Effect of metformin and flutamide on insulin, lipogenic and androgen-estrogen signaling, and cardiometabolic risk in a PCOS-prone metabolic syndrome rodent model

Polycystic ovary syndrome (PCOS) is highly associated with cardiometabolic risk and the metabolic syndrome (MetS), predisposing women to increased risk of developing type 2 diabetes and cardiovascular disease. Metformin is commonly used to treat insulin resistance-glucose intolerance, and flutamide, an androgen receptor (AR) antagonist, is used to target hyperandrogenemia and dyslipidemia. Currently, the physiological mechanism of action of these treatments on androgen, lipidogenic, and insulin signaling pathways remains unclear in PCOS. The aim of this study was to investigate the effects and mechanisms of action of metformin and flutamide on plasma lipid-apolipoprotein (Apo)B-lipoprotein and insulin-glucose metabolism, and endocrine-reproductive indices in a PCOS-prone MetS rodent model. PCOS-prone rodents were treated with metformin (300 mg/kg body wt), flutamide (30 mg/kg body wt), or metformin + flutamide combination treatment for 6 wk. Metformin was shown to improve fasting insulin and HOMA-IR, whereas flutamide and combination treatment were shown to reduce plasma triglycerides, ApoB48, and ApoB100, and this was associated with decreased intestinal secretion of ApoB48/triglyceride. Flutamide and metformin were shown to reduce plasma androgen indices and to improve ovarian primary and preovulatory follicle frequency. Metformin treatment increased hepatic estrogen receptor (ER)α, and metformin-flutamide decreased intestinal AR and increased ERα mRNA expression. Metformin-flutamide treatment upregulated hepatic and intestinal insulin signaling, including insulin receptor, MAPK1, and AKT2. In conclusion, cardiometabolic risk factors, in particular ApoB-hypertriglyceridemia, are independently modulated via the AR, and understanding the contribution of AR and insulin-signaling pathways further may facilitate the development of targeted interventions in high-risk women with PCOS and MetS.

Structure of the oligogalacturonate-specific KdgM porin

The phytopathogenic Gram-negative bacterium Dickeya dadantii (Erwinia chrysanthemi) feeds on plant cell walls by secreting pectinases and utilizing the oligogalacturanate products. An outer membrane porin, KdgM, is indispensable for the uptake of these acidic oligosaccharides. Here, the crystal structure of KdgM determined to 1.9 Å resolution is presented. KdgM is folded into a regular 12-stranded antiparallel β-barrel with a circular cross-section defining a transmembrane pore with a minimal radius of 3.1 Å. Most of the loops that would face the cell exterior in vivo are disordered, but nevertheless mediate contact between densely packed membrane-like layers in the crystal. The channel is lined by two tracks of arginine residues facing each other across the pore, a feature that is conserved within the KdgM family and is likely to facilitate the diffusion of acidic oligosaccharides.

[Rare cause of acute neck pain]

The acute calcific tendinitis of the longus colli muscle is a rare inflammatory process of the prevertebral muscles. The clinical picture includes acute neck pain, limited range of motion of the cervical spine with stiffness and odynophagia. The laboratory findings demonstrate inflammatory signs. The incidence of the disease peaks between the third and sixth decade. The knowledge of the characteristic radiologic findings and the self-limiting course prevents the patient from needless medical and surgical interventions.

Reversible, meniscus-free molecular combing of long-chain DNA

We introduce a method for reversibly orienting long-chain DNA on solid hydrophilic substrates without a fluid meniscus. End-tethered lambda-DNA mushrooms are elongated by a hydrodynamic flow in the presence of trivalent cations, resulting in electrostatic adsorption of the extended DNA to the surface. By complexation of the cations the part of the DNA which is unspecifically bound to the surface desorbs quantitatively, and the mushroom conformation is restored. With the use of multiple deposition-combing steps, combined with a final desorption step, tethering densities higher than attainable with single deposition steps can be obtained.

