Allelic variation in the cagA gene of Helicobacter pylori obtained from Korea compared to the United States

OBJECTIVE

Helicobacter pylori is an important factor in the development of duodenal ulcer disease and has been implicated in the pathogenesis of gastric adenocarcinoma. It has been suggested that the cagA gene is a marker for more virulent strains of H. pylori.

METHODS

We determined the prevalence of the cagA gene in 60 clinical isolates [34 from gastric carcinoma patients (CA), 26 from duodenal ulcer patients (DU)] from Korea, a country with a high incidence and mortality from gastric cancer. Genomic DNA was polymerase chain reaction-amplified by using two different primer sets for the cagA gene. The first cagA primer set amplifies a 297-bp product from the midregion of the cagA gene. The second primer set, which was previously established in a patient population from the Houston area (21 DU patients, 20 from individuals with asymptomatic gastritis) amplified a 1.4-kb region further downstream in the cagA gene.

RESULTS

The expected 297 bp polymerase chain reaction amplicon for cagA was identified in 59/60 (98.3%) H. pylori isolates from Korea (33/34 CA, 26/26 DU), and in 36/41 (88%) isolates from the Houston area (20/21 DU, 16/20 asymptomatic gastritis) (NS). Using the second cagA primer set, the expected 1.4-kb product was found in only 1/60 (1.7%) H. pylori isolates from Korea (1/34 CA, 0/26 DU), and in 36/41 (88%) of isolates from the Houston area (20/21 DU, 16/20 GST) (p < 0.001). Western blot analysis showed that all Korean H. pylori isolates expressed cagA.

CONCLUSIONS

The high prevalence of the cagA gene in H. pylori isolates from Korean patients with gastric adenocarcinoma or duodenal ulcers indicates that the cagA gene is common in H. pylori strains, and therefore, is not reliable as a single marker for the discrimination of H. pylori strains with respect to a specific disease. Our data further suggest that allelic variations in the genome of H. pylori strains may exist and that distinct H. pylori populations may circulate in different geographic regions.

A preliminary study on inherited tooth morphology characters of Japanese and Chinese young adults--with special reference to the Carabelli tubercle

A comparative study on inherited tooth morphology characters, in particular the incidence of Carabelli tubercles in the maxillary dentition, was conducted on standardized stone casts obtained from 240 Japanese (124 males (male) and 116 females (females)) and 160 Chinese (74 male, 86 female) young adults. The following results were obtained: 1) No significant differences in the incidence of Carabelli tubercles according to sex or body height were found between the two groups. 2) However, significant differences in the incidence of Carabelli tubercles according to sex were found in both groups. The tubercles occurred more frequently in males. 3) Significant differences between the bilateral and unilateral occurrence of Carabelli tubercles were observed in both the Japanese (p < 0.05) and Chinese (p < 0.01) groups; Carabelli tubercles on upper first molars were always bilateral. 4) The highest incidence of Carabelli tubercles was found in individuals with a body height of 166 approximately 175 cm in both groups, and a significant difference (p < 0.05) between the 156 approximately 165 cm and 166 approximately 175 cm groups was particularly evident in the Japanese adults. The authors postulate that bilateral occurrence of Carabelli tubercles was originally an inherited character in the molar region, but that the character was inhibited during the process of evolution of the masticatory system and regression of the molar dentition.

Serum insulin-like growth factor binding protein profiles in postmenopausal women: their correlation with bone mineral density

OBJECTIVE

The objective of this study was to evaluate the relationship between serum insulin-like growth factor binding protein profiles and bone mineral density measurements and biochemical markers of bone turnover in postmenopausal women.

STUDY DESIGN

Sera from 37 normal healthy postmenopausal women and 14 postmenopausal women with osteoporosis were analyzed for insulin-like growth factor binding proteins and osteocalcin by Western ligand blotting and radioimmunoassay, respectively. Bone mineral density measurements were performed by dual-energy x-ray absorptiometry. Urinary calcium and creatinine excretion were also determined. The data were analyzed statistically by analysis of variance and the least-squares method.

RESULTS

The serum insulin-like growth factor binding protein-2 ratio (insulin-like growth factor binding protein-2 intensity/total insulin-like growth factor binding protein intensity) in postmenopausal women with osteoporosis was significantly higher (p < 0.02) than that in normal healthy postmenopausal women, but the serum insulin-like growth factor binding protein-3 ratio in women with osteoporosis was significantly lower (p < 0.01). The serum insulin-like growth factor binding protein-2 ratio correlated negatively with the bone mineral density of the lumbar spine (p < 0.0001), femoral neck (p < 0.05), trochanter (p < 0.01), and Ward's triangle (p < 0.05), but there was a significant positive correlation between the serum insulin-like growth factor binding protein-3 ratio and the bone mineral density of the lumbar spine (p < 0.001) and trochanter (p < 0.05). No correlations between serum insulin-like growth factor binding protein levels or serum ratios and biochemical markers of bone turnover were noted.

CONCLUSION

The measurement of serum insulin-like growth factor binding protein profiles might be useful in identifying postmenopausal women at risk for osteoporosis.

Clinical implication of preoperative oral cholecystogram for laparoscopic cholecystectomy

BACKGROUND

The aim of this study was to retrospectively assess the usefulness of the preoperative oral cholecystogram (OCG) as an index to the feasibility of laparoscopic cholecystectomy (LC) and the operative pathologic findings. Laparoscopic cholecystectomy has become the standard treatment for symptomatic gallbladder (GB) disease. However, no definite diagnostic modality that can predict the feasibility of LC and severity of pathologic anatomy has been proposed.

METHODS

Retrospective data were collected on 240 consecutive patients undergoing LC at St. Vincent Hospital, Catholic University Medical College, from October 1991 until December 1993. Radiologic interpretations of OCG were standardized according to the method of Koehler and Kyaw--from grade 0 to 4. And the operative findings--pericholecystic adhesion, color of GB, and thickness of the GB wall--were evaluated simultaneously.

