PerBrain: a multimodal approach to personalized tracking of evolving state-of-consciousness in brain-injured patients: protocol of an international, multicentric, observational study

BACKGROUND

Disorders of consciousness (DoC) are severe neurological conditions in which consciousness is impaired to various degrees. They are caused by injury or malfunction of neural systems regulating arousal and awareness. Over the last decades, major efforts in improving and individualizing diagnostic and prognostic accuracy for patients affected by DoC have been made, mainly focusing on introducing multimodal assessments to complement behavioral examination. The present EU-funded multicentric research project "PerBrain" is aimed at developing an individualized diagnostic hierarchical pathway guided by both behavior and multimodal neurodiagnostics for DoC patients.

METHODS

In this project, each enrolled patient undergoes repetitive behavioral, clinical, and neurodiagnostic assessments according to a patient-tailored multi-layer workflow. Multimodal diagnostic acquisitions using state-of-the-art techniques at different stages of the patients' clinical evolution are performed. The techniques applied comprise well-established behavioral scales, innovative neurophysiological techniques (such as quantitative electroencephalography and transcranial magnetic stimulation combined with electroencephalography), structural and resting-state functional magnetic resonance imaging, and measurements of physiological activity (i.e. nasal airflow respiration). In addition, the well-being and treatment decision attitudes of patients' informal caregivers (primarily family members) are investigated. Patient and caregiver assessments are performed at multiple time points within one year after acquired brain injury, starting at the acute disease phase.

DISCUSSION

Accurate classification and outcome prediction of DoC are of crucial importance for affected patients as well as their caregivers, as individual rehabilitation strategies and treatment decisions are critically dependent on the latter. The PerBrain project aims at optimizing individual DoC diagnosis and accuracy of outcome prediction by integrating data from the suggested multimodal examination methods into a personalized hierarchical diagnosis and prognosis procedure. Using the parallel tracking of both patients' neurological status and their caregivers' mental situation, well-being, and treatment decision attitudes from the acute to the chronic phase of the disease and across different countries, this project aims at significantly contributing to the current clinical routine of DoC patients and their family members.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT04798456 . Registered 15 March 2021 - Retrospectively registered.

Hydrochlorothiazide does not lead to phototoxic reactions and DNA damage in healthy volunteers the HCTox study

Purpose

Hypertension represents the most common cardiovascular risk factor for premature death worldwide. Hydrochlorothiazide (HCTZ) is one of the most commonly used antihypertensive and diuretic drug worldwide. Recently, pharmacoepidemiologic studies associated the use of HCTZ with increased risk of skin cancer. As a result, prescriptions of HCTZ decreased, leading to worsening of blood pressure therapy in a significant proportion of patients. However, whether HCTZ causes skin cancer remains elusive. We aimed to examine the photosensitive potential of HCTZ in vivo. To further enlighten the pathophysiologic mechanisms of carcinogenesis and phototoxicity caused by HCTZ in vitro, we conducted a series of laboratory experiments.

Methods

This randomized, double-blinded, placebo-controlled clinical trial assessed the phototoxic properties of HCTZ. We randomly assigned 30 healthy adult volunteers in a 2:1 ratio to either HCTZ 25 mg daily or placebo once daily for 15 days. Skin photosensitivity by phototesting for UV-A and UV-B radiation, office blood pressure, serum-vitamin-D status and urinary excretion of thymidine-dimers were measured. To further assess the pathophysiologic mechanisms of possibly HCTZ induced photosensitivity, human keratinocytes (HaCaT) were incubated with HCTZ and then irradiated with UV-B radiation (311 nm one burst of 100 J/cm2). rt-PCR-testing and western blots were performed to analyze reactive oxygen species, inflammation and carcinogenesis.

Results

All 30 participants were adherent to the protocol, as confirmed by toxicological analysis of serum and urine. Skin photosensitivity to exposure of UV-A and UV-B radiation remained unchanged in both groups (UVB-MED: HCTZ Δ = 0.0 J/cm2 vs. placebo Δ = −0.2 J/cm2; p=0.06). No thymidine-dimers were detected in urine of either group. Systolic blood pressure decreased in both groups but was not different between HCTZ and placebo (HCTZ Δ = −5.2 mmHg vs. placebo Δ = −5.4 mmHg; p=0.94). The same was found for diastolic blood pressure (HCTZ Δ = −1.9 mmHg vs. placebo Δ = −4.3 mmHg; p=0.34). Serum-vitamin-D increased in both groups (HCTZ Δ = +2.7 ng/ml vs. placebo Δ = 0.9 ng/ml; p=0.56). In addition, combination of HCTZ and a high intensity burst of UV-B radiation did not increase expression of inflammatory proteins or increase formation of reactive oxygen species (SOD-1, SOD-2, and catalase).

Conclusions

HCTZ did not significantly increase photosensitivity for UV-A or UV-B radiation in healthy volunteers compared with placebo. Moreover, no relevant DNA-damages were detected in either group. HCTZ alone did not increase inflammation, formation of reactive oxygen species or carcinogenesis in human keratinocytes. Furthermore, the combination of a UV-B burst of 100 J/cm2 and HCTZ was not associated with additive effects on inflammation, reactive oxygen species or carcinogenisis.

HCTZ in a cumulative dose of 375 did not increase photosensitivity or DNA-damages in vivo.

Funding Acknowledgement

Type of funding sources: None.

