Value of chromoendoscopy and magnification endoscopy in the evaluation of duodenal abnormalities: a prospective, randomized comparison

BACKGROUND AND STUDY AIMS

Endoscopic staining methods are increasingly being used to evaluate lesions in the esophagus and colon. The aim of this prospective study was to investigate chromoendoscopy and magnification endoscopy for the evaluation of mucosal lesions in the duodenum.

PATIENTS AND METHODS

Consecutive patients were randomly assigned to undergo conventional endoscopy without staining (group A) or intravital staining of the duodenal mucosa with indigo carmine and evaluation with a conventional video endoscope (group B) or a magnification endoscope (group C). Visible lesions were characterized before and after staining, and biopsies were taken for histological assessment.

RESULTS

A total of 118 patients was examined. Chromoendoscopy detected significantly more lesions in the duodenal bulb (98 vs. 28; P = 0.0042) in more patients (29 vs. 15; P = 0.0025) compared with conventional endoscopy (group A). After mucosal staining, there was no difference between video endoscopy and magnification endoscopy with regard to the number or extent of the lesions identified. Significantly more targeted biopsies were possible after intravital staining. The most commonly identified lesions on targeted biopsies included (staining/control groups): gastric metaplasia (14/3), hyperplastic Brunner's glands (6/3), inflammatory changes (7/6), villous atrophy (1/3), adenoma (1/0).

CONCLUSIONS

Intravital staining of the duodenum with indigo carmine may be useful for detecting mucosal abnormalities, delineating their extent, and allowing targeted biopsies. Magnification endoscopy, when used in addition to chromoendoscopy, does not appear to further increase the diagnostic yield for detecting duodenal abnormalities.

[Surgery of hemorrhoids using the Long method and its complications]

BACKGROUND

The aim of this article is an assessment of new surgical procedure--stapled hemorroidectomy according to Longo. We do concentrate on surgical complications and possibilities of it's management.

METHODS

Prospective, clinical follow up of patients in which stapled hemorrhoidectomy was performed during the period of 2 years (1st December 2000--30st November 2002). Observation concentrates on surgical complications of this method. All patients had a clinical check up 3 weeks and 3 months after surgery. In case of any problems treatment and follow up continues.

RESULTS

Stapled hemorroidectomy was performed during the period of 2 years in 52 patients (100%). There was 11 patients (21.2%) with some of surgical complication. The most serious one was massive rectal bleeding after surgery, which has been observed in 4 patients (7.6%). Other surgical complications observed in our group were anal stenosis, local infection, acute anal fissure and retention of urine.

CONCLUSION

Stapled hemorroidectomy is now one of feasible alternatives for surgical treatment of hemorrhoids. Serious surgical complications observed in our patients were bleeding from the stapled suture line and anal stenosis. The aim of this article is to refer possible surgical complications of this method, it's prevention and management.

[Ceftriaxone versus Levofloxacin for antibiotic therapy in patients with acute cholangitis]

INTRODUCTION

For the therapy of acute cholangitis complete biliary drainage and antibiotic therapy is needed. The aim of the current study was to compare intravenous therapy of acute cholangitis with Ceftriaxone or Levofloxacin in a prospective and randomized fashion.

METHODS

Patients with biliary obstruction and clinical signs of infection received in addition to 1.5 g Metronidazole either 500 mg Levofloxacin/die or 2 g Ceftriaxone/die. Early on during ERCP, bile was aspirated via the cannulation catheter and cultured for bacteria under aerobic and anaerobic conditions. Minimal inhibitory concentrations of the respective antibiotics were determinate for each isolate. The clinical course was followed for at least 6 days with clinical and laboratory data.

RESULTS

60 patients with clinical signs of acute cholangitis were randomised. In 40 patients (66 %) biliary colonization with bacteria could be identified. In all bacterial species Levofloxacin showed significantly lower rates of in-vitro resistance as compared to Ceftriaxone. However, the percentage of patients with a clinical cure or significant improvement was the same in the two groups.

CONCLUSIONS

The clinical effect of Levofloxacin and Ceftriaxone in patients with acute cholangitis showed no significant differences. Because of improved in-vitro efficiency, a calculated therapy with Levofloxacin might be advantageous.

