Design of microfluidic channels to prevent negative filtration in implantable hemofiltration devices.

In order to improve the quality of life of dialysis patients, our group have been developing an implantable hemofiltration device (IHFD) composed of multiple layers of dialysis membranes and microfluidic channels. To improve the hemodialysis performance of IHFD, preventing the negative filtration, which is caused by the oncotic pressure of blood, is mandatory. In this study, we fabricated IHFDs with five different microchannel designs and experimentally investigated the performance of each device in in vitro experiment. In addition, the successful IHFD was further evaluated by ex vivo experiments with a beagle dog. The experiments verified the effectiveness of the microchannel design, which will be used for the IHFD for in vivo experiments with pigs in the future.

Therapeutic results of the modified cadenat procedure for acromioclavicular joint separations compared with the modified dewar procedure / Resultados terapéuticos del procedimiento de cadenat modificado para las separaciones de la articulación acromioclavicular en comparación con el procedimiento de dewar modificado

AIM AND BACKGROUND: The surgical treatment for acromioclavicular joint dislocations is recommended for Rockwood's classification types 4, 5 and 6. In this study, we evaluate the therapeutic results of the modified Cadenat procedure on type 5 acromioclavicular joint dislocation, and report on a comparative study of the modified Dewar procedure also on type 5 acromioclavicular joint dislocation. SUBJECTS AND METHODS: The modified Cadenat procedure was performed on 73 patients (66 males and 7 females, group C). The mean age at the time of the surgery was 35.4 years. On the other hand, the modified Dewar procedure was performed on 55 patients (51 males and 4 females, group D). The mean age at the time of the surgery was 34.5 years. RESULTS: The mean therapeutic results were 28.2 points in group C and 27.3 in group D according to the UCLA scoring system. In group C, the subluxation that represented less than 5 mm superior translation of the clavicle, occurred only in 18 of 73 patients. Meanwhile, in group D, the subluxation that represented less than 5 mm, occurred only in 14; that which represented 5 to 10 mm was in seven patients, and the complete dislocation occurred in three patients. Also, the occurrence ofosteoarthritic changes in the acromioclavicular joint was nine patients in group C and 20 in group D, respectively. CONCLUSION: The modified Cadenat procedure could provide satisfactory therapeutic results and avoid postoperative failure of reduction compared to the modified Dewar procedure. However, the modified Cadenat procedure does not aim to restore the anatomical coracoclavicular ligaments. It is believed that anatomic restoration ofboth coracoclavicular ligaments could best restore the function ofthe acromioclavicular joint.

OBJETIVO Y ANTECEDENTES: El tratamiento quirúrgico para las dislocaciones de la articulación acromioclavicular se recomienda para los tipos 4, 5, y 6 de la clasificación de Rookwood. En este estudio, se evalúan los resultados terapéuticos del procedimiento de Cadenat modificado en dislocación de la articulación acromioclavicular de tipo 5, y también se informa sobre el estudio comparativo con el procedimiento de Dewar modificado practicado sobre el tipo 5 de dislocación de la articulación acromioclavicular. SUJETOS Y MÉTODOS: El procedimiento de Cadenat modificado se realizó en 73 pacientes (66 varones y 7 hembras, grupo C). La edad promedio en el momento de la cirugía era 35.4 años. Por otro lado, el procedimiento de Dewar modificado se realizó en 55 pacientes (51 varones y 4 hembras, grupo D). La edad promedio en el momento de la cirugía era 34.5 años. RESULTADOS: Los resultados terapéuticos promedio fueron 28.2 puntos en el grupo C y 27.3 en el grupo D de acuerdo con el sistema de puntuación UCLA. En el grupo C, la subluxación que representó menos de 5 mm de traslación superior de la clavícula, sólo ocurrió en 18 de 73 pacientes. Entretanto, en el grupo D, la subluxación que representó menos de 5 mm, sólo ocurrió en 14; la subluxación que representó de 5 a 10 mm ocurrió en siete pacientes; yla dislocación completa ocurrió en tres pacientes. También, la ocurrencia de cambios osteoartríticos en la articulación acromioclavicular fue de nueve pacientes en el grupo C y 20 en el grupo D, respectivamente. CONCLUSIÓN: El procedimiento de Cadenat modificado podría proporcionar resultados terapéuticos satisfactorios, y podría evitar el fracaso postoperatorio de la reducción en comparación con el procedimiento de Dewar modificado. Sin embargo, el procedimiento de Cadenat modificado no esta dirigido a restaurar los ligamentos coracoclaviculares anatómicas. Se entiende que la restauración anatómica de ambos ligamentos coracoclaviculares pudiera restaurar mejor la función de la articulación acromioclavicular.

