Clinical trial of insulin-like growth factor-1 in Phelan-McDermid syndrome

Background

Phelan-McDermid syndrome (PMS) is caused by haploinsufficiency of the SHANK3 gene and is characterized by global developmental delays and autism spectrum disorder (ASD). Based on several converging lines of preclinical and clinical evidence supporting the use of insulin-like growth factor-1 (IGF-1) in PMS, this study aims to follow-up a previous pilot study with IGF-1 to further evaluate this novel therapeutic for core symptoms of ASD in children with PMS.

Methods

Ten children aged 5–9 with PMS were enrolled. Participants were randomized to receive IGF-1 or placebo (saline) using a 12-week, double-blind, crossover design. Efficacy was assessed using the primary outcome of the Aberrant Behavior Checklist—Social Withdrawal (ABC-SW) subscale as well as secondary outcome measures reflecting core symptoms of ASD. To increase power and sample size, we jointly analyzed the effect of IGF-1 reported here together with results from our previous controlled trail of IGF-1 in children with PMS (combined N = 19).

Results

Results on the ABC-SW did not reach statistical significance, however significant improvements in sensory reactivity symptoms were observed. In our pooled analyses, IGF-1 treatment also led to significant improvements in repetitive behaviors and hyperactivity. There were no other statistically significant effects seen across other clinical outcome measures. IGF-1 was well tolerated and there were no serious adverse events.

Limitations

The small sample size and expectancy bias due to relying on parent reported outcome measures may contribute to limitations in interpreting results.

Conclusion

IGF-1 is efficacious in improving sensory reactivity symptoms, repetitive behaviors, and hyperactivity  in children with PMS.

Trial registration NCT01525901.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13229-022-00493-7.

Lameness in fattening pigs - Mycoplasma hyosynoviae, osteochondropathy and reduced dietary phosphorus level as three influencing factors: a case report

BACKGROUND

Multiple diagnostic procedures, their results and interpretation in a case with severe lameness in fattening pigs are described. It is shown that selected diagnostic steps lead to identification of various risk factors for disease development in the affected herd. One focus of this case report is the prioritization of diagnostic steps to verify the impact of the different conditions, which finally led to the clinical disorder. Assessing a sufficient dietary phosphorus (P) supply and its impact on disease development proved most difficult. The diagnostic approach based on estimated calculation of phosphorus intake is presented in detail.

CASE PRESENTATION

On a farrow-to-finishing farm, lameness occurred in pigs with 30-70 kg body weight. Necropsy of three diseased pigs revealed claw lesions and alterations at the knee and elbow joints. Histologic findings were characteristic of osteochondrosis. All pigs were positively tested for Mycoplasma hyosynoviae in affected joints. P values in blood did not indicate a P deficiency, while bone ashing in one of three animals resulted in a level indicating an insufficient mineral supply. Analysis of diet composition revealed a low phosphorus content in two diets, which might have led to a marginal P supply in individuals with high average daily gains with respect to development of bone mass and connective tissue prior to presentation of affected animals. Finally, the impact of dietary factors for disease development could not be evidenced in all submitted animals in this case.

CONCLUSIONS

Mycoplasma (M.) hyosynoviae was identified to be an important etiologic factor for disease. Other, non-infectious factors, such as osteochondrosis and claw lesions might have favored development of lameness. In addition, a relevant marginal P supply for pigs was found in a limited time period in a phase of intense growing, but the potential interaction with infection by M. hyosynoviae is unknown. The presented case of severe lameness in fattening pigs revealed that three different influences presumably act in pathogenesis. Focusing only on one factor and ignoring others might be misleading regarding subsequent decision-making for prevention and therapy. Finally, clinical symptoms disappeared after some changes in diet composition and anti-inflammatory treatment of individual animals.

