Trichoplusia ni (Lepidoptera: Noctuidae) Qualitative and Quantitative Sequestration of Host Plant Carotenoids.

Carotenoids are fundamental precursors for hormones and antioxidants, and insects must acquire carotenoids from their diet. Previous research has shown that insects can selectively absorb dietary carotenoids, often modifying them qualitatively or quantitatively, and quantities may be proportional to those found in the diet. Trichoplusia ni Hübner is a generalist herbivore with host plants varying greatly in carotenoid profiles and concentrations. Larvae sequester carotenoids in their hemolymph, and carotenoid sequestration contributes to their cryptic green coloration. Our objectives were to compare the types of carotenoids found in T. ni and their host plants to determine whether qualitative changes occurred, and compare the amounts of sequestered carotenoids in T. ni reared upon different host plants to determine whether quantitative variation influences sequestration. To fulfill these objectives, larvae were fed romaine lettuce (Lactuca sativa L. [Asterales: Asteraceae] var. longifolia) or kale (Brassica oleracea L. [Brassicales: Brassicaceae] var. sabellica) for a period of 5 d, and sequestered carotenoids from the entire insect were resolved with thin-layer chromatography and measured with spectrophotometer. All carotenoids resolved from plants were also resolved from larvae, and although the carotenoids of plants differed quantitatively, the sequestered carotenoids did not differ between host plants. Regardless of host plant species, T. ni sequestered carotenoids at concentrations up to 20 times higher than the concentrations found in the plants. Future research may be able to explicitly identify enzyme systems involved in the transport and modification of carotenoids in T. ni and other animals.

Sensitivities of radioimmunoprecipitation assay and PCR for detection of human T-lymphotropic type II infection.

Five hundred forty-eight uncoagulated blood specimens from intravenous drug users infected with human T-lymphotropic virus type II (HTLV-II) were used to evaluate the sensitivities of the radioimmunoprecipitation assay (RIPA) and PCR for detecting HTLV-II-infected people. The sensitivities of both RIPA and PCR were found to be dependent on the HTLV-II antibody titer, as determined by the immunofluorescence assay. Neither of these recommended confirmatory methods was as sensitive for detecting weakly reactive HTLV-II specimens as the immunofluorescence assay, Western blotting (immunoblotting), or a modified licensed enzyme immunoassay. Use of RIPA and PCR to determine the reliabilities of other tests may sometimes give erroneous results.

Evaluation of two commercial human T-cell lymphotropic virus western blot (immunoblot) kits with problem specimens.

We evaluated two commercial human T-cell lymphotropic virus (HTLV) Western blot (WB; immunoblot) kits, Cambridge Biotech Corp. (CBC) and Diagnostic Biotechnology Ltd. (DBL). Both methods employ HTLV type I (HTLV-I) viral lysate and rgp21. The DBL WB kit also distinguishes between HTLV-I and HTLV-II antibodies, using an HTLV-I-specific and an HTLV-II-specific recombinant. Fifty weakly reactive HTLV-II-positive plasma specimens which were falsely negative with the Abbott enzyme immunoassay (EIA) and 50 Ortho EIA false-positive samples were selected to determine sensitivity and specificity. The sensitivities of the CBC and the DBL WB kits were 90 and 68%, respectively. All positive samples reacted with rgp21 in both kits, but some did not display core bands. Five samples were typed as HTLV-I and four were typed as dual infection by the DBL WB kit. The specificities of the CBC and DBL kits were 48 and 70%, respectively. The most prevalent WB reaction with the negative samples was with the core protein, p19, followed by p24 and p28 for CBC and rgp21 and p28 for DBL. DBL had two false-positive interpretations, and CBC had none, rgp21 was the most sensitive antigen in both kits for the weakly reactive HTLV-II samples. If all samples not reacting with this protein were interpreted as WB negative, regardless of other bands, the specificity would improve to 90% for CBC and 86% for DBL.

Coronary arteriographic findings in black patients and risk markers for coronary artery disease.

