A histological study of the invasive and developmental processes of the aphid pathogen Erynia neoaphidis (Zygomycotina: Entomophthorales) in the pea aphid Acyrthosiphon pisum

1990 ◽  
Vol 68 (10) ◽  
pp. 2153-2163 ◽  
Author(s):  
T. M. Butt ◽  
A. Beckett ◽  
N. Wilding

On landing on the surface of an aphid host, the primary conidium of Erynia neoaphidis produced either a secondary conidium, a germ tube, or an appressorium. Appressoria were usually globose or clavate and each produced a single penetration peg. A circular bore hole marked the penetration site. Once the fungus had breached the cuticle, it formed protoplasts that failed to elicit an obvious immune response and multiplied rapidly in the haemocoel and in tissues. When the body of the host was occluded (about 3 days after penetration at 20 °C), the protoplasts regenerated a wall and differentiated into rhizoids, which were confined to the midventral region of the dead insect, pseudocystidia, and conidiophores. The rhizoids terminated in a digitate holdfast that adhered firmly to the plant cuticle but did not penetrate it. Conidiophores appeared to break out through the host cuticle using a combination of enzymatic and mechanical means. Key words: Erynia neoaphidis, Entomophthorales, infection, development, aphid.

1974 ◽  
Vol 52 (10) ◽  
pp. 2119-2128 ◽  
Author(s):  
George C. Carroll ◽  
Fanny E. Carroll

Sequential developmental stages from synchronously sporulating cultures of Phialocephala dimorphospora Kendrick have been examined. Apical vesicles characterize growth of the primary conidium. These are not, however, seen during secondary conidium formation; instead, large vesicles containing minute membrane fragments develop just below the phialide neck and contribute to wall formation as they fuse with the plasmalemma. The occurrence of microtubules in the neck of the phialide is restricted to primary conidium formation. Just as the primary conidial initial begins to swell, electron-dense granules 50-75 nm in diameter arise in association with the plasmalemma. Such granules are not seen during secondary conidium formation; they are thought to be involved in pigment deposition in the collarette. During both primary and secondary conidium production the conidia go through a sequence of maturation in which the cytoplasm becomes very dense and contains lipid bodies and flocculent aggregations of electron-transparent granules. Subsequently the conidia become less electron dense and reveal a simple internal substructure consisting of a nucleus, mitochondria, micro-bodies, free ribosomes, and presumed storage bodies. The plasmalemma becomes convoluted in a network of interdigitated grooves. Septum formation occurs rapidly and involves the fusion of vesicles with the lateral wall. Mature septa are non-perforate. Although Woronin bodies have been repeatedly observed in young conidia, they are never seen in mature conidia. Myelin figures associated with mitochondria occur consistently in the body of the phialide during conidiation. These may be the source of the lipid bodies in the conidia. In phialides from cultures over 1 week old, signs of senescence are apparent. These include vacuolization of the upper portion of the phialide and the presence of many disorganized sheets of membrane. Spores still present within the collarette of such phialides are smaller than those produced early in the life of the phialide.


Author(s):  
А.С. Казицкая ◽  
Т.К. Ядыкина ◽  
М.С. Бугаева ◽  
А.Г. Жукова ◽  
Н.Н. Михайлова ◽  
...  

