Biomedical subjects

H J Harn

Publications and source records attributed to H J Harn.

45 records · Page 3Linked to original sources

PubMed1994

Selective expression of CD44 messenger RNA splice variants in four high grade human brain tumour cell lines.

Changes in CD44 transcripts have been previously found to be associated with metastasis in animal models. The purpose of this study was to investigate CD44V changes in four well established high grade human brain tumor cell lines, known to possess prominent invasive behavior. In Northern blot analysis, CD44S and CD44V were expressed strongly in three high-grade glioblastoma multiforme cell lines (GBM 8401, GBM 8909, GBM 8804) and one malignant meningioma cell line (IOMM). By RT-PCR and blot hybridization, three variant transcripts (650 bps, 850 bps, and 1,000 bps) were detected in GBM 8804 and two isoform transcripts (650 bps, 850 bps) were recognized in GBM 8401 and 8909. Further, in a malignant meningioma cell line (IOMM), only one weak isoform (650 bps) was detected. However, by Northern blot analysis, neither CD44S or CD44V could be expressed in normal brain and meningeal tissue. These results indicate that discrete CD44 mRNA splice variants are expressed in high grade glial cell tumors and malignant meningioma and suggest a possible role in the invasion of malignant brain tumors.

Base Sequence↗

PubMed1994

Fibrous dysplasia of the rib presenting as a huge chest wall tumor: report of a case.

Fibrous dysplasia of the rib is not uncommon, but is rarely demonstrated as a huge chest wall mass with severe clinical symptoms. A 59-year-old patient, presenting with a huge, rapidly expanding chest wall tumor compressing the lung, liver and heart accompanied by chest pain and dyspnea, is reported. The tumor was success-fully excised by local radical resection.

Diagnosis, Differential↗

PubMed1994

Gastric lymphoepithelioma-like carcinoma associated with Epstein-Barr virus proved by in situ hybridization study: a case report.

Undifferentiated gastric carcinoma with prominent lymphoid infiltration and a striking resemblance to nasopharyngeal lymphoepithelioma has rarely been reported. Recently, the Epstein-Barr virus (EBV) genome has been demonstrated in some cases of gastric carcinoma with a morphology similar to undifferentiated nasopharyngeal carcinoma (NPC). One such case has been identified here by immunohistochemistry; it was explored for the EBV genome by RNA in situ hybridization (ISH) with an EBERs (Epstein-Barr virus encoded RNAs) probe. EBV RNAs were detected uniformly in the carcinoma cells or adjacent dysplasia epithelium, but were not present in the related lymphoid infiltration or in normal gastric mucosa. These findings add to the growing body of evidence suggesting the strong association of EBV with gastric lympho-epithelioma-like carcinoma (LELC), and also indicate that a latent EBV infection may play a role in undifferentiated epithelial cells.

Carcinoma, Squamous Cell↗

PubMed1993

Recurrent ascending myelitis: an unusual presentation of herpes simplex virus type 1 infection.

We report on a healthy female with a unique relapsing transverse myelitis accompanied by herpes simplex virus type 1 (HSV-1) infection. Magnetic resonance imaging showed cord enlargement and increased signal intensity on T1-weighted image with gadolinium enhancement from T-4 to T-10 during the first attack and from C-1 to C-2 during the second episode. She was not diagnosed during the first attack. During the second episode, laboratory studies disclosed IgM and IgG antibodies to HSV at the outset with greater than fourfold increases in antibody levels in the serum and cerebrospinal fluid (CSF). Cells cultured from the CSF were positive for HSV-1 according to the immunofluorescence method. The presence of HVS-1 DNA in CSF was documented by polymerase chain reaction (PCR) technique. Acyclovir was given with a partial recovery. We anticipate that PCR assay of CSF will assist early diagnosis of herpetic central nervous system disorders.

Aged↗

PubMed1992

The complex CD44 transcriptional unit; alternative splicing of three internal exons generates the epithelial form of CD44.

