Ethanolamine, but not phosphoethanolamine, potentiates the effects of insulin, phosphocholine, and ATP on DNA synthesis in NIH 3T3 cells--role of mitogen-activated protein-kinase-dependent and protein-kinase-independent mechanisms

NIH 3T3 fibroblasts express a phospholipase D activity hydrolyzing phosphatidylethanolamine (PtdEtn) which produces ethanolamine (Etn) in response to a variety of growth regulating agents. The main objective of this work was to evaluate the effects of Etn on mitogenesis and to determine whether these effects require its metabolism to phosphoethanolamine (PEtn) or PtdEtn. To increase conversion of Etn to PEtn, an Etn-specific kinase derived from Drosophila was highly expressed in NIH 3T3 cells. Overexpression of this Etn kinase resulted in large (10-12.5-fold) increases in PEtn formation, but only in modest (1.2-1.7-fold) increases in PtdEtn synthesis. In both vector control and Etn kinase overexpressor cells, Etn had biphasic effects on insulin-induced DNA synthesis with maximal (approximately 2-fold) potentiating effects being observed at 0.5-1 mM concentrations, followed by an inhibitory phase at higher Etn concentrations. In the Etn kinase overexpressor lines, the inhibitory phase was elicited by lower Etn concentrations and it was partially blocked by 5 mM choline due to decreased formation of PEtn. In both vector control and Etn kinase overexpressor cells, phosphocholine (PCho) and insulin synergistically stimulated DNA synthesis; their effects were further enhanced by physiologically relevant (5-60 microM) concentrations of Etn by a mechanism independent of mitogen-activated protein (MAP) kinase. Concentrations of Etn >50 microM also enhanced the effects of both PCho and the synergistic effects of PCho plus ATP; however, in the latter case 20 microM Etn was inhibitory. The magnitude of both the potentiating and inhibitory effects of Etn on PCho-induced as well as PCho + ATP-induced DNA synthesis were similar in the vector control and Etn kinase overexpressor cells; they were associated with stimulation and inhibition, respectively, of p42 MAP kinase activity. The results indicate that in NIH 3T3 cells Etn exerts significant effects on DNA synthesis which, except inhibition of insulin-induced DNA synthesis by higher concentrations of Etn, do not correlate with the metabolism of Etn to PEtn or PtdEtn.

Computerised estimation of the baseline fetal heart rate in labour: the low frequency line

OBJECTIVE

To develop and evaluate a computerised algorithm for the estimation of the fetal heart rate baseline (low frequency line) during labour.

DESIGN

Retrospective observational study.

METHODS

Fetal heart rate signals were obtained from women in labour using the Nottingham fetal ECG monitor. The computerised algorithm for the baseline estimation was developed for intrapartum applications and is based on averaging modal fetal heart rate values. Evaluation was carried out on sixty cardiotocographic recordings by 12 experts and by the computer. These estimates were compared with those obtained from the computerised system using paired differences and intraclass correlation.

RESULTS

The study showed that it is possible to produce a low frequency line from data obtained from intrapartum records. The system could not estimate the low frequency line in four records, whereas experts were also unable to estimate between one and seven tracings. The 95% CI for the paired differences between computer and experts was -12 to 15 bpm, whereas between the experts this was -10 to 10. With the exception of one expert, there was a high concordance between experts and between computer and experts (intraclass correlation > 0.9).

CONCLUSIONS

The performance of this computerised algorithm cannot be distinguished from that of experienced clinicians. There were no significant differences between baseline values obtained by the computerised algorithm and those by the clinicians.

Urinary retention in the post-partum period. The relationship between obstetric factors and the post-partum post-void residual bladder volume

OBJECTIVE

The three objectives of this study are: to investigate the incidence of post-partum urinary retention after vaginal delivery, to investigate the relationship between various obstetric parameters and the post-partum post-void residual bladder volume and to study the natural progression of the post-void residual bladder volume in patients with covert post-partum urinary retention.

METHODS

Women who had a vaginal delivery (n = 691) in a teaching hospital during a 2-month period were studied. They were classified into three groups: normal patients, those with overt urinary retention, and covert urinary retention. Their day 1 post-partum post-void residual bladder volume were recorded and analyzed with respect to the obstetric parameters. Patients with covert retention were followed up daily with ultrasound to monitor their post-void residual volume.

