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Facial nerve intraparotid neuromas are rare. We report two cases with no facial paralysis. In the first case, the clinical protocol for the evaluation of a parotid mass did not suggest the intramastoid tumor extension. This extension was shown by CT and MRI and confirmed by gross and microscopic appearance. In the second case, no intrapretrous extension was observed with MRI. The diagnosis of neuroma was made during surgery. With a literature review, we discuss the diagnostic difficulties encountered in the investigation of parotid facial nerve tumors, emphasizing on the usefulness of CT and MRI in its diagnosis.

Rationale and Objectives: Nodal response to chemotherapy in head and neck squamous cell carcinoma depends on the vascularization. The authors assessed different techniques in detecting nodal vascularization., Methods: Fourteen patients with head and neck tumor were included before surgical treatment. The largest metastatic lymph node (mean axial scanographic diameters 30 x 20 mm) was studied by color and pulsed Doppler, and dynamic magnetic resonance images, processed by factor analysis of medical image sequences (FAMIS), which estimates physiologic contrast enhancement kinetics (factors) and their spatial distributions (factor images). Results were compared with the histologic microvessel density (MVD). Using light microscopy, MVD was estimated by the vascular surface (by staining endothelial cells) to the stroma surface ratio x 100., Results: Three factors were identified by FAMIS: a constant factor in necrosis, an earlier F1 factor and a later F2 factor in normal lymphoid areas and neoplastic stroma. Color flow signal was detected when the MVD was greater than 6.36., Conclusions: Only one model of vascularization was extracted by FAMIS, with no difference between neoplastic and spared lymphoid areas. The presence of color-flow signals could help predict the response of metastatic lymph nodes to chemotherapy.

The aim of this study was to establish the feasibility, evaluate the response rate, and assess the impact on local control and survival in locally advanced (bulky nodal) squamous cell carcinoma of the head and neck (SCCHN) patients treated with neoadjuvant chemotherapy consisting of cisplatin followed by continuous infusion of vindesine and fluorouracil with intermittent i.v. folinic acid. Eligibility criteria included histologically proven SCCHN, previously untreated locally advanced stage III-IV with measurable or evaluable disease, no distant metastases, an Eastern Cooperative Oncology Group (ECOG) performance status of less than 2, patient age of at least 18 years, and adequate bone marrow, hepatic, and renal functions. The protocol consisted of three cycles (day 1, day 21, day 42) of Cisplatin (CDDP) 100 mg/m2/day i.v. on day 1 immediately followed by 4 days (96 h) of continuous infusion of vindesine 0.8 mg/m2/day and 5-fluorouracil (5-FU) 600-700 mg/m2/day with folinic acid 150 mg/m2 i.v. every 6 h x 16 doses before locoregional treatment with radiotherapy preceded by radical surgery when appropriate. Twenty-nine patients were enrolled in this study, and 28 were evaluable for activity; an objective response rate of 55% (four complete responses, 12 partial responses) was achieved. Leukopenia and mucositis were the most frequent and severe toxicities. The addition of vindesine did not improve the activity of the CDDP-FU-folinic acid combination, but this may be partly because of the particularly poor prognosis of the present patient population, with 75% of stage IV bulky nodal disease (N2c-N3).

In the oral cavity and oropharynx, the predominant disease is cancer, which arises, in most cases, from the oral mucosa. Therefore, radiologists have a minor role in the detection of the disease but help to define the exact extent of the lesion and have an important role in therapeutic planning. Computed tomography and magnetic resonance imaging are the imaging modalities of choice. In the salivary glands, nonmodalities are numerous and include computed tomography, magnetic resonance imaging, sialography, sonography, and scintigraphy. The role of radiologists is to select the best study to determine the nature of the lesion and its extent and consequences. The choice of first study is primarily based on physical examination.

