Genotoxicity evaluation in chronic renal patients undergoing hemodialysis and peritoneal dialysis, using the micronucleus test

Patients with chronic renal disease have an increased incidence of cancer. It is well known that long periods of hemodialysis treatment are linked to DNA damage due to oxidative stress. This genotoxic effect may cause the loss of chromosome fragments, or even entire chromosomes, which form micronuclei after cell division, and can be detected by the micronucleus test. In the present case-control study, we evaluated the genotoxic effect of hemodialysis treatment in 20 patients undergoing hemodialysis, and 20 subjected to peritoneal dialysis, matched for gender and age with 40 controls. Genetic damage was assessed by examining the frequency of micronuclei in 2000 exfoliated buccal cells per individual. Our results revealed that patients undergoing hemodialysis treatment have a significantly higher frequency of micronucleated cells (MNC; 5.60 ± 5.31) compared to control subjects (1.50 ± 2.01, p < 0.01). Interestingly, the same was not observed for the peritoneal dialysis patients who showed no significant differences in MNC (2.85 ± 2.96) frequency compared to control individuals (3.25 ± 3.85). In addition, we evaluated the possible association between creatine levels, smoking, alcohol intake, age, duration of treatment, and incomes of the individuals (separately analyzed according to their gender) and the frequency of micronuclei. The results reported here indicate that the duration of treatment is the only factor associated with increased MNC frequency among hemodialysis patients (Spearman coefficient of 0.414, p = 0.01). The number of MNC found in individuals with six years or less of treatment was significantly lower (2.91 ± 2.74) compared to patients with seven or more years of treatment (8.89 ± 5.96, p < 0.05). Overall, peritoneal dialysis may be a safer choice of treatment, but further studies need to be performed to investigate the risks and benefits of both treatments.

Patau syndrome with a long survival: a case report

Trisomy 13 is a clinically severe entity; 85% of the patients do not survive beyond one year, and most children die before completing six months of age. We report a female child, 28 months old, white, the fourth child of a non-consanguineous couple, who presented trisomy 13. The child was born at term, from a vaginal delivery, weighing 2600 g. At birth, she was cyanotic, icteric, spastic, and cried weakly. The initial clinical examination detected polydactyly in the left hand, congenital clubfoot and convex soles, ocular hypertelorism, a low nasal bridge, numerous hemangiomas distributed throughout the body, cardiomegaly, and perimembranous inter-ventricular communication. There was no cleft lip or palate. On physical examination at 18 months old, the child weighed 6,900 g, had a cephalic perimeter of 41 cm, a thoracic perimeter of 43 cm and was 76 cm tall. At 28 months, she weighed 10,760 g and was 88.5 cm tall. Neuropsychomotor development retardation was evident from birth and, according to the psychologist and the social assistant of APAE (Handicapped Parents and Friends Association) in Cangucu, Rio Grande do Sul, there was a noticeable improvement after physiotherapy and recreational sessions.

Cytogenetics of genetic counseling patients in Pelotas, Rio Grande do Sul, Brazil

From 1986 to 2002, we examined the chromosomal composition of 916 patients attended by two genetic counseling services in the city of Pelotas, in the Brazilian State of Rio Grande do Sul, to determine the genetic causes of their disturbances. Patterns of G-banding using trypsin and Giemsa (GTG) and C-banding using barium and Giemsa (CBG) were studied using phytohemagglutinin M-stimulated lymphocytes cultured from peripheral blood. Among the patients, 110 had Down's syndrome, 7 had Edward's syndrome, 4 had Patau's syndrome, 29 had Turner's syndrome, 5 had Klinefelter's syndrome, and 3 had [quot ]cri-du-chat[quot ] syndrome. Abnormal chromosomes were observed in 29.3% of the patients. Most of these (56.3%) were numerical abnormalities, with the remaining being structural variants.

Fever induction pathways: evidence from responses to systemic or local cytokine formation

The immune and central nervous systems are functionally connected and interacting. The concept that the immune signaling to the brain which induces fever during infection and inflammation is mediated by circulating cytokines has been traditionally accepted. Administration of bacterial lipopolysaccharide (LPS) induces the appearance of a so-termed "cytokine cascade" in the circulation more or less concomitantly to the developing febrile response. Also, LPS-like fever can be induced by systemic administration of key cytokines (IL-1ß, TNF-alpha, and others). However, anti-cytokine strategies against IL-1ß or TNF-alpha along with systemic injections of LPS frequently lead to attenuation of the later stages of the febrile response but not of the initial phase of fever, indicating that cytokines are rather involved in the maintenance than in the early induction of fever. Within the last years experimental evidence has accumulated indicating the existence of neural transport pathways of immune signals to the brain. Because subdiaphragmatic vagotomy prevents or attenuates fever in response to intraperitoneal or intravenous injections of LPS, a role for vagal afferent nerve fibers in fever induction has been proposed. Also other sensory nerves may participate in the manifestation of febrile responses under certain experimental conditions. Thus, injection of a small dose of LPS into an artificial subcutaneous chamber results in fever and formation of cytokines within the inflamed tissue around the site of injection. This febrile response can be blocked in part by injection of a local anesthetic into the subcutaneous chamber, indicating a participation of cutaneous afferent nerve signals in the manifestation of fever in this model. In conclusion, humoral signals and an inflammatory stimulation of afferent sensory nerves can participate in the generation and maintenance of a febrile response