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Biomedical subjects

J Strandberg

Publications and source records attributed to J Strandberg.

10 recordsLinked to original sources
PubMed2001

Photodynamic therapy in the canine prostate using motexafin lutetium.

Our purpose was to determine the feasibility of comprehensive treatment of the canine prostate with photodynamic therapy (PDT) using motexafin lutetium (Lu-Tex) and to evaluate the toxicity and tissue effects associated with this treatment. Twenty-five adult male beagles with normal prostate glands were given an i.v. injection of the second-generation photosensitizer Lu-Tex (2-6 mg/kg). An additional two dogs were used as controls and did not receive any photosensitizing drug. All 27 dogs underwent laparotomy to expose the prostate. Three hours postinjection, a total dose of 75-150 J/cm of 732 nm laser light was delivered interstitially and/or transurethrally to the prostate via cylindrical diffusing fibers. Dogs were euthanized between 2 days and 3 months after PDT. All subjects were monitored for clinical evidence of toxicity. Specimens were examined macroscopically and microscopically to characterize the tissue reaction and assess extent of tissue effect as a result of treatment. Interstitial and/or transurethral PDT were successfully delivered in all dogs with no perioperative complications. No clinical evidence of acute urinary obstruction or rectal bleeding was noted. At all dose levels, macroscopic and microscopic evaluation revealed a prostatic tissue reaction characterized initially (within 48 h) by inflammation and necrosis followed by fibrosis and glandular epithelial atrophy. Comprehensive treatment of the entire prostate could be achieved using the interstitial alone approach or combined transurethral and interstitial approach. The transurethral alone approach did not result in complete coverage of the prostate. Dogs receiving transurethral or combined interstitial and transurethral treatment developed erythema and urethral epithelial disruption at all dose levels. Those receiving combined treatment at the highest dose level (Lu-Tex 6 mg/kg, 150 J/cm light) developed urethral fistulae and peritonitis. Dogs treated with the interstitial alone approach were found to have the least amount of urethral damage. Comprehensive treatment of the canine prostate with Lu-Tex PDT is feasible using an interstitial alone or combined interstitial and transurethral approach. The interstitial alone technique results in the least amount of toxicity. The prostatic tissue reaction to treatment is characterized by initial inflammation and necrosis followed by fibrosis and glandular epithelial atrophy.

Animals↗
PubMed1998

Real-time bronchoscope tip localization enables three-dimensional CT image guidance for transbronchial needle aspiration in swine.

STUDY OBJECTIVE: To determine the feasibility of using real-time bronchoscope position technology coupled with previously acquired three-dimensional CT data to enhance transbronchial needle aspiration (TBNA). DESIGN: Eight swine were given percutaneously created target lesions for TBNA. A miniature position sensor was placed at the tip of a bronchoscope, and real-time position information during bronchoscopy was presented on a monitor simultaneously displaying previously acquired three-dimensional CT data. INTERVENTIONS: TBNA of target lesions and submucosal ink-spot injection of computer-generated targets. MEASUREMENTS AND RESULTS: TBNA specimens revealed successful aspiration of target material. Distances between ink marks made at computer-generated tracheal targets varied, on average (+/- SD), 4.2 mm +/- 2.6 mm from predetermined computer-distance coordinates. CONCLUSION: Real-time bronchoscope position technology coupled with previously acquired CT images may aid with TBNA of nonvisible extrabronchial lesions.

Animals↗
PubMed1995

[Emergency psychiatric treatment of survivors of the Estonia disaster].

The sinking of the car ferry, Estonia, was one of the world's most devastating marine disasters of all time. Mass casualty situations tend to give rise to more mental than physical injuries among the survivors. Psychiatric crisis intervention is in the process of becoming established as one arm in the management of disaster victims. In the article is described the emergency psychiatric care which University Hospital, Abo, was able to offer survivors of the Estonia catastrophe. On the basis of the experience gained, the authors suggest that emergency psychiatric plans should be drawn up at all larger hospitals, as there is no time for careful planning in the event of a major incident.

