Receptor function studies in specimens from the proximal human urethra obtained by transurethral resection

Summary During transurethral resection (TUR) for prostatic hyperplasia, specimens were taken from the proximal urethra. Muscle strips thus obtained were mounted in an organ bath and muscle contraction was induced by adding increasing concentrations of noradrenaline (NA), methoxamine (₁-agonist) and clonidine (₂-agonist). NA and methoxamine induced a dose-dependent muscle contraction, but clonidine had no effect. The influence of prazosin (₁-antagonist) and yohimbine (₂-antagonist) on the NA-induced muscle contraction was also evaluated. Both antagonists had an inhibitory effect,which was much more potent with prazosin. The specimens taken during TUR were found to be suitable for in vitro receptor function studies. The -adrenergic receptor function in the proximal human urethra was found to be mainly of the -type.     

Clinical significance of α1-adrenoceptor selectivity in the management of benign prostatic hyperplasia

Alpha₁-adrenoceptor antagonists have beenshown to provide effective relief from symptomsof benign prostatic hyperplasia (BPH) withattendant improvements in quality of life.Although the _1A-adrenoceptorsubtype predominates over other subtypes of₁ adrenoceptors in the prostategland, there is no evidence that a subselective-adrenoceptor antagonist provides aclinical advantage over a selective₁-adrenoceptor antagonist in thetreatment of patients with BPH. Thepharmacokinetic profiles of_1A-adrenoceptorantagonists and their documented penetration ofthe blood-brain barrier (CNS adverse effects)preclude a clinical benefit of subselective-adrenoceptor blockers over selective₁ blockers.     

Renal α-adrenergic receptors and genetic hypertension

The hypothesis has been proposed that an increase in the number of renal -adrenergic receptors may contribute to the pathogenesis of genetic hypertension. Herein we review recent findings regarding expression of renal ₁ (_{1 a},_{1 b})- and ₂ (_{2 a},_{2 b})-adregenergic subtypes and we provide an updated revision of the above-stated hypothesis. Enhancement in receptor number or in post-receptor components responsible for ₁- and ₂-adregenergic mediated sodium reabsorption in proximal tubule may contribute to sodium retention and an elevation in blood pressure. Perhaps such changes contribute to the increase in blood pressure in genetically determined hypertension in humans, although direct tests of this notion have not yet been performed.     

Comparison of adrenoceptor subtype expression in porcine and human bladder and prostate

We have quantified and characterized ₁-, ₂-and -adrenoceptor subtypes in porcine bladder detrusor and bladder neck, human bladder detrusor, and porcine and human prostate. ₁-, ₂- and -adrenoceptor were identified in radioligand binding studies using [³H]prazosin, [³H]RX 821002 and [¹²⁵I]iodocyanopindolol, respectively, as the radioligands. In porcine male and female detrusor and bladder neck and male prostate, adrenoceptors were detected in the order of abundance > _{2 1} (not detectable), with no major differences between the sexes or between detrusor and bladder neck. In human detrusor and prostate the order of abundance was > _{2 1} (not detectable) and ₁ > ₂. respectively. The ₂-adrenoceptors in all tissues were homogeneously of the _2A-subtype as evidenced by competition binding studies with yohimbine, prazosin, ARC 239 and oxymetazoline. The -adrenoceptors represented a mixed population with a dominance of the ₂-subtype in all tissues as demonstrated by competition binding with ICI 118,551 and CGP 20,712A. We conclude that pigs may be a suitable model for studies of detrusor function with respect to adrenoceptor expression. They may be less suitable for studies of bladder neck or prostate function.     

Lysosomal localization of secretory prostatic acid phosphatase in human hyperplastic prostate epithelium

Summary The ultrastructural localization of secretory prostatic acid phosphatase (PAP) in human benign prostate tissue was accomplished using the immunogold technique on ultrathin Lowicryl sections. Polyclonal antibodies directed against secretory PAP (MW 50 kD) and the lysosomal enzymes -glucosidase and -galactosidase as well as an antiserum dircted against prostatic antigen (PA) were used. PAP was found in secretory vacuoles of columnar secretory epithelial cells. In addition, double labeling experiments revealed that secretory PAP was also localized in electrondense organelles of columnar epithelial cells containing -glucosidase and -galactosidase. PA was exclusively found in secretory vacuoles of columnar secretory epithelial cells. The results demonstrate the presence of secretory PAP within functional lysosomes and secretory vacuoles of the prostatic columnar epithelial cells and the absence of such PAP-containing lysosomes in the basal cells of the prostatic acini.     

