Search PubMed⌕ Search

Biomedical subjects

M A Jackson

Publications and source records attributed to M A Jackson.

At least 91 records · Page 5Linked to original sources
PubMed1987

Palliative retreatment of locally-recurrent lung cancer after radical radiotherapy.

Twenty-two patients who had received high-dose radiotherapy (50-60 Gy) for non-small-cell lung cancer were retreated with palliative radiotherapy for symptoms that were due to locally recurrent disease. Twelve of the 23 (one patient was retreated twice) repeat courses produced symptomatic benefit. One patient developed spinal-cord injury after retreatment, but this was probably not related to the second course. There were no other serious complications, even though total tumour doses as high as 120 Gy were achieved. This experience demonstrates that repeated courses of radiotherapy can be given successfully and safely in spite of previous radical dosage.

Adenocarcinoma↗
PubMed1987

The role of diet in prostate cancer.

This is a one-to-one, age- and race-matched case-control study involving 55 histologically confirmed black prostate cancer patients and 55 controls who were seen at three major hospitals in Washington, DC from 1982 to 1984. Personal interviews were conducted to obtain the number of times food items of specified serving size were consumed per week by cases and controls; the subjects were grouped according to the age periods 30-49 and 50 years and older. We then calculated the average daily consumption of each of 18 nutrients per 1,000 calories. There was a significant negative association between linoleic acid (p less than 0.04) for the 50 years and older group, thiamin (p less than 0.05) for those 30-49 years old, riboflavin (p less than 0.03) for the 50 and older group, and iron (p less than 0.05) for those 30-49 years old. The results of this study suggest that the intake of thiamin and iron (in subjects 30-49 years old), linoleic acid and riboflavin (in subjects 50 years and over) could be protective because control subjects consumed more of these nutrients than did the cases.

Adult↗
PubMed1987

Antigenic characterization of the oligosaccharide portion of the lipooligosaccharide of nontypable Haemophilus influenzae.

Monoclonal antibodies (MAbs) directed against epitopes in the oligosaccharide portion of the lipooligosaccharide (LOS) of nontypable Haemophilus influenzae (NTHI) were used to characterize the LOS of this pathogen. Western blot (immunoblot) analysis with four LOS-specific MAbs and proteinase K-derived LOS preparations from 69 NTHI strains allowed the classification of these strains into nine LOS antigenic groups. The use of these MAbs in a more sensitive colony blot radioimmunoassay system together with these same NTHI strains identified 14 LOS antigenic groups. Extensive cross-reactivity was detected between the LOS epitopes of these NTHI strains and the LOS of H. influenzae type b. The epitopes recognized by these MAbs were not accessible to antibody on the surface of every strain. These LOS epitopes were also not stably expressed by NTHI growing in vitro; the observed frequency of LOS antigen variation ranged from 1 to 24% when large numbers of colonies of NTHI strains were screened for reactivity with the LOS-directed MAbs in the colony blot radioimmunoassay. This LOS antigenic variation was sometimes associated with alterations in the profile of the LOS molecule as resolved by dodecyl sulfate-polyacrylamide gradient gel electrophoresis followed by staining with silver. These data indicate that considerable antigenic diversity exists among NTHI strains with regard to the oligosaccharide epitopes in their LOS molecules.

Antibodies, Bacterial↗
PubMed1986

Toxicity of particles emitted from combustion of waste crankcase oil: in vitro and in vivo studies.

The ever-rising cost of energy provides incentives for the utilization of low-cost waste crankcase oil (WCO) for space heating. Although WCO is known to contain toxic heavy metals, the potential health hazards of emissions and waste products resulting from the combustion of WCO are unknown. Thus, the toxicity of the emission particles and waste products from two different types of burners, a Dravo atomizing oil burner (AOB) and a Kroll vaporizing oil burner (VOB), is evaluated using automotive WCO. Samples are characterized by performing elemental analysis and scanning electron microscopy. Both burners emitted fine (less than or equal to 3 microns), respirable particles. The AOB emission particles contained high concentrations of toxic heavy metals, especially Pb, which showed concentrations as high as 7.5%. The VOB retained a significant amount of heavy metals in the burner residue and emitted a much smaller quantity into the air. The toxicity of AOB emission particles, VOB emission particles, and VOB waste residue is evaluated in three bioassay systems, including a rabbit alveolar macrophage (RAM) cytotoxicity in vitro assay, an intratracheal injection infectivity assay, and a peritoneal irritancy test in mice. The emission particles from both burners and leachate from VOB residue produce a dose-related reduction in viability and cellular adenosine triphosphate (ATP) in alveolar macrophages following 20-hr exposure. Acidity of the RAM medium due to the presence of VOB emission particles and waste leachate contributes to its toxicity.(ABSTRACT TRUNCATED AT 250 WORDS)

Air Pollutants↗
PubMed1985

Ductal spread in prostatic carcinoma.

