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Chitosan (CS) nanoparticles have been extensively studied for siRNA delivery; however, their stability and efficacy are highly dependent on the types of cross-linker used. To address this issue, three common cross-linkers; tripolyphosphate (TPP), dextran sulphate (DS) and poly-D-glutamic acid (PGA) were used to prepare siRNA loaded CS-TPP/DS/PGA nanoparticles by ionic gelation method. The resulting nanoparticles were compared with regard to their physicochemical properties including particle size, zeta potential, morphology, binding and encapsulation efficiencies. Among all the formulations prepared with different cross linkers, CS-TPP-siRNA had the smallest particle size (ranged from 127 ± 9.7 to 455 ± 12.9 nm) with zeta potential ranged from +25.1 ± 1.5 to +39.4 ± 0.5 mV, and high entrapment (>95%) and binding efficiencies. Similarly, CS-TPP nanoparticles showed better siRNA protection during storage at 4˚C and as determined by serum protection assay. TEM micrographs revealed the assorted morphology of CS-TPP-siRNA nanoparticles in contrast to irregular morphology displayed by CS-DS-siRNA and CS-PGA-siRNA nanoparticles. All siRNA loaded CS-TPP/DS/PGA nanoparticles showed initial burst release followed by sustained release of siRNA. Moreover, all the formulations showed low and concentration-dependent cytotoxicity with human colorectal cancer cells (DLD-1), in vitro. The cellular uptake studies with CS-TPP-siRNA nanoparticles showed successful delivery of siRNA within cytoplasm of DLD-1 cells. The results demonstrate that ionically cross-linked CS-TPP nanoparticles are biocompatible non-viral gene delivery system and generate a solid ground for further optimization studies, for example with regard to steric stabilization and targeting.

Abstract Background The Caenorhabditis elegans male exhibits a stereotypic behavioral pattern when attempting to mate. This behavior has been divided into the following steps: response, backing, turning, vulva location, spicule insertion, and sperm transfer. We and others have begun in-depth analyses of all these steps in order to understand how complex behaviors are generated. Here we extend our understanding of the sperm-transfer step of male mating behavior. Results Based on observation of wild-type males and on genetic analysis, we have divided the sperm-transfer step of mating behavior into four sub-steps: initiation, release, continued transfer, and cessation. To begin to understand how these sub-steps of sperm transfer are regulated, we screened for ethylmethanesulfonate (EMS)-induced mutations that cause males to transfer sperm aberrantly. We isolated an allele of unc-18, a previously reported member of the Sec1/Munc-18 (SM) family of proteins that is necessary for regulated exocytosis in C. elegans motor neurons. Our allele, sy671, is defective in two distinct sub-steps of sperm transfer: initiation and continued transfer. By a series of transgenic site-of-action experiments, we found that motor neurons in the ventral nerve cord require UNC-18 for the initiation of sperm transfer, and that UNC-18 acts downstream or in parallel to the SPV sensory neurons in this process. In addition to this neuronal requirement, we found that non-neuronal expression of UNC-18, in the male gonad, is necessary for the continuation of sperm transfer. Conclusion Our division of sperm-transfer behavior into sub-steps has provided a framework for the further detailed analysis of sperm transfer and its integration with other aspects of mating behavior. By determining the site of action of UNC-18 in sperm-transfer behavior, and its relation to the SPV sensory neurons, we have further defined the cells and tissues involved in the generation of this behavior. We have shown both a neuronal and non-neuronal requirement for UNC-18 in distinct sub-steps of sperm-transfer behavior. The definition of circuit components is a crucial first step toward understanding how genes specify the neural circuit and hence the behavior.

