A single 36-h water-only fast vastly remodels the plasma lipidome

Background

Prolonged fasting, characterized by restricting caloric intake for 24 h or more, has garnered attention as a nutritional approach to improve lifespan and support healthy aging. Previous research from our group showed that a single bout of 36-h water-only fasting in humans resulted in a distinct metabolomic signature in plasma and increased levels of bioactive metabolites, which improved macrophage function and lifespan in C. elegans.

Objective

This secondary outcome analysis aimed to investigate changes in the plasma lipidome associated with prolonged fasting and explore any potential links with markers of cardiometabolic health and aging.

Method

We conducted a controlled pilot study with 20 male and female participants (mean age, 27.5 ± 4.4 years; mean BMI, 24.3 ± 3.1 kg/m2) in four metabolic states: (1) overnight fasted (baseline), (2) 2-h postprandial fed state (fed), (3) 36-h fasted state (fasted), and (4) 2-h postprandial refed state 12 h after the 36-h fast (refed). Plasma lipidomic profiles were analyzed using liquid chromatography and electrospray ionization mass spectrometry.

Results

Several lipid classes, including lysophosphatidylcholine (LPC), lysophosphatidylethanolamine (LPE), phosphatidylethanolamine, and triacylglycerol were significantly reduced in the 36-h fasted state, while free fatty acids, ceramides, and sphingomyelin were significantly increased compared to overnight fast and fed states (P < 0.05). After correction for multiple testing, 245 out of 832 lipid species were significantly altered in the fasted state compared to baseline (P < 0.05). Random forest models revealed that several lipid species, such as LPE(18:1), LPC(18:2), and FFA(20:1) were important features in discriminating the fasted state from both the overnight fasted and postprandial state.

Conclusion

Our findings indicate that prolonged fasting vastly remodels the plasma lipidome and markedly alters the concentrations of several lipid species, which may be sensitive biomarkers of prolonged fasting. These changes in lipid metabolism during prolonged fasting have important implications for the management of cardiometabolic health and healthy aging, and warrant further exploration and validation in larger cohorts and different population groups.

Human fasting modulates macrophage function and upregulates multiple bioactive metabolites that extend lifespan in Caenorhabditis elegans: a pilot clinical study

BACKGROUND

Periodic prolonged fasting (PF) extends lifespan in model organisms and ameliorates multiple disease states both clinically and experimentally owing, in part, to its ability to modulate the immune system. However, the relationship between metabolic factors, immunity, and longevity during PF remains poorly characterized especially in humans.

OBJECTIVE

This study aimed to observe the effects of PF in human subjects on the clinical and experimental markers of metabolic and immune health and uncover underlying plasma-borne factors that may be responsible for these effects.

METHODS

In this rigorously controlled pilot study (ClinicalTrial.gov identifier, NCT03487679), 20 young males and females participated in a 3-d study protocol including assessments of 4 distinct metabolic states: 1) overnight fasted baseline state, 2) 2-h postprandial fed state, 3) 36-h fasted state, and 4) final 2-h postprandial re-fed state 12 h after the 36-h fasting period. Clinical and experimental markers of immune and metabolic health were assessed for each state along with comprehensive metabolomic profiling of participant plasma. Bioactive metabolites identified to be upregulated in circulation after 36 h of fasting were then assessed for their ability to mimic the effects of fasting in isolated human macrophage as well as the ability to extend lifespan in Caenorhabditis elegans.

RESULTS

We showed that PF robustly altered the plasma metabolome and conferred beneficial immunomodulatory effects on human macrophages. We also identified 4 bioactive metabolites that were upregulated during PF (spermidine, 1-methylnicotinamide, palmitoylethanolamide, and oleoylethanolamide) that could replicate these immunomodulatory effects. Furthermore, we found that these metabolites and their combination significantly extended the median lifespan of C. elegans by as much as 96%.

CONCLUSIONS

The results of this study reveal multiple functionalities and immunological pathways affected by PF in humans, identify candidates for the development of fasting mimetic compounds, and uncover targets for investigation in longevity research.

Lipid-Based Nutrient Supplementation Increases High-Density Lipoprotein (HDL) Cholesterol Efflux Capacity and Is Associated with Changes in the HDL Glycoproteome in Children

Prenatal plus postnatal small-quantity lipid-based nutrient supplements (SQ-LNS) improved child growth at 18 months in the International Lipid-Based Nutrient Supplements DYAD trial in Ghana. In this secondary outcome analysis, we determined whether SQ-LNS versus prenatal iron and folic acid (IFA) supplementation improves the cholesterol efflux capacity (CEC) of high-density lipoprotein (HDL) particles and alters their lipidomic, proteomic, or glycoproteomic composition in a subset of 80 children at 18 months of age. HDL CEC was higher among children in the SQ-LNS versus IFA group (20.9 ± 4.1 vs 19.4 ± 3.3%; one-tailed p = 0.038). There were no differences in HDL lipidomic or proteomic composition between groups. Twelve glycopeptides out of the 163 analyzed were significantly altered by SQ-LNS, but none of the group differences remained significant after correction for multiple testing. Exploratory analysis showed that 6 out of the 33 HDL-associated proteins monitored differed in glycopeptide enrichment between intervention groups, and 6 out of the 163 glycopeptides were correlated with CEC. We conclude that prenatal plus postnatal SQ-LNS may modify HDL protein glycoprofiles and improve the CEC of HDL particles in children, which may have implications for subsequent child health outcomes. This trial was registered at clinicaltrials.gov as NCT00970866.

