Non-pituitary origin sellar tumours mimicking pituitary macroadenomas.

Although the large majority of sellar tumours are pituitary adenomas, several other pituitary and non-pituitary origin tumours arise in the sellar and parasellar regions. Given their location, non-adenomatous lesions frequently mimic pituitary macroadenomas and can pose a diagnostic challenge for the radiologist. Distinguishing rare sellar lesions from the common macroadenoma helps to direct the correct surgical approach and reduce the risk of incomplete resection and/or complications such as cerebrospinal fluid leak with the potential for meningitis. The purpose of this article is to review the imaging features of non-pituitary-origin sellar tumours, focusing on characteristics that may distinguish them from pituitary macroadenomas. Lesions include meningioma, metastatic disease, epidermoid cyst, germinoma, chondrosarcoma, giant cell tumour, and giant aneurysm.

Sterol synthesis in vitro in freshly isolated blood mononuclear leukocytes from familial hypercholesterolemic patients treated with probucol.

Sterol synthesis rates were measured in freshly isolated blood mononuclear leukocytes obtained from familial hypercholesterolemic patients undergoing treatment with either probucol alone or probucol plus cholestyramine. Subjects with heterozygous familial hypercholesterolemia on probucol had a significant 31% reduction in mononuclear cell sterol synthesis rates as compared to control patients; sterol synthesis in cells from homozygous familial hypercholesterolemic patients on probucol did not differ from that in control subjects. Addition of cholestyramine to probucol therapy in heterozygous familial hypercholesterolemic patients caused an increase in sterol synthesis rates equal to but not greater than control values, thus negating the decreased mononuclear leukocyte sterol synthesis associated with probucol administration alone. Probucol treatment effectively decreased plasma cholesterol levels in both homozygous and heterozygous familial hypercholesterolemic subjects; however, the data suggest that the drug may exert different effects on sterol synthesis in peripheral tissues depending upon the presence or absence of cellular receptors for low-density lipoproteins.

Chordoid Meningioma: Differentiating a Rare World Health Organization Grade II Tumor from Other Meningioma Histologic Subtypes Using MRI.

BACKGROUND AND PURPOSE: Meningiomas are very commonly diagnosed intracranial primary neoplasms, of which the chordoid subtype is seldom encountered. Our aim was to retrospectively review preoperative MR imaging of intracranial chordoid meningiomas, a rare WHO grade II variant, in an effort to determine if there exist distinguishing MR imaging characteristics that can aid in differentiating this atypical variety from other meningioma subtypes. MATERIALS AND METHODS: Ten cases of WHO grade II chordoid meningioma were diagnosed at our institution over an 11-year span, 8 of which had preoperative MR imaging available for review and were included in our analysis. Chordoid meningioma MR imaging characteristics, including ADC values and normalized ADC ratios, were compared with those of 80 consecutive cases of WHO grade I meningioma, 21 consecutive cases of nonchordoid WHO grade II meningioma, and 1 case of WHO grade III meningioma. RESULTS: Preoperative MR imaging revealed no significant differences in size, location, signal characteristics, or contrast enhancement between chordoid meningiomas and other meningiomas. There were, however, clear differences in the ADC values and normalized ADC ratios, with a mean absolute ADC value of 1.62 ± 0.33 × 10(-3) mm(2)/s and a mean normalized ADC ratio of 2.22 ± 0.47 × 10(-3) mm(2)/s in chordoid meningiomas compared with mean ADC and normalized ADC values, respectively, of 0.88 ± 0.13 × 10(-3) mm(2)/s and 1.17 ± 0.16 × 10(-3) mm(2)/s in benign WHO grade I meningiomas, 0.84 ± 0.11 × 10(-3) mm(2)/s and 1.11 ± 0.15 × 10(-3) mm(2)/s in nonchordoid WHO grade II meningiomas, and 0.57 × 10(-3) mm(2)/s and 0.75 × 10(-3) mm(2)/s in the 1 WHO grade III meningioma. CONCLUSIONS: Chordoid meningiomas have statistically significant elevations of ADC and normalized ADC values when compared with all other WHO grade I, II, and III subtypes, which enables reliable preoperative prediction of this atypical histopathologic diagnosis.

Lowering of plasma cholesterol levels in free-living adolescent males; use of natural and synthetic polyunsaturated foods to provide balanced fat diets.