Blood Fluidity as a Consequence of Red Cell Fluidity: Flow Properties of Blood and Flow Behavior of Blood in Vascular Diseases

Blood is known to be an extremely non-Newtonian material, the fluidity (or reciprocal of viscosity) of which can vary in vivo between that of plasma alone and zero, that is, the total lack of fluidity in the absence of coagulation. The fluidity of blood under high driving pressures and in small blood vessels is un usually high when compared to that of all other known suspensions or emul sions. The high fluidity of blood is caused by the fluidity of the red cells, which adapt to the forces of flow and participate in flow much like fluid droplets. When subjected to high forces the blood behaves dynamically like an emulsion of extremely low viscosity. In the absence of adequate flow forces, the erythro cytes are aggregated into rouleaux and rouleaux networks, which render to blood the properties of a reticulated suspension. Under these flow conditions, the fluidity of blood strongly decreases if the hematocrit value is normal or slightly elevated. If the flow forces fall below a critical level, the fluidity ap proaches zero, under which conditions the flow of blood ceases altogether (de spite the presence of residual driving pressures). The fluidity of blood is further jeopardized by an enhanced tendency to aggregation and biochemical erythro cyte rigidification, for example, by lactacidosis, hyperosmolarity, or loss of ATP. However, an actual loss of fluidity under these conditions occurs only if the biochemical changes are strictly associated with a drop in driving pressures (locally or generally).

Restitution of blood fluidity can be achieved most simply by isovolumic he modilution, by defibrinogating agents, or by drugs that protect against rigid ifying effects of acidosis or other biochemical sequelae of stagnation anoxia.

[Hyperbaric oxygen therapy for necrotizing soft tissue infections: contra]

INTRODUCTION

Hyperbaric oxygen therapy (HBOT) is discussed as an adjuvant option to treat necrotizing soft tissue infections (NSTI). While the Federal Joint Committee decided in 2007 not to support HBOT for the indication necrotizing fasciitis and Fournier's gangrene, it was decided to accept HBOT for treatment of clostridial myonecrosis for the German health insurance. Thus, in Germany necrotizing fasciitis (NF) is not a confirmed indication for HBOT. Against this background the cons of the clinical benefits of HBOT should be formulated.

METHODS

A literature search (MEDLINE/EMBASE/COCHRANE/manual search) using the keywords "necrotizing fasciitis", "Fournier's gangrene", "necrotizing cellulitis", "necrotizing soft tissue infections" as well as "hyperbaric medicine", "hyperbaric therapy" and "hyperbaric treatment" was carried out. An analysis of the spatial distribution of German hyperbaric oxygen chambers enabling intensive care (HOC-IC) was made.

RESULTS

A total of 250 articles with n=2,556 NSTI patients (n=993 treated by HBOT) was found and 50% of the articles were case reports or series. There were only ten retrospective studies comparing the effects of HBOT with non-HBO treatment and none of them verified the benefit of HBOT in NF patients. In Germany only nine hyperbaric oxygen chambers (HOC-IC) enable intensive care. Currently, patient data are not included in scientific studies or multicenter studies, while studies assessing the benefit with higher evidence levels have been required for more than 15 years.

CONCLUSIONS

The previously published human clinical studies do not confirm any therapeutic benefit of HBOT in NF patients. Any time delay in the start of surgical therapy by HBOT would not be acceptable. In Germany a comprehensive clinical care with HOC is not possible. On average the additional costs of HBO treatment for NF patients is approximately 8,000-25,000 <euro>/patient which is not generally reimbursed by health insurance companies. Initializing a register study to assess the benefit of HBOT in NF patients appears feasible and is urgently needed.

Physical determinants of vascular network remodeling during tumor growth

The process in which a growing tumor transforms a hierarchically organized arterio-venous blood vessel network into a tumor specific vasculature is analyzed with a theoretical model. The physical determinants of this remodeling involve the morphological and hydrodynamic properties of the initial network, generation of new vessels (sprouting angiogenesis), vessel dilation (circumferential growth), vessel regression, tumor cell proliferation and death, and the interdependence of these processes via spatio-temporal changes of blood flow parameters, oxygen/nutrient supply and growth factor concentration fields. The emerging tumor vasculature is non-hierarchical, compartmentalized into well-characterized zones, displays a complex geometry with necrotic zones and "hot spots" of increased vascular density and blood flow of varying size, and transports drug injections efficiently. Implications for current theoretical views on tumor-induced angiogenesis are discussed.

