Hepatic tissue engineering on 3-dimensional biodegradable polymers within a pulsatile flow bioreactor

BACKGROUND

An optimal method for hepatocyte transplantation is not yet determined. With the principles of tissue engineering in vitro conditioning of hepatocytes on biodegradable polymer in a flow bioreactor before implantation forming spheroids may achieve increased cell mass and function to replace lost organ function in vivo.

METHODS

Biodegradable poly-L-lactic (PLLA) polymer discs were seeded with rat hepatocytes in a concentration of 10 x 10(6) cells per ml and exposed to a medium flow of 24 ml/min for 1, 2, 4 and 6 days. The number and diameter of spheroidal aggregates was measured by phase-contrast microscopy. H&E histology was performed. Albumin production as hepatocyte specific function was determined by ELISA.

RESULTS

Spheroids of viable hepatocytes of 50-200 microm in diameter were formed. Both the number and diameter of the spheroids increased during the first 2 days and then remained constant until day 6. Albumin production was maintained throughout the culture period.

CONCLUSION

Short (2- 3 days) pre-transplant conditioning of hepatocytes in a flow bioreactor on biodegradable PLLA resulted in formation of spheroids with a liver-like morphology and preserved specific metabolic function. Tissue engineered hepatocyte spheroids on polymer may represent a functionally active and easy transplantable neotissue and may serve as an in vivo substitute for lost liver function.

Partitioning methods for multifactorial risk attribution

The epidemiological problem of risk attribution in the framework of multiple exposures has been the subject of intensive research activities in the last decade. In particular, partitioning methods have been developed to define new multidimensional measures of attributable risk putting the task of quantifying a proportion of disease events in a population that can be ascribed to the adverse health effects of certain risk factors into a multifactorial perspective. The parameters generalize the concept of attributable risk to different multifactorial frameworks in which multiple exposures might be arranged in hierarchically ordered classes or in equally ranking groups. Partitioning methods are reviewed and differences between the multifactorial variants of attributable risk are illustrated by a component causes model.

Prevention of cisplatin-induced emesis by the oral neurokinin-1 antagonist, MK-869, in combination with granisetron and dexamethasone or with dexamethasone alone

PURPOSE

The NK1-receptor antagonist MK-869 (L-754,030) has demonstrated antiemetic activity in humans receiving chemotherapy. Objectives of the present trial included the first assessment of oral MK-869 plus dexamethasone compared with a 5HT(3) antagonist plus dexamethasone for prevention of acute and delayed emesis after high-dose cisplatin. Furthermore, the study sought to confirm that addition of MK-869 to a 5HT(3) antagonist plus dexamethasone was more effective than just the 5HT(3) antagonist plus dexamethasone for prevention of acute and delayed emesis.

METHODS

This multicenter, double-blind, parallel-group trial in 351 cisplatin-naïve patients evaluated prevention of acute (0 to 24 hours) and delayed emesis (primary efficacy parameter; days 2 to 5) after cisplatin (> or =70 mg/m(2)). Patients were randomized to four groups (I to IV) (n = number randomized; number evaluable): granisetron (10 microg/kg intravenously) pre-cisplatin followed by placebo on days 2 to 5 (group I) (n = 90; 90); granisetron and MK-869 (400 mg PO [by mouth]) pre-cisplatin, followed by MK-869 (300 mg PO) on days 2 to 5 (group II) (n = 86; 84); MK-869 (400 mg PO) the evening before and pre-cisplatin, followed by MK-869 (300 mg PO) on days 2 to 5 (group III) (n = 89; 88); or MK-869 (400 mg PO) pre-cisplatin, followed by MK-869 (300 mg PO) on days 2 to 5 (group IV) (n = 86; 84). All patients also received dexamethasone (20 mg PO) before cisplatin. Additional medication was available to treat emesis or nausea at any time.