Coronary arteriographic results are reported in 1535 black patients: 751 men (mean age 57 +/- 11) and 784 women (mean age 59 +/- 11). Among the black men 19%, 15%, 21%, and 4% had single-, double-, and triple-vessel and left main disease, respectively. Among the black women there were 12%, 10%, 15%, and 3% with similar involvement. Logistic regression models showed that most of the recognized risk factors were positively correlated with significant (at least one artery with > or = 50% stenosis) coronary disease, but a history of hypertension was not a significant independent predictor in either sex. ECG evidence of previous infarction increased the odds of detecting significant coronary disease by the greatest amount when controlling for other significant risk markers in women. In men both previous infarction and atypical pain (negative) were equally important. This study confirms but does not explain previous reports that have revealed less than expected angiographic evidence of significant coronary artery disease in black compared with white persons.

Distensibility of small pulmonary blood vessels.

Although vasomotor activity in small pulmonary vessels has been studied extensively in the past, using the concept of resistance to flow, information on the distensibility of these vessels is very sparse. In an attempt to reduce this deficit, we adapted a theoretical method developed for small systemic vessels, to estimate distensibility of pulmonary resistance vessels in experimental animals and man. Pressure-flow data from 11 dogs and 10 human subjects (5 control subjects and 5 patients with long-standing left heart failure) were used to calculate distensibility of small pulmonary vessels. The conductance, G, was calculated from these data as the ratio of blood flow to driving pressure. The slope of the relationship between the logarithm of G1/4 and the average distending pressure (ADP) provides a graphic picture of circumferential extensibility, E, defined as percent change in radius for an infinitesimal change in ADP. Results indicate that: (1) the value of E in dogs was 1.85 +/- .40 mmHg-1 for the control state, which decreased to 1.45 +/- .43 mmHg-1 during norepinephrine administration; however, the decrease in the value was not statistically significant (p = 0.53); (2) the value of E in control human subjects was 3.38 +/- .47 mmHg-1 and the value of E in patients with left heart failure was -0.64 +/- 0.39 mmHg-1; the difference was significant (P = .0001).(ABSTRACT TRUNCATED AT 250 WORDS)

Thrombomodulin expression by human blood monocytes and by human synovial tissue lining macrophages.

Thrombomodulin is an essential cofactor for the activation of the anticoagulant protein C by thrombin. We have identified the expression of thrombomodulin messenger RNA (mRNA) and protein in peripheral blood monocytes. While untreated monocytes expressed thrombomodulin mRNA by Northern blot analysis, lipopolysaccharide-treated cells had decreased mRNA expression. Thrombomodulin antigen was shown in the cytoplasm and on the surface of monocytes by immunohistochemical staining, and thrombomodulin activity was shown on the surface of intact monocytes. One population of synovial lining cells that normally expressed mononuclear phagocyte antigens also expressed thrombomodulin in both noninflamed osteoarthritic synovium and in inflamed rheumatoid arthritis synovium. However, these cells did not express another endothelial protein, von Willebrand factor. We conclude that both circulating and tissue mononuclear phagocytes are capable of expressing thrombomodulin.

Comparison of Western immunoblot antigens and interpretive criteria for detection of antibody to human T-lymphotropic virus types I and II.

Twenty human T-lymphotropic virus type I (HTLV-I) antibody-positive sera from Japan, Hawaii, and the Marshall Islands and 15 HTLV type II (HTLV-II) antibody-positive sera from intravenous drug users in the United States were tested by immunoblotting with two recombinant HTLV-I proteins and three commercial kits to determine whether there were any differences in reactions between HTLV-I- and HTLV-II-positive sera by the Western immunoblot method and, also, to evaluate the ability of these reagents to detect HTLV-I- and HTLV-II-seropositive individuals by using the recommended Western blot interpretation. These sera were first extensively characterized by immunofluorescence, enzyme immunoassay, radioimmunoprecipitation assay, and Western blot using HTLV-I and HTLV-II viral lysates and an envelope (env) recombinant protein. Although both HTLV-I- and HTLV-II antibody-positive sera reacted with the env protein gp68, reactions with the gp46 env antigens appeared to be specific for HTLV-I. It was found that the use of either p19 or p24 core bands plus an env reaction instead of only the p24 plus env reaction (as presently recommended) increased the number of positive interpretations for HTLV-I but had no effect on the number of HTLV-II-positive interpretations.