Pharmacological inhibition of acetylcholine-regulated potassium current (IK,ACh) and associated A1- and M2-pathways prevent atrial arrhythmogenic changes in a rat model for obstructive sleep apnea

Background

In obstructive sleep apnea (OSA), intermittent hypoxemia and intrathoracic pressure fluctuations may increase vagal tone and adenosine release, potentially resulting in an increased acetylcholine-regulated potassium current (IK,ACh). Here we elucidated acute atrial electrophysiological effects of obstructive respiratory events simulated by intermittent negative upper airway pressure (INAP) and the role of atrial IKACh activation by A1-receptor and M2-receptor activation.

Methods

In sedated spontaneously breathing rats (2% isoflurane), either IK,ACh-inhibitor (XAF-1407: 1mg/kg), M2-receptor inhibitor (atropine; 1μg/kg), A1-receptor inhibitor (Rolofylline; 1μg/kg) or a buffer-based vehicle was perfused (Control). INAP was applied non-invasively by a negative pressure device 14 times throughout 70 minutes. Simulated apneas were maintained for one minute with a four minute resting period. Atrial effective refractory period (AERP) and atrial activation time were acquired by a programmed atrial pacing protocol before, during and after applied INAP throughout the study.

Results

Independent of IK,Ach-inhibition, single INAP applications prolonged transiently atrial activation times (Control: INAP vs. pre-INAP p=0.034; XAF-1407: INAP vs. pre-INAP p=0.039). In control-rats, seventy minutes of repetitive INAP decreased AERP by 15.45±0.06% (vs. baseline p=0.0015), which was reversible upon 1 hour of recovery. AERP shortening correlated with the cumulative pressure applied per body weight (Pearson r=−0.773; p=0.025). Whilst only XAF-1407 and atropine increased baseline AERP, all drug interventions, XAF-1407, atropine and Rolofylline could prevent INAP-associated AERP shortening (end INAP-protocol vs. respective baseline XAF-1407 p=0.994; atropine p=0.984; Rolofylline p=0.951). Drops in oxygen saturation and applied INAP were comparable in all groups.

Conclusion

Short-term simulated OSA is associated with progressive AERP shortening, which was determined by the cumulative negative airway pressure applied. This potentially represents an important insight in future OSA treatment. Pharmacological IK,ACh inhibition prevented INAP-associated AERP-shortening suggesting an involvement in acute atrial arrhythmogenesis in OSA. However, if IK,Ach and its potential upstream activating A1- and M2-pathway pose a pharmacological treatment target for OSA-patients with AF, requires further investigation.

Funding Acknowledgement

Type of funding source: None

Obstructive respiratory events transiently impair electromechanical coupling and increase premature ventricular contraction rate in a drug-induced Long-QT-2 pig model

Background

Obstructive sleep apnea (OSA) is characterized by intermittent negative thoracic pressure fluctuations and intermittent hypoxemic events. Recent findings associate OSA with impaired ventricular repolarization during sleep and increased risk of sudden cardiac death, which may have special implications for Long-QT-2-syndrome patients. Therefore, we elucidated changes in ventricular repolarization and electromechanical coupling (electromechanical window; EMW) during either obstructive respiratory events simulated by intermittent negative upper airway pressure (INAP) or hypoxemic events simulated by intermittent hypoxia (IH) in vehicle (VEH) and dofetilide (DOF) treated pigs, as a simulation of drug induced Long-QT-2 syndrome.

Methods

In sedated spontaneously breathing pigs, either VEH or DOF (50 μg/kg) was perfused and INAP was applied by a negative pressure device connected to the intubation tube. For IH-application the device was connected and left turned off. INAP or IH was maintained for 75 seconds followed by a ten-minute resting period. In order to evaluate the electromechanical window, the time difference between electrical (QT-duration) and mechanical systole (Q-wave to the end of left ventricular pressure signal, QLVPend) was measured before (pre-INAP/-IH), during and 60 seconds after INAP/IH (post-INAP/-IH). Incidence rates of premature ventricular contractions (PVC) and ventricular tachycardia were compared pre- to post-INAP/-IH.

Results

In VEH-pigs, EMW shortened throughout INAP and post-INAP periods steadily (VEH: pre-INAP: 81.69±2.31ms; INAP: 55.65±6.13ms; post-INAP: 38±8.89ms. p=0.008). EMW shortening during post-INAP was associated with an increase in PVCs (VEH: pre-INAP 5.41±1.87 vs. post-INAP 26.5±8.15; p=0.04). In DOF-pigs, INAP-associated EMW-shortening was further potentiated (DOF: pre-INAP: 61.16±7.18ms; INAP: 38.09±9.84ms; post-INAP: 14.93±9.24ms. p=0.016), which was associated with an increase in PVCs (DOF: pre-INAP 4.75±2.36 vs. post-INAP 36.58±10.92; p=0.017). Administration of Atenolol could prevent post-INAP shortening of the EMW and decrease counts of premature ventricular contractions. While desaturations were comparable in INAP and IH, IH did not result in EMW-shortening or increased arrhythmia risk.

Conclusion

Transient dissociation of the ventricular electromechanical coupling during a simulated obstructive apnea, but not during IH, creates a dynamic and sympathetically driven arrhythmogenic substrate. Apnea associated ventricular electromechanical uncoupling was aggravated in a drug-induced Long-QT-2 simulation. Whether OSA represents a modifiable arrhythmogenic risk factor in Long-QT-2-patients warrants further studies.

Funding Acknowledgement

Type of funding source: Foundation. Main funding source(s): Novo nordisk fonden

741Pharmacological inhibition of the acetylcholine-regulated potassium channel (IK,ACh) prevents atrial arrhythmogenic changes in a rat model for obstructive sleep apnea

Background

In obstructive sleep apnea (OSA), intermittent hypoxemia and intrathoracic pressure fluctuations may increase vagal tone, resulting in an increased acetylcholine-regulated potassium current (IK,ACh). Here we elucidated acute atrial electrophysiological effects of obstructive respiratory events simulated by intermittent negative upper airway pressure (INAP) and the role of atrial IKACh activation.