Purpose: To evaluate factor analysis of medical image sequences (FAMIS), a means whereby physiologic contrast enhancement kinetics, called factors, and their spatial distribution, termed factor images, are estimated after acquisition of dynamic MR images. The method is intended to recognize and characterize the different tissue kinetics automatically., Methods: This method was evaluated in a series of 22 patients with head and neck tumors. Eleven patients presented with a previously untreated lesion. Six were examined for tumor recurrence, previously treated by multiple therapies. Five patients had preoperative chemotherapy and underwent MR before and after chemotherapy. In all cases, MR images were correlated with surgical and pathologic data. MR examinations were performed on a 1.5-T unit with static sequences and dynamic sequences acquired after bolus injection of gadolinium and processed by FAMIS., Results: FAMIS was able to identify three factors representing contrast-enhancement kinetics and their associated factor images. The neoplastic component was associated with the earlier factor image, F1. Fibrosis and chemotherapy and/or radiation-induced changes were associated with the two later factors, F2 and F3. The limits of this method were highly vascularized tissues whose earlier factor was similar to that of neoplastic tissues (mucosae and salivary glands), patient motion, responsible for artifacts in FAMIS, and lesions of less than 5 mm., Conclusion: FAMIS of dynamic MR studies was useful for differentiating neoplastic tissue from tissue having undergone changes by chemotherapy and/or radiotherapy, but it did not improve the ability of MR to characterize neoplastic tissues in previously untreated patients.

Purpose: To develop a method for direct measurement, using anatomic specimens, of the precision of MR-guided stereotaxic location and to describe its application to a 1.5-T MR unit with a Leksell stereotaxic frame., Methods: Small pieces of gelfoam (1 X 1 X 1 mm), soaked in gadopentetate dimeglumine, were stereotaxically introduced into formalin-fixed human heads using a Leksell D (three experiments) or G (nine experiments) stereotaxic frame. The head and the frame were then introduced into a 1.5-T MR unit. The target coordinates (as set on the stereotaxic frame by one investigator) were then compared with the MR-determined stereotaxic coordinates (calculated independently by another investigator). The imprecisions Ex, Ey, and Ez in each direction were defined as the differences between the calculated and the chosen coordinates., Results: Regarding the three targets studied with the D frame, mean imprecision Ex was 1.08 +/- 0.50 mm (mean +/- SEM), Ey 0.83 +/- 0.58 mm, and Ez 0.75 +/- 0.25 mm. For the nine targets studied with the G frame, Ex was 0.48 +/- 0.17 mm, Ey 0.69 +/- 0.14 mm, and Ez 0.82 +/- 0.13 mm. Statistical analysis of the results showed no significant difference between Ex or Ey and half the size of a pixel, indicating that, in the axial plane, stereotaxic MR precision is limited only by pixel size. A statistically significant difference was observed in the coronal plane between Ez and half the size of a pixel, but it must be stressed that Ez remained smaller than 1 mm., Conclusion: MR-guided stereotaxic location can be used with confidence for most diagnostic, functional, and therapeutic procedures.

This prospective study was done to validate an earlier retrospective study demonstrating a relationship between complete response to chemotherapy and nodal density as estimated in contrasted computed tomography (CT scans) in head and neck squamous cell carcinoma (HNSCC). CT scans of 36 patients were evaluated by two radiologists blinded to therapeutic outcome. The density of the largest node (> 2 cm) was compared to that of nuchal muscles. A node was classified as hypodense if more than 33% of the nodal surface area consisted of hypodense zones. Density and nodal staging were related: 67% (10 of 15) of patients with N3 disease but only 29% (six of 21) with N1-N2 exhibited isodensity, p < 0.05. Complete response to chemotherapy was noted in 63% (10 of 16) of the isodense group but only in 15% (three of 20) of the hypodense group, p < 0.01. We believe that nodal density can be used for therapeutic decision-making in high nodal volume HNSCC.

The authors present three cases of histologically proved synovial sarcoma. CT is useful in assessing erosive or destructive changes in bone, and in demonstrating calcifications. MR characteristics are nonspecific; calcifications within these tumors can be missed on MR. MR can help to assess tumor extension, vascular invasion, and hemorrhage within the tumor.

Two cases of aneurysmal bone cyst of the jaws, one in the mandible and the other in the maxilla, are reported in young girls 7 and 15 years old. One was a primary lesion; the other was associated with fibrous dysplasia. In both cases CT and MR demonstrated characteristic fluid-fluid levels. The diagnosis was confirmed after biopsy and surgical resection of the lesions.

