High altitude retinal hemorrhages in a Colorado skier

High altitude retinal hemorrhages are commonly seen at altitudes above 4270 m. While these hemorrhages are generally asymptomatic, macular involvement may result in permanent visual acuity deficit. We present the case of a 29-year-old male recreational skier who traveled to a ski resort at 2930 m, ascended to 3470 m, and developed acute mountain sickness, high altitude pulmonary edema, and bilateral retinal hemorrhages. A funduscopic examination to determine if macular retinal hemorrhage is present may be performed by clinicians in the final assessment of patients following altitude illness.

Fewer women than men have positive SPECT and PET cardiac findings among patients with no history of heart disease

A lower detection rate of coronary artery disease (CAD) has been reported for SPECT imaging in women, despite the fact that similar numbers of women and men die each year of heart disease. Ruling out instrumentation as a possible source of this low detection rate for CAD in women could be important in determining the root cause of this difference.

METHODS

Patients were referred by cardiologists and randomized to PET or SPECT by the imaging center. A total of 210 patients (106 women, 104 men) were enrolled in this study, with 105 imaged by dual-isotope SPECT and 105 imaged by 82Rb PET. Rest/stress scanning was performed using dipyridamole. The effects of sex, prior history of CAD, and instrumentation on the detection of positive scans were determined using multiple logistic regression analysis with positive scans as the endpoint.

RESULTS

For the total study population, sex and prior history of CAD are significantly associated with positive scans, whereas imaging modality and age are not. There was no significant interaction between sex and prior history of CAD. Men have 4.1-fold greater odds of having a positive nuclear scan than women, and patients with prior history of CAD have 5.2-fold greater odds of a positive scan after controlling for the confounding effects of age and imaging modality. In the subgroup of patients with no prior history of heart disease, men have 3.9-fold greater odds of a positive scan than women, and the odds ratio of a positive scan is 2.5-fold greater for PET than for SPECT. There was no statistical difference in the number of positive scans by SPECT or PET, or positive scans by sex in patients with documented history of CAD.

CONCLUSION

Fewer women than men have positive nuclear cardiology scans by both PET and SPECT, despite similar symptoms. Instrumentation characteristics alone do not account for this sex-based difference and suggest the possibility that early CAD may present differently in women than in men.

Magnetic electroanatomical mapping for ablation of focal atrial tachycardias

Uniform success for ablation of focal atrial tachycardias has been difficult to achieve using standard catheter mapping and ablation techniques. In addition, our understanding of the complex relationship between atrial anatomy, electrophysiology, and surface ECG P wave morphology remains primitive. The magnetic electroanatomical mapping and display system (CARTO) offers an on-line display of electrical activation and/or signal amplitude related to the anatomical location of the recorded sites in the mapped chamber. A window of electrical interest is established based on signals timed from an electrical reference that usually represents a fixed electrogram recording from the coronary sinus or the atrial appendage. This window of electrical interest is established to include atrial activation prior to the onset of the P wave activity associated with the site of origin of a focal atrial tachycardia. Anatomical and electrical landmarks are defined with limited fluoroscopic imaging support and more detailed global chamber and more focal atrial mapping can be performed with minimal fluoroscopic guidance. A three-dimensional color map representing atrial activation or voltage amplitude at the magnetically defined anatomical sites is displayed with on-line data acquisition. This display can be manipulated to facilitate viewing from any angle. Altering the zoom control, triangle fill threshold, clipping plane, or color range can all enhance the display of a more focal area of interest. We documented the feasibility of using this single mapping catheter technique for localizing and ablating focal atrial tachycardias. In a consecutive series of 8 patients with 9 focal atrial tachycardias, the use of the single catheter CARTO mapping system was associated with ablation success in all but one patient who had a left atrial tachycardia localized to the medial aspect of the orifice of the left atrial appendage. Only low power energy delivery was used in this patient because of the unavailability of temperature monitoring in the early version of the Navistar catheter, the location of the arrhythmia, and the history of arrhythmia control with flecainide. No attempt was made to limit fluoroscopy time in our study population. Nevertheless, despite data acquisition from 120-320 anatomically distinct sites during global and more detailed focal atrial mapping, total fluoroscopy exposure was typically < 30 minutes and was as little as 12 minutes. The detailed display capabilities of the CARTO system appear to offer the potential of enhancing our understanding of atrial anatomy, atrial activation, and their relationship to surface ECG P wave morphology during focal atrial tachycardias.

Perinatal outcomes in women with systemic lupus erythematosus

OBJECTIVE

Pregnancies of women with systemic lupus erythematosus (SLE) were studied to assess the effects interaction of this disease and pregnancy.