В условиях непрерывного воздействия неблагоприятных факторов окружающей и производственной среды на человека особую актуальность приобретает изучение механизмов, поддерживающих гомеостаз организма. Длительное поступление фторидов в организм приводит к формированию хронической фтористой интоксикации, патогенез которой вызывает многочисленные споры и дискуссии. До сих пор недостаточно внимания уделяется изучению висцеральной патологии, обусловленной нарушениями иммунного статуса в условиях воздействия на организм соединений фтора. Практически отсутствуют исследования по изучению иммунной реактивности, определяющей морфофункциональный характер ответной реакции печени на ранних стадиях развития фтористой интоксикации. Цель работы - изучение действий патофизиологических механизмов иммунной реактивности печени при субхроническом действии на организм соединений фтора. Методика. Опыты проведены на 210 лабораторных крысах-самцах массой 180-220 г., разделенных на 2 группы: контрольную (n=80) и группу животных с субхроническим действием фторида натрия (n=130). Экспериментальные животные в течение 12 нед имели свободный доступ к водному раствору фторида натрия (концентрация 10 мг/л, что составляет суточную дозу фтора 1,2 мг/кг массы тела). Для изучения иммунологических и биохимических показателей забирали кровь из хвостовой вены через 1, 3, 6, 9, 12 нед от начала эксперимента. Для оценки состояния гуморального звена иммунитета определяли уровень сывороточных иммуноглобулинов (IgA, IgG, IgM) иммуноферментным анализом с помощью наборов реактивов ЗАО «Вектор-Бест» (Новосибирск). Уровень сывороточных цитокинов: TNF-α, IL-1β, 2, 4, 6, 10 определяли на анализаторе Multiskan EX методом иммуноферментного анализа с использованием наборов «Вектор Бест» (Новосибирск). Подсчет общего количества лейкоцитов произведен классическим способом в камере Горяева, анализ лейкоцитарной формулы - в окрашенных мазках периферической крови. Метаболические изменения оценивали по активности ферментов в ткани печени: щелочной фосфатазы (ЩФ), аланин- и аспартатаминотрансфераз (АЛТ, АСТ), лактатдегидрогеназы (ЛДГ), гаммаглутамилтранспептидазы (γ-ГТ). Активность ферментов определяли унифицированными методами с помощью наборов реактивов ЗАО «Вектор-Бест» (Новосибирск) на фотометре PM-750 (Германия). Гистологические исследования печени осуществляли после декапитации крыс, проводимой под эфирным наркозом. Результаты. Показано, что субхроническое воздействие фторида натрия сопровождается формированием внутриклеточных и внутрисосудистых повреждений печени. Активация медиаторов воспаления и развитие иммунологических нарушений в динамике эксперимента способствуют формированию системной воспалительной реакции, которая приводит к появлению стойких морфологических нарушений в печени и изменению активности ферментов основных метаболических путей. Заключение. Полученные результаты могут быть использованы при разработке и проведении профилактических мероприятий в условиях воздействия на организм высоких концентраций фтора с последовательным применением детоксикационной, иммуномодуляторной и органопротекторной коррекции. Studying mechanisms, which maintain the body homeostasis, is particularly important in the conditions of continuous impact of adverse environmental and manufacturing factors. Long-term exposure to fluorides leads to chronic fluoric intoxication, the pathogenesis of which is a subject of multiple controversy and discussions. Not enough attention is still paid to elucidating the visceral pathology associated with fluorine-induced immune disorders. There are virtually no studies of immune reactions that define the morphofunctional nature of the liver response to early stages of fluoric intoxication. Aim. To study pathophysiological mechanisms of hepatic immune reactivity in subchronic exposure of the body to fluorine compounds. Methods. Experiments were performed on 210 male rats weighing 180-220 g. The animals were divided into two groups: 1) control (n=80) and 2) subchronic exposure to sodium fluoride (n=130). The rats had free access to a 10 mg/l aqueous solution of sodium fluoride (daily dose, 1.2 mg/kg body weight) for 12 weeks. Blood was withdrawn from the caudal vein at 1, 3, 6, 9, and 12 weeks of the experiment for immunological and biochemical tests. Histological study of the liver was performed after decapitation of rats under ether anesthesia. Results. The subchronic exposure to sodium fluoride was associated with intracellular and intravascular damage of the liver. Activation of inflammatory mediators and development of immunological disorders during the experiment contributed to a systemic inflammatory reaction, which resulted in persistent morphological injuries of the liver and changes in enzyme activities in major metabolic pathways. Conclusion. The study results can be used for development and implementation of preventive measures against the effects of high fluorine concentrations, which would include a successive use of detoxification, immunomodulation and organ protection.


