Early house moves, indoor air, heating methods and asthma

OBJECTIVES

To assess whether house moves or certain housing conditions are a risk factor for the development of childhood asthma.

DESIGN

A case-control study of asthmatic and non-atopic children aged 4-16 years.

SUBJECTS

One hundred children with confirmed asthma in a group general practice of 11000 patients in Plymouth, U.K. Each was matched by age and gender with a child with no history of wheeze, eczema or hay fever.

MAIN OUTCOME MEASURES

House moves and main heating methods, prior to the age of onset of asthma in cases and controls.

RESULTS

There was a non-significant association between early house moves and the subsequent development of asthma. No association was found with heating methods, except for ducted-air heating which, because of the small numbers involved could have occurred by chance. None of the other factors studied affecting indoor air showed an association.

CONCLUSION

Moving house at an early age may increase the risk of developing asthma, or may be associated with other more important risk factors, such as increased general mobility and hence, exposure to viral infections. Heating methods or other factors likely to affect the indoor air quality in early life were not useful predictors of subsequent asthma in children.

The Middle Years Group: a holistic approach to the management of the menopause in primary care

OBJECTIVES

The menopause is attaining greater significance as symptoms and long-term sequelae are amenable to hormone replacement treatment. However, hormone replacement treatment is no panacea and all women undergoing the menopause need to make informed decisions about its use. The aim of this study was to assess the effects of a series of group sessions for women aged 45-55 years, dealing with physical, social, emotional and medical aspects of the climacteric.

METHODS

All women registered at the Roborough surgery were invited to join a group for four sessions, led by the health visitor and counsellor, with a doctor leading one session on hormone replacement treatment. Women's views on the group were obtained by questionnaire. Prescribing data on hormone replacement treatment and antidepressants were analysed for attenders and a matched group of those invited who did not attend.

RESULTS

Twelve percent of invited women attended. All stated that sessions helped an understanding of the physical and emotional changes at this time. No significant differences were found in the use of hormone replacement treatment, antidepressants or in subsequent use of the counsellor's services between the attenders and a matched group of non-attenders.

CONCLUSIONS

This group offered all women at risk the opportunity to discuss, share and learn about all aspects of the menopause. It was well received and made no major differences to the uptake of hormone replacement treatment.

A retrospective study of the relationship between childhood asthma and respiratory infection during gestation

BACKGROUND

Wheeze in children has been found to be associated with prior antepartum haemorrhage and raised levels of IgE in cord blood, and acute wheezing episodes are intimately linked with respiratory viral infections.

OBJECTIVE

To assess the relationship between maternal presentation with respiratory tract infections in pregnancy and childhood asthma, taking into account factors which could affect presentation.

METHODS

This was a case-control study of 200 asthmatic children, 5-16-year-old, age-matched with one control, having no recorded history of wheeze. Data on respiratory tract infections, maternal wheeze, atopy and smoking was collected from primary care records. Deprivation score was assessed according to small residential areas and subjects were equally distributed between four general practices in Plymouth, UK.

RESULTS

Presentation with respiratory tract infections during pregnancy was significantly associated with childhood asthma (OR 1.69, 95% confidence interval 1.05-2.77, P = 0.03). The association was marginally stronger for infections in the first trimester (OR 2.30, 95% CI 1.05-5.41, P = 0.04) and for those with cough during pregnancy (OR 2.24, 95% CI 1.23-4.22, P = 0.007). The associations remained significant after allowing for the effect of the independent variables (gender, maternal smoking, maternal wheeze, allergic rhinitis, eczema, asthma treatment in pregnancy and deprivation [Townsend] score), using multiple logistic regression analysis (ORs and 95% CIs 1.91, 1.14-3.22; 2.32, 1.01-5.34 and 2.29, 1.17-4.48, respectively). There was also an association between numbers of presentations with respiratory infections and childhood asthma (test for trend, P = 0.02).

CONCLUSIONS

This study has shown an association between presentation with respiratory infection during gestation and childhood asthma. The results were not affected by the other independent variable factors studied and therefore provide some evidence to support the theory that respiratory viruses may be implicated in the aetiology of asthma.

