Torsten Wahlström

Spatial and temporal pattern of cellular myc oncogene expression in developing human placenta: Implications for embryonic cell proliferation

We have analyzed staged human placentas by Northern, dot blot, and in situ hybridization to human c-myc probes. Placental RNA exhibits a stage-specific appearance of a 2.4 kb transcript of the c-myc gene. The frequency of this transcript varies 20 to 30 fold over the course of placental development, showing a peak at 4-5 weeks after conception, where the myc transcripts comprise about 0.05% by weight of the total placental mRNA. A clear decline in placental c-myc transcription is seen before the end of the first trimester of pregnancy. In situ hybridization to 125I-labeled myc probes demonstrates an unequal spatial distribution of myc transcripts in placental with particularly high expression in the cytotrophoblastic shell of early placenta. Labeling of placental explants with 3H-thymidine, the localization of myc transcripts to cytotrophoblasts, and the temporal pattern of myc expression all support a strong correlation between myc transcript abundance and cytotrophoblast proliferation. We argue for a role for the c-myc gene in the proliferation of normal cells in this tissue.

Controlled Release of Lidocaine from Injectable Gels and Efficacy in Rat Sciatic Nerve Block

AbstractPurpose. Methods of delaying the action of local anesthetics are important, since short duration of action limits their use in the treatment of postoperative and chronic pain. The present study evaluated the use of low-viscosity gels in prolonging the release of lidocaine. Methods. Release of lidocaine from 2% lidocaine-HC1 containing methylcellulose (MC), hydroxypropylmethylcellulose (HPMC), sodiumcarboxymethyl cellulose (CMC), and poloxamer 407 (PO) gels was studied in phosphate buffer, pH 7.4, at 37°C. Commercial metylcellulose gel (MCcom) served as control. The in vivo efficacy of the respective gel formulations were evaluated in rats. The gel was injected into the vicinity of the sciatic nerve and nociception and motor function were tested. Results. The cumulative amount of lidocaine released during 8 hr was slowest from the PO gel, followed by the CMC, HPMC and MC gels. The antinociceptive effect was not prevented by the motor block and lasted longest with the PO gel. Good linear and rank order correlation was obtained between in vitro and in vivoresults. The microscopic examination of the tissue samples revealed only mild or no irritation of the skeletal muscle tissue by the PO, HPMC, and CMC gels. Conclusions. Based on these results poloxamer gel proved to be the most promising carrier for lidocaine.

In vitro segregation of the metanephric nephron

Abstract In vitro segregation of the metanephric nephron was examined using three probes for the main segments: fluorochrome-conjugated wheat germ agglutinin (WGA) binding to the glomerular epithelial surface, an antiserum against the brush-border antigens (BB) of the proximal tubules, and an antiserum against the Tamm-Horsfall glycoprotein (TH) of the distal tubules. In vivo , these markers appeared sequentially on Days 13 to 15. The same sequence was obtained in experimental recombinants of the metanephric mesenchyme and its inductor. When the inductor was removed after a 24 hr initial transfilter contact with the mesenchyme, segregation was similarly observed after subculture of the isolated mesenchyme. Hence, the sequential, multiphase differentiation of the nephron is initiated during a short induction period.

Evidence for divergence of DNA copy number changes in serous, mucinous and endometrioid ovarian carcinomas.

