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Biomedical subjects

S Said

Publications and source records attributed to S Said.

At least 55 records · Page 3Linked to original sources
PubMed1997

Invasive versus non-invasive diagnosis of renal bone disease.

At present, bone histomorphometry remains the gold standard for the diagnosis of the various types of renal bone disease. In the search for a non-invasive method of diagnosis, biochemical serum markers of bone remodelling, in addition to serum intact parathyroid hormone and aluminium determinations, have been proposed as the most reliable tools and are at present widely used in clinical practice. Their respective diagnostic values, as separate items and in combined analysis, are thoroughly discussed in the present review.

Aluminum↗
PubMed1997

Cryogen spray cooling during Nd:YAG laser treatment of hemangiomas. A preliminary animal model study.

BACKGROUND: Successful laser treatment of hemangiomas requires selective photothermal destruction of dilated cutaneous vessels without damaging the overlying epidermis. Delivering a short cryogen spurt, on the order of milliseconds, has been shown to result in localized cooling of the superficial skin structures during laser irradiation. OBJECTIVE: The purpose of this study was to examine the effectiveness of cryogen spray cooling (CSC) in protecting superficial tissue structures during continuous Nd:YAG laser irradiation of an in vivo model hemangioma. METHODS: The highly vascularized chicken comb was selected as the animal model for hemangiomas. The Nd:YAG laser irradiation ranged from 2.6 to 35.1 J/mm2. A feedback system utilizing infrared radiometry monitored the comb surface temperature and controlled delivery time of the cryogen spurt. When comb surface temperature during laser irradiation reached 36-42 degrees C, a 30-100 msec cryogen spurt was delivered. Animals were euthanized 1 hour to 21 days following each experiment. Gross and histologic analyses were performed. RESULTS: Nd:YAG laser irradiation resulted in deep (up to 6.1 mm) tissue photocoagulation, while CSC preserved the overlying epidermis and papillary dermis. CONCLUSION: The results demonstrate that CSC is effective in protecting the epidermis and papillary dermis, while achieving deep tissue photocoagulation during Nd:YAG laser irradiation. Further pilot studies in humans appear warranted.

Aerosols↗
PubMed1997

TEM--minimal invasive therapy of rectal cancer?

The aim of this study is to outline the use of transanal endoscopic microsurgery (TEM) for local excision of rectal carcinoma. Thus the clinical and long-term results regarding endorectal excision of the rectal lesions at the University Hospital of Cologne and Berlin will be presented. During the period July 1983 till December 1993 the system has been employed on 405 cases (17.8% carcinomas) at the University Hospital of Cologne and on 60 cases (20% carcinomas) during the period September 1994 till September 1996 at the University Hospital of Berlin, Charité. Early postoperative complications consisted of intraperitoneal perforations (five cases); rectovaginal fistulas (four cases); haemorrhages (four cases), death due to cardiopulmonary failure (two cases). All the complications occurred within the first 4 years of the learning phase. The cancer-specific 3-year survival rate of patients with "low risk" pT1 cancers amounted to 91%. Two recurrences after local excision of pT1 cancers occurred 1 year postoperatively, which were treated successfully using the TEM system. Most of the histologic findings of the subsequent radical operations following local resections of infiltrative rectal cancers revealed that the carcinoma had already been totally removed. The main indication for TEM is the removal of sessile adenomas. Early rectal carcinomas (pT1) of the "low risk" type, with favourable histological grading (grade 1 and 2) and clinical staging (CS I) were also considered for endorectal therapeutical approach. Even though our initial results do show encouraging results, regarding endorectal excision of pT2 cancers, more experience is needed to clarify the indication for locally amenable pT2 cancers of the "low risk" type and rule out the role of adjuvant therapy after complete excision of these carcinomas. The indication for TEM encloses also confined (< 4 cm) infiltrative cancers (> pT1) in cases where the patient is unwilling to undergo extensive surgery or due to medical reasons. The technique allows accurate endoscopic microsurgical excision of early cancers for cure with minimal morbidity and excellent presentation of specimen for complete histological analysis. Diligent follow-up is mandatory, since most (60-80%) of local recurrences can be treated successfully. Thus demolitive surgery can be avoided in selected cases with rectal cancer.

Adenoma↗
PubMed1997

[Introduction of video endoscopic vascular surgery of the pelvic area].

