Expression of nitric oxide synthase isoforms (NOS II and NOS III) in adult rat lung in hyperoxic pulmonary hypertension

Breathing air with a high oxygen tension induces an inflammatory response and injures the microvessels of the lung. The resulting development of smooth muscle cells in these segments contributes to changes in vasoreactivity and increased pulmonary artery pressure. This in vivo study determines the temporal and spatial expression of endogenous endothelial nitric oxide synthase (NOS III) and inducible NOS (NOS II), important enzymes regulating vasoreactivity and inflammation, in the adult rat lung during the development of experimental pulmonary hypertension induced by oxidant injury. We analyzed the cellular distribution of these NOS isoforms, using specific antibodies, and assessed enzyme activity at baseline and after 1-28 days of hyperoxia (FIO2 0.87). The number of NOS III-immuno-positive endothelial cells increased early in hyperoxia and then remained high. By day 28, the relative number of these cells had increased from 40% in proximal vessels and 13-16% in distal alveolar vessels of the normal lung to 73-86% and 40-59%, respectively, in hyperoxia. Pulmonary alveolar macrophages (PAMs), normally few in number and only weakly immunopositive for NOS II or III in the normal lung, increased in number in hyperoxia and were strongly immunopositive for each isoform. These morphological data were supported by a temporal increase in total and calcium-independent NOS activity. Thus NOS expression and activity significantly increased in hyperoxia as pulmonary hypertension developed, and NOS III expression increased selectively in vascular endothelial cells, while both NOS isoforms were expressed by the PAM population. We conclude that this increase in expression of a potent vasodilator, an antiproliferative agent for smooth muscle cells, and an antioxidant molecule represents an adaptive response to protect the lung from oxidant-induced vascular and epithelial injury.

Tumor-associated antigen TA-90 immune complex assay predicts subclinical metastasis and survival for patients with early stage melanoma

BACKGROUND

TA-90 is a tumor-associated antigen first identified in the urine and sera of patients with metastatic melanoma. In the early stages of disease, TA-90 is present in circulating immune complexes (ICs) that may be detected with an antigen specific enzyme-linked immunosorbent assay (ELISA). In this study, the authors evaluated the efficacy of the TA-90 IC assay in detecting subclinical metastasis of early stage melanoma and predicting the survival of patients with this disease.

METHODS

Archival sera were collected preoperatively from 114 patients who underwent wide excision with or without regional lymphadenectomy in the treatment of clinical Stage I melanoma. Sera were analyzed for TA-90 IC in a blinded fashion, and results were correlated with the patient's clinical course as determined by database and chart review. Subclinical metastases were considered present at the time of surgery if the lymphadenectomy specimen was pathologically positive and/or the patient subsequently developed recurrence.

RESULTS

The TA-90 IC assay predicted subclinical metastasis in 43 of 56 patients (P < 0.0001), with 14 false-positive and 13 false-negative results. Sensitivity and specificity for the detection of occult metastasis were 77% and 76%, respectively. Positive and negative predictive values were 75% and 77%, respectively. Fifteen of 18 tumor positive regional lymph node basins (83%) and 34 of 46 recurrences (74%) were accurately predicted when considered independently (P < 0.004). Preoperative TA-90 IC status was also highly correlated with survival: 5-year overall and disease free survival rates were 63% and 46%, respectively, for the TA-90 IC positive group, compared with 88% and 82%, respectively, for the TA-90 IC negative group (P=0.0001). A multivariate analysis with standard prognostic variables identified preoperative TA-90 IC status as a strong, independent prognostic factor for both overall and disease free survival.

CONCLUSIONS

To the authors' knowledge, TA-90 is the first tumor marker that accurately predicts subclinical metastatic disease and survival for patients with early stage melanoma. For this reason, the TA-90 IC assay has the potential to improve dramatically the prognostic evaluation of patients with this disease. Its role in postoperative risk stratification and early detection of recurrence is being evaluated in a prospective study.

