The clinical value of proton magnetic resonance spectroscopy in adult brain tumours

Proton magnetic resonance spectroscopy (1H MRS) non-invasively provides information on the biochemical profile (typically including up to nine metabolites and mobile lipids) of brain tissue, which varies according to the underlying disease process. A number of studies have assessed its accuracy in the diagnosis of adult brain tumours. This article describes the basic principles of 1H MRS, the metabolic profiles of different brain tumours, and practical points to aid interpretation of spectra. The literature is reviewed regarding the role of 1H MRS in the diagnosis of brain tumours and more specifically where it has proven to be of additional benefit over conventional magnetic resonance imaging.

Advancement in post-meningitic lateral semicircular canal labyrinthitis ossificans

Objective: To assess whether lateral semicircular canal (LSCC) ossification is more advanced than that in the cochlear basal turn, in order to judge the value of the former as a predictor.

Methods: Retrospective review of 33 paediatric patients from our cochlear implant programme, with profound sensorineural hearing loss after bacterial meningitis. Magnetic resonance imaging (MRI), computed tomography (CT) scans and operative findings were reviewed.

Results: On CT, LSCC ossification scores were more advanced than those for the cochlear basal turn in 69.9 per cent of implanted ears. Forty-five per cent (15/33) of children had ossification at surgery. In predicting this, the sensitivity of CT LSCC ossification was 90 per cent and that of MRI LSCC ossification was 83.3 per cent.

Conclusions: The more advanced ossification found in the LSCC, compared with that in the cochlear basal turn, adds to previous findings of LSCC pathology predicting cochlear ossification. Surprisingly, CT of the LSCC appears to be no less valuable than MRI in pre-operative cochlear implant assessment of post-meningitic children.

Cerebral venous sinus thrombosis in children: risk factors, presentation, diagnosis and outcome

Neuroimaging and management advances require review of indications for excluding cerebral venous sinus (sinovenous) thrombosis (CSVT) in children. Our goals were to examine (i) clinical presentations of CSVT, (ii) prothrombotic risk factors and other predisposing events, (iii) clinical and radiological features of brain lesions in CSVT compared with arterial stroke, and (iv) predictors of outcome. We studied 42 children with CSVT from five European paediatric neurology stroke registries. Patients aged from 3 weeks to 13 (median 5.75) years (27 boys; 64%) presented with lethargy, anorexia, headache, vomiting, seizures, focal signs or coma and with CSVT on neuroimaging. Seventeen had prior chronic conditions; of the 25 previously well patients, 23 had recent infections, eight became dehydrated and six had both. Two children had a history compatible with prior CSVT. Anaemia and/or microcytosis (21 probable iron deficiency, five haemolytic, including two with sickle cell disease and one with beta-thalassaemia) was as common (62%) as prothrombotic disorder (13/21 screened). High factor VIII and homozygosity for the thermolabile methylene tetrahydrofolate reductase polymorphism were the commonest prothrombotic disorders. The superficial venous system was involved in 32 patients, the deep in six, and both in four. Data on the 13 children with bland infarction and the 12 with haemorrhage in the context of CSVT were compared with those from 88 children with ischaemic (AIS) and 24 with haemorrhagic (AHS) arterial stroke. In multiple logistic regression, iron deficiency, parietal infarction and lack of caudate involvement independently predicted CSVT rather than arterial disease. Five patients died, three acutely, one after recurrence and one after 6 months being quadriparetic and blind. Follow-up ranged from 0.5 to 10 (median 1) years. Twenty-six patients (62%) had sequelae: pseudotumour cerebri in 12 and cognitive and/or behavioural disabilities in 14, associated with epilepsy in three, hemiparesis in two and visual problems in two. Eighteen patients, including six with haemorrhage, were anticoagulated. Older age [odds ratio (OR) 1.54, 95% confidence limits (CI) 1.12, 2.13, P = 0.008], lack of parenchymal abnormality (OR 0.17, 95% CI 0.02, 1.56, P = 0.1), anticoagulation (OR 24.2, 95% CI 1.96, 299) and lateral and/or sigmoid sinus involvement (OR 16.2, 95% CI 1.62, 161, P = 0.02) were independent predictors of good cognitive outcome, although the last predicted pseudotumour cerebri. Death was associated with coma at presentation. Of 19 patients with follow-up magnetic resonance (MR) venography, three had persistent occlusion, associated with anaemia and longer prodrome. A low threshold for CT or MR venography in children with acute neurological symptoms is essential. Nutritional deficiencies may be modifiable risk factors. A paediatric anticoagulation trial may be required, after the natural history has been further established from registries of cases with and without treatment.

Metabolic profiles of human brain tumors using quantitative in vivo 1H magnetic resonance spectroscopy

Proton spectroscopy can noninvasively provide useful information on brain tumor type and grade. Short- (30 ms) and long- (136 ms) echo time (TE) (1)H spectra were acquired from normal white matter (NWM), meningiomas, grade II astrocytomas, anaplastic astrocytomas, glioblastomas, and metastases. Very low myo-Inositol ([mI]) and creatine ([Cr]) were characteristic of meningiomas, and high [mI] characteristic of grade II astrocytomas. Tumor choline ([Cho]) was greater than NWM and increased with grade for grade II and anaplastic astrocytomas, but was highly variable for glioblastomas. Higher [Cho] and [Cr] correlated with low lipid and lactate (P < 0.05), indicating a dilution of metabolite concentrations due to necrosis in high-grade tumors. Metabolite peak area ratios showed no correlation with lipids and mI/Cho (at TE = 30 ms), and Cr/Cho (at TE = 136 ms) best correlated with tumor grade. The quantified lipid, macromolecule, and lactate levels increased with grade of tumor, consistent with progression from hypoxia to necrosis. Quantification of lipids and macromolecules at short TE provided a good marker for tumor grade, and a scatter plot of the sum of alanine, lactate, and delta 1.3 lipid signals vs. mI/Cho provided a simple way to separate most tumors by type and grade.

