Apparent thermodynamic parameters of ligand binding to the cloned rat mu-opioid receptor

This study examined the involvement of spinal dopamine D2 receptors in the cardiovascular effects induced by intravenous administration of the selective dopamine D2 receptor agonist quinpirole, as has been previously reported for the hypotensive action of systemic bromocriptine. In normotensive pentobartitone-anaesthetised rats, intravenous injection of quinpirole (25 to 1000 microg/kg) decreased mean aortic pressure and heart rate in a dose-related manner. The intravenous (0.5 mg/kg) or intrathecal (40 microg/rat at T9-T10) pretreatment with domperidone, a dopamine D2 receptor antagonist that does not cross the blood-brain barrier, significantly reduced the maximal hypotensive and bradycardic responses to intravenous quinpirole (1000 microg/kg). In contrast, the latter effects were fully abolished either by intravenous metoclopramide (5 mg/kg) or combined pretreatment with intravenous and intrathecal domperidone. In addition, when injected intrathecally at the T9-T10 level of the spinal cord, quinpirole (7.7 to 61.4 microg/rat) also produced dose-dependent depressor and bradycardic effects which could be blocked by intrathecal, but not intravenous, domperidone pretreatment. This suggests that, in anaesthetised normotensive rats, the hypotensive and bradycardic responses to intravenous quinpirole are fully mediated by dopamine D2 receptors, some of which are located in the peripheral circulation and some of which are located within the spinal cord. The latter finding is novel, suggesting that partial spinal mediation may not be peculiar to bromocriptine, as was previously thought. Rather, partial spinal mediation may be common to most dopamine D2 receptor agonists.     

Microwave-hydrothermal synthesis of Al-substituted tobermorite from zeolites

Here, we report the rapid synthesis of Al-substituted tobermorites from zeolites under microwave-hydrothermal (M-H) conditions. The synthesized phases were characterized by powdered XRD analysis, SEM and selective Cs exchange determination. Zeolites served as aluminosilicate sources and M-H conditions yielded highly crystalline Al-substituted tobermorites in 2 h at 180°C and they showed high selectivity for Cs. For example, an Al-substituted tobermorite synthesized from phillipsite showed Cs exchange K_d of 2161±465 and 118,589±44,928 from 0.02N NaCl and 0.02N CaCl₂ solutions (both contained 0.0002N CsCl), respectively. Al-substituted tobermorites are expected to be useful for the selective separation of radioactive Cs and tobermorites can be incorporated in cement and/or concrete matrix for Cs immobilization.     

Recombination of baculovirus DNA following lipofection of insect larvae

By injection of a liposomal complex containing baculovirus DNA directly into the hemocoel of insect larvae a polyhedrosis disease was induced. After cotransfection of insect larvae with circular viral DNA and transfer vector DNA recombinant viruses were generated with a frequency of about 2%, similar to what is obtained in vitro using insect cell cultures. Based on these results an alternative strategy for the generation of recombinants can be derived for baculoviruses for which susceptible cell lines are not readily available. This strategy involves the injection of baculovirus DNA into susceptible larvae followed by in vivo cloning.     

Survival and tumour characteristics of breast-cancer patients with germline mutations of BRCA1

BACKGROUND: Hereditary breast cancer has been associated with mutations in the BRCA1 and BRCA2 genes and has a natural history different from sporadic breast cancer. We investigated disease-free and overall survival for patients with a proven BRCA1 alteration. METHODS: We estimated disease-free and overall survival for 49 Dutch patients from 19 consecutive families with a proven specific BRCA1 mutation and one family with strong evidence for linkage to the BRCA1 gene. We compared clinical outcome and data on tumour size, histology, axillary nodal status, contralateral breast cancer, and oestrogen-receptor and progesterone-receptor status with those of 196 patients with sporadic breast cancer, matched for age and year of diagnosis. FINDINGS: Disease-free survival for BRCA1 and sporadic patients at 5 years was 49% (95% CI 33-64) and 51% (43-59), respectively (p=0.98). Overall survival at 5 years was 63% (47-76) and 69% (62-76), respectively (p=0.88). Recurrence and death rates did not differ significantly between groups. Hazard ratios for recurrence and death among BRCA1 patients were 1.00 (0.65-1.55) and 1.04 (0.63-1.71) relative to sporadic patients (p=0.88), and these did not differ significantly after adjustment for prognostic factors. Patients with BRCA1-associated breast cancer had twice as many progesterone-receptor-negative tumours (p<0.005) and development of contralateral breast cancer was four to five times as frequent as in the sporadic group (p<0.001). INTERPRETATION: We showed that disease-free and overall survival were similar for sporadic and hereditary breast cancer in the presence of different tumour characteristics, which has implications for screening prophylactic therapy, and different treatments of hereditary breast cancer.     