Comparative genomic hybridization was applied to detect and map changes in DNA copy number in 24 well or moderately differentiated epithelial ovarian carcinomas (eight serous, eight mucinous and eight endometrioid carcinomas). Twenty-three of the 24 tumours showed changes in DNA copy number in one or several regions (median 4, range 1-17). Gains were more frequent than losses (ratio 1.6:1.0). The most frequent gains occurred in chromosomes 1q (38%), 2p (29%), 7q (25%), 8q(38%) and 17q (38%), and the most common losses were located in chromosomes 8p (21%), 9p (25%) and 13q (21%). High-level amplifications were detected in seven tumours at 1q22-32, 2p15-22, 3qcen-23, 6p21-22 and 8q. In the three histological subtypes the copy number karyotypes showed substantial differences. Gains at 1q were observed in endometrioid (five cases) and serous tumours (four cases). Increased copy number at 10q was seen in endometrioid tumours only (four cases), whereas gains at 11q occurred mostly in serous tumours (four cases). In mucinous tumours, the most common copy number change was a gain at 17q (six cases). The results show that, in epithelial ovarian carcinoma, changes in DNA copy number are a rule rather than an exception, chromosomes 1, 2, 7, 8, 9, 13 and 17 being the most frequently affected. The diverging pattern of genetic changes seen in epithelial ovarian carcinomas with different histological phenotypes suggests that various pathways may lead to tumorigenesis and/or progression in these subgroups.

DISTINCTION BETWEEN ENDOCERVICAL AND ENDOMETRIAL ADENOCARCINOMA WITH IMMUNOPEROXIDASE STAINING OF CARCINOEMBRYONIC ANTIGEN IN ROUTINE HISTOLOGICAL TISSUE SPECIMENS

The differential diagnosis of endocervical and endometrial adenocarcinomas can be improved by the demonstration of carcinoembryonic antigen (CEA) in tissue by means of immunoperoxidase staining. Tissue from 131 (80%) of 163 patients with endocervical adenocarcinoma but only 11 (8%) of 137 patients with endometrial adenocarcinoma was CEA-positive. The commonest exceptions were endocervical mesonephroid adenocarcinomas (which were CEA-negative) and endometrial adenosquamous carcinomas (which were CEA-positive). After exclusion of these on simple morphological criteria, 86 of 107 endocervical adenocarcinomas (80%) were CEA-positive, and all 122 endometrial adenocarcinomas were CEA-negative. The remarkable difference in the expression of CEA between endocervical and endometrial adenocarcinomas suggests a novel application of immunohistochemistry in routine clinical practice.

Corticotrophin-releasing factor in human placenta: Localization, concentration and release in vitro

Corticotrophin-releasing factor (CRF) immunoreactivity was demonstrated by immunohistochemical staining in the cytotrophoblast of the early pregnancy placenta, in the decidua and in the amnion. This localization is different from that of adrenocorticotrophic hormone (ACTH) and beta-endorphin, which are present in the syncytiotrophoblast. The release of immunoreactive CRF was demonstrated from both early and term placental tissues in vitro. The mean amounts of CRF in the early and term pregnancy placental/decidual extracts were 0.99 +/- 0.5 ng/g and 19.7 +/- 3.1 ng/g, respectively. A slightly greater amount of CRF was found in extracts from term placentae and in cord venous plasma collected after spontaneous vaginal delivery than in those collected at elective caesarean section performed before the beginning of labour.

Placental protein 12 (PP12) is induced in the endometrium by progesterone

The occurrence of PP12 was studied by the biotin-avidin immunoperoxidase method in the endometrium of 106 premenopausal and postmenopausal women at various phases of the menstrual cycle or during estrogen and progestogen replacement therapy. No PP12 was found in the endometrium under the following conditions: (1) during the proliferative phase, (2) in cystic glandular hyperplasia, (3) during the first 3 postovulatory days in ovulatory cycles, (4) in atrophic postmenopausal endometrium, and (5) in estrogen-stimulated postmenopausal endometrium. PP12 was found in the endometrium under the following conditions: (1) in the secretory endometrium from the fourth postovulatory day onward, (2) in the endometrium during progestogen treatment of previously anovulatory premenopausal women, and (3) in the endometrium from postmenopausal women treated with estrogen followed by combined estrogen and progestogen replacement therapy. These results suggest that PP12 is a P-dependent protein which, in natural cycles, appears in the endometrium around the time of implantation and, in postmenopausal women, can be induced by progestogens after estrogen priming.

