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.

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)

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.

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.

Radiologic characteristics and results of surgical management of Rathke's cysts in 43 patients

Although Rathke's cysts are a relatively common autopsy finding, rarely have they been reported as a clinical entity. Because of recent improvements in neuroradiological imaging, cystic intrasellar and suprasellar lesions are discovered often, leading to questions about proper management. Against this background, we reviewed the data from 43 patients with Rathke's cysts treated by one neurosurgeon over a 13-year period, and present the results here. The 43 patients had a mean age of 34 years, and 77% were female. Headache was the most common symptom, followed by galactorrhea, visual field loss, and hypopituitarism. Computed tomographic (CT) scans were reviewed in 20 cases, magnetic resonance (MR) images were reviewed in 15, and both CT and MR studies were reviewed in 5 cases. Although all Rathke's cysts were discrete and well-defined by both CT and MR imaging, the diversity of locations, CT attenuations, and MR signal intensity make it difficult to establish the diagnosis by radiological criteria. Forty patients underwent transsphenoidal surgery and three underwent craniotomy. There was one recurrence at 25 months requiring a second operation, and the mean follow-up period was 62 months. Seven patients had persistent headaches. For symptomatic lesions suspected to be Rathke's cysts, the recommended treatment is simple drainage of the cyst with biopsy of the wall, when this can be done safely. Follow-up imaging should be minimal for asymptomatic patients, and radiation therapy is not indicated.

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.

Late manifestations of esthesioneuroblastomas in the central nervous system: report of two cases

Two patients with esthesioneuroblastomas that disseminated in the central nervous system (CNS) and elsewhere are reported. The latest recurrences in the CNS were 19 years after the diagnosis in patient and 9 years after the diagnosis in the other. Because the treatment of patients with such late recurrences is complicated by previous surgical procedures and radiation therapy, we review therapeutic options for these patients. The literature has not previously stressed the occurrence of late metastases, including those to the CNS, after prolonged disease-free intervals.

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.

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.

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.

Evaluation of multiple reticulorumen selenium pellets as a health risk in growing Hereford steers

Five groups of Hereford steers were monitored for 293 days. One group of 3 was not given selenium supplementation; the other 4 groups of 3 steers each were given 2, 4, 6, or 8 reticulorumen selenium pellets. Health, body weight, and blood selenium concentration were monitored during the study. At the finish, steers were slaughtered, and various tissues from the carcasses were analyzed for selenium content. Initial blood selenium concentration did not differ significantly among groups. However, significant (alpha = 0.01) difference among means was detected during the early period of rapid increase in blood selenium concentration in steers of supplemented groups. Means of maximal blood selenium concentration also differed among groups; however, even the highest value, 0.253 micrograms/g, was lower than the 3 micrograms/ml reported in chronic clinical cases of toxicosis in the literature. Carcass analysis indicated significant (alpha = 0.05) differences in selenium concentrations among treatment groups for almost all tissues tested. Only kidney samples (7.9 micrograms/g) from steers of the 8-pellet treatment group exceeded published normal values (7.6 micrograms/g). Health variables for most dates were not significantly different among groups, and selenium toxicosis was not evident in any steer. Analysis did not indicate risk to human beings consuming tissues from these steers.

Effect of mesangial cell lysis and proliferation on glomerular hemodynamics in the rat