The role of Na+-H+ exchange in fluid and solute transport in the rat efferent ducts

In vivo microperfusion techniques were used to investigate the role of Na+-H+ exchange in the efferent ducts of the rat. Individual efferent ducts were perfused with a Krebs-Ringer bicarbonate solution (KRB) containing 0, 1, 3, 5 or 7.5 mM amiloride. Concentrations of 1-5 mM amiloride inhibited fluid reabsorption from the efferent ducts in a linear dose-dependent manner with an apparent Km of 3 mM. Inhibition was maximal at 5 mM with reabsorption reduced by about 70 %. The effects of amiloride were completely reversible and there was little effect of amiloride on luminal osmolality and concentrations of Na+, Cl- or K+. It is concluded that Na+-H+ exchange is one of the principal mechanisms responsible for fluid and electrolyte reabsorption in the efferent ducts and offers a means by which the efferent ducts are able to achieve flow-dependent, autoregulated fluid reabsorption.

Investigation into avian pneumovirus persistence in poults and chicks using cyclosporin A immunosuppression

One-day-old poults or two-week old chicks were infected oculonasally with avian pneumovirus. Cloacal swabs were collected for virus isolation as were selected tissues (Harderian gland, turbinates, trachea, lungs and kidneys) from birds killed at regular intervals up to 33 days post infection (p.i.) for poults, and up to 40 days p. i. for chicks. In an attempt to induce virus re-excretion, the T-cell-suppressor cyclosporin A (CSA) was given for 12 days starting from three weeks p.i. in poults and from four weeks p.i. in chicks. Birds were sampled for virus isolations up to day 12 post CSA treatment. Virus was recovered only up to day nine p.i. in poults, and day five p.i. in chicks during the acute phase of the infection. Despite T-cell suppression, there was no evidence of re-excretion of the virus, and hence no evidence for the persistence of virus in the tissues examined.

To store or mature spermatozoa? The primary role of the epididymis

The function of the epididymis is considered in the context that it is necessary to transport spermatozoa for internal fertilization, but is also an adaptation involved in the competition between males to achieve paternity. Post-testicular sperm maturation and storage occur in lower vertebrates, such as the chondrichthyes, in which sperm storage is essential due to the slow rate of spermatogenesis. These roles persist in higher vertebrates, including mammals. However, they are less important in certain birds, in which the rate of sperm production by the testes is sufficient to supply enough spermatozoa to cope with the demands of a competitive mating system. There is no evidence for mammals, other than humans, that spermatozoa can achieve the capacity to fertilize an ovum without passing through some of the proximal epididymis. Storage of spermatozoa in the epididymis is probably not essential for a male to achieve conception in a protected mating system, but is very important in a competitive mating system. There is some variation between species in the magnitude of the epididymal storage region. This is related to the descent of the epididymides (and testes) into a scrotal sac in some species and/or the demands of the mating system in other species. The claims that humans are not dependent on post-testicular sperm maturation and storage need to be qualified, as they are based on studies of abnormal tracts and tests of fertility which are not rigorous. Nevertheless, the claims are of considerable clinical significance and may indicate that humans are less dependent on post-testicular sperm maturation and storage than other mammals. This may be an adaptation of the testes and epididymides to the scrotal conditions of modern man or a response to changing environmental factors.

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.

Infectious bronchitis virus: Immunopathogenesis of infection in the chicken

The immunopathogenesis of infectious bronchitis virus (IBV) infection in the chicken is reviewed. While infectious bronchitis (IB) is considered primarily a disease of the respiratory system, different IBV strains may show variable tissue tropisms and also affect the oviduct and the kidneys, with serious consequences. Some strains replicate in the intestine but apparently without pathological changes. Pectoral myopathy has been associated with an important recent variant. Several factors can influence the course of infection with IBV, including the age, breed and nutrition of the chicken, the environment and intercurrent infection with other infectious agents. Immunogenic components of the virus include the S (spike) proteins and the N nucleoprotein. The humoral, local and cellular responses of the chicken to IBV are reviewed, together with genetic resistance of the chicken. In long-term persistence of IBV, the caecal tonsil or kidney have been proposed as the sites of persistence. Antigenic variation among IBV strains is related to relatively small differences in amino acid sequences in the S1 spike protein. However, antigenic studies alone do not adequately define immunological relationships between strains and cross-immunisation studies have been used to classify IBV isolates into 'protectotypes'. It has been speculated that changes in the S1 protein may be related to differences in tissue tropisms shown by different strains. Perhaps in the future, new strains of IBV may arise which affect organs or systems not normally associated with IB.

