STUDIES ON VITAL STAINING : IV. INDIA INK AND BRILLIANT VITAL RED. IMPORTANCE OF CONSIDERING LIVER EXCRETION IN THE STUDY OF "BLOCKADE OF THE RETICULO-ENDOTHELIAL SYSTEM"

When brilliant vital red is injected into the blood stream of dogs much of it is slowly taken up into numerous phagocytes scattered throughout the tissues ("reticulo-endothelial system" of Aschoff). The rate at which the dye leaves the blood stream is determined in large part by the action of these phagocytic cells, but the excretion of dye into the bile is also in part responsible for the loss of dye from the plasma. The injection of a small amount of India ink into the blood stream results in lowering the rate at which the dye disappears from circulation. The fact that much of the carbon of the ink is promptly taken up by the phagocytes would lead one to suspect that they were saturated with foreign materials, or "blocked" against the entrance of dye, but it is shown that the ink causes a remarkable inhibition of the excretion of dye into the bile, and this alone seems to account for the longer retention of dye in the blood stream. There is no evidence that any of the retention is due to defective activity on the part of the phagocytes. Thus, prolonged retention of foreign materials in the blood stream cannot be cited to prove "blockade of the reticulo-endothelial system" unless one can rule out such peculiar reactions on the part of excretory organs. It is felt that the literature of "blockade" should be studied with such sources of error in mind. Preliminary studies indicate that the suppression of dye excretion by the liver is not due to the carbon content of the ink. Studies of other components of the ink are now in progress.

EFFECTS OF EXCESS DIETARY CYSTEIC ACID, dl-METHIONINE, AND TAURINE ON THE RAT LIVER

1. Cysteic acid fed to albino rats as 12.5 to 15 per cent of the McCollum stock diet caused portal necrosis and cirrhosis of the liver within 2 weeks. Concentrations of cysteic acid of 6.25 per cent or less in the diet produced no liver lesions within 2 weeks. 2.dl-Methionine fed as 6.4 to 12.4 per cent of the McCollum stock diet or of a low protein, low fat diet, resulted in severe atrophy of the liver cells but no cirrhosis of the liver. 3. Taurine fed as 1 to 10 per cent of the McCollum stock diet produces no liver lesions. 4. For reasons discussed in the paper, it is concluded that the liver necrosis and cirrhosis produced by cystine and cysteic acid are not dependent upon the S-S linkage of the cystine, the oxidation of the sulfur, the formation and excretion of large amounts of urinary sulfate, or the presence of an amino group separated from a sulfur molecule by a 2 carbon chain.

STUDIES ON MOUSE LEUKEMIA : XI. METABOLIC EFFECTS OF HOST CONSTITUTION

1. Two highly inbred strains of mice of different genetic constitution (Storrs-Little and C58) were used in a study of the influence of hosts on metabolism of cells of transmissible lymphatic leukemia. The experiments were carried out with leukemic cells of transmission Line I as well as with Line M-liver. About 50 per cent of the Storrs-Little mice were killed by each line of cells at this time, while 100 per cent of the C58 mice were killed. 2. The normal lymphoid tissues of the two strains of mice were significantly the same in regard to rates of oxygen consumption and both aerobic and anaerobic glycolysis. 3. Leukemic cells of Line I, growing in hosts of Strain Storrs-Little, gave significantly lower rates of aerobic and anaerobic glycolysis than when growing in hosts of Strain C58. Oxygen consumption was significantly higher. Leukemic cells of Line M-liver, growing in hosts of Strain Storrs-Little, gave significantly lower rates of aerobic and anaerobic glycolysis than when growing in Strain C58. Oxygen consumption was not significantly different. 4. After one to three passages through hosts of Strain Storrs-Little, the cell lines were returned to hosts of Strain C58, with immediate return to significantly the same metabolic rates originally given by each line in hosts of Strain C58. 5. These results lead to the more general conclusions that: (a) The genetic constitution of the host modifies the metabolism of the cell line. (b) The same host constitution may modify the metabolism of different cell lines in different ways. (c) Host constitution does not appear to modify the inherent constitution of the leukemic cells, but acts as a determining environmental factor on their metabolism.