Two hundred and twenty-nine adolescent male pupils, attending two boarding schools, participated in a study, under free-living dietary conditions, designed to assess the effects on plasma lipids of altering only the type and not the amount of dietary fat. The students were monitored for 6 weeks on three different diets. During the first study period, dietary changes comprised substituting a polyunsaturated dried "filled" milk and products derived therefrom for conventional dairy products (diet A). The second dietary phase involved replacing all meat and dairy products with equivalent polyunsaturated ruminant fat products (diet B). The third period consisted of a control diet of conventional dairy and meat products. During both polyunsaturated diets a 14% reduction in plasma cholesterol was achieved compared with control levels. Low-density lipoprotein cholesterol was similarly suppressed. A greater decrease in plasma cholesterol of 19-21% was recorded in those pupils with initial cholesterol levels greater than 230 mg/dl. There was no significant difference in plasma triglycerides between diet A and the control diet whereas the triglyceride levels were 16.5% lower during diet B. The fall in plasma cholesterol coincided with an increase in plasma triglyceride linoleate from 8% to 19% of total triglyceride fatty acids. Dietary analysis of the pupils' diet indicated an increase in the ratio of polyunsaturates to saturates from 0.27 during the control period to 1.08 on the dried filled milk and 0.90 on the polyunsaturated ruminant fat products. A palatability survey showed that both the dried filled milk and the polyunsaturated ruminant fat products were as well accepted by the pupils as the conventional products. The results suggest that such products could, if introduced to the general population, play an important part in plasma cholesterol suppression in the hope that this would significantly reduce the incidence of coronary artery disease.

Influence of type of carbohydrate on atherosclerosis in baboons fed semipurified diets plus 0.1% cholesterol.

Five groups of six (three male, three female) baboons (Papio ursinus) were maintained for 17 months on a semipurified diet containing 40% carbohydrate, 25% casein, 13.9% coconut oil, 0.1% cholesterol, 15% cellulose, 5% salt mix (USP XIV) and 1% vitamin mix. The carbohydrates fed were: fructose, sucrose, starch, glucose, and lactose. A fifth group was used as control and was fed bread, fruit, and vegetables. Serum, liver, and tissue lipids were analyzed at the end of the feeding period as were cholesterol absorption (as 3H-cholesterol) and synthesis (from 14C-mevalonic acid). Serum cholesterol and beta-lipoprotein levels were elevated in all the test groups compared to final control levels or to starting levels for all the baboons. Average serum cholesterol levels of the test groups were not significantly different. Liver lipids were elevated in all test groups except that fed glucose. Baboons on the test diets absorbed more exogenous cholesterol (3H) but biosynthesis of this sterol was not inhibited. The ratio of biliary primary/secondary bile acids was below normal levels only in the animals fed fructose and sucrose. Cholesteryl ester fatty acid spectra of serum and liver reflected the dietary fat. Fecal weight was 69% higher in lactose fed animals and 31% lower in sucrose fed animals than in the controls. The ratio of endogenous or exogenous neutral/acid steroids was considerably lower in the fructose-fed baboons than in the other animals. On this diet average aortic sudanophilia (percentage of surface) was: fructose, 11.3; sucrose, 10.4; starch, 21.3; glucose, 17.2 lactose, 65.8; and control, 1.4. Gross atheromatous lesions were seen in five of six baboons fed lactose; three of six baboons fed fructose; two of six baboons fed sucrose, and one of six baboons fed starch. In a second experiment three groups of baboons were fed the control diet, the semipurified diet in which the carbohydrate was lactose, and the semipurified diet containing lactose plus 0.1% cholesterol for 8.5 months. Serum lipids were elevated in the two test groups but liver lipids were not significantly different from control levels. Average aortic sudanophilia (percentage of area) was: lactose, 2.2; lactose-cholesterol, 20.8; and control, 0.3%. One of the six baboons in the lactose-cholesterol group had visible atherosclerotic lesions. These experiments represent the first successful attempt to produce severe atherosclerosis in baboons by dietary means alone.

Cognition in relation to magnetic resonance imaging in head-injured children and adolescents.

To investigate the relationship between cognitive sequelae and magnetic resonance imaging (MRI) findings following closed head injury of varying severity in the pediatric age range, 76 head-injured children and adolescents were studied at least 3 months after trauma and compared with 57 normal controls. Problem solving, planning, verbal and design fluency, memory, and response modulation were assessed. Significant effects of injury were obtained on all of the cognitive measures. Cognitive impairment was more consistently present on the various outcome measures in children who were 6 to 10 years old at the time of the study than in the older children and adolescents. Magnetic resonance imaging disclosed areas of abnormal signal in the frontal lobes of 42 patients, whereas focal lesions restricted to the extrafrontal region were found in 15 children. Regression analyses disclosed that taking into account the size of frontal lobe lesion enhanced the relationship between cognitive performance and the severity of injury.