Protectotypic differentiation of avian infectious bronchitis viruses using an in vitro challenge model

Two vaccine and three virulent strains of infectious bronchitis virus (IBV) were used to infect day-old specific-pathogen-free chickens. Precocious development of oviducts was induced in young female chicks by oestrogen injections. Tracheal and oviduct organ cultures prepared from immunised chickens were challenged in vitro with homologous and heterologous viruses to assess tracheal and oviduct cross-protection. Tracheal cross-protection was seen between serologically related and unrelated viruses. Protection at at the level of the oviducts was lower compared to that seen at the tracheal level. However, the yields of the homologous challenge viruses from immunised oviducts were significantly reduced as compared to yields from normal oviducts. After challenge, tracheal and oviduct ciliary scores were used to group the five strains of IBV into protectotypes. The five viruses could be grouped into three protectotypes and four serotypes. The virulent IBV strains were found to have caused complete stasis of oviduct cilia when examined at three weeks post-infection. Oestrogen treatment of chicks did not significantly alter the lymphocyte proliferation responses to concanavalin A or pokeweed mitogen. The applicability of this model for the study of protection afforded to the oviducts, in terms of protection against virus-induced damage, rather than drop in egg production, is discussed.

Alpha 3 beta 1 integrin has a crucial role in kidney and lung organogenesis

A mutation was targeted to the murine alpha3 integrin gene. Homozygous mutant mice survived to birth, but died during the neonatal period. The mutation caused abnormal kidney and lung development. Mutant kidneys displayed decreased branching of the medullary collecting ducts, although the number of nephrons was not altered. Proximal tubules exhibited two distinct subsets of abnormalities, with the epithelial cells either containing excess lysosomes or becoming microcystic. In addition, glomerular development was markedly affected. In mutant kidneys, the extent of branching of glomerular capillary loops was decreased, with capillary lumina being wider than normal. The glomerular basement membrane was disorganized and glomerular podocytes were unable to form mature foot processes. Branching of the bronchi in lungs of mutant mice was also decreased and the large bronchi extended to the periphery. These results indicate a role for integrin receptors in basement membrane organization and branching morphogenesis.

Sublabral recess of the superior glenoid labrum: study of cadavers with conventional nonenhanced MR imaging, MR arthrography, anatomic dissection, and limited histologic examination

PURPOSE

To evaluate size, location, and appearance of the sublabral recess of the superior glenoid labrum, which mimics a superior labral tear oriented in the anterior to posterior direction (SLAP) lesion with conventional magnetic resonance (MR) imaging, MR arthrography, gross dissection, and limited histologic evaluation.

MATERIALS AND METHODS

Twenty-six cadaveric shoulder specimens that were freshly frozen were examined with nonenhanced MR imaging and with MR arthrography after intraarticular injection of dilute contrast material with gadolinium. In all specimens, the appearance of the superior glenolabral junction was categorized and was correlated to that seen at gross anatomic dissection. Histologic sections were obtained of two shoulders with large sublabral recesses in the plane of the MR sections.

RESULTS

A sublabral recess was present in 19 (73%) shoulders and was deeper than 2 mm in 10 (39%). MR arthrography better demonstrated the sublabral recess than nonenhanced MR imaging. In 16 of 19 shoulders, the sublabral recess was located in the most anterior section obtained through the superior labrum. There was no definite correlation between subject age and sex and glenolabral junction type. At histologic examination of the two shoulders, a synovial lining of the sublabral recess was seen and there was no evidence of fibrosis to suggest a traumatic cause.

CONCLUSION

A sublabral recess is common in cadaveric shoulders and has an appearance similar to that of published examples of SLAP lesions. Histologic findings were consistent with normal anatomic structure rather than with acquired, posttraumatic lesions.