[Knee dislocation--a simple diagnosis? Compartment syndrome with occlusion of the popliteal artery and lesion of the peroneal nerve after inadequate trauma]

Knee dislocations are rare and often associated with damage to the surrounding structures. We present a case where a soldier sustained a complex knee dislocation during routine training. This trauma was associated with a compartment syndrome, occlusion of the popliteal artery, lesion of the peroneal nerve and multiple lesions of ligaments and tendons of the knee.

Vascular remodelling of an arterio-venous blood vessel network during solid tumour growth

We formulate a theoretical model to analyze the vascular remodelling process of an arterio-venous vessel network during solid tumour growth. The model incorporates a hierarchically organized initial vasculature comprising arteries, veins and capillaries, and involves sprouting angiogenesis, vessel cooption, dilation and regression as well as tumour cell proliferation and death. The emerging tumour vasculature is non-hierarchical, compartmentalized into well-characterized zones and transports efficiently an injected drug-bolus. It displays a complex geometry with necrotic zones and "hot spots" of increased vascular density and blood flow of varying size. The corresponding cluster size distribution is algebraic, reminiscent of a self-organized critical state. The intra-tumour vascular-density fluctuations correlate with pressure drops in the initial vasculature suggesting a physical mechanism underlying hot spot formation.

Infectious complications after allogeneic stem cell transplantation: incidence in matched-related and matched-unrelated transplant settings

BACKGROUND

Bacterial, viral, and fungal pathogens frequently cause severe, life-threatening infections in immunocompromised patients after allogeneic hematopoietic stem cell transplantation (SCT).

OBJECTIVE

To compare the frequency of infections in patients with matched-related (Group A) or with human leukocyte antigen (HLA)-matched-unrelated donors (Group B).

PATIENTS AND METHODS

Patients treated at our transplantation unit between April 2004 and April 2005 were enrolled into this analysis. Documentation comprised demographic data, conditioning treatment, stem cell source, clinical course, as well as microbiological and clinical data and mortality.

RESULTS

We analyzed 59 patients, 22 in Group A and 37 in Group B. Both groups were well balanced regarding demographic data. Diagnoses were acute myeloid leukemia (30 of 59 patients, 50.8%), multiple myeloma (15.2%), acute lymphoblastic leukemia (11.9%), and chronic myeloid leukemia (10.2%). Patients in Group A developed infections in 95.5% of the cases compared with 97.3% in patients in Group B. Most frequently detected pathogens were Staphylococcus species, human herpesvirus-6, and Epstein-Barr virus. Three proven fungal infections were detected in Group A compared with 9 proven fungal infections in Group B. Lung infiltrations were observed in equivalent incidence in both groups. Two years after transplantation, 55.9% of patients were alive (Group A: 68.2%; Group B: 48.6%, not significant).

CONCLUSION

Allogeneic SCT from HLA-matched-unrelated donors does not have a higher infection risk than patients transplanted from matched-related donors.

Emergent vascular network inhomogeneities and resulting blood flow patterns in a growing tumor

Tumors acquire sufficient oxygen and nutrient supply by coopting host vessels and neovasculature created via angiogenesis, thereby transforming a highly ordered network into chaotic heterogeneous tumor specific vasculature. Vessel regression inside the tumor leads to large regions of necrotic tissue interspersed with isolated surviving vessels. We extend our recently introduced model to incorporate Fahraeus-Lindqvist- and phase separation effects, refined tissue oxygen level computation and drug flow computations. We find, unexpectedly, that collapse and regression accelerates rather than diminishes the perfusion and that a tracer substance flowing through the remodeled network reaches all parts of the tumor vasculature very well. The reason for decreased drug delivery well known in tumors should therefore be different from collapse and vessel regression. Implications for drug delivery in real tumors are discussed.

Risk factors for clinical anastomotic leakage and postoperative mortality in elective surgery for rectal cancer

BACKGROUND AND AIMS

Clinical anastomotic leakage remains a major problem after anterior or low anterior resection for rectal cancer. The aim of this study was to assess the association between risk factors and anastomotic leakage and postoperative mortality.

MATERIALS AND METHODS

Two hundred seventy-six elective anterior or low anterior resections with anastomosis were performed and documented on-line from January 1995 to December 2004. Univariate and multivariate analyses with Bonferroni adjustment were carried out to identify relevant risk factors.

