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Biomedical subjects

D L Anderson

Publications and source records attributed to D L Anderson.

At least 73 records · Page 4Linked to original sources
PubMed1984

A morphometric comparison of five axenic Giardia isolates.

The length and width of trophozoites from axenic cultures of 5 Giardia isolates were measured both live and after fixation and Giemsa staining. These isolates, as named on the basis of host source, are classified as G. lamblia (3 isolates), G. felis (1 isolate), and G. caviae (1 isolate). The size of live, unstained trophozoites from the 5 isolates, measured without regard to the presence or absence of median bodies, showed only occasional significant differences in length. Statistically significant differences in length and/or width were observed for all comparisons when stained preparations of the isolates were compared. These size differences occurred between isolates assigned to different species as well as among the 3 G. lamblia isolates. These data and previously reported isozyme studies of these isolates most appropriately led to a re-examination of the presently utilized criteria for Giardia speciation.

Animals↗
PubMed1983

Percutaneous transluminal angioplasty of a large septal artery.

A severely stenotic, large-caliber, first septal artery was successfully dilated in a patient with refractory angina and nonsurgical, multivessel coronary artery disease. The success of this dilatation was related to favorable coronary anatomy and to the availability of a guidewire-directed dilatation catheter. Septal artery stenosis with or without surgically accessible stenoses in other coronary vessels represents a potential indication for percutaneous transluminal coronary angioplasty.

Angioplasty, Balloon↗
PubMed1983

Lower cranial height vs craniofacial dimensions in Angle Class II malocclusion.

From the serial sample of the Burlington Growth Centre, 68 children with Angle Class II malocclusion were contrasted with 148 children with Class I occlusion. Body height, cranial height, cranial base flexure and jaw position relative to the cranium were compared at ages 8, 12 and 16 years. In the Class II groups, the cranial base angle was significantly (P less than .05) larger, upper cranial height was slightly larger, lower cranial height was slightly smaller, the maxilla was slightly more posterior to Sella, and the mandible was significantly more posterior. Between ages 8 and 16 years, lower cranial height increased and cranial base angle decreased, with a strong negative correlation. Lower cranial height and the anterior position of the maxilla and mandible from Sella correlated significantly (P less than .01) with body height in Class I children, but in Class II only in boys 8 and 12 years of age. This lower correlation in Class II children was accounted for by those with a moderate to tall stature but disproportionately small lower cranial height. In Class II children the jaws, especially the mandible, had a more posterior position under the cranium, and there was a more open flexure of the cranial base and shorter lower cranial height. Correlation of stature with lower cranial height and with the anterior position of the jaws relative to the cranium was much lower in Class II children, especially in girls.

Adolescent↗
PubMed1983

Morphogenesis of bacteriophage phi 29 of Bacillus subtilis: oriented and quantized in vitro packaging of DNA protein gp3.

The assembly of phage phi 29 occurs by a single pathway, and the DNA protein (DNA-gp3) of "packaging intermediates" can be obtained after DNase I interruption of in vitro complementation. A broad spectrum of DNA molecules of variable length was isolated from DNase I-treated proheads. Restriction endonuclease EcoRI digestion and electrophoretic analysis of these DNA molecules suggested that DNA-gp3 packaging was oriented with respect to the physical map and was a complex process. Proteinase K-treated exogenous DNA was not packaged. When exogenous DNA-gp3 was predigested with the restriction endonucleases BstEII. EcoRI, HpaI, and HpaII, the left-end fragments, ranging in size from 8 to 0.9 megadaltons, were selectively and efficiently packaged. During in vivo and in vitro assembly, DNA-gp3 is packaged into proheads, the "core-scaffolding" protein gp7 exits from the particles, and the DNA-filled heads assume the angular morphology of phage phi 29. The packaging of a 4.1-megadalton DNA-gp3 left-end fragment (one third of the genome) resulted in the exit of gp7 and the transition to angularity.

Bacillus subtilis↗
PubMed1982

Morphogenesis of bacteriophage phi 29 of Bacillus subtilis: DNA-gp3 intermediate in in vivo and in vitro assembly.

