Cross-sectional evaluation of the saccharin transit time test for primary ciliary dyskinesia: did we discard this tool too soon?

ABSTRACT BACKGROUND: Primary ciliary dyskinesia (PCD) is a rare and heterogeneous disease that is difficult to diagnose and requires complex and expensive diagnostic tools. The saccharin transit time test is a simple and inexpensive tool that may assist in screening patients with PCD. OBJECTIVES: This study aimed to compare changes in the electron microscopy findings with clinical variables and saccharin tests in individuals diagnosed with clinical PCD (cPCD) and a control group. DESIGN AND SETTING: An observational cross-sectional study was conducted in an otorhinolaryngology outpatient clinic from August 2012 to April 2021. METHOD: Patients with cPCD underwent clinical screening questionnaires, nasal endoscopy, the saccharin transit time test, and nasal biopsy for transmission electron microscopy. RESULTS: Thirty-four patients with cPCD were evaluated. The most prevalent clinical comorbidities in the cPCD group were recurrent pneumonia, bronchiectasis, and chronic rhinosinusitis. Electron microscopy confirmed the clinical diagnosis of PCD in 16 of the 34 (47.1%) patients. CONCLUSION: The saccharin test could assist in screening patients with PCD due to its association with clinical alterations related to PCD.

Age-related changes in pancreatic histology and ultrastructure in rats / 中华老年医学杂志

Objective:To investigate age-related histological and ultrastructural changes of the pancreas in Sprague-Dawley(SD)rats, and to provide a theoretical basis for the high incidence of pancreatic diseases in the elderly.Methods:Thirty 6-month-old specific pathogen-free male SD rats were fed until 6, 12, 18 and 25 months of age.Five rats of each age group were randomly selected, killed and then sampled to make histological(HE staining)and electron microscopic sections to observe age-related changes in pancreatic histology and ultrastructure.Results:The pancreatic tissue of rats showed increasing fibrosis with age, especially around the duct.Fat infiltration of the pancreatic tissue also increased with age( H=15.88, P=0.001). With the increase of age, the number(density)of pancreatic islets decreased gradually( F=3.55, P=0.039), but the average cross-sectional area of islets increased significantly( F=7.76, P=0.002), and the round and oval islets became irregular.Nuclear pyknosis, mitochondrial dehydration, mitochondrial swelling, and dilatation and loose organization of rough endoplasmic reticula were observed in the cytoplasm of pancreatic acinar cells and islet beat cells in aged rats.With the increase of age, the number of zymogen granules at the apical pole of pancreatic acinar cells of rats decreased( F=9.73, P<0.001), and the average area and total area of granules were significantly decreased( F=6.51, P=0.001; F=22.18, P<0.001); The number of non-senescent mitochondria and senescent mitochondria in the cytoplasm of acinar cells increased significantly( H=8.22, P=0.045; H=32.95, P<0.001); The amount of proinsulin in islet beta cells was significantly decreased( F=16.20, P<0.001). Conclusions:With aging, the rat pancreas exhibits a series of degenerative manifestations(stromal hyperplasia, adipose tissue infiltration, decreased numbers of zymogen granules in acinar cells, increases in the number of senescent mitochondria, reduced islets and reduced proinsulin in islet beta cells), while there are some compensatory phenomena(increasing numbers of islets and non-senescent mitochondria).

Ultrastructural aspects of the skin in lipoid proteinosis (Urbach-Wiethe disease)

Abstract Lipoid proteinosis is a rare autosomal recessive disease, characterized by hyaline deposits of PAS-positive material in tissues due to mutations in the ECM1 gene. This study evaluated the ultrastructure of the skin of a 6-year-old child affected by this condition. The light microscopy identified PAS-positive hyaline deposits, which were more intense in the papillary dermis. Scanning electron microscopy of the dermis showed a compact papillary dermis and fibrillar deposits in the middle dermis. Transmission electron microscopy clearly showed the deposition of fibrillar material in the dermis, forming clusters adherent to elastic fibers, between the collagen bundles and the collagen fibers, and also filling up the cytoplasm of dermal fibroblasts.

