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Biomedical subjects

C B Wilson

Publications and source records attributed to C B Wilson.

At least 181 records · Page 10Linked to original sources
PubMed1993

Meningiomas induced by high-dose cranial irradiation.

Although meningiomas are known to be induced by low doses of cranial irradiation, such as those given to treat tinea capitis, little experience has been reported on the induction of meningiomas by high-dose cranial irradiation. The authors describe a series of 10 patients with meningiomas and a previous history of high-dose radiation therapy, usually given for a primary brain tumor. Of the 10 patients, eight were female, three had multiple meningiomas, and the majority had other stigmata of previous radiation therapy. Eight meningiomas were examined pathologically and one-half were classified as either aggressive or atypical, or were noted to have a high bromodeoxyuridine labeling index. The average time from radiation therapy to diagnosis of a meningioma was 24 years (range 5 to 40 years), a shorter interval than that previously reported for meningiomas induced by lower doses of irradiation. Within this series, patient age at irradiation was significantly correlated with tumor latency; individuals who were younger at the time of radiation therapy had a shorter time to meningioma formation. The latency of meningioma formation is therefore influenced by both the radiation dose and the age of the patient at irradiation.

Adolescent↗
PubMed1993

Endovascular treatment of vertebral artery dissections and pseudoaneurysms.

Sixteen patients with dissecting aneurysms or pseudoaneurysms of the vertebral artery, 12 involving the intradural vertebral artery and four occurring in the extradural segment, were treated by endovascular occlusion of the dissection site. Patients with vertebral fistulas were excluded from this study. The dissection was caused by trauma in three patients (two iatrogenic) and in the remaining 13 no obvious etiology was disclosed. Nine patients presented with subarachnoid hemorrhage (SAH), two of whom had severe cardiac disturbances secondary to the bleed. The nontraumatic dissections occurred in seven women and six men, with a mean age on discovery of 48 years. Fifteen patients were treated with endovascular occlusion of the parent artery at or just proximal to the dissection site. One patient had occlusion of a traumatic pseudoaneurysm with preservation of the parent artery. Four patients required transluminal angioplasty because of severe vasospasm produced by the presenting hemorrhage, and all benefited from this procedure with improved arterial flow documented by transcranial Doppler ultrasonography and arteriography. In 15 patients angiography disclosed complete cure of the dissection. One patient with a long dissection of extracranial origin extending intracranially had proximal occlusion of the dissection site. Follow-up angiography demonstrated healing of the vertebral artery dissection but persistent filling of the artery above the balloons, which underscores the need for embolic occlusion near the dissection site. No hemorrhages recurred. One patient had a second SAH at the time of therapy which was immediately controlled with balloons and coils. This patient and one other had minor neurological worsening resulting from the procedure (mild Wallenberg syndrome in one and minor ataxia in the second). Symptomatic vertebral artery dissections involving the intradural and extradural segments can be effectively managed by endovascular techniques. Balloon test occlusion and transluminal angioplasty can be useful adjuncts in the management of this disease.

Adult↗
PubMed1993

Thyrotropin-producing pituitary adenomas.

To evaluate the biology of thyrotropin (TSH)-producing pituitary adenomas, the authors reviewed the charts of 19 patients who underwent transsphenoidal surgery within a 15-year period at the University of California, San Francisco (UCSF). Between 1989 and 1991, the period during which immunostaining techniques were used consistently for diagnosis, 2.8% of the pituitary adenomas treated at UCSF were TSH-producing. The rate of reoperation for tumor recurrence was 10.5%. Before pituitary surgery, more than one-third of the 19 patients had undergone thyroid ablation. Two patients had a history of Hashimoto's thyroiditis. The female:male ratio was 1.7:1. Women tended to develop these tumors at a younger age and had a longer history of symptoms but their tumors were smaller and less often invasive than those seen in men. About 50% of the tumors were purely TSH-producing and 50% were plurihormonal, including five that produced both TSH and adrenocorticotroph hormone. All tumors were macroadenomas. Before surgery, 46% of the patients had abnormal electrocardiographic findings; 16% had a rapid onset of severe neurological conditions either before or after surgery. It is concluded that TSH-producing adenomas are more common in patients who undergo surgical treatment than was previously thought. In addition, they occur more frequently in women, have a different biology in women than in men, and tend to be associated with potentially life-threatening cardiovascular and neurological complications.