Isolation of HDL by sequential flotation ultracentrifugation followed by size exclusion chromatography reveals size-based enrichment of HDL-associated proteins

High-density lipoprotein (HDL) particles have multiple beneficial and cardioprotective roles, yet our understanding of their full structural and functional repertoire is limited due to challenges in separating HDL particles from contaminating plasma proteins and other lipid-carrying particles that overlap HDL in size and/or density. Here we describe a method for isolating HDL particles using a combination of sequential flotation density ultracentrifugation and fast protein liquid chromatography with a size exclusion column. Purity was visualized by polyacrylamide gel electrophoresis and verified by proteomics, while size and structural integrity were confirmed by transmission electron microscopy. This HDL isolation method can be used to isolate a high yield of purified HDL from a low starting plasma volume for functional analyses. This method also enables investigators to select their specific HDL fraction of interest: from the least inclusive but highest purity HDL fraction eluting in the middle of the HDL peak, to pooling all of the fractions to capture the breadth of HDL particles in the original plasma sample. We show that certain proteins such as lecithin cholesterol acyltransferase (LCAT), phospholipid transfer protein (PLTP), and clusterin (CLUS) are enriched in large HDL particles whereas proteins such as alpha-2HS-glycoprotein (A2HSG), alpha-1 antitrypsin (A1AT), and vitamin D binding protein (VDBP) are enriched or found exclusively in small HDL particles.

Whole egg consumption compared with yolk-free egg increases the cholesterol efflux capacity of high-density lipoproteins in overweight, postmenopausal women

BACKGROUND

Postmenopausal women are at higher risk for cardiovascular disease (CVD) than their younger counterparts. HDL cholesterol is a biomarker for CVD risk, but the function of HDL may be more important than HDL cholesterol in deciphering disease risk. Although diet continues to be a cornerstone of treatment and prevention of CVD, little is known about how diet affects the functionality of HDL.

OBJECTIVES

The aim of this study was to characterize the effects of whole eggs compared with yolk-free eggs on HDL function and composition in overweight, postmenopausal women and determine how changes in HDL composition are related to HDL functional parameters.

METHODS

The study was a 14-wk, single-blind, randomized crossover dietary trial with two 4-wk intervention periods in 20 overweight, postmenopausal women. The crossover treatments were frozen breakfast meals containing 100 g of liquid (∼2) whole eggs compared with 100 g of (∼2) yolk-free eggs per day, separated by a 4-wk washout. Fasting blood samples were taken at the beginning and end of each treatment period to determine the effects on HDL composition and function.

RESULTS

Cholesterol efflux capacity increased in the whole-egg treatment (mean ± SD percentage change: +5.69% ± 9.9%) compared with the yolk-free egg treatment (-3.69% ± 5.3%) (P < 0.01), but there were no other significant changes in HDL functions or antioxidant or inflammatory markers. ApoA-I, total cholesterol (TC), LDL cholesterol, and HDL cholesterol also did not change in response to the egg treatment.

CONCLUSIONS

The consumption of 2 whole eggs/d by overweight, postmenopausal women showed a significant increase in cholesterol efflux capacity. This increase in cholesterol efflux capacity was seen without significant changes in apoA-I, TC, LDL cholesterol, or HDL cholesterol, supporting the idea that HDL function rather than HDL cholesterol should be addressed in this population. This trial was registered at clinicaltrials.gov as NCT02445638.

Regional brain atrophy in cognitively intact adults with a single APOE 4 allele

OBJECTIVE

To determine whether cognitively intact adults with the APOE epsilon3/epsilon4 genotype show reduced gray matter density on voxel-based morphometry (VBM) vs those homozygous for the epsilon3 allele.

METHODS

Participants were healthy, cognitively intact, right-handed adults, age 19 to 80, who completed genotyping, neuropsychological testing, and MRI. Forty-nine participants had the epsilon3/epsilon3 genotype and 27 had the epsilon3/epsilon4 genotype. Gray matter data were analyzed using the general linear model as implemented in the Statistical Parametric Mapping package, adjusting for age and sex.

RESULTS

The epsilon3/epsilon4 participants showed lower gray matter density than the epsilon3/epsilon3 participants in right medial temporal and bilateral frontotemporal regions as well as other areas. There were no regions in which epsilon3/epsilon4 participants showed higher gray matter density than epsilon3/epsilon3 participants.

CONCLUSIONS

Regionally reduced gray matter density is detectable in cognitively intact adults with a single copy of the APOE epsilon4 allele.

Medically intractable, localization-related epilepsy with normal MRI: presurgical evaluation and surgical outcome in 43 patients

PURPOSE

High-resolution magnetic resonance imaging (MRI) plays a crucial role in the presurgical evaluation of patients with medically refractory partial epilepsy. Although MRI detects a morphologic abnormality as the cause of the epilepsy in the majority of patients, some patients have a normal MRI. This study was undertaken to explore the hypothesis that in patients with normal MRI, invasive monitoring can lead to localization of the seizure-onset zone and successful epilepsy surgery.

METHODS

A series of 115 patients with partial epilepsy who had undergone intracranial electrode evaluation (subdural strip, subdural grid, and/or depth electrodes) between February 1992 and February 1999 was analyzed retrospectively. Of these, 43 patients (37%) had a normal MRI.

RESULTS

Invasive monitoring detected a focal seizure onset in 25 (58%) patients, multifocal seizure origin in 12 (28%) patients, and in six patients, no focal seizure origin was found. Of the 25 patients with a focal seizure origin, cortical resection was performed in 24, of whom 20 (83%) had a good surgical outcome with respect to seizure control. Six of the 12 patients with multifocal seizure origin underwent other forms of epilepsy surgery (palliative cortical resection in two, anterior callosotomy in two, and vagal nerve stimulator placement in two).

