The effect of transient dopamine antagonism on thyrotropin-releasing hormone-induced prolactin release in pregnant rats

The effect of transient dopamine (DA) antagonism on the sensitivity of pituitary lactotrophs to the PRL-releasing effect of TRH was investigated in rats on days 3, 9, 15, and 21 of pregnancy. Each animal, bearing an indwelling intraatrial catheter, received injections of either the DA antagonist domperidone (0.01 mg/rat, iv) or saline at 0930 h on the day of the experiment. Five minutes later, all animals were given the DA agonist 2-bromo-alpha-ergocryptine maleate (CB-154; 0.5 mg/rat, iv), followed 60 min later by the administration of TRH (1.0 microgram/rat iv). Plasma samples obtained during the experiment were assayed by RIA for PRL and progesterone (P). The results showed that transient DA antagonism increased the sensitivity to TRH as a PRL-releasing stimulus on the morning of day 3 of pregnancy, but not on days 9 and 15. However, the response was present on day 9 in animals that were hysterectomized (HS) on day 6 of pregnancy. The increase in sensitivity of lactotrophs to TRH after DA blockade was observed on day 21 of pregnancy. Plasma levels of P were high on days 3, 9, and 15, but decreased markedly by day 21. In a second experiment, the anterior pituitary (AP) PRL content was determined on days 3, 9, 15, and 21 of pregnancy. The results demonstrated that AP PRL significantly decreased between days 3 and 9 of pregnancy in both intact and HS animals. However, AP PRL concentrations in animals killed on days 15 and 21 were significantly greater than that on day 9 but were not different from that observed on day 3 of pregnancy. We conclude that the ability to transform AP PRL to a TRH-releasable pool by the transient blockade of DA is present in early and late pregnancy, but is absent in midpregnancy. Since this secretory mechanism is retained on day 9 after hysterectomy on day 6 of pregnancy, it appears that the secretory products of the uterine-placental unit are inhibitory to transformation. Further, this inhibitory effect at midpregnancy cannot simply be the result of decreased AP PRL content or changes in plasma P. Finally, the return of the transformation mechanism on the day before parturition (day 21) may be due to the increase in estrogen secretion that occurs in late pregnancy, since we have previously shown that estrogen can induce this AP secretory mechanism.     

The effects of transient dopamine antagonism on thyrotropin-releasing hormone-induced prolactin release in pseudopregnant rats

The effectiveness of TRH in releasing PRL after transient dopamine (DA) blockade was investigated in female rats between days 3 and 11 of pseudopregnancy (PSP). At 0930 h on the morning of the experiment, each animal was injected with the DA antagonist domperidone (0.01 mg/rat, iv) or vehicle (acetic acid in saline); 5 min later, the DA agonist 2-bromo-alpha-ergocryptine maleate (CB-154; 0.5 mg/rat, iv) was administered. Sixty minutes later, TRH (1.0 micrograms/rat, iv) was administered. Blood samples were withdrawn via indwelling catheters before, 5, 20, 40, and 70 min after domperidone or vehicle administration, and 5 and 10 min after TRH administration. On day 3 of PSP, TRH-induced PRL release was significantly enhanced by the domperidone-CB154 treatment compared to that in vehicle-treated control rats. By day 9 of PSP, the effectiveness of TRH in stimulating PRL release after domperidone treatment was decreased by 50% compared to that on day 3 of PSP. This reduction in PRL response to TRH was not due to decreased progesterone levels, as no difference was observed in plasma progesterone between days 3 and 9. Rats that were given domperidone on day 11 of PSP did not exhibit a significant increase in sensitivity to TRH; however, the effectiveness of TRH was enhanced by domperidone on day 11 of PSP in animals that were hysterectomized on day 2 of PSP. Since DA receptor blockage increased the sensitivity to a putative PRL-releasing factor (TRH) and this mechanism was eliminated around the time that the PRL surges of PSP disappear, we suggest that this pituitary mechanism is a critical component of the PRL release mechanism during the surges of PSP. Further, the observed loss of the mechanism between days 9 and 11 of PSP may be due to the direct influence at the anterior pituitary of a uterine PRL inhibitory factor which has been recently described.     