Heterogeneity in spasmodic dysphonia. Neurologic and voice findings.

Spasmodic dysphonia is a disturbance of phonation with laryngeal spasms. We report voice and neurologic examination findings in 45 subjects. Neurologic abnormalities were found in 32 subjects (71.1%). Rapid alternating movement abnormalities, weakness, and tremor were common. Incoordination and spasticity were rare. Lower extremity findings were frequent. Abnormalities were bilateral. Spasmodic dysphonia severity was related to age. Type, severity, and duration of vocal symptoms were not different for subjects with or without neurologic abnormalities. Vocal tremor was more frequent in neurologically abnormal subjects. Involvement of a pallidothalamic-supplementary motor area system could account for neurologic findings, brain imaging findings, and clinical heterogeneity. The view emerging is that spasmodic dysphonia is a manifestation of disordered motor control involving systems of neurons rather than single anatomical sites.

Detection of tuberous sclerosis in parents by magnetic resonance imaging.

We performed a detailed physical examination and MRI without gadolinium DTPA contrast in 60 couples with at least 1 child having tuberous sclerosis (TS). Eight parents had TS diagnosed by physical examination, family history, or various diagnostic procedures including MRI. Eight additional subjects and 6 control subjects had nonspecific high-signal white matter changes on MRI. MRI confirmed the diagnosis of TS in only 1 parent without physical findings of the disease, similar to the results of earlier studies using computed cranial tomography. CT may be less sensitive than MRI but is probably more specific for TS. Either CT or MRI may occasionally help substantiate the diagnosis of TS in a parent with few other findings. Both studies may need to be done in some parents to maximize the accuracy of genetic counseling.

Use of 31P magnetic resonance spectroscopy to characterize evolving brain damage after perinatal asphyxia.

We investigated postasphyxial brain damage with 31P magnetic resonance spectroscopy (MRS) and correlated it with neurologic assessment and standard laboratory evaluation during the first 10 months of life in 1 infant, baby G. We compared these observations to 31P MRS data from 7 healthy term newborns, 1 normal infant examined serially over the first 8.5 months of life, and 5 other term infants following perinatal asphyxia. MRS noninvasively provides biochemical correlates of the evolution of brain damage following perinatal asphyxia and suggests that pH derived from the inorganic phosphate peak may serve as a marker for brain injury.

Reduction of corpus callosum growth after severe traumatic brain injury in children.

OBJECTIVE: To study effects of closed head injury (CHI) severity on development of corpus callosum (CC) in children, using MRI. BACKGROUND: Vulnerability of CC to diffuse axonal injury has been shown in adults and children by neuropathologic and MRI studies. Given continued development of CC through the second decade, serial MRI could characterize effects of CHI on CC growth in children. METHOD: MRI performed at 3 and 36 months after severe (mean age = 10.3 years, n = 25) and mild to moderate (mean age = 9.7 years, n = 28) CHI. Mild to moderate and severe CHI groups did not differ in demographic features. Morphometry of T1-weighted midsagittal CC by two operators with satisfactory interrater reliability yielded uncorrected and corrected CC volume. RESULTS: An interaction of occasion with CHI severity was present as CC area decreased from 3 to 36 months in severely injured children and increased in the mild to moderate CHI group. Uncorrected CC area was correlated with acute CHI severity and functional outcome at 36 months postinjury. CONCLUSIONS: Morphometric measurement of CC area provides a useful index of diffuse injury, which is related to functional outcome of CHI in children.

Word fluency in relation to severity of closed head injury, associated frontal brain lesions, and age at injury in children.

Effects of closed head injury (CHI) severity, focal brain lesions, and age at injury on word fluency (WF) were studied longitudinally in 122 children (78 severe, 44 mild); 112 CHI patients (68 severe, 44 mild CHI) and 104 uninjured normal controls participated in a cross-sectional study. WF was measured by asking the child to generate as many words as possible beginning with a designated letter within 60 s, repeated for three letters. Intellectual ability, receptive vocabulary, narrative discourse, and word list recall were also measured. Results of the cross-sectional study showed a significant group effect with poorer WF in severe CHI than mild CHI and control groups. Growth curve analysis of longitudinal data revealed an interaction of age, follow-up interval, and CHI severity as WF recovery was slower after severe CHI in younger children as compared to severe CHI in older children or mild CHI in younger children. An interaction of left frontal lesion with age and interval indicated a more adverse effect on WF in older children. Right frontal lesion effect was nonsignificant and did not interact with age. Correlations of WF with receptive vocabulary, word list recall, and narrative discourse were moderate and weak with estimated intellectual ability. Differences in focal lesion effects after traumatic versus nontraumatic brain injury in children, the contribution of diffuse white matter injury, reduced opportunity for language development, and functional commitment of left frontal region at time of CHI were discussed.

