Response of Normal Cells Following Multiple Radiation Exposure under Radiotherapy Setting

Radiotherapy is an established approach for killing of tumour cells. During the process, most of the normal cells also get affected due to direct exposure or by bystander effects. To measure the damage pattern in healthy cells, a pilot study was designed under radiotherapy settings. Right leg region of Strain ‘A’ male mice was locally exposed to Cobalt60 gamma radiation with a dose of 2 Gy/ day for 5 consecutive days. After completion of each fraction, blood haematology and γH2AX studies were performed at 1 h time point in blood and bone marrow cells. Chromosomal aberration study in bone marrow was carried out at 24 h post irradiation of each fraction for evaluation of DNA damage. γH2AX and chromosomal aberration were found significantly (p<0.001) increased with each consecutive dose upto 4th fractions. Blood hematology showed a linear reduction in total WBC counts which included the reduction in lymphocytes and increased granulocytes with each passing dose up to 4th fraction. However, non significant damage (p>0.05) for all parameters have been observed for 4th and 5th split doses. The study indicated that repeated exposure leads to damage fixation in normal cells, possibly indicating a state of adaptation.

Relapse episodes in childhood primary nephrotic syndrome treated by alternate or three consecutive daily dose prednisone therapy

Background Prednison is still the drug of choice for the treatmentof nephrotic syndrome, especially for those with minimal change.Methods of treatment to optimize the effectiveness and efficacyare still in discussion.Objectives To evaluate the episode of relapsing minimal changenephrotic syndrome patients who received prednisone therapy byalternate or by three consecutive dose methods.Methods We performed a retrospective cohort study using medicalrecords of the patients with primary nephrotic syndrome admittedto Division of Nephrology, Sardjito Hospital, Yogyakarta fromJanuary 1995 to January 2005. Subjects were divided into twogroups, the first group treated with alternate days while thesecond group with three consecutive days prednisone program.Evaluation had been done to compare both treatment program(alternate days or consecutive days).Results Relapse episodes after six month recovery periods withalternate days treatment was 33% while those with consecutivedays was as high as 83% (P>O.Ol).Conclusion Alternate dose group has a lower relapse eventcompared to three consecutive dose group in children withnephrotic syndrome.

Pertussis-Specific Memory B-Cell and Humoral IgG Responses in Adolescents after a Fifth Consecutive Dose of Acellular Pertussis Vaccine

ABSTRACTIn order to impede the increase in pertussis incidence in the adolescent group, a school-leaving booster dose administered at the age of 14 to 16 years will be introduced in Sweden in 2016. Preceding this introduction, an open-label, randomized, multicenter, clinical trial without a control group and with blinded analysis was performed, investigating both safety and immunogenicity. Reported here are the memory B-cell and serological responses detected in a smaller cohort (n= 34) of the 230 subjects recruited to the study. All subjects had received primary vaccination consisting of three doses of diphtheria–tetanus–5-component pertussis (DTaP5) vaccine, at 3, 5, and 12 months of age, and a tetanus–low-dose diphtheria–5-component pertussis (Tdap5) vaccine booster at 5.5 years. In this study, the subjects were randomly assigned and received either a Tdap1 or Tdap5 booster. Of the 230 participants, 34 subjects had samples available for evaluation of IgG-producing memory B-cell responses. Both vaccine groups had significant increases in pertussis toxin-specific serum IgG levels, but only the 1-component group showed significant increases in pertussis toxin-specific memory B cells. The 5-component group had significant increases in filamentous hemagglutinin- and pertactin-specific memory B-cell and serum IgG levels; these were not seen in the 1-component group, as expected. In conclusion, this study shows that a 5th consecutive dose of an acellular pertussis vaccine induces B-cell responses in vaccinated adolescents. (This study has been registered at EudraCT under registration no. 2008-008195-13 and at ClinicalTrials.gov under registration no. NCT00870350.)

Characteristics of tachyphylaxis to inhaled histamine in anesthetized dogs

Three consecutive dose-response curves to aerosolized histamine were obtained in 11 anesthetized dogs. All dogs showed desensitization (i.e., tachyphylaxis) to high doses of histamine. Tachyphylaxis was highly reproducible. No tachyphylaxis occurred with inhaled acetylcholine or methacholine. Beta-Adrenergic blockade with propranolol or muscarinic blockade with atropine given intravenously had no effect on the histamine tachyphylaxis. Duration of thiamylal anesthesia did not alter the histamine responsiveness. Histamine tachyphylaxis was also seen with chloralose-urethan anesthesia. Since tachyphylaxis is not observed with acetylcholine, it cannot be attributed to a general decline in muscle contractility. We conclude that histamine tachyphylaxis in vivo is not explained by effects of cholinergic reflexes, catecholamine release, duration of anesthesia, or, probably, type of anesthetic agent.