An autoradiographic study of the organization of intrahippocampal association pathways in the rat

The longer associational connections of the hippocampal formation have been studied autoradiographically in a series of adult rats after small injections of ³H-amino acids into each of its various cytoarchitectonic fields. The major findings can be summarized as follows. The dentate gyrus projects in a topographically ordered manner upon the pyramidal cells of the regio inferior by way of the supra- and infrapyramidal bundles of mossy fibers. Certain cells in the hilar region of the dentate gyrus (which operationally may be defined as constituting field CA₄ of Ammon's horn) give rise to a hippocampodentate projection to the inner one-quarter of the molecular layer of the dentate gyrus. Either the same or closely related cells give rise to fibers which join the Schaffer collateral system from field CA₃ to the stratum radiatum and stratum oriens of the regio superior. The regio inferior is also characterized by a longitudinally directed associational bundle which runs throughout the septo-temporal extent of the hippocampus and is centered in the region of subfield CA_3a. The regio superior has no reciprocal projection to the regio inferior but sends a substantial projection back to the subiculum and to the entorhinal area. There is also a projection to the subiculum from the regio inferior, and the subiculum itself probably contributes significantly to the projection to the entorhinal and perirhinal cortices. There is a striking parallelism between certain of these associational connections and the commissural projections to the hippocampus and dentate gyrus. Each cytoarchitectonic field that contributes a commissural projection also gives rise to an ipsilateral associational pathway which in its intrahippocampal course and its mode of termination exactly matches that of the commissural projection, although in general, the associational connections are more extensive in their distribution along the septo-temporal extent of the hippocampus than the corresponding commissural connections. The reverse is not true; there are a number of associational projections which are not paralleled by commissural projection. All of the associational projections are topographically arranged, but those which extend across the transverse axis of the hippocampus usually show considerable divergence so that afferents from different levels overlap fairly considerably within their respective projection fields.     

Early ultrastructural changes in RU-486-exposed decidua

An antiprogesterone (RU-486) was administered to women undergoing voluntary interruption of pregnancy. Five patients received 100 mg 12 h before surgical interruption, 5 others received 100 mg twice, 24 and 12 h before interruption, respectively, and another 5 received no drug at all and served as controls. Placentas and deciduae were examined morphologically with the light microscope and by electron microscopy. No specific lesions were detected in placental tissue. With conventional histology, the deciduae showed various degrees of interstitial edema and necrosis, changes which did not enable a distinction between treated cases and controls, although stromal disintegration tended to be more marked in RU-486-treated patients. At the ultrastructural level, the endothelium of decidual capillaries showed striking hyperplasia of the endoplasmic reticulum. Morphometric evaluation showed a statistically significant difference between RU-486-treated patients (2 X 100 mg) and controls. A possible link between these morphological changes and the induction of prostaglandin synthesis by the antiprogesterone is suggested. However, the full significance of the observed lesions remains uncertain and does not allow definite conclusions concerning the abortifacient effect of RU-486.     

Anterior femoroacetabular impingement: part II. Midterm results of surgical treatment

Femoroacetabular impingement has been shown to cause labral and chondral lesions and leads to osteoarthrosis of the hip. With the elimination of the pathogenic cause we hope to prevent or delay additional degeneration of the hip. Fourteen men and five women with a mean age of 36 years (range, 21-52 years) were treated with a surgical dislocation and offset creation of the hip. The followup averaged 4.7 years (range, 4-5.2 years). Using the Merle d'Aubigné hip score, 13 hips were rated excellent to good, with the pain score improving from 2.9 points to 5.1 points at the latest followup. There was no avascular necrosis of the femoral head. Five of the 19 patients, two with Grade 2 osteoarthrosis, two with Grade 1 osteoarthrosis but severe acetabular cartilage damage, and one with untreated ossified labrum had subsequent total hip arthroplasty (THA). In the stable hips without subluxation of the head into the acetabular cartilage defect, no additional joint space narrowing occurred. Surgical dislocation with correction of femoroacetabular impingement yields good results in patients with early degenerative changes not exceeding Grade 1 osteoarthrosis. This procedure is not suitable for patients with advanced degenerative changes and extensive articular cartilage damage.     

Influence of ceftriaxone treatment on FDG uptake--an in vivo [18F]-fluorodeoxyglucose imaging study in soft tissue infections in rats

Our aim was to determine the influence of antibiotic treatment using ceftriaxone on [18F]-fluorodeoxyglucose (FDG) uptake in experimental soft tissue infections. PET scans were performed in two groups (treated n=4; non-treated n=4) at days 3, 5, and 6 after inoculation of the infection. Additional autoradiography was performed in four animals at day 7 and in three animals at day 11. The difference of FDG uptake on day 5 (after three days of antibiotic treatment) between both groups proved to be significant (df=6; T=2.52; p=0.045). FDG uptake determined at the other days did not reveal significant difference between the two groups. It seems to be possible that the effect of antibiotic treatment on FDG uptake is less evident than reported for therapy monitoring of cancer treatment. The change of FDG uptake over time in treated and untreated infections is complex and further in vivo experiments have to be initiated to investigate the potential value of clinical FDG PET in therapy monitoring of infection.     