The assembly of phage phi 29 occurs by a single pathway, and DNA-protein (DNA-gp3) has been shown to be an intermediate on the assembly pathway by a highly efficient in vitro complementation. At 30 degrees C, about one-half of the viral DNA synthesized was assembled into mature phage, and the absolute plating efficiency of phi 29 approached unity. DNA packaging at 45 degrees C was comparable to that at 30 degrees C, but the burst size was reduced by one-third. When cells infected with mutant ts3(132) at 30 degrees C to permit DNA synthesis were shifted to 45 degrees C before phage assembly, DNA synthesis ceased and no phage were produced. However, a variable amount of DNA packaging occurred. Superinfection by wild-type phage reinitiated ts3(132) DNA synthesis at 45 degrees C, and if native gp3 was covalently linked to this DNA during superinfection replication, it was effectively packaged and assembled. Treatment of the DNA-gp3 complex with trypsin prevented in vitro maturation of phi 29, although substantial DNA packaging occurred. A functional gp3 linked to the 5' termini of phi 29 DNA is a requirement for effective phage assembly in vivo and in vitro.

Bacillus subtilis↗
PubMed1982

Effect of gibberellic acid on production characteristics of aged and force molted chickens in cages.

Production characteristics of individually caged 72-week-old brown egg type hens or 86-week-old hens of a similar strain that had previously been subjected to different watering systems (continuous flow cups vs. intermittent flow troughs) and the stress and recovery of a forced molting program were evaluated in two trials over a 4 to 5-week interval following 6 alternate day subcutaneous injections (2.4 mg/bird) of gibberellic acid (GA3). Egg production and feed consumption of the 72-week-old hens maintained at constant temperature (20.0 +/- 1.0 C), humidity (55%), and light intensity (10.76 1x) were significantly greater (GA3 X time, P less than .05) in the GA3 treated birds and were accompanied by significantly larger eggs (Ga3 X time, P less than .05) with generally thinner shells. In the second trial, the 86-week-old hens responded with similar trends but the differences were less and related in part to prior watering system. No statistically significant differences were found for egg production, feed consumption, and egg weight as previously observed, but there was significantly greater shell thickness of eggs from the GA3 -treated birds previously adapted to cups as compared to trough waterers (GA3 X time X waterer, P less than .025). No statistically significant effects of GA3 on body weight were observed in either trial. The data suggest that the differences in response between the two trials may be related to the initial differences in egg production and, thus, the levels of circulating gonadal hormones, since GA3 has been shown to have androgenic activity in chicks, and estrogenic as well as other hormonal activity in other species.

Aging↗
PubMed1982

Activity of ivermectin against canine intestinal helminths.

The anthelmintic activity of ivermectin was tested in 98 dogs against adult ascarids (Toxocara canis, Toxascaris leonina), hookworms (Ancylostoma caninum, A braziliense), and whipworms (Trichuris vulpis), and against experimentally induced infections (4th-stage larvae) of T canis and A caninum. Dosage levels tested were single subcutaneous injections of 50, 100, 200, or 400 micrograms/kg of body weight with appropriate vehicle-treated controls. A minimum of 4 (usually 5) dogs were tested with each parasite and dosage level. The lowest dosage level, 50 micrograms/kg, and all higher dosage levels expelled greater than 99% of the adult forms of both species of hookworms and intestinal larval forms of A caninum, as determined by worm counts at necropsy. A dosage level of 100 micrograms/kg was required to expel greater than 99% of whipworms and 200 micrograms/kg was necessary to expel adult (91%) and larval (97%) stages of T canis. Ivermectin was only marginally effective (34.2%, 46.2%, 69.2%, and 53.8%) against Toxascaris leonina at 50, 100, 200, and 400 micrograms/kg, respectively, and had no effect against occasional infections with the tapeworms, Dipylidium caninum (14 dogs) and Taenia spp (3 dogs).

Ancylostomiasis↗
PubMed1981

Association of relatively delayed emergence of mandibular molars with molar reduction and molar position.

