Prognostic impact of MRI-derived feature tracking myocardial strain in patients with non-ischaemic dilated cardiomyopathy: a systematic review and meta-analysis

AIM

To evaluate the clinical utility of feature tracking (FT)-derived myocardial strain in patients with non-ischaemic dilated cardiomyopathy (NIDCM).

MATERIALS AND METHODS

Electronic database searches of PubMed, Web of Science Core Collection, Cochrane advanced search, and EMBASE were performed. Studies on NIDCM were divided into categories according to left ventricular ejection fraction (LVEF; <30%, 30-40%, >40%), and correlations between strains and prevalence of late gadolinium enhancement (LGE) were evaluated by weighted correlation coefficients. Global longitudinal strain (GLS) hazard ratios were also integrated for prediction of future adverse events.

RESULTS

The present meta-analysis analysed data from 5,767 patients with NIDCM from 30 eligible studies. GLS and global circumferential strain significantly differed across the three LVEF categories (all p<0.05); however, global radial strain did not. Only GLS showed a strong correlation with the prevalence of LGE (Spearman's correlation coefficient = 0.61). The pooled HR of GLS for predicting adverse events was 1.15 (95% confidence interval [CI]: 1.07-1.23, p<0.001).

CONCLUSION

In this meta-analysis, FT-derived GLS was strongly correlated with myocardial fibrosis and was an important predictor of future adverse events. These results suggest that FT-derived GLS may be useful in the pathological evaluation and risk stratification of NIDCM.

Delta-like 1-Expressing Cells at the Gland Base Promote Proliferation of Gastric Antral Stem Cells in Mouse

BACKGROUND & AIMS

Notch pathway signaling maintains gastric epithelial cell homeostasis by regulating stem cell proliferation and differentiation. We previously identified NOTCH1 and NOTCH2 as the key Notch receptors controlling gastric stem cell function. Here, we identify the niche cells and critical Notch ligand responsible for regulating stem cell proliferation in the distal mouse stomach.

METHODS

Expression of Notch ligands in the gastric antrum was determined by quantitative reverse-transcriptase polymerase chain reaction and cellular localization was determined by in situ hybridization and immunostaining. The contribution of specific Notch ligands to regulate epithelial cell proliferation in adult mice was determined by inducible gene deletion, or by pharmacologic inhibition using antibodies directed against specific Notch ligands. Mouse gastric organoid cultures were used to confirm that Notch ligand signaling was epithelial specific.

RESULTS

Delta-like 1 (DLL1) and Jagged 1 (JAG1) were the most abundantly expressed Notch ligands in the adult mouse stomach, with DLL1 restricted to the antral gland base and JAG1 localized to the upper gland region. Inhibition of DLL1 alone or in combination with other Notch ligands significantly reduced epithelial cell proliferation and the growth of gastric antral organoids, while inhibition of the other Notch ligands, DLL4, JAG1, and JAG2, did not affect proliferation or organoid growth. Similarly, DLL1, and not DLL4, regulated proliferation of LGR5+ antral stem cells, which express the NOTCH1 receptor.

CONCLUSIONS

DLL1 is the key Notch ligand regulating epithelial cell proliferation in the gastric antrum. We propose that DLL1-expressing cells at the gland base are Notch niche cells that signal to adjacent LGR5+ antral stem cells to regulate stem cell proliferation and epithelial homeostasis.

Multisystem Inflammatory Syndrome in Children (MIS-C) with COVID-19: Insights from simultaneous familial Kawasaki Disease cases

Recently, an increasing number of SARS-CoV-2 patients with COVID-19 syndrome, which overlaps with Kawasaki Disease (KD), have been reported, supporting the suggestion that infection is one of the triggers of KD. We summarized the reports of simultaneous familial KD cases to better understand the etiopathogenesis of both KD and Multisystem Inflammatory Syndrome in Children (MIS-C) related to COVID-19. Here we discuss the etiology of these syndromes from the point of view of infection and genetic susceptibility.

Diagnostic test accuracy of antigenaemia assay for PCR-proven cytomegalovirus infection-systematic review and meta-analysis

OBJECTIVES

We aimed to assess diagnostic test accuracy of antigenaemia assay for PCR-proven cytomegalovirus (CMV) infection.