2018 ◽  
Vol 18 (2) ◽  
pp. 171-175
Author(s):  
Ashraf A. ◽  
Hassan F. ◽  
Batool S. ◽  
Nadeem M. ◽  
Irshad M. ◽  
...  

The objective of present study was to analyze and compare the nephroprotective effects of petroleum ether extracts of seeds of Nigella sativa and Silybum marianum in Swiss albino mice. Petroleum ether extracts of seeds of Nigella sativa and Silybum marianum were administered (200 mg kg–1) orally for 14 days following one dose of cisplatin injection (16 mg kg–1 i.p.) on 4th day. Cisplatin toxicity was identified in mice by loss of body weight, reduced triglycerides levels, elevated blood glucose, blood urea nitrogen and creatinine levels (P < 0.05). Silybum marianum and Nigella sativa significantly enhanced the body weight (9%) of diabetic rats. Silybum marianum had significantly reduced the elevated blood glucose (–106%), and BUN levels (–9%) as compared to the Nigella sativa administration. Silybum marianum extract also significantly elevated the levels of triglycerides (257%) which were much reduced after the cisplatin injection. Histological study showed that the cisplatin treated group demonstrated the necrosis signs in the glomerulus of Bowman’s capsule, hyalinization and severe cellular damage. The animals administered with extracts showed nearly normal kidney architecture, however, the kidney tissues of Silybum marianum-treated animals showed some improvement with slight signs of cellular damages.


PEDIATRICS ◽  
1970 ◽  
Vol 46 (1) ◽  
pp. 66-73 ◽  
Author(s):  
C. F. Geiser ◽  
A. Baez ◽  
A. M. Schindler ◽  
V. E. Shih

A 13-month-old boy with hepatoblastoma and hemihypertrophy is presented; this is the fifth known case with this association. Histological study showed that hemihypertrophy was related to cellular hyperplasia but not to hypertrophy of individual cells. Karyotypes of leukocytes and of skin fibroblasts from both sides of the body were normal. The association of hemihypertrophy and hepatoblastoma stresses the dysontogenetic origin of this neoplasm and signals the possibility of this tumor in children with asymmetry. Our patient showed cystathioninuria, which was related to the high content of cystathionine in his tumor. The presence of cystathioninuria in 7 of 10 patients with hepatoblastoma so far examined, shows the usefulness of urinary amino acid screening in the diagnosis of this rare childhood neoplasm.


2018 ◽  
Vol 20 (92) ◽  
pp. 222-228
Author(s):  
R. S. Dankovych ◽  
V. V. Tumanov

For today, the actual problem of veterinary medicine is the poisoning of animals with organophosphorus pesticides, which are used as insecticides and acaricides, fungicides, herbicides, rodenticides, nematocides. One of the highly effective nonspecific organophosphorus insecticides is diazinon, which enters the body causing poisoning of various species of birds. The basis of the toxic action of diazinon is the ability to block the enzyme acetylcholinesterase. As a result, acetylcholine is accumulated in cholinergic synapses, excessive stimulation of the nerves and muscles is noted, and in the future, a violation of the normal passage of nerve impulses develops. Research was carried out of domestic turkeys (Meleagris gallopavo) in which spontaneous poisoning with diazinon was recorded. Detailed study of clinical signs that develop as a result of poisoning. The activity of the acetylcholinesterase of the serum of blood in the experimental birds was determined by the method of Hestrin. The section of birds that were killed was carried out by the method of Shore. Sections of organs were fixed in 10% neutral formalin, 96% ethanol and Carnoua liquid. The histo-cuttings were made by means of a stent microtome, stained with hematoxylin and eosin. The histological study of the preparations and their photographing was performed using a Leica DM-2500 (Switzerland) microscope, a Leica DFC450C camera and the Leica Application Suite Version 4.4 software. For the production of ultrathin sections, as well as for conducting electron microscopy, pieces of organs were fixed in Millonig’s buffer pH 7,36. Half-thin and ultrathin cuts were made on ultramicrotome LKB-2188 Ultrotome NOVA. The specimens were viewed and photographed in a Tesla BS-500 transmissive electron microscope, at an accelerating voltage of 60, 90 kV. In the pathoanatomical study, expressed discirculatory processes in the form of acute congestive hyperemia, stasis, perivascular edema and hemorrhages, as well as necrotic changes in cardiomyces, hepatocytes, nephrocytes and brain neurons. An electron microscopic study also found destruction of synapses in the cerebral cortex, cerebellum and medulla oblongata. When autopsy selected material (feed the masses crop of birds) for chemical-toxicological research. As a result the research the extract of selected content crop of birds by the method of thin-layer chromatography paper manifestation of iodine bismuth quality received positive reaction on the compound diazinon.


