[Calcium antagonists in the therapy of hypertension]

Cancer immunotherapy with γδ T cells: many paths ahead of us

γδ T cells play uniquely important roles in stress surveillance and immunity for infections and carcinogenesis. Human γδ T cells recognize and kill transformed cells independently of human leukocyte antigen (HLA) restriction, which is an essential feature of conventional αβ T cells. Vγ9Vδ2 γδ T cells, which prevail in the peripheral blood of healthy adults, are activated by microbial or endogenous tumor-derived pyrophosphates by a mechanism dependent on butyrophilin molecules. γδ T cells expressing other T cell receptor variable genes, notably Vδ1, are more abundant in mucosal tissue. In addition to the T cell receptor, γδ T cells usually express activating natural killer (NK) receptors, such as NKp30, NKp44, or NKG2D which binds to stress-inducible surface molecules that are absent on healthy cells but are frequently expressed on malignant cells. Therefore, γδ T cells are endowed with at least two independent recognition systems to sense tumor cells and to initiate anticancer effector mechanisms, including cytokine production and cytotoxicity. In view of their HLA-independent potent antitumor activity, there has been increasing interest in translating the unique potential of γδ T cells into innovative cellular cancer immunotherapies. Here, we discuss recent developments to enhance the efficacy of γδ T cell-based immunotherapy. This includes strategies for in vivo activation and tumor-targeting of γδ T cells, the optimization of in vitro expansion protocols, and the development of gene-modified γδ T cells. It is equally important to consider potential synergisms with other therapeutic strategies, notably checkpoint inhibitors, chemotherapy, or the (local) activation of innate immunity.

Diminished responses to nifedipine imply severe end-organ damage in spontaneously hypertensive rats

This study was designed to investigate the effect of end-organ damage (EOD), the initial blood pressure levels, and baroreflex sensitivity (BRS) on the blood pressure-lowering effect of nifedipine in spontaneously hypertensive rats (SHRs). Nifedipine was intravenously administered at a dose of 1 mg/kg. BP was continuously recorded in the conscious state before and after nifedipine administration. BRS was determined before drug administration. Two days after the blood pressure (BP) recording, rats were killed for organ-damage evaluation. Univariate correlation analysis showed that BP changes induced by nifedipine injection were negatively correlated with EOD score and aortic weight/length but positively correlated with left kidney weight/body weight and basal BP levels. Stepwise multiple linear regression analysis demonstrated that increase in overall end-organ damage was most significantly related to the decrease in hypotensive effect of nifedipine; increase in aortic hypertrophy was also related to a decreased fall in systolic and diastolic BP induced by nifedipine, whereas increase in initial BP levels was associated with increased hypotensive effect of nifedipine. In conclusion, the severity of overall EOD contributed more than basal BP levels to the diminished responses to nifedipine, and aortic hypertrophy was also involved in diminished drug responses.

Effects of sublingual administration of nifedipine on arterial pressure, plasma renin activity, and glomerular filtration rate in essential hypertension

Effects of sublingual administration of nifedipine on systemic arterial pressure (BP), plasma renin activity (PRA), aldosterone level (AL), and serum sodium (Na) and potassium (K) levels, have been determined. A significant decrease was observed in systolic and diastolic blood pressure five minutes after the sublingual administration of nifedipine in 21 patients with mild or moderate essential hypertension. Furthermore, in an observation period of six hours, it was also established that the effect of nifedipine on systolic and diastolic blood pressure continued. An increase was observed in glomerular filtration rate, whereas there were no changes in PRA, AL, or serum Na and K levels.

Effect of nifedipine on carbohydrate metabolism in the rat

The potential role of an oral administration of nifedipine was investigated in the rat. Therefore, animals were fed on a nifedipine-containing or control diet for 12 days. Nifedipine caused a significant decrease of liver glycogen (47.9 +/- 4.9 vs 132.6 +/- 17.1 micrograms/mg protein), whereas liver glucose (213.1 +/- 15.3 vs 110.4 +/- 6.4 micrograms/mg) and lactate (44.8 +/- 4.1 vs 26.5 +/- 1.8 nmol/mg) concentrations increased. Various concentrations of nifedipine failed to influence glycogenolysis but stimulated gluconeogenesis in isolated rat hepatocytes. Blood lactate and pyruvate levels were significantly elevated in the nifedipine pretreated rats, whereas ketone bodies remained constant. Nifedipine pretreatment also increased the rates of excretion of various electrolytes and water followed by significantly lower plasma sodium, potassium, phosphate, and normal glucose values. We conclude that nifedipine-induced liver glycogenolysis may deteriorate glucose tolerance in patients with an already impaired carbohydrate metabolism.