Preparticipation echocardiographic screening for cardiovascular disease in a large, predominantly black population of collegiate athletes.

Sudden death in young competitive athletes is most commonly due to underlying cardiovascular disease. Echocardiography has the potential to identify structural cardiovascular abnormalities, such as hypertrophic cardiomyopathy (HC), that have been incriminated in such events. In this study, echocardiography (2-dimensional and M-mode) was used as a primary screening test to assess 265 Howard University collegiate athletes for cardiovascular disease; 262 (99%) were black. Most athletes (234, 88%) had no definitive echocardiographic evidence of HC or other major cardiovascular diseases, but 30 (11%) had mitral valve prolapse, and 1 other athlete had a small atrial septal defect. In addition, 4 athletes were identified as having mild systemic hypertension. Most athletes (236 of 265) showed normal left ventricular wall thickness of less than or equal to 12 mm, but an important minority (29, 11%) had maximal ventricular septal thicknesses of greater than or equal to 13 mm that could not always be distinguished (by morphology alone) from mild anatomic expressions of nonobstructive HC. Based on this experience, preparticipation athletic screening using echocardiography as the primary test does not appear to be justified on a cost-effective basis. In addition, the substantial minority of subjects with increased wall thickness made clinical interpretation of the echocardiographic findings difficult in individual athletes.

Comparison of immunofluorescence, enzyme immunoassay, and Western blot (immunoblot) methods for detection of antibody to human T-cell leukemia virus type I.

A total of 3,349 serum samples were screened by the immunofluorescence (IF) method for antibody to human T-cell leukemia virus type I (HTLV-I). Only 9 of 2,409 specimens from selected individuals, blood bank donors, patients with encephalitis-meningitis, and human immunodeficiency virus antibody-positive homosexual or bisexual men were reactive by IF. In addition, 940 serum samples from intravenous drug abusers were tested by IF and also by an HTLV-I enzyme immunoassay (EIA) method. Of these, 222 (24%) were positive for both HTLV-I and HTLV-II antigens by IF, and 191 of these 222 were also reactive in the HTLV-I EIA. Of the 31 IF-positive, EIA-negative serum samples, 20 exhibited optical density readings greater than or equal to 70% of the positive cutoff in the EIA, and 29 samples reacted with 1 or more bands in the Western blot (immunoblot) test. An additional 10 specimens that were EIA negative reacted only with HTLV-I by IF. Differences in staining morphology and in reactions on HTLV-I and HTLV-II antigens before and after absorption of the serum specimens with HTLV-I and HTLV-II-infected cell pellets revealed six distinct serological patterns by IF. These results indicate that infections by HTLV-I or by another closely related retrovirus(es) occur in California. Further studies utilizing statistically valid sampling methods are needed to estimate true prevalence rates among various groups. IF and Western blot tests should supplement the EIA method to maximize sensitivity and specificity of test procedures.

Evaluation of reproductive parameters in adult male Wistar rats after subchronic exposure (gavage) to benomyl.

Proven-breeder 102-d-old male Wistar rats were gavaged daily with 0, 1, 5, 15, or 45 mg/kg.d benomyl. The animals were bred to untreated females after 62 d and killed after 76-79 d for evaluation of selected male reproductive end points. Minimal to moderate changes were observed in rats dosed with 45 mg/kg.d; these included decreased testis and epididymis weight, reduced cauda sperm reserves, decreased sperm production, increased numbers of decapitated spermatozoa, and increased numbers of seminiferous tubules containing multinucleated giant cells. Reproductive performance, seminal vesicle and prostate weight, sperm motility, serum luteinizing hormone, follicle-stimulating hormone, prolactin, and androgen binding protein were not affected by any of the dosages tested. Based on these end points, the no-effect level was 15 mg/kg.d.