Infrequent genetic alterations of the tumor suppressor gene PTEN/MMAC1 in squamous cell carcinoma of the oral cavity

BACKGROUND

Fifty tumor specimens from primarily untreated patients were analyzed to elucidate the involvement of the tumor suppressor gene PTEN/MMAC1 in the development of oral squamous cell cancer.

METHODS

Eight microsatellite markers, spanning 10 cM of genomic DNA located centromeric, telomeric or intragenic of PTEN/MMAC1 were used for loss of heterozygosity (LOH) and breakpoint analysis. The microsatellite panel within or in close proximity (1 cM) to the 10q23.3 locus showed a LOH rate of 12%. Complete sequence analysis of the genes coding region was performed in all 10 cases that exhibited LOH in one of the eight microsatellite markers within or around the PTEN/MMAC1 gene. Comparative multiplex PCR reactions served to screen for homozygous deletions.

RESULTS

There was no association between allelic loss of the gene, overall patient survival and recurrence-free survival. Sequencing did not reveal any mutation in the coding region of PTEN/MMAC1. Differential PCR analysis failed to detect any homozygous deletion.

CONCLUSIONS

We conclude that PTEN/MMAC1 gene alterations do not play a key role in tumorigenesis of oral squamous cell cancers.

Time independence of the prognostic impact of tumor cell detection in the bone marrow of primary breast cancer patients

PURPOSE

Tumor cell detection (TCD) in bone marrow is an outstanding prognostic factor in breast cancer. There is only one other study that has investigated more than 300 patients with a median follow-up of more than 5 years (J. L. Mansi et al., Lancet, 354:197-202, 1999). We report data from 727 patients with a median follow-up period of 6.5 years.

EXPERIMENTAL DESIGN

In a prospective study, intraoperatively aspirated bone marrow was screened for micrometastatic cancer cells. We used an immunocytological method (monoclonal mucin antibody 2E11; the avidin-biotin complex method).

RESULTS

Forty-three percent of the patients were TCD positive. Sixty percent of the patients with distant metastases were tumor cell positive (155 of 258 patients). Forty-nine percent of the patients with positive TCD developed distant metastases (155 of 315 patients). TCD was an independent prognostic factor for clinical outcome after a median follow-up time of 6.5 years. The prognostic impact of TCD and tumor size remains constant with the time, whereas the impact of grading and progesterone receptor on risk seems to decrease with longer follow-up time.

CONCLUSIONS

TCD remains an independent prognostic factor The impact of TCD does not change with longer follow-up time. TCD is a reliable prognostic factor and provides important information about the process of metastasis.

Chromoendoscopy with indigocarmine improves the detection of adenomatous and nonadenomatous lesions in the colon

BACKGROUND AND STUDY AIMS

Depressed early cancers and flat adenomas have a high potential for malignancy with possible infiltrating growth, despite the small size of the lesion. Japanese investigators have shown that early diagnosis and classification of these lesions is possible with the help of chromoendoscopy. The aim of this study, therefore, was to evaluate the usefulness of chromoendoscopy during routine colonoscopy.

PATIENTS AND METHODS

During routine colonoscopy, vital staining with indigocarmine solution (0.4 %, 1 - 10 ml) was performed on all visible lesions in 100 consecutive patients without visible inflammatory changes. If findings on macroscopic examination were unremarkable, the sigmoid colon and rectum were stained with indigocarmine over a defined segment (0 - 30 cm ab ano) and inspected for lesions visible only after staining. Each lesion was classified with regard to type (polypoid, flat, or depressed), position and size. The staining pattern was classified according to the pit pattern classification.

RESULTS

A total of 52 patients had 105 visible lesions (89 polypoid, 14 flat and two depressed). The mean size of the lesions was 1.4 cm. Among the 48 patients with mucosa of normal appearance, 27 showed 178 lesions after staining (176 flat, two depressed) with a mean size of 3 mm. On histological investigation, 210 lesions showed hyperplastic or inflammatory changes, 67 were adenomas and six were cancers. Use of the pit pattern system to classify lesions (adenomatous, pit patterns III-V; nonadenomatous, pit patterns I-II) was possible, with a sensitivity of 92 % and a specificity of 93 %. Lesions with pit patterns III - V showed higher rates of dysplasia.