Adenoma↗
PubMed1992

Measurements of blood flow and exchanging water space in breast tumors using positron emission tomography: a rapid and noninvasive dynamic method.

A noninvasive dynamic method for the measurement of blood flow, using 15O-labeled water and positron emission tomography, has been developed and used to study 20 patients with breast carcinoma. The mean tumor flow was 29.8 +/- 17.0 (SE) ml/dl/min of tissue, while normal breast flow was 5.6 +/- 1.4 ml/dl/min of tissue. The exchanging water space of tissue known as the volume of distribution of the tracer (Vd) was also derived. This is defined as the volume of water in tissue that exchanges with a unit volume of water in arterial blood during the period of the study (7 min). The mean tumor Vd was 0.56 +/- 0.15 ml/ml while normal breast Vd was 0.14 +/- 0.05 ml/ml. The low value in normal breast is partly due to the high fat content of the tissue. The mean flow per unit of exchangeable volume was similar in tumor (52.8 +/- 22.0) and normal breast tissue (45.2 +/- 20.0). This suggests that the major discrepancy seen in measured values of flow between breast tumors and normal breast principally reflects the different composition of the two tissues. This method is rapid and suited for studying the reactivity of human tumor vasculature, so extending studies are being performed on animal tumors.

Adult↗
PubMed1992

Cell kinetic analysis of human brain tumors by in situ double labelling with bromodeoxyuridine and iododeoxyuridine.

Fifty-seven patients with brain tumors (29 gliomas, 23 meningiomas, 5 miscellaneous) received infusions of intravenous iododeoxyuridine (IUdR) and bromodeoxyuridine (BUdR) 1-5 hr apart shortly before tumor removal. Excised tumor specimens were stained sequentially for BUdR and IUdR. The percentage of BUdR-labelled cells was determined to establish the labelling index (LI), or S-phase fraction, and the ratio of cells labelled only with IUdR to cells labelled with BUdR or with BUdR and IUdR was determined to calculate the duration of S-phase (Ts) and the potential doubling time (Tp) of each tumor. The BUdR LIs varied from less than 1% to 20%, reflecting the malignancy of each tumor. Despite the difference in LIs, however, Ts was fairly uniform (mean +/- SD, 8.7 +/- 2.0 hr). Tp varied from 2 days to more than 1 month and correlated closely with the BUdR LIs (Tp = 23/LI0.93; r2 = 0.91). Double-labelling studies with IUdR and BUdR allow the S-phase fraction, Ts and Tp to be determined from a single biopsy specimen and thus provide more useful information on the growth characteristics of individual tumors than can be obtained by single-labelling studies with BUdR.

Brain Neoplasms↗
PubMed1992

Histochemical study of pituitary adenomas with Ki-67 and anti-DNA polymerase alpha monoclonal antibodies, bromodeoxyuridine labeling, and nucleolar organizer region counts.

The growth potential of 65 pituitary adenomas was determined by histochemical analysis with Ki-67 and anti-DNA polymerase alpha monoclonal antibodies, bromodeoxyuridine (BrdUdR) labeling, and counts of argyrophilic nucleolar organizer regions (Ag-NORs). The mean proliferating cell indices (PCIs) determined by Ki-67 and anti-DNA polymerase alpha and the BrdUdR labeling index (LI) were generally very low [1.0 +/- 0.2%, 1.1 +/- 0.2%, and 0.5 +/- 0.1% (+/- SE), respectively]. Apart from adrenocorticotropic hormone-positive adenomas, which had significantly higher indices, there were no statistically significant differences in the indices among the other subtypes of pituitary adenomas. Recurrent tumors had higher Ki-67 and DNA polymerase alpha PCIs and BrdUdR LIs (3.6%, 4.2%, 1.4%) than primary tumors (0.8%, 0.8%, 0.3%; P less than 0.005). The number of Ag-NORs did not correlate significantly with any of the three indices. The mean number of Ag-NORs was higher in nonfunctioning adenomas than in functioning adenomas (2.04 vs 1.66, P less than 0.005); among prolactin-positive adenomas, those treated preoperatively with bromocriptine had more Ag-NORs than untreated tumors (1.75 vs 1.57, P less than 0.005). These results suggest that the Ki-67 and DNA polymerase alpha PCIs and the BrdUdR LI predict the growth potential of individual pituitary adenomas, whereas the number of Ag-NORs appears to correlate with hormone production rather than with the proliferative potential.

