Spinocerebellar ataxia type 17 associated with an expansion of 42 glutamine residues in TATA-box binding protein gene

BACKGROUND

Spinocerebellar ataxia type 17 (SCA17) is caused by abnormal expansions of CAG/CAA trinucleotides within the TATA-box binding protein gene (TBP). The currently accepted critical threshold of abnormal expansions is ≥43.

OBJECTIVE

To investigate the minimal CAG/CAA expansion within the TBP in SCA17.

RESULTS

285 patients with autosomal-dominant ataxia were examined, and abnormal or borderline expansions of CAG/CAA within TBP in eight cases were found. Of those, four patients from three families had exactly 42 CAG/CAA trinucleotides, that is, one codon less than the currently accepted critical threshold of 43. The four patients presented with a relatively benign phenotype. All had dysdiadochokinesia and dysarthria. Mild gait ataxia was observed in three of the four patients.

CONCLUSION

The reference definition of at least 43 CAG/CAA codons for pathological SCA17 alleles should be lowered to 42.

Mass-transport limitations in spot-based microarrays

Mass transport of analyte to surface-immobilized affinity reagents is the fundamental bottleneck for sensitive detection in solid-support microarrays and biosensors. Analyte depletion in the volume adjacent to the sensor causes deviation from ideal association, significantly slows down reaction kinetics, and causes inhomogeneous binding across the sensor surface. In this paper we use high-resolution molecular interferometric imaging (MI2), a label-free optical interferometry technique for direct detection of molecular films, to study the inhomogeneous distribution of intra-spot binding across 100 micron-diameter protein spots. By measuring intra-spot binding inhomogeneity, reaction kinetics can be determined accurately when combined with a numerical three-dimensional finite element model. To ensure homogeneous binding across a spot, a critical flow rate is identified in terms of the association rate k(a) and the spot diameter. The binding inhomogeneity across a spot can be used to distinguish high-affinity low-concentration specific reactions from low-affinity high-concentration non-specific binding of background proteins.

Differential phase-contrast BioCD biosensor

Common-path differential phase-contrast interferometry measures the spatial gradient of surface dipole density on a bio-optical compact disk (BioCD) and is sensitive to small changes in dipole density following molecular binding of target molecules out of solution. The recognition molecules are antibody IgG proteins that are deposited in periodic patterns on the BioCD using soft lithography or photolithography on the silanized silica surfaces of dielectric mirrors. Spatial carrier-wave sideband demodulation extracts the slowly varying protein envelope that modulates the protein carrier frequency. The experimental interferometric profilometry has surface height sensitivity down to 20 pm averaged over a lateral scale of 70 microm with a corresponding scaling mass sensitivity limit of 1.5 pg/mm. Under the conditions of an IgG immunoassay with background changes caused during incubation, the scaling mass sensitivity is approximately 7 pg/mm. A saturated reverse immunoassay performed with IgG at 100 ng/ml showed false positive and false negative rates of 0.2%.

Stages of sleep pathology in spinocerebellar ataxia type 2 (SCA2)

BACKGROUND

Autosomal dominant spinocerebellar ataxia type 2 (SCA2) bears clinical and neuropathologic similarities to sporadic multisystem atrophy (MSA) or Parkinson disease, in which sleep pathology is well documented. However, those clinical entities have a marked variability of the reported sleep disturbances, and their etiology is heterogeneous. In contrast, the study of SCA2 provides an opportunity to examine a molecularly homogeneous patient group, in which disease stages can be defined not only based on disease duration and ataxia scores, but also with regard to modulatory effects of mutation size.

OBJECTIVE

To examine the presence and progression of sleep pathology in SCA2.

METHODS

We analyzed eight patients with disease durations of 3 to 31 years, all with medium size SCA2 expansions (CAG 38 to 49), using clinical scores, sleep interviews, and video-polysomnography (VPSG) recordings.

RESULTS

Almost all patients reported good subjective sleep quality and negated incidents of REM behavior disorder (RBD). At early disease stages, however, REM without atonia in four patients' VPSG suggested subclinical RBD. This was accompanied by a consistent reduction of REM density. In three patients at later SCA2 stages, REM sleep was undetectable, whereas slow wave sleep (SWS) was markedly increased at the cost of light sleep. Periodic leg movements, apnea, or hypopnea were not prominent.