To elucidate an involvement of mesangial cells in the regulation of glomerular hemodynamics, renal micropuncture techniques and glomerular morphometry were employed in Munich-Wistar rats with mesangial cell lytic or proliferative lesions induced by administration of an antibody reactive with Thy-1.1-like antigens on the mesangial cell surface. The antibody-induced mesangial cell lysis at day 1 resulted in a significant decrease in glomerular ultrafiltration coefficient, leading to reduction in single nephron glomerular filtration rate (SNGFR) in spite of a significant increase in both glomerular hydrostatic pressure and single nephron plasma flow (SNPF). During the antibody-induced proliferative lesion at day 6, glomerular ultrafiltration coefficient and SNGFR remained reduced; however, SNPF was now decreased. Morphometric analysis showed the enlargement of capillary luminal volume and the development of new open space in the mesangium accessible for blood flow in the mesangial cell-lytic glomeruli at day 1. An increase in mesangial cell volume was found in the proliferative glomeruli at day 6. The total area of peripheral glomerular basement membrane, presumed as the probable filtration area, was unchanged in these glomeruli. These results indicate that mesangial lesions decrease glomerular ultrafiltration coefficient, and suggest that mesangial cells participate in regulation of glomerular filtration rate.

Evaluation of bromodeoxyuridine in glioblastoma multiforme: a Northern California Cancer Center Phase II study

In a study activated in 1983 and closed in 1987, the Brain Tumor Research Center of the University of California and the Northern California Cancer Center evaluated the effect of bromodeoxyuridine in the treatment of glioblastoma multiforme. A total of 160 patients were evaluable of 173 entered. Patients were to receive a bromodeoxyuridine infusion of 0.8 g/m2 daily over 24 hours for 4 days of each of 6 weeks of radiotherapy directed to the tumor plus a margin delivering a total of 60 Gy. Eligibility requirements included Karnofsky performance status greater than or equal to 70, biopsy or resection and central pathology review by one of the authors. Following radiotherapy patients were to receive chemotherapy with procarbazine, CCNU, and vincristine for 1 year. Median survival was 55.7 weeks and time to failure, 34.5 weeks for the evaluable group of 160 patients. In a univariate analysis the variables that influence survival and time to failure were: age, Karnofsky performance status, bromodeoxyuridine dose and the delivery of at least one procarbazine, CCNU, and vincristine cycle following radiotherapy. In multivariate analysis, age, Karnofsky performance status, and bromodeoxyuridine dose remain significant for time to failure; age and Karnofsky performance status remain significant for survival.

Signal transduction in human alveolar macrophages: diminished chemotactic response to FMLP correlates with a diminished density of Gi proteins and FMLP receptors

Alveolar macrophages (AM) migrate less well in response to chemotactic ligands than do monocytes and neutrophils. The response of monocytes and neutrophils to chemotactic ligands is mediated at least in part by pertussis toxin-sensitive guanine nucleotide binding proteins (Gi proteins). Whether this is also true in AM is uncertain. We hypothesized that decreased chemotaxis by AM was due in part to diminished Gi protein and/or chemotactic receptor density in AM. G proteins are heterotrimers made up of alpha, beta, and gamma subunits; the predominant pertussis toxin-sensitive Gi proteins are those containing alpha i2 or alpha i3 subunits. Pertussis toxin pretreatment (0.5 microgram/ml) significantly reduced AM, monocyte, and neutrophil chemotaxis to N-formyl-L-methionyl-L-leucyl-L-phenylalanine (FMLP) and human zymosan-activated serum (P less than 0.05). However, as previously noted, AM chemotaxis was much less than that observed in monocytes and neutrophils. Immunoblots using antibodies that are specific for alpha i2 and alpha i3 showed that AM contained approximately 3-fold less alpha i2 and approximately 10-fold less alpha i3 per microgram of plasma membrane protein than did monocytes or neutrophils. Similar results were obtained in immunoblots made using antibodies to common alpha subunit determinants and to the beta 36 subunit. A comparable approximately 4-fold reduction in density of receptors for [3H]FMLP was found in AM compared to neutrophils. The diminished density of Gi proteins and FMLP receptors was not due to a generally decreased density of plasma membrane proteins in AM, since the density of the membrane-associated tyrosine kinase hck was similar in AM, monocytes, and neutrophils.(ABSTRACT TRUNCATED AT 250 WORDS)

Lymphocytic adenohypophysitis: a pituitary mass lesion occurring in pregnancy. Proposal for medical treatment