Comparison of detection of antibody to the acquired immune deficiency syndrome virus by enzyme immunoassay, immunofluorescence, and Western blot methods.

There was 100% agreement between enzyme immunoassay (EIA) (Abbott Laboratories), Western blot, and indirect immunofluorescence (IF) when these three methods were used to measure antibody to the acquired immune deficiency syndrome (AIDS) virus in sera from 142 high-risk individuals, indicating that IF was a sensitive alternative method for detecting antibody to this agent. Thirty-two (64%) of 50 EIA-positive plasma specimens from a blood bank and 6 (21%) of 28 EIA-positive sera from alternative testing sites were negative by IF. In addition, two EIA-negative sera from the latter group were positive by IF. Western blotting agreed with IF on those 40 specimens which gave discrepant results by EIA and IF. The IF method was determined to be equal to Western blotting in sensitivity and specificity for detection of AIDS antibody, and it was found to be useful for confirming positive EIA results, especially in specimens from individuals in low-risk groups.

Early changes in experimental hydrocephalus.

In acute obstruction of the cerebral spinal fluid (CSF) absorption pathways, fluid is produced more rapidly than it is absorbed, and the ventricles enlarge proximal to the obstructions. Communicating hydrocephalus results from a difference between the rates of production and absorption of cerebrospinal fluid. In animals with chronic communicating hydrocephalus, the initial pathologic changes appear to involve the periventricular tissue near the angles of the lateral ventricles. The present investigation was designed to identify the various changes associated with the production of communicating hydrocephalus in acutely hydrocephalic preparations and to relate these findings to those found in experimental animals with chronic communicating hydrocephalus. The results of this study seem to confirm that the changes noted in the chronically hydrocephalic animals occur as early as 12 hours after the restriction of the normal flow of CSF.

Influence of NMR measuring sequences and gradient variation on signals from flowing systems. Magnetic resonance tomography on experimental models.

The influence of flow on MR tomography images and signal intensities has been studied using experimental model tubes and an aqueous NiCl2 solution having the same relaxation time as human blood. We applied the inversion recovery (IR) and the spin-echo (SE) sequence on a .15T MR tomography system. The influence of RF pulse distance (tau) in the IR and SE experiment as well as the influence of magnetic z-gradient strength on the flow images has been investigated. IR images revealed that signals from flowing systems recover more rapidly due to influx of non-inverted longitudinal magnetization into the scan slice. SE images in presence of flow are characterized by signal intensity loss with increasing time caused by the outflow and dephasing of transverse magnetization. With increasing strength of the z-gradient, the MR signals of flowing fluids decrease drastically. Thus for detection of flow, all the above mentioned parameters are of importance.

Enzyme immunoassay versus plaque neutralization and other methods for determination of immune status to measles and varicella-zoster viruses and versus complement fixation for serodiagnosis of infections with those viruses.

Results by an enzyme immunoassay method (EIA) performed at one serum dilution and results by indirect immunofluorescence (IFA) and hemagglutination inhibition (HI) tests performed at step dilutions were correlated with results by a neutralization test (50% plaque neutralization [PN]) performed at step dilutions on single serum samples for serologic evaluation of immunity status to measles virus. PN results were taken as true indicators of immunity, and the other tests were evaluated on that basis. The predictive value of a positive result being positive also by PN was 95.3% for HI and 93.3% for EIA and IFA. The predictive value of a negative result being negative also by PN was 81.1% for HI, 100% for EIA, and 75.0% for IFA. A similar study on immunity status to varicella-zoster virus by EIA and by an anticomplement immunofluorescence test versus PN showed a 100% predictive value of a positive or negative result by EIA. By the anticomplement immunofluorescence test, the predictive value of a positive result was 97.7%, and that of a negative result was 88.5%. Studies on the comparative ability of EIA versus complement fixation (CF) to detect significant changes in antibody concentration between acute-phase and convalescent-phase serum samples indicative of a current infection were also done. Both tests were satisfactory for the serodiagnosis of measles or varicella-zoster virus infections. However, EIA was preferable to CF because it was less technically difficult, less labor intensive, and could be performed on sera that were anticomplementary in CF reactions.

