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.

Controlled ovarian hyperstimulation and intrauterine insemination in subfertility. How many treatment cycles are sufficient?

OBJECTIVE

To examine the combined effects of factors influencing the pregnancy rates following controlled ovarian hyperstimulation (COH) and intrauterine insemination (IUI).

STUDY DESIGN

After utilizing the couple as the unit of analysis, 416 couples undergoing COH and IUI with the husband's sperm were studied retrospectively.

RESULTS

The woman's age, postwash total motile sperm counts and number of IUI treatment cycles were three major factors that affected the results of IUI. The predicted cumulative pregnancy rates under different values of the above three factors were therefore calculated using multiple logistic regression analysis and were compared to the pregnancy rate achieved by a cycle of in vitro fertilization and tubal embryo transfer.

CONCLUSION

Three treatment cycles of IUI are optimal for women aged < or = 34 with postwash total motile sperm counts > 5 x 10(6). For women either aged > or = 35 or with postwash total motile sperm counts < 5 x 10(6), the cumulative pregnancy rates achieved by IUI are extremely low, and other means of assisted reproduction are recommended for couples in those categories. However, this conclusion pertains to our clinics, and other institutions should establish their own data.

The aryl hydrocarbon receptor interacts with transcription factor IIB

The aryl hydrocarbon receptor (AHR) and its DNA binding partner, the AHR nuclear translocator (ARNT), are basic helix-loop-helix transcription factors that mediate many of the toxic and carcinogenic effects of polyhalogenated aromatic hydrocarbons. The basic regions of the AHR and ARNT contact the GCGTG recognition site, whereas both their helix-loop-helix domains and periodicity-ARNT-single-minded domains participate in heterodimerization. To delineate the transcription factors that may facilitate DNA binding and transcriptional activation of the AHR/ARNT heterodimer, we questioned whether transcription factor IIB (TFIIB) may interact with either the AHR or ARNT and whether this interaction may affect the ability of the AHR/ARNT complex to bind DNA. Coaffinity precipitation assays demonstrated that both the AHR and ARNT were capable of interacting with TFIIB. Domain mapping experiments revealed that TFIIB interacts with the periodicity-ARNT-single-minded and carboxyl-terminal regions of the AHR. To determine whether the interaction between TFIIB and the AHR may affect DNA binding of the AHR and ARNT complex, we performed gel shift experiments in the absence and presence of TFIIB. The addition of TFIIB significantly increased the formation of the AHR/ARNT DNA binding complex, but only if TFIIB was first allowed to interact with the AHR before the addition of ARNT. These results indicate that TFIIB interacts with the AHR and may stabilize the DNA binding form of the AHR and thereby augment the ability of the AHR/ARNT complex to interact with its DNA recognition site.

Effects of repeated abdominal paracentesis on uterine and intraovarian haemodynamics and pregnancy outcome in severe ovarian hyperstimulation syndrome

The aims of this study were to investigate the effects of paracentesis on uterine and intraovarian haemodynamics by colour Doppler ultrasound and the influences of repeated paracentesis on pregnancy outcome in severe ovarian hyperstimulation syndrome (OHSS). Forty-one abdominal paracenteses were performed on seven pregnant women with tense ascites and eight thoracocenteses were performed on three pregnant women with pleural effusion. Pulsatility index (PI) and maximum peak systolic velocity (MPSV) of uterine and intraovarian arteries were measured before and after each intervention. The mean PI of uterine arteries was decreased significantly after paracentesis, but not after thoracocentesis. Furthermore, uterine PI was decreased in 13 out of 14 (92.9%) paracenteses with <2500 ml ascites removed, compared with eight out of 13 (61.5%) with >2500 ml ascites removed. After paracentesis, there were no significant changes in the intraovarian PI and MPSV in either group. The 24-hour urine output increased significantly in the paracentesis group, but not in the thoracocentesis group. There were no significant changes in haematocrit and electrolytes as a result of paracentesis. However, gradual falls in serum total proteins and albumin concentrations were observed in all patients after repeated paracentesis, necessitating post-paracentesis albumin infusion. There was no significant difference in miscarriage rates between the two groups. We conclude that repeated abdominal paracentesis increases uterine perfusion and has no adverse effects on pregnancy outcome in severe OHSS. Extraction of 2500 ml of ascitic fluid did not impair uterine perfusion.

