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Biomedical subjects

K Hagen

Publications and source records attributed to K Hagen.

At least 55 records · Page 3Linked to original sources
PubMed1995

Epidermal growth factor receptor and transforming growth factor alpha expression in papillary and nonpapillary renal cell carcinoma: correlation with metastatic behavior and prognosis.

Papillary renal carcinomas are a cytogenetically unique subset of renal carcinomas that have been reported to be clinically less aggressive. We have examined 19 papillary tumors for immunohistochemical expression of the epidermal growth factor receptor (EGF-R) and its ligand, transforming growth factor alpha (TGF-alpha). EGF-R and TGF-alpha expression was also studied in 149 nonpapillary tumors and 7 mixed papillary/solid tumors. EGF-R and TGF-alpha expression were compared to histology, stage, metastatic behavior, and survival. Formalin-fixed, paraffin-embedded nephrectomy specimens collected between 1977 and 1986 were stained with antibodies to EGF-R and TGF-alpha. Patients with papillary tumors were found to present with earlier stage disease and had significantly longer survival. Papillary tumors had a significantly lower rate of EGF-R positivity than solid pattern tumors (21% versus 73%, P < 0.001). Intermediate or strong cell membrane immunoreactivity for EGF-R was associated with high tumor grade and poor disease-specific survival. EGF-R positivity in the primary tumor was associated with the presence of metastatic disease and with metastatic spread to lung versus bone. Tumor parenchymal TGF-alpha staining was present in 50% of the cases and was not associated with stage or grade. Unrelated to tumor parenchymal TGF staining, tumor vessels stained for TGF-alpha in 56% of the cases. Vessel TGF-alpha staining was absent in papillary tumors (P < 0.001). The improved clinical behavior of papillary tumors as compared to nonpapillary renal tumors may be related, in part, to their relatively lower levels of EGF-R expression.

Adult↗
PubMed1994

Immunomodulating activities of cocaine--evaluation of lymphocyte transformation related to other immune functions.

Cocaine dosages ranging from 2.5 mg/kg/day to a highly toxic dose of 50 mg/kg/day were injected intramuscularly or intraperitoneally into different groups of mice for 4-10 days. The effects of cocaine were evaluated by tumor growth, lymphocyte transformation, phagocytosis, and IgM plaque-forming cells. At all dosages, including toxic doses, cocaine does not inhibit lymphocyte transformation of the splenic or the peripheral blood lymphocytes. However, all other immunological parameters of the same animal were suppressed. These results suggest that lymphocyte transformation may not be a proper indicator for the immune status of mice treated with cocaine. The same may be true when testing human drug abusers.

Adjuvants, Immunologic↗
PubMed1993

Comparison of laser phacovaporization using the Er-YAG and the Er-YSGG laser.

OBJECTIVE: To study the interaction of the erbium (Er)-YAG (2.94 microns) and the Er-YSGG (2.79 microns) lasers with the human crystalline lens tissue. METHODS: Fresh human crystalline lens sections were used to measure the photovaporization threshold, rate, and damage zone of the two lasers. RESULTS: We found the photovaporization threshold for the Er-YAG and the Er-YSGG lasers to be 1.4 J/cm2 and 5.5 J/cm2, respectively. At 10 J/cm2, the photovaporization rate is 67.9 microns per pulse for the Er-YAG laser and 18.4 microns per pulse for the Er-YSGG laser. The increased rate of photovaporization as a function of radiant energy for the Er-YAG laser is almost twice that for the Er-YSGG. Damage zones for the Er-YAG laser ranged from 4 to 9 microns compared with 10 to 22 microns for the Er-YSGG. CONCLUSIONS: It is apparent that both lasers can adequately photovaporize human crystalline lens tissue and should be further studied for this purpose.

Cataract Extraction↗
PubMed1993

A prototype erodible mask delivery system for the excimer laser.

