Significant Mass Effect Research Articles

Inflammatory progressive multifocal leukoencephalopathy after antiretroviral treatment

Progressive multifocal leukoencephalopathy (PML), a demyelinating disease of the central nervous system caused by the human polyomavirus JC (JCV), results from a lytic infection of the oligodendrocytes that typically occurs in profound immunosuppression. Characteristically, the inflammatory response is not observed on histopathological findings, and neuroimaging studies rarely show contrast-enhancing lesions [1]. Atypical presentations of some diseases arising from pre-existing infections and inflammatory reactions against several opportunistic pathogens have been described in AIDS patients soon after starting HAART [2]. We describe a case of PML with an inflammatory response occurring shortly after initiating HAART that was misinterpreted as neurotoxoplasmosis. A 32-year-old Brazilian man naive of antiretroviral treatment was diagnosed HIV-1 positive in May 2004 as a result of chronic diarrhoea and weight loss. The physical examination disclosed oral candidiasis and seborreic dermatitis and his CD4 cell count was 18 × 106 cells/μl. He promptly received a combination of zidovudine, lamivudine, and efavirenz, as well as prophylaxis against Pneumocystis carinii and Toxoplasma gondii. Three weeks later, he was admitted because of mental confusion and left hemiparesis. His CD4 cell count was 146 × 106 cells/μl and his viral load was 750 000 copies (5.87 log/ml). A brain magnetic resonance imaging (MRI) scan revealed a large white matter lesion on the right parietal lobe without gadolinium enhancement (Fig. 1a and b). Empiric anti-Toxoplasma treatment was initiated. His clinical condition continued to deteriorate and 2 weeks later he was submitted to another brain MRI scan that showed an increase in the previous lesion and an irregular gadolinium enhancement (Fig. 1c and d). A lumbar puncture was performed and the analysis of the cerebrospinal fluid (CSF) disclosed 3 mononuclear cells/ml3, 65 mg/dl of proteins, 42 mg/dl of glucose, the presence of HIV-1 antibodies, and an IgG index of 1.05. JCV DNA was detected by a nested polymerase chain reaction (PCR) developed for the amplification of a 386 bp fragment of the T antigen region of the virus. Treatment for neurotoxoplasmosis was interrupted but the antiretroviral regimen was maintained. His neurological condition began to improve 3 weeks later, and he was discharged with a CD4 cell count of 261 cells/μl and undetectable viral load. A further brain MRI scan, performed 5 months later, showed the persistence of the white matter lesion but without gadolinium enhancement (images not shown) and a further CD4 cell count of 407 cells/μl.Fig. 1: Brain magnetic resonance imaging scans showing a large demyelinating lesion (a) that enlarged after 5 weeks of HAART (c) (flair images); at this moment gadolinium enhancement is observed (arrow in d; compare with b) (T1 with contrast).This report raises important observations that must be considered in the management of any AIDS patients presenting with unexpected neurological symptoms soon after initiating HAART. In our case, neurological symptoms appeared a few weeks after the introduction of HAART in a patient with profound immunosuppression. Even in the absence of the typical brain lesions of neurotoxoplasmosis, this patient was subjected to anti-Toxoplasma therapy. Although cerebral toxoplasmosis is a very frequent neurological complication in HIV patients, mainly in developing countries, it is more common in patients with milder immunodeficiency. Therefore, in cases of severe immunosuppression, other opportunistic infections and tumours should be appropriately ruled out [3]. In this setting and in the absence of a mass effect a CSF analysis with PCR could be a non-invasive and reliable method of obtaining the correct diagnosis. For example, with regard to PML, the PCR for JCV has a sensitivity ranging from 61 to 100% and a specificity of 99%. Although the incidence of opportunistic infections and tumours has decreased since the introduction of HAART, the incidence of PML remains stable [4,5]. PML cases appearing soon after starting HAART have been described and associated with immune reconstitution inflammatory syndrome [6–9]. Prominent perivascular inflammatory infiltration has been seen [6] and maybe this inflammatory reaction accounts for the unusual contrast enhancement observed [8], as seen in our case (Fig. 1d). Therefore inflammatory PML could be a characteristic of patients experiencing immune reconstitution of their CD4 cell counts during the first weeks of HAART. An interesting point is the relative good prognosis described in PML associated with immune reconstitution inflammatory syndrome, as in our case, and corticosteroids should be used only in severe inflammatory reactions with significant oedema and mass effect [10,11]. In conclusion, indiscriminate empiric anti-Toxoplasma therapy may no longer be appropriate as a first-line approach to all HIV-positive patients with focal brain lesions, even in developing countries. New diagnostic strategies should be considered to identify the underlying disorders, especially in atypical settings. In cases in which lumbar puncture is not contraindicated, the routine clinical usage of CSF PCR in AIDS patients should be encouraged to reach a correct diagnosis.