Lymphocytic adenohypophysitis is a nonneoplastic, autoimmune cause of pituitary enlargement and insufficiency. Forty-eight of the 50 reported cases have occurred in women, nearly all in association with pregnancy. Left undiagnosed and untreated, it can progress to pituitary insufficiency and death. Histologic studies show characteristic changes of autoimmune disease with lymphocytic infiltration and destruction of anterior pituitary tissue with fibrotic replacement. Lymphocytic adenohypophysitis is currently diagnosed after other pituitary mass lesions are excluded and has been treated with a combination of neurosurgery and end-organ hormone replacement. However, with improved knowledge of the pathophysiologic characteristics and natural history of the disease and with the ability to make a prospective diagnosis, we believe glucocorticoids may suppress the inflammatory response and protect remaining pituitary tissue. Two previously unreported pregnancy-associated cases are described, including one prospectively diagnosed and treated without neurosurgery during pregnancy. Obstetrician-gynecologists must place lymphocytic adenohypophysitis in the differential diagnosis of pituitary enlargement associated with pregnancy, since treatment is available and the sequelae may be life-threatening.

Magnetic resonance imaging of vertebrobasilar ectasia in tic convulsif. Case report

A patient with trigeminal neuralgia and hemifacial spasm was evaluated using multiplanar magnetic resonance (MR) imaging with gadolinium enhancement. Preoperative images demonstrated massively ectatic vertebral and basilar arteries and their distortion of the brain stem and the trigeminal and facial nerves. Surgical manipulation included selective trigeminal rhizotomy, cushioning of the residual nerve at the point of maximal distortion by the underlying basilar artery, and microvascular decompression of the seventh nerve from the anterior inferior cerebellar artery which was being pushed dorsomedially by the vertebral artery. Postoperatively, the patient had neither trigeminal neuralgia nor facial spasm. Gadolinium-enhanced MR imaging not only excludes other etiologies such as tumor or arteriovenous malformation, but also demonstrates cranial nerve compression by ectatic vertebral and basilar arteries. The choice of preoperative imaging modality is discussed and the literature concerning the etiology of tic convulsif is reviewed.

Differential regulation of lymphotoxin and tumor necrosis factor genes in human T lymphocytes

Lymphotoxin (LT) and tumor necrosis factor (TNF) are related cytokines that share many biological effects. The genes for LT and TNF are adjacent to each other on chromosome 6 in man, but previous data indicate that the kinetics of their production differ markedly. To explain the mechanisms for this difference, we compared the regulation of these two genes in human T lymphocytes, isolated from peripheral blood, after stimulation with the mitogens concanavalin A and phorbol myristate acetate. Differences in the kinetics of protein secretion were paralleled by differences in cognate mRNA accumulation. TNF mRNA accumulated rapidly after stimulation, peaked by 6 h, and returned to unstimulated (base-line) levels by 24 h. In contrast, LT mRNA accumulated slowly after stimulation, usually peaked at approximately 18 h, and remained increased above base-line levels at 48-72 h. By nuclear transcription run-on assays, increased transcription of TNF mRNA and LT mRNA was demonstrated after stimulation. However, TNF transcription peaked earlier and appeared to be 4-10 times greater than that of the LT gene. In contrast, the half-life of LT mRNA was 8-10-fold longer than that of TNF mRNA as demonstrated by actinomycin D pulse-chase experiments. Cycloheximide did not block LT or TNF mRNA accumulation, indicating that new protein synthesis was not required for induction of either gene. These results suggest strongly that the LT and TNF genes are regulated differently in human T lymphocytes after mitogen stimulation. TNF mRNA accumulates rapidly primarily because of increased transcription and decreases rapidly related to its brief half-life. In contrast, LT mRNA accumulates more slowly but persists much longer; the accumulation of this mRNA appears to be controlled largely by post-transcriptional mechanisms.