STUDY DESIGN

Charts of pregnant women with a discharge diagnosis of lupus were reviewed. Inclusion criterion was SLE diagnosed by the criteria of the American College of Rheumatology. All patients were cared for at the University of North Carolina Hospitals, a tertiary level university center.

RESULTS

Between January 1988 and June 1995, we participated in the care of 21 women with the diagnosis of SLE. Their obstetric histories included a total of 56 pregnancies spanning 19 years. Obstetric histories were divided into pregnancies occurring before the patient was diagnosed with lupus and those pregnancies occurring after she had been given the diagnosis. The diagnosis of lupus was made during the course of five pregnancies; those five were categorized as occurring after diagnosis. Of the pregnancies that occurred before a woman's diagnosis of SLE, 46% resulted in live births, 36% ended in spontaneous abortion, and 18% ended in an intrauterine fetal demise. Among pregnancies occurring after the diagnosis of SLE, 85% resulted in live birth, 10% in spontaneous abortion, 3.3% in intrauterine fetal demise, and 3.3% in neonatal death. Of all live births, 53% were delivered before 37 weeks' gestation. The most common causes of maternal morbidity were joint involvement (n = 8) and dermatologic disorders (n = 6). Other clinical manifestations of SLE included nephritis (n = 5), hypertension (n = 4), pleuritis (n = 3), and thrombocytopenia (n = 3). One maternal death occurred as a result of pulmonary disease. Four pregnancies were complicated by preeclampsia. Seven patients were hospitalized during their pregnancies for lupus-related complications.

CONCLUSIONS

Substantial fetal, neonatal, and maternal risks still exist for pregnant women with lupus.

Stimulation of endometrial cancer cell growth by tamoxifen is associated with increased insulin-like growth factor (IGF)-I induced tyrosine phosphorylation and reduction in IGF binding proteins

A significant increase in endometrial cancer incidence in tamoxifen-treated breast cancer patients has been reported in many recent studies. The major growth stimulators of endometrial tumors are estrogens, but paradoxically, tamoxifen, a known antiestrogen, also stimulates their growth. The mode of action of estrogen can be partially explained by the modulation of insulin-like growth factor (IGF) autocrine or paracrine action. The purpose of the present study was to examine the involvement of the IGF system in the tamoxifen-stimulated growth of Ishikawa endometrial cancer cells by quantitating the IGF-I receptors and their phosphorylation, as well as membrane associated and secreted IGF-binding proteins (IGFBPs). Tamoxifen did not affect the number or affinity of IGF-I receptors. On the other hand, tamoxifen, similar to estradiol, increased IGF-I-stimulated tyrosine phosphorylation of cellular substrates. In contrast, in MCF-7 mammary cancer cells, tamoxifen reduced IGF-induced tyrosine phosphorylation in the presence of estradiol. The pure antiestrogen LY156758 did not affect Ishikawa basal cell growth but inhibited estradiol- and tamoxifen-induced growth. Growth inhibition by LY156758 of tamoxifen and estradiol-stimulated cells was accompanied by a corresponding inhibition of IGF-stimulated tyrosine phosphorylation. Tamoxifen caused a 3-fold decrease in membrane-associated IGFBPs. Moreover, a reduction in soluble IGFBPs was also observed, making the IGF peptides more available to the receptors. A parallel decrease in IGFBP-3 mRNA was also detected. These experiments suggest that tamoxifen, like estradiol, directly sensitizes endometrial cancer cells to the effects of IGFs that act through the type I receptor. Furthermore, the decrease in IGFBPs and the increase in tyrosine phosphorylation in the presence of tamoxifen provides a molecular mechanism that accounts for the uterotropic effects that are seen with tamoxifen therapy.

Successful catheter ablation of an inferoseptal accessory pathway within the coronary sinus in a patient with a previously unsuccessful attempt at surgical interruption. Coronary sinus ablation for Wolff-Parkinson-White syndrome

In a patient with Wolff-Parkinson-White syndrome and a right inferoseptal accessory pathway who had had a previously unsuccessful surgical attempt at accessory pathway ablation, the accessory pathway was found to be adjacent to a branch of the coronary sinus. Radiofrequency energy was delivered within this branch to ablate the pathway successfully. This demonstrates an alternative approach to the more common method of radiofrequency ablation of accessory pathways from a tricuspid or mitral annular location.

