Echocardiographic diagnosis of a stenotic double orifice parachute mitral valve with a single papillary muscle

We present the case of a patient with a single papillary muscle that is supporting both orifices of a stenotic double orifice mitral valve. With the use of both transthoracic and transesophageal echocardiography, we were able to prospectively define this entity, which was confirmed at surgery.

Hormone-related factors and risk of breast cancer in relation to estrogen receptor and progesterone receptor status

Risk factors were examined for subgroups of breast cancer characterized by estrogen receptor (ER) and progesterone receptor (PR) status. Data from the Carolina Breast Cancer Study, a population-based, North Carolina case-control study of 862 breast cancer cases aged 20-74 years diagnosed during 1993-1996 and 790 controls frequency matched on race and age, were obtained by personal interview. ER and PR status was retrieved from medical records (80%) or was determined in the authors' laboratory (11%) but was missing for 9% of cases. The receptor status distribution was as follows: 53% ER+PR+, 11% ER+PR-, 8% ER-PR+, and 28% ER-PR-. Several hormone-related factors were associated with stronger increased risks for ER+PR+ than for ER-PR- breast cancer: the elevated odds ratios were strongest for ER+PR+ breast cancer among postmenopausal women who had an early age at menarche (odds ratio (OR) = 1.6, 95% confidence interval (CI): 1.0, 2.4), nulliparity/late age at first full-term pregnancy (OR = 1.7, 95% CI: 0.9, 3.2 and OR = 1.6, 95% CI: 1.0, 2.7, respectively), or a high body mass index (OR = 1.6, 95% CI: 0.9, 3.0) and among pre-/perimenopausal women who had a high waist-hip ratio (OR = 1.9, 95% CI: 1.2, 3.1). In contrast, family history of breast or ovarian cancer and medical radiation exposure to the chest produced higher odds ratios for ER-PR- than for ER+PR+ breast cancer, especially among pre-/perimenopausal women.

Transesophageal echocardiographic identification of left subclavian artery stenosis with steal phenomenon

In this report, we present the first case of the transesophageal echocardiographic identification of left subclavian artery stenosis and steal phenomenon.

Transesophageal three-dimensional echocardiographic assessment of anomalous coronary arteries

We describe the usefulness of transesophageal three-dimensional echocardiography in the evaluation of anomalously arising coronary arteries in four adult patients recently studied by us.

Risk of breast cancer according to the status of HER-2/neu oncogene amplification

We examined risk factors for breast cancer after subdividing cases based on the presence of HER-2/neu oncogene amplification in their tumors. Data were from the Carolina Breast Cancer Study, a population-based, case-control study of 577 invasive breast cancer patients, diagnosed during 1993-1996 and ages 20-74 years, and 790 controls frequency-matched on race and age. Information on breast cancer risk factors was obtained from structured personal interviews. About 20% of paraffin-embedded tissues from the breast cancers of cases were identified as positive for HER-2/neu amplification (HER-2/neu+) by differential PCR. Early age at menarche, higher waist:hip ratio, and family history of breast or ovarian cancer were associated with elevated odds ratios (ORs) for both HER-2/neu+ and HER-2/neu- breast cancers. Breastfeeding for at least 1 year was inversely associated with HER-2/neu+ breast cancer [OR, 0.3; 95% confidence interval (CI), 0.1-0.7] more so than HER-2/neu- breast cancer (OR, 0.8; 95% CI, 0.5-1.2). Most of the remaining risk factors had ORs around 1.0 for both HER-2/neu+ and HER-2/neu- breast cancers, although a few exhibited possible associations with one disease subtype in analyses stratified by menopausal status. These study results suggest that most recognized breast cancer risk factors do not operate through HER-2/neu amplification in breast carcinogenesis. Differential effects of long-term breastfeeding by HER-2/neu amplification status have been observed in earlier studies and are provocative; however, the direction and magnitude of the associations have not been consistent.