Low-dose craniospinal radiation therapy for medulloblastoma

At the University of California, San Francisco, 65 children with medulloblastoma of the posterior fossa were treated postoperatively with craniospinal irradiation; the dose to the posterior fossa was 54 Gy. The 26 children initially treated had only radiation therapy, receiving 30 to 40 Gy to the spine and 40 to 50 Gy to the brain. Subsequently, 39 children were treated with low-dose craniospinal irradiation and chemotherapy; 24 to 30 Gy was directed to the whole brain and 24 to 26 Gy to the spinal axis. Chemotherapy generally consisted of procarbazine just before, and hydroxyurea during, radiation therapy. Poor-risk and good-risk patients (defined by tumor resection less than 75% or greater than 75%, positive or negative myelogram, positive or negative cerebrospinal fluid analysis, age less than or greater than 2 years, respectively) were evenly distributed between the low-dose and high-dose craniospinal radiation therapy groups. Median follow-up was 51 months (range, 24 to 228 months). Kaplan-Meier actuarial survival for all patients was 73% at 5 years, 70% at 10 years. Freedom from disease progression was 68% at 5 years, 65% at 10 years. Whereas poor-risk patients treated with low-dose craniospinal irradiation and chemotherapy had a 5-year survival of 58% and a 5-year freedom from disease progression of 39%, those figures in the comparable good-risk patients were 83% and 77%, respectively. For both good-risk and poor-risk patients, the posterior fossa was the primary site of recurrence. Tumors recurred in the frontal region, probably under blocks, in three patients receiving low-dose irradiation and in two receiving the higher dose. Reducing the dose of whole-brain and spinal irradiation and giving chemotherapy did not result in a higher rate of recurrence in the brain or spinal cord. Intellectual and social function appeared better in patients receiving the lower dose. We did not study whether chemotherapy benefitted good-risk patients. Craniospinal axis irradiation at a lower dose than conventionally used does not compromise local control or survival in patients with medulloblastoma, and may reduce toxicity.

Quantitative measurement of monoclonal antibody distribution and blood flow using positron emission tomography and 124iodine in patients with breast cancer

The uptake and in vivo quantitation of monoclonal antibodies (MAbs) has been measured non-invasively using positron emission tomography (PET) and 124iodine in 9 patients with breast ductal carcinoma. Blood-flow measurements were also made using 15oxygen-labelled water and PET to evaluate antibody delivery; 7 patients were studied with HMFGI antibody and 2 patients with a non-specific antibody. Tumour uptake ranged from 2-7.7 x 10(-3)% of injected dose per gram of tissue. Values for normal tissues including liver, lung and bone were also obtained. In 2 out of 7 patients studied with the specific antibody, uptake was greater than that seen with the non-specific antibody. There was no correlation between antibody uptake and blood flow. This report exemplifies the potential of PET for the non-invasive and accurate quantitative assessment of targeted antibody which is a prerequisite to therapy.

A variant of arteriovenous fistulas within the wall of dural sinuses. Results of combined surgical and endovascular therapy

Dural arteriovenous (AV) fistulas are thought to be acquired lesions that form in an area of thrombosis within a sinus. If the sinus remains completely thrombosed, venous drainage from these lesions occurs through cortical veins, or, if the sinus is open, venous drainage is usually into the involved sinus. Among 105 patients with dural AV fistulas evaluated over the the past 5 years, seven had a unique type of dural AV fistula in the superior sagittal, transverse, or straight sinus in which only cortical venous drainage occurred despite a patent involved sinus; the fistula was located within the wall of a patent dural sinus, but outflow was not into the involved sinus. This variant of dural AV fistulas puts the patient at serious risk for hemorrhage or neurological dysfunction caused by venous hypertension. Three patients presented with hemorrhage, one with progressive neurological dysfunction, one with seizures, and two with bruit and headaches. A combination of surgical and endovascular techniques was used to close the fistula while preserving flow through the sinus.

