Search PubMed⌕ Search

Biomedical subjects

H C Jackson

Publications and source records attributed to H C Jackson.

72 records · Page 4Linked to original sources

Rabies in the Federal Republic of Germany, 1950-81: the influence of landscape.

Rabies statistics for 1950-81 were studied to investigate regional differences in the occurrence of rabies in the Federal Republic of Germany. At the level of Landkreis (administrative unit with a mean area of 1013 km(2)), four basic patterns of rabies incidence were identified: insignificant occurrence, low undulations, intermittent peaks, and high oscillations. The distribution of these four epidemiological patterns of rabies was geographically localized. Insignificant occurrence of rabies was found almost exclusively on land under 100 m above sea level with less than 10% forest cover. High oscillations in rabies occurrence were found most often in areas over 200 m above sea level with an average of at least 35% forest cover.

Altitude↗

Rabies in the Federal Republic of Germany.

During the present epizootic (sylvatic rabies), rabies has been present in the Federal Republic since 1950. In general rabies incidence is lower in the low lying land of the north and west. In the central Federal Republic, rabies incidence is higher east of the Rhine than to the west. In addition, the pattern of incidence appears to differ on either side of the river.

Animals↗

Population dynamics of fox rabies in Europe.

A simple mathematical model for the overall dynamics of the interaction between fox populations and rabies is presented. The model helps to explain epidemiological patterns observed in Europe, including the 3 to 5 year cycle in fox populations infected with rabies, threshold densities and average levels of prevalence of infection. We give a quantitative discussion of the possibilities of controlling rabies by culling or vaccinating foxes (or by a mixture of the two).

Animals↗

Bombesin-induced behavior in infant rats.

The behavioral effects of bombesin in 5-, 10- and 20-day-old rat pups have been investigated and the peptide was found to induce scratching (1, 10 mg/kg IP) and grooming (10 mg/kg IP) as early as 5 days after birth. Bombesin did not produce any other overt activities in the developing pups in doses of up to 10 mg/kg, however, lower doses of the peptide (0.1, 1 mg/kg IP) reduced intake of a wet mash diet in deprived 15-day-old rat pups resulting in significant decreases in body weight compared with control animals. These behavioral responses agree with the well-documented effects of bombesin in adult rats and are also in accordance with results from biochemical studies which have shown the existence of receptors for bombesin-like peptides in the rat central nervous system from an early age.

Aging↗

Behavioral profile of the TRH analogue RX77368 in developing rats.

The behavioral effects of the TRH analogue RX77368, dimethyl proline-TRH (3, 10 and 30 mg/kg IP), in 5-, 10- and 20-day-old rat pups were investigated. The peptide induced shaking behavior and increased locomotion as early as 5 days after birth. At 20 days RX77368 also produced rearing, stereotyped mounting and grooming (mainly licking and chewing of the forepaws). Additionally, RX77368 produced hypothermia and antinociception in the infant rats. These responses, which were generally, although not always, comparable with those found in adults, agree with biochemical studies showing high levels of TRH receptors in the brain and spinal cord in the first three weeks following birth.

Age Factors↗

Detection and quantification of Pneumocystis carinii using a sandwich ELISA.

Antigenic sites on Pneumocystis carinii, the basis for organism enumeration by an enzyme-linked immunosorbent assay (ELISA) were adversely affected by incubation in detergents. However, stronger detergent concentrations were needed to eliminate high levels of non-specific background. Good P. carinii quantification was obtained with low non-specific background when the detergent was used only in the washing steps and not in cell suspension solutions. Formalin fixation of the cells resulted in good ELISA quantification of organism numbers with low non-specific background. No adverse effects were observed using a detergent on fixed cells. Although the system's range of accuracy needs to be expanded, a reduction in the number of organisms in response to the effects of pentamidine in vitro could be demonstrated by ELISA.

Animals↗

Exploitation of a 650 bp probe for quantification of Pneumocystis carinii.

Signals obtained from serial dilutions of rat-derived Pneumocystis carinii DNA were used to assess the sensitivity of a 650-bp DNA probe which recognises both cystic and non-cystic forms. Enhanced chemiluminescence was selected as a non-radioactive detection method and signals could be semi-quantitated by scanning densitometry. This technique was used to examine the inhibitory effect of pentamidine in vitro indicating that DNA probes might be useful tools in the search for a novel therapeutic agent.

Animals↗

Analysis of the dynamics of Pneumocystis carinii in vitro.

Three culture systems employing mammalian lung cell monolayers were evaluated in terms of their ability to support the replication of primary isolates of rat-derived Pneumocystis carinii. For each system, analysis of variance was used to identify changes in the numbers of P. carinii over time. Significant replication was consistently demonstrated over lung fibroblasts (MRC-5), however, increases perceived in the culture supernatant were clearly influenced by the density of the underlying monolayer.

Animals↗