Rembrandt's 'Beggar with a wooden leg' and other comparable prints.

Rembrandt's etching of a beggar with a wooden leg is notable because the two lower limbs of the presumed beggar are present and not deformed. Using the facilities of four specialised Dutch art institutes, we carried out a systematic investigation to find other etchings and engravings of subjects with artificial legs supporting non-amputated limbs, from the period 1500 to 1700 AD. We discovered 28 prints produced by at least 18 artists. Several offered clues to a disorder of a knee, the lower leg or the foot. All individuals were adult males, suggesting the probability of traumatic lesions. We conclude that in this period artificial legs were not only used in the case of absence of part of a lower limb, but also for other reasons, notably disorders of the knee, lower leg or foot. They may also have been used to attract compassion.

Tibolone and metabolites induce prolactin production in human endometrial stromal cells in vitro: evidence for cell-specific metabolism.

In this study, we assessed the effects of tibolone and its metabolites on the production of a progesterone sensitive parameter, prolactin, in human endometrium stroma cells in vitro. In addition, the metabolism of the compounds by isolated stromal and epithelial cells was evaluated. The reference compounds, progesterone, Org 2058, and DHT all induced prolactin production. Oestradiol also slightly induced prolactin production and enhanced the response to Org 2058. Tibolone and Delta4-tibolone were similar with regard to potency to induce prolactin levels in the culture supernatant. Their potency was lower than that of Org 2058, similar to that of progesterone and higher than that of DHT. The efficacies of tibolone, Delta4-tibolone and Org 2058 were similar (approximately 200-fold induction). The estrogenic tibolone metabolites 3alpha- and 3beta-OH tibolone also significantly stimulated prolactin production. Their potency, however, was low since significance was reached only at the highest concentrations tested. The PR antagonist Org 31710 inhibited both tibolone- and Delta4-tibolone-induced prolactin production. The responses of tibolone and Delta4-tibolone were not affected by co-incubation with the androgen receptor antagonist OH-flutamide. The effect of tibolone, but not Delta4-tibolone, was antagonized approximately 50% in combination with the highest dose (1 microM) estrogen receptor antagonist, ICI 164384. The induction of prolactin by 3alpha- and 3beta-OH tibolone was antagonized most potently by Org 31710, but also by ICI 164384 and OH-flutamide. Tibolone is metabolized differently in epithelial and stromal cells of the human endometrium. The epithelial cells mostly produce the progestagenic/androgenic Delta4-tibolone. The stromal cells produce predominantly the 3beta-OH tibolone, and some Delta4-tibolone, but the net effect observed with regard to prolactin production is progestagenic. When the metabolites 3alpha-OH, 3beta-OH, and Delta4-tibolone were added to the cultures no conversions were observed. The HPLC analyses showed no evidence for the production of sulfated metabolites. In conclusion, the net effects on endometrial stromal cells are predominantly progestagenic. Tibolone is converted by epithelial cells into Delta4-tibolone which displays progestagenic and androgenic activities, whereas in stromal cells also the estrogenic metabolites 3alpha- and 3beta-OH tibolone are formed.

Is minimally invasive surgery less invasive in total hip replacement? A pilot study.

It has been suggested that minimally invasive surgery (MIS) in total hip replacement (THR) is less traumatic than standard techniques. This study was designed to address the question of whether an anterior MIS approach generates less inflammation and muscle damage than the standard posterolateral (PL) approach. Inflammation parameters such as interleukin-6 (IL-6), muscle damage parameters like heart type fatty acid binding protein (H-FABP), and haemoglobin (Hb) levels were determined pre-operatively and at five consecutive points post-operatively in 10 patients operated through a MIS anterior approach and in 10 patients operated through a PL approach. The mean IL-6 concentration increased from 3 pg/ml in both groups pre-operatively to 78.5 pg/ml (PL group) vs 74.8 pg/ml (MIS group) at 6 hours post-operatively and reached a maximum of 100 pg/ml (PL group) vs 90.5 pg/ml pg/ml (MIS group) after 24 hours. Up to this time point, there was a decrease in both groups. The post-operative mean H-FABP concentration increased to 10.7 microg/l in the PL group vs 15.8 microg/l in the MIS group. It formed a plateau and decreased after 24 hours post-operatively. The Hb levels were 14.5 g/dl before surgery and decreased to 10.7 g/dl (PL group) and 10.0 g/dl (MIS group) at 72 hours post-operatively. No significant differences were found between the two approaches either in inflammation and muscle damage or blood loss. Although the absence of a learning curve may explain the lack of a difference between both techniques, we speculate that the term MIS is at least doubtful in terms of being less traumatic.

