Biomedical subjects

A Behrens

Publications and source records attributed to A Behrens.

At least 37 records · Page 2Linked to original sources

PubMed2000

Occurrence of precursors of regular tricyclopolyprenoids in recent sediments

[structure: see text] Two novel C24 tricyclic alkenes of the cheilanthane series have been isolated from the solvent extract of a sulfur-rich recent sediment and their structures determined by NMR studies. They represent the first example of functionalized tricyclic hydrocarbons structurally related to the tricyclopolyprenanes widespread in ancient sediments and petroleum identified in recent sediments.

Journal Article↗

PubMed2000

Inhibition of rabbit keratocyte and human fetal lens epithelial cell proliferation by retrovirus-mediated transfer of antisense cyclin G1 and antisense MAT1 constructs.

The aim of this study is to evaluate the potential of gene transfer of cell cycle control genes as treatment of corneal haze or secondary cataract formation. The guiding hypothesis is that strategic modulation of the cyclin G1 or MAT1 gene by retrovirus-mediated gene transfer will inhibit proliferation of rabbit keratocytes (RabK) and fetal human lens epithelial (FHLEpi) cells in vitro. RabK and FHLEpi cell cultures were transduced in triplicate with retroviral vectors bearing either a nuclear-targeted beta-galactosidase, an antisense cyclin G1 (aG1), an antisense MAT1 (aMAT1) construct, or the neo(r) gene. The presence of beta-galactosidase activity in the transduced cultures was detected by immunohistochemical X-Gal staining, while cyclin G1 and MAT1 protein expression levels were evaluated by Western analysis. Proliferation of RabKs and FHLEpi cells was analyzed by counting the number of cells in the aG1 and aMAT1 vector-transduced cultures over 5 days. The mean transduction efficiency was 34.4% (SD 1.41) for RabKs and 19.7% (SD 1.83) for FHLEpi cells. Downregulation of cyclin G1 and MAT1 protein expression was noted 24 hr after transduction of RabK cultures with the respective vectors. Cytostatic effects of the aG1 and aMAT1 vectors in both RabKs and FHLEpi cells were most pronounced on the fifth day (RabKs, p < 0.0007; FHEpi cells, p < 0.001). An increased incidence of apoptosis was identified in both aG1 and MAT1-transduced FHLEpi cells. Taken together, these data suggest the potential utility of developing aG1 and aMAT1 retroviral vectors in gene therapy protocols for corneal haze and secondary cataract formation.

Animals↗

PubMed2000

Thermal load of laser aperture masks in nonmechanical trephination for penetrating keratoplasty with the Er:YAG laser: comparison between stainless steel and ceramic masks.

PURPOSE: Thermal effects on the laser aperture mask may play a major role in the thermal loading of the cornea during nonmechanical trephination in penetrating keratoplasty. The purpose of this study was to assess the temperature increase on the laser mask using the 2.94-microm Er:YAG laser in order to find suitable parameters for avoidance of thermal damage to the cornea. METHODS: Thermal load measurements were performed on donor (7.5 mm trephination diameter, 0.7 mm thickness, central hole 3.0 mm) and recipient (7.5 mm trephination diameter, 0.7 mm thickness, outer diameter 13.0 mm) aperture masks. The masks were either mounted on a thermal isolator or fixed directly on porcine corneal samples. Temperature increase was measured either under static conditions in the ablation area (setup 1) and at the opposite side of the mask (setup 2) or in the ablation area under dynamic conditions, rotating the whole globe to simulate a constant trephination speed with the mask positioned directly on a porcine cornea (setup 3). We used the NWL Er:YAG solid-state laser in a 1.3-mm free-running spot mode focused on the trephination margin (half of the beam on the mask and half of it on the cornea) with a pulse energy of 200 or 400 mJ and 18CrNi10 stainless steel versus three different types of ceramic masks (silicium carbide, silicium nitrite, aluminum oxide). Temperature was assessed using an infrared pyrometer with automatic data acquisition software for a personal computer. RESULTS: Overall, the temperature rise ranged between 43.6 K (metal donor mask at the trephination area with 400 mJ pulse energy) and 3.3 K (silicium carbide recipient mask at the opposite side of the mask with 200 mJ pulse energy). With all setups and both energy levels, the heating of the metal mask was significantly higher (P<0.02) than the heating of the three types of ceramic masks. The silicium carbide masks revealed the lowest temperature rise. Comparing the three setups, the temperature rise was maximal under static conditions in the ablation area and minimal at the opposite side, with the dynamic setup ranging in between. Temperature rise was significantly greater (P<0.04) in donor masks than in recipient masks for each mask material and both energy levels. CONCLUSION: The physical characteristics of silicium carbide masks seem superior to those of metal masks with regard to minimizing the thermal load of the epithelium or superficial stroma during Er:YAG laser trephination of the cornea for penetrating keratoplasty.

