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Biomedical subjects

J Brooks

Publications and source records attributed to J Brooks.

At least 127 records · Page 7Linked to original sources
PubMed1989

Antipneumococcal effects of C-reactive protein and monoclonal antibodies to pneumococcal cell wall and capsular antigens.

Antibodies to pneumococcal capsular polysaccharides are well known for their ability to protect against pneumococcal infection. Recent studies indicate that antibodies to cell wall antigens, including pneumococcal surface protein A and the phosphocholine (PC) determinant of teichoic acids as well as human C-reactive protein (which also binds to PC), can protect mice against pneumococcal infection. In the present study we compared the protective effects of these agents as measured by mouse protection, the blood bactericidal assay, and clearance of pneumococci from the blood and peritoneal cavity. Our findings extend previous results indicating that human C-reactive protein and antibodies to noncapsular antigens are generally less protective than anticapsular antibodies. The new results obtained indicate the following: (i) mouse protection studies with intraperitoneal and intravenous infections provide very similar results; (ii) monoclonal immunoglobulin G2a (IgG2a) antibodies to PC, like IgG1, IgG2b, and IgG3 antibodies to PC, are highly protective against pneumococcal infection in mice; (iii) human antibody to PC is able to protect against pneumococcal infection in mice; (iv) antibodies to PspA are effective at mediating blood and peritoneal clearance of pneumococci; (v) complement is required for the in vivo protective effects of both IgG and IgM antibodies to PC; (vi) IgG1, IgG2b, and IgG3 anti-PC antibodies all mediate complement-dependent lysis of PC-conjugated erythrocytes; and (vii) antibodies and human C-reactive proteins that are reactive with capsular antigens but not cell wall antigens are able to mediate significant antibacterial activity in the blood bactericidal assay.

Animals↗
PubMed1988

Induction of lymphomas and fibrosarcomas in nude mice after implantation of simian virus 40-transformed human meningioma.

Human cells transformed by Simian virus 40 (SV40) usually show little or no tumor formation after implantation in nude mice. In long-term studies, however, we have observed that 127 to 366 days after subcutaneous injection of SV40-transformed human meningioma cells (KJ-M2-T) into nude mice (Nu/Cox), 6 of 15 animals developed lymphomas or fibrosarcomas, usually at the site of inoculation. The induced tumors were of murine origin and were positive for SV40-T antigen. Chromosome analysis and G11 staining revealed no evidence of hybridization between human and mouse cells. No spontaneous shedding of SV40 was noted with KJ-M2-T cells in vitro; however, SV40 could be rescued after fusion of KJ-M2-T with BS-C-1 monkey kidney cells, but not with L929 mouse fibroblasts. A parallel study using SV40-transformed human fetal brain cells failed to induce tumors in nude mice despite the demonstration that infectious SV40 could also be rescued from this line after fusion with BS-C-1 but not with L-929. Subcutaneous injection of 5 X 10(3) TCID's of SV40 (strain J436) into nude mice resulted in the induction of fibrosarcomas at the injection site in 6 of 15 mice after 273 to 396 days. The induction of malignant lymphomas after implantation of SV40 transformed cells contrasted with the development of fibrosarcomas after injection of free virus. This study suggests that after subcutaneous implantation into nude mice, some SV40-transformed human tumor cell lines can serve as vectors for transmitting SV40 to murine cells causing transformation and tumor development in the host animal.

Animals↗
PubMed1987

The fate of women requesting reversal of tubal sterilization.

Although it was not possible to identify by simple demographic measurements those women who would elect not to pursue full investigation, this study has highlighted the high drop-out rate of women requesting reversal, and suggested that discussion with the couple at the first visit is a valid procedure, particularly if it allows as many as one-third of patients to elect not to proceed to invasive procedures. Finally, this study underscores that when gynecologists are counseling patients with respect to sterilization and the question of reversibility is opened, the success rate is not in excess of 50% when it is considered a function of the number of women regretting reversal rather than a function of women who undergo surgery.

Abortion, Spontaneous↗
PubMed1987

Changes in nasal mast cell numbers in and out of the pollen season.

