Fibular osteosynthesis for delayed type II and type III femoral neck fractures in children.

Seventeen transcervical/basal femoral neck fractures in children were treated by free fibular graft and cancellous lag screw. Two cases were failures of a previous surgery, and 15 had been untreated for 3 weeks or more. Four cases had radiological evidence of avascular necrosis of the head and one of the neck preoperatively; five cases had neck resorption. At an average of 48.1 months postsurgery all fractures had united and there was only one new case of avascular necrosis. Four cases had coxa vara, and four cases had premature epiphyseal closure. There were 13 good, three fair, and one poor result(s) using Ratliff's criteria. We recommend this procedure in cases with delayed initial appearance or failed previous surgery. Complications of the procedure such as long screw/graft and fibular fracture are preventable. The incidence of coxa vara in cases with neck resorption may be reduced by adding subtrochanteric osteotomy to the procedure.


The use of Ender nails in femoral shaft fractures: what are the remaining indications?

The use of Ender nails for the treatment of femoral shaft fractures has been described as technically easier and less time consuming than current intramedullary nailing techniques. We reviewed our results with unlocked Ender nails in 26 stable and 17 unstable fracture patterns an average of 3-4 years after injury. Because of continued instability, 42% of the stable and 76% of the unstable groups required adjunctive stabilization in the form of skeletal traction, a cast, or an external fixator. Additionally, nail migration and shortening and loss of motion at the knee were seen in 14 fractures in each group. Although two thirds of the patients with stable fracture patterns obtained good or excellent results, no outcome in the unstable group was rated excellent and only 19% were considered good. We therefore recommend that rigid locked intramedullary nails be used in femoral diaphyseal injuries. The use of Ender nails should be limited to stable fracture patterns and locked with screws or wires. They may be particularly useful for fractures in femora with small medullary canals (less than or equal to 8 mm), fractures below noncemented femoral prostheses, and fractures in young children requiring intramedullary stabilization without injuring the physeal plates.


Alignment of supracondylar/intercondylar fractures of the femur after internal fixation by AO/ASIF technique.

Fifty-nine supracondylar-intercondylar fractures of the femur in 57 patients were evaluated after a mean follow-up of 5 years 7 months (range 2 years to 11 years 3 months) after internal fixation using AO/ASIF technique. Axial alignment was compared with that of the uninjured side by orthoroentgenography in the upright position and by bilateral anteroposterior (AP) and lateral views of the femur. Identical values for varus/valgus were noted in 24%, for ante/recurvation in 72%, and for rotation in 61%; differences were within 5 degrees of varus/valgus in 74%, of ante/recurvation in 78%, and of rotation in 83%. Alignment differences were more frequent in complicated and intercondylar fractures according to the AO classification of fractures. We conclude that restoration of the distal femoral angle is far more difficult than restoration of the sagittal plane and rotation, but a satisfactory functional result appears to be compatible with angulation differences of less than or equal to 5 degrees in any plane and that this difference appears to be within the reasonably achievable limits. 93% of the patients were satisfied; 64% of patients were pain-free, and 27% had slight intermittent pain (not interfering with daily activity); 67% of the patients had unlimited walking distance, and 78% of the patients were able to walk without aid. Excellent and good results according to the rating systems of Neer et al., Pritchett, and Schatzker and Lambert were noted in 82, 39, and 26%, respectively. This discrepancy between alignment, pain, function, and results according to different rating systems underlines the need for future standardized, clearly defined reporting and classification of rating.


Assessment of bone viability in patients with osteomyelitis: preliminary clinical experience with laser Doppler flowmetry.

