Biomedical subjects

T Barth

Publications and source records attributed to T Barth.

At least 37 records · Page 2Linked to original sources

PubMed1997

Utility of biological markers during outpatient treatment of alcohol-dependent subjects: carbohydrate-deficient transferrin responds to moderate changes in alcohol consumption.

A group of 25 alcohol-dependent subjects in outpatient treatment were monitored for a period of 4 weeks. They were weekly interviewed for their alcohol consumption and their serum levels of carbohydrate-deficient transferrin (CDT) and gamma-glutamyltransferase (GT) were analyzed. The majority of the patients reported an excessive and fairly constant alcohol intake during the observation period. When selecting those patients that reported periods of 1 or 2 weeks with moderate changes in alcohol consumption, corresponding changes in CDT were demonstrated. Thus, of 14 patients reporting an increased alcohol consumption for 2 weeks (mean values increased from 57 to 101 g/day), 11 showed an increase in CDT at the end of the period. The mean CDT value of all 14 increased from 5.5 to 6.7% (p < 0.05). Slight, but not significant, increases were noted in GT, indicating that CDT is more sensitive than GT in detecting increased alcohol consumption. Furthermore, of 17 patients that reported decreased alcohol consumption for one or several weeks, 14 showed decreased CDT and GT values. The mean values of all 17 were reduced from 5.1% to 4.5% (CDT) and from 126 units/liter to 97 units/liter (GT) (p < 0.05 for both parameters). The results indicate that CDT responds to moderate changes in alcohol consumption in alcohol-dependent patients and may thus be useful as a corrective tool to self-reports of alcohol consumption during outpatient treatments.

Adult↗

PubMed1996

Detection of disturbed autoregulation of the peripapillary choroid in primary open angle glaucoma.

BACKGROUND AND OBJECTIVE: This study is concerned with perfusion-pressure videoangiographic investigations, performed by combining oculo-oscillo-dynamography and videoangiography. Perfusion-pressure videoangiography permits an evaluation of local vascular resistance in the choroid relative to ciliary perfusion pressure. PATIENTS AND METHODS: Twelve healthy subjects, 21 patients with primary open angle glaucoma (POAG), and 27 patients with ocular hypertension were examined. RESULTS: Perfusion-pressure videoangiograms revealed that the peripapillary choroid (nasal main ciliary artery) filled at distinctly lower perfusion pressures than the paramacular region (temporal main ciliary artery) in all 12 healthy subjects, with a perfusion pressure difference of 12.5 +/- 4.9 mm Hg. In the 21 patients with POAG, the perfusion pressure difference between the beginning of peripapillary and paramacular perfusion was as small as 3.7 +/- 4.5 mm Hg. In the 27 patients with ocular hypertension, the perfusion pressure difference between the two circulatory regions was almost as high as in the healthy subjects. CONCLUSIONS: These examinations showed that (1) there exists efficient autoregulation in the peripapillary choroids of healthy subjects, (2) autoregulation is diminished or even absent in POAG, and (3) autoregulation is normal, increased, or slightly reduced in ocular hypertension.

Adolescent↗

PubMed1995

Effects of the non-peptide inhibitor OPC-21268 on oxytocin and vasopressin stimulation of rat and human myometrium.

OPC-21268 (1-[-1-[4-(3-acetylaminopropoxy)benzoyl]-piperidyl]-3,4- dihydro-2(1H)-quinolinone), a non-peptide vasopressin V1 receptor antagonist, inhibited oxytocin- and vasopressin-induced contractions of myometrial strips from rats and from full-term pregnant women. Administered intravenously in rats the drug also inhibited uterine contractions caused by infusion of oxytocin. When incubated with purified plasma membranes from rat or human myometrial tissue, OPC-21268 inhibited the specific receptor binding of tritiated oxytocin and vasopressin in a dose-dependent and reversible way.

Anesthesia↗

PubMed1995

Differential expression of beta 1, beta 3 and beta 4 integrins in sarcomas of the small, round, blue cell category.