Segment distributions of end-tethered polymers in a good solvent

We use confocal fluorescence microscopy to study the conformation of single DNA molecules end-tethered to a solid substrate. The segment distribution rho(z) measured for chains with contour lengths 15.4 microm <or= L <or= 59.4 microm as a function of the distance from the substrate can be scaled onto a master curve depending only on the scaled distance z/R(g), in quantitative agreement with theoretical predictions for end-tethered polymers in a good solvent. The scaling of the radius of gyration R(g) approximately L(0.57+/-0.05) shows the presence of excluded-volume interactions between the charged DNA segments. Independent measurements of R(g) from end-segment distributions are in good agreement with values obtained from the segment distributions and provide evidence that the radius of gyration of end-tethered chains in a good solvent is identical to that of the free chain.

Acoustomechanical properties of open TTP® titanium middle ear prostheses

OBJECTIVE

The purpose of the study was to identify acoustcomechanical properties of various biostable and biocompatible materials to create a middle ear prosthesis with the following properties: (i) improved handling including a good view of the head of the stapes or footplate and adjustable length, (ii) improved acoustical characteristics that are adequate for ossiculoplastic. The identified material should serve to build CE and FDA approved prostheses for clinical use in patients.

METHODS

Test models made of Teflon, polyetheretherketone, polyethylenterephtalate, polysulfone, gold, Al2O3 ceramics, carbon and titanium were investigated for their potential to fulfill the requirements. Acoustical properties were investigated by laser Doppler velocimetry (LDV) in mechanical middle ear models (MMM). Measured data were fed in to a recently created computer model of the middle ear (multibody systems approach, MBS). Using computer-aided design (CAD) measured and computed data allowed creation and fine precision of titanium prostheses (Tübingen Titanium Protheses, TTP). Their handling was tested in temporal bones. Acoustomechanical properties were investigated using the MBS and mechanical middle ear models.

MAIN OUTCOME MEASURES

Input impedance, mass, stiffness, and geometry of test models and prostheses were determined. Furthermore, their influence on the intraprosthetic transfer functions and on coupling to either tympanic membrane or stapes was investigated.

RESULTS

Final results were FDA- and CE-approved filigreed titanium prostheses with an open head that fulfilled the four requirements detailed above. The prostheses (TTP) were developed in defined lengths of between 1.75 and 3.5 mm (partial) and 3.0 and 6.5 mm (total) as well as in adjustable lengths (TTP-Vario).

CONCLUSIONS

The results suggest acoustomechanical advantages of TTPs because they combine a significantly low mass with high stiffness. In contrast to closed prostheses, the open head and filigreed design allow an excellent view of the prosthesis foot during coupling to the head or footplate of stapes, contributing to an improved intraoperative reliability of prosthesis coupling.

Triacylglycerol hydrolase: role in intracellular lipid metabolism

Recent scientific advances have revealed the identity of several enzymes involved in the synthesis, storage and catabolism of intracellular neutral lipid storage droplets. An enzyme that hydrolyzes stored triacylglycerol (TG), triacylglycerol hydrolase (TGH), was purified from porcine, human and murine liver microsomes. In rodents, TGH is highly expressed in liver as well as heart, kidney, small intestine and adipose tissues, while in humans TGH is mainly expressed in the liver, adipose and small intestine. TGH localizes to the endoplasmic reticulum and lipid droplets. The TGH genes are located within a cluster of carboxylesterase genes on human and mouse chromosomes 16 and 8, respectively. TGH hydrolyzes stored TG, and in the liver, the lipolytic products are made available for VLDL-TG synthesis. Inhibition of TGH activity also inhibits TG and apolipoprotein B secretion by primary hepatocytes. A role for TGH in basal TG lipolysis in adipocytes has been proposed. TGH expression and activity is both developmentally and hormonally regulated. A model for the function of TGH is presented and discussed with respect to tissue specific functions.