The intraoperative determination of bone viability is of fundamental importance in the surgical management of osteomyelitis. Recurrent infection will result from inadequate debridement, whereas reconstructive problems will be magnified by overzealous resections. The purpose of this article is to report the use of laser Doppler flowmetry (LDF) as a surgical adjunct allowing quantitative determination of bone viability in patients with osteomyelitis. Twenty-five patients with osteomyelitis underwent surgical debridement using LDF to assist with the intraoperative identification of necrotic bone and have been observed for at least 6 months. The LDF probe is placed directly on the bone and the output signal is channeled into an oscilloscope that calculates and displays the mean value of the signal in millivolts (mV). All patients underwent radical surgical debridement, including hardware removal if present and resection of nonviable bone. Bone debridement was continued when possible until LDF measurements in excess of 100 mV were obtained. Information regarding bone vascularity obtained with the LDF had a direct influence on the extent of bone debridement in all cases. The patients have been observed for an average of 16 months. No complications were associated with the use of LDF. All readings were pulsatile. Five patients had recurrence of infection. The average LDF reading following debridement for patients with recurrent infection was 72 mV, compared to 107 mV for patients without recurrence (p less than or equal to 0.025). All fractures were healed, although some required supplemental surgical management, including bone grafting or external fixation.(ABSTRACT TRUNCATED AT 250 WORDS)


Type II floating knee: ipsilateral femoral and tibial fractures with intraarticular extension into the knee joint.

Thirty-four patients with ipsilateral fractures of the femur and tibia with intraarticular extension into the knee of at least one fracture were reviewed at an average follow-up of 38 months. Joint involvement was present in 22 (65%) femoral fractures and 23 (68%) tibial fractures. In 11 (32%) patients, both fractures were intraarticular. In 71% of the patients, there were major associated injuries. Open fractures were common, occurring in 21 (62%) extremities. Associated vascular injuries were seen in seven (21%) cases. Ninety percent of the fractures were surgically stabilized. The average time to healing was 39 and 37.5 weeks for the femur and tibia, respectively. The average flexion of the knee was 96 degrees (5-140 degrees) with flexion contractures occurring in five (15%) knees. Results were graded according to criteria established by Karlström and Olerud. Only eight (24%) patients had good or excellent results. Complications were frequent, with deep infections occurring in 11 (32%) extremities, leading to above-knee amputations in three (9%) patients. This subgroup of floating knee injuries appears to be associated with a higher degree of systemic trauma, a higher percentage of open injuries, and a much graver prognosis.


Indirect reduction and percutaneous screw fixation of displaced tibial plateau fractures.

Indirect reduction and percutaneous screw fixation were attempted in 20 displaced tibial plateau fractures in 20 patients. Closed, indirect reduction was successful in 18 fractures; two others, both Schatzker type II fractures, required open reduction. The 18 fractures were followed for an average of 16.2 months (range, 12-24 months). Of the fractures successfully reduced with indirect techniques, 13 were reduced anatomically (72.2%), and five were considered nonanatomic (27.8%). Four of the five fractures with a nonanatomic reduction were type II fractures. Clinically, there were six excellent (33%), 10 good (56%), and two fair (11%) results. No fracture lost reduction; no patient developed an infection. Indirect techniques could effectively reduce only split fragments. Depressed fragments could not be reduced reliably with either ligamentotaxis or percutaneous elevation with a tamp. There was no correlation between radiographic reduction and clinical outcome. It did not matter whether two, three, or four screws were used to stabilize the fracture.


Tibialis posterior muscle: the fifth compartment?

The posterior aspect of 51 embalmed cadaver legs in 50 cadavers was dissected to establish the prevalence of a separate compartment for the tibialis posterior muscle (TP). All dissections revealed the presence of a superficial and a deep posterior compartment. No distinct fascial septum separated the TP from the flexor digitorum longus (FDL) and flexor hallucis longus (FHL). We conclude that the TP does not commonly rest within its own osseofascial compartment and thus does not require isolated decompression for acute compartment syndrome of the leg. An incidental observation, frequently overlooked in the anatomy literature, was a supplemental tendon of origin of the FDL. In addition to the classically described tibial origin, several cadavers exhibited a proximal fibular tendon of origin for the FDL. One cadaver demonstrated the FDL to have an extensive fibular origin that completely covered the TP, forming a myotendinous fifth compartment. We feel that the variable fibular origin can explain the chronic exertional compartment syndrome of the TP described previously by Davey et al. and serves as a basis for a minor alteration in our fasciotomy technique.