CONCLUSIONS

Progressive loss of dream recall in spinocerebellar ataxia type 2 was found and correlated with stages of REM more than non-REM pathology in video-polysomnography. These stages correspond to the progressive atrophy from the pons, nigrostriatal projection, and locus ceruleus to the thalamus.

High-Speed Interferometric Detection of Label-Free Immunoassays on the Biological Compact Disc

Background: We describe a direct-detection immunoassay that uses high-speed optical interferometry on a biological compact disc (BioCD).

Methods: We fabricated phase-contrast BioCDs from 100-mm diameter 1.1-mm thick borosilicate glass disks coated with a 10-layer dielectric stack of Ta2O5/SiO2 that serves as a mirror with a center wavelength at 635 nm. The final layer is a λ/4 layer of SiO2 onto which protein patterns are immobilized through several different chemical approaches. Protein on the disc is scanned by a focused laser spot as the disc spins. Interaction of the light with the protein provides both a phase-modulated signal and a local reference that are combined interferometrically to convert phase into intensity. A periodic pattern of protein on the spinning disc produces an intensity modulation as a function of time that is proportional to the surface-bound mass. The binding of antigen or antibodies is detected directly, without labels, by a change in the interferometric intensity. The technique is demonstrated with a reverse assay of immobilized rabbit and mouse IgG antigen incubated against anti-IgG antibody in a casein buffer.

Results: The signal increased with increased concentration of analyte. The current embodiment detected a concentration of 100 ng/L when averaged over ∼3000 100-micron-diameter protein spots.

Conclusions: High-speed interferometric detection of label-free protein assays on a rapidly spinning BioCD is a high-sensitivity approach that is amenable to scaling up to many analytes.

Point-of-care biosensor systems for cancer diagnostics/prognostics

With the growing number of fatalities resulting from the 100 or so cancer-related diseases, new enabling tools are required to provide extensive molecular profiles of patients to guide the clinician in making viable diagnosis and prognosis. Unfortunately with cancer-related diseases, there is not one molecular marker that can provide sufficient information to assist the clinician in making effective prognoses or even diagnoses. Indeed, large panels of markers must typically be evaluated that cut across several different classes (mutations in certain gene fragments--DNA; over/under-expression of gene activity as monitored by messenger RNAs; the amount of proteins present in serum or circulating tumor cells). The classical biosensor format (dipstick approach for monitoring the presence of a single element) is viewed as a valuable tool in many bioassays, but possesses numerous limitations in cancer due primarily to the single element nature of these sensing platforms. As such, if biosensors are to become valuable tools in the arsenal of the clinician to manage cancer patients, new formats are required. This review seeks to provide an overview of the current thinking on molecular profiling for diagnosis and prognosis of cancers and also, provide insight into the current state-of-the-art in the biosensor field and new strategies that must be considered to bring this important technology into the cancer field.

An autosomal dominant ataxia maps to 19q13: Allelic heterogeneity of SCA13 or novel locus?

The autosomal dominant spinocerebellar ataxias (ADCAs) represent a growing and heterogeneous disease phenotype. Clinical characterization of a three-generation Filipino family segregating a dominant ataxia revealed cerebellar signs and symptoms. After elimination of known spinocerebellar ataxia (SCA) loci, a genome-wide linkage scan revealed a disease locus in a 4-cM region of 19q13, with a 3.89 lod score. This region overlaps and reduces the SCA13 locus. However, this ADCA is clinically distinguishable from SCA13.

Simultanes nichtinvasives Monitoring mit Laser-Doppler-Flussmessung und Gewebespektrometrie bei fasziokutanen Radialislappen und osteokutanen Fibulatransplantaten

AIM

In the literature currently available monitoring devices are usually divided into two major groups: those for monitoring perfusion and those for measuring tissue oxygenation. The O(2)C (oxygen to see) system combines these two ways of monitoring free flap viability. The aim of this prospective study was to determine the necessity of flap revision and when unnecessary revision can be avoided. Another point of interest was the question of whether critical values for the successful course of free flaps could be defined and in addition whether such values would differ for different flap types.

PATIENTS AND METHODS

In a prospective study 82 free flaps (61 radial forearm flaps and 21 fibula flaps) were monitored with the O(2)C monitoring unit. Measurements were carried out intraoperatively and postoperatively up to 14 days.

