteins. Oxidative stress parameters do not significantly differ between LHON individuals with different primary mutations. Both symptomatic and asymptomatic LHON patients have an augmented level of oxidative stress which suggests that primary mutations exhibit a pro-oxidative phenotype. Gender and smoking habit significantly influence examined biochemical parameters when LHON patients are compared with the control group. Different mitochondrial haplogroups are characterized by altered levels of OSI in LHON group. The absence of physiological correlations between redox parameters reflects the deregulation of homeostatic oxidative/antioxidative balance in LHON patients. This is the greatest series of LHON patients that were evaluated for oxidative stress and the first case-controlled study that evaluated TOS, TAS, OSI, and AOPP and their influence on disease phenotype. It is evident that the presence of oxidative stress represents an important pathophysiological event in LHON and that it could potentially serve as a circulatory biomarker for a therapy efficacy understanding.

Correction to: Redox Status and Antioxidative Cofactor Metals Influence Clinical and Pathological Characteristics of Papillary Thyroid Carcinoma and Colloid Goiter

The original version of this article unfortunately contained a mistake.

Redox Status and Antioxidative Cofactor Metals Influence Clinical and Pathological Characteristics of Papillary Thyroid Carcinoma and Colloid Goiter

Papillary thyroid carcinoma (PTC) is the endocrine neoplasm that occurs the most often worldwide, and its molecular pathophysiology is still not well characterized. Redox status is recognized as an important factor of carcinogenesis, but its influence on the PTC's clinical course needs to be better elucidated. The aim of this research was to determine the tissue redox status of 65 PTC and 45 colloid goiter (CG) patients together with antioxidative cofactor metal profiling. The malondialdehyde (MDA) concentration was used to access the prooxidation level, while antioxidant mechanisms were estimated by assaying the activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and glutathione reductase (GR). The antioxidative cofactor metals included quantification of Se, Cu, Zn, and Mn concentration. PTC tissues had normal prooxidation levels and increased GPx and GR activity. The activity of SOD has been significantly reduced in multicentric PTC dissemination and increased in smokers. SOD activity was directly dependent on MDA levels in CG tissues. CG patients with retrosternal goiter had reduced MDA concentration and SOD activity. Numerous correlations between redox parameters in PTC tissues reveal good co-activation of antioxidative mechanisms and cooperative response on prooxidation. PTC tissues had decreased Se levels and increased concentration of Cu and Mn in comparison to other tissues. MDA concentration and SOD activity were significant predictors of PTC's multicentric dissemination and for the existence of lymph node metastases, respectively. Particularly, the concentration of Cu predicted the retrosternal localization in CG patients. Significant findings presented in this study provide a possibility for development of novel prognostic molecular biomarkers of PTC and CG.

Ectopic thyroid tissue in adrenal gland, case report and review of literature

Ectopic thyroid tissue is a rare pathological finding bellow the diaphragm and extremely rare finding is ectopic thyroid tissue in the adrenal gland (ETTAG). Thyroid tissue can be located anywhere along the way of embryological migration pathway of thyroglossal duct. In most cases of ectopic thyroid tissue, it is located in the neck. Here we present a case of 29 years old patient that was laparoscopically operated because of adrenal incidentaloma which showed 28 mm in maximal diameter on MRI. The patient had normal adrenal function. Pathohistological finding confirmed ETTAG. Follicular cells express TTF-1, Thyroglobulin, PAX8, and cytokeratin 7, and lack expression of calretinin. This is the 15th such case described in literature. Women are much more affected than men (14:1), and it usually presents in the fifth decade (mean age 49). In all cases ETTAG was composed of normal follicular cells, and C cells were not found. Review of the literature reveals that adrenal ectopic thyroid tissue is almost always cystic, and has distinctive pathologic features. The most important thing is that ETTAG must be distinguished from metastatic deposits from thyroid gland carcinoma. Our patient had normal thyroid function, without any nodules in thyroid gland. We report the youngest patient with ectopic thyroid tissue located in the adrenal gland.