RESULTS

The rate of anastomotic leakage was 14.9% (41 of 276 patients) with a mortality of 12.2% (5 of 41 patients). Overall mortality was 2.5% (7 of 276 patients). Multiple regression analysis showed that smokers had an increased risk of anastomotic leakage [odds ratio (OR), 6.42; 95% confidence interval (CI), 2.68-15.36] as well as patients with coronary heart disease (OR, 7.79; 95% CI, 2.52-24.08). Smokers (OR, 13.20; 95% CI, 2.48-7.24) and patients with coronary heart disease (OR, 23.46; 95% CI, 4.33-27.04) also had an increased risk of postoperative mortality in the univariate analysis as well as patients with anastomotic leakage (OR, 16.25; 95% CI, 3.04-16.92).

CONCLUSIONS

Smoking and coronary heart disease are important risk factors for anastomotic leakage and postoperative mortality after elective resection for rectal cancer.

Chemoembolization with carboplatin of the lung. Feasibility and toxicity in a pig model

OBJECTIVES

Chemoembolization of the lung was evaluated as a novel treatment for unresectable lung metastases. Based on our encouraging results in a rodent model (rat), the aim was to prove the safety and effectiveness of this novel method in a large animal model before clinical application of this therapy.

MATERIALS AND METHODS

Eight pigs underwent femoral vein puncture. The tumor-supplying pulmonary arteries were selectively explored and chemoembolization with degradable starch microspheres (DSM) and carboplatin was administered. Survival, hemodynamic parameters, ventilation gas exchange, digital subtraction angiography (DSA) and pulmonary X-rays were documented during and after chemoembolization. As a follow-up, a pulmonary X-ray was assessed every week for six months after chemoembolization when the animals were sacrificed and the lungs histologically examined.

RESULTS

Selective and reversible chemoembolization of the right lung was recorded by DSA. Only slight hemodynamic effects were seen during selective chemoembolization of the lung. X-ray examinations showed no early or late abnormalities. The histological examination of the lung tissue six months after chemoembolization showed that the parenchyma was normal.

CONCLUSION

This is the first study of chemoembolization of the lung in a large animal model. The feasibility, mild hemodynamic acute effects and the absence of long-term toxicity were documented. These observations justify patient studies in unresectable lung metastases.

Chemoembolization of lung metastases--pharmacokinetic behaviour of carboplatin in a rat model

AIM

To improve tumor control in lung metastases using a novel method: unilateral chemoembolization of the lung by instillation of degradable starch microspheres (DSM) and cytotoxic agents via the pulmonal artery.

MATERIALS AND METHODS

A rodent model of solitary metastasis (CC531 adenocarcinoma) was studied. The animals were randomized into three groups: the control group receiving carboplatin (45 mg/kg) intravenously, an isolated lung perfusion (ILP) group recieving buffered starch solution and carboplatin (15 mg/kg) and a third group receiving chemoembolization with carboplatin (15 mg/kg) and DSM (2 ml/kg). The total platinum concentration in serum, lung and lung tumor at defined times (15, 30, 60, 120 min) was measured using an inductively coupled plasma mass spectrometer (ICP-MS).

RESULTS

The area under concentration (AUC) versus time curves showed a 7.9- to 42.6-fold higher concentration in the tumor tissue comparing the ILP and chemoembolization group to the control group (p < 0.01). In the comparison of the AUCs of ILP versus chemoembolization, the tumor tissue of the lung showed a 5.4-fold higher concentration in the chemoembolization group (p < 0.01).

CONCLUSION

This is the first study to measure the concentration of carboplatin during chemoembolization of the lung. Compared to intravenous therapy, chemoembolization produced higher tumor tissue concentrations. Comparing chemoembolization to ILP, there was also an increase of carboplatin in the tumor tissue, without histological damage of the surrounding lung parenchyma.

Phase II study of regional chemotherapy using the hypoxic abdominal perfusion technique in advanced abdominal carcinoma. 5-FU pharmacokinetics, complications and outcome

The aim of this study was to verify the rationale of a hypoxic abdominal perfusion (HAP) technique for the perfusion of 5-FU, mitomycin C and cisplatin in patients with inoperable, recurrent abdominal cancer.