CONCLUSIONS

Chromoendoscopy allows easy detection of mucosal lesions in the colon and facilitates visualization of the margins of flat lesions. This technique unmasks multiple mucosal lesions which are not identified by routine video colonoscopy. The pit pattern seen after staining allows differentiation between hyperplastic and adenomatous lesions which may have consequences with regard to the endoscopic interventions needed.

[Interventional ERCP in patients with cholestasis. Degree of biliary bacterial colonization and antibiotic resistance]

Interventional ERCP in patients with cholestasis. Degree of biliary bacterial colonization and antibiotic resistance. Biliary obstruction together with bacterial colonization of the bile duct may lead to development of acute cholangitis. The aim of our prospective study was to investigate the presence and degree of biliary bacterial colonization by means of bile aspiration during ERCP in patients with biliary obstruction. Furthermore, we evaluated antibiotic therapy regimens, which would cover the bacterial species obtained by ERCP and subsequent culture in each patient. In addition, analysis of risk factors was performed that would predispose to the development of cholangitis.80 patients with clinical and laboratory evidence of biliary obstruction underwent ERCP with initial aspiration of bile via the cannulation catheter. This material was used to culture aerobic and anaerobic bacteria and determine the colony count/ml bile, followed by identification of each species and antibiotic resistance testing. The minimal inhibitory concentration for Levofloxacin, Ciprofloxacin, Piperacillin, Ampicillin, Ceftriaxone, Imipenem, Gentamycin und Metronidazole was determined. Immediately after the ERCP or if the body temperature (after ERCP) rose to > 38 degrees C blood cultures were obtained. In 45 (56 %) patients biliary colonization with bacteria could be identified (56 %). In 20 patients a single isolate was cultured, in 25 cases mixed infection was present. A total of 83 species were isolated. The most common bacteria were E. coli, Enterococcus and Klebsiella. 9.6 % of all isolates were obligatory anaerobes. In 9 of 80 patients bloodcultures tested positive for bacterial growth (rate of bacteremia: 11.3 %). 10 patients had acute cholangitis clinically before ERCP, 13 patients developed signs of infection after ERCP. Statistically significant factors contributing to the risk of infection were age of the patient, the clinical condition of the patient before ERCP and the biliary colony count. Patients with development of infection after ERCP showed a significantly higher incidence of bacterial colonization of the biliary tree and a higher colony count. In all bacterial species Imipenem (4.5 %) or Levofloxacin (2.2 %) exhibited the lowest rate of in-vitro resistance. Based on these data, the implementation of Levofloxacin in combination with anaerobic coverage is advantageous as a calculated therapy for patients with acute cholangitis.

Cross-reactive binding of cyclic peptides to an anti-TGFalpha antibody Fab fragment: an X-ray structural and thermodynamic analysis

The monoclonal antibody tAb2 binds the N-terminal sequence of transforming growth factor alpha, VVSHFND. With the help of combinatorial peptide libraries it is possible to find homologous peptides that bind tAb2 with an affinity similar to that of the epitope. The conformational flexibility of short peptides can be constrained by cyclization in order to improve their affinity to the antibody and their stability towards proteolysis. Two cyclic peptides which are cross-reactive binders for tAb2 were selected earlier using combinatorial peptide libraries. One is cyclized by an amide bond between the N-alpha group and the side-chain of the last residue (cyclo-SHFNEYE), and the other by a disulfide bridge (cyclo-CSHFNDYC). The complex structures of tAb2 with the linear epitope peptide VVSHFND and with cyclo-SHFNEYE were determined by X-ray diffraction. Both peptides show a similar conformation and binding pattern in the complex. The linear peptide SHFNEYE does not bind tAb2, but cyclo-SHFNEYE is stabilized in a loop conformation suitable for binding. Hence the cyclization counteracts the exchange of aspartate in the epitope sequence to glutamate. Isothermal titration calorimetry was used to characterize the binding energetics of tAb2 with the two cyclic peptides and the epitope peptide. The binding reactions are enthalpically driven with an unfavorable entropic contribution under all measured conditions. The association reactions are characterized by negative DeltaC(p) changes and by the uptake of one proton per binding site. A putative candidate for proton uptake during binding is the histidine residue in each of the peptides. Hydrogen bonds and the putative formation of an electrostatic pair between the protonated histidine and a carboxy group may contribute markedly to the favorable enthalpy of complex formation. Implications to cyclization of peptides for stabilization are discussed.