Methods

In sedated spontaneously breathing rats (2% isoflurane), either IK,ACh-inhibitor (XAF-1407: 1mg/kg) or a buffer-based vehicle was perfused (Control). INAP was applied non-invasively by a negative pressure device 14 times throughout 70 minutes. Simulated apneas were maintained for one minute with a four minute resting period. Atrial effective refractory period (AERP), inducible atrial fibrillation (AF)-durations and atrial activation time were acquired by a programmed atrial pacing protocol before, during and after applied INAP throughout the study.

Results

During single INAP applications atrial activation times prolonged transiently in both groups (Control: INAP vs. pre-INAP p = 0.034; XAF-1407: INAP vs. pre-INAP p = 0.039). In control-rats, seventy minutes of repetitive INAP prolonged P-wave duration (+10.8 ± 2.7% vs. baseline, p = 0.008) and decreased AERP by 14.6 ± 3.1% (vs. baseline p = 0.001). AERP shortening correlated with the cumulative pressure applied per body weight (Pearson r= -0.773; p= 0.025). XAF-1407 could prevent P-wave prolongation and AERP shortening. Inducible AF-durations (CTR 0.94 ± 0.34s vs. XAF-1407 0.1 ± 0.09s p = 0.049) were shorter in XAF-1407 treated rats. Drops in oxygen saturation or applied INAP were comparable in control and XAF-1407 rats.

Conclusion

Short-term simulated OSA is associated with AF-related arrhythmogenic changes, which could be prevented by pharmacological IK,ACh inhibition. Moreover, the cumulative negative airway pressure applied determined aERP shortening and may represent a target for OSA treatment. These findings have important implications for the antiarrhythmic management of AF patients with OSA.

P2561Withdrawal of simulated obstructive sleep apnea partially reverses atrial arrhythmogenic substrate in rats

Background

Obstructive sleep apnea (OSA) is associated with structural alterations of the left atria (LA) and increased occurrence of atrial fibrillation (AF). Obstructive respiratory events lead to intermittent hypoxia (IH) and ineffective inspiration against the occluded upper airways, which result in intrathoracic and cardiac transmural pressure changes. Data on reversibility of LA-structural remodeling processes after withdrawal of OSA are still missing.

Objectives

Aim of the study was to develop a novel AF animal model mimicking intrathoracic pressure changes in addition to IH and to analyze the effect of OSA-withdrawal on atrial remodeling reversibility.

Method

In sedated rats (2% isoflurane), IH (n=9) was applied by intermittent increase in the respiratory dead volume. Standardized obstructive respiratory events were induced by defined intermittent negative upper airway pressure (INAP = inverse CPAP) applied via a customized mask connected to a negative pressure device (n=9). One minute of IH or INAP was followed by a rest period of nine minutes for four hours every second day. Rats with comparable anesthesia were used as controls (CTR). After three weeks, the animals were sacrificed. To analyze atrial structural remodeling reversibility, additional INAP-rats (n=5) were sacrificed after INAP-withdrawal of three weeks and compared to respective CTR (n=7).

Result

Blood pressure was not affected by IH or INAP. Intermittent desaturation and post-apneic hyperventilation were comparable in INAP- and IH-rats, but INAP-rats showed significantly higher breathing efforts during apneas compared to IH-rats. LA connexin43 (Cx43) protein expression assessed by quantitative immunofluorescence was reduced in both groups compared to CTR (0.77±0.07% in CTR vs. 0.45±0.06% in IH, p=0.02; CTR vs. 0.39±0.06% in INAP, p=0.005). However, LA interstitial fibrosis content (7.03±0.58% vs. CTR, p=0.01) and LA myocyte diameters (13.23±0.34μm vs. CTR, p=0.03) were increased in INAP-rats, but not in IH-rats. This was associated with longer inducible AF-durations in INAP-rats (11.65±4.43s vs. 0.72±0.33s in CTR, p=0.03) but not in IH-rats (1.28±0.33s vs. CTR, p=0.31). Three weeks of INAP-withdrawal (INAP-W) normalized interstitial fibrosis content (INAP-W vs. CTR, p=0.50) and LA-myocyte diameter (INAP-W vs. CTR, p=0.31). However, LA Cx43 protein expression remained low after three weeks of INAP withdrawal and inducible AF-episodes were still prolonged compared to respective CTR.

Conclusion

Application of INAP in rats mimics important components of OSA beyond IH and allows the study of an arrhythmogenic substrate in the atrium independent of the development of risk factors. In our model, withdrawal of INAP resulted in partial reversibility of structural LA remodeling but was not sufficient to abolish inducible AF-episodes completely. Future clinical studies are warranted to determine the anti-arrhythmic effect of isolated sleep apnea treatment in AF-patients.

Acknowledgement/Funding

Else Kröner-Fresenius-Stiftung, SFB-TRR219-M02/S-02

P6294NLRP3 inflammasome is activated in the atrium of an ovine model of sustained obesity

Introduction

Obesity and enhanced inflammatory response are two independent risk factors involved in the pathogenesis of atrial fibrillation (AF). Components of the NLRP3 inflammasome have been found to be expressed in cardiomyocytes and cardiac fibroblasts and that increased inflammasome activation contributes to the pathogenesis of AF. The NLRP3 inflammasome is a multi-protein signaling complex that is activated in two steps: 1st) a priming event that includes a NFκB-activating stimuli which increases the expression of pro-inflammatory cytokines, and 2nd) a triggering event that includes the assembly of the inflammasome complex and activation of caspase-1 which promotes the production of pro-inflammatory cytokines like interleukin 1 beta (IL-1b).

