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[Ultrastructure of the surface complex of acanthocephalans with the example of Filicollis anatis (Palaeacanthocephala: Polymorphidae) and Neoechinorhynchus crassus (Eoacanthocephala: Neoechinorhynchidae)].

Fine morphology of external tegument (surface complex) of young and mature acanthocephalans Filicollis anatis and young Neoechinorhynchus crassus is described. Based on comparative analysis of the obtained results and literature data, the surface complex of all examined acanthocephalans is shown to have principally similar structure at all stages of life cycle. Differences between species examined are found in quantitative characters only and they are related either to age or ecology of worms (embryonic larvae).

Acanthocephala↗

The thermo-photoelectric (TPE) properties of the hornet cuticle: correlation with the morphological structure.

The present study investigated thermoelectric phenomena in the cuticle of the Oriental hornet Vespa orientalis (Hymenoptera, Vespinae). This was done in dependence on the pigment extant at various cuticular region, that is, the brown cuticle in which the primary pigment is melanin and embedded within the cuticle, and the yellow stripes in which the yellow pigment is comprised of purines and pteridines that are located in special pockets between the upper part of the cuticle and the basement membrane. The yellow pigment could be separated from the cuticle proper, but the brown pigment was not thus separable. We found that all cuticular regions of the gaster evinced a thermoelectric response, in that with rise in temperature there was a rise in the thermoelectric current, and vice versa. Additionally, the intact hornet displayed a negative photoelectric response in each of its yellow segments, so that upon illumination with UV light, the maximal current dropped by about 40-50%. Measurements taken on individual stripes in the gaster segments revealed that the photoelectric response is elicited only in the yellow stripes. In all the latter the photoelectric response persists but the maximal current level is lower than in the intact whole hornet. If the yellow pigment is detached mechanically or by bacterial incubation, the photoelectric property of the cuticle is abrogated. Likewise the photoelectric property is abrogated upon immersion of the cuticle in alcohol, even though the yellow pigment is still retained. The specific heat of the yellow stripes in the cuticle is about twice as high as that of the same stripes that had been depleted of their yellow pigment, amounting to 1.8-1.9 J/g.K vs. 0.8 J/g.K.

Animals↗

Integument pattern formation involves genetic and epigenetic controls: feather arrays simulated by digital hormone models.

Pattern formation is a fundamental morphogenetic process. Models based on genetic and epigenetic control have been proposed but remain controversial. Here we use feather morphogenesis for further evaluation. Adhesion molecules and/or signaling molecules were first expressed homogenously in feather tracts (restrictive mode, appear earlier) or directly in bud or inter-bud regions ( de novo mode, appear later). They either activate or inhibit bud formation, but paradoxically colocalize in the bud. Using feather bud reconstitution, we showed that completely dissociated cells can reform periodic patterns without reference to previous positional codes. The patterning process has the characteristics of being self-organizing, dynamic and plastic. The final pattern is an equilibrium state reached by competition, and the number and size of buds can be altered based on cell number and activator/inhibitor ratio, respectively. We developed a Digital Hormone Model which consists of (1) competent cells without identity that move randomly in a space, (2) extracellular signaling hormones which diffuse by a reaction-diffusion mechanism and activate or inhibit cell adhesion, and (3) cells which respond with topological stochastic actions manifested as changes in cell adhesion. Based on probability, the results are cell clusters arranged in dots or stripes. Thus genetic control provides combinational molecular information which defines the properties of the cells but not the final pattern. Epigenetic control governs interactions among cells and their environment based on physical-chemical rules (such as those described in the Digital Hormone Model). Complex integument patterning is the sum of these two components of control and that is why integument patterns are usually similar but non-identical. These principles may be shared by other pattern formation processes such as barb ridge formation, fingerprints, pigmentation patterning, etc. The Digital Hormone Model can also be applied to swarming robot navigation, reaching intelligent automata and representing a self-re-configurable type of control rather than a follow-the-instruction type of control.

Animals↗

The thermoelectric properties of hornet cuticle: correlation with measuring body sites and activity status.

Our study focused on the thermoelectric properties of hornet cuticle at different body compartments and under varying states of awakeness. We also measured the temperature alteration patterns in various body parts of the hornet. Electric voltage and current were dependent on: a) the state of wakefulness; b) the part of the body. The current was lowest in dead hornet cuticle, somewhat higher in narcotized hornet cuticle, considerably higher in the cuticle of hornets awakening from anesthesia and highest in fully awake hornets. Voltage values were of the same order for dead and narcotized hornets, but considerably higher in unanesthetized awake hornets and highest in the cuticle of hornets awakening from anesthesia. At optimal temperature (29 degrees C) the hornet body temperature was higher on the abdominal cuticle than on other body parts. At an ambient temperature of 20 degrees C, the highest temperatures were recorded on the head and thorax, and the lowest on the abdomen. Body temperatures of live hornets were higher than the cooler ambient temperature outside the nest at night. The results suggest that the hornets possess an intrinsic biological heat pump mechanism, which can be used to achieve active thermoregulation.

