Preoperative Scoring System for Prediction of Early Adjacent Vertebral Body Fracture After Balloon Kyphoplasty Using X-Rays Taken in a Non-Weight-Bearing Position

BACKGROUND

Prevention of adjacent vertebral body fracture (AVF) following balloon kyphoplasty (BKP) is a key challenge. The objective of this study was to develop a scoring system that could be more extensively and effectively used to determine the surgical indications for BKP.

METHODS

The study involved 101 patients aged 60 years or older who had undergone BKP. Logistic regression analysis was used to identify risk factors for early AVF within 2 months following BKP. Scoring was based on the odds ratio for risk factors, and cut-off values were determined from the receiver operating characteristics curve. The correlation between the total scores and the incidence of early AVF, and the area under the curve for the logistic regression model predicting early AVF using the scoring system were investigated.

RESULTS

29 cases (28.7%) experienced early AVF after BKP. The scoring system was created as follows: 1) age (<75 years: 0 points (P), ≥75 years: 1P), 2) number of previous vertebral fractures (0: 0P, 1 or more: 2P), and 3) local kyphosis (<7°: 0P, ≥7°: 1P). The total scores were found to be positively correlated with the incidence of early AVF (r = 0.976, P = 0.004). The area under the curve of the scoring system for predicting early AVF was 0.796. The incidence of early AVF was 4.2% at ≤1P and 44.3% at ≥2P (P < 0.001).

CONCLUSIONS

A scoring system which can be applied to a broader patient population was developed. In cases where the total score is 2P or more, alternatives to BKP should be considered.

The relationship between global sagittal balance and the incidence of early adjacent vertebral fractures following balloon kyphoplasty

BACKGROUND

Recently, it is widely known that global sagittal balance (GSB) influences the postoperative outcome of the spine. The purpose of this study was to investigate the relationship between GSB and the incidence of early adjacent vertebral fracture (AVF) following BKP.

METHODS

This study included 96 patients (19 males, 77 females, mean age 77.4±5.5 years) who underwent BKP for osteoporotic vertebral fracture and who were over 60 years old. We investigated the effect of GSB on early AVF within 2 months after surgery. Of the 96 patients, 76 patients (16 males, 60 females, mean age 77.0±5.4) underwent BKP at the thoracolumbar junction (T11-L2) and were investigated independently. After the two-group comparison, logistic regression analysis was performed.

RESULTS

During the observation period (18.3±14.7 months), 27 of 96 patients (28.1%) suffered AVF after BKP, and 24 of 96 patients (25.0%) suffered early AVF. In the logistic regression analysis, spinopelvic parameters were not detected as significant risk factors. In cases of BKP at the thoracolumbar junction (T11-L2), 24 of 76 patients (31.6%) suffered AVF after BKP during the observation period (15.3±19.5 months), and 21 of 76 patients (27.6%) suffered early AVF. Logistic regression analysis detected PT: odds ratio 1.087 (P = 0.046*) and local kyphosis: 1.147 (P = 0.003*) as risk factors for early AVF. The cutoff value was PT≥29° from the ROC curve.

CONCLUSIONS

At the thoracolumbar junction, PT equal to or greater than 29° is one of the risk factors of early AVF following BKP.

The effects of various therapeutic measures on shoulder range of motion and cross-sectional areas of rotator cuff muscles after baseball pitching

AIM

The purpose of this study was to investigate the effects of various therapeutic measures on the shoulder range of motion (ROM) and muscle cross-sectional area (mCSA) of rotator cuff muscles after baseball pitching.

METHODS

EXPERIMENTAL DESIGN

a mode of therapeutic measures was classified in 4 groups; the control (CON), ice treatment (IT), light shoulder exercise (LSE) and ice treatment with LSE (ILSE) groups. Each therapeutic measure was performed after pitching.

PARTICIPANTS

7 healthy, skilled baseball pitchers.

MEASURES

ROM and mCSA were measured before pitching, immediately after pitching, at the time of the therapeutic measure, and 24 hours after pitching. Shoulder ROM at 90 inverted exclamation mark of abduction included internal rotation (IROM), maximum internal rotation (IMROM), external rotation (EROM) and maximum external rotation (EMROM).