RESULTS

In the acute period, 57%, 80%, 46%, and 43% of patients were without emesis in groups I, II, III, and IV, respectively (P <.01 for group II v group I). In the delayed period, the proportion of patients without emesis in groups I, II, III, and IV was 29%, 63%, 51%, and 57%, respectively (P <.01 for groups II, III, and IV v group I). The distribution of nausea scores in the delayed period was lower when comparing group II with group I (P <.05 for days 1 to 5 and days 2 to 5). One serious adverse event (dizziness) was rated as possibly related to MK-869.

CONCLUSION

Once daily oral administration of MK-869 was effective in reducing delayed emesis and nausea after high-dose cisplatin. However, the combination of the 5HT3 antagonist plus dexamethasone was numerically superior to MK-869 plus dexamethasone in reducing acute emesis. Confirming and extending previous findings, the triple combination of a 5HT(3) antagonist, MK-869, and dexamethasone provided the best control of acute emesis.

Thyroid function, thyroid immunoglobulin status, and urinary iodine excretion after enteral contrast-agent administration by endoscopic retrograde cholangiopancreatography

BACKGROUND AND STUDY AIMS

The aim of this study was to examine the occurrence of clinically relevant changes in thyroid function after enteral administration of contrast agent by endoscopic retrograde cholangiopancreatography (ERCP).

PATIENTS AND METHODS

In this study 70 patients without a history of thyroid disease who had not recently undergone thyroid-specific or thyroid-influencing therapy were examined. Patients were examined on two or three occasions using a standardized questionnaire regarding symptoms of hypothyroidism and hyperthyroidism. The parameters of thyroid function (TT3, TT4, FT4, thyroid-stimulating hormone (TSH)) and urinary iodine excretion were measured on day 0 and on day 21 post-ERCP, and in 23 patients additionally on day 42 post-ERCP. Based on ultrasonographic results, four groups differing in thyroid morphology were distinguished.

RESULTS

The data show that an average amount of only 4.7 g of enterally applied iodine is associated with a lasting decrease of TSH, especially in patients with enlarged organs with nodular transformation. As far as TT3 is concerned, there was a significant increase in all patient groups; regarding FT4 we only observed a marked increase in the group with enlarged, nodular thyroid glands. There was a notable increase in urinary iodine excretion on day 21, and a further increase on day 42 post-ERCP. Clinical symptoms of hyperthyroidism did not occur.

CONCLUSIONS

We conclude that before administration of iodine-containing contrast agent for ERCP in patients without a history of thyroid disease, thyroid ultrasonographic examination, rather than TSH measurements, should be performed, in order to identify patients already at risk for hyperthyroidism before diagnostic enteral contrast-medium application.

First-line, single-agent Herceptin(R) (trastuzumab) in metastatic breast cancer. a preliminary report

Following confirmation of the appropriate dosage, safety and potential efficacy of Herceptin(R) (trastuzumab) in small-scale phase I and II trials involving patients with refractory disease, a large trial was conducted in 222 patients with breast cancer who had relapsed after one or two chemotherapy regimens for their metastatic disease. The results showed a positive and durable overall response rate (15% according to a response evaluation committee (REC) assessment) using trastuzumab monotherapy (initial dose 4 mg/kg intravenously (i.v.) followed by 2 mg/kg i.v. weekly). In another recently completed phase II trial, 113 patients were randomised to two dose levels (initial dose of 4 mg/kg i.v. dose followed by 2 mg/kg i.v. weekly, or initial dose of 8 mg/kg followed by 4 mg/kg i.v. weekly) of single-agent trastuzumab as first-line therapy for metastatic disease. The preliminary overall response rate was 23% based on investigator assessment, and tolerability was excellent as in previous trials; efficacy was similar in both dose groups, but the side-effects tended to be more frequent in the higher dose group. The preferred dosage is therefore the same as that currently recommended, i.e. an initial dose of 4 mg/kg i.v. followed by 2 mg/kg weekly i.v. until disease progression.