RESULTS

The incidences of overt and covert retention in our unit were 4.9% and 9.7%, respectively. The overall incidence of post-partum urinary retention after vaginal delivery was 14.6%. The duration of the first and second stages of labor were significantly associated with the post-partum post-void residual bladder volume. In all patients with covert retention, their post-void residual volume returned to normal within 4 days.

CONCLUSION

Post-partum urinary retention is a common phenomenon that may be related to the process of parturition. Covert retention is a self-limiting phenomenon and specific treatment is unnecessary.

Physiological alcohol dependence as a "specifier" of risk for medical problems and relapse liability in DSM-IV

OBJECTIVE

This study tested the ability of DSM-IV physiological alcohol dependence to predict multiple indices of medical problems and relapse behavior. It also tested the ability of three additional variables--DSM-IV nonphysiological dependence, an alternative dichotomous criterion for coding physiological dependence and a dimensional measure of physiological dependence--to predict medical problems and relapse behavior in alcoholism.

METHOD

A heterogeneous group of 365 patients was recruited from eight addictions treatment programs in the northeastern United States. A multidimensional assessment battery able to diagnose the presence of physiological dependence according to each of three systems--the criteria of DSM-IV, alternative dichotomous criteria and a dimensional scale-- was administered about 2 weeks after admission, and 241 subjects were reinterviewed 6 months later. The three systems were compared for their ability to predict a variety of external measures of medical complications and relapse liability.

RESULTS

Physiological alcohol dependence as diagnosed by DSM-IV bore no relationship to either risk for medical problems or relapse behavior. Further analyses showed that this failure was due to operational problems of physiological dependence in DSM-IV, rather than to a lack of conceptual merit for physiological dependence per se as a course specifier. Use of alternative criteria for coding physiological dependence which are difficult and less internally consistent, and use of a dimensional measure, found improved relationships with the external validators.

CONCLUSIONS

Contrary to early reports, physiological dependence can serve as a course specifier for alcohol problems, but must be more sensitively scaled than it was in DSM-IV. Tests of alternative options suggest that a multistage criterion to replace DSM-IV's dichotomous criterion is the best remedy.

A familial predisposition toward lumbar disc injury

STUDY DESIGN

A retrospective case-control study was performed.

OBJECTIVES

To test the hypothesis that there is a familial predisposition to lumbar disc pain and injury.

SUMMARY OF BACKGROUND DATA

The few studies that have addressed this question have suggested that a familial predisposition is present, but the techniques used for identifying discogenic pain and accounting for potentially confounding extrinsic factors make it difficult to formulate a clear conclusion.

METHODS

Immediate relatives of index patients who had surgically proven lumbar disc herniations (disc/case subjects) or repetitive upper extremity overuse syndromes (upper extremity/control subjects) were given a questionnaire that had been tested previously and found to reliably identify discogenic lower back pain. The prevalence of lumbar disc pain and injury was determined in the two groups of patients; logistic regression was used to control for demographic factors and activities known to increase risk for lumbar disc injury.

RESULTS

The questionnaire was returned by 60 (59%) of 102 disc subjects and 41 (50%) of 81 upper extremity subjects. Sixteen (28%) disc subjects and one (2%) of the upper extremity subjects met questionnaire criteria for discogenic lumbar pain; seven (12%) disc subjects and no upper extremity subjects had received surgical therapy for lumbar disc pain. Logistic regression analysis identified familial grouping and a history of lifting as the only variables associated with a positive response on the questionnaire. Information obtained from index patients about their nonresponding relatives' history of significant back pain suggested similar findings.

CONCLUSIONS

There is a familial predisposition toward lumbar disc pain and injury. This information may be helpful in occupational counseling or for targeting specific populations with preventative, interventional strategies.

A medical approach to management of spontaneous abortion using misoprostol. Extending misoprostol treatment to a maximum of 48 hours can further improve evacuation of retained products of conception in spontaneous abortion

BACKGROUND

To compare a 48 hour non surgical policy in the management of spontaneous abortion with a policy of routine, universal uterine curettage.