Survivin expression in human osteosarcoma is a marker for survival

AIMS

Osteosarcoma is the most frequent malignant bone tumor with a peak incidence in the second and third decade of life. Evaluation of prognosis of patients with osteosarcoma is limited to clinical parameters whereas molecular markers of tumor aggression have not yet been identified. Inhibition of apoptotic cell death could play a role in the development or progression of neoplasia. Survivin is a member of the inhibitor of apoptosis (IAP) protein gene family and is expressed both during normal fetal development and in human cancer.

METHODS

The localization and distribution of survivin was investigated immunohistochemically in high-grade osteosarcomas by an indirect immunoperoxidase method.

RESULTS

Survivin was detected in the cytoplasm in 23/40 and in the nucleus in 20/40 cases of osteosarcoma. Nuclear localization of survivin expression was significantly correlated with a prolonged survival (P=0.0347) but cytoplasmic staining showed no correlation with patient outcome.

CONCLUSIONS

The results of this study indicates that the evaluation of survivin expression might be a useful prognostic marker in osteosarcoma. Patients with osteosarcoma exhibiting nuclear survivin expression could potentially benefit from stratification of neoadjuvant chemotherapy.

[The shock for life: early defibrillation in first aid and by the professional paramedic]

The Automated External Defibrillation is the key link of the chain of survival for patients in cardiac arrest. A lot of case series and trials have shown the effectiveness of early defibrillation by first rescuers and trained lay persons. The earlier the defibrillation is performed, the better is the rate of survival to hospital discharge. To increase the survival rate healthcare providers, first rescuer citizens at worksites and trained lay rescuers should be authorized, equipped and encouraged to perform early defibrillation combined with effective cardiopulmonary resuscitation (CPR). The new generation of Automated External Defibrillators (AED) are sophisticated, computerized devices that are reliable and simple to operate, enabling also lay rescuers to administer this lifesaving intervention to victims of cardiac arrest. For the concept of recurrent adequate and qualified training in the use of the AED integrated in effective DPR is recommended.

Placental insufficiency and maternal death caused by advanced stage of breast cancer in third trimester

We describe a case with placental, and general metastases, resulting in transient intrauterine and general hypoxia, and with additionally clinical features similar to HELLP syndrome. A patient in the third trimester with dyspnea at rest developed right heart failure during c-section. During emergency thoracotomy the patient went into generalized shock and died after intense CPR. Placental insufficiency was based on a multilocal metastatic event, decreasing the utero-placental perfusion.

Total implantation of the active hearing implant TICA for middle ear disease: a temporal bone study

A subpopulation of hearing-impaired patients has conductive hearing loss that cannot be improved by classic tympanoplasty. Other patients have a mixed hearing loss and cannot be helped by present forms of ear surgery or by hearing aids. Possible help for some patients may come from current implantable hearing devices if these are modified for the patient's specific anatomic situation. The TICA LZ 3001 is a hearing implant for total implantation used to treat moderate to severe sensorineural hearing loss. Most patients who use it have a normal ossicular chain that allows coupling of the implant to the incus. The present temporal bone study demonstrates that the TICA can also be used in patients with an interrupted ossicular chain. If the incus long process shows a defect, the TICA may be coupled to the incus body, and connection between the stapes and the long process of the incus can be achieved with a commercially available titanium-angle prosthesis or liquid ionomeric cement. In cases of an absent incus, the coupling axis of the transducer may be coupled to the stapes head via a modified coupling element. With an absent stapes, the coupling axis may be coupled directly to the perilymph by a coupling element similar to a gold stapes prosthesis.

Open Tübingen titanium prostheses for ossiculoplasty: a prospective clinical trial

OBJECTIVE

The overall purpose of the study was the evaluation of the efficacy of Tübingen titanium prostheses (TTPs) for ossiculoplasty.

STUDY DESIGN

A two-part clinical study of 216 patients undergoing ossiculoplasty was performed. The first part was a prospective study using TTPs (n = 114). The second part involved study of historical control patients (n = 102) with gold and ceramic prostheses.

INTERVENTIONS

All patients underwent ossiculoplasty.

