Possible environmental, occupational, and other etiologic factors for Parkinson's disease: a case-control study in Germany

In a case-control study, we investigated the possible etiologic relevance to Parkinson's disease (PD) of rural factors such as farming activity, pesticide exposures, well-water drinking, and animal contacts; toxicologic exposures such as wood preservatives, heavy metals, and solvents; general anesthesia; head trauma; and differences in the intrauterine environment. We recruited 380 patients in nine German clinics, 379 neighborhood control subjects, and 376 regional control subjects in the largest case-control study investigating such factors and collected data in structured personal interviews using conditional logistic regression to control for educational status and cigarette smoking. The latter was strongly inversely associated with PD. There were significantly elevated odds ratios (OR) for pesticide use, in particular, for organochlorines and alkylated phosphates, but no association was present between PD and other rural factors. A significantly elevated OR was present for exposure to wood preservatives. Subjective assessment by the probands indicated that exposure to some heavy metals, solvents, exhaust fumes, and carbon monoxide was significantly more frequent among patients than control subjects, but this was not confirmed by a parallel assessment of job histories according to a job exposure matrix. Patients had undergone general anesthesia and suffered severe head trauma more often than control subjects, but a dose-response gradient was not present. Patients reported a significantly larger number of amalgam-filled teeth before their illness than control subjects. The frequency of premature births and birth order did not differ between patients and control subjects. Patients reported significantly more relatives affected with PD than control subjects. These results support a role for environmental and genetic factors in the etiology of PD.

Hematopoietic progenitors and interleukin-3-dependent cell lines synthesize histamine in response to calcium ionophore

The calcium ionophore A23187 promotes histamine synthesis in murine bone marrow cells by increasing the expression of mRNA encoding histidine decarboxylase (HDC), the histamine-forming enzyme. The cells responsible for this biological activity copurify with hematopoietic progenitors in terms of density, light scatter characteristics, and rhodamine retention, similar to interleukin (IL) 3-induced histamine-producing cells. Yet, the effect of calcium ionophore is not mediated by IL-3. The most purified rhodamine-bright bone marrow subset contains 80% cells that respond to calcium ionophore by increased HDC mRNA expression. This high frequency makes the involvement of one particular progenitor subset in histamine synthesis unlikely. The finding that all IL-3-dependent cell lines tested so far exhibit increased histamine production and HDC mRNA expression in response to calcium influx lends further support to this notion. Cell lines requiring other growth factors or proliferating spontaneously lack this ability. Finally, it should be noted that IL-3-dependent cell lines do not produce histamine in response to their growth factor. It might, therefore, be suggested that the pathway transducing the signal for increased histamine synthesis after IL-3 receptor binding in normal hematopoietic progenitors is modified in these cell lines.

Fetal hydrops secondary to human parvovirus infection in early pregnancy

Parvovirus B19 infection has been associated with fetal anaemia, hydrops, and in some cases demise. Most of the reported cases of fetal hydrops were detected in second-trimester fetuses. We report a series of three cases in which human parvovirus infection was associated with hydropic changes at an earlier gestational age. Spontaneous resolution of hydrops occurred in all fetuses. A greater understanding of the natural history of human parvovirus infection is needed prior to deciding on the mode of therapy (conservative management versus in utero fetal therapy).

Simultaneous magnetic resonance phase and magnitude temperature maps in muscle

Noninvasive magnetic resonance temperature maps that are used to monitor thermal ablation of tissue are described. In magnetic resonance images, thermally induced proton nuclear magnetic resonance frequency shifts, and changes in the longitudinal relaxation time produce both phase and magnitude changes in the MR signal. Temperature maps with improved sensitivity are derived from the complex-difference nuclear magnetic resonance signal. Bovine muscle specimens were heated with focused ultrasound to model thermal surgery and create a known thermal distribution to test the method. Resulting MR images acquired in 2 s produce temperature maps with 1 min resolution and 2 degrees C temperature sensitivity. The temperature sensitivity was increased by extending the acquisition to 5 s, by decreasing the receiver bandwidth, and increasing the echo time.

