Biomedical subjects

R Vihko

Publications and source records attributed to R Vihko.

At least 73 records · Page 4Linked to original sources

PubMed1990

The gene for 17 beta-hydroxysteroid dehydrogenase maps to human chromosome 17, bands q12-q21, and shows an RFLP with ScaI.

The gene encoding human 17 beta-hydroxysteroid dehydrogenase (17-HSD; EC 1.1.1.62) is assigned to chromosome 17 by Southern blotting analyses of panels of human x rodent somatic cell hybrids and independently to 17q12-q21 using chromosomal in situ hybridization. A search for physical linkage between 17-HSD and the proto-oncogenes. THRA1 and ERBB2 (both reported to be located in this region of chromosome 17) was performed by pulsed-field gel electrophoresis (PFGE) using several rare-cutting restriction endonucleases. Because all three genes hybridized to DNA fragments of different lengths it seems unlikely that the gene for 17-HSD is located very close to THRA1 and ERBB2. Further evidence for this assumption was obtained from the absence of any coamplification of the 17-HSD gene in 9 breast tumors with amplification of the ERBB2 gene. Analyses of Southern blots of ScaI-digested DNAs from unrelated individuals from Northern Finland revealed a relatively infrequent diallelic restriction fragment length polymorphism, the allele frequencies of which were 0.04 (A1) and 0.96 (A2).

17-Hydroxysteroid Dehydrogenases↗

PubMed1990

Biodistribution in normal mice of an 111In-labelled prostatic acid phosphatase-specific antibody and its F(ab')2 fragments derivatized site-specifically or via bicyclic diethylenetriaminepentaacetic acid anhydride.

In this study we examined optimization of derivatization of monoclonal antibodies and their fragments intended for use as radiopharmaceutical in radioimaging and/or radioimmunotherapy of prostatic cancer. Two different principles were used to conjugate diethylenetriaminepentaacetic acid (DTPA) to a monoclonal antibody (Mab, subclass IgG1) raised against human prostatic acid phosphatase (PAP). In addition, the F(ab')2 fragments of this Mab were also derivatized. We used the cyclic anhydride of DTPA (CA-DTPA) as a chelating agent for these two protein moieties. Furthermore, the Mab and the F(ab')2 fragments were modified site-specifically by attaching linkers, N-(p-aminobenzyl)diethylenetriaminetetraacetic acid (p-NH2-Bz-DTTA) and 1-(p-aminobenzyl)diethylenetriaminepentaacetic acid (p-NH2-Bz-DTPA), to the carbohydrate components of the parent molecules. In this study, biodistribution of the 111In-labelled derivatives was investigated in normal mice. All the derivatives of IgG1 demonstrated a slower blood clearance than the corresponding derivatives of the F(ab')2 fragments. This property was particularly pronounced in the site-specifically conjugated derivatives of IgG1. All the derivatives studied accumulated in the liver, kidney, and spleen. The CA-DTPA derivatives of F(ab')2 fragments showed the highest kidney-to-blood ratios of radioactivity compared with the other compounds studied. The derivatives of IgG1 showed a higher percentage of the injected dose in liver and spleen tissues than the derivatives of the F(ab')2 fragments. The F(ab')2 fragments studied also gave rise to site-specific derivatives, which demonstrated that carbohydrates were also present in this part of the molecule. They behaved similarly to the CA-DTPA F(ab')2 derivative in other respects, but the kidney accumulation was lower at 72 and 120 h.(ABSTRACT TRUNCATED AT 250 WORDS)

Acid Phosphatase↗

PubMed1990

Carcinoma of the breast in children.