Purpose

We used a sheep model of sustained obesity to characterize the association between atrial myocardial fat infiltration, atrial activation of the NLRP3 inflammasome and the development of an atrial arrhythmogenic substrate for AF.

Methods

Eight sheep were fed ad libitum calorie-dense diet over 40 weeks to gain weight and were maintained in this state of sustained obesity for another 40 weeks. Eight lean, weight-controlled and aged-matched sheep served as control. Atrial fat infiltration was determined by oil-red staining and NLRP3 inflammasome activation was assessed by immunoblot in atrial whole-tissue lysate. Atrial effective refractory periods (aERPs) were evaluated (twice diastolic threshold, cycle length (CL) of 400 ms, S1S2 -protocol).

Results

Sustained obesity was associated with increased atrial fat infiltration (lean: 0.8±0.3% vs. obese: 2.3±1.2%, p=0.1) and shorter aERP (lean: 169±22ms vs. obese: 138±26ms, p=0.03). Protein levels of caspase-1 and mature IL-1β were significantly enhanced (p=0.04 and p=0.01, respectively). Further shortening of aERP correlated with increasing atrial protein levels of caspase-1 (r=0.59, p=0.02). In contrast, levels of TNFα and NFκB were not significantly changed in atria of sheep with sustained obesity.

Conclusions

Sustained obesity is associated with increased expression of NLRP3 inflammasome-related proteins and the development of an arrhythmogenic substrate for AF. Our study suggest that the increased activity is due to increased triggering, rather than increased gene transcription. Whether NLRP3 inflammasome activation represents a modifiable target to prevent AF in obesity warrants further study.

[Torsion of a pedunculated subserous myoma - a rare differential diagnosis of the acute abdomen]

We report about a rare case of acute abdomen in a 43 years old female patient who noticed a sudden onset of severe lower abdominal pain, increasing in strength within a few hours. The transabdominal and transvaginal ultrasound showed an enlarged leiomyomatous uterus with a questionable torsion of a pedunculated subserous leiomyoma. The following magnetic resonance imaging confirms this diagnosis. During the laparoscopy a myomectomy has been performed.

Effects of AT1- and beta-adrenergic receptor antagonists on TGF-beta1-induced fibrosis in transgenic mice

BACKGROUND

Transforming growth factor-beta1 (TGF-beta1) is involved in interstitial remodelling promoting collagen synthesis and suppressing collagen degradation by inhibition of collagenases. TGF-beta1 mediates angiotensin II-dependent effects and modulates beta1-adrenergic signalling. To study the effect of neuroendocrine antagonism on TGF-beta-induced hypertrophic and fibrotic phenotype, we treated TGF-beta1 (Cys223,225Ser) transgenic mice (TGF-beta1-TG) with either the beta1-receptor blocker metoprolol (MET), the angiotensin II type I (AT1)-receptor antagonist telmisartan (TEL) or an antibody blocking TGF-beta1 signalling (TGFbeta1-sR-Ab).

MATERIAL AND METHODS

Transforming growth factor-beta1-TG mice (8 weeks) overexpressing TGF-beta1 were treated with either TEL (10 mg kg(-1)), MET (350 mg kg(-1)) or a soluble TGF-beta1 receptor antibody (1 mg kg(-1)) for 6 weeks. Morphological analyses of interstitium and cardiomyocytes were related to expression of matrix metalloproteinases (MMPs) and their inhibitors (TIMPs) by immunoblotting and zymography.

RESULTS

In TGF-beta1-TG mice, myocardial interstitial total collagen content was fourfold elevated compared to that of controls (P < 0.05) and was lowered under the treatment with TEL (P < 0.05). Protein expression of TIMP-1 and -4 was increased in TGF-beta1-TG but inhibited by TEL (TIMP-1 and TIMP-4) and MET (TIMP-1), while collagenase activity was decreased in TGF-beta1-TG and normalized by treatment with TEL (MMP-1 and MMP-13) and MET (MMP-1) (P < 0.05). Morphometric measurements of cardiomyocyte diameter and area demonstrated similar antihypertrophic effects for all treatment groups.

CONCLUSION

The AT1-antagonist TEL reduced myocardial hypertrophy and interstitial fibrosis in TGF-beta1-TG mice by normalizing MMP/TIMP ratio. beta1-Adrenergic inhibition by MET as well as TGF-beta1 antagonism induced antihypertrophic rather than antifibrotic effects. Inhibition of both renin-angiotensin system and beta1-adrenergic system may exert different but synergistic effects to reduce myocardial remodelling.

[Laparoscopy in the management of endometrial cancer]

Recent advance in laparoscopy have changed the surgical approach of endometrial cancer patients. The Swissendos Center, Fribourg, in collaboration with AGO (Groupe de travail pour la gynécologie oncologique) and AGE (groupe de travail pour la gynécologie endoscopique) have established a consensus based on the available evidence for the use of laparoscopy in the management of patients with endometrial cancer The main objective was to define Swiss clinical practice guidelines appropriate to the country and consistent with the needs of the physicians.

[Stereotactic Mammotome breast biopsy: routine clinical experience and correlation with BI-RADS--classification and histopathology]

BACKGROUND

Stereotactic breast biopsy using the Mammotome system allows minimal invasive tissue sampling of suspicious lesions of the breast cancer, e.g. clustered microcalcifications BI-RADS type 3 and 4, and has widely replaced open surgical biopsies. The aim of this retrospective study was to review the results of these biopsies in regard of technical feasibility and complications as well as to correlate initial BI-RADS assessment with histopathology.