We have utilized the polymerase chain reaction (PCR) to isolate a 3.5 kilobase pair (kb) genomic fragment that encodes the additional extracellular domain unique to the epithelial isoform of CD44 (CD44E). Nucleotide sequence was determined for this complete region and sequence comparison to our previously determined CD44R1 and CD44R2 cDNA sequences revealed the R region to be comprised of three exons of 102 bp, 90 bp, and 204 bp. Northern blot analysis of CD44 expressing cell lines confirmed the presence of CD44R1 transcripts and indicates that the epithelial domain may be inserted through alternative splicing into all CD44 transcript classes. Southern blot analysis of the CD44E genomic fragments is consistent with a single copy per human haploid genome. The data presented here further supports our model of the human CD44 transcriptional unit as a single gene complex that utilizes an invariant 5' initiation site, alternative internal and 3' end splicing, and multiple poly (A) sites to generate through RNA processing a diverse number of human CD44 isoforms.

Amino Acid Sequence↗

PubMed1991

The multispecific cell adhesion molecule CD44 is represented in reticulocyte cDNA.

Identified originally as erythrocyte p80, whose expression is down regulated by the Lutheran inhibitor gene (In[Lu]), the In(Lu) related-p80 glycoprotein represents the red cell isoform of the human cell adhesion/recognition molecule CD44. The presence of a CD44 transcript within a reticulocyte cDNA library was indicated by the PCR amplification of an appropriately sized product generated by a pair of deoxyoligonucleotide primers derived from CD44 cDNA sequence. The amplified product was subsequently utilized to screen and isolate a positively hybridizing full-length reticulocyte cDNA clone (RETIC CD44) that contained an 1809 base pair insert that was DNA sequenced by the dideoxy chain termination method. This first isolate of a reticulocyte CD44 cDNA appears to be generated by a combination of RNA processing events that includes production of 3' mRNA heterogeneity by utilization of multiple poly(A) sites. Remarkably, the 3' untranslated (3'UT) region of this mRNA, encoding a prototypic hematopoietic CD44 isoform, has been previously reported present on only a transcript that encodes a CD44 epithelial isoform.

Amino Acid Sequence↗

PubMed1991

Screening recombinant DNA libraries: a rapid and efficient method for isolating cDNA clones utilizing the PCR.

We describe an expeditious method for the isolation of cDNA clones utilizing PCR-based amplification of target sequences from cDNA libraries. This method is rapid, less labor-intensive and inexpensive when compared with screening libraries with radiolabeled probes. This method can be applied to isolate multiple members of a protein family as well as homologous genes in different species by designing appropriate primers to amplify the most conserved regions. Utilizing this method, a novel reticulocyte CD44 transcript was isolated.

Bacteriophage lambda↗

PubMedDate not supplied

Xanthoma of bone in a normolipidemic child: report of one case.

Xanthoma invasion of the bone is a very rare disease especially in normolipidemic children. Bone erosion can be found in patients with this disease. However, due to the similarity of the symptoms of xanthoma with many other diseases including malignancy, the other diseases may initially be to be suggested and xanthoma may not even be considered. In this paper, we present an 8-year-old normolipidemic male child with a parietal bone xanthoma proved using tissue diagnosis. The clinical, radiographic and histological findings are also reviewed.

Child↗

PubMedDate not supplied

Subglottic hemangioma associated with cutaneous and cerebellar hemangiomas detected by MRI: report of one case.

Subglottic hemangioma (SGH) is a benign neoplasm that may cause severe and life-threatening respiratory obstruction in infants. However, patients usually present with inspiratory stridor in the first few months of life and may be mistakenly diagnosed as recurrent or persistent croup. Definitive diagnosis is made by image studies, endoscopic examination and biopsy or all. We report a 2-month-old female infant of SGH with initial clinical manifestations of dyspnea and inspiratory stridor co-existing with cutaneous and cerebellar hemangiomas. Clinicians must be alert the possibility of SGH when associated with cutaneous hemangioma. This patient has received oral steroid treatment for more than two months with improvement of the airway obstruction. Although purplish patch lesions over left side of face, eyelid, cheek, and peri-oral regions regressed, the size of the SGH on the followed MRI was slightly enlarged. The diagnosis and various treatments of SGH are discussed and reviewed in this paper.

Adrenal Cortex Hormones↗