Venous leg ulcers and microcirculation

Incompetence of venous valves do not lead per se to trophic skin changes of the lower limb. In severely concerned patients suffering from dermatoliposclerosis or venous leg ulcers retrograde pressure waves were detected in the nutritive capillaries of the skin by the "servo nulling" pressure measurement during simulated calf muscle contraction. Between the degree of trophic skin change and the capillary density and cutaneous oxygen partial pressure a close correlation was found. Healing of venous ulcers occurred only if the cutaneous microangiopathy in the ulcer area improved. Capillary density and transcutaneous oxygen partial pressure were of prognostic impact as to healing of venous ulcers.

Frequency of mediastinal lymph node metastases in patients undergoing EUS evaluation of pancreaticobiliary masses

BACKGROUND

Mediastinal lymph node metastases have rarely been reported in patients with pancreatic cancer. Our aim was to determine the frequency of mediastinal lymph node metastases in patients with pancreaticobiliary masses by using EUS-guided fine needle aspiration.

METHODS

Sixty-six consecutive patients with pancreatobiliary masses were evaluated on EUS for the presence of mediastinal lymph node metastases. All masses were staged by commonly used EUS criteria by using sector scanning echoendoscopes. Mediastinal lymph nodes with EUS features that suggested malignancy were aspirated.

RESULTS

Of the 66 patients (mean age 65.6 years; 38 men), 4 had biliary masses, 5 had lesions of the major duodenal papilla, and 57 had pancreatic masses. Eleven patients (10 pancreatic masses, 1 biliary mass) had enlarged mediastinal lymph node (12-30 mm) on EUS; in 2 patients these had a benign appearance and were not aspirated. Nine patients underwent EUS-guided fine needle aspiration: in 1 the cytology was inconclusive (patient subsequently had a negative Whipple resection); in 4 the mediastinal lymph node cytology was benign; the remaining 4 patients had adenocarcinoma cells in the aspirate from mediastinal lymph node. These 4 pancreatic tumors were staged by EUS as T2N1M1 (1), as T4N0M1 (2, one later found to also have a lung mass), and T4N1M1 (1).

CONCLUSION

Enlarged mediastinal lymph nodes were found on EUS in 16.6% (95% CI [7.7%, 25.6%]) of patients with pancreatobiliary masses and in 17.5% (95% CI [7.6%, 27.4%]) of patients with pancreatic masses. The frequency of mediastinal lymph node metastases in pancreatobiliary masses was 6.1% (95% CI [0.34%, 11.9%]) and in pancreatic masses 7.0% (95% CI [0.4%, 13.6%]). Routine EUS evaluation of the mediastinum in patients with pancreatic masses is warranted.

The Structure of calnexin, an ER chaperone involved in quality control of protein folding

The three-dimensional structure of the lumenal domain of the lectin-like chaperone calnexin determined to 2.9 A resolution reveals an extended 140 A arm inserted into a beta sandwich structure characteristic of legume lectins. The arm is composed of tandem repeats of two proline-rich sequence motifs which interact with one another in a head-to-tail fashion. Identification of the ligand binding site establishes calnexin as a monovalent lectin, providing insight into the mechanism by which the calnexin family of chaperones interacts with monoglucosylated glycoproteins.