In vitro T cell unresponsiveness following low-dose injection of anti-CD3 MoAb

Anti-CD3 MoAb treatment is widely used as an immunosuppressive therapy. In the present study we examined the in vitro T cell response in mice having received 24 h before a single i.v. injection of 10 microgram of anti-CD3 MoAb. We found that splenocytes from these mice displayed a dramatically decreased proliferative response to the T cell mitogens concanavalin A (Con A), anti-CD3, phytohaemagglutinin (PHA) and phorbol myristate acetate (PMA) + calcium ionophore, while the effect of lipopolysaccharide (LPS) was not impaired. T cell suppression persisted for about 10 days after anti-CD3 injection, returning to normal within 15 days. The F(ab')2 fragment of anti-CD3 had no such effect, indicating the requirement for in vivo activation. At the dose used, anti-CD3 resulted neither in T cell depletion nor in down-modulation of the CD3/T cell receptor (TCR) complex. The low proliferation was also not explained by apoptosis, following secondary challenge with Con A. Splenocytes from anti-CD3-injected mice were highly responsive to IL-2, but generated little or no IL-2, IL-3, IL-4 and interferon-gamma (IFN-gamma) when exposed to Con A. Normal cytokine production could not be restored by the addition of optimal doses of IL-2 during Con A stimulation. Transforming growth factor-beta (TGF-beta) was the only cytokine whose mRNA expression was not modified in stimulated splenocytes from anti-CD3-injected mice. Furthermore, anti-TGF-beta antibodies increased Con A-induced T cell proliferation, but not cytokine production.

Surveillance of growth-retarded fetuses with computerized fetal heart rate monitoring combined with Doppler velocimetry of the umbilical and uterine arteries

OBJECTIVE

To define guidelines for surveillance of growth-retarded fetuses with a computerized fetal heart rate (FHR) monitor and Doppler device.

STUDY DESIGN

Eighty-one growth-retarded fetuses with birth weights < 10th percentile and lacking major anomalies were studied. One hundred ninety-two tests (one to six per patient), including computerized FHR monitoring and Doppler studies of the umbilical and uterine arteries, were performed. The relationship between Doppler velocimetry or FHR variation and fetal outcome was examined.

RESULTS

Fetuses with an abnormal FHR variation or abnormal Doppler velocimetry had a significantly higher rate of cesarean deliveries for fetal distress and a higher number of admissions to the neonatal intensive care unit (NICU) as compared with fetuses with normal results on both tests. The best distinction was noted when the growth-retarded fetuses were partitioned into four analytic groups based on the presence of normal or abnormal FHR variation or Doppler velocimetry. The group with the poorest results was composed of fetuses with abnormal umbilical flow velocity and reduced FHR variation. These fetuses had significantly lower birth weights (1,250 g) and significantly higher rates of cesarean deliveries for fetal distress (92%) and admission to the NICU (100%). Thirty percent of these fetuses died.

CONCLUSION

Fetal surveillance with Doppler and computerized FHR monitoring allows better understanding of the management of fetuses that are small for gestational age.

Spatial mapping of the percentage cellularity in human bone marrow using magnetic resonance imaging

A noninvasive assay for the spatial distribution of the percentage cellularity in human bone marrow is presented. Twelve individuals were studied using two magnetic resonance imaging techniques: (1) fast spin echo imaging with frequency selective presaturation, and (2) three-point chemical shift imaging. The data were compared to results obtained using a previously validated stimulated echo spectroscopic method. The results of this study demonstrate that a measure of the percentage cellularity in bone marrow is possible using magnetic resonance imaging techniques provided that high-quality water or lipid suppression is achieved across the region of interest. Since the method is applicable to bone marrow at any anatomic location, it may prove useful in dosimetric calculations during and after a course of internal or external beam radiotherapy.

Pulsed magnetization transfer contrast for MR imaging with application to breast

The relative populations and transverse relaxation times of the solid-like hydrogen pool (PB and T2B) and the magnetization transfer (MT) rates between the solid-like and liquid-like hydrogen pools (kappa) have been determined for three different agar gel concentrations (2%, 4%, and 8% by weight) as well as excised fibroglandular breast tissue specimens. PB was determined to be .003(.001), .01(.002), .02(.01), and .06(.01); T2B was determined to be 13.0(.2), 14.0(.1), 14.5(.1) and 15.2(1.3) microseconds; and kappa was determined to be 0.78(.01), 1.15(.02), 2.00(.02), and 3.55(1.5) sec-1 for the 2%, 4%, and 8% agar gels and the fibroglandular tissue, respectively. The image signal intensities of a pulsed MTC-prepared gradient-echo imaging technique are predicted using these MT parameters and are shown to agree well with experimental data obtained from a clinical MR imaging system. This technique is shown to suppress signal intensity of fibroglandular breast tissue by 40%-50% without exceeding SAR limits (< or = 8 W/kg) and is helpful for visualizing lesions and silicone implants.