Iron saturation of serum ferritin in patients with adult onset Still's disease.

OBJECTIVE: Patients with Still's disease show a prominent acute phase reaction. Our hypothesis is that under these circumstances the iron uptake of ferritin will not keep pace with its synthesis, and is therefore not a valid reflection of the iron status in these patients. METHODS: Previously we developed a method to measure the iron content of ferritin; we investigated the usefulness of this method to establish the iron status of patients with anemia of inflammation. RESULTS: In 9 patients with adult onset Still's disease (AOSD) we observed high ferritin concentrations and measured the iron saturation of ferritin. The mean value of saturation was 9.1%, while saturation in the healthy control group was 17.8%, a statistically significant difference (p < 0.005). Soluble transferrin receptor concentrations indicated a functional iron deficiency. CONCLUSION: We conclude that the acute phase ferritin in patients with AOSD contains less iron in comparison to ferritin in healthy controls. We suggest that soluble transferrin receptor is the method of choice in estimating the iron status of patients with an acute phase reaction.

The effect of cooling on muscle co-ordination in spasticity: assessment with the repetitive movement test.

PURPOSE: Cooling muscles might produce a temporary reduction of spasticity. This study investigated muscle co-ordination in spasticity under the influence of cooling. METHODS: A repetitive movement (RM-) test of the ankle was used, while measuring the angle and surface-electromyography (EMG) of the m. tibialis anterior and m. triceps surae. Ensemble averaging provided quantified measures of muscle activation. Sixteen patients with spasticity in their lower extremity due to stroke or spinal cord injury participated in the study. Physical examination and the RM-test was done before and after cooling the m. triceps surae for 20 minutes by coldpacks. RESULTS: The results show that Achilles hyperreflexia and clonus were abolished in all, and all but one patient, respectively. The EMG of the m. triceps surae, acting as a prime mover, was increased (p = 0.028). However, this improved muscle co-ordination resulted in just a slightly increased active range of motion (less than 2 degrees at p = 0.049). CONCLUSION: Apparently, the increase in excitability of the alpha motoneuron pool in voluntary movements of patients with spasticity is not followed by an improvement in the ability to move.

Intestinal permeability in newborns with necrotizing enterocolitis and controls: Does the sugar absorption test provide guidelines for the time to (re-)introduce enteral nutrition?