METHODS

A prospective, observational study on 354 women admitted to hospital with spontaneous abortion. Of these, 225 who had retained products of conception were treated with misoprostol for up to 48 hours after 101 were excluded because they had an empty uterus on transvaginal scan (TVS) and another 28 women because they were unsuitable for conservative management. Follow-up was conducted over a 3 week period to assess morbidity. A reference group of 137 women, all of whom had an evacuation of retained products of conception (ERPC) as a routine after they had a TVS documenting retained products of conception (POCs), was used for comparison.

RESULTS

Evacuation of the uterus occurred within 24 hours in 107 women and in 148 at 48 hours after misoprostol treatment was started. There were three uterine curettages up to 14 days after discharge from hospital for persistent bleeding and two cases of pelvic infection. An ectopic pregnancy was diagnosed at follow-up in one woman. In the reference group, there were nine women who had complications, four requiring another ERPC and five had infection, an overall complication rate of 6.6% in the reference group and 1.7% in the protocol treatment group.

CONCLUSION

A 48 hour regimen using transvaginal ultrasound and misoprostol for the management of spontaneous abortion was successful in avoiding surgery in 249 out of a possible 354 (70.6%) women with spontaneous abortion, with a low rate of subsequent morbidity.

ATP-dependent choline phosphate-induced mitogenesis in fibroblasts involves activation of pp70 S6 kinase and phosphatidylinositol 3'-kinase through an extracellular site. Synergistic mitogenic effects of choline phosphate and sphingosine 1-phosphate

In serum-starved NIH 3T3 clone 7 fibroblasts, choline phosphate (ChoP) (0.5-1 mM) and insulin synergistically stimulate DNA synthesis. Here we report that ATP also greatly enhanced the mitogenic effects of ChoP (0.1-1 mM) both in the absence and presence of insulin; maximal potentiating effects required 50-100 microM ATP. The co-mitogenic effects of ATP were mimicked by adenosine 5'-O-(3-thiotriphosphate), adenosine 5'-O-(2-thiodiphosphate), ADP, and UTP, but not by AMP or adenosine, indicating the mediatory role of a purinergic P2 receptor. Externally added ChoP acted on DNA synthesis without its detectable uptake into fibroblasts, indicating that ChoP can be a mitogen only if it is released from cells. Extracellular ATP (10-100 microM) induced extensive release of ChoP from fibroblasts. ChoP had negligible effects, even in the presence of ATP or insulin, on the activity state of p42/p44 mitogen-activated protein kinases, while in combination these agents stimulated the activity of phosphatidylinositol 3'-kinase (PI 3'-kinase). Expression of a dominant negative mutant of the p85 subunit of PI 3'-kinase or treatments with the PI 3'-kinase inhibitor wortmannin only partially (approximately 40-50%) reduced the combined effects of ChoP, ATP, and insulin on DNA synthesis; in contrast, the pp70 S6 kinase inhibitor rapamycin almost completely inhibited these effects. ATP and insulin also potentiated, while rapamycin strongly inhibited, the mitogenic effects of sphingosine 1-phosphate (S1P). Furthermore, even maximally effective concentrations of ChoP and S1P synergistically stimulated DNA synthesis. The results indicate that in the presence of extracellular ATP and/or S1P, ChoP induces mitogenesis through an extracellular site by mechanisms involving the activation of pp70 S6 kinase and, to a lesser extent, PI 3'-kinase.

Transrectal drainage of deep pelvic abscesses in children using a combined transrectal sonographic and fluoroscopic guidance

The authors review their experience with transrectal drainage of pelvic abscesses in seven children and adolescents (6-16 years old). Initial access was guided by transrectal ultrasound with an endovaginal transducer followed by fluoroscopy for placement of self-retaining catheters (8.5-10 F) using the Seldinger technique. All abscesses were successfully drained without complications. A transrectal catheter was well tolerated by most patients without spontaneous dislodgment. Catheters were removed after an average of 4 days (range 3-7 days). Transrectal drainage of pelvic abscess with transrectal sonographic and fluoroscopic guidance seems to be a safe and effective procedure in children.