Immune response to polyvalent melanoma cell vaccine in AJCC stage III melanoma: an immunologic survival model

BACKGROUND

Our polyvalent, allogeneic melanoma cell vaccine (MCV) induces immunoglobulin M (IgM) and immunoglobulin G (IgG) class antibodies to a 90-kDa glycoprotein melanoma-associated antigen (MAA). Additionally, MCV induces delayed-type hypersensitivity (DTH) responses that we previously correlated with survival. We hypothesized that early DTH responses to MCV and early humoral responses to the 90-kDa MAA expressed on MCV cells may be predictive of overall survival. We tested this hypothesis by monitoring immunologic profiles in 59 patients with melanoma who were receiving MCV after surgical resection of regional lymph node or soft-tissue metastases.

METHODS

Blood was drawn before vaccine administration, biweekly for 6 weeks, and then monthly. DTH to MCV was recorded at 0, 2, 4, and 8 weeks of MCV therapy. Mean antibody titers during the first 6-week interval were calculated. Changes in DTH were calculated as the difference between peak and prevaccine values (delta DTH).

RESULTS

At a median follow-up of 75.6 months (range 5-138), univariate analysis assigned prognostic significance to gender (p = 0.046), lymph node involvement (p = 0.024), delta DTH (p = 0.044), mean anti-90-kDa MAA IgG (p = 0.0009), and mean anti-90-kDa MAA IgM (p = 0.0014). In multifactorial analysis, only the three immunologic variables significantly impacted survival (p = 0.046, 0.0005, and 0.0053, respectively). A mathematical model based on delta DTH and mean anti-90-kDa MAA IgG and IgM titers closely approximated the observed individual and overall survival rates.

CONCLUSIONS

The correlation between overall survival and initial humoral/cellular immune responses to MCV immunotherapy may be useful in selecting patients most likely to benefit from prolonged adjuvant immunotherapy.

Local antibody production in the oviduct and gut of hens infected with a variant strain of infectious bronchitis virus

Following infection of 16-week old specific pathogen-free (SPF) female chickens with an enterotropic variant of infectious bronchitis virus (IBV) strain G, IBV-specific Immunoglobulin G (IgG) and IgA were detected in tears, tracheal washes, oviduct washes, duodenal and caecal contents using class-specific monoclonal antibodies in enzyme linked immunosorbent assays (ELISA). IgG antibody content was highest in tears on Day 7 post-infection (p.i.) and was still detectable on Day 23 p.i. Significant levels of IgG antibody were present in oviduct washes on Days 7 and 23 p.i. Tears showed the highest IgA antibody concentration of any sample on Day 7 p.i. but this decreased to an insignificant level by Day 17 p.i. Oviduct and tracheal washes had IgA antibodies on Day 7 p.i. Significant levels of both antibody classes were detected in duodenal contents on Day 17 p.i. only but neither was present in caecal contents. Using a method which compares titre of antibody produced from pieces of tissue at 4 degrees C with that at 37 degrees C as an indicator of local secretion, IgG and IgA antibody synthesis was demonstrated in the Harderian gland on Days 7 and 17 p.i. Local IgG antibody synthesis was seen in the oviduct on Day 7 p.i. but on Day 23 p.i. the optical density at 4 degrees C was higher than at 37 degrees C, suggestive of high concentrations of extracellular antibody. In a separate experiment, passively administered IBV antibody transuded from serum into oviduct washes but did not do so in the trachea. In a third experiment, ELISA and haemagglutination-inhibition (HI) titres of serum and oviduct washes from ten hens previously infected when day-old were compared with egg production. Maximum positive correlation was seen between HI titres of oviduct washes and egg production.

Prenatal hormonal therapy improves pulmonary morphology in rats with congenital diaphragmatic hernia