Background and Objectives: Cervical spinal cord injury results in devastating loss of function. Nerve transfers can restore functional use of the hand, the highest priority function in this population to gain independence. Transfer of radial nerve branches innervating the supinator to the posterior interosseous nerve (SUP-PIN) has become a primary intervention for the recovery of hand opening, but few outcome reports exist to date. We report single-surgeon outcomes for this procedure., Methods: The SUP-PIN transfer was performed on adults with traumatic spinal cord injury resulting in hand paralysis. Outcome measures include Medical Research Council strength grade for extension of each digit, and angles representing critical apertures: the first web space opening of the thumb, and metacarpophalangeal angle of the remaining fingers. Factors affecting these measurements, including preserved tone and spasticity of related muscles, were also assessed., Results: Twenty-three adult patients with a C5-7 motor level underwent SUP-PIN transfers on 36 limbs (median age 31 years, interquartile range [21.5, 41]). The median interval from injury to surgery was 10.5 (8.2, 6.5) months, with 9 (7.5, 11) months for the acute injuries and 50 (32, 66) months for the chronic (>18 months) injuries. Outcomes were observed at a mean follow-up of 22 (14, 32.5) months. 30 (83.3%) hands recovered at least antigravity extension of the thumb and 34 (94.4%) demonstrated successful antigravity strength for the finger extensors, providing adequate opening for a functional grasp. Chronic patients (>18 months after injury) showed similar outcomes to those who had earlier surgery. Supination remained strong (at least M4) in all but a single patient and no complications were observed., Conclusion: SUP-PIN is a reliable procedure for recovery of finger extension. Chronic patients remain good candidates, provided innervation of target muscles is preserved. Higher C5 injuries were more likely to have poor outcomes., (Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc., on behalf of the Congress of Neurological Surgeons.)

Background and Objectives: Spastic equinovarus foot (SEF) is a common complication of stroke and other upper motor neuron injuries. It is characterized by a plantigrade and inverted foot, often with toe curling, causing significant disability from pain, gait, and balance difficulties. Management includes physical therapy, antispasticity drugs, orthoses, chemical neurolysis, or botulinum toxin, all of which may be insufficient, sedating, or transient. Selective tibial neurotomy (STN) provides a surgical option that is effective and long-lasting. Our goal is to provide a concise description of our technique for performing the STN for treatment of SEF. We discuss the standard posterior approach with surgical variations used by other groups and a medial approach, should the posterior approach be insufficient., Methods: A posterior leg approach allows access to the tibial nerve and its branches to the bilateral gastrocnemius muscles, soleus, posterior tibialis, and extrinsic toe flexors. A medial approach is used if the toe flexors cannot be accessed sufficiently from the posterior approach. Nerve branch targets identified by preoperative functional assessment are carefully exposed and fully neurolysed distally to identify all terminal branches to each muscle of interest before neurotomy., Results: The STN is a powerful tool for treating SEF, with an immediate and lasting effect. Approximately 80% of the target muscle should be denervated to ensure long-term efficacy while maintaining adequate function of the muscle through collateral innervation., Conclusion: The STN is a safe and effective outpatient procedure that can be performed by an experienced nerve surgeon to improve balance and ambulation and reduce pain for patients with SEF. Large clinical trials are necessary to further establish this underutilized procedure in the United States., (Copyright © Congress of Neurological Surgeons 2023. All rights reserved.)

Objective: In patients with Parkinson Disease (PD), self-initiated or internally cued (IC) actions are thought to be compromised by the disease process, as exemplified by impairments in action initiation. In contrast, externally-cued (EC) actions which are made in response to sensory prompts can restore a remarkable degree of movement capability in PD, particularly alleviating freezing-of-gait. This study investigates the electrophysiological underpinnings of movement facilitation in PD through visuospatial cuing, with particular attention to the dynamics within the posterior parietal cortex (PPC) and lateral premotor cortex (LPMC) axis of the dorsal visual stream., Methods: Invasive cortical recordings over the PPC and LPMC were obtained during deep brain stimulation lead implantation surgery. Thirteen PD subjects performed an action selection task, which was constituted by left or right joystick movement with directional visual cuing in the EC condition and internally generated direction selection in the IC condition. Time-resolved neural activities within and between the PPC and LPMC were compared between EC and IC conditions., Results: Reaction times (RT) were significantly faster in the EC condition relative to the IC condition (paired t-test, p = 0.0015). PPC-LPMC inter-site phase synchrony within the β-band (13-35 Hz) was significantly greater in the EC relative to the IC condition. Greater PPC-LPMC β debiased phase lag index (dwPLI) prior to movement onset was correlated with faster reaction times only in the EC condition. Multivariate granger causality (GC) was greater in the EC condition relative to the IC condition, prior to and during movement., Conclusion: Relative to IC actions, we report relative increase in inter-site phase synchrony and directional PPC to LPMC connectivity in the β-band during preparation and execution of EC actions. Furthermore, increased strength of connectivity is predictive of faster RT, which are pathologically slow in PD patients. Stronger engagement of the PPC-LPMC cortical network by an EC specifically through the channel of β-modulation is implicated in correcting the pathological slowing of action initiation seen in Parkinson's patients., Significance: These findings shed light on the electrophysiological mechanisms that underlie motor facilitation in PD patients through visuospatial cuing., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.)