RESULTS

In all groups, both IROM and IMROM were significantly decreased after pitching compared with the pre-exercise values and conversely both EROM and EMROM were significantly increased. The mCSA of all rotator cuff muscles were increased significantly after pitching. For IMROM, ILSE showed a significant recovery at the post-therapeutic measure compared with the others and at 24 hours after pitching compared with IT, respectively. For IROM, both LSE and ILSE showed significant recovery compared with CON at the post-therapeutic measure. For the mCSA of external muscles, ILSE showed a greater decrease at the post-therapeutic measure than the others, and at 24 hours after pitching than CON.

CONCLUSION

This study suggested the possibility that ILSE was more effective to recover ROM and decrease mCSA than the other methods.

The effects of various therapeutic measures on shoulder strength and muscle soreness after baseball pitching

AIM

This study was intended as an investigation of the effects of various therapeutic measures on the shoulder strength and muscle soreness after baseball pitching.

METHODS

EXPERIMENTAL DESIGN

participants threw 98 pitches in a simulated single game. The mode of the therapeutic measures after pitching were classified into 4 groups; the control group (CON), the ice treatment group (IT), the light shoulder exercise group (LSE) and the ice treatment with LSE group (ILSE). Each therapeutic measure was applied to the dominant shoulder immediately after pitching.

PARTICIPANTS

7 healthy, skilled baseball pitchers.

MEASURES

both shoulder strength and muscle soreness were measured before pitching, immediately after pitching (Post-P), at the time of the therapeutic measure (Post-TM), and 24 hours after pitching (Post-24 h).

RESULTS

All 4 groups showed shoulder strength losses in shoulder abduction, internal/external rotation with no shoulder abduction or with the shoulder abducted to 90 degrees immediately after pitching. ILSE had greater recovery from Post-P values at Post-TM or Post-24 h than the other methods in all 5 shoulder strengths. On the other hand, the soreness in shoulder internal rotation was increased significantly from Post-P and continued by Post-24 h. Both IT and ILSE had beneficial effects on reducing the shoulder muscle soreness at Post-TM or Post-24 h.

CONCLUSION

The findings of this study suggested that ILSE was the optimal therapeutic measure against decreased shoulder strength or increased shoulder muscle soreness resulting from the repetitive baseball pitching.

A new method for evaluating the bitterness of medicines by semi-continuous measurement of adsorption using a taste sensor

We describe a new method for the evaluation of the bitterness of medicines by semi-continuous measurement of adsorption using a multichannel taste sensor or 'electric tongue'. The bitterness of 10 basic medicines was evaluated by both the taste sensor and in human gustatory sensation tests with 11 volunteers. The sensor part of the taste sensor consists of eight electrodes made of lipid/polymer membranes. Three variables were obtained from the taste sensor data: sensor output (S), the change of membrane potential caused by adsorption, corresponding to aftertaste (C), and the ratio C/S. These variables were used to predict an estimated bitterness score in multiple regression analysis. Semi-continuous measurement of C (every 30 s up to 150 s) was adopted as an additional explanatory variable, and the attenuation rate of C was defined as C'. These data were also subjected to multiple regression analysis. The correlation coefficient (r) estimated for the bitterness score predicted by the taste sensor, using C' for channel 2 and C/S for channel 4, and the score obtained by human gustatory sensation, was 0.824. This value was greater than that obtained using C/S for both channels 2 and 4 (0.734). The method described in the present study seems to offer good predictability for the evaluation of bitterness.

Preparation and characterization of insulin-loaded acrylic hydrogels containing absorption enhancers

The objectives of this study were to prepare insulin-loaded acrylic hydrogel formulations containing various absorption enhancers, to perform in vitro and in vivo characterization of these formulations, and to evaluate the factors which affecting insulin availability on rectal delivery of insulin using this hydrogel system. The acrylic block copolymer of methacrylic acid and methacrylate, Eudispert, was used to make the hydrogel formulations. As absorption enhancers, 2,6-di-O-methyl-beta-cyclodextrin (DM-beta-CyD), lauric acid (C12), or the sodium salt of C12 (C12Na), were incorporated into the hydrogels. In an in vitro release test, the release rate of insulin from the hydrogels decreased as the polymer concentration of the hydrogel increased. The addition of C12Na to the hydrogel further increased the insulin release rate, which was greater at higher concentrations of the enhancer. A portion of the C12Na was found to remain bound to the acrylic polymer in dissolution medium. Serum insulin levels were determined at various time points after the administration of insulin solution or insulin-loaded (50 units/kg body weight) Eudispert hydrogels containing 5% (w/w) of C12, C12Na, or DM-beta-CyD to in situ loops in various regions of the rat intestine. The most effective enhancement of insulin release was observed with formulations containing C12Na. The bioavailability of insulin from the hydrogels was lower than that from the insulin solutions. Hydrogel formulations containing 7% or 10% Eudispert remained in the rectum for 5 h after rectal administration. However, the 5% (w/w) C12Na solution stained with Evan's-blue had diffused out and the dye had reached the upper intestinal tract within 2 h. Finally, the rectal administration of insulin-loaded hydrogels, containing 4%, 7%, or 10% (w/w) Eudispert and 5% (w/w) of enhancer (C12, C12Na, or DM-beta-CyD) to normal rats was shown to decrease serum glucose concentrations. The greatest effect was found with insulin-loaded 7% (Eudispert) hydrogel containing C12Na which having cosiderable large insulin release rate and bioadhesive characteristics.

