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M Eichner

Publications and source records attributed to M Eichner.

At least 37 records · Page 2Linked to original sources
PubMed1997

Multiplication of different Legionella species in Mono Mac 6 cells and in Acanthamoeba castellanii.

Survival and distribution of legionellae in the environment are assumed to be associated with their multiplication in amoebae, whereas the ability to multiply in macrophages is usually regarded to correspond to pathogenicity. Since most investigations focused on Legionella pneumophila serogroup 1, we examined the intracellular multiplication of different Legionella species in Mono Mac 6 cells, which express phenotypic and functional features of mature monocytes, and in Acanthamoeba castellanii, an environmental host of Legionella spp. According to the bacterial doubling time in Mono Mac 6 cells and in A. castellanii, seven clusters of legionellae could be defined which could be split further with regard to finer differences. L. longbeachae serogroup 1, L. jordanis, and L. anisa were not able to multiply in either A. castellanii or Mono Mac 6 cells and are members of the first cluster. L. dumoffi did not multiply in Mono Mac 6 cells but showed a delayed multiplication in A. castellanii 72 h after infection and is the only member of the second cluster. L. steigerwaltii, L. gormanii, L. pneumophila serogroup 6 ATCC 33215, L. bozemanii, and L. micdadei showed a stable bacterial count in Mono Mac 6 cells after infection but a decreasing count in amoebae. They can be regarded as members of the third cluster. As the only member of the fourth cluster, L. oakridgensis was able to multiply slight in Mono Mac 6 cells but was killed within amoebae. A strain of L. pneumophila serogroup 1 Philadelphia obtained after 30 passages on SMH agar and a strain of L. pneumophila serogroup 1 Philadelphia obtained after intraperitoneal growth in guinea pigs are members of the fifth cluster, which showed multiplication in Mono Mac 6 cells but a decrease of bacterial counts in A. castellanii. The sixth cluster is characterized by intracellular multiplication in both host cell systems and consists of several strains of L. pneumophila serogroup 1 Philadelphia, a strain of L. pneumophila serogroup 2, and a fresh clinical isolate of L. pneumophila serogroup 6. Members of the seventh cluster are a strain of agar-adapted L. pneumophila serogroup 1 Bellingham and a strain of L. pneumophila serogroup 1 Bellingham which was passaged fewer than three times on BCYE alpha agar after inoculation and intraperitoneal growth in guinea pigs. In comparison to members of the sixth cluster, both strains showed a slightly enhanced multiplication in Mono Mac 6 cells but a reduced multiplication in amoebae. From our investigations, we could demonstrate a correlation between prevalence of a given Legionella species and their intracellular multiplication in Mono Mac 6 cells. Multiplication of members of the genus Legionella in A. castellanii seems to be dependent on mechanisms different from those in monocytes.

Acanthamoeba↗
PubMed1996

Eradication of poliomyelitis: when can one be sure that polio virus transmission has been terminated?

Most polio virus infections are silent. Vaccination reduces the incidence of infection, and the period between clinical cases of poliomyelitis becomes longer. As the point of eradication is approached, it becomes increasingly difficult to use the case-free period to determine whether silent infections have ceased. In this paper, the authors use stochastic computer simulations to relate case-free periods to the presence or absence of silent infections. After 2 years without paralytic cases in a population of 200,000 inhabitants, the probability for the presence of silent infections can still be as high as 38%. The case-free period must exceed 3 years before one can be 95% certain that there has been local extinction of the wild polio virus infection. Even after 5 years without cases, the probability of silent polio virus transmission can still be in the range of 0.1-1.0%.

Computer Simulation↗
PubMed1995

Deterministic models for the eradication of poliomyelitis: vaccination with the inactivated (IPV) and attenuated (OPV) polio virus vaccine.

Currently two polio vaccines, IPV and OPV, are in use which differ markedly in their epidemiological parameters. A simple epidemiological model in terms of ordinary differential equations is proposed to study the effects of vaccination campaigns using these vaccines. The numbers of interest are the reproduction number of the disease in the presence of vaccination and the critical vaccination coverage necessary to prevent an outbreak. For these numbers explicit representations are determined which can be used in comparing different vaccination strategies.

Adult↗
PubMed1991

Development of Onchocerca volvulus microfilariae injected into Simulium species from Cameroon.

Microfilariae (mff) of the savanna and forest strains of Onchocerca volvulus (Leuckart) were injected intrathoracically into adult females of Simulium damnosum Theobald sensu stricto, S.sirbanum Vajime & Dunbar, S.squamosum Enderlein and S.mengense Vajime & Dunbar. Nine days post infection (pi) 27-29% of the savanna mff and 31-38% of the forest strain had developed to third-stage larvae (L3), irrespective of the fly species, size or injection dose (5, 10 or 15 mff). Savanna flies supported the development of forest O.volvulus better than forest flies, in contrast to the results after per os infections. Therefore, in these four species of the S.damnosum complex from Cameroon, the peritrophic membrane is considered to be the main factor limiting the success rate of microfilarial development following the ingestion of blood infections, while the fly's haemolymph and intracellular environment play minor roles.