MR spectroscopy in stroke

Magnetic resonance spectroscopy (MRS) is a non-invasive in vivo method that allows the investigation of biochemical changes in both animals and humans. The application of MRS to the study of stroke has made possible dynamic studies of intracellular metabolism of cerebral ischaemia. The majority of the stroke studies have been carried out using proton [1H]-MRS which allows the detection of N-acetyl aspartate (NAA), a neuronal marker. [1H]-MRS changes in humans demonstrate that after an infarct, lactate appears, while NAA and total creatine are reduced compared to the contralateral hemisphere. Longitudinal studies demonstrate a further reduction of NAA suggesting that ischaemic injury continues for more than a week following infarction. Major advances in the treatment of acute stroke require the accurate prediction of the mortality of stroke patients. Patients with large infarcts are known to do badly. In patients with small infarcts, less than 80 cm3, the addition of core NAA concentrations and cerebral blood flow have enabled the identification of some of the patients likely to benefit from new drug treatment.

Measurement of initial N-acetyl aspartate concentration by magnetic resonance spectroscopy and initial infarct volume by MRI predicts outcome in patients with middle cerebral artery territory infarction

BACKGROUND AND PURPOSE

(1)H MR spectroscopy can be used to study biochemical changes occurring in the brain in stroke. We used it to examine the relationship between metabolite concentration (N-acetyl aspartate [NAA], lactate, cholines and creatines), size of infarct, clinical deficit, and 3-month clinical outcome in patients with middle cerebral artery (MCA) territory infarction.

METHODS

Thirty-one patients with acute MCA territory infarction were recruited within 72 hours of the onset of symptoms. Single-voxel short echo time stimulated echo acquistion mode spectroscopy was used to obtain metabolite data from the infarct core. Metabolite concentrations were determined with use of variable projection time domain-fitting analysis. Infarct size was determined with T2-weighted images. Patient outcome groups at 3 months were "independent," "dependent," or "dead."

RESULTS

All patients (100%; 95% CI 75% to 100%) who had an infarct >70 mL did poorly. Eighteen of 20 patients (90%; 95% CI 68% to 99%) with a core NAA concentration <7 mmol/L did poorly at 3 months, whereas 7 of 11 patients (64%; 95% CI 31% to 89%) with an initial NAA concentration >7 mmol/L did well. Combining these results showed that all patients who had an initial infarct volume >70 mL did poorly, irrespective of the NAA concentration. Of those patients with infarcts <70 mL, those who had a core NAA concentration >7 mmol/L did well (88%; 95% CI 47% to 100%), whereas those with a lower NAA concentration did poorly (80%; 95% CI 44% to 97%). There was no association between other metabolite concentrations and outcome.

CONCLUSIONS

Infarct volume and NAA concentration can together predict clinical outcome in MCA infarction in humans.

Aging of the adult human brain: in vivo quantitation of metabolite content with proton magnetic resonance spectroscopy

The purpose of this study was to examine the effect of aging on brain metabolite concentrations, including N-acetyl aspartate (NAA), the major marker of neurones, using short echo proton spectroscopy. Single-voxel proton spectra (TE 30 msec, TR 2 seconds) were obtained from white and gray matter using automated software (PROBE, G.E., Milwaukee, WI). Spectra were analyzed using the variable projection technique. Thirty healthy volunteers were studied within the age range 24-89 years. No significant trend in change of concentrations of NAA, total creatine, total choline or myo-inositol were seen with age. The total creatine concentration of parietal white matter in the over 60 age group (6.5 +/- 0.3 mmol/l) was significantly higher than the under 60 age group (6.0 +/- 0.4 mmol/l:; P < 0.05). No other significant difference between the two age groups was seen. The tissue concentration of the major neuronal marker, NAA, does not decline with age. No age-related changes in the concentrations of choline and myo-inositol and occipital gray matter total creatine were observed. These results provide a normal range of values for spectroscopically detectable metabolites within the regions studied, against which neurological diseases such as Alzheimer's disease can be compared in vivo.

