Biomedical subjects

J Falk

Publications and source records attributed to J Falk.

At least 19 recordsLinked to original sources

PubMed2005

[Traumatic partial amputation of a penis--a reconstruction of the circumstances of the accident].

A 61-year-old man was admitted to hospital with a partially severed penis. The head of the penis (glans) had been completely severed, and the skin of the shaft and the corpora cavernosa had been ripped open. In the hospital the patient reported that his penis got caught in the hose attachment of an old Kobold vacuum cleaner that he was using to inflate an air mattress. He later made contradictory statements in his report to the insurance company, so we were asked to reconstruct the circumstances of the accident. The literature available to us only makes clinical observations about similar accidents, always with the assumption that the vacuum cleaner was used during masturbation or in order to achieve an erection. According to our reconstruction of the accident and an investigation of the vacuum cleaner attachment, however, we could not rule out the possibility of a household accident as described by the patient.

Accidents, Home↗

PubMed2000

[Smoking habits and attitude toward tobacco use among health professionals in Denmark in 1996].

The purpose of the study was to investigate smoking habits in different groups of health professionals. A total of 7844 were interviewed using postally distributed questionnaires. The response rate was 85%. The study showed a much lower smoking prevalence among groups of health professionals compared to the normal population apart from social assistants and hospital porters, where the smoking rate was even higher than in the Danish population. Among medical doctors, dentists, nurses and midwives the smoking rate had decreased faster from earlier investigations than among the Danish population. Future strategy in Danish policy concerning campaigns in the population and among health professionals as role-models is discussed. Fifty-two percent of the interviewed agreed that health professionals should not smoke, while on duty, but with quite big differences between the groups (min. 31% among hospital porters, max. 73% among dentists).

Attitude of Health Personnel↗

PubMed2000

Isolation of endothelial cells and their progenitor cells from human peripheral blood.

PURPOSE: We have developed techniques to isolate endothelial cell (EC) progenitors from human peripheral and umbilical cord blood. METHODS: Human adult peripheral and umbilical cord blood monocytes were isolated by centrifugation, and progenitor cells were separated with the use of magnetic polystyrene beads that were coated with a monoclonal antibody specific for the CD34 cell-membrane antigen. Cells were propagated in selective media, and developing cultures were immunostained for CD31, CD34, factor VIII, and vascular endothelial growth factor cell receptors. ECs that developed were transfected with a gene for prourokinase and used to line ePTFE grafts, which were evaluated in vitro in a pulsatile flow system. RESULTS: Umbilical cord monocyte cultures demonstrated colonies that resembled ECs at approximately 2 weeks, with growth being best supported by EC growth media plus 20% calf serum with iron. Immunostaining of colonies was positive for CD31 and factor VIII. After 18 days in culture, CD34(+) cells from adult peripheral blood were noted, which had the typical cobblestone appearance of ECs and immunostained positively for CD31 and factor VIII-related antigens. Cultures of umbilical cord-derived cells and adult peripheral blood-derived cells developed complex line formations within 1 week in culture that stained positively for vascular endothelial growth factor receptor-2. Urokinase-transfected ECs were shown to overexpress urokinase. Prosthetic grafts lined with transfected cells showed 87.33% +/- 4.97% cell adherence after 2 hours in a pulsatile flow system at clinically relevant shear stress. CONCLUSION: We conclude that endothelial progenitor cells can be isolated from human adult peripheral and umbilical cord blood and developed into EC cultures as a source of cells for vascular graft seeding and gene therapy.

Adult↗

PubMed2000

The eye irritation and odor potencies of four terpenes which are major constituents of the emissions of VOCs from Nordic soft woods.

