Systemic in vivo lentiviral delivery of miR-15a/16 reduces malignancy in the NZB de novo mouse model of chronic lymphocytic leukemia.

Similar to human chronic lymphocytic leukemia (CLL), the de novo New Zealand Black (NZB) mouse model has a genetically determined age-associated increase in malignant B-1 clones and decreased expression of microRNAs miR-15a and miR-16 in B-1 cells. In the present study, lentiviral vectors were employed in vivo to restore miR-15a/16, and both the short-term single injection and long-term multiple injection effects of this delivery were observed in NZB. Control lentivirus without the mir-15a/16 sequence was used for comparison. We found that in vivo lentiviral delivery of mir-15a/16 increased miR-15a/16 expression in cells that were transduced (detected by GFP expression) and in sera when compared with control lentivirus treatment. More importantly, mice treated with the miR-expressing lentivirus had decreased disease. The lentivirus had little systemic toxicity while preferentially targeting B-1 cells. Short-term effects on B-1 cells were direct effects, and only malignant B-1 cells transduced with miR-15a/16 lentivirus had decreased viability. In contrast, long-term studies suggested both direct and indirect effects resulting from miR-15a/16 lentivirus treatment. A decrease in B-1 cells was found in both the transduced and non-transduced populations. Our data support the potential use of systemic lentiviral delivery of miR-15a/16 to ameliorate disease manifestations of CLL.

Immune tolerance induction in haemophilia A patients with high-responding inhibitors to factor VIII: experience at a single institution.

Inhibitor antibodies to transfused factor VIII pose significant challenges in the management of haemophilia A patients. The main concern is the inefficacy of replacement therapy in patients with high-titre antibodies, who have a shorter life-span and a greater morbidity compared to subjects without inhibitors. The ultimate goal in treating these patients is to eliminate the inhibitor antibody entirely, allowing the recommencement of specific replacement therapy. The results of an immune tolerance regimen based on pharmacokinetic parameters are reported here. In 12 high-responder haemophilia A patients immune tolerance induction (ITI) was attempted with daily administration of factor VIII concentrates of very high purity, either plasma-derived or produced by recombinant-DNA technology. Patients were given 100 IU kg(-1) day(-1) until the inhibitor was shown to be absent by at least two negative assays 1 month apart, with normal recovery of infused factor VIII and normal half-life (> 6 h), as assessed after a 3-day washout period. After the patient was judged to be inhibitor-free, immune tolerance treatment was continued with unmodified factor VIII doses for 2 months. Doses were thereafter gradually reduced and finally, regular prophylaxis by administration of 25 IU kg(-1) three times weekly was instituted. Immune tolerance was achieved in 10 of the 12 patients (including six of seven with long-standing inhibitors) within a median time of 8 months. Outcome of immune tolerance was not influenced by age at start of ITI nor by the interval between inhibitor development and ITI. The success rate and the inhibitor disappearance time of our immune tolerance regimen, utilizing high-purity factor VIII, agrees with those reported by other investigators.

Adolescencia: análisis de indicadores de atención en embarazo, parto y recién nacidos en la población asistida en el Hospital "C.Argerich" de Buenos Aires. 1987-1996 / Adolescence: indicators analysis of attention of the pregnancy, lasbor and childbirth in the population attended in the Hospital "C.Argerich" of Buenos Aires. 1987-1996

En Latinoamerica la proporción de adolescentes era el 20 por ciento en el año 1985 y ha continuado incrementandose en términos proporcionales y absolutos. En nuestro país supera los 6 millones de individuos, estando más del 80 por ciento radicadoen áreas urbanas(AU)

Adolescencia: análisis de indicadores de atención en embarazo, parto y recién nacidos en la población asistida en el Hospital "C.Argerich" de Buenos Aires. 1987-1996 / Adolescence: indicators analysis of attention of the pregnancy, lasbor and childbirth in the population attended in the Hospital \"C.Argerich\" of Buenos Aires. 1987-1996

En Latinoamerica la proporción de adolescentes era el 20 por ciento en el año 1985 y ha continuado incrementandose en términos proporcionales y absolutos. En nuestro país supera los 6 millones de individuos, estando más del 80 por ciento radicadoen áreas urbanas

Race, culture, and medications.