MR findings in four patients with MR evidence of congenital cystic dilatation of the ventriculus terminalis were reviewed retrospectively. The ventriculus terminalis is a small cavity of the conus medullaris that forms during embryonic development as result of canalization and retrogressive differentiation. The dilated ventriculus terminalis appears on MR images as a small ovoid cavity with regular margination; intralesional fluid resembles cerebrospinal fluid on all MR sequences. After injection of contrast material, MR imaging shows no enhancement of the cyst or its wall, and thus differentiates congenital dilatation of the ventriculus terminalis from cystic tumors, which occur more frequently in this region.

The therapy of colorectal cancer may be improved by biologic response modifiers that enhance natural killer (NK) cell and antibody-dependent tumoricidal mechanisms. This study examined the effect of a recently discovered cytokine purified from the supernatant of an Ebstein-Barr virus-transformed B-lymphoblastoid cell line (RPMI-8866), natural killer cell stimulatory factor (NKSF), on NK and antibody-dependent cellular cytotoxicity (ADCC) of human colon adenocarcinoma cell lines. Human peripheral blood lymphocytes were cultured for 24 hr in the presence or absence of NKSF (3.6 pM) or interleukin-2 (1 nM). The cultured lymphocytes were analyzed for lytic potential toward chromium-51-labeled colon carcinoma targets SW 1116, 498 LI, and WC 1. ADCC was measured by incubating chromium-51-labeled SW 1116 or WC 1 targets with the monoclonal antibody CO17-1A, an IgG2a antibody reactive with gastrointestinal cancer-associated cell antigen, or control mouse IgG prior to testing NKSF-treated or control PBL effectors in a 6-hr cytotoxicity assay. NKSF significantly enhanced NK cytolysis of colon carcinoma and NK-resistant lymphoma cell lines, and on a molar basis was approximately 300 times more potent than interleukin-2 in generating NK cytotoxicity. Furthermore, NKSF significantly augmented lymphocyte-mediated ADCC against colon carcinoma targets, and the combination of NKSF with the antibody CO17-1A had an additive effect on lymphocyte tumoricidial capacity. Thus, NKSF may have a potential role in the treatment of colon cancer.

Neuroblastoma remains a common and deadly childhood tumor, resistant to both surgical and chemo/radiotherapeutic intervention in its advanced stages. The role of immunotherapy in such cancers has yet to be defined. In previous work, we found that the addition of interferon gamma (IFN-gamma) to 3-day in vitro tissue cultures of the murine neuroblastoma C1300, led not only to the tumor's increased cell surface expression of the immunologically important major histocompatibility complex (MHC) class I antigen, but also to an increased susceptibility of such modified tumor to subsequent lymphokine activated killer (LAK) cell lysis. In this study, we sought to determine the in vivo applicability of these findings. Initial dose-response studies helped define a regimen of rIFN-gamma's administration that upregulated MHC class I without activating host natural killer (NK) activity. A/J mice bearing 7-day-old subcutaneous C1300 were randomized to receive daily morning injections of either 0, 25,000, 50,000, or 100,000 U of rIFN-gamma intraperitoneally for 6 days. Animals were killed at days 3, 6, and 9 after initiation of rIFN-gamma therapy, and tumors were excised, digested, and stained for both MHC class I and II expression. At the time of sacrifice, splenocytes from each animal were tested for NK cytotoxicity toward YAC (an NK-sensitive lymphoma) and C1300. These studies defined 3 days of therapy with 25,000 U as a "priming" dose that increased expression of class I with minimal impact on NK activity.(ABSTRACT TRUNCATED AT 250 WORDS)

In order to assess the value of MR in the depiction of intracranial nerves, we retrospectively reviewed 60 patients investigated over a period of 2 years. The aim of this study was: 1) to assess the score of MR in the detection of cranial nerves III to XII; 2) to determine accurate landmarks allowing for easy detection of those cranial nerves. Cranial nerves III, V, VII, VIII are well seen (70 to 100%), very often in both axial, sagittal and coronal sections. Nerves IX to XII are correctly studied only on axial planes [81 and 83%), but it is difficult to distinguish between the vagal nerve and the glossopharyngeal and spinal nerves. Due to their oblique direction and small size, fourth and sixth nerves are rarely visualized. The more important landmarks are the chiasma, the colliculi, the Meckel's cave, the internal auditory canal, the jugular foramen, the hypoglossal canal and the different brainstem structures. We suggest the following scanning protocol: short spin echo sequences (TR = 600 ms, TE = 20 msec), 3 to 5 continuous sections, 16 to 20 cm field of vue with respectively 4 or 2 excitations, 256 x 256 matrix, with at least one acquisition plane (axial), but preferably two or three planes. Thus MR is sensitive exam in the recognition of cranial nerves, and it must be the first step exam in patients presenting with cranial nerve disease.

