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1.
Comput Biol Med ; 178: 108774, 2024 Jun 18.
Article in English | MEDLINE | ID: mdl-38897149

ABSTRACT

Histological assessment of centroblasts is an important evaluation in the diagnosis of follicular lymphoma, but there is substantial observer variation in assessment among hematopathologists. We aimed to perform quantitative morphological analysis of centroblasts in follicular lymphoma using new artificial intelligence technology in relation to the clinical prognosis. Hematoxylin and eosin slides of lesions were prepared from 36 cases of follicular lymphoma before initial chemotherapy. Cases were classified into three groups by clinical course after initial treatment. The 'excellent prognosis' group were without recurrence or progression of follicular lymphoma within 60 months, the 'poor prognosis' group were those that had relapse, exacerbation, or who died due to the follicular lymphoma within 60 months, and the 'indeterminate prognosis' group were those without recurrence or progression but before the passage of 60 months. We created whole slide images and image patches of hematoxylin and eosin sections for all cases. We designed an object detection model specialized for centroblasts by fine-tuning YOLOv5 and segmented all centroblasts in whole slide images. The morphological characteristics of centroblasts in relation to the clinical prognosis of follicular lymphoma were analyzed. Centroblasts in follicular lymphoma of the poor prognosis group were significantly smaller in nuclear size than those in follicular lymphoma of the excellent prognosis group in the following points: median of nuclear area (p = 0.013), long length (p = 0.042), short length (p = 0.007), nuclear area of top 10 % cells (p = 0.024) and short length of top 10 % cells (p = 0.020). Cases with a mean nuclear area of <55 µm2 had poorer event-free survival than those with a mean nuclear area of ≥55 µm2 (p < 0.0123). AI methodology is suggested to be able to surpass pathologist's observation in capturing morphological features. Small-sized centroblasts will likely become a new prognostic factor of follicular lymphoma.

2.
Int J Surg Pathol ; : 10668969231212428, 2023 Nov 19.
Article in English | MEDLINE | ID: mdl-37981745

ABSTRACT

SARS-CoV-2 vaccines have been administered in many countries after the COVID-19 pandemic. Lymphadenopathy is a side effect of SARS-CoV-2 vaccine. We report a rare example of Kikuchi disease in the cervical lymph nodes after SARS-CoV-2 vaccination. A 41-year-old man complained of a swollen neck and fever 9 days after the first dose of SARS-CoV-2 mRNA-1273 vaccine. Computed tomography revealed enlarged cervical lymph nodes. Fine needle aspiration and resection were performed, and the clinicopathological diagnosis was consistent with Kikuchi disease. Histologically, the resected lymph nodes lost their polarity, and many histiocytes were aggregated with karyorrhectic nuclear debris and apoptosis. SARS-CoV-2 positive cells were small lymphocytes detected by immunohistochemistry. This is the first report that demonstrated SARS-CoV-2 expression in Kikuchi disease post-SARS-CoV-2 vaccination.

3.
Cureus ; 15(3): e36373, 2023 Mar.
Article in English | MEDLINE | ID: mdl-36945236

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a novel coronavirus that is causing a worldwide pandemic since the spring of 2020. In Osaka, the second biggest prefecture in Japan, we identified a novel SARS-CoV-2 variant from a coronavirus disease 2019 (COVID-19) patient that was detected by polymerase chain reaction (PCR) using E primers, but not by real-time quantitative reverse transcription polymerase chain reaction (RT-qPCR) using the N1 and N2 primer-probe sets recommended by CDC. We analyzed the S and N gene regions by reverse-transcription and nested PCR using the S and N specific primers, and DNA sequencing, and found that this BA.5 variant contained point mutations in the probe sequences of both the N1 and N2 primer-probe regions. This finding led us to affirm the importance of monitoring the genome sequence of the SARS-CoV-2 variants continuously.

4.
Jpn J Clin Oncol ; 52(9): 1062-1066, 2022 Sep 18.
Article in English | MEDLINE | ID: mdl-35750041

ABSTRACT

The object in this study is to develop an artificial intelligence-based deep learning algorithm for prediction of time to castration-resistant prostate cancer by combined androgen blockade therapy in metastatic hormone-naïve prostate cancer. We included 180 metastatic hormone-naïve prostate cancer patients who initially received combined androgen blockade. We first evaluated whether time to castration-resistant prostate cancer was a significant prognostic factor. Then, using the patients' needle-biopsy specimen images, we developed and validated our deep learning algorithm. The results are shown below. First, we confirmed that time to castration-resistant prostate cancer correlated with overall survival (P < 0.001). Next, we selected two groups by time to castration-resistant prostate cancer of >24 months (n = 18) and <6 months (n = 6) and developed a deep learning algorithm by artificial intelligence-based machine deep learning. In 16 other metastatic hormone-naïve prostate cancer patients used as an external validation set, we confirmed the prediction accuracy remained significant (P < 0.05). In conclusion, our obtained deep learning algorithm has high predictive ability for the effectiveness of combined androgen blockade.