METHODS

One hundred thirty-five vacuum-assisted breast biopsies in 124 patients were evaluated. Before biopsy, the mammograms were classified according to the Breast Imaging Reporting and Data System (BI-RADS). All mammograms were reviewed with knowledge of the final histologic diagnosis. Patients with benign diagnoses underwent mammographic follow-up. Excisional biopsy was recommended for diagnoses of in-situ or invasive carcinoma.

RESULTS

No serious complications of the biopsies were observed. Histopathology revealed 105 (78%) benign lesions. Benign lesions were classified as BI-RADS 3 in 49 (36%) and as suspicious (BI-RADS 4) in 56 (41%). Thirty lesions (22%) were malignant, of which 26 (87%) were classified BI-RADS 4 or 5. The frequency of malignancy in BI-RADS 4 and 5 was 19 of 75 (25%) and 7 of 7 (100%), respectively. Of the 53 BI-RADS 3 lesions, 4 (8%) were malignant.

CONCLUSIONS

Mammotome biopsy was shown to be a safe and well-tolerated technique for the work-up of mammographic lesions. The frequency of malignant histopathologic findings in BI-RADS 3 lesions was higher than expected, reflecting the difficulties in the mammographic differentiation of benign and malignant clustered microcalcifications.

[Right sided lower abdominal pain two weeks after delivery]

We report the CT imaging findings of a 33 year old patient who presented to the emergency department with increasing right lower abdominal pain and shivering. She delivered a healthy baby two weeks ago after induction in the 39th week of pregnancy due to a large fetus. Two days after delivery, sterilisation was performed. Clinically the primary differential diagnosis was appendicitis. However, computed tomography revealed thrombosis of the right ovarian vein. Consequently, management was altered appropriately with administration of antibiotics as well as a therapeutic dose of low molecular weight heparin.

Shorter PFA-100-closure times in laparoscopic versus conventional hysterectomy are not caused by increased vasopressin levels

BACKGROUND/OBJECTIVES

Bleeding problems during laparoscopic surgery are infrequent. We hypothesised that increased abdominal pressure during the application of the pneumoperitoneum would lead to an increased release of endogenous vasopressin which could then contribute to the hemostasis by increasing platelet reactivity, FVIII and von Willebrand-factor.

PATIENTS AND METHODS

We compared the vasopressin levels, the platelet function as measured by the PFA-100-test, aPTT and FVIII in 39 consecutive patients who underwent elective hysterectomy (20 with the laparoscopic and 19 with the conventional, "open" method). Blood was sampled the day before surgery and 2, 4 and 72 h after the induction of anaesthesia.

RESULTS

After two hours, the PFA-100 closure times with collagen/ADP decreased to lower levels in the laparoscopic group (from 93 +/- 22 to 82 +/- 20, mean +/- SD) and even further down to 65 +/- 13 s (compared to 82 +/- 20 s) (p = 0.024)) four hours after the beginning of surgery. Vasopressin levels and F VIII increased in both groups but there was no significant difference between the groups (21 vs. 17.8 pmol/l for vasopressin, differences of the mean). Bleeding was minimal, with a trend to lower Hb-levels in the laparotomy group.

CONCLUSIONS

The procedural difference of laparoscopic vs. open hysterectomy appears to enhance platelet reactivity by other mechanisms than increased vasopressin levels and may contribute to an enhanced hemostatic competence in laparoscopic surgery.

[Ultrasound-guided fine-needle aspiration of the breast]

PURPOSE

Retrospective analysis of the results of all ultrasound (US)-guided fine needle aspirations (FNA) of the breast performed at our institution between 1988-2002.

MATERIALS AND METHODS

The radiologic and pathologic information database was retrospectively searched for all referrals, in whom an US-guided FNA of the breast was performed as further diagnostic work-up of sonographically unclear or suspicious findings. Percutaneous tissue diagnosis was performed under US-guidance using a 20-Gauge-needle. Results were correlated with histology or sonographic and/or mammography follow-up examination, respectively.

RESULTS

The total study population consisted of 324 patients (19-92 years). In 20 cases (6.2%), results of FNA were non-diagnostic, a cytologic diagnosis was established in the remaining 304 (93.8%) cases. Cytologically, malignancy was diagnosed in 60 cases; 2 of those were shown to be false positive by subsequent histologic work-up. In 33 of 244 surgery was performed. 9 cases were false negative. No complication was observed. The accuracy was 96.4% with a sensitivity of 86.6% and specificity of 99.2%.

CONCLUSION

If a skilled cytopathologist is available, US-guided FNA is a highly accurate and minimal-invasive technique. False negative findings may occur, thus clinical and imaging findings should be taken into account for further therapeutic decision.

Binding and repair of mismatched DNA mediated by Rhp14, the fission yeast homologue of human XPA

Rhp14 of Schizosaccharomyces pombe is homologous to human XPA and Saccharomyces cerevisiae Rad14, which act in nucleotide excision repair of DNA damages induced by ultraviolet light and chemical agents. Cells with disrupted rhp14 were highly sensitive to ultraviolet light, and epistasis analysis with swi10 (nucleotide excision repair) and rad2 (Uve1-dependent ultraviolet light damage repair pathway) revealed that Rhp14 is an important component of nucleotide excision repair for ultraviolet light-induced damages. Moreover, defective rhp14 caused instability of a GT repeat, similar to swi10 and synergistically with msh2 and exo1. Recombinant Rhp14 with an N-terminal hexahistidine tag was purified from Escherichia coli. Complementation studies with a rhp14 mutant demonstrated that the tagged Rhp14 is functional in repair of ultraviolet radiation-induced damages and in mitotic mutation avoidance. In bandshift assays, Rhp14 showed a preference to substrates with mismatched and unpaired nucleotides. Similarly, XPA bound more efficiently to C/C, A/C, and T/C mismatches than to homoduplex DNA. Our data show that mismatches and loops in DNA are substrates of nucleotide excision repair. Rhp14 is likely part of the recognition complex but alone is not sufficient for the high discrimination of nucleotide excision repair for modified DNA.

