Presence of calcitonin-like peptide in rat milk: possible physiological role in regulation of neonatal prolactin secretion

Previous results have shown that salmon calcitonin (sCT), a peptide in rat brain and pituitary gland, inhibits basal and TRH-stimulated PRL release and reduces PRL mRNA levels in isolated anterior pituitary cells of adult rats in culture. Rat milk contains a variety of neuropeptides and hormones, some of which are absorbed in bioactive form to exert endocrine influences in the developing offspring. The present studies were undertaken to investigate whether a CT-like peptide is present in rat milk. Circulating PRL levels in neonatal rats are low, and there is an abrupt increase in the basal secretion of this hormone at weaning. A second objective was to examine whether CT plays a role in the regulation of PRL secretion in neonatal animals. A sensitive and specific RIA for sCT was developed and used to assay rat milk on various days of lactation for sCT-like immunoreactivity. sCT-like activity was present in the water-soluble (infranatant) fraction of milk throughout lactation in concentrations as high as 1589 pg/ml. There were no statistically significant differences in immunoreactive levels of the peptide in milk samples from different days of lactation. sCT-like immunoreactivity in rat milk infranatant coeluted with synthetic sCT on reverse phase HPLC, and these HPLC fractions inhibited basal PRL release when added to cultures of anterior pituitary cells. This inhibition of PRL release by the sCT-immunoreactive HPLC fractions was comparable to that exerted by equivalent concentrations of synthetic sCT. Newborn rats were injected sc with 10 microliters normal rabbit serum or anti-sCT serum from the day of birth until postpartum day 10. The rats were killed on day 11, and their sera were analyzed for PRL. Anti-sCT-injected rats showed a significant increase in serum PRL levels compared to those in untreated or normal serum-treated rats. These results demonstrate that a CT-like peptide, which is a potent inhibitor of PRL release, is present in rat milk throughout lactation, and that passive immunization with a highly specific anti-sCT serum leads to an increase in serum PRL levels in neonatal rats. CT, possibly of milk origin, may be a physiologically relevant PRL-inhibiting factor during the neonatal period.     

New norms for a new generation: cognitive performance in the framingham offspring cohort

A previous publication presented normative data on neuropsychological tests stratified by age, gender, and education based on the Original Cohort of the Framingham Heart Study. Many contemporary investigations include subject samples with higher levels of education, a factor known to affect cognitive performance. Secular change in education prompted the reexamination of norms in the children of the Original Cohort. The study population consisted of 853 men and 988 women from the Offspring Study, free of clinical neurological disease, who underwent a neuropsychological examination, which included tests given to their parents in 1974 to 1976 as well as additional newer tests to provide a more comprehensive battery. The Offspring population overall was more evenly distributed by gender and better educated. Their performance on cognitive tests was superior to that of the Original Cohort. Multivariable analyses revealed that more years of education explained only a part of the cohort differences. These findings suggest that continued surveillance of each generation is necessary to document the impact that unique social and economic variables have on cognitive function. Here, the authors provide updated normative data.     

Hormone dependency of rat mammary carcinoma--a comparison of two assay systems.

Succinic dehydrogenase activity of the DMBA induced tumor explants cultured with or without hormones was assessed histochemically while receptors for estrogen (ER) and progesterone (PgR) were estimated from the cytosol fraction of the tumor tissue. Tumor regression following ovariectomy (OVX) was kept as the end point for determining hormone dependency. By in vitro method positive correlation was observed in 5 of 6 responsive or hormone dependent tumors, and 13 out of 14 independent tumors. Presence of receptors (ER + PgR, PgR) correlated with responsiveness in 4 of 6 tumors while their absence in the non-responsive group correlated in 6 of 14 tumors. Prolactin responsive tumors did not regress following OVX even if ER + PgR or ER/PgR were present. Using the same tumor tissue the results of hormone dependency by the two methods were identical in only 9 of 20 tumors.     

Lymphocyte DNA in Aplastic Anaemia

Using ultracentrifugation on alkaline sucrose density gradients the DNA of lymphocytes from 14 patients with aplastic anaemia and 23 controls was studied before and after exposure to bleomycin, an agent known to cause strand breaks in DNA. Before exposure to bleomycin the DNA from aplastic patients had more strand breaks than the DNA from the controls of similar ages. Following exposure to bleomycin an abnormal number of DNA strand breaks was produced in 10 of 14 patients and this molecular evidence of drug sensitivity correlated well with the sensitivity of the proliferating lymphocytes to bleomycin in tissue culture. Furthermore, two relatives of patients with aplastic anaemia showed similar abnormality of DNA before and after exposure to bleomycin and increased sensitivity to bleomycin in tissue culture. These results suggest that an abnormality of DNA structure and/or repair may be present in some patients with aplastic anaemia.     