Spectrum of subdural fluid collections in spontaneous intracranial hypotension

Spontaneous intracranial hypotension is a noteworthy but commonly misdiagnosed cause of new daily persistent headaches. Subdural fluid collections are frequent radiographic findings, but they can be interpreted as primary rather than secondary pathological entities, and uncertainties exist regarding their optimal management. The authors therefore reviewed their experience with subdural fluid collections in 40 consecutive patients with spontaneous spinal cerebrospinal fluid (CSF) leaks and intracranial hypotension. The mean age of the 26 female and 14 male patients was 43 years (range 13-72 years). Subdural fluid collections were present in 20 patients (50%); 12 of these patients (60%) had subdural hygromas alone, and eight (40%) had subacute to chronic subdural hematomas (SDHs) associated with significant mass effect. The subdural hygromas resolved within several days to weeks following treatment of the underlying CSF leak. Three patients with SDHs underwent evacuation of the hematoma prior to the establishment of the diagnosis of spontaneous intracranial hypotension, but the SDHs did not resolve until the underlying spinal CSF leak was treated. In the remaining five patients, the CSF leak was treated primarily and the SDHs resolved over a 1- to 3-month period without the need for evacuation. Subdural fluid collections are common in spontaneous intracranial hypotension, varying in appearance from thin subdural hygromas to large SDHs associated with significant mass effect. These collections can be safely managed by directing treatment at the underlying CSF leak without the need for hematoma evacuation.

Paradoxical Cerebral Herniation Secondary to Lumbar Puncture after Decompressive Craniectomy for a Large Space-occupying Hemispheric Stroke: Case Report

The risk of transtentorial herniation after removal of cerebrospinal fluid from the lumbar cistern in the setting of a supratentorial lesion with significant mass effect, increased cerebrospinal fluid pressure, or midline shift is well known. We report a case of cerebral herniation from intracranial hypotension (so-called paradoxical herniation) secondary to a lumbar puncture 1 month after decompressive hemicraniectomy for a large right hemispheric stroke. A 50-year-old woman was transferred to our neurosurgical service for obtundation 4 days after a lumbar puncture to rule out meningitis and 1 month after decompressive craniectomy for a large right hemispheric stroke. Eighty grams of mannitol was administered before transfer. On arrival at our hospital, the patient was intubated and a computed tomographic scan was performed. The patient was diagnosed with low-pressure herniation after review of the computed tomographic scan. Rehydration was initiated, and the patient was placed in the Trendelenburg position. She became easier to arouse, but her pupils remained dilated. She experienced a sudden severe cardiac arrhythmia leading to a cardiac arrest. Attempted resuscitation was unsuccessful, and the patient was pronounced dead. Lumbar punctures may result in lethal intracranial hypotension in patients after hemicraniectomy and are thus contraindicated unless care is taken to remove the pressure gradient of atmospheric air across the lumbar cistern.