Transmission and scanning electron microscopy of cutis rhomboidalis

Abstract Cutis rhomboidalis nuchae was assessed in a 65-year-old patient. Optical microscopy showed basophilic agglomerations in the reticular dermis with decreased elastic fibers. Trans- mission electron microscopy showed elongated, curved and fragmented structures, and in their interior the presence of electron-dense lumps was reduced and irregular, similar to modified elastic fibers, whereas the collagen fibers had a normal aspect. Scanning electron microscopy showed deposits between the bundles of collagen, resembling pebbles or stones. These findings demonstrate that, at one stage of the disease, the collagen remains normal and the alterations are seen in the elastic tissue.

Cutaneous collagenous vasculopathy: light and transmission electron microscopy

Abstract Cutaneous collagenous vasculopathy is a rare acquired idiopathic microangiopathy characterized by progressive development of diffuse asymptomatic telangiectasias and histologically by accumulation of collagen type IV around the affected vessels. It is diagnosed by its clinical history, confirmed by light microscopy with collagen-specific immunostaining. We report a case of a patient with extensive acquired telangiectasias on the left arm, clinically resembling unilateral nevoid telangiectasia. Dilated blood vessels with thickened walls were observed in the dermis. Immunohistochemistry with collagen IV antibodies revealed marked collagen deposition around the vessels, confirming the diagnosis. Transmission electron microscopy observed duplicate and triplicate vascular basal membrane associated with deposition of amorphous material around the membranes.

Apolipoprotein A1 localization in sperms and its antibody′s effect on human sperm function / 中华检验医学杂志

Objective To investigate the presence of apolipoprotein A 1 (APOA1) and its function in human spermatozoa. Methods The expression assays for APOA 1 were carried out by immunofluorescence and Western blotting in human sperm cells . Set up a blank control group , rabbit polyclonal IgG group , which contain anti-APOA1 antibody 10 μg/ml, 20 μg/ml and 40 μg/ml, to treat normal semen samples and incubated at 37 ℃for 1 h, 2 h and 3 h.The progressive motility of spermatozoa was determined bya computer-assisted motion analyzer ( CASA ) , apoptosis rate by flow cytometry and ultrastructural changes by electron microscopy .Comparisons of sperm progressive motility and apoptosis rate were performed by independent sample t tests.Results The study showed APOA1 protein mainly located in the sperm head , the molecular size was 31000.A significant decline in sperm progressive motility was observed after 1,2 and 3 hours of incubation with APOA1 antibody.There was a statistically significant difference between the blank control group and the APOA 1 antibody concentration of 20 μg/ml and 40 μg/ml groups [ 1 hour after incubation , blank control group ( 68.65％ ±15.70％) with 20 μg/ml group (48.45％±5.20％), 40 μg/ml group(39.25％±7.89％), t=2.442, 3.345 , both P<0.05;2 hours after incubation, blank control group(55.33％±10.12％) with 20 μg/ml group(28.68％±11.70％), 40μg/ml group(18.13％ ±10.52％), t=3.445, 5.097,both P<0.05; 3 hours after incubation, blank control group(35.73％±14.08％) with 20μg/ml group(15.53％±8.42％), 40μg/ml group(9.98％± 7.08％), t=2.462, 3.268,both P<0.05].After incubation 2 hours, the percentage of apoptotic cells increased from 16.02％ ±4.28％ in the blank control group to 21.72％ ±2.67％ ( 20 μg/ml APOA1 antibody)and 28.01％±3.93％(40 μg/ml APOA1 antibody), respectively (t=3.177, 5.834, both P<0.01).Treatment with 40 μg/ml APOA1 antibody for 4 hours resulted in major morphological changes to sperm cells observed by electron microscope , including membrane distension ,vacuole formation and different periods of apoptosis cells .Conclusion APOA1 plays an important role in maintaining sperm motility and survival rate,however the mechanism needs further study .

Ultrahistopathological features of six cases of symmetrical acrokeratoderma under transmission electron microscope / 中华皮肤科杂志

