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Biomedical subjects

W Benson

Publications and source records attributed to W Benson.

36 records · Page 2Linked to original sources
PubMed1985

Atrial flutter in infancy: diagnosis, clinical features, and treatment.

The clinical features and treatment of atrial flutter in eight infants (four male and four female) less than 2 months of age are presented. Atrial flutter was noted during the first week of life in six of the infants and between 6 and 8 weeks of life in the other two infants. Four of the eight infants had associated structural or functional cardiovascular disease, and in three infants a central venous pressure catheter was present in the atrium at the time atrial flutter was diagnosed. Classic flutter waves were apparent on 12-lead ECGs in only two infants. In six infants, flutter waves were not obvious on standard ECGs, but transesophageal electrogram recordings demonstrated the presence of atrial flutter with second degree atrioventricular block. The atrial cycle length during flutter ranged from 135 to 180 ms (mean 149 ms; mean atrial rate 403 beats per minute); there was a 2:1 ventricular response to atrial flutter. Successful termination of atrial flutter was accomplished using three modes of electrical cardioversion in seven of the eight infants: direct current cardioversion in one, transvenous atrial pacing in one, and transesophageal atrial pacing in five. One asymptomatic infant converted to normal sinus rhythm 24 hours following digoxin administration. One infant had multiple atrial flutter recurrences and required chronic procainamide therapy. In seven of the eight infants, no recurrences have been noted in 6 months to 3 1/2 years of follow-up. These results demonstrate that atrial flutter may be difficult to diagnose in infants with tachycardia unless transesophageal electrogram recording is utilized for evaluation.(ABSTRACT TRUNCATED AT 250 WORDS)

Atrial Flutter↗
PubMed1983

A study of cells present in lymph draining from a contact allergic reaction in pigs sensitized to DNFB.

Pigs were skin-painted with the contact sensitizing agent 1-fluoro 2,4 dinitrobenzene (DNFB) and lymph cells coming from the site were collected. Half the animals were sensitive to DNFB and half were normal controls. Special attention was paid to cells belonging to the veiled cell series. At 20 hr after DNFB application, some blast cells--on morphological grounds belonging to the veiled cell series--could be observed in the lymph of presensitized animals. But the most predominant finding in these pigs was that, approximately 30 hr after painting, the total cell output began to increase, reaching 10 times the normal level at 70 hr. The increase in the output of lymphoblasts was the most marked, suggesting peripheral sensitization. Such changes were not observed in normal animals. Here the most striking alterations were seen in the veiled cells. Some of these cells were moving ponderously about, apparently in pursuit of other lymph-borne cells, and this activity resulted in the formation of large cellular aggregates. Since it is known that veiled cells are involved in antigen handling, this behaviour probably facilitates the induction of the T-cell immune response. By contrast, the veiled cells from presensitized animals behaved in a more normal manner and the proportion found in aggregates was only briefly increased. In these animals lymphocytes were seen to interact with veiled cells in a manner reminiscent of peripolesis, apparently recognizing antigenic signals on the surface of the veiled cells. It is discussed that this might result in deletion of the antigen-presenting veiled cells, thus controlling the magnitude of the immune response.

Animals↗
PubMed1983

Association of Sjögren's syndrome with C4 deficiency, defective reticuloendothelial function and circulating immune complexes.

A case of Sjögren's syndrome with the sicca complex is presented which was associated with persistently low or absent C4 levels, high levels of circulating immune complexes and abnormal reticuloendothelial clearance of damaged or IgG antibody sensitized autologous red blood cells (RBCs). Investigation of normal relatives of the patient revealed low C4 levels and abnormal reticuloendothelial clearance of damaged or sensitized RBCs. HLA, A, B, DR typing revealed a high incidence of the HLA B8, DR3 haplotype and of homozygous null alleles at the C4A locus in the family members. These results suggest that the C4 deficiency and the abnormal reticuloendothelial function in the patient was in part genetically determined and may have predisposed to the development of Sjögren's syndrome. These findings serve to emphasize the possible importance of abnormal macrophage function in the pathogenesis of Sjögren's syndrome and suggest that further investigation of these aspects may increase understanding of this disease.

Antigen-Antibody Complex↗
PubMed1982

Vitrectomy in ocular toxocariasis.

Subtotal pars plana vitrectomy was performed in four patients with chronic toxocaral endophthalmitis. In two instances, chronic intraocular inflammation proved unresponsive to intensive corticosteroid therapy, but improved dramatically following vitrectomy. In one patient, a dense retrolenticular membrane was removed, and intractable amblyopia was prevented. Vitrectomy relieved vitreoretinal traction involving the macula in two instances and cured a peripheral traction retinal detachment in a third. Information gleaned from these cases suggests new guidelines for the laboratory confirmation of ocular toxocariasis. Patients with toxocaral endophthalmitis may benefit from pars plana vitrectomy when chronic inflammation does not respond to medical measures or when such inflammation causes permanent structural changes that threaten or interfere with central vision.

Adolescent↗
PubMed1981

Panfunduscope contact lens for argon laser therapy.