Adeno-associated virus vector mediated transduction of primary normal human breast epithelial cells

Cultured human breast epithelial cells from reduction mammoplasty specimens were transduced using an adeno-associated virus vector encoding the marker gene E. coli -galactosidase. Subconfluent, growing, breast epithelial cells were more easily transduced than confluent, quiescent, cells. Transduction of non-dividing confluent cells could be greatly increased by ultraviolet light-induced DNA damage or by prior exposure to the DNA synthesis inhibitor hydroxyurea. The effects of ultraviolet light and hydroxyurea on transduction were additive when these agents were applied together.

Pheochromocytoma complicated with cardiomyopathy after delivery--a case report and literature review

Pheochromocytoma in pregnancy is very rare but it is associated with very high maternal and fetal mortality. Therefore, it is important to include pheochromocytoma in the differential diagnosis of hypertension associated with pregnancy. It is difficult to make a diagnosis of pheochromocytoma in pregnancy before delivery. The characteristic symptoms of pheochromocytoma could be initiated during delivery because the process of delivery, general anesthesia, fetal movement, induce acute surge of catecholamine release, which could also induce cardiomyopathy. Early diagnosis and intensive care can affect the prognosis of cardiomyopathy induced by pheochromocytoma. Proper management with alpha-blockade, beta-blockade and angiotension converting enzyme inhibitor could acutely reverse the course of cardiomyopathy.

Postsynaptic responses of horizontal cells in the tiger salamander retina are mediated by AMPA-preferring receptors

The postsynaptic responses of sign-preserving second-order retinal neurons (horizontal cells (HCs) and off-bipolar cells) are mediated by CNQX-sensitive AMPA/KA glutamate receptors. In this study we used receptor-specific allosteric regulators of desensitization and selected antagonists to determine the glutamate receptor subtypes in tiger salamander horizontal cells. Two approaches were employed in this study. The first was to measure postsynaptic currents induced by exogenously applied glutamate under voltage clamp conditions in living retinal slices; and the second was to record voltage responses controlled by endogenous glutamate released from photoreceptors in whole retinas. Application of 100 microM cyclothiazide (a specific AMPA receptor desensitization blocker) enhanced the glutamate-induced current by about 5 fold. In contrast, 300 microgram ml-1 Co nA (a specific kainate receptor desensitization blocker), had no effect. GYKI 52466 (a specific AMPA receptor antagonist) at 30 microM almost completely suppressed the glutamate-induced inward current in HCs. Cyclothiazide at 100 microM depolarized the HC dark membrane potential by about 5 mV and reduced the amplitudes of the voltage responses to dim lights, but enhanced the voltage responses to bright lights. Cyclothiazide had no effect on either the dark potential or the light responses of rods and cones. Con A at 300 microgram ml-1 had no effect on either the dark potential or the light responses of the HC. GYKI 52466 (30 microM) hyperpolarized the HC dark membrane potential by about 55 mV and almost completely suppressed the light responses. We conclude from these results that the postsynaptic glutamate- and light-induced responses in the tiger salamander retinal horizontal cells are mediated by AMPA-preferring, and not kainate-preferring glutamate receptors. The functional roles of AMPA receptors and their desensitization kinetics in visual information processing are discussed.

