Immunohistochemical localization of receptors for progesterone and oestradiol-17 beta in the implantation site of the rhesus monkey

The aim of the present study was to examine the cellular basis of the involvement of oestradiol and progesterone in blastocyst implantation in the primate. To this end, the cellular distribution of receptors for oestradiol (ER) and progesterone (PR) in fetal trophoblast cells and in endometrial compartments of timed lacunar (pre-villous) and villous stages of placentation in primary implantation sites collected on days 13-22 of gestation were investigated in rhesus monkeys. Both in pre-villous stage tissue and in villous stage tissue, cytotrophoblast cells and syncytiotrophoblast cells and other trophoblast derived cells were PR positive, while they were generally ER negative. Maternal endometrial cells were ER negative, while epithelial cells, stromal cells and vascular endothelial cells in maternal endometrium showed heterogeneous staining patterns for PR depending on their relative location; these patterns, however, correlated well with glandular hyperplasia and differentiation, stromal-decidual transformation and vascular response seen during blastocyst implantation.     

Analysis of two types of cone bipolar cells in the retina of a New World monkey, the marmoset, Callithrix jacchus.

Two types of cone bipolar cells, the blue cone bipolar cell and the diffuse bipolar cell (DB3), were labelled immunohistochemically and investigated in the retina of a New World monkey, the marmoset. Blue cone bipolar cells were labelled with an antiserum against cholecystokinin. Short-wavelength-sensitive (SWS) cones were labelled with an antiserum against the SWS cone opsin. The DB3 cells were labelled with antibodies to calbindin. Blue cone bipolar cells in marmoset do not form a regular mosaic but instead follow the random distribution of the SWS cones. Nevertheless, the SWS cone to blue cone bipolar cell connectivity in marmoset is very similar to that previously described for macaque. In contrast to the blue cone bipolar cells, the DB3 cells form a regular mosaic. The synaptic connectivity of DB3 cells in the inner plexiform layer was analyzed. They make output synapses onto ganglion cells and amacrine cells, and gap junctions with each other. Our results provide further evidence for the existence of parallel bipolar cell pathways in the primate retina and support the view that the retinae of Old World and New World primates have common neuronal connectivity. The random distribution of SWS cones and blue cone bipolar cells is an exception to the general rule of a regular mosaic distribution of cell populations in the retina.     

Midget and parasol ganglion cells of the primate retina express the alpha1 subunit of the glycine receptor

Glycine is a major inhibitory neurotransmitter in the mammalian retina and has been shown to influence the responses of ganglion cells. Midget and parasol ganglion cells serve distinct physiological roles in the primate retina and show differences in their response characteristics to light stimuli. In the present study, we addressed the question of whether the expression of glycine receptors differs in midget and parasol ganglion cells. Ganglion cells in the retinae of marmoset and macaque monkeys were injected with Neurobiotin in a live in vitro retinal whole-mount preparation. Retinal pieces were then processed with an antibody against the alpha1 subunit of the glycine receptor. Strong punctate immunoreactivity indicative of synaptic localization is present in the ON and OFF sublamina of the inner plexiform layer. Many of the immunoreactive puncta coincide with the dendrites of both midget and parasol ganglion cells. Immunoreactive puncta are present on distal and proximal dendrites of ON and OFF cells. These results suggest that ON and OFF midget and parasol cells do not differ with respect to the distribution of the alpha1 subunit of the glycine receptor.     

Immunohistological localisation of vascular endothelial growth factor in human endometrium.

Several polypeptide growth factors regulate epithelial and stromal development in endometrium under the influence of estrogen and progesterone, and thereby regulate growth and differentiation of endometrium during menstrual cycle. However, little is known about the angiogenic growth factors that may affect endometrial vasculature throughout each menstrual cycle. Vascular endothelial growth factor (VEGF) is suggestively an important angiogenic growth factor in the female reproductive tract. The aim of the present study was to immunolocalize and assess semi-quantitatively VEGF immunostaining in cells of proliferative phase (n = 3), secretory phase (n = 6) and hyperplastic (n = 6) human endometrial samples. VEGF concentrations were significantly higher in glandular (P < 0.001) and stromal (P < 0.01) compartments of proliferative stage endometrium compared with those in secretory stage and hyperplastic endometrial samples, with no difference in the scores for glandular and stromal compartments between secretory stage and hyperplastic endometrial samples. Generally, glandular expression of VEGF was higher as compared to stromal compartment. Thus, it appears that endometrial VEGF expression and concentration are enhanced by estrogen, and may be correlated with neovascularization and increased vascular permeability during late proliferative period. Additionally, there was no enhancement in VEGF expression in hyperplastic glands, suggesting that regulation of glandular growth and that of angiogenesis in human endometrium operate through different mechanisms.     

Design and models for estimating antagonist potency (pA2, Kd and IC50) following the detection of antagonism observed in the presence of intrinsic activity