In silico model of mtDNA mutations effect on secondary and 3D structure of mitochondrial rRNA and tRNA in Leber's hereditary optic neuropathy

The Leber's hereditary optic neuropathy (LHON) is a rare disease caused by mitochondrial DNA (mtDNA) mutations. Beside primary mutations, the effect of secondary mtDNA mutations in still unclear. We examined the effect of secondary mtDNA mutations on secondary structure of different mitochondrial RNAs. Whole mitochondrial genome sequence of LHON patients has been obtained from in six non related pedigrees by Sanger sequencing method. The effect of mutations located in mitochondrial RNA genes was examined by creating in silico models of RNA secondary and regional 3D structure, accompanied by sequence conservation analysis. All three primary LHON mutations (m.3460G>A, m.11778G>A and m.14484 T>C) were revealed in study families. Four mutations in MT-RNR1 gene (m.750A>G, m.956delC, m.1438A>G and m.1555A>G) were identified and only an m.1555A>G causes significant changes of secondary structure of mitochondrial 12S ribosomal RNA (rRNA), while it is the only mutation which does not alter its 3D structure. Five mutations (m.1811A>G, m.2706A>G, m.2831G>A, m.3010G>A and m.3197T>C) were discovered in MT-RNR2 gene and all of them induced substantial alterations of mitochondrial 16S rRNA secondary structure. Significant changes of mitochondrial 16S rRNA 3D structure are caused by m.1811A>G, m.2706A>G, m.3010G>A and m.3197T>C. A single insertion variant (m.15986insG) has been found in the MT-TP gene which encodes mitochondrial transfer RNA for Proline (tRNA Pro). This mutation does not cause substantial changes of tRNA for Proline secondary structure, while the 3D geometry remains without major changes. Most of the mutation loci exhibited high level of sequence conservation. Presence of multiple mutations in a single family appears to cause more extensive changes in mitochondrial 12S and 16S rRNA, then their individual influence. The effect of discovered mutations on in silico modelled RNA structure is in a significant correlation with the present knowledge about the potential of these mutation to participate in the pathophysiology of LHON and other human diseases. The presence of certain multiple mitochondrial RNA mutations could be a possible explanation of LHON clinical presentation in some families. All revealed mutations have been evaluated for the first time in terms of in silico structural modelling. The application of bioinformatics tools such as secondary and 3D RNA structure prediction can have a great advantage in better understanding of the molecular standpoint of the LHON pathophysiology and clinical phenotype.

Case-control study of primary hyperparathyroidism in juvenile vs. adult patients

OBJECTIVES

Primary hyperparathyroidism in juveniles is extremely rare condition, but in the last few decades the incidence is increasing. The aim of this study was to compare biochemical and clinical characteristics of juvenile and adult primary hyperparathyroidism patients.

METHODS

A retrospective case-control study was conducted from 2004 until 2017 in high volume endocrine surgery center. Juvenile group consisted of all primary hyperparathyroidism patients younger than 20 who have undergone parathyroidectomy, and two-fold more patients older than 20 were classified in control (adult) group.

RESULTS

A total of 14 patients with the age ≤20 years were included in the juvenile group, while 28 patients older than 20 were selected for the control group. Female-to-male ratio in juveniles was 1:1, and in adults 8:1 (p = 0.005). The most common form of the disease in juveniles was bone disease (42.9%) and most of adults were asymptomatic (39.3%). Mean preoperative serum calcium level was significantly higher in juveniles than in adults, 3.47 ± 0.74 mmol/L vs. 2.96 ± 0.25 mmol/L, p = 0.025. Mean preoperative PTH level was higher in juveniles than in control group, 572.6 ± 533.3 ng/L vs. 331.8 ± 347.5 ng/L, p = 0.089.

CONCLUSION

Clinical manifestations of primary hyperparathyroidism significantly differ in juvenile and adult patients. Juvenile primary hyperparathyroidism represents more severe form of the disease, often with end-organ damages, and it should be considered in patients with unspecific symptoms.

Analysis of secondary mtDNA mutations in families with Leber's hereditary optic neuropathy: Four novel variants and their association with clinical presentation

Leber's hereditary optic neuropathy (LHON) is a mitochondrial disease characterized by subacute optic atrophy which results in severe visual impairment. The penetrance, clinical expression and disease onset are variable, and frequently associated with other extraocular symptoms. The disease phenotype remains to be an intriguing question which is dependent upon primary as well as secondary mtDNA mutations. In this study we analyzed the whole mtDNA sequence in six LHON families from Serbian population. The mtDNA sequencing was performed by Sanger's method and various bioinformatic tools were used for analysis of detected mutations. LHON patients carry all three (m.3460G > A, m.11778G > A and m.14484 T > C) primary mutations, together with numerous secondary mtDNA mutations. Four novel mutations (m.4516G > A, m.8779C > T, m.13138G > A and m.15986insG) in four different families were discovered. The m.8779C > T and m.13138G > A mutations could have a potential influence on LHON symptoms, but the issue of effect of secondary mtDNA mutations in LHON patients needs to be better clarified in future studies.