RESULTS

The analysis showed that preoperative OCG can predict intraoperative GB perforation (p = 0.022), intraoperative controllable bleeding (p = 0.034), and operating time (p = 0.0001) according to the grade of visualization of GB. Grade 2- or -better visualized groups had more patients who had blue-colored GB (p = 0.000) and who had thin GB wall (p = 0.000).

CONCLUSIONS

Preoperative oral cholecystogram may be an accurate index of the feasibility of laparoscopic cholecystectomy--represented by operating time and important intraoperative minor complications related to the operative pathological findings.

Prevalence of Helicobacter pylori infection in Korean children: inverse relation to socioeconomic status despite a uniformly high prevalence in adults

The prevalence of Helicobacter pylori infection in US adults was shown to be inversely correlated with the socioeconomic status of the family during childhood, and it was suggested that this was additional evidence of transmission occurring in childhood. The present study of H. pylori infection was conducted in South Korea, which has emerged as a developed country in the last two decades. The authors attempted to determine whether there was a difference in prevalence of H. pylori infection in Korean children of different socioeconomic classes despite the high prevalence of infection in childbearing adults. The authors also attempted to identify the factors responsible for the different patterns of transmission by estimating the age-specific prevalence of H. pylori infection in 413 healthy 1- to 75-year-old asymptomatic volunteers who resided in Seoul. H. pylori status was evaluated using an enzyme-linked immunosorbent assay for anti-H. pylori immunoglobulin G. Demographic data were obtained from each individual, and socioeconomic class was assessed by the education level of the adults and of the children's parents as well as family income. H. pylori infection was present in 75% of adults and 22% of children, and its prevalence increased with age (p < 0.001). In adults, the rate of infection was high and independent of socioeconomic class. In children, it was inversely related to the socioeconomic class of the child's family: 12% among upper socioeconomic class, 25% among the middle class, and 41% among the lowest class (p = 0.016). No associations were found between prevalence of H. pylori infection and any factor tested including sex, smoking, and alcohol consumption. In addition, type of housing, whether owned or rented, number of family members living in the same household, water source, and type of community in which a child grew up were not found to be risk factors influencing H. pylori infection prevalence. The prevalence of H. pylori infection in Korea appears to be changing with markedly lower prevalence in children of families of higher socioeconomic status. The factor(s) responsible for the break in the pattern of transmission in children of the higher socioeconomic class was not discovered. Future studies will concentrate on possible differences, eating practices, hygiene, and sanitary practices.

LC50 of 2-bromopropane

LC50 of 2-bromopropane was reexamined by using the OECD guideline in ICR mouse. The mice, 3 males and 3 females, were exposed to 2-bromopropane at five different concentrations for 4 h in inhalation chambers. The exposed animals were observed for 14 days. The animals which had survived and died were counted for the LC50 determination. The LC50 was calculated by using a dose-mortality curve at a 95 percent confidence level. The LC50 was 31,171 ppm, and the lowest lethal concentration (LLC) was lower than 29,528 ppm and the lethal concentration at 100% (LC100) was higher than 32,905 ppm.

Detection of antiendometrial antibodies in sera of patients with endometriosis by dual-colored, double-labeling immunohistochemical method and western blot

PROBLEM

This study was undertaken to determine whether specific binding activities against endometrial proteins in sera of patients with endometriosis are detectable and, if so, to identify endometrial antigens involved in autoimmunity in endometriosis.

METHOD

Sera from 33 patients with endometriosis and 20 cord sera (controls) were tested against endometria of patients and their protein extracts by dual-colored, double-labeling immunohistochemical method, and Western blotting.

RESULTS

Antiendometrial binding activities were detected in sera of 2 (10.0%) control patients and 13 (48.2%) patients with endometriosis by the immunohistochemical method. Endogenous immunoglobulin G (IgG) binding to endometrial proteins had molecular weights (MW) of 26, 28, 54, 85, 107 and 116 kDa. Most sera of both control and patients showed reactivity against endometrial proteins with MW of 34, 36, 56 and 77 kDa. However, there were specific IgG autoantibodies reactive against the endometrial proteins of 71, 92, and 103 kDa in sera of 55.2% (16/29) of patients but not in the control sera. Over 80% (10/12) of patients' sera with binding activities detectable by the immunohistochemical method also tested positive by Western blot analysis.

CONCLUSIONS

These data show that specific IgG antibodies reactive against endometrial antigens are detectable in sera from some patients with endometriosis.

Expression of myelin transcription factor I (MyTI), a "zinc-finger" DNA-binding protein, in developing oligodendrocytes

The production of myelin by oligodendrocytes requires the coordinated, massive synthesis of myelin components, a program that is dependent on transcriptional controls. Myelin transcription factor I (MyTI) was named for its ability to recognize the proteolipid protein (PLP) gene, the most abundantly transcribed central nervous system myelin gene (Kim and Hudson: Mol. Cell Biol. 12:5632, 1992). MyTI is a zinc-dependent, DNA-binding protein of the Cys2-His-Cys class. The pattern of MyTI expression, documented in the present study, suggests that MyTI may be instrumental in early stages of oligodendrocytic development and myelin production. MyTI mRNA transcripts are more highly expressed in oligodendrocyte progenitors than in differentiated oligodendrocytes. In vitro and in vivo analyses show that MyTI immunoreactivity is stronger in oligodendrocytic progenitors than in mature oligodendrocytes which have already accumulated PLP. In oligodendrocyte progenitors, MyTI immunoreactivity appears as speckles within the nucleus, suggestive of an association of MyTI with a function that is spatially segregated into discrete nuclear domains. MyTI continues to be expressed in cells transcribing PLP. However, as oligodendrocytes accumulate PLP, MyTI immunoreactivity becomes restricted to the cytoplasm and progressively diminishes. Since MyTI has two widely separated sets of DNA-binding domains and initial MyTI expression markedly precedes PLP expression, we hypothesize the following model: MyTI may play a role in assembling transcriptionally active complexes of PLP, perhaps by bending the DNA of the promoter region to induce an appropriate conformation to enable subsequent binding of additional regulatory proteins.