Objective To investigate ultrahistopathological features of symmetrical acrokeratoderma.Methods Biopsy specimens were obtained from skin lesions and perilesional normalappearing skin of 6 patients with symmetrical acrokeratoderma,as well as from normal skin of 3 healthy volunteers.Then,these skin specimens were subjected to transmission electron microscopy (TEM).Results TEM showed obviously thickened stratum corneum,irregular morphology of keratinocytes and discontinuous cornified envelope.Aggregation and abnormal arrangement of keratin filaments occurred in all epidermal layers.Many vacuoles of different sizes were observed in the transitional zone between the stratum corneum and stratum granulosum.Hypogranulosis,abnormal shape and different sizes of keratohyalin granules,and reduction of membrane-coating granules were found in the stratum granulosum.Increased melanocytes with a large number of stage Ⅳ melanosomes in the cytoplasm were observed in the basal layers.Moreover,there was infiltration of a few lymphocytes in the superficial dermis.Perilesional normal-appearing skin tissues showed similar but milder ultrastructural changes.Conclusion Abnormal metabolism of keratins,epidermal differentiation complex proteins and lipids may exist in skin lesions of symmetrical acrokeratoderma,which may contribute to epidermal thickening and impairment of skin barrier function.

Ultrastructural aspects of pseudoxanthoma elasticum

Abstract: We report the ultrastructural findings in a case of a 72-year-old black woman with confluent yellowish papules in the cervical region. She had no comorbidities. Ophthalmological examination, electrocardiogram, and echocardiogram were normal. Hematoxylin-eosin staining of the affected skin showed strong alterations in the mid-dermis with irregular clumps of eosinophilic material and loss of the normal parallel arrangement of collagen bundles. Orcein staining revealed that the elastic fibers lost their normal linear configuration, showing clump fragmentation, sometimes forming square structures. Transmission electron microscopy showed aberrant elastic fibers with an irregular outline and heterogenic inner structures. We also observed small elastic fibers. Collagen fibers showed a normal structure with irregular distribution. Scanning electron microscopy revealed important disorganization of collagen fibers and small stone-like deposits measuring around 5 µm associated with bigger structures ranging from 10-16 µm. Higher magnification revealed that these small stone-like structures were sometimes polyhedral-shaped or squared.

A histomorphometric study of unmyelinated fibers of the fibular nerve in Wistar rats / Histomorfometria das fibras amielínicas do nervo fibular em ratos Wistar

ABSTRACT There are few histomorphometric studies on the unmyelinated fibers of the fibular nerve in rats, and the number of experimental studies using this nerve has been increasing in the last years. Sixty-two percent of the endoneurial area from 10 fibular nerves of adult Wistar rats was scanned by electron microscopy, and digitized. The total number of unmyelinated axons (1.882 ± 271) was significantly lesser, and their axon diameters (0.2 µm to 2.8 µm) significantly higher than that determined in previous studies. The histogram peaked at 1 µm. The differences could be due to the nerve sampled area, the number and the age of the animals evaluated, and the laboratory techniques used. This study brings new and referential data to be used in experimental investigations involving histomorphometric evaluation of the rat fibular nerve.

RESUMO Embora o nervo fibular de ratos venha sendo incluído progressivamente em maior número de estudos experimentais nos últimos anos, há poucos estudos a respeito das suas fibras amielínicas. Os nervos fibulares de 10 ratos Wistar adultos foram avaliados através de microscopia óptica e eletrônica. Varredura sistemática através de microscopia eletrônica de transmissão das áreas fasciculares da porção distal no nervo foi realizada. Em média, 62% da área endoneural foi digitalizada. O número total de axônios amielínicos encontrados (1.882 ± 271) foi significativamente menor e as medidas dos diâmetros axonais (0,2 µm a 2,8 µm) maiores do que o determinado em estudos prévios. O pico do histograma foi constituído por fibras de 1µm. As diferenças podem ser devidas à amostragem de maior área endoneural, ao número e à idade dos animais avaliados, e as técnicas laboratoriais utilizadas. Os dados obtidos podem ser considerados referenciais para o nervo fibular de ratos Wistar adultos.

Optimization of ultrastructure observation of human embryonic stem cell-derived retinal pigment epithelial cells / 中华实验眼科杂志

