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Biomedical subjects

J Jordan

Publications and source records attributed to J Jordan.

At least 163 records · Page 9Linked to original sources
PubMed1986

A stillbirth with aspirated squamous pearls and fetoplacental thromboembolism: a new finding and reminder of the importance of placental and fetal pathologic conditions.

Fetal aspiration of squamous epithelial pearls has probably never been reported. Because of deficient perinatal pathology examinations, the occurrence of fetoplacental thromboembolism is incompletely known. This case report of the two phenomena includes emphasis that placentas should never be frozen; they should be stored at standard refrigerator temperature.

Adult↗
PubMed1986

Effect of manganese on human placental spin-lattice (T1) and spin-spin (T2) relaxation times.

Human placentas were obtained immediately following delivery and incubated with manganese chloride (MnCl2) in concentrations ranging from 0.002 to 2.0 mM. Proton density, T1 and T2 were measured at times ranging from 5-200 minutes. There was rapid uptake of manganese by the placenta producing a dose-dependent decrease in placental T1 and T2. The major effect of manganese uptake was shortening of T1 suggesting that the contrast between placenta and myometrium will be enhanced predominantly for T1-dependent imaging pulse sequences.

Chlorides↗
PubMed1985

Developmental morphometry of the vagus nerve in the opossum.

Developmental morphology of the vagus nerve has been described for placental but not marsupial mammals such as the opossum which undergo even greater postnatal maturation. In the present study, the cervical vagus nerve of opossums from the seventh postnatal day to the adult were compared after 3% glutaraldehyde immersion, postfixation in osmium tetroxide and staining with uranyl acetate and lead citrate. At 7 days of age, axons were unmyelinated. Only 4 myelinated axons were present at the 25th postnatal day and by 50 days of age only 11% of adult values were reached. The number of Schwann cells increased from 105 at age 7 days up to 640 in the adult. The number of myelin lamellae surrounding the largest axons increased from 9 at 25 days up to 102 +/- 9 at adulthood. In the newborn kitten and rabbit, the number of myelinated vagal fibers comprised 10% (n = 326) and 18% (n = 653), respectively, of that reached in the adult animal. Comparable values are not obtained in the opossum until the 50th postnatal day.

Animals↗
PubMed1984

Interaction of von Willebrand factor with human platelets in the plasma milieu.

The binding of von Willebrand factor (vWf) to stimulated platelets in the plasma milieu was performed using a radiolabeled monoclonal antibody to vWf. Plasma proteins specifically inhibited the thrombin- and ADP/epinephrine-induced vWf binding to activated platelets but did not inhibit the ristocetin-induced vWf binding. When normal plasma was heat defibrinated, monoclonal-labeled vWf was bound to platelets following thrombin or ADP/epinephrine stimulation. Furthermore, monoclonal-labeled vWf from afibrinogenemic plasma bound normally to platelets. The binding of vWf to stimulated platelets in either heat-defibrinated normal plasma or afibrinogenemic plasma was specifically inhibited by the addition of normal plasma fibrinogen in a concentration-dependent manner. At levels of fibrinogen less than 1 mg/ml, however, vWf binding could be demonstrated. The inhibition by fibrinogen of vWf binding to platelets was competitive and overcome by increased concentrations of vWf. These studies show that thrombin-induced and ADP/epinephrine-induced vWf binding to platelets does not occur in the plasma milieu, although at reduced levels of fibrinogen, vWf binding to stimulated platelets can be demonstrated.

Adenosine Diphosphate↗
PubMed1984

A necropsy study of distribution of petechiae in non-sudden infant death syndrome.

The distribution of visceral petechiae in patients whose deaths were caused by upper airway obstruction and disorders other than sudden infant death syndrome (SIDS) has not been systematically studied. The clinical and necropsy records and microscopic slides of 50 such cases were retrospectively reviewed. In cases in which the cause of death could reasonably be ascribed to lethal upper airway occlusion, petechiae were found only in thoracic viscera. When death was apparently not preceded by terminal changes in intrathoracic pressure, petechiae were found in viscera above and below the diaphragm. These findings suggest that intrathoracic petechiae occur as a consequence of pressure changes within the chest and indirectly support the hypothesis that the terminal mechanism in SIDS is upper airway obstruction.