Modulation of insulin-like growth factor I (IGF-I) receptors and membrane-associated IGF-binding proteins in endometrial cancer cells by estradiol

Insulin-like growth factor I (IGF-I) receptors and membrane-associated IGF-binding proteins (IGFBPs) were examined in Ishikawa endometrial cancer cells. Our findings suggest that about 95% of [125I]IGF-I is bound to membrane-associated IGFBPs rather than to IGF-I receptors. Specifically, [125I]IGF-I binding to cell membranes could be completely displaced by cold IGF-I or IGF-II, but not by insulin, suggesting that binding was primarily due to IGFBPs. This was confirmed by using [125I]des-(1-3)IGF-I as the ligand. Des-(1-3) IGF-I binds with high affinity to IGF-I receptors, but with markedly lower affinity to IGFBPs. [125I]Des-(1-3)IGF-I bound to Ishikawa cells was displaced by IGF-I, IGF-II, and insulin. These results suggest that measuring IGF-I receptor levels using labeled IGF-I may be misleading. Accordingly, we evaluated the differential binding of [125I]IGF-I and [125I]des-(1-3)IGF-I to study the involvement of the IGF system in the stimulation of Ishikawa cell growth by estradiol. IGF-I stimulates Ishikawa cell proliferation, but at low concentrations, and this stimulation is largely dependent on the presence of estradiol. Estradiol caused a 2.5-fold increase in IGF-I receptor levels. Moreover, estradiol reduced soluble IGFBP levels, presumably increasing the availability of IGFs for their receptors. This elevation in IGF-I receptor levels and the decrease in IGFBP levels were accompanied by a 3.5-fold increase in IGF-I receptor messenger RNA and a 2.5-fold decrease in IGFBP messenger RNAs. These experiments suggest that estradiol sensitizes endometrial cancer cells to the effects of IGFs by simultaneously elevating receptor levels and decreasing (potentially inhibitory) IGFBP levels.

Components of the IGF system mediate the opposing effects of tamoxifen on endometrial and breast cancer cell growth

The involvement of the IGF system in the growth regulation of hormone-dependent (e.g. endometrial and breast) cancer cells was studied. We chose two opposing effects of tamoxifen: the paradoxical stimulation of Ishikawa endometrial cancer cells growth and its inhibitory effect on MCF-7 mammary cancer cells. The results clearly confirm our working hypothesis that the IGF system is involved in growth regulation of these cancer cells irrespective of the direction of the drug effect. The following parameters of the IGFs system were studied: IGF-I receptors, IGF-I stimulated protein tyrosine phosphorylation, and membrane-associated and secreted IGF-binding proteins (IGFBPs). In Ishikawa cells, tamoxifen, similar to estradiol, increased IGF-I stimulated tyrosine phosphorylation of cellular substrates in accordance with its effect on cell growth. This effect of tamoxifen was inverted in MCF-7 cells. Tamoxifen did not affect the number or affinity of IGF-I receptors in both Ishikawa and MCF-7 cells, however, it caused a three-fold decrease in membrane-associated IGFBPs in the endometrial cells but an increase in these proteins in breast cancer cells. Similar but much less pronounced changes in soluble IGFBPs were observed. Our results indicate that the opposing growth effects of tamoxifen an endometrial and mammary cancer cells are associated with modulation of the IGF system components, mainly with reciprocal changes in membrane-associated IGFBPs.

Direct growth inhibition of human endometrial cancer cells by the gonadotropin-releasing hormone antagonist SB-75: role of apoptosis

OBJECTIVE

Our objective was to study the direct action of the gonadotropin-releasing hormone antagonist SB-75 and the agonist buserelin on the proliferation of endometrial cancer cells.

STUDY DESIGN

Two human endometrial cell lines that differ in histologic subtype and estrogen receptor content were treated with gonadotropin-releasing hormone analog. We measured the number of viable cells, cell cycle parameters, and apoptotic processes.

RESULTS

Growth of the Ishikawa cells was inhibited by SB-75 in a dose-dependent manner. 17 beta-Estradiol partially abolished the inhibitory effect of SB-75. The growth of the HEC-1A cells was not affected by the antagonist. Neither endometrial cancer cell line showed significant sensitivity to the agonist buserelin. Tenfold concentration of the gonadotropin-releasing hormone agonist did not abolish the inhibitory effect of the antagonist on cell growth. The growth inhibition was not associated with any change in cell cycle parameters but was associated with an induction of apoptosis.

CONCLUSION

The gonadotropin-releasing hormone antagonist SB-75 directly inhibits the growth of some human endometrial cancer cells and thus may be suitable for the treatment of endometrial tumors.