[Significance of care for children and adolescents victims of domestic violence]

This is a phenomenological and hermeneutic study. Its objective is to reveal the meaning of "care" for children and adolescents who have suffered domestic violence. The investigation was carried out in two casas-lares (orphanage houses) in Florianópolis. These houses functioned as temporary shelters for either girls or boys who had suffered some kind of violence in their homes. The descriptions obtained through the answers and drawings of eighteen children and adolescents enabled us to characterize "care" as a way of promoting life, expressing oneself, relating to the environment, denying past experiences and resisting in order to survive.

First-line, single-agent Herceptin(trastuzumab) in metastatic breast cancer: a preliminary report

Following confirmation of the appropriate dosage, safety and potential efficacy of Herceptin(trastuzumab) in small-scale phase I and II trials involving patients with refractory disease, a large trial was conducted in 222 patients with breast cancer who had relapsed after one or two chemotherapy regimens for their metastatic disease. The results showed a positive and durable overall response rate (15% according to a response evaluation committee (REC) assessment) using trastuzumab monotherapy (initial dose 4 mg/kg intravenously (i.v.) followed by 2 mg/kg i.v. weekly). In another recently completed phase II trial, 113 patients were randomised to two dose levels (initial dose of 4 mg/kg i.v. dose followed by 2 mg/kg i.v. weekly, or initial dose of 8 mg/kg followed by 4 mg/kg i.v. weekly) of single-agent trastuzumab as first-line therapy for metastatic disease. The preliminary overall response rate was 23% based on investigator assessment, and tolerability was excellent as in previous trials; efficacy was similar in both dose groups, but the side-effects tended to be more frequent in the higher dose group. The preferred dosage is therefore the same as that currently recommended, i.e. an initial dose of 4 mg/kg i.v. followed by 2 mg/kg weekly i.v. until disease progression.

Regulation of prostaglandin endoperoxide H synthase-2 induction by dioxin in rat hepatocytes: possible c-Src-mediated pathway

The tumor promoter 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is known to increase the expression of prostaglandin endoperoxide H synthase (PGHS)-2. This study focused on the regulatory mechanism of TCDD-mediated transcriptional activation of PGHS-2. Treatment of rat hepatocytes with TCDD led to a dose-dependent induction of PGHS-2 mRNA levels associated with an increased synthesis of prostaglandin E(2), whereas expression of PGHS-1 was not affected. In vitro experiments with c-Src inhibitors, such as herbimycin A and geldanamycin, and in vivo studies with c-Src-deficient mice indicated that up-regulation of PGHS-2 but not the cytochrome P450 gene CYP1A1 by TCDD is mediated via a c-Src-dependent pathway. Transient transfection studies with different reporter constructs of the murine PGHS-2 promoter mutated in the xenobiotic-responsive element (XRE) or CCAAT/enhancer binding protein (C/EBP) element revealed that a C/EBP-binding site is an important regulatory cis-acting factor for trans-activation of the PGHS-2 gene by TCDD. Consistent with transfection studies, gel mobility shift assays showed that TCDD led to an enhanced DNA-binding activity of C/EBP beta transcription factor. The experimental data presented in this article reveal a XRE-independent and c-Src-mediated activation of the PGHS-2 gene by TCDD through the C/EBP response element located in its promoter region.