Therapeutic results of the modified Cadenat procedure for acromioclavicular joint separations compared with the modified Dewar procedure.

AIM AND BACKGROUND: The surgical treatment for acromioclavicular joint dislocations is recommended for Rockwood's classification types 4, 5 and 6. In this study we evaluate the therapeutic results of the modified Cadenat procedure on type 5 acromioclavicular joint dislocation, and report on a comparative study of the modified Dewar procedure also on type 5 acromioclavicular joint dislocation. SUBJECTS AND METHODS: The modified Cadenat procedure was performed on 73 patients (66 males and 7 females, group C). The mean age at the time of the surgery was 35.4 years. On the other hand, the modified Dewar procedure was performed on 55 patients (51 males and 4 females, group D). The mean age at the time of the surgery was 34.5 years. RESULTS: The mean therapeutic results were 28.2 points in group C and 27.3 in group D according to the UCLA scoring system. In group C, the subluxation that represented less than 5 mm superior translation of the clavicle, occurred only in 18 of 73 patients. Meanwhile, in group D, the subluxation that represented less than 5 mm, occurred only in 14; that which represented 5 to 10 mm was in seven patients, and the complete dislocation occurred in three patients. Also, the occurrence of osteoarthritic changes in the acromioclavicular joint was nine patients in group C and 20 in group D, respectively. CONCLUSION: The modified Cadenat procedure could provide satisfactory therapeutic results and avoid postoperative failure of reduction compared to the modified Dewar procedure. However the modified Cadenat procedure does not aim to restore the anatomical coracoclavicular ligaments. It is believed that anatomic restoration of both coracoclavicular ligaments could best restore the function of the acromioclavicular joint.

High pressure nmr study of dihydrofolate reductase from a deep-sea bacterium Moritella profunda.

We have investigated the effect of pressure and temperature on the structural and thermodynamic stability of a protein dihydrofolate reductase from a deep-sea bacterium Moritella profunda in its folate-bound form in the pressure range between 3 and 375 MPa and the temperature range between -5 and 30 degrees C. The on-line cell variable pressure 1H NMR spectroscopy has been used to analyze the chemical shift and signal intensity in one-dimensional 1H NMR spectra. Thermodynamic analysis based on signal intensities from protons in the core part indicates that the thermodynamic stability of Moritella profunda DHFR is relatively low over the temperature range between -5 and 30 degrees C (deltaG0=15.8 +/- 4.1 kJ/mol at 15 degrees C), but is well adapted to the living environment of the bacterium (2 degrees C and 28 MPa), with the maximum stability around 5 degrees C (at 0.1 MPa) and a relatively small volume change upon unfolding (deltaV= 66 +/- 19 ml/mol). Despite the relatively low overall stability, the conformation in the core part of the folded protein remains intact up to approximately 200 MPa, showing marked stability of the core of this protein.

Correction of cyclovertical strabismus induced by limited macular translocation in a case of age-related macular degeneration.

PURPOSE: To report a case of strabismus surgery performed to treat cyclovertical strabismus induced by limited macular translocation. METHODS: Case report. RESULTS: A 62-year-old man suffering with age-related macular degeneration and subfoveal choroidal neovascularization, RE, underwent limited macular translocation surgery. The fovea was rotated downward, and his visual acuity improved from 20/100 to 20/25 postoperatively. Cyclovertical diplopia persisted for 6 months after the operation. A Hess screen test revealed a pattern that simulated an underaction of the superior oblique muscle and inferior rectus muscle with an overaction of the ipsilateral inferior oblique muscle. To treat the diplopia, advancement of the superior oblique muscle tendon and resection of the ipsilateral inferior rectus muscle were performed. Binocular single vision with 140 seconds of arc for stereopsis was obtained. CONCLUSION: Cyclovertical strabismus after limited macular translocation is corrective with conventional surgery on the treated eye.

Prism adaptation response is useful for predicting surgical outcome in selected types of intermittent exotropia.