Prognostic and predictive significance of ErbB-2 breast tumor levels measured by enzyme immunoassay

PURPOSE

A retrospective analysis to assess the prognostic and predictive clinical value of breast tumor ErbB-2 receptor expression quantified by enzyme immunoassay (EIA), to compare levels measured by EIA with ErbB-2 status determined by immunohistochemistry (IHC), and to correlate receptor content with levels of phosphorylated (Y1248-P) ErbB-2, a measure of functional tyrosine kinase activity.

MATERIALS AND METHODS

EIA quantification of ErbB-2 was performed on membrane extracts from 3,208 well-characterized primary breast cancers. Overall, relapse-free, distant disease-free, and local/regional-free patient survival data were available on 1,123 of these tumors. IHC scoring for ErbB-2 status (HercepTest; DAKO, Glostrup, Denmark) was performed on adjacent sections of 151 cases, and receptor functionality was measured in 230 tumors by an antibody specific for phosphorylated (Y1248-P) ErbB-2.

RESULTS

Unlike nonmalignant breast tissues, breast tumors showed increased ErbB-2 levels in a bimodal distribution, with 12% constituting a distinct set of ErbB-2-overexpressing tumors. The intermodal threshold value for ErbB-2 overexpression distinguished tumors with reduced estrogen and progesterone receptor content, high IHC score for ErbB-2, and significantly increased levels of phosphorylated (Y1248-P) ErbB-2 receptor. By multivariate analysis, EIA-determined ErbB-2 overexpression predicted significantly reduced patient survival that was unaffected by tamoxifen or cyclophosphamide, methotrexate, and fluorouracil adjuvant therapy.

CONCLUSION

Determination of ErbB-2 receptor expression by EIA offers a clinically valuable alternative to semiquantitative IHC assessment of breast tumor ErbB-2 overexpression and affords the opportunity to evaluate ErbB-2 phosphorylation, which may represent an important predictive parameter of receptor functionality.

Arthroscopy of meniscal injuries with tibial plateau fractures

We examined 36 consecutive patients with closed tibial plateau fractures under anaesthesia and by diagnostic and operative arthroscopy before treating them by closed or open reduction and internal fixation. Following the principle of Hohl (1967) (Fig. 1) there were 9 minimally displaced fractures (type I), 6 with local depression (type II), 13 with split depression (type III), 7 with total condylar depression (type IV), and one bicondylar comminuted upper tibial fracture (type V). Seventeen (47%) of knees were found to have associated meniscal injuries which required surgical treatment; five repairs and 12 partial meniscectomies. Neither the type of plateau fracture nor the presence or absence of ligament injury correlated with meniscal tear. There were no intraoperative or postoperative complications from arthroscopy.

Arthroscopy of meniscal injuries with tibial plateau fractures

We examined 36 consecutive patients with closed tibial plateau fractures under anaesthesia and by diagnostic and operative arthroscopy before treating them by closed or open reduction and internal fixation. Following the principle of Hohl (1967) (Fig. 1) there were 9 minimally displaced fractures (type I), 6 with local depression (type II), 13 with split depression (type III), 7 with total condylar depression (type IV), and one bicondylar comminuted upper tibial fracture (type V). Seventeen (47%) of knees were found to have associated meniscal injuries which required surgical treatment; five repairs and 12 partial meniscectomies. Neither the type of plateau fracture nor the presence or absence of ligament injury correlated with meniscal tear. There were no intraoperative or postoperative complications from arthroscopy.

Cell-wall tension of the inner tissues of the maize coleoptile and its potential contribution to auxin-mediated organ growth

Plant organs such as maize (Zea mays L.) coleoptiles are characterized by longitudinal tissue tension, i.e. bulk turgor pressure produces unequal amounts of cell-wall tension in the epidermis (essentially the outer epidermal wall) and in the inner tissues. The fractional amount of turgor borne by the epidermal wall of turgid maize coleoptile segments was indirectly estimated by determining the water potential ψ(*) of an external medium which is needed to replace quantitatively the compressive force of the epidermal wall on the inner tissues. The fractional amount of turgor borne by the walls of the inner tissues was estimated from the difference between -ψ(*) and the osmotic pressure of the cell sap (πi) which was assumed to represent the turgor of the fully turgid tissue. In segments incubated in water for 1 h, -ψ(*) was 6.1-6.5 bar at a πi of 6.7 bar. Both -ψ(*) and πi decreased during auxin-induced growth because of water uptake, but did not deviate significantly from each other. It is concluded that the turgor fraction utilized for the elastic extension of the inner tissue walls is less than 1 bar, i.e. less than 15% of bulk turgor, and that more than 85% of bulk turgor is utilized for counteracting the high compressive force of the outer epidermal wall which, in this way, is enabled to mechanically control elongation growth of the organ. This situation is maintained during auxin-induced growth.