Aging↗

Ultrastructure of the tegument of the anoplocephalid cestode Mosgovoyia ctenoides (Railliet, 1890) Beveridge, 1978.

The tegument of the mature proglottids of M. ctenoides was examined by means of TEM. The tegument of this species consists of two layers: (1) the external cytoplasm, and (2) the tegumental perikarya situated in the cortical parenchyma. The tegument surface is covered by typical microtriches. The anucleated external layer of cytoplasm is rich in vesicles of different shape and electron-density, but it lacks mitochondria. Large pore canals penetrate the external cytoplasmic layer. This layer is separated from the perikarya by a basal lamina, being connected with the tegument cell bodies by cytoplasmic bridges. The granular cytoplasm of perikarya contains typical cell organelles such as mitochondria, GER, Golgi complexes, free rybosomes, numerous vesicles and lipid droplets inclusions. The large nuclei of the perikarya with prominent nucleoli frequently contain large intranuclear, highly osmiophilic lipid droplets.

Animal Structures↗

[The enzymatic activity of fungi strains isolated from the skin and skin appendages of humans returning from the tropics].

The aim of the work was to assess the enzymatic activity of 11 fungi strains isolated from the skin of 10 Lódź residents who had visited the tropics over 1998-1999. The strains were cultured by Jeske and Lupa of The Voivodeship Outpatient Clinic of Infectious, Parasitic and Tropical Diseases and Fungal Infections in Lódź. They were as follows: Trichophyton rubrum and Acremonium kiliense from Zambia, Myriodontium keratinophilum, Beauveria bassiana, Cladosporium herbarum, Candida famata and Trichophyton yaoundei from Sudan, Trichophyton tonsurans from Ethiopia, Trichophyton phaseliforme from Egypt, Acremonium strictum from Zimbabwe and Microsporum racemosus from Tanzania. The enzymatic activity was determined with the use of API ZYM of bioMérieux enabling 19 hydrolases to be revealed. In general, all tropical strains were characterised by a weak hydrolytic activity.

Dermatomycoses↗

Toxicities of hydrazines: a review.

The toxic properties of sixty carcinogenic hydrazines are reviewed and presented. Many of these chemicals are synthesized by man and used in industry, agriculture and medicine, while others occur in nature as ingredients of fungi and plants. The human population is, therefore, exposed to them to a considerable degree. These compounds, in addition to being carcinogens, have toxic effects in the gastrointestinal tract, respiratory, nervous, lymphoreticular, hematopoietic, cardiovascular, genitourinary, integumentary, musculoskeletal systems, etc., of 15 animal species and man. Because they caused toxic damage in practically every organ and tissue, earlier claims concerning their tissue specificity are discounted. Their hazardous properties deserve careful attention.

Animals↗

Rheumatoid arthritis: new science, new treatment.

Rheumatoid arthritis (RA) is a chronic systemic inflammatory disease that occurs two to four times as often in women as in men and increases in incidence with advancing age. It affects synovial-lined joints and can also affect the pulmonary, cardiac, nervous, integumentary, and reticuloendothelial systems. RA is manifested clinically by malaise and fatigue, followed by a symmetric pattern of joint inflammation characterized by pain and stiffness. RA most likely occurs in the setting of a genetically predisposed individual, triggered by infectious agents or endogenous antigens. Many of the newer treatments being studied involve blocking cytokine-mediated interactions between cells of the synovium.

Aged↗

Bilateral Wilms tumor. Review of outcome, associated abnormalities, and late effects in 36 pediatric patients treated at a single institution.