Animals↗

PubMed2000

Experimental evaluation of two current-generation automated microkeratomes: the Hansatome and the Supratome.

PURPOSE: To compare flap dimensions, cut quality, and blade deterioration after reuse in an experimental setting using two current-generation microkeratomes for laser-assisted in situ keratomileusis. METHODS: Two pivoting-head principle microkeratomes, the Hansatome and the Supratome, were used to perform a corneal flap in 50 freshly enucleated pig cadaver eyes, with an intended thickness of 160 microm. Provided stainless steel blades were used from one to five times. Flap diameter was measured by planimetry and thickness calculated using ultrasonic pachymetry at three different locations. Scanning electron microscopy of stromal beds and blades' cutting edges were performed to assess the cut and blade deterioration after repeated use. RESULTS: Mean flap central thickness (Hansatome/Supratome) was 151 microm (SD 18)/192 microm (SD 32). Progressive thinning/thickening of the flap was observed in the direction toward the hinge (P = .003/P = .021). Mean vertical flap diameters of 8.9 mm (SD 0.3)/8.0 mm (SD 0.4) differed significantly (P = .001). No correlation was found between thickness and diameter (r = 0.03, P = .935/r = 0.12, P = .603). At scanning electron microscopy, smooth cuts were observed with both keratomes using a new blade. Periodical chatter lines at keratectomy edge were present and were more pronounced after blade reuse. Cut quality, blade deterioration, and small tissue remnants on the blade surface were noted with repeated blade use, especially using the Supratome. CONCLUSIONS: Local flap thickness and flap diameter variations are inherent to the instrument used. Comparable cut-surface quality can be obtained with new blades. Although cut and blade deterioration appears to be minor after two reuses, the presence of tissue remnants on the blade surface still limits its reuse.

Animals↗

PubMed2000

Synthesis and reactivity studies of model complexes for molybdopterin-dependent enzymes.

The molybdenum cofactor (Moco)-containing enzymes are divided into three classes that are named after prototypical members of each family, viz. sulfite oxidase, DMSO reductase and xanthine oxidase. Functional or structural models have been prepared for these three prototypical enzymes: (i) The complex [MoO2(mnt)2]2- (mnt2- = 1,2-dicyanoethylenedithiolate) has been found to be able to oxidize hydrogen sulfite to HSO4- and is thus a functional model of sulfite oxidase. Kinetic and computational studies indicate that the reaction proceeds via attack of the substrate at one of the oxo ligands of the complex, rather than at the metal. (ii) The coordination geometries of the mono-oxo [Mo(VI)(O-Ser)(S2)2] entity (S2 = dithiolene moiety of molybdopterin) found in the crystal structure of R. sphaeroides DMSO reductase and the corresponding des-oxo Mo(IV) unit have been reproduced in the complexes [M(VI)O(OSiR3)(bdt)2] and [M(VI)O(OSiR3)(bdt)2] (M = Mo,W; bdt = benzene dithiolate). (iii) A facile route has been developed for the preparation of complexes containing a cis-Mo(VI)OS molybdenum oxo, sulfido moiety similar to that detected in the oxidized form of xanthine oxidase.