BACKGROUND: In necrotizing enterocolitis (NEC), (sub)mucosal edema, hemorrhage, ulceration, or necrosis will disturb intestinal integrity, as reflected by an increased intestinal permeability. Enteral substrate is therefore withheld for a variable period up to 3 weeks (in many clinics). The authors used the sugar absorption test to measure intestinal permeability changes in surgically treated necrotizing enterocolitis patients and surgical controls to evaluate the usefulness of this test in timing the (re-)introduction of enteral feeding in NEC patients as intestinal integrity recovers. METHODS: Changes in intestinal permeability to lactulose and rhamnose were evaluated prospectively in 13 children with NEC and 10 operated control patients. The patients were given 1 mL/kg body weight lactulose/rhamnose solution at different time intervals after admission. The lactulose to rhamnose (L/R) ratio was determined by gaschromatography in 4-hour urine samples. RESULTS: The L/R ratios in NEC patients were increased for prolonged periods of time with a tendency to decrease in the third week after the start of NEC. However, in some cases, the increased L/R ratios even exceeded the 3-week period of starvation. High peaks in the L/R ratio were seen in patients suffering from bowel perforation or sepsis. Compared with necrotizing enterocolitis patients, L/R ratios of control patients were increased only in the first days after surgery and normalized more rapidly. The results of the L/R tests in this study corroborated the clinical condition of the patients. CONCLUSIONS: The sugar absorption test shows an individual variability in the recovery of intestinal permeability in a group of seriously ill newborns with advanced stages of NEC. An individual approach in restarting enteral nutrition seems to be justified; however, the optimal time-point to restart enteral nutrition cannot be determined by the sugar absorption test alone. Combining parameters of intestinal integrity and function could enable a more accurate determination of this optimal timepoint. J Pediatr Surg 36:587-592.

Measuring subluxation of the hemiplegic shoulder: reliability of a method.

OBJECTIVE: Subluxation of the shoulder after stroke can be measured according to the method described by Van Langenberghe and Hogan. METHODS: To evaluate the reliability of this method, the shoulder radiographs of 25 patients were available for this study. Two independent raters each assessed these radiographs twice. RESULTS: The intrarater reliability was good: percentage of agreement was 88 and 84%, weighted kappa, 0.69 [95% confidence interval (CI), 0.38-1.0] and 0.78 (95% CI, 0.60-0.95) for raters 1 and 2, respectively. The interrater reliability was poor: percentage of agreement was 36 and 28%, kappa, 0.11 (95% CI, 0.0-0.31) and 0.09 (95% CI, 0.0-0.23) in sessions 1 and 2, respectively. Subsequently the original method was adjusted by combining two categories (no subluxation and beginning subluxation) into one ("no clinically important subluxation"). CONCLUSIONS: After this adjustment of the categories, the interrater reliability improved [percentage of agreement, 72%, and kappa, 0.49 (95% CI, 0.18-0.80)], but did not reach acceptable values.

Iron saturation of ferritin in the course of phlebotomy treatment in patients with haemochromatosis.

This paper describes the iron saturation of ferritin in haemochromatosis patients during phlebotomy therapy. The iron saturation of ferritin does not change during therapy and cannot be used as a parameter to follow therapy. Furthermore, the iron saturation seems to be a constant characteristic of a given person. It does not vary with the body iron stores in patients with haemochromatosis.

Expression of a marker for colonic crypt base cells is correlated with poor prognosis in human colorectal cancer.

BACKGROUND: There is a need for markers in colorectal cancer which will allow subclassification of stage groups into subgroups with high versus low risk of recurrent disease. AIMS: To develop monoclonal antibodies that recognise antigens or immature crypt base cells, on the assumption that in a neoplasm undifferentiated but not the terminally differentiated cells will be responsible for tumour progression. METHODS: Colon crypt cells which were isolated from human colonic mucosa by EDTA/EGTA incubation were studied. By stepwise harvesting, crypt base cell enriched fractions were obtained, and after incubation with antibodies against dominant antigens, used as immunogens. RESULTS: Of one crypt base cell specific antibody (5E9), the reactive epitope appeared to be a non-terminal carbohydrate in the mucin O-glycans of the colon. The epitope did not seem to be colon specific, but was expressed in a variety of other tissues. In colorectal carcinomas, 5E9 immunoreactivity identified a subgroup of patients with a tendency for worse prognosis. CONCLUSION: A mucin associated maturation epitope was identified in colonic crypt base cells, the expression of which in Dukes' stage B3 colorectal carcinoma may be associated with poor prognosis.

The iron content of serum ferritin: physiological importance and diagnostic value.

