A case of actinic granuloma associated with periumbilical perforating pseudoxanthoma elasticum

We report an unusual case of actinic granuloma of the face and periumbilical perforating pseudoxanthoma elasticum located superior to the umbilicus in a 57-year-old Korean woman. Histopathologically, these two dermatoses have a similar degeneration of elastic fibers, but they show different host reactions to the altered elastic fibers. In the actinic granuloma, actinically damaged elastic fibers were followed by granulomatous infiltration on the sun-exposed area, while in the perforating pseudoxanthoma elasticum, the altered elastic fibers induced a foreign body reaction, with subsequent transepidermal elimination. This is the first case report showing both actinic granuloma and periumbilical perforating pseudoxanthoma elasticum in the same patient, which suggests that the basic mechanism eliciting these dermatoses is similar.

GERI-BP002-A, novel inhibitor of acyl-CoA: cholesterol acyltransferase produced by Aspergillus fumigatus F93

A new inhibitor of acyl-CoA:cholesterol acyltransferase (ACAT), designated GERI-BP002-A, was isolated from the culture broth of Aspergillus fumigatus F93 by acetone extraction, EtOAc extraction, SiO2 column chromatography and reverse phase HPLC. Spectroscopic analyses of the compound identified bis (2-hydroxy-3-tert-butyl-5-methylphenyl) methane as the structure and its molecular weight and formula to be 340 and C23H32O2, respectively. GERI-BP002-A inhibited ACAT activity by 50% at the concentration of 50 microM in an enzyme assay system using rat liver microsomes.

Cross-neutralization of hantaviruses with immune sera from experimentally infected animals and from hemorrhagic fever with renal syndrome and hantavirus pulmonary syndrome patients

Plaque-reduction neutralization tests were done with eight of nine known representative hantaviruses and immune sera from experimentally infected animals and from patients with hemorrhagic fever with renal syndrome (HFRS) or hantavirus pulmonary syndrome (HPS). Results obtained with animal sera demonstrated each virus to be antigenically unique. Neutralization with the HPS patient sera was highest with Sin Nombre (SN) virus and to a lesser extent with Black Creek Canal (BCC) virus. Sera from Korean HFRS patients reacted best with Hantaan virus, but cross-reactivity with all other viruses except Thottapalayam (TPM) virus was also observed. Sera from Swedish HFRS patients reacted best with Puumala virus but cross-reacted with Prospect Hill, SN, and BCC viruses and to a lesser extent with all of the other viruses except TPM virus.

Antisense GLUT1 RNA suppresses the transforming phenotypes of NIH 3T3 cells transformed by N-Ras

An antisense approach was attempted to investigate the role of antisense GLUT1 RNA in suppressing tumor cell phenotypes using N-ras-transformed NIH 3T3 cells. The established cell line transformed by ras showed typical biological characteristics of cancer cells, such as increased glucose transport, GLUT1 mRNA contents, and the ability to form colonies on the soft agar. In this system, the plasmids (pMAM-GLUT1(rev)) which can transcribe the antisense GLUT1 RNA were transfected and the accompanying changes in the phenotypes of the ras-transformed cells were observed. The expression of antisense GLUT1 RNA by induction with dexamethasone reduced the glucose transport by 30% (1.97 +/- 0.13 nmoles) after 4 min incubation when compared to the non-induction group of transformed cell (2.85 +/- 0.19 nmoles). Also, the number of colonies sized over 50 microns on the soft agar was reduced significantly in the antisense RNA expressing group compared to non-induction group. These results suggest that the expression of antisense GLUT1 RNA reduced the glucose transport and transforming potential in soft agar possibly by hybridization with GLUT1 mRNA in N-ras-transformed NIH 3T3 cells.

Erythrocyte enzymes decomposing reactive oxygen species and gestational age

Superoxide dismutase (SOD; EC 1.15.1.1), catalase (CAT; EC 1.11.1.6) and glutathione peroxidase (GSH-Px; EC 1.19.1.1) were assayed in erythrocytes from neonates over a range of gestational ages. Both SOD and CAT activities were found to increase, but GSH-Px to decline, with gestational age. Enzyme activities in the erythrocytes of 13 babies who had respiratory distress syndrome (RDS) were not significantly different from controls matched for gestational age, but four with bronchopulmonary dysplasia (BPD) were found to have lower SOD activity. The importance of SOD in the preparation for extrauterine life is substantiated.