The antagonist activity of the metabotropic glutamate receptor ligand (2S,1'S,2'S)-2-methyl-2(carboxycyclopropyl)glycine (MCCG) was examined using the [35S]GTPgammaS binding and forskolin (FSK)-stimulated adenosine 3':5'-cyclic monophosphate (cAMP) assays with recombinant Chinese hamster ovary (CHO) cells expressing the G protein-coupled human subtype 2 metabotropic glutamate (hmGlu2) receptor. Whereas MCCG proved to be a partial agonist in the GTPgammaS binding assay, it not only antagonized the agonist effect of (IS,3R)-ACPD in the cAMP assay but further produced an anomalous increase of the cAMP level relative to baseline. The anomalous MCCG response was also observed following treatment of the cells with MCCG in the absence of added agonist. Determination of the glutamate concentration in the incubate at the start and end of the cAMP reaction revealed the existence of micromolar concentrations of cellularly released glutamate throughout the course of the assay, reaching levels which exceeded its reported affinity for the mGlu2 receptor. Considering MCCG's partial agonist effect in the GTPgammaS binding assay and its pseudo-inverse agonist effect in the cAMP assay, available methods of estimating its antagonist potency were inappropriate since the classical Schild method and the alternative model suggested by Waud both assume the antagonist to lack a concentration-response relationship. We derived an alternate design and models that permit estimation of the pA2 (pAx), Kd and IC50 for antagonists which produce a concentration related effect when applied by themselves. With their use, the data acquired in both assays support the designation of MCCG as a competitive antagonist of the hmGlu2 receptor and provide similar pA2 estimates between assays. In addition, the newly derived models and design permit the determination of antagonist potency for partial and inverse agonists so characterized in studies employing the Schild design.     

Antemortem diagnosis of Leigh’s disease: Role of magnetic resonance studies

A two-and-a-half-year-old male child presented with recurrent attacks of intractable vomiting, psychomotor retardation since 14 months of age. He had also lower cranial nerve palsy and corticospinal involvement. Magnetic resonance imaging had shown multiple well circumscribed areas of hypointusity in T, weighted image which were brightly hyperintense in heavily T₂-weighted image. The lesions were seen in basal ganglia, thalamii and brainstenvand spared mamillary bodies. Magnetic resonance spectroscopy demonstrated lactate peak in the affected areas confirming the diagnosis of Leigh’s disease. The child responded well to large dose of vitamin ‘B’, therapy.     

Transverse trachero-oesophagoplasty a new one-stage operation for construction of a 'Neo-Larynx'

A new one-stage operation of constructing a 'Neo-Larynx' after total laryngectomy, transverse tracheo-oesophagoplasty, for a good alaryngeal ('Tracheo-Oesophageal') speech is described. A 'Neo-Epiglottis' is constructed from the posterior tracheal wall and a 'Pseudo-Glottis' in the tracheo-oesophagenal partition wall with a valvular mechanism for preventing aspiration into the trachea during deglutition. No extraneous tissue is used for the construction of the 'Neo-Larynx' and no practice is necessary on the part of the patient for developing alaryngeal 'Tracheo-Oesophageal' speech. The patient can phonate immediately after removal of the feeding tube and the silastic sheet and is ready for discharge five weeks after operation. Adequate surgical ablation is ensured and at the same time good functional rehabilitation is offered without jeopardizing the principles of cancer surgery, i.e. to be on the overdoing side rather than on the underdoing one in a futile attempt at retaining the function.     

Studies on the mechanism of synthesis and release of the procoagulant activity from leukaemic cells

The synthesis and release of procoagulant activity (PCA) from leukaemic leucocytes was studied in anin vitro culture system stimulated by endotoxin. Puromycin, actinomycin-D, vinblastine, colchicine, dibutyryl cyclic AMP and ouabaln were added to the culture system to study some of the metabolic processes of these cells in relation to synthesis and release of PCA. It was found that production of PCA is an active process and depends on new protein synthesis. The release of PCA from cells can be inhibited by vinblastine, an inhibitor of microfilament and microtubules in the cell. The optimal release of PCA occurs at pH 7.2-@#@ 7.4 at 37°C and is not inhibited by the ATPase inhibitor ouabaln. Dibutyryl cyclic AMP inhibits the release/synthesis of PCA. Gram negative septicaemia and endotoxinaemia are capable of increased production and release of PCA from leukaemic cells and could contribute to the coagulation fallure seen in this disease.     

Enhanced Delivery of 5-Iodo-2′-Deoxyuridine to the Brain Parenchyma

5-Ester derivatives of 5-iodo-2-deoxyuridine (IDU) with varying degrees of lipophilicity were examined to evaluate the effectiveness of lipophilic ester prodrugs for enhanced and sustained delivery of IDU to the brain parenchyma. Approximately 1.0% (1.0 ± 0.19; n = 4) of the total radioactivity was found in the brain at 30 min following intravenous administration of the lipophilic benzoyl-5-ester of ¹²⁵I-labeled IDU, whereas IDU per se yielded only 0.01% (0.01 ± 0.06; n = 4). Since the IDU 5-esters generated significantly higher levels of IDU in the brain, an HPLC analysis of IDU in the presence of 5-esters and the metabolite 5-iodouracil was developed to characterize IDU uptake in the brain. The drug was detected at levels of 6.6 and 9.5 µg/g of brain tissue at 3 hr following intravenous administration of valeryl and benzoyl IDU, respectively, at a dose level of 40 mg/kg IDU equivalent each. IDU, on the other hand, when injected at a similar dose level, produced concentration levels below 0.01 µg/g of brain tissue, which was too low to be detected accurately by the HPLC assay. These results suggest that the 5-ester derivatives cross the blood-brain barrier effectively and generate significantly higher brain levels of the parent drug in the brain parenchyma. The regenerated hydrophilic drug because of its polarity is locked in the brain and is subsequently metabolized by pyrimidine phosphorylase to 5-iodouracil. A higher concentration of IDU was generated following administration of the benzoyl ester probably because the ester itself is slowly hydrolyzed by the brain cholinesterases, thereby competitively inhibiting the metabolism of IDU to 5-iodouracil by brain pyrimidine phosphorylase. 5-Benzoyl IDU appears to be a promising bioreversible analogue which can provide enhanced and sustained delivery of IDU to the brain parenchyma.