In this paper we present a method for determining the iron saturation of ferritin as a possible independent predictor of iron stores. Serum ferritin was purified by immunochemical precipitation, and could be completely recovered from serum without any contamination from transferrin. The iron content of the precipitated ferritin was determined by flameless atomic absorption spectrophotometry (FAAS) and the ferritin-iron saturation was calculated using the original serum ferritin concentration. The intra- and inter-assay variation coefficients were 4.2% and 13.4% respectively. The first results with this assay indicate that serum ferritin contains a considerable amount of iron. Furthermore the results show that the iron saturation of ferritin in patients with acute phase response is significantly lower than the saturation found in healthy volunteers (19.3% and 24.3% respectively). These results suggest a possible role for the ferritin-iron saturation in the assessment of iron stores in patients suffering from acute phase response. In addition, the considerable amount of iron in ferritin suggests the need to revise the physiological role of this substance in relation to the serum iron homeostasis.

p21ras in carcinogenesis.

The activation of p21ras proteins is required in signal transduction pathways that lead to cell proliferation. More recently, a role for p21ras proteins has also been suggested in pathways to apoptosis and in the regulation of the cell cycle. Pointmutated p21ras oncogenes code for constitutively activated p21ras proteins, which disturb the balance between cell growth and cell death in favour of cell growth. In this way, p21ras oncoproteins may contribute to carcinogenesis. The binding of growth factors to their receptors triggers a cascade of protein interactions, including activation of the p21ras proteins. In turn, p21ras proteins set the machinery for cell division in motion by stimulating different effector proteins which regulate the morphological alterations, the nutritional requirements, and the changes in gene expression necessary for cell division. The presence of p21ras oncoproteins constitutively stimulate proliferation, whilst the apoptotic pathway is suppressed along with the loss of cell cycle regulation. This review describes the function of the p21ras proteins in signal transduction pathways that control proliferation and apoptosis, and regulate the cell cycle. The dysregulation of these signal transduction pathways due to the presence of p21ras oncoproteins is discussed in the context of early carcinogenesis.

Spatial selectivity in a rotationally symmetric model of the electrically stimulated cochlea.

A rotationally symmetric model of electrical stimulation of the guinea pig cochlea with active neural elements is used to study the influence of temporal stimulus parameters and electrode configurations on the spatial selectivity of electrical stimulation by cochlear implants. The width of the excitation patterns is determined with respect to the position of the stimulating electrode pairs in the cochlea. Computed O10 AB values are compared against single fibre data from the cat cochlear nerve as measured by Van den Honert and Stypulkowsky (1987). It turns out that the use of charge-balanced asymmetric rather than symmetric biphasic pulses approximately doubles the number of independent channels that can be applied in a cochlear implant with longitudinal bipolar electrodes, like a configuration with radial electrode pairs using symmetric biphasic pulse stimulation will also do. Finally, the influence on Selectivity of the physiological variation in diameter of the cochlear nerve fibres and of a possible loss of their peripheral processes is studied.

Tumorigenic behaviour of c-Ha-ras oncogene transfected CaCo 2 cells is associated with increased proteolytic potency.

BACKGROUND: Point mutations within the family of the ras genes are detected in approximately 50% of human colorectal adenomas and carcinomas. Therefore, it is generally accepted that the occurrence of ras-point mutations constitute an important step in colorectal carcinogenesis. In addition, many studies have demonstrated that the tumorigenicity of the human colorectal carcinoma cell line, CaCo 2, strongly increases after transfection with the c-Ha-ras oncogene. This cell line is suitable for gaining more insight into the mechanism of c-Ha-ras induced tumorigenesis. MATERIAL AND METHODS: Proliferation, differentiation, and proteolytic capacity of c-Ha-ras oncogene transfected CaCo 2 cells were studied in vitro. RESULTS: It was found that gelatinolytic capacity and production of urokinasetype plasminogen activator increased, whereas the production of tissue-type plasminogen activator was similar. Proliferative activity, as measured by the potential doubling time, did not alter. The expression of the differentiation markers sucraseiso-maltase, mucin, and chromogranin A was not different from that of the parental CaCo 2 cell line, which indicates that an increased tumorigenic capacity of c Ha-ras oncogene transfected CaCo 2 cells is not accompanied by loss of differentiation. CONCLUSION: These data demonstrate that the highly increased tumorigenic capacity of c Ha-ras oncogene-transfected CaCo 2 cells is associated with an enchanced proteolytic capacity.

c-Ha-ras oncogene transfection does not affect NK cell sensitivity of human colorectal carcinoma cell lines.

