Pteridine and riboflavin patterns during tail regeneration in Triturus species and the effects of chloramphenicol, isoxanthopterin and reserpine

Tetrahydrobiopterin as a mediator of PC12 cell proliferation induced by EGF and NGF

Epidermal growth factor and nerve growth factor increased the proliferation of rat phaeochromocytoma PC12 cells through obligatory elevation of intracellular (6R)-tetrahydrobiopterin (BH4). Epidermal growth factor and nerve growth factor increased intracellular BH4 by inducing GTP-cyclohydrolase, the rate-limiting enzyme in BH4 biosynthesis. Specific inhibitors of BH4 biosynthesis prevented growth factor-induced increases in BH4 levels and proliferation. The induction of GTP cyclohydrolase, BH4 and cellular proliferation by nerve growth factor was mediated by cAMP. Elevation of BH4 biosynthesis occurred downstream from cAMP in the cascade used by nerve growth factor to increase proliferation. Thus, intracellular BH4 is an essential mediator of the proliferative effects of epidermal growth factor and nerve growth factor in PC12 cells.

Measurement of urinary neopterin in normal pregnant and non-pregnant women and in women with benign and malignant genital tract neoplasms

Urinary neopterin was measured in healthy women (n = 209) and men (n = 208), in patients with benign gynecological tumors (n = 53), in women with precancerous lesions of the cervix and the endometrium (n = 24) and in women with cancer of the genital tract (n = 108). In addition urinary neopterin measurements were made in 109 pregnant women and 20 women in the puerperium. No significant difference was found between mean neopterin values in patients with benign gynecological tumors, in women with precancerous lesions and in healthy women. Patients with cancer had significantly higher mean urinary neopterin levels than the control group. Raised neopterin levels were found in 56% of patients with genital tract cancer, the figures varying between 93% for ovarian cancer and 47% for cancer of the cervix. Some of the cancer patients had serial urinary neopterin measurements and in about 80% there was some relation between urinary neopterin values and clinical progress as judged clinically and radiologically, the best agreement existing in patients with ovarian cancer. Significantly higher mean neopterin values were found during normal pregnancy and in the early puerperium than in non-pregnant healthy controls. Raised urinary neopterin excretion may be due to enhanced cell proliferation and alloantigenic activation of T-lymphocytes.

Determination of neopterine in human urine by reversed-phase high-performance liquid chromatography

Since the analysis of urinary neopterine is important in diagnosing malignancy, a method has been developed for its rapid and sensitive separation and quantitation using high-performance liquid chromatography (HPLC) on reversed phase. Eluted neopterine is monitored by fluorescence at a excitation wavelength of 353 nm and measured at 438 nm. Separation was optimized by elution with 15 mmol/l potassium phosphate (pH 6.4) at a flow-rate of 0.8 ml/min. Urinary neopterine was related to creatinine with the aim of reducing variations due to fluctuating urinary concentrations. The proposed method has good performance characteristics and is not influenced by the presence of reduced neopterine in urine. Using this HPLC method, urinary neopterine related to creatinine was determined for 148 healthy male adults (mean neopterine/creatinine 113 mumol/mol), 146 healthy female adults (mean neopterine/creatinine 140 mumol/mol) 60 healthy children (mean neopterine/creatinine 163 mumol/mol). The neopterine levels for four healthy individuals were measured daily over a period of one month.

Urinary neopterine as marker for haematological neoplasias

Urinary neopterine levels were studied in 79 normal subjects and in 112 patients with haematological neoplasias. The mean values in 79 patients with active disease were significantly raised compared to the control group. Results obtained in 79 patients with active disease indicate that 91% had neopterine levels higher than the mean value of 79 normal individuals +3 SD. There is only a little overlap between the range of neopterine levels in cancer patients and the range in healthy subjects. No significant difference was found between the mean urinary neopterine levels of 33 patients with non-Hodgkin's or with Hodgkin's lymphoma in remission and the healthy group. Only 15% of these patients had elevated neopterine levels. The mean urinary neopterine levels correlated well with the tumor stage in patients with chronic lymphocytic leukaemia and with non-Hodgkin's disease. In patients with chronic leukaemia those without hepatosplenomegaly excreted significantly more neopterine than controls, and patients with hepatosplenomegaly significantly more than those without hepatosplenomegaly. It is concluded that urinary neopterine levels are of value for following the progression of haematological neoplasias.

Production of retarded, albino, regenerates in newts by alpha-methyl-p-tyrosine

Inhibition of tyrosine hydroxylase with alpha-methyl-p-tyrosine retarded growth and prevented melanization of limb regenerate in adult newts (Triturus cristatus).