Protein kinase Calpha is a major mediator of the stimulatory effect of phorbol ester on phospholipase D-mediated hydrolysis of phosphatidylethanolamine

Stimulation of phospholipase D (PLD)-mediated hydrolysis of phosphatidylcholine (PtdCho) by phorbol 12-myristate 13-acetate (PMA) has been shown to be mediated by the alpha- and betaI-isoforms of protein kinase C (PKC). To determine the role of various PKC isozymes in the regulation of PLD-mediated phosphatidylethanolamine (PtdEtn) hydrolysis, MCF-7 human breast carcinoma cells overexpressing the alpha- and theta-isoforms, and R6 rat fibroblasts overexpressing the alpha-, betaI-, and epsilon-isoforms were used. In the vector control MCF-7 cells, which contain low levels of PKC-alpha, PMA (100 nM) had only small effects on the hydrolysis of PtdEtn (1.1-1.35-fold) and PtdCho (1.15-1.6-fold). Stable expression of PKC-alpha in MCF-7 cells, which was accompanied by increased levels of the betaI- and theta-isoforms as well, greatly enhanced both PMA-induced PLD-mediated formation of phosphatidylethanol (approximately 5-fold) and the hydrolysis of PtdEtn (2.5-2.9-fold) and PtdCho (5.5-7.2-fold). The effects of PMA on the hydrolysis of PtdEtn (and PtdCho) in MCF-7/PKC-alpha cells were significantly inhibited by 0.5-3 microM concentrations of Gö 6976, a selective inhibitor of the conventional PKC subfamily. Stable expression of PKC-alpha in R6 fibroblasts enhanced, at a shorter (10 min) incubation time, the effects of PMA on the hydrolysis of both PtdEtn and, to a lesser extent, PtdCho. In contrast, stable expression of PKC-betaI in R6 fibroblasts, which originally did not contain this enzyme, enhanced the effects of PMA only on PtdCho, but not PtdEtn, hydrolysis. Overexpression of either PKC-theta in MCF-7 cells or PKC-epsilon in R6 and NIH 3T3 fibroblasts had no detectable effects on PMA-induced hydrolysis of PtdEtn. Collectively, the results suggest that PKC-alpha has a major role in the mediation of phorbol ester action on PtdEtn hydrolysis, while PtdCho hydrolysis may be regulated by both the alpha and betaI isoforms.

Musculoskeletal magnetic resonance imaging: how we do it

This paper reviews the techniques that we employ to perform musculoskeletal magnetic resonance imaging in the pediatric patient. We examine the procedures for preparation and screening of the patient and the protocols for sedation. The selection of imaging coils and sequences for the evaluation of the pediatric musculoskeletal system is also addressed, followed by a summary of scanning protocols.

Diagnosis and management of agenesis of the right lung and left pulmonary artery sling

The diagnostic, developmental, and surgical aspects of left pulmonary artery sling associated with right lung agenesis in 3 patients are described. Cardiac catheterization may be avoided by the combined use of echocardiography and magnetic resonance imaging and/or computed tomography.

Staging in the onset of DSM-IV alcohol symptoms in adolescents: survival/ hazard analyses

OBJECTIVE

This research examined staging in the time to onset of DSM-IV alcohol symptoms in adolescents. Consistent staging in the onset of symptoms provides important tests of the construct validity of diagnostic systems, and aids the development of early case identification strategies.

METHOD

The Structured Clinical Interview for the DSM (SCID), adapted to assess DSM-IV alcohol abuse and dependence symptoms, was used to determine time to symptom onset in 102 male and 97 female adolescent drinkers with and without alcohol use disorders. The sample provided a broad range of drinking practices and alcohol-related problems. Symptom onset patterns were examined using survival-hazard analyses.

RESULTS

Survival and hazard data suggested three stages of alcohol problems distinguished by time to onset: heavy and heedless drinking with associated social and role obligation problems, psychological dependence, and withdrawal. This three-stage model fit both the male and female data, and described staging patterns in 70% of the subjects.

CONCLUSIONS

The symptom onset model suggested a first stage of adolescent alcohol symptoms characterized by heavy and heedless drinking with associated interpersonal and role obligation problems. The data did not support the construct validity of DSM-IV alcohol abuse when applied to adolescents, and suggested staging among DSM-IV alcohol dependence symptoms. Implications for the diagnosis and early identification of adolescent alcohol problems are discussed.