Ethanol elevates c-Myc levels in cultured mouse preimplantation embryos

A brief exposure to ethanol accelerates the rate of early mouse embryonic development in vitro, increasing blastocyst formation, trophoblast outgrowth, and implantation rates after embryo transfer. The physiological effects of ethanol during preimplantation development are associated with rapid changes in gene expression and apparently arise from the ability of ethanol to elevate cytoplasmic free Ca2+ and alter cellular signaling pathways. The purpose of this study was to examine whether the abundance of c-Myc, a transcription factor that promotes cell proliferation and is required for blastocyst development, is upregulated in mouse blastocysts challenged with ethanol. After exposure of mouse blastocysts to 0.1% (17.5 mM) ethanol, wc determined the levels of: 1) c-Myc mRNA, using reverse transcription and the polymerase chain reaction; and 2) c-Myc protein levels, using specific monoclonal antibodies. Within 10 min of exposure to ethanol, the relative abundance of c-Myc mRNA increased 6-fold, then rapidly returned to baseline levels within 1 hr. As expected, elevation of c-Myc mRNA by ethanol was attenuated in embryos that were first treated with the intracellular Ca2+ chelator, BAPTA-AM. Western blot analysis of solubilized embryos revealed that c-Myc mRNA was translated into a single 62-kD protein that increased in intensity 30 min after treatment with ethanol. Immunocytochemical staining demonstrated that c-Myc was localized exclusively in nuclei and that staining intensity increased significantly after 10 min. Peak levels of c-Myc protein were found 30 min after ethanol exposure and persisted for at least 2 hr. The c-myc proto-oncogene seems to be an immediate early response gene for ethanol that may regulate the transcription of other genes that influence early embryogenesis and growth.

Discrimination of metabolite from lipid and macromolecule resonances in cerebral infarction in humans using short echo proton spectroscopy

Short-echo proton spectroscopy allows the noninvasive study of metabolites, lipids, and macromolecules in stroke patients, but spectra are difficult to interpret and quantify because narrow metabolite peaks are added to a broad background of lipid and macromolecule peaks. "Metabolite nulling" was used to distinguish the lactate peak from underlying lipid and macromolecule peaks. Increases in the lipid and macromolecule peaks were initially observed within the region of infarction in all patients, and further increases in lipid peaks were seen in five of the six patients during the following 6 weeks. The initial high lactate concentration decreases during the first 2 weeks after stroke, whereas lipid and macromolecule signals show a persistent elevation during the same period. Differences in the time courses of the observed changes suggest that lipid, macromolecule, and lactate signals arise from more than one source.

Alcohol reduces neurofilament protein levels in primary cultured hippocampal neurons

High concentrations of alcohol (> or = 1.8%) were shown previously to impair health and viability of cultured hippocampal neurons. Because neurofilament proteins are essential for neuronal process outgrowth and differentiation, the effects of alcohol on these proteins were determined in the neuronal processes of primary cultured gestational day 18 rat hippocampal neurons. At the relatively lower concentrations used in the present study, alcohol caused a concentration-dependent reduction (< or = 47%) in 68 and 200 kDa neurofilament proteins (p < 0.05). Alcohol caused a 32% downward trend in 160 kDa neurofilament protein levels. Alcohol up to 1% (72-h exposure) produced no obvious alterations in neurite extension or explant morphology, and there were no visual signs of cell death. The sensitive MTT dye reduction assay showed no biochemical evidence of decreased cell viability at < or = 0.5% alcohol. The 32-47% reductions in neurofilament protein levels in vitro may hold implications for later hippocampal neuronal differentiation events in animals prenatally exposed to alcohol.

Paclitaxel-induced apoptosis in MCF-7 breast-cancer cells

A study of MCF-7 human breast cancer cells was undertaken to ascertain the degree of apoptosis induction by paclitaxel and if the induction of apoptosis could be enhanced by caffeine. Paclitaxel (0-20 ng/ml) caused concentration-dependent increases in morphologically identifiable apoptotic cells (up to 43% of cell population) and cells with DNA strand breaks (up to 38%), a commonly cited marker of apoptosis. Maximal DNA strand breakage occurred after 16 hr of exposure to paclitaxel and maximal apoptotic-appearing cells occurred after 24 hr. The remaining non-apoptotic paclitaxel-exposed cells were growth arrested in G2. A 4-hr exposure to caffeine concentration-dependently (0-20 mM) increased apoptosis to 88% of the cell population. Our results show induction of apoptosis in breast cancer cells by paclitaxel, and enhancement of this process by caffeine.

Application of magnetic resonance neurography in the evaluation of patients with peripheral nerve pathology

Currently, diagnosis and management of disorders involving nerves are generally undertaken without images of the nerves themselves. The authors evaluated whether direct nerve images obtained using the new technique of magnetic resonance (MR) neurography could be used to make clinically important diagnostic distinctions that cannot be readily accomplished using existing methods. The authors obtained T2-weighted fast spin-echo fat-suppressed (chemical shift selection or inversion recovery) and T1-weighted images with planes parallel or transverse to the long axis of nerves using standard or phased-array coils in healthy volunteers and referred patients in 242 sessions. Longitudinal and cross-sectional fascicular images readily distinguished perineural from intraneural masses, thus predicting both resectability and requirement for intraoperative electrophysiological monitoring. Fascicle pattern and longitudinal anatomy firmly identified nerves and thus improved the safety of image-guided procedures. In severe trauma, MR neurography identified nerve discontinuity at the fascicular level preoperatively, thus verifying the need for surgical repair. Direct images readily demonstrated increased diameter in injured nerves and showed the linear extent and time course of image hyperintensity associated with nerve injury. These findings confirm and precisely localize focal nerve compressions, thus avoiding some exploratory surgery and allowing for smaller targeted exposures when surgery is indicated. Direct nerve imaging can demonstrate nerve continuity, distinguish intraneural from perineural masses, and localize nerve compressions prior to surgical exploration. Magnetic resonance neurography can add clinically useful diagnostic information in many situations in which physical examinations, electrodiagnostic tests, and existing image techniques are inconclusive.