Influence of fluorophor dye labels on the migration behavior of polymerase chain reaction--amplified short tandem repeats during denaturing capillary electrophoresis

The determination of the length of polymerase chain reaction (PCR)-amplified short tandem repeats (STRs) by denaturing capillary electrophoresis (CE) is a standard procedure for purposes of genotyping. We show that dye-specific mobility anomalies exist for 5'-fluorophor-labelled single-stranded DNA (ssDNA) fragments in CE using the performance-optimized polymer 4 (POP4) buffer sieving matrix, containing the entangled poly(N,N-dimethylacrylamide) polymer, urea, and 2-pyrrolidinone. The dye-specific retardation effects relative to coseparated GeneScan-500 [TAMRA] standard fragments can lead to wrong genotyping, even for allele-specific fragments of pentanucleotide STRs, when comparing the relative calculated sizes of identical fragments, labelled with rhodamine (ROX, TAMRA) or fluorescein dyes (FAM, 6-FAM, HEX, JOE, NED, TET): The size of fluorescein dye-labelled fragments of appr. 100 b in length appears to be smaller by up to 6.5 b. This effect becomes more dramatic with decreasing size: a 6-FAM-labelled 24-mer oligonucleotide appeared to be smaller by 11 b. In contrast, in classical urea/polyacrylamide slab-gel electrophoresis only a small dye-specific retardation of identical fragments is observed. The dye-specific effects are superimposed by weaker size and sequence-dependent anomalies of fragment mobility. Therefore, in denaturing CE the coseparation of a defined allele ladder labelled with the same dye as the unknown sample fragments remains the method of choice for accurate genotyping.

Signal and nutrient exchange at biotrophic plant-fungus interfaces

Biotrophic interfaces are formed in mutualistic and parasitic plant-fungus interactions. They result from coordinated developmental programs in both partners and represent specialized platforms for the exchange of information and nutritional metabolites. New data on the establishment and the components of functional interfaces have been obtained in a number of ways. First, by isolation of symbiotically defective mutants; second, by characterization of new genes and their products; and, third, by the identification and localization of components of biotrophic interfaces, such as cell-wall proteins, H+-ATPases and nutrient transporters.

Influence of fluorophor dye labels on the migration behavior of polymerase chain reaction--amplified short tandem repeats during denaturing capillary electrophoresis

The determination of the length of polymerase chain reaction (PCR)-amplified short tandem repeats (STRs) by denaturing capillary electrophoresis (CE) is a standard procedure for purposes of genotyping. We show that dye-specific mobility anomalies exist for 5'-fluorophor-labelled single-stranded DNA (ssDNA) fragments in CE using the performance-optimized polymer 4 (POP4) buffer sieving matrix, containing the entangled poly(N,N-dimethylacrylamide) polymer, urea, and 2-pyrrolidinone. The dye-specific retardation effects relative to coseparated GeneScan-500 [TAMRA] standard fragments can lead to wrong genotyping, even for allele-specific fragments of pentanucleotide STRs, when comparing the relative calculated sizes of identical fragments, labelled with rhodamine (ROX, TAMRA) or fluorescein dyes (FAM, 6-FAM, HEX, JOE, NED, TET): The size of fluorescein dye-labelled fragments of appr. 100 b in length appears to be smaller by up to 6.5 b. This effect becomes more dramatic with decreasing size: a 6-FAM-labelled 24-mer oligonucleotide appeared to be smaller by 11 b. In contrast, in classical urea/polyacrylamide slab-gel electrophoresis only a small dye-specific retardation of identical fragments is observed. The dye-specific effects are superimposed by weaker size and sequence-dependent anomalies of fragment mobility. Therefore, in denaturing CE the coseparation of a defined allele ladder labelled with the same dye as the unknown sample fragments remains the method of choice for accurate genotyping.

The role of haustoria in sugar supply during infection of broad bean by the rust fungus Uromyces fabae

Biotrophic plant pathogenic fungi differentiate specialized infection structures within the living cells of their host plants. These haustoria have been linked to nutrient uptake ever since their discovery. We have for the first time to our knowledge shown that the flow of sugars from the host Vicia faba to the rust fungus Uromyces fabae seems to occur largely through the haustorial complex. One of the most abundantly expressed genes in rust haustoria, the expression of which is negligible in other fungal structures, codes for a hexose transporter. Functional expression of the gene termed HXT1 in Saccharomyces cerevisiae and Xenopus laevis oocytes assigned a substrate specificity for D-glucose and D-fructose and indicated a proton symport mechanism. Abs against HXT1p exclusively labeled haustoria in immunofluorescence microscopy and the haustorial plasma membrane in electron microscopy. These results suggest that the fungus concentrates this transporter in haustoria to take advantage of a specialized compartment of the haustorial complex. The extrahaustorial matrix, delimited by the plasma membranes of both host and parasite, constitutes a newly formed apoplastic compartment with qualities distinct from those of the bulk apoplast. This organization might facilitate the competition of the parasite with natural sink organs of the host.