CONCLUSIONS

Successful epilepsy surgery is possible in patients with normal MRIs, but appropriate presurgical evaluations are necessary. In patients with evidence of multifocal seizure origin during noninvasive evaluation, invasive monitoring should generally be avoided.

Human chromosome 9 pericentric homologies: implications for chromosome 9 heteromorphisms

Pericentromeric polymorphisms of chromosome 9 include variations in the size of heterochromatin, pericentric inversions, and, more rarely, additional C-band-negative, G-band-positive material in either the proximal short arm or long arm or within the heterochromatin. It has been postulated that rearrangements involving the different classes of satellite DNA present in this relatively unstable region of the human genome constitute a mechanism for the origin of these variants. We report the identification, by molecular cytogenetic investigations, of homologous stretches of euchromatin shared by the proximal short and long arms of chromosome 9 that suggest that exchanges involving these regions may be an additional mechanism for the origin of chromosome 9 polymorphisms.

Molecular studies of an ependymoma-associated constitutional t(1;22)(p22;q11.2)

We previously described a patient with a de novo constitutional translocation, t(1;22)(p22;q11.2), who developed a malignant ependymoma at age 5, and we proposed that the translocation predisposed the child to the development of the tumor. As a step toward isolation of a putative cancer gene, we have characterized the breakpoints of the (1;22) translocation at the molecular level. The chromosome 22 breakpoint has been narrowed to a region between ARVCF and D22S264. The chromosome 1 breakpoint has been mapped onto a doubly-linked Whitehead YAC contig by PCR analysis of the STS contents of the patient's derivative chromosomes isolated in somatic cell hybrids. Loss-of-heterozygosity (LOH) studies of the patient's ependymoma and of sporadic ependymomas showed no evidence of consistent loss in the breakpoint regions, suggesting that activation of an oncogene, rather than inactivation of a tumor suppressor gene, is the more likely molecular mechanism involved in this case. The gene for Edg-1, a neurally expressed, seven-segment transmembrane receptor, maps to the region of the chromosome 1 breakpoint but does not appear to be interrupted by the translocation. Molecular characterization of the breakpoint regions reported here represents an important step in the identification of the gene(s) affected by this translocation.

Pure alexia: clinical-pathologic evidence for a lateralized visual language association cortex

Traditional views of pure alexia have held that the disorder results from a disconnection between the secondary visual cortices of both hemispheres and the angular gyrus of the dominant hemisphere. Evidence has accumulated, however, suggesting the importance of the posterior inferior temporal area in visual language processing. We describe clinical-pathological support for the presence of a lateralized visual language association area residing in the dominant posterior inferior temporal lobe.

Analysis of the allele-specific PCR method for the detection of neoplastic disease

PCR assays for the presence of mutant K-ras or p53 sequences are potentially useful as sensitive tests for tumor diagnosis. The technical challenge is to design assays sensitive enough to detect a few molecules of mutant DNA yet sufficiently specific that a false positive signal is not produced by a 10(5)- or 10(6)-fold excess of normal DNA. We determined the detection limit of allele-specific PCR (ASA) as a function of the particular mismatch involved using all 12 possible mismatches in two different DNA sequence contexts (K-ras codon 12 and p53 codon 273). Depending on the identity of the mismatch, mismatched template was amplified 10(2)-10(4)-fold less than perfectly matched template. In other words, a mutant allele could be detected by ASA if it represented > 1-0.01% of the total DNA from that locus. Peptide nucleic acid (PNA) clamping was used to improve the K-ras ASA assay. Selective amplification of mutant sequences was achieved using a PNA complementary to the normal sequence to inhibit the amplification of wild-type DNA. PNA clamping followed by ASA resulted in significant improvement in sensitivity and specificity, permitting the detection of tumor DNA diluted with a 300,000-fold excess of normal human DNA.

Weekly paclitaxel with and without concurrent radiation therapy: toxicity, pharmacokinetics, and response

Paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ) has shown in vitro and clinical activity against non-small cell lung cancer and astrocytic brain tumors, tumors traditionally thought of as relatively resistant to chemotherapy and radiotherapy. Because of its ability to block dividing cells in the G2/M portion of the cell cycle (the most radiosensitive phase of the cell cycle), paclitaxel is also a potentially potent radiosensitizer. To exploit these and other properties of paclitaxel, we explored a weekly, outpatient administration schedule, with and without concurrent radiation therapy, in patients with non-small cell lung cancer and astrocytic brain tumors. Our experience has shown that weekly outpatient administration is feasible, that remarkably high dose intensities can be achieved with acceptable toxicity, and that the specific dose-limiting toxicity appears to depend on administration schedule, type of concurrent radiotherapy, and certain patient characteristics. Preliminary response data are very encouraging. At the same time, pharmacokinetic studies have suggested possible reasons for our ability to use such exorbitant dose intensities safely, and also have shown that sustained plasma paclitaxel levels above the putative radiosensitizing threshold can be achieved continuously during a 6-week course of radiotherapy. Specific results, dosing recommendations, and plans for future studies are discussed.

Telomere associations in desmoplastic infantile ganglioglioma

A four and a half year old male was diagnosed with desmoplastic infantile ganglioglioma. To our knowledge, the cytogenetics of this tumor have never been reported. In our analysis of 40 cells, no consistent clonal abnormalities were observed; however, the majority of cells (25 of 40) showed structural rearrangements (telomere associations) resulting in dicentrics and other derivative chromosomes. Breakpoints most often observed included 17q25 (6 of 40), 19p13.3 (4 of 40), 17p13 (3 of 40), 14q32 (3 of 40), 11q25 (3 of 40), 9p24 (2 of 40), 5q35 (2 of 40), and 22q13 (2 of 40).