Preparation and characterization of acrylic hydrogels neutralized by basic amino acids

Basic amino acids were used as neutralizers in the gellation of Eudispert as an acrylic hydrogel. Arginine and lysine successfully neutralized Eudispert, as did sodium hydroxide, and formed hydrogels. A gentle rise of pH was observed as the dosage of the base increased when arginine and lysine were used, in contrast to the sharp rise of pH observed when sodium hydroxide was used. The rank of viscosity of the prepared hydrogels was as follows: lysine > arginine > NaOH. The release rate of model drugs (salicylic acid, theophylline, and bovine insulin) from the prepared hydrogels ranked as follows: NaOH>lysine>arginine, the sustained-release profile being observed with arginine. The rate of diffusion of the model drug from the hydrogel was inversely proportional to the molecular weight of the cationized neutralizer used. It is concluded that the strategy of neutralization of acidic polymers by basic amino acids has advantage with the respect to both the sustained-release characteristics of the gel and the biocompatibility of the basic amino acids themselves.

Quantitative evaluation of the bitterness of commercial medicines using a taste sensor

The bitterness of 11 commercial medicines was evaluated both by a multichannel taste sensor and in human gustatory sensation tests with 15 volunteers. For basic drugs with amino groups in the molecule, such as quinine, there was a comparatively strong relative response electric potential (mV) of channels 1 or 2, those containing negatively charged membranes and the bitterness determined by human gustatory sensation tests. The suppression of the bitterness of quinine by sucrose and aspartame could be quantified using the artificial taste sensor and the results concurred with those from gustatory sensation tests. The usefulness of the sensor was thus confirmed for this type of compound. Anionic drugs, such as diclofenac sodium or salicylic acid gave rise in a negative response electric potential in channels 5 or 6, those containing positively charged membrane, seemed to be useful information even though their tastes are being sour rather than bitter. For drugs with both an amino (cationic) group and carboxylic acid (anionic) group in the molecule, such as theophylline, caffeine, and metronidazole, the relative response electric potential (mV) of channels containing negatively charged membranes was not increased, even though bitterness was observed in human gustatory sensation tests. Therefore, a different design of membrane component is required for more general evaluation of the bitterness of various medicines.

Effects of hyperbaric oxygen on procollagen messenger RNA levels and collagen synthesis in the healing of rat tendon laceration

In the present study, we examined the effect of intermittent exposure to hyperbaric oxygen (HBO) on experimentally induced tendon laceration in the right hind limb of 56 male Wistar rats. We compared animals treated by HBO (2 atmospheres absolute [ATA] 100% O(2) x 60 min x once per day) with control animals (without HBO) at 3, 7, 14, and 28 days after wound creation. Histology, and pro-alpha1 (I) mRNA by Northern hybridization, pro-alpha1 (III) mRNA, transforming growth factor-beta1 (TGF-beta1) mRNA by RT-PCR were studied. Our results indicate the use of HBO influences the pro-a1 (I) mRNA expression. The level of pro-alpha1 (I) mRNA was especially increased at 7 14 days after laceration by HBO. These results suggest that intermittent oxygen exposure may play a significant role in collagen synthesis and be beneficial for producing the extracellular matrices in tissue engineering.