CIRRHOSIS OF THE LIVER CAUSED BY EXCESS DIETARY CYSTINE

1. Cystine fed to young albino rats as 10 per cent of the diet resulted in: (a) Portal hemorrhagic necrosis, resembling eclampsia, within 3 or 4 days. (b) A high mortality rate. (c) Fatty infiltration of hepatic cells in all rats surviving the initial acute lesion. (d) Cirrhosis of the liver in rats surviving more than 2 weeks. 2. 5 per cent dietary cystine produced marked fatty infiltration of the liver, followed by portal hemorrhagic necrosis. Cirrhosis was present in one of the two rats on the diet for 6 weeks. 3. The livers of rats fed 5 or 10 per cent cystine diets followed by the McCollum stock diet, showed evidence of residual cellular damage, and of regeneration as shown by mitotic figures. 4. In this series of 30 rats on excess dietary cystine, a renal lesion was found in only one case.

DEPRESSION OF ANAEROBIC GLYCOLYSIS OF EMBRYONIC TISSUE BY WESTERN STRAIN OF EQUINE ENCEPHALOMYELITIS VIRUS. PREVENTION OF THIS EFFECT BY SPECIFIC IMMUNE SERUM

Studies were made on the effect of mixing the Western strain of equine encephalomyelitis virus (W.E.E.) and embryonic tissue on the rate of anaerobic glycolysis of the tissue. Whole chick embryo, chick embryo from which brain and spinal cord had been removed, and embryonic skeletal muscle were employed. 1. W.E.E. virus depressed the rate of anaerobic glycolysis of embryonic tissues within 2 days after its addition to the tissue. The decrease in anaerobic glycolysis varied from 17 to 82 per cent and was apparent 2 to 4 days after the addition of the virus. No significant effect of the virus was observed 4 hours and 6 days after mixing it with the tissue. 2. Anti-W.E.E. immune serum prevented the inhibiting action of W.E.E. virus on the anaerobic glycolysis of embryonic skeletal muscle.

THE EFFECT OF VARIOUS DIETS ON THE LIVER DAMAGE CAUSED BY EXCESS CYSTINE

1. The effect of 9 different diets on the liver lesions resulting from excess dietary cystine has been studied in 130 rats. 2. The incidence and severity of each of the following liver lesions were varied by changes in the composition of diets containing 5 or 10 per cent cystine: (a) Hemorrhage was least severe with low fat diets. (b) Necrosis was most severe with synthetic diets. (c) Cirrhosis was delayed by a diet high in lard, 20 per cent, and cod liver oil, 5 per cent, but not by a diet high in butter, 25 per cent. (d) Fatty infiltration was found consistently only with low protein, high fat diets. In other words, the pathogenesis of the liver lesion due to excess dietary cystine can be modified by diet. 3. In the presence of cystine as 5 per cent of a low protein, high fat diet, 1 per cent choline inhibited fatty infiltration but did not protect the liver against damage by cystine. 4. In these experiments there was no apparent correlation between fatty infiltration of the liver and the incidence or degree of cirrhosis.

The influence of coronal plane deformity on mediolateral ligament status: an observational study in varus knees

Most surgeons believe that varus deformity leads to progressive tightness of the medial soft tissue envelope and laxity on the lateral side. It is, however, unclear at what stage of the deformity such ligament alterations occur, and whether these are the consequence of intrinsic alterations in the ligaments themselves, or rather due to extrinsic factors such as osteophytes, adhesions to the underlying bone, or other factors which may cause a tightening effect. Thirty-five varus knees that were scheduled for TKA were investigated. Ligament status was evaluated after temporary correction of alignment and removal of osteophytes, using varus/valgus testing with computer navigation technology. Knees with <10 degrees varus deformity were easily correctable to neutral after correction of the extrinsic factors that could cause medial tightness, and these knees maintained normal mediolateral laxity during varus/valgus stress testing. When coronal plane deformity exceeded 10 degrees, progressive shortening of the medial collateral ligament was noted, as well as progressive stretching of the lateral structures (P < 0.001). This study, therefore, demonstrates that the medial collateral structures become intrinsically shortened when preoperative varus deformity exceeds 10 degrees. Likewise, the lateral soft tissues become stretched. None of these occur when the preoperative deformity is <10 degrees.