PURPOSE: The authors developed an erodible mask delivery system for the argon-fluoride 193-nm excimer laser, which offers the possibility of correcting hyperopia and astigmatism as well as myopia. METHOD: Masks were made of polymethylmethacrylate on a quartz window, with intended corrections for myopia and hyperopia of 2.5 and 5 diopters (D). Ablations using the mask and control ablations using an expanding diaphragm were performed in 30 eyes of 15 pigmented rabbits with an Excimed UV200 laser (Summit Technology, Inc, Waltham, MA). The rabbits were followed for 134 days with regular biomicroscopy and retinoscopic examination by two observers. RESULTS: Ablations with the mask to correct myopia were successful and produced stable corrections, although the higher-power mask produced undercorrections. Hyperopic masks produced paradoxic myopic corrections, possibly due to the lack of a transition zone at the edge of the mask. Corneas ablated with the mask had less sub-epithelial haze than those ablated with the diaphragm at all examinations. Results of histopathologic examination showed epithelial hyperplasia over the ablation zone in all eyes. Dichlorotriazinyl aminofluorescein collagen staining showed subepithelial new collagen in all eyes, but there was no relation between the depth of ablation at any point on the cornea and the amount of new collagen deposited there. CONCLUSIONS: Myopic ablations are feasible with the erodible mask, although additional calibration is needed. Hyperopic ablations were unsuccessful with the current design. Corneas ablated with the mask may be clearer than corneas ablated with the diaphragm, possibly due to a smoother ablated surface. Regression of effect after laser ablation in the rabbit model is likely due more to epithelial hyperplasia than to stromal remodeling.

Animals↗
PubMed1993

Understanding Ehlers-Danlos syndrome.

Ehlers-Danlos syndrome is an inherited condition in which the body produces defective collagen. Manifestations are highly variable, and include numerous skin abnormalities. Nurses play an important role in helping patients and their families live with this unusual disorder.

Activities of Daily Living↗
PubMed1992

Detection of c-erbB-2 activation in paraffin-embedded tissue by immunohistochemistry.

Commercially available monoclonal antibodies were tested for their ability to detect increased levels of c-erbB-2 protein in formalin-fixed, paraffin-embedded breast carcinomas. Of five antibodies studied, four (TAB-250, CB11, 3B5, and N3/D10) showed strong cytoplasmic membrane reactivity in 23% (11 of 47) of routinely processed tumors, although interpretation of the immunoreactivity with 3B5 and N3/D10 occasionally was difficult due to cytoplasmic granular staining. Since the c-erbB-2 oncogene is activated by DNA amplification and overexpression of mRNA and protein, the same tumors were analyzed for c-erbB-2 activation by other techniques. c-erbB-2 activation in these 11 tumors was confirmed by immunohistochemistry of frozen tissue (nine of nine tumors), in situ hybridization (nine of 11 tumors), and Southern blot analysis (five of eight tumors). In some of these tumors the failure to demonstrate c-erbB-2 DNA amplification may be due to the small percentage of malignant cells. One additional tumor showed probable c-erbB-2 protein overproduction based on strong immunoreactivity with two antibodies (TAB-250 and CB11), although no definite activation could be demonstrated by additional techniques. Three other tumors (6%) showed equivocal c-erbB-2 protein overproduction based on weak immunoreactivity only with TAB-250, although unequivocal activation could not be demonstrated by additional techniques. The 32 carcinomas (68%) that showed no significant immunoreactivity with any antibodies in routinely processed tissue also showed no detectable c-erbB-2 activation by additional techniques. We conclude that TAB-250 and CB11 are reliable antibodies for detecting c-erbB-2 protein overproduction in routinely processed tissue. TAB-250 also weakly stains a few tumors showing no definite c-erbB-2 activation by other techniques. Two additional antibodies (3B5 and N3/D10) detect c-erbB-2 protein overproduction in paraffin-embedded tissue, but are more difficult to interpret. A fifth antibody, TA-1, is an excellent reagent for use on frozen tissue, but prolonged formalin fixation may impair recognition of its antigenic epitope.

Adenocarcinoma↗
PubMed1992

The thromboprophylactic effect of a low-molecular-weight heparin (Fragmin) in hip fracture surgery. A placebo-controlled study.

A prospective, randomized, double-blind trial concerning thromboprophylaxis in 82 patients in whom hip fracture surgery was performed was conducted to compare a new low-molecular-weight heparin (Fragmin) with placebo. Deep venous thrombosis (DVT) was detected by 125-I-fibrinogen uptake test followed by ascending phlebography when positive. Sixty-eight patients completed the study, and a 50% reduction in the incidence of DVT was demonstrated: nine of 30 patients in the treatment group (30%) and 22 of 38 patients in the placebo group (58%) developed DVT. This significant difference was achieved by one daily dose of 5000 IU Fragmin subcutaneously, commenced preoperatively and continued for six days. There were no differences in bleeding or other complications in the two groups. Fragmin given once daily offers an effective and safe thromboprophylaxis in hip fracture surgery.