Natural human IgG inhibits the production of tumor necrosis factor-α and interleukin-1α through the Fc portion

The overproduction of cytokines such as the tumor necrosis factor- (TNF-) and interleukin-1 (IL-1) may cause further deterioration in the already critical condition of patients with shock, sepsis, and acute inflammation. The effectiveness of infusion therapy of natural human IgG to such patients is suggested to depend partly upon the inhibition of the productivity of these cytokines. In this study, we investigated the modulation effects of IgG and its fragments on the production of TNF- and IL-1, on human peripheral blood mononuclear cells (PBMC). The production of TNF- and IL-1 was found to be dose-dependently inhibited by IgG when stimulated by lipopolysaccharide (LPS), phytohemagglutinin (PHA), concanavalin A (Con A), and interleukin-2 (IL-2). However, no inhibition was seen when stimulated by phorbormyristate acetate (PMA). The F(ab)₂ fragment showed enhancing effects on cytokine production by LPS, while the Fc fragment showed not as much inhibitory effect as whole intact IgG. IgG showed no direct cytotoxic effect on PBMC. These data suggest that natural human IgG inhibits TNF- and IL-1 production by PBMC through the Fc portion. The results of this study led us to conclude that whole intact IgG may be the best form of therapeutic delivery.     

Estrogen Receptor Alpha in Human Breast Cancer: Occurrence and Significance

Estrogens have long been recognized as being important for stimulating the growth of a large proportion of breast cancers. Now it is recognized that estrogen action is mediated by two receptors, and the presence of estrogen receptor (ER)³ correlates with better prognosis and the likelihood of response to hormonal therapy. Over half of all breast cancers overexpress ER and around 70% of these respond to anti-estrogen (for example tamoxifen) therapy. In addition, the presence of elevated levels of ER in benign breast epithelium appears to indicate an increased risk of breast cancer, suggesting a role for ER in breast cancer initiation, as well as progression. However, a proportion of ER-positive tumors does not respond to endocrine therapy and the majority of those that do respond eventually become resistant. Most resistant tumors remain ER-positive and frequently respond to alternative endocrine treatment, indicative of a continued role for ER in breast cancer cell proliferation. The problem of resistance has resulted in the search for and the development of diverse hormonal therapies designed to inhibit ER action, while research on the mechanisms which underlie resistance has shed light on the cellular mechanisms, other than ligand binding, which control ER function.     

Plasma proteins present in human cortical bone: Enrichment of theαHS-glycoprotein

The spectrum of plasma proteins present in human cortical bone and permanent dentine has been determined. One plasma glycoprotein, theHS-glycoprotein, was found to be present at a high concentration in both bone and dentine and was shown to be concentrated in the mineralized tissues with respect to the other plasma proteins by factors of between 30 and 100. In this respect theHS-glycoprotein is analogous to the G2B-glycoprotein and -glycoprotein of bovine and rabbit b one, respectively. The binding ofHS-glycoprotein and albumin to calcium phosphates generated within serum samples has been studied at different serum: precipitate ratios. In each case all theHS-glycoprotein was removed from the samples and theHS-glycoprotein was concentrated with respect to albumin by factors ranging from 370 at the highest serum: precipitate ratio to 25 at the lowest ratio. The plasmaHS-glycoprotein concentrations of patients with Paget's disease of bone were shown to be substantially lower than the normal range, with significant negative correlation between theHS-glycoprotein concentration and the plasma alkaline phosphatase activity.     

Collagen distribution in human membranous glomerulonephritis

In membranous glomerulonephritis (MGN), thickening of the glomerular basement membrane (GBM) is partly due to the accumulation of basement membrane material between and around immune deposits located on the epithelial aspect of the GBM. We investigated the distribution of type IV collagen chains (1/2, 3, 4, 5, 6) and of types I, III, V, and VI collagen in the glomeruli from 16 patients, by indirect immunofluorescence in 13 and the high-resolution immunogold technique in 6. No changes were detected in stage I MGN. The spiky projections of the GBM in stage II MGN and the basement membrane layers encircling immune deposits in stage III contained the 3, 4, and 5 chains of type IV collagen. In contrast, the 1/2 chains of type IV, as well as type VI collagen accumulated in the subendothelial aspect of the GBM. No significant staining for types I, III, and V collagens or for the 6 chain of type IV collagen was detected. The results show that, as in the normal glomeruli, the different chains of type IV collagen are not co-distributed in the glomerular extracellular matrix in MGN. They also indicate that type IV collagen chains and type VI collagen play an important role in the thickening of the GBM in human MGN.     