2001 ◽  
Vol 37 (No. 1) ◽  
pp. 17-24 ◽  
Author(s):  
Ľ. Cagáň ◽  
M. Barta

The seasonal dynamics of the pea aphid, Acyrthosiphon pisum Harris, and entomopathogenic fungi from the order Entomophthorales attacking the aphid were analysed in alfalfa and field pea crops during the growing seasons of 1998 and 1999 at Nitra-Malanta. In both years, pea aphid populations on pea showed a pattern with one peak, culminated at flowering and pod formation. The infestation level on alfalfa was low in both years. Entomopathogenic fungi attacking the pea aphid were identified as Erynia neoaphidis Remaudičre and Hennebert and Conidiobolus obscurus (Hall and Dunn) Remaudičre and Keller. Both pathogens infected the aphid on pea, but only E. neoaphidis was found in the alfalfa plots. Infected aphids were not found on alfalfa during 1999. The maximum levels of infected aphids on pea were 10.30% and 48.39% in 1998 and 1999, respectively. During both years alate aphids were more frequently attacked than apteral ones. Correlation coefficients indicated a positive relationship between the number of infected aphids and precipitation, but this relationship was weak or moderately strong. A strong correlation was found between the number of dead aphids and number of alate aphids counted 5 to 10 days earlier.


1898 ◽  
Vol 3 (6) ◽  
pp. 611-638 ◽  
Author(s):  
F. B. Mallory

The typhoid bacillus produces a mild diffusible toxine, partly within the intestinal tract, partly within the blood and organs of the body. This toxine produces proliferation of endothelial cells which acquire for a certain length of time malignant properties. The new-formed cells are epithelioid in character, have irregular, lightly staining, eccentrically situated nuclei, abundant, sharply defined, acidophilic protoplasm, and are characterized by marked phagocytic properties. These phagocytic cells are produced most abundantly along the line of absorption from the intestinal tract, both in the lymphatic apparatus and in the blood-vessels. They are also produced by distribution of the toxine through the general circulation, in greatest numbers where the circulation is slowest. Finally, they are produced all over the body in the lymphatic spaces and vessels by absorption of the toxine eliminated from the blood-vessels. The swelling of the intestinal lymphoid tissue of the mesenteric lymph nodes, and of the spleen is due almost entirely to the formation of phagocytic cells. The necrosis of the intestinal lymphoid tissue is accidental in nature and is caused through occlusion of the veins and capillaries by fibrinous thrombi, which owe their origin to degeneration of phagocytic cells beneath the lining endothelium of the vessels. Two varieties of focal lesions occur in the liver: one consists of the formation of phagocytic cells in the lymph spaces and vessels around the portal vessels under the action of the toxine absorbed by the lymphatics; the other is due to obstruction of liver capillaries by phagocytic cells derived in small part from the lining endothelium of the liver capillaries, but chiefly by embolism through the portal circulation of cells originating from the endothelium of the blood-vessels of the intestine and spleen. The liver cells lying between the occluded capillaries undergo necrosis and disappear. Later the foci of cells degenerate and fibrin forms between them. Invasion with polymorphonuclear leucocytes is rare. Many of the phagocytic cells pass through the liver and lungs, and get into the general circulation. A few come from the abdominal lymphatics through the thoracic duct.