Animals↗

PubMed2000

Lens opacities after nonmechanical versus mechanical corneal trephination for keratoplasty in keratoconus.

PURPOSE: To compare the lens opacity formation after penetrating keratoplasty (PKP) using nonmechanical excimer laser corneal trephination and mechanical motor trephination. SETTTING: University Eye Clinic, University of Erlangen-Nürnberg, Erlangen, Germany. METHODS: Ninety-six patients with keratoconus (96 eyes) and clear crystalline lenses were randomly assigned to the nonmechanical trephination (NMT) group (n = 46; 35 men; mean age 38.2 years +/- 10.8 [SD]) or the mechanical trephination (MT) group (n = 50; 35 men; mean age 34.4 +/- 9.0 years). Suturing and postoperative treatment were identical. Dilated pupil biomicroscopy and slitlamp lens photography were performed preoperatively and postoperatively at 3 month intervals. Opacities were identified as cortical, nuclear, and posterior subcapsular and graded from 1 (mild) to 3 (severe). RESULTS: Mean follow-up in the NMT/MT group was 3.2 +/- 1.3 years/3.4 +/- 1.1 years. Overall, incident opacities appeared in 23.9%/32.0% of eyes (4.3%/6.0% cortical; 19. 6%/26.0% posterior subcapsular; 0%/0% nuclear) (P =.833). All cortical opacities in both groups were grade 1; posterior subcapsular opacities were grade 1 in 66.6%/61.5% of eyes and grade 2 in 22.2%/30.8% of eyes. One patient in each group presented grade 3 posterior subcapsular opacities. No differences between trephination methods were seen in a 5 year Kaplan-Meier cumulative risk of lens opacity formation (P =.763 cortical, P =.530 posterior subcapsular). CONCLUSIONS: In addition to its optical advantages, nonmechanical corneal trephination appears to have no adverse impact on cataract formation after PKP for keratoconus.

Adolescent↗

PubMed2000

Comparative investigation of concentrations of major and trace elements in organic and conventional Danish agricultural crops. 1. Onions (Allium cepa Hysam) and peas (Pisum sativum ping pong).

210 samples of onions (Allium cepa Hysam) from 11 conventionally and 10 organically cultivated sites and 190 samples of peas (Pisum sativum Ping Pong) from 10 conventionally and 9 organically cultivated sites in Denmark were collected and analyzed for 63 and 55 major and trace elements, respectively, by high-resolution inductively coupled plasma mass spectrometry. Sampling, sample preparation, and analysis of the samples were performed under carefully controlled contamination-free conditions. Comparative statistical tests of the element concentration mean values for each site show significantly (p < 0.05) different levels of Ca, Mg, B, Bi, Dy, Eu, Gd, Lu, Rb, Sb, Se, Sr, Ti, U, and Y between the organically and conventionally grown onions and significantly (p < 0.05) different levels of P, Gd, and Ti between the organically and conventionally grown peas. Principal component analysis (PCA) applied to the 63 elements measured in the individual onion samples from the 21 sites split up the sites into two groups according to the cultivation method when the scores of the first and third principal components were plotted against each other. Correspondingly, for peas, a PCA applied to the 55 elements measured as mean values for each site split up the 19 sites into two groups according to the cultivation method when the scores of the third and fourth principal component were plotted against each other. The methodology may be used as authenticity control for organic cultivation after further method development.

Food, Organic↗

PubMed2000

[Posterior corneal curvature after penetrating keratoplasty before and after suture removal].

