Decreased connexin expression and intercellular communication in human bladder cancer cells.

Connexins make up a gene family encoding proteins that form intercellular channels known as gap junctions. Decreases in connexin expression and loss of intercellular communication have been associated with the malignant phenotype in some animal and human cells. The expression of connexin 26 and 43 mRNA was evaluated in cultured normal and malignant human urothelial cells. The normal urothelial cells were shown by Northern analysis to express both connexins. Increased confluence of the cultured normal human urothelial cells was associated with upregulation of connexin 26 mRNA. Connexin 26 mRNA expression was decreased in the bladder cancer cells. Using a human connexin 26 complementary DNA probe, nuclear run-on assays demonstrated that the decreased expression in the cancer cells was due to a failure of transcription. Southern blot analysis did not reveal any alterations in the genomic DNA. Assessment of gap junction function by scrape loading of lucifer yellow demonstrated dye transfer in normal urothelial cells but not in bladder cancer cells. Downregulation of connexin 26 mRNA was associated with functional loss of intercellular communication in the human bladder cancer cells. Connexin 43 expression varied considerably in the bladder cancer cell lines and did not correlate with dye transfer of lucifer yellow. These data suggest that alterations in the regulation of connexin 26 expression are associated with and may contribute to the malignant phenotype in bladder cancer.

Isolation of an X-ray-responsive element in the promoter region of tissue-type plasminogen activator: potential uses of X-ray-responsive elements for gene therapy.

Tissue-type plasminogen activator (t-PA) was induced over 50-fold after X irradiation in radioresistant human melanoma cells (Boothman et al., Cancer Res. 51, 5587-5595, 1991). Activities of t-PA were induced 14-fold in ataxia telangiectasia, 9-fold in Bloom's syndrome and 6-fold in Fanconi's anemia cells, compared to normal human fibroblasts (Fukunaga et al., Int. J. Radiat. Oncol. Biol. Phys. 24, 949-957, 1992). X-ray-inducible synthesis of the protease, t-PA, may play a role(s) in damage-inducible repair processes in mammalian cells, similar to the SOS repair systems in lower eukaryotes and prokaryotes. DNA band shift and DNase I footprinting assays were used to determine binding if transcription factors to a previously unknown X-ray-responsive element (XRE) in the t-PA promoter. The major goals of our research with XREs are to understand (a) which transcription factor(s) regulates t-PA induction after X rays, and (b) the role(s) of t-PA in DNA repair, apoptosis or other responses to X rays. The purpose of this paper is to discuss the potential use of an XRE, such as the one in the t-PA promoter, for gene radiotherapy. Several gene therapy strategies are proposed.

The living shunt: a tissue engineering approach in the treatment of hydrocephalus.

Tissue engineering is the use of cultured cells seeded into biodegradable polymers to create custom designed, living implantable devices. As a first approach to the use of this technique in the treatment of hydrocephalus, we have prepared chondrocyte-seeded polyglycolic acid (PGA) tubes coated with polylactic glycolic acid (PGLA), implanted initially with thin silastic stents removed four weeks after shunt insertion. The use of bovine xenograft cells in athymic (nude) rats resulted in more efficient seeding with chondrocytes, stiffer tube walls, and better patency. When implanted in 6-week-old rats made hydrocephalic by cisternal injection of kaolin at 4 weeks of age, six of eight 'living shunts' remained patent to radio-opaque contrast injection at two weeks after stent removal. At four weeks after stent removal, all four of the shunts had occluded at the ventricular end, three of the four apparently due to growth of the animal. We conclude that polymer type, cell type, and cell density will require considerable optimization, but a working tissue engineered shunt is feasible and may one day address some problems of interactions of living tissue and inert polymer.

A comparative study of cervical cytology, colposcopy and PCR for HPV in female sex workers in Singapore.

This study examined the prevalence of human papillomavirus (HPV) infection in a cohort of female sex workers in Singapore. HPV infection was diagnosed by clinical examination, Papanicolaou (Pap) smears, histology and polymerase chain reaction (PCR). One hundred and eighty-seven female sex workers who came for their routine medical screening were enrolled into the study. PCR was positive for HPV in 27 (14.4%), 20 of these had a single HPV type detected, while 7 had multiple types of HPV detected. The most common HPV types identified were types 16, 58 and 18. In conclusion, HPV infection is moderately prevalent among sex workers as tested by PCR, but routine screening with Pap smears does not appear to be a sensitive method of diagnosis for HPV infection.