The fact that operative lethality and other typical postoperative complications following surgical treatment of aortoiliac atherosclerotic disease are mainly related to the surgical trauma (derived from the extensive abdominal incision and dissection), but not to the classical arterial reconstruction itself, has led us to develop a videoendoscopic aortoiliacal surgical method which is supposed to diminish the potential postoperative complications. Thus, a new endoscopic instrument set for vascular surgery has been developed in close cooperation with Aesculap AG Tuttlingen, Germany. After evaluating the basic techniques of videoendoscopic patching and end-to-side anastomosis with the newly designed instruments on a training model (n = 50), the feasibility of videoendoscopic vascular surgery on aortoiliacal vessels was tried out on human corpses (n = 8). The positive results of the initial survey have finally encouraged us to conduct our first series of animal studies on piglets (n = 25). The investigation regarding ultrasonically monitored blood flow in the femoral arteries after videoendoscopic aortofemoral bypass grafting and other systemic, hemodynamic parameters showed positive results. No complications were encountered in any of the standardized animal studies. Favorable activity levels were recorded. Meanwhile we have performed 5 extraperitoneal videoendoscopic aortofemoral artery bypasses in patients with aortoiliac occlusive diseases. One patient in whom we had occluded the inferior mesenteric artery died due to an ischaemic colitis. The other patients had an uneventful postoperative course. The videoendoscopic vascular procedures were carried out according to the rules of conventional vascular surgery. Nevertheless, further experimental research and development of endoscopic instruments have yet to be done, to optimize the new surgical method and to clarify the advantages of videoendoscopic vascular surgery.

Animals↗
PubMed1996

Videoendoscopic vascular surgery on aortoiliac vessels. An experimental study.

BACKGROUND: In order to avoid the postoperative complications following conventional surgical treatment of aortoiliac atherosclerotic occlusive disease, a new concept in videoendoscopic vascular surgery on the infrarenal aortoiliacal artery was created. METHODS: New instruments for endoscopic vascular surgery were therefore developed. Having elaborated the practicability of "videoendoscopic surgery" in four short-term pilot studies in piglets, we performed a standardized acute study in healthy male piglets (32 +/- 2 kg). Blood flow was monitored ultrasonically in the femoral arteries and systemic and hemodynamic parameters were evaluated in all animals. RESULTS: The investigation regarding ultrasonically monitored blood flow in the femoral arteries (four aortofemoral bypasses, four iliac patchplasties) and other systemic, hemodynamic parameters after videoendoscopic vascular reconstruction revealed positive results. The following series of standardized long-term animal experiments revealed that 2-7 weeks after the aortofemoral bypass grafting (n = 5), the animals were all doing well. The angiographic examination showed that the prostheses were patent. CONCLUSIONS: Even though it was possible to carry out the endoscopic vascular method according to the rules of conventional vascular surgery, further experimental research and development of endoscopic instruments have yet to be done in order to optimize the new surgical method. This is the subject of our ongoing long-term animal studies.

Animals↗
PubMed1996

Anomalous pancreatico-biliary junction--report of a new experimental model and review of the literature.

A model of anomalous pancreatico-biliary junction was developed and used to investigate a possible role in the development of choledochal cyst and tumors of the biliary tract. An anastomosis was constructed between an isolated pancreas-duodenal segment and the gallbladder in 20 minipigs, but the results did not show any subsequent dilatation of the biliary tract, although intestinal metaplasia was observed in 20% of the animals. The severity of the epithelial changes was proportional to the duration of the experiment and may represent a premalignant change. A critical review of all reported animal models of anomalous pancreaticobiliary junction also is provided.

Amylases↗
PubMed1996

Clinical evaluation of the therapeutic effectiveness of ethinyl oestradiol and oestrone sulphate on prolonged bleeding in women using depot medroxyprogesterone acetate for contraception. World Health Organization, Special Programme of Research, Development and Research Training in Human Reproduction, Task Force on Long-acting Systemic Agents for Fertility Regulation.

A placebo-controlled randomized clinical trial was conducted in six centres to compare the effects of a 14 day treatment with either 50 micrograms ethinyl oestradiol daily or 2.5 mg oestrone sulphate daily, on depot medroxyprogesterone acetate (DMPA)-induced prolonged bleeding. Out of 1035 women admitted to the study, 278 requested treatment and were given ethinyl oestradiol (n = 90), oestrone sulphate (n = 91) or placebo (n = 97). Ethinyl oestradiol was successful in stopping the bleeding episode in 93% of cases, compared with oestrone sulphate and placebo which had success rates of 76 and 74% respectively. However, the relative advantage of ethinyl oestradiol was marginal, with an average reduction of 1 bleeding day and 3 spotting days compared with the other two groups. Immediately after treatment, women given ethinyl oestradiol had less bleeding but a more unpredictable pattern than the other two groups. In the long term, there were no differences between the bleeding patterns or the discontinuation rates for any reason in the three groups, and the most important single reason for discontinuation in those groups remained 'menstrual problems'. In summary, the study showed that treatment of DMPA-induced prolonged bleeding with ethinyl oestradiol had a limited short-term effect but no beneficial effect on the acceptability of DMPA as a contraceptive method. Treatment with oestrone sulphate was no different from placebo.