Prostaglandin H synthases and their importance in chemical toxicity

The metabolism of a xenobiotic is an important stage resulting in its toxification (bioactivation) or detoxification. The most common reaction is the oxidation catalyzed by the cytochrome P450 (CYP) enzyme system. An alternate enzyme for chemical oxidation is the prostaglandin H synthase (PGHS) also known as cyclooxygenase (COX). The PGHS is the initial enzyme in arachidonate metabolism and formation of prostanoids such as prostaglandins (PG), prostacyclins, and thromboxanes. However, 25 years ago it was found that during the reduction of the endogenous substrate, hydroperoxy-endoperoxide (PGG2) to hydroxy-endoperoxide (PGH2), the PGHS enzyme is capable to "co-oxidize" chemicals. In this reaction, a broad spectrum of chemicals can serve as electron donors such as phenolic compounds, aromatic amines, and polycyclic aromatic hydrocarbons. In contrast to numerous CYP enzymes in liver, the PGI is an alternate enzyme for xenobiotic metabolism in extrahepatic tissues. In respect of tissue distribution, PGHS can play an essential role in the bioactivation of e.g. procarcinogenic chemicals in certain target tissues that possess low CYP monooxygenase activity. Two PGHS isozymes have been identified: PGHS-1 and PGHS-2, which have very similar kinetic properties, but differ in regard to expression and regulation. In recent studies it was shown that not only endogenous stimuli but also drugs and environmental chemicals can activate PGHS-2 expression. Therefore the PGHS enzymes provide two interesting aspects for pharmacology and toxicology: a) the co-oxidation of chemicals and b) the altered synthesis of prostanoids after exposure to certain xenobiotics which can be essential for their ultimate toxicity.

Symposium overview: estrogens and antiestrogens in managing the patient with breast cancer

The prevalence of breast cancer (a hormonally driven neoplasm) in the United States, the potential health benefits of estrogen replacement therapy for postmenopausal women, and the burgeoning research focusing on selective estrogen receptor modulators (SERMs) have resulted in additional complexity in managing breast cancer. In an attempt to clarify existing data, the Society of Surgical Oncology sponsored a symposium entitled "Estrogens and Antiestrogens in Managing the Patient with Breast Cancer" at its 52nd Annual Cancer Symposium. This conference was held in March 1999 and was chaired by Dr. S. Eva Singletary, Professor of Surgery and Chief of the Surgical Breast Section at The University of Texas M. D. Anderson Cancer Center in Houston, Texas. The following is a review of the material presented by the symposium participants.

Effects of high dose raloxifene in selected patients with advanced breast carcinoma

BACKGROUND

An earlier trial of raloxifene, conducted in women with metastatic breast carcinoma who initially had responded to tamoxifen and subsequently developed disease progression, suggested no antitumor activity for raloxifene in tamoxifen-refractory disease. However, preclinical studies and preliminary clinical data in healthy women suggest that raloxifene antagonizes growth of estrogen-dependent neoplasia.

METHODS

Raloxifene HCl 150 mg twice daily was given to 22 postmenopausal women with metastatic (American Joint Committee on Cancer Stage IV) or locoregionally recurrent, initially estrogen receptor positive breast carcinoma. Prior systemic treatment of metastatic disease was not allowed. Prior adjuvant chemotherapy or hormonal therapy was required to have been completed at least 1 year before study entry. Tumor response was evaluated every other month either radiographically or by physical examination. Evaluable disease was defined as bidimensionally measurable lesions.

RESULTS

Twenty-one patients were eligible for efficacy analysis; 6 had been treated previously with tamoxifen. There were no complete tumor responses. Four patients (19%; 95% confidence interval [95% CI], 2.2%, 36%) had partial tumor responses lasting 6.3, 17.5, 23.9, and 28.1 months, respectively. Prolonged stable disease (i.e., tumor size stable for > or = 6 months) was observed in 3 patients (14%; 95% CI, 0.0%, 29%) and lasted 7.9, 12.2, and 25.1 months, respectively. Combining partial responses and prolonged stable disease yielded an overall clinical benefit rate of 33% (95% CI, 13%, 53%). Adverse events generally were consistent with the disease state; there were no serious adverse events or laboratory changes believed to be therapy-related.

CONCLUSIONS

Raloxifene HCl, 150 mg, administered twice daily was safe, well tolerated, and modestly effective in highly selected postmenopausal women with advanced breast carcinoma. Further study of high dose raloxifene as monotherapy for advanced breast carcinoma most likely is unwarranted.

