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Biomedical subjects

S Jordan

Publications and source records attributed to S Jordan.

At least 19 recordsLinked to original sources
PubMed1992

Effects of ultra-low volume and thermal fog malathion, Scourge and naled applied against caged adult Culicoides furens and Culex quinquefasciatus in open and vegetated terrain.

The adulticidal effect of ULV and thermal fog malathion, Scourge and naled was tested at 2x label dosage (1.42, 0.22, 0.39 oz/acre, respectively) against caged Culicoides furens and Culex quinquefasciatus in open and vegetated (orange grove) terrain. Cages were at 122 cm elevation and positioned at 15.2, 45.7, 76.2, 106.7, 137.2 and 167.6 m from the line of insecticide release. Ultra-low volume applications of all 3 insecticides were markedly more effective than thermal fog under all conditions, especially in vegetated terrain. Of the 3 insecticides, malathion performed the poorest, especially against Cx. quinquefasciatus (in which there was some resistance) and particularly when applied as thermal fog. Scourge and naled were about equally effective. The best adulticide against C. furens was naled, which was clearly superior applied as ULV. It yielded 75% mortality out to 283 m in the open, and to 38 m in the presence of dense vegetation.

Aerosols↗
PubMed1991

Co-ordinate expression of the alpha-6 integrin laminin receptor sub-unit and laminin in breast cancer.

Interactions between cells and extracellular matrices are mediated in part by a family of heterodimeric molecules known as integrins. We have investigated, using immunohistology, the distribution of six integrin alpha sub-units in normal breast tissue and 26 breast carcinomas. Alpha-1 integrin (collagen/laminin receptor sub-unit) was detected in myoepithelium, but not in luminal epithelium nor in most (20/26) carcinomas. Its expression on fibroblasts was enhanced in desmoplastic stroma. Both benign and malignant epithelium showed uniform positive staining for alpha-2 (collagen receptor sub-unit) and for alpha-3 (collagen/fibronectin/laminin receptor sub-unit). All epithelium was negative for alpha-4 (sub-unit of a fibronectin receptor). Epithelial staining for alpha-5 (fibronectin receptor sub-unit) was weak in all samples. Alpha-6 (sub-unit of two integrin laminin receptors) showed conspicuous changes in all invasive carcinomas. In normal tissues, there was weak staining of epithelial cytoplasm with alpha-6 antibody and moderate cell membrane staining. Strongest staining was present in a basement membrane distribution. In carcinomas, loss of cytoplasmic and cell membrane staining was variable, but basal membrane staining was diminished or absent in all tumours. Loss of basal membrane staining for alpha-6 integrin corresponded closely to loss of immunoreactivity for its ligand laminin in invasive breast cancer.

Adenofibroma↗
PubMed1991

Influence of humidity and temperature on the diel periodicity of oviposition of Toxorhynchites moctezuma (Diptera: Culicidae) in the field.

The diurnal pattern of oviposition by Toxorhynchites moctezuma (Dyar & Knab), ambient relative humidity, and ambient air temperature were monitored hourly between 0600 and 1800 hours for 46 consecutive d in a tropical rainforest in Trinidad, West Indies. The mean number of eggs per ovitrap per hour was correlated negatively with mean ambient relative humidity and positively with air temperature. Partial correlation coefficients among these variables and contingency table analysis indicated a stronger relationship between the oviposition rate and relative humidity than between oviposition rate and temperature. We suggest that this relationship is further evidence of the ability of female Tx. moctezuma to detect suitable oviposition sites using humidity gradients.

Animals↗
PubMed1991

The role of histamine in the acute inflammatory responses to intradermal platelet activating factor.