Using qualitative loop analysis we have extended our examination of a Delaware Bay plankton community to include an investigation of the roles played by the various entities (population, guild or nutrient) in the community. In an entity removal exercise, we used stability relationships as a probe into community structure. Six types of stability change are possible as a result of entity removal from the system: stable to stable (s-->s); stable to unstable (s-->u); stable to disconnected (s-->d); unstable to stable (u-->s); unstable to unstable (u-->u); unstable to disconnected (u-->d). Using these changes as an investigative tool, we found that in order to account for the stability-instability patterns, it was necessary to construct a refined trophic structure model. The observed connections between the entities in the larger model could be grouped into two different types of stability substructures: a simple pattern and a more complex branching pattern. These patterns map easily onto the refined trophic structure model. Using stability analysis it is also possible to model community structure in ways other than the traditional trophic approach. Patterns of system necessity and relative contribution to stability are observed. These patterns match the refined trophic structure model derived previously. The roles that the various entities play in the overall community were followed over an annual cycle. Entities were seen to change their roles as a function of time and status within a subgroup. These results show that stability determinations have the potential to be used as a valuable tool in community analysis.

Megestrol acetate was administered as first-line therapy to 152 patients with advanced breast cancer. Forty-three of 136 evaluable patients (32%) obtained an objective response (95% confidence interval, 24% to 40%). Toxicity was minimal, with only 4 patients requiring dose reduction. Megestrol acetate is an effective, well-tolerated agent in previously untreated patients with advanced breast cancer.

A case of cystic schwannoma that presented as an intraaxial lesion on CT is reported. Magnetic resonance was able to detect the extraaxial origin of the tumor.

Protein malnutrition is prevalent in cancer patients, however the influence of protein-calorie malnutrition on anti-tumor immune effector mechanisms is unclear. In addition, the effect of malnutrition on host immunological and biological responsiveness to recombinant interleukin-2 (rIL-2) is unknown. In Swiss mice (n = 100), we observed that T cell activation, T cell response to rIL-2, T suppressor cell generation, cytotoxic T lymphocyte development, and the cytolytic activity of LAK cells were not significantly impaired by two or three weeks of feeding with a 2.5% protein diet compared with mice fed an isocaloric diet in which protein calories constituted 24% of the total. In CBA/J mice (n = 100), we observed a significant (P less than 0.05) impairment of poly(I:C)-inducible natural killer cell function in mice ingesting the 2.5% diet. In both A/J (n = 40) and Swiss mice (n = 40), cytotoxic responses after 3 days treatment with rIL-2 (5 X 10(6) U/kg body wt. three times daily) were comparable in both dietary groups. These studies demonstrate that protein depletion is associated with impaired poly (I:C)-induced natural killer cell function in CBA/J mice. However, T cell function and biological responsiveness to high-dose rIL-2 were not significantly impaired.

Single snapshot measurements of resting energy expenditure (REE) suggest that hypermetabolism contributes to cancer cachexia, but tumor impact on total 24-hr energy expenditure (TEE) is unknown. Automated multicage indirect calorimetry was employed to measure daily energy expenditure in adult Buffalo rats (n = 16) randomized to tumor inoculation or controls. Measurements included baseline REE, activity EE (AEE), thermic response to food (TEF), and TEE. Rats (n = 16) were randomized. Metabolic measurements, tumor size, and body weight were recorded weekly. Animals were sacrificed at Week 5 for analysis of host and tumor composition. Significant depletion of total lean body mass occurred in TB rats (greater than 15% wt loss, ANOVA P less than 0.001) which inversely correlated with tumor growth (r = -0.81, P less than 0.001). REE, TEF, AEE, and TEE did not change in controls (ANOVA P = n.s.). In TB rats, a 19.5% increase in REE occurred (119.4 +/- 3.3 to 138.7 +/- 1.8 kcal/kg LBM/day, P less than 0.01). TEE remained unchanged (157.3 +/- 5.6 vs 152.9 +/- 3.6 kcal/kg LBM/day, P = n.s.) due to a 66% decrease in AEE (32.9 +/- 3.1 to 10.5 +/- 1.7 kcal/kg LBM/day, P = 0.01). TEF did not change (4.7 +/- 0.8 vs 5.0 +/- 0.3 kcal/kg LBM/day, P = n.s.). Both TB and controls demonstrated a decreased REE in response to a 24-hr fast (7.9% vs 4.8%, P = n.s.). Respiratory quotient decreased in both groups when comparing fed to fasted values: TB (0.86 to 0.76) and controls (0.86 to 0.71), but the decline was greater in controls (P = 0.04).(ABSTRACT TRUNCATED AT 250 WORDS)