METHODS

We systematically searched studies that provide data both on sensitivity and specificity of the CMV antigenaemia assay using the PCR as the reference standard. Adults, children, infants, individuals who were immunocompromised for any reason, symptomatic patients and asymptomatic individuals were all included. A hierarchical summary receiver operating characteristics model was used for diagnostic meta-analysis. Study quality was assessed by Revised Tool for the Quality Assessment of Diagnostic Accuracy Studies. Protocol registration identification is CRD42016035892.

RESULTS

We identified 75 eligible articles including 9058 CMV PCR-positive individuals and 22 232 PCR-negative individuals. The diagnostic odds ratio for positive antigenaemia was 30 (95% CI 24-38, I² = 28%) and the area under the hierarchical summary receiver operating characteristic curve was 0.86 (95% CI 0.83-0.88). The summary estimates of sensitivity and specificity were 0.65 (95% CI 0.59-0.70) and 0.94 (95% CI 0.93-0.95), respectively. The positive likelihood ratio of 10.9 (95% CI 8.5-14.0) suggested that a positive result from the antigenaemia assay greatly increased the probability of PCR-proven CMV infection, but a negative likelihood ratio of 0.38 (95% CI 0.32-0.44) indicated that a negative result led to a small decrease in the probability of PCR-proven CMV infection. Sensitivity and subgroup analyses replicated these results.

CONCLUSIONS

The antigenaemia assay overlooked 35% of PCR-proven CMV infections; hence, a negative result of an antigenaemia assay could not rule out a CMV infection.

Long-term Inflammation Transforms Intestinal Epithelial Cells of Colonic Organoids

BACKGROUND AND AIMS

Patients with ulcerative colitis [UC] are at an increased risk of developing colitis-associated cancer [CAC], suggesting that continuous inflammation in the colon promotes the transformation of colonic epithelial cells. However, the mechanisms underlying cell transformation in UC remain unknown. We therefore aimed to investigate the effect of long-term inflammation on intestinal epithelial cells [IECs] using organoid culture.

METHODS

IECs were isolated from mouse colon, and were cultured according to a method for a three-dimensional [3D] organoid culture. To mimic chronic inflammation, a mixture of cytokines and bacterial components were added to the medium for over a year. Cell signal intensity was assessed by 3D immunofluorescence. Cell transformation was assessed by microarray with gene set enrichment analysis.

RESULTS

Stimulation with cytokines resulted in a significant induction of target genes for the nuclear factor [NF]-κB pathway in colonic organoids. Following 60 weeks of continuous stimulation, cell differentiation was suppressed. Continuous stimulation also resulted in significant amplification of NF-κB signalling. Amplified NF-κB signalling by long-term stimulation remained in colonic organoids even 11 weeks after the removal of all cytokines. Some genes were specifically upregulated only in colonic organoids after the removal all cytokines following long-term stimulation.

CONCLUSIONS

Colonic organoids stimulated with cytokines for a prolonged period were established as in vitro model to assess long-term epithelial responses to inflammatory cytokines. Chronic inflammation led to sustained NF-κB signalling activation in colonic organoids, resulting in cell transformation that might be related to the carcinogenesis of CAC in UC.

Caudal type homeobox 2 expression induced by leukocytapheresis might be associated with mucosal healing in ulcerative colitis

BACKGROUND AND AIM

Ulcerative colitis (UC) is a chronic inflammatory disease of the colon with an intractable, recurrent course. Although the goal of UC therapy has recently been to target mucosal healing, the molecular mechanism of mucosal healing remains unknown. In this study, we aimed to elucidate the molecular dynamics related to the proliferation and differentiation of intestinal epithelial cells during cytapheresis therapy in a short duration.

METHODS

Endoscopy was performed in 26 patients with UC in multicentre hospitals, and biopsy specimens were collected from the rectum before and within two weeks after leukocytapheresis (LCAP). The expression of representative proteins in intestinal epithelial cells and pathological findings was compared before and after LCAP.

RESULTS

The expression of caudal type homeobox 2 (CDX2) and a hes family bHLH transcription factor 1(HES1) markedly increased after LCAP. Patients with endoscopic improvement after LCAP showed the expression of CDX2 before LCAP. Moreover, the number of goblet cells significantly increased after LCAP. Patients without endoscopic improvement after LCAP did not show the expression of CDX2 before LCAP. However, the expression of CDX2 markedly increased after LCAP.