MAIN OUTCOME MEASURES

Measures included median air conduction thresholds and air-bone gaps.

RESULTS

All patients were per-protocol patients. When the air-bone gap "gold standard" (i.e., < or =10 dB) was investigated in the main speech spectrum, partial TTPs reached this level at 2 kHz in 44% (n = 22) and at 3 kHz in 38% (n = 19). Gold and ceramics revealed significantly lower values. Similar results were obtained for total prostheses. Differences for TTPs and ceramics were statistically significant (Mann-Whitney U test, alpha = 5%).

CONCLUSION

The use of TTPs for ossiculoplasty is an efficient treatment method.

A novel microperfusion system for the long-term local supply of drugs to the inner ear: implantation and function in the rat model

Local therapy is practiced for middle and inner ear diseases but is usually restricted to cases of ear drum perforation or repeated invasive intratympanic drug application. Perfusion of drugs on the round window or through the scalae of animals using a pump system suggests that the chronic local drug treatment might also be feasible in humans. However, drug delivery systems that are currently on the market involve repeated reimplantation if they are to be used for long-term drug supply. A bone-anchored, totally implantable micro-drug delivery system (MDS) for patient-controlled drug supply has been developed [Lehner et al., 1997]. In this study, we show the first successful long-term in vivo test of the MDS micro-pump in rats. The process of implantation and first functional tests will be described. The biomaterial used to manufacture the delivery system did not cause any inflammation reaction in any of the 9 animals successfully implanted. After activation of the micro-pump, the drug reservoir and port was found to be fluid-tight. Bolus applications of tetrodotoxin (TTX) to the round window induced a transient decrease of evoked brainstem responses. In 2 animals which carried the MDS for more than 8 months the proper functioning of the pumping device was examined in a 2-3 week interval over a 3 month period. The MDS can be autoclaved even after long-term implantation and can then be reused for subsequent implantations. Designed for life-long implantation in humans, the demonstration of an effective long-term drug supply to the inner ear using the MDS provides an encouraging first step towards future long-term drug treatment of the inner ear in humans.

A role for Sp1 in the transcriptional regulation of hepatic triacylglycerol hydrolase in the mouse

Microsomal triacylglycerol hydrolase (TGH) hydrolyzes stored triacylglycerol in cultured hepatoma cells (Lehner, R., and Vance, D. E. (1999) Biochem. J. 343, 1-10). We studied expression of TGH in murine liver and found both protein and mRNA increased dramatically at 27 days after birth. Nuclear run-on assays demonstrated that this was due to increased transcription. We cloned 542 base pairs upstream of the transcriptional start site of the murine TGH gene. Electrophoretic mobility shift assays demonstrated enhanced binding of hepatic nuclear proteins from 27-day-old mice to the murine TGH promoter, yielding three differentially migrating complexes. DNase I footprint analysis localized these complexes to two distinct regions: site A contains a putative Sp binding site, and site B contains a degenerate E box. We transfected primary murine hepatocytes with a series of 5'-deletion constructs upstream of the reporter luciferase cDNA. Positive control elements were identified in a segment containing site A. Competitive electrophoretic mobility shift assays and supershift assays demonstrated that site A binds Sp1 and Sp3. Transcriptional activation assays in Schneider SL-2 insect cells demonstrated that Sp1 is a potent activator of the TGH promoter. These experiments directly link increased TGH expression at the time of weaning to transcriptional regulation by Sp1.

The cloning and expression of a murine triacylglycerol hydrolase cDNA and the structure of its corresponding gene

A novel murine cDNA for triacylglycerol hydrolase (TGH), an enzyme that is involved in mobilization of triacylglycerol from storage pools in hepatocytes, has been cloned and expressed. The cDNA consists of 1962 bp with an open reading frame of 1695 bp that encodes a protein of 565 amino acids. Murine TGH is a member of the CES1A class of carboxylesterases and shows a significant degree of identity to other carboxylesterases from rat, monkey and human. Expression of the cDNA in McArdle RH7777 hepatoma cells showed a 3-fold increase in the hydrolysis of p-nitrophenyl laurate compared to vector-transfected cells. The highest expression of TGH was observed in the livers of mice, with lower expression in kidney, heart, adipose and intestinal (duodenum/jejunum) tissues. The murine gene that encodes TGH was cloned and exon-intron boundaries were determined. The gene spans approx. 35 kb and contains 14 exons. The results will permit future studies on the function of this gene via gene-targeting experiments and analysis of transcriptional regulation of the TGH gene.