Physical extensibility of maize coleoptile cell walls: apparent plastic extensibility is due to elastic hysteresis

Segments of maize (Zea mays L.) coleoptiles demonstrate plastic cell-wall extensibility (Epl) as operationally defined by the amount of irreversible strain elicited by stretching living or frozen-thawed tissue under constant load in an extensiometer (creep test). Changes of Epl are correlated with auxin- and abscisic-acid-dependent growth responses and have therefore been causally related to hormone-controlled cell-wall loosening. Auxin induces an increase of Epl specifically in the outer epidermal wall of maize coleoptiles which is considered as the growth-limiting wall of the organ. However, detailed kinetic measurements of load-induced extension of frozen-thawed coleoptile segments necessitates a revision of the view that Epl represents a true plastic (irreversible) wall deformation. Segments demonstrate no significant irreversible extension when completely unloaded between loading cycles. Moreover, Epl can be demonstrated repeatedly if the same segment is subjected to repeated loading cycles in the extensiometer. It is shown that these phenomena result from the hysteresis behaviour of the cell wall. Stress-strain curves for loading and unloading form a closed hysteresis loop, the width of which represents Epl at a particular load. Auxin-treatment of segments leads to a deformation of the hysteresis loop, thereby giving rise to an increase of Epl. These results show that the creep test estimates the viscoelastic (retarded elastic) properties rather than the plastic properties of the wall.

Growth at reduced turgor: irreversible and reversible cell-wall extension of maize coleoptiles and its implications for the theory of cell growth

The relationship between steady-state elongation rate (G) and turgor pressure (P; G/P curve) was investigated using isolated segments of maize (Zea mays L.) coleoptiles incubated in osmotic solutions of a water potential range of 0 to -10 bar (polyethylene glycol 6000 as osmoticum). Short-term elongation measurements revealed curvilinear G/P curves with a steep slope at high turgor and a shallow slope at low turgor. Owing to a decrease of osmotic pressure and turgor, there was a tendency for straightening of the G/P curves during long-term elongation. An elongation rate of zero was adjusted by lowering the turgor by 4.5 bar at a constant osmotic pressure of 6.7 bar. Auxin increased - whereas abscisic acid decreased - the slope of the G/P curve but these hormones had no effect on the threshold turgor of growth (Y = 2.2 bar). It is concluded that extensibility of the growing cell walls represented by the 'yielding coefficient' of Lockhart's growth equation is turgor-dependent and therefore decreases to a very low value as the turgor approaches Y. When the turgor was kept at Y, a constant segment length was maintained over at least 6 h. However, separation of reversible (lrev) and irreversible (lirr) components of total (in vivo) length (ltot = lrev + lirr) W measuring segment length before and after freezing/thawing revealed that lirr increased continuously and lrev decreased continuously at constant ltot. After a step-down in turgor the segments grew in lirr although they shrank in ltot over the whole turgor range of 0<P<Y. This phenomenon is termed 'cryptic growth'. It is concluded that Y represents the turgor at which irreversible cell extension and decrease of the reversible length fraction of the cell walls cancel each other out and therefore net extension becomes zero. Cryptic growth at P = Y is accompanied by a decrease in cell-wall elasticity. The finding that auxin promotes cryptic growth supports the notion that a wall-stiffening process is a constitutive component of the mechanism by which the hormone induces irreversible cell elongation.

[Pneumocystis carinii pneumonia in HIV-negative immunosuppressed patients]

During a period of 10 years 129 immunosuppressed HIV-negative patients were evaluated for pulmonary complications. A definite diagnosis could be established in 72 cases (56%): Pneumocystis carinii pneumonia (PCP) (25), pulmonary involvement of underlying disease (10), drug toxicity (8), mycobacterioses (6), bacterial pneumonias (5), aspergillosis (5), others (13). The underlying conditions in patients with PCP were: lymphatic neoplasias (11), immunosuppression after solid organ (9) and after bone marrow transplantation (3), cytotoxic therapy for lupus erythematodes (1) and carcinoma (1). In 8 of 9 transplant patients anti-rejection therapy preceded the episode of PCP. Six patients (24%) died from respiratory failure 1 to 25 days after diagnosis of PCP, despite mechanical ventilation in four. Two patients recovered completely after mechanical ventilation for 14 and 30 days respectively. The frequency of PCP has markedly increased during the last few years: 1981-1987: 2 cases (6%), 1988: 4 (14%), 1989: 8 (42%) and 1990: 11 (26%). This can hardly be explained by improved diagnostic sensitivity or an increased number of immunosuppressed patients. Apart from the use of more potent immunosuppressive agents, the increased prevalence of Pneumocystis carinii may play an important role.

Acid- and Enzyme-Mediated Solubilization of Cell-Wall beta-1.3,beta-1.4-d-Glucan in Maize Coleoptiles : Implications for Auxin-Mediated Growth

The release of soluble carbohydrates from isolated cell wall of maize (Zea mays L.) was investigated in the range of pH 1 to 8.5. The pH profile demonstrated two peaks, a broad peak at pH 6 due to enzymatic breakdown of beta-glucan to monosaccharides (wall autolysis) and a sharp peak at pH 2.5 due to acid-mediated, nonenzymatic liberation of macromolecular beta-glucan from the wall. The pH dependence of acid-induced growth and cell-wall extensibility of coleoptile segments closely agrees with the pH dependence of acid-mediated beta-glucan solubilization in the isolated wall. However, there is no evidence that enzymatic or nonenzymatic beta-glucan solubilization is involved in the mechanism of auxin-mediated growth.

