Method for assessment of vascular reactivity in bone: in vitro studies on resistance arteries isolated from porcine cancellous bone.

Knowledge about vascular regulation in bone is central to the understanding of both normal and pathological bone physiology. This article describes a new method for direct assessment of the reactivity of bone blood vessels. Resistance arteries (diameter approximately 250 microns) were isolated from epiphyseal cancellous bone (porcine femoral condyle). Arterial segments (2 mm long) were mounted as ring preparations on a myograph, and isometric force development was measured continuously. Fifty-nine vessels from 31 pigs were investigated. The active force development was maximal at 0.9 x L100 in nine of 12 investigated arteries (L100 corresponds to the circumference the vessel would have if relaxed and exposed to a luminal pressure of 100 mm Hg [13.3 kPa]). In all subsequent experiments, the vessels were stretched to 0.9 x L100. Noradrenaline (2 x 10(-8) to 10(-5) M) induced a concentration-dependent vasoconstriction; mean maximal tension development was 3.69 N/m. This force development would enable the arteries to contract against a pressure of more than 22 kPa (165 mm Hg), indicating preserved function of the media smooth muscle. Response to acetylcholine (10(-7) to 10(-5) M) was observed in only two of 12 arteries. Bradykinin (10(-11) to 10(-6) M) induced a concentration-dependent and reproducible relaxation in all vessels; the relaxation was endothelium-dependent, since no effect of bradykinin was detected after mechanical removal of the endothelium. Sodium nitroprusside (10(-4) M) induced a reproducible and endothelium-independent vasorelaxation. The results demonstrate preserved function of both smooth muscle and endothelium in this preparation. The model allows pharmacological investigations of bone arteries under well defined conditions and enables studies on focal bone lesions and human bone tissue.

Hormone replacement therapy after transcervical resection of the endometrium.

OBJECTIVE: To determine if women who have undergone transcervical resection of the endometrium can be treated safely with estrogens alone. METHODS: Sixty-two postmenopausal women who had undergone endometrial resection were recruited into a double-blind, randomized study. Twenty-one had menopausal symptoms at the primary operation and were recruited at the time of the surgery, and 38 were recruited an average of 20 months (range 8-42) after the primary endometrial resection and underwent a second resection to remove any residual endometrium before entering the study. Three patients were excluded from the study. Subjects were allocated randomly to one of two hormone replacement therapy (HRT) regimens: 17-beta-estradiol 2 mg alone or combined with norethisterone 1 mg. Clinical and ultrasound data were collected every 3 months. Hysteroscopically standardized endometrial biopsies were taken after 1 year. RESULTS: In the single-agent therapy group, endometrial hyperplasia without atypia was found in six subjects and proliferative endometrium in eight after 1 year. No such cases occurred among women receiving combined therapy. Endometrial thickness and menstrual bleeding were significantly greater in the single-agent therapy group than in those receiving combined therapy. These differences between single-agent and combined therapy were statistically significant. CONCLUSION: Postmenopausal HRT in patients who have undergone transcervical resection of the endometrium should include progestagen for protection of the endometrium.

The prognostic value of oncogenic antigen 519 (OA-519) expression and proliferative activity detected by antibody MIB-1 in node-negative breast cancer.

The prognostic value of oncogenic antigen 519 (OA-519) expression and tumour proliferative activity was evaluated in a retrospective series of 118 patients with low-risk breast cancer. Low risk was defined as negative axillary nodes, tumour diameter < or = 50 mm, and no histological evidence of invasion of skin or deep fascia (= T1N0M0 and T2N0M0). The median follow-up time was 104 months (range 5-143 months). Immunohistochemical analysis of OA-519 expression was performed on formalin-fixed, paraffin-embedded tissue. The proliferative activity was estimated using a Ki-67 equivalent monoclonal antibody (MIB-1), which is applicable on formalin-fixed, paraffin-embedded tissue after microwave pretreatment. OA-519 was expressed in about one-third of the tumours and the percentage of proliferating cells (the MIB-1 index) ranged between 1 and 72 per cent (median 17 per cent). Using multivariate Cox analysis, both the MIB-1 index and OA-519 expression were of independent prognostic value (2p < or = 0.01), and the combined immunohistological approach may therefore be useful in selecting patients with node-negative breast cancer who might benefit from adjuvant therapy.

Angiotensin-converting enzyme activity and contractile effects of angiotensin I and II in human uteroplacental arteries.