PURPOSE: After penetrating keratoplasty (PK), peripheral swelling effects, malapposition of the graft in the recipient bed and suture tension may result in a changed ratio of curvature between anterior and posterior corneal surface. The purpose of this pilot study was to assess the posterior corneal curvature after PK with and without sutures and to compare this data to the posterior curvature of normal individuals. PATIENTS AND METHODS: In this cross-sectional study, 44 eyes after PK with a double running 16-bite diagonal antitorque suture in place (mean age 37 +/- 14 years, spherical equivalent (SEQ) -0.1 +/- 3.2 diopters (D)), 36 eyes with "all-sutures-out" (mean age 40 +/- 18 years, SEQ -0.8 +/- 3.5 D), and 464 normal control eyes (mean age 34 +/- 16 years, SEQ -0.3 +/- 2.2 D) were included. Based on Orbscan slit scanning topography analysis the following parameters were assessed: posterior power, posterior astigmatism, and posterior asphericity in various segments. RESULTS: With sutures in place the posterior central power ranged from -7.36 to -4.53 (mean -5.90 +/- 0.62) D, astigmatism ranged from 0.13 to 1.15 (mean 0.42 +/- 0.20) D, and asphericity ranged from 0.20 to 2.97 (mean 1.13 +/- 0.76, 56% oblate). With "all-sutures-out" the central power ranged from -7.56 to -4.93 (mean -6.41 +/- 0.53) D, astigmatism ranged from 0.13 to 1.15 (mean 0.39 +/- 0.19) D, and asphericity ranged from 0.26 to 3.04 (mean 1.25 +/- 0.76, 44% oblate). In the control group the central power ranged from -7.20 to -4.90 (mean -6.01 +/- 0.29) D, astigmatism ranged from 0.01 to 1.04 (mean 0.12 +/- 0.10) D, and asphericity ranged from 0.33 to 3.13 (mean 1.06 +/- 0.37, 47% oblate). Mean negative posterior power in grafts with "all-sutures-out" was significantly greater than in grafts with "all-sutures-in" and normal controls (p < 0.001), but showed no difference between the two latter groups (p = 0.56). Posterior astigmatism did not differ significantly comparing grafts with and without sutures (p = 0.44). However, astigmatism was significantly higher in grafts than in the control group (p < 0.0001). Asphericity did not differ significantly comparing grafts with and without sutures (p = 0.49) or comparing grafts to controls (p > 0.38). CONCLUSIONS: Except for the amount of astigmatism, the posterior corneal curvature of grafts with a double running suture in place does not seem to differ significantly from that of normal corneas. The removal of a double running suture tends to steepen the central posterior curvature. Knowledge about the individual posterior corneal curvature may have a favorable impact on the precision of intraocular lens power calculation for cataract surgery in eyes after PK.

Adult↗

PubMed2000

[Mid- and long-term results after trabeculectomy in patients with juvenile and late-juvenile open-angle glaucoma].

BACKGROUND: To determine success rate of trabeculotomy in patients with juvenile and late-juvenile glaucoma in a retrospective study. PATIENTS AND METHODS: 46 eyes of 41 juvenile glaucoma-patients (24 female, 17 male) were submitted to trabeculotomy during the period of 1980-1997. Patients age at the time of surgery was 30.2 +/- 10.5 years (11-49 years, median 21 years). Follow-up time was 35 +/- 46 months (1-155 months). RESULTS: Median preoperative visual acuity was 1.0 (range 0.002 to 1.25), postoperative visual acuity at the end of the follow up period was 0.8 (median) with a range from 0.002 to 1.2. In all patients preoperative intraocular pressure was elevated and a glaucomatous configuration of the optic disc was noticed. Preoperative intraocular pressure (IOP) ranged from 30.5 +/- 13.2 mm Hg, after surgery IOP was 16.2 +/- 5 mm Hg. Mean decrease of the IOP postoperatively was 54.4%. In 37% of the eyes IOP was lower than 23 mm Hg without additional medication, in 47% of the eyes IOP was lower than 23 mm Hg with additional medication. In 8 eyes additional antiglaucoma-surgery was necessary. After a follow-up time of 60 months 81% of the patients (n = 37 eyes) had an IOP below 23 mm Hg, after 120 months in 80% of the patients (n = 29 eyes) IOP was below 23 mm Hg. CONCLUSION: The success rate of trabeculotomy (defined as the ability to lower intraocular pressure lower than 23 mm Hg with or without antiglaucoma medication) in our patients is 84%. After second operation, success rate is 89%. Trabeculotomy for patients with juvenile open angle glaucoma is a safe procedure and avoids problems and complications of filtering procedures.