Tamoxifen induces selective membrane association of protein kinase C epsilon in MCF-7 human breast cancer cells

Tamoxifen, a synthetic antiestrogen, is known for its antitumoral action in vivo; however, it is well accepted that many tamoxifen effects are elicited via estrogen receptor-independent routes. Previously, we reported that tamoxifen induces PKC translocation in fibroblasts. In the present study, we investigated the influence of tamoxifen, and several triphenylethylene derivatives, on protein kinase C (PKC) in MCF-7 human breast cancer cells. As measured by Western blot analysis, tamoxifen elicited isozyme-specific membrane association of PKC-epsilon, which was time-dependent (as early as 5 min post-treatment) and dose-dependent (5.0-20 microM). Tamoxifen did not influence translocation of alpha, beta, gamma, delta or zeta PKC isoforms. Structure-activity relationship studies demonstrated chemical requirements for PKC-epsilon translocation, with tamoxifen, 3-OH-tamoxifen and clomiphene being active. Compounds without the basic amino side chain, such as triphenylethylene, or minus a phenyl group, such as N,N-dimethyl-2-[(4-phenylmethyl)phenoxy]ethanamine, were not active. In vitro cell growth assays showed a correlation between agent-induced PKC-epsilon translocation and inhibition of cell growth. Exposure of cells to clomiphene resulted in apoptosis. Since PKC-epsilon has been associated with cell differentiation and cellular growth-related processes, the antiproliferative influence of tamoxifen on MCF-7 cells may be related to the interaction with PKC-epsilon.

The specificity of peptides bound to human histocompatibility leukocyte antigen (HLA)-B27 influences the prevalence of arthritis in HLA-B27 transgenic rats

Human histocompatibility leukocyte antigen B27 is highly associated with the rheumatic diseases termed spondyloarthropathies, but the mechanism is not known. B27 transgenic rats develop a spontaneous disease resembling the human spondyloarthropathies that includes arthritis and colitis. To investigate whether this disease requires the binding of specific peptides to B27, we made a minigene construct in which a peptide from influenza nucleoprotein, NP383-391 (SRYWAIRTR), which binds B27 with high affinity, is targeted directly to the ER by the signal peptide of the adenovirus E3/gp19 protein. Rats transgenic for this minigene, NP1, were made and bred with B27 rats. The production of the NP383-391 peptide in B27(+)NP1(+) rats was confirmed immunologically and by mass spectrometry. The NP1 product displaced approximately 90% of the 3H-Arg-labeled endogenous peptide fraction in B27(+)NP1(+) spleen cells. Male B27(+)NP1(+) rats had a significantly reduced prevalence of arthritis, compared with B27(+)NP- males or B27(+) males with a control construct, NP2, whereas colitis was not significantly affected by the NP1 transgene. These findings support the hypothesis that B27-related arthritis requires binding of a specific peptide or set of peptides to B27, and they demonstrate a method for efficient transgenic targeting of peptides to the ER.

Sustained pulmonary hypertension and right ventricular hypertrophy after chronic hypoxia in mice with congenital deficiency of nitric oxide synthase 3

Chronic hypoxia induces pulmonary hypertension and right ventricular (RV) hypertrophy. Nitric oxide (NO) has been proposed to modulate the pulmonary vascular response to hypoxia. We investigated the effects of congenital deficiency of endothelial NO synthase (NOS3) on the pulmonary vascular responses to breathing 11% oxygen for 3-6 wk. After 3 wk of hypoxia, RV systolic pressure was greater in NOS3-deficient than in wild-type mice (35+/-2 vs 28+/-1 mmHg, x+/-SE, P < 0.001). Pulmonary artery pressure (PPA) and incremental total pulmonary vascular resistance (RPI) were greater in NOS3-deficient than in wild-type mice (PPA 22+/-1 vs 19+/-1 mmHg, P < 0.05 and RPI 92+/-11 vs 55+/-5 mmHg.min.gram.ml-1, P < 0.05). Morphometry revealed that the proportion of muscularized small pulmonary vessels was almost fourfold greater in NOS3-deficient mice than in wild-type mice. After 6 wk of hypoxia, the increase of RV free wall thickness, measured by transesophageal echocardiography, and of RV weight/body weight ratio were more marked in NOS3-deficient mice than in wild-type mice (RV wall thickness 0.67+/-0.05 vs 0.48+/-0.02 mm, P < 0.01 and RV weight/body weight ratio 2.1+/-0.2 vs 1.6+/-0.1 mg. gram-1, P < 0.05). RV hypertrophy produced by chronic hypoxia was prevented by breathing 20 parts per million NO in both genotypes of mice. These results suggest that congenital NOS3 deficiency enhances hypoxic pulmonary vascular remodeling and hypertension, and RV hypertrophy, and that NO production by NOS3 is vital to counterbalance pulmonary vasoconstriction caused by chronic hypoxic stress.

