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Biomedical subjects

S Said

Publications and source records attributed to S Said.

At least 19 recordsLinked to original sources
PubMed1997

Nd:YAG laser irradiation in conjunction with cryogen spray cooling induces deep and spatially selective photocoagulation in animal models.

Successful laser treatment of haemangiomas requires selective photocoagulation of subsurface targeted blood vessels without thermal damage to the overlying epidermis. We present an in vivo experimental procedure, using a chicken comb animal model, and an infrared feedback system to deliver repetitive cryogen spurts (of the order of milliseconds) during continuous Nd:YAG laser irradiation. Gross and histologic observations show deep-tissue photocoagulation is achieved, while superficial structures are protected from thermal injury due to cryogen spray cooling. Experimental observation of epidermis protection in chicken comb animal models suggests selective photocoagulation of subsurface targeted blood vessels for successful treatment of haemangiomas can be achieved by repetitive applications of a cryogen spurt during continuous Nd:YAG laser irradiation.

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↗
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↗
PubMed1994

[Laparoscopic appendectomy. A review of the literature].

Laparoscopic methods are becoming increasingly popular in surgery. In the course of a review concerning laparoscopic appendectomy undertaken up to 31 December 1993 all publications were evaluated by computer-assisted research. Out of a total of 90 publications only 14 deal with the comparison of the laparoscopic versus open appendectomy. Two prospective randomized studies are published. Because of the low number of patients the evaluation of the laparoscopic method is not yet definite.

Adolescent↗
PubMed1994

Blood coagulation, fibrinolytic, and inhibitory proteins in end-stage renal disease: effect of hemodialysis.

Patients with end-stage renal disease (ESRD) are at risk of ischemic cardiovascular complications and vascular thrombosis. These observations prompted the present survey of the blood coagulation, fibrinolytic, and inhibitory proteins in a group of 31 ESRD patients and 32 normal controls. Immunologic and functional assays were used to quantitate plasma antigen concentrations and/or functional activities of factors XII, XI, IX, VIII, VII, X, II, and XIII, von Willebrand factor, fibrinogen, fibronectin, high molecular weight kininogen, D-dimer, antithrombin III, protein C, protein S, plasminogen, tissue-type plasminogen activator, plasminogen activator inhibitor, alpha 2-antiplasmin, alpha 1-antitrypsin, and alpha 2-macroglobulin as well as antiplasmin activity. The coagulant activities of factors XII, IX, X, and II were significantly reduced in ESRD patients despite their normal or increased plasma antigen concentrations. In addition, the ESRD patients showed hyperfibrinogenemia and significant elevations of plasma concentrations of D-dimer, von Willebrand factor, factor VII, and factor XIII antigens. They also exhibited significant reductions of antithrombin III, free protein S, plasminogen, and tissue-type plasminogen activator concentrations. Despite ultrafiltration, plasma factor IX activity and von Willebrand factor and fibrinogen concentrations decreased after hemodialysis with little or slight changes in other measured parameters. The ESRD patients studied here exhibited numerous abnormalities of coagulation, fibrinolytic, and inhibitory proteins at multiple levels. These abnormalities may be involved in the pathogenesis of cardiovascular complications and vascular thrombosis in this population. The precise mechanism(s) and clinical significance of the observed abnormalities are unknown and await further investigation.

Antithrombin III↗
PubMed1994

Adynamic bone disease in patients with uremia.

Adynamic (or aplastic) bone disease is a bone histologic pattern characterized by decreased bone formation rate, low cellularity, and normal or decreased osteoid thickness. It was first described in symptomatic patients undergoing dialysis who were overloaded with aluminum because of contaminated dialysate or chronic ingestion of aluminic phosphate binders; the evidence of the overload was extensive coloration (more than 25%) with aurin tricarboxylic acid, whereas the Perls stain coloration for iron was negative. We have, however, reported these histologic changes in asymptomatic patients with uremia who were never exposed to aluminum, in two patients before end-stage renal failure and in six patients undergoing dialysis. The main step in the prevention of adynamic bone disease is the absolute exclusion of aluminum exposition even by so-called "safe doses" of aluminum phosphate binders because in the long term they are never actually safe. Because idiopathic adynamic bone disease may nevertheless occur, parathyroid hormone suppressive treatment by oral calcium taken with meals as phosphate binders (+/- 1 alpha-hydroxyvitamin D3 derivatives) should be carefully monitored by measurements of plasma concentrations of not only calcium and phosphate but also of intact parathyroid hormone levels. In order to have normal bone formation rate levels, patient intact parathyroid hormone levels should be between one and three times the upper limit of the normal level. Although adynamic bone disease may not be a true bone disease when not due to aluminum, it is a risk factor for increased incidence of hypercalcemia and hyperphosphatemia and therefore for metastatic calcifications. Therefore, when hypercalcemia occurs with hyperphosphatemia and normal intact parathyroid hormone in patients treated with 1 alpha-hydroxyvitamin D3, it is proposed that the latter drug should be discontinued first, whereas oral calcium is increased to correct hyperphosphatemia, and calcium concentration is decreased in the dialysate to prevent hypercalcemia, even though plasma parathyroid hormone may increase up to three times the upper limit of the normal level. In patients previously exposed to aluminum, a deferoxamine test should be performed and a deferoxamine treatment started if the test is positive.

Aluminum↗
PubMed1994

Minimal invasive surgery in the local treatment of rectal cancer.

At the Surgical Department of the University of Cologne, a system has been developed for transanal endoscopic surgery, which allows all the conventional surgical techniques within the rectal cavity. The clinical and long-term results regarding local excision of broad based adenomas and small (< 4 cm) carcinomas of the rectum were the subject of the study. The main indication was the removal of sessile adenomas. Early rectal carcinomas with favourable histological grading (Grade 1 and 2) and staging (Mason I and II) were also suitable for endorectal therapeutical approach. Infiltrative cancers can be removed endoscopically in one session, but the authors performed local excisions of these cancers only in cases where the patient was unwilling to undergo extensive surgery or due to medical reasons. Nevertheless several Dukes B carcinomas were removed locally. Most of the histological findings of the subsequent radical operations (rectum resection, rectum extirpation) revealed that the carcinoma had already been totally removed. During the period July 1983 to December 1992, the techniques have been employed on 313 patients in 348 cases. Early postoperative complications consisted of intraperitoneal perforations (five cases); rectovaginal fistulae (four cases); haemorrhages (four cases), death due to cardiopulmonary failure (two cases). All the complications occurred within the first three years of the learning phase. The recurrence rate of adenomas amounted to 5%. The technique allows accurate endoscopic microsurgical excision of giant adenomas and early cancers with minimal morbidity and excellent presentation of specimens for complete histological analysis. Open invasive surgery can thus be avoided.

Adenoma↗