Airway Obstruction↗
PubMed1983

[Psychological coping mechanisms in open heart surgery in relation to the personality structure of the patient. The possibilities for cooperation between psychosomatic medicine and cardiology].

At the very beginning of the essay we would like to give a short survey of the temporary results and questions of scientific research about psychopathological reactions after open heart surgery under extracorporeal circulation. Then the case report will show how the patient copes with the surgery 8 weeks before until about 5 weeks after. Within the case report and the following discussion, special attention will be payed to interaction between patient and doctors as well as cooperation between psychosomatic therapists and cardiologists. The essay is a contribution to the discussion of possibilities and limits of psychosomatic liaison services.

Adaptation, Psychological↗
PubMed1982

The relationship between life change events, social supports, and dysmenorrhea.

A survey of 156 female undergraduate nursing students was conducted to determine the relationship between life change events and dysmenorrhea and the mediating effect of social supports on this relationship. Data were collected using the Anderson College Schedule of Recent Experience (subjects estimated personal readjustment to life changes), the Moos Menstrual Distress Questionnaire, and a social support index constructed by the authors. Correlations were obtained separately for high and low social support groups; these ranged from .19 to .62 and were significant (p less than .05) for both groups. Presence or absence of a confidant was the most discriminating social support dimension (r = .32 for those with a confidant and .62 for those without). For subjects using oral contraceptives there was no relationship between life change and dysmenorrhea, while users of other contraceptives showed a significant positive relationship (p less than .05). Life change and social supports together accounted for only 16% of the variance in menstrual distress scores. Methodological difficulties in using the life change and social support tools were identified.

Adolescent↗
PubMed1982

Characterization of Giemsa dark- and light-band DNA.

Using synchronized cultures of V79-8 Chinese hamster lung fibroblasts, we either alternately labeled early- and late-replicating DNA, or substituted one of these with bromodeoxyuridine to separate them in CsCl density gradients or to identify the bromodeoxyuridine-containing chromosome bands by fluorescence microscopy. The Giemsa light R bands were shown to replicate in the first half of S phase, and the dark G bands were shown to replicate in the last half of S phase. S phase was bimodal, with a distinct pause in the rate of DNA synthesis that separated the period of R-band DNA synthesis from that of G-band DNA synthesis. G-band DNA was found to be 3.2% richer in AT than R-band DNA. Surprisingly, G- and R-band DNA appeared equally transcriptionally active in that alternate labels in chromatin were digested with the same kinetics by DNAase I, and in reassociation experiments, total poly(A)+ RNA drove nick-translated G- and R-band DNA probes similarly. G- and R-band DNA also reassociated with identical kinetics, demonstrating that they contain equal proportions of all kinetic-complexity classes of sequences.

Animals↗
PubMed1982

A second zone of compensation during atrial premature stimulation: evidence for decremental conduction in the sinoatrial junction.

125 consecutive patients with premature atrial stimulation were studied. Three demonstrated sinus node return cycles that were fully compensatory following premature atrial stimuli delivered early in diastole. This second zone of compensation was unaccompanied by significant alterations in the post-return cycle lengths or in P-wave morphology of the return cycle. To account for the occurrence of a complete compensatory pause following very early premature atrial depolarizations, we consider the possibility that retrograde conduction of the early atrial premature depolarization (APD) in the sinoatrial junction was delayed for a sufficient length of time to allow the sinus node to depolarize spontaneously on schedule. Collision between the APD and sinus beat would then occur despite the marked prematurity of the APD. Thus, the early APD had encountered the relative refractory period of the sinoatrial junction, suggesting that decremental conduction takes place within the sinoatrial region in man. These findings imply that there is the potential for reentry in the region of the human sinoatrial junction.

Aged↗
PubMed1982

The cellular electrophysiologic mechanism of the dual actions of disopyramide on rabbit sinus node function.