BACKGROUND, MATERIALS AND METHODS: To investigate whether a c-Ha-ras oncogene, pointmutated in codon 12, modulates NK sensitivity of human colorectal tumor cells, this oncogene was introduced in two colorectal carcinoma cell lines, i.e. CaCo2 and SW480. RESULTS: Although transfection with this oncogene increased the levels of c-Ha-ras mRNA (4- to 5-fold) and induced phenotypic and genotypic changes, respectively, in the CaCo2 and SW480 cell lines, the susceptibility to NK cell lysis was only marginally affected. However, CaCo2 and SW480 cell lines transfected with a plasmid containing the wild type of the c-Ha-ras gene were found to be more sensitive to NK cells. CONCLUSIONS: The present study suggests that the sensitivity of human colorectal carcinoma cells to NK cell activity in vitro depends only marginally on the expression of the c-Ha-ras oncogene.

In vivo and in vitro invasion in relation to phenotypic characteristics of human colorectal carcinoma cells.

In this study we investigated the tumorigenicity, growth pattern and spontaneous metastatic ability of a series of nine human colorectal carcinoma cell lines after subcutaneous and intracaecal xenografting in nude mice. CaCo2 cells were found to be poorly tumorigenic to non-tumorigenic in either site; the other cell lines were tumorigenic in both sites. SW1116, SW480 and SW620 did not show local invasive in the NCI-H716 and LS174T cells were both invasive in the caecum, but only NCI-H716 was invasive in the subcutis. HT29 and 5583 (S and E) cells were invasive in the caecum and from that site metastatic to the lungs and/or the liver. HT29 and 5583S cells were both invasive in the subcutis, but 5583E cells were not. Of each category of in vivo behaviour in the caecum, one cell line was further investigated with regard to invasion in vitro (into embryonic chick heart fragments), E-cadherin expression in vivo and in vitro and in vitro production of u-PA and t-PA. These parameters were chosen in view of their purported role in extracellular matrix degradation and intercellular adhesion, which are all involved in the invasive and metastatic cascade. Invasion in vitro was not predictive for invasion or metastasis in vivo. In the cell line which showed invasion in embryonic chick heart tissue, heterogeneous E-cadherin expression was observed in vitro together with a relatively high production of u-PA. The non-invasive cell lines showed in vitro homogeneous expression of E-cadherin with a relatively low production of u-PA. In vivo expression of E-cadherin was either absent or heterogeneous. We conclude that: (1) colorectal carcinoma xenografts show site-specific modification of in vivo invasive and metastatic behaviour; (2) invasion in vitro does not correlate with invasion and metastasis in vivo; (3) in vitro non-invasion might be associated with homogeneous E-cadherin expression and low production of u-PA; (4) E-cadherin expression in vitro differs from E-cadherin expression in vivo. The results support the notion that the microenvironment in which cancer cells grow is one of the factors involved in the regulation of invasive and metastatic behaviour.

Type and number of Ki-ras point mutations relate to stage of human colorectal cancer.

Point mutations in the Ki-ras gene belong to the genetic key events in tumorigenesis of colorectal cancer. The type and number of point mutations were detected in specimens from patients with colorectal carcinomas stages as Dukes B and C using single-stranded conformational polymorphism analysis and sequencing. G-A transitions in codon 12 were exclusively found in Dukes B tumors, G-T transversions mainly in Dukes C, and G-C transversions only in Dukes C tumors. Apparently, the G-T and G-C transversions are associated with metastatic behavior of colorectal carcinomas, while G-A transitions are not. In several samples, multiple point mutations could be detected in codon 12, the frequency of multiple mutations increasing with the stage of the tumor.