Perioperative blood transfusion has been associated with decreased survival in cancer patients. The immunologic consequences of H-2 incompatible blood transfusion as related to neoplasia are unclear. This report examined the effect of multiple allogeneic blood transfusions, compared to syngeneic transfusions and saline infusion, on cellular immunity, tumor growth, and host survival in a murine C1300 neuroblastoma model. A/J mice were randomized to receive two weekly transfusions of washed whole blood cells from C57 Bl/6 or A/J donors or saline. Animals transfused with allogeneic blood, compared to syngeneic transfusions or saline infusions, had a significantly diminished lymphocyte response to mitogen (P less than 0.001), reduced donor-specific (P less than 0.001) and third party alloantigen (P less than 0.01) MLR, and reduced cytotoxicity against a natural killer (NK) cell-sensitive target (P less than 0.001). These in vitro deficits in cellular immunity correlated with a significantly greater Day 21 tumor weight to total body weight ratio in the allogeneic group (0.33) compared with the syngeneic (0.25) and saline (0.28) groups P less than 0.05). Median host survival was reduced in the allogeneic group (24 days) compared with the syngeneic (30 days) and saline (31 days) groups. There were no significant differences in cellular immunity, tumor growth, or survival between syngeneic and saline control groups. Allogeneic blood transfusion had an adverse affect on NK and T-lymphocyte function which was associated with enhanced tumor growth and reduced survival in tumor-bearing mice.

The purpose of this study was to determine if a 3-day in vitro culture of the murine neuroblastoma C1300 with 500 U/mL of recombinant interferon gamma resulted in a protective crossreactivity to parent C1300. Twenty A/J mice received either a vaccine of 1 x 10(6) irradiated C1300 tumor cells intradermally or an equivalent inoculum of C1300 that had been incubated in recombinant interferon gamma (C1300*). One week later, all animals were rechallenged with 1 x 10(6) viable C1300. Animals immunized with C1300* had a significantly delayed early tumor incidence that translated into a survival advantage for the group. At the time of tumor rechallenge, a significantly increased level of nonspecific systemic immunity was conferred by the C1300* immunization. Thus, modification of tumor with recombinant interferon gamma before introduction as a vaccine may improve that vaccine's protective capability.

Supplemental dietary arginine has anti-tumor properties but the degree and mechanisms are unclear. In non-tumor-bearing CBA/J mice (n = 60), 1% arginine supplementation significantly enhanced thymic weight, spleen cell mitogenesis, and interferon-activated natural killer cell activity; no further enhancement was observed with 2% or 4% supplementation. Supplemental 1% arginine, when compared with 1.7% glycine, enhanced interferon-induced natural killer cell activity, lymphokine-activated killer cell generation, and macrophage cytotoxicity. In A/J mice (n = 420), bearing either a moderately immunogenic (C1300) or weakly immunogenic (TBJ) murine neuroblastoma, 1% arginine significantly (p less than 0.05) retarded tumor growth and prolonged median survival time compared with glycine or no supplementation. Dietary arginine enhanced T-cell function and significantly increased responsiveness to autologous C1300 tumor in a mixed lymphocyte tumor cell culture (MLTC). The immunomodulatory effects of arginine provide nutritional and immunologic support of the tumor-bearing host and may be helpful when given concommitant with immunotherapy.