The high mortality of congenital diaphragmatic hernia (CDH) is due to associated pulmonary hypoplasia, which resembles that seen in premature newborns with respiratory distress syndrome (RDS). By use of successful therapies extrapolated from RDS, quantitative stereologic morphometry techniques were applied to evaluate pulmonary development following prenatal hormonal therapy in rats with nitrofen-induced CDH. Antenatal hormonal therapy was administered on Days 18.5 and 19.5 prior to delivery on Day 21.5 (term = Day 22), using dexamethasone (Dex), thyrotropin-releasing hormone (TRH), Dex-TRH, or normal saline (NS) as vehicle control. Lungs from CDH rats (n = 5) and non-nitrofen-fed controls (n = 5) were studied, and 10 morphometric airspace parameters were determined by point counting 18-30 fields/lung/animal. Indices of maturation, including total internal surface area (SA), airspace volume fractions (V(Valv)), duct fractions (V(Vducts)), and radial alveolar count (RAC), were improved by Dex and Dex-TRH compared with NS-CDH controls (P = 0.0001), as were five other morphometric airspace parameters (P < 0.05). Strikingly, Dex and Dex-TRH treatment corrected average airspace volume (AAV) and the volume fraction of air-conducting elements (V(Vducts)) toward normal values seen in non-nitrofen-fed control animals. TRH therapy alone had minimal beneficial effects. Prenatal steroid +/- TRH thus improved multiple morphometric parameters of lung maturity in CDH rats, supporting the potential use of in utero hormonal therapy to treat humans with antenatally diagnosed CDH.

In vivo microperfusion of the ductuli efferentes testis of the rat: flow dependence of fluid reabsorption

Individual ducts from the initial zone of the efferent ducts of the rat were microperfused in vivo using a double cannulation procedure, which allowed the recovery of perfused fluids for analysis and determination of the rate of fluid reabsorption from the perfused duct. The ducts were perfused at rates from 0.025 to 0.4 microliters min-1 with either Krebs-Ringer bicarbonate (KRB) solution or the native rete testis fluid (nRTF) that perfuses the ducts in situ. Reabsorption of KRB solution increased linearly with a perfusion rate of between 0.025 and 0.1 microliter min-1 (from 17.4 +/- 1.5 to 34.3 +/- 3.2 nl (10 mm duct)-1 min-1), then increased no further. Reabsorption of nRTF increased linearly between 0.025 and 0.2 microliters min-1 (from 17.7 +/- 1.5 to 61.4 +/- 13.5 nl (10 mm duct)-1 min-1) and then declined. The reabsorption rate from nRTF perfusates was significantly higher than from KRB perfusates. As a proportion of the luminal perfusate, reabsorption declined from 73.0 +/- 6.0 to 7.4 +/- 3.0% (10 mm duct)-1 for KRB solution and from 73.1 +/- 6.0 to 4.1 +/- 1.3% (10 mm duct)-1 for nRTF. There was no significant change in the concentration of either Na+ or Cl- in KRB solution or nRTF during perfusion through the efferent ducts, indicating that the reabsorption of these ions was isomolar. However, the reabsorption of K+ from nRTF occurred at a greater rate than that of water, and the initial [K+] declined from 17.2 +/- 0.4 mM in nRTF perfusates to 5.7 +/- 0.5 mM in collectates (perfusion rate, 0.1 microliter min-1) to achieve equilibrium with blood plasma (4.7 +/- 0.4 mM). The osmotic pressure of both KRB and nRTF perfusates equilibrated with blood plasma, indicating a high permeability of the epithelium to water. The results of this study provide further evidence that fluid reabsorption in the efferent ducts is isosmotic, or close to isosmotic, and have shown that, as in the homologous proximal kidney tubule, reabsorption is dependent on luminal flow rate. In contrast to the proximal tubule, however, reabsorption in the efferent ducts is not maintained as a constant proportion of the perfusion load. It is concluded that microperfusion in vivo provides a useful technique for studying fluid reabsorption in the efferent ducts of the rat.

Evaluation of neoadjuvant chemotherapeutic response of locally advanced breast cancer by magnetic resonance imaging

BACKGROUND

The implementation of new treatment protocols for locally advanced breast cancer is currently limited by inaccurate evaluation of response to neoadjuvant chemotherapy. A recently developed dedicated breast magnetic resonance imaging (MRI) method (RODEO MRI) was evaluated as a tool for determining tumor response and extent of residual disease after neoadjuvant chemotherapy.

METHODS

Thirty-nine patients with Stage II, III, or IV breast carcinoma were prospectively evaluated prior to and following neoadjuvant chemotherapy by MRI, physical examination, and mammography. Assessment of response determined by the three methods was compared. In addition, detailed pathologic correlation of residual disease was determined by serial sectioning of 31 mastectomy specimens from 30 patients. Nine patients had breast conservation, and were included in the response evaluation only. Estimates of tumor response were made by both surgical and medical oncologists. Independent interpretations of MRI studies without knowledge of clinical response were made by three radiologists.

