Optical control of light polarization in heliconical cholesteric liquid crystals

We show here that light polarization of a beam propagating through a heliconical cholesteric cell can be controlled by tuning the Bragg resonance of the structure. We demonstrate that this control is achieved by varying either the low-frequency electric field or the intensity of a pump beam impinging on the sample. The study confirms the recently reported phenomenon of optical tuning of the heliconical cholesterics and opens the door for the development of simple and efficient polarization modulators controlled electrically or optically.

Label-free detection of DNA single-base mismatches using a simple reflectance-based optical technique

Rapid and quantitative detection of the binding of nucleic acids to surface-immobilized probes remains a challenge in many biomedical applications. We investigated the hybridization of a set of fully complementary and defected 12-base long DNA oligomers by using the Reflective Phantom Interface (RPI), a recently developed multiplexed label-free detection technique. Based on the simple measurement of reflected light intensity, this technology enables to quantify the hybridization directly as it occurs on the surface with a sensitivity of 10 pg mm(-2). We found a strong effect of single-base mismatches and of their location on hybridization kinetics and equilibrium binding. In line with previous studies, we found that DNA-DNA binding is weaker on a surface than in the bulk. Our data indicate that this effect is a consequence of weak nonspecific binding of the probes to the surface.

An optofluidic constriction chip for monitoring metastatic potential and drug response of cancer cells

Cellular mechanical properties constitute good markers to characterize tumor cells, to study cell population heterogeneity and to highlight the effect of drug treatments. In this work, we describe the fabrication and validation of an integrated optofluidic chip capable of analyzing cellular deformability on the basis of the pressure gradient needed to push a cell through a narrow constriction. We demonstrate the ability of the chip to discriminate between tumorigenic and metastatic breast cancer cells (MCF7 and MDA-MB231) and between human melanoma cells with different metastatic potential (A375P and A375MC2). Moreover, we show that this chip allows highlighting the effect of drugs interfering with microtubule organization (paclitaxel, combretastatin A-4 and nocodazole) on cancer cells, which leads to changes in the pressure-gradient required to push cells through the constriction. Our single-cell microfluidic device for mechanical evaluation is compact and easy to use, allowing for an extensive use in different laboratory environments.

An integrated optofluidic device for single-cell sorting driven by mechanical properties

We present a novel optofluidic device for real-time sorting on the basis of cell mechanical properties, measured by optical stretching. The whole mechanism, based on optical forces, does not hamper the viability of the tested cells, which can be used for further analysis. The device effectiveness is demonstrated by extracting a sample population enriched with highly metastatic cells from a heterogeneous cell mixture.

Evaluation of the non-catalytic binding function of Ts26GST a glutathione transferase isoform of Taenia solium

Taenia solium glutathione transferase isoform of 26.5 kDa (Ts26GST) was observed to bind non-catalytically to porphyrins, trans-trans-dienals, bile acids and fatty acids, as assessed by inhibition kinetics, fluorescence spectroscopy and competitive fluorescence assays with 8-anilino-1-naphthalene sulfonate (ANS). The quenching of Ts26GST intrinsic fluorescence allowed for the determination of the dissociation constants (KD) for all ligands. Obtained data indicate that Ts26GST binds to all ligands but with different affinity. Porphyrins and lipid peroxide products inhibited Ts26GST catalytic activity up to 100% in contrast with only 20-30% inhibition observed for bile acids and two saturated fatty acids. Non-competitive type inhibition was observed for all enzyme inhibitor ligands except for trans-trans-2,4-decadienal, which exhibited uncompetitive type inhibition. The dissociation constant value KD = 0.7 μM for the hematin ligand, determined by competitive fluorescence assays with ANS, was in good agreement with its inhibition kinetic value Ki = 0.3 μM and its intrinsic fluorescence quenching KD = 0.7 μM. The remaining ligands did not displace ANS from the enzyme suggesting the existence of different binding sites. In addition to the catalytic activity of Ts26GST the results obtained suggest that the enzyme exhibits a ligandin function with broad specificity towards nonsubstrate ligands.