To determine the contribution of disopyramide's suggested opposing direct depressant and indirect acceleratory actions on sinus node function, we studied the effects of disopyramide, 1 x 10(-7) to 1 x 10(-4) M, on isolated rabbit sinus node preparations using standard microelectrode techniques. Transmembrane potentials were recorded simultaneously from the sinus node and adjoining crista terminalis area. Disopyramide, as much as 1 x 10(-5) M, had no effects on the sinus cycle length. At a concentration of 1 x 10(-4) M, sinus cycle length was significantly prolonged due to prolongation of the sinus nodal action potential duration. During cholinergic blockade with atropine, 1 x 10(-6) M, disopyramide, 1 x 10(-7) to 1 x 10(-4) M, significantly prolonged sinus cycle length as a result of a prolongation of the sinus nodal action potential duration and a decrease of the slope of phase 4 depolarization. During cholinergic stimulation with carbamyl choline, 1 x 10(-9) M, disopyramide, 1 x 10(-7) to 1 x 10(-6) M, tended to reverse carbamyl choline-induced prolongation of the sinus cycle length (NS). This acceleratory action of disopyramide was caused by a significant increase of the slope of phase 4 depolarization. Disopyramide, 1 x 10(-7) to 1 x 10(-4) M, had no significant effects on corrected sinus node recovery time or on sinoatrial conduction time under any conditions studied. We conclude that disopyramide has a direct depressant action on normal sinus node cells at the upper therapeutic and toxic levels, which is enhanced during cholinergic blockade, and that disopyramide's acceleratory action appears only at much lower concentrations and only during cholinergic stimulation.

Action Potentials↗
PubMed1981

Detection of herpes simplex virus (HSV) type-1 IgG and IgM antibodies by enzyme-linked immunosorbent assay (ELISA).

A sensitive enzyme linked immunosorbent assay (ELISA) is described for detection of herpes simplex virus (HSV) type 1, IgG and IgM antibodies. The antigen consisted of a crude extract of HSV infected human foreskin fibroblast cells. Specific horseradish peroxidase conjugated antisera were used to detect total immunoglobulin, IgG and IgM antibodies bound to viral antigen. The substrate was a solution of 5-aminosalicylic acid and hydrogen peroxide, which yielded a readily visible endpoint. Results obtained by the ELISA method were compared with the micro-complement fixation (CF) method on 36 sera. ELISA was shown to be at least 10-20 fold more sensitive than CF, with a correlation coefficient of 0.752 (p less than .001). HSV antibodies in these sera were mainly IgG, although IgM antibodies could also be detected by ELISA. HSV antibodies were not found in 16 cerebrospinal fluids from patients without HSV encephalitis (HSVE). ELISA appears to be a rapid, sensitive, and specific method for demonstration of IgG and IgM HSV antibodies. It may have possible application in the diagnosis of HSVE.

Aminosalicylic Acids↗
PubMed1981

Effects of prostaglandin D2 on perinatal circulation.

Prostaglandin D2 (PGD2) is a powerful antiaggregatory agent and contracts various types of smooth muscle preparations, including isolated canine and bovine pulmonary vessels. Pulmonary vascular responses of anesthetized fetal and adult goats and newborn lambs to PGD2 were evaluated in situ by means of an isolated perfused lower left lobe preparation. These experiments indicate that PGD2 is a pulmonary vasodilator in fetal goats, both a pulmonary vasodilator and vasoconstrictor in newborn lambs depending on the dose used, and a pulmonary vasoconstrictor in adult goats. Evidence is presented of an age-related change in pulmonary vascular response to prostaglandins. The responses of the pulmonary vasculature are dose dependent; however, there is not a significant dose-dependent relationship for systemic arterial pressure or heart rate with intrapulmonary infusions of PGD2. The inhibition of prostaglandin synthesis potentiates the pulmonary response to PGD2 in fetal goats. In contrast with other prostaglandins, PGI2, PGE2, and PGE1, which dilate both the fetal pulmonary and systemic circulations, PGD2 has minimal action on the systemic circulation over a wide range of doses.

Aging↗