High doses of intravenous calcitriol in the treatment of severe secondary hyperparathyroidism

BACKGROUND: In hemodialysis (HD) patients, secondary hyperparathyroidism (HPTH) is a severe common disease. Calcitriol administration has been demonstrated as an effective therapy. In this prospective study, our aim was to determine the necessary calcitriol dose required to control severe HPTH preventing hypercalcemia or hyperphosphatemia and avoiding parathyroidectomy. METHODS: Eighteen dialysis patients suffering from severe HPTH during a 12-month period received intravenous (i.v.) calcitriol pulse doses (2-8 mcg/3x/week). Multislice helical computed tomography (CT) cardiac imaging was performed to measure coronary artery calcifications. RESULTS: Fourteen patients showed an improvement (parathyroid hormone (PTH) level < 400 pcg/mL), one patient an incomplete reduction, and three patients starting from PTH levels between 1100 and 2386 pcg/mL did not appear to benefit from the therapy. After a 6-month therapy in 15/18 patients PTH levels were significantly lower (p<0.05). In a large portion of the group, as well as in the control group, coronary calcification values were high when compared to the normal range. CONCLUSIONS: According to our data, we concluded that severe HPTH could be treated successfully by i.v. calcitriol pulse doses reaching high doses (up to 8 mcg/3x/week) and for a prolonged period of time (6 months). In such cases, close monitoring is necessary to prevent hyperphosphatemia and hypercalcemia episodes.     

Time-dependent inhibition of hippocampal LTP in vitro following contextual fear conditioning in the rat

The effects of contextual fear‐learning on hippocampal synaptic excitability were investigated by means of high frequency tetanic stimulation (HFS) in rat brain slices (hippocampal CA1 region), prepared at different intervals (immediately, 24 h or 7 days) after a one‐trial contextual fear conditioning paradigm session. In the latter, rats that had previously received aversive electrical footshocks in the experimental apparatus exhibited freezing (the conditioned response) when placed again in the same apparatus (retrieval test). It was shown that contextual fear‐learning affects the hippocampal synaptic response. In fact, the HFS produced a decrease in the amplitude of short‐term (STP) and long‐term potentiation (LTP) when compared to control ‘naïve’ subject values. This decrease in STP amplitude could be observed only in slices prepared immediately after the training session. A decrease in the amplitude of long‐term but not short‐term potentiation was also observed at 24 h. At 7 days, no decreases in amplitude were observed. These modifications may be thought of as specifically associated with the learning process as they were not recorded in brain preparations from ‘shock‐only’ rats (i.e. those that received the same number of aversive stimuli of equal intensity as the conditioned group but with the shocks compressed temporally so that the shocked subjects could not associate nociceptive stimulation and surroundings – no conditioned freezing during retention testing). In ‘exploration’ preparations (brain slices from rats having only freely explored the experimental apparatus without receiving any adverse stimulation) a decrease in LTP amplitude was recorded only immediately after the training session, and STP was never modified. The synaptic response modifications do not appear to be due to presynaptic events, as they are not associated with paired‐pulse facilitation curve (PPF) modifications. The present results show that contextual fear conditioning and exploration of a novel environment (i) reduce the ability to induce synaptic plasticity; (ii) differentially influence STP and LTP and that (iii) the persistence of synaptic modifications depends on an animal's prior experience.     

Prospective study of mother-to-infant transmission of hepatitis C virus: a 10-year survey (1990-2000)

BACKGROUND: The purpose of this study was to determine the rate of vertical transmission of hepatitis C virus (HCV). We also aimed to analyze the time of clearance of maternal antibodies in the serum of non-infected babies. METHODS: Between March 1990 and March 2000, 170 consecutive anti-HCV-positive women and their 188 babies entered this prospective study. All women were analyzed for HCV-RNA using polymerase chain reaction (PCR). The babies were followed-up until HCV-antibody clearance or until the diagnosis of HCV infection. RESULTS: The vertical transmission rate was 2.7% overall, and it was higher in HIV co-infected women (5.4%, 2/37) than in HIV-negative women (2.0%, 3/151). All infected infants were born to mothers who had HCV viremia at delivery. The transmission rate was influenced by maternal levels of viremia. 37.2% of uninfected children became HCV-antibody negative by 6 months and 88.0% by 12 months. Babies born from HCV-RNA-positive mothers lost anti-HCV antibodies later (9.21 +/- 3.72 months) than babies born from HCV-RNA-negative mothers (7.47 +/- 3.46 months) ( p < 0.05, Kolmogorov-Smirnov test). CONCLUSIONS: The risk of HCV vertical transmission is very low in HCV-positive/HIV-negative women and it is restricted to infants born to HCV viremic mothers. High maternal viral load is predictive of the vertical transmission. The clearance time of antibodies in non-infected babies is significantly longer if the mother is viremic.     

Urethral adenocarcinoma associated with urethral diverticulum in a patient with progressive voiding dysfunction

Urethral adenocarcinoma associated with urethral diverticulum is a rare condition that requires a high index of suspicion to ensure early diagnosis and appropriate therapy. The development of urethral stenosis in a patient with a urethral diverticulum warrants early biopsy to rule out a malignant lesion.     

The diagnosis of functional ovarian cysts using transvaginal ultrasound combined with clinical parameters,CA125 determinations,and color Doppler

OBJECTIVES: To investigate the role of transvaginal ultrasound combined with clinical parameters, CA125 determinations, and color Doppler in the differentiation between functional cysts and other adnexal masses. STUDY DESIGN: Two hundred and eighty-seven consecutive persistent adnexal masses were submitted to B-mode transvaginal ultrasonography associated with color and power Doppler imaging. Plasma CA125 concentrations were measured before surgery. RESULTS: According to the obtained logistic regression equation, the presence of anechoic tumors without echogenic portions or septa and CA125 <25IU/ml was associated with a 75% probability of presence of follicular cysts. The visualization of fine trabecular jelly-like content or of a heterogeneous mass with hypoechoic content, absent or only peripheral arterial flow, and age <40 years was associated with a 56% probability of presence of luteal cysts. CONCLUSIONS: Addition of findings to B-mode ultrasonography can help to differentiate functional cysts from other adnexal masses.     

The effect of lupus anticoagulant in the second-generation assay for activated protein C resistance

The activated protein C resistance (APCR) assay is the test of choice to screen for factor V Leiden. We evaluated the effect of lupus anticoagulant on the baseline clotting time of the second-generation APCR assay with plasma samples from 54 patients to determine whether a falsely low APCR ratio could be predicted. We also assessed whether a modification of the assay could make it more reliable in the presence of strong lupus anticoagulants. Of 54 plasma samples, 5 yielded a false-positive APCR ratio, and all 5 had a prolonged baseline clotting time. Further dilution (1:40) of the plasma samples in factor V-deficient plasma led to correction of the APCR ratio and did not affect the sensitivity of the test for factor V Leiden. Our data support that the baseline clotting time is a good predictor of a false-positive APCR test result and should be checked before calculating the ratio. The modified APCR assay reliably identified the false-positive ratios and could be used to screen for factor V Leiden in samples with strong lupus anticoagulant.