Cerebral aspergillosis due to Aspergillus fumigatus in AIDS patient: first culture - proven case reported in Brazil

Cerebral aspergillosis is a rare cause of brain expansive lesion in AIDS patients. We report the first culture-proven case of brain abscess due to Aspergillus fumigatus in a Brazilian AIDS patient. The patient, a 26 year-old male with human immunodeficiency virus (HIV) infection and history of pulmonary tuberculosis and cerebral toxoplasmosis, had fever, cough, dyspnea, and two episodes of seizures. The brain computerized tomography (CT) showed a bi-parietal and parasagittal hypodense lesion with peripheral enhancement, and significant mass effect. There was started anti-Toxoplasma treatment. Three weeks later, the patient presented mental confusion, and a new brain CT evidenced increase in the lesion. He underwent brain biopsy, draining 10 mL of purulent material. The direct mycological examination revealed septated and hyaline hyphae. There was started amphotericin B deoxycholate. The culture of the material demonstrated presence of the Aspergillus fumigatus. The following two months, the patient was submitted to three surgeries, with insertion of drainage catheter and administration of amphotericin B intralesional. Three months after hospital admission, his neurological condition suffered discrete changes. However, he died due to intrahospital pneumonia. Brain abscess caused by Aspergillus fumigatus must be considered in the differential diagnosis of the brain expansive lesions in AIDS patients in Brazil.

Giant cavernous angioma of the temporal lobe: a case report and review of the literature

Cavernous angiomas of the central nervous system are angiographically occult vascular lesions and are easily diagnosed by magnetic resonance imaging (MRI). Giant cavernous angiomas (GCA) are rare, with only 11 cases reported in the literature. Imaging appearance of GCAs has not been reviewed previously. We report a GCA of the temporal lobe, and discuss its computed tomography and MRI findings in the view of the literature. Imaging appearance of GCAs is variable. Some GCAs have features that are similar to those of typical cavernous angiomas, whereas some lesions may be purely cystic; and some present with significant contrast enhancement and mass effect, mimicking neoplasms. While the presence of hemosiderin, blood degradation products, and calcification may be helpful in the diagnosis of some cases, the correct diagnosis is not apparent until histopathological evaluation of the specimen is made in many instances.

Endonasal Transsphenoidal Transclival Removal of Prepontine Epidermoid Tumors: Technical Note

Prepontine retroclival tumors have typically been removed through a variety of anterolateral, lateral, and posterolateral cranial base approaches. Here, we describe an endonasal transclival cranial base approach for removal of prepontine epidermoid tumors. Two men, 40 and 52 years old, each presented with a history of headaches and cranial nerve deficits. In each patient, magnetic resonance imaging showed a large T1 hypointense/T2 hyperintense mass occupying the posterior suprasellar, premesencephalic, and prepontine cisterns, with significant mass effect on the brainstem. Both patients underwent an endonasal transsphenoidal transclival cranial base tumor removal with the operating microscope and endoscopic assistance. The dural and bony defects were repaired with abdominal fat grafts, collagen sponge, titanium mesh, and cerebrospinal fluid diversion. One patient developed a postoperative cerebrospinal fluid leak and meningitis requiring two reoperations to repair, ultimately with fat and fascia lata grafts. At 1 year after surgery, both patients have improved compared with their preoperative neurological state, and volume analysis of preoperative and 1-year postoperative magnetic resonance imaging scans confirm a marked reduction in mass effect on the brainstem, with a 78% tumor removal in one patient and 76% removal in the other. Both patients have normal endocrine function. The endonasal approach offers a minimally invasive, anatomically direct route for removing prepontine epidermoid tumors that obviates brain retraction. The use of angled endoscopes is essential for gaining lateral, cephalad, and caudal visualization to augment the limited microscope view. Inadequate repair of clival dural defects remains the greatest potential pitfall in attempting transsphenoidal transclival tumor removal.

Magnetic resonance imaging findings in fatal primary cerebral infection due to Chaetomium strumarium

This report describes MRI findings of a rare case of biopsy-proven fatal cerebral infection with Chaetomium strumarium in a 28-year-old man with a history of i.v. drug abuse. Magnetic resonance imaging revealed rapidly progressing lesions with irregular peripheral enhancement, possible central haemorrhage and significant mass effect. Only six cases of cerebral infection with Chaetomium have been reported in the English literature. This is the first report in the radiology literature describing the imaging findings. The previously reported cases of cerebral infection by the Chaetomium species are also reviewed.