Alterations of signal transduction pathways involved in 2,3,7,8-tetrachlorodibenzo-p-dioxin-induced malignant transformation of human cells in culture

Effects of signal transduction pathways in TCDD-induced neoplastic transformation of human cells were assessed with respect to PLC-coupled signaling pathways, adenylyl cyclase-mediated responses and PKC isozyme expressions. A lower stimulation of the intracellular free calcium levels with exposure to extracellular ATP or histamine was observed in the transformed cells, as compared to the parental cells. While the steady-state level of IP3 was higher in the transformed cells, the magnitude of stimulation of IP3 generation by ATP or histamine was significantly lower in the transformed cells than the parental cells. These results indicate that a downregulation PLC-coupled signaling pathways may be involved in the TCDD-induced transformation of human cells. While the steady-state levels of cAMP accumulation were similar between the two cell lines, treatment of PGE2, a potent differentiation inducer, stimulated a higher accumulation of cAMP in the parental cells but isoproterenol, a typical beta-adrenergic agonist, did not induce a significant difference between the two cell lines. These results suggest that desensitization of cAMP-mediated response to extracellular signals including differentiation signals may be associated with a possible mechanism of the carcinogenesis. Elevated expression of PKC-alpha, -gamma, -zeta, -epsilon, -lambda, and -tau were observed in TCDD-transformed cells, indicating a possible association of altered expression of PKC isozymes with TCDD-induced transformation of human cells. The present study demonstrates that alterations of signal transduction pathways are involved in the TCDD-induced transformation of human cells and provides a valuable basis to investigate effects of signaling pathway as a possible mechanism of TCDD-induced carcinogenesis in human cells.

Spermatozoa recovered by IxaPrep gradient have improved longevity and better motion characteristics than those by Percoll gradient

To compare the effectiveness of various sperm preparation methods, we examined sperm concentration, percentage of progressive motility, recovery rate, and various motion characteristics in 32 semen samples after Percoll and IxaPrep preparations. Except for sperm concentration, which was much higher after IxaPrep preparation, no statistical differences existed between these two methods in terms of motile sperm concentration (MSC), recovery rate, mean curvilinear velocity (VCL), mean straight-line velocity (VSL) and mean amplitude of lateral head displacement (ALH). Among 22 samples that were allocated in a 37 degrees C, 5% CO2 incubator, the mean MSC after 3 hours was significantly higher following IxaPrep preparation than following Percoll preparation (63.2 x 10(6)/mL vs. 42.8 x 10(6)/mL, p < .03). VCL and VSL were much higher after IxaPrep preparation than after Percoll preparation, both at 3 hours (p < .01) and at 24 hours (p < .03). ALH was also higher after IxaPrep preparation than after Percoll preparation, and it was statistically significant after 3 hours of incubation (p < .03). We conclude that the IxaPrep gradient may be adopted as the preferred method to the Percoll gradient in preparing spermatozoa for assisted reproduction because of the spermatozoa's persistent and better motion activities after incubation.

Small mechanical strains selectively suppress matrix metalloproteinase-1 expression by human vascular smooth muscle cells

Mechanical forces and biochemical stimuli may interact to regulate cellular responses. In this study, we tested the hypothesis that very small mechanical strains interact with growth factors in the regulation of matrix metalloproteinase (MMP)-1. Human vascular smooth muscle cells (VSMCs) were cultured on a precoated silicone membrane in a device that imposes a highly uniform biaxial strain. VSMCs cultured on fibronectin were treated with cyclic 1-Hz strains of 0, 1, or 4%, and MMPs were assayed by Western analysis or gelatin zymography. Small strains did not induce MMP-1 in VSMCs, but strain was a potent inhibitor of platelet-derived growth factor (PDGF)- or tumor necrosis factor-alpha-induced synthesis of MMP-1. In contrast, MMP-2 and TIMP-2 levels were not changed by PDGF and/or mechanical strain. VSMCs strained on the 120-kDa chymotryptic fragment of fibronectin or RGD peptides suppressed PDGF-induced expression of MMP-1, indicating that this effect is not mediated by the heparin-binding domain or connecting segment-1 of fibronectin. Northern analysis of ets-1, a transcriptional activator of MMP-1 expression, showed that strain down-regulated ets-1 expression, whereas c-fos expression was augmented. Thus, small deformations can selectively suppress MMP-1 synthesis by VSMCs, demonstrating the exquisite sensitivity of the cell to mechanical stimuli.