Retrospective comparative study of efficacy,safety and outcome of percutaneous intervention for Budd-Chiari syndrome patients with bilirubin less than 3 and 3–6 mg/dl

Objective:Comparing the efficacy, safety and outcome of percutaneous intrervention for Budd-Chiari Syndrome (BCS) patients with bilirubin less than 3 and 3–6 mg dl⁻¹.Methods and materials:188 BCS patients having serum bilirubin ≤6 mg dl⁻¹ and underwent percutaneous interventions were divided into two groups based on bilirubin level: 151 patients having bilirubin <3 mg dl⁻¹ were included in Group 1; and 37 patients having bilirubin 3–6 mg dl⁻¹ were included in Group 2. Both group were compare for technical success (successful recanalization of hepatic venous stenosis or creation of portocaval shunt with post-procedure gradient ≤5 mm of Hg), Safety (procedure-related mortality/morbidity or patient required transplantation) and outcome (resolution of clinical symptoms and survival).Results:Technical success was 94.7% in Group 1–89.1% in Group 2 with overall success rate was 93.6%. No significant differences observed between the two groups in regards to procedure related complication. Overall transplant-free survival at 1 and 5 years after intervention in both groups was 96.3 and 91.2% respectively. 1-year and 5-year survivals in Group 1 was 96.7%, and 93.1%, whereas Group 2 was 94.6 and 90.1% with no statically significantly difference between the two groups (p = 0.59). Percutaneous intervention results are good in patients having bilirubin up to 6 mg dl⁻¹, i.e. mild to moderate liver dysfunctions.Conclusion:Technical success, survival and outcome of percutaneous intervention in BCS patients having serum bilirubin 3–6 mg dl⁻¹ was comparable to patients having bilirubin level <3 mg dl⁻¹.Advances in knowledge:Percutaneous intervention treatment is suitable for treatment for symptomatic BCS patients having bilirubin up to 6 mg  dl⁻¹.     

Importance of ablating all potential right atrial flutter circuits in postcardiac surgery patients

OBJECTIVES: In patients with atrial flutter (AFL) and postoperative right atrial incisional scars, we sought to assess if the use of additional ablative lesions that targeted all potential re-entrant circuits, regardless of the presenting type of flutter, would prevent long-term recurrence. BACKGROUND: Patients with AFL and incisional scars have a complex atrial substrate that may promote multiple mechanisms of intra-atrial re-entry. METHODS: Twenty-nine patients with single right atrial incisional scars undergoing ablation for scar-dependent (n = 15) and cavotricuspid isthmus (CTI)-dependent (n = 14) flutter were studied. RESULTS: In the scar-dependent group, 9 of 15 (60%) patients had inducible or spontaneous CTI-dependent flutter immediately after ablation. In the group with CTI flutter, 7 of 14 (50%) patients had scar-related flutter immediately after ablation. If a second type of flutter was found during the initial ablation, a second ablation was performed either along the isthmus (scar-dependent group) or from the scar to another anatomic boundary (isthmus-dependent group). Patients were followed for 24 +/- 5 months and 18 +/- 6 months in the scar- and CTI-dependent groups, respectively. In the scar-dependent group, five of six (83%) who underwent only a single flutter line had recurrence at 3 +/- 1 months. In the isthmus-dependent group, three of seven (42%) patients who had only one flutter line performed had recurrence at 5 +/- 3 months. There was no flutter recurrence in patients who initially received two different flutter lines or in patients who subsequently underwent a second flutter line at follow-up. CONCLUSIONS: In patients with postoperative right atrial incisional scar and flutter, multiple ablation lines that target both scar-related and classic isthmuses appear necessary to prevent long-term recurrence.     

Dynamic photoacoustic imaging of neurovascular coupling in salivary glands

The purpose of this study was to apply photoacoustic imaging (PAI), a relatively new imaging method, to non-invasively map neurovascular dynamics in salivary glands. Dynamic PAI with co-registered ultrasound (US) was performed in mice to monitor salivary gland hemodynamics in response to exogenous muscarinic receptor stimulation (pilocarpine) and blockade (atropine). Pilocarpine increased salivary gland oxygen saturation (%sO₂) within minutes after administration, which was abrogated by atropine. A significant correlation was observed between change in %sO₂ measured by PAI and saliva secretion. PAI is a novel imaging method that can be used for functional assessment of neurovascular dynamics in salivary glands.