Increased urine volume in chronic schizophrenic patients

Polydipsia and polyuria have a long association with schizophrenia. To assess the prevalence of polydipsia and polyuria in schizophrenia, urine volume was examined in medication-free chronic schizophrenic patients, normal controls, and nonschizophrenic patients. Mean urine volume was significantly higher in the schizophrenic patients (2319 +/- SD 2052 ml/24 hours) than in the other two groups (1054 +/- SD 471 ml/24 hours for nonschizophrenic patients and 1265 +/- SD 613 ml/24 hours for normals). Seven of 35 patients with schizophrenia but 0/7 nonschizophrenics had urine volumes greater than any normal control. Polyuria was associated with a good premorbid history and a positive neuroleptic response. Among polyuric patients, those with hyponatremia may represent a different, distinct subgroup. Neuroleptic treatment was associated with a further, significant increase in urine volume. Hence, polydipsia and polyuria appear to be relatively common in schizophrenia.     

Ethmoid sinus disease: CT evaluation in 400 cases. Part II. Postoperative findings

Clinical, pathologic, and computed tomographic (CT) findings were reviewed in 400 patients with ethmoid sinus disease, including 272 who had undergone surgery. The postoperative appearance of ethmoid sinuses on CT scans is a highly neglected subject in radiologic literature. The unique ethmoid anatomy permits a variety of surgical approaches, and radiologists must be familiar with the postoperative appearances if they are to recognize the effects of prior surgery and detect, when possible, the recurrence of disease. It is often difficult to evaluate the clinical significance of soft-tissue disease, despite good clinical correlation.     

Volvulus of the stomach--an unusual cause of pulsus paradoxus

A patient with a strangulated diaphragmatic hernia presented as an emergency and was noted to have pulsus paradoxus. The mechanism of this physical sign, previously unrecorded in association with an intrathoracic hernia, is discussed.     

Acrylic frontal cranioplasty

The correction of contour defects of the frontal bone has been accomplished with a variety of autogenous and alloplastic materials. We report our experience in reconstructing 11 cases of congenital, traumatic, and postsurgical frontal defects with acrylic. The acrylic was cured intraoperatively within the defect in some patients, or prefabricated into a prosthesis and wired into position in others. The operative techniques for both methods of repair are detailed. The reconstruction was successful in all cases and there were no complications. The acrylic implant has been found to be well tolerated after 2-10 yr follow-up. The value of the construction of a facial moulage is stressed, especially when restoration of the orbital rim is required.     

白头翁中毛莨甙及合成毛茛甙的高效液相色谱测定法

白头翁为毛莨科属植物Pulsatilla chinensis,以根入药,其煎剂能抑制阿米巴原虫的生长、杀灭阴道滴虫等作用,用于细菌性痢疾和阿米巴痢疾的治疗。白头翁中主要成分有原白头翁素[protoanemonin,系由毛莨甙(ranunculin)酶解而得]、白头翁素(anemonin)等,其结构如下:     

Three months' treatment with cyclophosphamide, VP-16-213 followed by methotrexate and thoracic radiotherapy for small cell lung cancer

One hundred eleven patients with inoperable but limited-stage small cell lung cancer were treated with three courses of cyclophosphamide (1.5, 2.5, and 3.5 g/m2, respectively) and VP-16-213 followed by methotrexate and thoracic radiotherapy. The total duration of treatment was 3 months. Patients were included who had pleural effusions, contralateral neck nodes, and bone marrow infiltration. The complete response (CR) rate was 56%, the majority confirmed by repeat bronchoscopy, with an 81% overall response rate. The minimum follow-up was 14 months. Median survival for all 111 patients was 11 months and 14 months (1-34+) for complete responders; the median survival was also 11 months for the 91 patients with conventional limited-stage disease, although 15 of the 19 patients alive at 14 months or more were from this subpopulation. There was no significant difference in the survival of those CR patients whose response was confirmed bronchoscopically and patients whose CR was assessed only radiologically and clinically. Forty-four patients with leukopenia (less than 1000 cells/microliter) received intravenous antibiotics for malaise and suspected infection. Close monitoring between treatments and direct access of patients to the hospital was encouraged. The majority of patients improved symptomatically as assessed by Karnofsky and Respiratory scores. These results support the view that short but intensive treatment without long-term or maintenance chemotherapy is beneficial.