A case of ischemic colitis associated with pheochromocytoma

A 40-year-old woman was admitted because of abdominal pain and diarrhea. She sometimes experienced paroxysmal hypertension, sweating, headache, and palpitation. Sigmoidoscopic findings showed well-demarcated diffuse mucosal edema, hyperemia, and easy touch bleeding from distal descending colon up to the splenic flexure area. Barium x-ray showed loss of haustral marking, thumb printing appearance, and diffuse luminal stenosis in the transverse, descending, and sigmoid colon. On the abdominal computed tomogram, a 3.8-cm sized well-enhanced right adrenal mass was incidentally found. Twenty-four hour urinary excretion of vanillyl mandelic acid, norepinephrine, and normetanephrine were increased. Iodine131 metaiodobenzylguanidine scan showed hot uptake on the right adrenal gland compatible with pheochromocytoma. Exploratory laparotomy was done under the impression of ischemic colitis associated with pheochromocytoma. Adrenalectomy and resection of the stenotic left colon were performed. After surgery, pain subsided, blood pressure fell gradually, blood sugar and catecholamine level became normal, and bowel habit returned to normal.

Secondary angiosarcoma following irradiation--case report and review of the literature

Angiosarcoma is a rare malignant tumor that accounts for 1% to 2% of all soft tissue sarcomas. This paper reports a case of radiation-associated angiosarcoma with a literature review of 66 cases. Twenty-nine years after transabdominal hysterectomy and adjuvant radiation therapy for uterine cervix cancer, cutaneous angiosarcoma developed in the abdominal wall of a 63-year-old woman. She underwent wide excision of the abdominal wall mass, radiation therapy, and chemotherapy, and has been alive and well without any evidence of metastasis for 23 months since the initial diagnosis of angiosarcoma. After an intensive literature review, we found 66 cases of radiation-associated angiosarcoma. The most common primary disease was breast cancer (44%), with gynecologic cancer (21%) next. Eighty-five percent of radiation-associated angiosarcomas developed in the cutaneous area. The median age at diagnosis was 65 years, and the median latency period from irradiation to diagnosis was 96 months. The median survival period of 48 patients whose survival lengths could be reviewed was 12 months.

Long GnRH-agonist protocol in an IVF program. Is it appropriate for women with normal FSH levels and high FSH/LH ratios?

OBJECTIVE

To determine whether subjects with an elevated ratio of follicle-stimulating hormone (FSH) to luteinizing hormone (LH) but normal basal FSH levels should be regarded as poor responders to controlled ovarian hyperstimulation.

STUDY DESIGN

One hundred twenty-five women undergoing in vitro fertilization (IVF) for the first time were recruited in this retrospective cohort study. Women over 40 years old or having serum basal FSH > 10 mIU/mL were excluded.

RESULTS

Various cutoff values for the FSH/LH ratio were chosen, and the ratio demonstrated that pregnancy rates were apparently higher in patients with the long protocol than with the short one if they had an FSH/LH ratio < 3.0 (48.5% vs. 25.8%, P = .034), < 2.5 (53.3% vs. 28.6%, P = .030) or < 2.0 (57.8% vs. 21.7%, P = .005). Pregnancy rates were similar with the long and short protocols in patients with FSH/LH > or = 3.0 (57.1% vs. 70%, P = .521), FSH/LH > or = 2.5 (40% vs. 53.8%, P = .435) or FSH/LH > or = 2.0 (40% vs. 55.6%, P = .281).

CONCLUSION

This study failed to demonstrate that FSH/LH was a useful parameter for predicting reproductive outcome in IVF programs and for patient selection for the long or short gonadotropin-releasing hormone agonist protocol.

Tumors of the orbit. Pitfalls of the surgical approach in 37 children with orbital tumor

The authors review their experience with 37 children with orbital tumors, summarizing their surgical techniques, the indications applied, and the pitfalls of each surgical approach. Tumors located in the retro-ocular or intraorbital space were surgically excised through a transcranial approach (28 cases), while for tumors in other sites lateral orbitotomy (5 cases), medial orbitotomy (1 case) and biopsy (3 cases) were performed. A transcranial approach was used for tumors with intracranial extension and for those located in the orbital apex and deep medial orbital compartment. Lateral orbitotomy was used for tumors located in the superior, temporal or inferior compartment of the orbit and those in the lateral apex. A medial orbitotomy was used for tumors located medial to the optic nerve. Outcomes of the surgical intervention varied, depending on the pathology, location and extent of the individual tumors. To obtain optimal exposure and minimize functional deficits, the pitfalls of surgical approaches to orbital tumors are discussed.