Stage IE non-Hodgkin's lymphoma involving the dura: A clinicopathologic study of five cases

OBJECTIVE AND DESIGN

Non-Hodgkin's lymphomas rarely present as a localized mass involving the dura. In this report we describe the clinical, histologic, and immunohistochemical features of five cases of stage IE non-Hodgkin's lymphoma involving the dura.

PATIENTS

Four women and one man, 36 to 67 years of age (median 50.6 years).

RESULTS

Myelography and magnetic resonance imaging scans revealed discrete expansile masses involving the dura of the cervical, thoracic, and lumbar regions of the spinal cord and the frontal lobe of the brain. Histologically, the tumors were classified in the Working Formulation as small lymphocytic (2), diffuse large cell (2), and large cell immunoblastic (1) (anaplastic large cell lymphoma). Four tumors were of B-cell lineage and the anaplastic large-cell lymphoma was of T-cell lineage. The two small lymphocytic neoplasms had immunoglobulin heavy-chain gene rearrangements as shown by either Southern blot hybridization or the polymerase chain reaction. Four patients underwent decompression laminectomy; three received spinal radiation; two received chemotherapy (one intrathecal, one systemic) for lymphocytosis of the cerebrospinal fluid. The dural mass overlying the frontal lobe was excised and focally irradiated. Clinical follow-up was available for all patients. Four patients were alive 12 to 40 months after diagnosis and showed no evidence of recurrent or disseminated disease. The patient with anaplastic large-cell lymphoma died 10 days after laminectomy, secondary to pulmonary thromboemboli.

CONCLUSIONS

We conclude that non-Hodgkin's lymphomas of varied histologic types and of either B- or T-cell lineage may rarely present as a stage IE dural mass. These lesions appear to have a good initial response to treatment; however, longer clinical follow-up is necessary to assess the incidence of relapse and final outcome.

Constitutional de novo t(1;22)(p22;q11.2) and ependymoma

There is a body of evidence suggesting the presence of a tumor suppressor gene on chromosome 22 which plays a role in the pathogenesis of ependymomas. We report a patient with a de novo constitutional t(1;22)(p22;q11.2) who developed a malignant ependymoma at age 5. The patient is otherwise phenotypically normal. By fluorescence in situ hybridization (FISH) analysis, the chromosome 22 breakpoint has been localized to the region between the DiGeorge locus and BCR. Since NF2 and EWS are both distal to BCR, the are presumable not involved in this rearrangement. This patient may offer a unique opportunity to identify the chromosome 22 ependymoma tumor suppressor gene by cloning the translocation breakpoint.

A comparison of polymerase chain reaction examination of cerebrospinal fluid and conventional cytology in the diagnosis of lymphomatous meningitis

BACKGROUND

Inherent limitations of conventional cytology often result in a failure to diagnose lymphomatous meningitis in cerebrospinal fluid (CSF) specimens from patients who actually have the disease. The development of polymerase chain reaction (PCR) techniques for the diagnosis of lymphoma based on the detection of clonal rearrangements of the immunoglobulin or T-cell receptor genes offers an alternative, DNA-based test for the diagnosis of lymphoma in the CSF.

METHODS

In this retrospective study, 31 CSF specimens from 21 patients were examined by a PCR technique that can detect clonal immunoglobulin gene rearrangements. Twenty-four of the specimens came from 14 patients who eventually had definitive histologic or cytologic diagnoses of B-cell lymphoma. The other seven patients had other neurologic diagnoses, including two patients with reactive lymphocytosis, three with glioblastoma, one with metastatic carcinoma, and one with multi-infarct dementia. The results of the PCR examinations were compared with cytologic evaluation of the same CSF specimens.

RESULTS

Five of seven specimens from patients with central nervous system lymphoma that were suspicious for, but not diagnostic of, lymphoma by conventional cytology were positive by PCR. Of 13 specimens from patients with lymphoma that showed no cytologic evidence of malignancy, 5 were positive by PCR. Two of four specimens for which conventional cytology showed definitive evidence of lymphoma were positive by PCR. Two specimens from patients with a reactive lymphocytosis showed a polyclonal pattern by PCR. Specimens from patients with other neurologic diseases were negative by PCR even when cytologically malignant (glioblastoma) cells were present in the specimen.

CONCLUSIONS

PCR examination of CSF is practical, complements conventional cytology, and sometimes provides the correct diagnosis when conventional cytology yields only ambiguous results.

Phase I study of weekly outpatient paclitaxel and concurrent cranial irradiation in adults with astrocytomas

PURPOSE

Astrocytomas are extremely resistant to currently available treatments. Cranial irradiation is a mainstay of frontline therapy, but tumor recurrence is nearly universal. Paclitaxel has shown antitumor efficacy against astrocytoma cell lines, and is a potent radiosensitizer. For these reasons, we conducted a phase I study of weekly paclitaxel and concurrent cranial irradiation in patients with newly diagnosed astrocytomas.

PATIENTS AND METHODS

Patients with astrocytomas were eligible for this study following initial surgery if they had a Karnofsky performance score (KPS) > or = 60%; normal hematologic, liver, and renal function; and could give informed consent. Beginning on day 1 of treatment, patients received paclitaxel by 3-hour infusion once weekly for 6 weeks, concurrent with standard cranial irradiation. Pharmacokinetic studies were performed on 10 patients.