Recruitment of a heparan sulfate subunit to the interleukin-1 receptor complex. Regulation by fibronectin attachment

In this study, we identified an adhesion-regulated subunit of the interleukin-1 (IL-1) receptor complex. Transfection of fibroblasts with an IL-1 receptor-EGFP construct showed that the fusion protein was located at focal adhesions in cells attaching to fibronectin. Fibronectin attachment caused enhancement in endogenous IL-1 type I receptor levels from on average 2500 to 4300 receptors/cell. In addition, matrix attachment resulted in a decrease in binding affinity (Ka) from 1.0 x 10(9) (M-1) to 5.6 x 10(8) (M-1), due to a 2-fold reduction in association rate constant. The adhesion-mediated effects were reversed by soluble heparin. Cross-linking experiments showed that in cells attached to fibronectin, 50-70% of the radiolabeled IL-1 was associated with a heparinase sensitive, high molecular mass component of about 300 kDa, with a core protein of 80-90 kDa. Formation of the complex was dependent on cell interaction with the heparin binding region in fibronectin and required IL-1/type I IL-1 receptor binding. This report demonstrates the recruitment of a heparan sulfate to the IL-1 receptor complex, following attachment to fibronectin, which correlates with alterations in receptor function. The data suggest that the heparan sulfate constitutes an attachment regulated component of the IL-1 receptor complex with the role of mediating matrix regulation of IL-1 responses.

Chromatin structure and cardiac gene expression

Gene activation is often preceded by or accompanied by a perturbation of the chromatin structure. Recently, several co-factors of transcription factors have been identified as histone acetyltransferases. In addition, retinoblastoma protein and some co-factors can form a complex with histone deacetylases. These discoveries provide direct evidence that modification of chromatin structure is crucial for gene activation. However, the role of chromatin structure in cardiac-specific expression has not yet been elucidated. The potential significance of chromatin structure in cardiac-specific gene expression is indicated by: (1) heterogeneous human SWI/SNF chromatin remodelling factors among various tissues; (2) several chromatin remodelling factors shown to be expressed preferentially in the heart; (3) the demonstration of chromatin remodelling of the cardiac beta-myosin heavy chain gene (MyHC) during cardiac development. We therefore propose to study cardiac-specific chromatin remodelling activity in order to elucidate mechanisms controlling the reactivation of the fetal heart genetic program in the hypertrophic heart.

Chromatin remodelling of the cardiac beta-myosin heavy chain gene

To investigate the role of chromatin structure in cardiac gene expression, we used the DNase I and micrococcal nuclease to probe the chromatin structure of the hamster cardiac beta-MyHC gene. Two cardiac-specific DNase I hypersensitive sites (DHS) were identified, one of which was mapped to the -2.3 kb (beta-2.3 kb) region and the other to the proximal promoter region of the beta-MyHC gene. The two sites were readily detectable using nuclei from neonatal hamster heart; however, the proximal promoter site disappeared when adult hamster heart nuclei were used, and the -2.3 kb site decreased in intensity. We were able to demonstrate the gradual disappearance of this proximal promoter DHS by comparing heart nuclei isolated from animals at late-gestation and 1-day-old stages. Furthermore, injecting thyroid hormone caused the disappearance of the proximal promoter DHS in late gestational fetal ventricular nuclei. Digestion of nuclei from various tissues by micrococcal nuclease revealed that the beta-MyHC gene proximal promoter exists in an array of three specifically-positioned nucleosomes only in fetal heart chromatin. The beta-MyHC gene proximal promoter is DNase I hypersensitive within one of the nucleosomal particles. Our data suggest that chromatin structure may participate actively in cardiac gene expression.

Multiple muscle-specific regulatory elements are associated with a DNase I hypersensitive site of the cardiac beta-myosin heavy-chain gene