Postoperative radiographs as predictors of clinical outcome in unstable ankle fractures.

This study reviews a group of 80 consecutive displaced ankle fractures treated operatively and followed for an average of 3.2 years. Fractures included bone or combined bone and ligamentous injuries in which the initial talar displacement was greater than or equal to 2 mm. The immediate postoperative roentgenograms were examined for several features, which included widening of the syndesmosis, fibular length, talo-crural angle, talar tilt, presence and size of a posterior malleolar fracture, and an abnormality of the medial clear space. Patients were examined at follow-up per Cedell, and their clinical evaluations were correlated with the analysis of radiographic features and demographic data. Good to excellent results were seen in 80% of the cases. The radiographic factors most predictive of a poor outcome were abnormal medial clear space and the presence of a large (greater than 20%) posterior malleolar fracture (p less than 0.05). Fibular shortening, talar tilt, and syndesmotic widening suggested a poor result, but these findings were not statistically significant. Multiple (two or more) radiographic abnormalities correlated with a poor prognosis. Conversely, a perfect radiographic result did not guarantee an excellent clinical outcome. Older patients and those with a delay between injury and surgery greater than 7 days tended to have a poorer result.


Use of radial forearm flaps to treat complications of closed pilon fractures.

Between 1986 and 1990, five patients have been treated for full-thickness skin loss proximal to the level of the anterior joint line of the ankle following open reduction and internal fixation of closed C3 (ASIF) pilon fractures. The average delay from injury to the initial open reduction and internal fixation was 4.6 days. Anteromedial and posterolateral incisions were used to expose the fractures, resulting in a bipedicle flap over the anterior aspect of the ankle joint at the time of the initial surgery. The minimum distance between these two incisions for these five patients was 6.0 to 9.0 cm (average of 7.4 cm). Free tissue transfers using the radial forearm flap were effective in providing durable but thin coverage for this difficult problem of soft-tissue coverage in an area requiring a thin flap with a long vascular pedicle. The risk for skin necrosis at the time of surgery may be minimized by spacing the incisions up to 12.0 cm apart in addition to avoiding the period of maximal tissue ischemia occurring 3 to 6 days after the injury.


Severe intracranial injury from a fall in the halo external fixator.

This is a report of a rheumatoid arthritis patient after atlantoaxial stabilization and halo external fixator immobilization who presented with intracranial injury after an accidental fall. Global aphasia and an impaired consciousness resulted from a cerebral hemorrhagic contusion below an impressed bone chip at the left posterior halo-pin site. Cranial penetration of a halo pin has been previously reported; however, brain injury associated with it has not. Since there is a considerable risk of falls in the elderly and in patients with myelopathic gait disturbances, this rare but potentially hazardous complication should be kept in mind during the halo vest fixation.


Combined shear fractures of the trochlea and capitellum associated with anterior fracture-dislocation of the elbow.

This article presents two unusual cases of combined shear fractures of the trochlea and capitellum associated with anterior fracture-dislocation of the elbow. The mechanism of injury was thought to be a fall on the dorsum of a partially flexed forearm, in which the trochlea and capitellum are displaced by the fractured olecranon and the radial head.


Transpedicular bone grafts misplaced into the spinal canal.

After open reduction of a burst fracture of L1, transpedicular bone grafting of the fractured vertebral body was performed. Bone grafts accidentally slipped into the spinal canal through the damaged medial wall of the pedicle. No adverse effects were noted clinically, but this case illustrates that transpedicular bone grafting is a potentially dangerous procedure. Computed tomography after 1 year showed complete resorption of the intraspinal bone grafts.


Open reduction and internal fixation of an acetabular fracture during pregnancy.