OBJECTIVE: Our purpose was to study local angiotensin-converting enzyme activity and the mechanical effects of angiotensin I and II in human uteroplacental arteries. STUDY DESIGN: Angiotensin-converting enzyme activity was measured by a simple radioimmunoassay with tritiated benzoyl-glycyl-glycyl-glycine as substrate in isolated human intramyometrial arteries from nonpregnant (n = 8) and term pregnant women (n = 8) and placental (n = 8) stem villous arteries. Moreover, in these vessels the mechanical effects of angiotensin I and II were investigated in organ bath experiments. Endothelium-intact and endothelium-denuded arteries were used, and the integrity of the endothelium was examined by histologic studies. RESULTS: The activity of angiotensin-converting enzyme ranked the intramyometrial arteries from pregnant women >> intramyometrial arteries from nonpregnant women > fetal stem villous arteries. Angiotensin-converting enzyme activity was unaffected by removal of the endothelium. Angiotensin II 10(-5) mol/L produced contractile responses in the intramyometrial arteries without significant differences between arteries from nonpregnant and pregnant women. In fetal stem villous arteries the effects of angiotensin II 10(-5) mol/L were less pronounced. As for angiotensin II, the contractile responses to angiotensin I 10(-5) mol/L showed marked development of tachyphylaxis. In the endothelium-denuded preparations the contractile responses to angiotensin I 10(-5) mol/L were significantly enhanced in intramyometrial arteries from nonpregnant women but remained unchanged in intramyometrial arteries from pregnant women and in fetal stem villous arteries. In all preparations pretreatment with captopril or perindopril (10(-5) mol/L) markedly reduced angiotensin-converting enzyme activity, whereas no effects were observed on the contractile responses to angiotensin I. Saralasin 10(-5) mol/L completely abolished the contractile responses to angiotensin I and II. CONCLUSION: Local angiotensin-converting enzyme activity in human intramyometrial arteries seems to be markedly increased during pregnancy and shows marked differences between maternal and fetal uteroplacental arteries. High concentrations of angiotensin I may imply direct effects on the angiotensin II receptor independent of the local angiotensin-converting enzyme activity.

Classification of tubulo-papillary renal cortical tumours using estimates of nuclear volume.

The classification of renal cortical tumours is problematic, with no clear division of benign from malignant tumours. Unbiased stereological estimates of volume-weighted nuclear volume (nuclear vv) were obtained by point sampling of nuclear intercepts in a retrospective study of 36 variably sized tubulo-papillary basophilic cell renal cortical tumours. There was no clear pattern of evolution of nuclear vv with increasing macroscopic tumour diameter. Estimates of nuclear vv could not distinguish between 21 tumours classified as renal adenomas with macroscopic diameters < 3 cm (average nuclear vv = 241 microns 3) and 15 tumours classified as renal cell carcinomas with diameters > 3 cm, or aggressive histological pattern (average nuclear vv = 229 microns 3) (2p = 0.68). In this subtype of renal cortical tumours, estimates of nuclear vv do not support the historical convention of using a 3 cm tumour diameter as the dividing line between adenomas and carcinomas, but support the theory of a single group of tumours. As most of the truly incidental renal cortical tumours are less than 1 cm in diameter, this limit could be considered. Such small benign cortical nodules have never been reported to metastasize, and would thus be excluded from being diagnosed and registered as malignant. Although this dividing line is again arbitrary, and cannot be justified by the stereological measurements, it is a practical solution to a clinical problem. There were too few examples of disease progression to assess the prognostic significance of nuclear vv in these tumours.

Human skeletal muscle digitalis glycoside receptors (Na,K-ATPase)--importance during digitalization.

The aims of the present study were to evaluate in humans the putative importance of skeletal muscle digitalis glycoside receptors (Na,K-ATPase) in the volume of distribution of digoxin and to assess whether therapeutic digoxin exposure might cause digitalis receptor upregulation in skeletal muscle. Samples of the vastus lateralis were obtained postmortem from 11 long-term (9 months to 9 years) digitalized (125-187.5 micrograms daily) and eight undigitalized subjects. In intact samples from digitalized patients, vanadate-facilitated 3H-ouabain binding increased 15% (p < 0.02) from 150 +/- 18 to 173 +/- 13 pmol/g wet wt. (mean +/- SEM) after clearing receptors of bound digoxin by washing samples in excess specific digoxin antibody fragments. 3H-ouabain binding in the untreated group was 257 +/- 28 and 274 +/- 26 pmol/g wet wt. (7%, p > 0.30) before and after washing in specific digoxin antibody fragments, respectively. Thus, the present study indicates a approximately 13% occupancy of skeletal muscle digitalis glycoside receptors with digoxin during digitalization. In light of the large skeletal muscle contribution to body mass, this indicates that the skeletal muscle Na,K-ATPase pool constitutes a major volume of distribution for digoxin during digitalization. The results gave no indication of skeletal muscle digitalis glycoside receptor upregulation in response to digoxin treatment. On the contrary, there was evidence of significantly lower (37%, p < 0.005) digitalis glycoside receptor concentration in the vastus lateralis of the digitalized patients, which may be of importance for skeletal muscle incapacity in heart failure.