Adenoma↗
PubMed1992

Highly anaplastic astrocytoma: a review of 357 patients treated between 1977 and 1989.

Between May 1977 and August 1989, 357 patients (199 male, 158 female; median age 40 years) with highly anaplastic astrocytomas other than glioblastoma multiforme were treated according to any of several protocols used in studies by the University of California, San Francisco, and the Northern California Oncology Group. The data evaluated were age, Karnofsky Performance Score, survival, time to tumor progression, therapy, and the effect of treatment at the time of progression. The records of 219 patients were taken from the University of California database, and those of the other 138 were taken from the Northern California Oncology Group computer files. Their median Karnofsky Performance Score was 90% (range 40-100%), the overall median survival was projected as 170.9 weeks, and the median time to first tumor progression was 127.3 weeks. The median survival time measured after the first progression was 41.3 weeks. Age and Karnofsky Performance Score had a significant influence on survival and on time to the first tumor progression, whereas extent of surgery and the use of interstitial brachytherapy in the initial therapy did not. We conclude that these patients can expect a median survival of over 3 years, that young age and high Karnofsky Performance Score have a positive influence on survival, and that salvage therapies can extend survival after the onset of tumor progression for nearly a year. Although it did not lengthen survival when used in initial therapy, interstitial brachytherapy used at the time of tumor progression was associated with increased survival.

Adolescent↗
PubMed1992

Re-irradiation of pituitary adenoma.

Fifteen patients initially irradiated for pituitary adenoma were subsequently treated with a second course of radiotherapy at the University of California at San Francisco between 1961 and 1989. The re-irradiation followed surgery in all but two cases. The median time to recurrence was 9 years (range 2-17) and median follow-up after the second course of radiotherapy was 10 years (range 1-30). The median initial radiation dose was 4084 cGy; that at recurrence was 4200 cGy. Local control has been maintained in 12 patients. One failed locally with a benign adenoma that was surgically salvaged. Two developed pituitary carcinomas which were poorly controlled. Of the patients who presented with visual abnormalities at the time of recurrence, 50% improved and the remainder stabilized after re-irradiation. There are no long-term visual complications. Hypopituitarism was present in nine patients prior to the second course of radiotherapy and developed in the remaining six patients after re-irradiation. Temporal lobe injury was seen in two patients. Careful analysis of each patient's pituitary and temporal lobe doses, intervals between treatments, treatment volume, neurets, relative decay factors, absolute decay factors, TDF and modified LQF values, and dose-volume relationships, revealed no correlation with complication or likelihood of local control. Repeat radiotherapy for recurrent pituitary adenoma with the doses used in these patients appears to carry acceptable risk with good local control.

Adenoma↗
PubMed1992

Interstitial brachytherapy for newly diagnosed patients with malignant gliomas: the UCSF experience.

Although interstitial brachytherapy appears to be effective in treating recurrent malignant gliomas, it has been studied less extensively in patients with newly diagnosed tumors. To examine the effect of this treatment when used at the time of primary diagnosis, we retrospectively reviewed the records of 88 patients who received temporary interstitial implants of 125I for newly diagnosed malignant gliomas. This brachytherapy was preceded by a course of external radiation therapy and followed, in some cases, by chemotherapy. The median duration of survival after the beginning of external radiation therapy was 87 weeks in patients with glioblastoma multiforme and 160 weeks in those with anaplastic gliomas. In 46% of patients with glioblastoma multiforme and 56% of those with anaplastic gliomas, a second operation was necessary to remove symptomatic radiation necrosis, recurrent tumor, or both. Our results support the conclusion that interstitial brachytherapy used at the primary diagnosis lengthens survival in selected patients with glioblastoma multiforme. However, the toxicity is significant in terms of the need for surgical resection of symptomatic necrosis. In patients with anaplastic gliomas, the toxicity associated with the treatment probably outweighs its advantages.

Adolescent↗
PubMed1992

The effect of type-specific polysaccharide capsule on the clearance of group B streptococci from the lungs of infant and adult rats.