Adult↗

PubMed1999

Free-running erbium:YAG laser for nonmechanical trephination in penetrating keratoplasty: first results of experimental trephination of human donor corneas.

BACKGROUND: A study was carried out to evaluate the potential suitability of a free-running erbium:YAG 2.94-microm laser for trephination of human corneas in penetrating keratoplasty. METHODS: Two human donor corneas were placed in an artificial anterior chamber and moved with an automated rotation device (one rotation per minute). An erbium:YAG laser beam (pulse duration 400 micros, repetition rate 2/s, energy density 2.5 and 15.0 J/cm(2)) was focused on the outer edge of a round ceramic mask placed on the human donor corneas for ablation of tissue. RESULTS: With a fluence of 15.0 J/cm(2), perforation was achieved after 500 pulses. Perpendicular central cut edges with mild stromal ridges and, by light microscopy, a 12 to 45-microm area of stromal thermal effects and focal endothelial changes up to 200 microm central to trephination were observed. CONCLUSIONS: The erbium:YAG laser could be a promising "low-cost alternative" to the excimer laser for nonmechanical trephination in penetrating keratoplasty. Further studies will have to focus on reduction of thermal damage and on wound healing.

Animals↗

PubMed1999

Amino-terminal phosphorylation of c-Jun regulates stress-induced apoptosis and cellular proliferation.

c-Jun is a major component of the heterodimeric transcription factor AP-1 and is essential for embryonic development, as fetuses lacking Jun die at mid-gestation with impaired hepatogenesis and primary Jun-/- fibroblasts have a severe proliferation defect and undergo premature senescence in vitro. c-Jun and AP-1 activities are regulated by c-Jun N-terminal phosphorylation (JNP) at serines 63 and 73 through Jun N-terminal kinases(JNKs). JNP is thought to be required for the anti-apoptotic function of c-Jun during hepatogenesis, as mice lacking the JNK kinase SEK1 exhibit liver defects similar to those seen in Jun-/- fetuses. To investigate the physiological relevance of JNP, we replaced endogenous Jun by a mutant Jun allele with serines 63 and 73 mutated to alanines (Jun(tm1wag); hereafter referred to as JunAA). Here we show that primary JunAA fibroblasts have proliferation- and stress-induced apoptotic defects, accompanied by reduced AP-1 activity. JunAA mice are viable and fertile, smaller than controls and resistant to epileptic seizures and neuronal apoptosis induced by the excitatory amino acid kainate. Primary mutant neurons are also protected from apoptosis and exhibit unaltered JNK activity. Our results provide evidence that JNP is dispensable for mouse development, and identify c-Jun as the essential substrate of JNK signalling during kainate-induced neuronal apoptosis.

Animals↗

PubMed1999

"Orientation teeth" in non-mechanical laser corneal trephination for penetrating keratoplasty: 2.94 microm Er:YAG v 193 nm ArF excimer laser.

BACKGROUND/AIMS: "Orientation teeth" at the donor trephination margin and correspondent "notches" at the host margin facilitate graft orientation and avoid "horizontal torsion" induced by asymmetric suture placement. In this study the quality and reproducibility of these structures created by non-mechanical laser corneal trephination were compared using two laser emissions. METHODS: The procedure was performed in 20 enucleated pigs' eyes using open metal masks with eight "orientation teeth/notches" (0.3 x 0.15 mm, base x height), an automated globe rotation device, and either a 193 nm ArF excimer laser or a Q switched 2.94 microm Er:YAG laser. "Teeth/notches" were analysed by planimetry and scanning electron microscopy (SEM). RESULTS: Mean size was 0.30 (0.027) x 0. 16 (0.017) mm for "teeth" and 0.30 (0.035) x 0.15 (0.021) mm for "notches" (excimer), and 0.31 (0.022) x 0.16 (0.015) mm and 0.30 (0.031) x 0.14 (0.021) mm respectively (Er:YAG). Overall, variability of notches was higher than that of teeth. By SEM, comparable cut regularity and sustained ablation profile were observed with both lasers. However, the corneal surface at the cut edge appeared slightly elevated (</=35 microm) in the Er:YAG group. CONCLUSION: Orientation teeth/notches resembling those obtained with the excimer laser can be created using the Q switched Er:YAG laser, with potential advantages of lower costs, convenient equipment size, and solid state safety.