CONCLUSION

This study suggests that cytapheresis might induce CDX2 expression without affecting the cell proliferation, thus resulting in mucosal healing with goblet cell restoration.

NOTCH1 and NOTCH2 regulate epithelial cell proliferation in mouse and human gastric corpus

The Notch signaling pathway is known to regulate stem cells and epithelial cell homeostasis in gastrointestinal tissues; however, Notch function in the corpus region of the stomach is poorly understood. In this study we examined the consequences of Notch inhibition and activation on cellular proliferation and differentiation and defined the specific Notch receptors functioning in the mouse and human corpus. Notch pathway activity was observed in the mouse corpus epithelium, and gene expression analysis revealed NOTCH1 and NOTCH2 to be the predominant Notch receptors in both mouse and human. Global Notch inhibition for 5 days reduced progenitor cell proliferation in the mouse corpus, as well as in organoids derived from mouse and human corpus tissue. Proliferation effects were mediated through both NOTCH1 and NOTCH2 receptors, as demonstrated by targeting each receptor alone or in combination with Notch receptor inhibitory antibodies. Analysis of differentiation by marker expression showed no change to the major cell lineages; however, there was a modest increase in the number of transitional cells coexpressing markers of mucous neck and chief cells. In contrast to reduced proliferation after pathway inhibition, Notch activation in the adult stomach resulted in increased proliferation coupled with reduced differentiation. These findings suggest that NOTCH1 and NOTCH2 signaling promotes progenitor cell proliferation in the mouse and human gastric corpus, which is consistent with previously defined roles for Notch in promoting stem and progenitor cell proliferation in the intestine and antral stomach.

NEW & NOTEWORTHY

Here we demonstrate that the Notch signaling pathway is essential for proliferation of stem cells in the mouse and human gastric corpus. We identify NOTCH1 and NOTCH2 as the predominant Notch receptors expressed in both mouse and human corpus and show that both receptors are required for corpus stem cell proliferation. We show that chronic Notch activation in corpus stem cells induces hyperproliferation and tissue hypertrophy, suggesting that Notch may drive gastric tumorigenesis.

BRAFV600E cooperates with CDX2 inactivation to promote serrated colorectal tumorigenesis

While 20–30% of colorectal cancers (CRCs) may arise from precursors with serrated glands, only 8–10% of CRCs manifest serrated morphology at diagnosis. Markers for distinguishing CRCs arising from ‘serrated’ versus ‘conventional adenoma’ precursors are lacking. We studied 36 human serrated CRCs and found CDX2 loss or BRAF mutations in ~60% of cases and often together (p=0.04). CDX2^Null/BRAF^V600E expression in adult mouse intestinal epithelium led to serrated morphology tumors (including carcinomas) and BRAF^V600E potently interacted with CDX2 silencing to alter gene expression. Like human serrated lesions, CDX2^Null/BRAF^V600E-mutant epithelium expressed gastric markers. Organoids from CDX2^Null/BRAF^V600E–mutant colon epithelium showed serrated features, and partially recapitulated the gene expression pattern in mouse colon tissues. We present a novel mouse tumor model based on signature defects seen in many human serrated CRCs – CDX2 loss and BRAF^V600E. The mouse intestinal tumors show significant phenotypic similarities to human serrated CRCs and inform about serrated CRC pathogenesis.

DOI:http://dx.doi.org/10.7554/eLife.20331.001

Atonal homolog 1 protein stabilized by tumor necrosis factor α induces high malignant potential in colon cancer cell line

Patients with inflammatory bowel disease (IBD) have an increased risk of developing colitis-associated colorectal cancer (CAC). CAC cells often develop chemoresistance, resulting in a poorer prognosis than that of sporadic colorectal cancer (CRC). The mechanism by which CAC enhances malignant potential remains unknown. We have previously reported that the proteasomal degradation of the transcription factor Atonal homolog 1 (Atoh1) protein results in the non-mucinous form of CRC. It also remains unknown whether Atoh1 protein is expressed in CAC. Therefore, in the present study, we investigated whether Atoh1 protein stabilizes in CAC. Consequently, the treatment with TNF-α stabilized Atoh1 protein through the inactivation of GSK-3β via Akt, resulting in the mucinous form of CRC cell lines. Atoh1 protein also enriched cancer stem cells with upregulated Lgr5 expression and cells in G0/G1 cell cycle phase, resulting in both the chemoresistance to 5-fluorouracil and oxaliplatin and the promotion of cell migration. Immunofluorescence of the human mucinous CAC specimens showed the accumulation of NF-κB p65 at nuclei with the expression of Atoh1 in mucinous cancer. In conclusion, the inflammation associated with carcinogenesis may preserve the differentiation system of intestinal epithelial cell (IEC), resulting in the acquisition of both the mucinous phenotype and high malignant potential associated with the enrichment of cancer stem cell.