Subject(s)
Deep Learning , Prostatic Neoplasms, Castration-Resistant , Androgen Antagonists/therapeutic use , Androgens , Artificial Intelligence , Humans , Male , Pilot Projects , Prostatic Neoplasms, Castration-Resistant/pathology
6.
Front Cell Dev Biol ; 7: 111, 2019.
Article in English | MEDLINE | ID: mdl-31316980

ABSTRACT

Cell adhesion molecule 1 (CADM1) is an immunoglobulin superfamily member strongly expressed on renal tubular epithelia in the urinary tract. Enzymatic cleavage of its ectodomain increases in chronic kidney disease (CKD), and is assumed to contribute to tubulointerstitial lesion formation. Because the cleaved ectodomain fragments are likely to be released into the urine, a sandwich enzyme-linked immunosorbent assay (ELISA) system for urinary CADM1 was developed using two anti-ectodomain antibodies. Urinary CADM1 concentrations in patients with CKD based on various forms of glomerulonephritis and nephropathy (n = 127) were measured. A total of 44 patients (35%) had elevated CADM1 concentrations over the normal upper limit (362 pg/mL), with a mean of 1,727 pg/mL. Renal biopsy specimens of all patients were pathologically scored for tubulointerstitial lesions using epithelial degeneration, interstitial inflammation, and fibrosis. There were no correlations between urinary CADM1 concentrations and pathological scores or any widely used renal markers, including glomerular filtration rate (GFR), but there was a weak inverse correlation between pathological scores and GFR (R2 = 0.292). Notably, this correlation gradually increased in patients with increasing CADM1 concentrations, and reached a maximum R 2 (0.899) at a cutoff of 1,569 pg/mL. The results of this study suggest that urinary CADM1 is a useful marker indicating tubulointerstitial damage from elevated GFR levels in CKD.

7.
Sci Rep ; 8(1): 10337, 2018 07 09.
Article in English | MEDLINE | ID: mdl-29985436

ABSTRACT

While motor learning approaches are effective in rehabilitating Parkinson's disease (PD) patients, many studies reported deficits in sequential motor learning in these patients. We hypothesised that preserved explicit learning of visuomotor sequences in PD patients contributed to the effectiveness of motor learning approaches. However, there are very few studies analysing explicit learning of visuomotor sequences during the progression of PD. We investigated this phenomenon in 23 patients with moderate to severe PD (Hoehn-Yahr stages II-IV) and 17 age-matched controls using sequential button-press tasks (2 × 5 task). We found (1) no significant differences in numbers of errors in the 2 × 5 task among control and PD groups. (2) There was a significant difference in response times while exploring correct sequences (ERT) among control and PD groups; ERTs in stage-IV patients tended to be longer than those of control and stage-II groups. (3) All four groups significantly improved their performance (i.e., reduced ERTs in the 2 × 5 task) with sequence repetition, although stage-III:IV patients were slower. Thus, even patients with severe PD can learn visual sequences and can translate them into visuomotor sequences (explicit visuomotor sequence learning), albeit slower than controls, providing evidence for effective motor learning approaches during rehabilitation of patients with advanced PD.


Subject(s)
Parkinson Disease/pathology , Psychomotor Performance/physiology , Aged , Case-Control Studies , Disease Progression , Female , Humans , Male , Middle Aged , Neuropsychological Tests , Photic Stimulation , Reaction Time , Severity of Illness Index
8.
Eur Neurol ; 76(1-2): 35-9, 2016.
Article in English | MEDLINE | ID: mdl-27351804