Avoidance of patellar eversion improves range of motion after total knee replacement: a prospective randomized study

Minimally invasive surgery has recently been introduced in TKA surgery. The purpose of this study was to evaluate the effect of eversion of the patella, on safety and functional result after TKA. In a prospective, randomised, double blinded trial, 60 patients were divided in two groups: group A underwent TKA through a standard medial parapatellar arthrotomy, with patellar eversion. Group B underwent the same exposure, except for the fact that the patella was subluxed laterally. All other treatment protocols were identical. Outcomes were measured until 1 year postoperatively. Radiographic evaluation included AP, lateral, skyline and full leg standing radiographs. VAS, WOMAC score, Knee Society Knee and Function score were performed. Active and passive range of motion (ROM) and knee proprioception was measured. All patients underwent isokinetic strength testing. The mean passive ROM changed from 121 degrees preoperatively to 121 degrees postoperatively in group A, compared to 118 degrees -131 degrees respectively in group B at 1 year (P = 0.003). The mean active ROM changed from 112 degrees to 115 degrees in group A, and from 108 degrees to 125 degrees in group B (P = 0.005). All other parameters were not significantly different. Patellar dislocation without eversion for exposing the knee during TKA is a safe procedure and improves ROM at 1 year postoperatively.

A common reference frame for describing rotation of the distal femur

The understanding of rotational alignment of the distal femur is essential in total knee replacement to ensure that there is correct placement of the femoral component. Many reference axes have been described, but there is still disagreement about their value and mutual angular relationship. Our aim was to validate a geometrically-defined reference axis against which the surface-derived axes could be compared in the axial plane. A total of 12 cadaver specimens underwent CT after rigid fixation of optical tracking devices to the femur and the tibia. Three-dimensional reconstructions were made to determine the anatomical surface points and geometrical references. The spatial relationships between the femur and tibia in full extension and in 90° of flexion were examined by an optical infrared tracking system.

After co-ordinate transformation of the described anatomical points and geometrical references, the projection of the relevant axes in the axial plane of the femur were mathematically achieved. Inter- and intra-observer variability in the three-dimensional CT reconstructions revealed angular errors ranging from 0.16° to 1.15° for all axes except for the trochlear axis which had an interobserver error of 2°. With the knees in full extension, the femoral transverse axis, connecting the centres of the best matching spheres of the femoral condyles, almost coincided with the tibial transverse axis (mean difference −0.8°, sd 2.05). At 90° of flexion, this femoral transverse axis was orthogonal to the tibial mechanical axis (mean difference −0.77°, sd 4.08). Of all the surface-derived axes, the surgical transepicondylar axis had the closest relationship to the femoral transverse axis after projection on to the axial plane of the femur (mean difference 0.21°, sd 1.77). The posterior condylar line was the most consistent axis (range −2.96° to −0.28°, sd 0.77) and the trochlear anteroposterior axis the least consistent axis (range −10.62° to +11.67°, sd 6.12). The orientation of both the posterior condylar line and the trochlear anteroposterior axis (p = 0.001) showed a trend towards internal rotation with valgus coronal alignment.

International Cartilage Repair Society (ICRS) and Oswestry macroscopic cartilage evaluation scores validated for use in Autologous Chondrocyte Implantation (ACI) and microfracture

OBJECTIVE

For young patients with cartilage defects, the emergence of clinically applicable cell therapy for biological joint reconstruction is an appealing prospect. Acceptation of this method as a means of standard care requires proof of being reproducible, having long-lasting mechanical integrity, and having a good clinical outcome. This study evaluates the reliability of the International Cartilage Repair Society (ICRS) score and the Oswestry Arthroscopy Score (OAS) in the assessment of regenerative cartilage repair.