Survival and prognostic factors for survival, cancer specific survival and disease free interval in 239 patients with Hurthle cell carcinoma: a single center experience

BACKGROUND

Hurthle cell carcinoma makes up 3 to 5% of all thyroid cancers and is considered to be a true rarity. The aim of our study was to analyze clinical characteristics and survival rates of patients with Hurthle cell carcinoma.

METHODS

Clinical data regarding basic demographic characteristics, tumor grade, type of surgical treatment and vital status were collected. Methods of descriptive statistics and Kaplan-Meier survival curves were used for statistical analysis. Cox proportional hazards regression was used to identify independent predictors.

RESULTS

During the period from 1995 to 2014, 239 patients with Hurthle cell carcinoma were treated at our Institution. The average age of the patients was 54.3, with female to male ratio of 3.6:1 and average tumor size was 41.8 mm. The overall recurrence rate was 12.1%, with average time for relapse of 90.74 months and average time without any signs of the disease of 222.4 months. Overall 5-year, 10-year and 20-year survival rates were 89.4%, 77.2%, 61.9% respectively. The 5-year, 10-year and 20-year cancer specific survival rates were 94.6%, 92.5%, 87.4%, respectively. When disease free interval was observed, 5-year, 10-year and 20-year rates were 91.1%, 86.2%, 68.5%, respectively. The affection of both thyroid lobes and the need for reoperation due to local relapse were unfavorable independent prognostic factors, while total thyroidectomy as primary procedure was favorable predictive factor for cancer specific survival.

CONCLUSION

Hurthle cell carcinoma is a rare tumor with an encouraging prognosis and after adequate surgical treatment recurrences are rare.

Molecular Dissection of Renal Ischemia-Reperfusion: Oxidative Stress and Cellular Events

Ischemic reperfusion kidney injury (IRKI) is a complex pathophysiological event, which is the most common cause of the acute kidney injury. The key characteristic of IRKI is a reduction in glomerular filtration rate, which implies an underlying impairment in hemodynamic regulation. In recent decades, convincing evidence illuminated the molecular and pathological events in the acute kidney injury, revealing the role of ischemia/reperfusion, oxidative stress, apoptosis, inflammation, fibrosis and changes in gene expression which activate different signaling pathways. The cascade of inflammation events is a key mediator of IRKI, which includes the inflammation process, complement activation and mobilization of innate immunity. Oxidative stress represents the increased presence of various free radicals that cannot be buffered by the antioxidant capacity which comprises of enzymatic and non-enzymatic components. Renal tissue injury during ischemia/reperfusion comes as a result of membrane lipids peroxidation, oxidative damage of proteins and DNA and results in apoptosis and necrosis. It is evident from many studies that augmentation of the antioxidant defense mechanisms has a protective role on kidney tissue. In recent years, the importance of heat-shock proteins and MicroRNAs in the pathogenesis of IRKI has been revealed and there are promising indications that in future they could serve as diagnostic biomarkers or therapeutic targets. Striking changes in global gene expression were shown, providing a great potential for fundamental understanding and clinical management of IRKI. The clinical outcome among patients with kidney transplantation will have the furthermost advance from the better understanding of the underlying molecular pathology of IRKI.