Mast cells were counted in biopsies of the nasal mucous membrane from 8 patients with allergic rhinitis during (July 1985) and after (October 1985 and January 1986) the grass pollen season in both the superficial epithelium and the deeper lamina propria. There was an eightfold increase in the total number of mast cells in the nasal mucous membrane during the grass pollen season when compared to midwinter. In addition, there was a striking change in the number of mast cells present in the surface epithelial layer from almost total absence in biopsies taken in midwinter to counts of between 2,000 and 28,000/mm3 in all but 1 patient during the summer.

Adult↗
PubMed1986

Low frequencies of apparently fragile X chromosomes in normal control cultures: a possible explanation.

Low frequencies of apparently fragile X [fra(X)] chromosomes have been reported in normal control, short-term, whole blood cultures, and they have been noted in both amniocyte and fetal blood cultures. However, there is currently no universal agreement on the lowest frequency for fra(X)(q27) that is diagnostic for the fragile X syndrome. Here, we present our observations on low levels of apparently fra(X) chromosomes in normal samples. We observed frequencies of 0.5% in short-term whole blood cultures and 0.9% in amniotic fluid cell cultures. In 1982, Steinbach et al. described nonspecific telomeric structural changes (TSC) and suggested that such low frequencies of apparently fra(X) chromosomes in normal material may be occurring by the same mechanism that is responsible for TSC formation. To determine if TSC formation can explain the significant baseline frequencies of fra(X) in normal controls, 10,457 cells were screened from 178 individuals referred for fra(X) analysis. Our findings indicated that TSC are not randomly distributed across chromosomes but tend to occur at specific sites. Based on our observations, we offer the hypothesis that the low frequency of apparent fra(X) in normal individuals may be due to nonrandom TSC distribution.

Amnion↗
PubMed1984

Experience with prenatal fragile X detection.

We have attempted the prenatal detection of the fra(X) 9 times. Three fra(X) positive fetuses have been diagnosed: 2 males and one female. The diagnosis on the 2 males has been confirmed. The testes of the 2 fra(X) positive fetuses appeared large for gestational age. However, results of anthropometric, bone age, anatomical and neurohistological studies were normal. Normal outcome was confirmed after birth in 2 males and one female on the basis of whole blood fra(X) studies. A presumptively positive female and a presumptively negative female await confirmation. Two presumptively negative males remain unborn. Further experience is needed to establish the reliability of the prenatal detection of fra(X) (q27).

Adrenal Cortex↗
PubMed1984

Folic acid therapy in the fragile X syndrome.

Two brothers with fra(X) positive X-linked mental retardation (XLMR) were treated with folic acid. Initially a double blind cross-over design was employed followed by a long-term high dose trial. A decrease in the frequency of fra(X) positive cells was observed when low folic acid culture medium was used but not when an FUdR induction system was employed. Selected behavioral characteristics improved in both while receiving folic acid. Decreased hyperactivity, greater attention span, increased motor coordination, increased quantity and quality of speech were noted. Improvement in Leiter mental age and regression after cessation of treatment was seen in one subject but not in the other. Further controlled trials with larger numbers of subjects using high doses of folic acid over longer periods of time are needed to assess the possible benefits of this experimental form of treatment.

Adolescent↗
PubMed1981

Therapy of locally unresectable pancreatic carcinoma: a randomized comparison of high dose (6000 rads) radiation alone, moderate dose radiation (4000 rads + 5-fluorouracil), and high dose radiation + 5-fluorouracil: The Gastrointestinal Tumor Study Group.

One-hundred-ninety-four eligible and evaluable patients with histologically confirmed locally unresectable adenocarcinoma of the pancreas were randomly assigned to therapy with high-dose (6000 rads) radiation therapy alone, to moderate-dose (4000 rads) radiation + 5-fluorouracil (5-FU), and to high-dose radiation plus 5-FU. Median survival with radiation alone was only 51/2 months from date of diagnosis. Both 5-FU-containing treatment regimens produced a highly significant survival improvement when compared with radiation alone. Forty percent of patients treated with the combined regimens were still living at one year compared with 10% of patients treated with radiation only. Survival differences between 4000 rads plus 5-FU and 6000 rads plus 5-FU were not significant with an overall median survival of ten months. Significant prognostic variables, in addition to treatment, were pretreatment performance status and pretreatment CEA level.

Adenocarcinoma↗