Sclerosis of hepatic cavernous hemangioma: CT findings and pathologic correlation

We report a case of hepatic cavernous hemangioma with computed tomographic findings of well demarcated nodular lesser attenuation foci within the main low attenuation mass on precontrast scans and non-enhancement of the foci even on the delayed contrast scans. These have been described as one of the atypical findings of cavernous hemangioma earlier in the literature. Surgery proved that sclerosis accounted for the hypodense nodular densities within the hepatic cavernous hemangioma.

Autoimmune premature ovarian failure

Premature ovarian failure (POF) may be caused by a variety of factors that result in the depletion of responsive ovarian follicles. There is a increasing body of evidence that suggests an autoimmune etiology in some POF patients. Data in support of an autoimmune etiology include: (1) lymphocytic and plasma cell infiltration of the ovary and alteration of T cell subsets; (2) circulating autoantibodies to ovarian antigens; (3) association with other "autoimmune" disorders; (4) recovery of ovarian function after regression of autoimmune status. The mechanism for ovarian autoimmunity is unknown. Genetic or environmental factor might be involved in the stimuli inducing immune response. The possibility that major histocompatibility complex antigen and cytokines are implicated in human autoimmune POF has been proposed. The relative contribution of cell-mediated immunity and antibody-mediated immunity remains obscure in animal models and in POF patients. Currently, in vitro fertilization and/or gamete intrafallopian transfer with donated oocytes are the best therapeutic options to achieve pregnancy although ovulation induction and immunosuppressive treatment might be used in approved experimental protocols. A newly developed double bridged enzyme linked immunosorbent assay (ELISA) might be useful in screening POF patients to identify those for whom temporary treatments may improve fertility.

Selectivity of oxomemazine for the M1 muscarinic receptors

The binding characteristics of pirenzepine and oxomemazine to muscarinic receptor were studied to evaluate the selectivity of oxomemazine for the muscarinic receptor subtypes in rat cerebral microsomes. Equilibrium dissociation constant (KD) of (-)-[3H]quinuclidinyl benzilate([3H]QNB) determined from saturation isotherms was 64 pM. Analysis of the pirenzepine inhibition curve of [3H]QNB binding to cerebral microsome indicated the presence of two receptor subtypes with high (Ki = 16 nM, M1 receptor) and low (Ki = 400 nM, M3 receptor) affinity for pirenzepine. Oxomemazine also identified two receptor subtypes with about 20-fold difference in the affinity for high (Ki = 84 nM, OH receptor) and low (Ki = 1.65 microM, OL receptor) affinity sites. The percentage populations of M1 and M3 receptors to the total receptors were 61:39, and those of OH and OL receptors 39:61, respectively. Both pirenzepine and oxomemazine increased the KD value for [3H]QNB without affecting the binding site concentrations and Hill coefficient for the [3H]QNB binding. Oxomemazine had a 10-fold higher affinity at M1 receptors than at M3 receptors, and pirenzepine a 8-fold higher affinity at OH receptors than at OL receptors. Analysis of the shallow competition binding curves of oxomemazine for M1 receptors and pirenzepine for OL receptors yielded that 69% of M1 receptors were of OH receptors and the remaining 31% of OL receptors, and that 29% of OL receptors were of M1 receptors and 71% of M3 receptors. However, M3 for oxomemazine and OH for pirenzepine were composed of a uniform population. These results suggest that oxomemazine could be classified as a selective drug for M1 receptors and also demonstrate that rat cerebral microsomes contain three different subtypes of M1, M3 and the other site which is different from M1, M2 and M3 receptors.

Helicobacter pylori infection and development of gastric or duodenal ulcer in arthritic patients receiving chronic NSAID therapy. The Misoprostol Study Group

OBJECTIVES

Helicobacter pylori infection and nonsteroidal anti-inflammatory drug use are both common causes of peptic ulcer. It remains unclear whether H. pylori/NSAID interactions occur, and if they do, with what result(s).

METHODS

We prospectively evaluated development of gastric or duodenal ulcers in 181 arthritics followed for up to 3 months while receiving an NSAID chronically and with no active anti-ulcer medications. H. pylori status was determined with a sensitive, specific ELISA for anti-H. pylori IgG.

RESULTS

H. pylori infection was present in 51%; peptic ulcers developed in 24. H. pylori infection was present in only 36% of those who developed a duodenal ulcer. Stepwise logistic regression analysis indicated none of the variable factors of age, gender, alcohol consumption, type of arthritis, or H. pylori status were significantly associated with development of peptic ulceration.

CONCLUSIONS

These data suggest that H. pylori does not confer increased risk of ulceration in arthritics receiving NSAIDs chronically.

Rudimentary polydactyly

A case of rudimentary polydactyly on the radial aspect of the thumb of a 4-year-old male was examined. Histologic examination revealed hyperkeratosis and acanthosis in the epidermis and large numbers of nerve bundles in the dermis. With immunoperoxidase staining for S-100 protein, the nerve corpuscles were positively stained. We think that rudimentary polydactyly is a kind of congenital traumatic neuroma and that the possible cause may be intrauterine amputation.