A model of myelinated nerve fibres for electrical prosthesis design.

Starting with the spatially extended non-linear node model (Reilly et al., 1985), which incorporates Frankenhaeuser-Huxley non-linearities at each of several nodes in a row, a model is developed to describe many aspects of the behaviour of mammalian nerve fibres in a quantitative way. By taking into account the effects of temperature and by introducing a realistic nerve morphology, a good fit is obtained between the shape, duration and conduction velocity of simulated and in vivo action potentials in mammals. The resulting model correctly predicts the influence of physiological variations of body temperature on various aspects of nerve behaviour. It is shown that the absolute refractory period predicted by the model is within physiological ranges. Both in vivo and in the model, the spike amplitude and the spike conduction velocity are reduced in the relative refractory period. It is concluded that single-node models (although widely used) cannot replace this multiple nonlinear node model, as the stimulus repetition rates that can be followed by the simulated nerve fibre are limited by impulse conduction properties, rather than by the frequency following behaviour of a single node.

A quantitative approach to modeling mammalian myelinated nerve fibers for electrical prosthesis design.

This paper presents an upgraded cable model of mammalian myelinated nerve fibers in an extracellularly applied field. The kinetics of the nodes is based upon voltage clamp data in rat motor fibers at 37 degrees C, while the resting membrane potential is computed with the Goldman equation. The resulting spike shape, conduction velocity, strength/duration behavior, and absolute and relative refractory period are in good quantitative agreement with published experimental data in mammals at normal body temperature and at 20 degrees C. Results at intermediate temperatures however, suggest that the widely used concept of a constant Q10 for the rate constants is invalid. In addition, the model generates realistic abortive spikes towards the end of the absolute refractory period and it can describe the consequences of repetitive firing. The results stress the advantages of a multiple nonlinear node model even if only time aspects of nerve behavior are under study. It turned out, that the model presented here describes in vivo neural properties relevant for electrical prosthesis design better than previous models in literature.

Immunohistochemical study of hepatic fibrosis induced in rats by multiple galactosamine injections.

Multiple injections of D-galactosamine induce liver fibrosis and cirrhosis in rats. The purpose of this immunopathological study was to correlate inflammation and hepatic extracellular matrix remodeling after repeated administration of galactosamine. Rats were given 10, 20, 30, 40, 60, 80, 100 and 140 intraperitoneal injections of D-galactosamine (500 mg/kg body wt, three times weekly). Controls received injections of saline solution. Cryostat sections of liver tissue obtained on biopsy or autopsy were immunostained with a panel of monoclonal and polyclonal monospecific antibodies reactive with macrophages, T and B lymphocytes, desmin, the extracellular matrix components fibronectin; laminin; collagen types I, III and IV; and the fibronectin receptor alpha 5 beta 1. Total RNA was extracted and Northern-blot analysis was performed with a specific cDNA probe for rat collagen type III. Spotty liver cell necrosis and mild portal and parenchymal inflammation was seen after 10 injections of galactosamine. After 20 to 40 injections, expansion of protal tracts, prominent bile ductular proliferation and gradual formation of fibrous septa were encountered with the development of cirrhosis at later intervals. These progressive histological changes were paralleled by a gradual increase of desmin-positive cells in developing septa with deposition of fibronectin; collagen types I, III, and IV; and laminin. Northern-blot analysis showed that this accumulation of extracellular matrix was not accompanied by increase of mRNA for collagen type III. In conclusion, repetitive administration of galactosamine causes progressive liver disease with prominent bile ductule proliferation and development of fibrous septa. These pathological alterations bear some resemblance to the morphological changes in chronic biliary disease in human beings.