Using nuclei isolated from neonatal cardiomyocytes, we have mapped the DNase I hypersensitive sites (DHSs) residing within the 5'-upstream regions of the hamster cardiac myosin heavy-chain (MyHC) gene. Two cardiac-specific DHSs within the 5 kb upstream region of the cardiac MyHC gene were identified. One of the DHSs was mapped to the -2.3 kb (beta-2.3 kb) region and the other to the proximal promoter region. We further localized the beta-2.3 kb site to a range of 250 bp. Multiple, conserved, muscle regulatory motifs were found within the beta-2.3 kb site, consisting of three E-boxes, one AP-2 site, one CArG motif, one CT/ACCC box and one myocyte-specific enhancer factor-2 site. This cluster of regulatory elements is strikingly similar to a cluster found in the enhancer of the mouse muscle creatine kinase gene (-1256 to -1050). The specific interaction of the motifs within the beta-2.3 kb site and the cardiac nuclear proteins was demonstrated using gel mobility-shift assays and footprinting analysis. In addition, transfection analysis revealed a significant increase in chloramphenicol acetyltransferase activity when the beta-2.3 kb site was linked to a heterologous promoter. These results suggest that previously undefined regulatory elements of the beta-MyHC gene may be associated with the beta-2.3 kb site.

A conserved GATA motif in a tissue-specific DNase I hypersensitive site of the cardiac alpha-myosin heavy chain gene

Transgenic analysis has indicated that far upstream regulatory elements of the cardiac alpha-myosin heavy chain (MyHC) gene are required for appropriate transgene expression [Subramaniam, Gulick, Neumann, Knotts and Robbins (1993) J. Biol. Chem. 268, 4331-4336]. In an attempt to identify these as-yet-undefined regulatory elements, we mapped the DNase I hypersensitive sites (DHSs) in the 4 kb upstream region of the hamster cardiac alpha-MyHC gene. When using nuclei isolated from late-gestational and adult heart ventricles, a strong DHS was identified in the -1.9 kb region (alpha-1.9 kb site). It cannot be detected in kidney, liver or cardiofibroblast nuclei. Within this site, we found a conserved GATA-motif that interacts specifically with GATA-binding factors in nuclear extracts of cardiomyocytes at various developmental stages. These data provide further evidence to support the role of GATA factors in the regulation of cardiac alpha-MyHC gene expression.

Animal fatty acid synthase: functional mapping and cloning and expression of the domain I constituent activities

Animal fatty acid synthase (FAS; EC 2.3.1.85) is a homodimer of a multifunctional subunit protein and catalyzes the synthesis of palmitate from acetyl-CoA, malonyl-CoA, and NADPH. The subunit (Mr approximately 270,000) carries seven distinct component activities and a site for the prosthetic group 4'-phosphopantetheine (acyl carrier protein). Based on proteolytic mapping, the organization of the activity domains along the subunit polypeptide from the N terminus is as follows: beta-ketoacyl synthase, acetyl and malonyl transacylases, beta-hydroxyacyl dehydratase, enoyl reductase, beta-ketoacyl reductase, acyl carrier protein, and thioesterase. By comparing the amino acid sequences of the chicken, rat, and human synthases, we found that kallikrein cleavage sites occur in the least conserved regions of the FAS polypeptide subunit. Determining the amino acid sequences of the N-terminal end of the major kallikrein cleavage peptides helped delineate the most likely boundaries of the component activities in the cDNA-derived amino acid sequence. To confirm this organization, we cloned the chicken FAS cDNA coding for domain I and expressed it in Escherichia coli as a maltose-binding fusion protein. The isolated recombinant protein contained the activities of the acetyl and malonyl transacylases and the beta-hydroxyacyl dehydratase. Based on the boundaries of the acetyl and malonyl transacylases and the beta-hydroxyacyl dehydratase, we also cloned the appropriate cDNA fragments encoding the domains that contain the transacylases and the dehydratase in pET vectors and expressed them in E. coli as thioredoxin-6xHis fusion proteins. The purified recombinant proteins contained, respectively, the activities of the acetyl and malonyl transacylases and the dehydratase. These results not only confirmed the order of the component activities in domain I, but also paved the way for successful expression and characterization of the remaining activities.

Single site electronic spectra of free base porphin in an n-octane crystal at 5 K

The single site fluorescence and excitation spectra of free base porphin in an n-octane crystal at 5 K are reported. The vibrational frequencies of the ground and excited states (Qx, Qy, and B bands) have been determined from the spectra. The Qx region is very similar to the previously reported results from supersonic jet expansion. However, the Qy region is quite different in the jet and mixed crystal: the crystal spectrum exhibits extensive vibronic coupling. The Soret band shows little vibronic structure.