Jejunal inflammatory fibroid polyp presenting as intussusception--a case report with review of the literature

A 52-year-old woman was presented with intermittent abdominal pain and vomiting for 10 days. Abdominal CT scan disclosed a dilated small bowel loop with a round solid mass in the right anterior supravesical space. The clinical impression was intussusception caused by small bowel tumor. She underwent an exploratory laparotomy. The macroscopic and microscopic findings confirmed an inflammatory fibroid polyp of jejunum causing intussusception. To the best of our knowledge, this was the 5th reported case of such a presentation in English medical literature.

Mammalian heterogeneous ribonucleoprotein A1 and its constituent domains. Nucleic acid interaction, structural stability and self-association

With a view toward further understanding the structure-function relationships of the eukaryotic heterogeneous ribonucleoprotein (hnRNP) A1, and in particular its multiplicity of nucleic acid-interactive domains, we have studied the nucleic acid binding properties of the globular N-domain (UP1) and sequence-repetitive, flexible C-domain, the thermal denaturation of UP1 and the concomitant effects of binding polynucleotide, and the self-associative properties of the full-length protein. Utilizing protein tryptophan fluorescence as a probe, polynucleotide binding was shown to stabilize UP1 against thermal unfolding. The denaturation profile of UP1-poly(thymidylic acid) complexes was biphasic, suggesting that unfolding of the two subdomains of UP1 can occur independently. This is in agreement with a previously proposed structure in which only one of the two UP1 subdomains binds the nucleic acid. The subdomains of UP1 can be prepared by controlled proteolysis of A1, further indicating that these two globular segments within A1 are connected by an exposed, flexible linkage. Circular dichroism measurements on UP1 confirm previous data that this portion of A1 binds single-stranded nucleic acids non-co-operatively. UP1 clearly shows a preference for single-stranded nucleic acids with a 2'-OH, since its affinity for poly(U) is three times higher than for poly(dU), and five times higher than its affinity for poly(2'-OCH3U). The nucleic acid-interactive properties of the C-domain were further examined by preparing a synthetic peptide polymer (M(r) approximately 12,000) containing about seven repeats of a 16-residue sequence, GNFGGGRGGNYGGSRG, which in turn comprises two copies of the C-terminal consensus, GN(F/Y)GG(G/S)RG. The polymer of this sequence exhibited significant affinity for the fluorescent polyribonucleotide, poly(ethenoadenylic acid), binding stoichiometrically at < or = 0.2 M-Na+. Complex formation was accompanied by an increase in aggregate formation, as indicated by the appearance of scattering. For purposes of comparison, the data were analyzed via the linear co-operative model of McGhee and von Hippel, though this model may not be fully descriptive of the protein-nucleic acid complex(es) formed in this case. In contrast to the non-co-operative binding mode of the UP1 domain, the C-polymer exhibited moderate co-operativity, comparable to that seen with full-length A1. Although addition of sufficient NaCl reversed the interaction, a sigmoidal binding isotherm could still be observed (with sufficient added polymer) at 0.8 M-NaCl. This suggests that non-electrostatic interactions contribute significantly to the free energy of binding.(ABSTRACT TRUNCATED AT 400 WORDS)

Novel member of the zinc finger superfamily: A C2-HC finger that recognizes a glia-specific gene

A novel member of the zinc finger superfamily was cloned by virtue of its binding to cis-regulatory elements of a glia-specific gene, the myelin proteolipid protein (PLP) gene. Named MyTI (myelin transcription factor I), this gene is most highly transcribed in the developing nervous system, where expression precedes induction of its presumptive target, PLP. Low levels of MyTI transcripts can be detected in nonneural tissues only by polymerase chain reaction analysis. Zinc is a necessary cofactor for DNA binding of MyTI, as the zinc-chelating agent 1,10-orthophenanthroline eliminates binding activity. Zinc may stabilize the DNA-binding domain of MyTI by coordinating three cysteine and one histidine residue in a Cys-X5-Cys-X12-His-X4-Cys (C2-HC) arrangement. The MyTI protein has six fingers of the C2-HC class arranged in two widely separated clusters. These two domains of DNA binding can function independently and recognize the same DNA sequence, suggesting that MyTI may contribute to the higher-order structure of a target promoter by simultaneously binding both proximal and distal sites. The six fingers are highly conserved, suggesting that they arose from successive duplication events, while the linker regions diverge in size and sequence. Both amino acid sequence comparisons and secondary-structure predictions indicate that the C2-HC fingers of MyTI do not resemble the zinc-mediated loops of C2-H2 fingers, C2-C2 fingers, or Cx clusters. MyTI may therefore be the prototype of a new structural family of zinc-stabilized DNA binding proteins.

Induction of vesicle-to-micelle transition by bile salts for DOPE vesicles incorporating immunoglobulin G

The vesicle-to-micelle transition of immunoliposomes formed by dioleoylphosphatidyl-ethanolamine (DOPE) and palmitoyl-immunoglobulin G (p-IgG) was investigated in the presence of bile salts and conjugated bile salts. Turbidity and the release of calcein from liposomes were measured as a function of the amount of bile salts added and compared with the solubilizing profiles of the salts according to the number and configurational state of hydroxy groups in the cholate. The solubilizing phenomena by bile salts conjugated with glycine or taurine were investigated in comparison with non-conjugated bile salts. The solubilizing effect of bile salts on the bilayer of immunoliposomes increased remarkably with the number of hydroxy groups, but was not influenced by the configurational state of the hydroxy group. The half-maximal concentration of bile salts, defined as the concentration giving the half-maximum turbidity of liposome solutions, decreased with hydrophobicity in the phosphatidylcholine (PC) bilayer. The increase in the hydrophobicity of bile salts induces the ability to permeabilize and solubilize phospholipid vesicles. In the case of PC or PE liposome bilayers with inserted protein, bile salts conjugated with taurine or glycine had lower hydrophobicity than non-conjugated bile salts and showed a lower half-maximal concentration. The conjugated bile salts are believed to interact with lipids and solubilize the bilayers, while the head groups of bile salts interact with the inserted protein and extract it from the lipid bilayer.