Blood cell induction in Xenopus animal cap explants: effects of fibroblast growth factor, bone morphogenetic proteins, and activin

Cultures of Xenopus blastula animal caps were used to explore the haematopoietic effects of three candidate inducers of mesoderm: basic fibroblast growth factor (bFGF), bone morphogenetic proteins (BMPs) and activin A. In response to either bFGF or activin A, explants expanded into egg-shaped structures, and beneath an outer layer of epidermis, a ventral mesodermal lining surrounded a fluid-filled cavity containing "blood-like cells". Immunocytochemistry identified some of these cells as early leukocytes, but erythrocytes were rare. BMP-2 or BMP-4 induced primitive erythrocytes as well as leukocytes, and a high concentration was required for these cells to differentiate in only a small proportion of explants. BMP-2 but not BMP-4 induced ventral mesoderm concomitantly. High concentrations of activin A dorsalized explants, which contained infrequent leukocytes, and an optimal combination of activin A and bFGF caused differentiation of muscle with few blood cells. By contrast, BMP-2 or BMP-4 plus activin A synergistically increased the numbers of both leukocytes and erythrocytes. Explants treated with BMPs plus activin contained a well organized cell mass in which yolk-rich cells mixed with blood cells and pigmented cells did not. BMP-2 plus bFGF also induced numerous leukocytes and fewer erythrocytes, but BMP-4 antagonized the leukopoietic effect of bFGF. The data suggest that the signalling pathways these three factors use to induce leukopoiesis overlap and that erythropoiesis may be activated when inducers are present in combination.

Evidence that far-infrared radiation promotes growth of Xenopus laevis

In most ectotherms, environmental temperature has differential effects on growth and differentiation. For example, amphibian size at maturity decreases with increasing temperature. To address how radiant heat in the form of far-infrared radiation (FIR) may affect development of the aquatic ectotherm Xenopus laevis, we continuously irradiated swimming larvae as they developed into young adults. Here we report evidence that FIR promotes growth of these organisms in an aqueous environment.

Evidence that far infrared radiation promotes growth of Xenopus laevis

In most ectotherms, environmental temperature has differential effects on growth and differentiation. For example, amphibian size at maturity decreases with increasing temperature. To address how radiant heat in the form of far-infrared radiation (FIR) may affect development of the aquatic ectotherm Xenopus laevis, we continuously irradiated swimming larvae as they developed into young adults. Here we report evidence that FIR promotes growth of these organisms in an aqueous environment.

Induction of blood cells in Xenopus embryo explants

A Xenopus-specific anti-leukocyte monoclonal antibody designated XL-2 was isolated and used to identify leukocytes in tailbud embryos and activin A-treated explants of blastula animal cap. XL-2 bound to a 135-kDa polypeptide in western blots of protein extracts from adult thymocytes, tailbud embryos, tadpoles, and explants. In cell suspensions, it immunostained the cell surface of all types of adult leukocytes including lymphocytes, monocyte/macrophages, thrombocytes, and granulocytes. At embryonic stage 24, immunocytochemistry revealed XL-2-positive leukocytes, the earliest time at which such cells have been recognized. Whole-mount staining of tailbud embryos and tadpoles showed a widely dispersed population of XL-2-reactive leukocytes, many of which had elongated shapes and ameboid pseudopodia. In activin A-treated animal caps, XL-2 recognized a subpopulation of cells within the lumen of the central fluid-filled cavity as well as cells in the interstitium of mesenchymal and mesothelial components of the explant. Together, activin A and human interleukin-11 induced 100% of explants to form lumenal blood cells. Compared to activin A alone, murine stem cell factor plus activin A significantly increased the numbers of XL-2-reactive leukocytes and erythrocytes. These results support the view that activin A induces leukocyte and erythrocyte progenitors during Xenopus embryogenesis.

[Diagnosis of orbital lymphoma by molecular genetic analysis]

Recent advances in molecular genetics have made a great contribution to the investigation of lymphoid malignancies. We diagnosed orbital malignant lymphomas by molecular genetic analysis. Molecular genetic analysis elucidates gene rearrangements within lymphocytes that are responsible for immunoglobulin produced by B-lymphocytes, or the expression of cell surface antigen recognition receptors in T-lymphocytes. The cells of most malignant tumors are considered to be genetically homogeneous because they are assumed to represent a single clone descended from one abnormal cell. The determination that a malignancy is of clonal origin has been used as a diagnostic aid to distinguish benign from malignant proliferations. Analysis of the immunoglobulin genes and the T-cell antigen receptor genes using DNA from biopsied specimens is very useful, as it can reveal the origin of tumor cells and clonality of tumor cell characteristics which cannot be distinguished by morphological analysis. Genetic analysis was found to be superior to immunophenotyping for identifying the monoclonality of tumor cells in instances when there were no definitive cell-lineage specific markers, or when there was a preponderance of normal counterparts with mixed appearance of neoplastic and non-neoplastic cells in malignant lymphoma. Molecular genetic analysis is used to 1) distinguish clonal from polyclonal lymphoproliferations, 2) determine the B-cell or T-cell identity of malignancies with admixed normal cells, 3) determine the genetic lineage of neoplasms lacking definitive surface antigens, and 4) determine the developmental stage of early B-cell or T-cell precursors.