Prospective 12-year follow-up study of clinical and hemodynamic sequelae after deep vein thrombosis in low-risk patients (Zürich study)

BACKGROUND

No prospective study of the long-term sequelae of more than 10 years after acute deep vein thrombosis exists so far. Therefore, 58 low-risk patients with DVT were included in a prospective study to evaluate the natural history of postthrombotic syndrome.

METHODS AND RESULTS

Clinical and hemodynamic examinations were performed at the time of admission; after 3, 6, and 12 months; after the 2nd, 3rd, 4th, 5th years; and finally after the 12th year. All patients received heparin initially and oral anticoagulants subsequently. After 12 years, 64% of the patients exhibited normal findings. Mild skin changes were found in 28%, marked trophic changes in 5%, and only one venous ulcer occurred. Regular use of compression stockings was reported by 54% of the patients with multilevel thrombosis. Although mean maximum venous outflow was significantly reduced from the acute event to 12 years later (P<.003) compared with the contralateral leg, a significant (P<.05) improvement was observed 6 months later. Recanalization of calf vein thrombosis was detected by Doppler sonography after 3 months. Sixty-four percent of the multilevel thromboses were recanalized completely or in part after 1 year; in 69%, valvular incompetence was found.

CONCLUSIONS

In contrast to earlier reports, this prospective study up to 12 years after deep vein thrombosis demonstrates a low incidence of postthrombotic syndrome by administration of oral anticoagulants and regular compression therapy. However, the adverse clinical event rate (mortality 14%) and a recurrence rate of 24% show that the prognosis after deep vein thrombosis does not appear favorable even in low-risk patients.

Ovarian cancer after successful ovulation induction: a case report

BACKGROUND

Questions have been raised regarding the potential association of ovulation-inducing drugs and ovarian cancer. Worldwide there have been 13 cases of ovarian carcinoma reported to occur in women previously treated with ovulation-inducing drugs (clomiphene citrate and/or gonadotropins).

CASE

A 40-year-old woman complained of secondary infertility. She conceived after five cycles of human menopausal gonadotropins with intrauterine insemination. Eight months after cesarean delivery, she presented with right lower quadrant pain and a right adnexal mass. At exploratory laparotomy the patient was found to have a poorly differentiated papillary serous carcinoma of the ovary.

CONCLUSION

Ovarian carcinoma developed within 18 months of exposure to ovulation-inducing agents, human menopausal gonadotropins. It would be prudent to gather a registry of cases to assess the risk associated with human menopausal gonadotropins with or without gonadotropin-releasing hormone analogs.

An evaluation of the safety and efficacy of fluconazole in the treatment of onychomycosis

Sixteen subjects were enrolled in this open-label noncomparative study to evaluate the safety and efficacy of fluconazole as a single daily dose for a period of 6 months. Liver function enzymes were monitored to assess safety. An adverse function questionnaire was used on a monthly basis to assess patient tolerance. A visual analogue scale was used to assess efficacy of treatment. After 6 months of fluconazole, all subjects experienced improvement in the appearance of their nails. None of the subjects evidenced any elevation in liver function enzymes. Adverse reactions were limited and consistent with other studies involving fluconazole. Fluconazole proved to be safe and efficacious in the treatment of onychomycosis. Further studies are needed to determine a cost-effective dosing regimen for the treatment of onychomycosis with fluconazole.

Vanadate and bafilomycin A1 are potent inhibitors of the ATPase activity of the reconstituted bacterial ATP-binding cassette transporter for maltose (MalFGK2)

Vanadate and Bafilomycin A1 were shown to inhibit the ATPase activity of the reconstituted binding protein-dependent ATP-binding Cassette (ABC) transporter for maltose (MalFGK2) of Salmonella typhimurium in the micromolar range. This is in sharp contrast to the recent finding that the isolated ATPase subunit MalK was insensitive to both compounds. Our data provide the first experimental evidence for the view that functional coupling of the ATPase domain of an ABC transporter to the membrane-integral domains is crucial for conferring sensitivity to vanadate and bafilomycin A1. Possible consequences for the mode of action of ABC transport proteins are discussed.