Identification of cis-regulatory elements in the myelin proteolipid protein (PLP) gene

Regulatory elements of the proteolipid protein (PLP) gene were identified physically by footprinting and gel mobility shift assays and functionally by transfecting glial cell lines with PLP-chloramphenicol acetyltransferase chimeric genes. In both human and rat glial cells, only several hundred base pairs of upstream sequence were sufficient for high level activity of the human PLP promoter. This region contains five sites that contact nuclear proteins in vitro. More distal recognition sites may exist, as regions upstream of -524 displayed silencing activity indicative of a negative regulatory element. A series of site directed mutations revealed one essential positive element (ATGGA at -118) which is found in other genes encoding myelin proteins. Our combined biochemical and functional analyses indicate that the key cis sites for maximal tissue-specific expression of PLP in cultured glial cells are clustered near the promoter. Within this cluster are several conserved motifs that may coordinate the regulation of myelin-specific genes.

Papillomavirus found in anorectal squamous carcinoma, not in colon adenocarcinoma

We used polymerase chain reaction DNA amplification methods for the detection and typing of genital human papillomaviruses in paraffin-embedded tissue sections of five patients with anorectal squamous cell carcinoma and 22 patients with colonic adenocarcinoma. The cases were further tested by in situ hybridization with biotin-labeled probes specific for human papillomavirus types 6/11, 16/18, and 31/33/35. By polymerase chain reaction, human papillomavirus DNA was demonstrated in all of the cases of anorectal squamous cell carcinoma and in none of the cases of colonic adenocarcinoma for which analyzable DNA was available. Tumor cell nuclei stained for human papillomavirus DNA by in situ hybridization in four of the five cases of squamous cell carcinoma and in none of the cases of colonic adenocarcinoma. We conclude that human papillomavirus types usually associated with malignant transformation are uniformly present in anorectal squamous cell carcinoma but are absent from adenocarcinoma of the colon.

Percutaneous mitral valvuloplasty in a mid-term pregnant woman with severe rheumatic mitral stenosis

A 28-year-old woman with severe mitral stenosis underwent percutaneous mitral valvuloplasty at 26 weeks' gestation. Balloon dilation using a double 18-18 mm balloon resulted in improvement in mean mitral pressure gradient (32 to 8 mmHg) and in calculated mitral valve area (0.9 to 2.4 cm2) without complications and any evidence of fetal distress during procedures with an estimated radiation exposure to the fetus of 0.13 rem. This procedure resulted in the disappearance of symptoms of congestive heart failure and allowed for normal full term spontaneous delivery of a 3.51 Kg boy without any complication.

A study on the isolation of aflatoxin-producing strains from agricultural products in Korea

In order to isolate aflatoxin-producing strains from agricultural products in the Youngnam district of Korea, rice, barley, unhulled barley, corn, soybean, Meju (soybean paste), peanut, and soil samples were collected from markets or homes. From the 347 samples, 280 strains of Aspergillus spp. were isolated. As a result of screening by thin layer chromatography (TLC), 29 strains showed fluorescent spot and four strains had the same Rf values as those of standard aflatoxins. The percentage of contamination of aflatoxin-producing strains was 1.4%. The four strains were classified as the Aspergillus flavus group by the examination of characteristics and morphology.

A biotin-streptavidin enzyme immunoassay for detection of antibodies to porcine granulosa cell antigens

A colorimetric solid-phase enzyme immunoassay has been developed which quantifies antibodies to porcine granulosa cell membrane antigens in rabbits immunized with porcine granulosa cells. A cell-free, particulate membrane preparation of porcine granulosa cells was used as coating antigen. A biotinylated second antibody in conjunction with a streptavidin-beta-galactosidase conjugate was utilized to amplify reactivity. The enzyme beta-galactosidase was used due to high background obtained using peroxidase, presumably due to endogenous peroxidase activity of the tissue. Sigmoidal serum dilution curves were obtained with immune rabbit sera indicating that absorbance was related to the concentration of antibodies. Assay activity was reduced by preincubation of immune serum with granulosa cell membranes. Sera from ovariectomized or pre-immune rabbits did not yield any specific binding in the assay. This assay has potential applicability for quantifying antiovarian and antigranulosa cell antibodies in women suspected of having autoimmune premature ovarian failure.

Vesicle to micelle transitions of egg phosphatidylcholine liposomes induced by nonionic surfactants, poly(oxyethylene) cetyl ethers

Vesicle to micelle transitions of sonicated liposomes of egg yolk phosphatidylcholine (EPC) induced by a homologous series of nonionic surfactants, poly(oxyethylene) cetyl ethers [POE(n) cetyl ether], were investigated by using the method of turbidity titrations. The turbidities of the mixed dispersions of sonicated vesicles and surfactant were systematically measured as a function of the surfactant added for a wide range of lipid concentrations (from 0.51 to 6.35 mM EPC). From the titration curves, two threshold points representing onset and complete solubilization of liposomal membranes were determined as a probe for the effect of the length of ethylene oxide (EO) moiety on the phase behavior of ternary system of POE(n) cetyl ethers-EPC-excess water. Patterns of turbidity curves and the surfactant concentrations at two threshold points as well as widths of region between two transitions, where lamellar sheets and mixed micelles may coexist, mainly depended on the length of EO head group. With changing the lengths, solubilization of liposomes and phase diagram showed optimal behavior. That is, in the middle range of EO numbers, it resulted in narrowest coexistence region between onset and complete solubilization. Assuming the equilibrium partitioning model, critical effective molar ratios of surfactant to lipid, Rsat, free surfactant concentrations, Dw, and the partition coefficient of surfactant between bilayer and aqueous phase, K, in surfactant-saturated liposomes were quantitatively determined as a function of EO number. Effective ratios, Rsol, and free surfactant concentration in mixed micelles were also determined. In addition, the effects of CMC and HLB of surfactants on the solubilization of liposome were discussed.