Carcinoma of the breast in children is an extremely rare disease, only 44 patients have been reported in the world literature. We report on a case of breast cancer in a 9-year-old girl, who was admitted to the hospital because of a four-month history of a painless mass in the right breast. Clinical examination and mammography resulted in a strong suspicion of malignancy. The histology corresponded to juvenile secretory carcinoma, the histological type without the characteristics of prepubertal cancer cases. Electron microscopy demonstrated intracellular large vacuoles and acini filled with secretory material. The mitotic index was low, the highest measured value was 4 mitotic figures per 10 high power fields corresponding to 2.78 mitotic figures per mm2 of epithelium in the microscope field. Flow cytometry showed that the neoplastic cells were diploid and had a low S-phase fraction. A simple mastectomy including axillary evacuation was performed. No lymph node or distant metastases were found. Postoperative radiation treatment or chemotherapy were not administered. Our patient has been in follow-up for six years without recurrence. In this case simple mastectomy with axillary evacuation seems to have given a cancer-free development into adulthood. Earlier reports have also shown a favourable outcome in these tumours.

Breast↗

PubMed1990

Endocrine determinants of fertility: serum androgen concentrations during follow-up of adolescents into the third decade of life.

We have completed a 13-yr longitudinal study of endocrine features in females originally aged 7-17 yr and report now factors related to fertility in these women, mainly serum testosterone (T) and androstenedione (A) concentrations in relation to becoming pregnant. Longitudinal regression analysis, corrected for the effect of age, showed that current serum T and A concentrations are correlated with those measured 12 yr earlier (T: r = 0.47, P less than 0.01; A: r = 0.57, P less than 0.001). Age-adjusted serum T and A concentrations before any pregnancies were higher in women who subsequently had no pregnancies than in those who had been pregnant (T: never pregnant, mean +/- SEM, 1.10 +/- 0.06 nmol/L, pregnant 0.81 +/- 0.07 nmol/L, P = 0.004; A: never pregnant 4.00 +/- 0.28 nmol/L, pregnant 2.98 +/- 0.33 nmol/L, P = 0.03). Serum androgen concentrations were not related to variables reflecting sexual behavior and the use of oral contraception. The data therefore show that adolescent serum androgen concentrations are preserved into adulthood and are reflected in fertility patterns during the third decade of life. Higher serum androgen concentrations are associated with lower fertility. Together with our previous findings, these data demonstrate that endocrine characteristics formed during puberty seem to persist at least until 30 yr of age.

Adolescent↗

PubMed1990

Time-resolved immunofluorometric assay of human prostate-specific antigen.

Assay of human serum prostate-specific antigen (PSA) is gaining importance in diagnosis and follow-up of prostatic cancer. In this time-resolved immunofluorometric assay of PSA, strip-wells were coated with a polyclonal antibody against PSA. To prepare the label, a monoclonal antibody displaying high affinity towards PSA was purified and derivatized with diethylenetriaminepentaacetic acid. With use of this derivative, seven to eight Eu atoms could be combined with one antibody molecule with no decrease in immunoreactivity. The minimum detectable concentration of PSA was 0.12 microgram/L. In 60 of 63 women studied, the PSA concentration in serum was less than 0.2 microgram/L. The increase in PSA in serum of asymptomatic men 51 years old or older, as compared with that for younger subjects, was possibly a result of "occult" prostatic hyperplasia. Most of the patients with prostatic hyperplasia or prostatic cancer had higher PSA concentrations than did subjects of ages less than 50 years or asymptomatic age-matched healthy subjects. Results compared favorably with those by an established technique relying on the use of radioactive label. Our method for measuring PSA in human serum is convenient, inexpensive, and well compatible with present clinical practice.

Aged↗

PubMed1990

Bovine steroid hormone and SHBG concentrations postpartum and during the oestrous cycle.