Inter-laboratory comparison of DNA preservation in archival paraffin-embedded human brain tissue from participating centres on four continents

DNA extracted from formalin-fixed and paraffin-embedded brain tissue is known to contain as yet ill-characterized inhibitors of the PCR process. As part of a project that aims to clarify the role of mitochondrial DNA sequence variation in human neurodegenerative diseases using DNA from various ethnic backgrounds, we have investigated factors that influence the preservation of archival DNA and its suitability for PCR. In this study, neuropathological tissue samples were analysed that had been routinely processed in 18 international centres on four continents. Following DNA extraction, PCR amplification of mitochondrial and nuclear DNA sequences was performed with and without additional purification of the template DNA. In addition, the DNA used for PCR was analysed by HPLC. Phosphate-buffered formalin proved to be a superior fixative compared with unbuffered aldehyde: DNA extraction resulted in greater yields, the molecular weight of the isolated DNA was higher and PCR was more successful. PCR inhibitors were identified as (1) high concentrations of small (<300 bp) DNA fragments that competitively compete with template DNA and (2) contaminants of the DNA template solution including denatured protein that cannot be completely removed by phenolic extraction. HPLC analysis did not reveal significant qualitative differences between DNA isolated from fresh-frozen tissue samples and DNA recovered from formalin-fixed, paraffin-embedded brain tissue. The fact that DNA could be amplified from the majority of tissue specimens in this study suggests that rare diseases and diseases where ethnic background plays an important role can be sampled for genetic polymorphism analysis on a global scale using archival neuropathological collections.

Estimating the relapse stage in chronic myeloid leukaemia patients after allogeneic stem cell transplantation by the amount of BCR-ABL fusion transcripts detected using a new real-time polymerase chain reaction method

We have used a new single-step real-time reverse transcription polymerase chain reaction (RT-PCR) method to quantify BCR-ABL transcripts, thereby estimating the relapse stage in chronic myeloid leukaemia patients after allogeneic transplants. In 402 samples from 172 patients, BCR-ABL expression was determined and normalized, using the GAPDH housekeeping gene product as an endogenous reference. In our real-time RT-PCR assay, serial dilutions of RNA of the K562 cell line remained positive down to 7.5 pg. The median normalized BCR-ABL amount differed significantly (P < 0.001) between the various disease stages and was 0.06% (range 0.001-1.55%), 3.2% (range 1.4-5.6%) and 21.5% (range 6.8 -827%) in 17 patients with a molecular relapse, in eight patients with a cytogenetic relapse and in 10 patients with a haematological relapse respectively.

Interaction of cisplatin with methionine- and histidine-containing peptides: competition between backbone binding, macrochelation and peptide cleavage

The pH- and time-dependent reaction of cis-[PtCl2(NH3)2] with the methionine- and histidine-containing peptides H-Gly-Met-OH, H-Gly-Gly-Met-OH, Ac-His-Gly-Met-OH, and Ac-His-(Ala)3-Met-OH at 313 K has been investigated by ion-pairing reverse phase HPLC and NMR spectroscopy. For equimolar solutions (c=0.8 mM, pH approximately equals 3 or 8.8), initial formation of the kinetically favored S-bound complex is followed by relatively rapid metallation of the neighboring methionine amide nitrogen NM to afford a kappa2NM,S six-membered chelate. The strong trans effect of the methionine S then favors facile NH3 substitution, leading to generation of tridentate complexes such as [Pt(H-Gly-MetH(-1)-OH)-kappa3NG,NM,S)(NH3)]+ or [Pt(H-Ac-His-GlyH(-1)-MetH(-1)-OH-kappa3NG,NM,S)(NH3)]. In the case of H-Gly-Gly-Met-OH, this reaction is accompanied by loss of a second NH3 ligand in alkaline solution to generate the tetradentate kappa4NG1,NG2,NM,S species. In contrast, cleavage of the backbone C(O)-N bond to the second metallated amide nitrogen after t>100 h is common to the tridentate complexes of the tri- and pentapeptides at pH<5. Although an imidazole-coordinated kappa2N3H,S macrochelate is formed throughout the whole range 2.5 < or = pH < or = 10 for Ac-His-Gly-Met-OH, it slowly decays (t=10-1000 h) to the thermodynamically more stable tridentate kappa3NG,NM,S complex. All major final products were separated and fully characterized by NMR and MS.