Cultural, ethnic, and environmental influences on medical therapy add to the complexities encountered by practicing health care professionals. Ignoring such studies may inadvertently result in increased patient suffering, an increase in side effects, or both. Pharmacokinetic drug differences, especially polymorphism, are more relevant if the patient's condition is severely compromised and the drug has a narrow therapeutic range. However, if the drugs is carefully selected and the dosage is calculated according to the patient's therapeutic response, adverse outcomes can usually be reduced.

Incidence of factor VIII inhibitor development in hemophilia A patients treated with less pure plasma derived concentrates.

Very-high-purity Factor VIII concentrates produced by monoclonal or recombinant technology have been postulated to be more antigenic resulting in an increased risk of inhibitor development in hemophilia A patients. However, previous reports, mainly based on prevalence figures, may have underestimated the "true" risk of this complication in patients treated with less pure Factor VIII concentrates. The present study, started in 1975, has been designed to calculate the risk of inhibitor development in patients with severe or moderate hemophilia A, followed since their first exposure to intermediate or high-purity Factor VIII concentrates, produced by conventional technologies. Sixty-four hemophiliacs fulfilled the enrollment criteria. Inhibitors developed in 20.3% (13/64) of all patients and in 23% (11/48) of those with severe Factor VIII deficiency. Eleven patients manifested a strong anamnestic response after exposure to Factor VIII (high responders) and 2 had low inhibitor concentrations despite repeated Factor VIII infusions (low responders). The incidence of inhibitor development was 24.6 per 1000 patient-years of observation. The cumulative risk of inhibitor formation was 19.9% at age of 6 years, and 20.3% at 5 years after the first exposure. The risk was 19.3% at 70 days of exposure to Factor VIII concentrates, and 17.2% after a total of 50,000 units of Factor VIII given. Further studies are needed to confirm the above risk of acquiring an inhibitor, which indicates an under-estimation by previous studies. In addition, more data is needed to demonstrate whether very-high-purity Factor VIII concentrates may be more antigenic than conventional preparations.

Ovariectomy-induced bone loss and the hematopoietic system.

To investigate the relationship of the hematopoietic system to the loss of bone due to ovarian hormone deficiency, we examined the effects of ovariectomy and estrogen administration on the thymus, spleen and the bone marrow, and on the proliferation of marrow progenitors of osteoclasts. We also assessed the effects of daily administration of interleukin-1 receptor antagonist (IL-1ra) on bone loss due to ovarian hormone deficiency. Ovariectomy resulted in decreased cancellous bone volume, increased trabecular osteoblast and osteoclast numbers, and increased serum alkaline phosphatase levels that were prevented by 17 beta-estradiol treatment. Thymus weight, spleen weight, thymus and spleen lymphocytes, and bone marrow monocytes and lymphocytes also increased significantly following ovariectomy, and the increases were suppressed by 17 beta-estradiol. Ovariectomy, in addition, caused a 4-fold increase in the number of tartrate resistant acid phosphatase (TRAP)-positive multinucleated cells formed in cultures of marrow cells and the increase was partially inhibited by 17 beta-estradiol. IL-1ra administration did not prevent the bone loss due to ovariectomy. Our findings indicate that ovariectomy-induced bone loss in the rat is accompanied by marked changes in the hematopoietic system, and that these changes are modulated by estrogen administration. In spite of the negative finding with IL-1ra, the nature of the involvement of the hematopoietic system in the pathogenesis of bone loss due to ovarian hormone deficiency merits continued exploration.

In vivo effects of transforming growth factor-beta 2 in ovariectomized rats.