Fractures of the pelvis and acetabulum are common injuries in a mechanized society and frequently occur in the younger age groups. Commonly associated injuries such as hemorrhage, urethral tears, gastrointestinal injuries, and major vessel damage are well reported and well known to orthopaedic surgeons. Another less frequently reported complication of pelvic fractures is the potential association with pregnancy and subsequent childbirth. This problem was first described by Malgaigne in 1857 in his classic article on double vertical fractures of the pelvis, in which he described a 34-year-old woman with a pelvic fracture who subsequently died during childbirth. A review of the literature reveals numerous articles addressing potential problems with parturition subsequent to a pelvic fracture and several articles dealing with pelvic fractures occurring during pregnancy. The current literature on pelvic fractures during pregnancy, however, recommends only nonoperative treatment and, to our knowledge, there have been no reports of operative fixation during pregnancy. The purpose of this article is to report a case of an acetabular fracture in a pregnant woman treated with open reduction and internal fixation, who went on to carry a full-term baby and have a normal delivery.


Avascular necrosis of the femoral head--an unusual complication of an intertrochanteric fracture.

Avascular necrosis of the femoral head is an uncommon complication after intertrochanteric fracture. We report six patients with this unusual complication 1-5 years after intertrochanteric fracture. The possible etiologies of this complication include a more proximal intertrochanteric fracture, a high-energy injury with fracture displacement resulting in vascular damage, and adverse influences of the operative procedures on the vascularity of the femoral head.


Tibio-talo-calcaneal fusion with a free vascularized fibular graft in comminuted open fractures of the talus and the calcaneus.

An operation is described in which a free vascularized fibular graft with a peroneal cutaneous flap is used for tibio-talo-calcaneal fusion and simultaneous skin coverage in treatment of comminuted open fractures of the talus and the calcaneus involving large skin loss. Nine months postoperatively, the tibio-talo-calcaneal arthrodesis was successful, with good coverage of the skin defect on the medial aspect of the sole. One year 7 months postoperatively, the patient is free of pain and able to walk with full weightbearing on the foot.


Critical analysis of mandibular reconstruction using AO reconstruction plates.

Forty-one cases (37 patients) of mandibular reconstruction using AO plates were reviewed. The patients' ages ranged from 27 to 83 years (mean, 52.3 +/- 18.1 years) and their cases were followed for 6 to 42 months (mean, 12.7 +/- 8.3 months). Cases were grouped by the location of reconstruction: anterior mandible crossing midline as group A (12 cases), body segment of the mandible as group B (16 cases), condyle and ramus of the mandible as group C (13 cases). The incidence of revision as a measure of outcome was calculated by actuarial methods accounting for loss to follow-up or death. Revision or plate removal occurred in 22.2% (9 of 41 cases), with an incidence of 52.2% (6 of 12 cases) in group A, 12.5% (2 of 16 cases) in group B, and 7.7% (1 of 13 cases) in group C. Combined use of an AO plate and bone graft had a revision rate of 33.3% (4 of 12 cases), whereas the reconstructions with only a plate had a revision rate of 17.2% (5 of 29 cases). The difference between the immediate reconstructions (19.2%; 5 of 26 cases) and delayed reconstructions (26.7%; 4 of 15 cases) was not significant, but delayed reconstruction of the anterior mandible resulted in the highest failure rate (57.1%; 4 of 7 cases). The revision incidence was significantly higher when the area had been radiated (33.3% of 24 radiated cases and 5.7% of nonradiated cases required revision). In particular, the radiated group A had a remarkably higher failure rate (63.2% of 10 cases).(ABSTRACT TRUNCATED AT 250 WORDS)


Rigid reconstruction plates for immediate reconstruction following mandibular resection for malignant tumors.