Renal artery velocity mapping with MR imaging

An MR phase imaging sequence with a very short echo time was used to assess blood velocity and flow at the renal artery bifurcation. Cardiac-gated MR imaging data were obtained in six healthy subjects in sagittal planes adjacent to the abdominal aorta and transverse planes above and below the renal artery bifurcation. Average renal artery flow rate was 23.8 +/- 9 mL/sec. A strong individual variability was found for the velocity profiles in the abdominal aorta during end-systolic regurgitation. Flow rate was also determined in three patients with reduced renal artery blood flow. Two patients received therapy with percutaneous transluminal angioplasty. The successful outcome was documented with MR imaging. A reliable assessment of renal artery flow with MR phase imaging is feasible. Measurement of the velocity profiles yields valuable insights in the complicated flow regime at the renal artery bifurcation.

Cross-resistance to camptothecin analogues in a mitoxantrone-resistant human breast carcinoma cell line is not due to DNA topoisomerase I alterations

We have previously described a mitoxantrone-resistant human breast carcinoma cell line, MCF7/MX, in which resistance was associated with a defect in the energy-dependent accumulation of mitoxantrone in the absence of P-glycoprotein overexpression (M. Nakagawa et al., Cancer Res. 52: 6175-6181, 1992). We now report that this cell line is highly cross-resistant to the camptothecin analogues topotecan (180-fold), 9-aminocamptothecin (120-fold), CPT-11 (56-fold), and SN38 (101-fold), but is only mildly cross-resistant to the parent compound camptothecin (3.2-fold) and 10,11-methylenedioxy-camptothecin (2.9-fold). Topotecan accumulation was decreased in MCF7/MX cells compared to parental MCF7/WT cells, and there was a corresponding reduction in topotecan-mediated stimulation of the enzyme/DNA complex formation in MCF7/MX cells compared to MCF7/WT cells. No overexpression of the multidrug resistance-associated protein was detected compared to parental MCF7/WT cells. Furthermore, both sensitive MCF7/WT and mitoxantrone-resistant MCF7/MX cells contain equal amounts of DNA topoisomerase I protein, and DNA relaxation activities were equal in both cell lines and inhibited to the same extent by topotecan and camptothecin. Thus, these results suggest a novel mechanism of resistance to topoisomerase I inhibitors in cancer cells.

The MalK protein of the ATP-binding cassette transporter for maltose of Escherichia coli is accessible to protease digestion from the periplasmic side of the membrane

The ATP-hydrolyzing subunit MalK of the ATP-binding cassette transporter for maltose of Escherichia coli is demonstrated to be accessible to digestion by proteinase K in right-side-out membrane vesicles. This finding suggests a partial transmembrane orientation of the protein.

Precise epitope mapping of three monoclonal antibodies raised against tms1 protein of fission yeast

Recently we described the production of two monoclonal antibodies 10G2 and 10C4 of IgG3 subclass raised against the recombinant tms1 protein of fission yeast. Here we introduce a new monoclonal antibody 2E2 of IgG1 subclass and present the precise epitope mapping of these monoclonal antibodies using tms1 deletion mutants and synthetically produced oligopeptides spanning the tms1 protein by immunoblot analysis.

A new therapeutic approach to popliteal artery entrapment syndrome (PAES)

OBJECTIVES

An alternative therapeutic approach to popliteal artery entrapment syndrome (PAES) with vascular complications.

MATERIALS

Three male patients (16, 42 and 68 years) with thrombotic and/or embolic obstructions of popliteal or crural vessels as a consequence of popliteal entrapment syndrome.

METHODS

Combined catheter treatment consisting of percutaneous transluminal thrombembolectomy (PTEE), local thrombolysis (LTL) and percutaneous transluminal dilatation (PTA) was performed for thrombotic and embolic obstructions of popliteal or crural vessels. The aberrant tendomuscular structures were surgically corrected at a later date.

RESULTS

After the procedure systolic ankle/arm pressure ratios in the three patients improved from 0.66 to 1.13, 0.57 to 1.07 and 0.46 to 1.10. Twelve, 8 and 4 months later the patients were asymptomatic. None of the patients showed popliteal artery compression during plantar flexion on Duplex scanning.

CONCLUSIONS

This new therapeutic approach avoids direct vascular surgery with bypass or patch implantation in patients with PAES who are often young. The long term results remain to be evaluated.