Prolactin inhibits the apoptosis of chondrocytes induced by serum starvation

The apoptosis of chondrocytes plays an important role in endochondral bone formation and in cartilage degradation during aging and disease. Prolactin (PRL) is produced in chondrocytes and is known to promote the survival of various cell types. Here we show that articular chondrocytes from rat postpubescent and adult cartilage express the long form of the PRL receptor as revealed by immunohistochemistry of cartilage sections and by RT-PCR and Western blot analyses of the isolated chondrocytes. Furthermore, we demonstrate that PRL inhibits the apoptosis of these same chondrocytes cultured in low-serum. Chondrocyte apoptosis was measured by hypodiploid DNA content determined by flow cytometry and by DNA fragmentation evaluated by the ELISA and the TUNEL methods. The anti-apoptotic effect of PRL was dose-dependent and was prevented by heat inactivation. These data demonstrate that PRL can act as a survival factor for chondrocytes and that it has potential preventive and therapeutic value in arthropathies characterized by cartilage degradation.

Expression of prolactin gene and secretion of prolactin by rat retinal capillary endothelial cells

PURPOSE

Prolactin fragments inhibit blood vessel formation, whereas anti-prolactin antibodies induce angiogenesis in the cornea. Endothelial cells from brain capillaries and the umbilical vein produce prolactin, and this study was undertaken to determine whether retinal capillary endothelial cells could be a source for prolactin in the eye.

METHODS

Primary cultures of rat retinal endothelial cells were investigated for the expression of prolactin mRNA by reverse transcription-polymerase chain reaction (RT-PCR) and Southern blot analysis and by in situ hybridization. The prolactin protein was analyzed by immunocytochemistry, enzyme-linked immunoabsorbent assay, Western blot analysis, and the Nb2-cell bioassay. The effect of prolactin and the 16-kDa prolactin fragment on retinal endothelial cell proliferation was investigated, and the expression of the cloned prolactin receptor was analyzed by RT-PCR and Southern blot analysis.

RESULTS

Retinal endothelial cells expressed prolactin mRNA and full-length 23-kDa prolactin. Prolactin was observed in the cytoplasm of cells and in their conditioned medium at levels 300 times those described in endothelial cells from other vessels and species. Exogenous 16-kDa prolactin inhibited rat retinal endothelial cell proliferation, whereas 23-kDa prolactin was inactive. No evidence was obtained for the expression of the cloned prolactin receptor in these cells, but the prolactin receptor was amplified in whole rat retina.

CONCLUSIONS

Endothelial cells from the microcirculation of rat retina produce and release prolactin. That the cloned prolactin receptor was not expressed in these cells argues against direct autocrine effects of prolactin. Possible paracrine effects are suggested by the expression of the prolactin receptor in retinal tissue.

Human umbilical vein endothelial cells express multiple prolactin isoforms

Members of the prolactin (PRL) hormonal family have direct effects on endothelial cell proliferation, migration and tube formation. Moreover, isoforms of PRL may function as autocrine regulators of endothelial cells. Bovine brain capillary endothelial cells (BBCEC) express the PRL gene, while anti-PRL antibodies inhibit BBCEC proliferation. Here, we show the expression of the PRL gene into various PRL isoforms in endothelial cells from the human umbilical vein. Reverse transcription-polymerase chain reaction of total RNA from human umbilical vein endothelial cells (HUVEC) detected the full-length PRL mRNA as well as a 100 bp smaller PRL transcript similar to the one previously reported in BBCEC. HUVEC were positive to PRL immunocytochemistry. In addition, various PRL immunoreactive proteins were detected in HUVEC extracts and HUVEC conditioned media by metabolic labelling immunoprecipitation analysis. These PRL immunorelated proteins had apparent molecular masses of 60, 23, 21, 16 and 14 kDa. In contrast to previous findings in BBCEC, HUVEC conditioned media contained very little PRL bioactivity as determined by the selective bioassay of Nb2 cell proliferation. Moreover, some polyclonal or monoclonal antibodies directed against PRL stimulated HUVEC proliferation, in contrast to the inhibitory effect seen in BBCEC. The present findings extend the previous observations about the expression of PRL gene in endothelial cells from bovine brain capillaries to human cells of the umbilical vein, implicating that endothelium from different types of vessels and species share the expression of PRL gene but may differ in the putative autocrine role of the PRL isoforms expressed.

