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1.
The life cycle of the itch mite Sarcoptes scabiei (L.), an intracutaneous parasite of man and animals, has been studied. The paper concerns morphological adaptations, embryonal and postembryonal development, life cycle pattern, scabious passage as a reproductive formation, invasive stages, feeding, reproduction and topical relationships with the host, distribution and survival in the environment.  相似文献   

2.
In an epidemic of prosthetic valve endocarditis caused by Staphylococcus epidermidis the surgeon was found to be the source of contamination. The probable route was accidental puncture of gloves during operation. During the epidemiological investigation a second cluster of patients contaminated with Staph epidermidis during open heart surgery was found also related to one surgeon. This strain caused no detectable signs or symptoms of infection. Carriage of virulent staph epidermidis has rarely been recognised as a hazard but may have serious consequences.  相似文献   

3.
Kiehr M  R Delhey  J Lusto 《Phyton》2015,84(2):423-426
A new disease of lettuce has been observed in the surroundings of Bahía Blanca, Argentina. The symptoms include dwarfing, general chlorosis, wilting, root rot, and leaf blight, sometimes followed by plant death. Pythium tracheiphilum Matta was found to be consistently associated with those symptoms. The morphological and morphometric characteristics of this oomycete are described. Isolates obtained from field-infected lettuce plants were inoculated to lettuce and caused similar symptoms as those found in natural infections. Seedling emergence was also severely affected following experimental inoculation. Koch’s Postulates were fulfilled by recovering the fungus from inoculated plants. The new disease shows a high destructive potential but currently has a limited prevalence and incidence.  相似文献   

4.
The influence of number and date of pregnancies, births, and spontaneous and induced abortions on body shape, age at menopause and menopausal symptoms have been studied for 110 postmenopausal Viennese women. A significant correlation between fertility and age at menopause was not found, but several menopausal symptoms showed statistically significant correlations with fertility. With a higher number of pregnancies the individual symptoms became more severe.  相似文献   

5.
The immotile-cilia syndrome is a congenital disorder characterized by all cilia in the body being either immotile or showing an ineffective beating pattern. Most symptoms, not unexpectedly, come from the ciliated epithelia, but two further symptoms are: (1) male sterility caused by the spermatozoa being unable to swim progressively (the sperm tail has the same structure as a cilium), and (2) situs inversus in 50% of the cases possible caused by an inability of embryonic cilia to shift the heart to the left side. By electron microscopy, one can see directly which of the many ciliary components is the missing one. The molecular basis of this congenital defect can then be detected, and it has been found to be a heterogeneous disease. There are many genes that, when mutated, will cause the cilia to be dysfunctional or totally immotile. The fact that many genes may be responsible for the syndrome will also explain why it has a relatively high prevalence and why previous investigators have been unable to locate the (assumed single) gene by linkage analysis. The trait, situs inversus, is of particular interest as it occurs in only 50% of the assumed homozygotes. I conclude that the wild-type genes code for a control of the proper body asymmetry and the mutated ones for a lack of control, and, hence, to a random situs determination.  相似文献   

6.
There have been few reports of vasodepressor carotid sinus syncope, as opposed to the cardioinhibitory type, and no definitive treatment has been described. A 58 year old man developed episodes of syncope after surgery and radiotherapy for a laryngeal tumour. The episodes were characterised by hypotension, sharp pain in the right neck, dizziness, and bradycardia. A temporary pacemaker failed to prevent the symptoms, but ephedrine and fludrocortisone produced substantial improvement. Of the four types of treatment used in carotid sinus syncope, irradiation was ruled out because the patient had had irradiation before developing syncope, surgery was inappropriate because of the laryngeal tumour, and pacing failed. Combined drug treatment with a vasoconstrictor and plasma volume expander produced an improvement in symptoms but did not eliminate them.  相似文献   