Cheng's method for reconstruction of a functionally sensitive penis

This article introduces a new surgical method for one-stage reconstruction of the penis. It is applied to the reconstruction of the microphallus as well as to traumatic cases with the residual stump of the amputated penis not less than 3 cm long. By transferring the original glans or the residual penile stump to the anterior portion of the newly reconstructed penile body with microsurgical techniques, we have thus rebuilt a penis with more satisfactory results in both appearance and erotic sensation. Seven patients are reported here who were operated on by this method and who have been followed up for 18 months to 10 years. The good results achieved and the method's advantages over other methods are demonstrated and discussed.

Cloning and expression of the multifunctional human fatty acid synthase and its subdomains in Escherichia coli

We engineered a full-length (8.3-kbp) cDNA coding for fatty acid synthase (FAS; EC 2.3.1.85) from the human brain FAS cDNA clones we characterized previously. In the process of accomplishing this task, we developed a novel PCR procedure, recombinant PCR, which is very useful in joining two overlapping DNA fragments that do not have a common or unique restriction site. The full-length cDNA was cloned in pMAL-c2 for heterologous expression in Escherichia coli as a maltose-binding protein fusion. The recombinant protein was purified by using amylose-resin affinity and hydroxylapatite chromatography. As expected from the coding capacity of the cDNA expressed, the chimeric recombinant protein has a molecular weight of 310,000 and reacts with antibodies against both human FAS and maltose-binding protein. The maltose-binding protein-human FAS (MBP-hFAS) catalyzed palmitate synthesis from acetyl-CoA, malonyl-CoA, and NADPH and exhibited all of the partial activities of FAS at levels comparable with those of the native human enzyme purified from HepG2 cells. Like the native HepG2 FAS, the products of MBP-hFAS are mainly palmitic acid (> 90%) and minimal amounts of stearic and arachidic acids. Similarly, a human FAS cDNA encoding domain I (beta-ketoacyl synthase, acetyl-CoA and malonyl-CoA transacylases, and beta-hydroxyacyl dehydratase) was cloned and expressed in E. coli using pMAL-c2. The expressed fusion protein, MBP-hFAS domain I, was purified to apparent homogeneity (M(r) 190,000) and exhibited the activities of the acetyl/malonyl transacylases and the beta-hydroxyacyl dehydratase. In addition, a human FAS cDNA encoding domains II and III (enoyl and beta-ketoacyl reductases, acyl carrier protein, and thioesterase) was cloned in pET-32b(+) and expressed in E. coli as a fusion protein with thioredoxin and six in-frame histidine residues. The recombinant fusion protein, thioredoxin-human FAS domains II and III, that was purified from E. coli had a molecular weight of 159,000 and exhibited the activities of the enoyl and beta-ketoacyl reductases and the thioesterase. Both the MBP and the thioredoxin-His-tags do not appear to interfere with the catalytic activity of human FAS or its partial activities.

The use of 5,6 benzo-[alpha]-pyrone (coumarin) and heating by microwaves in the treatment of chronic lymphedema of the legs

Sixty patients with leg lymphedema from a variety of etiologies were divided into randomized two groups, matched by Grade, duration, age, sex, and cause of lymphedema. Using a double-blind format, one group received 5,6 benzo-[alpha]-pyrone (coumarin 1,2 benzopyrone, 400 mg/day) for six months; the other received a placebo. For the next six months, both groups received a standardized regimen of heat (using microwaves) coupled with compression garments. Benzopyrone produced approximately 20% reduction in the volume (p = 10(-4)) and improvement in circumferences and tonometry (p = 10(-5) and 10(-7)). Symptoms (feelings of swelling, pain, heaviness and loss of mobility) were also significantly improved (p = 0.03 to 10(-7)). During the second six months, when microwave heat therapy was added to drug therapy, the patients who had previously received the placebo showed significant improvement (p = 0.03 to 10(-9)) in signs and symptoms of lymphedema. Some, but not all, of the group that was receiving benzopyrones were also significantly improved by heat therapy (p = 0.8 to 0.002). Taking benzopyrones for 12 months plus heat treatment for six months was significantly better, for some criteria, than the placebo plus heat therapy (p = 0.7 to 0.04). On the other hand, heat plus either placebo or benzopyrone was often significantly better than either the active or inactive drug without heat (p = 0.8 to 10(-9)).