PATIENTS AND METHODS

In a phase II study, 59 patients with various non-resectable abdominal tumours were treated with 102 perfusions by the HAP-technique. The HAP-technique was performed by using double-balloon arterial-venous catheters that selectively isolated the abdominal vascular section and perfusion was provided by an extracorporal pump for 20 min. Thirty-four patients with unresectable colorectal cancer, 11 with unresectable gastric cancer, eight with unresectable pancreatic cancer and six with cancer of the gall bladder were included. They were treated with a combination of 5-fluorouracil (5-FU 1 g/m(2)), mitomycin C (MMC, 10 mg/m(2)) plus cisplatin (50 mg/m(2)) infused into the isolated abdominal compartment. The cytostatic concentration of 5-FU was determined intrainterventionally within the systemic and regional compartment. Toxicity- and procedure-related complications were documented. Tumour responses were assessed by computer tomography.

RESULTS

5-FU concentration was 16.3-fold higher within the regional compared to the systemic compartment at its maximum, and the area under the curve (AUC) was 7.9 times larger. During the procedure two major complications were experienced (1x perforation of the A. iliaca, lx deep vein thrombosis), no deaths occurred during surgery or in the postoperative period. Minimal systemic and local toxicities were observed (WHO grade III-IV 1%, grade I-II 33%). No complete response but 22 partial responses were observed. Median survival was 15.5 months for colorectal cancer, 12. 5 months for gastric cancer, 12.7 months for pancreatic cancer and 7.8 months for gall bladder cancer.

CONCLUSION

The hypoxic abdominal perfusion is a safe and effective palliative treatment for patients with unresectable advanced colorectal, gastric and pancreatic carcinoma. The HAP has not shown promising results for advanced gall bladder cancer. These encouraging clinical results require further evaluation.

Complete ulcer healing as primary endpoint in studies on critical limb ischemia? A critical reappraisal

OBJECTIVES

Although complete ulcer healing is the mandatory primary efficacy criterion in current European guidelines for drug trials in critical limb ischemia (CLI), the appropriateness of this endpoint has been questioned for some time. We carried out a systematic review to assess the value of this endpoint in studies on reconstructive measures, considered to be the standard of care for CLI.

METHODS

A computerized literature search (1985-2005) was performed to track down clinical studies on endovascular and surgical interventions by using the search terms CLI and ulcer healing and their synonyms.

RESULTS

1,914 papers on revascularization in CLI were identified. Complete ulcer healing was reported in 17 studies (0.9%). Among these, there were no randomized controlled trials, five prospective cohorts on endovascular procedures, and six retrospective cohorts for endovascular and surgical procedures, respectively. If healing rates or time to ulcer healing were available, they differed greatly between the studies without consistent correlation to types of therapy.

CONCLUSIONS

In past and current literature, complete ulcer healing is not a consistently reported criterion for success of revascularization in CLI. Thus, its appropriateness for efficacy assessment of drug studies in CLI patients has to be questioned.

Hepatic arterial infusion (HAI). Comparison of 5-fluorouracil, folinic acid, interferon alpha-2b and degradable starch microspheres versus 5-fluorouracil and folinic acid in patients with non-resectable colorectal liver metastases

BACKGROUND

The prognosis of patients with advanced colorectal tumor is poor. Therefore, other therapy regimes for non-resectable hepatic metastases are necessary. In this prospective study, two regional chemotherapy protocols were compared.

PATIENTS AND METHODS

An arterial port system was implanted in 64 patients. Sixty patients were assigned to the two therapy protocols for hepatic arterial infusion (HAI): protocol A (n=24): 5-FU/FA (300 mg/m2 folinic acid and 600 mg/m2 5-fluorouracil daily for 5 days with a 14-day interval); protocol B (n=36): 5-FU/FA/IFN/DSM (450 mg starch microspheres (DSM) with 5 million IU recombinant interferon (IFN), alpha 2b 500 mg/m2 FA and 600 mg/m2 5-FU).