Changes in consecutive estimates of milk progesterone concentrations and serum steroid hormone and sex hormone-binding globulin (SHBG) concentrations in the postpartum period were examined in Finnish Ayrshire and Friesian dairy cows which were divided according to feeding into a hay group and a silage group. Milk progesterone concentrations rose above 10 nmol/l, indicating the start of ovarian luteal activity, slightly earlier in the silage group (28.4 +/- 8.7 (S.D.) days, n = 19) than in the hay group (33.4 +/- 10.3, n = 28) after calving. Likewise, the first normal oestrous cycles began slightly earlier in cows fed with silage. On the other hand, no differences in the beginning of ovarian luteal activity were observed between the breeds. Serum oestradiol-17 beta, oestrone, testosterone, 5 alpha-dihydrotestosterone (5 alpha-DHT), pregnenolone and progesterone concentrations were fairly unchanged during postpartum anoestrus after uterine involution and before ovarian cyclic activity. After first ovulation, considerable increases in milk and serum progesterone concentrations were observed. The increase was accompanied by elevations in serum pregnenolone and 5 alpha-DHT concentrations. In the late luteal phase, progesterone, 5 alpha-DHT and pregnenolone concentrations rapidly declined, leading to low hormone levels in pro-oestrus. Thereafter, serum pregnenolone and 5 alpha-DHT concentrations slightly increased during the follicular phase. On the other hand, oestradiol-17 beta concentrations were elevated in pro-oestrus and decreased after that, being lowest at met-oestrous. Serum testosterone concentrations appeared to be unchanged during postpartum anoestrus and over the oestrous cycle. Serum SHBG concentrations were unchanged during postpartum anoestrus and over the oestrous cycle, as well as in pregnant animals. The serum SHBG concentrations were about double those found in women with normal menstrual cycles, whereas oestradiol concentrations were much lower. At present, it cannot be explained how the biological effects of oestradiol become evident under such conditions.

Anestrus↗

PubMed1990

Direct solid-phase time-resolved fluoroimmunoassay of 17 alpha-hydroxyprogesterone in serum and dried blood spots on filter paper.

We describe a direct, solid-phase time-resolved fluoroimmunoassay (TRFIA) for measuring 17 alpha-hydroxyprogesterone (17OHP) in serum and blood spots on filter paper. We used 17OHP-3-carboxymethyloxime (17OHP3CMO) coupled to polylysine as the label, which enabled incorporation of up to 34 atoms of europium per molecule of 17OHP, for a very high specific activity. The assay is based on competition between labeled 17OHP3CMO and 17OHP in blood specimens for polyclonal rabbit anti-17OHP antibodies. The antibody-label complex is separated by binding to anti-rabbit antibodies coated onto microtiter strips. The assay buffer contains danazol to displace 17OHP from steroid-binding proteins in serum. For serum samples, the assay is accomplished in 1 h of incubation at room temperature. The blood spot assay with filter paper discs involves incubation overnight at 4 degrees C. Results for both types of specimens from the same subjects correlated well. The lowest measurable concentrations of 17OHP (nmol/L) were 0.10 (3 SD) and 0.75 (3 SD) for serum and dried blood on filter paper, respectively. Intra- and interassay CVs were about 5-15% for both types of samples.

17-alpha-Hydroxyprogesterone↗

PubMed1989

Some endocrine characteristics of early menarche, a risk factor for breast cancer, are preserved into adulthood.

Early menarche is a risk factor for breast cancer. In a longitudinal manner, we have investigated the endocrine features of girls with early menarche. This study extends our investigations to the third decade of life in a cohort of girls followed up for 13 years. The group studied comprised 44 women, 20-31 years of age. Eleven women had had their menarche before 12.0 years, 14 women at 12.0-12.9 years and 19 women at 13.0 years or more. The women who had had early menarche had higher serum oestradiol concentrations during the follicular phase of the menstrual cycle than the women who had had their menarche later. The serum oestradiol concentrations increased rapidly at the beginning of cycle in these "early menarche" women. If there is a threshold which serum oestradiol concentrations must exceed to increase the risk of breast cancer, then these women have more days at risk than other women. In addition, the serum SHBG (sex-hormone-binding globulin) concentration was about 30% lower in the follicular-phase specimens of the women who had had their menarche before 12.0 years compared with those who had had their menarche at 13.0 years. Our data therefore indicate that women with early menarche are subject to a high degree of oestrogen stimulation at least until approximately 30 years of age. Our findings may have important consequences for the design of intervention programs for breast cancer prevention.