Epidermoid cysts of the brain stem. Report of three cases

The authors report the cases of three patients with epidermoid cysts which insinuated themselves into the brain stem. In all three patients, the tumor occupied the pons, although in one it was predominantly located in the medulla. The cyst contents and nonadherent tumor capsule were removed in all three patients, but no attempt was made to remove tumor densely adherent to the brain stem. One patient's cyst was removed in one operation, but maximal resection in the other two required two operations. After surgery, sixth nerve function completely returned in one patient; another patient had a stable pontine gaze palsy but developed new facial weakness; and the third patient had stable cranial nerve deficits with a diminished hemiparesis. The last patient developed a pseudomeningocele and communicating hydrocephalus, and required a lumboperitoneal shunt. In all three patients, computerized tomography scans demonstrated hypodense tumors not enhanced by contrast material. Magnetic resonance imaging was performed on two patients; in both, the tumors showed increased signal intensity relative to brain on T1-weighted images and decreased signal intensity relative to brain on T2-weighted studies. Magnetic resonance imaging, the most accurate modality for localizing these lesions and determining their extent, was also invaluable for postoperative monitoring and follow-up evaluation. Safe and adequate resection includes decompression of cyst contents and removal of nonadherent portions of the cyst capsule. Cyst wall adherent to the brain stem, however, should not be removed.

Multiple dural arteriovenous fistulas of the cranium and spine

Dural arteriovenous fistulas are acquired lesions that usually involve the dura around the cavernous sinus. The transverse, sigmoid, and superior sagittal sinuses may be affected occasionally. With the exception of bilateral cavernous sinus dural arteriovenous fistulas, the simultaneous occurrence of dural arteriovenous fistulas at two locations is rare. Among 105 patients evaluated for dural arteriovenous fistulas, we identified seven patients with fistulas at two sites. The age of the patients ranged from 27 to 74 years. Presentation was related to hemorrhage in three patients, loss of vision in four, and a bruit and headaches in one. Patients were treated with combined surgical and endovascular techniques. All treated lesions were completely closed with no mortality or permanent morbidity. The presence of multiple fistulas must be considered in patients being evaluated for dural arteriovenous fistulas. Patients with multiple fistulas usually present with life-threatening hemorrhages or acute neurologic decline; the risk factor for hemorrhages, including those related to venous outflow obstruction, is high in patients with multiple dural arteriovenous fistulas.

Unilateral hydrocephalus in adults

The authors report 14 cases of unilateral hydrocephalus in adults. Headache was the most common presenting symptom. Unilateral hydrocephalus was documented in each patient with computed tomography scans; magnetic resonance imaging was also used in seven patients in the latter part of the series. Unilateral hydrocephalus was caused by tumor (seven patients), venous angioma (one patient), ependymal cyst (one patient), postinflammatory gliosis (one patient), and was idiopathic in four patients. The primary surgical treatment was craniotomy with fenestration of the septum pellucidum, which relieved symptoms in eight of nine patients for whom long-term follow-up data were available.

Cellular and molecular mechanisms for reduced interleukin 4 and interferon-gamma production by neonatal T cells