1. The role of histamine in PAF-induced acute inflammatory responses (flare and weal) in the skin has been evaluated in a series of three separate studies. 2. Terfenadine, a potent H1-selective histamine antagonist virtually abolished the flare response and significantly inhibited the weal response. 3. Histamine depletion in the skin using compound 48/80 resulted in similar effects on the flare and weal response. Two consecutive daily injections of compound 48/80 were found to deplete comprehensively skin sites of histamine and the ability of skin to respond to PAF was completely restored within 2 weeks of compound 48/80 treatment. 4. Intradermally injected PAF was associated with acute rises in plasma histamine in blood drawn from a draining vein with peak concentrations occurring within 5 min of injection. 5. No difference in PAF-induced flare and weal response was found between atopic and non-atopic subjects and this was reflected in the peak plasma histamine results. A significantly higher baseline plasma histamine was found in the atopic group, however, when compared with the non atopic group. 6. It is concluded that histamine has an important role in the acute inflammatory responses to intradermally injected PAF, although there does appear to be a significant direct vascular component in the PAF-induced weal response.

Benzhydryl Compounds↗
PubMed1991

Influence of vegetation on the spatial distribution of Toxorhynchites moctezuma ovipositions in the field.

The influence of the vegetation surrounding black-painted calabash ovitraps on the number of eggs of the mosquito Toxorhynchites moctezuma they attracted was investigated using oviposition data gathered from a seasonal-deciduous forest in Trinidad, West Indies. More eggs were laid into ovitraps situated either within or directly adjacent to trees or bamboo stools than those not associated with trees or bamboo. This result is discussed in terms of the initial oviposition-site searching behavior of female Toxorhynchites.

Animals↗
PubMed1991

Influence of tree trunks on the spatial distribution of Toxorhynchites r. rutilus ovipositions in a coastal oak/palm hammock in Florida.

The number of Toxorhynchites r. rutilus eggs occurring in 20 ground-level oviposition traps was monitored daily for 14 days in an area of coastal oak/palm hammock forest in Florida. Ten of these ovitraps (modified 2-liter plastic soda bottles) were placed in contact with tree trunks, the others at least 2 m from the base of the nearest tree. There was no significant difference in the mean number of eggs observed in egg-positive ovitraps for either type of trap site. However, ovitraps abutting trees were egg-positive significantly more often than expected. This result is discussed in terms of the initial oviposition-site searching behavior of female Toxorhynchites.

Animals↗
PubMed1990

Spherical connective tissue inclusions in epithelial hyperplasia of the breast ("collagenous spherulosis").

Partial myoepithelial differentiation is common in simple epithelial hyperplasia (epitheliosis) of the breast but functional myoepithelial differentiation with basement membrane production is exceedingly rare. A peculiar change of hyaline globules within benign epithelial hyperplasia has been recognised before as "collagenous spherulosis" and type IV collagen has been shown by immunohistochemistry. Another seven cases are described which show the presence of laminin and collagens IV and III within the proliferation. Electron microscopy examination of two cases using material retrieved from the wax block showed varying degrees of myoepithelial differentiation of the cells immediately surrounding the spherules and basal lamina material, including mature collagen fibrils in one case. The degree of myoepithelial differentiation of the cells surrounding the spherules seemed to correlate with the differing types and amounts of extracellular matrix in the spherule. Histopathologists should be aware of this rare change as it may be misinterpreted as in situ carcinoma.

Adult↗
PubMed1989

A classification of temporomandibular joint disk morphology.

Disk morphology has been recognized as an important feature of internal derangements of the temporomandibular joint and as a suspect in functional impediments. A classification of disk shapes was devised by means of corrected lateral cephalometric arthrotomograms and histopathologic sagittal sections. Five basic shapes were identified: bow tie (normal), straight, funnel, bulge, and Y. Statistical analyses were performed. The normal condyle-disk-fossa relationship and slight-to-moderate disk displacement occurred with disk shape 1 (bow tie). Severe disk displacement without reduction occurred predominantly with disk shape 4 (bulge). Beaking of dye in the anterior recess of the inferior joint space was an indicator of abnormal disk morphology and displacement.

Cartilage, Articular↗
PubMed1988

Generation of nitro radical anions of some 5-nitrofurans, and 2- and 5-nitroimidazoles by rat hepatocytes.