RESULTS

Perfusion compromise occurred in 12 (14.6%) of 82 monitored free flaps. Operative exploration was performed in seven cases, in five of them successfully. Five flaps (three radial forearm and two fibula flaps) were lost due to vascular compromise, which led to an overall success rate of 93.4%. Venous congestion was identified by a rapid increase in hemoglobin concentration of more than 30%. An abrupt decline of blood flow and hemoglobin oxygenation indicated arterial occlusion. Vascular complications were detected in all cases prior to clinical assessment with no false positive or negative results. For radial forearm flaps a hemoglobin oxygenation of 15%, a superficial flow of 10 AU, and a deep flow of 20 AU were identified as minimum values for flap viability. For fibula flaps a hemoglobin oxygenation of 10%, a superficial flow of 5 AU, and a deep flow of 15 AU were determined as minimum values.

CONCLUSION

O(2)C combines laser Doppler flowmetry and tissue spectrophotometry and for the first time allows simultaneous measurement of the microcirculatory parameters including blood flow, flow velocity, hemoglobin concentration, and hemoglobin oxygenation. We found this new noninvasive technique to be a reliable and accurate method for evaluating flap viability and improving the success rate in free flap transfer.

Reversible ischaemia after raising a radial forearm flap with ulceration of three fingers in a cigarette smoker

The radial forearm flap is a standard method for the reconstruction of intraoral defects of soft tissues. We report the case of a middle-aged man who developed ischaemia in three fingers after a fasciocutaneous radial flap had been raised. The preoperative Allen test to diagnose occlusion of radial or ulnar artery was satisfactory. Soon after the operation the patient resumed smoking and four weeks later he developed ulcers on the thumb, index, and middle fingers. Only after he had stopped smoking and been given acetylsalicylic acid and heparin did blood flow and capillary hemoglobin oxygenation increase. As a result, his radial fingers recovered completely.

Attenuation of Leukocyte Sequestration by Selective Blockade of PECAM-1 or VCAM-1 in Murine Endotoxemia

BACKGROUND

Molecular mechanisms regulating leukocyte sequestration into the tissue during endotoxemia and/or sepsis are still poorly understood. This in vivo study investigates the biological role of murine PECAM-1 and VCAM-1 for leukocyte sequestration into the lung, liver and striated skin muscle.

METHODS

Male BALB/c mice were injected intravenously with murine PECAM-1 IgG chimera or monoclonal antibody (mAb) to VCAM-1 (3 mg/kg body weight); controls received equivalent doses of IgG2a (n = 6 per group). Fifteen minutes thereafter, 2 mg/kg body weight of Salmonella abortus equi endotoxin was injected intravenously. At 24 h after the endotoxin challenge, lungs, livers and striated muscle of skin were analyzed for their myeloperoxidase activity. To monitor intravital leukocyte-endothelial cell interactions, fluorescence videomicroscopy was performed in the skin fold chamber model of the BALB/c mouse at 3, 8 and 24 h after injection of endotoxin.

RESULTS

Myeloperoxidase activity at 24 h after the endotoxin challenge in lungs (12,171 +/- 2,357 mU/g tissue), livers (2,204 +/- 238 mU/g) and striated muscle of the skin (1,161 +/- 110 mU/g) was significantly reduced in both treatment groups as compared to controls, with strongest attenuation in the PECAM-1 IgG treatment group. Arteriolar leukocyte sticking at 3 h after endotoxin (230 +/- 46 cells x mm(-2)) was significantly reduced in both treatment groups. Leukocyte sticking in postcapillary venules at 8 h after endotoxin (343 +/- 69 cells/mm2) was found reduced only in the VCAM-1-mAb-treated animals (215 +/- 53 cells/mm2), while it was enhanced in animals treated with PECAM-1 IgG (572 +/- 126 cells/mm2).

CONCLUSION

These data show that both PECAM-1 and VCAM-1 are involved in endotoxin-induced leukocyte sequestration in the lung, liver and muscle, presumably through interference with arteriolar and/or venular leukocyte sticking.