Animals↗

PubMed1998

Stromal thermal effects induced by nonmechanical (2.94-mum) erbium:YAG laser corneal trephination.

OBJECTIVE: To determine stromal thermal changes after erbium (Er):YAG laser corneal trephination with the use of 2 open masks. METHODS: Corneal trephination was performed in 89 enucleated pig eyes with an Er:YAG laser (400-microsecond pulse duration), 4 open masks (2 metallic and 2 ceramic) for both donors and recipients, and an automated globe rotation device. Different combinations of laser settings were used: pulse energy, 100, 200, and 400 mJ; repetition rate, 2 and 5 Hz; and spot size, 1.3 and 3.2 mm. Thermal effects in corneal stroma and regularity of the cut edges were quantitatively assessed by light microscopy, transmission and scanning electron microscopy. RESULTS: Best regularity and minimal thermal effects of the cut were observed with the use of ceramic masks at 200 mJ, 2 Hz, and 3.2-mm spot size, with middepth thermal changes of 18 +/- 2 microm. Effects increased with cut depth and were lower in donor corneas and with the use of ceramic masks (P<.001). Regularity of the cut was higher in the donors (P = .05) with lower repetition rates (P<.001). CONCLUSIONS: Even with the "free-running" Er:YAG laser mode, features of the trephination cut resembling those created by the 193-nm excimer laser along metal mask were achieved. Ceramic masks may be more suitable than metal masks. The Er:YAG laser seems to have the potential to be a compact and low-cost alternative in nonmechanical trephination for penetrating keratoplasty. CLINICAL RELEVANCE: Thermal effects after corneal trephination with the free-running Er:YAG laser (2.94 mm) are limited and predictable.

Animals↗

PubMed1998

Experimental 193-nm excimer laser trephination with divergent cut angles in penetrating keratoplasty.

PURPOSE: To study the morphologic properties of divergent cut angles after nonmechanical trephination for penetrating keratoplasty in donors and recipients and to assess its implications for donor-recipient stability in an experimental porcine model. METHODS: An excimer laser 193-nm corneal trephination was performed in 30 enucleated porcine eyes by using a modified "open mask" (stainless steel sheet 10CrNi18), to obtain round donor buttons and corresponding recipient beds 7 mm in diameter at the level of Bowman's layer. An automated globe-rotation device allowed different cut angles toward the optical axis. Three cut angles were intended: 0 degrees, 15 degrees divergent, and 35 degrees divergent. Quality of the cuts was assessed by means of histology and scanning electron microscopy (SEM). In a different setting, after alignment of the donor button and corresponding recipient bed in an artificial anterior chamber, intracameral pressure was increased stepwise, modifying the height of a bottle of balanced saline solution connected to the chamber. Criterion for "instability" was the movement of the donor button in all four quadrants during observation with a surgical microscope (x12). RESULTS: Reproducible cut angles and smooth cut surfaces of donors and recipients were confirmed by histologic and SEM evaluation. Macroscopically, a good alignment of a divergent donor button in a corresponding recipient bed was achieved. Instability of the donor buttons occurred with a water column niveau at 2 cm in the 0 degrees cut, at 3 cm in 15 degrees divergent cuts, and at 4.5 cm in 35 degrees divergent cuts. CONCLUSION: The stability of a corneal donor button in a recipient bed seems to increase in proportion with the degree of divergence of the trephination angle. Considering the good histologic quality and macroscopic alignment obtained, divergent cut angles may allow a reduction of sutures, assuring a water-tight wound closure in penetrating keratoplasty.

Animals↗

PubMed1997

Corneal topography.