Localization of telomerase hTERT protein and survivin in placenta: relation to placental development and hydatidiform mole

OBJECTIVE

To find if a difference in telomerase or survivin expression exists between non-neoplastic tissues and hydatidiform moles, and explore expression of those proteins in normal placental development, post-term gestation, and preeclampsia.

METHODS

Formalin-fixed placental tissues were selected from collections of the Department of Pathology at the University of Colorado. Five specimens of each trimester, five each of preeclamptic and post-term placentas, and 23 molar pregnancies were selected. The telomerase catalytic protein hTERT was localized in placental tissues using the catalyzed signal amplification system, and survivin was localized by conventional immunoperoxidase method. Staining was graded on a scale of zero to 4.

RESULTS

hTERT staining was detected in sections of 42 of 48 specimens (23 of 23 hydatidiform moles, 19 of 25 non-neoplastic placental tissues). The intensity of staining for hTERT was higher in hydatidiform moles (mean 3.3, median 3) compared with levels in non-neoplastic placental tissues (mean 0.92, median 1) (P <.001). Survivin was detected in 39 of 48 specimens (22 of 23 hydatidiform moles, 17 of 25 non-neoplastic placental tissues). Compared with non-neoplastic tissues (mean 0.88, median 1), survivin levels were elevated in hydatidiform moles (mean 1.35, median 1) (P =.031).

CONCLUSION

Survivin and telomerase were increased in hydatidiform moles, suggesting that regulation of apoptosis and stabilization of telomere length might be involved in neoplastic transformation of the placenta. The patterns of expression observed for survivin and telomerase in non-neoplastic placental tissues suggest that the control of apoptosis and stabilization of telomeric DNA might also be involved in normal gestational development.

Prognostic influence of delays between exploratory and definitive laparotomy in the treatment of malignant ovarian tumors

BACKGROUND

The aim of this retrospective study was to evaluate whether a delay between a preliminary exploratory laparotomy and a definitive staging laparotomy and interval chemotherapy between the two operations affected the prognosis of ovarian cancer.

METHODS

Of 504 patients with malignant tumors of the ovary who were treated at the Department of Obstetrics and Gynecology between 1980 and 1993, there were 24 who had a delayed definitive staging laparotomy.

RESULTS

Sixteen patients did not have chemotherapy between their two operations. After definitive laparotomy, 13 patients (54.2%) were free of disease and 11 patients had residual disease (45.8%).

CONCLUSIONS

The value of chemotherapy between preliminary and definitive laparotomy in halting tumor growth was not demonstrated by the results of our analysis.

Expression of survivin in normal, hyperplastic, and neoplastic colonic mucosa

The regulation of apoptotic cell death may have a profound effect on the pathogenesis and progression of colon cancer. Survivin, a member of the inhibitor of apoptosis gene family, has been detected in fetal tissue and in a variety of human malignancies. In the current study, we investigated survivin expression by an immunohistochemical approach in benign, hyperplastic, premalignant, and malignant lesions of the colon. Survivin was detected in all cases of normal colonic mucosa (20/20), hyperplastic polyps (20/20), adenomatous polyps (20/20), and in both well differentiated and moderately differentiated colonic adenocarcinomas (20/20). In the normal colonic mucosa, survivin expression was mostly restricted to the base of the colonic crypts. All epithelial cells showed uniformly intense staining for survivin in hyperplastic polyps. By contrast, adenomas and adenocarcinomas showed a heterogeneous staining pattern with cell-to-cell, gland-to-gland, and regional variability in the intensity of survivin staining. In contrast to the basal preponderance of staining in normal colonic mucosa, numerous survivin positive cells were present at the luminal surface of hyperplastic polyps, adenomatous polyps, and adenocarcinomas. In conclusion, the expression of survivin is not a specific marker of adenocarcinoma of the colon but does show characteristic and reproducible patterns of expression in non-neoplastic proliferative lesions and in normal colonic mucosa.

