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The sensitive detection of circulating tumour cells in patients with differentiated thyroid cancer may precede the detection of relapse by other diagnostic studies – such as serum thyroglobulin – and thus may have important therapeutic and prognostic implications. We performed reverse transcription-polymerase chain reaction (RT-PCR) on blood samples from patients diagnosed with thyroid disease using two different RT-PCR sensitivities. Additionally, tissue specificity of TG mRNA-expression was determined using RNA extracts from 27 different human tissues. The lower limit of detection was 50–100 TG mRNA producing cells/ml blood using a ‘normal’ RT-PCR sensitivity and 10–20 cells/ml blood using a ‘high’ sensitivity. With the normal sensitivity TG mRNA was detected in 9/13 patients with thyroid cancer and metastasis, 63/137 patients with a history of thyroid cancer and no metastasis, 21/85 with non-malignant thyroid disease and 9/50 controls. With the high sensitivity TG mRNA was detected in 11/13 patients with thyroid cancer and metastasis, 111/137 patients with a history of thyroid cancer and no metastasis, 61/85 with non-malignant thyroid disease and 41/50 controls. Interestingly, using the normal RT-PCR sensitivity TG mRNA transcripts are specific for thyroid tissue and detectable in the peripheral blood of controls and patients with thyroid disease, which correlates with a diagnosis of metastasized thyroid cancer. However, with a high RT-PCR sensitivity, TG mRNA expression was found not to be specific for thyroid tissue and was not correlated with a diagnosis of thyroid cancer in patients. As a consequence, to date TG mRNA detected by RT-PCR in the peripheral blood cannot be recommended as a tumour marker superior to TG serum-level.
In the late 1980s, laparoscopy was essentially a gynecologist's tool. One of the French private surgeons, Phillipe Mouret of Lyon, shared his surgery practice with a gynecologist and thus had access to both laparoscopic equipment and to patients requiring laparoscopy. In March of 1987, Mouret carried out his first cholecystectomy by means of electronic laparoscopy. Although he never published anything about this experience, the news on his technique reached Francois Dubois of Paris. Although having no prior laparoscopic experience, Dubois acted immediately. He borrowed the instruments from gynecologists, performed his first animal experiments and, in April 1988, carried out the first laparoscopic cholecystectomy (LC) in Paris. Inspired by Dubois, Jacques Perissat of Bordeaux, introduced endoscopic cholecystectomy in his clinic and presented this technique at a SAGES meeting in Louisville in April 1989. Very soon, news of the French work in LC soon swept beyond the country's borders. Dubois and Perissat spoke enthusiastically about their work at the meetings and were largely responsible for establishing what is today called the French technique.
At the end of the 20th century, access to information provided by the World Wide Web (WWW) is changing as never before. The fast availability of current medical literature and the availability of tools for easy access to information, as well as for the easy production of information, have confronted research physicians, scholars, and students with new kinds of problems, many of which concern us personally. Quality control, difficulty establishing basic citation components, lack of standard guidelines for citing, as well as the short lifetime of Internet addresses concern us deeply. Some of these problems could be solved by the concept of an "Online-Library of Medicine" presented in the following paper. Since, however, at the present time there are no good answers to the problems regarding citing Internet-based sources, a Web surfer must keep in his or her mind the motto “caveat lector” (let the reader beware) - or, rather, in the spirit of our time: click c@refully before you cite.
Enzymatic and antisense effects of a specific anti-Ki-ras ribozyme in vitro and in cell culture
(1999)
Due to their mode of action, ribozymes show antisense effects in addition to their specific cleavage activity. In the present study we investigated whether a hammerhead ribozyme is capable of cleaving mutated Ki-ras mRNA in a pancreatic carcinoma cell line and whether antisense effects contribute to the activity of the ribozyme. A 2[prime]-O-allyl modified hammerhead ribozyme was designed to cleave specifically the mutated form of the Ki-ras mRNA (GUU motif in codon 12). The activity was monitored by RT-PCR on Ki-ras RNA expression by determination of the relative amount of wild type to mutant Ki-ras mRNA, by 5-bromo-2[prime]-deoxy-uridine incorporation on cell proliferation and by colony formation in soft agar on malignancy in the human pancreatic adenocarcinoma cell line CFPAC-1, which is heterozygous for the Ki-ras mutation. A catalytically inactive ribozyme was used as control to differentiate between antisense and cleavage activity and a ribozyme with random guide sequences as negative control. The catalytically active anti-Ki-ras ribozyme was at least 2-fold more potent in decreasing cellular Ki-ras mRNA levels, inhibiting cell proliferation and colony formation in soft agar than the catalytically inactive ribozyme. The catalytically active anti-Ki-ras ribozyme, but not the catalytically inactive or random ribozyme, increased the ratio of wild type to mutated Ki-ras mRNA in CFPAC-1 cells. In conclusion, both cleavage activity and antisense effects contribute to the activity of the catalytically active anti-Ki-ras hammerhead ribozyme. Specific ribozymes might be useful in the treatment of pancreatic carcinomas containing an oncogenic GTT mutation in codon 12 of the Ki-ras gene.
Objectives: The possible etiologic relevance of occupational factors such as cadmium, cutting oils, diesel fuel and fumes, herbicides, polycyclic aromatic hydrocarbons (PAH), polychlorinated biphenyls, soot, tar, mineral oil, and solvents to prostate cancer was studied.