Decompressive Hemicraniectomy for Poor-grade Aneurysmal Subarachnoid Hemorrhage Patients with Associated Intracerebral Hemorrhage: Clinical Outcome and Quality of Life Assessment

Decompressive hemicraniectomy has been proposed as a potential treatment strategy in patients with poor-grade aneurysmal subarachnoid hemorrhage presenting with focal intracerebral hemorrhage causing significant mass effect. Although hemicraniectomy improves overall survival rates, the long-term quality of life (QoL) for survivors in this patient population has not been reported. Using adjudicated outcome assessments, we compare long-term clinical outcomes and QoL between a group of patients with poor-grade aneurysmal subarachnoid hemorrhage receiving decompressive hemicraniectomy (n=12) and a control group of similar patients managed more conservatively (n=10). Patients receiving decompressive hemicraniectomy experienced a statistically insignificant decrease in short-term mortality compared with controls (25 versus 42%); however, long-term QoL in hemicraniectomy survivors was generally poor. Furthermore, hemicraniectomy patients did not experience an increase in mean quality-adjusted life years over control patients (2.31 versus 2.22 yr). Decompressive hemicraniectomy prolongs short-term survival in patients with poor-grade aneurysmal subarachnoid hemorrhage with associated intracerebral hemorrhage; however, this trend is not statistically significant, and the overall QoL experienced by survivors is poor. Decompressive hemicraniectomy may be indicated if performed early in a select subset of patients. On the basis of our preliminary data, large prospective studies to investigate this issue further may not be warranted.

Calcified brain metastasis of osteosarcoma: CT findings

Brain metastasis of osteosarcoma is uncommon. In this report, we present a 21-year-old man with calcified brain metastasis of the osteosarcoma of the left proximal tibia following pulmonary relapse. Cranial computed tomography (CT) scan demonstrated a single calcified mass lesion involving the right temporal, parietal and occipital lobes with surrounding vasogenic edema and significant mass effect on the midline structures.

Signals from R-parity violating top quark decays at LHC

We evaluate the potential of the CERN LHC collider to observe rare decays of the top quark in channels involving R-parity violating ( ) interactions. We stress the importance of calculating top quark production and decay simultaneously as a true 2→4 process. The process of t pair production followed by decay of one of the top quarks is analyzed with fast detector simulation. We show that intermediate supersymmetric particles can be observed as resonances even if they are heavier than the top quark due to the significant off-shell top quark mass effects. The approach where the top quark is produced on-mass-shell and then decays into 2- or 3-body final state would in general lead to incorrect kinematical distributions and rates. The rates of the 2→4 process with top quark production and 3-body decay depend on the total width of the heavy intermediate sfermion which could, therefore, be measured indirectly. We find that the LHC collider offers a unique potential to study rare top quark decays in the framework of supersymmetry with broken R-parity for branching fractions of top decays as low as 10−6.

The Distribution of Forces between the Upper and Lower Back during Load Carriage

To determine the effects of backpack mass on the forces exerted by the backpack on the carrier and on the distribution of these forces between the upper back (including shoulders) and lower back (sacrum and iliac crest). Eleven male volunteers (mean age 22.7 SEM 1.1 yr) walked on a level treadmill at 1.34 m.s(-1) carrying a backpack loaded to three different masses (13.6, 27.2, and 40.8 kg). The backpack's hip belt was connected to force transducers that measured the forces exerted on the lower back. The total force between the subject and backpack was determined from the backpack's mass and acceleration. Forces on the upper back were calculated as total force minus the forces exerted on the lower back. There was a significant effect of backpack mass on the vertical and anterior/posterior forces exerted on the upper and lower back, and on the total force exerted on the backpack center of mass. Regardless of mass, approximately 30% of the vertical force was borne by the lower back; the upper back and shoulders supported the remaining 70%; this is based on data averaged across the stride. Dimensionless analysis revealed peak forces on the upper and lower back increased proportionately to backpack mass whereas the peak forces exerted on the backpack COM increased disproportionately. The backpack exerts consistent anterior force on the lower back, which likely contributes to the occurrence of low-back pain associated with load carriage. Approximately 30% of the vertical force generated by the backpack can be transferred to the lower back by using an external frame backpack with a hip belt.