Intercondylar notch encroachment following anterior cruciate ligament reconstruction: a prospective study

Intercondylar notch impingement is a recognized cause of graft failure following anterior cruciate ligament (ACL) reconstruction and typically is attributed to anterior tibial tunnel placement or inadequate notchplasty. This prospective study assessed the incidence and nature of notch regrowth following initial ACL reconstruction. The study population was comprised of 36 patients who underwent ACL reconstruction using a patellar tendon-bone autograft. A 3- to 5-mm notchplasty was performed in all patients, and an intraoperative radiograph was taken confirming proper tunnel placement. Magnetic resonance imaging (MRI) was performed the first week following surgery and again at 6 months. The MRIs were reviewed by two skeletal radiologists to evaluate postoperative notch and graft changes. Of the 36 study patients, 28 (78%) knees showed no evidence of graft impingement as defined by graft indentation and intra-substance edema. The MRIs of 8 (22%) patients showed evidence of graft impingement. Four patients had clinical signs of graft impingement, namely persistent effusion or lack of full extension. Arthroscopically, 3 of these patients demonstrated graft encroachment and impingement by fibrocartilage with areas of immature bone. These results indicate that graft impingement from regrowth of the notch is a clinically relevant phenomenon that could potentially result in late graft demise in the ACL-reconstructed knee.

Evaluation of axillary lymphadenectomy without axillary drainage for patients undergoing breast-conserving therapy

BACKGROUND

The routine use of drainage after axillary node dissection in patients undergoing breast-conserving therapy (BCT) is being questioned. To determine the value of routine drainage, we evaluated the postoperative course of patients with primary breast carcinoma who underwent axillary dissection with or without axillary drainage.

METHODS

A retrospective review of 69 patients prompted a prospective randomized trial of 46 patients undergoing BCT at our tertiary cancer center. Variables studied were age, treatment (drain or no drain), number and tumor status of excised lymph nodes, size of primary tumor, duration of drainage or aspiration, number and volume of aspirations, number of office visits, incidence of complications and degree of pain, change in arm or forearm circumference, and body mass index (BMI). Data from prospective and retrospective studies were pooled for analysis.

RESULTS

Of 115 patients, 72 were treated with a drain (Drain group) and 43 were not (No-drain group). Overall there was no difference in the number or tumor status of excised nodes, the size of the primary tumor, or the incidence of complications between the two groups. Aspiration was required in 50% of the No-drain patients and 8.3% of the Drain patients. The incidence of drain placement or replacement postoperatively was 9.3% for the No-drain patients and 4.2% for the Drain patients. The No-drain patients had more office visits (5.1 +/- 0.4 vs. 3.6 +/- 0.1; P = .0002) and a longer interval between operation and last aspiration or drain removal (16.2 +/- 1.4 days vs. 11.3 +/- 0.6 days; P = .0040). Findings were similar in the subgroup of 46 prospectively studied patients, who included 24 Drain patients and 22 No-drain patients. In this group, pain evaluation using a scale of 0 to 10 showed a mean rating of 4.2 +/- 2.6 in Drain patients and 2.7 +/- 0.4 in No-drain patients (P = .0062).

CONCLUSIONS

Axillary node dissection can be managed with or without a drain. More office visits but less pain can be expected if a drain is not used.

Cyclic-GMP-binding, cyclic-GMP-specific phosphodiesterase (PDE5) gene expression is regulated during rat pulmonary development