The normal immune system has local and systemic components which are influenced by a variety of alterations. Impaired host immunity is associated with neoplasia, protein calorie malnutrition, and the administration of immunosuppressive drugs. It is well accepted that protein calorie malnutrition impairs host immunity with particular detrimental effects on the T-cell system, resulting in increased opportunistic infection and increased morbidity and mortality in hospitalized patients. Individual nutrient substrates may also have a major influence on the immune system. Individual amino acids are often described as essential, based on requirements for optimal growth and maintenance of positive N balance. Arginine has been demonstrated to be essential to the traumatized host and may have tissue-specific properties which influence components of the immune system. Thus, arginine may be of value in clinical situations where the immune system is compromised. In a series of experiments in normal animals, arginine was demonstrated to enhance cellular immune mechanisms, in particular T-cell function. It also has a marked immunopreserving effect in the face of immunosuppression induced by protein malnutrition and increases in tumor burden. In postoperative surgical patients, arginine supplementation results in enhanced T-lymphocyte response and augmented T-helper cell numbers, with a rapid return to normal of T-cell function postoperatively compared with control patients. These data suggest that arginine supplementation may enhance or preserve immune function in high-risk surgical patients and theoretically improve the host's capacity to resist infection.

In order to assess the value of MRI in the depiction of intracranial nerves, we retrospectively reviewed 60 patients investigated over a 2-year period. The purposes of this study were: 1) to determine the score of MRI in detecting cranial nerves III to XII, and 2) to establish accurate landmarks for easy detection of these nerves. Cranial nerves III, V, VII and VIII are well seen (70 to 100%), very often on axial, sagittal and coronal sections. Nerves IX to XII are correctly studied only on axial planes (81 and 83%), but it is difficult to distinguish between the vagus nerve and the glossopharyngeal and spinal nerves. Due to their oblique direction and small size, nerves IV and VI are seldom visualized. The most important landmarks are the chiasma, the colliculi, Meckel's cavity, the internal auditory canal, the jugular foramen, the hypoglossal canal and the brainstem structures. We suggest the following scanning technique: short spin-echo sequences (TR 600 ms, TE 20 ms), 3 to 5 mm thick contiguous sections, 16 to 20 cm field of view with 4 or 2 excitations respectively, 256 x 256 matrix, and at least one acquisition plane (axial plane), but preferably two or three planes. MRI is a sensitive examination in the recognition of cranial nerves. It should be the first-step exploratory procedure in patients with cranial nerve pathology.

Nine cases of recurrent petrous cholesteatomas have been studied by a 1,5 T MR unit. Gadolinium was injected in 1 case. In all cases, comparison between MR, CT and clinical findings were made. MR allows for accurate topographic study and assessment of cholesteatomas extension, in particular in the posterior fossa and skull base. Relationships with the internal carotid artery and the jugular vein are clearly depicted.

Human neuroblastoma (NRB) cell lines are markedly sensitive to natural killer (NK) cell lysis in vitro, but patients with NRBs have low or absent NK activity. This study evaluated the NK sensitivity of murine NRBs (C1300 and TBJ) in the regulation of NRB growth and determined the effects of recombinant (r) interferon gamma and recombinant interleukin 2 (rIL-2). Both basal (8% +/- 3% specific cytotoxicity) and induced (20% +/- 3%) NK lyses of C1300-NRB were observed. In vivo depletion of NK cells with anti-asialo GM-1 significantly enhanced growth of C1300-NRB and decreased survival. Treatment with r-interferon gamma or rIL-2 on days 1 through 3 after C1300-NRB inoculation significantly prolonged the mean tumor latency period, decreased the tumor growth rate, and enhanced in vitro NK killing of C1300-NRB and YAC-1. The effects of r-interferon gamma and IL-2 were abrogated by pretreatment with anti-asialo GM-1. These results demonstrated that NK cells form one important component of regulation of a murine NRB, but immunomodulation with potent lymphokines requires cooperation of more than one cell type.

During the napoleonic expedition to Egypt (1798-1801), a new ophthalmic disease, the "egyptian ophthalmia", was discovered by the french physicians. We analysed a contemporary study published by the surgeon Jean-Dominique Larrey. The accuracy of the clinical description enables us to suggest hypotheses upon the origin if the egyptian ophthalmia: Weeks' conjunctivitis, gonorrheal conjunctivitis, trachoma. Treatments are also reviewed. Larrey is to be seen as a symbol of the transition from the old medical vision to modern clinical medicine.