1991 ◽  
Vol 69 (6) ◽  
pp. 1284-1287 ◽  
Author(s):  
G. L. Barron ◽  
E. Szijarto

Harposporium trigonosporum is described as new. After ingestion by rotifers, the traingular conidia lodge any place between the mouth and the anus but most frequently in the lower gut. A filiform germination hypha develops from each corner of the conidium and penetrates through the gut wall into the body cavity of the host. The host frequently responds to this invasion by laying down deposits around the advancing germ tube that sometimes causes the germinating conidium to abort. More frequently a germination hypha breaks through the host deposits at one or more of the three points of attack and proliferates inside the body, resulting in the death of the rotifer. Key words: Harposporium, endoparasite, rotifer.


1911 ◽  
Vol 13 (1) ◽  
pp. 98-114
Author(s):  
Fraser B. Gurd

The cutaneous lesions in pellagra consist of an early erythema, or, in occasional cases, of vesicles or bullous formations which are followed by hyperkeratosis and pigmentation, resulting in a dry, dark brown scaliness. These various lesions are similar to those normally produced by the action of sunlight, but are much more marked. The histological phenomena of the erythematous and bullous stage are those of a mild acute inflammatory reaction, together with a degeneration in the superficial layers of the corium. Following this degeneration, which involves not only the general connective tissue but the connective tissue of the blood vessels, there is a reparative change evidenced histologically by an increased cellularity of the corium and the presence of fibroblasts. The capillaries also are increased in number and much dilated. Apparently as a result of this increased vascularity of the corium, there is an increased proliferation of the epithelium resulting in a thickening of the epidermis. This increase in thickness of the epithelial layer is especially marked in the prickle cells and the stratum granulosum. In the later stages, in an effort to secure a firm basement membrane, the epithelium is seen to dip down deeply into the rarefied connective tissue. About the blood vessels during the reactionary process are found collections of lymphoid cells, a few plasma cells, but no mast cells or eosinophiles. That the irritant producing the degeneration in the corium is sunlight in the presence of some predisposing factor, is suggested by the enormous increase in pigment formation in the epithelial cells and by the large number of chromatophores in the superficial layers of the corium. This pigmentation is autochthonous in both types of cell. There is no reason for believing that the pigment is formed in the cells of the corium and thence discharged into the epithelium, or that the reverse process takes place. The predisposing factor inducing the changes in the corium is, apparently, a lessened resistance of the epithelium to the violet and ultra-violet rays, due to some metabolic insufficiency on the part of the epithelial cells. Further observation may justify the conclusion that throughout the body, pellagra is a disease essentially of the epithelium, including the nervous system, this pathological condition manifesting itself by an insufficient or altered function.


2020 ◽  
Vol 37 (1) ◽  
pp. 111-117
Author(s):  
V. D. Elkin ◽  
M. Yu. Kobernik ◽  
E. N. Borodina

Cutaneous amyloidosis is a rare disease that represents mesenchymal dysproteinosis and is characterized by amyloid deposition in the dermis. Generally, it has a benign course, but nodular-plaque option with progression can go into systemic form with unfavorable prognosis, therefore, a regular dynamic assessment of somatic status is necessary. A case of nodular-plaque amyloidosis of the skin is described. On the body of a 64-year old woman, on the outer surface of the lower extremities, symmetrically there were found multiple pinkish-cyanotic nodes 12 cm in diameter, having a dense consistency, which merged into irregularly-shaped tuberous plaques up to 6 cm in size with excoriated surface, covered with erosions and ulcerations, serohemorrhagic crusts, scaled desquamation. Foci of lichenification, depigmentation and cicatricial-atrophic changes in the skin were also determined. On the basis of clinical data and histological study, cutaneous nodular-plaque amyloidosis was diagnosed. Laboratory and instrumental research and consultations of related specialists (neurologist, therapist) allowed to exclude the systematic process. Describing this case, we would like to draw attention to a unique dermatosis, the only variant of cutaneous amyloidosis with potentially systemic lesion that requires special monitoring and control.


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