Lipomatous medulloblastoma: a rare adult tumor variant with a uniquely favorable prognosis

Background Lipomatous medulloblastoma is a rare but apparently distinct variant of medulloblastoma. There have been only 14 prior published cases. We report an additional case of an adult who presented with a multicentric form of this unique lesion. Methods A 45-year-old woman underwent magnetic resonance imaging for evaluation of progressive headaches, nausea/vomiting, vertigo, and ataxia. Multiple bilateral mass lesions in the posterior fossa were noted, along with obstructive hydrocephalus and significant mass effect. Results Via a right suboccipital and retrosigmoid craniotomy the largest cerebellar lesion was resected and a second lesion biopsied. The third mass on the contralateral side was not disturbed. Postoperatively the patient received fractionated radiotherapy to a dose of 54 Gy and chemotherapy with cisplatin, PCNU, and vincristine for 1 year. She is alive without deficit, with a Karnofsky Performance Status of 100, and with no evidence of disease on neuroimaging 3 years after diagnosis. Conclusion This distinct variant of medulloblastoma appears to occur in adults only and has a uniquely favorable prognosis, even with incomplete resection with institution of appropriate adjuvant therapies. Multicentricity does not imply a less favorable prognosis.

Harem choice and breeding experience of female southern elephant seals influence offspring survival

Female mammals can increase their lifetime fitness through modification of investment potential and by providing better rearing environments with improved breeding experience. We examined the relationships between reproductive fitness and the behavioural decisions that female southern elephant seals (Mirounga leonina) made during the breeding season. We examined whether mother age and breeding experience influenced reproductive success (measured as 1st-year survival probability), and whether there was a change in the choice of harem size with increasing age. Pups produced by young mothers had lower 1st-year survival probability than pups produced by older mothers. A significant increase in mean female mass with age required an analysis of both these effects on offspring survival. There was a significant positive effect of both female age and mass, and the interaction between the two, on 1st-year pup survival. The proportion of young mothers ( 6 years old) increased with increasing harem size (harems surveyed from 1997 to 2001). Females chose larger harems in which to breed as they aged. Females demonstrated fidelity to breeding areas among successive breeding seasons, with older females displaying greater breeding-site fidelity than younger females. The mean number of previous breeding attempts per female within a harem (breeding experience) increased significantly with increasing harem size. Breeding females returned to breed later in the breeding season as they aged—we hypothesize that young, subordinate females gain a priority advantage by returning earlier. These results lend support to the hypothesis that there are fitness advantages, in terms of offspring survival, that are conferred to females that breed in successively larger harems with age. Potential mechanisms that select for females to improve their breeding conditions include improved mate selection and the avoidance of conspecific harassment in harems.

Historical dynamics of the Australian fur seal population: evidence of regulation by man?

The Australian fur seal (Arctocephalus pusillus doriferus) was severely over-exploited in the 18th and 19th centuries and until relatively recently its population had remained steady at well below estimated presealing levels. However, the population is now increasing rapidly (6%–20% per annum) throughout its range and there is a need to understand its dynamics in order to assess the potential extent and impact of interactions with fisheries. Age distribution (n = 156) and pregnancy rate (n = 110) were determined for adult females collected at a breeding colony on Seal Rocks, southeast Australia, in 1971–1972. Mean ± SE and maximum observed ages were 9.37 ± 0.41 and 20 years (n = 1), respectively. A stochastic modelling approach was used to fit an age distribution to the observed age-structure data and calculate rates of recruitment and adult survival. Annual adult female survival and recruitment rates between 1954 and 1971 were 0.478 ± 0.029 (mean ± SE) and 0.121 ± 0.007, respectively, suggesting that the population was experiencing a decline during the 1960s. The pregnancy rate increased from 78% at 3 years of age to an average of 85% between 4–13 years of age before significantly decreasing in older females (the oldest was 19 years of age). There was no significant effect of body mass or condition on the probability of a female being pregnant (P > 0.5 in both cases) and the nutritional burden of lactation did not appear to affect pregnancy rates or gestational performance. These findings suggest that the low survivorship was due to density-independent effects such as mortality resulting from interactions with fishers, which are known to have been common at the time. The recent increase in the population is consistent with anecdotal evidence that such interactions have decreased as fishing practices have changed.