Increased nitric oxide (NO) production plays a critical role in the mammalian pulmonary vascular adaptation to extrauterine life. NO activates soluble guanylate cyclase, increasing intracellular cGMP concentrations, thereby inducing relaxation of vascular smooth muscle. cGMP is inactivated by cyclic nucleotide phosphodiesterases (PDEs). One PDE isozyme, PDE5, specifically hydrolyzes cGMP, is abundant in lung tissues, and modifies the pulmonary vasodilatory response to exogenous NO. To investigate the regulation of PDE5 gene expression during pulmonary development, PDE5 mRNA levels, as well as cGMP-metabolizing PDE enzyme activity, were measured in the lungs of perinatal and adult rats. RNA blot hybridization revealed that PDE5 mRNA was detectable in fetal lung tissue as early as 18.5 d of the 22-d term gestation and reached maximal levels in neonatal lungs. mRNA levels in adult rat lungs were 3-4-fold less than the levels measured in lungs of 1- and 8-d-old rats. Pulmonary cGMP hydrolytic activity in 1-d-old animals was 30-fold greater than the cGMP hydrolytic activity of adult rat lungs. Zaprinast, a specific PDE5 antagonist, inhibited 52 and 56% of cGMP hydrolytic activity in lungs of 1- and 8-d-old rats, respectively, but only 18% of the activity in adult lungs. In situ hybridization revealed that PDE5 mRNA transcripts were present in the vascular smooth muscle cells of neonatal and adult lungs. PDE5 mRNA was also detected in the alveolar walls of neonatal rat lungs. These results demonstrate that the gene encoding PDE5 is abundantly expressed in the lungs of perinatal rats, and is available to participate in the mammalian pulmonary vascular transition to extrauterine life. Extravascular PDE5 gene expression in neonatal lungs suggests a potentially important nonvascular role for this enzyme during pulmonary development.

Ratio of IgG:IgM antibodies to sialyl Lewis(x) and GM3 correlates with tumor growth after immunization with melanoma-cell vaccine with different adjuvants in mice

Human melanoma cells (from biopsies and culture) express sialyl-Lewis(x) and sialyl Lewis(a), the ligands for ECAM. These ligands may facilitate tumor progression and metastasis in human cancers. To test whether the antibodies to these ligands inhibit tumor progression, IgG and IgM responses to sLe(x) and sLe(a) were induced in C57BL/6j mice (n = 76) by immunization with human melanoma cells, with or without adjuvants (BCG, MPL, KLH). Control mice were treated with saline or BCG. Tumor growth and antigen expression were monitored after challenge with B16 mouse melanoma cells expressing sLe(x), sLe(a) and the ganglioside GM3. Tumor growth was reduced in mice immunized with BCG alone or cells with BCG or MPL, while tumors in mice receiving cells without adjuvants grew larger than in the control. Augmentation of IgM titers to sLe(x) and GM3 after immunization with BCG, or with cells with BCG or MPL correlated with retarded tumor growth, while increased IgG titers to sLe(x) significantly correlated with aggressive tumor growth in mice immunized with cells without adjuvants. SLe(x), sLe(a) and GM3 were expressed in tumors from mice treated with saline or BCG. SLe(x) expression, in particular, was lost in tumors growing in mice immunized with cells with or without adjuvants. Anti-sLe(x) antibodies may promote or prevent tumor growth by antigenic modulation or by cytotoxic killing of tumor cells. Since early anti-sLe(x) IgM correlated with tumor regression, in contrast to anti-sLe(x) IgG, it may serve as a potential early endpoint for the effectiveness of melanoma vaccines expressing the antigens.

The metabolic properties of spermatozoa from the epididymis of the tammar wallaby, Macropus eugenii

The utilization of various substrates by sperm from the cauda epididymidis of the tammar was examined because the major naturally occurring sugar in the semen of this species is N-acetyl-D-glucosamine (NAG) and not furctose, as in eutherian mammals. The sperm displayed a high level of endogenous respiration that supported motility for relatively prolonged periods of time in vitro. They also metabolised exogenous 14C-labelled glucose, NAG, sucrose, and acetate through glycolytic and/or oxidative processes to produce lactate and 14CO2 at varying rates. The rate of uptake of NAG by tammar sperm was about four times greater than that of other substrates. Glucose and/or NAG stimulated the rate of oxygen consumption by about 20%, but acetate stimulated oxygen consumption by more than 40%. The most striking findings were that NAG almost completely inhibited the oxidation of glucose and sucrose by the sperm and depressed the uptake of glucose, 3-O-methylglucose, and sucrose. Acetate oxidation also was inhibited by NAG, but only by about 50%. Tammar sperm generated substantial amounts of free glucose during incubation with NAG, but this and the inhibitory effects of NAG on glucose oxidation were not mimicked by rat sperm. It is proposed that tammar sperm fail to oxidise glucose in the presence of NAG because of the rapid cellular uptake of NAG relative to glucose. Also, the intracellular glucose and acetate liberated from NAG would compete with exogenous glucose for processing in the Embden-meyerhof and tricarboxylic acid (TCA) cycle pathways. It is also suggested that tammar sperm oxidise sucrose after extracellular hydrolysis into its glucose and fructose components. The biological implications of these metabolic and transport properties of tammar sperm have as yet to be determined.