Intravenous albumin does not prevent the development of severe ovarian hyperstimulation syndrome

OBJECTIVE

To determine the efficacy of IV albumin in the prevention of severe ovarian hyperstimulation syndrome (OHSS).

DESIGN

Prospective study group with historical control.

SETTING

University hospital-based IVF program.

PATIENT(S)

Between 1993 and 1995, 42 consecutive patients undergoing IVF-ET or tubal ET who had serum E2 levels > or = 3,600 pg/mL (conversion factor to SI unit, 3.671) on the day of hCG administration and/or > or = 20 oocytes retrieved were considered at high risk for severe OHSS and were selected as the control group. From December 1995 to October 1996, IV albumin was given to 30 consecutive patients who fulfilled these criteria.

INTERVENTION(S)

The treatment group received IV albumin after oocyte retrieval.

MAIN OUTCOME MEASURE

Occurrence of severe OHSS.

RESULT(S)

None of the 16 patients in the treatment group in nonconception cycles developed severe OHSS, compared with 5 (21.7%) of 23 in the control group. In conception cycles, 4 (28.6%) of 14 patients in the treatment group developed severe OHSS, compared with 9 (47.4%) of 19 in the control group. All 4 patients with multiple pregnancies in the treatment group developed severe OHSS, compared with 3 (60%) of 5 in the control group. None of the 10 patients with singleton pregnancies in the treatment group developed severe OHSS, compared with 6 (42.9%) of 14 in the control group.

CONCLUSION(S)

Intravenous albumin prevents severe OHSS in high-risk patients who did not conceive or who carried singleton pregnancies, but not in the patients with high-order pregnancies.

Purification and characterization of a human RNA adenosine deaminase for glutamate receptor B pre-mRNA editing

The glutamate receptor subunit B (GluR-B) pre-mRNA is edited at two adenosine residues, resulting in amino acid changes that alter the electrophysiologic properties of the glutamate receptor. Previous studies showed that these amino acid changes are due to adenosine to inosine conversions in two codons resulting from adenosine deamination. Here, we describe the purification and characterization of an activity from human HeLa cells that efficiently and accurately edits GluR-B pre-mRNA at both of these sites. The purified activity contains a human homolog of the recently reported rat RED1 (rRED1) protein, a member of the family of double-stranded RNA-dependent deaminase proteins. Recombinant human RED1 (hRED1), but not recombinant dsRAD, another member of the family, efficiently edits both the Q/R and R/G sites of GluR-B RNA. We conclude that the GluR-B editing activity present in HeLa cell extracts and the recombinant hRED1 protein are indistinguishable.

Characterization of glutamate transporter function in the tiger salamander retina

Glutamate transporters in the tiger salamander retina were studied by autoradiographic and intracellular recording techniques. When the retina was incubated with 15 microM L-[3H]glutamate, photoreceptors and Muller cells were labeled, indicating that these cells had high-affinity glutamate uptake transporters. A much higher dose of glutamate than kainate was required in the bath to produce the same membrane depolarization in horizontal cells (HCs), and the time course of glutamate-induced depolarization was much slower than that of the kainate-induced depolarization. Since glutamate is a substrate of glutamate transporters whereas kainate is not, we attribute these differences to the buffering of extracellular glutamate by glutamate transporters in the retina. D-aspartate (D-asp) increased the efficacy of bath-applied glutamate. Dihydrokainate (DHKA) exerted little effect on glutamate efficacy when applied alone, but it increased glutamate efficacy in the presence of D-asp. These results are consistent with the notion that glutamate transporters in Muller cells are D-asp sensitive and those in photoreceptors are DHKA and D-asp sensitive. Application of DHKA (1-2 mM) did not affect the dark membrane potential or the light responses in rods and cones, but it depolarized the HC dark membrane potential and reduced the HC peak and tail light responses. Our results suggest that DHKA-sensitive glutamate transporters in photoreceptors regulate glutamate levels in rod and cone synaptic clefts. They modulate dark membrane potential and the relative rod cone inputs in retinal HCs.