Eye goggles were used to estimate human thresholds for sensory eye irritation from four monoterpenes: (+)3-carene, (-)limonene and (+)alpha-pinene and (rac)alpha-terpineol all known as air pollutants emitted from wood. Only a ranking of the irritation thresholds relative to that of n-butanol is given. The measurements showed that the thresholds for eye irritation of the terpenes ranged from subthreshold to below 1,250 mg/m3. It appears that the irritation of 3-carene and limonene in contrast to the expectations was of the same size as or less than that of n-butanol. Too few subjects reported eye-irritation for alpha-pinene and alpha-terpineol to allow estimates of thresholds of these compounds which therefore have much less irritative potency than n-butanol, 3-carene, and limonene. The measurements of one terpene alcohol do not support the hypothesis that monoterpene alcohols, would have lower eye irritation threshold than monoterpene hydrocarbons. The sequence from strongest odorant to weakest was alpha-terpineol, 3-carene, n-butanol, limonene and alpha-pinene. In conclusion, the tested terpenes can probably be ruled out as cause of acute eye irritation indoors. The measured odor thresholds did not deviate from the few values reported in the literature.

Air Pollution, Indoor↗

PubMed1999

The Dysphagia Outcome and Severity Scale.

The Dysphagia Outcome and Severity Scale (DOSS) is a simple, easy-to-use, 7-point scale developed to systematically rate the functional severity of dysphagia based on objective assessment and make recommendations for diet level, independence level, and type of nutrition. Intra- and interjudge reliabilities of the DOSS was established by four clinicians on 135 consecutive patients who underwent a modified barium swallow procedure at a large teaching hospital. Patients were assigned a severity level, independence level, and nutritional level based on three areas most associated with final recommendations: oral stage bolus transfer, pharyngeal stage retention, and airway protection. Results indicate high interrater (90%) and intrarater (93%) agreement with this scale. Implications are suggested for use of the DOSS in documenting functional outcomes of swallowing and diet status based on objective assessment.

Adult↗

PubMed1999

NrCAM, cerebellar granule cell receptor for the neuronal adhesion molecule F3, displays an actin-dependent mobility in growth cones.

The neuronal adhesion glycoprotein F3 is a multifunctional molecule of the immunoglobulin superfamily that displays heterophilic binding activities. In the present study, NrCAM was identified as the functional receptor mediating the inhibitory effect of F3 on axonal elongation from cerebellar granule cells. F3Fc-conjugated microspheres binding to neuronal growth cones resulted from heterophilic interaction with NrCAM but not with L1. Time-lapse video-microscopy indicated that F3Fc beads bind at the leading edge and move retrogradely to reach the base of the growth cone within a lapse of 30-60 seconds. Such velocity (5.7 microm/minute) is consistent with a coupling between F3 receptors and the retrograde flow of actin filaments. When actin filaments were disrupted by cytochalasin B, the F3Fc beads remained immobile at the leading edge. The retrograde mobility appeared to be dependent on NrCAM clustering since it was induced upon binding with cross-linked but not dimeric F3Fc chimera. These data indicate that F3 may control growth cone motility by modulating the linkage of its receptor, NrCAM, to the cytoskeleton. They provide further insights into the mechanisms by which GPI-anchored adhesion molecules may exert an inhibitory effect on axonal elongation.

Actins↗

PubMed1999

Adenocarcinoma of the pancreatic head: a community teaching hospital's experience from 1982 to 1992.

The treatment of adenocarcinoma of the pancreatic head remains variable, with multiple therapeutic options including surgery, biliary stenting, chemotherapy, and radiation therapy. We retrospectively reviewed our experience from 1982 through 1992, which included 160 patients with this diagnosis, evaluating their treatments and outcomes. There were 66 males and 94 females, with a mean age of 70+/-11 years. Forty patients (25%) had no surgery; of these, 27 had no further treatment, whereas 13 received chemotherapy and/or radiation therapy (CT/RT). Of 120 patients who had surgical exploration, only 19 (16%) were resectable for a potential cure. Eleven of these resected patients had no additional therapy, whereas 8 patients received adjuvant CT/RT. Of the 101 unresectable patients, 62 had no further therapy and 39 received CT/RT. Twenty-two patients (14%) had biliary stents placed, 11 in lieu of surgery, 7 preoperatively, and 4 postoperatively. Perioperative mortality was no different for resectable patients (16%) versus unresectable patients (14%). Overall, 90 patients (56%) had one or more complications related to their disease or treatment, with no differences between groups. Median survivals were as follows: no treatment, 1 month; no surgery with CT/RT, 3.5 months; unresectable with no further treatment, 4 months; unresectable with CT/RT, 8 months; resection with no additional treatment, 17 months; and resection with CT/RT, 13 months. Patients with resectable disease had a significantly longer survival than patients who had no surgery (P < 0.001) or who were unresectable at exploration (P < 0.001); the addition of CT/RT after resection had no effect on survival (P = 0.8). The addition of CT/RT significantly increased survival for patients who had no surgery (p = .001) and for patients who were explored but were unresectable (p = .002). In conclusion, despite dismal results, surgery remains the mainstay of treatment for adenocarcinoma of the pancreatic head. Although CT/RT did not increase the median survival after resection, it doubled the median survival after noncurative surgery.