Fluorescent labelling of intestinal epithelial cells reveals independent long-lived intestinal stem cells in a crypt

BACKGROUND AND AIMS

The dynamics of intestinal stem cells are crucial for regulation of intestinal function and maintenance. Although crypt stem cells have been identified in the intestine by genetic marking methods, identification of plural crypt stem cells has not yet been achieved as they are visualised in the same colour.

METHODS

Intestinal organoids were transferred into Matrigel® mixed with lentivirus encoding mCherry. The dynamics of mCherry-positive cells was analysed using time-lapse imaging, and the localisation of mCherry-positive cells was analysed using 3D immunofluorescence.

RESULTS

We established an original method for the introduction of a transgene into an organoid generated from mouse small intestine that resulted in continuous fluorescence of the mCherry protein in a portion of organoid cells. Three-dimensional analysis using confocal microscopy showed a single mCherry-positive cell in an organoid crypt that had been cultured for >1year, which suggested the presence of long-lived mCherry-positive and -negative stem cells in the same crypt. Moreover, a single mCherry-positive stem cell in a crypt gave rise to both crypt base columnar cells and transit amplifying cells. Each mCherry-positive and -negative cell contributed to the generation of organoids.

CONCLUSIONS

The use of our original lentiviral transgene system to mark individual organoid crypt stem cells showed that long-lived plural crypt stem cells might independently serve as intestinal epithelial cells, resulting in the formation of a completely functional villus.

[Undifferentiated carcinoma of the jejunum producing granulocyte colony-stimulating factor]

An 80-year-old man presented with abdominal fullness and vomiting. Laboratory data revealed severe anemia, an inflammatory response, and elevated white blood cell counts. Abdominal computed tomography indicated ileus caused by a jejunal tumor measuring 8cm in diameter. Although small-bowel endoscopy enabled visualization of the tumor, adequate biopsy specimens could not be obtained for accurate diagnosis. The patient's condition rapidly deteriorated, because of which surgical treatment could not be initiated. The patient died approximately 3 weeks after admission. High serum granulocyte colony-stimulating factor (G-CSF) levels were detected at autopsy. Immunohistochemical staining of the autopsy specimen indicated positive G-CSF levels in the jejunal tumor. On the basis of these findings, a final diagnosis of undifferentiated carcinoma of the jejunum producing G-CSF was made.

Development and validation of a tuberculosis prognostic score for smear-positive in-patients in Japan

BACKGROUND

No scoring system has ever been used to estimate the prognosis of individual tuberculosis (TB) patients.

OBJECTIVE

To develop and validate a tuberculosis prognostic score.

METHODS

This retrospective cohort study conducted in Japan comprised the development (n = 179; mean age 65.9 ± 18.8 years) and validation (n = 244; mean age 64.3 ± 20.1 years) of a tuberculosis prognostic score among patients with newly diagnosed smear-positive non-multidrug-resistant pulmonary tuberculosis without human immunodeficiency virus infection. The score (raw score) was defined by modifying a logistic regression formula using known risk factors as independent variables and in-patient death as a dependent variable.

RESULTS

The raw score was calculated as follows: age (years) + (oxygen requirement, 10 points) - 20 × albumin (g/dl) + (activity of daily living: independent, 0 point; semi-dependent, 5 points; totally dependent, 10 points). The raw scores were grouped into risk groups 1 (raw score < -30) to 5 (raw score ≥ 60) using 30-point intervals. Every increase in risk group was equivalent to a 7.3-fold increase in the odds ratio for in-hospital death (P < 0.001). The area under the receiver operating characteristics curve by risk group for in-patient death was 0.875 (P < 0.001).