Deep brain stimulation (DBS) has become an established treatment for medically refractory movement disorders including Parkinson's disease, essential tremor, and dystonia. The field of DBS continues to evolve with advances in patient selection, target identification, electrode and pulse generator technology, and the development of more effective stimulation paradigms such as closed-loop stimulation. Furthermore, as the safety and efficacy of DBS improves through better hardware design and deeper understanding of its mechanisms of action, the indications for DBS will continue to expand to cover a wider range of disorders. Finally, the recent approval of MR-guided focused ultrasound for the treatment of essential tremor and potentially other movement disorders heralds a resurgence in lesion creation as a viable alternative to DBS for selected patients., (© 2018 S. Karger AG, Basel.)

Larval Drosophila offer a study case for behavioral neurogenetics that is simple enough to be experimentally tractable, yet complex enough to be worth the effort. We provide a detailed, hands-on manual for Pavlovian odor-reward learning in these animals. Given the versatility of Drosophila for genetic analyses, combined with the evolutionarily shared genetic heritage with humans, the paradigm has utility not only in behavioral neurogenetics and experimental psychology, but for translational biomedicine as well. Together with the upcoming total synaptic connectome of the Drosophila nervous system and the possibilities of single-cell-specific transgene expression, it offers enticing opportunities for research. Indeed, the paradigm has already been adopted by a number of labs and is robust enough to be used for teaching in classroom settings. This has given rise to a demand for a detailed, hands-on manual directed at newcomers and/or at laboratory novices, and this is what we here provide. The paradigm and the present manual have a unique set of features: The paradigm is cheap, easy, and robust;The manual is detailed enough for newcomers or laboratory novices;It briefly covers the essential scientific context;It includes sheets for scoring, data analysis, and display;It is multilingual: in addition to an English version we provide German, French, Japanese, Spanish and Italian language versions as well.The present manual can thus foster science education at an earlier age and enable research by a broader community than has been the case to date.

Background and Purpose: Developmental venous anomalies are the most common intracranial vascular malformation and are typically regarded as inconsequential, especially when small. While there are data regarding the prevalence of MR imaging findings associated with developmental venous anomalies, FDG-PET findings have not been well-characterized., Materials and Methods: Clinical information systems were used to retrospectively identify patients with developmental venous anomalies depicted on MR imaging examinations who had also undergone FDG-PET. Both the MR imaging and FDG-PET scans were analyzed to characterize the developmental venous anomalies and associated findings on the structural and functional scans. Qualitative and quantitative assessments were performed, including evaluation of the size of the developmental venous anomaly, associated MR imaging findings, and characterization of the FDG uptake in the region of the developmental venous anomaly., Results: Twenty-five developmental venous anomalies in 22 patients were identified that had been characterized with both MR imaging and FDG-PET, of which 76% (19/25) were associated with significant metabolic abnormality in the adjacent brain parenchyma, most commonly hypometabolism. Patients with moderate and severe hypometabolism were significantly older (moderate: mean age, 65 ± 7.4 years, P = .001; severe: mean age, 61 ± 8.9 years, P = .008) than patients with developmental venous aberrancies that did not have abnormal metabolic activity (none: mean age, 29 ± 14 years)., Conclusions: Most (more than three-quarters) developmental venous anomalies in our series of 25 cases were associated with metabolic abnormality in the adjacent brain parenchyma, often in the absence of any other structural abnormality. Consequently, we suggest that developmental venous anomalies may be better regarded as developmental venous aberrancies., (© 2015 by American Journal of Neuroradiology.)