A new perspective in ocular infection and the role of antibiotics

A new concept of ocular infectious diseases includes two modes of pathogenesis, one being an acute inflammation caused by the attachment of free-floating bacteria, and another being intractable biofilm-related ocular infections. 15-20% of Staphylococcus epidermidis strains isolated from human conjunctiva exhibit slime formation and can be pathogens causing inflammation. Topical application, in the form of, for example, eye drops, of a combination of two antimicrobial agents is usually applied to treat such infections. Any antimicrobial agent having a post-antibiotic effect is generally administered in a twice-a-day regimen.

[A case of bilateral MALT (mucosa-associated lymphoid tissue) type conjunctival malignant lymphoma]

A case of bilateral MALT (mucosa-associated lymphoid tissue) type conjunctival malignant lymphoma is reported. The patient, a 32 year old female, was referred to our hospital with the diagnosis of allergic conjunctivitis. We performed histopathological, immunohistochemical, and molecular genetical examination. The histopathological findings showed proliferation of CCL (centrocytelike) cells, lymphoepithelial lesion, and follicular colonization. Monoclonality of the tumor cells was revealed by molecular genetical analysis. On the basis of these detailed examinations, the patient was diagnosed as having MALT type malignant lymphoma. MALT type malignant lymphoma was first described by Isaacson in 1983. Both histological and clinical features are characteristic and quite different from other lymphomas. Some patients are affected bilaterally. Immunohistochemical and molecular genetical examinations in MALT type malignant lymphomas were found to be useful.

Comparative studies on the antiallergic effects of kampo medicines used for the therapy of respiratory diseases

Eight kinds of kampo medicines mainly used for the treatment of asthma and other respiratory diseases, whose comparative effects were still unproven, were selected for comparison of their antiallergic activity in the present study. 1) In an experiment on 48-hr PCA reaction in rats passively sensitized with anti egg albumin IgE antisera, inhibitory effects were observed in those groups orally administered with the tested kampo medicines. Among the drugs tested, TJ-19 showed a potent inhibitory activity as effective as that of tranilast (TL). 2) In the study of extraction method, the effects of kampo drugs varied widely according to the extraction method by which they were prepared. This suggests that the routine methods for preparing these extracts should be reconsidered to achieve the optimal efficacy. 3) In the study of histamine release from rat peritoneal cells stimulated with compound 48/80, TJ-55, TJ-19 and TL exerted a strong inhibition, but TJ-119, TJ-29 and TJ-96 had a weak inhibition. 4) TJ-96, TJ-19 and TL exerted a strong inhibitory effect on LTC, release from rat peritoneal mast cells induced by calcium (Ca) ionophore A23187, but TJ-95, TJ-55 and TJ-119 exerted only a weak inhibition. To sum up of the results, any of these kampo medicines have unique pharmacological action and antiallergic effects. Besides, the method for extraction affects the efficacy of kampo medicine in vitro.

[A nation-wide survey on the occurrence of amoebic keratitis in Japan]

Acanthamoeba keratitis in Japan was first reported by Ishibashi in 1988. Since then, the incidence of Acanthamoeba keratitis has gradually increased. We retrospectively analyzed 39 cases, 42 eyes, of amoebic keratitis reported in Japan from 1988 to September 1993. Of the 39 patients, 35 (89.7%) wore contact lenses, 32 (82.1%) soft contact lenses, and 3 (7.7%) hard contact lenses, and 4 (10.3%) did not wear contact lenses. Of the 4 patients without contact lenses, 3 had a history of trauma. Acanthamoeba keratitis is often difficult to diagnose. Twenty-four cases were misdiagnosed as herpetic keratitis. Early diagnosis and adequate therapy are important.

The phenol red thread tear test: a cross-cultural study

PURPOSE

To examine the results of the phenol red thread tear test in a cross-cultural comparison.

METHODS

Two groups of 500 controlled normal subjects who do not wear contact lenses from the United States and Japan were investigated.