Renal dysfunction after myocardial revascularization: risk factors, adverse outcomes, and hospital resource utilization. The Multicenter Study of Perioperative Ischemia Research Group

Preclinical studies with murine tumor models have demonstrated that tumor cell vaccines engineered to secrete certain cytokines in a paracrine fashion elicit systemic immune responses capable of eliminating small amounts of established tumor. In particular, tumors that express the cytokine GM-CSF produce potent systemic antitumor immune responses against poorly immunogenic murine tumors. These results have encouraged the development of paracrine-cytokine secreting tumor vaccines for gene therapy of human cancer. GM-CSF recruits professional antigen-presenting cells, which in turn activate effector T cells. These findings suggest that allogeneic as well as autologous tumor cells can be used as the tumor source for developing cancer vaccines. A major obstacle to creating genetically modified human allogeneic tumor vaccines is the absence of stable cell lines required for efficient gene transfer, because most human tumors isolated from primary surgical specimens fail to proliferate in long-term culture. We have developed a method for the routine generation of in vitro cell lines from primary tumors of the pancreas. This method overcomes the common problem of stromal and fibroblast overgrowth that can inhibit the in vitro expansion of many histologic types of tumors. In addition, we have analyzed 12 of these cell lines for cytokeritin and mutated K-ras expression to demonstrate that they derive from the original epithelial tumor tissue. The lines can be genetically modified to stably express the cytokine GM-CSF. These methods should be helpful to investigators attempting to establish cell lines from other histologic tumor types for the development of allogeneic genetically modified tumor vaccines.     

Porcine steroidogenic factor-1 gene (pSF-1) expression and analysis of embryonic pig gonads during sexual differentiation

The porcine steroidogenic factor-1 gene (pSF-1) was cloned using a combination of genomic and RT-PCR based cloning methods. pSF-1 consists of an open reading frame of 1383 nt corresponding to a deduced amino acid sequence of 461 aa, similar to bovine and human SF-1. Sequence homologies between pSF-1 and human, bovine and mouse molecules indicate strong evolutionary conservation at both the nt and aa levels. Northern analysis of pSF-1 expression in adult steroidogenic tissues correlated with porcine steroidogenic acute regulatory protein gene (pStAR) and porcine side chain cleavage (pP450scc) gene expression. Notably, pSF-1 expression was readily detected in neonatal testes, absent at 3 weeks of age, and again readily detected at 3 months and in adult testes. pSF-1 expression was weak but detectable in placental tissues at various times of gestation, and was correlated with pStAR and pP450scc expression, indicating classical steroidogenesis in this organ. In developing gonads from 6-12 weeks of gestation, i.e. during the time of sex differentiation in the pig, Northern analysis demonstrated increasing expression of PSF-1 in fetal testes and no expression in ovaries. This expression pattern was paralleled for pStAR, pP450scc, and porcine Müllerian inhibitory substance (pMIS), consistent with pSF-1 involvement in both steroid and protein hormone secretions of the developing testes during sex differentiation. Porcine SRY HMG-box related gene-9 (pSOX-9) expression also paralleled that of pSF-1 in developing testes. In contrast, DSS-AHC critical region on the X chromosome, gene 1 (pDAX-1) was expressed predominantly in the developing ovaries, indicating a possible reciprocal regulation of pSF-1 and pDAX-1 genes in developing pig testes and ovaries.     