Human studies of a piezoelectric transducer and a microphone for a totally implantable electronic hearing device

OBJECTIVE

For the surgical treatment of patients with moderate and severe sensorineural hearing loss, the authors have developed a totally implantable hearing device, the totally integrated cochlea amplifier (TICA). To evaluate the effectiveness of transducer and microphone of this device, three separate human studies were conducted.

STUDY DESIGN

The first study using transducer prototypes involved self experiments in investigators with normal hearing. The second study used the transducer prototypes in patients with hearing loss, and the third study involved the temporary implantation of the final transducer prototype and microphone in patients undergoing otologic surgery.

PATIENTS

In routine middle ear surgery, transducer prototypes were coupled to the ossicular chain of 28 patients. In addition to the transducer, in 5 patients the microphone was placed beneath the skin of the auditory canal, allowing the skin to cover the microphone membrane completely.

RESULTS

The piezoelectric transducer reached an equivalent sound pressure level of 145 dB SPL < or =10 kHz. The dynamics for music reached 32 dB, which was identical with the results of the preoperative investigations using high-fidelity headsets (33 dB). The low nonlinear distortions of <0.1% and the frequency range of 10 kHz are reflected in the positive evaluation of the sound quality by 84% of the patients involved. When phonetically balanced speech material and music were presented under free field conditions at a sound level of 65 dB SPL, understanding of the phonetically balanced speech material was 100%. Most patients judged the presentations of music as clear and undistorted with all broadband components.

CONCLUSIONS

Data in humans on the performance of the two main components of the TICA implant, the transducer and the microphone, are reported.

Alcohol consumption during methadone maintenance treatment

Alcohol consumption during methadone maintenance treatment (MMT) often becomes a problem. We investigated a group of 68 patients undergoing MMT in our care. Mean duration of MMT was 50 months. A set of risk factors for problematic alcohol use ('alcohol indicators') was set up consisting of patients' account and laboratory parameters. 52% of patients were positive for these 'alcohol indicators' and 32% of patients fulfilled more severe criteria for alcohol abuse. There was exactly the same proportion of patients with 'alcohol indicators' at the start of MMT as at follow-up examination. In 79% of these patients 'alcohol indicators' were found on both occasions, testifying that alcohol problems were a stable trait. While patients without 'alcohol indicators' showed an improvement of liver parameters over time, those with 'alcohol indicators' suffered a considerable deterioration, indicating that the amount of alcohol consumption had increased.

Ectopic pregnancy

Ectopic pregnancy is a implantation occurring elsewhere than in the cavity of the uterus, whereas ninety-nine percent of extrauterine pregnancies occur in the fallopian tube. The incidence of extrauterine pregnancy has increased from 0.5% thirty years ago, to a present day 1-2%. The most frequent cause of tubal pregnancy is previous salpingitis. Mortality rates for tubal pregnancies used to be approximately 1.7% in the 1970s but dropped to 0.3% in 1980s.

DIAGNOSIS

Using transvaginal ultrasound it is possible to obtain positive evidence of an ectopic pregnancy at a very early stage. In cases of hCG titers>2,000 IU/l, intrauterine pregnancy can be diagnosed with certainty. The most important differential diagnosis of ectopic pregnancy is early intrauterine pregnancy.