Integrins are a large and complex family of membrane spanning alpha beta heterodimeric cell surface glycoproteins mediating cell/cell and cell/matrix interactions. Small, round, blue cell sarcomas (SRBCS) are a group of poorly differentiated tumours of various and in part uncertain histogenesis displaying similar cytomorphology. Among them are rhabdomyosarcomas (RMS), ganglioneuroblastomas [(G)NB], primitive peripheral neuroectodermal tumours (pPNET) and Ewing's sarcomas (ES). Thirty-two SRBCS were studied immunohistochemically for the distribution of beta 1, beta 3 and beta 4 integrins in situ. We found complex and to some extent differential patterns of beta 1, beta 3 and beta 4 integrin subunit expression in different types of SRBCS: all of the sarcomas studied were consistently beta 1+, beta 4-, alpha 2-. Four of nine RMS were completely negative for all other integrin subunits studied while one RMS was alpha 5+ throughout and three RMS were focally alpha 5+. Three RMS expressed the alpha 6 and alpha v chains. In contrast to RMS, pPNET and ES, all of which were alpha 1-, alpha 3-, (G)NB were alpha 3+ and frequently co-expressed alpha 1. The eight pPNET and seven ES studied showed a similarly restricted integrin profile that was limited to the expression of beta 1 and alpha 5 in nearly all cases. In summary, RMS were beta 1+, alpha 1-, alpha 3- and heterogeneously expressed alpha 5 and alpha 6. (G)NB were generally beta 1+, alpha 1+, alpha 3+, alpha 5-, alpha 6-. pPNET and ES were beta 1+, alpha 1-, alpha 3-, alpha 5+, alpha 6-. The data illustrate a complex expression pattern of various integrins in SRBCS, a differential expression pattern of some of the integrin subunits among different types of SRBCS and almost identical integrin profiles in pPNET and ES.

Ganglioneuroblastoma↗

PubMed1995

[Normal synoviocytes and synoviocytes from osteoarthritis and rheumatoid arthritis bind extracellular matrix proteins differently].

Extracellular matrix proteins are increased in inflammatory synovitis. We showed previously that the in situ expression of the corresponding extracellular matrix receptors (beta 1-integrins) is enhanced in synoviocytes (SC) of synovitis of different etiology (16). To investigate the adhesion of SC to extracellular matrix proteins, we examined the attachment of SC from normal and inflamed synovia to fibronectin, tenascin, laminin and collagen type IV. Compared to normal SC and SC of osteoarthritis, SC of rheumatoid arthritis showed an increased binding to tenascin, laminin, fibronectin and collagen type IV, suggesting a distinctive interaction of SC and extracellular matrix proteins in rheumatoid arthritis. Furthermore, the increased binding of SC of rheumatoid arthritis to extracellular matrix proteins may play a role in tissue remodelling associated with rheumatoid arthritis.

Arthritis, Rheumatoid↗

PubMed1994

Application of capillary and free-flow zone electrophoresis and isotachophoresis to the analysis and preparation of the synthetic tetrapeptide fragment of growth hormone-releasing peptide.

The use of high-performance electromigration separation methods, capillary zone electrophoresis (CZE) and capillary isotachophoresis (CITP) and continuous free-flow arrangements of these two separation principles, free-flow zone electrophoresis (FFZE) and free-flow isotachophoresis (FFITP), was investigated in the analysis and purification of the synthetic C-terminal tetrapeptide fragment (H2N-Ala-Trp-D-Phe-Lys.NH2) of the growth hormone-releasing peptide. CZE and CITP were used for microanalysis of peptide preparations after different steps of their purification. The homogeneity of the peptide preparations, including fractions of preparative separations, was quantified by relative zone length (CITP) and/or relative peak height (CZE). In addition, the data obtained by CZE and CITP (electrophoretic and electroosmotic flow migration velocities) were utilized for conversion of micro-scale capillary separations (nano- to picomole level) into the preparative separations realized by FFZE and FFITP with a capacity from tens to hundreds of milligrams per hour.