Aged↗
PubMed1991

Thromboprophylaxis by low-molecular-weight heparin in elective hip surgery. A placebo controlled study.

In a double-blind, randomised study of thromboprophylaxis in patients undergoing total hip replacement, we compared a low-molecular-weight heparin with a placebo. Of the 120 patients enrolled, 112 completed the trial; 58 in the treatment group and 54 in the placebo group. Nine (16%) patients in the treatment group and 19 (35%) in the placebo group developed deep venous thrombosis, diagnosed by the 125I-fibrinogen uptake test (p < 0.02). Verification was obtained by phlebography in 86% of the patients. Prolonged surgery increased the risk of thrombosis in the placebo group but not in the treatment group (p < 0.05). There were significantly more cases of deep venous thrombosis in the placebo group during the first four postoperative days (p < 0.02). The groups did not differ with respect to peroperative and postoperative bleeding. Low-molecular-weight heparin offers safe and easily administered thromboprophylaxis in total hip replacement.

Adult↗
PubMed1990

[Decompression of the carpal tunnel. Apropos of 16 reoperated cases].

The aim of surgery is the healing of disease, and also the preservation or even the reconstruction of the function of an anatomical structure. In 12 out of 16 second look operations after carpal tunnel release we found luxation or subluxation of the intracarpal content. This suggests that the instability created by surgical release of the retinaculum flexorum is an important factor in postoperative symptoms. Therefore we suggest replacing the lengthwise incision of the retinaculum flexorum by widening of this structure. This serves to enlarge the carpal tunnel without forfeiting the function of the retinaculum flexorum. It acts as a pulley, serves as an anchor to the thenar muscles, and allows mechanical protection to the underlying nerve. The satisfactory results obtained after secondary functional reconstructive surgery suggest the same principle should be applied at the first operation.

Adult↗
PubMed1990

Aldicarb immunotoxicity: functional analysis of cell-mediated immunity and quantitation of lymphocyte subpopulations.

Adult female B6C3F1 mice received distilled water only or water containing 1.0, 10, or 100 ppb of aldicarb daily for 34 days. The target concentration of aldicarb present in the 100 ppb dosing solution was analytically verified. To further develop an immune profile of this compound, following aldicarb exposure, the ability of splenic natural killer cells and specifically sensitized cytotoxic T-lymphocytes to lyse YAC-1 lymphoma and P815 tumor cells, respectively, was evaluated. To supplement the functional assays, the impact of aldicarb exposure on the percentages and absolute numbers of total T-cells, T-suppressor, T-helper, and B-cells was evaluated. The absence of statistically significant effects on any of these parameters supports earlier reports that aldicarb does not result in adverse effects on the immune system of mice.

Aldicarb↗
PubMed1990

Periodontal repair in dogs: effect of saliva contamination of the root surface.

This study evaluated whether periodontal repair following reconstructive surgery may be compromised by saliva contamination of the root surfaces during the surgical procedure. Circumferential periodontal defects, 5 to 6 mm in vertical dimension, were surgically created in the mandibular premolars in 9 beagle dogs and immediately treated. The denuded root surfaces in left and right jaw quadrants in 4 dogs were treated with either filter sterilized saliva or saline, while in the remaining 5 dogs the root surfaces were treated with unfiltered saliva or saline. The wounds were closed and allowed to heal for 4 weeks. The dogs were sacrificed and tissue blocks prepared for histometric analysis. Results showed no difference between teeth treated with filtered or unfiltered saliva and the saline treated controls. Connective tissue repair to the root surfaces exceeded 70% of the defect height in all experimental groups. Regeneration of cementum and alveolar bone was limited and did not exceed 30% of the defect height. The results indicate that contamination of the root surface by saliva during the surgical procedure does not necessarily compromise connective tissue repair to the root surface.

Alveolar Bone Loss↗
PubMed1990

[Recurrent carpal tunnel syndrome. Problems and treatment].

Of 16 patients surgically treated for recurrent carpal tunnel syndrome, 60% demonstrated some degree of palmar subluxation or even luxation of the median nerve and flexor tendons intraoperatively, subsequent to previous simple division of the flexor retinaculum. During the past years, therefore, we have been performing a widening Z-plasty and reconstruction of the flexor retinaculum for surgical treatment of primary or recurrent carpal tunnel syndrome. In this paper, we present and discuss our operative technique and results.