Exposure of embryonic cells to alcohol: contrasting effects during preimplantation and postimplantation development

Alcohol is a known teratogen that causes a broad variety of developmental anomalies, including fetal growth retardation, craniofacial anomalies, and neurological disorders. The etiology of this multiple defect syndrome, known as fetal alcohol syndrome, has been studied in animal models that reproduce many of the attributes of the human disease. These studies show that ethanol is most teratogenic during organogenesis and development of the nervous system. The molecular basis of fetal alcohol effects has been further investigated using embryo and cell culture systems. Recent studies show that signal transduction pathways controlling cell proliferation are perturbed during ethanol exposure. Ethanol can induce the release of intracellular calcium stores, which stimulates the cell cycle, and it also up-regulates the expression of myc proteins associated with cell proliferation. Increased proliferation is advantageous during the preimplantation period, but ethanol interference with terminal differentiation events within developing tissues during organogenesis may underlie alcohol teratogenicity.

Measurement of infarct size using MRI predicts prognosis in middle cerebral artery infarction

BACKGROUND AND PURPOSE

An accurate measure of the severity of ischemic insult and the resulting prognosis is needed to assess the effectiveness of new treatments for acute stroke. We studied the reproducibility and accuracy of measurements of infarct volume with MRI and correlated the measurements with outcome.

METHODS

Infarct volume was measured on T2-weighted images with the Analyze image analysis software. This technique was found to be highly accurate and reproducible.

RESULTS

Measurements of infarct volume were found to be highly accurate and reproducible. Twenty-one patients (mean age, 66.5 years; range, 28 to 90 years) with cortical middle cerebral artery territory infarcts in whom adequate data could be obtained were studied within 72 hours from onset (mean delay to MRI, 27.5 hours; range, 5 to 72 hours). The Scandinavian Stroke Scale was used to calculate a prognostic score, and clinical outcome was assessed at 3 months. Infarct volume was found to significantly predict outcome. Mean infarct volume in the independent patients was 35.7 +/- 29.7 cm3 compared with 88.3 +/- 71.3 cm3 in dependent patients and 166.5 +/- 65.9 cm3 in dead patients (F = 10.52, P < .001). Patients with an initial infarct volume less than 80 cm3 were found to have a better outcome than those with larger infarct volumes. Secondary hemorrhage visible on MRI also predicted a poor outcome. In contrast, the Scandinavian Stroke Scale did not significantly predict outcome.

CONCLUSIONS

The results demonstrate that measurement of the size of middle cerebral artery infarction with MRI is a useful tool in assessing prognosis and will have a valuable role in assessing new therapeutic agents.

Alcohol inhibits neurite extension and increases N-myc and c-myc proteins

Alcohol teratogenesis may be due, in part, to inhibition of neuronal differentiation by alcohol. Because decreases in the N-myc and c-myc proteins are believed to be linked causally to neuronal differentiation, we hypothesized that alcohol would increase N-myc and c-myc proteins in undifferentiated neuronal cells and would oppose the decreases in these two proteins that normally precede differentiation. In undifferentiated LA-N-5 cultured human neuroblastoma cells, alcohol increased N-myc protein levels (178% vs. control cells) and c-myc levels (222% of control). Retinoic acid decreased N-myc and c-myc and induced neurite outgrowth (a differentiation marker). Alcohol prevented retinoic acid-elicited decreases in both myc isoforms and prevented neurite outgrowth. A significant 100% increase in c-myc and an upward trend (48%) in N-myc were observed in CA1 pyramidal neurons of the dorsal hippocampus in mouse fetuses exposed prenatally to alcohol. These data suggest that increases in N-myc and c-myc protein levels are associated with inhibition of neurite extension by alcohol.

Inhibition of breast and ovarian carcinoma cell growth by 1,25-dihydroxyvitamin D3 combined with retinoic acid or dexamethasone

This study examined the growth inhibitory effects of combining 1,25-dihydroxyvitamin D3 (calcitriol) with retinoic acid or dexamethasone against cultured breast and ovarian carcinoma cells. Retinoic acid (12.5-50 nM) increased the effectiveness of calcitriol (12.5-50 nM) against MCF-7 and NIH:OVCAR3 cells, with synergistic interactions at two of the three ratios tested. Dexamethasone augmented calcitriol effects, with synergism at 0.05 and 0.1 nM dexamethasone in MCF-7 cells and 5 nM in Caov-4 ovarian cells. This study showed favorable interactions for calcitriol-retinoic acid and calcitriol-dexamethasone combinations in breast and ovarian cancer cell lines.

Continuing ischemic damage after acute middle cerebral artery infarction in humans demonstrated by short-echo proton spectroscopy

BACKGROUND AND PURPOSE

Proton MR spectroscopy is a noninvasive method of monitoring in vivo metabolite concentration changes over time. The aim of this work was to study the ischemic penumbra in humans by measuring the metabolic changes that occur after a middle cerebral artery territory infarction.