Many patients with metastatic breast cancer (MBC) have been treated previously with taxanes and/or anthracyclines, which renders reinduction of anthracyclines in the palliative setting impossible because of the high cardiotoxicity of these drugs. Pegylated liposomal doxorubicin represents a means of reinducing anthracyclines without increasing cardiotoxicity. The aim of this retrospective study was to evaluate the efficacy and toxicity of Caelyx in patients with MBC. Patients with histologically confirmed MBC were eligible for this retrospective study if they had received palliative chemotherapy with pegylated liposomal doxorubicin between 1 January 2002 and 31 December 2006 at the Department for Gynecology and Obstetrics at the University of Heidelberg (Germany). The main endpoints were time to progression, overall survival, and safety of the treatment with pegylated liposomal doxorubicin. In all, 141 patients were included in this retrospective trial. The median age of the patients was 54 years (range 24-84 years). Of the patients, 43% had received five to six previous chemotherapy regimens before pegylated liposomal doxorubicin was recommended. In 33% of patients, more than three organs were involved. The most commonly involved organs were bones, liver, and lungs; 37 patients had received three or at least six cycles of Caelyx. During the treatment with pegylated liposomal doxorubicin, left ventricular ejection function was not reduced by more than 15%. The major effects (grade 4) were hematological toxicity (anemia, leukopenia, and thrombocytopenia), hand-foot syndrome, and stomatitis. In nine patients, the dose was reduced and in three patients chemotherapy with Caelyx was stopped owing to hematological toxicity. In 20 patients, the dose was reduced and in nine patients chemotherapy was stopped owing to nonhematological toxicity. The median time to disease progression was 6.5 months; the overall median survival was 13 months after the first course of pegylated liposomal doxorubicin was initiated. This retrospective study confirmed the efficacy and good tolerability of pegylated liposomal doxorubicin in patients with MBC who had been treated previously with anthracycline. A dosage of 40 mg/m² body surface every 4 weeks is equally effective with less toxicity.

The Drosophila larva is an emerging model for studies in behavioral neurogenetics because of its simplicity in terms of cell number. Despite this simplicity, basic features of neuronal organization and key behavior faculties are shared with adult flies and with mammals. Here, we describe a pavlovian-type learning assay in fruit fly larvae. A group of larvae is sequentially exposed to specific odors in the presence or the absence of sugar, and then tested to determine whether they prefer the odor previously experienced with the reward. The protocol uses a two-group, reciprocal training design: One group of Drosophila larvae is exposed to n-amyl acetate (AM) with a sugar reward (+), then subsequently exposed to 1-octanol (OCT) with no reward (denoted AM+/OCT). The other group receives the reciprocal training (AM/OCT+). The two groups of larvae are then tested for their choices between AM and OCT. Relatively higher preferences for AM after AM+/OCT training than after AM/OCT+ training reflect associative learning and are quantified by the learning index (LI). This method offers a robust, simple, cheap, and reasonably quick test for learning ability (an aversive version is available as well, using either high-concentration salt or quinine as punishment). With the concerted efforts of the Drosophila research community, we anticipate it will allow us to unravel the full circuitry underlying odor-taste learning on a single-cell level.

Severe immune suppression is frequent in late-stage tumor patients and promotes tumor immune evasion and subsequent tumor progression. Regulatory T cells (Treg) are major suppressors of anti-tumor immune responses. Therefore, targeting of Treg has become a key goal of anti-tumor therapy. Several preclinical and clinical observations suggest that Treg can be depleted by cyclophosphamide. Over a period of 3 months, we investigated the effect of metronomic low-dose cyclophosphamide on Treg numbers, suppressive capacity and proliferation on endogenous anti-tumor T-cell responses and on their correlation to clinical outcome in 12 patients with treatment-refractory metastasized breast cancer who received single-agent 50 mg cyclophosphamide p.o. daily. Cyclophosphamide treatment initially caused a significant reduction in circulating Treg by more than 40% (P = 0.002). However, Treg numbers completely recovered during the treatment due to increased proliferative activity and maintained their suppressive capacity. Treg depletion coincided with a strong increase in breast tumor-reactive T cells (P = 0.03) that remained at high levels during the whole period. Numbers of tumor-reactive T cells but not of Treg correlated with disease stabilization (P = 0.03) and overall survival (P = 0.027). We conclude that metronomic low-dose cyclophosphamide only transiently reduces Treg but induces stable tumor-specific T-cell responses, which correlate with improved clinical outcome in advanced-stage breast cancer patients.

