Low parathyroid hormone levels after parathyroidectomy reduce cardiovascular mortality in chronic hemodialysis patients.

BACKGROUND: The aim of the study is to elucidate whether parathyroid hormone (PTH) levels after parathyroidectomy affect the prognosis of patients with secondary hyperparathyroidism. SUBJECTS AND METHODS: Two hundred and ninety-five patients, who underwent PTx without autotransplantation from July 1998 to December 2011, were divided into the low (n = 148) and high (n = 147) PTH groups, using the median value of each mean value of intact PTH after surgery (16.6 pg/mL). After observation for 5.00 years, we evaluated demographic factors, influences of postoperative mineral metabolism, magnitude of uremia, and vitamin D receptor activators on their prognosis, with the multivariate Cox proportional hazard model. RESULTS: While overall survival rates in the high and low PTH groups were 54.9 and 74.2 %, respectively (P = 0.1500), cardiovascular survival rates were 71.6 and 94.4 %, respectively (P = 0.0256). The hazard ratio for cardiovascular mortality in the high PTH group (≥16.6 pg/mL) was 3.132 (P = 0.0470), and those in groups with the median age more than 59 years and with cardiovascular disease were 2.654 (P = 0.0589) and 3.377 (P = 0.0317), respectively. The intact PTH level 6 days after surgery and the mean postoperative intact PTH value showed a strong correlation (Spearman ρ = 0.9007, P < 0.0001, y = 0.4725x + 30.395, R 2 = 0.51798). CONCLUSION: The present study suggests that maintaining low PTH levels after parathyroidectomy reduces cardiovascular mortality and improves the prognosis. Total parathyroidectomy (more than 4 glands) without autotransplantation seems to be one of the treatment options for managing severe secondary hyperparathyroidism.

Suppression of peritoneal thickening by histamine in a mouse model of peritoneal scraping.

BACKGROUND: Inflammatory reactions play an important role in peritoneal sclerosis in patients on peritoneal dialysis. Since histamine affects inflammatory reactions and immune responses, we investigated effects of intraperitoneal administration of histamine on peritonitis induced by mechanical scraping in mice. METHODS: After anesthesia, the right peritoneum was scraped 90 times over 1 min, and bilateral peritonea were observed by light microscopy after 7 days. RESULTS: Thickness of the peritoneal membrane on the right side was 174 ± 77 µm (mean ± SD, n = 8), while that on the left side was 24 ± 19 µm. Intraperitoneal administration of histamine (0.3 or 1.0 mmol/L, 0.5 mL each) twice daily for 7 days after scraping decreased thickness of the right peritoneum to 42 and 43 % of that in saline-injected animals, respectively (P < 0.01), although histamine (0.1 mmol/L) did not affect it. Promethazine (5 nmol, twice daily for 7 days), a histamine H1 receptor antagonist, abolished the amelioration caused by histamine (1.0 mmol/L). Neither ranitidine (15 nmol), a histamine H2 receptor antagonist, nor thioperamide (7.5 nmol), a histamine H3/H4 receptor antagonist, affected the outcome in histamine-treated mice. CONCLUSION: These findings indicate that histamine H1 action partly prevents the development of peritoneal fibrosis caused by mechanical scraping.

Total parathyroidectomy improves survival of hemodialysis patients with secondary hyperparathyroidism.

BACKGROUND AND AIMS: To compare the prognosis of chronic hemodialysis patients with or without parathyroidectomy. METHODS: Among 158 chronic hemodialysis patients who underwent total parathyroidectomy between July 1998 and April 2009, 88 patients were matched with 88 controls for sex, age, underlying disease and prior dialysis history. Then a retrospective evaluation of their prognosis was performed over a median observation period of 4.41 years. RESULTS: The overall survival rate was 90.4% in the parathyroidectomy group and 67.4% in the control group. The cardiovascular death-free survival rate was 94.6% in the parathyroidectomy group and 76.3% in the control group. During observation, intact parathyroid hormone was measured every 6 months, and its average serum level was 37 ± 92 ng/L in the total parathyroidectomy group versus 274 ± 233 ng/L in the control group (p=0.0001). The total parathyroidectomy group had a significantly lower corrected calcium level and higher serum albumin level. Multivariate analysis revealed that parathyroidectomy, atrial fibrillation and serum albumin were significant factors for both total and cardiovascular mortality. CONCLUSION: Total parathyroidectomy was associated with better survival, probably due to decreased cardiovascular mortality.

Reduction of the infarct size by simultaneous administration of L-histidine and diphenhydramine in ischaemic rat brains.

AIMS: While diphenhydramine is a histamine H(1) receptor antagonist, the agent has been shown to inhibit histamine-N-methyltransferase, a histamine inactivating enzyme in the brain. Since an increase in the brain concentration of histamine ameliorates reperfusion injury after cerebral ischaemia, effects of postischaemic administration of diphenhydramine were evaluated in rats treated with l-histidine, a precursor of histamine. METHODS: The right middle cerebral artery was occluded for 2h, and the infarct size was determined 24h after reperfusion of cerebral blood flow. Brain oedema was evaluated by comparing the area of the right hemisphere to that of the left hemisphere. RESULTS: Focal cerebral ischaemia provoked marked damage in saline-treated control rats, and infarct volumes in the striatum and cerebral cortex were 56 (49-63) mm(3) and 110 (72-148) mm(3), respectively (means and 95% confidence intervals, n=6). Administration of l-histidine (1000mg/kg, intraperitoneal) immediately after reperfusion did not affect the infarct size. Simultaneous administration of diphenhydramine (20mg/kg, intraperitoneal) with l-histidine reduced the infarct size to 25% and 21% of that in the control group, respectively. The combination therapy completely reduced ischaemia-induced brain oedema. CONCLUSION: Because histamine H(1) action does not influence ischaemic brain damage, elevation of the central histamine concentration by blockade of histamine-N-methyltransferase may be a likely mechanism responsible for the alleviation.

Identification of a novel WT1-derived peptide which induces human leucocyte antigen-A24-restricted anti-leukaemia cytotoxic T lymphocytes.

We previously reported the establishment of a Wilms' tumour (WT)1-derived peptide (CMTWNQMNL)-specific and human leucocyte antigen (HLA)-A24-restricted anti-leukaemia cytotoxic T lymphocyte (CTL) line, TAK-1. In this study, we have established a novel WT1-derived peptide (RWPSCQKKF)-specific CD8+ CTL line, designated NIM-1. NIM-1 lysed HLA-A24-positive leukaemia cells, but not HLA-A24-negative leukaemia cells or normal cells. The effects of TAK-1 and NIM-1 on cytotoxicity against leukaemia cells were not synergistic, suggesting that recognition of a single epitope on the tumour-specific antigen by CTLs is sufficient to exert maximal cytotoxic activity against tumour cells.