ABSTRACT

BACKGROUND: Camptocormia in Parkinson's disease (PD) is unresponsive to various therapies and induced difficulties in their day-to-day life. OBJECTIVE: This study, an open trial, was aimed at assessing the efficacy of selegiline in the treatment of mild camptocormia in PD patients. METHODS: Participants were administered 5 mg of selegiline for the first 8 weeks and 7.5 mg for the second 8 weeks. RESULTS: As primary endpoints, the degree of thoracolumbar anteflexion decreased from 23.2° (mean) (11.8° (SD)) at baseline to 18.3° (7.1°) at 16 weeks, and the area of postural sway measured using a Gravicorder increased. However, the differences were not significant. Thoracolumbar anteflexion improved in 60% of the participants. CONCLUSIONS: In this study, 60% of the participants showed an improvement in anteflexion of the thoracolumbar spine with selegiline, but the change in the degree of anteflexion was 5°, which was not statistically significant. Participants with significant improvement in thoracolumbar anteflexion had an increased postural sway. This change was induced by a decrease in truncal muscle tonus or change in the center of gravity. This study combined the study of anteflexion and stability, and provides information on the treatment of short-term or mild camptocormia.


Subject(s)
Antiparkinson Agents/therapeutic use , Muscular Atrophy, Spinal/drug therapy , Parkinson Disease/drug therapy , Selegiline/therapeutic use , Spinal Curvatures/drug therapy , Aged , Female , Humans , Male , Middle Aged , Muscular Atrophy, Spinal/complications , Parkinson Disease/complications , Spinal Curvatures/complications , Treatment Outcome
10.
Mov Disord Clin Pract ; 1(3): 200-212, 2014 Sep 01.
Article in English | MEDLINE | ID: mdl-25328906

ABSTRACT

BACKGROUND: The Movement Disorder Society (MDS)-sponsored revision of the Unified Parkinson's Disease (PD) Rating Scale (UPDRS) (MDS-UPDRS) has been developed and is now available in English. Part of the overall program includes the establishment of official non-English translations of the MDS-UPDRS. We present the process for completing the official Japanese translation of the MDS-UPDRS with clinimetric testing results. METHODS: In this trial, the MDS-UPDRS was translated into Japanese, underwent cognitive pre-testing, and the translation was modified after taking the results into account. The final translation was approved as Official Working Draft of the MDS-UPDRS Japanese version and tested in 365 native-Japanese-speaking patients with PD. Confirmatory analyses were used to determine whether the factor structure for the English-language MDS-UPDRS could be confirmed in data collected using the Official Working Draft of the Japanese translation. As a secondary analysis, we used exploratory factor analyses to examine the underlying factor structure without the constraint of a pre-specified factor organization. RESULTS: Confirmatory factor analysis revealed that Comparative Fit Index for all Parts of the MDS-UPDRS exceeded the minimal standard of 0.90 relative to the English version and therefore Japanese translation met the pre-specified criterion to be designated called an OFFICIAL MDS TRANSLATION. Secondary analyses revealed some differences between the English-language MDS-UPDRS and the Japanese translation, however, these differences were considered to be within an acceptable range. CONCLUSIONS: The Japanese version of the MDS-UPDRS met the criterion as an Official MDS Translation and is now available for use (www.movementdisorders.org).

11.
Parkinsonism Relat Disord ; 19(8): 725-31, 2013 Aug.
Article in English | MEDLINE | ID: mdl-23639756

ABSTRACT

PURPOSE: We examined the prevalence and risk of clinical symptoms in a large number of Japanese patients with Parkinson's disease (PD) (n = 1453; 650 males). METHODS: Events were analyzed using Kaplan-Meier survival curves, logistic regression, and Cox proportional-hazards models. RESULTS: The mean age (SD) was 67.7 (10.0), age of onset was 58.0 (11.5), and disease duration was 9.7 (6.6) years. The mean modified Hoehn and Yahr stage was 2.8 (1.2). Most patients (88.9%) received levodopa (547.7 (257.6) mg/day). A large proportion (81.3%) received dopamine agonists (136.2 (140.7) mg/day). About 23.4% received pain treatment 6.9 (5.1) years after the onset; females (p < 0.05) and patients with late-onset PD (≥60 years, p < 0.001) were more likely to be affected. About 44.7% of patients had wearing-off 7.5 (4.7) years after the onset, and it was more common in females (p < 0.001) and patients with early-onset PD (p < 0.001). Camptocormia was found in 9.5% of patients 8.1 (6.2) years after the onset, and it was more common in females (p < 0.05) and patients with late-onset PD (p < 0.05). About 28.6% of patients developed psychosis 9.0 (5.4) years after the onset, and it was more likely to occur in patients with late-onset PD (p < 0.001). Late-onset PD and cerebrovascular disease were also associated with increased risk of pneumonia. CONCLUSIONS: Considering that very few studies have assessed numerous clinical symptoms in the same report, these data provide a useful reference for the clinical course of PD.