Thirty-four primary alloplastic reconstructions of segmental mandibular defects caused by surgery for oral malignancy were performed during a 6-year period. Eighty-eight percent of the tumors were classified as stage III or IV. One third of the patients died during follow-up, nine with their primary reconstruction plate in place. During the follow-up, 12 patients required plate removal because of complications; four of them were treated with another plate. Nineteen of 21 patients alive at the end of follow-up were free of disease. Ten had their primary plate in place, and four had had a secondary plate installed because of plate fracture or screw loosening. Three patients had their mandible permanently reconstructed with bone. The functional and esthetic results were considered excellent or fair in a majority of the cases. Because the 5-year survival rate for patients with advanced mandibular malignancies is 15% to 20%, extensive, definitive reconstructive procedures during primary surgery are usually not justified.


Positional changes of the mandibular condyle assessed by three-dimensional computed tomography.

This investigation was designed to test the validity and reliability of three-dimensional computed tomography (3-D CT) for quantification of positional changes of the condyle in a laboratory model. The model consisted of a mounted dried human skull and a mandibular condyle attached to a micromanipulator. Controlled changes in condylar position were made and the condyle/fossa was imaged. Positional changes were measured by triangulation methods based on specific 3-D CT landmarks. The data were analyzed using descriptive statistics, analyses of variance to evaluate the sources of variability, and linear contrasts to evaluate the differences between observed and expected values. The results indicated that selection of appropriate anatomic landmarks for assessment of movement influences technique accuracy. The data also indicate that 3-D CT is most accurate in detecting inferior condylar movements. Lateral and posterior movements were assessed with less accuracy than the inferior positional changes. The clinical significance of these differences has yet to be determined.


Use of postauricular skin grafts for vestibular reconstruction.

The use of full-thickness postauricular skin grafts for vestibular reconstruction is described. The procedure offers the advantages of a concealed donor scar, minimal patient discomfort and morbidity, ease of procurement, and confinement of the operations to a single region. Its use in 17 patients (31 grafts) resulted in complete take in 90.3% of the grafts. Maintenance of vestibular depth in most patients was maintained at 1-year follow-up. The disadvantages of the procedure are the limited amount of skin available and the need to suture the graft to the recipient site.


Evaluation of dexamethasone for reduction of postsurgical sequelae of third molar removal.

Sixty patients with bilaterally symmetrical impacted third molars participated in this double-blind, within-subject study to quantify the effects of 4 mg of dexamethasone on reducing postsurgical sequelae. Each patient's surgery was staged by mouth side and completed in two appointments 5 to 6 weeks apart. A preoperative dose of dexamethasone given intravenously was randomized to mouth side and surgical appointment; sterile water served as a control. Major areas assessed in this study were facial swelling, pain, and trismus. No difference in swelling and daily pain was noted. However, trismus and global pain were significantly affected by the steroid. Patients had a daily postsurgical increase in incisal opening of 4 to 6 mm over the control side during the examination period. Patients evaluated pain by choosing the least painful side. By a greater than 4:1 margin, patients chose the steroid side as the least painful side. No increase in the rate or type of complications was detected between control and steroid sides.


Soft-tissue cephalometric norms in Chinese adults with esthetic facial profiles.

Using a double selection process comprised of professional and lay judges, the cephalometric tracings on a final sample of 48 Chinese adults with esthetically pleasing profiles were analyzed. The soft-tissue cephalometric norms and standard deviations of two widely accepted soft-tissue analyses, the Legan and Burstone analysis and the Holdaway analysis, were determined. In comparison with white norms, the Chinese nose was less prominent (P < .01), the nasolabial angle was less obtuse (P < .01), both the upper and lower lips were more protrusive (P < .05), the upper lip curvature was greater (P < .01), and the soft-tissue chin thickness was less (P < .05). This variance between racial types emphasizes the need to recognize that soft-tissue lateral cephalometric norms are specific for the racial group and cannot always be applied across different racial types.


A model for osteoarthritis of the temporomandibular joint.

