Expression of the endothelial markers PECAM-1, vWf,and CD34 in vivo and in vitro

EC culture models are essential to study pathological alterations of endothelial cells (ECs) in pulmonary vascular diseases under standardized conditions. Nevertheless, little is known about the spectrum of alterations of vessel-specific endothelial phenotypes in monolayer cultures. For the comparative study of endothelial markers in vivo and in vitro we investigated immunohistochemically the expression of PECAM-1, vWf, and CD34 by pulmonary ECs in vivo and in stimulated/unstimulated human umbilical vein endothelial cells (HU-VEC) and human pulmonary microvascular endothelial cells (HPMEC). In vivo, vessel type-specific expression patterns were found for vWf and CD34, while PECAM-1 was homogeneously and strongly expressed. While all HUVEC showed a marked vWf staining, about two-thirds of HPMEC exhibited a strong and the rest a moderate vWf staining. In both in vitro models all ECs were clearly PECAM-1-positive. However, only about 20% of the HUVEC and HPMEC were CD34-positive. Our results demonstrate the reduced expression of vessel type-specific endothelial phenotypes by endothelial monolayer cultures, stressing the need to improve culture conditions as well as develop cocultures and three-dimensional culture models. Moreover, the need for endothelial markers specific for single microvascular type ECs becomes obvious in order to establish cultures consisting of only one microvascular ECs subpopulation.     

Egg-sharing in assisted conception: ethical and practical considerations

The present acute shortage of eggs for donation cannot be overcomeunless adequate guidelines are set to alleviate the anxietiesregarding payments, in cash or kind, to donors. The currentHuman Fertilisation and Embryology Authority (HFEA) guidelinesdo not allow direct payment to donors but accept the provisionof lower cost or free in-vitro fertilization (IVF) treatmentto women in recognition of oocyte donation to anonymous recipients.Egg-sharing achieved in this way enables two infertile couplesto benefit from a single surgical procedure. However, the practicalguidelines related to this approach are ill-defined at the presenttime leading to some justifiable uncertainty. A pilot studywas therefore undertaken in order to establish the place ofegg-sharing in an assisted conception programme. The currentHFEA guidelines on medical screening of patients, counselling,age and rigid anonymity between the donor and recipient werefollowed. The study involved 55 women (25 donors and 30 recipients)in 73 treatment cycles involving fresh and frozen-thawed embryos.Donors were previous IVF patients who, regardless of their abilityto pay, shared their eggs equally with matched anonymous recipients.They paid only for their consultations and tests right up tothe point of being matched with a recipient The sole recipientpaid the cost applicable in egg donation of a single egg collection,although both received embryo transfers. The results indicatethat although the recipients were older than the donors (41.4± 0.9 versus 31.6 ± 0.5 years), and there wasno difference in the mean number of eggs allocated, the percentagefertilization rates, or the mean number of embryos transferred,there were more births per patient amongst recipients than amongstdonors (30 versus 20%). We conclude that providing the donorsare selected carefully, this scheme whereby a sub-fertile donorhelps a sub-fertile recipient is a very constructive way ofsolving the problem of the shortage of eggs for donation. Thereare also the advantages of including a group of women who wouldotherwise be denied treatment Problems related to ‘patientcoercion’ can, in our view, be fully overcome by the applicationof strict common-sense safeguards. The ideal of pure altruismis not without its medical and moral risk. The success of egg-sharingdepends on shared interests and a degree of altruism betweenthe donor, the recipient and the centre. The current HFEA guidelinesshould be applauded for enabling a highly effective conceptof mutual help to develop.     

Immunohistological detection of Legionella pneumophila in lung sections.

Immunohistology was used for the detection of Legionella pneumophila serogroup I in necropsy tissue. Study of pneumonic lung from the recent Stafford outbreak has shown that this technique has a high sensitivity. A retrospective postmortem examination showed that L pneumophila serogroup 1 was an unusual cause of pneumonia in Oxfordshire during the study period. L pneumophila serogroup 1 can be successfully subgrouped, using a panel of monoclonal antibodies on formalin fixed paraffin embedded sections. Immunohistological methods have a potentially useful role in the diagnosis of Legionellosis at postmortem examination and in the epidemiological investigation of individual cases and outbreaks.     

Cellular immunity in Peyer''s patches of rats infected with Trichinella spiralis.