CONCLUSIONS

In this study we were able to develop and validate a tuberculosis prognostic score.

[A case of idiopathic interstitial pneumonia that responded well to intermittent intravenous administration of high doses of cyclophosphamide and a steroid]

A 78-year-old man was hospitalized on February 29, 2000 because of dyspnea. A chest radiograph showed diffuse bilateral interstitial shadows associated with pulmonary volume loss. We could not obtain histological evidence of idiopathic interstitial pneumonia (IIP) because of his advanced age and severe respiratory dysfunction. IIP was diagnosed on the basis of radiographic findings and clinical symptoms. The patient was intubated and mechanical ventilation was performed. After one course of pulsed cyclophosphamide (CPM) and methylprednisolone therapy, the hypoxemia improved and it became possible to wean the patient from the ventilator. After five courses of pulsed CPM therapy, the dose of oral corticosteroid was tapered. CPM was administered safely without any severe side effects. Pulsed CPM therapy appears to be a viable alternative method of treatment for IIP.

Close relationship of tissue plasminogen activator-plasminogen activator inhibitor-1 complex with multiple organ dysfunction syndrome investigated by means of the artificial pancreas

BACKGROUND

Glucose tolerance (GT) has not been taken into consideration in investigations concerning relationships between coagulopathy and multiple organ dysfunction syndrome (MODS), and endothelial cell activation/endothelial cell injury (ECA/ECI) in septic patients, although coagulopathy is known to be influenced by blood glucose level. We investigated those relationships under strict blood glucose control and evaluation of GT with the glucose clamp method by means of the artificial pancreas in nine septic patients with glucose intolerance. The relationships between GT and blood stress related hormone levels (SRH) were also investigated.

METHODS

The amount of metabolized glucose (M value), as the parameter of GT, was measured by the euglycemic hyperinsulinemic glucose clamp method, in which the blood glucose level was clamped at 80 mg/dl under a continuous insulin infusion rate of 1.12 mU/kg per min, using the artificial pancreas, STG-22. Multiple organ failure (MOF) score was calculated using the MOF criteria of Japanese Association for Critical Care Medicine. Regarding coagulopathy, the following parameters were used: disseminated intravascular coagulation (DIC) score (calculated from the DIC criteria of the Ministry of Health and Welfare of Japan) and the parameters used for calculating DIC score, protein-C, protein-S, plasminogen, antithrombin III (AT-III), plasminogen activator inhibitor-1 (PAI-1), and tissue plasminogen activator-PAI-1 (tPA-PAI-1) complex. Thrombomodulin (TM) was measured as the indicator of ECI.

RESULTS

There were no significant correlations between M value and SRH, parameters indicating coagulopathy and the MOF score. The MOF score and blood TM levels were positively correlated with DIC score, thrombin-AT-III complex and tPA-PAI-1 complex, and negatively correlated with blood platelet count.

CONCLUSIONS

GT was not significantly related to SRH, coagulopathy and MODS under strict blood glucose control. Hypercoagulability was closely related to MODS and ECI. Among the parameters indicating coagulopathy, tPA-PAI-1 complex, which is considered to originate from ECA, seemed to be a sensitive parameter of MODS and ECI, and might be a predictive marker of MODS. The treatment for reducing hypercoagulability and ECA/ECI were thought to be justified as one of the therapies for acutely ill septic patients.

Churg-Strauss syndrome associated with pregnancy

Churg-Strauss syndrome, an uncommon condition, occurs even more rarely in association with pregnancy. One month postpartum, a 25-year-old Japanese woman was hospitalized for dyspnea, fever, diarrhea, and complaints of dysesthesia in the right lower limb and right lumbar and abdominal region. Marked eosinophilia was present. Symptoms of bronchial asthma had developed early in the pregnancy, which concluded with delivery of a healthy baby at 39 weeks of gestation. Churg-Strauss syndrome was diagnosed and prednisolone was administered with a good response leading to remission. Three years after the first pregnancy, low-dose steroid therapy was continued through another pregnancy. The patient delivered another healthy baby at 39 weeks of gestation, this time with no exacerbation of symptoms.