The mechanisms by which T lymphocytes acquire the capacity to produce interleukin 4 (IL-4) and other lymphokines during intrathymic and extrathymic development are poorly understood. To gain insight into this process, we determined the capacity of human neonatal and adult T lineage cell populations to produce IL-4 after polyclonal activation. IL-2 and interferon-gamma (IFN-gamma) production were studied in parallel, since their production by neonatal T cells is known to be similar or diminished, respectively, compared to adult T cells. Production of IL-4 by neonatal CD4+ T cells and IFN-gamma by neonatal CD4+ and CD8+ T cells was markedly lower compared with analogous adult cell populations, whereas IL-2 production was similar. Transcription of IL-4, as determined by nuclear run-on assays, and IL-4 mRNA-containing cells, as determined by in situ hybridization, were undetectable in neonatal T cells, whereas both were detectable in adult T cells. IFN-gamma transcription and IFN-gamma mRNA-containing cells were reduced in neonatal T cells compared with adult T cells. Reduced lymphokine production by neonatal T cells correlated with their lack of a CD45R- (putative memory T cell) population; cells with this surface phenotype comprised 30-40% of the adult CD4+ T cells and were highly enriched for IL-4 and IFN-gamma, but not IL-2 production. IL-4, IFN-gamma, and IL-2 mRNA expression by neonatal CD4+CD8- thymocytes was similar to that found in circulating neonatal CD4+ T cells. Taken together, these findings suggest that the extrathymic generation of memory T cells during postnatal life may result in an increased capacity for IL-4 and IFN-gamma gene expression. In addition, IFN-gamma and IL-2 mRNA were significantly more abundant than IL-4 mRNA in activated neonatal CD4+CD8- thymocytes and CD4+ T cells, as well as adult CD4+ CD45R- T cells. Therefore, the capacity of T lineage cells to express the IL-4 gene may be more restricted compared to other lymphokine genes beginning in intrathymic development. This restricted capacity appears to persist during postnatal extrathymic maturation of T cells.

Nitrous oxide and epinephrine-induced arrhythmias

We asked whether the sympathomimetic effect of nitrous oxide (N2O) predisposed patients receiving N2O to arrhythmias in response to epinephrine administration. We also asked whether aging contributed to the development of arrhythmias, with or without N2O. One hundred patients having transsphenoidal hypophysectomy were randomly assigned to receive anesthesia including (n = 49) or excluding (n = 51) N2O. All patients were given an injection of epinephrine 1:200,000, with 0.5% lidocaine to produce hemostasis. Using intermittent 12-lead and continuous lead II electrocardiography, we determined the incidence of premature ventricular contraction, isorhythmic atrioventricular (AV) dissociation, and changes in T-wave morphology. Patients given N2O had a significantly higher incidence of isorhythmic AV dissociation (61.2% vs 41.2%). A trend toward a higher incidence of multiple premature ventricular contractions (16.3% vs 7.8%) was not statistically significant. Both anesthetic groups had a high incidence of postoperative changes in T-wave morphology (46.9% in the N2O group vs 50.9% in the group not given N2O). Aging alone did not affect the incidence of ventricular ectopic beats, isorhythmic AV dissociation, or changes in electrocardiographic morphology, but correlated with the development of ventricular ectopy during N2O anesthesia. We conclude that the use of N2O correlated with a higher incidence of isorhythmic AV dissociation in response to injection of epinephrine with lidocaine.

Aneurysm mimicking intracranial growth of optic nerve sheath meningioma

A patient with a 30-year history of blindness in the right eye developed progressive temporal visual loss in the left eye. Examination showed right optic atrophy with optociliary shunts and left band atrophy. These clinical findings suggested that the visual deficit was caused by a right optic nerve sheath meningioma that had grown intracranially to involve the chiasm. Magnetic resonance imaging and surgical exploration revealed a perioptic meningioma extending from the orbit through the optic canal and over the tuberculum sellae. The tumor did not impinge on the optic chiasm or the left optic nerve. The chiasm was compressed by a thrombosed giant right internal carotid artery aneurysm.

Modulation of in vitro monocyte cytokine responses to Leishmania donovani. Interferon-gamma prevents parasite-induced inhibition of interleukin 1 production and primes monocytes to respond to Leishmania by producing both tumor necrosis factor-alpha and interleukin 1