RESULTS

The response rate was 50% in protocol A patients and 69.4% in protocol B. The median times for disease progression were 11 months for protocol A and 20 months for protocol B (p = 0.038), while median survival times of 14 months and 26 months, respectively, were obtained (p = 0.015). There were no significant differences in terms of toxic side-effects. Major toxicity problems were observed in 12% of the protocol A-treated patients and in 11% of the protocol B-treated patients.

CONCLUSION

Combination therapy with HAI-5-FU/FA/IFN/DSM was superior to HAI-5FU/FA, with a high response rate (69% vs. 55%) and few toxic side-effects. These findings suggest that these combinations should be evaluated in larger studies as first- or second-line therapy in patients with hepatic metastases of colorectal cancer.

Vascular network remodeling via vessel cooption, regression and growth in tumors

The transformation of the regular vasculature in normal tissue into a highly inhomogeneous tumor specific capillary network is described by a theoretical model incorporating tumor growth, vessel cooption, neo-vascularization, vessel collapse and cell death. Compartmentalization of the tumor into several regions differing in vessel density, diameter and in necrosis is observed for a wide range of parameters in agreement with the vessel morphology found in human melanoma. In accord with data for human melanoma the model predicts that microvascular density (MVD), regarded as an important diagnostic tool in cancer treatment, does not necessarily determine the tempo of tumor progression. Instead it is suggested that the MVD of the original tissue as well as the metabolic demand of the individual tumor cell plays the major role in the initial stages of tumor growth.

Wenn die Hüfte nicht „nur“ luxiert

BACKGROUND

Traumatic hip dislocation combined with fracture of the femoral head is a rare condition for which little known in terms of long-term prognosis. The aim of the retrospective study presented here was to evaluate the clinical and radiological outcome of this specific injury.

PATIENTS AND METHODS

In a 23 year period, 18 patients (17 male) with an average age of 25.6 (range 15-55 years) were treated. There were four type-I, three type-II, no type-III, and 11 type-IV fractures according to the Pipkin classification (1957).

RESULTS

The average time to sufficient reduction was 136 min (60-420 min), two by open means. A total of 16 patients were operated for open reduction and internal fragment fixation, 13 through a dorsal approach. All patients filled out a standardized questionnaire, and clinical and radiological examinations were also carried out on average 12.6 years (range 59-247 months) after injury. Four scoring systems were used to classify the outcome: Thompson and Epstein (1951): very good = 1, good = 10, fair = 4, poor = 3; Merle D'Aubigne (1954): very good = 9, good = 5, fair = 0, poor = 4; Harris (1969): Pipkin I = 81 points, Pipkin II = 97 points, Pipkin IV = 73 points (mean); Brooker (1973): grade I = 5, grade II = 1, grade IV = 2.

CONCLUSION

Quality of life was not reduced in most patients in the long term, however three of four patients suffering Pipkin type-IV fractures developed functional restrictions with poor results. We conclude that acute reduction of the dislocated joint and anatomical reconstruction of the femoral head instead of primary hip replacement may end in good to excellent results in type-I and type-II fractures. Due to the young age of these patients, joint reconstruction should always be the first choice even in type-IV fractures with a higher probability of poor prognosis.

[Neurotrophic factors of the GDNF family and their receptors are detectable in spiral ganglion cells of normal hearing as well as of deafened rats]

BACKGROUND

Recent studies have shown that neurotrophic factors like BDNF, NT-3 and GDNF induce protective effects on spiral ganglion cells after noise- or drug-induced hearing loss. According to these studies it is suggested that deafness leads to a lack of neurotrophic factor or relating receptor expression in spiral ganglion cells, that has to be compensated by local cochlear application of these factors.

METHODS

In the present study we examined the expression pattern of members of the GDNF family (GDNF, Neurturin, Artemin, Persephin) and their relating receptors (Ret, GFRalpha1 - 3) as well as BDNF and trkB on spiral ganglion cells of normal hearing and experimentally deafened rats (10 % neomycine). Indirect immunofluorescence was carried out to determine protein expression of these factors and their receptors 26 days following deafening.

RESULTS

Our results demonstrate neurotrophic factor and receptor expression on spiral ganglion cells of normal hearing as well as experimentally deafened animals.