A 5-year follow-up study on the use of a levonorgestrel intrauterine system in women receiving hormone replacement therapy.

OBJECTIVE To investigate endometrial histology, bleeding, and the effects of replacing the levonorgestrel intrauterine system (LNG IUS, Mirena/Levonova, Leiras Oy, Turku, Finland) after 5 years of combined use with estrogen. DESIGN Prospective cohort study. SETTING Private outpatient clinic. PATIENT(S) Forty postmenopausal women started hormone replacement therapy with LNG IUS and either a patch (50 microg/24 h) or oral (2 mg) estradiol valerate protocol. Thirty-nine completed 12 months of treatment. Twenty-nine of them had used LNG IUS with continuous estradiol replacement therapy for 5 years. Seven of them volunteered to a 3-month treatment-free period before reinsertion; 22 opted for immediate reinsertion. INTERVENTION(S) Endometrial sampling for histology, endometrial thickness, and location of the LNG IUS by ultrasound at removal and after washout. The women completed bleeding diaries from 3 months prior to removal to 3 months after reinsertion. MAIN OUTCOME MEASURE(S) Endometrial histology was evaluated and estrogen and progestin effects were also investigated. Endometrial thickness was measured. Bleeding was examined based on bleeding diaries. The investigator and the women evaluated the insertion, removal, and reinsertion of the LNG IUS. RESULT(S) At 6 and 12 months endometrial histology was nonproliferative. At removal, all endometria were suppressed and a strong progestin effect was seen. The thickest endometrium was 3.6 mm. After washout, all seven endometria were atrophic. Before the IUS was replaced, 26 women were amenorrheic, whereas three had minor spotting. After replacement 5 women had no bleeding and an additional 10 women had only spotting. The bleeding or spotting discontinued within 18 days. The insertion of LNG IUS was characterized as easy by the investigator and it was well tolerated by the women. Cervical dilatation and/or paracervical blockade was used in 10 insertions. CONCLUSION(S) Intrauterine levonorgestrel effectively protects against endometrial hyperplasia. In most women it induces amenorrhea, which is only temporarily affected by replacement of the LNG IUS.

Vaginal polyps with pseudosarcomatous features: A clinicopathologic study of seven cases

Seven cases of vaginal polyps with atypical stromal cells were investigated. Three of the cases were classified as vaginal rhabdomyoma and four as fibroepithelial polyps with atypical stromal cells. All of the patients were adult women with minor or no symptoms. None of the tumor recurred or metastasized. The recognition of the vaginal polyps with bizarre stromal cells is important in order to avoid misdiagnosis of sarcoma, particularly botryoid rhabdomyosarcoma.

Microvillus-specific Mr 75,000 plasma membrane protein of human choriocarcinoma cells

We have previously purified from cultured JEG-3 choriocarcinoma cells an Mr 75,000 protein, originally detected using antibodies to a retrovirus-related synthetic peptide. Using polyclonal antibodies, we have now localized this protein immunocytochemically in JEG-3 cells at both light and electron microscopic levels. In immunofluorescence microscopy of saponin-permeabilized cells, the antigen appeared as dots and short strands at the apical cell surface. In pre-embedding immunoperoxidase electron microscopy, the Mr 75,000 protein was specifically localized to microvilli on the apical cell surface. Immunoferritin electron microscopy was used to assess more quantitatively the antigen distribution in the plane of the plasma membrane, and to define the position of the antigenic site(s) with respect to the membrane. The immunoferritin results confirmed the microvillus specificity of the Mr 75,000 protein and showed that the antigenic portion of the protein is within a few nanometers from, and on the cytoplasmic side of, the lipid bilayer. In detergent extraction experiments, the Mr 75,000 antigen was highly enriched in the soluble fractions. These results demonstrate that the Mr 75,000 protein is a membrane protein highly specific for microvilli.