Background: Disturbed skin microcirculation in patients with peripheral arterial occlusive disease (PAOD) might be affected by prostaglandin E1 (PGE1). The purpose of this study was to investigate local skin perfusion at the forefoot and toe of PAOD patients during different modes of administration of PGE1., Patients and Methods: In 17 patients with severe PAOD local intradermal haemoglobin oxygen saturation (SHB) and dermal vascular reserve capacity, transcutaneous oxygen pressure (tcPO2) and laser Doppler flux (LDF) were determined during intra-arterial (1.5 ng/kg body weight/min) and intravenous (6 ng/kg body weight/min) infusion of PGE1., Results: SHB significantly increased at both locations during intravenous PGE1; intra-arterial administration significantly increased SHB in the skin of the forefoot only. Reserve capacity increased during intravenous administration and was markedly reduced during intra-arterial infusion. No significant changes were found regarding tcPO2 and LDF., Conclusions: These data suggest different therapeutic mechanisms for intra-arterial and intravenous administered of PGE1.

Background: Oxygen saturation (SHB) and concentration (CHB) of dermal haemoglobin play an important role in the nutrition of the skin. In patients with severe peripheral arterial occlusive disease (PAOD) they are reduced at the forefoot. We investigated the changes of the named parameters during an acute ischemia and during reactive hyperemia using an occlusion test., Patients and Methods: Dermal reflection spectra were conducted from the forefoot of 11 healthy subjects and 39 patients with peripheral arterial occlusive disease of various stages at rest, during, and after an arterial occlusion at the thigh. Using a multicomponent analysis SHB and CHB were calculated iteratively. The halftime of the post-occlusive increase of SHB (post-occlusive recovery halftime PORHT) and the relation of post- to pre-occlusive CHB (post-occlusive reactive hyperemia PORH) were calculated to estimate the dynamic of the post-occlusive inflow of blood. TcPO2 (37 degrees C) was additionally determined at the forefoot., Results: In patients from stage III and IV all resting values were lower compared to controls. TcPO2 decreased in all persons to 0 mm Hg during the occlusion, SHB was between 0 and 10%, while CHB remained unchanged. In healthy subjects and in patients with claudication the post-occlusive values exceeded the preocclusive ones, while in some patients with higher stages of the disease this could not be found. There was a marked, on the stage of the disease depending difference in the post-occlusive course between controls and patients: in healthy subjects it took only 5.5 +/- 4.8 s until SHB reached half of the maximum value, in patients from the stage IIa group 26.8 +/- 16.9 s (p < 0.001) was measured while in stage III and IV the value was 132 +/- 75 s (p < 0.001)., Conclusions: During ischemia a decrease of the haemoglobin oxygen saturation (SHB) and tcPO2 was found. Haemoglobin concentration (CHB) remained constant, hence a significant shift of blood from skin to muscle did not take place. PORHT was selectively dependent on the stage of the disease. The occlusion manoeuvre enhances the significance of reflection photometry in PAOD.

Background: Since there is a need for an objective parameter of microcirculation in follow-up of patients with Raynaud's syndrome we evaluated the reproducibility of the reaction to a cold exposure test with nailfold capillaroscopy and laser Doppler fluxmetry during a winter period., Patients and Methods: 10 healthy subjects and 16 patients with primary Raynaud's syndrome were evaluated with nailfold capillaroscopy and laser Doppler fluxmetry of the finger tips during and after a standardized cold exposure stress test. The measurements were repeated in the controls within 2 weeks, in the patient population twice within 24 weeks., Results: In the healthy controls the percentage of capillaries with flow stop was stable (r = 0.785) and the duration of flow stop was reproducible (r = 0.993). Both parameters were significantly lower in controls than in the patients. The flow stop durations in patients varied intra-individually to a great extent between the different weeks without any significant correlation. For all calculated laser Doppler perfusion and time parameters we did not find any significant differences between controls and patients nor any consistent correlations in the intra-individual comparison within the different weeks for both, controls and patients., Conclusion: Nailfold capillaroscopy during cold exposure is able to discriminate between healthy persons and patients with primary Raynaud's syndrome, but seems to be of minor value for follow-up evaluation of patients because of intraindividual variations. Laser Doppler fluxmetry is invalid for both purposes when using the applied cold exposure test.