Distribution of sensory properties among axotomized cutaneous C-fibres in adult rats

A few hours after peripheral axons of cutaneous afferent neurons have been transected, some of their novel endings become excitable by physical or chemical stimuli. It has been assumed that these axon endings preferentially respond to those stimuli which have excited their previous receptive endings. We studied the prevalence of sensory properties among 784 unmyelinated sural nerve fibres which had been axotomized 2-24 h before, by applying mechanical and thermal forces to the nerve lesion site. Among 126 responding C-fibres, the majority was unimodal, responding exclusively to mechanical (31%), cold (23%) or heat (18%) stimuli. The remainder were either mechano-heat sensitive (10%), mechano-cold sensitive (6%) or heat and cold sensitive (12%). The distribution of sensory properties among acutely axotomized sural nerve C-fibres is therefore largely similar to the recently published distribution of receptor types among intact sural nerve C-fibre afferents. Thus, the hypothesis that responses of axotomized afferent fibres reflect their original receptive properties is corroborated. Knowledge of underlying transduction mechanisms may lead to specific pharmacological tools for suppression of ectopic discharges in unmyelinated axotomized afferents, which probably contribute to neuropathic pain states.

Multicenter, phase II trial of exemestane as third-line hormonal therapy of postmenopausal women with metastatic breast cancer. Aromasin Study Group

PURPOSE

To assess the antitumor activity, safety, and hormone-suppressive effects of the irreversible aromatase inactivator, exemestane (Aromasin, Pharmacia & Upjohn, Kalamazoo, MI), administered as third-line hormone therapy to postmenopausal women with metastatic breast cancer that is refractory to tamoxifen and megestrol acetate.

PATIENTS AND METHODS

Exemestane was administered at a dose of 25 mg/d orally until patients experienced disease progression. The efficacy and safety of exemestane were clinically and radiographically evaluated. The impact of exemestane treatment on tumor-related signs and symptoms was assessed. The effect of exemestane on serum levels of estrogens and other steroidal hormones was determined.

RESULTS

Ninety-one patients were treated. There were four complete responses (CR) and eight partial responses (PR), for an objective response rate of 13% in the entire treated population. The overall success rate (CR, PR, or stable disease [SD] >/= 24 weeks) was 30%. The median duration of response and overall success was 9 months and 8 months, respectively. Most patients with CR/PR (83%; 10 of 12 patients) and SD >/= 24 weeks (80%; 12 of 15 patients) had improved or stable tumor-related signs and symptoms. Mean levels of circulating estrone (E(1)), estradiol (E(2)), and estrone sulfate decreased to 11%, 22%, and 13% of baseline levels, respectively (at week 8 or 16 of treatment). One half of the patients had undetectable E(1) and E(2) levels during treatment, including at the time of disease progression. Mild nausea (20% of patients) and hot flashes (20%) were the most common drug-related adverse events and were generally grade 1.

CONCLUSION

Exemestane is an active and well-tolerated third-line hormonal therapy that represents a new treatment option for postmenopausal patients with advanced breast cancer that has become refractory to standard first- and second-line hormonal therapies.

Procainamide, a drug causing lupus, induces prostaglandin H synthase-2 and formation of T cell-sensitizing drug metabolites in mouse macrophages