Hexabrix as a contrast agent for hysterosalpingography.

Hexabrix, a monoacidic dimeric iodinated contrast material, was compared with Renografin 60 (diatrizoate meglumine) for safety, tolerance, and efficacy in hysterosalpingography, in a double blind study of 52 patients. No serious adverse reactions were noted in either group of patients. Discomfort during and after the procedure was not statistically different in the two groups. No difference in radiographic quality was seen. It was concluded that Hexabrix, despite reduced osmolality and increased viscosity, offers no significant benefit over Renografin 60, but it is a safe and acceptable contrast agent for hysterosalpingography.

Digital subtraction angiography: limitations for the detection of pulmonary embolism.

Perfusion lung scanning, magnification pulmonary arteriography, and digital subtraction angiography (DSA) were performed prior to and following Gelfoam embolization of selected pulmonary arteries in eight canines. The sites of embolization were identified in 75% of perfusion lung scans, in 93% of magnification pulmonary arteriograms, in 75% of arterial phase DSA studies, and 100% of parenchymal phase DSA examinations. With technological advances, DSA has the potential to become the examination of choice for the evaluation of patients suspected of having pulmonary emboli.

Lymphocyte migration in inbred Syrian hamsters with acute measles virus encephalitis.

The migratory pattern of 51Cr-labeled adult lymphocytes, as measured by 51Cr concentration in various tissues, was followed in inbred weanling Syrian hamsters infected intracranially with measles virus. Donor-labeled lymphocytes were inoculated intracardially into infected and control recipients. Increased passage of labeled lymphocytes across the blood-brain barrier was first seen on day 3 post virus inoculation and 1 day prior to development of clinical signs of acute measles encephalitis. 51Cr concentration in the brain increased progressively along with neurologic signs until the death of the hamsters. Aberration of lymphocyte migration peripherally, manifested by reduced presence of labeled cells in lymph nodes and spleen, first occurred 4 days post virus inoculation in those hamsters with clinical signs of disease. By days 5 and 6 post virus inoculation, the concentration of 51Cr in lymph nodes was 30% and 20%, respectively, of that in lymph nodes of control hamsters. Concentration of labeled lymphocytes in lymph nodes and spleen of the occasional virus-inoculated animal that appeared clinically well at time of autopsy was always greater than that in ill hamsters, and was closer to and sometimes equal to the concentration in the corresponding tissues of control hamsters. Thus, increased passage of labeled lymphocytes into the brain and decreased recovery of labeled lymphocytes in lymph nodes and spleen occurred concomitantly with increased neurologic signs of disease. No differences in presence of labeled cells in other tissues tested (liver, lung, thymus and blood) between infected and control hamsters were noted. Labeled lymphocytes from either measles virus or ovalbumin-immunized donors appeared to pass more readily into the brains of ill recipients than labeled lymphocytes from unimmunized donors.

Relationship of renal hemodynamic and functional changes following intravascular contrast to the renin-angiotensin system and renal prostacyclin in the dog.

Deterioration in renal function has been observed after the use of intravascular contrast media. In an attempt to identify factors responsible for this phenomenon, meglumine iothalamate (Conray 60), in a dosage range of 2.5-3.3 ml/kg, was injected as a bolus into the aorta of dogs. Serial measurements were made of parameters of renal function as well as of changes in aortic and renal venous levels of angiotensin II, renin activity, and 6-keto-PGF1 alpha, the stable metabolite of prostacyclin. The major findings were (1) an initial, brief increase followed by approximately a 20% sustained decrease in renal blood flow and creatinine clearance, (2) no significant changes in angiotensin II and renin levels, and (3) a significant decline in the renal secretory rate of 6-keto-PGF1 alpha. These observations suggest that the suppression of prostacyclin, rather than the activation of the renin-angiotensin system, may contribute to the renal function changes attending the use of intravascular contrast media.