An outbreak of Brainerd diarrhea among travelers to the Galapagos Islands

In 1992, an outbreak of chronic diarrhea occurred among passengers on a cruise ship visiting the Galapagos Islands, Ecuador. Passengers (548) were surveyed, and stool and biopsy specimens from a sample who reported chronic diarrhea were examined. On completed questionnaires, returned by 394 passengers (72%), 58 (15%) reported having chronic diarrhea associated with urgency (84%), weight loss (77%), fatigue (71%), and fecal incontinence (62%). Illness began 11 days (median) after boarding the ship and lasted 7 to >42 months. Macroscopic and histologic abnormalities of the colon were common, but extensive laboratory examination revealed no etiologic agent. No one responded to antimicrobial therapy. Patients were more likely than well passengers to have drunk the ship's unbottled water or ice before onset of illness and to have eaten raw sliced fruits and vegetables washed in unbottled water. Water handling and chlorination on the ship were deficient. Outbreaks of a similar illness, Brainerd diarrhea, have been reported in the United States. Although its etiology remains unknown, Brainerd diarrhea may also occur among travelers.     

Febrile morbidity in severe and critical ovarian hyperstimulation syndrome: a multicentre study

The objective of this study was to define the incidence of febrile morbidity and its causes in severe and critical ovarian hyperstimulation syndrome (OHSS). For this purpose, we reviewed the medical records of all OHSS patients hospitalized in 16 out of 19 tertiary medical centres in Israel between January 1987 and December 1996. Febrile morbidity was defined as at least one episode of temperature rise above 38 degrees C lasting > or =24 h. A total of 2902 patients (3305 hospitalizations) with OHSS was identified, of whom 196 had severe, and 13 critical, OHSS. Among the 209 patients investigated the incidence of febrile morbidity was 82.3%, of which 20.5% was attributed to urinary tract infection, 3.8% to pneumonia, 3.3% to upper respiratory tract infection, 2.0% to intravenous line phlebitis, 1.0% to cellulitis at an abdominal puncture site, 1.0% to postoperative wound infections and 0.5 % to gluteal abscess at the site of progesterone injection. Non-typical organisms were frequently isolated, such as Pseudomonas, Proteus, Klebsiella and Enterobacter species. No infectious aetiology was found in 105 patients (50.2%). Hypoglobulinaemia was recorded in most patients, while ascitic and pleural fluids aspirated from these patients contained high globulin concentrations. We conclude that infection-related febrile morbidity in severe and critical OHSS is high, and may be attributed to some degree of immunodeficiency associated with loss of plasma globulins to the third space. However, non-infection-related febrile morbidity is even higher and may be attributed to endogenous pyrogenic mechanisms.     

Multivariate behavioral genetic analysis of achievement and cognitive measures in reading-disabled and control twin pairs

In recent years behavioral genetic studies have provided conclusive evidence that reading disability and related learning disorders, such as mathematics disability, are due at least in part to heritable factors (DeFries et al. 1987; Alarcón et al. 1997). Although the observed relationship between performance in these areas also may be due substantially to genetic influences (Light and DeFries 1995; Thompson et al. 1991), relatively few studies have examined the genetic and environmental etiology of this covariation in a multivariate framework. In the present study data from 196 identical (monozygotic; MZ) and 155 same-sex fraternal (dizygotic; DZ) twin pairs in which at least one member of each pair evidenced reading problems in school (reading disabled) were subjected to a multivariate behavioral genetic analysis. Structural equation models were fitted to twin data for verbal IQ (VIQ), phonological decoding ability (PHON), reading performance (READ), and mathematics performance (MATH) to assess the extent to which VIQ and PHON mediate the observed covariation between READ and MATH. Results suggest that VIQ and PHON account for most of the covariation between READ and MATH. Moreover, approximately 82% of the observed correlation between READ and MATH was due to genetic factors that also influence VIQ and PHON. When data from 132 MZ and 91 same-sex DZ control twin pairs in which neither twin had a history of reading problems were subjected to the same analyses, the covariation between READ and MATH was found to be due to both genetic and shared environmental influences. Thus genetic factors that influence VIQ and PHON also contribute to the observed covariation between READ and MATH in both a reading-disabled and a control twin sample.