Background Normal ultrastructure is the anatomical basis of retinal pigment epithelial(RPE) cells to perform normal physiological function.At present the precipitation method is often used to detect the ultrastructure of RPE cells with transmission electron microscopy(TEM).Objective The aim of this study was to explore a simple and feasible approach to examine the ultrastructure of human embryonic stem cell-derived retinal pigment epithelial (hESC-RPE) cells.Methods hESCs were induced and differentiated into RPE cells by the spontaneous differentiation method,and the expressions of microphthalmia associated transcription factor MITF and paired-box gene 6 (PAX6),specific protein of RPE cells,in the cells were detected by immunofluorescence assay.hESC-RPE cells were inoculated into Transwell filter,and the ultrastructure of the cell sheet was examined under the TEM.Then the ultrastructure of the cell sheet specimens was compared with those of hESC-RPE cells from cell precipitation and RPE cell specimens of 90-day-old Long Evans rats.Results MITF and PAX6 were positively expressed in hESC-RPE cells.The normal ultrastructure were visible in the RPE cells of rats under the TEM,including apical microvilli,polarized melanin granules,cellular nucleus,basement membrane and intercellular junctions,and the ultrastructure of hESC-RPE cell sheet on Transwell was similar to the RPE cells in rats.However,only scatter melanin granules,nonpolar nucleus and scanty microvilli were observed under the TEM in the hESC-RPE cells by cell precipitation method.Conclusions Without digestion process,hESC-RPE cell sheet on Transwell can retain the normal ultrastructure of hESC-RPE cells under the TEM,with a more simple and reliable advantage.

Mechanism of Escherichia coli injury under UV disinfection / 军事医学

Objective To study the inactivation kinetics and injury mechanism of Escherichia coli under UV disinfection in drinking water.Methods The inactivation kinetics of E.coli ATCC 25922 was determined by plate count methods in the UV disinfection experiment.The morphology,cell membrane permeabilization and injury of biological macromolecules were observed under a transmission electron microscope (TEM).The rate of ONPG hydrolysis and changes in activities of antioxidant enzymes were observed Raman spectroscopy.Results the changes of damaged cells involved morphological damage such as loss of the structural integrity of the wall and membrane,condensation of cellular material and leakage of significant amounts of cytoplasmic material,a more than four-fold increase of cell membrane permeabilization and damage to the structure of protein,nucleic acids and phospholipid.Conclusion UV disinfection can lead to a multi-target damage.

Histopathological characteristics of melasma / 中华皮肤科杂志

Objective To investigate histopathological and ultrastructural differences between melasma tissues and normal skin tissues around pigmented nevus. Methods Eight patients with melasma and 16 patients with facial pigmented nevus were included in this study. Two millimeter punch biopsies were taken from melasma lesions and adjacent normal skin of facial pigmented nevus. Biopsy specimens were then subjected to hematoxylin?eosin (HE) staining, Fonton?Masson staining, Verhoeff?van Gieson staining, and immunohistochemical staining with monoclonal antibodies HMB45 and NKI/beteb. Transmission electron microscopy was used to observe the tissue specimens. Semi?quantitative analysis was performed under a light microscope, and quantitative analysis by using a computerized image analysis system. Results Histopathological study revealed increased number of melanin granules mainly in the basal and prickle cell layers, sometimes in the dermis, in melasma tissues compared with normal skin tissues. Melanocytes were only observed in the epidermis of melasma tissues. Compared with normal skin tissues, melasma tissues showed no significant difference in the quantity of melanocytes, but a significant increase in the volume, staining intensity and dendrite number of melanocytes. In all of the 8 patients with melasma, mild to moderate lymphocytic infiltration was observed in the superficial dermis and around capillaries, with moderate telangiectasis in the superficial dermis. Electron microscopy revealed that there were more melanosomes in melanocytes and keratinocytes, and melanocyte dendrites extended into the dermis in melasma tissues. Conclusions Among the 8 patients, there were only two types of melasma, i.e., epidermal melasma and mixed melasma, and no dermal melasma was found. Inflammation and telangiectasis may induce or aggravate melasma.

Atypical infantile genital Molluscum contagiosum

Abstract Genital molluscum contagiosum is rare in children. We report a molluscum contagiosum around the vulva and anus of 9-year-old girl, which has atypical presentations and was finally confirmed by histopathological and electron microscopy findings.

Effects of amphotericin B and voriconazole on ultrastructure of a clinical isolate of Penicillium marneffei / 中华皮肤科杂志