PURPOSE: To evaluate the prevalence of prism adaptation response in Japanese patients with intermittent exotropia (X [T]) using the prism adaptation test and to assess whether patients with selected types of X [T] benefit from surgical outcome to which prism adaptation response may contribute. METHODS: In a prospective study, 128 consecutive patients with X [T] between 1990 and 1995 were enrolled. The prism adaptation test was conducted by neutralizing the angle of deviation for 2 to 3 hours. Patients who showed an increase in exodeviation by 10triangle up or more with the prism adaptation test were defined as having a prism adaptation response. For classification of the pattern of X [T], we chose a value of 15triangle up as the difference between the distance and near measurements. RESULTS: The percentage of patients in whom the prism adaptation response was observed at near fixation was significantly larger than those at distance fixation [35 (27%) patients versus 10 (8%) patients, P <.05]. Of 35 patients shown to have a prism adaptation response at near fixation, 21 patients (83%) had the basic type of exotropia. Fourteen patients (17%) with the basic type were changed to convergence insufficiency type because of an increase in near deviation and were defined as pseudo basic type. Patients with pseudo basic type had a significantly better surgical outcome compared with that of true basic type, whereas in the convergence insufficiency type, no definite tendency was found between the two subtypes, true and pseudo types. CONCLUSION: Patients with the pseudo basic type of X [T] in whom a prism adaptation response was demonstrated had a more favorable surgical outcome.

Large Bielschowsky head-tilt phenomenon and inconspicuous vertical deviation in the diagnostic positions in congenital superior oblique palsy.

PURPOSE: To report a case of congenital superior oblique palsy with an unusually large Bielschowsky head-tilt phenomenon (BHP) and disproportional inconspicuous vertical deviation. METHODS: Case report. RESULTS: An 18-year-old woman presented with slight compensatory head tilting and a Bielschowsky head-tilt phenomenon of 50 Delta on left tilting. Magnetic resonance imaging revealed atrophy of the left superior oblique muscle. A Hess screen test showed a slight underaction of the left superior oblique muscle, but neither an obvious overaction of the ipsilateral inferior oblique muscle nor inhibitory palsy of the contralateral superior rectus muscle was found. With a 3-mm recession of the ipsilateral superior rectus muscle, Bielschowsky head-tilt phenomenon decreased to 25 Delta. CONCLUSION: A large Bielschowsky head-tilt phenomenon was possibly caused by an increased gain of the otolith-ocular reflex affecting the vertical rectus muscle.

Induction of unseasonable hibernation and involvement of serotonin in entrance into and maintenance of its hibernation of chipmunks T. asiaticus.

Chipmunks that had been housed at 22 degrees C under a light-dark cycle of 14L:10D for at least one year were exposed to a short photoperiod (10L:14D) and low temperature to induce unseasonable hibernation. We were able to induce hibernation at any time of year and there was no significant difference in the duration of the hibernation bout, the duration of interbout euthermia and duration of bouts of torpor throughout the year; however entrance into hibernation took about 60 days in summer but only about 30 days in any other seasons. In addition, interbout euthermia predominantly occurred during the light phase in winter, whereas in spring interbout euthermia occurred equally in the light and dark phases. These results suggest that both the circadian and circannual systems are linked to hibernation in chipmunks. Subcutaneous infusion of a serotonin antagonist, para-chlorophenylalanine (PCPA), facilitated entrance into and interrupted hibernation in aroused and hibernating chipmunks in summer, respectively. On the other hand, opioid antagonist, naloxone, did not affect hibernation, but extended the period of interbout euthermia. These results suggest that the role of serotonin in entrance into and maintenance of hibernation in chipmunks is independent of the circannual system, and that opioid system may not be involved in hibernation in chipmunks.

Comparative study of brain lesions detected by magnetic resonance imaging between strabismus and nonstrabismus in infancy.

PURPOSE: To elucidate the causative factors in infantile esotropia, we evaluated morphological abnormalities in brain structures of esotropia patients showing any abnormal neurological signs in comparison to those of normal controls. METHODS: Sixty-five developmentally normal children participated in this study. Of these 65, 38 demonstrated infantile esotropia and 27 were normal controls. All underwent magnetic resonance imaging (MRI) of the brain between 2 and 30 months. RESULTS: Abnormal brain findings were noted in 3 (7. 9%) children in the strabismus group, whereas none of the children in the normal control group showed brain lesions. In these 3 cases, brain lesions involved periventricular leukomalacia, enlargement of the lateral ventricles with hypoplasia of the corpus callosum and myelination delay at the anterior horn adjacent to the lateral ventricles. CONCLUSIONS: Brain lesions that may disturb normal maturation of the visuomotor system and eventually lead to strabismus could be found in some patients without any episode that would cause birth injury.

Prognostic factors for successful surgical outcome with preoperative prism adaptation test in patients with superior oblique palsy.