Cytokines produced by mononuclear cells are important regulatory and effector molecules and evidence has been presented to support a role at least for tumor necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma) in host defense against Leishmania. In the present study, we examined the production of TNF-alpha and interleukin 1 (IL-1) by resting and IFN-gamma-primed peripheral blood monocytes infected in vitro with Leishmania donovani. Monocytes produced neither IL-1 nor TNF-alpha during challenge with Leishmania. Cells preinfected with Leishmania synthesized normal amounts of TNF-alpha, but had diminished production of IL-1 in response to stimulation with either S. aureus or lipopolysaccharide (LPS). The induction by S. aureus or LPS of IL-1 beta mRNA accumulation in infected cells was normal despite diminished intracellular or supernatant IL-1 protein and bioactivity. Thus, inhibition of IL-1 production by Leishmania most probably reflected diminished translation of IL-1 beta mRNA. Pretreatment of cells with IFN-gamma abrogated infection-induced inhibition of IL-1 production and primed cells for the production of both IL-1 and TNF-alpha upon subsequent exposure to Leishmania. These results indicate that L. donovani has evolved the capacity to infect mononuclear phagocytes, without stimulating the production of two potentially host-protective monokines. The ability of IFN-gamma to prime monocytes to produce TNF-alpha and IL-1 in response to infection with Leishmania and to prevent inhibition of IL-1 production may have implications for immunotherapy with this lymphokine.

Dural arteriovenous fistulas supplied by ethmoidal arteries

Eight patients with dural arteriovenous fistulas (DAVFs) located on the floor of the anterior cranial fossa and supplied by enlarged ethmoidal branches of the ophthalmic artery are described. Five patients showed the classical symptom of intracerebral hemorrhage (all five had ipsilateral frontal lobe hematomas and one also had an associated a subdural hematoma). Two patients exhibited atypical symptoms of proptosis, chemosis, elevated intraocular pressure, and loss of vision secondary to an ethmoidal DAVF, which drained posteriorly to the cavernous sinus. The eighth patient exhibited proptosis and chemosis secondary to a cavernous sinus DAVF and was incidentally found to have an asymptomatic ethmoidal DAVF. One additional patient had two separate dural fistulas: one located on the cribriform plate and the second located in the posterior fossa. Seven of the eight patients were cured by surgical excision of the fistula site; in the remaining patient spontaneous obliteration followed a surgical procedure for a cavernous DAVF. DAVFs involving the floor of the anterior cranial fossa usually present with hemorrhage, but can present with ocular symptoms or be entirely asymptomatic and are effectively treated by surgical excision of the fistula site.

Basis and implications of selectively diminished cytokine production in neonatal susceptibility to infection

The human neonate is unduly susceptible to infection with viruses and other pathogens, such as Toxoplasma and Listeria, that survive and replicate within cells. Cellular immunity is the major mechanism of host defense against these intracellular pathogens. Selective immaturity in certain functions of T lymphocytes appears to be a major factor in the neonate's susceptibility to these infections. Particularly striking is the deficiency in production of interferon-gamma. We review the data regarding the deficiency in the production of interferon-gamma by cells of healthy and infected neonates, discuss what is known regarding the cellular and molecular mechanisms for this deficiency, and review the unique role played by interferon-gamma in host defense against intracellular pathogens. The response of the neonate's effector cells to the immunoenhancing effects of interferon-gamma appears to be variable; diminished enhancement by interferon-gamma of cytotoxic cell function and the production of tumor necrosis factor by macrophages may further compound the effects of diminished production of interferon-gamma.

Cerebrospinal fluid rhinorrhea in patients with untreated pituitary adenoma: report of two cases

We report the cases of two patients with untreated pituitary adenoma who presented with cerebrospinal fluid rhinorrhea. The surgical treatment and mechanisms involved in this rare condition are discussed.