Diffusion Tensor Imaging of Brain Tumours at 3 T: A Potential Tool for Assessing White Matter Tract Invasion?

AIM: To determine whether diffusion tensor imaging (DTI) of brain tumours can demonstrate abnormalities distal to hyperintensities on T2-weighted images, and possibly relate these to tumour grade. MATERIALS AND METHODS: Twenty patients with histologically confirmed supratentorial tumours, both gliomas (high and low grade) and metastases, were imaged at 3 T using T2-weighted and DTI sequences. Regions of interest (ROI) were drawn within the tumour, in white matter at various distances from the tumour and in areas of abnormality on DTI that appeared normal on T2-weighted images. The relative anisotropy index (RAI)—a measure of white matter organization, was calculated for these ROI. RESULTS: The abnormality on DTI was larger than that seen on T2-weighted images in 10/13 patients (77%) with high-grade gliomas. New abnormalities were seen in the contralateral white matter in 4/13 (30%) of these cases. In these high-grade tumours the RAI in areas of white matter disruption with normal appearance on T2-weighted images was reduced (0.19±0.04). Even excluding patients with previous radiotherapy this difference remains significant. In all non high-grade tumours (WHO grade II gliomas and metastases) the tumour extent on DTI was identical to the abnormalities shown on T2-weighted imaging and RAI measurements were not reduced (0.3±0.04). CONCLUSIONS: Subtle white matter disruption can be identified using DTI in patients with high-grade gliomas. Such disruption is not identified in association with metastases or low-grade gliomas despite these tumours producing significant mass effect and oedema. We suggest the changes in DTI may be due to tumour infiltration and that the DTI may provide a useful method of detecting occult white matter invasion by gliomas.

PERSISTENT SHOULDER PAIN IN A MALE WEIGHTLIFTER

HISTORY M.E. is a 28 year old male right hand dominant graduate student who presented to the Primary Care Sports Medicine Clinic with a chief complaint of 21/2 years of bilateral shoulder pain, left greater than right. The onset of symptoms occurred during weight-lifting. During activities such as bench press the patient described feeling a sensation of his shoulders “shifting” out of place. He would manipulate the shoulders to relieve the symptoms. He denied any history of major trauma. His pain was dull in nature, was localized to the anterior shoulders and radiated to mid-humerus. Recently in the last six months he had an increase in left arm pain with new radiation to the pinky finger and he was unable to sleep on the left shoulder. PMH: allergic rhinitis; ALLERGIES: environmental; MEDS: ibuprofen and naprosyn prn; SPORTS: former competitive swimmer now a weight-lifter. Previous treatment involved physical therapy prescribed 10 months ago by his internist with no improvement in symptoms on the left. No radiographs were obtained. PHYSICAL EXAMINATION Revealed a well-developed male with multiple tattoes. Subtle infraspinatus atrophy on the left was noted. His shoulder was non-tender to palpation. He demonstrated full range of motion. Circumduction revealed bilateral crepitus. He had a positive apprehension test bilateraly but only a positive relocation test on the left with negative impingement signs. 3+ strength was found on the left with Jobe's test, Speeds test and resisted external rotation with 4+ grip strength. DIFFERENTIAL DIAGNOSIS Impingement syndrome with instability. Calcific tendonitis. Rotator cuff tear. Labral injury. Suprascapular neuropathy. Neoplasm. TESTS AND RESULTS Plain radiographs revealed a large ossification superimposed over the superior aspect of the glenoid. A subsequent MRI demonstrated a 3.5 × 3.2 cm heterogeneous lesion in the suprascapular notch extending inside the joint and into the spinoglenoid notch with significant mass effect on the supraspinatus muscle. FINAL/WORKING DIAGNOSIS myositis ossificans versus osteochondroma. TREATMENT AND OUTCOMES The patient was referred for surgical evaluation. The densely calcified mass was excised via an open procedure and was identified as an osteochondroma (osteocartilaginous exostosis). The patient subsequently returned to physical therapy and was treated with indocin. By three months post-surgery he was pain-free and was weight-lifting and swimming.