METHODS

Diagnostic MRI and short-echo time MR spectroscopy were performed on a 1.5-T system. Localized proton MR spectroscopy was performed within the area of cerebral infarction and in a homologous area of the contralateral hemisphere. The residual water resonance in the spectra was removed with the use of the Hankel Lanczos singular value decomposition method, after which peak area estimates were obtained by means of the variable projection time domain fitting analysis. The unsuppressed water signal was used as an internal concentration standard. Ten patients with acute middle cerebral artery infarction were studied within 28 hours of stroke onset and followed up for a period of up to 3 months.

RESULTS

Significant changes were seen in the initial spectra from the infarct compared with the contralateral spectra. Lactate, a marker of anaerobic metabolism, was present within the infarct but not detected in the contralateral hemisphere. N-Acetyl aspartate, a neuronal marker, and total creatine were significantly reduced. The initial choline signal, arising from choline-containing compounds within the cell and cell membrane, remained unchanged in the infarct core compared with the contralateral hemisphere. Further reductions in N-acetyl aspartate and total creatine concentrations occurred within the first week. A fall in the lactate concentration was seen within the infarct core during the first 7 to 10 days. Similar reductions in the choline concentration were observed during this period.

CONCLUSIONS

The demonstration of the continuing loss of cerebral metabolites within an infarct region suggests that further cell loss occurs up to 10 days after infarction. The continuing loss of neurons may represent continued ischemic damage after middle cerebral artery infarction.

Reversal of alcohol's effects on neurite extension and on neuronal GAP43/B50, N-myc, and c-myc protein levels by retinoic acid

Alcohol teratogenesis may be due in part to inhibition of neuronal differentiation by ethanol. We showed previously that alcohol decreased neuronal differentiation (neurite extension) and increased N-myc and c-myc neuronal protein levels. Since Growth-Associated Protein 43 (GAP43/B50) levels must increase for neurons to differentiate, alcohol may decrease GAP43/B50. Alcohol dose-dependently (0-0.5%) decreased GAP43/B50 protein levels by up to 92% in immature LA-N-5 cells. Five nM retinoic acid alone induced differentiation and increased GAP43/B50 levels to 230% of control. These retinoic acid-induced increases in GAP43/B50 and neurite outgrowth, and decreases in N-myc and c-myc, were reversed dose-dependently by alcohol (0-0.5%). Conversely, the adverse effects of 0.25% alcohol on neurite extension, GAP43/B50, N-myc, and c-myc were prevented by 15 and 45 nM retinoic acid. These results suggest that inhibition of neuronal differentiation by alcohol and prevention of such effects by retinoic acid are related to changes in GAP43/B50, N-myc and c-myc.

Magnetic resonance neurography of the median nerve

A magnetic resonance imaging sequence, combining fat and flow suppression with T2 weighting, has been used to produce high conspicuity images of the median nerve within the carpal tunnel. Standard maximum intensity projection techniques were then used to produce three-dimensional (3D) reconstructions of the nerve. Comparison of 3D projections with the wrist in a neutral position and wrist flexed at 45 degrees depicted changes in the shape and course of the median nerve through the carpal tunnel of normal volunteers. In some cases of carpal tunnel syndrome evidence of a localized compression was observed. A 3D image of a nerve may help in the diagnosis of peripheral neuropathy and be an aid to surgery of or near major nerves.

HIV disease. Psychosocial issues for patients and doctors

How a patient responds to a diagnosis of HIV disease depends on personality and coping skills learned throughout life. Health care professionals are seriously challenged to meet the psychosocial needs of HIV patients and their networks of partners, families, and friends. We find great satisfaction in being able to help these patients.

Gay patients. Context for care

Gays and lesbians are a part of our society and our practices: real people with real lives, not stereotypes. Understanding their inner world and their social milieu is the first step to providing care that is holistic and appropriate. The "coming out" process and other unique health issues are described. Guidance is provided on how to identify and relate to gay and lesbian patients.

Additive inhibition of RL95-2 endometrial carcinoma cell growth by carboplatin and 1,25 dihydroxyvitamin D3

Responses of stage III/IV endometrial adenocarcinomas to cytotoxic agents have been partial and of short duration, results which indicate a need for new agents and therapeutic strategies. This study was undertaken to determine the effects of carboplatin and the active metabolite of vitamin D, 1,25 dihydroxyvitamin D3 (calcitriol), on the growth of RL95-2 endometrial carcinoma cells. Carboplatin is a second-generation platinum-based cytotoxic agent. Calcitriol is a biologic agent that has activity against multiple solid tumors, including ovarian carcinomas. Carboplatin inhibited the growth of RL95-2 cells in a concentration-dependent manner with maximal inhibition (78%) at 200 micrograms/ml. Calcitriol also inhibited RL95-2 growth in a concentration-dependent manner. Maximal inhibition (29%) was elicited by 80 nM calcitriol. Addition of 10-50 nM calcitriol to 5-20 micrograms/ml carboplatin resulted in improved growth inhibition. The degree of interaction between carboplatin and calcitriol was assessed using isobolographic analysis and was found to be additive at all drug concentrations and ratios examined. These results suggest that carboplatin and calcitriol each inhibit the growth of RL95-2 endometrial carcinoma cells and that the combination of these two agents acts additively to inhibit the growth of RL95-2 cells. These agents merit further investigation for their utility against endometrial carcinomas.