Regulation of endometrial cancer cell growth by insulin-like growth factors and the luteinizing hormone-releasing hormone antagonist SB-75

The involvement of IGFs in growth regulation of the Ishikawa endometrial tumor cell line and the possible interference of LH-RH analogues with a potential autocrine or paracrine loop involving IGFs was evaluated. The mitogenic effects of IGF-I, IGF-II, and insulin were compared. IGF-I was found to be 3-fold more potent than IGF-II and 30-fold more potent than insulin, suggesting that the effects of these growth factors are mediated by the IGF-I receptor. Ishikawa endometrial cancer cells secrete IGF-II, but not IGF-I, and insulin (1 microM) stimulates IGF-II release. The LH-RH antagonist [Ac-D-Nal(2)1, D-Phe(4Cl)2, D-Pal(3)3, D-Cit6, D-Ala10]-GnRH (SB-75, CETRORELIX) inhibited basal and IGF-induced growth. Moreover, this antagonist almost completely inhibited IGF-II release from Ishikawa cells, while having no significant effect on the number or affinity of IGF-I binding sites. Inhibition of IGF-II release occurred at a lower SB-75 concentration than that needed for a reduction in cell number. The ED50 of SB-75 for IGF-II release was 0.3 microM as compared to 1.5 microns concentration which is required for reduction in cell number, suggesting that inhibition of growth factor release precedes cell growth inhibition. We conclude that the LH-RH antagonist SB-75 can inhibit the growth of endometrial cancer cells by interfering with the autocrine action of IGF-II and also by directly inhibiting the growth-stimulatory effects of IGFs, probably through effects on a post-receptor mechanism.

Role of midcycle FSH surge in follicular development

The present study was undertaken to examine the importance of the proestrous surge of FSH for follicular development during the following cycles in the rat. The midcycle FSH surges were blocked in several consecutive cycles (1-5) by injecting proestrous rats with pentobarbital. The rats were sacrificed on the day of proestrus following the appropriate number of blocked FSH surges and their ovaries were removed for either direct measurements or for histological workout. The number and diameter of follicles were determined in the excised ovaries. Two or three cycles of barbiturate treatment reduced the number and diameter of the follicles. No large follicles (greater than 0.4 mm) were observed in the ovaries of rats in which four or five gonadotropin surges were blocked. A repeat experiment with concomitant supplementary hCG administration yielded the same results. Addition of exogenous FSH canceled the effect of pentobarbital. The cohort observed on ovaries after four cycles of treatment with pentobarbital and FSH resembled that observed in control rats. Histological measurements supported the results obtained with fresh ovaries. It is therefore suggested that in the third cycle preceding the ovulatory one, the midcycle FSH surge determines which follicles will be able to adequately develop in the following three cycles. In the cycle preceding the ovulatory one, the midcycle FSH peak 'rescues' a group of follicles and prepares them for a proper response to the FSH elevation taking place at the beginning of the subsequent ovulatory cycle. This process allows the selection of the dominant follicles which will respond by ovulation to the ensuing LH peak.

Combined anesthetic and surgical treatment of reflex sympathetic dystrophy following a healed crush injury of the foot

Reflex sympathetic dystrophy is an often overlooked diagnostic cause of posttraumatic pain. After wound healing, persistent pain frequently is treated with continued analgesic administration, physical therapy, acupuncture, nerve blocks, psychotherapy and sometimes even ignored in hopes that either the pain or the patient will "go away." The authors relate successful evaluation and treatment of reflex sympathetic dystrophy in the case of a young man with disabling pain following a healed crush injury to his foot.

Thromboembolization complicating left ventricular pseudoaneurysm: serial two-dimensional and color-flow Doppler echocardiographic observations

A left ventricular pseudoaneurysm was diagnosed by two-dimensional echocardiography and color-flow Doppler imaging, and confirmed by computerized tomography and angiocardiography, in a man with known coronary disease who had had recent recurrent systemic emboli. A thrombus within the pseudoaneurysm was visualized, and its disappearance on serial echocardiograms coincided with the occurrence of embolization to the aortic bifurcation.

Inhibition of Chlamydia trachomatis growth in endometrial cells by copper: possible relevance for the use of the copper IUD

There is agreement that the relative risk of developing pelvic inflammatory disease (PID) increases among women who use the intrauterine contraceptive device (IUD). The role of Chlamydia in causing PID among IUD users is not clear. The present study demonstrates that Chlamydia trachomatis growth can be inhibited in cultured human endometrial cells by copper ions at concentrations known to be released by the copper IUDs. More than 98% inhibition was produced with 10(-5) and 10(-6) M of copper. Both C. trachomatis serovar E and a lymphogranuloma venereum Chlamydia serovar L2 (LGV) were inhibited by the copper ions. Although the mechanism of the inhibition is not known, the continuous presence of the copper ions during and after adherence appeared to be necessary for maximal effect. If such inhibition occurs in vivo, it is possible that copper ions released from the copper-containing IUD may partially protect against chlamydial infection.