Gelatinases A and B and Antioxidant Enzyme Activity in the Early Phase of Acute Myocardial Infarction

Oxidative stress plays important roles in the pathophysiology of acute myocardial infarction (AMI). The aim of this study was to investigate the correlation of the oxidative stress status and matrix metalloproteinase activity in AMI patients in comparison to controls. This study included 136 subjects: 68 patients with AMI (42 males/26 females; mean age 58.5 ± 10.5 years) and 68 controls (37 males/29 females; mean age 60.2 ± 12.4 years). Gelatinases A and B were assayed using gelatin zymography, enzyme activities were obtained spectrophotometrically. Gelatinase A and B activities were increased in the AMI patients' group compared to the control. Activities of serum superoxide dismutase (SOD) and xanthine oxidase (XO) were significantly higher in AMI patients (106.53 ± 23.45 U/l, P < 0.001 and 158.18 ± 29.59 U/l, P < 0.001) than in the control group (55.99 ± 10.79 U/l and 79.81 ± 7.93 U/l). The activity of catalase (CAT) in the sera of AMI patients was lower (271.31 ± 7.53 U/l, P < 0.005) than in the control group (305.94 ± 97.28 U/l). Plasma glutathione peroxidase (GPx) and glutathione reductase (GR) in AMI patients were significantly higher (582.47 ± 184.81 U/l, P < 0.001 and 59.64 ± 21.88 U/l, P < 0.001) than in the control group (275.32 ± 104.69 U/l and 47.71 ± 20.05 U/l). The present findings demonstrate activation of gelatinases A and B and oxidative stress markers in the early stage of AMI. Gelatinases, detected at high levels in AMI patients only, indicate their noticeable predisposition for becoming additional biomarkers of the early phase of AMI.

Matrix Metalloproteinase-2 and -9, Lactate, and Malate Dehydrogenase and Lipid Peroxides in Sera of Patients with Colorectal Carcinoma

Matrix metalloproteinases (MMPs) are involved in tumour invasion and metastasis of colorectal carcinoma. Oxidative stress represents one of the possible mechanisms that activate inactive MMPs. Oxidative stress increases lipid peroxidation, which causes impaired membrane permeability and leakage of lactate dehydrogenase (LDH) and malate dehydrogenase (MDH) into circulation. Our aim was to assess the activity of MMP-2 and MMP-9 and its relation to the parameters of oxidative stress and membrane damage markers in patients with different TNM (tumour, lymph nodes, metastasis) stages of colorectal carcinoma. MMP-2 and -9 activities were evaluated by gelatin zymography. Oxidative stress was examined by quantifying serum malondialdehyde (MDA) concentration. LDH and MDH activities were determined spectrophotometrically. The activities of MMP-2 and -9 were significantly higher in the sera of colorectal carcinoma patients when compared to healthy subjects. There was a stage-dependent increase in relative MMP-2 activity compared to the overall serum gelatinolytic activity. The activity of MMP-9 was the highest in TNM III. The MDA concentration and the LDH and MDH activities were significantly higher in colorectal carcinoma patients than in controls, while LDH and MDH activities were stage dependent. There was significant correlation between serum MMP-2 and LDH activity in TNM II, III and IV patients. A stage-dependent increase of LDH and MDH activity was observed. We highlight here that MMP-9 could be a 100% sensitive marker of TNM stage III of colorectal carcinogenesis. In this study it was shown for the first time that gelatinolytic activity in colorectal carcinoma is associated with redox imbalance.

The results of molecular genetic testing for RET proto-oncogene mutations in patients with medullary thyroid carcinoma in a referral center after the two decade period

BACKGROUND

Medullary thyroid carcinoma (MTC) is a type of thyroid neoplasm which originates from parafollicular cells, and it is commonly diagnosed by calcitonin screening. Besides the sporadic form, the heritable form of MTC is characterized by constitutive activation of the RET (REarranged during Transfection) proto-oncogene caused by different mutations.

METHOD

We collected data regarding RET genetic screening performed in the Center for Endocrine Surgery in Belgrade during a 20-year-period. The study group included 249 MTC patients who were genetically tested for RET mutations by Sanger's sequencing method.

RESULTS

Genetic screening of the study population revealed nine different mutations of the RET gene in 42 carriers. The most common mutation was C634F, and it has been detected in 31 % (13/42) of individuals, while C618R, L790F, and S904S were present in only 2 % (1/42) each in the study group. Detected mutations were unequally distributed in different RET gene exons. Among MTC patients, 67 % (28/42) had mutation harbored in exon 11, while the rarest mutation was located in exons 10 and 15, each present in only 2 % (1/42) of patients.

CONCLUSIONS

The RET gene mutation profile has a unique distribution in this study population when compared with the other European populations. The mutations in codon 634 are most common; therefore the cost-reducing genetic screening should primarily target this codon, and if the negative outcome appears, then other codons should be examined in the order that depends on their occurrence. Hippokratia 2016, 20(3): 187-191.