METHOD

A total of 101 macroscopic images of cartilage repair were made during arthroscopy 12 months post-treatment of either Autologous Chondrocyte Implantation (ACI) or microfracture. These images were examined by seven independent observers with differing levels of experience. The ICRS and OAS scores were randomly presented twice at a 4-week interval. All observers stated their predicted outcome according to actual treatment and defect size.

RESULTS

ICRS and OAS scores showed both good inter- and intra observer reliability (0.62 and 0.56 for ICRS; 0.73 and 0.65 for OAS, respectively). Internal consistency (Cronbach's alpha) was satisfactory for research purposes (0.79 and 0.74, respectively). Correlation (equivalence concordance) between both scoring systems was excellent (r=0.94). All observers were inconsistent in predicting actual treatment. Test-re test reliability of estimated defect size and its correlation to true defect size were poor. These results were also applicable to the sub-analyses of the experience of the observer and the quality of imaging.

CONCLUSION

The ICRS and OAS are reliable and relevant scores that are now both validated for macroscopic evaluation of cartilage repair as a research tool.

High-flexion, motion-guided total knee arthroplasty: who benefits the most?

A multicenter study was performed to determine which patients have the most potential to benefit from total knee arthroplasty (TKA) with a high-flexion, guided-motion design. In 201 consecutive TKAs, the mean gain in range of motion (ROM) was 14 degrees at 3 months and 24 degrees at 6 months. The gain in flexion was significant at 3 and 6 months postoperatively. No differences were found based on preoperative diagnosis, age, or sex. There was a poor correlation between body mass index and ROM. Pre- and postoperative flexion also displayed a weak correlation. Patients with the least preoperative flexion (<90 degrees) gained the most degrees of flexion (26 degrees). We conclude that the use of a high-flexion, guided-motion TKA allows a significant functional improvement in patients with preoperative stiffness and the preservation of good flexion in patients with normal preoperative flexion.

Comparison of computational algorithms applied on transthoracic impedance waveforms to predict head-up tilt table testing outcome

The goal of the present study was to develop and evaluate new algorithms for the prediction of the outcome of a head-upright tilt test (HUTT). Using transthoracic impedance and its first derivative, we attempted to determine if indexes computed on these waveforms could detect a positive outcome to a 70 degrees -45min HUTT with reliable sensitivity and specificity. The methods were evaluated retrospectively in a group of 70 patients and validated prospectively in a group of 59 patients. The best detector obtained used a neural network. It compares very favorably with published results for other syncope detectors.

[Characterization of premature ventricular contraction initiating ventricular fibrillation]

The aim of this study is to characterize the electrocardiographic features of premature ventricular contractions (PVC) from different anatomical region that trigger ventricular fibrillation (VF).

METHODS AND RESULTS

36 consecutives patients (20 males, 42+/-14 yrs) undergoing VF ablation from 7 centres were studied (22 with idiopathic VF, 4 associated with a long QT syndrome, 3 with Brugada syndrome, 4 with ischaemic cardiomyopathy and 3 associated with other substrate). Mapping of these PVC showed 2 different origins, which were then confirmed by ablation: right ventricular outflow tract (RVOT) (22%) and peripheral Purkinje network (81%). One patient had PVC from both origins (Brugada). RVOT PVC were frequent but had triggered only 5+/-5 episodes of VF for 26+/-33 months. Purkinje PVC were more likely to be present during electrical storm with 18+/-28 episodes of VF for 33+/-45 months. Right Purkinje PVC have a left bundle branch block with superior axis morphology whereas left Purkinje ones have a right bundle branch block. The axis of activation showed variation from inferior to superior depending on the area of origin from the Purkinje network and the exit site to the myocardium. However Purkinje PVC were characterized by short QRS duration (126+/-18 vs 145+/-13ms for RVOT PVC; p=0.05). In addition the coupling interval was significantly shorter compared to RVOT PVC (292+/-45 vs 358+/-37ms respectively; p=0.005).

CONCLUSION

PVC initiating VF demonstrate specific electrocardiographic features that facilitate determination of their origin. Ablation of these typical PVC is feasible in order to reduce ICD shock.