Procainamide (PA) may cause drug-induced lupus, and its reactive metabolites, hydroxylamine-PA (HAPA) and nitroso-PA, are held responsible for this. Here, we show that N-oxidation of PA to these metabolites can take place in macrophages and lead to formation of neoantigens that sensitize T cells. Murine peritoneal macrophages (PMvarphi), exposed to PA in vitro, generated neoantigens related to HAPA as indicated by (1) their capacity to elicit a specific recall response of HAPA-primed T cells in the adoptive transfer popliteal lymph node (PLN) assay and (2) the appearance of metabolite-bound protein in PA-pulsed PMvarphi, as determined by Western blot. Analysis of five phase I enzymes that might be responsible for HAPA formation by PMvarphi pointed to prostaglandin H synthase-2 (PGHS-2) as a likely candidate. Experimental evidence that PA can be oxidized to HAPA by PGHS was obtained by exposing PA to PGHS in vitro. The resulting metabolites were identified by mass spectral analysis and covalent protein binding in ELISA. In vitro, PA exposure of PMvarphi of slow acetylator A/J and fast acetylator C57BL/6 mice failed to show significant strain differences in enzyme mRNA expression, enzyme activities, or formation of HAPA-related neoantigens. By contrast, after long-term PA treatment in vivo only in slow acetylators the PMvarphi harbored HAPA-related neoantigens and T cells were sensitized to them. PMvarphi of fast acetylator C57BL/6 mice only contained HAPA-related neoantigens, and their T cells were only sensitized to them if, in addition to long-term PA treatment, their donors had received injections of phorbol myristate acetate (PMA), a known enhancer of oxidative enzymes in phagocytes. In conclusion, PA treatment leads to N-oxidation of PA by enzymes, in particular PGHS-2, present in antigen-presenting cells (APC) and, hence, to generation of neoantigens which sensitize T cells. The enhanced neoantigen formation and T cell sensitization seen in slow acetylators might be explained by their higher concentration of PA substrate that is available for extrahepatic N-oxidation in APC.

Vinorelbine as first-line chemotherapy for advanced breast cancer in women 60 years of age or older

BACKGROUND

Older patients with advanced breast cancer are less likely to receive chemotherapy than younger patients. Vinorelbine is an attractive alternative in this setting because of its clinical activity and low frequency of side effects. This multicenter, phase II trial was designed to assess the safety and efficacy of intravenous vinorelbine as first-line therapy in women > or = 60 years old.

PATIENTS AND METHODS

Fifty-six women (median age, 72 years; range 60-84 years), with measurable advanced breast cancer and no prior chemotherapy for metastatic disease, were enrolled and included in the analysis. Vinorelbine 30 mg/m2 was administered weekly for 13 weeks and then every two weeks until development of progressive disease; doses were reduced or delayed to manage toxicity.

RESULTS

The objective response rate was 38% (95% confidence interval (95% CI): 24%-51%); median duration of response, nine months; median time to disease progression in all patients, six months. The major dose-limiting toxicity was hematologic, which led to a median dose intensity of 20.6 mg/m2/week. Grade 3-4 nonhematologic toxicity consisted of asthenia (7%); nausea and generalized pain (5%); vomiting, chest pain, abdominal pain, and elevated AST (4%); fever, diarrhea, constipation, and injection site reaction (2%). Neurotoxicity and alopecia were grade 1-2 and relatively infrequent.

CONCLUSIONS

Vinorelbine offers a promising alternative for the management of advanced breast cancer in elderly patients who are concerned about the subjective side effects of cytotoxic chemotherapy. The dose-limiting toxicity is neutropenia, which is readily managed with dose adjustment. Nonhematologic toxicity, including gastrointestinal side effects, is minimal. Randomized studies are warranted to compare the activity of vinorelbine with that of other regimens in elderly patients.

Multicenter phase II study of capecitabine in paclitaxel-refractory metastatic breast cancer

PURPOSE

Capecitabine is a novel, oral, selectively tumor-activated fluoropyrimidine carbamate. This large multicenter phase II trial tested the efficacy and safety of twice-daily oral capecitabine at 2,510 mg/m2/d given for 2 weeks followed by a 1-week rest period and repeated in 3-week cycles, in patients with paclitaxel-refractory metastatic breast cancer.

PATIENTS AND METHODS

Patients were to have received at least two but not more than three prior chemotherapeutic regimens, one of which had to have contained paclitaxel given for metastatic disease. One hundred sixty-three patients were entered onto the study at 25 centers, and 162 patients received capecitabine. One hundred thirty-five patients had bidimensionally measurable disease, and 27 patients had assessable disease.