Rupioid psoriasis associated with arthropathy

We reported a rare case of rupioid psoriasis associated with arthropathy. A 28-year-old male had suffered from severe arthritis for 6 months and had limpet-like, cone-shaped skin lesions on the extremities for 3 months. The histopathology revealed remarkable Munro's and Kogoj microabscesses, intense dermal edema, and moderate inflammatory cell infiltration. The radiological examination showed bilateral sacroilitis. The skin lesions and arthritis responded dramatically in three weeks to i.m. methotrexate combined with topical steroids and emollients and occlusive dressing technique. There was no recurrence of such skin lesions during the two year follow-up period.

Malignant ovarian germ cell tumors

OBJECTIVES

Fifty patients with malignant ovarian germ cell tumors, which accounts for 10.8% of all ovarian malignancies, were treated from 1977 through 1994. Their cases are reviewed.

METHODS

The histology includes endodermal sinus tumor (EST) in 15 patients, immature teratoma in 14, dysgerminoma in 13, and mixed germ cell tumor in eight. The mean age at presentation was 21.5 years and mean primary tumor diameter was 16 cm. All patients underwent surgery as the initial treatment, and 10 received more than one operation. Postoperative adjuvant chemotherapy was not given to cases with stage Ia immature teratoma and dysgerminoma. VAC (vincristine, actinomycin D, cyclophosphamide) and BVP (bleomycin, vinblastine, cisplatin) regimens were utilized in early 1980s for EST and advanced-stage tumors of immature teratoma and dysgerminoma. BEP (bleomycin, etoposide, cisplatin) and EP (etoposide, cisplatin) regimens were applied in advanced-stage disease and some stage I disease since 1990. VIP (VP-16, ifosfamide, cisplatin) regimen was employed as salvage regimen in cases where other combinations failed.

RESULTS

alpha-Fetoprotein (AFP) was elevated in every tumor containing endodermal sinus element, and AFP served as a good indicator for prediction of tumor recurrence. The follow-up time ranged from 5 to 144 months with the mean of 54.5 months.

CONCLUSIONS

The survival rate for EST was 54%, that for immature teratoma and dysgerminoma was 85% and 90%, respectively.

Agenesis of the ductus venosus in a case of monochorionic twins which mimics twin-twin transfusion syndrome

We describe a pair of monochorionic twins with clinical manifestation of twin-twin transfusion syndrome, including discordant fetal growth, hydrops of the larger twin, and the 'stuck twin' phenomenon of the smaller twin. In the hydropic twin, we found agenesis of the ductus venosus and an abnormal umbilical vein draining directly into the inferior vena cava. There was also marked enlargement of the right atrium, representing the volume overload on it. We believe that the agenesis of the ductus venosus in the larger twin may have contributed to the 'unbalanced shunting' between the monochorionic twins. This then led to a clinical picture mimicking that seen in the authentic twin-twin transfusion syndrome.

Adenoviral-mediated gene transfer into primary human and mouse mammary epithelial cells in vitro and in vivo

Primary mammary epithelial cells from both the human and mouse mammary glands can be genetically altered under a variety of situations using the replication-defective adenoviral vector containing a marker gene encoding the E. coli beta-galactosidase. Primary human and mouse mammary epithelial cells in monolayer culture and in three-dimensional collagen gel culture systems were transduced by adenovector at high efficiency. Successful gene transfer was also accomplished in situ and in vivo. In the mouse mammary gland, anatomically restricted gene transfer and expression was demonstrated by micro-injection of adenoviral vector directly into the main duct of the mammary gland. Injection of adenoviral vector directly into the human mammary tissues from reduction mammoplasty specimens, into the mouse mammary gland-free fat pad containing the previously transplanted dissociated human mammary epithelial cells, and intratumorally into the human breast cancer xenografts in nude mice, all resulted in successful gene transfer to human mammary epithelial cells. High efficiency introduction of genetic material into primary mammary epithelial cells is important in the study of mammary carcinogenesis and potentially for gene therapy of human breast cancer.