7.
1. The marsh fritillary Euphydryas aurinia is one of our most endangered butterflies, and the only to be protected under European legislation as well as British. It persists in fragile subpopulations threatened by habitat fragmentation and degradation. 2. A combination of swaling and cattle grazing are accepted to be best practice for managing wet, unimproved grasslands??the favoured habitat for E. aurinia in Cornwall. These two well-endorsed methods of management were used to increase and improve the quality of habitat for E. aurinia over a 5 years period, 2004?C2008, at a stronghold network of habitat patches in mid Cornwall, south-west England. 3. Analyses of adult and larval densities over 5 years in fifty-four transects across nine sites found E. aurinia to favour habitat patches with higher densities of the larval food plant (Devil??s-bit scabious Succisa pratensis), higher sward height in autumn, and intermediate optimum levels of stock grazing. 4. Main findings indicated most sites experienced significant declines in numbers. Unfavourable weather in the last 2 years of monitoring was likely to have had a significant impact on the response of individual subpopulations to habitat management though poor recovery rates may also reflect a time-lag in colonisation events after habitat improvement has occurred. 5. Habitat management produced an improvement, albeit an inconsistent improvement in habitat variables across patches??S. pratensis shows a clear recovery at some sites. Autumn sward height increased significantly at one site, and a quadratic relationship between stock grazing and important habitat variables has been found which will aid further improvement over all sites for the long term persistence of E. aurinia.  相似文献   

8.
Auricular electroacupuncture (AES) has been found to be successful in the suppression of withdrawal symptoms of morphine-addicted mice. In abrupt withdrawals precipited by naloxone, the plasma adrenocorticotropin (ACTH) rises to a high level which can also be effectively suppressed by AES. This elevation of plasma ACTH is not due to naloxone, as naloxone has no effect on the ACTH level in non-addicted mice. The possible physiological effect produced by AES is discussed.  相似文献   

9.
癫痫是大脑神经元高度同步化异常放电所导致的短暂的大脑功能障碍的一种慢性疾病。癫痫的发病原因十分复杂,目前主要治疗方式是药物治疗,但仍然有30%左右的难治性癫痫患者依靠药物治疗未能控制癫痫发作,因此从分子角度研究癫痫的发病机制及治疗是近年来癫痫研究的热点。微小RNA(miRNA)在癫痫患者及癫痫动物模型海马组织中存在差异性表达,通过抑制miRNA的差异表达在一定程度上可以缓解癫痫的症状,这为癫痫的治疗开辟了新的途径和方向。因此随着miRNA与癫痫相关性研究深度的不断加深,有望能够为癫痫的诊断及治疗提供一个全新的思路。  相似文献   

10.
Endocrine functions were investigated in a case of "beta-adrenergic hyperdynamic circulatory state". This state was diagnosed by (1) typical symptoms of cardiac awareness, (2) physical findings (increments of pulse rate and blood pressure by changing positions or walking), (3) increase in cardiac output (5.25 l/min leads to 14.03 l/min) and decrease in circulatory time (10.8 sec leads to 5.5 sec) by isoproterenol infusion (0.02 mug/min/kg body weight), (4) rapid loss of symptoms and above findings by propranolol treatment (30 mg per os daily) and reappearance by discontinuing medication. The mechanism of insulin response to glucose has been a controversy as to whether the secretion is transmitted by beta-receptor or independent glucose receptor. And in this physiologic beta-adrenergic state, it was found that insulin responses in IVGTT and OGTT were within normal limit. When beta-adrenergic condition was corrected by propranolol treatment, insulin responses were shown lowered, though in the normal range. This could be reproduced by discontinuing medication. Insulin, glucagon and growth hormone secretions caused by arginine were also found normal, but during the period the patient was on propranolol therapy, all responses were decreased, within the normal range. These results do not positively support the idea that glucose receptor is linked to beta-receptor. They do not either agree with the contention that secretions of insulin, glucagon and growth hormone induced by arginine are mediated through beta-receptors.  相似文献   

11.
A new haemoglobin variant (haemoglobin Arya), is described from an Iranian female. The substitution is at residue 47 (CD5) of the alpha chain in which aspartic acid has been substituted by asparagine. The presence of haemoglobin Arya was not associated with clinical symptoms. This variant has normal stability at 50 degrees C, but is slightly unstable when tested at 55 degrees C.  相似文献   