PURPOSE: This study evaluated the surgical outcome of patients managed with preoperative prism adaptation test (PAT) and investigated prognostic factors for successful motor alignment in adult patients with superior oblique palsy. METHODS: Prospective study of preoperative PAT was performed. Fifty-seven patients with superior oblique palsy, aged 16 to 81 years, participated in this study. Patients were assigned to surgery with the target angle based on either the original angle or the prism compensated angle. When the amount of neutralizing prism exceeded 4delta or more compared to the original angle of deviation, the patient was defined as having prism compensation, and the target angle for surgery was based on the amount of neutralizing prism. The motor success rate was compared between the 2 groups at the 3-month postoperative follow-up. RESULTS: The prism responders group showed a superior outcome compared to that of the prism non-responders group (77% successful outcome compared with 46%, p = 0.0397). The presence of prism compensation and the amount of vertical deviation were significant prognostic factors for successful motor alignment. CONCLUSION: Preoperative PAT is a useful prognostic indicator of successful surgical outcome in patients with superior oblique palsy.

[Hyperhomocysteinemia in CAPD patients: peritoneal transport of total homocysteine at peritoneal equilibration test and daily elimination of total homocysteine].

Peritoneal equilibration tests (PET) were performed in patients on continuous ambulatory and automated peritoneal dialysis (CAPD, APD) to evaluate the peritoneal transport capabilities for total homocysteine (tHcy) and other amino acids. Forty-five patients (24 males, 21 females, 50.6 +/- 12.8 years old) maintained on PD for 43.4 +/- 30.3 months participated in the study. PET revealed a markedly lower dialysate to plasma (D/P) ratio of tHcy at 4 hours (0.148 +/- 0.047) than those of other amino acids. A significant positive correlation between the D/P ratio of tHcy and the D/P ratio of creatinine was found, as well as between the D/P ratio of tHcy and the D/P ratio of albumin. The most significant positive correlation was found between dialysate and plasma levels of tHcy at 4 hours. There was no difference in the D/P ratio of tHcy between patients with D/P ratios of creatinine higher than the sample median of 0.68 and with D/P ratios of creatinine below 0.68, while the D/P ratios of other amino acids except threonine in the former patients tended to be higher than those of the latter patients. The D/P ratio of tHcy in patients with serum levels of albumin higher than 4.0 g/dl was significantly higher than that in patients with a ratio less than the sample median of 3.9 g/dl, whereas there were no significant differences in the D/P ratios of other amino acids. These observations suggest that the dialysate level of tHcy is primarily affected by the plasma level of tHcy, and that protein-bound Hcy mainly regulates the D/P ratio of tHcy. Daily peritoneal elimination of tHcy in 20 PD patients was 40.6 +/- 28.4 micromol. A significant positive correlation between the elimination of tHcy and plasma level of tHcy was also found. Daily elimination of tHcy in 7 patients with APD tended to be lower than that in 13 patients with CAPD. These findings indicate that the daily peritoneal elimination of tHcy does not compensate for the daily amount of tHcy metabolized in normal kidney, and that other therapies, such as folic acid administration, are required to improve hyperhomocysteinemia in patients on PD.

Biometric confirmation of the Hirschberg ratio in strabismic children.

PURPOSE: In the Hirschberg eye position test, the ratio of strabismic angle to decentration of the corneal reflex is dependent on two biometric parameters of the eye: the radius of the corneal curvature and the depth of the anterior chamber. This study was designed to confirm whether the Hirschberg conversion ratio (HR) previously determined for adults can be used for children of various ages despite structural growth of the eye. METHODS: For 262 eyes of 131 children with strabismus (age range, 6 months to 11 years), the radius of the corneal curvature was measured with an auto-keratometer and the anterior chamber depth with an A-scan ultrasound unit under general anesthesia before the surgery. Using these measurements, the HR was computed on the basis of a geometric model. RESULTS: The calculated HR was constant across the age range, and the mean+/-SD was 19.9+/-1.9 prism diopters/mm (95% confidence interval, 16.1-23.6 prism diopters/mm). The ratios for the two eyes in each subject showed good correlation (R = 0.854, P = 0.0001). Neither of the biometric measurements was significantly correlated with age, although considerable scatter of the measurements was observed. CONCLUSIONS: These results indicate that the averaged HR can be applied in children regardless of the patient's age, although intersubject variance of the ratio should be taken into account.

Characteristics and variability of vertical phoria adaptation in normal adults.