RESULTS

Sixty patients were enrolled; 56 were fully assessable. Forty-eight had glioblastomas (GBMs), 10 anaplastic astrocytomas (AAs), and two astrocytomas. Age ranged from 21 to 81 years (median, 55); KPS ranged from 60 to 100 (median, 70). The paclitaxel dose was escalated from 20 mg/m2 to 275 mg/m2. No clinically significant anemia or thrombocytopenia occurred. Only one patient (175 mg/m2) became neutropenic. Sensory neuropathy was dose-limiting. The maximum tolerated dose (MTD) was 250 mg/m2. Paclitaxel pharmacokinetic profiles in study patients were identical to those of previously reported patients with other solid tumors.

CONCLUSION

The MTD of paclitaxel administered weekly for 6 weeks by 3-hour infusion is 250 mg/m2. Since patients with brain tumors often have preexisting neurologic deficits, we suggest 225 mg/m2 as the optimum dose for phase II trials in this group of patients.

PCR-detection of tumor-derived p53 DNA in cerebrospinal fluid

The sensitivity of polymerase chain reaction (PCR)-based methods for the detection of DNA offers opportunities for tumor diagnosis from the small amounts of tumor-derived DNA released into body fluids. Tumor-derived DNA can be distinguished from DNA derived from non-neoplastic cells by the presence of tumor specific genomic alterations, such as mutations in the p53 gene. This case report describes the use of allele-specific PCR (A-PCR) to detect a C-->T transition in p53 codon 273 in DNA extracted from the cerebrospinal fluid (CSF) of a patient whose glioblastoma contained the same mutation. The results of this study were confirmed by a second independent A-PCR reaction that detected the corresponding G-->A transition on the opposite strand. The specificity of the A-PCR protocol was demonstrated by negative controls, including pooled human placental DNA and the patient's non-tumor DNA, and by the use of A-PCR primers to detect all four possible bases at the site of the mutation. The methodology used in this study is suitable for use as a diagnostic clinical test. Because about half of all human tumors contain p53 mutations, PCR examination of CSF for the presence of mutant p53 sequences may be useful in the diagnosis of recurrent or metastatic tumors. Patients with known carcinoma of the breast or lung might be particularly benefited by this test.

Detection of tumor-derived DNA in cerebrospinal fluid

The sensitivity of PCR-based methods for the detection of DNA offers opportunities for tumor diagnosis from the small amounts of tumor-derived DNA released into body fluids. We report the detection of tumor DNA in the cerebrospinal fluid (CSF) of two patients with intracranial neoplasms. One patient had a metastatic breast carcinoma which contained amplified HER-2/neu genes, and amplified HER-2/neu gene sequences were present in her CSF. The other patient had a glioblastoma which contained amplified epidermal growth factor receptor (EGFR) genes, and amplified EGFR gene sequences were present in her CSF. This report demonstrates that CSF sometimes contains tumor-derived DNA and suggests that PCR examination of CSF DNA may be diagnostically useful.

Expression of neuropeptide processing enzymes and neurosecretory proteins in ependyma and choroid plexus epithelium

Recent studies suggest that brain ependyma and choroid plexus produce neuropeptide processing enzymes. To facilitate the understanding of these cells and their ability to produce biologically active peptides, we developed cultures of defined cell type. Ependymal cells were characterized by morphological criteria, and choroid plexus epithelial cell lines were characterized by the presence of the mRNA for IGF-II and transthyretin, a thyroxine binding protein produced in liver and choroid plexus. The ependymal cells and the choroid plexus epithelial cell lines were then examined for the presence of mRNAs for various neuropeptide processing enzymes. Northern blot analysis revealed high levels of furin, carboxypeptidase E, and peptidyl glycine alpha-amidating monooxygenase mRNAs, with levels in ependymal cells comparable to those in brain or pituitary. Carboxypeptidase E activity was detected in medium from cultured ependymal cells; this activity was identified as carboxypeptidase E based on the acidic pH optimum and sensitivity to various inhibitors. The mRNAs for other neuropeptide processing enzymes, such as prohormone convertases 1 and 2, were not detected on Northern blots of RNA from ependyma or choroid plexus epithelium. Since ependyma and choroid plexus epithelium express a subset of processing enzymes, we suggest that these cells have the capacity to produce biologically active peptides. Initial screening by reverse transcriptase-polymerase chain reaction assays has demonstrated the presence of mRNA for the neurosecretory proteins chromogranin B and secretogranin II in both ependyma and choroid plexus epithelium.

Acute toxicology of an enkephalinase inhibitor (SCH 32615) given intrathecally in the ewe

Intrathecal application of the enkephalinase inhibitor, SCH 32615, yields antinociception in animal paradigms. Our purpose was to identify possible acute behavioral effects, neurotoxicity, or systemic toxicity of intrathecal SCH 32615 administration during 9 days in the ewe. Seventeen ewes were implanted with lumbar silicone intrathecal catheters and subcutaneous access ports for repeated injection. Baseline and serial daily behavioral assessments were made during 9 days of 2-mL intrathecal injection twice daily of either normal saline (SAL group) or a 20 mg/mL isotonic sterile solution of SCH 32615 (SCH group). Data were analyzed by treatment group (SCH versus SAL) by taking the group means of individual ewe cumulative scores during 9 days. At 15-18 h after the last injection, the ewes were euthanized and the spinal cords and leptomeninges were grossly examined and prepared for histological assessment. Histological evaluation of the lumbar (at catheter entrance site and catheter tip), thoracic, and cervical sections of all animals was performed by two neuropathologists. Several mild, reversible, and apparently nonprogressive behaviors (Stepping/Placing and Hindlimb Stretching/Splaying) were observed almost exclusively in SCH-treated ewes. These behaviors were interpreted as mild temporary irritative effects, without significant neuropathological sequelae. Pathological findings primarily consisted of mild, focal dural thickening and white matter compression. These changes were distributed equally between drug-treated and control groups and were attributable to catheter implantation and local compressive effects. There were no pathological bases identified in this study to preclude the clinical study of SCH 32615 within the dose range studied.