Murine hematopoietic progenitors are capable of both histamine synthesis and uptake

We examined various murine hematopoietic cell populations for their capacity to interact with radiolabeled histamine. Only bone marrow cells (BMC) retained substantial amounts of radioactivity, in contrast to thymus, spleen, and peritoneal cells. The characteristics of this interaction are consistent with histamine uptake rather than receptor binding. Indeed, this process is temperature and sodium dependent and reduced by various metabolic inhibitors. Furthermore, the effect of antagonists or agonists of the H1, H2, and H3 receptor subtypes is not in accordance with the involvement of either of these receptors in histamine binding. The target cells of histamine copurify with hematopoietic progenitors in the low-density BM population. They are most enriched in the subset sorted from the blast cell window on the basis of high rhodamine retention. This fraction contains on the average 80% to 90% immature cells and is highly enriched for several clonogenic progenitor subsets. Sixty percent of the Rh-bright cells are labeled by 3H-histamine, as assessed by autoradiography, suggesting that a variety of immature cells participates in this phenomenon. Furthermore, in all sorting procedures used here, the cells capable of histamine uptake coenrich with those producing histamine in response to interleukin-3, indicating at least a partial identity between these cells.

Effects of monoionic and nonionic radiographic contrast media on cutaneous microcirculation in patients with peripheral arterial occlusive disease

The purpose of the study was to compare the in vivo effects of two low-osmolar radiographic contrast media, a monoionic (sodium/-meglumine ioxaglate, Hexabrix) and a non-ionic one (iopromide, Ultravist 300) on the cutaneous microcirculation in patients with peripheral arterial occlusive disease in a prospective randomised double-blind study. In 20 patients with peripheral arterial occlusive disease scheduled for percutaneous transluminal angioplasty skin microcirculation was assessed by laser Doppler fluxmetry and transcutaneous oxygen tension measurements at the foot dorsum for continuous recordings of the cutaneous microvascular perfusion and skin oxygenation. Before angioplasty 10 ml nondiluted contrast medium was injected intraarterially and the acute effect on transcutaneous oxygen tension and laser Doppler flux was registered. Mean laser Doppler flux and oxygen tension were evaluated initially, after arterial puncture and after contrast medium injection. In addition, flux motion was analysed with respect to frequency and amplitudes changes. No significant changes in laser Doppler flux and fluxmotion patterns were found between both groups after contrast medium injection. However, mean transcutaneous oxygen tension of the patients receiving monoionic ioxaglate dropped significantly (P = 0.01). The differences of both contrast media on red blood cell aggregation shown in vitro do not correlate to intravital microcirculatory measurements in patients with arterial occlusive disease of the lower limb. Microvascular skin blood flow and flux motion at the foot in these patients do not change significantly after intraarterial injection of ioxaglate and iopromide. However, oxygen supply of the skin is transient impaired after interarterial injection of the anionic contrast agent ioxaglate, which was not associated with clinical symptoms.

Role of interleukin-2 receptors in the suppressive effect of spleen cells from anti-CD3-treated mice

In the present study, we demonstrate that unresponsive spleen T cells from mice injected with a low dose of anti-CD3 mAb (single 10 micrograms i.v. injection) significantly inhibit Con A-induced proliferation of normal spleen cells. The induction of this phenomenon requires in vivo activation since spleen cells from mice injected with the F(ab')2 fragment of anti-CD3 mAb fail to promote it. Suppression of normal T cell proliferation is concomitant with increased expression of IL-2 receptor on spleen cells from anti-CD3-treated mice. It disappears within 3 days when IL-2R has returned to background levels. A normal proliferative response to Con A can be restored when high concentrations of IL-2 are added together with the "suppressor" cells. Taken together, these data support the notion that activated spleen cells from anti-CD3-injected mice exert their inhibitory effect by competing for the IL-2 generated during culture.

Heavy ion-induced DNA double-strand breaks with yeast as a model system

Cells of diploid yeast, Saccharomyces cerevisiae, were exposed to a variety of energetic heavy ions (provided by the UNILAC facility at the Gesellschaft für Schwerionenforschung, GSI), 241Am alpha-particles and 80-keV x-rays after which they were assessed for DNA double-strand breaks (DSB) using either the neutral sedimentation or the pulsed-field gel electrophoresis (PFGE) technique. Both yielded comparable results. The DSB production cross-sections are compared with inactivation studies performed for the same cells under identical conditions. The measurements show that with lighter ions DSB induction cross-sections increase with linear energy transfer (LET), but the situation is less clear with the heavier ions. A close parallelism was found between DSB induction and cell inactivation in these yeast cells.