Animals↗
PubMed1990

Differential length of Onchocerca volvulus infective larvae from the Cameroon rain forest and savanna.

Infective larvae from the savanna strain of Onchocerca volvulus are significantly longer (662.6 +/- 66.8 microns; n = 99) than those from the forest strain (624.2 +/- 62.0 microns; n = 236). The length of the infective larvae is not influenced by the size, species or age post infectionem (pi) of the Simulium damnosum s. l. vectors nor by their localization in the fly's head, thorax or abdomen, the worm load per fly or the thoracic volume per larva. However, the lengths of infective larvae within one individual fly have a conspiciously low variance.

Analysis of Variance↗
PubMed1987

Giant sialolithiasis appearing as odontogenic infection.

The dentist frequently is called on to diagnose pathoses of the head and neck region. Two reports of giant submandibular sialoliths that were originally diagnosed as submandibular space odontogenic infections are presented. Careful history, and physical and radiographic examinations are necessary to assure proper diagnosis and treatment of this condition.

Abscess↗
PubMed1985

The significance of Babinski signs in children with head trauma.

A prospective study was undertaken to investigate the significance of Babinski signs in children with head trauma. Thirty-eight children between the ages of 1 and 15 were studied. Twenty-four of the children were admitted to the hospital for observation; 14 were sent home, with 24-hour follow-up in the pediatrics clinic. Of the 24 children admitted, six were believed to have altered CNS status or other focal findings on examination in the emergency department, and 18 were judged by two independent observers to have Babinski signs, either unilateral or bilateral, as their only neurological finding. Twelve hours after admission, all 18 children who had been admitted on the basis of Babinski signs alone had downgoing toes and they continued to have Babinski signs. The isolated presence of Babinski signs in a child with a history of head injury is not indicative of poor neurological outcome. An otherwise asymptomatic child who presents with a history of head injury and a solitary finding of Babinski sign(s) may be observed safely at home rather than being admitted to the hospital for observation.

Adolescent↗
PubMed1980

[Quick residue control of plant and animal food, tobacco and tobacco-products by sweep-co-analysis. 2. Herbicide residues].

The applications of herbicides in agriculture are very intensive. A great number of admitted compounds and their use require a consequent control of residues, especially in vegetables and fruits. Because the analysis are very costly in time and material only multi-residue-methods are practicable. The Sweep-Co-Method can improve the present situation.

Chromatography, Gas↗
PubMed1978

[Quick residue control of plant and animal food, tobacco, and tobacco-products by Sweep-Co analysis. 1 (author's transl)].

Control of Pesticides residues in imports and on market-places are only practicable, if a true statement is possible very quickly. The multi residue methods, which determinate a great number of pesticides in one analysis are well known, but very costly in time and material and cannot be automated completely. The Sweep-Co-Method can improve the present situation.

Food Analysis↗
PubMed1978

Augmentation of in vitro pituitary biotransformation of testosterone due to orchidectomy and its relation to serum gonadotropins in the rat.

The biotransformation of testosterone to its metabolites by the anterior pituitary gland and the relation between the products formed and the circulating levels of LH and FSH were examined in male rats at various stages of sexual maturation. The animals were either intact controls or castrated 4 and 7 days prior to the investigation. Castration greatly increased testosterone biotransformation to its 5alpha-reduced products, but did not affect the formation of androstendione. It was concluded that castration and the eventual rise of LH-RH stimulated the 5alpha-reductase activity but not the 17beta-ol-dehydrogenase system. This is reflected in the significant relationship between the circulating gonadotropins and 5alpha-metabolites of testosterone but not androstendione.

Androstenedione↗
PubMed1977

Age related changes in pituitary responsiveness to luteinizing hormone-releasing hormone in the male rat.

Changes in pituitary and serum concentrations of LH and FSH, determined by radioimmunoassay, were studied after administration of LH-RH to intact male rats of various ages. Although injection of LH-RH resulted in a depletion of pituitary LH and FSH in almost all age groups, thereby increasing the serum levels of these hormones, the magnitude and time course of the effects varied. Serum LH in the prepubertal and pubertal rats was maximal at 10 min after LH-RH injection, whereas the mature animals showed maximal increase only after 30 min. Peak serum concentrations of FSH found at 10 min in the prepubertal animals, but between 30 and 60 min in the pubertal and adult animals. At 35 days of age, significant pituitary depletion of LH and FSH occurred.

Age Factors↗
PubMed1975

Effects of experimental bilateral cryptorchidism and castration on the plasma gonadotropins in male rats during sexual maturation.

The effect of bilateral cryptorchidism and castration on serum LH and FSH was assessed in rats throughout their sexual maturation. After short time (4 days) castration marked elevations of FSH and increases of LH in plasma are recorded in all developmental stages. Bilateral cryptorchidism caused after 4 days in different age groups elevations of LH regardless of the sexual maturation. FSH was elevated in these cryptorchid animals only in more mature animals.

Age Factors↗