[Importance of microcirculation in plastic surgery]

The article summarizes distinct microcirculatory models for use in surgical research with a special interest to plastic surgery. Methods for the quantitative analysis of the microcirculation in burns, flaps and wounds are presented. Vascularization of biomaterials can be observed by means of the dorsal skinfold chamber model in hamsters and mice. Developing capillary sprouts can be assessed by means of videomicroscopy and angiogenetic drugs can be tested using this model. Hairless mice allow for direct, long-term observation of the microcirculation in burns as well as during healing of dermal wounds. The pathophysiology of diabetic wound healing can also be studied. A mouse model to assess flap microcirculation during ischemia/reperfusion injury with special emphasis on platelet/endothelium interaction in vivo is described. Platelets adherent to the inner vessel wall are known to trigger compromised perfusion in flaps. The model allows us to test anti-thrombotic drugs. The use of a special microscopic device (OPS imaging) allows us to study the microcirculation at sites of burn injury and chronic wounds in humans. Microcirculatory research in plastic surgery has increased the understanding of the pathophysiology of vascularization of biomaterials, wound healing and ischemia/reperfusion.

Limitationen der Blutversorgung des Hautlappens beim Facelifting

BACKGROUND

Besides nerve injuries or hematomas, one of the main risks of face lift surgery is the development of skin necrosis. We therefore investigated which arteries contribute to the blood supply of the face lift skin flap and how extensively mobilization can be performed before arterial cutaneous circulation is endangered.

MATERIAL AND METHOD

In six cadavers, selective dye injections into the branches of the carotid external artery were performed to determine the location of their vascular territories in relation to the face lift region. In another 12 cadavers, face lift flaps were raised with different extension of the undermined skin area before dye injections were performed.

RESULTS

It was shown that the facial artery provides blood supply to the area of the face lift flap by perforating vessels in the paranasal, perioral and submental regions and the transverse facial artery by a perforating vessel below the malar bone prominence. Although the perforating vessel of the transverse facial artery was transected by standard mobilization, the face lift flaps were sufficiently perfused via the paranasal and perioral perforating vessels of the facial artery alone.

CONCLUSION

We conclude that undermining of the face lift flap should not exceed the nasolabial fold to preserve the perforating vessels of the facial artery in the centrofacial region.

Botulinumtoxin zur Behandlung des gustatorischen Schwitzens

BACKGROUND

Botulinum toxin A has meanwhile become a proven method for treatment of gustatory sweating (focal hyperhidrosis, Frey's syndrome). Clear-cut recommendations regarding dosage of botulinum toxin A in Frey's syndrome are currently not available. The aim of this prospective randomized study therefore was to investigate botulinum toxin A with respect to its efficacy in Frey's syndrome, the ideal dose yielding maximal duration of the effect, and patient contentedness as well as unwanted side effects in patients of the Clinic of OMF Surgery at the Ruhr-University of Bochum.

PATIENTS AND METHOD

Twenty patients suffering from severe Frey's syndrome as a result of operations of the parotid gland were examined with the starch iodine test according to Minor. The gustatory skin areas were re-examined after intracutaneous injection of botulinum toxin A for up to 1 year. The patients ( n=20) were randomly assigned to two different treatment groups (group I: 2 MU/cm(2), n=10; group II: 3 MU/cm(2), n=10).

RESULTS

Mean sweating skin areas in the two treatment groups ranged between 39+/-9 and 32+/-12 cm(2), respectively. A single injection of 3 MU botulinum toxin A resulted in a nearly complete blockade of gustatory sweating for the observation period of 1 year. In the group treated with 2 MU botulinum toxin A, 44% of the total gustatory skin areas were still sweating, thus necessitating a second injection of botulinum toxin A in these patients.

CONCLUSION

Intracutaneous injection of botulinum toxin A represents a highly effective and minimally invasive procedure for the treatment of Frey's syndrome. This study shows for the first time that a dosage of 3 MU/cm(2) of botulinum toxin A achieves a complete and reliable blockade of gustatory sweating lasting for at least 12 months. This dose may therefore be recommended for treatment of this syndrome.

[Management of zygomatic fractures via a transconjunctival approach with lateral canthotomy while preserving the lateral ligament]

INTRODUCTION

This study reports on a modified approach to treat zygomatic fracture. For the surgical approach, a transconjunctival incision and, instead of a lateral canthotomy, a superficial incision of the skin and subcutaneous tissue was used, preserving the lateral ligament. The results are compared with those of previous techniques, especially the subciliary incision.