Metabolic and thermal physiology of pigeons and doves.

Pigeons and doves (Columbidae) are an interesting group to examine for physiological adaptations to climate and diet because this cosmopolitan family comprises more than 300 species that are mostly granivores, although some are specialized frugivores. We determined allometric and phylogenetic effects on body temperature (T(b)), basal metabolic rate (BMR; J h(-1)), and wet thermal conductance (C(wet); J h(-1) C(-1)), and we examined mass (M) and phylogenetically corrected residuals for further effects of climate, diet, and landmass size (mainland or island). Independent contrasts, correlograms, autoregression, and phylogenetic eigenvector regression (PVR) were used to examine phylogenetically related effects. We found a small but significant phylogenetic pattern for body mass of columbids. For T(b), there was no significant effect of mass or phylogeny. There was a significant effect of climate on T(b) and no significant effects of diet or landmass without mass or phylogenetic correction, but after mass and phylogenetic correction, there were no effects of climate, diet, or landmass. For BMR, there was a strong allometric effect, and residuals were significantly lower for arid and tropical species but not for temperate species, compared to predictions for nonpasserine birds. There was a nearly significant autoregressive phylogenetic relationship for BMR parl0;r=0.44), and the strong allometry of BMR remained for independent contrasts (slope=0.731), autoregressive residuals (0.698), and PVR (0.705). Residuals, from regression of autoregression and PVR residuals of M and BMR, were significantly associated with climate: arid pigeons had a lower BMR residual than tropical and temperate pigeons. PVR residuals were significantly affected by landmass (island columbids had a smaller residual than mainland columbids), but autoregression residuals were not. There was no association of autoregression or PVR residuals with diet. For C(wet), there was a strong allometric effect, and residuals for columbids were significantly higher compared to other birds. There was no significant relationship for C(wet) of columbids to climate, diet, or landmass. There was no significant autoregressive or PVR relationship for C(wet), and the strong allometry remained after phylogenetic analysis by independent contrasts (slope=0.501), autoregression (0.509), and PVR (0.514). Residuals from autoregression and PVR were not significantly correlated with climate, diet, or landmass (mainland/island).

Sarcoma granulocítico de sistema nervoso central pós transplante de medula óssea: relato de caso

Granulocytic sarcoma is a solid tumor, composed by granulocytic precursor cells at various levels of differentiation, located at an extra-medullary site. It is associated with acute myeloid leukemia, and its presence reveals a bad prognostic factor. The treatment usually consists of radiotherapy and chemotherapy. A case of an intracranial granulocytic sarcoma occurring six months after a bone marrow transplant in a patient with acute myeloid leukemia is reported. The patient presented with headache and left hemiplegia caused by a large fronto-parietal lesion with significant mass effect. After a complete surgical resection there was a full recovery of the deficit. The patient completed radiotherapy and chemotherapy with no evidence of disease after three months of follow-up. Surgery is indicated in the presence of progressive neurological deficit. Surgical decompression may provide rapid improvement and therefore, affect quality of survival.

Leiomyosarcoma arising from the superior mesenteric vein

Surgery 2002;132:108-9.

A CASE OF BRAIN ABSCESS.

A CASE OF BRAIN ABSCESS.