PDGF stimulation of inositol phospholipid hydrolysis requires PLC-gamma 1 phosphorylation on tyrosine residues 783 and 1254

PDGF binding to its receptor promotes the association with and stimulates the phosphorylation of PLC-gamma 1 at tyrosine and serine residues. Also, PDGF induces an increase in the hydrolysis of inositol phospholipids by PLC. How PDGF activates PLC was investigated by substituting phenylalanine for tyrosine at PLC-gamma 1 phosphorylation sites 771, 783, and 1254 and expressing the mutant enzymes in NIH 3T3 cells. Phenylalanine substitution at Tyr-783 completely blocked the activation of PLC by PDGF, whereas mutation at Try-1254 inhibited and mutation at Tyr-771 enhanced the response. Like the wild type, PLC-gamma 1 substituted with phenylalanine at Tyr-783 became associated with the PDGF receptor and underwent phosphorylation at serine residues in response to PDGF. These results suggest that PLC-gamma 1 is the PLC isozyme that mediates PDGF-induced inositol phospholipid hydrolysis, that phosphorylation on Tyr-783 is essential for PLC-gamma 1 activation. These results provide direct evidence that growth factor receptors activate the function of intracellular protein by tyrosine phosphorylation.

The efficacy of a combination administration of gonadotropin-releasing hormone agonist and gonadotropins for controlled ovarian hyperstimulation in IVF program

In 105 patients with the past history of poor response to the previous controlled ovarian hyperstimulation (COH) due to poor follicular growth or premature LH surge, the efficacy of pituitary suppression with gonadotropin-releasing hormone agonist (GnRHa) in IVF/GIFT program was evaluated in 112 cycles of COH using a combination regimen of leuprolide acetate (Lupron) and FSH/hMG or pure FSH from May to December, 1989. After suppression phase, serum E2 and progesterone levels decreased significantly, but there was no change in serum LH and FSH levels. There was no occurrence of premature LH surge during COH. Eleven cycles (9.8%) were cancelled, and 3 cycles (3.0%) failed in the transvaginal oocytes retrieval. The 7.00 +/- 3.32 follicles (FD greater than or equal to 12 mm) were observed, and 6.11 +/- 4.15 oocytes were retrieved. The 3.59 +/- 2.57 oocytes were fertilized and cleaved with the cleavage rate of 55.7%. In 83 IVF patients, 4.08 +/- 2.39 embryos were transferred, and 16 pregnancies were obtained with the pregnancy rate per ET of 19.3%. In 6 GIFT patients, 7.83 +/- 3.31 oocytes were available for transfer. When compared with the previous 108 cycles, the cancellation rate during COH was decreased and all the parameters of the outcome of COH including the pregnancy rate were increased. These data suggest that GnRHa therapy for pituitary suppression is an effective adjunct to the current gonadotropin regimens for COH in IVF/GIFT and can increase the probability of oocytes retrieval and pregnancy, especially in the previous poor responders.

Survival and cell acquisition rates after preimplantation embryo biopsy: use of two mechanical techniques and two mouse strains

Two strains of mouse embryos at the four- and eight-cell stages had biopsy specimens obtained by means of two different mechanical techniques: aspiration and displacement. Embryos and biopsy specimen cells were evaluated for survival and development. Blastomere acquisition rates were significantly higher with the displacement biopsy technique; however, no difference in survival or developmental rates was found in blastomere biopsy specimens removed from either four-cell or eight-cell embryos. A maximum of one blastomere can be removed from a four-cell embryo, whereas three blastomeres can be taken at biopsy from an eight-cell mouse embryo without significantly affecting embryo development, although mouse strain differences were noted. Intact, viable, biopsied blastomeres will develop in vitro when cocultured with morphologically intact embryos. Births of live offspring after embryo biopsy are reported.

Factors affecting penetration of zona-free hamster ova

The sperm penetration assay is an expensive, time-consuming test to assess male fertility in vitro. Although some investigators are enthusiastic in its application, others feel that it is not sensitive or specific enough to be used as part of the routine infertility evaluation. Indeed, this bioassay is not a faithful reproduction of in vivo conditions. However, if the SPA is abnormal, it is unlikely that sperm will fertilize a human ovum in vivo. Conversely, a normal SPA does not guarantee successful in vivo fertilization. No bioassay can be absolute in its predictive value, but false-negative results must be kept to a minimum for this bioassay to be of any clinical significance. Each laboratory performing the SPA should optimize the assay for sensitivity, reproducibility, and minimization of false-negative results and then establish normal and abnormal ranges of its own. If the limitations of the SPA are kept in mind, and if we employ it very selectively, it may still be useful.

Isolation and characterization of rat carcinoembryonic antigen

A rat tumor-associated antigen with properties similar to those of human carcinoembryonic antigen (CEA) has been detected with rabbit immune sera in extracts of transplantable rat colonic adenocarcinoma, RCA-1. This antigen, termed rat CEA, was also detectable by a monkey antihuman CEA serum and a rat monoclonal antibody to rat CEA. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of perchloric acid extracts of RCA-1 tumor, followed by immunoblotting with the above-mentioned anti-CEA reagents, revealed that rat CEA activity resided in components with a molecular weight of approximately 350 kD. The glycoprotein nature of these components was indicated by positive staining with periodic acid-Schiff. Sephadex G-200 chromatography, as well as Sepharose 4B chromatography with and without sodium dodecyl sulfate indicated that the 350-kD components existed in the extracts as molecular aggregates. The 350-kD material, which had been purified by an affinity column containing rat monoclonal antibodies to rat CEA, reacted with the rabbit and monkey anti-CEA sera. This provided strong evidence that serological activity of rat CEA was confined to the 350-kD components.