Objective To observe ultrastructural changes in a clinical isolate of Penicillium marneffei(PM) before and after treatment with amphotericin B or voriconazole by using scanning electron microscopy (SEM)and transmission electron microscopy (TEM). Methods A microdilution method was performed to determine the minimum inhibitory concentration (MIC)of amphotericin B and voriconazole against a clinical isolate of PM. Then, the PM isolate was treated with amphotericin B or voriconazole at their MICs and 10-fold MICs for 24, 48 and 72 hours. The ultrastructural changes in this isolate before and after the treatment were observed by using SEM and TEM. Results After the treatment with amphotericin B, SEM showed that the conidia or yeast cells of the PM isolate were gradually damaged, and their outer layers experienced detachment, shrinkage, breakage and adhesion with the increase in treatment duration and concentrations of amphotericin B; TEM also showed degenerated mitochondria, broken nuclei and cell walls, and shrunken cytoplasmic membrane with disappearance of cytoplasmic organelles. Similarly, the damage, shrinkage, shriveling and collapse of PM cells were seen by using SEM, and TEM showed many high-density electron-dense granules in cytoplasm, degeneration of mitochondria, roughening of cell wall surface, damage and shrinkage of cytoplasmic membrane, and disappearance of cytoplasmic organelles after voriconazole treatment. Conclusions Amphotericin B and voriconazole both had a strong antifungal effect on PM, and could induce evident ultrastructural changes, which were positively associated with treatment duration and concentrations. Moreover, amphotericin B caused more severe damage to PM compared with voriconazole.

The detection of motor nerve injury by MUNE in an animal model of diabetes / 天津医药

Objective To investigate motor nerve function status in rats with diabetes mellitus by motor unit number estimation (MUNE), and discuss it′s early diagnostic value in diabetic peripheral neuropathy (DPN). Methods Diabetic rat model (DM group) was induced by streptozotocin. The MUNE of gastrocnemius muscle and motor nerve conduction (MCV, CMAP) of the sciatic nerve were measured at the 4th, 8th and 12th week after onset of hyperglycemia in the DM group and the control group (normal SD rats). The ultrastructure of sciatic nerve was observed by electron microscope. Results At the 4th week, MUNE of gastrocnemius muscle was significantly decreased in DM group compared to that of the control group (275.88 ± 87.87 vs 369.71 ± 75.64,P<0.05). There were no significant differences in MCV and CMAP of sciatic nerve be?tween two groups. The electron microscopy observation showed that most nerve fibers were normal;a small amount of axonal atrophy, and myelin lamellar structure was separated in DM group. At the 8th week, compared with the control group, MUNE were reduced in gastrocnemius muscle in DM group (357.49±72.68 vs 221.26±92.41, P<0.01). There were no significant dif?ferences in MCV and CMAP of the sciatic nerve between DM group and control group. The electron microscope observation showed that part of nerve fibers were normal, the myelin focal plate layer was loose and separated, axonal atrophy, the axonal membrane and myelin sheath inner layer was separated with big gap. At the 12th week, MUNE of gastrocnemius muscle (127.87±19.80 vs 366.85±51.25), sciatic nerve MCV [(35.06±4.43) m/s vs (50.47±6.07) m/s] and CMAP [(2.91±1.37) mV vs (5.98±2.14) mV] were significantly decreased in DM group than those of control group (P<0.01). The electron microscopy observation showed severely damaged myelin flex and axonal squeeze. Conclusion MUNE is much earlier in detecting ear?ly motor nerve dysfunction in DM than conventional motor nerve conduction test.

Ultrastructure and phagocytotic function of human placental mesenchymal stem cells / 中国组织工程研究

BACKGROUND:Placental mesenchymal stem cel s with rich sources are similar to bone marrow mesenchymal stem cel s in terms of morphology, surface markers and differentiation potential, which are one of ideal mesenchymal stem cel s in human body. However, there are few studies addressing the ultrastructure and phagocytotic function of human placental mesenchymal stem cel s and its physiological role in the the placenta has been little explored. OBJECTIVE:To investigate the ultrastrcture and phagocytotic function of placental mesenchymal stem cel s. METHODS:Placental mesenchymal stem cel s obtained from five placentae of normal pregnancy were cultured in vitro and observed for ultrastructure under transmission electron microscope. The fluorescent beads were added in the supernatant for 3 hours, and then the phagocytosis of placental mesenchymal stem cel s was evaluated by flow cytometry. RESULTS AND CONCLUSION:Under the transmission electron microscope, placental mesenchymal stem cel s had large nuclei with prominent nucleoli. In the cytoplasm, a plenty of rough endoplasmic reticula was seen, dilated or stacked. The cytoplasm was also rich in Golgi apparatus and lysosomes. The cel surfaces were covered by microvil i. The intercel ular junctions could be seen occasional y. A part of cel s from these five samples could phagocytose fluorescence beads, which ranged from 49.6%to 18.4%. The ultrastructural characteristics of placental mesenchymal stem cel s suggested these cel s were active to synthesize and secrete proteins and had phagocytotic function, indicating placental mesenchymal stem cel s may play a role in keeping the balance of micro-environments and clean the foreign substances in the placenta.