Results of in vitro fertilization in women with antisperm antibodies in serum, cervical mucus, and follicular fluid

This study was undertaken to investigate the presence of antisperm antibodies (ASA) in serum, cervical mucus, and follicular fluid (FF) of women undergoing in vitro fertilization and embryo transfer (IVF-ET). IgG and IgA ASA directed mostly against sperm head were found at similar concentrations in serum, cervical mucus, and FF of 2 of 34 patients. Ninety-one percent fertilization and 100% cleavage rates, respectively, were observed in one of the two patients. No fertilization occurred in the second patient. In both women, in vitro sperm penetration tests revealed hostile mucus and repeated postcoital tests were poor. It is concluded that the sperm-cervical mucus penetration test and mucus ASA measurements are useful in establishing the diagnosis of immunological infertility.

Acid phosphatase levels in follicular fluids following induction of ovulation in in vitro fertilization patients

Considerable evidence indicates that changes in acid phosphatase (AP) activity at the ovarian level play a role in the process of ovulation. In this study the concentrations of AP were determined in follicular fluids collected from follicles of 52 women at the time of laparoscopy performed in connection with an in vitro fertilization program. In each of the 52 women at least one ovum was harvested. Of the 52 ova, 28 cleaved in vitro, while in 24 ova cleavage was not seen. Levels of AP in follicular fluids of women whose ova did not cleave were significantly lower than those found in follicular fluids of women with at least one ovum undergoing cleavage: 0.45 +/- 0.14 (SE) and 4.78 +/- 0.37 Bess Lowry Units (BLU), respectively. Comparison of AP levels in follicular fluids of women who conceived (5) and women whose ova cleaved, but in whom pregnancy was not achieved (23), did not reveal significant differences: 5.87 +/- 1.29 and 4.55 +/- 0.35 BLU, respectively. Moreover, the enzyme level was typical for a woman and not for a follicle. Fluids of two different follicles of the same woman, when one ovum cleaved and one did not, showed similar AP levels. AP levels were high in all samples follicles of women in whom at least one ovum cleaved. These findings indicate that the presence of certain levels of acid phosphatase represents an important, albeit not the sole, condition for ovum maturation. Moreover, the follicular fluid levels of AP could serve as an indicator of proper timing of the follicular puncture in relation to the human chorionic gonadotropin injection (or the luteinizing hormone peak).

The effects of contraceptive hormones on the replication of Chlamydia trachomatis in human endometrial cells

Several recent reports have documented a lower incidence of pelvic inflammatory disease (PID) among oral contraceptive users. The interpretation of this observation is difficult because the action of the contraceptive hormones may be directly by action on a specific host cell-parasite relationship, or indirectly via their action on other systems. In the present study we investigated the susceptibility of cultured human epithelial cells of the endometrium to infection by chlamydia and the influence of contraceptive steroids (ethinyl estradiol, mestranol and medroxyprogesterone acetate) upon replication of chlamydia in these cells. Forty-eight hours post-infection, elementary and reticulate bodies were observed in vacuoles of the infected endometrial cells by electron microscopy. Treatment of chlamydial-infected cells with contraceptive steroids in three different concentrations (10(-5)M, 10(-6)M and 10(-7)M) resulted in no effect on chlamydial replication, as examined by one-step growth curve. These results indicate that contraceptive hormones do not prevent chlamydial infection by direct effect on the replication of the agent.

Specific IgG and IgA antibodies to Chlamydia trachomatis in infertile women

IgG, IgA, and IgM antibody titers to Chlamydia trachomatis were determined in sera of 80 infertile women and 100 controls by a single antigen (L-2) immunoperoxidase assay. The infertile women included 50 with unexplained infertility and normal hysterosalpingogram (HSG) and 30 with abnormal HSG. The control sera included 50 from primiparous and 50 from multiparous women. The prevalence of C. trachomatis IgG antibody was significantly higher in infertile women with abnormal HSG as compared with infertile patients with normal HSG and controls (87% v. 20% and 10%, respectively). The geometric mean titer (GMT) of C. trachomatis IgG antibodies of infertile women with abnormal HSG was significantly higher than those of controls (20.7 v. 5.6). A significantly higher prevalence of C. trachomatis IgA antibodies was found in infertile women with both abnormal and normal HSG than in controls (77% and 14% v. 3% respectively). No C. trachomatis IgM antibodies (less than 2) were found in any of the infertile or control groups. The possibility that serum C. trachomatis IgA antibodies may serve as a marker for early recognition of persistent C. trachomatis is discussed.