Intraventricular hemorrhage caused by lateral ventricular meningioma: a case report.

Meningiomas causing intracranial hemorrhage are rare, and hemorrhage from a lateral ventricular meningioma seems to be even rarer. We report a case of trigonal meningioma in a 43-year-old woman who presented with intraventricular hemorrhage, and describe the CT, MRI and angiographic findings.

'Swiss cheese' lymphangiectasia in a case of solitary morphea profunda.

Reports of lymphangiectases that occur in lesions of morphea are rare. We describe a 24-year-old woman with a solitary morphea profunda associated with lymphangiectasia. Unlike previously reported cases, our case showed lymphatic dilatation resembling Swiss cheese and developed around a milium.

Complications of eyelash and eyebrow tattooing: reports of 2 cases of pigment fanning.

Eyelash and eyebrow tattooing are commonly performed procedures that have a very low rate of reported complications. We describe one case of infraorbital pigmentation after eyelash tattooing and another of periorbital pigmentation after eyebrow tattooing. Although most complications related to eyelash and eyebrow tattooing, including pigment fanning, have been reported by ophthalmologists, pigment fanning is also of concern to dermatologists.

Leukemic macrocheilia associated with chronic lymphocytic leukemia.

Specific cutaneous infiltrates in chronic lymphocytic leukemia presenting as a tumor or a large nodule on the face, scalp, and upper trunk are rare; involvement of the oral mucosa is extremely rare. We report a case of leukemic macrocheilia that occurred three years before a diagnosis of chronic lymphocytic leukemia was made.

An unusual tumour metastasis to the cervix.

INTRODUCTION: The vast majority of tumours in the cervix are either primary carcinomas or direct extension of primary tumours from nearby sites such as the endometrium, myometrium, rectum and bladder. Patients usually present with abnormal bleeding, pain and dyspareunia. A smaller number of patients are asymptomatic and their tumours can be diagnosed early by PAP smears. CLINICAL PICTURE: We present an unusual case of an elderly lady with breast cancer that had metastasized to the cervix 4 years after primary treatment of the breast malignancy. Although the appearance of the cervix was "normal looking", it was firm and indurated on palpation. PATHOLOGY: A definite diagnosis of metastatic infiltration could only be made by colposcopic biopsy. Early PAP smears had shown some abnormal cells suggestive of metastatic lobular carcinoma but were not conclusive of metastasis from breast carcinoma. Subsequent bone scans and CT scans of the abdomen revealed metastatic lesions in the skull, spine, left femoral shaft and liver.

The influence of carotid artery catheterization technique on the incidence of thromboembolism during carotid artery stenting.

BACKGROUND AND PURPOSE: Thromboembolic events related to CAS continue to be the main limitation to the widespread use of this technique as a first-line treatment for carotid occlusive disease. Our aim was to evaluate thromboembolism during CAS using DWI for catheterization techniques of the carotid artery. MATERIALS AND METHODS: Thirty-two consecutive patients with symptomatic carotid stenosis underwent CAS involving 1 of 2 carotid artery catheterization techniques: One used a 7F or 8F catheter (group 1, n = 16) and the other used a coaxial system in which a 7F or 8F catheter was used in conjunction with a 4F or 5F catheter (group 2, n = 16). DWI was performed before and after CAS. Clinical variables, the number and location of NES on DWI after CAS, were compared between the 2 groups. RESULTS: NES on DWI occurred in 53% of all patients. The incidence of NES was significantly higher in patients 65 years of age and older versus those younger than 65 years of age (P = .013). All NESs were asymptomatic, and their rate of occurrence did not differ significantly between groups 1 and 2. The incidence of NES in the other territories that were outside that of the treated carotid artery (P = .004) and the incidence of multiple NESs (P = .04) were significantly higher in group 1. CONCLUSIONS: NES in the other territories mainly arises from the atherosclerotic aortic arch and arch vessels during the manipulation of endoluminal devices. The carotid artery catheterization technique using the coaxial system with a 7F or 8F catheter in conjunction with a 4F or 5F catheter reduced the incidence of NES in the other territories.

Prenatal diagnosis of cri-du-chat syndrome: importance of ultrasonographical markers.