Acute tissue effects during transcervical endometrial resection.

The acute tissue effects of transcervical endometrial resection (TCRE) with a standard Iglesias resectoscope using glycine 1.5% for irrigation were studied in 8 women prior to hysterectomy. Combinations of 80 or 120 W cutting current with blend 1 or 2 were applied for endometrial resection, preceded by cornual endometrial coagulation with the roller ball electrode with a coagulation effect of 40 or 60 W. The temperature was measured at the uterine vessels, ovarian ligaments and serosal surface. The increase in temperature at the serosal surface was 2.0 degrees C during cornual coagulation and 0.3 degrees C during endometrial resection, independent of the current effect applied. The maximum depth of tissue damage was 1.7 mm. No change in temperature was found at the uterine vessels or ovarian ligaments. The tissue destruction and the increase in temperature of the uterine surface are minimal, and TCRE offers excellent histological material. Careful coagulation/resection in the cornual and isthmus regions is recommended.

No upregulation of digitalis glycoside receptor (Na,K-ATPase) concentration in human heart left ventricle samples obtained at necropsy after long term digitalisation.

STUDY OBJECTIVE: The aim was to evaluate the hypothesis that digitalis glycosides increase the concentration of their specific receptor (Na,K-ATPase) in human myocardial tissue, thereby possibly reducing the inotropic effect of long term digitalis treatment. DESIGN: Intact samples of left ventricle were obtained at necropsy from patients who had been on long term treatment with digoxin and from patients not previously given digoxin. Digitalis glycoside receptors were quantified using vanadate facilitated 3H-ouabain binding before and after washing samples in buffer containing excess digoxin antibody fragments for 16 h at 30 degrees C. This washing procedure has previously been shown to reduce prior specific digoxin binding in human left ventricle by 95% and to allow subsequent vanadate facilitated complete quantification of 3H-ouabain binding sites. In this context it was performed to reduce occupancy of digitalis glycoside receptors by digoxin, caused by digitalisation before 3H-ouabain binding. SUBJECTS: 11 patients who had been on long term treatment with digoxin and eight who had not previously been given digoxin were studied. Left ventricle samples were obtained at necropsy at around 15 h after death. MEASUREMENTS AND MAIN RESULTS: Standard 3H-ouabain binding was 39% less in samples from digitalised than from undigitalised subjects (p less than 0.001). Washing samples in buffer containing excess digoxin antibody fragments induced an increase in 3H-ouabain binding from 174(SEM 10) to 265(20) pmol.g-1 wet weight (n = 11, p less than 0.001) in samples from digitalised patients. After washing, the digitalis glycoside receptor concentration in left ventricle samples showed a tendency to a lower value (14%, p greater than 0.10) in patients exposed to digoxin compared to left ventricle samples from individuals unexposed to digitalis glycoside treatment. Calculating 3H-ouabain binding relative to dry ventricular muscle weight confirmed the results obtained using wet weight as reference. CONCLUSIONS: The results suggest that digoxin treatment in life is associated with a 34% occupancy of digitalis glycoside receptors with digoxin. In the human heart there was no evidence for upregulation of digitalis glycoside receptor concentration due to long term digitalisation. Thus at receptor level there was no evidence for development of tolerance to digoxin therapy. The lower digitalis glycoside receptor concentration in the left ventricle observed in the heart failure patients may support the report of a relationship between Na,K-ATPase concentration as evaluated by 3H-ouabain binding and left ventricular function.

Renal angiomyolipoma: an ultrastructural investigation of three cases with histogenetic considerations.