Amino Acid Sequence↗

PubMed1994

Effects of cholecystokinin tetrapeptide and sulfated cholecystokinin octapeptide in rat models of anxiety.

The effects of the acutely administered cholecystokinin (CCK) agonists CCK tetrapeptide (BOC-CCK-4) and sulfated CCK octapeptide (CCK-8S) were examined in four animal models of anxiety in rats. In the elevated plus maze, BOC-CCK-4 reduced the time spent in the open arms and the number of entries into the open arms. BOC-CCK-4 but not the anorectic acting CCK-8S increased the suppression of feeding in a conflict paradigm based on novelty suppressed feeding in hungry rats. In the two-compartment black-and-white box, BOC-CCK-4 decreased the time spent and locomotor activity in the white compartment. In the ultrasound vocalization test, using rat pups separated from the mother, BOC-CCK-4 increased the number of distress calls. No evidence was found for inducing anxiety-like behaviour by CCK-8S.

Animals↗

PubMed1994

In situ expression of beta 1, beta 3 and beta 4 integrin subunits in non-neoplastic endothelium and vascular tumours.

Endothelial cells play an important role in adhesive interactions between circulating cells and extracellular matrix proteins. In vitro studies have shown that many of these processes are mediated by a superfamily of alpha beta heterodimeric transmembrane glycoproteins called integrins. The distribution patterns of beta 1, beta 3 and beta 4 integrin subunits in endothelial cells (EC) in situ were examined immunohistochemically on serial frozen sections of a wide range of non-neoplastic tissues and of vascular tumours, both benign and malignant. Expression of the beta 1 subunit was a constitutive feature of EC. Among the beta 1-associated alpha subunits, alpha 5 and alpha 6 were broadly distributed in EC, irrespective of vessel size and microenvironment. The alpha 3 subunit displayed intermediate levels of expression with a slight preference for small vessel EC. Presence of alpha 1 was confined to EC of capillaries and venules/small veins. Expression of alpha 2 in EC was inconsistent. With rare exceptions, the alpha 4 chain was absent in EC. The beta 3 and alpha v subunits were expressed in most EC, though not always concomitantly. In contrast to the beta 1 chain, however, these integrin subunits were absent in EC of glomerular capillaries and were expressed variably in sinusoidal EC. The beta 4 chain was evenly present in the great majority of EC, except for those of large vessels. In vascular tumours, the patterns of beta 1 and alpha 1 to alpha 6 subunit expression generally corresponded to those found in their non-neoplastic counterparts. Expression of beta 3, alpha v and beta 4 chains, however, decreased in neoplasia, especially in angiosarcomas. These data show that EC dispose of broad and at the same time differential repertoires of integrin subunits that presumably reflect vessel-type associated functional differences among these cells. In vascular tumours, the orthologous distribution patterns of beta 1 and alpha 1 to alpha 6 chains are conserved in most instances while the amounts of beta 3, alpha v and beta 4 subunits expressed in EC tend to decrease in the course of malignant transformation.

Antibodies, Monoclonal↗

PubMed1994

PMA-activation of peripheral blood and tonsillar B lymphocytes induces large adhesive cells reminiscent of large extrafollicular (monocytoid) B cells.

Extrafollicular (EF) B lymphocytes differ in size and morphology depending on the lymphatic organ involved and the kind of inflammatory reaction. On re-evaluating EF B cells in various sites and conditions we discriminated three forms: a small (lymphoid) and intermediate (centrocytoid), and a large (monocytoid) variant. Immunohistochemically, these variants could be discriminated by their differential expression of adhesion molecules CD62L (L-selectin) and CD11c: small EF B cells were strongly L-selectin+ and CD11c-; intermediate cells were moderately CD62L+ and CD11c-; large cells were faintly CD62L+ or - but expressed CD11c. In 72 h cultures of normal peripheral and tonsillar B cells, cross-linking surface immunoglobulin in the presence of interleukin-2 or interleukin-4 led to formation of clusters in vitro together with an increase in cell size and a slight up-regulation of CD11c, as determined by flow cytometry. Stimulation with phorbol 12-myristate 13-acetate (PMA), however, gave rise to large, plastic adherent cells which also showed strong homotypic adhesion, expressed CD62L at minimal levels and CD11c at comparably highest levels and altogether mimicked the large cell variant of EF B cells. We conclude that EF B cells are subjected to cytokine-induced metamorphosis and that differences in cell size and morphology reflect their state of activation and activation-associated adhesion properties. Our data suggest that EF B cells in all anatomical sites are functionally closely related cells which--possibly mediated by CD11c/CD18--may become sessile and proliferate locally once activated by appropriate signals.