Adolescent↗
PubMed1996

Measurement of regional myocardial blood flow in rats by unlabeled microspheres and Coulter channelyzer.

A relatively inexpensive, expeditious, new nonradioactive microsphere method for measuring regional myocardial blood flow (RMBF) was developed with unlabeled microspheres and a Coulter Channelyzer. To validate the efficiency of this method, hearts from rats were perfused ex vivo by retrograde aortic cannulation. Unlabeled microspheres of varying size were injected into a side arm in the aortic cannula or added to blood samples collected from the rats. Microspheres were then recovered from the cardiac tissue and blood samples. It was found that > 97% of perfused microspheres (diam > 9.4 microns) were retained in the myocardium and that 94.8 +/- 2.2% of the trapped microspheres were recovered and counted successfully using a Counter Channelyzer. The percent recovery of microspheres from 2- and 0.5-ml blood samples were 95.4 +/- 2.3 and 95.3 +/- 3.1%, respectively. Blood flow to the anterior and posterior halves of the ventricular free walls and septum were measured in six rats; excellent agreements were found between the results yielded by 10-, 15-, and 20-microns unlabeled microspheres injected simultaneously. The transmural flow gradients in the left ventricular free wall estimated by 10- and 15-microns spheres did not significantly differ from each other. Thus the method developed here provides a new alternative for measurement of RMBF, which currently allows at least three measurements for nontransmural gradient RMBF and at least two measurements for transmural gradient RMBF.

Animals↗
PubMed1996

[Laparoscopic gastrectomy. A case report].

Although laparoscopic techniques in gastric surgery have become an important part of upper gastrointestinal surgery, they are mainly utilized for organ preserving procedures. A standardized technique for laparoscopic gastrectomy has not yet been described in detail. The purpose of this study was to develop a standardized technique for laparoscopic gastrectomy with reconstruction by a stapled termino-lateral esophago-je-junostomy and Roux-en-Y-anastomosis in a cadaver model. The resected stomach was removed through an enlarged trocar incision. The described technique has been successfully performed in one patient with early gastric cancer.

Adenoma, Villous↗
PubMed1996

[10 years experiences with transanal endoscopic microsurgery. Histopathologic and clinical analysis].

The clinical and long-term results encountered from July 1983 to December 1992 are subject of this study. Contrary to other (transanal and transabdominal) surgical treatments the endorectal system permits therapeutic local excisions of large, rectal adenomas and early rectal carcinomas of the "low-risk" type within the entire rectum with minimal morbidity. A superior or comparable rate of adenoma recurrence (4.8%, n = 228) as well as a more favourable operative result (complication rate 3.9%; lethality 0.6%; n = 348) can be achieved with the transanal endoscopic microsurgery. Under palliative conditions, transanal endoscopic surgery is more effective than other conservative treatments in cases of circumscribed, non-stenotic carcinomas of the rectum. Thorough surgical training is required in order to successfully practice transanal endoscopic surgery.

Adult↗
PubMed1996

[Video endoscopic vascular surgery at the pelvic level in the animal experiment: introduction of a new surgical method and development of laparoscopic vascular surgery instruments].

In order to avoid the perioperative complications following conventional surgical treatment of aortoiliac atherosclerotic occlusive disease, taking advantage of the generally favourable postoperative recovery after endoscopic surgery, a new concept of videoendoscopic vascular surgery and new instruments have been developed. Thus a standardized study on human cadavers and piglets was performed successfully finally enabling us to carry out two aortobifemoral arterial bypasses on two patients with iliac occlusive diseases. Even though it was possible to perform the endoscopic vascular method according to the rules of conventional vascular surgery, further experimental research and refinement of endoscopic instruments are still needed to optimize the new surgical method.

Animals↗
PubMed1995

Monoamine oxidase A and B activities in heavy smokers.

There is a strong association between depression and smoking. Because monoamine oxidase (MAO) inhibition leads to antidepressant effect and in vitro studies have shown that cigarette smoke inhibits MAO activity, it is conceivable that smoking may have an antidepressant effect, if smokers have reduced MAO activity. Therefore, we assessed platelet MAO-B activity and plasma concentration of catecholamine metabolites reflecting MAO-A activity in heavy dependent smokers and nonsmokers matched for sociodemographic characteristics. Platelet MAO-B activity, plasma 3,4-dihydroxyphenylglycol, plasma 3,4-dihydroxyphenylacetic acid, and plasma 3,4-dihydroxyphenylalanine concentrations were significantly lower in smokers than in nonsmokers, whereas plasma norepinephrine did not differ. Significantly more smokers reported previous history of depression, manic episode, panic attack, agoraphobia, and simple phobia. Smokers had higher scores (p < 0.001) on the Montgomery-Asberg Depression Rating Scale (MADRS) and the Hamilton Anxiety Scales. It is concluded that the activities of both forms of the MAO are reduced in heavy dependent smokers.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1995

Implantation metastasis of unsuspected gallbladder carcinoma after laparoscopy.