Background: Oxygen saturation (SHB) and concentration (CHB) of dermal hemoglobin are important parameters for the supply of the skin. They may be non-invasively assessed by means of reflection photometry as hemoglobin is predominantly contributing to the skin reflection spectrum., Methods and Results: Dermal reflection spectra from the middle of the forefoot and from the tip of the toe of 20 healthy subjects and 61 patients suffering from peripheral arterial occlusive disease (PAOD) were recorded and compared to transcutaneous oxygen pressure (tcPO2). SHB, and tcPO2 were significantly higher in controls: compared to patients (ankle pressure (AP) > 50 mmHg) SHB in the skin of the forefoot was 63.8 vs. 54.5% (p < 0.05), CHB was 0.89 vs. 0.62 aU (p < 0.01). In the great toe SHB was 92.9 vs. 59.9% (p < 0.001), CHB was 2.21 vs. 0.92 aU (p < 0.001). Heating the skin of the forefoot to 44 degrees C yields local dermal vascular reserve capacity: SHB and CHB increased in all healthy subjects (96.4%; 1.44 aU, respectively). SHB decreased at the forefoot in 14 and at the toe in 18 of 21 patients with AP < 50 mmHg. At the toe decrease was found in 50 of 61 patients (sensitivity 82%, specificity 100%)., Conclusions: Local vascular reserve capacity of dermal perfusion is reduced in patients with PAOD, depending on AP. It should be determined preferably in patients with severe PAOD.

Venous incompetence often leads to ulceration of the skin of the lower limb due to a disturbance of skin microcirculation. We investigated 10 healthy subjects and 18 patients with chronic venous insufficiency by means of a fast scanning reflection photometer and determined noninvasively the hemoglobin oxygen saturation (S(HB)) and the relative concentration of hemoglobin (C(HB)) in the skin of the forefoot and at the calf, 10 cm proximal of the inner malleolus during positional changes. In supine position no significant differences were found. During sitting and standing S(HB) dropped and was significantly lower in patients at both locations (calf, standing, patients 22.2 +/- 10.6% vs controls 48.2 +/- 13.5%, P < 0.001). C(HB) increased in patients during standing from 0.71 to 2.13 +/- 0.33 aU (in controls from 0.69 to 1.49 +/- 0.28 aU, P < 0.001). Activation of the muscle pump decreased C(HB) and increased S(HB) in patients and in controls. After the movements were stopped, S(HB) decreased again and fell to the initial low values eight times faster in patients (7.4 +/- 5.3 vs 57.5 +/- 19.6 sec, P < 0.001). C(HB) increased four times faster in patients (7.2 +/- 6.1 vs 29.9 +/- 13.6 sec). In sitting and standing positions hemoglobin oxygenation in the skin of the lower limb was markedly reduced in patients, but normal perfusion conditions were restored in supine position, indicating reversibility of the changes. Reflection oxymetry seems a valuable tool for the assessment of chronic venous insufficiency. The substantially reduced oxygenation of dermal hemoglobin in standing patients may contribute to the development of venous ulcers.

Skin surface oxygen pressure fields (tcPO2 [37 degrees C]) reproducibly characterize skin microcirculation in patients with peripheral arterial occlusive disease. These appear suited for investigation of short- and long-term effects of vasoactive drug treatment. The authors studied whether skin surface oxygen pressure histograms change depending on dosage and route of administration of prostaglandin E1 (PGE1), whether they are of predictive value for patients' clinical outcome, and whether they normalize after therapy with PGE1. The authors investigated 15 patients with various degrees of disease and measured forefoot oxygen histograms consisting of at least 80 single tcPO2 (37 degrees C) values before and during intraarterial infusion (1.5, 3, or 6 ng/kg/minute) and intravenous infusion (4.5, or 9 ng/kg/minute). The measurements were repeated two and six hours after the end of intraarterial application of 1.5 ng/kg/minute. Furthermore, the orthostatic vasoconstrictor response was tested. Skin oxygen pressure histograms were controlled after a period of twenty-two (mean) days of intraarterial PGE1 therapy. Resting histograms were left shifted with median tcPO2 (37 degrees C) between 1 and 7 mm Hg. During intraarterial application, histograms were shifted to lower tcPO2 (37 degrees C) values in most patients. Only in 3 diabetic subjects with proximal or acral obliterations was a marked increase observed. The alterations were detectable at least two hours after the end of the infusion. During intravenous infusion, histograms did not change in most cases. After long-term therapy, histograms were substantially unchanged. A pathologic vasoconstrictor response, which was present in 10 patients, could not be restored. Despite a marked deterioration of the histograms the clinical outcome was favorable in 7 patients. Patients with a high resting tcPO2 (37 degrees C) (median 4 mm Hg and more) and those with a vasoconstriction on orthostasis are likely to respond to PGE1 therapy.