PATIENTS

In a prospective study, 30 patients (9 females and 21 males, mean age 32.1 years) with zygomatic fractures were operated using this approach. Mean follow-up time was 6 months after removal of the plates. Fractures were caused by trauma due to fighting, bicycle falls, or sport accidents. Follow-up radiographs were used to evaluate the position of the zygoma after reduction and rigid fixation.

RESULTS

Reduction and rigid fixation of the fractures were possible to perform in all cases. The access to the orbital floor and the exposure of the inferior and lateral rim were satisfactory and an additional latero-orbital cut was not necessary. The disadvantage of the complete incision of the lateral ligament with the necessity of intraoperative refixation and possible ectropium of the eyelid could be avoided. Injuries or infections of the cornea or the bulbus did not occur. Postoperative complications such as scar formation resulting in entropium or ectropium were not seen.

CONCLUSION

These results show that the transconjunctival approach with lateral superficial incision preserving the lateral ligament for treatment of zygomatic fractures is satisfactory in all cases of rigid fixation of both inferior and lateral rims. Because of its esthetic and functional advantages this approach has become standard in our department.

Restoration of blood flow and evaluation of corresponding angiogenic events by scanning electron microscopy after a single dose of VEGF in a model of peripheral vascular disease

The angiogenic effect of vascular endothelial growth factor (VEGF) has typically been assessed by indirect methods, including microsphere injection and angiography. Here, we use 3-D scanning electron microscopy (SEM) to directly visualize patterns of angiogenesis after a single bolus administration of VEGF in a model of peripheral vascular ischemia. Hind limb ischemia was induced by subcutaneous turniquet implantation in adult Wistar rats. The control group (group A, n = 10) was left untreated, group B (n = 10) received a single dose of VEGF (50 microg) injected in the peroneus muscle. LASER Doppler was applied for blood flow measurements. Animals were sacrificed on day 14 after ischemia induction and vascular casting was performed. Angiogenetic events such as 'tiny lateral sprouts', arcus formations', confluences and the angle of sprouting were assessed by SEM. Significant capillary sprouting was observed in both groups. VEGF-treated limbs demonstrated higher degrees of capillary growth (P = 0.01) and flow recovery (P = 0.028). 3-D-SEM showed sprouts to be more frequent in group B. Tiny lateral sprouts, which always left the mother vessel at an angle of 90 degrees and which were of small diameter and lacked imprints of endothelial cell nuclei, were more frequent in the VEGF-treated group (P = 0.018). Arcus formation was significantly higher in the treated group (P = 0.02). We have developed a simple and effective experimental model of ischemia. For the study of angiogenic phenomena, 3-D imaging of the microvasculature offers a direct and conclusive method for the study of angiogenic events.

Time gated fluorescence spectroscopy in Barrett's oesophagus

BACKGROUND AND AIMS

Specialised intestinal metaplasia and its dysplastic transformation, which precedes cancer in Barrett's oesophagus cannot be differentiated in standard gastroscopy. The aim of this study was to investigate whether laser induced protoporphyrin IX fluorescence permits the detection of specialised intestinal metaplasia and dysplasia during endoscopy and to take biopsy specimens in a guided rather than random manner.

METHODS

In 53 patients with Barrett's oesophagus 5-aminolaevulinic acid was sprayed on the mucosa. Approximately 60 to 120 minutes later, biopsy specimens were taken based on point-like measurements of delayed fluorescence intensity ratios of protoporphyrin IX in vivo. Two independent pathologists examined the 596 biopsy specimens taken, 168 of which were selected to be investigated by a third pathologist. Among these specimens only those (n=141) with a consensus diagnosis by at least two pathologists and p53 expression as additional marker were included in the analysis.

RESULTS

The median of normalised fluorescence intensity (ratio of delayed PpIX fluorescence intensity to immediate autofluorescence intensity) in non-dysplastic specialised intestinal metaplasia (0.51, 68% CI 0.09 to 1.92) and low grade dysplasia (1.89, 68% CI 0.55 to 3.92) differed significantly (p<0.005). Dysplasia was detected at a rate 2.8-fold higher compared with screening endoscopy despite taking fewer specimens. In addition, three early cancers were detected for the first time. Moreover, this method permitted differentiation of specialised intestinal metaplasia from junctional or gastric-fundic type epithelium (p<0.013).