Management of dural arteriovenous malformations of the anterior cranial fossa

Eight patients with dural arteriovenous malformations (AVM's) of the anterior cranial fossa are presented, and the pertinent literature is reviewed. Unlike cases of dural AVM's in other locations, sudden massive intracerebral hemorrhage was the most frequent reason for presentation. Other symptoms included tinnitus, retro-orbital headache, and a generalized seizure. The malformations were supplied consistently by the anterior ethmoidal artery, usually in combination with other less prominent feeding vessels. The lesion's venous drainage was through the superior sagittal sinus via a cortical vein; in addition, in two cases a subfrontal vein drained the AVM. A venous aneurysm was encountered near the site of anastomosis with the dural feeder in most cases, and was found in all patients who presented with hemorrhage. The AVM was obliterated surgically in six patients, with favorable results achieved in five. One patient died postoperatively from a pulmonary complication. Because of their anatomy and proclivity for hemorrhage, these vascular malformations represent a unique group of dural AVM's. Surgical management of anterior fossa dural AVM's carries low morbidity, and is indicated when the lesions have caused hemorrhage or when there is an associated venous aneurysm.

Unilateral hydrocephalus caused by an intraventricular venous malformation obstructing the foramen of Monro

Unilateral hydrocephalus in an adult was caused by obstruction of the left foramen of Monro by an intraventricular venous malformation. Magnetic resonance imaging of the region of the foramen of Monro demonstrated the lesion, which subsequently was confirmed to be a venous malformation by angiography and surgery.

The treatment of medulloblastoma. Results of a prospective randomized trial of radiation therapy with and without CCNU, vincristine, and prednisone

In a prospective randomized trial designed to study the effectiveness of adjuvant chemotherapy following standard surgical treatment and radiation therapy, 233 eligible patients with medulloblastoma were treated by members of the Children's Cancer Study Group and the Radiation Therapy Oncology Group. Eligible patients were randomly assigned to receive radiation therapy with or without adjuvant chemotherapy consisting of 1-(2-chloroethyl)-3-cyclohexyl-nitrosourea (CCNU), vincristine, and prednisone. The estimated 5-year event-free survival probability was 59% for patients treated with radiation therapy and chemotherapy and 50% for patients treated with radiation therapy alone, a difference which is not statistically significant. The 5-year survival probability was 65% for both groups. Although the treatment difference was not statistically significant when all patients were combined, in the small number of patients with more extensive tumors, event-free survival was better in the group receiving chemotherapy (48% vs. 0%, p = 0.006). In these latter patients the survival time is also significantly prolonged. Extent of disease (as measured by the M staging criteria described by Chang) and age at diagnosis were significantly associated with outcome; advanced disease and young age had a worse prognosis. The extent of tumor resection was not an independent prognostic factor. It is concluded that chemotherapy does not benefit patients with low-stage medulloblastoma, but may benefit those with more advanced stages of disease.

Radiation-induced bilateral cystic temporal lobe necrosis: reversal of memory deficit after fenestration and internal shunting. Case report

The authors report a case in which bilateral cystic temporal lobe necrosis developed after treatment of nasopharyngeal lymphoepithelioma with 7000 cGy of external beam radiation. The patient presented with an isolated memory deficit that was documented by neuropsychological testing. After fenestration and internal shunting of both cysts, there was striking resolution of the lesions and of the memory deficit.

Cryptic vascular malformations of the spinal cord: diagnosis by magnetic resonance imaging and outcome of surgery

The cases of seven patients with intramedullary, cryptic vascular malformations of the spinal cord are reported. In all patients, the clinical course was progressive; a Brown-Séquard syndrome was the most common presenting symptom complex. Magnetic resonance (MR) imaging was performed in all patients. The pattern seen most often was a focus of high signal (on both T1- and T2-weighted MR images) surrounded by a larger zone of low signal (best seen on T2-weighted images), and was remarkably similar for all patients. Six patients underwent surgical exploration; removal of the lesions halted the progression of symptoms in five patients, and one patient had worsened sensory function after surgery. Motor function did not decrease postoperatively in any patient. The one patient who refused surgery has continued to decline neurologically. Histopathological examination of surgical specimens showed a cavernous malformation in one patient, a venous malformation in one, venous varices in two, and organizing hematomas in two; these findings are markedly different from those in previously reported cases of cryptic vascular malformations.