Antigens, CD↗

PubMed1994

Synoviocytes in chronic synovitis in situ and cytokine stimulated synovial cells in vitro neo-express alpha 1, alpha 3 and alpha 5 chains of beta 1 integrins.

The expression of the beta 1 integrins was examined immunohistochemically in synoviocytes from normal synovitis membrane and from chronic synovitis of different aetiology and intensity. Normal synoviocytes were alpha 6 beta 1-positive but lacked alpha 1 through alpha 5. In mild inflammation type A synoviocytes neo-expressed alpha 1, alpha 3, and alpha 5 chains. In severe inflammation both type A and B synoviocytes expressed alpha 3, alpha 4, alpha 5, and alpha 6 chains. The effects of inflammatory cytokines, as single agents or in combination, on the beta 1 integrin expression in cultured normal synoviocytes was determined by immunocytochemistry and flow cytometry. The alpha 1 chain, while absent in unstimulated synoviocytes, was induced by interleukin-1 beta (IL-1 beta), tumour necrosis factor-alpha (TNF-alpha), and interferon-gamma (IFN-gamma). This effect was enhanced by combining IL-1 beta and TNF-alpha. Expression of the alpha 3 chain was up-regulated by IL-1 beta and, more intensely, by IFN-gamma. Transforming growth factor beta (TGF-beta) inhibited the up-regulating effect of IL-1 beta and antagonized the effect of IFN-gamma on alpha 3 chain expression. Expression of the alpha 5 chain was up-regulated significantly by co-stimulation through IL-1 beta together with TGF-beta or TNF-alpha. Thus, the beta 1 integrin profile of cytokine activated synoviocytes in vitro resembled that of synoviocytes in synovitis in situ. These data suggest that IL-1 beta, TNF-alpha, IFN-gamma, and TGF-beta are likely to be among the effectors regulating beta 1 integrin expression in synoviocytes in vivo.

Cells, Cultured↗

PubMed1994

Semisynthetic insulin analogues modified in positions B24, B25 and B29.

New semisynthetic analogues of human insulin, modified in the C-terminal region of the B-chain, were prepared to refine our understanding of the importance of particular amino acid residues in the expression of hormone biological properties. The following insulin analogues were synthesized by trypsin-catalyzed peptide-bond formation between the C-terminal arginineB22 of des-octapeptide(B23-B30)-insulin and synthetic octapeptides with the epsilon-amino group of lysineB29 protected by a phenylacetyl group: [L-Lys(Pac)B29]insulin, [D-PheB24,B25,L-Lys(Pac)B29]insulin and [D-Phe(p-Et)B24, L-Lys(Pac)B29]insulin. Enzymatic deprotection using immobilized penicillin amidohydrolase yielded: human insulin, [D-PheB24,B25]insulin and [DPhe(p-Et)B24]-insulin. Biological in vitro potencies (specific binding to cultured human lymphocytes IM-9 and lipogenic potency in isolated rat adipocytes) of the semisynthetic analogues were estimated, ranging from 0.2 to 100% relative to porcine insulin.

Adipocytes↗

PubMed1994

Differential expression of beta 1 integrins in nonneoplastic smooth and striated muscle cells and in tumors derived from these cells.