Pigmented villonodular synovitis of a lumbar facet joint

We describe the CT appearance of suspected pigmented villonodular synovitis involving a lumbar facet in a 51-year-old woman, and discuss how the histologic and radiologic appearances may differ from those of synovial cysts.

Benign nasal polyposis presenting as an intracranial mass: case report

An interesting case of benign nasal polyposis with intracranial extension and subsequent abscess formation is described. Its diagnosis and treatment are presented and the pathology is demonstrated. The literature related to this rare disease process is discussed in detail.

Peptidylglycine alpha-amidating monooxygenase (PAM) in Schwann cells and glia as well as neurons

We raised an antiserum against the synthetic peptide FKETTRSFSNECLGTTR corresponding to the amino terminus of the enzyme peptidylglycine alpha-amidating monooxygenase (PAM). Control experiments were performed to determine the specificity of the antiserum and its suitability for the immunohistochemical identification of PAM-containing cells. An immunoaffinity column made with the antibody coupled to Sepharose permitted the isolation of the active enzyme. Peptide-agarose immunoadsorbant removed the antibodies responsible for the characteristic staining patterns in immunohistochemical experiments. As expected from the widespread distribution of amidated peptides in the nervous system, PAM immunoreactivity was detected in perikarya in a variety of locations, including the pituitary, the hypothalamic periventricular and supraoptic nuclei, neocortex, and sensory ganglia. Punctate immunostained fibers, especially around neuronal perikarya, were observed in regions known to receive amidated peptidergic afferents. In addition, PAM immunoreactivity was observed in some neurons not known to produce amidated peptides (e.g., pyramidal cells of the hippocampus). This result suggests that these neurons also produce an amidated peptide. PAM immunoreactivity was also detected in several unexpected cell types, including ependyma, choroid plexus, oligodendroglia, and Schwann cells. The presence of enzymatically active PAM in Schwann cells was confirmed by measurements of amidating activity in ligated and control sciatic nerve. These results suggest that these non-neuronal cells may produce amidated peptides.

Selective effect of nerve growth factor on some Golgi and lysosomal enzyme activities of rat pheochromocytoma (PC12) cells

Treatment with neuronal growth factor (NGF) results in the growth of neuronal processes by PC12 cells and a concomitant 70% increase in the area of the Golgi apparatus. To define the observed morphologic changes in biochemical terms, we investigated the effect of NGF treatment on some Golgi and lysosomal enzyme activities of PC12 cells. Enzyme activities characteristic of the Golgi apparatus, lysosomes, plasma membranes, mitochondria, and endoplasmic reticulum were measured in cell homogenates, in post-mitochrondrial supernatants, and in Golgi-enriched fractions from control and from NGF-stimulated PC12 cells. Treatment of PC12 cells with NGF did not change the level of the Golgi activity of UDPGal:GlcNAc galactosyltransferase while that of CMP-sialic acid:lactosylceramide sialyltransferase was increased three- to fivefold in all fractions studied. For lysosomal enzymes, NGF treatment resulted in a two- to threefold higher level of arylsulfatase activity compared to either acid phosphatase or acid alpha-mannosidase activities. These results indicate that there is a selective increase of at least one Golgi and one lysosomal activity as a result of NGF stimulation of PC12 cells. Both of these enzymes are involved in glycolipid metabolism. It is possible that the dramatic morphologic changes observed during NGF-induced differentiation of PC12 cells are associated not only with increased synthesis in the Golgi apparatus of plasma membrane components such as gangliosides, but also with increased degradation in lysosomes of other plasma membrane components such as sulfatide.

Positron emission tomography in a patient with progressive multifocal leukoencephalopathy

A 56-year-old man with chronic lymphocytic leukemia, progressive multifocal leukoencephalopathy, and a dense left homonymous hemianopia had 18F-fluorodeoxyglucose positron emission tomography. Cortical glucose metabolism was decreased in the right cerebral hemisphere and the left cerebellar hemisphere. To our knowledge, this is the first demonstration of cerebral and cerebellar hypometabolism due solely to white matter disease.

Transneuronally transported wheat germ agglutinin labels glia as well as neurons in the rat visual system

Following intraocular injection in adult rats of 125I-labeled wheat germ agglutinin (I-WGA), the ultrastructural distribution of label in the superior colliculus and lateral geniculate was examined by electron microscope autoradiography. Three days after injection, 5.4% of the label in the lateral geniculate was associated with neuronal perikarya, and 3.6% was associated with glial perikarya. The corresponding figures for the superior colliculus were 5.1% and 0.8%. When the data were expressed as number of grains per micron 2 cytoplasm, there was no statistically significant difference between the grain density over neuronal or glial cytoplasm in either the lateral geniculate or the superior colliculus. A statistical analysis of the distance between the silver grains and the cell membranes showed that in both neurons and glia, the observed labeling was the product of internalized I-WGA and not the result of scatter from the neuropil or from label bound to the surface of the cells. These results indicate that much of the WGA released from axons and axon terminals is not confined to a specific "transsynaptic" pathway, but produces a generalized labeling of nearby cells, much like a microinjection of WGA into the region.