Remittances and inequality: a question of migration stage and geographic scale

The impact of migrant remittances on the place of migrant origin is examined using data from a 1988 household study undertaken in central Zacatecas state, Mexico. The focus is on whether remittances tend to increase or to decrease income inequalities. "Interfamilial inequalities are found first to decrease and then to increase as a place's migration experience deepens. Throughout this experience, however, rural incomes improve relative to urban ones, since remittances are targeted to the predominantly rural areas of origin."

A new MHC locus that influences class I peptide presentation

We have investigated the HLA-B27-restricted CTL response to HY minor histocompatibility antigens in rats and mice transgenic for HLA-B27 and human beta2-microglobulin. A polymorphism was found at a locus within the H2 complex, producing two distinct but overlapping sets of B27-presented HY peptides. The locus, named Cim2, mapped between the K and Pb loci, and its product is therefore distinct from TAP, LMP, and tapasin. Identical findings in rats and mice, including identical HY peptide sequences and the failure of a rat Tap2A transgene to alter CTL recognition, suggest that a homologous locus with similar polymorphism exists in the rat. Cim2, or a closely linked locus, was found to exert a broad effect on peptide loading of both HLA-B27 and mouse class I alleles. The data thus establish a strong, previously unrecognized MHC-encoded influence on the class I antigen pathway.

Experimental inoculation of mice with trypsin-resistant and trypsin-sensitive avian reoviruses

Groups of sucking Swiss albino mice were inoculated by the intracerebral (i.c.), intraperitoneal (i.p.) or oral route with a trypsin-sensitive avian reovirus (TR1) or a trypsin-resistant (R2) reovirus. The viruses caused a number of effects, the most severe occurring after i.c. inoculation and the least after oral inoculation. They included incoordination and tremors, oiliness of the hair, and retarded growth. Patterns of viral persistence in tissues were similar for the two viruses, with high titres in the brain on days 3 and 6 after i.c. or i.p. injection. Both viruses were still present in the brain 21 days after i.c. injection. No virus was found in any tissue when TR1 was given orally. All groups "seroconverted" except the one infected orally with TR1, but neutralization titres were low. The effects resembled those described for mammalian reoviruses in mice. The results indicate that, for short periods, wild mice may be capable of transmitting avian reoviruses between poultry flocks. Furthermore, in the production of monoclonal antibodies to avian reoviruses in mice, it is possible that pathological changes will occur.

Perturbation of fluid reabsorption in the efferent ducts of the rat by testosterone propionate, 17beta-oestradiol 3-benzoate, flutamide and tamoxifen

The regulation by oestradiol and testosterone of fluid reabsorption in the efferent ducts of the rat was investigated by determining the effects of administering the hormones and their antagonists. Untreated rats were compared to animals treated for 7 days with testosterone propionate (1 mg d(-1)), oestradiol benzoate (400 microg d(-1)), flutamide (10 mg d(-1)) or tamoxifen (1 mg d(-1)). Two procedures were used to measure perturbation of transepithelial fluid fluxes in vivo. The first procedure used cannulation of the proximal epididymal duct and micropuncture of the rete testis to compare the rate at which fluid enters and leaves the efferent ducts. Oestradiol administration increased (p < 0.001) the volume of fluid entering the epididymal duct from the efferent ducts (i.e. reduced reabsorption) while flutamide and tamoxifen decreased (p < 0.05) the amount of fluid entering the epididymal duct (i.e. increased fluid reabsorption). Testosterone did not have a statistically significant effect, although it produced a small increase in fluid reabsorption. There was some perturbation of the concentration of electrolytes and the osmotic pressure of the fluid leaving the efferent ducts, but as these were not large, it is suggested that the treatments had little effect on the basic mechanisms of osmotic water transport via solute-solvent coupling. The second procedure used to test the effect of the steroids involved microperfusing individual efferent ducts, and the results were consistent with those of the first study. Oestradiol decreased fluid reabsorption by the efferent ducts (p < 0.05), and testosterone (p < 0.05, lowest perfusion rate only), flutamide (p < 0.001) and tamoxifen (p < 0.01) increased reabsorption. The similar responses to flutamide and testosterone administration suggest that flutamide acted as an androgenic agonist by elevating systemic and luminal androgen. It is concluded that fluid reabsorption in the efferent ducts is perturbed by oestrogens and androgens. Although their actions have not been completely resolved, it is proposed that they are involved in a chronic regulation, with androgens stimulating and oestrogens suppressing fluid reabsorption by the ducts.