The histologic appearances of ductal invasion were studied in 139 cases of prostatic adenocarcinoma diagnosed in the Department of Pathology, Howard University Hospital, during the period January 1980 through October 1983. Intraductal spread was found in almost half (48%) of the prostatic glands examined. Ductal spread was associated with the local extent (P less than 0.001) rather than with the grade of the tumor (P less than 0.01). Three distinct patterns of ductal penetration were recognized. The duct wall was completely destroyed in microinvasion. In foci of ductal permeation the integrity of the basement membrane was generally preserved, and the duct wall was infiltrated mainly by solitary tumor cells. When the tumor spread was by extension in continuity within the duct wall, the neoplastic cells appeared to grow between the pre-existing epithelial layers. It was concluded that prostatic carcinoma cells have the ability to penetrate the wall of benign ducts and progressively replace the normal epithelial elements. In this process the general framework of the affected duct appears to be preserved.

Adenocarcinoma↗
PubMed1985

Nutrition and prostate cancer: a case-control study.

This one-to-one, age- and race-matched case-control study involved 181 histologically confirmed black prostate cancer patients and 181 controls seen at three major hospitals in Washington, DC, during the period 1979-1982. Personal interviews were conducted to obtain the number of times food items of specified serving size were consumed per week by cases and controls during the age periods 30-49 and 50 years and older. Then the average daily consumption of each of 18 nutrients per 1,000 calories was calculated. There was risk enhancement associated with increased intake of proteins, total fat, saturated fat, oleic acid, and vitamin A during the age period 30-49 years. The association was highly significant for vitamin A and approached statistical significance for the other four nutrients. A hypothesis based on disturbance of the zinc-retinol binding protein-vitamin A axis was put forward to explain the relative risk enhancement effect of vitamin A on prostate cancer.

Adult↗
PubMed1985

Nitropyrene: DNA binding and adduct formation in respiratory tissues.

Binding of 1-nitro (14C)pyrene (NP) or its metabolites to cellular DNA and protein in cultures of rabbit alveolar macrophages, lung tissue, and tracheal tissue was examined. DNA binding in tracheal tissue (136 +/- 18.3 pmole NP/mg DNA) was four to five times the levels measured in either lung tissue (38 +/- 9.4 pmole NP/mg DNA) or macrophages (26 +/- 7.5 pmole NP/mg DNA). Adduct analysis of DNA isolated from lung tissue incubated with 1-nitro[H3]pyrene in vitro resulted in the identification of 2 to 5% of the NP adducts as C8-deoxyguanosine 1-aminopyrene. NP was also bound to cellular protein in tracheal tissue and lung tissue, and at a lower level in macrophages. Cocultivation of the macrophages with lung and tracheal tissue decreased the DNA binding in tracheal tissue by 45%. Following intratracheal instillation of diesel particles (5 mg) vapor-coated with 14C-NP (380 ppm, 0.085 muCi/mg) particles into rats, 5-8% of the radioactivity remained in the lungs after 20 hr. Most of the diesel particles were also deposited in the lung. Examination of DNA and protein binding in this tissue showed 5 to 12% of the pulmonary 14C bound to protein and no detectable levels of 14C bound to DNA.

Animals↗
PubMed1984

The Fitness to stand trial Interview Test: how four professions rate videotaped fitness interviews.

The results of this study provide some preliminary support for the use of the FIT as a method for providing structure to interviewers. The FIT may be particularly useful as a guide for making initial decisions about fitness. It was suggested that a screening evaluation based on the FIT could be completed by any properly trained individual with some professional background. The more difficult cases can be referred for lengthier evaluations. Of course, further research on the use of the FIT with actual defendants in real assessments will need to occur before such a procedure can be used as a matter of routine. Finally, the FIT promises to be an effective research tool for isolating professional group differences in definitions of fitness and the importance of different aspects of it, from both a legal and a mental health perspective.