Crisis Intervention↗
PubMed1990

Mutational specificity of the anti 1,2-dihydrodiol 3,4-epoxide of 5-methylchrysene.

An SV40-based pS189 shuttle vector, which contained a supF target gene and was replicated in human cells (Ad293), was used to determine the mutational specificity of anti 5-methylchrysene 1,2-dihydrodiol 3,4-epoxide, the active metabolite of the environmentally prevalent carcinogen 5-methylchrysene. The frequency of supF mutants containing point mutations increased with dose to approximately 40 times the spontaneous frequency. The induced mutations were not randomly distributed but occurred preferentially at mutagenic hotspots, which were not all identical to those reported by others for benzo[a]pyrene dihydrodiol epoxide, a metabolite with similar chemistry.

Base Sequence↗
PubMed1989

Mutagenic specificity of a potent carcinogen, benzo[c]phenanthrene (4R,3S)-dihydrodiol (2S,1R)-epoxide, which reacts with adenine and guanine in DNA.

Mutations were induced in the supF gene of the pS189 shuttle vector by treatment with optically active benzo[c]phenanthrene (4R,3S)-dihydrodiol (2S,1R)-epoxide in vitro and replication in human cells. The induced mutation frequency was 60-fold greater than the spontaneous rate, and most of the mutations analyzed were transversions (86%), which principally consisted of similar numbers of A.T----T.A and G.C----T.A changes. The unusual susceptibility of A.T pairs to mutation by this chemical agent is consistent with its chemical reactivity toward adenine and argues that the mutations are targeted to the adducts formed. The central base in the sequences 5'-AGA-3', 5'-AAC-3', and 5'-GAG-3' was particularly susceptible to mutation. Twelve "hotspots" in the supF gene accounted for most mutations seen. Some of these hotspots differed from those found by others for racemic benzo[a]pyrene dihydrodiol epoxide and, even when a hotspot was common, the mutagenic changes were not always the same. Although adenine insertion opposite a noninstructional lesion could account for most of the data, no single mutagenic mechanism could encompass all of it. The cellular machinery that converts chemical damage to mutations must determine the mutational result to a large extent, but the findings herein show that the chemical agent itself plays a large role in determining both the location and the nature of the mutations that arise.

Adenine↗
PubMed1981

Mortality in robins (Turdus migratorius) due to avian malaria.

Two juvenile robins (Turdus migratorius) died shortly after being captured in Baltimore, Maryland. Both had high erythrocytic parasitemias of mixed Plasmodium infections. Postmortem examination revealed large numbers of exo-erythrocytic malarial schizonts in the liver, spleen, lungs and brain of both cases. Avian malaria was considered the primary cause of death.

Animals↗
PubMed1978

Granular cell variants in a rat schwannoma. Evidence of neurogenic origin of granular cell tumor (myoblastoma).

A large, intraabdominal rat schwannoma had numerous granule-containing cells cytologically identical to cells of granular cell tumor (myoblastoma). The small eosinophilic granules stained positively by the periodic acid-Schiff (PAS) reaction, with intensity not reduced by diastase pretreatment. Granules stained positively with the Tibor Pap silver impregnation for reticulin and by electron microscopy were identical to myoblastoma cell granules. The nuclei of granular cells were morphologically identical to those of the neoplastic Schwann cells. The granular cells were in numerous foci within the tumor, frequently were seen in mitosis, and possessed an extremely variable volume of cytoplasm. They seemed to evolve from neoplastic Schwann cells. Cells with only a narrow perinuclear rim of granular cytoplasm were of the same size and general configuration as adjacent neoplastic Schwann cells, while cells with increasing volumes of granular cytoplasm were increasingly swollen and round. One area of the tumor was composed almost entirely of such large cells and was histologically identical to classic granular cell tumor.

Animals↗