CONCLUSIONS

Our data indicate that within a period of 26 days after deafening no detectable reduction of the GDNF-family member expression and their receptors was ascertainable on spiral ganglion cells by immunohistochemistry. Thus, a lack of neurotrophic factor expression is unlikely to be the only cause of spiral ganglion cell loss following deafening.

Flow correlated percolation during vascular remodeling in growing tumors

A theoretical model based on the molecular interactions between a growing tumor and a dynamically evolving blood vessel network describes the transformation of the regular vasculature in normal tissues into a highly inhomogeneous tumor specific capillary network. The emerging morphology, characterized by the compartmentalization of the tumor into several regions differing in vessel density, diameter, and necrosis, is in accordance with experimental data for human melanoma. Vessel collapse due to a combination of severely reduced blood flow and solid stress exerted by the tumor leads to a correlated percolation process that is driven towards criticality by the mechanism of hydrodynamic vessel stabilization.

Improvement in 5-fluorouracil (5-FU) and 5-fluoro-2'-deoxyuridine (FdUrd) concentration by 5-fluorouracil-polyethylene-glycol-liposomes in abdominal stop-flow: treatment of VX2 liver-tumor-bearing rabbits

The application of liposome-encapsulated cytostatics results in higher concentrations in tumor tissue. This effect can be further increased by blood flow retardation with longer retention time in the tumor and by arterial administration. In abdominal stop-flow therapy, a separate partial circulation with a defined flow is realized via a roller pump under hypoxic conditions. Forty chinchilla rabbits with VX-2 liver tumors were treated either intra-aortally (stop-flow therapy) or systemically with 50 mg 5-FU or 5-FU-PEG liposomes. During therapy, pH and pO2 were measured at regular intervals. After 20 minutes, concentrations of 5-FU and its metabolite FdUrd were determined by HPLC in different organs and the liver tumor. Compared to the i.v. application of monosubstances, the combination of i.a. 5-FU-PEG liposomes and flow retardation increased the concentration in tumor tissue by a factor of 44 and even 100-fold in the para-aortal lymph nodes (LN). The concentration of 5-FU and FdUrd was increased by flow reduction, intraaortal application and liposomal encapsulation of 5-FU.

Dilution-controlled quantum criticality in rare-earth nickelates

A microscopic model for the diluted spin-mixed compounds (RxY1-x)2BaNiO5 (R=magnetic rare earth) is studied using quantum Monte Carlo simulations. The ordering temperature is shown to be a universal function of the impurity concentration x and the intrinsic Ni-chain correlation length. An effective model for the critical modes is derived. The possibility of a quantum critical point driven by the rare-earth concentration and the existence of a quantum Griffiths phase in the high dilution limit is investigated. Several possible experimental approaches to verify the results are put forward.

Aging and memory effects in a clathrate

The out-of-equilibrium low-frequency complex susceptibility of the orientational glass methanol(73%)-beta-hydroquinone-clathrate is studied using temperature-stop protocols in aging experiments. Although the material does not have a sharp glass transition aging effects including rejuvenation and memory similar to the effects in spin glasses are found at low temperatures.

[Ecthyma contagiosum (Orf) as an uncommon differential diagnosis of infections of the hand]

Orf of the hand is considered as an uncommon viral infection which is usually acquired through contact with infected sheep and goats. Indirect infections through contaminated knives or meat have been reported. Many authors feel that the disorder is more common than reported because the disease is often misdiagnosed and the course is usually self-limiting with spontaneous healing within several weeks. Diagnosis is mainly made by patient's history and clinical course. It is important to know the benign nature of human orf, since complications seem to be caused by overtreatment.

Critical behavior of the frustrated antiferromagnetic six-state clock model on a triangular lattice

We study the antiferromagnetic six-state clock model with nearest neighbor interactions on a triangular lattice with extensive Monte Carlo simulations. We find clear indications of two phase transitions at two different temperatures: Below T(I) a chirality order sets in and by a thorough finite-size-scaling analysis of the specific heat and the chirality correlation length we show that this transition is in the Ising universality class (with a nonvanishing chirality order parameter below T(I)). At T(KT) (<T(I)) the spin-spin correlation length as well as the spin susceptibility diverges according to a Kosterlitz-Thouless (KT) form and spin correlations decay algebraically below T(KT). We compare our results to recent x-ray diffraction experiments on the orientational ordering of CF3Br monolayers physisorbed on graphite. We argue that the six-state clock model describes the universal feature of the phase transition in the experimental system and that the orientational ordering belongs to the KT universality class.