Effects of Sex Steroid Receptor Specificity in the Regulation of Skeletal Metabolism

The interaction between estrogens and androgens, with their protective effects in bone, and parathyroid hormone (PTH), a calcitropic peptide hormone, is complex but may be better understood with murine models. The purpose of this study was to characterize skeletal phenotypes of mice deficient in estrogen receptor alpha (ER), androgen receptor (AR, mutant tfm), or both, and determine if ER and AR alter osteoblast differentiation and/or PTH response in vitro. Loss of ER resulted in increased long bone length in females, but reduced length in males, suggesting loss of ER reversed sex steroid-dependent skeletal dimorphism. The AR deficient tfm mice (genetically male but phenotypically female) had the longest bones and, similar to males, lengths were reduced with loss of ER. Loss of AR and/or ER resulted in a reduction in femoral bone mineral density (BMD) compared to male wildtype (WT) mice, suggesting tfm mice follow the female sex for BMD. In males or tfm mice, but not females, loss of AR and/or ER caused a reduction in cortical width of the tibia compared to male WT mice. Reduced trabecular bone was found in tibiae of female and tfm mice versus male littermates, suggesting that tfm mice follow the female sex for trabecular bone but loss of ER did not alter trabecular bone levels. Primary calvarial osteoblasts of male WT mice were less responsive to PTH stimulation of cAMP than all other genotypes, suggesting the female chromosomal sex and/or loss of ER or AR results in increased sensitivity to PTH. In conclusion, tfm mice follow the male pattern of long bone development, but imitate females in bone density and trabecular bone. Loss of ER and/or AR results in increased osteoblast sensitivity to PTH and may explain actions of PTH noted in hypogonadal humans.     

Cytotoxic effect of diphtheria toxin used alone or in combination with other agents on human renal cell carcinoma cell lines

Treatment of renal cell carcinoma (RCC) by conventional chemotherapy and immunotherapy has resulted in minimal remissions. Alternative forms of therapy are therefore being sought. The present study investigated the sensitivity of RCC cell lines to several toxins used alone and in combination with other agents. RCC lines were relatively sensitive to the direct cytotoxic effect of diphtheria toxin (DTX), Pseudomonas aeruginosa exotosin A (PEA) and ricin. Furthermore, DTX in combination with tumor necrosis factor- (TNF-) resulted in synergistic cytotoxic activity. The mechanism of synergy was examined. A possible mechanism of resistance to TNF- in tumor cells is the expression of TNF- mRNA or protein. R11 cells did not constitutively express mRNA for TNF-, however, treatment of R11 cells with TNF- induced the expression of TNF- mRNA. When DTX was used in combination with TNF-, the level of TNF- mRNA induced by TNF- was markedly reduced. These studies suggest that DTX in combination with TNF- can overcome the resistance of RCC lines and that the marked downregulation of TNF- mRNA by DTX may play a role in the enhanced cytotoxicity seen with the combination of DTX and TNF-. Furthermore, the combination treatment might also potentiate the antitumor host responses. The implications of these findings in clinical therapy are discussed.     

Effects of 1α-hydroxyvitamin D3 on serum calcium and immunoreactive parathyroid hormone in patients with chronic renal insufficiency

Six patients with chronic renal failure on regular dialysis treatment were given low doses (0.5–1.0 g/day) of 1-hydroxyvitamin D₃, monitoring the serum calcium, inorganic phosphate, immunoreactive parathyroid hormone concentration (IPTH) and alkaline phosphatase activity. The serum calcium rose in all patients after 7 days' treatment, in some subjects to hypercalcemic range; this effect persisted 6–14 days after withdrawal of 1-hydroxyvitamin D₃. The elevated serum IPTH rose in the first days of treatment, but later decreased to normal values. It is suggested that active vitamin D metabolites are necessary for normal response of parathyroid glands to variation in serum calcium. Low-dose 1-hydroxyvitamin D₃ treatment appears to be a promising method of correcting hypocalcemia and secondary hyperparathyroidism in chronic renal failure. Careful control of serum calcium is necessary, as hypercalcemia may occur even after minute doses of 1-hydroxyvitamin D₃.     