Inhibition of c-myc in breast and ovarian carcinoma cells by 1,25-dihydroxyvitamin D3, retinoic acid and dexamethasone

The role and regulation of the c-myc protooncogene in breast and ovarian neoplasms is receiving increased attention. The downregulation of the c-myc protooncogene by 1,25-dihydroxyvitamin D3 (calcitriol), retinoic acid (RA) and dexamethasone (Dex) is closely associated with growth inhibition in leukemic cells. Calcitriol, RA and Dex have anti-proliferative activity in breast and gynecologic carcinoma cells; however, the regulation of c-myc by these agents in breast and ovarian cancers is mostly unknown. We have addressed the regulation of c-myc in these cancers using an adaptation of a novel method which employs an immunohistochemical procedure to detect c-myc protein followed by quantification of c-myc staining with computerized image analysis. This system represents an alternative to protein product assay by Western blotting and is straightforward, rapid (1 day), can be carried out on a small scale and provides a sample size that readily facilitates statistical analysis of assay data. In MCF-7 human breast cancer cells, c-myc was suppressed 29% by 0.5 nM Dex, 45% by 0.01 nM RA and 54% by 100 nM calcitriol after 24 h of drug treatment. At the same hormone concentrations, growth was inhibited 18% by Dex, 18% by RA and 39% by calcitriol after 3 days of treatment (p < 0.05 for all hormones). Similar patterns of growth and c-myc inhibition were seen in T47D human breast cancer cells and NIH:OVCAR3 human ovarian cancer cells, with the exception of Dex in T47D cells, which caused no inhibition of c-myc or growth.(ABSTRACT TRUNCATED AT 250 WORDS)

Proton spectroscopy in vivo

1H magnetic resonance spectroscopy (MRS) has attracted much attention in recent years. Since the proton is the most sensitive stable nucleus for MRS, and since almost all metabolites contain hydrogen atoms, it is possible to perform a noninvasive chemical analysis on tissues deep within the body of a subject. Technical solutions to the elimination of water and lipid signals as well as resolution of the large number of potential metabolite peaks have been found. Most current work is on the brain, much of it in humans. This review begins with a consideration of these technical problems and also localization, editing, quantitation, and interpretation of spectra. Two diseases are considered in detail: cerebral ischemia (including stroke and neonatal ischemic/hypoxic injury) and cancer; a further section briefly reviews studies on other diseases. In the immediate future, 1H MRS is likely to benefit from a number of technical advances: higher field magnets, better control of gradients and eddy currents, more sophisticated radiofrequency (RF) pulses, and 1H-observe/13C-edited spectroscopy all offer potential improvements. Another major improvement will come from increased user-friendliness of clinical spectrometers and use of automated objective methods for spectroscopic data analysis.

Are race differences in the prevalence of hypertension explained by body mass and fat distribution? A survey in a biracial population

Body mass and body fat distribution are important considerations in the study of hypertension. However, few studies have investigated the relationships with regards to race differences in elevated arterial pressure. A population-based sample of black and white adults was assessed by interview and physical measurement. The prevalence of hypertension (defined as 140/90 mmHg and/or medically treated) was disproportionately higher among blacks than whites. In addition, blacks had a higher prevalence of the more severe hypertension (160/95 mmHg) and hypertension with higher prevalence at earlier ages than whites. Black females had a significantly higher distribution of body mass index (BMI) than white females, while no difference was found in the distributions of males. White males had a higher distribution of waist to hip ratio (WHR) than black males, while black females had the higher values compared to white females. The prevalence of hypertension increased with BMI and WHR. Blacks maintained higher rates of hypertension after controlling for BMI and WHR, however, the margin of difference diminished when BMI and WHR was considered together. The black-white difference in hypertension was not completely explained by BMI and WHR. In addition, the strength of the association of hypertension and body size was different for blacks and whites which suggests possible differences in the mechanisms regulating blood pressure.

Receptors for 1,25-dihydroxyvitamin D3 in gynecologic neoplasms

To determine if gynecologic malignancies are candidates for 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) therapy we measured vitamin D receptor (VDR) levels in 11 tumor specimens using a radiolabeled ligand-binding assay. VDR was demonstrated in 3 of 6 ovarian tumors and 1 of 1 uterine sarcomas, but not in endometrial tumors (2), cervical tumors (1), or Krukenberg tumors (1). Scatchard plots revealed that [3H]1,25(OH)2D3 was bound to a single class of high-affinity (Kd = 0.3 to 0.6 nM), saturable sites characteristic of authentic 1,25(OH)2D3 receptors. Specificity of binding activity for 1,25(OH)2D3, the active vitamin D3 metabolite, was demonstrated by failure of 25-hydroxy- and 24,25-dihydroxyvitamin D3 to compete effectively against 1,25(OH)2D3 binding in total cellular tumor extracts. The ovarian carcinoma cell line NIH:OVCAR3 was shown to possess VDR (binding capacity = 137 fmol/mg protein, Kd = 0.48 nM). A 3-day incubation of NIH:OVCAR3 cells with 100 nM 1,25(OH)2D3 resulted in 49% inhibition of cell growth. The growth inhibition of an ovarian carcinoma line and the observation that 36% of gynecologic tumors assayed were shown to be VDR-positive suggest that further study is warranted to delineate the mechanism and possible therapeutic aspects of 1,25(OH)2D3 action in gynecologic tumors.