Percutaneous transcatheteral biliary biopsy (PTBB)--a report of two cases

In two patients with obstructive jaundice, percutaneous transhepatic cholangiography (PTC) and percutaneous transhepatic biliary drainage (PTBD) were performed. During PTBD, the percutaneous transcatheteral biliary biopsy (PTBB) with the biopsy forceps of the gastrofiberscope was performed through the biliary stent catheter. Biopsy specimens were successfully obtained and histopathologic findings were satisfactory in both cases.

Carcinoembryonic antigen: a rat model

It has been shown that a TAA termed rat CEA had the tissue distribution and physico-chemical properties similar to those of human CEA. In addition, it has been demonstrated that these two antigens shared antigenic determinants. These findings supported our contention that rat CEA and human CEA are analogous moieties. The production of CEA-specific autoantibodies and the induction of resistance to CEA-positive rat tumors after immunization of rats with extracts containing rat CEA raises the possibility that human CEA may be immunogenic in man. Treatment with heat, proteolytic enzymes and periodate oxidation revealed that rat CEA, similar to human CEA contained both carbohydrate and protein epitopes. The epitopes shared by rat and human CEA that were detectable by the monkey anti-human CEA serum appeared to be carbohydrate, whereas the epitopes on rat CEA with which the rat mAb combined appeared to be protein, and those detected by the rabbit anti-rat CEA serum appeared to be carbohydrate, as well as protein. These studies also indicated that, although the rat, rabbit and monkey produced antibodies specific for rat CEA, the epitopes detectable by antibodies from one species appeared to be distinct from those detectable by antibodies from the other two species. These observations have important implications in studies on human CEA. Its use as a reliable diagnostic marker for malignancy hinges on the detection of tumor-specific epitopes on the molecule. Such epitopes have not yet been clearly identified by antibodies produced in foreign species. Indeed, our finding that the rat mAb to rat CEA bound only to tumor extracts and not to extracts of normal tissues, including intestinal tissues, suggests that human beings would be the most likely source of a tumor-specific antibody to human CEA. In future studies, the role antibodies play in immunity against CEA-positive tumors will be explored and attempts will be made to determine whether all of the serologically detectable epitopes on rat CEA can induce tumor resistance, or whether this activity is limited to epitopes detectable only by rat antibodies. This information could have important implications in the use of human CEA in the immunotherapy of malignancies.

Liposarcoma arising in a giant lipomatous polyp of the esophagus

A case of liposarcoma in a giant pedunculated lipoma of the esophagus in a 49-year-old Korean woman who presented intermittent swallowing difficulty for 3 years is reported. Endoscopy and esophagography revealed that a giant smooth longitudinal tumor mass almost entirely occupied the esophageal lumen. A total esohagectomy was done. The tumor was 20 cm in length and 7 cm in average diameter with an obvious stalk measuring 3 cm in length and 1 cm in diameter. Microscopic examination disclosed a lipoma with focal ulceration and liposarcomatous change infiltrating into interstitial fibrous tissue at its distal end.

Monoclonal rat antibodies to rat carcinoembryonic antigen

An IgM-class rat monoclonal antibody, designated 5B1, was produced against rat carcinoembryonic antigen. This antibody, which can be considered an autoantibody, formed a single precipitation line in a gel diffusion test with an extract of the CEA-positive rat colonic adenocarcinoma, RCA-1. This line gave a reaction of complete identity with a line formed by a rabbit antiserum specific for rat CEA. 5B1 also bound to extracts of the RCA-1 tumor in EIA, but did not bind at all to extracts of the CEA-negative rat colonic adenocarcinoma, RCA-2, nor to extracts of normal rat tissues including liver, kidney and intestine. Inhibition tests showed that the activity of the monoclonal antibody in EIA was abolished by extracts of RCA-1 tumor, but was hardly affected by extracts of the other tissues.

Intramural hematoma of the esophagus: unusual complication of esophageal variceal sclerotherapy

The authors report a case of esophageal hematoma in a 35-year-old man after esophageal variceal sclerotherapy with intravariceal injection of 5% ethanolamine oleate. A huge submucosal hematoma of the esophageal wall was demonstrated endoscopically and radiologically. Resolution occurred spontaneously after conservative treatment.

Serological relationship between rat and human carcinoembryonic antigen

Enzyme immunoassays showed that a rabbit antiserum to rat carcinoembryonic antigen (CEA) had high activity with extracts containing human CEA, which was almost completely inhibited by extracts containing human or rat CEA. Little or no inhibition was obtained with extracts of normal human or rat tissues or by human blood group A or B substances. A monkey antiserum to human CEA had strong activity against extracts containing rat CEA, and little or no activity against extracts of normal rat liver or kidney or a CEA-negative rat colon tumor. Activity of the monkey antiserum against rat CEA was almost completely inhibited by extracts containing rat or human CEA. Little or no inhibition was obtained with extracts of normal rat or human tissues. These results suggest that human and rat CEA share antigenic determinants and that they may be analogous moieties.