Treatment of homozygous familial hypercholesterolaemia with portacaval shunt.

Thirteen patients with homozygous familial hypercholesterolaemia (HFH) were treated with portacaval shunt operations. One patient died postoperatively and the others were followed for 2-6 years. The main beneficial effects were regression of xanthomas and sustained falls in serum total and LDL cholesterol levels of about 18% in the majority of cases, sustained rises in HDL cholesterol values in most patients, and the long period of survival after the operation without further deaths or serious cardiac complications. Other favourable effects were improvement of angina pectoris, ejection systolic múrmurs or electrocardiograms in some cases. Growth and development of patients after the operation were normal and there were no clinical or biochemical signs of liver damage or portal systemic encephalopathy. Apart from the patient who died, negative or adverse effects of the operation included shunt closure causing portal hypertension and bleeding varices in 1 case, unsatisfactory clinical responses in half the patients, small or unsustained falls in serum total cholesterol in one third of cases, and failure of total cholesterol to fall below 12.0 mmol/l in any patient. Enlargement of the spleen appeared to be an invariable consequence of the operation and possible reasons for this are discussed. Finally the place of portacaval shunts in the management of HFH is reviewed.

Intensive radiation therapy concurrent with up to 7-week continuous-infusion paclitaxel for locally advanced solid tumors: phase I studies.

Patients with locally advanced solid tumors of the lung, head and neck, and malignant astrocytomas usually succumb to their disease despite aggressive standard therapy. Laboratory data suggest that the addition of 1.0 to 10 nmol/L paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ), a microtubule stabilizing drug, to radiation therapy may result in significant radiation sensitization, perhaps due to accumulation of cells at G2/M. Relatively low concentrations (1.0 to 10 nmol/L) appear to be optimal for direct cytotoxicity and radiosensitization in vitro. Within this dose range, more prolonged exposure seems to result in higher response rates. The phase I trials reported here are designed to test the combination of paclitaxel, administered by continuous intravenous infusion (24 hours a day, 7 days a week), and standard, curative-intent radiation therapy. The ultimate goal of this study is to improve local and systemic control and survival for patients with these three tumor types. To date, 39 evaluable patients are enrolled in this study; there has been no dose-limiting toxicity up to 6.5 mg/m2/d. Observed toxicities include anemia, lymphopenia, mucositis, and cutaneous toxicities.

Prevalence of familial hypercholesterolemia in Johannesburg Jews.

The prevalence of heterozygous familial hypercholesterolemia was determined in a representative sample of 403 young Jewish men resident in Johannesburg, South Africa. Preliminary screening by measurement of serum total cholesterol demonstrated that 25 of them had levels greater than or equal to 7.5 mmol/l (290 mg/dl). On the basis of subsequent clinical, biochemical, and family studies, 6 men, or about 1 in 67 of the total sample, were considered to be heterozygotes. This very high prevalence, about 7 times greater than that found in other Caucasian populations, is probably related to founder effect. It may help to explain the high frequency of coronary heart disease in Johannesburg Jews.

Observed relationship between ratios HDL-cholesterol/total cholesterol and apolipoprotein A1/apolipoprotein B.

Epidemiological evidence suggests that the ratio HDL-cholesterol (HDL-C)/total cholesterol (TC) or apolipoprotein A1 (apo A1)/apolipoprotein B (apo B) are good indicators of coronary heart disease risk. In investigating the distribution of these ratios in the typical population served by our routine laboratory, we analysed the lipid results of 541 serum samples submitted over a 2-month period for TC, HDL-C, apo A1, and apo B. Good correlation was observed between HDL-C and apo A1 (r = 0.664), and between TC and apo B (r = 0.674). Surprisingly, the correlation between the ratios HDL-C/TC (range: 0.05-0.40) and apo A1/apo B (range: 0.27-3.71) was even higher (r = 0.822). Similar significant correlations were observed in 31 heterozygous and 20 homozygous familial hypercholesterolemic subjects, viz. the correlations between HDL-C/TC (ranges: 0.04-0.24 and 0.02-0.12, respectively) and apo A1/apo B (ranges: 0.47-1.84 and 0.15-1.12, respectively) were r = 0.951 and r = 0.972, respectively.

