Effects of dibutyl phthalate in male rabbits following in utero, adolescent, or postpubertal exposure.

We evaluated sequelae in male rabbits following exposure to dibutyl phthalate (DBP) at a dose level known to adversely affect testicular function in rodents without causing systemic toxicity. Because rabbits have a relatively long phase of reproductive development simulating better than rodents the reproductive development of humans, and because the use of rabbits facilitates multiple evaluations of mating ability and seminal quality, we used this animal model. Rabbits were exposed to 0 or 400 mg DBP/kg/day in utero (gestation days [GD] 15-29) or during adolescence (postnatal weeks [PNW] 4-12), and male offspring were examined at 6, 12, and 25 weeks of age. Another group was exposed after puberty (for 12 weeks) and examined at the conclusion of exposure. The most pronounced reproductive effects were in male rabbits exposed in utero. Male offspring in this group exhibited reduction in numbers of ejaculated sperm (down 43%; p < 0.01), in weights of testes (at 12 weeks, down 23%; p < 0.05) and in accessory sex glands (at 12 and 25 weeks, down 36%; p < 0.01 and down 27%; p < 0.05, respectively). Serum testosterone levels were down (at 6 weeks, 32%; p < 0.05); a slight increase in histological alterations of the testis (p < 0.05) and a doubling in the percentage (from 16 to 30%, p < 0.01) of abnormal sperm; and 1/17 males manifesting hypospadias, hypoplastic prostate, and cryptorchid testes with carcinoma in situ-like cells. In the DBP group exposed during adolescence, basal serum testosterone levels were reduced at 6 weeks (p < 0.01) while at 12 weeks, testosterone production in vivo failed to respond normally to a GnRH challenge (p < 0.01). In addition, weight of accessory sex glands was reduced at 12 weeks but not at 25 weeks after a recovery period; there was a slight increase in the percentage of abnormal sperm in the ejaculate; and 1/11 males was unilaterally cryptorchid. In both of these DBP-treated groups, daily sperm production, epididymal sperm counts, mating ability, and weights of body and nonreproductive organs were unaffected. Thus, DBP induces lesions in the reproductive system of the rabbit, with the intrauterine period being the most sensitive stage of life.     

Evaluation of platelet-rich plasma in combination with anorganic bovine bone in the rabbit cranium: a pilot study

PURPOSE: Platelet-rich plasma (PRP) is potentially useful as an adjunct to allograft and xenograft materials in oral and maxillofacial bone and implant reconstructive surgery. This study compares bone healing and formation in 4 cranial defects in rabbits grafted with autogenous bone, xenograft, and xenograft with PRP (with a no-graft group as a control). MATERIALS AND METHODS: Fifteen New Zealand white rabbits were included in this randomized, blind, prospective pilot study. Four identical 8-mm-diameter defects were created in each rabbit cranium and immediately grafted with the above materials. Five rabbits were evaluated at 1 month, 5 at 2 months, and 5 at 4 months. Radiographs were used to evaluate bone density. RESULTS: Radiographically, sites at which Bio-Oss, autogenous bone, and Bio-Oss + PRP were grafted showed a significant increase in bone density at 1 month (P = .05 for Bio-Oss, P = .02 for autogenous bone, P = .008 for Bio-Oss + PRP) and at 4 months (P = .02 for Bio-Oss, P = .04 for autogenous bone, P = .05 for Bio-Oss + PRP). Autogenous bone sites (P < .001) and Bio-Oss + PRP sites (P < .001) also showed significant increases at 2 months. Histomorphometrically, autogenous bone sites showed a significantly greater increase than control sites (P = .08 at 1 month, P = .03 at 2 months, P = .01 at 4 months), Bio-Oss sites (P < .001 at all 3 evaluation points), or Bio-Oss + PRP sites (P = .009 at 1 month, P = .02 at 2 months, P = .01 at 4 months). Furthermore, Bio-Oss + PRP sites showed a significantly greater increase in bone area at 1, 2, and 4 months than Bio-Oss alone (P = .003 at 1 month, P = .02 at 2 months, P = .006 at 4 months). DISCUSSION: Radiographs showed significantly greater bone density at the Bio-Oss, autogenous bone, and Bio-Oss + PRP sites than at control sites at nearly every point in time evaluated; however, clinical significance is difficult to determine, since all materials appeared dense on the radiograph. Histomorphometry showed that the increase in bone area at autogenous sites was significantly greater than that seen with other grafting materials or at the control sites. CONCLUSION: This study showed a histomorphometric increase in bone formation with the addition of PRP to Bio-Oss in non-critical-sized defects in the rabbit cranium.     

Long-term effects on psychotherapy of initial treatment conditions

The special importance of events at the start of psychotherapy has been recognized by a number of clinicians and investigators^(1,2,3) but there are relatively few objective studies of the different consequences of variations in treatment at the start of psychotherapy. In the present study we will examine the long-term consequences of three different medication treatments and two different psychotherapy conditions administered at the start of clinic contacts. This study is a follow-up of a sample of patients from a larger project concerned with the effects of chlordiazepoxide (Librium) that has been reported elsewhere.⁽⁴⁾     

Blood pressure in the arm and thigh of man: I. A study of averages,variations, and differences between thigh and arm

Blood pressure, pulse pressure, the difference of blood pressure in thigh and arm, and the pulse rate in 112 subjects in the horizontal posture showed great variability from person to person.The tendency of the diastolic blood pressure to increase while the systolic blood pressure remained essentially the same on changing from the horizontal to the standing position is in agreement with the results reported by others.Fifty-nine and five-tenths per cent of all blood pressures fell within 10 per cent, and 86.5 per cent fell within 20 per cent, of the average for the group. These results are almost identical with those of Strang.¹⁶Differential blood pressures between thigh and arm revealed a wide range of values; the average was 35 mm., systolic, and 27 mm., diastolic, for the horizontal posture. Assumption of the standing posture resulted in a differential pressure of 78 mm., systolic, and 66 mm., diastolic.No apparent correlation was noted between differential pressures and factors such as age, sex, or occupation.No significant differences were found between blood pressures in the left and right thighs of normal subjects.Knowledge of the range of blood pressure in the normal, nonhyperreacting subject, as contrasted to that in the normal, hyperreacting, or hypertensive, hyperreacting subject, is particularly important for those who are trying to evaluate therapeutic attempts to lower or raise the blood pressure.     

Blood pressure in the arm and thigh of man: III. Effect of venous engorgement

The production of congestion of an extremity by means of a tight cuff usually results in little change in systolic blood pressure, but, in some cases, it may result in considerable increase in diastolic pressure and a decrease in the intensity of the diastolic auscultatory sounds in that extremity. It is not known why some persons exhibit these tendencies, whereas others do not. Possible mechanisms are discussed.Slow or intermittent deflation of a blood pressure cuff below the level of systolic pressure may tend to increase the value of the diastolic blood pressure in some cases. Suggestions are offered to obviate this tendency.