Urinary unconjugated 5α-androstane-3α, 17β-diol in patients with prostatic tumours

Summary A sensitive and reliable radioimmunoassay (RIA) for urinary unconjugated 5-androstane-3, 17-diol is described. The mean overall recovery of unconjugated 5-androstane-3, 17-diol was found to be 57.4%. The sensitivity of the assay was 79 fmol per assay tube and the intra and inter-assay variations ranged between 7.2% and 11.4%. The mean ± SEM for the concentration of this androgen in the urine of normal men was 339.6±66.8 nmol/24h. The corresponding values for patients with benign prostatic hypertrophy (BHP) and carcinoma of the prostate (Ca) were 297.8±44.7 and 1592.1±622.7 respectively. The mean value for Ca patients was significantly higher than either BPH (p<0.05) or normal subject (p<0.02), suggesting a differential urinary excretion pattern for unconjugated 5-androstane-3, 17-diol between BPH and Ca patients. It is concluded that the combined measurement of this androgen in the plasma and urine provides a more accurate assessment of the profile of this hormone than a single plasma estimation.     

Antibodies directed at mouse IL-2-R α and β chains act in synergy to abolish T-cell proliferation in vitro and delayed type hypersensitivity reaction in vivo

The anti-mouse IL-2-R chain mAb TM-1 which, by itself, does not affect IL-2-dependent proliferation throught the high affinity mouse IL-2 receptor, was shown to cooperate in a synergistic way with a set of anti-IL-2-R chain mAbs both in vitro and in vivo. In vitro, when associated at equimolar concentrations, the TM-1/anti- mAb association was four to ten times more efficient at inhibiting the proliferation of the CTL-L2 cell line than was a similar concentration of anti- mAb alone. In addition, a bispecific antibody in which a Fab' fragment of TM-1 was covalently linked to a Fab' fragment of one of the anti- mAb (5A2) was shown to be as efficient as the TM-1/5A2 association. The association of TM-1 with 5A2 was also tested in vivo in a sheep red blood cell-induced delayed type hypersensitivity (DTH) model. TM-1 which, by itself, had no effect on DTH, induced a two- to threefold decrease in the doses of 5A2 required to suppress this cell-mediated immune reaction.     

G-Proteins in alpha1-adrenoceptor mediated prostatic smooth muscle contraction

The role of signal transducing guanine-nucleotide binding proteins (G-proteins) in ₁-receptor mediated smooth muscle contractions was investigated in human hyperplastic prostatic tissue. The selective ₁-receptor agonist phenylephrine (PE) evoked dose dependent contractions antagonized by the ₁-receptor blockers prazosin (EC₅₀ 10 nM) and YM 617 (EC₅₀ 3 nM). Application of nifedipine (1–10,000 nM), a blocker of voltage-dependentl-type Ca^2--channels (VDCC), inhibited the PE evoked contraction up to 65.4%. Pretreating the tissue strips with pertussis toxin (PTX, exotoxin from Bordetella pertussis; 5–25 g/ml), inactivating a subpopulation of G-proteins, inhibited the PE induced contractions up to 73.9%. PTX pretreatment had no effect on contractions elicited by 125 mMK^-. Application of nifedipine to PTX pretreated tissue led to an additional inhibition of 13.7%. Our findings demonstrate the involvement of PTX-sensitive G-proteins in the signal transduction pathway of ₁-receptor induced contractions of prostatic smooth muscle. The remaining contractility of PTX pretreated tissue suggests additional participation of PTX insensitive mechanisms in ₁-receptor mediated prostatic smooth muscle contractions.     

Proteins of the periodontium

Summary Cyanogen bromide (CNBr) peptides were prepared of the insoluble collagen of bovine dental cementum. Following chromatographic separation, the peptides were identified by their amino-acid composition. Type I collagen ([1(I)]₂2) accounted for more than 90% of the organic matrix, while Type III collagen ([1(III)]₃) was present at a level of approximately 5%. Amino-acid analyses revealed that the CNBr peptides from 1(I) and 2 chains of cementum closely resembled the corresponding peptides from calf skin. The only systematic difference was a higher level of hydroxylation of prolyl and lysyl residues of the cementum peptides.     