A simplified intravenous glucose loading protocol for fluorine-18 fluorodeoxyglucose cardiac single-photon emission tomography

The myocardial uptake of fluorine-18 fluorodeoxyglucose (FDG) has emerged as the most sensitive and specific technique for the assessment of myocardial viability. With the development of FDG single-photon emission tomography (SPET) and dual head coincidence imaging, a hindrance to the widespread clinical use of FDG cardiac imaging is the complexity of the preinjection glucose loading necessary for obtaining interpretable myocardial FDG scans. In a population of 209 patients undergoing dual-isotope single acquisition (DISA) FDG/sestamibi (MIBI) SPET, we describe the improvements in both image quality and time efficiency using a new short, simple glucose/insulin/potassium (GIK) infusion protocol prior to FDG injection as compared to a conventional oral glucose loading protocol. DISA FDG/MIBI SPET scans were performed in 111 nondiabetic patients after oral loading with 50 g of glucose (group 1). Ninety-eight consecutive nondiabetic patients were subsequently scanned following preparation with a fixed-concentration GIK infusion administered at a standardized rate (group 2). A three-point grading scale was used to assess image quality. The time to FDG injection following glucose administration was significantly shorter for the group 2 patients (39.9+/-15.6 min; range 20-105 min) than for the group 1 patients (99.5+/-30.3 min; range 56-270 min) (P<0.0001), representing a 1-h decrease in patient preparation time. More of the group 1 patients (n=30; 27%) required supplemental intravenous boluses of regular insulin than did the group 2 patients (n=13; 13%) (P<0.02). There were more excellent and good quality graded images using the GIK method (group 2) than the more traditional oral loading protocol (group 1) (P<0.02). Nine of 111 scans (8%) in group 1 were uninterpretable, whereas only one of 98 scans (1%) in group 2 was uninterpretable. Standardized infusion of a fixed concentration of GIK prior to FDG administration and continued during myocardial FDG uptake is an effective yet simple method of obtaining consistently good to excellent quality FDG SPET cardiac scans. It is preferable to conventional oral glucose loading due to decreased patient preparation time and improved image quality. The technique is safe and should improve both the clinical use and the cost-effectiveness of FDG SPET imaging for the identification of injured but viable myocardium.

Failure of maternal antibodies to protect young turkey poults against challenge with turkey rhinotracheitis virus

Groups of turkey poults with high levels of maternal antibodies (MA+) to turkey rhinotracheitis virus (TRTV) were challenged with virulent TRTV at 1, 5, and 10 days of age. A maternal antibody-free group (MA-) was also challenged at 1 day of age. Before each challenge, levels of maternal antibodies to TRTV were measured by enzyme-linked immunosorbent assay. Clinical signs were scored for each group. Unchallenged poults showed no signs. Respiratory signs in poults infected at 10 days of age resembled those seen in MA- birds infected at 1 day of age but both were more severe than in MA+ birds infected at 1 day of age, when the maternal antibodies were highest. However, overall, the presence of high levels of maternal antibodies did not prevent the development of clinical disease.

Pulmonary vasoconstriction and hypertension in mice with targeted disruption of the endothelial nitric oxide synthase (NOS 3) gene

NO, synthesized in endothelial cells by endothelial NO synthase (NOS 3), is believed to be an important endogenous pulmonary vasodilator substance that contributes to the normal low pulmonary vascular resistance. To selectively investigate the role of NOS 3 in the pulmonary circulation, mice with targeted disruption of the NOS 3 gene were studied. Pulmonary hemodynamics were studied by measuring pulmonary artery pressure, left ventricular end-diastolic pressure, and lower thoracic aortic flow by using a novel open-chest technique. Transient partial occlusion of the inferior vena cava was used to assess the pulmonary artery pressure-flow relationship. Tension developed by isolated pulmonary artery segments after acetylcholine stimulation was measured in vitro. The histological appearance of NOS 3-deficient and wild-type murine lungs was compared. NOS 3-deficient mice (n = 27), when compared with wild-type mice (n = 32), had pulmonary hypertension (pulmonary artery pressure, 19.0 +/- 0.8 versus 16.4 +/- 0.6 mm Hg [mean +/- SE]; P < .05) that was due to an increased total pulmonary resistance (62 +/- 6 versus 33 +/- 2 mm Hg.min.g.mL-1; P < .001). In vitro, acetylcholine induced vasodilation in the main pulmonary arteries of wild-type but not NOS 3-deficient mice. The morphology of the lungs of NOS 3-deficient mice did not differ from that of wild-type mice. We conclude that NOS 3 is a key enzyme responsible for providing basal pulmonary NO release. Congenital NOS 3 deficiency produces mild pulmonary hypertension in mice.