12.
Intoxication by elemental mercury or by methylmercury is revealed primarily by changes in behavior and by neurological signs. Disorders of movement and posture have been most widely reported, both in animal experiments and in cases of human exposure. Specific sensory symptoms are also prominent in human methylmercury poisoning. Recent data indicate similar symptoms in monkeys during long-term exposure to methylmercury. Similar sensory impairment has not been described in experiments with subprimates. Variations in the profile of behavioral and neurological effects are discussed in terms of differences in species and differences between acute and long-term exposure. The latter condition poses the most difficult questions for human health, yet has been less frequently studied. Procedures are suggested that may help to revolve these problems. In particular, tests of learned behavior hold great promise toward identifying specific symptoms and toward understanding how mercury compounds affect behavior.  相似文献   

13.
Although peripheral-nerve injury has been described as clearly related to electrical injury, that electrical injury is usually associated with third- and often fourth-degree burns. The report presented here describes three cases of low-voltage electrical injury with associated peripheral-nerve symptoms but without clinically significant cutaneous burns. The symptoms and clinical findings resembled peripheral-nerve compression. The presence of these symptoms and findings in the upper- and lower-extremities and the presence of bilateral involvement suggest a systemic electrical injury that resembles a peripheral neuropathy. Symptoms were relieved by the decompression of nerves at multiple sites in each extremity. Perineurial fibrosis was identified at the time of nerve decompression. It is proposed that the electrical injury causes maximal heat production at areas of minimal limb cross-sectional area. In these areas, the peripheral nerve is in close proximity to bone and fibrous tissue. This results in perineurial fibrosis and symptoms of a compressive peripheral neuropathy.  相似文献   

14.
Praziquantel is the drug of choice for clonorchiasis. Since clonorchiasis is endemic in most river basins, praziquantel has been widely used for 30 years in Korea. A 54-year-old Korean woman suffered from hypersensitive reactions, such as nausea, dyspnea, rash, and urticaria after taking the first dose of praziquantel to treat clonorchiasis. She ingested one dose again and the same symptoms appeared, and she was treated at a clinic with anti-histamines. She tried one more dose with anti-histamines but found the same symptoms. Later, she was found to pass eggs of Clonorchis sinensis and medicated with flubendazole. The hypersensitive reaction to praziquantel is rare but occurs. This is the 5th case report in the world.  相似文献   

15.
A disease of mature tomato plants is described, the symptoms of which include brown discoloration and/or necrosis and collapse of the pith. These are sometimes accompanied by vascular browning, external dark brown to black stem lesions, bacterial flux from stem wounds and adventitious root formation. The disease, which appears to be favoured by high humidity and/or free water on the plant surfaces and by high N fertiliser, has been widespread on many glasshouse holdings in England since 1971 but has caused severe loss on only a few. It is thought to be caused by a new species of the genus Pseudomonas for which the name P. corrugata Roberts and Scarlett is proposed.  相似文献   

16.
The pollens of apple flowers have been treated with simulated acid rain solutions in range of pHs 2.9 to 5.0 in order to determine the threshold proportion values that lead the observed symptoms of detriments of acid rain. Compared to controls (pH 6.5), pollen germination decreased by 41.75% at pH 3.3 and pollen tube elongation decreased by 24.3% at pH 3.4. Acid rain threshold proportion value was around pH 3.3 and 3.4 for apple pollen germination and pollen tube elongation, respectively. Furthermore, pollen tube elongation was determined to be more sensitive to acid rain than pollen germination. The pH values below 3.1 resulted in complete destruction of pollen tubes. Pollen germination entirely stopped at around pH 3.0. Finally, it has been shown that the acid rain has a blocking effect on pollen germination and pollen tube elongation in apple. The conclusion is that not only pH value but also the quantity of acid rain is important factor in germination. The results were found statistically significant through the LSD test at levels of p < 0.05 and p < 0.01.  相似文献   