A rat model of Trichinella spiralis gut infection was used to observe the sequence of developing cellular immunity in Peyer's patches and other lymphoid tissues. Whereas cellular reactivity (lymphocyte blastogenesis) for worm antigens was evident in mesenteric lymph nodes draining the gastrointestinal tract within 3 days after infection, Peyer's patch lymphocytes developed maximal reactivity 2 to 3 weeks later at the same time as the spleen and other lymphoid tissues. Furthermore, the immune reactivity found in Peyer's patches was only transient. Thus, in this parasitic gut infection, the Peyer's patch lymphoid tissue does not appear to be the first site of cellular responsiveness but rather to acquire cellular reactivity only when other lymphoid elements in the infected host have also acquired similar antigen-induced reactivity.     

Renin and angiotensin-like levels in foetal, new-born and adult sheep

1. Plasma renin (measured as rate of formation of angiotensin I ng/ml.hr(-1) in the presence of added substrate at pH 7.5 and 37 degrees C) was much lower in recently nephrectomized foetal, new-born and older lambs than in intact siblings or other similar lambs.2. Angiotensin II-like concentrations were measured using a superfusion technique in an extracorporeal circuit. Resting concentrations in acute experiments under anaesthesia were deduced by comparison of carotid blood of intact lambs with that from recently nephrectomized lambs.3. Angiotensin II-like activity (mean +/- S.E. of mean, 315 +/- 117 pg/ml.) was readily detectable in foetal blood at 123-138 days gestation. The highest concentrations (mean +/- S.E. of mean 839 +/- 96 pg/ml.) were found in lambs less than 8 hr old, delivered vaginally. The lowest concentrations of angiotensin II-like activity occurred in lambs delivered by Caesarean section (mean +/- S.E. of mean < 123 +/- 12 pg/ml.). Concentrations declined with post-natal age.4. Hypovolaemia as a result of haemorrhage evoked an increase in angiotensin II-like concentrations in foetus, new-born lambs and adult sheep. The greatest increase of angiotensin-like concentrations was seen in new-born lambs. This rise was associated with increase of plasma renin.5. The rise of arterial pressure during bilateral carotid occlusion in new-born lambs was accompanied by an increase of angiotensin II-like concentration.6. It is concluded that the renin-angiotensin system is functional and can be stimulated during intra-uterine life. The increase of angiotensin II-like concentration following parturition is probably transient and associated with the trauma of delivery. This contrasts with observations made in the rabbit which suggest that full functional maturity of the renin angiotensin system is delayed until the second week of life.     

Olfactory bulb removal affects partner preference development and estrus induction in female prairie voles.

In female prairie voles (Microtus ochrogaster) bilateral olfactory bulbectomy reduced affiliative behavior, as measured by social contact, and prevented the formation of partner preferences. Unilateral olfactory bulb removal did not significantly influence affiliative behavior, but did inhibit partner preferences. Bilateral, but not unilateral, bulbectomy significantly reduced the proportion of females exhibiting behavioral estrus following male exposure. In contrast to affiliative and sexual behavior, parental behavior was not significantly affected by either bilateral or unilateral olfactory bulbectomy. These results suggest that divergent sensory-neural pathways underlie social, sexual, and parental behaviors in this species.     

Morphology of cardiac muscle in septic shock. Observations with a porcine septic shock model

The morphology of cardiac muscle was investigated in a porcine model of septic shock, created by intermitted application of Escherichia coli-endotoxin. The earliest lesions, found after 18 h of septic shock, were endothelial cell swelling, marked leucostasis and slight ischaemic alterations of the muscle fibres. At the end point of the experiments, after 48 h, some fibrin thrombi were found associated with more pronounced ischaemic alterations of cardiac muscle cells and some necrotic fibres. Comparing these findings with the severe endothelial and muscle fibre lesions found in skeletal muscle, the endothelial cells of the heart microvasculature, are clearly more resistant to the attack of the endotoxins and mediators liberated in septic shock.     

A photoetched cell relocation matrix for long-term, quantitative observations of selected individual neurons in culture

A photoetched matrix of indium tin oxide (ITO) on glass has been developed and tested as a tool to assist in the relocation and identification of individual neuronal cells in culture. The matrix is formed by 10-15 micron wide and 300 A thick ITO lines which subdivide a 1-cm2 area into 625 smaller squares. Each of the smaller squares measures 400 micron on a side and contains a photoetched two-letter "address". The address code allows precise relocation of specific regions of a culture as well as verification of the identities of individual neurons selected for repeated observation. Marks at 50 micron intervals along the sides of the address squares permit quantitative analysis of morphological changes, cell migration, reaggregation, etc. The ITO is transparent and does not interfere with visualization of even fine details of cells with high power microscopy.