Sentinel lymphadenectomy in breast cancer

PURPOSE

We previously demonstrated increased detection of axillary metastases using sentinel lymphadenectomy (SLND) and immunohistochemistry. These methods have evolved and we now report our current use of these techniques and our most recent results of axillary staging with SLND.

PATIENTS AND METHODS

One hundred seven consecutive women (previously unreported) with breast cancer underwent SLND followed by completion axillary lymphadenectomy (ALND). All sentinel nodes were examined intraoperatively with frozen section and postoperatively with hematoxylin and eosin staining (H&E) plus immunohistochemical staining (IHC) using antibody to cytokeratin. The nonsentinel axillary nodes were examined with H&E, but not IHC.

RESULTS

The median age was 56.6 years (range, 28 to 90). Most patients (58.9%) were postmenopausal, most primary tumors (62.6%) were palpable, and most operations (86.9%) were breast-conserving. The mean tumor size was 2.11 +/- 1.38 cm. Sentinel nodes were identified in 100 patients: 42 patients had metastases in sentinel nodes; of these, 28 (66.7%) had no other involved axillary nodes. On average, 1.8 +/- 1.1 sentinel nodes were examined and 20.3 +/- 7.8 nonsentinel nodes were removed. Of seven patients with no identified sentinel nodes, six had a tumor-negative axilla. SLND was 100% predictive of axillary status in these 100 women.

CONCLUSION

In this population of breast cancer patients, SLND with frozen section and IHC was a minimally invasive, highly accurate intraoperative method of axillary staging. We are evaluating the elimination of routine ALND for sentinel-node negative women to minimize the morbidity associated with standard dissections. The ability to identify node-negative patients without ALND would be a welcome addition to the management of women with breast cancer.

Effect of storage of chicken and turkey blood on the lymphocyte responses to concanavalin A and pokeweed mitogen

The effect of storage of whole blood of chicken and turkeys on the mitogen responses of lymphocytes to concanavalin A (con A) and pokeweed mitogen was investigated. It was found that, despite slight differences in optimum storage conditions with respect to mitogens, species and age of birds, blood could be stored for 24 h at 4 degrees C without significant reduction in the lymphoproliferative responses. However, even during the initial 24 h storage of blood at 4 degrees C, the levels of reduction in stimulation index (SI) values following con A stimulation, ranged from 27% for 3-4 week-old turkeys to 60% for 3-4 week-old white leghorn chickens.

Tamoxifen activates cellular phospholipase C and D and elicits protein kinase C translocation

The antiestrogen tamoxifen is widely used for endocrine therapy of breast cancer; however, the mechanisms of estrogen receptor-independent interactions of tamoxifen remain ill defined. Here we examine the effect of tamoxifen on the initial steps of cell signal transduction. To this end, phospholipid metabolism and protein kinase C (PKC) translocation were assessed in CCD986SK human mammary fibroblasts treated with tamoxifen. The addition of tamoxifen resulted in dose-dependent and time-dependent increases in the cellular second messengers phosphatidate (PA) and diacylglycerol (DG). On addition of ethanol to the medium, tamoxifen induced the formation of phosphatidylethanol, demonstrating that tamoxifen activates phospholipase D (PLD). Cellular DG also increased in the presence of ethanol, showing that tamoxifen also activates phospholipase C (PLC). In cells prelabeled with choline and ethanolamine, tamoxifen caused increases in choline, phosphorylcholine, ethanolamine and phosphorylethanolamine. Structure-activity relationship studies for activation of PLD revealed that tamoxifen was the most effective, whereas 4-hydroxy tamoxifen was nearly devoid of activity. Phorbol diesters also activated PLD, but estrogen had no influence. Pretreatment of cells with phorbol dibutyrate (PKC down-regulation protocol) blocked phorbol diester- and tamoxifen-induced PLD activity. Exposure of cells to the PKC inhibitor GF 109203X diminished tamoxifen-induced PLD activity. Addition of tamoxifen to cultures elicited selective membrane association of PKC epsilon. We conclude that tamoxifen exerts considerable extra-nuclear influence at the transmembrane signaling level. These events may contribute to effects beyond the scope of estrogen receptor-dependent actions.