[Radical resection of colorectal carcinoma in the oldest old]

INTRODUCTION

The percentage of old people with colorectal cancer is steadily increasing in Western industrialized countries. Since there are only a few reports on the extent of surgery, it is unclear whether radical lymphadenectomy can also be safely performed as a standard operation in this age group.

METHODS

In a prospective study, we analyzed all patients who were > or = 80 years of age at the time of surgery and who were submitted to surgery between 1/95 and 12/00 due to a colorectal carcinoma. Target parameters were postoperative morbidity and mortality.

RESULTS

Fifty-seven of 665 patients (8.6%) were > or = 80 years of age. The median age was 85 years (range: 80-92). The gender ratio was 1:1.6 (G:E). Palliative surgery was performed in 19 of 57 patients. The remaining 38 patients underwent curative radical lymphadenectomy; 32 were elective and 6 emergency procedures. Mean ASA scores were 2.1 +/- 0.3 and 2.5 +/- 0.6. The following operations were performed: 13 right-sided and 15 left-sided hemicolectomies, 5 rectal resections, 3 rectal extirpations and 2 Hartmann's procedures. Two anastomotic insufficiencies (6%) had a complication-free course after revision. The rate of major surgical complications was 11%, that of internal complications 16%. Three patients (8%) died, one after an elective procedure and two after emergency laparotomy. One of the latter was an 89-year-old woman who refused to undergo a revision due to bleeding after Hartmann's procedure. Pneumonia and myocardial infarction were the cause of death in the other two patients.

CONCLUSION

Radical resection can be safely performed even at an advanced age. Since age-corrected survival is comparable to that of younger patients, surgery should be performed in the elderly under elective conditions according to oncological criteria.

Random-bond Potts model in the large-q limit

We study the critical behavior of the q-state Potts model with random ferromagnetic couplings. Working with the cluster representation the partition sum of the model in the large-q limit is dominated by a single graph, the fractal properties of which are related to the critical singularities of the random-Potts model. The optimization problem of finding the dominant graph, is studied on the square lattice by simulated annealing and by a combinatorial algorithm. Critical exponents of the magnetization and the correlation length are estimated and conformal predictions are compared with numerical results.

Disorder-driven critical behavior of periodic elastic media in a crystal potential

A lattice model of a three-dimensional periodic elastic medium at zero temperature is studied with exact combinatorial optimization methods. A competition between pinning of the elastic medium, representing magnetic flux lines in a superconductor or charge density waves in a crystal, by randomly distributed impurities and a periodic lattice potential gives rise to a continuous roughening transition from a flat to a rough phase. A finite size scaling analysis yields the critical exponents nu approximately 1.3, beta approximately 0.05, gamma/nu approximately 2.9 that are universal with respect to the periodicity of the lattice potential. The small order parameter exponent is reminiscent of the random field Ising critical behavior in 3D.

[Late sequelae and treatment strategies of distal radio-ulnar dissociation after undetected Essex-Lopresti lesion]

The Essex-Lopresti lesion, a combination of radial head fracture and distal radioulnar dislocation, rarely occurs but nevertheless represents a frequently unknown result after forearm fracture. The responsible physician soon has to initiate surgical treatment to prevent his patient from permanent pain of the wrist. Previously unrecognised distal radioulnar dislocation remains to be an unsolved problem. A generally accepted management concept does not exist. Since rupture of the membrana interossea nearly ever occurs, resection of the radial head is followed by radial shifting and seems to be obsolete under these circumstances. An exemplary case is presented and surgical management in this situation is discussed.

Long-range correlations in the nonequilibrium quantum relaxation of a spin chain

We consider the nonstationary quantum relaxation of the Ising spin chain in a transverse field of strength h. Starting from a homogeneously magnetized initial state the system approaches a stationary state by a process possessing quasi-long-range correlations in time and space, independent of the value of h. In particular, the system exhibits aging (or lack of time-translational invariance on intermediate time scales) although no indications of coarsening are present.