Adult↗
PubMed1989

Intramuscular lipoma of the lower limb. Long-term follow-up after local resection.

We report 12 patients with infiltrating muscular lipomas of the lower limbs all treated by wide resection. During follow-up averaging seven years, the tumour recurred in five patients. Our results and those reported by others suggest that, in order to avoid recurrence, this tumour, although benign, should be treated by total excision of the muscle or by compartmental resection. Hormonal imbalance was suspected in 9 of the patients but an oestrogen receptor analysis of the histological samples proved negative.

Adult↗
PubMed1988

Correlation between concentrations of magnesium, zinc, and potassium in plasma, erythrocytes and muscles.

In 93 patients, consecutively subjected to laparotomy, we studied the correlation between concentrations of magnesium, zinc and potassium in plasma, erythrocytes and muscle tissue. Sixteen percent had hypomagnesemia, 27% hypozincemia, and 53% hypokalemia. There was no difference with regard to the concentration of magnesium and zinc in erythrocytes or in muscle tissue between patients with low and patients with normal/high plasma concentrations of these minerals. Potassium concentration per liter erythrocytes was slightly but significantly higher in patients with hypokalemia than in patients with normal plasma potassium. When expressed per mmol haemoglobin there was, however, no difference in erythrocyte potassium between these two groups. Neither did they differ with regard to potassium concentration in muscles. There was a highly significant correlation between the concentrations of magnesium, zinc and potassium in erythrocytes as well as in muscle tissue, and a significant correlation between magnesium and potassium in plasma. However, no correlation was found between the mineral concentrations in plasma, erythrocytes and muscles, neither for magnesium, nor for zinc or potassium. We therefore conclude that a valid test to estimate total body stores of these minerals cannot be based on analysis of erythrocytes.

Abdominal Muscles↗
PubMed1988

Paget's disease of the anal margin.

A follow-up study of 22 patients with Paget's disease of the anal margin was conducted to determine the prevalence of invasive disease and coexisting visceral carcinomas, cure and survival rates. Seventy-three per cent of the patients suffered from persistent pruritus ani. Seven (32 per cent) patients had malignancy (invasive Paget's disease (n = 5) and coexisting visceral carcinoma (n = 2] and six (27 per cent) developed malignancy (invasive Paget's disease (n = 4) and coexisting visceral carcinoma (n = 2] during follow-up, giving an overall occurrence of malignancies of 59 per cent (95 per cent confidence limits: 36-79). The median follow-up period was 9 (range 0.5-25) years. No difference in length of history could be found between patients with or without malignancy. The estimated cure rate by actuarial analysis among radically treated patients was 64 per cent (95 per cent confidence limits: 43-91) at 1 year and 45 per cent (95 per cent confidence limits: 18-72) at 8 years after primary treatment. The 5- and 10-year crude survival rates of 54 per cent and 45 per cent, respectively, were significantly lower than the corresponding values of 84 per cent and 60 per cent for the normal population (P less than 0.01). Patients with persistent pruritus ani and a perianal skin lesion should be biopsied frequently. If Paget's disease is diagnosed, physical examination of the patient and anorectal region must be done carefully and repeatedly.

Aged↗
PubMed1988

Adenocarcinoma of the anal ducts. A series of 21 cases.

The records of 21 patients treated for adenocarcinoma of the anal ducts between 1943 and 1982 were reviewed. The patients were followed until death or current status in April 1987. The median follow-up period was eight months (range, 3 to 144 months). Fifteen patients had an erroneous diagnosis made at first physician visit resulting in a median doctor's delay of 14 months (range, 3 to 24 months) before correct treatment was carried out. Nine of the tumors were localized perianally (ischiorectal space), seven anally, and five in a fistula-in-ano. Tumors localized anally were significantly smaller and had a significantly shorter history than perianally or fistula-in-ano localized tumors (P less than .05 for each localization). Three patients with anal tumors had their diagnosis made accidentally by routine histologic examination of an excised hemorrhoid. First examination revealed distant metastases in 13 patients and follow-up examination revealed regional or distant metastases in seven patients. Modes of treatment were wide local excision (N = 3), abdominoperineal resection (N = 3), colostomy (N = 9), and radiotherapy (N = 2). Twenty of the 21 patients died within 18 months due to the cancer. One long-term survivor was observed; the patient was alive 12 years after local excision of the tumor without evidence of recurrent disease. The crude five- and 10-year survival was only 4.8 percent.

Adenocarcinoma↗