RESULTS

The mean wet length of the thread for the United States was 23.9 mm (SD 9.5 mm). The mean for Japan was 18.8 mm (SD 8.6 mm). There was a significant difference between the two countries (P < 0.05). Males subjects had significantly longer wet lengths than females for both countries (P < 0.05). There was a moderate correlation between right and left eye results for both countries.

CONCLUSIONS

The phenol red thread tear test was found to be easy to administer. Results were in line with current knowledge and theories of the lacrimal system. Results also indicated that this test may disclose subtle differences not previously found with other tear tests.

[Clinical usefulness of the measurement of type-II procollagen carboxypeptide (C-II propeptide, pColl-II-C) in synovial fluid as a marker of collagen metabolism in cartilage]

Type-II procollagen-C-peptide (pColl-II-C) in synovial fluids was studied in 319 patients with osteoarthritis (OA; 151), rheumatoid arthritis (RA; 141), traumatic arthritis (TA; 27) and 15 healthy volunteers using the newly developed ELISA kit. The mean levels of pColl-II-C in synovial fluids of healthy controls, OA, TA, and RA were 0.3 +/- 0.1 ng/ml, 5.9 +/- 0.3 ng/ml, 6.8 +/- 1.4 ng/ml and 1.1 +/- 0.1 ng/ml, respectively. pColl-II-C levels in synovial fluids of OA and TA were significantly higher compared to those of healthy controls and RA. It was also demonstrated that pColl-II-C levels could reflect the quantitative and qualitative change of cartilage metabolism. Therefore, the quantification of this molecule in synovial fluid could be beneficial to know the synthetic activity of type II collagen of chondrocytes, since pColl-II-C is a part of the precursor molecule of type II collagen.

Involvement of HLA class II molecules in acquisition of staphylococcal enterotoxin A-binding activity and accessory cell activity in activation of human T cells by related toxins in vascular endothelial cells

Human umbilical vascular endothelial cells (HUVEC) express HLA class II molecules upon stimulation with recombinant human interferon-gamma (IFN-gamma). Staphylococcal enterotoxin (SE) A (SEA)-binding assay using [125I]-SEA showed the presence of specific SEA binding in HUVEC stimulated with IFN-gamma but not in unstimulated HUVEC. Levels of HLA class II expression and SEA-binding increased as the IFN-gamma concentration and the period of stimulation were increased. Binding of [125I]-SEA to the IFN-gamma-stimulated HUVEC was reduced markedly by an anti-DR/DP MoAb. T cells produced IL-2 upon stimulation with a group of SEs (SEA, SEB, SEC, SED and SEE) in the presence HUVEC stimulated with IFN-gamma but not in the presence of control HUVEC. The level of accessory cell activity in the IFN-gamma-stimulated HUVEC was related to the level of HLA class II expression and SEA-binding activity. Antibodies to HLA class II molecules almost completely inhibited the response. These results indicate that HLA class II molecules are directly involved in the acquisition of these activities in HUVEC.

Grating Discs: a simplified method of testing vision in infants and young children

We have developed a simple new method of evaluating visual function in young children about 15 to 36 months of age. Our Grating Discs system consists of six discs with a striped pattern and one homogeneous disc. One striped disc and the homogeneous disc are presented simultaneously, and the examiner observes whether the subject can discriminate between the two. The patterned discs have vertical stripes of different widths from 16 to 0.5 mm. At a testing distance of 57 cm, the visual resolution required for discriminating the grating ranges from 96 min of arc (0.01) to 3 min of arc (0.33) in one-octave steps; at a testing distance of 114 cm the required resolution ranges from 48 min (0.02) to 1.5 min (0.67). Using this system, we evaluated the visual acuity of normal infants and young children. Their ability to discriminate the finer gratings improved with increasing age, and more than 90% of the normal subjects in the 36-month group tested at 0.67. We also examined young children with known ocular pathologies and compared the results with acuity measurements obtained with the preferential looking test. The latter method gave acuities slightly better than those from the Grating Disc system, but the finding with the two techniques were generally in good agreement. Grating Discs are a simple, compact, effective tool for rapid assessment of visual function in young children.

Binocular function in unilateral aphakia. Correlation with aniseikonia and stereoacuity

Aniseikonia and stereoacuity were measured in patients with unilateral aphakia, most of whom were postoperative senile cataract cases. The New Aniseikonia test was used to evaluate aniseikonia and the Titmus Stereotest to measure stereoacuity. Ninety cases were studied, 57 (63.3%) of which had intraocular lens (IOL) implants; 27 (30%) had extended-wear soft contact lenses; and six (6.7%) had spectacle lenses. In the IOL group, aniseikonia averaged 2.8%, and 39 patients (68.4%) had good stereoacuity. In the contact lens group, aniseikonia averaged 4.6%, and 11 (40.7%) had good stereoacuity. In the spectacle lens group, aniseikonia averaged 17.8%; none of the patients had good stereoacuity. The authors concluded that in cases with unilateral aphakia, correction with an IOL implant is superior to the other alternatives in achieving good binocular function.