In a 73-year-old woman elective laparoscopic cholecystectomy for symptomatic cholelithiasis had to be changed to open cholecystectomy because of technical problems. Unsuspected microscopic adenocarcinoma of the gallbladder was found after operation. Two months later abdominal-wall metastasis developed at the periumbilical and the right abdominal laparoscopic tract through which the laparoscope and instruments had been introduced and removed. The paramedian abdominal wall incision for the laparotomy was free of tumor.

Abdominal Neoplasms↗
PubMed1995

Transanal endoscopic microsurgery in large, sessile adenomas of the rectum. A 10-year experience.

The clinical and long-term results of 286 cases encountered from 1983 to 1993 in our Department of Surgery regarding the local excision of large, sessile rectal adenomas (> 2 cm2) by the endoscopic surgical method and the influence of this selected series of adenomas on age, sex, size, grade of dysplasia, and architecture are subjects of this study. Histologically proven rectal carcinomas as well as non-neoplastic polyps were excluded from this trial. Early postoperative complications amounted to 3.4%. The 1-year and 5-year recurrence rates +/- SE of adenomas were 1.2 +/- 0.7% and 7.0 +/- 1.9%, respectively. Remarkably, there was no significant relationship between the histological type of the adenoma and the grade of dysplasia nor between the size and grade of dysplasia. However, there was a significant relationship between the size and histological type of the adenoma (P < 0.01). With the endoscopic minimal-invasive system, we are able to achieve a superior rate of recurrence compared to any other local treatment as well as a more favorable operative result compared to extensive surgical procedures.

Adenoma↗
PubMed1995

Elevated numbers of proliferating mononuclear cells in the peripheral blood of psoriatic patients correlate with disease severity.

Although psoriasis is characterized by the accumulation of activated proliferating lymphoid cells in the psoriatic skin lesion, it is not known whether these cells are activated and proliferating before entry into the psoriatic plaque. The current study evaluates the number and phenotype of proliferating lymphoid cells in the blood of psoriatic patients. Proliferation of peripheral blood mononuclear cells was evaluated on cytospun preparations of these cells using autoradiographic techniques after pulsing the mononuclear cells with 3H-methyl thymidine for 2 h. The phenotypes of the labeled peripheral blood mononuclear cells were determined combining autoradiography and immunohistochemistry with monoclonal antibodies directed at CD3, CD4, CD8, CD11c, CD22, and human leukocyte antigen-DR. The data demonstrated elevated numbers of proliferating lymphoid cells in the blood of psoriatic patients compared with normal nonpsoriatic volunteers (p < 0.01). Furthermore, the number of circulating proliferating mononuclear cells increased significantly with increasing psoriasis skin disease severity (correlation coefficient 0.95; p < 0.0001). When the phenotype of the proliferating cells in the blood was examined, the numbers of T cells (CD3+, CD4+, CD8+ cells), B cells (CD22+ cells), monocytes (CD11c+ cells), and human leukocyte antigen-DR+ cells were significantly elevated compared with nonpsoriatic skin (p < 0.01) and increased with increasing disease activity (correlation coefficient range 0.48-0.74; p < 0.05). The data suggest a generalized systemic activation of T, B, and monocytic cells that results in labeling of up to 0.16% of the circulating mononuclear cells with 3H-methyl thymidine (i.e., proliferating and presumably activated) when assayed in vitro.

Cell Division↗
PubMed1995

Vasoactive intestinal peptide and nerve growth factor effects on nerve regeneration.

Sixty rat sciatic nerves were used to study the effects of vasoactive intestinal peptide (VIP) and nerve growth factor (NGF) on nerve regeneration. They were divided into three groups. Groups 1 and 2 were treated with VIP and NGF, respectively, after dividing the nerves without repair and placing them in silastic chambers. Group 3 served a control. The rate and quality of nerve regeneration were compared among the groups using caliper measurements and histologic evaluation. Both VIP and NGF groups showed an enhanced rate of regeneration at three weeks as compared to controls (p < 0.05). The quality of nerve regeneration histologically and by axonal counting was not significantly different among the three groups, except for the presence of less vascularity in the VIP as compared with the NGF group. In addition to NGF, VIP appears to increase the rate of nerve regeneration as compared to controls.

Animals↗