Comparison between Taq DNA Polymerase and Its Stoffel Fragment for Quantitative Real-Time PCR with Hybridization Probes

In quantitative real-time PCR assays, fluorophor-labeled oligonucleotide probes are employed to generate sequence-specific signals for the quantitative evaluation. Whereas TaqMan® probes have to be hydrolyzed during PCR by the endonucleolytic activity of Taq DNA polymerase to generate a signal, the hybridization probes in Light-Cycler® assays must not be hydrolyzed. In this study, we demonstrate for four different targets that the probes are degraded during PCR by Taq DNA polymerase. Signal yield, quality of amplification curves, and accuracy of quantitative measurements can be improved using the Stoffel fragment lacking an endonucleolytic activity and TaqStart® antibody suppressing the formation of nonspecific products, without laborious efforts to optimize the amplification protocol.

[Status of hearing aid use by children in schools for the hearing impaired and deaf]

To evaluate and possibly improve the hearing aid fittings of children attending the Westphalian School for the Hearing Impaired or the Westphalian School for the Deaf, regular pedaudiologic consulting hours were established at both schools. During a 2-year period, 115 children were examined once, 35 children twice, and 5 children three times. The examinations comprised ear microscopy, audiometry, and a check of the hearing aids with a 0.6-cm3 coupler (children up to 7 years) or 2-cm3 coupler, respectively. The following criteria were used to assess the quality of the hearing aid setting: status of the external auditory canal and middle ear, acceptance of wearing the hearing aid, status of the ear mold, technical status of the hearing aid, and its setting. The results were related to four variables: gender, type of school, age, and mean hearing loss. Overall, just 40.9% of all children showed satisfactory hearing aid performance at the first examination and just 37.1% at the second. A significant influence of the variables on the hearing aid performance was documented for hearing loss only. The higher the hearing loss, the more likely the children were to have good hearing aid status. Analysis of the different parameters revealed that an incorrect setting was the main problem, with a rate of 20.9%; the rate of the other parameters varied from 6.1% to 15.7%. Thus, no parameter was of major relevance to the results. The results of the second examination were poorer in most parameters than those of the first. These alarming results, which are probably not only of regional significance, demonstrate that the hearing aid status of children attending schools for the hearing impaired or for the deaf is in urgent need of improvement.

Microcirculatory dysfunction in chronic venous insufficiency (CVI)