A quantitative electron microscopic study of the intracellular localization of wheat germ agglutinin in retinal neurons

Previous work has established that, following endocytosis, wheat germ agglutinin, like a number of other plasma membrane bound ligands, is transported to the Golgi apparatus-complex. Previous studies that provided qualitative information about the intracellular distribution of internalized wheat germ agglutinin used techniques that precluded any quantitative conclusions about the relative magnitude of the labeling of endosomes, lysosomes, and the Golgi apparatus-complex. Using quantitative ultrastructural autoradiography, this study compares the time course and relative magnitude of labeling of various intracellular compartments to the labeling in the Golgi area. Fifteen minutes after intraocular injection, wheat germ agglutinin is confined to the inner surface of the retina and the immediate subsurface neuropil with little labeling of the retinal ganglion cell perikarya. Thirty minutes after injection, the plasma membrane (6.97 +/- 1.17), endosomes (10.27 +/- 3.98), smooth vesicles and tubules (1.94 +/- 1.66), and lysosomes (2.42 +/- 1.21) of the retinal ganglion cells are labeled, while the Golgi apparatus-complex is not labeled (0.29 +/- 0.25). (Figures in parentheses are the calculated relative radioactive source density +/- the standard deviation.) The relative labeling density of the plasma membrane and endosomes decreases somewhat during the next 90 minutes (plasma membrane, 4.76 +/- 0.67; endosomes, 7.23 +/- 2.02), while the labeling density of smooth vesicles and tubules and of lysosomes rises (smooth vesicles and tubules, 5.56 +/- 0.94; lysosomes, 7.76 +/- 1.56). The Golgi apparatus-complex, which is unlabeled at 30 minutes, is weakly labeled at 2 hours (1.26 +/- 0.28). The fact that the lysosomes are already labeled at 30 minutes while the Golgi apparatus-complex is unlabeled at that time indicates that the transport of wheat germ agglutinin to the Golgi apparatus-complex is a relatively late phenomenon, and suggests that the bulk of the wheat germ agglutinin destined for lysosomes does not pass through the Golgi apparatus-complex.

Lectin affinity and PAGE analysis of soluble axonally transported glycoconjugates in the rat visual system

Recent reports of the transsynaptic transfer of wheat germ agglutinin (WGA) in several systems are consistent with the hypothesis that WGA binds to endogenous glycoproteins(s) which undergo transsynaptic transfer. Such molecules might be involved in trophic interactions between neurons. Since these hypothetical glycoproteins must be soluble proteins (it is unlikely that integral membrane proteins are exchanged between neurons) this preliminary study of the soluble, axonally transported glycoconjugates of the visual system was undertaken. Soluble, tritium-labeled macromolecules which accumulated in the rat lateral geniculate nucleus (LGN) and visual cortex after intraocular injections of tritiated fucose were studied by lectin affinity chromatography and polyacrylamide gel electrophoresis (PAGE). After correction for hematogenously or cerebrospinal fluid transported label, 9.6% of the radioactivity in the LGN and 17.9% of the radioactivity in the visual cortex was found in the soluble fraction of a phosphate-buffered saline homogenate. In the LGN, 31.3% of the axonally transported soluble label was bound by concanavalin-A (Con-A) agarose. The corresponding figure in the visual cortex was 25.7%. Most (greater than 90%) of the label which did not bind Con-A was soluble in 10% trichloroacetic acid (TCA). Eighty-eight percent of the label which bound Con-A was precipitated by 10% TCA. On 7.5% polyacrylamide SDS reducing gels, the Con-A bound material from either the LGN or the visual cortex migrated as a single peak near the origin of the gel (apparent molecular weight greater than 300,000 Da).(ABSTRACT TRUNCATED AT 250 WORDS)

Localization and quantification of beta-adrenergic receptors in human brain

Little information is currently available on the localization of noradrenergic systems in the human CNS. We used quantitative autoradiography with [125I] iodopindolol to examine beta-adrenergic receptors in postmortem human brain. The concentration of beta-receptors was highest in all subfields of the hippocampus, followed by cerebellum, and then thalamic nuclei, basal ganglia, midbrain, and cerebral cortex. Low levels were found in white matter and hypothalamus. This distribution differed from the distribution of beta-receptors reported in membrane homogenates of human brain and also from the distribution of beta-receptors in rat brain determined by autoradiography. The similarities and differences between the distribution of beta-receptors in the human and rat brains may have implications regarding the role of norepinephrine in the CNS of these two species.

Autoradiographic localization of thyrotropin releasing hormone receptors in human brain

We used quantitative autoradiography to localize thyrotropin releasing hormone (TRH) receptors in human brain. Highest concentrations of TRH receptors were localized within the cortical, basal, and lateral nuclei of the amygdala and the molecular layer of the hippocampus. Low levels were found in the cortex, diencephalon, and basal ganglia. The radioligand bound with similar affinity and pharmacology to pituitary gland as to brain. These data suggest that authentic TRH receptors in the hippocampus and amygdala may mediate the putative effects of TRH on the human brain.

Similar distribution of monoamine oxidase (MAO) and parkinsonian toxin (MPTP) binding sites in human brain

1-Methyl-4-phenyl-1,2,5,6-tetrahydropyridine (MPTP) causes parkinsonism in humans and other species. We found [3H] MPTP binding sites that were saturable, specific, and of high affinity. In autoradiographic studies, the highest binding densities of [3H] MPTP occurred in the hypothalamus, interpeduncular nucleus, and ependymal lining of the ventricles. High to moderate binding was seen in the dentate gyrus, caudate, putamen, substantia nigra, and cingulate cortex. The distribution of [3H] MPTP binding correlated with the distribution of [3H] pargyline binding to MAO. Human substantia nigra contains more MPTP binding sites than rat substantia nigra, and this may explain the sensitivity of humans to the neurotoxic effects of MPTP.