Dynamic changes of rat cartilage ultrastructure in the early process of papain-induced knee osteoarthritis / 中国组织工程研究

BACKGROUND:Papain-induced rat knee osteoarthritis is a common modeling method, which can obtain a stable osteoarthritis model. OBJECTIVE:To observe the change of ultrastructure of chondrocytes in the early process of papain-induced rat knee osteoarthritis under transmission electron microscope. METHODS:A total of 18 Sprague-Dawley rats were randomly divided into three groups. Two rats were considered as a normal control group, without intervention. The mixture of papain and L-cysteine was injected in right knee joint cavity of 16 rats to induce osteoarthritis models (osteoarthritis model group). Physiological saline was injected in the left side (physiological saline control group). At 1, 2, 4 and 6 weeks after injection, samples were col ected. Transmission electron microscope was used to observe the change of cartilage ultrastructure of the medial femoral condyle joint. RESULTS AND CONCLUSION:For the normal control group and physiological saline control group, their cytoplasm contained abundant rough endoplasmic reticulum and mitochondria. After 1 week of injection, mitochondria vacuoles and light expanded rough endoplasmic reticulum were visible. Two weeks later, lipid droplets appeared, mitochondria degeneration was distinct, vacuolization was serious and its number was reduced, and rough endoplasmic reticulum expansion was obvious. Four weeks later, lipid droplets became increased, and the number of mitochondria decreased significantly. Most of the rough endoplasmic reticula were highly expanded, and part of the rough endoplasmic reticula were dissolved and fractured. Six weeks later, a number of lipid droplets were visible in cytoplasm, most of the mitochondria disappeared, only a smal number of mitochondria existed, and most of the rough endoplasmic reticula were dissolved and fractured. These results confirmed that cartilage ultrastructure changes gradual y in the early process of papain-induced rat knee osteoarthritis under transmission electron microscope.

Impact of warm ischemia injury on mitochondrial morphology and function of rat donor liver after cardiac death / 中国组织工程研究

BACKGROUND:How to control functional activity of donor liver after cardiac death and maintain the optimal function of grafts are the key issues in organ transplantation study. OBJECTIVE:To preliminarily explore the effect of warm ischemia injury on the morphology and function of rat donor liver after cardiac death. METHODS:Cardiac death model was established in Sprague-Dawley rats and the successful models were divided into six groups:control group (warm ischemia for 0 minute), warm ischemia 10 group (warm ischemia for 10 minutes), warm ischemia 20 group (warm ischemia for 20 minutes), warm ischemia 30 group (warm ischemia for 30 minutes), warm ischemia 40 group (warm ischemia for 40 minutes) and warm ischemia 50 group (warm ischemia for 50 minutes). The rat liver specimens in each group were cut into ultrathin sections. The structure of liver cells was observed and photographed by electron microscopy. Flameng score was applied to analyze the degree of mitochondrial damage. Liver mitochondria were extracted and then spectrophotometry was used to assess the viability of cytochrome C oxidase. RESULTS AND CONCLUSION:Under electron microscopy, there were no significant changes in liver cells within 30 minutes of warm ischemia, nuclear membrane was intact, mitochondria mildly swel ed, no mitochondrial crista ruptured, and Flameng score was<2 points. With the extension of warm ischemia time, the cells became swel ing, nuclear chromatin condensated, apoptotic body was clearly visible, mitochondrial matrix coagulated, mitochondria exhibited vacuolation, and Flameng score was 3-4 points. The viability of cytochrome C oxidase showed no significant difference within 30 minutes of warm ischemia, but began to significantly decrease at 40 and 50 minutes. The mitochondrial structure and function after liver injury is not obviously affected by 30 minutes of warm ischemia, and significant changes appear after 40 minutes.