Among 234 children examined annually from age three to 20 years at the Burlington Growth Centre, there was statistically significant co-occurrence of early and late emergence sequences of the permanent first and second molars relative to the central incisors and second premolars in the same jaw and in both jaws. Alternatively, mandibular molar delay was not accompanied by corresponding maxillary molar delay, and the mandibular molars emerged later than the maxillary molars. This was strongly associated with Angle Class II malocclusion, indicating a relationship between relative time of emergence and relative position of opposing molars. Delay of the mandibular molar relative to the successional teeth or maxillary molars was associated with increased frequency of four cusped first and second molars and agenesis of third molars, indicating a tendency for co-occurrence of delay in timing of molar emergence with reduction in structure of the molars. These relationships were evident even though emergences were affected by early loss of a deciduous second molar which increased M1I1 and M2P2 sequences by earlier emergence of M1 and delayed emergence of P2.

Adolescent↗
PubMed1981

In vitro assembly of the Bacillus subtilis bacteriophage phi 29.

In vitro assembly of the Bacillus subtilis bacteriophage phi 29 that approaches the efficiency of assembly in vivo has been demonstrated. Proheads, DNA, and gene 16 product (gp16) were essential for DNA encapsidation, and the average yield in extracts was 180 phage per prohead donor cell. The in vitro maturation was very similar to in vivo assembly in terms of yield, intermediates, and abortive structures. More that 30% of the proheads in the extract were converted to phage, and about 20% of DNA--protein extracted from phage could be repackaged. In vitro assembly was blocked by the addition of DNase I, EDTA, pyrophosphatase, or the ATP analogues adenosine 5'-[alpha, beta-methylene]triphosphate and adenosine 5'-[beta, gamma-methylene]triphosphate. Less than 1% of the proheads isolated in sucrose gradients can accept DNA--protein in packaging in vitro.

Bacillus subtilis↗
PubMed1981

Carotid sinus reflex vasoconstriction in right coronary circulation of dog and pig.

This study was designed to evaluate the effects of the sympathetic nervous system on right ventricular and right coronary hemodynamics in the anesthetized vagotomized dog and pig during constant-pressure coronary perfusion. Carotid occlusion in the dog resulted in an increase in heart rate, aortic pressure, right ventricular dP/dt, and a sustained 13% decrease in right coronary artery blood flow and a 14% increase in coronary vascular resistance. This coronary vasoconstriction was not modified during beta-blockade with propranolol but was prevented by alpha- blockade with phentolamine. Similar hemodynamic data was obtained in the pig and, in addition, it was found that the O2 consumption of the right ventricle is low (4.8 +/- 0.4 ml O2.min-1.100 g-1) and is only slightly increased (5.l5 +/- 0.8 ml.min-1.100 g-1) during carotid occlusion. These data suggest that baroreflex-mediated sympathetic stimulation to the heart evokes only a minor increase in metabolic activity in the right ventricular myocardium so that the direct neural (alpha-vasoconstrictor) effect predominates over the metabolic vasodilator mechanism.

Animals↗
PubMed1981

Inpatient management of the chronic pain patient: a one-year follow-up study.

An inpatient chronic pain management unit stressing a multidimensional behavioral approach has been in operation since April 1979 at a 405-bed community hospital. Components of the program include chemical detoxification, physical, occupational, and relaxation therapies, group meetings, and family therapy. The first 13 patients to complete the program achieved 100 percent success in medication reduction and experienced decreases in depression, hysteria, hypochondriasis, and self-ratings of pain intensity. Many have returned to work. Follow-up at 1, 3, 6, and 12 months shows maintenance of improvement.

Behavior Therapy↗
PubMed1980

Anogenital warts contain several distinct species of human papillomavirus.

Anogenital warts from 26 patients were examined for the presence of human papillomavirus (HPV). Although no whole, intact virus could be identified, varying amounts of nonintegrated HPV DNA were detected in 18 tissue specimens (70%) by employing both an agarose gel-ethidium bromide staining method and the Southern blot hybridization procedure. When hybridization analysis was performed under stringent conditions, six anogenital warts were observed to contain HPV genomic sequences related to either of the cutaneous viruses HPV type 1 (HPV-1) or HPV-2. In 12 tissue samples lacking sequence homology to either HPV-1 or HPV-2 under stringent conditions, HPV-related sequences were detected when the hybridization was performed under less stringent conditions, indicating that an HPV distinct from both HPV-1 and HPV-2 is also associated with these lesions. This anogenital HPV also appeared to be distinct from the other characterized types of HPV. These data indicate that at least three HPVs are associated with anogenital wart disease.

Anal Canal↗