Proteolytic cleavage confers nitric oxide synthase inducing activity upon prolactin

Prolactin (PRL), originally associated with milk secretion, is now known to possess a wide variety of biological actions and diverse sites of production beyond the pituitary. Proteolytic cleavage is a common post-translational modification that can either activate precursor proteins or confer upon the peptide fragment unique biological actions not exerted by the parent molecule. Recent studies have demonstrated that the 16-kDa N-terminal proteolytic cleavage product of PRL (16K-PRL) acts as a potent inhibitor of angiogenesis. Despite previous demonstrations of 16K-PRL production in vivo, biological functions beyond its antiangiogenic actions remain unknown. Here we show that 16K-PRL, but not full-length PRL, acts to promote the expression of the inducible isoform of nitric oxide synthase (iNOS) and nitric oxide (*NO) production by pulmonary fibroblasts and alveolar type II cells with potency comparable with the proinflammatory cytokines interleukin-1beta, interferon gamma, and tumor necrosis factor alpha. The differential effect of 16K-PRL versus PRL occurs through a receptor distinct from known PRL receptors. Additionally, pulmonary fibroblasts express the PRL gene and endogenously produce 16K-PRL, suggesting that this pathway may serve both autocrine and paracrine roles in the regulation of *NO production. These results reveal that proteolytic cleavage of PRL confers upon this classical hormone potent iNOS inducing activity, suggesting its role in inflammatory/immune processes.

Changes in the expression of neurohypophyseal prolactins during the estrous cycle and after estrogen treatment

Estrogens are recognized regulators of the expression of neurohypophyseal hormones and of anterior pituitary prolactin (PRL). Here we have investigated whether the levels of PRL mRNA and of 23 and 14 kDa PRL variants present in the hypothalamo-neurohypophyseal system change during the estrous cycle or in response to estrogen treatment. The reverse transcription polymerase chain reaction (RT-PCR) was performed to examine PRL mRNA expression in isolated paraventricular (PVN) and supraoptic (SON) hypothalamic nuclei. In both nuclei PRL mRNA levels appeared higher in cycling females than in male rats, with the highest level occurring at estrus. This increase may involve estrogen action, since estrogen administration to ovariectomized rats was associated with apparently higher PRL mRNA levels in both the PVN and SON. Expression of the PRL gene at these sites may occur via both transcriptional factor Pit-1-dependent and -independent mechanisms. RT-PCR detected the mRNA for Pit-1 in the PVN but only at estrus. The concentration of the 23 kDa immunoreactive PRL determined in the neurohypophysis was significantly higher during estrus and after estrogen treatment. However, no difference was detected in the levels of the neurohypophyseal 14 kDa PRL-like fragment along the estrous cycle nor after estrogen administration. This lack of parallelism between neurohypophyseal PRLs could relate to an estrogen-induced inhibition of the proteolysis of 23 kDa PRL at this site, since estrogen treatment reduced the activity of neurohypophyseal proteolytic enzymes able to cleave PRL. Altogether our results are consistent with estrogens having a stimulatory effect on PRL gene expression in the hypothalamo-neurohypophyseal system and a concomitant inhibitory action on PRL proteolysis at this site.

Effect of a commercial competitive exclusion culture (Preempt) on mortality and horizontal transmission of Salmonella gallinarum in broiler chickens

A commercial competitive exclusion (CE) culture (PREEMPT) was evaluated for its ability to decrease mortality during the first 10-12 days posthatch resulting from the causative agent of fowl typhoid, Salmonella gallinarum. In the first experiment, chicks provided the CE culture on day of hatch and challenged with 10(5) S. gallinarum on day 3 had a significant decrease in mortality compared with non-CE-treated S. gallinarum-challenged chicks in all four replicates. Mortality for control chicks when averaged across all four replicates was 74% compared with 7.5% for the CE-treated chicks. A second experiment was performed that was designed to measure the efficacy of the CE culture in decreasing the horizontal transmission of this pathogen from infected to uninfected chicks when commingled. Day-of-hatch chicks that were directly infected (seeders) with 10(5) S. gallinarum and provided no CE culture averaged 86% S. gallinarum organ positive and 80% mortality during the first 12 days posthatch across four replicates. Untreated contact (not directly infected) chicks that were commingled with the seeder chicks averaged 84% S. gallinarum organ positive and 54% mortality, and the commingled CE-treated contact chicks (provided CE culture on day of hatch) average 35% S. gallinarum organ positive and 9% mortality during the same time period. These results are of importance to the poultry industry in geographic areas where poultry production is adversely affected by fowl typhoid and indicate that treating newly hatched chicks with this commercial CE culture may be a novel way of decreasing economic losses associated with this highly pathogenic organism.