Cri-du-chat syndrome is a chromosomal abnormality involving a 5p deletion and is characterised by a cat-like cry, mental retardation, microcephaly and abnormal facial features. We report a case of prenatally-diagnosed cri-du-chat syndrome. Although PAPP-A was low at first trimester screening (FTS), the combined risks of trisomies 21, 18 and 13 were low. Amniocentesis was, however, carried out following the ultrasonographical observation of a severely hypoplastic nasal bone, cerebellar hypoplasia, choroid plexus cyst and a single umbilical artery during the second trimester. This case report highlights the importance of careful examination of basic and extended foetal biometry and structures, as well as soft markers for the detection of rarer chromosomal abnormalities that may be missed at FTS.

Community-acquired Klebsiella pneumoniae complicated skin and soft-tissue infections of extremities: emphasis on cirrhotic patients and gas formation.

BACKGROUND: Klebsiella pneumoniae was rarely reported to cause complicated skin and soft tissue infections (cSSTIs). Our study was to delineate clinical characteristics and outcome of cSSTIs involving extremities caused by K. pneumoniae. PATIENTS AND METHODS: Adult patients aged 16 years or more with community-acquired cSSTIs, which involved the extremities and were caused by four common aerobic pathogens at a medical center in southern Taiwan during a 54-month period, were reviewed. RESULTS: Of 76 cases enrolled, Staphylococcus aureus was the most common pathogen (52 cases, 68%), followed by K. pneumoniae (16, 21%), beta-hemolytic streptococci (5, 7%), and Escherichia coli (3, 4%). Forty-six (61%) had underlying conditions, and diabetes mellitus was most common among K. pneumoniae and non-K. pneumoniae groups (63% and 45%, respectively). Compared to patients with cSSTIs caused by other bacteria, those with K. pneumoniae cSSTIs were predominantly male, more often had liver cirrhosis, malignant neoplasm and alcoholism. In addition, they were more likely to have fever, shock, bacteremia, gas formation, pyomyositis, metastatic infections, as well as longer durations of hospitalization. Using multivariate analysis, liver cirrhosis (adjusted odds ratio [aOR] 12.5, 95% confidence interval [CI] 2.0-79.1, p = 0.007) and male gender (aOR 11.5, 95% CI 1.1-116.8, p = 0.039) were significantly associated with K. pneumoniae cSSTIs. CONCLUSIONS: We highlight the role of K. pneumoniae in Taiwanese patients with cSSTIs involving extremities, and its potential for gas and pus formation, and metastatic infections. Empiric antimicrobial coverage of K. pneumoniae and close monitoring of metastatic infections are mandatory for patients with risk factors.

Long-term follow-up of shunting therapy.

Ventricular CSF shunting surgery has changed the overall outcome figures for hydrocephalic patients over the past three decades. The factors that have improved the outcome are evolution of the shunt systems, improvement of the surgical environment and use of potent antibiotics, technological advances in brain imaging, and refinements in the assessment of cognitive and functional outcomes and of actuarial statistical techniques. But the recent large studies revealed that nearly half of all shunt placements were for revision, and there is a low but real percentage of cases in which death and neurological impairment are related to shunt surgery. The most frequent complication was shunt obstruction, followed by infection, disconnection, hematoma and slit ventricle syndrome. This clearly means that the shunt systems and the techniques in current use involve many problems that have yet to be solved. To solve these problems, new shunt systems should be developed and continuous efforts at reducing shunt infection should be made. The overall complication rate in the authors' series was 31.7%, but we have been able to reduce the complication rate from 37% to 25% by exercising special care focused on the surgical environment and techniques. Careful, long-term follow-up using various parameters and proper statistical analysis is another important factor in improving surgical outcome. Multicenter and international studies will be easier with the development of a network, and it will give us a strong background to treat hydrocephalus.

Simplified processing method of dichromated gelatin holographic recording material.

We are concerned with new simplified procedures for obtaining sufficient initial bias hardness of dichromated gelatin film by inserting the dehydration process before exposure.

Translation of merD in Tn21.

All four sequenced examples of the mercury resistance (mer) operon of gram-negative bacteria have a promoter-distal reading frame, merD, whose removal has little effect on the resistance phenotype and whose translation has not previously been observed. Using merD-lacZ protein fusions, we show that merD is translated. However, Hg(II)-induced merD expression, as measured by beta-galactosidase activity and immunoblotting, is 10- to 15-fold lower than that of fusions to the gene immediately preceding it, merA.

Diffuse heterochromia of scalp hair.