Adenocarcinoma↗

PubMed1998

Improved adherence of genetically modified endothelial cells to small-diameter expanded polytetrafluoroethylene grafts in a canine model.

PURPOSE: A significant limitation to using genetically modified endothelial cells (ECs) to seed prosthetic grafts before implantation has been poor cell adherence to the graft lumen. Methodologic changes to improve cell adherence were evaluated in a canine carotid interposition graft model using 4 mm interior diameter expanded polytetrafluoroethylene. METHODS: ECs harvested from external jugular veins were grown in culture, with 80% of the cells from each culture transduced by incubation with an LXSN-type retroviral vector carrying a gene for human prourokinase and a neomycin resistance gene for selection in antibiotic G418. Control grafts had passive luminal coating with fibronectin and were seeded with transduced ECs immediately after G418 selection; these grafts were incubated for 2 days before implantation. Experimental grafts had fibronectin forcefully squeezed through the interstices and were seeded with ECs that had recovered in culture for 5 days after G418 selection; these grafts were incubated for 4 days before implantation. For each control (n = 9) and experimental (n = 12) graft, a graft prepared in the same fashion but seeded with the remaining autologous nontransduced cells was placed in the contralateral carotid artery. Grafts were explanted after 30 days and were evaluated for patency, thrombus-free surface area, and cell-free surface area. RESULTS: No significant differences in patency rates were seen between any groups. The thrombus-free surface area was improved for experimental grafts (90%) compared with control grafts (76%), but this improvement did not achieve statistical significance. The cell-free surface area for transduced cells on experimental grafts was 65% compared with 96% for control grafts (p = 0.021) and was comparable with that for nontransduced cells on both control grafts (62%) and experimental grafts (51%; p = 0.201). CONCLUSIONS: Adherence of genetically modified endothelial cells to small-diameter expanded polytetrafluoroethylene grafts in an in vivo physiologic flow model is significantly improved when cells have a more prolonged recovery from G418 selection, when the graft lumen is more uniformly coated with fibronectin before EC seeding, and when seeded grafts are left longer in culture before implantation to develop cell lining stability. The short-term patency rate of these seeded grafts is not affected by increased cell retention; long-term graft patency data and luminal healing require further evaluation.

Animals↗

PubMed1996

Transcriptionally active chromosomes (TACs) of barley chloroplasts contain the alpha-subunit of plastome-encoded RNA polymerase.

Transcriptionally active chromosomes (TACs) were isolated from mature chloroplasts of barley, from proplastids enriched in basal segments of barley primary foliage leaves, and from ribosome-deficient plastids of heat-bleached barley leaves. Immunological analysis with a specific antibody raised against the plastid rpoA gene product revealed that chloroplasts contain an immunoreactive protein of 38 kDa in the TAC fraction which appears to be identical to the alpha-subunit contained in the soluble RNA polymerase (sRNAP) fraction of the same chloroplasts. However, only traces of immunoreactive protein were detected in a TAC preparation derived from "proplastids". A positive correlation could be demonstrated between transcriptional activity and the amount of immunoreactive 38-kDa protein by analyzing different TAC fractions eluting at different times during gel filtration of a standard TAC preparation as well as in TAC preparations obtained under various detergent conditions.

Chloroplasts↗

PubMed1996