Carotene oxygenases: a new family of double bond cleavage enzymes

Beta,beta-carotene 15,15'-monooxygensae (betaCMOOX) is the key enzyme involved in the metabolism of provitamin A carotenoids to retinal. Although the enzyme has been known for >40 y, it has been only within the last 2 y that the cloning and the molecular characterization of the betaCMOOX from several species was reported in literature. New clones of the carotene metabolizing enzyme have emerged, all belonging to the family of double bond cleavage enzymes, suggesting common ancestry. BetaCMOOX cleaves beta,beta-carotene to retinal in an in vitro activity assay; no apo-carotenals were identified. The second enzyme involved in carotenoid metabolism, beta,beta-carotene 9',10'-dioxygenase, is responsible for the excentric cleavage pathway of carotenoids, cleaving beta,beta-carotene to 10'-apo-carotenal and beta-ionone. In an expression overview, the betaCMOOX was detected in duodenum, liver, kidney and in the lungs of chickens. In mice, the mRNA for the central cleavage enzyme was highly expressed in liver, testes, small intestine, and kidney. betaCMOOX expression was highest in epithelial and endothelial structures in both species. These results suggest that the source of vitamin A originates from carotenoids in the corresponding tissues, in addition to retinol supplied from liver stores.     

Costs attributable to AIDS at household level in Chad

This paper assesses the economic costs of AIDS at the household level in Chad, one of the poorest countries in the world. One hundred and ninety-three AIDS patients living in four different regions were found by case identification at hospital level and through community based organizations providing psycho-social relief. They were matched by age, sex, professional category and zone of residence with controls. Costs were evaluated through a standard questionnaire. Costs at household level attributable to AIDS up to death were US$836 per case. Costs related to productivity losses made up 28% of total costs. More than half of total costs (56%) were health care related expenditures and funeral costs contributed 16%. AIDS cases relied more often on borrowing and the selling of household assets than controls for treatment. Household expenditures of AIDS cases were much higher than control households mainly due to health related expenditure. The response of concerned families to HIV/AIDS implies high costs and for most households, especially in low-income settings, the consequences of AIDS are devastating. Innovative strategies on how best to assist households are thus requested and may include the strengthening of care and treatment services being offered to AIDS cases.     

Quality of life after mitral valve surgery: differences between reconstruction and replacement

BACKGROUND AND AIMS OF THE STUDY: Quality of life (QoL) is of increasing interest in major surgical procedures. Mitral valve reconstruction (MRr) is assumed to be better tolerated than mitral valve replacement (MVR). The study aim was to assess mid-term QoL in patients undergoing isolated mitral valve surgery. METHODS: QoL was monitored in 115 consecutive patients who had isolated mitral valve surgery (62 with MVR, 53 with MRr). Mid-term survival was assessed after a mean of 37 +/- 18 months using the SF-36 health survey questionnaire. RESULTS: Patients undergoing MVR were younger (61.9 +/- 12.7 versus 64.9 +/- 12.5 years; p <0.01) and had significantly more frequently a history of left heart failure (43.5% versus 13.2%; p <0.01) than patients with MRr. No significant difference was found between the two groups when considering preoperative NYHA functional class and left ventricular function. In-hospital mortality was significant higher in MVR than in MRr patients (6.4% versus 0%; p <0.01). QoL was significantly impaired in patients with MVR in physical function (PF), role function (RF) and general health (GH) compared with patients undergoing MRr. Nevertheless, only slight impairments in two of eight aspects in MVR, and in one of eight aspects in MRr, were found compared with an age- and sex-matched standard population. Mid-term survival was similar in both groups. CONCLUSION: Outcome after MVR was excellent, though these patients had a more advanced stage of the disease preoperatively than MRr patients. Mid-term outcome and QoL was, however, similar in the two groups.     

Virus inactivation and protein modifications by ethyleneimines

Virus inactivation by ethyleneimines was first introduced more than 30 years ago. Selective targeting of nucleic acids was reported for oligomeric ethyleneimines. In this study, trimeric ethyleneimine (TEI) was used to inactivate minute virus of mice (MVM; Parvoviridae) and Semliki forest virus (SFV; Togaviridae). The pH-dependency of the inactivation kinetics observed with MVM was different compared to the kinetics reported for other viruses. The higher inactivation rate at higher pH favoured the idea of a mechanism involving protein modifications. Alteration of the isoelectric point and changes in mass could be observed after treatment of soluble proteins with TEI. The uptake of MVM by host cells was reduced or completely blocked by TEI treatment, as shown by monitoring viral internalisation of DNA into target cells. The observed loss of virus infectivity coincided with the inhibition of virus uptake. Thus, virus inactivation by TEI is most likely also a result of chemical modifications of viral surface proteins.