Biomedical subjects

P Van Alphen

Publications and source records attributed to P Van Alphen.

4 recordsLinked to original sources

PubMed1995

Balloon dissection in extended retroperitoneoscopy.

The anatomy of the retroperitoneum, including the high retroperitoneum, was studied as it appears with balloon dissecting techniques. We used fresh cadavers in this study. A relatively unknown fascia that is located between the lateral aspect of the perirenal fascia and the posterior parietal peritoneum, called the paraconal fascia, was a constant finding. This structure is important because it protects delicate retroperitoneal organs: the duodenum, pancreas, celiac axis, and superior mesenteric artery. Locating this fascia is an important step in the dissection of the high retroperitoneum, which is of interest in advanced videoendoscopic procedures involving retroperitoneal organs.

Aorta, Abdominal↗

PubMed1992

Transcriptional activation of several heterologous promoters by the E6 protein of human papillomavirus type 16.

The E6 protein of human papillomavirus type 16 (HPV-16), along with E7, is responsible for the HPV-induced malignant transformation of the cervix. However, the mechanism of this transformation activity is not well understood. We investigated whether the entire E6 protein of HPV-16 could act as an activator of transcription. Experiments in which NIH 3T3 cells were cotransfected with an E6 expression vector together with the reporter chloramphenicol acetyltransferase (CAT) gene linked to various minimal promoters indicated that E6 could activate transcription from a series of viral TATA-containing promoters. Mutations or deletions that affected all upstream regulatory elements present in the thymidine kinase (TK) promoter, such as the GC and CAAT boxes, reduced the level of E6-induced transcription. However, compared with the basal level, these truncated promoters were still activated by E6. Although site-directed mutations of the TATA sequence present in the TK or human immunodeficiency virus long terminal repeat promoters reduced the level of basal transcription, they did not abolish the E6-mediated activation. Moreover, E6 could restore almost completely the full level of wild-type E6-induced transcription as long as the upstream regulatory elements (GC/CAAT in the TK promoter, NF-kappa B in the human immunodeficiency virus long terminal repeat) were intact. This dual interaction of HPV-16 E6 is reminiscent of the activity of a coactivator.

3T3 Cells↗

PubMedDate not supplied

Total DNA synthesis and cloning in Escherichia coli of a gene coding for the human growth hormone releasing factor.

A DNA containing a sequence coding for the human growth hormone releasing factor (hGRF) has been obtained by enzymatic assembly of chemically synthesized DNA fragments. The synthetic gene consists of a 140 base-pair fragment containing initiation and termination signals for translation and appropriate protruding ends for cloning into a newly constructed plasmid vector (pULB1219). Eleven oligodeoxyribonucleotides, from 14 to 31 bases in length, sharing pairwise stretches of complementary regions of at least 13 bases were prepared by phosphotriester solid-phase synthesis. The DNA sequence was designed to take into account the optimal use of E. coli codons. Oligomers were annealed in one step and assembled by ligation. The DNA fragment of the expected size (140 bp) was recovered and cloned into the pULB1219 vector. The expected sequence was confirmed by DNA sequencing.

Amino Acid Sequence↗

PubMedDate not supplied

Laparoscopic highly selective vagotomy.

BACKGROUND/AIMS: Ten percent of our population has had a gastroduodenal ulcer. Medical treatment heals ulcers in 90% of the cases but they recur in 50-70% of the patients. We present a proposal of surgical treatment for patients with recurrent ulcer after a long-term medical treatment or whose ulcer reappears as soon as medical treatment ceases. METHODOLOGY: Thirty-three patients underwent highly selective vagotomy (HSV) laparoscopic between April 1992 and March 1993. There were 26 male patients and 7 female patients aged 19-65 years (mean age: 38 years). Twenty-six patients were operated electively and preliminary medical treatment lasted an average 5.4 years (range: 0.5-26 years) and the disease had lasted 1-30 years (mean duration: 8.4 years). For patients with a chronic peptic ulcer disease, pre-operative assessment involved a recent gastroscopy, isotopic gastric study and a selection test. RESULTS: HSV proved feasible in 100% of the cases in spite of a history of previous surgery and peritonitis in patients with a perforated ulcer. There were neither conversions nor intra-operative complications. There was no mortality or morbidity. The mean hospital stay was 2 days (range: 1-5 days) for selectively operated patients and 7 days (range: 6-10 days) for patients operated for a perforated ulcer. Twenty-two patients were rated Visick I and II and 3 with Visick III after re-examining. The BAO had decreased by 61% to 89% and the MAO by 60% to 80%. CONCLUSIONS: The treatment of choice for gastro-duodenal ulcer is highly selective vagotomy. The laparoscopic approach shortens the hospital stay and improves patient's comfort.

Adult↗