In vitro studies indicate that transforming growth factor-beta (TGF-beta) has a role in the regulation of bone cell activities. However, little is known about the effects of TGF-beta on bone when it is administered systemically. This study was undertaken to evaluate the in vivo effects of TGF-beta 2 on bone and marrow cells in the ovariectomized rat bone loss model. Female Sprague-Dawley rats, aged 95 days, were divided into 4 groups. Group 1 was sham operated; groups 2-4 were ovariectomized. Groups 3 and 4 received daily injections of 10 micrograms and 50 micrograms of TGF-beta 2/kg body weight, respectively. Groups 1 and 2 received the solvent vehicle. All animals were sacrificed after 35 days. Ovariectomy caused a significant increase in, total mononuclear marrow cells, the number of TRAP positive multinucleated cells formed in culture of marrow cells, and the number of trabecular osteoclasts and osteoblasts. These increases were associated with loss of cancellous bone in the proximal tibia. TGF-beta 2 completely prevented the increase in the number of TRAP positive multinucleated cells, and caused a small but not statistically significant decrease in the number of trabecular osteoclasts. However, TGF-beta 2 had no significant effect on the number of total mononuclear marrow cells and on the loss of cancellous bone due to ovariectomy. We conclude that TGF-beta 2 probably plays a role in the regulation of the proliferation of osteoclast progenitors in bone marrow in vivo. Studies carried out over a longer period are required to determine whether it will modulate the increase in osteoclast and osteoblast numbers that occur in cancellous bone following ovariectomy.

A comparative study of the actions of tamoxifen, estrogen and progesterone in the ovariectomized rat.

This study was undertaken to examine the separate and combined effects of tamoxifen (T), estrogen (E2) and progesterone (P) treatment on ovariectomized (Ooph) rats. The animals were treated for 40 days. Ovariectomy reduced cancellous bone volume at the proximal tibia by 50%. Estradiol treatment completely prevented the bone loss and further increased bone volume 77% over the level for the control group. Tamoxifen also prevented the ovariectomy induced bone loss, but significantly reduced the increase in cancellous bone induced by estradiol. In the ovariectomized rats, cancellous bone apposition rate increased 23%. This increase was suppressed 63% by estradiol, and only 18% by tamoxifen. Tamoxifen significantly suppressed the inhibitory effect of estradiol on cancellous bone apposition rate. In contrast, the effect of progesterone treatment was only marginal. Our findings indicate that the action of tamoxifen on bone is influenced by the ambient level of circulating estradiol, such that in estrogen deficiency, tamoxifen has a weak estrogen agonist action on bone, and in the presence of estrogen it has anti-estrogen actions, with the dose level and mode of administration employed. These conclusions have implications for the use of tamoxifen in the treatment of pre- and postmenopausal women.

Preexisting bone loss associated with ovariectomy in rats is reversed by parathyroid hormone.

Previous studies have demonstrated that when parathyroid hormone (PTH) administration to rats is started immediately following ovariectomy, it prevents bone loss due to ovarian hormone deficiency. In this study, we examined whether bone loss induced by ovariectomy could be reversed by parathyroid hormone if hormone therapy is started after the bone loss had already occurred. In the first experiment, two groups of animals were ovariectomized or sham operated, killed after 40 days, and their bones examined to ensure that bone loss occurred. In the second experiment, three groups of rats were studied. Group 1 rats were sham operated, and rats in groups 2 and 3 were ovariectomized. Each rat in group 3 received a single subcutaneous injection of 8 micrograms parathyroid hormone [hPTH-(1-34); Bachem, CA] per 100 g body weight per day, starting 40 days following ovariectomy. Rats in groups 1 and 2 received solvent vehicle, and all animals were sacrificed on day 60. Ovariectomized rats had lost an appreciable amount of bone 40 days after surgery, as indicated by a significant decrease in femoral and vertebral densities and calcium and an over 55% loss of cancellous bone in the tibial metaphysis. The loss of bone was reversed by intermittent PTH administration. Increased cancellous bone in the parathyroid hormone-treated ovariectomized rats was associated with increased trabecular osteoblasts, decreased trabecular osteoclasts, and increased serum osteocalcin and urinary hydroxyproline. Our findings indicate that parathyroid hormone can substantially augment bone mass after the loss due to ovarian hormone deficiency has already occurred. The hormone caused positive bone balance in vivo in ovarian hormone-deficient animals by increasing bone formation and decreasing bone resorption.