CONCLUSIONS

For the first time it was possible to differentiate low grade dysplasia from non-dysplastic Barrett's mucosa during endoscopy based on delayed laser induced fluorescence endoscopy of PpIX. Furthermore, the method helps to detect specialised intestinal metaplasia in short Barrett's oesophagus.

[Oxygen-carrying solutions improve tissue oxygenation in striated skin muscle subjected to critical ischemia]

AIM

The aim of the present study was to investigate the effects of the oxygen-carrying hemoglobin solution DCLHb (diaspirin-crosslinked hemoglobin) on microvascular perfusion and tissue oxygenation in striated skin muscle after the induction of critical ischemia followed by reperfusion.

MATERIAL AND METHODS

Using intravital fluorescence microscopy the functional capillary density was analyzed in the striated skin muscle of Syrian golden hamsters before the induction of a 4-h period of ischemia and again after 0.5 h, 2 h and 24 h of reperfusion ( n=8 in each group). In other animals ( n=8 in each group), the identical protocol was applied to determine tissue oxygenation by means of the multi-wire surface electrode (MDO, Eschweiler, Kiel, Germany). Animals in the treatment group ( n=8) received a bolus infusion of 5 ml of DCLHb per kg of body wt. (10 g/dl; Baxter, Ill., USA) 15 min before reperfusion. Control animals ( n=8) received equivalent volumes of isotonic saline (Braun, Melsungen, Germany). RESULTS. Functional capillary density was dramatically reduced in control animals, while in DCLHb-treated animals significantly higher values were observed. Efficient restoration of tissue PO(2) was also seen in DCLHb-treated animals and not in control animals.

CONCLUSIONS

These results show that the oxygen-carrying solution DCLHb is significantly more efficient than the commonly used crystalloid solutions in restoration of tissue PO(2) after ischemia-reperfusion. The use of this solution therefore appears promising as a means of protecting the tissue put at risk by ischemia from reperfusion damage.

ACRC codes for a novel nuclear protein with unusual acidic repeat tract and maps to DYT3 (dystonia parkinsonism) critical interval in xq13.1

We searched for novel genes as candidates of X-linked dystonia parkinsonism (XDP) in the critical interval of Xq13.1 that harbors the disease locus (DYT3). A gene, ACRC (acidic repeat containing), was discovered by a combination of in silico and "wet" experiments. ACRC is composed of at least 12 exons and 11 introns. It is expressed in all tissues tested, including skeletal muscle, liver, kidney, pancreas, heart, lung, and brain. Highest levels of expression are found in skeletal muscle. The ACRC protein is characterized by a previously undescribed acidic repeat tract of 21 units of 8-10 amino acids. The N-terminal portion of the protein is highly acidic (pI=3.2), and the C-terminal region is basic (pI=10.2). There are nuclear localization signals in its C-terminal portion. Extensive mutation analysis of the transcribed region of the gene, including intron-exon boundaries and the 5' and 3' untranslated intervals, did not reveal a mutation in XDP patients. Exclusion of a mutation in the transcribed portion of this and all other known genes within the DYT3 critical interval suggests that XDP is most likely caused by a mutation in a regulatory region of a gene within the critical interval, or by a structural rearrangement.

Changes in the local blood and lymph microcirculation in response to direct mechanical trauma applied to leg: in vivo study in an animal model

BACKGROUND

The aim of this study was to investigate changes in the blood microcirculation of skin, subcutaneous tissue, and striated muscle, and the venous and lymphatic outflow from hind limb, after a standardized mechanical trauma.

METHODS

Trauma, defined as 50% of the minimal energy needed for tibia fracture (3.7 J/g), was applied to the leg of hairless mice. Intravenously injected fluorescein isothiocyanate-dextran 150 kDa and Rhodamine-6G were used for intra-vital fluorescence microscopy of blood vessels. Lymphatics were stained with fluorescein isothiocyanate-dextran injected into the footpad. A computer-assisted analysis system allowed measurement of the functional capillary density (FCD), vessel diameters, velocity of blood flow, and edema value expressed as extravasation index (EV). The percentage of slowly rolling and sticking leukocytes in postcapillary venules was estimated.