Subject(s)
Motor Skills Disorders/diagnosis , Motor Skills Disorders/epidemiology , Parkinson Disease/diagnosis , Parkinson Disease/epidemiology , Aged , Cohort Studies , Female , Follow-Up Studies , Humans , Male , Middle Aged , Motor Skills Disorders/physiopathology , Parkinson Disease/physiopathology , Prevalence , Retrospective Studies , Risk Factors
12.
J Biosci Bioeng ; 116(1): 52-8, 2013 Jul.
Article in English | MEDLINE | ID: mdl-23477741

ABSTRACT

Microbes with smaller genomes would be better chassis for analysis, design, and improvement in the fields of metabolic engineering, synthetic biology, and molecular breeding. To create an Escherichia coli strain with a smaller genome, we used a stepwise genome reduction approach. Beginning with strain MGF-01, which has a genome of 3.62 megabase pairs (Mbp), we generated two E. coli K-12 strains without any insertion sequence (IS), DGF-327 and DGF-298, with reduced genome sizes of 3.27 and 2.98 Mbp, respectively. During the strain construction, intrinsic mutations of ilvG and rph were functionally restored to accelerate initial growth after inoculation. The genomes of the two strains were sequenced, and their structures were confirmed. Both strains showed no auxotrophy, and had better growth fitness, especially in the initial phase, and better cell yield in a rich medium than the wild type K-12 strain. Transcriptome analysis revealed that ibpAB and lon, which encode a heat-shock chaperone and a protease for abnormal proteins, respectively, are down-regulated in DGF strains, compared to the ancestral strains with larger genomes. We concluded that down-regulation of the genes encoding chaperones and proteases is one of the factors that improve the fitness of DGF strains. The DGF strains with fewer genes and better cell yield will be good hosts for applications.


Subject(s)
Escherichia coli/genetics , Genome Size , Genome, Bacterial , Metabolic Engineering , DNA Repair , Down-Regulation , Escherichia coli/growth & development , Escherichia coli/metabolism , Escherichia coli Proteins/genetics , Escherichia coli Proteins/metabolism , Gene Expression Profiling , Molecular Chaperones/genetics , Molecular Chaperones/metabolism , Mutation
13.
Mov Disord ; 28(3): 388-91, 2013 Mar.
Article in English | MEDLINE | ID: mdl-23401296

ABSTRACT

BACKGROUND: We report neuropathologic findings in a patient with homozygous deletions of exons 2 to 4 of parkin. RESULTS: Although the absence of Lewy bodies has been considered a neuropathologic characteristic of parkin mutation, here we report a pathologic finding with the presence of Lewy bodies. METHODS: The patient was a 72-year-old woman with onset of the disease at age 61. Her autopsy revealed marked decrease in melanized neurons in the substantia nigra and the locus coeruleus. Lewy bodies were found in the substantia nigra, the locus coeruleus, the dorsal motor nucleus of the vagus, the basal nucleus of Meynert, the amygdaloid nucleus, and the sympathetic nerve bundles in the myocardium. CONCLUSIONS: Only 3 previous case reports described Lewy body formation in patients carrying parkin mutations. The distribution of Lewy bodies in our patient appeared to be reminiscent of sporadic Parkinson's disease.


Subject(s)
Gene Deletion , Lewy Bodies/pathology , Lewy Body Disease/genetics , Lewy Body Disease/pathology , Ubiquitin-Protein Ligases/genetics , Aged , Exons/genetics , Female , Homozygote , Humans , Lewy Bodies/genetics , Magnetic Resonance Imaging , Neurons/pathology , Substantia Nigra/pathology , alpha-Synuclein/metabolism
14.
Parkinsonism Relat Disord ; 18(8): 986-9, 2012 Sep.
Article in English | MEDLINE | ID: mdl-22682973

ABSTRACT

We report on 8 patients with Parkinson's disease (PD) who experienced suddenly episodes of speech unrelated to the topic of conversation or wrote sentences unrelated to the context. During these episodes and later, unless pointed out, patients were unaware of the behavior. We called this phenomenon Unrelated Communication Interlude (UCI). All patients were male; half of them with impulse control disorders (punding, hypersexuality, or pathological gambling). Four patients reported sleepiness when the episodes of UCI occurred. There were no significant differences in age at examination, age of onset of PD, and neuropsychological tests score (Mini-Mental State Examination, Frontal Assessment Battery, and Beck Depression Inventory) between patients with UCI and those without. To our knowledge, this is the first reported phenomena of such abnormal behavior in Parkinson's disease. UCI was considered as automatic behavior similar to that seen in narcolepsy and excessive daytime sleepiness. UCI might be occurring in relation to excessive daytime sleepiness in PD.