Integrins are a superfamily of transmembrane alpha beta heterodimers that play an important role in cell-matrix and cell-cell interactions by acting as receptors for extracellular matrix proteins and for cell adhesion molecules. Using monoclonal antibodies against beta 1, alpha 1 to alpha 6, and alpha v subunits, the in situ distribution pattern of beta 1 integrins was examined immunohistochemically in nonneoplastic smooth and striated muscle cells and in their tumors. Nonneoplastic smooth muscle cells were beta 1+, alpha 1+, alpha 3+, alpha v+ and, in diverse localizations, also alpha 5+ or even alpha 6+. The expression of the beta 1 chain was conserved in all leiomyomas and leiomyosarcomas. The distribution pattern of the alpha subunits by contrast underwent several changes during malignant transformation of smooth muscle cells. These alterations consisted in a neoexpression of alpha 2, alpha 4, and alpha 6 as well as in an abnormal abrogation of alpha 1 and alpha 3 in some leiomyosarcomas. Except for the absence of alpha 5 in the majority of epithelioid leiomyosarcomas, expression of the alpha 5 and alpha v subunits was mainly conserved. In addition, tumors with epithelioid differentiation differed from typical cases by the absence of alpha 1 and the simultaneous presence of alpha 4. Adult striated muscle cells were beta 1+ but alpha 1- to alpha 6- and alpha v-, whereas fetal striated muscle cells were not only beta 1+ but also alpha 3+/-, alpha 4+/-, alpha 5+ and alpha 6+. In all rhabdomyosarcomas the expression of beta 1 was retained. Furthermore, the majority of cases showed the expression of one or more alpha subunits most of which, ie, alpha 4, alpha 5, and alpha 6, were also found in fetal striated muscle cells. In conclusion, beta 1 integrins exhibited a differential expression pattern along the two lines of myogenic differentiation. This integrin profile underwent characteristic changes during malignant transformation. Nevertheless, the compiled distribution patterns of the alpha 1, alpha 3, and alpha v subunits allowed in most instances the discrimination between tumors of smooth (alpha 1+/alpha 3+/alpha v+) and striated muscle (alpha 1-/alpha 3-/alpha v-) differentiation.

Cell Transformation, Neoplastic↗

PubMed1994

[Effect of change in refraction by increasing intraocular pressure with the suction cup method on pattern reversal VECP].

When IOP is increased by the suction cup method, refraction changes will occur, depending on the shape of the cup and the height of the IOP increase. Similar refraction changes were simulated in six healthy volunteers by employing spherical and cylindrical glasses during pattern-reversal visual evoked cortical potential (VECP) with various check sizes and amount of contrast. While the pattern-reversal VECP latencies were not influenced, the amplitudes were reduced considerably. By using contact lenses and a suitably shaped suction cup, refraction changes could be compensated for. In 22 healthy volunteers pattern-reversal VECPs were derived with and without the application of contact lenses with artificially raised IOP. A comparison showed that the amplitudes differed significantly. Without contact lenses a negative pressure of more than 40 mmHg resulted in a drop in the amplitudes with a plateau formed between 80 and 120 mmHg. With compensation by contact lenses the amplitudes are found to be unaltered or even slightly increased until a negative pressure of 120 mmHg is reached in the suction cup, after which they drop. Plotting the pattern-reversal VECP amplitudes (obtained with refraction changes being compensated for by contact lenses) against ciliary perfusion pressure, one finds the characteristic curve described by Ulrich et al., suggesting an autoregulative capacity between 15 and 20 mmHg in healthy persons. The latencies, which remain uninfluenced by refraction changes, are also not altered within an IOP increase of 15-20 mmHg.

Adult↗

PubMed1994

Differential expression of beta 1, beta 3, and beta 4 integrin subunits in nonneoplastic neural cells of the peripheral and autonomic nervous system and in tumors derived from these cells.