We evaluated the characteristics of phoria adaptation for vertically induced retinal disparity. An adaptive change in the fusion-free ocular alignment, phoria adaptation, was measured with a computer-aided mirror haploscope at 10, 30, and 60 minutes after the start of wearing of a 3-prism-diopter base up prism by 35 normal subjects ranging in age from 21 to 67 years (mean: 37 years). The relationships between phoria adaptation and the subjects' age, the vertical fusional amplitude, the amount of heterophoria, and the starting time of the examination were evaluated. All subjects showed phoria adaptation, with the mean (+/- SD) degree of 0.78 +/- 0.28 degree, 0.96 +/- 0.26 degree and 1.02 +/- 0.30 degrees at 10, 30, and 60 minutes, respectively, after wearing the prism. The repeatability (95% confidence interval) for the measurements was less than +/- 0.24 degree. There was a significant correlation between the vertical fusional amplitude and the gain of phoria adaptation (at 10 and 60 minutes, P < 0.05). The gain of phoria adaptation measured at 60 minutes showed a significant decrease with age (P < 0.01). The results indicate that the time course of phoria adaptation in the vertical direction is similar to that in the horizontal direction and its gain differs considerably among subjects.

Chemical modification of amino acid residues in glycerinated Vorticella stalk and Ca(2+)-induced contractility.

The glycerinated stalk of the peritrich ciliate Vorticella, was treated with various reagents to chemically modify the amino acid residues. The influences of these modifcations on spasmoneme contractility were investigated. First, it was confirmed that the spasmoneme contraction is not inhibited by alteration of SH groups. It was also demonstrated that chemical modification of methionine and tryptophan residues abolishes spasmoneme contractility. The reagents used for chemical modification were N-bromosuccinimide (NBS), chloramine T, and 2-hydroxy-5-nitrobenzyl bromide (HNBB), which abolished spasmoneme contractility at concentrations of 40-50 microM, 200-300 microM, and 4 mM, respectively. These results suggest that, along with Ca2+ binding proteins, there are other as yet to be identified proteins involved in contractility.

Incidence of ocular complications in rheumatoid arthritis and the relation of keratoconjunctivitis sicca with its systemic activity.

To investigate the incidence of ocular complications in patients with rheumatoid arthritis under modern modalities of treatment and find the relationship between its systemic activity and ocular complications, routine ophthalmological examinations were done as a prospective study in 111 consecutive patients including 89 inpatients and 22 outpatients with rheumatoid arthritis seen from April to May 1995, in a hospital with a special clinic for rheumatology. Keratoconjunctivitis sicca (secondary Sjögren's syndrome) was found in 19 patients (17.1%), scleritis in one patient (0.9%), central retinal vein occlusion in 2 patients (1.8%), and idiopathic retinal hemorrhage in 3 patients (2.7%). Patients with keratoconjunctivitis sicca had significantly higher titers of rheumatoid factor (Mann-Whitney's U-test, p = 0.0048), higher levels of IgM (p = 0.0484), and lower levels of HDL-cholesterol (p = 0.0191), compared to patients without it. The incidence of ocular complications was comparable to the previous studies and keratoconjunctivitis sicca should be considered in patients with high titers of rheumatoid factor.

Seroepidemiological study of infection with West Nile virus in Karachi, Pakistan, in 1983 and 1985.

The prevalence of West Nile (WN) virus infection in Karachi, Pakistan, was unknown until 1982. It had been noticed that there were more than a few patients with encephalitides in Karachi, and it was supposed that Japanese encephalitis (JE) cases would be found among them. Therefore, a seroepidemiological study was conducted to define the prevalence of WN virus infection and the possible occurrence of JE virus infection in the Karachi area. Prevalences of haemagglutination inhibition (HI) and neutralization (NT) antibodies against WN virus were studied among 81 serum samples (in July, 33 samples; in September, 48) during 1983, and among 156 paired serum samples that were collected twice, in July and October of 1985. Nearly the same antibody-positive rates were obtained in July of both years (1983: HI 55%; 1985: HI 53%; NT 50%); the rates increased slightly during September/October (1983: HI 65%; 1985: HI 59%, NT 54%). Among 156 paired samples in 1985, 20 (13%) and 12 (8%) showed positive- or negative-antibody conversion between July and October. Two serum samples from each of 156 residents obtained in July had a significantly higher NT antibody titre against JE virus than against WN virus (in case 1, JE 1:80, WN less than 1:10; in case 2, JE 1:40, WN less than 1:10). This is the first report to show the prevalence of WN virus infection in Karachi, Pakistan.