Inter-individual variability in the response of human peripheral blood lymphocytes to ionizing radiation: comparison of the dicentric and micronucleus assays

Ionizing radiation can induce a wide range of DNA damage that leads to chromosomal aberrations. Some of those aberrations (dicentrics and micronuclei) are applied in biodosimetry. Biological dosimetry assumes similar radiosensitivity of each donor, but it does not exclude inter-individual variations in radiation susceptibility. Therefore, for biological reasons, it is always challenging to investigate inter-individual variability in response to radiation. For mechanistic reasons, it is also interesting to investigate the correlation between dicentric and micronuclei formation in response to radiation. In this experiment, irradiated blood specimens from 14 healthy male and female donors have been used to evaluate inter-individual variability in response to the genotoxic effects of X-ray radiation, as well as the dose-response relationship and test sensitivity using two endpoints (dicentrics and micronuclei). The results showed similar patterns of cytogenetic biomarker distribution between donors, but differences in the response of some donors at some doses. Data also showed that responses of male donors were better detected using the dicentric test, while for females, micronucleus frequencies were higher in response to the same dose of radiation. No influence of smoking status or age on specific responses was observed. Group variability in response to radiation was evaluated using coefficient of variation for each group of individuals irradiated with the same doses; as the dose increases, group variability becomes substantially lower. Despite sporadic inter-individual variability, trend of radiation-induced changes was similar. Produced calibration curves for both types of damage revealed dicentrics as genetic damage more typical for radiation than micronuclei.

Mitotic crossover - an evolutionary rudiment which promotes carcinogenesis of colorectal carcinoma

Mitotic crossover is a natural mechanism that is a main source of the genetic variability of primitive organisms. In complex organisms such as mammals, it represents an evolutionary rudiment which persisted as one of the numerous DNA repair mechanisms, and results in the production of homozygous allele combinations in all heterozygous genes located on the chromosome arm distal to the crossover. This event is familiar as loss of heterozygosity, which is one of the key mechanisms responsible for the development and progression of almost all cancers. We propose the hypothesis in which mitotic crossover is a principal source of the increased loss of heterozygosity that leads to the initiation and progression of colorectal carcinoma. The hypothesis could be tested by in vitro inhibition of Rad51 protein, orthotopic grafting of human colon cancer tissue into the gut of mice, and treatment with potential inhibitors. After these procedures, the frequency of mitotic crossover would be estimated. The development of selective inhibitors of mitotic crossover could stop further carcinogenesis of colorectal carcinoma, as well as many other neoplastic events. Loss of heterozygosity is an event responsible for carcinogenesis, its reduction by selective inhibitors of mitotic crossover could have a positive effect on cancer chemoprevention, as well as on growth reduction and a cessation in the progression of earlier developed tumors.

Acute pretreatment with chloroquine attenuates renal I/R injury in rats

BACKGROUND

Acute kidney injury (AKI) still remains an unresolved problem in pharmacotherapy and renal inflammation is a major factor in its development. Chloroquine, a well-known antimalarial drug, posses pleitropic effects as well: antiinflammatory, anticoagulant and vascular actions. The effects of chloroquine on renal function may involve significant increase in urine flow rate, glomerular filtration rate and sodium excretion, as well as stimulation of nitric oxide synthase. However, its role in experimental models of renal I/R injury is unknown. We aimed to analyze the acute effects of a single-dose intravenous chloroquine administered at three different times in the experimental model of I/R injury in rat.

METHODS

Rats were subjected to bilateral renal ischemia (45 min) followed by reperfusion with saline lasting 4 hours. Chloroquine was administered in doses of 0.3 mg/kg i.v. and 3 mg/kg i.v. 30 min before ischemia, 30 min before reperfusion and 5 min before reperfusion. Selected a hemodynamic, biochemical and morphological parameters were followed in the Sham-operated animals and rats subjected to I/R injury and pretreated with saline or chloroquine.

RESULTS

Chloroquine (0.3 and 3 mg/kg, i.v.) protected the I/R injured kidney in an U-shaped manner. Both doses were protective regarding biochemical and histological markers of the I/R injury (serum urea, creatinine and fractional excretion of sodium, as well as total histological score, tubular necrosis score and KIM-1 staining score) (P<0.05 vs. corresponding controls, i.e. rats subjected to I/R injury and treated with saline only). The protective effects of the lower dose of chloroquine were more profound. Time-related differences between pretreatments were not observed (P>0.05, all).