In the review period, limitations of individual Placido disk-based topography systems have been studied and new principles, such as raster photogrammetry, pancorneal slit topography, laser holographic interferometry, and confocal laser scanning topography, have been introduced for laboratory or clinical work. Both Fourier analysis and Zernike decomposition of topographic height data seem to be powerful new tools for cross-sectional analysis of complex topographic corneal images, such as after cataract surgery, penetrating keratoplasty, and refractive surgery, as well as for longitudinal studies of corneal changes, such as in schoolchildren. Subdividing into rational optical components may improve consistency and standardization of topography data from different systems. Topography-based flying-spot-mode excimer laser photoablation after Zernike decomposition of topography height data has been proposed for correction of irregular corneal astigmatism. Topography-based central power measurements are of increasing value for intraocular lens power calculation before cataract surgery in eyes with irregular corneal surfaces, such as in keratoconus or after refractive surgery procedures. Quantitative and qualitative classification of corneal topography maps after corneal transplantation following conventional mechanical and nonmechanical trephination or after refractive surgery may lead to a better understanding of impaired visual acuity despite a clear graft or despite significantly reduced ametropia or corneal astigmatism.

Cornea↗

PubMed1996

Peritoneal washing cytology in gynecologic cancers: long-term follow-up of 355 patients.

BACKGROUND: Microscopic evaluation of cells washed from the peritoneal cavity during surgery for gynecologic tumors is used to detect subclinical intraperitoneal metastases from these tumors. The prognostic significance of this test, however, has been questioned. PURPOSE: Stressing histologic correlation and pitfalls in interpretation, we previously reported that the sensitivity of intraoperative peritoneal washing cytology was lower than was suggested earlier. This study evaluates the clinical utility of this test in the long-term follow-up of our patients. METHODS: Staging (International Federation of Gynecology and Obstetrics [FIGO], 1971) and follow-up information was available for 355 unselected patients with primary tumors who had peritoneal washings performed during initial surgery at University Hospital-Stony Brook, NY, during the period from 1980 through 1989. There were 135 patients with endometrial carcinomas, 112 with ovarian carcinomas, 92 with cervical carcinomas, and 16 with borderline (i.e., of low malignant potential) ovarian tumors. The median follow-up of the patients was 57 months (range, 0-154 months). Follow-up data were obtained from the Tumor Registry at University Hospital-Stony Brook. Survival differences were determined by Kaplan-Meier analysis and were evaluated by two-tailed logrank test. RESULTS. Peritoneal washing cytology was positive at initial surgery for 120 (33.8%) of 355 patients, including 90 (80.4%) of 112 patients with ovarian carcinomas, five (31.2%) of 16 patients with borderline ovarian tumors, 17 (12.6%) of 135 patients with endometrial carcinomas, and eight (8.7%) of 92 patients with cervical cancers. For 203 patients with stage I tumors, the peritoneal cytology was positive in 29.4% of the patients with ovarian carcinomas, 18.2% with borderline ovarian tumors, 6.1% with endometrial carcinomas, and 5.2% with cervical carcinomas. By use of peritoneal histology as the standard, peritoneal cytology was highly specific (98.1%) but less sensitive (82.9%) in detecting intraperitoneal involvement. For patients with stage I tumors, 80.0% with ovarian carcinomas, 83.3% with endometrial carcinomas, and 100% with cervical carcinomas who showed positive cytology died of their cancer, compared with 25.0% with ovarian carcinomas, 13.0% with endometrial carcinomas, and 21.9% with cervical carcinomas who showed negative peritoneal cytology. Four (2.0%) patients with stage I tumors had positive peritoneal cytology but negative peritoneal histology. Of these patients, three (two with ovarian carcinoma and one with cervical carcinoma) died of their cancer, whereas one patient with a borderline ovarian tumor was free of disease at the last follow-up. Survival analysis indicated that peritoneal washing cytology stratified for stage provides better prognostic information for each primary cancer site studied than does stage alone. All patients with borderline ovarian tumors were alive at last follow-up, regardless of disease stage or peritoneal status. CONCLUSIONS: Regardless of FIGO stage, positive peritoneal washing cytology predicted poor prognosis for women with epithelial tumors of the genital tract, except for patients with borderline ovarian tumors. Patients in whom peritoneal cytology was the only evidence of intraperitoneal spread were few, but the disease in such patients was associated with poor outcome. IMPLICATIONS: Strict adherence to specialized cytologic criteria in peritoneal washing cytology allows for results that are highly predictive of survival. This information may be useful in stratifying women in therapeutic trials for treatment of genital tract carcinomas.