Thirteen patients with craniopharyngioma were explored with a 1.5 Tesla magnetic resonance imager. The results were compared with those of CT and with operative findings. The MRI signals were correlated with the biochemical composition of the cysts (proteins, lipids, iron, LDH) in 5 cases; 2 patients were studied after an intravenous injection of gadolinium DOTA. MRI proved vastly superior to CT to evaluate the spread and identify the various components of craniopharyngiomas (cysts, fleshy parts, haemorrhages), except for calcifications. Gadolinium improved the detection of fleshy parts and "active" cysts. The signals emitted by cysts were extremely variable on T1-weighted sequences. The correlation between MRI and biochemical data was complex, but it appeared that protein, lipid and iron concentrations had a major influence on cyst signals. MRI with gadolinium may be envisaged as first-line examination to improve the evaluation of spread, determine the prognosis and detect recurrences of craniopharyngiomas. CT could be reserved to difficult cases with invasion of bones and sinuses.

Dietary supplementation with the amino acid arginine augments T-lymphocyte activation in response to mitogens in clinical and experimental studies. In experimental models arginine enhances specific T cell antitumor immunity. The mechanism of these immunostimulatory effects of arginine on T cell function is unclear, and the scope and specificity of arginine's influence on other components of the effector immune response such as natural killer (NK) cells and macrophages are unknown. To evaluate the role of arginine in these responses, CBA/J mice (n = 100) were randomized to receive either 1% arginine supplementation or isonitrogenous (1.7%) glycine supplementation for at least 10 days. There was no significant differences in mean body weight between groups during feeding. Arginine supplementation significantly (p less than 0.05) enhanced cytotoxic T-lymphocyte development, poly IC-inducible NK activity, and the kinetics of interleukin-2 receptor expression on activated T cells. Basal- and endotoxin-induced macrophage interleukin-1 and superoxide production were not significantly influenced by supplemental arginine although macrophage cytotoxicity in response to gamma-interferon was augmented (p = 0.07). In subsequent in vitro studies we established that certain effects (NK, cytotoxic T-lymphocyte, and T cell activation) were reproducible after preincubation for 72 hours in pharmacologic levels of arginine. The data strongly suggest that arginine mediates a direct effect on components of the immune system, which results in enhanced production or use of lymphokines.

We studied the flow pattern of the ophthalmic artery by pulsed doppler. The technique of visualization of the artery using bidimensional echography and the method of flow calculation by pulsed doppler are described in this preliminary report. This direct, non-invasive and readily feasible technique may play a prominent role in the clinical diagnosis of ophthalmic artery diseases.

Magnetic resonance imaging (MRI) nowadays plays a predominant role in the diagnosis and evaluation of spinal canal pathologies and has reduced the other exploratory methods, including computerized tomography (CT) and myelography, to an ancillary role. These pathologies are divided into three groups: those where MRI is the only imaging method (syringomyelia, tumours in the spinal canal, phakomatoses, external pachymeningitis, spinal cord injuries, myelitis); those where MRI is the initial method and is completed by other examinations (vascular malformations, dysraphism, myelopathies due to cervical osteoarthritis) and those where MRI still play a lesser role than CT (degenerative lesions of the lumbar column).

In this paper we present results obtained with a computer simulation in which a community, described by Levins in his presentation of loop analysis (Levins, R., 1975, Evolution in communities near equilibrium, in: Ecology and Evolution of Communities, M.L. Cody and J.M. Diamond (eds) (Harvard University Press, Cambridge, Mass.) pp. 16-50), is analysed. We show how our simulation accurately reproduces Levins' calculations and further, (i) how our simulation can be used to answer questions raised by Levins but never answered, (ii) how the simulation can be used to dissect a community in order to analyse the roles played by the various entities, and (iii) how predictions relating to the evolution of this community, proposed by Levins, can be analysed with some interesting and unexpected results. In particular, it becomes clear that discussion of the type of selection that may take place needs to be done in the framework of the community in which it occurs.

The authors report the case of a 15-year-old female who presented with a history of vague but constant pain about the medial aspect of her right knee. X-ray established the presence of an expanding lesion in the medial tibial plateau. Computerized axial tomography (CT) and magnetic resonance imaging (MRI) were used in the evaluation of the lesion. The authors compare the preoperative CT and MRI findings with the microscopic histopathology of the amputation specimen and note that the CT scan underestimated the extent of the microscopic tumor boundaries, whereas MRI showed altered activity beyond these boundaries.