The effects of a mixed fish diet on platelet function, fatty acids and serum lipids.

Eight healthy subjects were fed a diet containing 1-4 g eicosapentaenoic acid (EPA) daily for 8-21 days. The EPA was derived from 300-400 g per day of sardines, pilchards, herring and/or kabeljou. Sources of arachidonic acid (AA) in the diet were reduced. At the end of the experimental period there was an increase in the ratio of EPA to AA in the platelets and a decrease in platelet aggregation to ADP, epinephrine and collagen. Aggregation to AA was not reduced. Thromboxane production in response to all four agonists was reduced. Serum total and HDL cholesterol levels fell significantly but platelet counts, LDL cholesterol and triglyceride values did not change. We conclude that even a relatively modest intake of EPA derived from a mixed fish diet together with a reduction in AA intake can alter in vitro platelet function and serum lipids significantly. A long term controlled trial of a palatable mixed fish diet to assess possible antithrombotic and antiatherogenic effects is justifiable.

Recurrent medulloblastoma: frequency of tumor enhancement on Gd-DTPA MR imaging.

Thirty-two children with medulloblastoma were evaluated postoperatively with conventional and gadolinium-enhanced MR imaging. Eleven patients had abnormal cranial MR studies; nine of these had recurrent tumor. In six patients recurrent tumor enhanced with Gd, while in the other three patients recurrent tumor did not enhance. The remaining two patients had areas of abnormal Gd enhancement that were caused by radiation-induced breakdown of the blood-brain barrier rather than by recurrent tumor. This study shows that not all recurrent medulloblastoma enhances and that the absence of Gd enhancement does not necessarily indicate the absence of recurrent tumor.

Fetal lung maturity tests on the 10,000 X g pellet.

Centrifugation has a profound effect on tests of fetal lung maturity performed on amniotic fluid. We have investigated the effect of a 700 X g centrifugal force for 10 min and a 10,000 X g force for 20 min on a battery of tests. While 91% of the OD650 was removed by the 10,000 X g centrifugal force, the supernatant fraction retained 34% and 38% of the L/S ratio and enzymatic lecithin respectively, when compared to the sample before centrifugation. Phosphatidylglycerol, when present in an amniotic fluid, was always absent from the 10,000 X g supernatant but present in the pellet formed by this centrifugal force. The pellet after 10,000 X g was unsuitable for OD650 and L/S ratio determinations but contained 63% of the enzymatic lecithin. When the pellet tests were subjected to a clinical trial, respiratory immaturity did not occur when phosphatidylglycerol was present or when the 10,000 X g pellet may be a useful means of detecting amniotic fluid surfactant and thus determining fetal lung maturity.

Semantic memory following pediatric head injury: relationship to age, severity of injury, and MRI.

The effects of closed head injury (CHI) severity (mild vs. severe) and age at injury were analyzed in a longitudinal study (3. 12 months postinjury) of semantic memory which used magnetic resonance imaging (MRI) to characterize focal brain lesions. Semantic memory was evaluated by word and category fluency, semantic verification, semantic clustering in word list recall, and vocabulary. Episodic memory was assessed by word list recall. Comparison of normal control (n = 104) data with the patients' data (n = 77) at 3 months postinjury disclosed semantic and episodic memory deficits in the severe CHI patients. Analysis of the longitudinal data revealed significant effects of age at injury for all of the semantic memory measures. The effects of injury severity were confined to the latency of verifying correct statements. Volume of left frontal and extrafrontal lesions was predictive of performance on several semantic memory measures, but less robust for right hemisphere lesions.

Corpus callosum damage and interhemispheric transfer of information following closed head injury in children.

We evaluated the relationship of corpus callosum atrophy and/or lesions on magnetic resonance imaging (MRI) to functional hemispheric disconnection following closed head injury (CHI) in 51 pediatric patients, including mild CHI, moderate to severe CHI with extracallosal lesions, and moderate to severe CHI with callosal atrophy and/or lesions. Interhemispheric transfer of information was assessed using auditory, motor, tactile, and visual tests in patients and in 16 uninjured children. Total and regional callosal areas were measured from the midsagittal MRI slice by morphometry. The corpus callosum lesion group demonstrated a greater right ear advantage on verbal dichotic listening than all other groups. Areas of the posterior corpus callosum were negatively correlated with laterality indices of verbal dichotic listening performance and tachistoscopic identification of verbal material. The relationship of corpus callosum atrophy and/or lesions to asymmetry in dichotic listening is consistent with previous investigation of posttraumatic hemispheric disconnection effects in adults.