Animal model for maturity-onset diabetes of the young generated by disruption of the mouse glucokinase gene

Glucokinase catalyzes a rate-limiting step in glucose metabolism in hepatocytes and pancreatic beta cells and is considered the "glucose sensor" for regulation of insulin secretion. Patients with maturity-onset diabetes of the young (MODY) have heterozygous point mutations in the glucokinase gene that result in reduced enzymatic activity and decreased insulin secretion. However, it remains unclear whether abnormal liver glucose metabolism contributes to the MODY disease. Here we show that disruption of the glucokinase gene results in a phenotype similar to MODY in heterozygous mice. Reduced islet glucokinase activity causes mildly elevated fasting blood glucose levels. Hyperglycemic clamp studies reveal decreased glucose tolerance and abnormal liver glucose metabolism. These findings demonstrate a key role for glucokinase in glucose homeostasis and implicate both islets and liver in the MODY disease.

Contrasting roles for Myc and Mad proteins in cellular growth and differentiation

The positive effects of Myc on cellular growth and gene expression are antagonized by activities of another member of the Myc superfamily, Mad. Characterization of the mouse homolog of human mad on the structural level revealed that domains shown previously to be required in the human protein for anti-Myc repression, sequence-specific DNA-binding activity, and dimerization with its partner Max are highly conserved. Conservation is also evident on the biological level in that both human and mouse mad can antagonize the ability of c-myc to cooperate with ras in the malignant transformation of cultured cells. An analysis of c-myc and mad gene expression in the developing mouse showed contrasting patterns with respect to tissue distribution and developmental stage. Regional differences in expression were more striking on the cellular level, particularly in the mouse and human gastrointestinal system, wherein c-Myc protein was readily detected in immature proliferating cells at the base of the colonic crypts, while Mad protein distribution was restricted to the postmitotic differentiated cells in the apex of the crypts. An increasing gradient of Mad was also evident in the more differentiated subcorneal layers of the stratified squamous epithelium of the skin. Together, these observations support the view that both downregulation of Myc and accumulation of Mad may be necessary for progression of precursor cells to a growth-arrested, terminally differentiated state.

Phorbol esters downregulate expression of the sodium/calcium exchanger in renal epithelial cells

The Na+/Ca2+ exchanger (NCE) contributes to Ca2+ reabsorption by connecting tubules of the nephron. A line of renal epithelial cells from monkey kidney (LLC-MK2) was used to investigate the regulation of NCE expression. After the activation of protein kinase C (PKC) by phorbol myristate acetate (PMA), NCE activity decreased exponentially by 75% in 48 h (half time approximately 19 h). PMA decreased NCE mRNA by 85% in 24 h. The decrease in NCE transcript preceded the downregulation of NCE activity. NCE protein was quantified with a monoclonal antibody to cardiac NCE. PMA decreased the binding of 3H-labeled antibody to cell sonicates by 40% in 24 h. Immunoblots show that PMA produced a marked and extended increase in membrane-associated PKC-alpha, although PMA depleted total PKC-alpha by 65% in 24 h. In vivo 32P labeling of myristolated alanine-rich C kinase substrate, a specific PKC substrate, confirmed that PMA produced a rapid and extended activation of PKC. 4 alpha-PMA, a stereoisomer of PMA that neither binds nor activates PKC, had no effect on NCE activity or transcript. These findings indicate that activation of PKC with phorbol esters downregulates NCE mRNA, protein, and activity in renal epithelial cells.

Mechanisms of neck and shoulder injuries in tennis players

Shoulder injuries are common among athletes involved in repetitive overhead arm movements, particularly baseball pitchers and tennis players. Due to the similarities between pitching and serving, both athletes often present with similar types of shoulder injuries. However, subtle differences in neck and shoulder movements between the pitcher and tennis player may be responsible for additional mechanisms of injuries specific to tennis players. This paper outlines the similarities and differences between the pitch and serve and discusses how these differences may relate to additional neck and/or shoulder injuries specific to tennis players. In the analyses of mechanisms of injuries sustained by tennis players, such detailed analyses of movement patterns occurring during the serve may optimize a clinician's sports-specific rehabilitation protocol.

Epidemiology and laboratory diagnosis of hantavirus (HTV) infections

Hantavirus (HTV) is recently discovered "hemorrhagic fever virus" belonging to the Bunyaviridae family, which is spread throughout the world by wild rodents and/or laboratory rats. During an epidemic in the Belgian-French Ardennes in 1993, more than 200 acute cases were recorded of the milder European form of HTV-illness, otherwise known as Nephropathia epidemica (NE). This variant may be recognized by the sudden onset of fever, acute renal failure, thrombocytopenia and sometimes by ophthalmologic complications. The symptomatology is rather aspecific and diagnosis can only be confirmed by serologic tests, of which the best option nowadays seems to be: screening by IgG EIA, followed by IgM confirmation with a mu-capture EIA test. Some of the tests described allow an evaluation of the causative serotype or even the moment of infection. Next to the "classic" serologic assays for detection of specific viral antibodies, we describe briefly our own experience with newer tests such as "high density particle agglutination" and "line immuno assay". Polymerase chain reaction for viral RNA genome typing and immunohistochemical colouring of the viral antigen in tissues seem to offer promising alternatives for the immediate future.