BACKGROUND: Extracellular matrix proteins and their receptors take part in physiologic neural development and organization and also in abnormal neoplastic growth and spread. There is increasing evidence for the implication of integrins in these processes. EXPERIMENTAL DESIGN: Human tissues containing nonneoplastic neural cells of the peripheral and autonomic nervous system and a comprehensive series of neural tumors were examined for the in situ expression of beta 1, beta 3, and beta 4 integrins. Serial frozen sections of each tissue sample were immunostained using an indirect streptavidin/biotin-peroxidase method and monoclonal antibodies against beta 1, alpha 1 to alpha 6, beta 3, alpha v, and beta 4 subunits. RESULTS: Both small- and large-diameter nerve fibers of normal peripheral nerve trunks were consistently beta 1+, alpha 6+, and beta 4+ in the absence of alpha 3, alpha 4, alpha 5, and beta 3. Small-diameter nerve fibers further expressed alpha 1, alpha 2, and alpha v. Meissner's corpuscles and inner cores of Pacinian corpuscles shared the integrin repertoire of small-diameter nerve fibers with additional expression of alpha 3; outer cores of Pacinian corpuscles were beta 1+, alpha 3+, alpha 6+, and beta 4+. Regenerating nerve fibers paralleled the integrin profile of normal peripheral nerves. By contrast, malignant schwannomas showed considerable changes in integrin expression. These alterations consisted mainly in a neoexpression of alpha 3, alpha 4, and alpha 5 and in an abnormal loss of alpha 6 and beta 4. Expression of alpha 1, alpha 2, and alpha v was variable; absence of beta 3 was generally conserved. In ganglion cells, integrin expression was restricted to beta 1 and alpha 3 subunits, and chromaffine cells of the adrenal medulla even lacked any detectable beta 1, beta 3, and beta 4 integrin subunits. (Ganglio)-neuroblastomas, however, were beta 1+, alpha 1+, and alpha 3+, whereas primitive peripheral neuroectodermal tumors were beta 1+ and alpha 5+. CONCLUSIONS: Nonneoplastic human neural cells exhibit a complex and, at the same time, differential pattern of beta 1, beta 3, and beta 4 integrin subunit expression. Malignant transformation leads to considerable changes in this integrin profile. The observation of neoplasia-associated abnormalities underlines the important role of integrins in the orderly development and maintenance of human neural tissue. Some aspects of the emerging integrin subunit patterns are useful for the differential diagnosis of neural soft-tissue tumors.

Adrenal Glands↗

PubMed1993

Antidiuretic activity and release of factor VIII by vasopressin analogues.

Vasopressin and in particular its structural analogue dDAVP (1-deamino-8-D-arginine vasopressin) can increase plasma concentrations of Factor VIII and tissue plasminogen activator (tPA) in some species of animals and in humans. For this reason dDAVP is used therapeutically in the treatment of bleeding episodes in patients suffering from haemophilia A and Von Willebrand's disease. However, the high antidiuretic activity of dDAVP constitutes and unwanted effect in this context. In the present study, a large number of analogues of vasopressin were designed, synthesized and tested in monkeys with the aim of producing compounds in which the Factor VIII-releasing activity was selectively isolated from the vasopressor and antidiuretic actions of the peptide. The results indicate that it is possible to separate these biological activities; however, none of the analogues tested so far possessed Factor VIII potencies comparable to that of dDAVP.

Amino Acid Sequence↗

PubMed1993

Differential expression of leukocyte differentiation antigens in small round blue cell sarcomas.