Expert Testimony↗
PubMed1983

Cellular toxicity in Chinese hamster ovary cell cultures. II. A statistical appraisal of sensitivity with the rabbit alveolar macrophage, Syrian hamster embryo, BALB 3T3 mouse, and human neonatal fibroblast cell systems.

Chinese hamster ovary, rabbit alveolar macrophage, Syrian hamster embryo, BALB 3T3 mouse, and human neonatal fibroblast cells were employed in a statistical evaluation of the relative sensitivity of the cells to toxic substances. The cells were exposed to 1,2,4-trichlorobenzene, 2,4-dimethylphenol, Aroclor 1248, cadmium chloride, lead sulfate, nickel nitrate, lead oxide-coated fly ash, and a fine particulate from coal combustion. A filter-disk technique was used to measure the inhibition of protein and DNA synthesis. A quantitative ranking of cell-system sensitivity was determined from comparisons of statistically significant differences (P less than or equal to 0.01) in protein and DNA synthesis expressed as a percentage of control. An overall ranking of sensitivity showed that rabbit alveolar macrophages, Syrian hamster embryo cells, and Chinese hamster ovary cells were more sensitive than another of the five cell systems in 75, 68, and 62% of the experiments, respectively. The corresponding values for BALB 3T3 mouse and human neonatal fibroblast cells were 38 and 28%, respectively, under our experimental conditions. Detailed data on the control cell cultures are also presented.

Animals↗
PubMed1983

A rapid technique for estimating DNA binding, used to evaluate 1-nitropyrene adduct formation.

A simple and rapid procedure for estimating binding of radio-labelled material to DNA and protein is described. Protein was extracted from lysed rabbit alveolar macrophages with chloroform: iso-amyl-alcohol:phenol extraction. Nucleic acids were precipitated from the lysate, and hydrolysed with protease and NaOH to remove residual protein and RNA respectively. Bound radioactivity was quantitated by precipitation of DNA onto glass fiber filters. Protein labelled with 3H-leucine and DNA and RNA adducts formed from 1-nitro[14C]pyrene by xanthine oxidase were used to define this procedure. 14C was shown to be bound to endogeneous protein and DNA isolated from rabbit alveolar macrophages that had been incubated with 1-nitro[14C]pyrene.

Animals↗
PubMed1983

Treatment of occult bacteremia: a prospective randomized clinical trial.

Antibiotic therapy for children without foci of infection and at risk for bacteremia is controversial. A prospective randomized clinical trial was conducted using expectant antibiotic therapy in children at risk for bacteremia. A total of 96 children (aged 6 to 24 months) with temperature of more than 40 degrees C, no identifiable source of infection, and a leukocyte count greater than or equal to 15,000/microL and/or sedimentation rate greater than or equal to 30 were enrolled. The following tests were performed on all children: blood culture, chest roentgenogram, urinalysis, and urine culture. A lumbar puncture was performed if a child was 12 months or less. Patients were randomized to receive either no antibiotic therapy or Bicillin C-R, 50,000 U/kg intramuscularly, followed by penicillin V, 100 mg/kg/d, orally four times a day for three days. Patients were examined at 24 and 72 hours. Fifty patients were treated expectantly and 46 received no antimicrobial therapy. Ten of the 96 patients were bacteremic (nine had Streptococcus pneumoniae, one had Haemophilus influenzae). Four of the five children treated for bacteremia showed improvement at the first follow-up visit (afebrile and no obvious focus of infection). The five untreated patients showed no improvement; four patients developed focal infections (two had meningitis, two had otitis media) (P less than or equal to .05, Fisher exact test). No complications of expectant therapy were detected. Thus, expectant antibiotic therapy for children who have no obvious source of infection and who meet these criteria associated with occult bacteremia is warranted.

Child, Preschool↗
PubMed1982

Cancer of the prostate and aging: an autopsy study in black men from Washington, DC, and selected African cities.

Age-related changes of arteries, veins, glands, and stroma in the prostate of black men from Washington, DC, and from Ibadan, Nigeria, and Accra, Ghana, West AFrica, were studied in a total of 795 consecutive, unselected prostate specimens removed at autopsy during a 7-year period (1973-1980). Except for age group 80 and over, aging changes in the prostate were more severe in all age groups in black men from Washington, DC, than in black men from Ibadan and Accra (P less than 0.01). However, when the intensity of age-dependent alterations was compared in either US or African black men with carcinoma and with no carcinoma, no significant differences were found. These findings do not support the idea that the aging process per se increases susceptibility to cancer.

Adult↗