17.
The data are based upon observations derived chiefly from twenty-four replicated manurial trials made on the potato crop in 1937 and from twenty-five further trials of a different design in 1938. They deal with the manurial and other factors that induce deficiency symptoms relating to potash, phosphates and calcium respectively on the potato plant. Leaf scorch, and the other potash-deficiency symptoms on the aerial part of the plant are normally induced by NP and not by nitrogen treatment. The presence of leaf scorch on the nitrogen plots in a number of trials has been satisfactorily correlated with a high level of available phosphates in the soil, as indicated both by a chemical test for phosphate solubility and the degrees of response to phosphate applications. An increase in the level of nitrogen in the NP treatment results in the intensification of potash-deficiency symptoms. A certain interaction between nitrogen and phosphates is shown to be the primary factor in inducing potash-deficiency symptoms on the part of the plant above ground. The blackening of cooked tubers which has hitherto been assumed to indicate potash deficiency has been found to result from a combination of high nitrogen with low potash in the soil. Phosphate deficiency is induced by nitrogen and NK treatments, but more strongly by the latter. Phosphate-deficiency symptoms and not potash-deficiency ones become evident on the nitrogen plants under conditions of low phosphates and low potash in the soil. Calciumdeficiency symptoms appeared at three centres on poor sandy soils with pH values ranging between 45 and 5. Observations failed to detect signs of magnesia deficiency on the plants at any centre and in either season. The results of this observation were borne out by the absence of significant yield responses to magnesia with one exception in each season.  相似文献   

18.
D. A. Dotten  W. Pruzanski  J. Olin  T. C. Brown 《CMAJ》1976,114(10):909-912
A 40-year-old woman had cryocrystalglobulinemia with IgG2(K1). To date, 27 other cases of spontaneous crystallization of a plasma protein have been reported. In all, the protein, a cryoglobulin, has been found to be an IgG molecule. The disease most commonly associated with this phenomenon has been multiple myeloma. None of the patients have had Raynaud''s phenomenon, but many have had purpuric skin lesions made worse by exposure to cold. In the two cases of essential cryocrystalglobulinemia, crystals were found in the peripheral blood film. Immunologic, biochemical and ultrastructural studies have so far not demonstrated any property common to all cryocrystalglobulins.  相似文献   

19.
The plant hormone ethylene has been hypothesized to play roles both in disease resistance and in disease susceptibility. These processes were examined by using isogenic virulent and avirulent bacterial pathogens and mutants of Arabidopsis thaliana that were altered in ethylene physiology. Ethylene-insensitive ein1 and ein2 mutants of Arabidopsis were resistant to Pseudomonas syringae pv. tomato made avirulent by the addition of the cloned avirulence genes avrRpt2, avrRpm1, or avrB; this suggests that ethylene is not required for active resistance against avirulent bacteria. In a second set of experiments, susceptibility was monitored with virulent P. s. pv. tomato, P. s. pv. maculicola, or Xanthomonas campestris pv. campestris strains. Wild-type Arabidopsis and ein1 mutants were susceptible to these strains, but ein2 mutants developed only minimal disease symptoms. Despite these reduced symptoms, virulent P. s. pv. tomato grew extensively within ein2 leaves. The Pseudomonas phytotoxin coronatine induces ethylene biosynthesis and diseaselike symptoms on many plant species, but the reduced symptomology of ein2 mutants could not be attributed to insensitivity to coronatine. The enhanced disease tolerance of ein2 plants suggests that ethylene may mediate pathogen-induced damage, but the absence of tolerance in ein1 mutants has yet to be explained.  相似文献   

20.
The parasite Blastocystis hominis has been found in 10% to 18% of stool specimens submitted to microbiology laboratories. Controversy exists as to whether this organism can cause illness in humans. We have reviewed the records of 65 symptomatic patients with B hominis in their stool. We conclude that B hominis is a potential pathogen that may or may not require drug therapy depending on the overall clinical circumstances, the severity of symptoms, and the presence of other pathogenic organisms.  相似文献   

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