Kinematics of posterior cruciate ligament-retaining and -substituting total knee arthroplasty: a prospective randomised outcome study

We performed a prospective, randomised trial of 44 patients to compare the functional outcomes of a posterior-cruciate-ligament-retaining and posterior-cruciate-ligament-substituting total knee arthroplasty, and to gain a better understanding of the in vivo kinematic behaviour of both devices. At follow-up at five years, no statistically significant differences were found in the clinical outcome measurements for either design. The prevalence of radiolucent lines and the survivorship were the same. In a subgroup of 15 knees, additional image-intensifier analysis in the horizontal and sagittal planes was performed during step-up and lunge activity. Our analysis revealed striking differences. Lunge activity showed a mean posterior displacement of both medial and lateral tibiofemoral contact areas (roll-back) which was greater and more consistent in the cruciate-substituting than in the cruciate-retaining group (medial p < 0.0001, lateral p = 0.011). The amount of posterior displacement could predict the maximum flexion which could be achieved (p = 0.018). Forward displacement of the tibiofemoral contact area in flexion during stair activity was seen more in the cruciate-retaining than in the cruciate-substituting group. This was attributed mainly to insufficiency of the posterior cruciate ligament and partially to that of the anterior cruciate ligament. We concluded that, despite similar clinical outcomes, there are significant kinematic differences between cruciate-retaining and cruciate-substituting arthroplasties.

[Cardiac manifestations of laminopathies]

Dilated cardiomyopathy (DCM) of genetic origin represents about 25% of all so-called primary DCM. Cases due to mutation of the gene which codes the lamins A and C (LMNA) carry a poor prognosis with a high risk of sudden death. The finding of primary DCM in a young person associated with conduction defects or arrhythmias should lead to investigation for mutation of the gene of lamins A and C, even in the absence of a suggestive family history. The authors report 5 cases of DCM, with and without associated skeletal muscular disease, due to laminopathies.

[Psychiatric complication of an implanted automatic defibrillator]

The implantable automatic defibrillator has completely changed the prognosis of potentially fatal ventricular arrhythmias by the delivery of an electric shock in the event of ventricular tachycardia or fibrillation. This vital device is sometimes poorly accepted from the psychological point of view by patients having been traumatised by experiences of sudden death from which they have been rescuscitated. Anxiety and depression are common and they have an important effect on the quality of life. The unpredictable occurrence of painful, multiple and uncontrollable electrical shocks may induce a state of acute stress with stunning, the resemblance of which to the model of learned helplessness described experimentally in the animal by Seligman, is discussed. The authors report the case of a 20 year old man whose automatic defibrillator was activated twenty times in one night. His state of stress and impotence was such that he lay prostate in his bed. Suicide seemed to be the only possible way of escaping from the electrical shocks of the device which was perceived as being dangerous. The management of this condition is not standardised but it requires the collaboration of the cardiac rhythmological and psychiatric teams. Medication with antidepressant drugs alone is not sufficient. The regulation of the sensitivity of the defibrillator gives the patient a feeling of mastering the situation: submission is not total! Research along this line should improve the patients' acceptation of the device and their quality of life.

A correlation study of objective functionality and WOMAC in total knee arthroplasty

Function studies after total knee arthroplasty (TKA) generally use either self-reported instruments or objective quantitative measurements of walking activities, but it is unclear how objective factors influence self-reports. This retrospective multicenter study assessed the impact of objective variables on subjective self-reported functional outcome after TKA in 128 patients at a mean of 41 months after TKA. Self-reported disability was measured by the Western Ontario and McMaster University (WOMAC) scale, and the quality of walking and representative daily activities were determined objectively by the DynaPort knee test. Objective assessment was found to be a poor predictor of WOMAC abnormality, with correlations of 0.343, 0.246, and 0.269 with WOMAC function, stiffness, and pain, respectively. The results of WOMAC are thus strongly influenced by factors other than quantitative parameters of the lower extremity. These findings provide support for including an objective assessment of activities of daily living together with a subjective self-report.