Angiotensin-converting enzyme in sarcoid and chalazion granulomas of the conjunctiva

Angiotensin-converting enzyme (ACE) was studied immunohistochemically in conjunctival biopsies from 6 patients with systemic sarcoidosis, 4 patients with posterior non-sarcoid uveitis and in specimens from 4 patients with chalazion of the eyelid. Specimens with sarcoid granulomas showed intense ACE-positive immunoreactivity in epitheloid cells of the granuloma, whereas chalazion granulomas did not contain ACE-immunoreactivity. There was no difference in staining patterns between specimens without granulomas. Thus immunohistochemical staining for ACE may be of help in differentiating conjunctival granulomatous tissue of a chalazion from sarcoid granuloma.     

Stage-dependent expression of an angiogenic agent and vascular organization in experimental skin tumor development

Increased angiogenesis and expression of antibodies to vascular endothelial growth factor (VEGF), an angiogenic agent, have been shown in the tumor development of many tissues. Areas of skin expressing VEGF and total volume of vessels expressing laminin in the wall were measured in chemical carcinogen-exposed mice using CAS-200 morphometry apparatus having a sensitivity exceeding 99% and reproducibility exceeding 99%. The area of VEGF expression was increased in carcinogen-exposed skin, dysplasia and in well-differentiated squamous cell carcinomas, but decreased in squamous cell carcinomas with decreased degree of differentiation. The vessel volume increased prior to the formation of tumors in carcinogen-exposed skin as well as in highly malignant neoplasms. In well-differentiated squamous cell carcinomas with an expansive growth pattern, the vessels were parallel to the basal membrane, in moderately differentiated tumors the vessels were in the direction of tumor invasion, and in poorly differentiated tumors, active angiogenesis consisted of numerous, enlarged vessels within the tumor. This study showed increased VEGF expression and number of vessels occurring in early stages of skin tumor development, pointing to a role of angiogenesis in chemical risk assessment and in cancer prevention. Altered vessel structure and vessel arrangement were distinct in later stages of tumor growth and in malignant neoplasms, pointing to the utility of detailed vessel analysis in neoplasm characterization.     

Chromosomal integrity maintained in five human embryonic stem cell lines after prolonged in vitro culture

There have been recent reports of human embryonic stem cell (hESC) lines developing chromosomal aberrations after long-term culture, indicating an unstable genomic status due to the in vitro milieu. This raises concern, since it would limit their use in therapeutics. In this study the chromosomal status of five well-characterized hESC lines, SA002, SA002.5, AS034.1.1, SA121 and SA461, was monitored during long-term in vitro culture. The criteria of defined hESCs were met by all of the five hESC lines (four diploid and one trisomic for chromosome 13). The genomes were screened for chromosomal aberrations and rearrangements using comparative genomic hybridization (CGH), interphase fluorescence in situ hybridization (FISH) and traditional karyotyping on several occasions while in culture. The genomic integrity was shown to be maintained after repeated freeze-thaw procedures and continuous culture in vitro for up to 22 months (148 passages). We discuss the most common de novo chromosomal aberrations reported in hESCs, as well as their possible origin.     

Erythropoietin and renin substrate in cerebellar haemangioblastoma

We examined eight cerebellar haemangioblastoma tumours from eight patients, aged 16-63 years, 5 females and 3 males. Preoperative haemoglobin values exceeded 180 g/l in four patients, and 150 g/l in four. All high Hb values were normalized upon surgical removal of the tumours. All tumours contained scattered cells which stained positively with antisera against pure human urinary erythropoietin and plasma renin substrate. We conclude that cerebellar haemangioblastomas produce immunoreactive erythropoietin, which shares common antigenic determinants with renin substrate.     

Immunohistochemical localization of syndecan-1 in normal and pathological human uterine cervix

Expression of syndecan-1, a cell surface proteoglycan that binds growth factors and extracellular matrix components, was studied in normal and pathological human uterine cervix using immunohistochemical methods. Normal cervical squamous epithelium showed positive staining for syndecan-1 in all cell layers, except the basal cell layer, whereas endocervical columnar epithelium stained weakly. In non-neoplastic reactive lesions, metaplastic squamous cells were positive for syndecan-1, whereas columnar cells showed weak or negative staining. In cervical condylomas, cells showing koilocytotic atypia were positive for syndecan-1. The progression of cervical intraepithelial neoplasia (CIN) grade I to grade III was associated with reduced syndecan-1 expression and localization of syndecan-1 to more superficial cell layers. In squamous cell carcinomas (SCCs), syndecan-1 expression correlated with histological differentiation, being absent from most poorly differentiated tumours. The results suggest that loss of syndecan-1 from atypical cells is an early event during cervical carcinogenesis and show a close association of syndecan-1 expression with preserved epithelial morphology and differentiation.     