The elevated ambulatory pressure in the peripheral venous system of chronic venous insufficiency (CVI) patients manifests itself not only in the form of disturbed macrocirculation but also and particularly in microangiopathic changes. For this reason, it is closely correlated with trophic disorders of the skin and can ultimately lead to ulceration. Using microcirculation research techniques, we are able to provide clear evidence of a typical microangiopathy in chronic venous insufficiency. Fifty CVI in Widmer stages I, II, and III were examined with fluorescence video microscopy, intravital video capillaroscopy, transcutaneous oxygen partial pressure measurement, TcpO2 and laser Doppler flowmetry. The effects of compression therapy with individually fitted compression stockings on capillary morphology were studied over a period of 4 weeks in 20 CVI patients in Widmer stages I and II. The capillary pressure was measured during simulated muscle contraction using a servo-null micropressure system. We periodically drew blood from the dorsalis pedis vein and a brachial vein of 11 healthy test persons and 8 patients with stage III CVI during experimental venous hypertension in order to evaluate the expression pattern of leukocyte adhesion molecules involved in inflammation: LFA-1 (CD11a), Mac-1 (CD11b), p150,95 (CD11c), CD18, VLA-4 (CD49d), and L-selectin (CD62L). In the same patients, we used immunohistochemical methods to examine clinically unaffected skin and the skin near an ulcer, focusing on the adhesion molecules ICAM-1, VCAM-1, and E-selectin. The microangiopathic changes observed with worsening clinical symptoms include a decrease in the number of capillaries, glomerulus-like changes in capillary morphology, a drop in the oxygen content (tcpO2) of the skin, increased permeability of the capillaries to low-molecular-weight substances, increased laser Doppler flux reflecting elevated subcutaneous flow, and diminished vascular reserve. These microangiopathic changes worsen in linear proportion to the clinical severity of chronic venous insufficiency. In patients with venous ulcerations, the baseline expression of LFA-1 and VLA-4 on lymphocytes, Mac-1 expression on the myeloid cell line, and L-selectin expression on all three cell lines was not significantly different form that in healthy controls. During orthostatic stress, there was a significant reduction in the expression of L-selectin in blood cells collected at foot level in the controls (p=0.002), but not in the patients. Clinical improvement by compression therapy was accompanied by an increase in the number of nutritive capillaries, while the diameter of the capillaries and the dermal papillae was reduced. When ulcers healed in a short period (<6 weeks), we observed a concomitant increase in the number of capillaries (p<0.05). Microangiopathy appears before tropic disorders of the skin develop. Even trophically normal skin areas may have dilated nutritive capillaries, an early sign of disturbed skin perfusion. These changes represent a plausible explanation for the development and to recurrency tendency of venous ulcers. The reduced expression of lymphocytic L-selectin in healthy controls during the orthostatic stress test may be an indication that the cells are activated by venous stasis. Clinically effective therapeutic measures improve the impaired microcirculation of the skin in the ankle area.

Structural analysis of high resolution in vitro MR images compared to stained grindings

The recent advancement of high resolution magnetic resonance imaging has opened up new avenues for the determination of structural characteristics of the trabecular network, which may significantly improve the diagnosis of osteoporosis. An analysis of the calcaneus in healthy women has shown similar age-related changes when comparing structural parameters in high resolution MR images and BMD as measured by DXA [1]. Here we undertook an in vitro study to further compare structural measurements in MR images with those from stained grindings. A 3D gradient echo sequence on a 1.5 T scanner was used to obtain four contiguous sagittal MR images with a slice thickness of 1 mm and an in plane pixel size of 195 microns. Twenty-one stained grindings with a slice thickness of 1 micron each were obtained from a 3 mm thick slab of the same volume investigated by MR. The stack of stained grindings was also used to simulate the influence of variations in slice thickness and in plane resolution. Results for structural parameters derived from the high resolution MR images differed considerably from those derived from the stained grindings because the MR images are heavily influenced by partial volume artifacts. This finding was supported by simulations which also revealed that even at a slice thickness of 500 microns and an in plane pixel size of 13 microns, accurate results could not be obtained when a histomorphometric type analysis was applied. Results also depended strongly on the segmentation method. However, contrary to the stained grindings, images averaged over several slices reveal the three-dimensional network character of the trabecular structure. New efforts should be undertaken to develop analysis strategies that are more adequate for in vivo high resolution images instead of using analysis techniques applied in classical histomorphometry.

[Hand-held ultrasound-guided vacuum biopsy of mammary lesions--first experiences]

OBJECTIVE

Evaluation of indications for ultrasound guided hand-held Mammotome-biopsy.

MATERIAL AND METHODS

To achieve breast diagnosis 50 ultrasound guided hand-held Mammotome-biopsies were performed between January 3rd and April 4th, 2000.

RESULTS

34 patients presented with non-palpable, 16 with palpable breast lesions. The benign-to-malignant ratio was 80% to 20%. Complete removal of the lesion we established in 22 (44%) of all 50 procedures. Definitive breast diagnosis of malignancies was achieved in all but one case.

CONCLUSIONS

We regard the ultrasound guided hand-held Mammotome-biopsy as diagnostic and surgical instrument that provides the clinician with a flexible and easy to use method of accurate breast diagnosis. Lesions too small, superficial, or deep for conventional core biopsy are indications for a ultrasound guided Mammotome-biopsy as well as abnormalities where wide sampling is considered important or small fibroadenomas. However, standard of care for breast diagnosis remains the conventional hand-held 14-gauge-core-biopsy. For malignant lesions hand held mammotomy must be regarded as a diagnostic and not a therapeutic procedure.