Methods: A case-referent study design was used to recruit 192 subjects with histologically confirmed prostate cancer and 210 referents who had prostate cancer histologically excluded either in one of two urologic practices (Hamburg and Frankfurt) or in the urological policlinic of the Frankfurt University. Data were gathered with a self-administered questionnaire and analyzed using logistic regression to control for age, region, and cigarette smoking. A job-exposure matrix was used for assigning exposure. For the calculation of dose-years, the duration of contact with specific substances was weighted by the intensity and probability of exposure according to a job-exposure matrix.
Results: The analysis of dose-years yielded a statistically significant association between occupational exposure to diesel fuel or fumes and prostate cancer (odds ratio 3.7, 95% confidence interval 1.4-9.8, for subjects exposed to more than 25 dose-years in a comparison with subjects never exposed). For the other substances, no statistically significant differences in exposure were found between the cases and referents. When only jobs with a high exposure probability were used to classify the participants as exposed, only exposure to PAH was significantly associated with prostate cancer.
Conclusion: In keeping with results from other studies, this study provides further evidence that exposure to diesel fuel or fumes - possibly mediated through PAH - may be associated with the development of prostate cancer.
Erich Mühe and the rejection of laparoscopic cholecystectomy (1985) : a surgeon ahead of his time
(1998)
During the early 1980s, news of Semm's laparoscopic appendectomy was rippling through German medical circles. Erich Mühe, fascinated by Semm's technique and spurred by successes of the Erlangen endoscopists, came up with the idea of laparoscopic removal of gallstones. In 1984, Mühe had already worked out the details of an operative laparoscope, the “Galloscope,” and on September 12, 1985, he carried out the first laparoscopic cholecystectomy. Later, he modified his technique and operated through a trocar sleeve. Finally, he designed an “open laparoscope” with a circular light. By March 1987, Mühe had conducted 97 endoscopic gallbladder removals. He published information about his technique at the Congress of the German Surgical Society (April 1986) and at other surgical meetings in Germany. His concept, however, was ignored. In the middle of the 1980s, the surgical community was still not prepared for the era of “minimally invasive therapy.” Erich Mühe was a surgeon ahead of his time.
In the late 1950s, Patrick C. Steptoe, a British gynecologist, established contact with Palmer of Paris and Frangenheim of Wuppertal, Germany, and studied laparoscopic technique under the tutelage of these pioneers. Despite the negative attitude among his colleagues, Steptoe soon became one of the most innovative researchers in the field of abdominal endoscopy, particularly laparoscopic sterilization. In the late 1960s, Steptoe began working with Robert Edwards, an embryologist, and launched an in-vitro fertilization project obtaining eggs by means of laparoscopy. Both researchers experienced years of frustration, disappointment, ethical and scientific criticism as well as a difficult relationship with the mass media. Finally, in July 1978, Louise Brown, the first test-tube baby, was born in England.
Like many of his colleagues in the 1950s and 1960s, Patrick Christopher Steptoe (1913-1988), a gynecologist in Oldham, Great Britain, was concerned about the number of unnecessary laparotomies. Unfortunately, the Oldham group of hospitals was not a university clinic and Steptoe had scanty opportunity to develop his own research. In the late 1950s, he searched the medical literature for an alternative form of examination and came across publications about Decker's culdoscopy, the vaginal approach to view the abdomen. Since this method was not widespread in England, Steptoe, in 1958, went to Montreal, Boston, and New York in order to observe and learn the practical use of culdoscopy. However, Steptoe left America disappointed.
Work on tubal insufflation marked the beginning of Kurt Semm's (b. 1927) scientific career. In the early 1960s, he directed his attention to the fact that, from a technical standpoint, tubal insufflation was similar to creating pneumoperitoneum. In the mid-1960s, Semm - himself a gynecologist - invested his time and financial resources and risked his university career to develop an automatic abdominal insufflation device. Later he tried it out in the Clinic for Internal Medicine. Since, at that time, the term “laparoscopy” had negative connotations associated with it, Semm formulated a new term “pelviscopy.” In 1967, Semm presented his invention to Melvin Cohen, an American pioneer of gynecological laparoscopy, at the meeting of the American Fertility Society, held in Washington.
In the 1970s, Semm developed thermocoagulation, adapted the Roeder Loop, and further invented extra- and intracoporeal endoscopic knotting to achieve endoscopic hemostasis. His numerous technical inventions, especially the electronic insufflator, allowed more complex operations to be performed laparoscopically. His technique, however, was not quickly adopted by the surgical community. When the first fully laparoscopic appendectomy was carried out by Semm in 1980, a veritable storm broke loose. In the opinion of many prominent surgeons, Semm exaggerated the problem of adhesions, and laparoscopic technique itself was regarded as very dangerous. Misunderstood by medical scientists, Semm displayed an ability to force his ideas through despite skepticism and suspicion. He realized that endoscopic surgery had tremendous potential, and promoted laparoscopic technique not only in his field of gynecology but among general surgeons as well. In 1985, Muhe, of Boblingen, Germany, used Semm's technique to remove the first gallbladder in the world laparoscopically. Three years later when Semm presented a videotape of his laparoscopic appendectomy in Baltimore, he gave impetus to McKernan and Save of Marietta. Georgia, to carry out the first laparoscopic cholecystectomy in the United States.