Immunoperoxidase assay for detection of specific IgG and IgA antibodies to human spermatozoa in infertile women

A new immunoperoxidase antibody-membrane antigen (IPAMA) technique for the detection of IgG and IgA antibodies specific for sperm antigens is described. The technique utilizes as antigen sperm cells dried on glass slides and stored at -70 degrees C. Sera of 82 infertile women, 50 primiparas, 50 multiparas and 25 children were tested by IPAMA. Results obtained with the IPAMA test for sperm-specific IgG are compared with the results obtained by the sperm immobilization test (SIT). By the IPAMA technique, 11 of 82 infertile women (13.4%) were positive for sperm-specific IgG antibodies, 12 (14.6%) for IgA antibodies and three (3.7%) for both. In the control groups only two of 125 subjects were positive for sperm-specific IgG and none for IgA antibodies. The difference in the prevalence of anti-sperm antibodies between the control groups and the infertility group was highly significant (P less than 0.001). There was agreement between the results of the IPAMA and SIT as to the presence or absence of antibodies in seven of the 11 IgG-positive sera in the infertility group. Four more sera were IgG positive by IPAMA only. The two positive sera in the control group were detected by both IPAMA and SIT. Since the IPAMA technique is simple, does not require special equipment and utilizes stored antigen, it seems that this method could be useful in mass screening of infertile couples.

Reactivation of cytomegalovirus in endometrial cells by estradiol

The present study uses an in vitro model to test the influence of hormones on the replication and reactivation of cytomegalovirus (CMV) in endometrial tissue culture. Infection of epithelial cells of the endometrium with CMV in the presence of a high concentration of estradiol resulted in only a slightly higher yield of infectious virus. Progesterone did not cause any effect on viral replication. Arrest of CMV replication was achieved by reduction of the pH of the incubation medium. No infectious virus was detectable after incubation of infected cultures at pH 5.8. In the above-described conditions following the arrest of CMV replication by low pH, estradiol treatment was capable of reactivating the virus. The possibility that the increase in CMV infection observed in pregnancy is caused by reactivation of latent virus provoked by hormonal factors will be discussed.

Serum IgG and IgA antibodies specific for Chlamydia trachomatis in salpingitis patients as determined by the immunoperoxidase assay

The feasibility of applying elevated Chlamydia trachomatis specific IgG antibody and serum IgA antibodies as a non-invasive screening test for C. trachomatis associated salpingitis was analysed in 54 salpingitis patients and 294 apparently healthy women by the single antigen (L2) immunoperoxidase assay (IPA). The prevalence rate of C. trachomatis IgG antibody (titre greater than or equal to 64) was significantly higher in the salpingitis patients in comparison to control (67% versus 23%). The prevalence rate of elevated C. trachomatis IgG titres (greater than or equal to 128, greater than or equal to 256 and greater than or equal to 512) was significantly higher in the salpingitis patients as compared to the controls. For example, at an IgG titre of greater than or equal to 128 the prevalence rate was 57% in the salpingitis patients and 8% in the healthy controls (p less than 0.0001). The prevalence of C. trachomatis IgA antibodies (titre greater than or equal to 16) was significantly higher in salpingitis patients in comparison to controls (37% versus 4%). The prevalence of elevated IgA titres (greater than or equal to 32 and greater than or equal to 64) was found to be significantly higher in salpingitis patients as compared to controls. All the IgG seropositive salpingitis patients were also found to have C. trachomatis IgG antibodies. It appears that testing for IgG antibodies at a serum dilution of 1:128, and for IgA antibodies at a dilution of 1:16 by the IPA test comprises the best combination for the differentiation between the salpingitis patients and apparently healthy controls, and it is suggested that this be used as a marker of active C. trachomatis infection.

Renal clearance of urea, inulin, and p-aminohippurate in heat-acclimated rats

Clearance values of urea, inulin, and p-aminohippurate (PAH) were measured in heat-acclimated (HA) rats exposed for 3 wk to 35 degrees C, in control rats (C) exposed to 23 degrees C, and in HA rats deacclimated (DA) for 3 wk. In HA rats, urea clearance was lower by 73%, inulin clearance by 61%, and PAH clearance by 56%, compared with C rats. The clearance values of these substances returned to the control values in DA rats. The data suggest that the low clearance values reflect both reduced renal blood flow and possible changes in the capacity of the glomeruli for filtration and the tubules for either reabsorption or secretion.