CONCLUSION

Our study shows for the first time that a single dose of chloroquine (0.3 mg/kg i.v.) could afford significant protection of the injured rat kidney.

Lactate dehydrogenase, catalase, and superoxide dismutase in tumor tissue of breast cancer patients in respect to mammographic findings

Lactate dehydrogenase (LDH), marker of anaerobic metabolism, is associated with highly invasive and metastatic breast cancer. Novel studies show that increased anaerobic metabolism (LDH), as well as activity of antioxidative enzymes (superoxide dismutase (SOD) and catalase (CAT)), is correlated with higher mammographic density, as known predictor of breast cancer risk. In this study, we measured LDH, MDH, and SOD activity in tumor and adjacent tissues of breast cancer patients by spectrophotometric assay. Mammograms were evaluated according to the American College of Radiology Breast Imaging Reporting and Data system. Mammographically dense breast tissue is associated with higher activity of LDH in tumor tissue of breast cancer patients. Moreover, patients with masses have significantly higher activity of LDH compared to patients with focal asymmetries or architectural distortion. Patients with spiculated mass margin had higher activity of LDH compared to patients with focal asymmetries or architectural distortion. Activity of LDH in patients significantly increases, while activity of CAT significantly decreases with the increase of BIRADS category. These results suggest that the association of activity of LDH and CAT in tumor tissue with mammographic characteristics could help in defining aggressive breast cancers.

Skin and sural nerve biopsies: ultrastructural findings in the first genetically confirmed cases of CADASIL in Serbia

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is an inherited vascular disorder caused by Notch3 gene mutations. The main histopathological hallmark is granular osmiophilic material (GOM) deposited in the close vicinity of vascular smooth muscle cells (VSMCs). The authors report the first 7 ultrastructurally and genetically confirmed cases of CADASIL in Serbia. Samples of skin and sural nerve were investigated by transmission electron microscopy. GOM deposits were observed around degenerated VSMCs in all the skin biopsies examined. Sural nerve biopsies revealed severe alterations of nerve fibers, endoneurial blood vessels with GOM deposits, endoneurial fibroblasts, and perineurial myofibroblasts. Total genomic DNA was extracted from peripheral blood leukocytes, and exons 2-6 of the Notch3 gene were amplified by PCR and subsequently sequenced. Four different mutations in exons 2 (Cys65Tyr), 3 (Gly89Cys and Arg90Cys), and 6 (Ala319Cys), which determine the CADASIL disease, were detected among all described patients. A novel missense mutation Gly89Cys involving exon 3 was detected. Due to the difficulties in the determination of the Notch3 mutations, these data suggest that electron microscopic analysis for GOMs in dermal vessel wall provides a rapid and reliable screening method for this disease.

Matrix metalloproteinases and membrane damage markers in sera of patients with acute myocardial infarction

Coronary artery disease is a multifunctional disease and represents one of the leading causes of death worldwide. Oxidative stress appears as an etiological factor for myocardial damage during acute myocardial infarction. Some data suggest that acute coronary syndromes may also be influenced by matrix metalloproteinases through degradation of the fibrous cap of vulnerable atherosclerotic lesions. It has been indicated that gelatinases A and B play a key role in acute myocardial infarction and deoxyribonuclease I has been postulated to be a novel early phase marker of disease. The aim was to study activity of gelatinases A and B in acute myocardial infarction and its association with some membrane damage markers. Seventy-five patients with disease and seventy-five healthy controls were enrolled. Activities of lactate dehydrogenase, malate dehydrogenase, and deoxyribonuclease I were estimated using standard spectrophotometric assay and isoforms of lactate and malate dehydrogenases were determined using direct zymography. Activity of dehydrogenases was significantly higher in patients, while deoxyribonuclease I was lower. Isoform 2 of lactate dehydrogenase was significantly higher in the patient group. Gelatinases A and B were detected only in patients group. The results suggest determination of serum malate dehydrogenase activity to be used as an additional parameter for acute myocardial infarction diagnosis. Those findings suggest important role of gelatinases A and B as biomarkers of early stage of acute myocardial infarction together with membrane damage parameters.