RESULTS

The surgical oncologists assessed complete response (CR), partial response (PR), and no response (NR) in 11, 22, and 7 cases, respectively. The medical oncologists assessed CR, PR, and NR in 12, 21, and 7 cases, respectively. The surgical and medical oncologists' clinical assessment of response agreed with the results of MRI in 52% and 55% of cases, respectively, and with each other in 30 of 40 cases (75%). Mammography correlated with MRI response in only 52% of cases. However, MRI accurately predicted the pathologic determination of residual disease in 30 of 31 cases (97%). There was no disagreement in the assessments of residual disease or response among the three radiologists.

CONCLUSIONS

RODEO breast MRI accurately estimates residual disease after induction chemotherapy. It assesses response to neoadjuvant chemotherapy better than traditional methods of physical examination or mammography. The information obtained from this MRI technique may be used as an objective tool during clinical trials, and to select patients better for breast conservation after neoadjuvant chemotherapy for locally advanced disease.

Regulation of the motility and metabolism of spermatozoa for storage in the epididymis of eutherian and marsupial mammals

The present review examines the mechanisms involved in sperm storage in the epididymis of therian mammals in terms of the supply of energy substrate and the regulation of motility and metabolism. Lipids, glucose, lactate and glycerol are possible metabolic substrates for sperm in the epididymis, but the role of these is uncertain and it may differ between marsupials and eutherians. Sperm are normally immotile in the epididymis, but ram and rabbit sperm may have an uncoordinated motility. Sperm metabolism is suppressed but is probably not strongly coupled to motility. Work on diluted sperm indicates that cyclic adenosine monophosphate, Ca2+, and pH play roles as intracellular messengers controlling the motility and metabolism of sperm, but no first messenger has been identified. A number of mechanisms of suppressing sperm motility and metabolism in the epididymis are considered, including a collective autoregulation, oxygen tension, osmotic pressure, viscosity and the extracellular concentration of H+, Ca2+, Na+, HCO3- and carnitine. However, there is no conclusive evidence for any of the mechanisms and there is clearly some variation between species in the mechanism of suppressing sperm activity. Sperm activation stimulates motility and a 4-5-fold increase in respiration rate that has not been reversed without compromising viability. Following activation, respiration supported by endogenous and/or exogenous substrates is much higher in marsupial than eutherian sperm, and marsupial sperm do not show a large stimulation of respiration on the addition of exogenous substrate, as is characteristic of most eutherian sperm.

Electron microscopy of the seminiferous epithelium in the triploid (ZZZ and ZZW) fowl, Gallus domesticus

The ultrastructure of cells of the seminiferous epithelium is described in both triploid ZZZ and ZZW fowls, especially cytological aberrations influencing the development of morphologically abnormal spermatids and spermatozoa. Mitotic divisions in triploid fowls are similar to those in diploid fowls, but meiosis in both the ZZZ and ZZW triploid fowl is abnormal and many defective gametes are produced. The majority of spermatids have structural abnormalities and this is attributed to the aneuploidy expected from meiotic chromosome pairing in a triploid. Some spermatids were observed to possess an irregularly shaped head, 2 centriolar complexes, 2 acrosomes and 2 tails and this type differentiated into large-headed spermatoza. Such spermatids and spermatozoa are suggested to be near diploid due to their large nuclear size and 2 sets of organelles. Other spermatids, observed with only 1 centriolar complex, 1 acrosome and 1 tail, are suggested to be near haploid. Differentiation of these spermatids is similar to the process observed in diploid fowls except that there is a high percentage of abnormally shaped heads. The fact that morphologically normal spermatozoa were rare is consistent with the expectation that very few spermatozoa would be exactly haploid. In both ZZZ and ZZW triploid fowls, triple pairing of chromosomes is observed in synaptonemal complexes (SC) during meiosis and recombination nodules are distributed at random in the central regions of the triple pairing SC. In ZZW triploid fowls gamete formation is more severely affected than in ZZZ triploid fowls and it is suggested that many of the degenerative changes occurring in ZZW fowls could be attributed to those spermatids that possess a W sex chromosome, since normal male fowls are the homogametic sex (ZZ) and normal spermatids and spermatozoa contain only a Z sex chromosome.