Detection of the cross-linking amino acid, histidinoalanine, in human brown cataractous lens protein

In human nuclear cataract, with its progression, high polymers protein mass, which is aggregated and strengthened by disulfide cross-links and other covalent cross-links, accumulates in the nuclear region to cause hardening of the lens nucleus. However, the structure of non-disulfide covalent cross-links has not been clearly confirmed yet. Recently a cross-linking amino acid, histidinoalanine, was discovered in connective tissue and is thought to cause hardening of the tissue with aging. The content of this amino acid in the lens nucleus was studied. Nuclear cataract was classified on the basis of nuclear color as described by Pirie (1986). The content of histidinoalanine was found to be 0.05 +/- 0.03 nmol mg-1 in normal nucleus; 0.06 +/- 0.03 nmol mg-1 in grade I (uniform pale yellow); 0.05 +/- 0.03 nmol mg-1 in grade II (deep yellow nucleus); 0.38 +/- 0.07 nmol mg-1 (P less than 0.01) in grade III (hazel-brown nucleus) and 3.35 +/- 2.76 nmol mg-1 (P less than 0.01) in grade IV (deep brown nucleus). The result suggests that histidinoalanine is one of the non-disulfide cross-links of lens proteins in nuclear cataract and is closely related to the grade of cataract.

Contact study of the hip joint. Load-deformation pattern, contact area and contact pressure

Contact study of the human hip joint was performed in order to understand load-deformation pattern under compressive loading, contact area and contact pressure by our method. Weight-bearing function of the hip joint was confirmed. Deformation of articular cartilage and subchondral bone were made reasonably and joint congruity was considered to be obtained with increasing load. Neither contact area nor distribution of the contact pressure were symmetrical or concentric, and both were dependent on the magnitude of load. The relationship between weight-bearing and early cartilage degeneration was discussed.

Clinical features of 53 cases with pustulotic arthro-osteitis

We have described clinical features of 53 cases with pustulotic arthro-osteitis. Anterior chest wall symptoms such as intersterno-costoclavicular or manubriosternal lesions were observed in all of 53 cases. Spondylitis or spondylodiscitis was found in 18 cases. Sacroiliitis resembling ankylosing spondylitis was seen in 7 cases. Peripheral inflammatory arthritis was seen in 14 cases, which were of nonerosive, of oligoarthritis type, and cured within 1 to 2 months, leaving no residue. HLA B27 was never found, and RAW factor was negative. Histological examinations revealed nonspecific chronic inflammation of bone and soft tissue. Pustulotic arthro-osteitis is apparently distinct from known rheumatic diseases such as rheumatoid arthritis, ankylosing spondylitis, psoriatic arthritis, and Reiter's disease. We have proposed that this condition should be classified as a member of the "seronegative spondylo-arthritis' group as designated by Wright and Moll.

[[HLA in rheumatoid arthritis (author's transl)]

Despite many reports on the association between ankylosing spondylitis and HLA-B27, most studies have failed to find a significant relationship between HLA-A or B antigen and rheumatoid arthritis. Stastny, however, showed a significantly high frequency of HLA-Dw4 in rheumatoid arthritis in 1976. The study of HLA antigens in Japanese patients with rheumatoid arthritis are thought to be significant in view of the pathogenesis of disease. Eighty-eight Japanese patients with "definite" or " classical" rheumatoid arthritis according to the ARA criteria and 104 normal individuals were typed for serologically detectable HLA-A, B, C, and D antigens. Though small discrepancies were observed in several of the HLA-A, B, and C, antigens, they were not definitely significant. The frequency of HLA-DR4 increased to 70.5% in patients compared to 46.1% in the control (i.e. normal) group (p less than 0.001). However, the frequency increased to 80.6% in male patients (p less than 0.0005). Of interest was the significantly high frequency of HLA-DR4 in males, compared to the low frequency of HLA-DR2 (p less than 0.02). Rheumatoid patients were subdivided into different groups according to the year of onset, the presence of the the rheumatoid factor or rheumatoid nodules, the functional grade and treatment. There were no significant differences in the frequency of HLA-DR4 among subgroups. The results indicate that rheumatoid arthritis, especially in males, is associated with genes of the HLA-D region and that immunogenetic factors linked to HLA have an important role in its pathogenesis.