Heterochromia of hair is the presence of more than one distinct color of hair in the same person. A color difference between scalp hair and a mustache or sideburns is not uncommon. Pubic and axillary hair and eyebrows and eyelashes are often darker than scalp hair in a fair-haired person. Rarely, a circumscribed patch of hair of different colors occurs. However, diffuse heterochromia of black and red scalp hair has not been previously reported. We describe a father and son with this condition.

In vivo DNA-protein interactions at the divergent mercury resistance (mer) promoters. I. Metalloregulatory protein MerR mutants.

Regulation of transcriptional initiation of the Tn21 mercury resistance (mer) operon occurs at the divergent promoter region lying between the structural genes (merTPCAD) and a regulatory gene (merR). During repression, both promoters are negatively regulated by MerR bound to a dyadic operator located between the -10 and -35 hexamers of PTPCAD. Upon Hg(II) induction, MerR activates transcription only from PTPCAD and continues to repress transcription from PR. Using in vivo dimethyl sulfate and KMnO4 footprinting of the merOP region of strains carrying wild-type MerR or MerR mutants, we have dissected the steps in MerR-mediated positive and negative regulation of the divergent mer promoters. The greater sensitivity of primer extension footprinting allowed the resolution of details previously undetectable in vivo. Two MerR mutants unable to bind merOP DNA allow RNA polymerase to form an open complex preferentially at PR. The intensity of the PR open complex is considerably less than that which occurs upon MerR-Hg(II) activation of PTPCAD and considerably greater than that which occurs at PTPCAD when MerR is deleted; this is the first in vivo estimate of the relative strengths of these two promoters. Although retaining the wild-type capacity to sequester RNA polymerase in the closed complex, the four MerR mutants defective in Hg(II) binding do not distort the dyad DNA or foster open complex formation when the inducer is added. Two activation-defective MerR mutants foster closed complex formation as well as wild-type, but they do not distort the dyad DNA or foster open complex formation when the inducer is added, although they are also able to bind Hg(II). Two semiconstitutive inducible MerR mutants differ from each other in that one (which lies nearer the COOH terminus) does distort the dyad center upon Hg(II) induction, whereas the other (which lies in near the center of merR) exhibits no dyad distortion upon induction. Paradoxically, despite their relatively strong semiconstitutive expression of mer-lac transcriptional fusions, neither of these mutants has a detectable open complex in the absence of added Hg(II).

Activator-dependent preinduction binding of sigma-70 RNA polymerase at the metal-regulated mer promoter.

Expression of the Tn21 mercury-resistance (mer) locus is controlled by the merR gene product, which represses mer structural gene (merTPCAD) transcription in the absence of mercuric ion [Hg(II)] and activates it in the presence of Hg(II). In vivo DNA methylation of the mer regulatory region (merOP) shows that, with or without the inducer Hg(II), MerR strongly protects four guanine residues in a dyadic region located between the -10 and -35 hexamers of the structural gene promoter (PTPCAD). Prior to induction by Hg(II), RNA polymerase is also bound at PTPCAD; occupancy of the uninduced promoter by RNA polymerase is dependent on MerR. Methylation and permanganate footprinting demonstrate that induction by Hg(II) results in MerR/Hg(II)-dependent promoter DNA melting in the -10 region of PTPCAD and in additional DNA structural distortions within the region of dyad symmetry. Thus, MerR fosters the binding of RNA polymerase to an inactive promoter, and upon induction, MerR/Hg(II) facilitates DNA distortions suitable for efficient formation of the active transcription complex.

Enhancement of accuracy in OTF measurement.

A knife-edge scanning method was developed to enhance the accuracy in OTF measurement. A slit image formed by the lens under test was scanned by a knife-edge which was moved by a stepping motor. It was possible to increase the signal-to-noise ratio with averaging 4-32 data at each point through a scan. The standard deviation was decreased to under 0.25% in the MTF unit.

Optimization of resolution and color reproduction by controlling luminance and contrast levels of a liquid-crystal display monitor.

The image quality of a color liquid-crystal display monitor is studied by changing the contrast and the luminance levels. The resolution is assessed with modulation transfer function area (MTFA) that is measured at nine different combinations of the luminance and contrast. At these combinations, we measure the chromaticity coordinates and luminance of red-green-blue channels as a function of the digital-analog convert value. We analyze the relations among MTFA value, constant-channel chromaticity, color gamut, and maximum luminance of a white pattern. From the results, the combination of levels is found that provides both high resolution and good color reproduction.