There is a need for a simple, reproducible animal model of advanced osteoarthritis of the temporomandibular joint (TMJ). In this study, gentle removal of the condylar articular layer in the sheep TMJ resulted in an eburnated condyle with peripheral osteophytes, thin or perforated discs, and temporal surface proliferation. This model can be used for both the study of osteoarthritis and the evaluation of therapeutic methods.


Growth of the mandible following replacement of the mandibular condyle with the sternal end of the clavicle: an experimental investigation in Macaca mulatta.

This study was designed to investigate the long-term effects of transplanted clavicles to the temporomandibular joint (TMJ) in juvenile monkeys. Sixteen juvenile female monkeys (Macaca mulatta) were used in this experiment. Eight animals were used as controls and were allowed to grow undisturbed for an 18-month period (group control). Eight animals were divided into two groups and underwent bilateral condylar excision via extraoral vertical ramus osteotomies. Four of these animals had their condylar segments removed and immediately replaced to serve as surgical controls (group condyle). The other four underwent condylar replacement with the sternal end of their clavicles (group SCJ). Standardized lateral cephalometric radiographs with the aid of tantalum bone markers were used to evaluate maxillary and mandibular growth. One-way analysis of variance (ANOVA) was used to determine the significance of differences between groups. All animals showed good mandibular function and a class I molar relationship following an 18-month evaluation period. Statistical analysis showed there was no significant difference in maxillary or mandibular growth between any of the three groups. The results of this investigation show that the sternal end of the clavicle may be a viable option in mandibular condylar transplant surgery.


Management of the oral and maxillofacial surgery patient with end-stage renal disease.

Chronic renal failure (CRF) is the consequence of a multitude of diseases that cause permanent destruction of the nephron. Concurrent with renal failure are a host of changes affecting the homeostatic functioning of the individual. This report outlines the pathophysiology of CRF and highlights its effects on surgical manipulation of the oral and maxillofacial region in this patient population. In addition, some of the common physical findings and alterations in blood chemistries frequently observed in these patients are discussed.


Chondrocytes in agarose culture synthesize a mechanically functional extracellular matrix.

The ability of chondrocytes from calf articular cartilage to synthesize and assemble a mechanically functional cartilage-like extracellular matrix was quantified in high cell density (approximately 10(7) cells/ml) agarose gel culture. The time evolution of chondrocyte proliferation, proteoglycan synthesis and loss to the media, and total deposition of glycosaminoglycan (GAG)-containing matrix within agarose gels was characterized during 10 weeks in culture. To assess whether the matrix deposited within the agarose gel was mechanically and electromechanically functional, we measured in parallel cultures the time evolution of dynamic mechanical stiffness and oscillatory streaming potential in uniaxial confined compression, and determined the intrinsic equilibrium modulus, hydraulic permeability, and electrokinetic coupling coefficient of the developing cultures. Biosynthetic rates were initially high, but by 1 month had fallen to a level similar to that found in the parent calf articular cartilage from which the cells were extracted. The majority of the newly synthesized proteoglycans remained in the gel. Histological sections showed matrix rich in proteoglycans and collagen fibrils developing around individual cells. The equilibrium modulus, dynamic stiffness, and oscillatory streaming potential rose to many times (>5x) their initial values at the start of the culture; the hydraulic permeability decreased to a fraction (approximately 1/10) that of the cell-laden porous agarose at the beginning of the culture. By day 35 of culture, DNA concentration (cell density), GAG concentration, stiffness, and streaming potential were all approximately 25% that of calf articular cartilage. The frequency dependence of the dynamic stiffness and potential was similar to that of calf articular cartilage. Together, these results suggested the formation of a mechanically functional matrix.


Subchondral damage after acute transarticular loading: an in vitro model of joint injury.