Non-linearity of neoplastic conversion induced in rat liver by low exposures to diethylnitrosamine

Neoplastic conversion induced in rat liver by diethylnitrosamine(DEN) was quantified by measuring preneoplastic and neoplasticlesions over a 34 week period in the beginning of which thecarcinogen was given at three dose levels and two dose ratesfor the first 10 weeks, after which animals were maintainedfor 24 weeks with either no further exposure or were fed phenobarbital(PB) to promote neoplastic development of cells converted byDEN. DEN was injected s.c. inmale F344 rats at weekly or biweeklyintervals for total doses of 1, 2 or 4 mmol/kg body wt and thenthe rats were maintained on basal diet alone or diet containing0.05% PB. At the end of exposure, DEN had produced a dose-relateddecrease in centrilobular glutamine synthetase-expressing (GS⁺)hepatocytes which is indicative of mild cytotoxicity. All dosesinduced foci that were     

Plasma renin substrate and oestrogens in normal pregnancy

Relationship between concentrations of serum oestrogens, plasma renin substrate and plasma renin activity were studied in six women throughout pregnancy. There was a significant positive correlation between serum oestradiol-17β and plasma renin substrate concentrations (r=0.60). Serum oestriol concentrations also correlated significantly with plasma renin substrate concentrations (r=0.68). Correlation coefficients calculated separately for each subject throughout pregnancy were higher than those for the whole group. Also, there was much individual variation in dose-response of serum oestrogens to plasma renin substrate concentrations. There was no significant correlation between serum oestrogens and plasma renin activity.

Our results support the view that oestrogens cause the increase in plasma renin substrate concentration during pregnancy, and emphasize the individual variation in response of renin substrate concentration to serum level of oestrogens.     

Availability of iron and degree of inflammation modifies the response to recombinant human erythropoietin when treating anemia of chronic disease in patients with rheumatoid arthritis

Forty-six patients with rheumatoid arthritis (RA) and documented anemia of chronic disease (Hb <100/110 g/l) were randomized to receive either human recombinant erythropoietin (r-HuEPO, n = 36, 300 U/kg body weight) or placebo (n = 10) for 12 weeks in a multicenter study. An adequate response was defined as elevation of Hb≥120 g/l. Relevant clinical and laboratory assessments were made to evaluate efficacy and secure safety. A significant elevation in Hb from week 10 onwards was noted in twenty-six patients (five drop-outs) out of nine patients receiving placebo (one drop-out) (12±1.2 g/l vs 4±0.5 g/l; Hb elevation from 95 g/l to 107 g/l vs 93 g/l to 97 g/l, P<0.05). Only 14.6%, however, were considered responders according to preset criteria. In the responders a lower initial CRP, a significant reduction in ESR but not in CRP was seen compared to the remaining r-HuEPO group. A significant elevation of energy level was noted in the r-HuEPO group; otherwise, no differences in clinical variables were seen. No serious adverse effects were noted. When analyzing patients receiving oral iron in combination with r-HuEPO and adding five additional, openly selected patients receiving both adequate iron supplementation and r-HuEPO, there was a significant weekly elevation of Hb from week 8 onwards in favor of combination therapy over the ones only receiving r-HuEPO (18±1.1 g/l vs 7±1.1 g/l, P<0.05). The initial six responders had now reached ten of whom seven belonged to the combination therapy group. Response to r-HuEPO in RA patients appears to be dependent on availability of iron and on the degree of inflammation. If r-HuEPO treatment is considered, iron deficiency should always be corrected and strenous efforts should have been made to control the disease itself. Received: 21 February 1997 / Accepted: 21 April 1997     

Baroreflex sensitivity and neurohormonal activation in patients with acute myocardial infarction.

OBJECTIVE--To examine the relationship between baroreflex sensitivity and neurohormonal activation in patients with an acute myocardial infarction. METHODS--Baroreflex sensitivity, plasma noradrenaline, atrial natriuretic factor, endothelin-1, and plasma renin activity were measured in 37 male patients about 10 days after their first myocardial infarction, and in 15 healthy controls. Baroreflex sensitivity was assessed from the regression line relating the change in RR interval to the change in systolic blood pressure following an intravenous bolus injection of phenylephrine. The measurements were repeated after a follow up of three months. RESULTS--There was a significant inverse correlation between baroreflex sensitivity and plasma noradrenaline measured before hospital discharge (r = -0.43, P < 0.01). Patients with increased plasma noradrenaline (> or = 2SD above the mean of the age matched control group) had significantly lower baroreflex sensitivity than patients with normal plasma noradrenaline (8.7 (SD 4.6) v 12.1 (6.1) ms/mm Hg, P < 0.05). The change in baroreflex sensitivity during the follow up showed a significant inverse correlation with the change of plasma noradrenaline (r = -0.450, P < 0.01). Furthermore, when patients with increased plasma noradrenaline before hospital discharge were analysed separately, baroreflex sensitivity at three months in patients in whom plasma noradrenaline had decreased to normal values was significantly higher than in patients in whom plasma noradrenaline had remained increased (14.6 (5.7) v 8.1 (8.1) ms/mm Hg, P < 0.05). On the other hand, baroreflex sensitivity was not related to the levels of plasma atrial natriuretic factor, plasma endothelin-1, or plasma renin activity. Neither was any relationship found between change in baroreflex sensitivity and change in plasma atrial natriuretic factor, endothelin-1, or plasma renin activity during the follow up. CONCLUSIONS--The impairment baroreflex sensitivity after myocardial infarction was associated with increased concentration of plasma noradrenaline, that is, sympathetic activation, but not with plasma atrial natriuretic factor, endothelin-1, or plasma renin activity. Baroreflex sensitivity provides information about cardiac vagal control as well as about the balance of cardiac sympathetic-parasympathetic regulation.