Biological and morphological characteristics of Penicillium marneffei under oxidative stress / 中华皮肤科杂志

Objective To observe the ultrastructure of dimorphic Penicillium marneffeiisolates from wild bamboo rats (Rhizomys pruinosus) in Guangxi region as well as from a patient with penieilliosis marneffei,and to compare their biological characteristics and anti-oxidative mechanisms.Methods Two Penicillium marneffei strains,including one isolated from wild bamboo rats (Rhizomys pruinosus) in Guangxi region and one from a patient with penicilliosis marneffei,were cultured with or without the presence of 2.0 mmol/L hydrogen peroxide in potato dextrose agar (PDA) at 25 ℃ and in brain-heart infusion (BHI) broth at 37℃ for seven days.The shape of colony and growth of both strains were observed.Light microscopy was carried out to study the morphology,and transmission electron microscopy to observe the ultrastructure,of both isolates.Results Ater incubation with hydrogen peroxide,there was a slowdown in the growth of both Penicillium marneffei isolates at both mycelial phase and yeast phase,with an increase in the production of pigment at mycelial phase at 25℃.No obvious changes were observed at 37 ℃ in the morphology of either the clinical isolate or the bamboo rat isolate when cultured with hydrogen peroxide compared with those cultured without hydrogen peroxide.Light microscopy showed attenuated spore formation by the clinical isolate when cultured at 25 ℃ with hydrogen peroxide,crenation of both isolates when cultured at 37 ℃ with hydrogen peroxide.Under a transmission electron microscope,the mycelial cells of both isolates exhibited smooth cell walls,intact cell membranes,with nuclei,mitochondria,endoplasmic reticulum,lipid body,vacuoles of various sizes in the cytoplasm at 25 ℃,and even microbodies at 37 ℃,when cultured without the presence of hydrogen peroxide.After incubation with hydrogen peroxide,the cell wall of both isolates became incomplete with defects in some areas and uneven thickness,the cell membrane discontinuous with shrinkages and projections,and the cytoplasm was inhomogeneous with obvious phagocytosis and numerous phagocytic vacuoles.Conclusions The clinical and bamboo rat isolates of Penicillium marneffei experience different biological and morphological changes under oxidative stress,hinting differences in antioxidative mechanism between them.

Electron microscopic observation of mitochondrial ultrastructure in melanocytes of perilesional skin from patients with vitiligo / 中华皮肤科杂志

Objective To evaluate the changes to mitochondrial ultrastructure in melanocytes of perilesional skin from patients with vitiligo.Methods Skin specimens were obtained from the perilesional area (0.5-1 cm distal to vitiligo lesions) of 10 patients with progressive vitiligo and 10 patients with stable vitiligo,as well as from the normal skin of 10 healthy volunteers.The morphology of melanocytes was observed by using transmission electron microscopy (TEM).Besides,stereological parameters of mitochondria,such as volume density (Vv),surface density (Sv) and numerical density (Nv),were measured.Results In melanocytes from the healthy controls,there were a large number of melanosomes with the number of melanosomes per melanocyte being 28.57± 3.21,which were mainly at stage Ⅲ and Ⅳ; mitochondria with normal structure and densely packed cristae were regularly arranged; autophagosomes were seen occasionally.Compared with the melanocytes from healthy controls,there was an obvious decrease in the number of melanosomes (especially stage Ⅲ melanosomes) in melanocytes from the perilesional skin of patients,with the number of melanosomes per melanocyte being 22.00 ± 6.16 (P ＜ 0.05) and 17.43 ± 6.24 (P ＜ 0.05) in patients with progressive vitiligo and stable vitiligo,respectively.TEM also showed disorganized or disrupted mitochondria in various shapes and sizes,most of which were swelling with obscure cristae and vacuolization,in melanocytes from the perilesional skin,and no autophagy was observed.The three stereological parameters were significantly different between the three groups of tissue specimens (all P ＜ 0.05),with the Nv,Vv and Sv of mitochondria being (7.194 ± 1.434) μm-3,(4.8 ± 1.2) ％,(2.42 ± 0.86) μ m-1 respectively in melanocytes from the healthy controls,(4.055 ± 0.906) μm-3,(7.4 ± 2.1)％,(3.58 ± 1.15)μm-1 respectively from patients with progressive vitiligo,(5.311 ± 0.873) μm-3,(6.5 ± 1.4)％,(2.82 ± 0.94) μm-1 respectively from patients with stable vitiligo.Conclusions Mitochondria are injured in melanocytes from perilesional skin of patients with vitiligo,and the degree of injury is more intense in progressive vitiligo than in stable vitiligo.