[A case of elderly patient with pulmonary tuberculosis considered to be caused by exogenous reinfection]

A 84-year-old woman presented with chronic febrile illness and anorexia from June 1998. She was diagnosed as pulmonary tuberculosis and was admitted to our hospital in August 1998. Her sputum smear was Gaffky 2, and the type of chest radiograph was b III 3. By family contact examination in August 1998, chest radiological examinations of her husband, a 86-year-old man, showed consolidation in middle lobe, right pleural effusion and two calcified mediastinal lymphnodes. He was diagnosed as pulmonary tuberculosis complicated with pleurisy. He had poor controlled diabetes mellitus. Tubercle bacilli isolated from their sputa showed the same pattern in restriction fragment length polymorphism analysis. Pulmonary tuberculosis of the husband was considered to be caused by exogenous reinfection.

[Serum soluble interleukin-2 receptor in patients with pulmonary mycobacterial diseases]

Serum soluble interleukin-2 receptor (sIL-2R) levels were measured in patients with untreated pulmonary tuberculosis (24 cases), patients with multidrug-resistant intractable pulmonary tuberculosis (7 cases) and patients with pulmonary non-tuberculous mycobacteriosis (27 cases). Serum sIL-2R levels were elevated in patients with pulmonary mycobacterial diseases and were elevated in untreated pulmonary tuberculosis patients than in other patients. In patients with new tuberculosis, serum sIL-2R levels were higher in patients with extensive lesions. Serum sIL-2R level showed significant positive correlation with serum C-reactive protein level and erythrocyte sedimentation rate, and significant negative correlation with serum albumin level. In patients with intractable tuberculosis and patients with non-tuberculous mycobacteriosis, serum sIL-2R levels were lower than in patients with new tuberculosis. Even in patients with extensive lesions, serum sIL-2R levels were not elevated. Lower levels of serum sIL-2R, marker of immunocompetent cell activity, suggested that immunocompetent cell activity was suppressed in intractable tuberculosis and in non-tuberculous mycobacteriosis.

Patients with methamphetamine psychosis admitted to a psychiatric hospital in Japan. A preliminary report

To examine the clinical characteristics of methamphetamine (MAP) psychosis in Japan, we evaluated 104 patients with MAP psychosis (80 men and 24 women) admitted to the closed psychiatric units of Tokyo Metropolitan Matsuzawa Hospital between 1988 and 1991. There has recently been a steep increase in the number of admissions for MAP psychosis, reflecting the growth of the epidemic of MAP abuse in Japan. Although more than half of the patients were discharged within one month, 16 patients were hospitalized for more than 3 months. Most of the patients showed paranoid psychotic state similar to schizophrenia, consistent with previous reports. Despite the abstinence from MAP and antipsychotic medication, psychotic symptoms tended to persist in some of the patients. The etiological role of MAP psychosis in the development of long-lasting psychotic state was discussed.

Neuropathologic changes in suckling and weanling rats with pyrithiamine-induced thiamine deficiency

Pregnant and nursing Wistar rats were fed a thiamine-deficient diet, and their offspring were injected daily with pyrithiamine. The pathologic lesions in the suckling rats were examined at different times of development. There were distinct changes at 22 days of age, by which time the rats are weaned, and the morphogenesis of the cerebellum is almost completed. Before 22 days of age, there were no pathologic changes except for scattered petechial hemorrhages in the brain. After 22 days of age, acute pathologic changes were observed, in decreasing order of severity, in the vestibular nuclei, inferior olivary nuclei, mammillary body, periventricular gray matter, thalamus, and quadrigeminal plates. The initial changes were swelling of post-synaptic dendrites and distension of the periaxonal space of myelinated axons in the parenchyma and ring-shaped hemorrhages in the perivascular space. Pyrithiamine injections into the offspring of rats fed a thiamine-deficient diet probably induce disturbance of the electrolyte permeability of the neuronal excitable membrane, resulting in swelling of this element. These changes were followed by the filtration of erythrocytes and plasma into the parenchyma and astrocytic swelling, which may be a secondary effect of neuronal changes on the brain vascular permeability.

Ultrastructure of Alzheimer type II glia in hepatocerebral disease

In a case of hepatocerebral disease of Inose type the astrocytes, corresponding to Alzheimer type II glia, had swollen cytoplasm containing glycogen granules and focal aggregates of lipofuscin granules. Their nuclei contained bodies of simple and of complex types as well as conglomerates of glycogen granules without any capsules. The nuclear bodies of simple type were also observed in the nuclei of endothelial cells. It is concluded that these changes in the appearance of Alzheimer type II glia suggest reactive and defensive changes in the brain against ammonium ions, rather than being merely degenerative in nature.