RESULTS

The overall response rate was 20% (95% confidence interval, 14% to 28%). All responding patients were resistant to or had failed paclitaxel, and all had received an anthracycline. Three complete responses were seen, with complete response durations of 106, 109, and 194+ days. Median duration of response was 8.1 months, median survival time was 12.8 months, and the median time to disease progression was 93 days. The most common treatment-related adverse events were hand-foot syndrome, diarrhea, nausea, vomiting, and fatigue. Diarrhea (14%) and hand-foot syndrome (10%) were the only treatment-related adverse events that occurred with grade 3 or 4 intensity in more than 10% of patients.

CONCLUSION

Capecitabine is an active drug in the treatment of paclitaxel-refractory metastatic breast cancer. It has a favorable toxicity profile with the added advantage of being an oral drug administered at home.

A malignant transformation of human cells by 2,3,7,8-tetrachlorodibenzo-p-dioxin exhibits altered expressions of growth regulatory factors

The neoplastic transformation of human cells in culture with exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) has recently been reported. In this study, expressions of growth regulatory factors were analyzed to examine their possible roles in TCDD-induced malignant transformation of human cells. Reverse transcription-polymerase chain reaction (RT-PCR) and immunoblot analysis were performed to detect altered expressions of genes associated with dioxin responses. The RT-PCR analysis showed that expressions of the growth regulatory factors, such as transforming growth factor-beta1 (TGF-beta1), plasminogen activator inhibitor-2 (PAI-2) and tumor necrosis factor-alpha (TNF-alpha), were significantly changed in the transformed cells as compared with the parental cells. Whereas parental cells showed a dose-dependent increase of PAI-2 mRNA levels following TCDD exposure, the transformed cells did not show any significant induction. In addition, constitutive levels of PAI-2 mRNA were 25 times lower in the transformed cells than in the parental cells. The mRNA stability assay suggests that downregulation of PAI-2 mRNA in the transformed cells may be associated with the posttranscriptional control. Expression of TGF-beta1 mRNA in the transformed cells was also four times lower than the parental cells. However, levels of TNF-alpha mRNA in the transformed cells were increased 3-fold. These results suggest that dysregulation of growth regulatory factors may be involved in TCDD-induced cellular transformation. Whereas plenty of studies demonstrated a number of immediate toxic effects by TCDD, this study revealed an initial evidence that altered expression of growth regulatory genes, such as PAI-2, TGF-beta1 or TNF-alpha, are some of the genetic events fixed in the genome following the successive cell divisions of TCDD-damaged cells. It is suggested that these changes may be associated with TCDD-induced malignant transformation of human cells.

Inflammatory mediators sensitize acutely axotomized nerve fibers to mechanical stimulation in the rat

Many axotomized myelinated as well as unmyelinated cutaneous nerve fibers are sensitive to mechanical stimuli applied to the cut nerve end within a few hours after nerve lesion. Here we investigated the influence of inflammatory mediators on this ectopic mechanosensitivity after cutting and ligating the sural nerve in anesthetized rats. Neural activity was recorded from single axons in filaments teased from the sural or sciatic nerve proximally to the lesion site 2-33 hr after axotomy. Using calibrated von Frey hairs (1.0-128.5 mN), 30 sec trains of phasic stimuli were applied to the cut nerve end immediately before and after local application of a mixture of inflammatory mediators [inflammatory soup (IS), consisting of bradykinin, 5-HT, prostaglandin E2, histamine (all 10 microM), and K+ 7 mM, pH 7.0] for 2 min. Before as well as after IS application, von Frey thresholds were significantly lower in myelinated (A) fibers than in unmyelinated (C) fibers. IS application enhanced the ectopic mechanical excitability, as expressed in reduced von Frey thresholds and increased response magnitudes, of most severed mechanosensitive C fibers (77%) and some mechanosensitive A fibers (46%). The sensitization lasted for 10-40 min after a 2 min IS application. Additionally, among axotomized nerve fibers unresponsive to probing of the nerve lesion site before IS application, 1 of 63 (1.6%) A and 3 of 106 (2.8%) C fibers became mechanosensitive immediately after IS application. The results indicate that after axotomy, inflammatory processes augment touch-evoked ectopic activity in lesioned sensory nerve fibers. Because many affected afferents are presumably of nociceptive function, their enhanced neural barrage may contribute to neuropathic pain states.