Age Factors↗

PubMed1989

Radiolabelling of monoclonal antibodies: optimization of conjugation of DTPA to F(ab')2-fragments and a novel measurement of the degree of conjugation using Eu(III)-labelling.

F(ab')2 fragments (at concentrations of 5-30 mg/ml) derived from monoclonal antibodies raised against human prostate specific acid phosphatase were derivatized with a bicyclic anhydride of diethylenetriaminepentaacetic acid (cDTPAA) in the molar ratios of cDTPAA/F(ab')2 of 1:1, 5:1, 10:1 or 50:1. The most optimal product, aimed at radioimaging of prostatic cancer was obtained when the antibody fragment concentration was at least 10 mg/ml and the molar ratio of cDTPAA to F(ab')2 was 5:1. cDTPAA was added dissolved in dimethylsulfoxide (DMSO). Under these conditions, 1.8-2.2 DTPA molecules/F(ab')2 molecule were bound, giving a coupling efficiency of 37%-44%, and the labelling efficiency with 111In (3 mCi/1 mg protein) was 95% +/- 3% (n = 7). The antibody fragment completely retained its immunoreactivity measured by radioimmunoassay and showed no aggregation when studied using sodium dodecyl sulfatepolyacrylamide gel electrophoresis (SDS-PAGE). For evaluation of the degree of conjugation of DTPA to the antibody fragment, a novel technique was developed relying on the use of EuCl3, and the measurement of europium fluorescence employing time resolved fluorometry. Results by EuCl3 labelling were identical to those obtained by the conventional 111InCl3 labelling method.

Acid Phosphatase↗

PubMed1989

Steroid sulfates in testis tissue of prostatic cancer patients treated for six months with the gonadotropin releasing hormone agonist buserelin.

In order to assess the extent of inhibition of testicular steroidogenesis during long-term treatment of prostatic cancer with GnRH agonist, we measured the intratesticular levels of 5 steroid sulfate conjugates in human testis tissue removed from patients after 6 months of intranasal treatment with buserelin. The most pronounced decreases were found in testosterone and pregnenolone sulfates, to 1.6 and 7.1%, respectively, of concentrations measured in testis tissue from primarily orchiectomized prostatic cancer patients. In contrast, clearly smaller decreases were found in three other steroid sulfates measured, those of dehydroepiandrosterone (to 26%), 17-hydroxyprogesterone (to 27%) and 5-androstene-3 beta, 17 beta-diol (to 62%). These results are in keeping with our previous analyses of unconjugated steroids in similar tissue samples, and indicate that testicular steroidogenesis per se is not totally blocked by long-term intranasal treatment with GnRH agonist. Testicular steroid sulfate conjugation may be specifically suppressed since the total concentration of these conjugates decreased more than free steroid levels in our earlier measurements.

Aged↗

PubMed1989

Endogenous steroids in the pathophysiology of breast cancer.

The search for major endocrine abnormalities as causes for breast cancer has not been successful, whether it has been directed at patients with this disease or at different groups or populations at risk. An early-onset, long-lasting ovulatory cycle function seems to be prevalent in different risk categories for breast cancer. Women with early menarche, compared with those with late menarche, are additionally characterized as having higher circulating estradiol and lower sex-hormone-binding globulin concentrations. A number of additional findings point to estradiol as a central agent in the development of breast cancer, and cyclic progesterone secretion does not seem to have a clearly opposing action.

Androgens↗

PubMed1989

Circulating sex hormone-binding globulin and testosterone in newborns and infants.