The Rodenstock panfunduscope lens adds significantly to the safety of argon laser pan retinal ablation by allowing easy and constant visualization of the relationship of burns to the fovea. One can constantly monitor the overall pattern of photocoagulation being achieved, thereby eliminating skipped areas. The increased safety and speed of the procedure may benefit both surgeon and patient.

Argon↗
PubMed1981

A method for following human lymphocyte traffic using indium-111 oxine labelling.

A method is described whereby large numbers of human lymphocytes are separated from peripheral blood and labelled in vitro with indium-111 oxine. Following autologous reinjection, the distribution within the body is followed by means of serial blood samples, surface-probe counting and gamma camera imaging. The distribution of radioactivity following reinjection of heat-damaged labelled lymphocytes and free indium-111 oxine is different from that of 'normal' lymphocytes. The results suggest that the separation and labelling procedure does not cause significant physical damage to the lymphocytes The importance of restricting the specific lymphocyte activity to 20-40 microCi per 10(8) cells in order to minimize radiation damage to the lymphocytes is emphasized. Good resolution of lymphoid structures is obtained using gamma camera imaging and the changes recorded in organ distribution correlate well with data from animal models of lymphocyte migration. Thus, indium-111 oxine labelling of human lymphocytes provides a non-invasive method whereby the migratory properties of human lymphocytes can be followed.

Cell Movement↗
PubMed1975

Total mercury levels in selected human tissues, Idaho-1973-74(1,2)

Total mercury levels were determined in human tissues taken at autopsy from six hospitals in the three basic geographical areas of Idaho. Of the 242 specimens analyzed, 76 percent contained detectable mercury. Levels were compared with respect to the age, sex, and geographic residence of autopsied individuals. Mean levels detected were 1.04 ppm in kidney tissue, 0.34 ppm in liver, and 0.08 ppm in brain. Mean mercury levels for the three geographical areas were: southeastern Idaho, 0.22 ppm; southwestern Idaho, 0.80 ppm; and northern Idaho, 0.43 ppm. The relatively high means in southwestern Idaho specimens may be related to the preponderance of natural cinnabar deposits in that portion of the State. Mercury levels were higher in women than men for all tissues in both the southwestern and northern areas, but the reverse was true in the southeast. Data were compared with findings of other investigators in an attempt to arrive at background levels of total mercury residues in human tissues.

Adolescent↗
PubMedDate not supplied

Unexpected opioid activity in a known class of drug.

Tifluadom, although structurally a 1,4 benzodiazepine, has no affinity for the 3H-flunitrazepam binding site, but is a potent displacer of 3H-bremazocine from its opioid binding site. Tifluadom is characterised as an opiate kappa-receptor agonist in vitro and in vivo with potent analgesic activity in animals and no dependence potential.

Animals↗
PubMedDate not supplied

Estrogenic and CYP1A response of mummichogs and sunshine bass to sewage effluent.

Recent studies demonstrating feminization of effluent-exposed wild-caught male fish in the UK have prompted much research regarding the estrogenic activity of effluent from municipal sewage treatment plants (MSTPs). To investigate the estrogenicity and cytochrome P450 1A (CYP1A) induction potency of MSTP effluent, two species of fish, adult male mummichogs, Fundulus heteroclitus, and juvenile sunshine bass, Morone saxatilis x Morone chrysops, were exposed to un-chlorinated effluent (75% effluent, 25% seawater) from a large MSTP in Yonkers, NY, USA. After a 21-day static-daily (75%) renewal exposure, significant elevations over controls were observed in levels of vitellogenin (VtG) in plasma (1730%) and liver (131%) in effluent-exposed sunshine bass. In contrast, hepatic VtG was not elevated in mummichogs; plasma VtG was not measured in this species. Effluent exposure elevated hepatic CYP1A protein (140-145%) and ethoxyresorufin-O-deethylase (EROD) activity (408-598%) in both species. These findings suggest ontogenetic and/or species differences in response to estrogenic compounds in MSTP effluent. Furthermore, the elevation of CYP1A in response to sewage effluent exposure indicates the presence of additional compounds that may alter xenobiotic and/or steroid biotransformation in fish.

Animals↗
PubMedDate not supplied

Strategies and willingness of rural restaurateurs to promote healthy foods.

Nutritionists need to understand the willingness of restaurateurs to prepare and sell healthy foods, as Canadians frequently eat meals at food services. The lunch trade restaurants under the jurisdiction of a rural and semi-rural Alberta health unit were surveyed by telephone. Two thirds of the restaurants were family-style and had 100 seats or fewer. Five of 20 healthy foods were rated as difficult to serve, due to: lack of customer demand; lack of food availability; and the need to maintain the quality of fresh vegetables, fruits and milk products. Many restaurateurs are willing to change internally by training staff (88%) and by trying new recipes (84%). Staff education materials perceived to be helpful by 80% of restaurateurs included video/audio tapes, information sheets and posters. Restaurateurs were most willing to use menu inserts (76%), table tents (68%) and door decals (72%) to promote healthy foods. Nutrition services should focus on how restaurants can make changes to include healthy foods through food preparation and menu items.

Alberta↗