Expression pattern of integrin adhesion molecules in endometriosis and human endometrium

Integrins are cell adhesion molecules that undergo cell-specific dynamic changes during the normal menstrual cycle in the human endometrium. Here, using immunohistochemistry, we have investigated the expression pattern of the integrins alphav, alpha2beta1, alpha3beta1, alpha3, alpha6, beta1, beta2 and beta3 in the human ectopic endometrium of 30 patients and in nine cases in the corresponding eutopic endometrium. The biopsies were obtained during the early or late follicular phase (25 cases), during the corpus luteum phase (four cases) and in one case after 6 months' treatment with a gonadotrophin releasing hormone (GnRH) agonist. The integrin expression was independent of the ovarian steroid situation at the time of biopsy. The integrin alpha6 was expressed in all endometriotic and endometrium samples. The integrin alpha3 was absent in all endometrium tissues of patients with endometriosis. However, the corresponding endometriotic lesions re-expressed this adhesion molecule in 15 cases. No change in integrin beta3 expression pattern could be demonstrated in either endometriotic lesions or endometrium samples, regardless of the menstrual cycle phase. A correlation between serum oestradiol and progesterone concentrations and the expression of the investigated integrins was not observed, thus indicating that these two hormones play a minor role in the regulation of the cell adhesion molecules examined. Our investigation suggests that endometriosis is a dedifferentiated disease as it expressed different integrins in comparison with the eutopic endometrium, and independently of the hormonal situation. The ability of endometriotic tissues to express integrins may explain the high recurrence rates in patients with endometriosis, as these samples retain their adhesion potency after retrograde menstruation and are thus able to establish cell-cell and cell-matrix interactions with the surrounding peritoneum.

Early dopaminergic drug-induced hallucinations in parkinsonian patients

OBJECTIVE

To characterize patients who develop hallucinations early in the course of dopaminergic therapy for Parkinson's disease (PD) and contrast them with patients developing hallucinations after chronic drug treatment.

METHODS

Parkinsonian patients who met diagnostic criteria for PD, experienced hallucinations, had a detailed hallucination interview at the onset time of their first hallucination, and had a 5-year clinical follow-up or an autopsy in those 5 years were identified and divided into two groups for comparison: 12 patients who developed early hallucinations within 3 months of starting levodopa therapy and 58 PD patients who developed hallucinations after 1 year of dopaminergic therapy. We contrasted the quality, content, diurnal nature, and emotional elements of the hallucinations, as well as the 5-year follow-up data on diagnosis, disease course, community home or nursing home outcome, and mortality.

RESULTS

Both groups experienced a predominance of visual hallucinations, visions of people and animals, and vivid colors and definition. Features distinctive to the early onset hallucinating patients included visions that persisted in daytime as well as nighttime, frightening content with paranoia, and accompanying nonvisual hallucinations, either auditory, olfactory, tactile, or combinations thereof. At the 5-year follow-up, none of the early onset hallucinators had PD as their sole disorder. Four of the 12 had an underlying psychiatric illness that included hallucinations or psychosis preceding their parkinsonism by several years. In the other eight patients at the 5-year follow-up, their parkinsonism evolved to include additional signs that were no longer consistent with PD. The primary diagnoses were diffuse Lewy body disease and Alzheimer's disease (AD) with extrapyramidal signs. Patients with early drug-induced hallucinations had significantly greater placement to nursing homes and greater mortality.

CONCLUSIONS

Early onset drug-related hallucinations are not typical of PD. Their presence should signal an investigation of two alternative diagnoses, either a comorbid psychotic illness (often unrevealed by the patient initially) or an evolving parkinsonism-plus syndrome.