RESULTS

At the site of injury, trauma resulted in significant reduction of FCD in skin, subcutaneous tissue, and striated muscle. There were no significant differences in the vessel diameter (skin subcutaneous and muscle arterioles and venules, and superficial saphenous artery and vein) or velocity of blood flow (subcutaneous tissue and muscle venules). The EV increased significantly in muscle venules and was higher in muscles, subcutaneous tissue, and superficial saphenous veins than in controls (nonsignificantly). An increased percentage of slowly rolling and sticking leukocytes was noted in the superficial saphenous vein at the site of injury and proximal to it. The lymphatics remained patent, with faster visualization and increased summarized cross-sectional areas in traumatized extremities.

CONCLUSION

Early changes occurring in soft tissues in response to mechanical injury were characterized by reduction in FCD of skin and muscles, and less in subcutis; increased EV, reflecting leakage of macromolecules; increased percentage of slowly rolling and sticking leukocytes; maintenance of lymphatic vessel continuity; and increased lymph formation and flow rate.

Heparin protects local skin microcirculation in 210 minutes-long intravital microscopy observations under general anaesthesia

Prolonged immobilization of severely ill, bed-ridden patients results in formation of pressure ulcers following inappropriate tissue blood perfusion, and local activation of leukocyte - endothelial cell interactions (L/EC). Various treatment modalities were implemented to improve local microcirculation with controversial results. The aim of our study was to investigate the influence of heparin and buflomedil, drugs improving the microcirculation, on local skin blood perfusion using intravital fluorescent microscopy (IVM) technique.

MATERIAL AND METHODS

Experiments were carried out on 24 male hairless mice under inhalatory isofluran anaesthesia. Intravenous injection of FITC-dextran (150 kD, 5%) allowed to visualize capillaries during IVM, after immobilisation of hind limb, in an observation chamber. Observations were performed after i.v. injection of heparin (66 IU/kg b.w., n = 8) or buflomedil (6 mg/kg b.w., n = 8) 30, 120 and 210 minutes after chamber installation. Observations were recorded in 30 sec sequences on S-VHS tapes and evaluated using special software. Functional capillary density (FCD), defined as a total length of red cells perfused capillaries per observation field (expressed in cm/cm(2)), postcapillary venule diameters, and number of sticking leukocytes per 0.2 mm vessel length during 30 sec observation time, served as parameters of skin blood perfusion and activation of L/EC interactions.

RESULTS

A statistically significant decrease of FCD from 152.7 +/- 38.5 to 100.7 +/- 36.7 cm/cm (2) (p<0.05) was observed in control animals during 210 min lasting observation. Administration of heparin prevented decrease in FCD occurring in control animals during intravital microscopy, whereas buflomedil was found ineffective. Both drugs induced a nonsignificant reduction in the number of sticking leukocytes, whereas no changes in postcapillary venule diameters could be observed.

CONCLUSION

The results suggest a protective effect of heparin in clinical therapeutic doses against impairment of skin perfusion during IVM. This observation may justify a trial on the effects of heparin in prevention of development of pressure ulcers.

Protoporphyrin IX occurs naturally in colorectal cancers and their metastases

Colorectal cancers exhibit a red fluorescence. The nature of the responsible fluorophore and its eventual diagnostic potential were investigated. Thirty-three consecutive colorectal resection specimen, 32 of which with histologically confirmed cancer, and a total of 1053 palpable mesenteric nodes were fluorimetrically characterized ex vivo. Furthermore, frozen material from 28 patients was analyzed, selected for the availability of primary tumor material and metastatic tissue, e.g., lymphatic and liver metastases from the same patient. Biochemical characterization was carried out through chemical extraction and reversed phase high-performance liquid chromatography. The fluorescence spectra of tissues, tissue extracts, and standard solutions of porphyrins were determined using a pulsed solid-state laser system for excitation and an imaging polychromator, together with an intensified CCD camera for time-delayed observation. Protoporphyrin IX (PpIX) was identified as the predominant fluorophore in primary tumors and their metastases. The fluorophore occurred in the absence of necrosis and in sterile locations. In untreated cases (n = 24), PpIX fluorescence discriminates metastatically involved lymph nodes from all other palpable nodes with a sensitivity of 62% at a specificity of 78% (P < 0.0001). After neoadjuvant treatment of rectal cancer, the PpIX fluorescence level of the primary tumors was reduced and a discrimination of lymph nodes based on PpIX-fluorescence was impossible. We conclude that colorectal cancer metastases accumulate diagnostic levels of endogenous PpIX as a result of a tumor-specific metabolic alteration.