Expression of prolactin mRNA and of prolactin-like proteins in endothelial cells: evidence for autocrine effects

Formation of new capillary blood vessels, termed angiogenesis, is essential for the growth and development of tissues and underlies a variety of diseases including tumor growth. Members of the prolactin hormonal family bind to endothelial cell receptors and have direct effects on cell proliferation, migration and tube formation. Because many angiogenic and antiangiogenic factors are produced by endothelial cells, we investigated whether endothelial cells expressed the prolactin gene. Here we show that bovine brain capillary endothelial cells (BBCEC) in culture express the full-length prolactin messenger RNA, in addition to a novel prolactin transcript, lacking the third exon of the gene. In addition cultures of BBCEC synthesize and secrete prolactin-like immunoreactive proteins with apparent molecular masses of 23, 21 and 14 kDa. The prolactin-like nature of these proteins in supported by the observation that Nb2-cells, a prolactin-responsive cell line, were stimulated to proliferate when co-cultured with endothelial cells and this stimulation was neutralized with prolactin-directed antibodies. Finally, consistent with a possible autocrine effect of endothelial-derived prolactins, polyclonal and monoclonal prolactin antibodies specifically inhibited basal and basis fibroblast growth-factor-stimulated growth of endothelial cells. Taken together, the present findings support the hypothesis of the prolactin gene being expressed in endothelial cells as proteins that could act in an autocrine fashion to regulate cell proliferation.

Assessment of the safety of intrauterine instillation of heated saline for endometrial ablation

OBJECTIVE

To evaluate the safety of pressure, temperature-controlled, continuously circulating hot saline (EnAbl system, InnerDyne Medical, Sunnyvale, CA) for endometrial ablation using the in vivo human uterus.

DESIGN

Clinical safety study.

SETTING

An academic research environment.

PATIENTS

Eleven women undergoing abdominal hysterectomy because of abnormal uterine bleeding.

INTERVENTION

Before uterine removal, endometrial cavities were exposed to 15 minutes of recirculatory normal saline heated to 70-85 degrees C.

MAIN OUTCOME MEASURE(S)

The uteri were analyzed for extent of thermal damage using standard histopathological techniques and tissue viability histochemical staining. Intrauterine pressures and serosal and subserosal temperatures were continuously monitored by computer.

RESULT(S)

In each treated specimen, histochemical staining demonstrated a depth of necrosis that extended through the entire endometrium and approximately 1-2 mm into the myometrium. The control specimen showed no thermal or mechanical damage. There were no observed negative effects or related complications with this system.

CONCLUSION(S)

The computer-controlled system employing continuously circulating hot saline is an effective method to destroy the endometrium. In four cases with clearly patent tubes, no spill was observed. In all 11 patients, serosal and subserosal temperatures were within safe levels (mean temperature, 37 degrees C).

Differential methylation in steroid 5 alpha-reductase isozyme genes in epididymis, testis, and liver of the adult rat

DNA methylation has been largely involved in the regulation of tissue-specific gene expression. The aim of the study was to determine the methylation pattern of steroid 5 alpha-reductase genes 1 and 2 in two reproductive tissues (testis and epididymis) and a nonreproductive tissue (liver) that exhibit different contents of steroid 5 alpha-reductase isozymes. These isozymes induce the bioconversion of testosterone to dihydrotestosterone that in mammals is a key molecule for external genitalia development. Genomic DNA from the testis, the epididymis, and the liver from normal adult rats was used to determine cytosine and adenine methylation pattern of steroid 5 alpha-reductase genes 1 and 2 by restriction fragment length polymorphism (RFLP) analysis using restriction enzymes sensitive to adenine (Mbo I and Sau3A I) and cytosine (Hpa II and MSP I) methylation. We also evaluated the expression of both steroid 5 alpha-reductase genes by northern blot. When genomic DNA was digested with Hpa II or Msp I, we found that steroid 5 alpha-reductase gene 2 was less cytosine methylated in the epididymis and in the testis than in the liver. In contrast, when genomic DNA was digested with Mbo I or Sau3A I, we observed that gene 2 was more adenine methylated in the epididymis and in the testis than in the liver. 5 alpha-Reductase gene 1 presented the same adenine- and cytosine-methylation pattern in the studied tissues. We also found a differential expression of steroid 5 alpha-reductase genes. Gene 2 was expressed both in the testis and the epididymis but not in the liver; whereas gene 1 was only expressed in the latter. Our results suggest that the differential methylation pattern in 5 alpha-reductase gene 2 in reproductive and nonreproductive tissues should be involved in the regulation of its expression.