Illness severity and self-efficacy as course predictors of DSM-IV alcohol dependence in a multisite clinical sample

Illness severity and self-efficacy are two constructs of growing interest as predictors of clinical response in alcoholism. Using alternative measures of illness severity (DSM-IV symptom count, Alcohol Dependence Scale, and Addiction Severity Index) and self-efficacy (brief version of the Situational Confidence Questionnaire) rigorously controlled for theoretically important background variables, we studied their unique contribution to multiple indices of relapse, relapse latency, and use of alternative coping behaviors in a large, heterogeneous clinical sample. The Alcohol Dependence Scale contributed to the prediction of 4 of 5 relapse indicators. The SCQ failed to predict relapse behavior or its precursor, coping response. The findings emphasize the predictive validity of severity of dependence as a course specifier and underline the need for more sensitive and externally valid measures of cognitive processes such as self-efficacy for application in future studies of posttreatment behavior.

A randomized, double blind, controlled trial of tocolysis to assist external cephalic version in late pregnancy

BACKGROUND

External cephalic version at term is not always successful. This trial was done to ascertain whether tocolysis has any effect on the success rate.

METHODS

A randomized, double blind, controlled trial, with continuous paired sequential analysis. Fifty-one consecutive patients with a singleton fetus in a breech presentation between 36 and 38 weeks gestation, external version being attempted on each. Ritodrine infusion or placebo was infused before attempt at external cephalic version.

SETTING

A university teaching hospital with 8000 confinements annually.

RESULTS

Version was successful in 17 of the 25 patients given tocolysis, but in only eight of the 25 given placebo (p < 0.01). A positive benefit for tocolysis was shown after version had been completed in 10 pairs of patients. However the trial was continued until 25 pairs had been analyzed. The benefit deteriorated during analysis of the last 15 pairs suggesting that the initial benefit may reflect a learning curve for the procedure.

CONCLUSION

Tocolysis is likely to improve the success rate of external cephalic version in late pregnancy, especially in nulliparous mothers or where doctors are learning the technique.

Cervical ripening before induction of labour in patients with an unfavourable cervix: a comparative randomized study of the Atad Ripener Device, prostaglandin E2 vaginal pessary, and prostaglandin E2 intracervical gel

One hundred and nineteen women with singleton pregnancy and cephalic presentation requiring induction of labour in the presence of an unfavourable cervix (Bishop score < or = 4) were studied. Five patients were excluded because of failure to comply with the protocol. Cervical ripening was carried out using 3 different methods; 36 used the Atad Ripener Device, 39 received 0.5 mg PGE2 intracervical gel and 39 received at least one 3 mg PGE2 intravaginal pessary. There were no differences in the demographic characteristics and the indications for induction. Five patients developed complications during the ripening period necessitating intervention; 3 required emergency Caesarean section and 2 delivered vaginally. Although statistically there were no differences among the 3 methods of cervical ripening, the power of the study is probably not large enough to show the differences. The PGE2 pessary appears to be more effective with 68% of patients either going into labour during cervical ripening or succeeding in the cervical ripening compared to around 50% in the Atad and PGE2 gel groups. The vaginal delivery rate was 87.2% in the pessary group compared to 72.2% in the Atad group and 84.6% in the gel group. The duration of labour was also shorter in the pessary group with 73.5% delivered within 24 hours compared to 57.7% in the Atad group and 57.6% in the gel group. Although the results of the Atad device seem to be inferior, the risk of uterine hyperstimulation from the use of the device is probably lower than that of the PGE2 and may therefore be preferable in women with fetuses at high risk of fetal hypoxia.

Yeast thiol-dependent protector protein expression enhances the resistance of Escherichia coli to hydrogen peroxide

A soluble protein from Saccharomyces cerevisiae specifically provides protection against a thiol-containing oxidation system but not against an oxidation system without thiol. This 25-kDa protein was thus named thiol-dependent protector protein (TPP). The role of TPP in the cellular defense against oxidative stress was investigated in Escherichia coli containing an expression vector with a yeast genomic DNA fragment that encodes TPP (strain YP) and mutants in which the catalytically essential amino acid cysteine (Cys-47) has been replaced with alanine (strain YPC47A) or tryptophan (Trp-82) has been replaced with phenylalanine (strain YPW82F) by a site directed mutagenesis. There was a distinct difference between these three strains in regards to growth inhibition kinetics, viability, modulation of activities of superoxide dismutase and catalase, and the accumulation of oxidized proteins. These results suggest that TPP may play a direct role in the cellular defense against oxidative stress by functioning as an antioxidant protein.