By a spectrophotometrical method, the oxygenation and relative concentration of hemoglobin in the skin of the forefoot was determined in 40 patients with advanced peripheral arterial occlusive disease. While the Hb-saturation at rest was hardly different from normals, leg elevation provoked a marked decrease of both parameters, especially in patients with critical ischemia. In these patients, reactive hyperemia was markedly delayed and impaired. External heat application failed to cause a hyperemic saturation increase in 14 patients and produced a decrease in 8 patients, 6 of whom experienced an infavourable clinical outcome. The method seems specially suited to assess states of severe ischemia.

In earlier studies we have shown that partial correction of anemia by recombinant human erythropoietin (r-HuEPO) already after 12 weeks results in a significant increase of exercise capacity in patients on chronic hemodialysis. As causative effect increased oxygen availability with improved oxygen delivery to the tissues was assumed. To elucidate the long-term effects of a partial correction of anemia with r-HuEPO on exercise capacity, oxygen uptake at maximum exercise and at the anaerobic threshold was measured by repetitive spiroergometry. Measurements were done before, 3 months and 6 months after initiation of r-HuEPO therapy. The results are summarized below: (table; see text) Our results show that a long-term improvement of peripheral oxygen availability leads to a further increase of anaerobic threshold in patients on chronic hemodialysis even without a further increase of hemoglobin levels and without exercise training. It appears that elimination of the chronic hypoxic condition results in a restoration of previously diminished mitochondrial enzymes in muscle, particularly for aerobic glycolysis. Besides acute improvement of aerobic and anaerobic exercise capacity, the long-term administration of r-HuEPO with its increased anaerobic threshold enhances the patients' everyday life working capacity.

To investigate the effect of partial correction of anemia in patients maintained by chronic intermittent hemodialysis on aerobic and anaerobic working capacity, eight patients underwent a bicycle spiro-ergometry before and after treatment with recombinant human erythropoietin (r-HuEPO). the initial mean (+/- SD) hemoglobin value was 5.9 mg/dl +/- 0.61 and increased during treatment to 10.9 +/- 0.59 mg/dl, P less than 0.0001). This partial correction of anemia resulted in a significant increase of both oxygen uptake at the anaerobic threshold and peak peripheral oxygen uptake at subjective exhaustion (P less than 0.01 and P less than 0.0002, respectively). The increase in oxygen uptake corresponded to significant increases in Watts, both at the anaerobic threshold and at maximum workload (P less than 0.02 and P less than 0.0004). These data show that partial correction of renal anemia results in a significant increase of both exercise capacity and maximum work.

Recombinant human erythropoietin (r-HuEPO) has recently become available for clinical trial and has been used for the first time in Austria for the treatment of transfusion dependent patients on chronic haemodialysis. Inclusion criteria into the study were baseline haemoglobin levels of less than or equal to 6 g/dl and transfusion requirements of greater than or equal to 1 unit of blood per month. r-HuEPO (CILAG/AMGEN/ORTHO) was administered intravenously 3 times weekly at the end of dialysis. The initial dose was 100 U/kg body weight at each administration and was increased by 25 U/kg if Hb levels failed to increase by greater than 5% of baseline at intervals of 3 weeks. All 9 patients studied showed an increase in Hb values to the desired value at least greater than or equal to 10 g/dl within 6 to 16 weeks and none of the patients required further blood transfusions. All patients reported subjective improvement of life quality and markedly increased working ability. Apart from minor episodes of bone pain and subfebrile temperatures after r-HuEPO administration no major side effects were noted. These preliminary results show that r-HuEPO (CILAG/AMGEN/ORTHO) is a safe and effective form of therapy for renal anaemia and one which opens new horizons in the management of patients on chronic haemodialysis.