Stereotactic breast biopsy as an alternative to open excisional biopsy

BACKGROUND

Health care cost continues to play a dominant role in our society. Technological advances are expensive, with the possible exception of stereotactic breast biopsy. We must learn other alternatives that give the same diagnostic accuracy at lower cost. The intention of this study was to find other acceptable alternatives to open excisional breast biopsies.

METHODS

Patients were referred to Baylor University Medical Center between May 1990 and June 1992 for stereotactic breast biopsy of nonpalpable mammographic abnormalities. Before stereotactic biopsy, lesions were categorized into low or high suspicion for malignancy based on screening mammography. Slides were reviewed by a pathologist and the histological diagnosis was compared with mammographic characterization. Benign histology confirming the low-suspicion mammographic abnormality demonstrated mammographic and histologic correlation. Mammographic follow-up was recommended.

RESULTS

Two hundred twenty-five women underwent 250 stereotactic breast biopsies. Malignancy was diagnosed in 47 patients; the remaining 203 lesions were benign on pathological examination and are being followed regularly. Seventy-eight percent of the lesions were characterized as low suspicion for malignancy, and 22% were characterized as high suspicion. The average cost savings per lesion using stereotactic biopsy was $1,629.

CONCLUSION

Stereotactic breast biopsy is an acceptable, less expensive alternative to open excisional biopsy for diagnosing nonpalpable mammographic findings.

Multiple personality disorder in an intellectually disabled man: a case report

The case of a young man with the dual diagnoses of severe intellectual handicap (IQ 30 and mental age 4 years) and Multiple Personality Disorder is presented. The intellectual handicap is probably due to hypoxia in infancy and the Multiple Personality Disorder follows prolonged physical and sexual abuse. The patient frequently switches between any of nine discrete but incompletely formed identities. Although some personalities seem more capable than others, all have similar levels of disability on testing. The diagnosis of psychiatric disorders coexistent with the intellectual handicap is hindered by the difficulty in separating psychiatric phenomena from the behavioural disturbances associated with the disability. Differential diagnosis and management are discussed.

Continuous nitric oxide inhalation reduces pulmonary arterial structural changes, right ventricular hypertrophy, and growth retardation in the hypoxic newborn rat

Breathing low oxygen levels for several weeks produces progressive pulmonary artery hypertension and smooth muscle hypertrophy and hyperplasia in many species. Because nitric oxide (NO) is an important regulator of pulmonary vascular tone, we examined whether the continuous inhalation of low levels of NO gas would attenuate pulmonary arterial structural changes in hypoxic rat pups. Nine-day-old rat pups and their mothers continuously breathed at FIO2 0.21 or 0.10 with or without adding 20 ppm (by volume) NO for 2 weeks. Lung tissue was obtained for vascular morphometric analysis, and the hearts were dissected to measure right ventricular weight and levels of mRNA encoding rat atrial natriuretic factor (rANF). In addition, femur and skull length were radiographically determined. Breathing at FIO2 0.10 for 14 days increased pulmonary arterial wall thickness and the proportion of muscular arteries in the lung periphery. Right ventricular weight and right ventricular rANF gene expression increased, whereas body weight and skeletal growth were reduced (all P < .05). Continuous inhalation of 20 ppm NO at FIO2 0.10 for 2 weeks decreased hypoxic pulmonary vascular structural changes and somatic growth retardation and prevented the increase of right ventricular weight and right ventricular rANF mRNA levels. These observations suggest that chronically breathing NO attenuates pulmonary vascular smooth muscle hypertrophy and/or hyperplasia and extension into distal arterial walls, right ventricular hypertrophy, and growth retardation of newborns breathing at a low oxygen level.