The Role of Transforming Growth Factor α Formulation on Aspirin-Induced Ulcer Healing and Oxidant Stress in the Gastric Mucosa

Purpose Transforming growth factor (TGF) accelerates wound healing, especially in gastric ulcers. Transforming growth factor can be affected by acid and pepsin in the gastric juice. Oxidative stress also plays a role in the formation of gastric lesions. This study was designed (1) to investigate the effects of microemulsion dosage form on the healing of gastric ulcers, and (2) to determine the relationship between oxidative mechanisms and TGF- during ulcer healing.Methods Gastric ulcers were induced in Wistar rats (male, 200 ± 25g), by 150mg/kg acidified aspirin application. The animals were divided into five groups consisting of 7–11 animals. The rats were killed after ulcer induction with aspirin (acute ulcer), or 2 days after ulcer induction (chronic ulcer), or after the daily application of microemulsion and TGF- for 2 days. The ulcer area was measured planimetrically. Thiobarbituric acid reactive substance, glutathione, and gastric mucus levels of tissues were measured by spectrophotometric methods. The total nitric oxide level was measured by a VCl₃ / Griess assay. Statistical comparisons were made by an analysis of variance and the Mann-Whitney U-test.Results The ulcer area and malondialdehyde level of gastric tissue both decreased and the glutathione level increased to intact gastric tissue levels, while the mucus and total nitric oxide levels increased significantly after the application of intragastric TGF-.Conclusion These findings suggest that TGF- accelerates the healing process after aspirin-induced gastric injury, and a relationship was observed between this application and the oxidative reactions.     

148. Magencarcinom und Serumelektrophorese

Zusammenfassung Es werden Merkmale des Magencarcinoms mit den Elektrophoresewerten von 350 Patienten korreliert. Bei folgenden Kriterien sind die Albumine vermindert, die -Globuline vermehrt: Höheres Alter, größerer Gewichtsverlust, zunehmende Penetration, Fernmetastasen (gegenüber Metastasenfreiheit). Hohe -Globuline finden sich beim Ulcuscarcinom und niedrige bei Lymphknotenmetastasen. Mit größerem Tumordurchmesser steigt nur das ₂-Globulin, nicht das ₁-Globulin. -Globuline zeigen ein divergierendes Verhalten. Auf die prognostische Bedeutung der Proteinfraktionen beim Magencarcinom wird hingewiesen.     

Serum levels of alpha-1 microglobulin and beta-2 microglobulin in bone marrow transplant recipients treated with cyclosporin A

The levels of alpha-1 microglobulin ( ₁m) and beta-2 microglobulin ( ₂m) in serum were estimated in 77 bone marrow transplant recipients. In comparison to pretransplant levels, the highest levels of ₁m and ₂m were found during impairment of renal function, i.e., during cyclosporin-induced nephrotoxicity and during treatment with other nephrotoxic drugs (P<0.001). The ₁m levels were less elevated during infections and acute graft-versus-host disease (P<0.01), while ₂m levels were markedly elevated during the same conditions (P<0.001). The linear correlations between serum creatinine and ₁m and creatinine and ₂m were r=0.7 and 0.8, respectively (P<0.001). The overall correlation between ₁m and ₂m was 0.4 (P<0.001). It is concluded that ₁m might be a complement to serum creatinine levels in monitoring renal function after bone marrow transplantation.     

The reducing end of αGal oligosaccharides contributes to their efficiency in blocking natural antibodies of human and baboon sera

Synthetic galactosyl oligosaccharides were tested for their ability to inhibit the cytotoxic reaction of human and baboon natural antibodies on PK15 cells in culture. Methyl--Gal gave weak inhibition, Gal1-3Gal substantially inhibited the reaction (400 M), and Gal1-3Gal2-4GlcNAc was ten times more efficient (30 M). The modification from to anomeric configuration of the nonreducing end resulted in a complete loss of activity, while substitutions at the reducing end induced only a partial loss of activity. These observations suggest that natural anti-Gal antibodies recognize the epitope from its nonreducing end, but that substitutions at the reducing terminus can modify the antibody-binding capacity. Modified tri- and tetrasaccharides are better inhibitors than the disaccharide but not as good as Gal1-3Gal1-4GlcNAc. The reducing terminus therefore contributes some energy to the reaction, indicating that certain oligosaccharides will be of more potential clinical use than others.