Adult↗

PubMed1996

Differential diagnosis of malignant tumours in the abdominal cavity of rats after intraperitoneal injection of crocidolite or benzo[a]pyrene.

In our investigation (i.p. test), crocidolite and benzo[a]pyrene, both caused a progression from initially reactive, then autonomously transformed proliferation of myofibroblasts and undifferentiated mesenchymal cells to malignant, multidirectionally differentiated (desmin and ED-1 positive) fibro-histiocytic tumours. Immunohistochemically these tumours showed no morphological characteristics (for example co-expression of vimentin and keratin in spindle-shaped tumour cells) of human asbestos-associated malignant mesotheliomas. On the other hand many tumour cells induced by crocidolite and benzo[a]pyrene had an ultrastructural appearance resembling fibroblasts and myofibroblasts. These have been demonstrated in only a few desmoplastic and sarcomatous mesotheliomas in human beings. None of the tumours revealed the typical ultrastructural features of epitheloid or transitional mesotheliomas. Apparently, both carcinogenic substances induce the transformation of undifferentiated pluripotent mesenchymal cells in rat peritoneum, regardless of their localization in the submesothelial compartment or perivascular connective tissue (preferentially after crocidolite application) or in the connective tissue pseudocapsule of major benzo[a]pyrene containing beeswax/tricaprylin depots in the mesometrium and mesenterial fatty tissue. In this way asbestos fibres in this animal experiment do not seem to induce an arrest in differentiation of intermediate or immature mesothelial cells as supposed formerly, but rather affect undifferentiated mesenchyme cells and myofibroblasts. This is an explanation for the immunohistochemical expression of markers of muscular differentiation in these tumour cells, which is known to occur in human malignant fibro-histiocytic tumours. If supplementary immunohistochemical investigations with different keratin antibodies also fail to confirm the mesothelial differentiation of the tumours induced in our i.p. test, the decision to call them "mesotheliomas" should be reconsidered. Further immuno-transmission-electron microscopical investigations with intermediate filament or macrophage antibodies are needed to clarify whether the term malignant "fibrohistiocytic sarcoma", "mesenchymoma" or "mesothelioblastoma" would be more correct from the morphological point of view.

Abdominal Neoplasms↗

PubMed1996

A newly identified immunodominant membrane protein (pMB67) involved in Mycoplasma bovis surface antigenic variation.

Mycoplasma bovis is a bovine pathogen able to cause systemic disease. It possesses a series of prominent, structurally related yet clearly distinguishable membrane lipoproteins on the cell surface. These variable surface proteins (Vsps) undergo highly dynamic and spontaneous changes in size and expression and are key immunogenic components. They may play a critical role as mediators of adherence to host cells and in escaping immune destruction. In this report, we define a novel, Vsp-unrelated membrane protein also associated with M. bovis surface antigenic variation. This protein has an apparent molecular mass of 67,000 Da in the type strain PG45 and was designated pMB67. Immunological and biochemical characterization of pMB67 demonstrated that it: (i) contains a specific epitope, (ii) is not modified by lipid but does contain cysteine, (iii) does not contain a Vsp-like repetitive periodic protein structure, (iv) is a predominant antigen recognized during M. bovis infections, (v) undergoes a high rate of phase variation in vitro and (vi) is size-variable. These results showed that M. bovis employs two types of specialized membrane proteins for surface diversification. The pMB67 protein may be useful in diagnostic assays and as a vaccine component.

Animals↗