CLINICAL MANAGEMENT AND THERAPY

Regardless of the therapeutic strategy selected by the physician, informing the patient is a major aspect of the management of ectopic pregnancy. If surgery is considered appropriate, the patient must be informed about the nature, side effects and complications of the procedure. However, it should be remembered that in some cases, the actual chances of cure first become apparent at surgery. In asymptomatic patients with a serum hCG titer <1,000 IU/l that is falling, it is appropriate to wait and watch. In clinically stable patients with an unruptured tubal pregnancy and steady hCG levels, systemic treatment with methotrexate might also be considered. In unruptured tubal pregnancy with a hCG titer between 1,000 and 2,500, a further therapeutic alternative is intratubal injection of prostaglandins, hyperosmolar glucose of NaCl. Generally speaking, the currently widespread laparoscopic surgical treatment of the fallopian tube hardly influences the risk of recurrence. If the gestational mass is larger, the serum hCG titer higher than the approximate limit of 2,500 mU/ml and/or the tube already ruptured, surgery is usually required.

PREVENTION

The most effective prevention is to avoid tubal inflammation or, in cases of preexisting inflammation, to administer effective therapy.

Contraceptive knowledge and behavior of conventionalists, careerists, idealists, bouncers, desperadoes, and outsiders

The aim of the survey was to determine the contraceptive behavior and knowledge on contraceptive methods of adolescents. We defined six clusters according to personality, leisure activities, and sociodemographic characteristics: conventionalists, careerists, idealists, bouncers, desperadoes, and outsiders. 1010 Austrian adolescents aged 14-24 years participated in the survey. 96%-100% indicated that they were familiar with the condom and the contraceptive pill. The two most popular contraceptive methods cited were the condom (39%) and OC (34%). Whereas 40% of conventionalists reported that OC were their preferred method of contraception, 53% of idealists indicated that they preferred the condom. 66% of the desperadoes indicated that they considered the pill expensive. 85% of conventionalists and careerists believe that OC offer the best protection against pregnancy. Clusters with higher self-esteem and those with a higher educational level were more likely to believe that this method is unreliable. The results obtained indicate that outsiders, desperatoes, and bouncers show deficits in sex education; only careerists and idealists appeared to be better informed. Research on adolescent contraceptive behavior should drop the traditional stratifying criteria and appreciate the diversity of adolescent populations in order to be better able to classify adolescents according to their contraceptive attitudes.

Cloning and expression of a cDNA encoding a hepatic microsomal lipase that mobilizes stored triacylglycerol

A microsomal triacylglycerol hydrolase (TGH) was recently purified from porcine liver [Lehner and Verger (1997) Biochemistry 36, 1861-1868]. To gain further insight into the function of TGH, we have cloned a cDNA encoding TGH from a rat liver cDNA library and generated McArdle RH7777 rat hepatoma cell lines that stably express the rat TGH. The putative protein derived from the cDNA sequence contains a cleavable signal sequence and a catalytic site serine residue present within a pentapeptide motif (GXSXG) that is conserved in all known lipases. TGH-transfected cells showed a 2-fold increase, compared with control cells, in the rate of depletion of prelabelled triacylglycerol stores. Thus, TGH is capable of hydrolysis of stored triacylglycerol. In contrast, the rate of turnover of labelled phosphatidylcholine was similar in both the vector- and TGH-transfected cells. Studies in TGH-transfected cells demonstrated that utilization of intracellular triacylglycerol pools for secretion was approx. 30% higher than in vector-transfected cells. Whereas phosphatidylcholine secretion was essentially the same in control and TGH-transfected cells, TGH-transfected cells also secreted an approx. 25% greater mass of triacylglycerol into the medium and had increased levels of apolipoprotein B100 in the very-low-density lipoprotein density range compared with control cells. The results suggest that the microsomal TGH actively participates in the mobilization of cytoplasmic triacylglycerol stores, some of which can be used for lipoprotein assembly.