Combined effects of 1,25-dihydroxyvitamin D3 and platinum drugs on the growth of MCF-7 cells

The effects of 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] and platinum treatments (both singly and combined) on the growth inhibition of MCF-7 cells, an epithelial cell line shown to possess specific receptors for 1,25(OH)2D3, were evaluated. The inhibitory effects of 1,25(OH)2D3 and platinum on MCF-7 cell proliferation in vitro were time and dose related. The data showed that 10 nM and 100 nM 1,25(OH)2D3 inhibited MCF-7 cell growth by 10.8 +/- 2.4% and 34.9 +/- 0.5% (mean +/- SE), respectively. The degrees of growth inhibition induced by 0.2 to 200 micrograms/ml of cis-diammine-1,1-cyclobutane dicarboxylatoplatinum(II) (carboplatin) were slightly less than those induced by 0.02 to 20 micrograms/ml of cis-diamminedichloroplatinum(II) (cisplatin). The combined administration of 10 nM and 100 nM 1,25(OH)2D3 with either carboplatin (200 to 0.2 micrograms/ml) or cisplatin (20 to 0.02 micrograms/ml) was evaluated. Addition of 1,25(OH)2D3 to the platinum resulted in marginal to marked enhancement of growth inhibition over that observed with either platinum alone. The strength of these interactions varied inversely with the dose of the platinum drugs. Evaluation of drug interactions with isobolograms showed that at near-serum levels, carboplatin or cisplatin interacted synergistically with 1,25(OH)2D3 to inhibit MCF-7 cell growth. Our findings suggest potential usefulness in combining 1,25(OH)2D3, a biological modifier, with cytotoxic agents for the treatment of malignant disease.

Involvement of vitamin D3 with cardiovascular function. III. Effects on physical and morphological properties

We have previously shown that depletion of vitamin D3 in rats results in a large increase in the contractile function of isolated hearts (R. E. Weishaar, J. Clin. Invest. 79: 1706-1712, 1987). To characterize the mechanism responsible for this increase, the effect of vitamin D3 depletion on key physical and morphological properties of cardiac muscle was examined. Depletion of vitamin D3 increased the heart weight/body weight ratio. This increase could neither be blocked by limiting hypocalcemia nor reversed by restoring increasing serum calcium levels. The cardiomegaly observed 9 wk after vitamin D3 depletion was not accompanied by an increase in myocardial water content or leakage of myocardial creatine phosphokinase and was not caused by myocardial cell hypertrophy. Histological examination of ventricular muscle from vitamin D3-deficient rats revealed a significant decrease in myofibrillar area and a significant increase in extracellular space. The increase in extracellular space was accompanied by a significant increase in myocardial collagen. Prevention of hypocalcemia in the vitamin D3-deficient rats did not prevent the increase in myocardial collagen. Such alterations in the physical and morphological properties of myocardial tissue might represent the basis for the change in myocardial contractile function that accompanies lengthy periods of vitamin D3 deficiency.

Role of porcine endometrial estrogen sulfotransferase in progesterone mediated downregulation of estrogen receptor

Estrogen sulfotransferase (EST) is a progesterone (Pg) induced secretory endometrial enzyme which may effect estrogen receptor levels by esterifying estradiol-17 beta (E2) to an inactive, sulfate form. The effects of this enzyme were studied using specific inhibitors of EST that do not bind to estrogen receptor (ER): 4-nitroestrone 3-methyl ether and 4-fluoroestrone 3-methyl ether. A 1 h pulse with 4 nM E2 caused ERn (i.e. E2-bound, chromatin-bound receptor) to increase 40% in incubations of proliferative gilt endometrium (no EST activity), while the same E2 treatment of secretory endometrium (high EST activity) caused no increase in ERn. ERn accumulation was completely restored in these experiments by preincubating secretory endometrium with 4 microM 4-fluoroestrone 3-methyl ether. Gilt endometrial explants cultured 7 days with 1 nM E2 plus 1 microM Pg (which induced EST activity) possessed half the ERn as explants devoid of EST activity which were cultured in E2 alone. The addition of 10 microM 4-nitroestrone 3-methyl ester to the cultures of secretory endometrium restored ERn to the levels seen in minces cultured with E2 alone. Furthermore, ovariectomized gilts injected daily with 250 micrograms E2 plus 25 mg Pg had much lower ERn (0.06 fmol/micrograms DNA) than gilts injected with E2 only (0.21 fmol/microgram DNA). ERn was restored completely by supplementing the E2 plus Pg injections with 0.5 g 4-nitroestrone 3-methyl ether administered by vaginal suppositories.(ABSTRACT TRUNCATED AT 250 WORDS)

Changing patterns of acute myocardial infarction: decline in period prevalence and delay in onset

The rural Pee Dee area of South Carolina has had the highest mortality rate in the nation for coronary heart disease. Community surveillance shows a 22.7% (p = 0.0008) decline in fatal and nonfatal acute myocardial infarction (AMI) rates during the period 1978 to 1985 in the Pee Dee area. Rates for white men decreased 32% (p = 0.001), whereas in other race-sex groups changes were not significant, although there was a downward trend (p = 0.18) among black men. Among white men decreases in the AMI rates occurred in each of the decades of age 35 to 64 years. In all race-sex groups there was a sharp increase in rates between 1978 and 1985 for those 65 to 74 years of age, suggesting that the incidence of AMI was delayed to a later age. Out-of-hospital AMI death rates declined markedly in all race-sex groups: 63% for white men, 62% for white women, 49% for black men, and 39% for black women. Overall case fatality rates declined from 14% (27 of 193) to 10% (23 of 232), but the decrease was not statistically significant.