Interpreting the results of pediatric central venous catheter studies

Radiographic evaluation of central venous catheters (CVCs) with contrast material is a commonly performed procedure in pediatric radiology, but the criteria for interpreting the results of such studies are not well described in the literature. Careful evaluation of the images from a contrast material-enhanced CVC study frequently demonstrates a cause of CVC malfunction. In a series of 166 contrast-enhanced CVC studies performed in children, 112 studies (67%) demonstrated abnormal results. The most common abnormalities were mural thrombus, catheter tip thrombus, catheter tip against the vessel wall, and sleeve thrombus. Other causes of catheter malfunction include reservoir thrombus, catheter break, and catheter malposition. When catheter malfunction is due to catheter thrombus formation, the patient is usually treated with urokinase (bolus injection or infusion). Short catheters that ended in the innominate or subclavian vein had a much higher frequency of abnormalities than longer catheters that ended in the superior vena cava or right atrium.

Percutaneous biopsy for prognostic testing of neuroblastoma

PURPOSE

To determine whether percutaneous biopsy can provide the diagnostic and prognostic information necessary to treat children with advanced neuroblastoma.

MATERIALS AND METHODS

From 1991 through 1995, 21 percutaneous biopsies were performed in 20 children with advanced neuroblastoma by using 15- or 16-gauge core biopsy needles. An average of six samples were obtained. Since September 1994, fresh tissue was sent to the reference laboratory, where touch preparations were prepared for N-myc evaluation.

RESULTS

Histologic confirmation and prognostic information (Shimada classification) were obtained in all cases. Genetic prognostic information was obtained in 19 patients (95%), DNA index (ploidy) in 18 (90%), N-myc gene expression in 14 (70%), and cytogenetic analysis in 10 (50%). N-myc and ploidy determinations were successful in all five biopsy specimens obtained since September 1994.

CONCLUSION

Percutaneous biopsy of advanced neuroblastoma is a feasible alternative to open biopsy.

Effect of oral estradiol on Lp(a) and other lipoproteins in postmenopausal women. A randomized, double-blind, placebo-controlled, crossover study

BACKGROUND

Lp(a) lipoprotein level is an independent risk factor for premature coronary artery disease and cerebrovascular accident. Concentrations of this lipoprotein tend to increase after menopause.

OBJECTIVE

To determine whether oral estrogen was effective in lowering concentrations of Lp(a) lipoprotein in postmenopausal women.

METHODS

A double-blind, placebo-controlled, cross-over study was conducted during a 12-month period in 100 postmenopausal women who had undergone hysterectomy. They were randomized into two groups: group 1 received oral estradiol, 2 mg/d, for the first 6 months and placebo for the second, and group 2 received these treatments in the reverse order. After completion of the crossover study, the effect of prolonged administration of oral estradiol was examined by placing all patients on active treatment and repeating the lipoprotein measurements approximately 12 months later.

RESULTS

No significant differences were noted between the two groups at the commencement of the study (median concentration of Lp[a] lipoprotein, 10.78 mg/dL [range, 2.2 to 108.5 mg/dL] in group 1 and 12.74 mg/dL [range, 0.8 to 98.1 mg/dL] in group 2). Crossover analysis showed a 9.62% reduction in values of Lp(a) lipoprotein with estradiol treatment compared with placebo during 12 months of treatment (P < .001). With prolonged treatment, the median concentration of Lp(a) lipoprotein for those in group 1 decreased from 8.12 mg/dL (range, 1.05 to 57.4 mg/dL) to 5.77 mg/dL (range, 0.84 to 75.39 mg/dL) (P < .001). In group 2, the median concentration decreased from 8.19 mg/dL (range, 2.52 to 99.82 mg/dL) to 7.07 mg/dL (range, 0.70 to 48.79 mg/dL), but this difference was not significant (P = .63).

CONCLUSIONS

The results of this study confirm the beneficial effect of oral estradiol on the basic lipoprotein pattern and demonstrate that this treatment is effective in reducing concentrations of Lp(a) lipoprotein in postmenopausal women.