Development of the gonads in the triploid (ZZW and ZZZ) fowl, Gallus domesticus, and comparison with normal diploid males (ZZ) and females (ZW)

Gonadal development in fowls aged from 1 day to more than 4.5 years was studied in 63 ZZW and 16 ZZZ triploid crossbreds and compared with normal diploid males (ZZ) and females (ZW). In the ZZW fowl, the right gonad developed into a testis (although this occurred earlier in the ZZ genotype), and a structurally-abnormal excurrent duct system containing some malformed spermatids and spermatozoa was associated with the gonad of young adults. The left gonad was an ovotestes at hatching and no excurrent ducts were associated with it. The ovarian component was much less developed than that in the ZW genotype-it started to degenerate by 1 week of age, and most of the oocytes had disappeared by about 3 weeks of age. The seminiferous tubules developed in the medullary region, but only abnormal spermatozoa were produced. Leukocytes infiltrated both gonads at about 9 months of age and the seminiferous epithelium had degenerated in most fowls over 1 year old. In ZZZ fowl, gonadal and excurrent duct development was normal, but occurred earlier than in the ZZ genotype. However, meiosis and spermiogenesis were abnormal and malformed spermatozoa were produced. The heads of spermatozoa from the ducts deferens were about 1.4-times longer in the ZZZ genotype than in the ZZ genotype, indicating that the former may be producing some diploid spermatozoa.

Early pathogenesis in chicks of infection with a trypsin-sensitive avian reovirus

Experiments are described which show how the sensitivity to trypsin of avian reovirus strain TR1 restricts its replication in the intestine of the chicken in comparison with a trypsin-resistant strain R2. Following oral infection with a high dose (5.3 log10 TCID50), the trypsin-sensitive virus generally showed lower titres than the resistant one in all tissues examined. Infection of chicks with strain TR1 via the respiratory route enabled the virus to spread throughout the body and localize in the hock joint, an important target site for reoviruses. Trypsin-sensitive reoviruses might be transmitted via the respiratory route, even though TR1 caused little damage to the respiratory epithelium. Dose-response studies showed that TR1 injected via the footpad can localize in the hock joint after very low doses, but high oral doses (4-5 log10) are necessary for such localization. Intranasal infection was intermediate in effect.

Micropuncture and cannulation studies of fluid composition and transport in the ductuli efferentes testis of the rat: comparisons with the homologous metanephric proximal tubule

Luminal fluids were collected in vivo by micropuncture and cannulation from the rete testis, efferent ducts and ductus epididymidis of the rat to determine the composition of efferent duct fluids and the rates of reabsorption of water and solutes by the efferent ducts. The concentration of spermatozoa increased by a factor of about 25 from 2.42 x 10(4) microliters-1 in the fluid from the rete testis to 6.00 x 10(5) microliters-1 in fluid at the end of the efferent ducts, indicating that 96.2% of the fluid leaving the testis is reabsorbed from the lumen of the efferent ducts. Most of this reabsorption (70.9% or 33.4 microliters h-1) occurs in the region between the rete testis and the middle of the coni vasculosi, with only 25.1% (11.8 microliters h-1) occurring between the coni and the beginning of the ductus epididymidis. However, reabsorption across the epithelium occurs at about the same rate in both regions, with the proximal region reabsorbing 17.2 microliters cm-2 h-1 (70.9% of fluid entering the region) and the distal region reabsorbing 12.2 microliters cm-2 h-1 (86.1% of fluid entering the region). Consequently, the fluid reabsorption rate for the whole efferent duct system (15.6 microliters cm-2 h-1) is similar to the values for individual regions. The principal solutes in luminal fluids from the efferent ducts are Na+ (137-144 mM) and Cl- (113-130 mM). The estimated sum contribution of Na+, Cl- and K+ to the osmotic pressure of luminal fluids was approximately 80% at each site sampled in the efferent ducts. The osmotic pressure of luminal fluid samples (301-307 mosmol kg-1) did not vary significantly along the ducts or differ significantly from that of blood plasma. The results demonstrate that there is a net reabsorption in the efferent ducts of nearly all the testicular output of water and inorganic electrolytes, and most of the protein, and that, in comparison, the ductus epididymidis is a negligible site of net fluid reabsorption. The results indicate that the ductus epididymidis, rather than the efferent ducts, is the site of accumulation of high concentrations of specific organic compounds like inositol. The efferent ducts are similar to the homologous proximal tubules of the metanephric kidney in that the luminal electrolyte composition (principal solutes Na+ and Cl-) and osmotic pressure remain relatively stable and that fluid reabsorption is close to isotonic and occurs at the same rate as the reabsorption of Na+.