To study the importance of the type-specific polysaccharide capsule of group B streptococci (GBS) in the pathogenesis of lung infections, bacterial clearance rates and lung cellular responses to encapsulated and unencapsulated variants of types III and Ia GBS strains were investigated in rats. Bacteria were instilled by direct intratracheal inoculation to simulate aspiration during parturition. Neonates failed to eliminate encapsulated or unencapsulated GBS strains within 6 h of inoculation, whereas adults cleared greater than 90% of each strain within 6 h. Neutrophils accumulated rapidly in the lungs of neonates and adults in response to all GBS strains. Immediately after inoculation, neonatal alveolar macrophages contained fewer encapsulated GBS than did adult alveolar macrophages and fewer encapsulated than unencapsulated GBS, suggesting that the capsule impairs the initial phagocytosis of GBS in the lungs of neonates. Animal age was a more important determinant of bacterial elimination from the lung than the type-specific GBS capsule. However, both age and the bacterial capsule were important determinants of systemic dissemination.

Animals↗
PubMed1992

Diminished interferon-gamma and lymphocyte proliferation in neonatal and postpartum primary herpes simplex virus infection.

Interferon (IFN)-gamma and tumor necrosis factor (TNF)-alpha production and lymphocyte proliferation in response to herpes simplex virus (HSV) antigen were assessed in 13 neonates and 3 parturient women with primary HSV infection. In comparison with 9 nonparturient adults, the neonates and parturient women showed significantly (P less than .01) diminished HSV antigen-stimulated lymphocyte proliferation and IFN-gamma production in the first 3-6 weeks after onset of infection. TNF alpha production did not differ significantly among HSV-infected groups. The impairment in neonatal cellular immunity was due, at least in part, to a specific deficit in response to HSV antigen. Lymphocyte proliferation and TNF alpha production in response to the mitogen concanavalin A (ConA) were comparable in adults and infants, but ConA-stimulated IFN-gamma production in infants was diminished throughout the study period. In contrast, HSV antigen-stimulated IFN-gamma production was comparable in infants and adults after 6 weeks. Not all patients with diminished cellular immune responses to HSV antigen manifested severe clinical disease. Nevertheless, patients with significant clinical morbidity had diminished cellular immune responses to HSV antigen. These results suggest that delayed acquisition of antigen-specific cellular immunity in primary HSV infection predisposes to more severe clinical disease.

Antibodies, Viral↗
PubMed1992

Advances in diagnostic techniques of pituitary tumors and prolactinomas.

The main advances in the diagnostic evaluation of pituitary tumors and prolactinomas have been in the areas of improved magnetic resonance techniques and in the use of inferior petrosal sinus sampling. New dynamic techniques of rapid acquisition magnetic resonance imaging during bolus contrast infusion have improved the sensitivity for the diagnosis of the small microadenoma. The development of three-dimensional volume imaging has also led to a further improvement in sensitivity to small lesions of the sella. The measurement of adrenocorticotropin levels in the inferior petrosal sinus in patients with Cushing's syndrome assists in the differentiation of adrenocorticotropin-secreting pituitary tumor from other peripheral causes of the syndrome. The use of corticotropin-releasing hormone concomitant with sampling has proven to be of value in improving sensitivity and specificity. Elevated levels of growth hormone in petrosal sinus sampling have also been shown to be valuable in the early diagnosis of acromegaly when peripheral hormone levels and imaging are nondiagnostic.

Adenoma↗
PubMed1992

Decreased granulocyte-macrophage colony-stimulating factor production by human neonatal blood mononuclear cells and T cells.

Impaired production and delivery of neutrophils to the site of infection have been implicated in the increased susceptibility of the neonate to infection. Because granulocyte-macrophage colony-stimulating factor (GM-CSF) and granulocyte colony-stimulating factor (G-CSF) play critical roles in the production of neutrophils from marrow precursors, we assessed the ability of leukocytes from neonates and adults to produce GM-CSF, G-CSF, and, for comparison, macrophage colony-stimulating factor (M-CSF) after stimulation with concanavalin A +/- phorbol myristate acetate [blood mononuclear cells (MC) and T lymphocytes] or lipopolysaccharide (monocytes). MC and monocytes from adult and neonatal subjects produced mRNA for GM-CSF, G-CSF, and M-CSF, whereas T cells produced only GM-CSF mRNA. Neonatal MC and T cells accumulated only approximately 30% as much GM-CSF mRNA as did adult MC and T cells. In contrast, the accumulation of GM-CSF mRNA by neonatal and adult monocytes was similar. Neonatal MC also accumulated similar amounts of G-CSF mRNA and somewhat more M-CSF mRNA than did adult MC; results with monocytes were similar to those with MC. Results of colony-stimulating activity bioassays on supernatants from neonatal and adult MC stimulated with concanavalin A paralleled the mRNA results.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