Antiresonant ring interferometric nonlinear spectroscopy for nonlinear-optical measurements

We describe a sensitive and simple single-beam technique to measure simultaneously the real and the imaginary contributions to the complex optical nonlinearity (the nonlinear refraction and absorption). We call this technique antiresonant ring interferometric nonlinear spectroscopy (ARINS). An antiresonant ring interferometer, which has improved stability, is used to detect very small changes in the phase and the amplitude of an optical beam. This allows very low intensities to be used and eliminates many interfering processes present in other techniques that require higher intensities. We demonstrate ARINS by measuring the optical nonlinearities of bulk ZnS, KDP, and C(70) thin films.

Determining the site and causes of colonic obstruction with sonography

OBJECTIVE

We studied the value of sonography in determining the site and cause of colonic obstruction.

MATERIALS AND METHODS

Sonographic findings in 26 patients with known (n = 21) or suspected (n = 5) colonic obstruction on the basis of clinical findings and abdominal radiographs were correlated with radiologic and surgical findings. Colonic obstruction was proved in all with findings from surgery (n = 18) or from barium enema and CT (n = 8). Causes of the obstructions included colorectal cancer (n = 13), ileocolic intussusception (n = 11), transverse colonic adhesion (n = 1), and sigmoid volvulus (n = 1). Sonographic criterion of obstruction was the demonstration of a continuous distension of colonic loop with an abrupt transition to an empty distal colon. The value of sonography in terms of indicating the level and cause of colonic obstruction was evaluated.

RESULTS

The location of colonic obstruction was established by using sonography in 22 (85%) of 26 cases, and the cause of obstruction was identified in 21 (81%) cases. Sonography depicted a mass (n = 5) or a segmental wall thickening (n = 5) in cases of colon cancer, and a target or doughnut sign in cases of ileocecal intussusception (n = 11). Sonography failed to depict the cause of obstruction in three cases of colon cancer and one case each of adhesion and sigmoid volvulus.

CONCLUSION

Our experience suggests that sonography is useful for examining patients with colonic obstruction to determine the level and cause of the obstruction.

Birefringence modulation in fiber-optic phase modulators

We report an unusually large birefringence modulation in fiber-optic phase modulators formed with cylindrical piezoelectric transducers when driven at a few hundred kilohertz. The magnitude of the birefringence modulation is a strong function of modulation frequency. A simple model is used to explain the phenomenon, and the theoretical predictions agree well with the experimental results.

Obstructive jaundice due to compression of the common hepatic duct by right hepatic artery--a case associated with the absence of the lateral segment of the left hepatic lobe

Various benign and malignant conditions can cause biliary obstruction. We present a rare case of obstructive jaundice due to the compression of the common hepatic duct by the anteriorly overriding right hepatic artery. This case was also associated with the absence of the lateral segment of the left hepatic lobe. The patient was a 39 year-old housewife with a 4-day history of jaundice and occasional febrile sensation. An abdominal computed tomography showed absence of the lateral segment of the left hepatic lobe and a percutaneous transhepatic cholangiography showed a band-like filling defect of 2 mm width at the level of the upper common hepatic duct. The anteriorly overriding right hepatic artery compressing the common hepatic duct and the absence of the lateral segment of the left hepatic lobe were confirmed by operation.

Serological relationships among viruses in the Hantavirus genus, family Bunyaviridae

We examined the serological relationships among 32 hantavirus isolates collected from numerous geographic regions and hosts. We prepared rat immune sera to each virus and used these sera in hemagglutination inhibition (HAI) tests, enzyme-linked immunosorbent assays (ELISA), and plaque-reduction neutralization tests to establish the antigenic relationships among the isolates. Our studies included viruses that had been partially characterized previously, as well as isolates for which little or no serological data were available. Our results indicate that, in addition to the four established serological groups of hantaviruses, represented by Hantaan, Seoul, Puumala, and Prospect Hill viruses, there exist at least two other distinct groups of hantaviruses. These groups are represented by Thailand 749 virus, an isolate from Bandicota in Thailand, and by Thottapalayam virus, an isolate from Suncus in India. To compare more closely the antigenic relationships of the isolates to prototype Hantaan virus, we examined the reactivities of Hantaan G1- or G2-specific monoclonal antibodies with the envelope proteins of a number of the isolates. We found that several epitopes defined by monoclonal antibodies to the G2 protein were highly conserved as detected by HAI tests and ELISA. Almost all of the isolates could be neutralized by at least one G2-specific monoclonal antibody. In contrast, epitopes defined by G1 monoclonal antibodies were conserved only among Hantaan-like viruses.