A quantitative comparison of the efficiency of orthograde axonal transport and transsynaptic transport of iodinated (125I) wheat germ agglutinin (I-WGA) and horseradish peroxidase labeled I-WGA (I-WGA-HRP) in the rat visual system

A quantitative study of the orthograde axonal transport of iodinated wheat germ agglutinin (I-WGA) and I-WGA conjugated to horseradish peroxidase (I-WGA-HRP) demonstrated labeling of both the lateral geniculate nucleus and the visual cortex following intraocular injections. I-WGA was 13 times more efficient than I-WGA-HRP as a marker of the primary projection from the retina to the geniculate and 3 times more efficient than I-WGA-HRP as a marker of the second order projection to the cortex.

Autoradiographic localization of thyrotropin-releasing hormone (TRH) receptors in human spinal cord

Thyrotropin-releasing hormone (TRH) exerts many effects upon spinal cord function in animals, and may also play a role in human spinal cord function. We have used the technique of quantitative autoradiography to anatomically localize specific receptors for TRH within human spinal cord. Highest concentrations of TRH receptors were localized within lamina II, the substantia gelatinosa. A moderate density of TRH receptors was found in lamina IX, the motor neurons of the anterior horn. Low levels of TRH receptors were noted throughout the remainder of the gray matter of the human spinal cord, and no TRH receptors were localized within white matter. This anatomic distribution of TRH receptors within the human spinal cord is consistent with the localization of endogenous TRH and the effects of exogenously applied TRH in animal studies. These results suggest that any effects of TRH on human spinal cord function may be mediated by TRH receptors.

Distribution of estrogen-concentrating, neurophysin-containing magnocellular neurons in the rat hypothalamus as demonstrated by a technique combining steroid autoradiography and immunohistology in the same tissue

The distribution of estrogen-concentrating cells in the rat brain has been previously described in detail as has the distribution of cells containing oxytocin, vasopressin, and their associated neurophysins. This report describes the simultaneous localization of [3H]estradiol by steroid autoradiography and neurophysin by immunohistology in cells in the rat hypothalamus. In the rat, neurophysin-containing cells were found in three major nuclei - the supraoptic nucleus, the paraventricular nucleus (PVN) and the anterior commissural nucleus - as well as in a number of accessory nuclei and as individual cells in the anterior hypothalamic area. Of these, only the PVN has appreciable numbers of cells which both concentrate estradiol and contain neurophysin. Within the PVN these cells are found predominantly in the posterior subnucleus.

Immunohistochemical analysis of magnocellular elements in rat hypothalamus: distribution and numbers of cells containing neurophysin, oxytocin, and vasopressin

A cell-by-cell analysis of the magnocellular elements in hypothalami of fifty Long-Evans (normal) and Brattleboro (diabetes insipidus) rats was done using the unlabeled antibody enzyme technique (PAP) with primary antisera directed against oxytocin (OXY), vasopressin (ADH), and the neurophysins. The magnocellular neurons of the hypothalamus were found in the supraoptic (SON), paraventricular (PVN), and anterior commissural (ACN) nuclei, a number of accessory nuclei, and as individual cells in the anterior hypothalamic area. SON was divided by the optic tract into the principal part and retrochiasmatic SON. In retrochiasmatic SON a majority of the cells contained vasopressin. Within the principal part of SON oxytocin-producing cells tended to be found rostrally and dorsally, while the vasopressin cells were more common caudally and ventrally. PVN was divided into three subnuclei, the medial, lateral, and posterior subnuclei, on the basis of cellular morphology and peptide content. The magnocellular cells of the medial and lateral PVN were closely packed together and nearly round, while those of posterior PVN were more separated and fusiform in shape with their long axis running in a medio-lateral direction. Medial PVN consisted primarily of oxytocin-producing cells, while lateral PVN was formed by a core of vasopressin-producing cells with a rim of oxytocin cells. Posterior PVN contained largely oxytocin-producing cells. Both ADH and OXY cells were found in the accessory nuclei. In the Long-Evans rat the SON had, on the average, 1443 OXY and 3236 ADH cells; the PVN had 1174 OXY and 976 ADH cells; and the accessory magnocellular groups in the hypothalamus (including the ACN) had 1286 OXY and 552 ADH cells. The Brattleboro strain animal had similar numbers of cells in these nuclei. (The cells which contain ADH in normal animals were identified in the Brattleboro rat as large, neurophysin-negative cells.) Thus, a large fraction of the magnocellular oxytocin- and vasopressin-producing cells in the rat were located outside of the PVN and SON. One accessory cell group in particular, ACN, had 616 OXY cells, or about 50% as many as PVN. In each nucleus the sum of the numbers of OXY and ADH cells was approximately the number of neurophysin cells.

Changes in oxytocin content in the magnocellular neurons of the rat hypothalamus following water deprivation or estrogen treatment. Quantitative immunohistological studies

The effect of water deprivation or estrogen treatment on the oxytocin content of rat hypothalamic cells was examined using a quantitative immunohistological technique. Oxytocin-containing cells were visualized using the immunoperoxidase technique of Sternberg and a primary antiserum directed against oxytocin. The optical density of the darkest 3.2 micrometer diameter spot in the cytoplasm of a cell was used as a measure of the oxytocin content of that cell. Water deprivation produced a significant decrease in anti-oxytocin staining in the anterior commissural nucleus of males and females. There was a similar decrease in the paraventricular nucleus of males, but not in the paraventricular nucleus of females or the supraoptic nucleus of either males or females. Estrogen treatment of ovariectomized female rats produced a fall in anti-oxytocin staining in the anterior commissural, but not paraventricular or supraoptic nuclei.