Subject(s)
Communication Disorders/diagnosis , Communication Disorders/psychology , Disorders of Excessive Somnolence/diagnosis , Disorders of Excessive Somnolence/psychology , Parkinson Disease/psychology , Adult , Aged , Aged, 80 and over , Communication Disorders/epidemiology , Disorders of Excessive Somnolence/epidemiology , Female , Humans , Male , Middle Aged , Parkinson Disease/epidemiology
15.
Neurobiol Dis ; 46(1): 101-8, 2012 Apr.
Article in English | MEDLINE | ID: mdl-22249108

ABSTRACT

Lithium, a drug used to treat bipolar disorders, has a variety of neuroprotective mechanisms including inhibition of glycogen synthase kinase-3 (GSK-3), a major tau kinase. Recently, it has been shown that, in various neurodegenerative proteinopathies, lithium could induce autophagy. To analyze how lithium is therapeutically beneficial in tauopathies, transgenic mice overexpressing human mutant tau (P301L) were treated with oral lithium chloride (LiCl) for 4 months starting at the age of 5 months. At first, we examined the effects of treatment on behavior (using a battery of behavioral tests), tau phosphorylation (by biochemical assays), and number of neurofibrillary tangles (NFTs) (by immunohistopathology). In comparison with control mice, LiCl-treated mice showed a significantly better score in the sensory motor tasks, as well as decreases in tau phosphorylation, soluble tau level, and number of NFTs. Next, we examined lithium effects on autophagy using an antibody against microtubule-associated protein 1 light chain 3 (LC3) as an autophagosome marker. The number of LC3-positive autophagosome-like puncta was increased in neurons of LiCl-treated mice. Neurons containing NFTs were completely LC3-negative, whereas LC3-positive autophagosome-like puncta contained phosphorylated-tau (p-tau). The protein level of p62 was decreased in LiCl-treated mice. These data suggested that oral long-term lithium treatment could attenuate p-tau-induced motor disturbance not only by inhibiting GSK-3 but also by enhancing autophagy in tauopathy model mice.


Subject(s)
Autophagy/drug effects , Lithium Chloride/pharmacology , Motor Skills Disorders/drug therapy , Tauopathies/drug therapy , Administration, Oral , Animals , Antimanic Agents/blood , Antimanic Agents/pharmacology , Humans , Lithium Chloride/blood , Mice , Mice, Inbred C57BL , Mice, Inbred DBA , Mice, Transgenic , Motor Skills Disorders/etiology , Motor Skills Disorders/pathology , Tauopathies/complications , Tauopathies/pathology , Time Factors
16.
Psychogeriatrics ; 12(4): 235-41, 2012 Dec.
Article in English | MEDLINE | ID: mdl-23279145

ABSTRACT

BACKGROUND: This multicentre open-label trial examined the efficacy and safety of the traditional Japanese medicine, or Kampo medicine, yokukansan (YKS), for behavioural and psychological symptoms of dementia (BPSD) in patients with dementia with Lewy bodies. METHODS: Sixty-three dementia with Lewy bodies patients with probable BPSD (M:W, 30:33; mean age, 78.2±5.8 years) were enrolled and treated with YKS for 4 weeks. RESULTS: Significant improvements in Neuropsychiatric Inventory scores (mean decrease, 12.5 points; P<0.001) and Zarit Burden Interview-Japanese edition tests (mean decrease, 3.6 points; P=0.024) were observed. In patients who consented to an assessment after 2 weeks of treatment, a time-dependent significant improvement was observed in the Neuropsychiatric Inventory score (n=23; mean decrease, 14.4; P<0.001), each subscale, including delusions and hallucinations, the Zarit Burden Interview-Japanese edition (n=22; mean decrease, 8.2; P<0.01) and the behavioural pathology in Alzheimer's disease insomnia subscale. The Mini-Mental State Examination and the Disability Assessment for Dementia (DAD) showed no significant change. Adverse events were observed in 11 (18%) patients. Three patients (5%) discontinued YKS due to adverse reactions, namely, spasticity and exacerbation of BPSD, edema, and nausea. Hypokalaemia (<3.5 mEq/L) was present in four patients (6%) at the study endpoint. Worsening of extrapyramidal symptoms was not observed. CONCLUSION: YKS improved BPSD in dementia with Lewy bodies patients and caregiver burden scores without deterioration in cognitive function. YKS is useful for the treatment of delusions and hallucinations in BPSD.