Assignment of the human GATA4 gene to 8p23.1-->p22 using fluorescence in situ hybridization analysis

Using fluorescence in situ hybridization, the human GATA4 gene, a member of the zinc-finger protein family recognizing the consensus GATA motif, was mapped to 8p23.1-->p22. This result, in conjunction with gene mapping data on other GATA-DNA binding proteins, suggests that genes encoding GATA-DNA binding proteins are dispersed throughout the genome, rather than clustered within a single locus.

Human fatty acid synthase: properties and molecular cloning

Fatty acid synthase (FAS; EC 2.3.1.85) was purified to near homogeneity from a human hepatoma cell line, HepG2. The HepG2 FAS has a specific activity of 600 nmol of NADPH oxidized per min per mg, which is about half that of chicken liver FAS. All the partial activities of human FAS are comparable to those of other animal FASs, except for the beta-ketoacyl synthase, whose significantly lower activity is attributable to the low 4'-phosphopantetheine content of HepG2 FAS. We cloned the human brain FAS cDNA. The cDNA sequence has an open reading frame of 7512 bp that encodes 2504 amino acids (M(r), 272,516). The amino acid sequence of the human FAS has 79% and 63% identity, respectively, with the sequences of the rat and chicken enzymes. Northern analysis revealed that human FAS mRNA was about 9.3 kb in size and that its level varied among human tissues, with brain, lung, and liver tissues showing prominent expression. The nucleotide sequence of a segment of the HepG2 FAS cDNA (bases 2327-3964) was identical to that of the cDNA from normal human liver and brain tissues, except for a 53-bp sequence (bases 3892-3944) that does not alter the reading frame. This altered sequence is also present in HepG2 genomic DNA. The origin and significance of this sequence variance in the HepG2 FAS gene are unclear, but the variance apparently does not contribute to the lower activity of HepG2 FAS.

Leigh syndrome presenting with dystonia: report of one case

A 22-month-old female presented with developmental delay and dystonia. The T2 weighted image of the brain MRI showed bilateral symmetrical high signal lesions over the putamen. An increased serum lactate pyruvate ratio (29.25) and a positive oral glucose lactate stimulation test were noted. Electron microscopic examination showed abnormal mitochondrial aggregation with band cristae in the subsarcolemmal area. These findings were indicative of clinical Leigh's syndrome. However, unusually the mt DNA analysis showed a point mutation at the nucleotide position 8344.

Molecular basis of glucose-6-phosphate dehydrogenase (G6PD) deficiency in three Taiwan aboriginal tribes

We have investigated glucose-6-phosphate dehydrogenase (G6PD) deficiency in 220 unrelated aboriginal male subjects who belong to three different tribes (Saisiat, Ami, and Yami) in Taiwan. Our results show that the G6PD deficiency rates for Saisiat, Ami, and Yami people are 9.0% (6/67), 6.1% (6/99), and 0% (0/54), respectively. Among these deficiency cases, 4 of 6 (66.7%) Saisiat subjects have the 493 A-->G mutation and one carries the 1376 G-->T mutation, whereas, in Ami subjects, we found that four of six (66.7%) affected males have the 592 C-->T mutation and one carries the 493 A-->G mutation. These results contrast with our previous findings for Taiwan Chinese, in whom the 1376 G-->T mutation is the major mutant allele and accounts for 52.3% of the deficiency cases. This is the first report of G6PD deficiency characterized at the DNA level in Taiwan aboriginal populations.

Lumboperitoneal shunt complicated with chronic tonsillar herniation: a case report

Lumbopritoneal shunt (L-P shunt) has been widely accepted as a treatment for communicating hydrocephalus. The technique offers many advantages such as easy insertion, a low infection rate, a reduced incidence of brain damage, et centera. Despite these advantages, there are also some associated complications, such as tonsillar herniation. This complication rarely occurs, but, when it does, it develops gradually. This report concerns an eight-year-old girl, who had received L-P shunt at the age of 20 days; she then developed tonsillar herniation, requiring operative decompression, eight years later. This case illustrates the necessity for carefully follow up patients who have undergone the L-P shunt procedure.