BACKGROUND: Small round blue cell sarcomas (SRBCS) comprise a group of cytomorphologically poorly differentiated neoplasms that are characterized by different histogenesis and biologic behavior. METHODS: Twenty-seven well-characterized SRBCS were examined immunohistochemically to detect the expression of a panel of leukocyte differentiation (CD) antigens and class I (HLA-A,B,C) and class II (HLA-DR) major histocompatibility complex antigen. RESULTS: Although various cell surface antigens were detectable in SRBCS, the pan-leukocytic-histiocytic CD53 antigen was absent in the neoplastic population of all tumors studied; this finding allowed the authors to discriminate these lesions from lymphomas and leukemias. Some antigens had a differential pattern of expression in the SRBCS group, in particular in the undifferentiated tumor cell populations. In most instances, neuroblastomas (NB) and ganglioneuroblastomas (GNB) were CD9+/CD24+/CD56+ but CD40-/HLA-A,B,C-. Rhabdomyosarcomas (RMS) were CD56+ in all specimens and CD9+ in many samples; generally, they showed CD24-/CD40-/HLA-A,B,C-. Ewing sarcomas (ES) and peripheral primitive neuroectodermal tumors (pPNET) were HLA-A,B,C+/CD40+ but CD9-/CD24-/CD56- in most instances. Thus, with few exceptions, the expression of CD9 and CD56 and the simultaneous absence of HLA-A,B,C and CD40 differentiated GNB, NB, and RMS from ES and pPNET. GNB, NB, and RMS differed in regard to their CD24 expression. CONCLUSIONS: These data show that various types of SRBCS have different patterns of cell surface antigens. Therefore, these antigens are considered to be helpful in the immunophenotypic subclassification of SRBCS: The immunophenotypic similarities between ES and pPNET, however, might be an additional argument for a close relationship between these two lesions.

Antigens, CD↗

PubMed1993

Refraction changes during elevation of intraocular pressure by suction cup, their reflection in the pattern visual evoked cortical potential and their compensation.

Visual evoked cortical potential studies using pattern stimuli with the intraocular pressure raised artificially by the suction cup method have been reported. Possible changes in the refraction of the eye due to the method employed and their influence on the pattern visual evoked cortical potential have not been considered. Changes in the refraction of the eye during artificial intraocular pressure elevation and the influence of such changes on pattern visual evoked cortical potentials were studied. The refraction changes were found to depend on the shape of the suction cup. They could be compensated for by employing properly shaped suction cups and contact lenses. The behavior of amplitude and latency of the pattern visual evoked cortical potential at artificially elevated intraocular pressure with compensation for refraction changes has been studied and found to depend in a characteristic manner on ocular perfusion pressure.

Adult↗

PubMed1993

Expression of beta 1 integrins in non-neoplastic mammary epithelium, fibroadenoma and carcinoma of the breast.

beta 1 Integrins were examined immunohistochemically in normal and mastopathic mammary glands, 12 benign tumours and 90 carcinomas of the breast using monoclonal antibodies against beta 1 and alpha 1 to alpha 6 subunits. When compared with epithelial cells of non-neoplastic mammary glands and of benign tumours, carcinoma cells showed considerable quantitative changes in the pattern of alpha 2, alpha 3 and alpha 6 subunit expression. In contrast, the distribution pattern of beta 1, alpha 1, alpha 4 and alpha 5 antigens corresponded to the situation observed in non-neoplastic mammary gland epithelium in most instances. An abnormal expression of alpha 2 was found in 71.0% of the carcinomas ranging from a remarkably low number of alpha 2-positive tumour cells in 27.5% of the cases to a complete absence of the alpha 2 molecule in 43.5% of the carcinomas. Of the carcinomas 39.9% exhibited quantitative changes in alpha 3 expression with an abnormally low content of alpha 3-positive neoplastic cells in 15.4% and a complete absence of this molecule in 24.5% of the cases. Expression of alpha 6 was abnormal in 73.2% of the carcinomas, consisting in a greater number of alpha 6-negative tumour cells in 31.9% and in a complete absence of alpha 6 in 41.3% of the tumours. The abnormally low expression/absence of alpha 2 and alpha 3 subunits correlated with oestrogen receptor negativity (P < 0.033 and P < 0.04, respectively). In addition, abnormally low expression/absence of alpha 2 correlated with poor differentiation of the tumours (P < 0.014). The quantitative changes in the expression pattern of beta 1-associated alpha subunits in breast carcinomas may cause a disturbed cell-cell and/or cell-matrix interaction that increases the invasive and migratory property of the tumour cells.

Adenofibroma↗