A new socket design for the dysplastic acetabulum in total hip replacement

A special socket was designed by holography for total hip replacement for the treatment of the dysplastic acetabulum and correction of the deformation pattern. Excellent clinical results of 12 cases demonstrate that the special socket design provides good stability as well as favorable redistribution of mechanical forces about the hip joint.

[Painful hip joint with epiphyseal dysplasia (author's transl)]

Among patients who visited our hip clinic, eighteen patients from ten families were diagnosed as mild or atypical cases of spondyloepiphyseal dysplasia or multiple epiphyseal dysplasia. Clinical and X-ray examinations of these patients showed common characteristic features as follows. 1. They usually had short stature but were not dwarfs. Their facial features and body proportions did not suggest hereditary bone dysplasia. 2. Although the disease might be transmitted in an autosomal dominant manner, its occurrence among these families was found to be sporadic. 3. Symptoms of the hip joint mainly resulted from limited range of motion, coxalgia being usually less than expected from X-ray findings. 4. Joints were always affected bilaterally although the degree might be different on each side. 5. In the majority of the cases, the spine, shoulder (in 7 cases), knee (in 6 cases), elbow (in 3 cases), ankle, and wrist joint (in 2 cases) were also affected. 6. Characteristic X-ray findings of the hip joints were as follows. a) Coxa vara, flattening or rectanglar deformity of the femoral head and shortening of the femoral neck. b) The trabecular pattern of the femoral head was irregular and subchondral cysts were often observed. c) Joint space was relatively better restored than expected from the deformity and subchondral bony changes of the femoral head. Spondyloepiphyseal dysplasia and multiple epiphyseal dysplasia are genetic disorders of the epiphyseal and apophyseal cartilage. The hip joint is loading greater mechanical force than any other joint. In both spondyloepiphyseal dysplasia and multiple epiphyseal dysplasia, the hip joint is always affected. As the hip joint is most vulnerable when there is some disorder of the epiphyseal cartilage, it is probably the only detectable abnormal joint. In relatively short period (1972-1978), the diagnosis of mild or atypical spondyloepiphyseal dysplasia was made in 18 patients in our hip clinic. This means that the mild or atypical cases of spondyloepiphyseal dysplasia is not so rare as expected. They might be misdiagnosed as aseptic necrosis, deformity of the femoral head due to Perthes disease or primary osteoarthrosis. An extreme care should be taken when we examine such patients.

Experimental repair of the medial collateral ligament of the knee in rabbits

In order to know the reparative process of the bone-ligament junction of the medial collateral ligament, the mechanical properties and histological findings of the medial collateral bone-ligament-bone preparations from adult rabbits were examined at 2, 4, 6, 8, 12, 16, 20 postoperative weeks. There were certain relations between the histological findings and the strength of the repaired medial collateral ligaments, but the healing process of the mechanical properties was slower and at half a year follow up the maximum load could only reach 3/4 of the control.

[Mechanical behavior of the subchondral bone in the experimentally induced osteoarthritis]

In order to evaluate the role of the subchondral bone (cancellous bone) in the development and progression of the joint degeneration, osteoarthritis of the knee joint was produced experimentally in the rabbits and viscoelasticity and strength of the subchondral bone from the femoral medial condyle have been investigated along with the pathological, histological study of the joint. The viscoelastic spectrometer and the Instron type testing machine were used. As the first change after operation, osteophyte formation around the joint margin has been observed before the initiation of the degeneration of articular cartilage and there is a possibility that mechanical properties of subchondral bone such as high deformability and low elasticity to the mechanism of osteophyte formation. Subchondral bone softening with marked increase of ultimate strain and phase lag, marked decrease of compressive elastic modulus and ultimate stress precedes or occurs concurrently with the degeneration of the articular cartilage. These facts indicate the relationship between the mechanical properties of the subchondral bone and joint degeneration. Once the joint degeneration starts, degeneration continues progressively while the subchondral bone tends to become brittle. These changes may be considered as a kind of functional adaptation to the damage or denudation of articular cartilage. It is postulated that some architectural changes of the subchondral bone may provide alterations of the mechanical properties. Biomechanical roles of the subchondral bone is suggested as one of the factors in the joint degeneration.