Nitrofurantoin, nifurtimox, nifuroxime, nitrofurazone, misonidazole, benznidazole, ronidazole, and ornidazole were reduced to their respective nitro radical anions by intact rat hepatocytes at pH 7.4. The nitrofurantoin radical anion and other nitro anion radicals generated inside these cells were detected with ESR spectroscopy. Broadening of the signals from nitrofurantoin anion radicals was accomplished with paramagnetic transition metals, implying that the radicals were outside the cell in the medium. Rat hepatocytes are well suited for in situ electron spin resonance investigations of free radical metabolites and represent a model for the as yet unobtained direct detection of free radical metabolites in liver.

Animals↗
PubMed1988

Determination of the radiographic position of the temporomandibular joint disk.

We describe a method of measuring displacement and reduction of the temporomandibular joint (TMJ) disk that makes use of reproducible geometric measurements from radiographs in the sagittal plane. This procedure leads to a simple quantitative classification scheme for condyle-disk-fossa/eminence relationships. The method was applied to microscopic sections of 12 human TMJs and then to 30 complete lateral corrected cephalometric arthotomographic studies of the TMJ. Statistical analyses of the classification scheme confirm that it is highly significant and consistent with clinical diagnoses.

Adult↗
PubMed1988

Lack of effect of gamma-globulin infusion on circulating immune complexes in patients with Kawasaki syndrome.

Previous studies have demonstrated circulating immune complexes (CICs) in sera of 70% of Kawasaki syndrome (KS) patients but the pathogenic role of these complexes in the illness is unknown. Infusions of gamma-globulin (GG) have been shown recently to reduce the prevalence of coronary artery aneurysms in KS patients. One of the proposed mechanisms of action of GG therapy is through an effect on CICs. We analyzed paired sera for CICs from 29 patients with KS, 19 of whom were treated with aspirin and GG and 10 of whom received aspirin only. Assay systems used for CIC detection were Raji-mu enzyme immunoassay, C1q solid phase assay-enzyme immunoassay and F(ab')2-anti-C3-mu enzyme immunoassay. Overall 20 of 29 patients had CICs detected by at least two of three assays used. Of the 19 GG-treated patients 14 had CICs detected: 5 in both paired sera; 2 in pretherapy sera; and 7 posttherapy specimens. There was no correlation between duration of fever, presence of myocarditis or the development of coronary artery aneurysms and the presence of CICs in the serum of KS patients. Although CICs can be found frequently in the sera of KS patients there seems to be no association between the presence of CICs and the duration of fever or the development of coronary artery aneurysms.

Antibodies↗
PubMed1987

Discriminative stimulus properties of toluene in the mouse.

Little is known about the nature of the acute intoxication produced by exposure to high concentrations of toluene such as that which occurs with spills and in solvent abusers. The intoxication may be similar to that produced by classic central nervous system depressants such as the barbiturates. To investigate this hypothesis, drug discrimination procedures were used to compare the acute effects produced by toluene and pentobarbital (PB). Mice were trained to discriminate toluene (100 mg/kg, ip) from vehicle in a two-lever task in which responding was under the control of a fixed-ratio 20 (FR20) schedule of food presentation. Generalization tests were conducted after 20-min inhalation exposures to toluene (150-3600 ppm) and 20 min after injections with either PB (5-30 mg/kg) or morphine (3-20 mg/kg). Most mice generalized to inhaled toluene and to PB in a concentration- or dose-related fashion, but not to morphine. These results show that the effects of injected toluene can be established as a discriminative stimulus in mice, and that these stimulus effects are independent of route of administration. Shared discriminative stimulus properties with PB suggest that toluene produces an acute intoxication like that of other classic CNS depressants.

Administration, Inhalation↗
PubMed1987

Accuracy of temporomandibular joint space measurements using corrected hypocycloidal tomography.

This study underscores the importance of obtaining radiographs in a tomographic plane bisecting the long axis of the condyle. The accuracy of joint relationships and clarity of the images produced using the horizontally and vertically corrected techniques were significantly greater than when both standard or only horizontally corrected techniques were used in the cases examined. Correlative clinical studies are recommended to be studied.

Humans↗