Ultrastructure of 6-aminonicotinamide (6-AN)-induced lesions in the central nervous system of rats. III. Alterations of the spinal gray matter lesion with aging

Following a single i.p. injection of 6-AN (10 mg/kg), the anterior horn cells of 20- and 25-month-old rats increased more in size and recovered slower from chromatolytic changes than those of 3-month-old rats. Neurofilamentous hyperplasia of the perikarya was more prominent in aged rats; proliferated neurofilaments were arranged in thick parallel bundles. In the acute stage, reactive and degenerative changes of glial and mesenchymal elements were more conspicuous in 3-month-old rats; however, they disappeared by day 14 with prominent proliferation of hypertrophic astrocytes. The older rats showed less intensity and slower progression of these changes; sponginess and swelling of the astrocytic cytoplasm were still observed at day 14. Our results suggest that these age-dependent changes in the response to neurotoxins are not only induced on the neuron without mitotic phenomena after birth, but also on neuroglial cells. Furthermore, an alteration or reduction in the support of the neuron augments its intensified and delayed susceptibility to neurotoxins.

Experimental carbon monoxide leucoencephalopathy in the cat

After left common carotid artery ligation, cats were exposed to different CO gas concentrations for different periods, and the cerebral lesions were examined by light and electron microscopy at different intervals after exposure. Exposure to the higher concentration produced severe cardiopulmonary disturbances, and swelling of astrocytes in the white matter on the ligated side. This change was maximal at 1 to 3 days after exposure and subsided within one week. In cats exposed longer, necrotic or cystic lesions were observed on the ligated side. Prolonged exposure to the lower concentrations resulted in edema and reactive and degenerative axonal changes, followed by disintegration and phagocytosis of myelin sheaths, patches of demyelination, such as are seen in Grinker's leucoencephalopathy, were observed on the ligated and, to a lesser degree, on the non-ligated side. These lesions in the cerebral white matter may be related to the degree and duration of anoxic or histotoxic anoxia, or both, induced secondarily by the effects of the CO gas on cardiopulmonary function, and to the survival intervals after exposure. We postulate that the pathological change in experimental Grinker's leucoencephalopathy may be due to Wallerian degeneration or a dying-back process, rather than to true demyelination.

Ultrastructure of 6-aminonicotinamide (6-AN)-induced lesions in the central nervous system of rats. II. Alterations of the nervous susceptibility with aging

Lesions in the CNS induced by 6-aminonicotinamide (6-AN) presented a spongy state of the gray matter and neuronal chromatolysis. With aging of the experimental animals the lesions extended from the phylogenetically early developed structures to those developed later, i.e., from spinal gray matter, dentate nuclei, and brain stem nuclei through limbic structures and striatum to the cerebral cortex. Changes of the neurons were more prominent with aging. Lesions in the CNS of rats at the age, corresponding to the involutional period in the human, were similar to those of Creutzfeldt-Jakob disease (C-J) disease) in the presenile age. In recent years, the resemblance between C-J disease and pellagra encephalopathy had been noted by several authors, and they resemble the lesions caused by 6-AN, an antimetabolite of nicotinamide used in our experiment. This evidence, therefore, has led to the hypothesis that dysfunction of NAD(H)- or NADP(H)-dependent enzymes in the CNS of the aged, even if not the primary cause, may be one possible pathogenetic factor of C-J disease.

Effects of long-term administration of chlorpromazine on the pineal gland of rats

Long-term (6 months) administration of 25 mg/kg body weight/day chlorpromazine (CPZ) to rats resulted in remarkable inhibition of normal increase with age of osmiophilic lipid droplets (OLD) in the pineal gland, and atrophy of pinealocytes. The breeding conditions such as illumination, humidity, and room temperature were strictly controlled. Hence, these changes were ascribed solely to the effects of the drug. OLD are considered as an indicator of physiological activity of the gland. In view of the possible functional relations of this organ to endocrine or autonomic nervous activity, our finding may give a clue to the clarification of the possible cause of some side-effects of the drug.