Adrenal independence of fluid and electrolyte reabsorption in the ductuli efferentes testis of the rat

The ductuli efferentes testis (efferent ducts) of the rat were studied to determine whether fluid and electrolyte reabsorption by the ducts is under the control of adrenal mineralocorticoids. Testicular fluid output and the rate of fluid reabsorption by the ducts were determined in sham-operated controls and in rats which had been adrenalectomized 10 days previously, adrenalectomized 10 days previously and given aldosterone therapy (75 micrograms kg-1 day-1 S.C.) from day 3 to day 10 post adrenalectomy, and in rats given injections of the aldosterone antagonist, spironolactone, for 10 days (10 mg kg-1 day-1 S.C.). The values for testicular fluid output and fluid flow from the efferent ducts (means +/- S.E.M.) in the sham-operated rats were 36.0 +/- 7.8 and 1.23 +/- 0.12 microliters h-1, respectively, resulting in an estimate of fluid reabsorption by the efferent ducts of 94.8 +/- 1.6% of the testicular fluid output. None of the treatments resulted in a significant change in testicular fluid output or in fluid reabsorption from the efferent ducts. Similarly, the treatments did not significantly alter the osmolality or electrolyte concentrations in fluid samples from the rete testis or the distal end of the efferent ducts (sham-operated values for rete testis and efferent duct fluid, respectively, were: osmolality, 311.2 +/- 1.7 and 302.7 +/- 5.7 mosmol kg-1; [Na+], 151.2 +/- 5.6 and 150.8 +/- 8.1 mmol l-1; [Cl-], 147.9 +/- 6.6 and 126.7 +/- 2.2 mmol l-1; [K+], 15.2 +/- 0.7 and 13.5 +/- 2.4 mmol l-1). It is concluded that, like the homologous proximal tubule of the metanephric kidney, fluid reabsorption from the efferent ducts is independent of adrenal mineralocorticoid control.

Cellular cancer vaccine induces delayed-type hypersensitivity reaction and augments antibody response to tumor-associated carbohydrate antigens (sialyl Le(a), sialyl Le(x), GD3 and GM2) better than soluble lysate cancer vaccine

Allogenic whole cell and lysate cancer vaccines are associated with very different clinical outcome, which could be due to different immune responses to critical tumor-associated antigens. We used a guinea pig model to evaluate the immune responses to melanoma-associated carbohydrate antigens administered in whole cell and soluble lysate vaccines produced from the same cell lines and administered with or without Bacille Calmette-Guerin (BCG). Animals immunized with whole cell vaccine developed a significantly higher delayed-type hypersensitivity (DTH) reaction. The IgG response to all tumor-associated carbohydrate antigens except GD2 was significantly higher in animals immunized with whole cell vaccine than lysate vaccine. This study indicates that whole cell vaccine is superior to soluble or lysate vaccine because it induces a better immune response against cell-surface antigens. The addition of BCG significantly increased the antibody response, suggesting that an exogenous adjuvant may immunopotentiate antigens better in the presence of an intact cell membrane.

Growth of infectious bronchitis virus vaccines in oviducts derived from oestrogen-treated chicks and embryos

Six commercial infectious bronchitis virus (IBV) vaccines and five IBV field strains were titrated in tracheal organ cultures (TOC) and oviduct organ cultures (OOC). Endpoints were determined in three different ways: ciliostasis (CD50), immunofluorescence staining (IFID50) and organ culture infectivity (OCID50). For the two most attenuated vaccine viruses, infectivity assessed by IFID50 and OCID50 was significantly higher than that assessed by CD50. No significant differences were found between IFID50 and CD50 with the five virulent viruses in either OOC or TOC. This suggests that the most attenuated viruses multiply in these tissues to a greater extent than assessed by their pathogenic potential i.e. ciliostasis. Comparison of IFID50 and CD50 may be a useful method for screening candidate live respiratory viral vaccines for attenuation. OOC prepared from oestrogen-treated embryos were not efficacious.