Primary peritoneal carcinoma after prophylactic oophorectomy in women with a family history of ovarian cancer. A report of the Gilda Radner Familial Ovarian Cancer Registry

BACKGROUND

According to previous reports, primary peritoneal carcinoma indistinguishable from primary ovarian adenocarcinoma had developed in five women with a history of familial ovarian cancer who had undergone prophylactic oophorectomy.

METHODS

The records from the Gilda Radner Familial Ovarian Cancer Registry were reviewed for instances of prophylactic oophorectomy and cases of primary peritoneal carcinoma occurring after prophylactic oophorectomy.

RESULTS

From 1981 through July 1992, the Gilda Radner Familial Ovarian Cancer Registry accessioned 931 families (a total of 2221 cases of familial ovarian cancer). Currently, 324 women in these families have undergone prophylactic oophorectomy as a preventive measure against the subsequent development of ovarian cancer. Primary peritoneal carcinoma indistinguishable histologically from primary ovarian adenocarcinoma has developed in six of these women 1-27 years after prophylactic oophorectomy.

CONCLUSIONS

Based on this finding and other reports of such primary peritoneal carcinoma, a prospective international study is planned. This study will compare the incidence of peritoneal carcinoma in first- or second-degree relatives who underwent prophylactic oophorectomy because of a family history of ovarian cancer with that of those who did not undergo prophylactic oophorectomy.

Damage in B2m genes and DNA methylation of H-2 genes are involved in loss of expression of class I MHC products on the membrane of LR.4, a cell line derivative of the T-cell lymphoma L5178Y

We have isolated an H-2 deficient cell line (LR.4) from the T-cell lymphoma L5178Y which grew without restrictions in the peritoneal cavity of different inbred strains of mice. The use of polyclonal anti-H-2 antiserum and complement indicated that LR.4 cells did not express class I determinants on the cell membrane. Southern blots of genomic DNA of LR.4 cells showed that B2m genes were severely damaged and that class I H-2 genes were extensively methylated. Consequently, LR.4 cells failed to transcribe mRNAs for both B2m and class I H-2 genes. On the other hand, specific immunity to LR.4 was demonstrated in C57BL/6J mice since, in subsequent challenges with either LR.4 or EL4.4, LR.4 did not grow, whereas EL4.4 grew and killed the mice. In C57BL/6J mice, rejection of LR.4 was accompanied by the production of cytotoxic antibodies. The immune response induced in C57BL/6J mice was determined by non-H-2 antigenic determinants in LR.4 cells.

Immunologic and genetic characterization of S180, a cell line of murine origin capable of growing in different inbred strains of mice

Some of the immunologic and genetic properties of the cell line S180 have been examined. These cells grew without restrictions in the peritoneal cavity of different inbred strains of mice and invariably killed the animals. With Northern blots it was demonstrated that S180 cells contained class I mRNAs but failed to transcribe B2m genes. However, under experimental conditions, a protective humoral immune response mediated by cytotoxic antibodies and complement against S180 cells was obtained through non-H-2 antigens in C57BL/6J mice.

Psychological kinship, love, and liking: preliminary validity data

Psychological kinship refers to valuing significant others as though they were members of one's own family. This construct has many implications for human relationships, including the client-therapist relationship (Bailey, 1988). A 60-item Kinship Scale was developed and administered to 63 undergraduates (39 females; 24 males), along with several other independent measures of sociality (Rubin Love and Liking scales; EPPS Affiliation, Nurturance, and Succorance scales; abbreviated UCLA Loneliness Scale) and the Spiritual Well-Being scales. Subjects took the Kinship, Love, and Liking scales under two cognitive sets, "closest family member" and "acquaintance," while the other scales were taken in regular fashion. The Kinship, Love, and Liking scales were all sensitive to the cognitive sets and appropriately yielded higher mean values and higher correlations with the independent measures vis-à-vis the "closest family member" as opposed to "acquaintance." Significant sex differences were noted, with stronger correlation patterns for males than females. Overall, the Kinship Scale performed very well and shows considerable promise for future research.