Subcellullar localization, developmental expression and characterization of a liver triacylglycerol hydrolase

The mechanism and enzymic activities responsible for the lipolysis of stored cytosolic triacylglycerol in liver and its re-esterification remain obscure. A candidate enzyme for lipolysis, a microsomal triacylglycerol hydrolase (TGH), was recently purified to homogeneity from pig liver and its kinetic properties were determined [Lehner and Verger (1997) Biochemistry 36, 1861-1868]. We have characterized the enzyme with regard to its species distribution, subcellular localization, developmental expression and reaction with lipase inhibitors. The hydrolase co-sediments with endoplasmic reticulum elements and is associated with isolated liver fat droplets. Immunocytochemical studies localize TGH exclusively to liver cells surrounding capillaries. Both TGH mRNA and protein are expressed in rats during weaning. The enzyme covalently binds tetrahydrolipstatin, an inhibitor of lipases and of triacylglycerol hydrolysis. The enzyme is absent from liver-derived cell lines (HepG2 and McArdle RH7777) known to be impaired in very-low-density lipoprotein (VLDL) assembly and secretion. The localization and developmental expression of TGH are consistent with a proposed role in triacylglycerol hydrolysis and with the proposal that some of the resynthesized triacylglycerol is utilized for VLDL secretion.

Influence of delayed staging laparotomy after laparoscopic removal of ovarian masses later found malignant

OBJECTIVE

To determine whether delayed laparotomy after attempted laparoscopic excision of an ovarian mass later found to be malignant has an impact on the stage of disease.

METHODS

A questionnaire regarding laparoscopic management of ovarian masses later found to be malignant was mailed to all gynecologic departments in Austria. Of the 70 cases reported, laparotomy was performed after laparoscopy in 48 cases. In 24 of these cases, laparotomy was performed within 17 days of laparoscopy, whereas 24 cases involved a delay of more than 17 days. Twenty-two patients in whom laparotomy was performed immediately after laparoscopy were used as controls.

RESULTS

In patients with borderline tumors who underwent laparotomy more than 17 days after laparoscopy, the odds ratio (OR) for International Federation of Gynecology and Obstetrics (FIGO) stage IIB-IV disease was 5.3 (95% confidence interval [CI] 0.40, infinity), compared with patients undergoing immediate laparotomy (multivariate analysis). Patients with invasive ovarian cancer who underwent laparotomy more than 17 days after laparoscopy had an OR of 9.2 (CI 0.92, 481) for stage IIB-IV disease compared with patients undergoing immediate laparotomy (multivariate analysis). In patients with borderline tumors, multivariate analysis showed that the timing of laparotomy is an independent prognostic factor for the stage of disease. In invasive ovarian cancer, none of the factors evaluated by multivariate analysis was found to be an independent prognostic factor for the distribution of disease stage. A delay between laparoscopy and laparotomy may affect adversely the distribution of disease stage.

CONCLUSION

The timing of subsequent laparotomy was found to be a factor predictive of the distribution of disease stage.

Lectin histochemistry of fallopian tube epithelial cells. Relation to ovum transport and ovum pickup

OBJECTIVE

Data on histochemical and biochemical characteristics of the human oviduct are scarce. The exact mechanisms of ovum transport and pickup are not fully understood.

STUDY DESIGN

Human fallopian tubes were obtained and prepared for histochemistry. We analyzed the distribution of negatively charged groups on the oviduct epithelium and cumulus cells and examined the distribution of glycoconjugates by means of lectin histochemistry. We tested the possible influence of poly-L-lysine and considered ABO blood group expression since these characteristics are determined by specific terminal sugar residues.

RESULTS

A negatively charged glycocalyx exists on tubal epithelial cells and cumulus cells. Adherence by affinities similar to sugar-lectin binding forces could be disproven in case of commonly used lectins. Poly-L-lysine inhibited the cationic binding reaction but did not influence lectin binding. The blood group A glycoprotein presents terminal D-N-acetyl-galactosamine residues, which are demonstrated by HPA lectin binding.

CONCLUSION

Our study indicates that it is unlikely that electrostatic interactions play a major role in ovum transport or pickup. Since poly-L-lysine has been described as inhibiting ovum transport, sugar-lectin binding affinities seem not to operate in ovum transport or pickup.