The effect of eccentricity and colour on negativity in pattern onset visual evoked potentials

The effects of stimulus size, eccentricity and colour on the amplitudes of N100 and N130 were investigated in pattern onset VEPs. For black-and-white pattern stimulation, the first set of stimuli was derived from a full dartboard pattern. Central stimulation of various extents was produced by patterns with reduced number of outer rings and for eccentric stimuli a number of central rings were removed from the full pattern. It was found that amplitude of N100 was maximal in VEPs to central stimuli and that it was greatly reduced when eccentric stimulation was applied. The amplitude of N130 showed no significant change in relation to the type of stimulus. When checkerboard stimuli of identical configuration were used for black-and-white pattern stimulation instead of dartboards, systematic changes in peak latencies of N100 were observed in relation to check size. In VEPs to centrally presented small checks the emergence of an early negative peak preceding N100 was recorded at 75 msec. In VEPs to coarse checkerboards presented centrally N100 was often observed with a delayed peak latency of 110 msec. Changes in N130 were not regular when checkerboards with different check sizes were presented centrally. For eccentric checkerboard stimulation, both negative peaks N100 and N130 were revealed. Their peak latencies were similar to those observed in the case of dartboard paracentral stimulation. In VEPs to patterns projected through red or blue filters, regular changes were observed in both negative peaks. Introduction of the red filter led to enhancement of the N100 amplitude in VEPs to dartboard and to checkerboards with fine checks, but it caused no effect on N100 in the VEPs to coarse checkerboards. Introduction of the blue filter led to a decrease in the N100 amplitude in VEPs to dartboard and fine checkerboards and to a slight increase of N100 in VEPs to coarse checkerboards. Changes in N130 were observed only when the blue filter was introduced and they corresponded to those which take place when the level of illumination changes from photopic to mesopic.

The undesirable effects of various changes of monoplane occlusion on complete denture retention

The most commonly seen undesirable alterations to the occlusal plane, when using monoplane occlusion with nonanatomic teeth, have been outlined verbally and graphically. The introduction of dislodging forces to denture retention brought about by these variations in the monoplane have been examined, as well as methods for their correction. The order of presentation of undesirable alterations to the occlusal plane is a guide for a step-by-step correction of these changes. It provides the practitioner with a sequential checklist for correcting undesirable occlusal changes in monoplane denture occlusion with nonanatomic teeth.

Antigenicity of sperm cells after freezing and thawing

Freezing and thawing is thought to result in removal of spermatozoal membrane antigens. We investigated the presence of sperm antigens before and after freezing and thawing by means of the immunoperoxidase assay (IPAMA), sperm immobilization test (SIT), and separation of proteins by gel electrophoresis. The results of the IPAMA and SIT assays showed no difference in the membrane antigens before and after freezing and thawing. Analysis of surface proteins by gel electrophoresis demonstrated that freezing and thawing did not remove any particular group of proteins from the surface membrane of spermatozoa. According to the evidence of the three tests performed, there is no meaningful removal of antigens from the sperm cell surface membrane by the process of freezing, preservation, and thawing when carried out by the specific methods used. This work does not support the suggestion that in cases of immunologic incompatibility between spermatozoa and cervical mucus it would be possible to overcome the couple's infertility by employing the process of freezing, preservation, and thawing.

Infection of endometrial cells with human cytomegalovirus

In order to understand the mechanism of congenital human cytomegalovirus (CMV) infection we studied the effect of CMV on epithelial cell culture of the endometrium. Endometrial cells proved to be sensitive to CMV as indicated by morphologic alterations, success to support growth of infectious virus and positive immunoperoxidase staining. The infected cells were enlarged, multinuclear and revealed intranuclear inclusions. Electron microscopy detected the presence of the viral particles in the CMV-infected endometrial cells. The possibility that CMV infection of the endometrial cells may play a role in transmitting the virus to the embryo will be discussed.

Human endometrium in cell culture: a new method for culturing human endometrium as separate epithelial and stromal components

The present study describes a simple method for culturing human endometrium as separate epithelial and stromal components. Fifty-two samples of normal human endometrium have been initiated in tissue culture: endometrium from both the proliferative and luteal phases of the menstrual cycle showed satisfactory growth in vitro with a success rate of about 94%. Epithelial cultures remained viable for 60 days, while from stromal cells it was possible to establish cell lines. Both cell types possessed estrogen receptors. Epithelial cells showed no clear estrogen or progesterone response. Our observations suggest that this simple method for culturing human endometrium may serve as a tool in further investigations.