Epidemiological study of duodenal erosive disease; its prevalence and nosological position in relation to ulcerative peptic disease

The prevalence of erosive lesions was found to be 27.5% in 11838 cases examined during the last 10 years. In almost 66% of the cases, erosive lesions were localized in the duodenal bulb but mainly isolated and less often in the antro-pyloric area. In 55% of the cases, duodenal erosions coexist with ulcerative peptic disease, 20% in "active" phase and 35% in "inactive" phase. Erosive lesions, appeared autonomously in 45% of the cases. Morphologically, they can be divided in: a) periulcerative marginal erosions closely connected with activity of the ulcers; b) clustered, complete or incomplete erosions, which may or may not be associated with the ulcerative disease and often have a prolonged acyclic behaviour; c) scattered flat erosions which can at times be associated with the ulcerative peptic disease but are always related to a chronic widespread duodenitis. An epidemiological study was performed on 564 cases which were divided into 3 groups: a) cases with autonomous erosive disease; b) those with erosions associated with post-ulcerative scars; and c) those with erosions associated with active ulcers. The control group of 111 cases was characterised by duodenal active ulcers with no erosions. Statistical evaluation of the percentage differences between the 4 groups revealed that in duodenal erosive disease predisposing factors such as psychic temper, environmental and work conditions and eating habits are evident. In autonomous disease drug intake and spices and, to a less extent, alcohol and/or stress situations play a more important role. In erosions associated with an active ulcer, a dominant obsessive temper facilitated by a difficult family situation, bad eating habits and a great amount of smoking are prominent factors.(ABSTRACT TRUNCATED AT 250 WORDS)

Healing rate of duodenal ulcer with hyper-aggressive peptic activity under H2-receptor antagonists

In 60 cases of hyper-aggressive duodenal ulcer an endoscopic examination was made, at short intervals (4,7,11,13,21,28 days) after the treatment with H2-receptor antagonists. The open trial was based on random cases under ranitidine 150 mg b.i.d. (31 cases) or cimetidine 400 mg b.i.d. (29 cases). The healing rate has been calculated from the regression slope of the ulcerative area in mm2. Regression does not have a linear slope; it is slow in the first week, increases in the second week, in which it reaches the maximum value, and then decreases gradually in the following weeks. H2-receptor antagonists have no doubt an accelerating effect on healing; cimetidine, in comparison with ranitidine, has a faster and more evident action in the first week. But then, it reduces its action more rapidly in the following weeks so that, on the whole, it turns out to be slightly less valuable. These results can be practically useful for the treatment of hyper-aggressive D.U. as far as early risks are concerned.

Hemodynamic changes with enalapril in pulmonary arterial hypertension secondary to congenital heart disease

Enalapril was used to treat five patients with pulmonary arterial hypertension secondary to congenital cardiopathy, three with ventricular septal defect, one with arterial septal defect, and one with patent ductus arteriosus. The dose of enalapril was 20 mg/day. All patients underwent pretreatment and posttreatment cardiac catheterization. It was concluded that enalapril may be a useful drug in the treatment of pulmonary arterial hypertension secondary to congenital cardiopathy.

[Use of enalapril, an angiotensin-converting enzyme inhibitor, in pulmonary artery hypertension]

Enalapril (E) was used to treat 16 patients with pulmonary arterial hypertension, 6 primary and 10 secondary, 5 of the latter with congenital heart disease and 5 with chronic obstructive pulmonary disease. The average dose of E was 20 mg/day. All patients underwent pre and post-treatment cardiac catheterization with determination of pressures at: right atrial (RA), main pulmonary artery (MPA), pulmonary capillary wedge pressure ( VCP) and systemic arterial (SA). Resistances forces were also measured as; total pulmonary (TPR), pulmonary arteriolar (PAR) and total systemic (TSR) as well as cardiac output (CO), and echo and electrocardiograms, chest x ray, stress test and respiratory function test. The functional class (NYHA) improved in all (p less than 0.001). The initial mean pressures were: RA 12.24 +/- 4.35; MPA 73.81 +/- 25.16; VCP 12 +/- 2.73 and SA 89 +/- 14; TPR 1477 +/- 761; PAR 1243 +/- 730 and TSR 1684 +/- 505.5; CO 4.5 +/- 1.29. The final values were: RA 9.66 +/- 2.46 (p less than 0.001); MPA 63.26 +/- 24.45 (p less than 0.001); VCP 11.33 +/- 2.38 (p = NS); SA 81 +/- 10 (p less than 0.001); TPR 1009.5 +/- 536.7 (p less than 0.001); PAR 829 +/- 511.5 (p less than 0.001); TSR 1309.6 +/- 296.3 (p less than 0.001); CO 5.2 +/- 1.44 (p less than 0.001). The average of minutes on treadmill was initially 8.2 +/- 2.45 and final 12.46 +/- 3.0 (p less than 0.001). It is concluded that enalapril is a useful drug in the treatment of pulmonary arterial hypertension of any etiology.