Water Relations of Growing Maize Coleoptiles : Comparison between Mannitol and Polyethylene Glycol 6000 as External Osmotica for Adjusting Turgor Pressure

Water relations of growing segments of maize (Zea mays L.) coleoptiles were investigated with osmotic methods using either mannitol (MAN) or polyethylene glycol 6000 (PEG) as external osmotica. Segments were incubated in MAN or PEG solutions at 0 to - 15 bar water potential (Psi(o)) and the effects were compared on elongation growth, osmotic shrinkage, cell sap osmolality (OC), and osmotic pressure (pi(i)). The nonpenetrating osmoticum PEG affects pi(i) in agreement with Boyle-Mariotte's law, i.e. the segments behave in principle as ideal osmometers. There is no osmotic adjustment in the Psi(o) range permitting growth (0 to -5 bar) nor in the Psi(o) range inducing osmotic shrinkage (-5 to -10 bar). Promoting growth by auxin (IAA) has no effect on the osmotic behavior of the tissue toward PEG. In contrast to PEG, MAN produces an apparent increase in pi(i) accompanied by anomalous effects on segment elongation and shrinkage leading to a lower value for Psi(o) which establishes a growth rate of zero and to an apparent recovery from osmotic shrinkage after 2 hours of incubation. These effects can be quantitatively attributed to uptake of MAN into the tissue. MAN is taken up into the apoplastic space and the symplast as revealed by a large temperature-dependent component of MAN uptake. It is concluded that MAN, in contrast to PEG, is unsuitable as an extemal osmoticum for the quantitative determination of water relations of growing maize coleoptiles.

Ligament injuries associated with tibial plateau fractures

Thirty-nine patients with tibial plateau fractures and concomitant ligament injury were evaluated at least one year after injury. Ligamentous injury was determined by stress roentgenograms, plain roentgenograms, operative findings, and Pelle-grini-Stieda's ossification. There were 22 isolated medial collateral, eight lateral collateral, one isolated anterior cruciate, and eight combined ligament injuries. All types of tibial plateau fractures were associated with ligamentous injury, although split compression and local compression were most common. Twenty patients (Group 1) did not have operative repair of the injured ligaments, and 19 patients (Group 2) had primary repair of the injured ligaments. Open reduction and internal fixation of the plateau fracture(s) were performed in 13 patients in Group 1 and 19 patients in Group 2. Follow-up evaluation (100-point scale), including subjective, functional, and anatomic factors, revealed 12 excellent and good, four fair, and three poor results in the 19 patients with ligamentous repair. There were ten excellent and good, two fair, and eight poor results in those without ligament repair. Ten of the 12 patients with 10 degrees or more of instability had poor results. These poor results included five unrepaired medial collateral ligaments, two unrepaired lateral collateral ligaments, and three patients with cruciate ligament injury. This study confirms the view that instability is a major cause of unacceptable results in tibial plateau fractures. Operative repair of medial and lateral collateral ligaments, with appropriate treatment of the bony plateau fracture, may reduce late instability and may improve overall morbidity in these concomitant injuries. Cruciate ligament injury associated with a tibial plateau fracture carries a poor prognosis.

The cast brace and tibial plateau fractures

Three hundred six tibial plateau fractures treated at the authors' institutions and in private practice were analyzed in relation to the use of a cast brace or fracture brace. One hundred forty-one of these patients had had a cast brace or fracture brace as part of their treatment program, either as the primary fracture treatment or after open reduction or traction. The aims of this study were (1) to determine if cast bracing could maintain alignment, fracture position, and range of motion and (2) to compare its results with those of other major long-term studies of similar fractures. There were 85 lateral, 24 medial, and 32 bicondylar fractures. Cast bracing was used for one to 17 weeks, with a mean of eight weeks. Ninety-nine of the 141 patients were followed for at least one year. Eighty-two of the patients maintained alignment with less than 5 degrees of deformity, and fracture position was maintained in 85% of cases, with only 15% having 4-8 mm of loss of position. Medial plateau and subcondylar fractures had an increased incidence of fracture position loss. Ninety-seven percent of patients had greater than 90 degrees of flexion, and 90% had full extension, i.e., less than 5 degrees of contracture. Pain was minimal or absent after heavy exercise in 90% of patients using cast bracing. Arthritic changes on roentgenographic analysis were absent or mild in 93.5% and moderate or severe in 6.5% of patients. Complications, including phlebitis, pulmonary emboli, wound infection, hardware slippage, and skin slough, occurred in nine patients.(ABSTRACT TRUNCATED AT 250 WORDS)

The significance of early motion in the treatment of tibial plateau fractures

Although the trend in management of tibial plateau fractures has been toward early motion, the period of immobilization that can be tolerated safely is open to question. In the present study, 160 acute tibial plateau fractures were reviewed in an effort to answer this question. The 112 fractures that were suitable for analysis were divided into undisplaced fractures, displaced fractures treated nonoperatively, and displaced fractures treated operatively. Among these groups, results were compared based on the period after injury that the knee was immobilized. Undisplaced fractures and displaced fractures that were treated nonoperatively regained full knee motion when immobilized up to six weeks. Fractures treated operatively tended to develop knee stiffness with only two weeks of immobilization. Loss of fracture reduction tended to occur in patients who were immobilized for relatively short periods. Immediate knee motion was correlated with prolonged hospitalization. Based on these results, knee mobilization following tibial plateau fractures is determined by the degree of fracture displacement, method of treatment, and quality of aftercare.

Tibial condylar fractures. Evaluation of treatment and outcome

One hundred ten tibial condylar fractures incurred during the period from 1972 to 1978 were reviewed retrospectively. Fifty-two knees were reviewed more than one year after initial injury and were subjected to critical evaluation using a point rating system. Overall, the results were acceptable in 84% of patients. The use of a cast of traction generally produced very good results. Case bracing was used in 31% of the series. Open reduction was reserved for 17 severe and challenging fractures; six of the 17 had unsatisfactory functional results.