BACKGROUND: Patients with bilateral Wilms tumor have an increased incidence of associated abnormalities and nephrogenic rests and require individualized multimodality therapy for cure. The authors reported the associated abnormalities, outcome, complications, and late effects of treatment in a group of children with bilateral Wilms tumor treated at St. Jude Children's Research Hospital, Memphis, Tennessee, over a 28-year period. METHODS: The records of 36 consecutive pediatric patients diagnosed with bilateral Wilms tumor between 1962-1990 were analyzed. Biopsy material was also reviewed, with particular emphasis on characterization of nephrogenic rests and histology. RESULTS: Twenty-nine patients had synchronous tumors and 7 had metachronous lesions. Associated physical abnormalities were present in 12 patients and involved the genitourinary, cardiovascular, integumentary, and musculoskeletal systems. The overall survival for patients with metachronous tumors (71%) was similar to that for those with synchronous tumors (70%). There was no effect of age or the presence of nephroblastomatosis. Two patients with synchronous tumors initially treated with nephrectomy eventually required bilateral nephrectomies for contralateral recurrence after chemotherapy and radiation therapy. Nephrogenic rests were present in 22 of 30 evaluable patients. Two of three patients with metachronous tumors had intralobar nephrogenic rests. Bilateral renal salvage procedures were demonstrated to be technically feasible and effective in controlling disease without compromising renal function or survival. Late effects included scoliosis in three patients treated before 1970, cardiomyopathy in one patient who received 300 mg/m2 doxorubicin and 12 Gy pulmonary irradiation, and benign tumors in two patients, one of whom also had a bowel obstruction. Serum creatinine, urea nitrogen, and blood pressure were normal in 23 of 26 survivors. CONCLUSIONS: The authors' experience supports a favorable outcome with minimal late effects for patients with bilateral Wilms tumor who receive individualized therapy at pediatric oncology centers.

Child↗

Border disease of sheep--aspects for diagnostic and epidemiologic consideration.

Border Disease (BD) is a condition of newborn sheep that results from congenital infection by a non-cytopathic pestivirus, occurring during the first half of gestation. The variations in expression of the virus directly relate to the age of the fetus at the time of infection. There are four distinct disease syndromes: (1) early embryonic death, (2) abortion and stillbirth, (3) birth of lambs with malformations, and (4) birth of small, weak lambs, lacking characteristic clinical signs, but bearing features of immunosuppression. In the newborn, the BD virus may be recovered from all tissues and teratogenic lesions are found in the endocrine, nervous, skeletal, integumentary and immune systems. These effects of virus infection are manifest in the clinical signs characteristic of the disease, such as tremors, ataxia, hairy birthcoat, low birth weight, facial bone malformations, short-boxy stature, and eye abnormalities. The consequences of the BD compromised immune system is an increased susceptibility to infection, a failure to produce specific antibody to BD virus, and an inability to clear the virus; features characteristic of the immuno-tolerant state. The lifelong shedding and persistence of virus is of epidemiologic importance. The persistently infected BD ewe remains a source of infection for the flock both through horizontal transmission (virus shedding) and congenital transmission (a persistently infected ewe will always bear a BD lamb). Detection of persistently infected individuals within a flock is difficult: clinical signs abate with time and most frequently no antibody to BD is produced.

Animals↗

Border disease of sheep: the disease in the newborn, adolescent and adult.

Border disease (BD) is a condition of newborn sheep that results from congenital infection by a non-cytopathic pestivirus occurring during the first half of gestation. The expression of the virus is largely determined by the age of the fetus at the time of infection, producing four distinct disease syndromes: (1) early embryonic death, (2) abortion and stillbirth, (3) birth of lambs with malformations, and (4) birth of small, weak lambs, lacking characteristic clinical signs, but bearing features of immunosuppression. The effects of the virus infection during the developmental stages of the fetus are most apparent as distinctive clinical signs at the time of birth but a state of specific immuno-tolerance with associated virus persistence remains for the lifetime of the sheep. Although the clinical signs disappear with time, some effects of virus persistence may continue into adolescence and often into adulthood. Characteristic lesions are found in the nervous, endocrine, skeletal and integumentary, and immune systems.

Aging↗

Bupivacaine: a review of 11,080 cases.

Bupivacaine (Marcaine) hydrochloride, a long-acting local anesthetic drug, was used in concentrations of 0.25, 0.5, or 0.75 percent with and without a vasoconstrictor, in amounts ranging from 25 to over 600 mg, for caudal, epidural (peridural), or peripheral nerve block for 11,080 surgical, obstetrical, diagnostic, or therapeutic procedures. Onset of anesthesia occurred in 4 to 10 minutes and maximum anesthesia in 15 to 35 minutes. Concentrations of 0.25, 0.5, and 0.75 percent consistently produced complete sensory anesthesia of the integumentary and musculoskeletal systems. With 0.25 and 0.5 percent, motor blockade ranged from minimal to complete. In intra-abdominal surgery, only 0.75 percent consistently produced profound muscle relaxation. Fifteen systemic toxic reactions occurred, but no untoward sequelae resulted from them. One inadvertent subarachnoid injection of 110 mg resulted in a total spinal block with an uneventful recovery.

Analgesia↗