Small-size ribosomal RNA species in Trypanosoma cruzi

Trypanosoma cruzi ribosomal RNA was analyzed electrophoresis. On agarose gels, where both large- and small-size species are grossly fractionable, it revealed two bands in the small-size region. These were similar in size to the mammalian 5.8 S and 5 S species. Increased resolution, however, showed these two bands to be composite. The pseudo 5.8 S band contained three, and the pseudo 5 S two, discretely sized molecules. The ribosomal binding of four of these five novel species is apparently dependent on large ribosomal subunit proteins. One species is hydrogen bonded to the beta species of 24 S ribosomal RNA. The five species were estimated to be 261, 217, 197, 141 and 110 nucleotides long.

[Synthesis of benzofuran derivatives with H2 antagonist activity]

N-[2-(7-Dimethylaminomethyl-5-methyl-2-benzofuranmethylthio)ethyl]-N'-methyl-2-nitro-1,1-ethenediamine (III) and N-cyano-N'-[2-(7-dimethylaminomethyl-5-methyl-2-benzofuranmethylthio)ethyl]-N"-methylguanidine (IV) were synthesized. The direct transformation of 2,2-dicarbethoxy-3-hydroxy-5-methyl-7-dimethylaminomethylcoumaran (VII) and of 2,2-dicarbethoxy-3-hydroxycoumaran (XVI) to the corresponding ethyl 2-benzofurancarboxylates (IX) and (XV) is also reported. A mechanism for this reaction is proposed. Compounds (III) and (IV) showed hystamine H2 receptor antagonist activity, but were less potent than cimetidine and ranitidine.

beta-Adrenoceptor activation induces prostaglandin E2 generation in guinea-pig trachea

Isoproterenol and salbutamol caused relaxation of guinea-pig trachea, and generation of PGE2. The phenomenon appears to be specific for beta-adrenergic agonists since the relaxant activity induced by atropine, theophylline and papaverine was not associated with generation of prostaglandin-like material from tracheal smooth muscles. Indomethacin reduced only slightly the relaxation of the tracheal tissue induced by isoproterenol and salbutamol. The possibility is discussed that the increased arachidonic acid metabolism during trachea beta-adrenergic relaxation represents a metabolic event involving phospholipid methylation and membrane fluidity.

Urinary excretion of kallikrein following myocardial infarction

Kinin has been hypothesized to be involved in the mechanism of the procordialgia, collapse, and shock in myocardial infarction. In spontaneous and experimental animal infarction, the long-lasting lowering of plasma kininogen is perhaps the expression of kinin release from the plasma precursor. More recently, a durable reduction of plasma prekallikrein and of the plasma inhibitor of kallikrein, both evaluated with the kaolin contact method, has been demonstrated to support the implication of the kinin system in the course of myocardial infarction. In the present study, the dialy urinary excretion of kallikrein, according to the Porcelli and Croxatto method, has been studied in a group of patients with acute myocardial infarction and in a group of control patients, Differences between the two groups have been observed. They consist mainly in strong daily oscillations in the amount of urinary kallikrein excretion during the 24 hour period in the group of patients with myocardial infaction. At this moment, however, it is not possible to give a definite interpretation of these results.

[Dopamine and shock. Preliminary clinical study of 7 cases]

Seven patients presenting a state of shock were treated with dopamine. The authors remark an undeniable effect on arterial pressure which rises again and on the diuresis.

[Nutrition in the surgical patient with complications]

Parenteral feeding in complicated abdominal surgery has been a definite therapeutic progress. However the authors emphasize the divergent attitudes concerning the amounts of nitrogen which should be supplied as well as the variations in the calories-nitrogen ratio. They propose a practical attitude which must be reevaluated individually.