Skeletal response of ovariectomized rats to low and high doses of 17 beta-estradiol.

Recent studies indicate that the mode of action of estrogen in preventing bone loss due to ovarian hormone deficiency may vary with the dose of the hormone. In this study four groups of ovariectomized animals were maintained on a wide range of doses of 17 beta-estradiol to further determine the relationship of dose to the mechanism by which estrogen prevents ovarian hormone deficiency bone loss. Ovariectomy caused a significant decrease in bone density and cancellous bone volume at the proximal metaphysis of the tibia. The decrease was prevented in a dose-dependent manner by estradiol. The rate of bone apposition in cancellous bone in the proximal tibia was increased by ovariectomy, and inhibited in a dose-dependent manner by estradiol. Similarly, ovariectomy increased the excretion of urinary hydroxyproline, an index of the rate of bone turnover, and serum alkaline and tartrate-resistant acid phosphatase. The increases were prevented in a dose-dependent manner by estradiol. In addition, the very high dose of estradiol, but not the lower doses, caused a marked (50%) decrease in serum osteocalcin. Our interpretation of these findings is that the low to very high doses of estradiol used in this study decreased the progression of the bone loss due to ovariectomy by suppression of the rate of bone turnover that involved the depression of both osteoclastic resorption and osteoblastic bone formation.

Use of combined exogenous gonadotropins and pulsatile gonadotropin-releasing hormone in patients with polycystic ovarian disease.

We previously tested a combined regimen based on the administration of gonadotropin in the early follicular phase followed by pulsatile gonadotropin-releasing hormone (GnRH) until complete follicular maturation in patients suffering from polycystic ovarian disease. Despite good clinical results, a high rate of premature luteinization was observed with this approach. We therefore evaluated in this study whether starting pulsatile GnRH therapy before gonadotropin administration might reduce premature luteinization. Eight women underwent induction of ovulation with both combined therapy and pure exogenous follicle-stimulating hormone alone using a crossover scheme. No premature luteinization and a single follicular growth were recorded with the modified combined regimen. Clinical results (8/8 versus 3/7 ovulatory cycles; 3/8 versus 1/7 pregnancies) favor the combined approach over gonadotropin alone.

Naltrexone in functional hypothalamic amenorrhea and in the normal luteal phase.

Fifteen young women with a diagnosis of secondary hypothalamic amenorrhea of at least 2 years' duration were given either 50 mg naltrexone daily or placebo, following a randomized double-blind crossover scheme. Seven patients did not menstruate with either therapy. In the other eight, the following results were recorded (mean +/- SD and range): a cycle length of 28.7 +/- 7.6 (12-45) days for naltrexone compared with 30.8 +/- 5.9 (16-43) days for placebo, a follicular phase length of 20.8 +/- 5.4 (14-34) days for naltrexone and 23.2 +/- 4.3 (19-32) days for naltrexone and 8.3 +/- 1.6 (5-10) days for placebo. The number of ovulatory cycles was 18 of 24 (75%) with naltrexone and eight of 24 (33%) with placebo (P less than .05). Most luteal phases were short. In five normally menstruating women, we gave either naltrexone or placebo in the luteal phase using a crossover blinded scheme. Steroidogenesis in the normal luteal phase was not impaired by naltrexone therapy. In functional hypothalamic amenorrheic patients with normal weight, menstruation might be restored by either placebo or naltrexone, but naltrexone provides a clinical and therapeutic advantage by increasing the ovulation rate.