Chronic exercise enhances endothelium-mediated dilation in spontaneously hypertensive rats

This study investigated the effect of physical training on endothelial function in spontaneously hypertensive rats (SHR). After 3 months, in conscious trained- and untrained-SHR body weight, systolic blood pressure and heart rate were 220 +/- 6 g vs 271 +/- 9 g, 172 +/- 7 mmHg vs 210 +/- 8 mmHg and 314 +/- 10 vs. 348 +/- 12 beats/min, respectively. In vitro, the dose-response curves of norepinephrine in isolated intact aortic and mesenteric rings form the exercise trained-SHR were significantly lower than those from the untrained-SHR. With denuded preparations, norepinephrine concentration-response curves were shifted to the left both in the trained- and untrained-SHR. This shift in the trained-SHR exceeded that in the untrained-SHR. The vasodilator response to acetylcholine in the trained-SHR was significantly greater than that in the untrained-SHR. Either N omega-nitro-L-arginine (100 mumol/l) or methylene blue (10 mumol/l) inhibited acetylcholine-induced vasodilator effect in aorta of trained- and untrained-SHR, but not in mesenteric artery of trained-SHR. Tetraethylammonium (10 mmol/l) inhibited significantly the N omega-nitro-L-arginine and methylene blue-resistant relaxation in mesenteric artery of trained-SHR, but not only by indomethacin (10 mumol/l). Collectively, these data demonstrate that chronic exercise increases EDRF/EDHF production (presumably by increasing endothelial shear stress), and may contribute to the enhanced effects of post-exercise hypotension.

Photoageing-associated mitochondrial DNA length mutations in human skin

It has recently been suggested that mitochondrial DNA (mtDNA) mutations are important contributors to human ageing and degenerative diseases. Using PCR techniques, we demonstrated three types of mtDNA length mutations, a 4977 bp deletion, a 7436 bp deletion and tandem duplications, in normal human skin tissues. We found that these mutations started to appear in the third decade of life, and the age at which the mutations could be detected in sun-exposed skin was usually younger than in non-exposed skin. Moreover, the incidences of these deletions and tandem duplications of mtDNA in sun-exposed skin were all significantly higher than those in non-exposed skin (P < 0.05). The 4977 bp deletion was the most prevalant mtDNA mutation in human skin, and the 7436 bp deletion was the least frequent among the three types of mtDNA mutations examined. We first demonstrated the existence of tandem duplications with sizes of about 260 bp, 200 bp and 150 bp in the D-loop region of mtDNA in the skin of elderly individuals. Among the three tandem duplications, the 200-bp duplication was found to occur most frequently in ageing skin. The tandem duplications were found to coexist with either or both of the deletions in some elderly individuals. The frequency of occurrence of mtDNA deletions and tandem duplications in skin was found to increase in an age-dependent manner. However, the incidence of tandem duplications was not well correlated with the age of the subject.(ABSTRACT TRUNCATED AT 250 WORDS)

Destructive encephalopathy in incontinentia pigmenti: a case report

We report a 2-day-old neonate with incontinentia pigmenti combined with destructive encephalopathy. Generalized seizures developed soon after birth; characteristic papulovesicles and hyperpigmented linear streaks appeared several days later. The brain CT scan showed multiple low density areas with cortical atrophy and ventricular enlargement. Histopathological examination favored the diagnosis of incontinentia pigmenti. Although a series of microbiological examinations failed to identify any infectious agent, the patient was still treated vigorously with anticonvulsants, systemic antibiotics, and acyclovir from the beginning of hospitalization. However, the seizures persisted, and the patient died 26 days after birth. Our report suggests that incontinentia pigmenti with encephalopathy may have a fatal prognosis.