The concentrations of sex hormone-binding globulin (SHBG) and testosterone (T) were measured in the cord blood of full-term newborns (14 boys, 15 girls) and pre-term newborns (10 boys, 5 girls), and in the venous circulation of 100 full-term infants aged 1-204 days. The ratio of T to SHBG (the 'free androgen index', FAI) was calculated to reflect the level of unbound T (the free, biologically active fraction). In boys' umbilical cord sera, T concentrations were significantly greater in arterial than in venous sera, while there was no such difference in the concentration of SHBG. Levels of SHBG in cord sera were considerably lower than those seen in the maternal circulation at term, but they were significantly greater in boys' than in girls' cord sera. Levels of T, and the FAI, were significantly greater in boys' arterial cord sera than in girls'. In early infancy, SHBG concentrations rose in both sexes, the highest values being seen in girls. In infant girls, levels of T and the FAI were constantly low. In infant boys, the expected peak in serum T concentrations was observed at 1-3 months the values approaching those seen in men. In contrast, values of the FAI at this age were relatively low, similar to those seen in women. This suggests that the elevation of male serum T during the first months of life lacks biological significance. However, it is important to realise that the FAI in male infants is about one order of magnitude larger than that in female infants at this time.

Androgens↗

PubMed1989

Interferon-gamma inhibits steroidogenesis and accumulation of mRNA of the steroidogenic enzymes P450scc and P450c17 in cultured porcine Leydig cells.

The inhibitory effects of recombinant porcine interferon-gamma (IFN gamma) on human CG (hCG)-stimulated testosterone production, and on mRNA concentrations of cholesterol side-chain cleavage (P450scc) and 17 alpha-hydroxylase/C17-20lyase (P450c 17) were investigated using porcine primary Leydig cell culture as a model. After preincubation of Leydig cells for 24 h with 1000 pM IFN gamma, hCG-stimulated (10 ng/ml, 2 h) testosterone production was inhibited by 50%, whereas no significant changes were seen in hCG-stimulated cAMP production. Incubation with 10 microM 5-cholestene-3 beta,22(R)-diol or 10 microM 5-cholestene-3 beta,20 alpha-diol together with hCG (10 ng/ml, 2 h) reversed most of the inhibitory effect of IFN gamma, suggesting that IFN gamma inhibits P450scc activity, possibly by inhibiting the substrate (cholesterol) availability for P450scc. Incubation with IFN gamma also decreased basal concentrations of P450scc (45%) and P450c 17 (35%) mRNA, although these changes probably did not contribute to the decreased testosterone production. Long-term treatment with hCG (100 ng/ml, 24 h) increased P450scc mRNA (3- to 4-fold) and P450c 17 mRNA (4- to 5-fold) concentrations. Simultaneous treatment with IFN gamma attenuated these hCG-induced increases in P450scc mRNA (50%) and P450c 17 mRNA (40-100%) concentrations, as well as in testosterone production (77%). This inhibition of testosterone production could only be partly reversed by the hydroxylated cholesterol derivatives. This suggests that in addition to possible suppression of cholesterol availability, decreased P450scc and/or P450c 17 activities (through decreased mRNA concentrations) were also involved in the IFN gamma suppressed steroidogenic capacity of porcine Leydig cells during long-term hCG stimulation.

Animals↗

PubMed1988

Complete amino acid sequence of human placental 17 beta-hydroxysteroid dehydrogenase deduced from cDNA.

cDNA clones for 17 beta-hydroxysteroid dehydrogenase (17-HSD; EC 1.1.1.62) were isolated from a placental lambda gt11 expression library using polyclonal antibodies against placental 17-HSD. The largest cDNA contained 1325 nucleotides, consisting of a short 5'-noncoding segment, a coding segment of 987 nucleotides terminated by a TAA codon, and a 329 nucleotide long 3'-noncoding segment. The open reading frame encoded a polypeptide of 327 amino acid residues with a predicted Mr of 34853. The amino acid sequence of 23 N-terminal amino acids determined from purified 17-HSD agreed with the sequence deduced from cDNA. The deduced amino acid sequence also contained two peptides previously characterized from the proposed catalytic area of placental 17-HSD.

17-Hydroxysteroid Dehydrogenases↗

PubMed1988

Tamoxifen and natural progesterone as supplements to low-dose postmenopausal estrogen therapy.