Studies on type II progesterone receptor in MCF-7 cells

These experiments demonstrate for the first time the existence of a Type II progesterone receptor (RpII) in MCF-7 human breast cancer cells. RpII was shown to have a lower affinity for tritiated progesterone ([3H]Pg) (Kd greater than or equal to 13 nM) than classical Rp (Kd less than or equal to 3 nM). RpII was detected by cytosolic, nuclear, and whole cell assays of MCF-7 cells. Scatchard analysis of [3H]Pg binding data revealed that classical Rp but not RpII could be recompartmentalized from the cytosolic to the nuclear pool by treating cells 1 h at 37 degrees C with 1 microM Pg. RpII levels were shown to be increased more than two-fold by growing MCF-7 cells for 4 days in 10 nM estradiol (E2) plus 100 nM Pg when compared to either untreated cells or to cells treated with only E2.

Growth of the cleft lip following a triangular flap repair

This study involves 50 children who had a triangular flap repair for unilateral cleft lip. They have been followed for 5 to 14 years by serial measurements, photographs, and clinical evaluation. During the first 5 years, the lips were designed to allow for future growth. The expected growth did not occur. During the second 5 years, the lip length was designed equal to the normal side with the belief that unequal growth does not occur. In this group, the results supported the premise that deviation from the correct lip length would now be equally divided between too long and too short. None of the entire group has a lip which started too short becoming equal or starting equal to become too long. It is the conclusion of the authors that a repaired unilateral cleft lip retains the configuration and length determined at the time of the initial repair.

Acute myocardial infarction: period prevalence, case fatality, and comparison of black and white cases in urban and rural areas of South Carolina

Community surveillance revealed 1085 prevalent cases of acute myocardial infarction (AMI) during 1978 in urban metropolitan Columbia and rural Pee Dee areas of South Carolina. Six hundred fifty-eight hospitalized cases met our criteria and were classified as definite or probable. Death certificates identified 427 who died before admission to the hospital and who were classified as unvalidated. However, there is need to verify death certificate diagnosis in out-of-hospital deaths which account for approximately two thirds of total cases in blacks and about one third of white cases. Other findings were: White males had higher AMI rates in the rural Pee Dee area than in urban Columbia, while black males and black females had higher rates in Columbia than in the Pee Dee area and white females had similar rates in both areas. Rates for out-of-hospital AMI mortality were higher in blacks than in whites. Out-of-hospital AMI mortality rates in Columbia and the Pee Dee area were four times higher than in Minneapolis-St. Paul in 1978. For definite and all criteria AMI, white males had the highest rates, double the black male rate except for all criteria AMI in Columbia, where white male and black male rates were similar. Urban cases of both races experienced more anterior infarctions than rural cases.

Effect of growth on the estrogen receptor levels in MCF-7 cells

MCF-7 cells have been shown to contain estrogen receptor in several cell fractions following homogenization: nuclei, microsomes, and cytosol. The amount of 17 beta-estradiol-binding capacity found in each cellular compartment depended on the inclusion of detergent in homogenization buffers and on the use of 0.25 M sucrose in the nuclear washes. 17 beta-Estradiol receptor (E2R) associated with nuclei (whole nuclei exchange assay, 0.6 M KCl soluble, and that found on membranes sheared from crude nuclear pellets by centrifugation in 0.25 M sucrose buffer) displayed a dissociation constant (Kd) of 0.77 +/- 0.01 (S.D.) nM (n = 7). KdS of the cytoplasmic (microsomes and soluble) receptors were determined to be 0.33 +/- 0.10 nM (n = 9). Exchangeable ligand on partially purified nuclei assumed its highest level in MCF-7 cells during logarithmic growth in serum-containing media (0.8 pmol/micrograms DNA) but declined after the culture reached confluence (0.2 pmol/micrograms DNA). Seventy-five % of the nuclear E2R declined linearly after feeding MCF-7 cells in logarithmic growth phase an estrogen- and serum-free medium (t1/2 3.5 days). Another class of salt-extractable nuclear receptor (0.2 pmol/micrograms DNA) persisted in postconfluent cultures whether fed estrogen (serum-containing media) or not (serum-free media). This residual binding capacity remained in nuclei of MCF-7 cells for an extended period of time. MCF-7 cells demonstrated functionality of E2R throughout their growth phases as evidenced by the replenishment of cytosolic E2R and the induction of progesterone receptor when given 17 beta-estradiol.

A second career in academic medicine

Career changes in all vocations are relatively common in the forties age group due to a variety of factors which include a crisis period caused by polarities of Generativity versus Stagnation as conceptualized by Erik H. Erikson. Generativity is served not only by procreativity but also by guiding the next generation through teaching. The result can be the strength of Care. Stagnation can result in unhappiness, irrational and destructive behavior, or withdrawal. Concepts of young, old and mortality also come into focus. A successful career change from private practice to academic medicine depends upon a combination of power, opportunity, and character. To be successful, the change should be made for positive reasons and be based upon youthful concepts in the cold reality of the financial and intellectual challenges of a new and competitive career. If properly done, both the personal rewards and the contribution to future medical care can be quite positive.