Identification of a GATA motif in the cardiac alpha-myosin heavy-chain-encoding gene and isolation of a human GATA-4 cDNA

In an attempt to identify the cardiac-specific genes regulated by the transcription factor GATA-4, we have identified a putative GATA-binding site located within the 5' flanking sequence of the human cardiac alpha-myosin heavy-chain-encoding gene. The 23-bp sequence surrounding the core GATA-binding site is conserved across species. The core motif and flanking sequences of this GATA-binding site are almost identical to that of a well-established GATA-binding site located within the 3' enhancer of the human beta-globin gene. Using electrophoretic mobility shift analysis, two distinct nuclear factors were found to bind specifically to this element. We have isolated a full-length cDNA clone for human GATA-4 (hGATA-4) by screening a human heart cDNA library. The hGATA-4 cDNA sequence shows 85% identity with murine GATA-4 in the protein coding region. The deduced amino-acid sequence within the two zinc-finger DNA-binding domains of human GATA-4 is 100% identical with murine GATA-4. Northern blot analysis reveals that this 4.4-kb transcript has higher expression in adult heart than in fetal heart. Our results suggest that GATA-4 may regulate a set of cardiac-specific genes and play a crucial role in cardiogenesis.

Histopathologic evaluation of proliferating cell nuclear antigen (PC10) in oral epithelial hyperplasias and premalignant lesions

As the therapeutic options for malignant lesions expand, early accurate diagnosis of premalignancy is becoming increasingly important in the concept of cancer prevention. Because it has been hypothesized that abnormal cell proliferation is related to subsequent malignant transformation, many proliferation markers such as proliferating cell nuclear antigen have been studied in a variety of malignant tumors. In oral surface epithelium, proliferating cell nuclear antigen activity is restricted to basal layers of normal squamous mucosa. In this preliminary study, 169 formalin-fixed, paraffin-embedded oral epithelial lesions, including 28 carcinomas in situ, 82 epithelial dysplasias, 21 epithelial atypia, and 38 typical epithelial hyperplasias, were studied with a monoclonal antibody, PC10, to determine whether proliferating cell nuclear antigen suprabasal expression correlated with premalignancy. The findings revealed that with progression of lesions toward malignancy, there was a significant predilection for basal/suprabasal staining pattern for proliferating cell nuclear antigen as compared with the strictly basal staining pattern seen in normal and benign epithelial conditions. One unexpected staining pattern, suprabasal positive stain only, was also noted mostly in reactive hyperplasia and dysplasia. The data suggested that a positive basal/suprabasal staining pattern for proliferating cell nuclear antigen is indicative of premalignancy in oral epithelial lesions.

Diphallus in an adult: microsurgical treatment--case report

A case of true, complete diphallus in an adult, associated with multiple malformations, is presented. The left urethra was perineal hypospadic; the right posterior urethra was small in caliber; and the right testis and spermatic cord were absent. The chordee was released; the right penis was resected and transferred to elongate the left one; and the urethra was reconstructed with a radial forearm free flap. Follow-up of more than 6 years shows that the patient has a good functional and cosmetic result.

Amino-terminal blocking group and sequence of the animal fatty acid synthase

We have cloned and sequenced the cDNA encoding the chicken fatty acid synthase. Based on the nucleotide-derived amino acid sequence of the chicken synthase, the N-terminal sequences are highly conserved among animal species, suggesting that translation of the animal synthases initiates with the same ATG codon. Like other fatty acid synthases, the NH2-terminal sequence of the chicken enzyme is blocked. We have isolated and purified the blocked NH2-terminal peptide from a tryptic digest of chicken synthase and have established that the blocking group is an acetyl group. The sequence of the native tryptic peptide confirmed the cDNA-derived amino acid sequence and suggested that all animal synthases begin with this homologous sequence. We developed simple procedures that can be used to isolate and characterize any blocked NH2-terminal peptide.