Renal angiomyolipoma is a rare lesion composed of smooth muscle cells, adipose tissue and abnormal vessels. It is currently classified as a benign, non-epithelial renal tumor. It has a high incidence in patients suffering from tuberous sclerosis but is more frequently found as an isolated renal lesion. Three cases of renal angiomyolipoma, 2 of which underwent perfusion-fixation, were studied by electron microscopy to clarify the cellular composition of this lesion. In the smooth muscle cells abundant accumulation of glycogen was found, whereas the lipocytes disclosed normal ultrastructural features. However, a smaller number of smooth muscle cells also contained lipid, thus simulating an intermediate cell stage between adipose- and smooth muscle cells. The abnormal thickening of the subendothelial spaces contained collagen fibrils in a homogeneous matrix, fibroblast-like cells and non-specific vesicular structures. These findings suggest a secondary vascular damage, i.e. the thickened vessels may not be a primary, integral part of renal angiomyolipoma. Evidence of a common precursor cell of renal angiomyolipoma was not disclosed. It is concluded that renal angiomyolipoma is a hamartoma composed of mature adipose cells and smooth muscle cells displaying different degrees of abnormal differentiation.

Ultrastructure of renal adenoma.

Renal adenomas, defined as minute cortical foci of proliferating epithelium, are frequently occurring lesions reported to be present in 15%-22% of all adult human kidneys. They can often be found in kidneys with renal cell carcinoma. Their light microscopic structure makes it improbable that they should represent intrarenal metastases. The concept does not include clear cell foci. Ultrastructure of these cortical foci in human kidneys is not well known. A series of 10 intrarenal adenomas in carcinoma-bearing kidneys has been studied using tissue fixed rapidly after nephrectomy by perfusion with 2% glutaraldehyde. The results confirm their tubular origin. Ultrastructural markers of different segments of the nephron were demonstrated. Several of these markers might be present in each single case. The interpretation is that their ultrastructural characteristics do not indicate an origin from a special segment of the nephron. They may reflect an abnormal gene expression associated with the neoplastic change of the cell clone. Some changes are similar to those seen in cells from renal cell carcinoma, although not as prominent as in malignant cells.

Expression of segment-specific antigens in the human nephron and in renal epithelial tumors.

The immunohistological staining patterns of several hundred monoclonal antibodies (Mabs) were studied in normal human kidney tissue. Seven Mabs, 3 hematopoietic (F103.12/CD10, MY7/CD13, 3C4/CD15) and 4 non-hematopoietic (LP34, E29, HEA81, HEA125) revealed a segment-specific or pan-nephron staining. The expression of antigens (Ags) labelled by the 7 selected Mabs was then studied in cryostat sections of a series of 43 renal epithelial tumors (31 renal cell carcinomas, 2 oncocytomas, 10 adenomas) in order to correlate the results with the prevailing hypothesis for the histogenesis of these tumors. The adenomas displayed poor expression of CD10-Ag (proximal nephron marker) compared to carcinomas. The chromophobic type of renal cell carcinoma and the benign oncocytoma did not express CD13-Ag, suggesting a possible histogenetic relationship. More than 95% of all tumors simultaneously expressed a proximal and a distal marker. Our results suggest that CD10-antibody may be of value in the distinction between benign and malignant small-sized renal tumors. We conclude that neoplastic transformation may imply such alterations in the expression of marker-Ags (proximal/distal) that no conclusion can be drawn regarding the tubular segment from which a renal epithelial tumor takes its origin.

Ultrastructure of nodular renal blastema and sclerotic metanephric hamartoma.

In the course of a prospective study of renal neoplasms involving rapid fixation by perfusion of the nephrectomy specimens, optimally perfusion-fixed tissue was obtained from complexes of nodular blastema and sclerotic hamartoma situated in a kidney with Wilms' tumour. Ultrastructure of these focal maturation defects showed great similarity to normal metanephric blastema and embryonal tubules as well as to blastemal and tubular components in diffuse nephroblastematosis and Wilms' tumours.

The phrenic syndrome in salpingitis ("acute perihepatitis") explained by absorption of exudates from the peritoneal cavity through the diaphragm.

Referring to a recent report given in Acta Chirurgica Scandinavica of 14 cases of acute perihepatitis in young females with genital inflammation, the pathogenesis of which was claimed unknown, a recapitulation is given of previously published investigations on the clinical significance of the absorption of exudates and particulate matters from the peritoneal cavity in man through the lymphatics of the diaphragm. The pathogenesis of metastases in the supraclavicular nodes (Virchow) and of ascites in peritoneal carcinomatosis is mentioned.