The effect of background illumination on pattern onset visual evoked potentials

The early part (first 200 msec) of pattern onset VEPs elicited by a dartboard pattern was studied in conditions of varying level of background illumination. The effect of pattern adaptation and pattern blurr was also studied. The observed complex behaviour of the main negativity within this part of the VEP can be best described in terms of a composite of two independent negative peaks labelled N100 and N130. In high luminance conditions peak N100 was dominant and the presence of N130 was indicated only by a 'notch' on the rising slope of the negativity. As luminance decreased the situation was reversed and N130 became a dominant feature of the negative wave. This finding did not depend on the particular choice of reference site. For checkerboard stimulation the same features were present, but variability of the VEP wave form was greater than in the case of dartboard stimulation. Present results relate the well-known pattern specific properties of the negativity in onset VEPs to N100 only, whereas N130 is not pattern specific. Lower and upper half-field stimulation produced peaks of opposite polarity at 100 msec but no change was observed in polarity of N130. These findings support the suggestion that these two parts of the negativity in pattern onset VEPs may have different cortical sources.

N1-P2 correlates of reaction time at the single-trial level

Using a template-matching pattern recognition technique evaluated in an earlier paper, the amplitude and latency of the N1-P2 wave of the vertex visual evoked potential was established on each trial of a reaction time task. This single-trial physiological information correlated meaningfully with trial-by-trial changes in performance, providing further indication of the validity and practicability of a single-trial approach to the analysis of human EP data.

Potentiation of the habituation of human brain potentials

A single-trial analysis, using the cross-covariance function to locate and quantify individual visual evoked potentials (VEPs), is employed to assess run-by-run changes in the habituation function of the N1-P2 wave of the vertex VEP. The characteristic exponential form of this function is shown to be less pronounced later in the experimental session. This finding is adduced as evidence of potentiation of VEP habituation and as such is argued to provide further justification for considering VEP habituation as genuine habituation in Thompson and Spencer's (1966) system.

"Stimulus generalization" between differentiated visual, auditory, and central stimuli

Cats were trained to discriminate between two different repetition rates of flicker and of click. Both approach-approach and avoidance-avoidance discriminations were used. After substantial overtraining, transfer of frequency discrimination was initiated to stimulation of the reticular formation using bursts of electrical pulses at the same two repetition rates. Significant levels of discriminated performance were obtained in all cats very quickly, indicating good cross-modal transfer between the peripheral discriminanda and the central stimuli. The literature on stimulus generalization and cross-modal transfer is reviewed and the findings of this experiment are discussed in that context. Certain conditions are defined which, if satisfied, justify the interpretation that stimulus generalization or rapid cross-modal transfer indicate that facilitation of subsequent tasks in a training sequence can be attributed to mediation by a specific neuronal mechanism established by training on a previous task. The present experiment was designed in view of such criteria. The evidence of good cross-modal transfer is interpreted to mean that brain mechanisms storing memories about discriminations between visual or auditory stimuli with different repetition rates can be effectively activated by gross electrical stimuli at the same repetition rates. Conflict trials were then carried out in which flicker or click at either frequency was contradicted by concurrent RF stimuli at the other frequency. As the current level of RF stimuli was parametrically increased, it was found that the central stimuli achieved almost complete control over the behavioral outcome in most cases. Concurrent transfer of training, using a counterbalanced training sequence, was then carried out to stimulation of the visual cortex, lateral geniculate, medial geniculate, and the intralaminar nuclei of the thalamus. In each case, rapid transfer was displayed by at least one animal. Once performance to brain stimulation at a given repition rate was established, little change was observed when the fine structure of the stimulus was altered by changing parameters of the stimulus burst. These findings are interpreted as providing support for a statistical theory of memory, since they constitute evidence that previously learned discriminative behavior can readily be elicited by compelling large ensembles of neurons in various brain regions to discharge with particular temporal patterns. It is difficult to reconcile these results with theories which postulate that learning establishes new synaptic pathways in which discharge must occur for memories to be retrieved.

Contradiction of auditory and visual information by brain stimulation

Cats with permanently implanted electrodes were trained to discriminate between trains of flashes or clicks at two different repetition frequencies. After substantial overtraining with these sensory stimuli, high levels of stimulus generalization were obtained to electrical stimulation of the reticular formation at either frequency stimultaneously with contradictory flicker or click stimulation at the opposite frequency resulted in control of the behavior by the reticualr stimulus. Lateral geniculate stimulation failed to show this effect.