Postmenopausal women received 1 mg estrone sulfate a day for 3 weeks in 12 sequences separated by a 7-day interval without medication and every second time by a 10-day treatment with natural progesterone, 100 mg 2 times daily (n = 16), or tamoxifen, 10 mg 2 times daily (n = 17). Both treatments alleviated climacteric symptoms, maturated the vaginal epithelium, and decreased follicle-stimulating hormone, luteinizing hormone, and prolactin concentrations while lipid metabolism remained unaltered. In the estrogen-progesterone group 4 women (25%) were persistently amenorrheic, 12 (75%) experienced 1-5 bleedings per year, and 4 women had proliferative endometrium after treatments. In the estrogen-tamoxifen group 11 women (65%) were amenorrheic, 6 (35%) had 1-4 bleedings per year, and 5 had proliferative endometrium. With the present treatment schedules, tamoxifen was more effective than natural progesterone in inhibiting estrogen stimulation of postmenopausal endometrium.

Alanine Transaminase↗

PubMed1988

Radioimaging of lymph node involvement in prostatic carcinoma.

We have previously shown that Tc-99m- or In-111-labelled derivatives of monoclonal antibodies against prostatic acid phosphatase can be used to reveal bone metastases of prostatic carcinoma. In this study, seven patients who were candidates for radical prostatectomy and two patients with bone metastases, were investigated to evaluate the applicability of this technique for preoperative staging of the patients. One milligram of monoclonal antibodies was injected bilaterally into the periprostatic space, and the patients were subjected to measurements by gamma camera. In one patient metastases were detected in the left para-aortic, iliac and obturator lymph nodes by this technique. The lesions incorporating radioactivity were confirmed to be metastases of prostatic cancer following staging pelvic lymphadenectomy. In the other four patients, radioimaging did not show any lymph node metastases, and this negative finding was confirmed at the operation. These early data indicate the possibility of preoperative staging of prostatic cancer by means of radiolabelled derivates of monoclonal antibodies, raised against prostatic acid phosphatase and injected into the periprostatic area.

Antibodies, Monoclonal↗

PubMed1987

Immunoscintigraphic evaluation of lymph node involvement in prostatic carcinoma.

Five patients who were candidates for radical prostatectomy were investigated. One milligram of diethylene triamine pentaacetic acid derivatives of purified F(ab')2 fragments of monoclonal antibodies against prostatic acid phosphatase, labeled with 99mTc, were bilaterally injected into the periprostatic space. The amount of radioactivity injected varied between 3 and 7 mCi. Imaging took place dynamically for the first hour following injection, then at 6 and 24 hr. In one patient, lymph node metastases were detected in the left paraaortic, iliac, and obturator lymph nodes by this technique. The lesions incorporating radioactivity were confirmed to be metastases of prostatic cancer following staging pelvic lymphadenectomy. Immunolabeling electron microscopy studies revealed internalized antibody in prostatic cancer cells. In the four other patients, radioimaging did not show any lymph node metastases, and this negative finding was confirmed at surgery. These early data indicate the possibility of preoperative staging of prostatic cancer using radiolabeled derivatives of monoclonal antibodies raised against prostatic acid phosphatase and injected into the periprostatic area.

Acid Phosphatase↗

PubMed1987

Follicular growth in relation to serum hormonal patterns in adolescent compared with adult menstrual cycles.

The purpose of this study was to clarify the endocrine regulation of the adolescent menstrual cycle, especially the relationships between ovarian follicular development, luteal phase progesterone secretion, and function of the hypothalamic-pituitary unit. One menstrual cycle of each of 17 women who were 15 and 16 years of age and 12 women who were 25 to 35 years of age was characterized by ultrasonography and hormone measurements. In both groups there was a close correlation between follicle size and serum estradiol concentrations. In the adolescents, follicle development was slower, and an eventual ovulation took place from a smaller follicle than in the older group. The immediate preovulatory follicle size correlated with the maximal serum progesterone concentration during the luteal phase. Late follicular development in adolescents may be related to the slow increase of serum follicle-stimulating hormone concentrations early in the cycle.

Adolescent↗