Kinetic studies on Cro repressor-operator DNA interaction

The six operators of phage lambda and their consensus sequence were synthesized as 21 base-pair DNAs and their interactions with Cro repressor were studied using a filter binding assay. The measured equilibrium dissociation constants suggest that Cro has the highest affinity to the consensus operator (KD = 1.2 X 10(-12) M) and then the OR3 operator (KD = 2.0 X 10(-12) M), after that the affinity becomes lower in the following order: OR1, OL1, OL2, OL3, OR2. The competition experiments show that Cro forms the most stable complex with the consensus operator (t1/2 = 150 min), which is followed by the complex with OR3 (t1/2 = 70 min), OR1, OL1, OL2, OL3 and OR2. The association rate constants (ka) were also measured. They are approximately the same (2 X 10(8) to 4 X 10(8) m-1 s-1) for the consensus, OR3, OR2 and OR1 operators. These experiments have thus shown that the sequence difference in the operator affects the dissociation (KD and kd) but not the association (ka) process. The operators' binding strengths relative to OR1 are 14 (for consensus operator), 7.6 (OR3), 0.73 (OL1), 0.42 (OL2), 0.16 (OL3) and 0.1 (OR2). Seven different lengths of OR-containing DNA fragments were prepared. Measurement of kinetic parameters shows that the affinity of Cro to operator DNA (measured by KD) is essentially constant and independent of the DNA length, while the association and dissociation rate constants increase as the DNA length increases. This is consistent with the idea that Cro locates and leaves its operator via a two-step mechanism. It appears that Cro binds first at an arbitrary site on DNA, then is transferred to its operator site by a facilitated mechanism. The process is reversed when Cro dissociates from the operator. Most of our data fit to the theoretical expression formulated by Berg, Winter & von Hippel for the sliding mechanism. We conclude that Cro slides along the DNA to locate and leave the operator.

Different interactions used by Cro repressor in specific and nonspecific DNA binding

The mode of interaction of Cro repressor with specific and nonspecific sites on DNA was explored by chemical modification and protection of lysine and tyrosine residues. Cro has 8 lysines. In the presence of DNA, lysines 32 and 56 are fully protected and lysines 21, 62, and 63 are partially protected from alkylation. However, the terminal amino group and lysines 8, 18, and 39 are not protected. Location of the protected and unprotected lysines on the three-dimensional Cro structure defines a DNA-binding region. The results provide direct experimental support for a mode of interaction between Cro and DNA, in which Cro buries its 2-fold related alpha-helices in consecutive DNA major grooves (Anderson, W. F., Ohlendorf, D. H., Takeda, Y., and Matthews, B. W. (1981) Nature 290, 754-758; Ohlendorf, D. H., Anderson, W. F., Fisher, R. G., Takeda, Y., and Matthews, B. W. (1982) Nature 298, 718-723). In the model, the carboxyl-terminal part of Cro was tentatively presumed to interact with the DNA minor groove. Protection of lysines 62 and 63 confirms the involvement of the carboxyl terminus in DNA binding. Although nonspecific and specific DNA protect the same lysine residues, there are differences in the nature of the interaction of Cro with nonspecific and specific DNA. Cro-nonspecific DNA interaction is salt-sensitive, suggesting that the interaction is predominantly electrostatic. On the other hand, Cro-specific DNA interaction is salt-resistant, suggesting that the interaction may include nonelectrostatic components (hydrogen bonds and hydrophobic interactions) as well. Protection experiments of tyrosine residues (against iodination) suggest that the conformation of Cro repressor changes in two stages: first, when Cro binds at nonspecific sites, and, second, when Cro binds to specific sites on DNA.

Pancreatic cholera syndrome: effect of a synthetic somatostatin analog on intestinal water and ion transport

The effect of a synthetic somatostatin analog was studied in a patient with severe secretory diarrhea due to pancreatic cholera syndrome. Basal intestinal perfusion studies indicated an absence of water and sodium absorption, and active chloride secretion in the small bowel. Intravenous administration of the somatostatin analog (1 microgram/kg.h) changed zero net water movement to absorption (122 mL/30 cm of the jejunum per hour). Chloride secretion changed to absorption (5.0 to 7.9 meq/30 cm.h), and plasma vasoactive intestinal polypeptide concentration was reduced from 330 to 45 pmol/L (normal, less than 51). When the analog was given subcutaneously, 100 micrograms twice daily, stool weight decreased, and plasma vasoactive intestinal polypeptide concentration fell toward the normal range (67 pmol/L). Plasma concentration of pancreatic polypeptide was initially elevated and dropped during intravenous infusion of somatostatin analog but returned to baseline on maintenance therapy with the analog delivered subcutaneously. The patient has not had further diarrhea during 9 months of therapy.

Therapeutic effect of dinitrochlorobenzene (DNCB) on verruca plana and verruca vulgaris

Fifty-nine patients with verrucae (45 with verrucae plana and 14 with verrucae vulgaris) were treated with dinitrochlorobenzene (DNCB) as a topical application on the normal uninvolved skin of the shoulder for sensitization and challenge. The patients were sensitized with 0.5 ml of 0.4% DNCB solution and then challenged with 0.1% DNCB ointment twice a week. Six cases of verrucae plana and 1 case of verrucae vulgaris were completely cured by sensitization only and 32 cases of verrucae plana and 7 cases of verrucae vulgaris were completely resolved by repeated challenges. The therapeutic effect was better in verrucae plana (84.4%) than in verrucae vulgaris (57.1%), and the verrucae were completely resolved within 10 weeks in more than 90% of the patients cured by challenge. The side effects of DNCB were mild allergic contact dermatitis and slight transitory hyperpigmentation at the site of application.

Eruptive vellus hair cysts

Of 11 patients with eruptive vellus hair cysts, seven were between ages 17 and 24 years when the dermatosis first appeared. The sites of predilection were mainly the anterior part of the chest and the extremities, though the lesions were also seen on the face, neck, axilla, and groin. In some lesions that regressed spontaneously, the cysts were connected to the surface, forming an opening pore. In other lesions, the cystic material formed foreign-body granulomas by degradation of the cyst walls.

[Burning feet caused by the rodenticide RH-787]

Four patients developed severe burning feet after ingestion of the rodenticide RH-787 (Vaccor-B) attempting suicide. Parenteral administration of vitamin-B-complex relieved the symptom in all patients. Based on the results of these four patients and other data in the literature, vitamin-B-deficiency is discussed as a possible cause of burning feet.