Subject(s)
Delusions/drug therapy , Drugs, Chinese Herbal/administration & dosage , Hallucinations/drug therapy , Lewy Body Disease/complications , Lewy Body Disease/psychology , Plant Extracts/administration & dosage , Activities of Daily Living , Aged , Aged, 80 and over , Delusions/etiology , Delusions/psychology , Disability Evaluation , Drugs, Chinese Herbal/adverse effects , Drugs, Chinese Herbal/therapeutic use , Female , Hallucinations/etiology , Hallucinations/psychology , Humans , Male , Mental Status Schedule , Neuropsychological Tests , Plant Extracts/adverse effects , Plant Extracts/therapeutic use , Treatment Outcome
19.
J Cereb Blood Flow Metab ; 30(2): 299-310, 2010 Feb.
Article in English | MEDLINE | ID: mdl-19826432

ABSTRACT

Vascular dementia is caused by blockage of blood supply to the brain, which causes ischemia and subsequent lesions primarily in the white matter, a key characteristic of the disease. In this study, we used a chronic cerebral hypoperfusion rat model to show that the regeneration of white matter damaged by hypoperfusion is enhanced by inhibiting phosphodiesterase III. A rat model of chronic cerebral hypoperfusion was prepared by bilateral common carotid artery ligation. Performance at the Morris water-maze task, immunohistochemistry for bromodeoxyuridine, as well as serial neuronal and glial markers were analyzed until 28 days after hypoperfusion. There was a significant increase in the number of oligodendrocyte progenitor cells in the brains of patients with vascular dementia as well as in rats with cerebral hypoperfusion. The oligodendrocyte progenitor cells subsequently underwent cell death and the number of oligodendrocytes decreased. In the rat model, treatment with a phosphodiesterase III inhibitor prevented cell death, markedly increased the mature oligodendrocytes, and promoted restoration of white matter and recovery of cognitive decline. These effects were cancelled by using protein kinase A/C inhibitor in the phosphodiesterase III inhibitor group. The results of our study indicate that the mammalian brain white matter tissue has the capacity to regenerate after ischemic injury.


Subject(s)
Brain Ischemia/pathology , Dementia, Vascular/pathology , Nerve Regeneration/physiology , Oligodendroglia/pathology , Phosphodiesterase 3 Inhibitors , Stem Cells/pathology , Adult , Animals , Brain/enzymology , Brain/pathology , Brain Ischemia/enzymology , Cell Differentiation/drug effects , Cilostazol , Dementia, Vascular/enzymology , Enzyme Inhibitors/pharmacology , Fluorescent Antibody Technique , Humans , Immunohistochemistry , Male , Maze Learning , Nerve Regeneration/drug effects , Neuroprotective Agents/pharmacology , Oligodendroglia/drug effects , Oligodendroglia/enzymology , Rats , Rats, Wistar , Stem Cells/drug effects , Stem Cells/enzymology , Tetrazoles/pharmacology
20.
Commun Integr Biol ; 2(3): 219-20, 2009 May.
Article in English | MEDLINE | ID: mdl-19641734

ABSTRACT

The bacterium Escherichia coli is rod-shaped, and a unit cell keeps regular dimensions of about 1.5 microm long and 0.5 microm wide. The rod-shaped cell is composed of two parts: a cylinder in the center and caps at both ends. The length of the cylinder corresponds to the length of the rod cell. A recent paper reported the genetic regulation of the cell length by rodZ. RodZ is a membrane protein with bitopic topology that assembles underneath the cell membrane to form helical filaments along the lateral axis of the cell with the bacterial actin MreB. RodZ filaments probably interact with enzymes that contribute to peptidoglycan synthesis. Cells lacking rodZ shorten only along the lateral axis of the cell so that the cells become round-shaped instead of rod-shaped. Such spheroidal cells consist only of caps due to the loss of almost all of the cylinder. In addition, carbon metabolism is remarkably disturbed by the deficiency of RodZ. This suggests that the transport of nutrients at the surface of the cylinder is reduced in rodZ mutant cells. Thus, cell morphology is also critical for proper metabolism for cell proliferation.

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