Intact canine metacarpophalangeal and metatarsophalangeal joints were subjected to a variety of loads in vitro. Intraarticular fracture occurred in 19 joints loaded to an average force of 2.4 +/- 0.4 kN with a corresponding loading rate of 88 +/- 23 kN/s. The remaining 29 joints were without gross evidence of fracture with an average load and loading rate of 1.7 +/- 0.9 kN and 64 +/- 32 kN/s, respectively. In the fractured specimens, damage to the zone of calcified cartilage and subchondral bone was much more extensive than was initially evident by gross inspection when assessed by scanning electron microscopy. Cracks with associated step-off displacement at the zone of calcified cartilage were found distant to the gross fractures. These findings were confirmed histologically. In addition, cracks localized to the zone of calcified cartilage were commonly identified histologically in specimens loaded in the range of 1.9-2.8 kN, but were not grossly fractured. The contact area determined with pressure-sensitive film increased with increasing load up to the point of fracture. The average pressure generated at the articular cartilage surface at the time of fracture in this model is > or = 40 MPa, and the fracture occurred at the contact site. Our findings suggest that failure in acute transarticular loading begins in the zone of calcified cartilage and subsequently involves the subchondral bone and overlying cartilage. This type of injury may contribute to the development of osteoarthritis after intraarticular fracture, or at high loads that do not result in gross fracture.


Identification of integrin cell-substratum adhesion receptors on cultured rat bone cells.

The interactions of bone cells with their extracellular matrix is of major importance in bone development, repair, and disease. We examined the ability of rat calvarial bone cells to adhere to various matrix proteins and to define the role of integrin cell-substrate adhesion receptors in these interactions. Isolated newborn rat calvarial bone cells prelabeled with 3H-thymidine and plated on plastic wells that had been precoated with serial dilutions of various substrates showed typical dose-response adherence curves to fibronectin, fibrinogen, laminin, vitronectin, and collagen I and IV. Cell adherence to poly-D-lysine, a nonspecific cell adherent, was high at all substrate concentrations > 0.0001 micrograms/ml. A polyclonal anti-rat integrin antibody blocked cell adhesion to all substrates tested except poly-D-lysine. Isolated rat calvarial bone cells were surface labeled with 125I, extracted, and immunoprecipitated with polyclonal antibodies made against the rat integrin complex and peptides derived from the cytoplasmic domains of the alpha 2, alpha 3, and alpha 5 subunits. Analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (nonreduced) identified four bands representing a mixture of integrins including the alpha 1 beta 1 laminin/collagen receptor, the alpha 5 beta 1 fibronectin receptor, and the alpha V beta 3 (or possibly alpha V beta 5) vitronectin receptor. These experiments show that bone cells adhere to a wide variety of extracellular matrix proteins via specific integrins. Increased knowledge about the regulation of these receptors and the mechanisms by which they transmit information to the cell will be important for a more complete understanding of bone physiology and pathophysiology.


Effect of short-term hypomagnesemia on the chemical and mechanical properties of rat bone.

Magnesium is known to have an essential role in determining the properties of bone, but the way in which Mg exerts its actions remains unclear. Although long-term Mg deficiency is known to produce osteopenia, the effects of short-term Mg deficiency have not been established. To test the hypothesis that Mg deficiency results in an altered pattern of initial mineralization and concomitant altered bone properties, the radiographic, histologic, chemical, and mechanical properties of the bones of rats given a Mg-deficient diet were compared to those of rats pair-fed the same diet supplemented with Mg. Short-term Mg-deficiency in the diet of growing rats produced a significant decrease in both the trabecular bone volume and the mineral content of the newly formed metaphysis, a significant increase in the Ca:P ratio, and a slight, but significant increase in hydroxyapatite crystallite size and/or perfection in the metaphysis. Comparable, but not significant, trends were found in the diaphyses. Metaphyseal bone osteocalcin levels were reduced in the Mg-deficient rats and lipid was more easily extracted from their bones. No detectable alterations in radiographic microstructure were noted. Mechanically, a significant decrease in the maximum three-point bend strength of the femurs of Mg-deficient rats was observed. These data support the hypothesis that short-term Mg deficiency affects the pattern of bone mineral formation.


Cast immobilization and tibial diaphyseal blood flow: an initial study.

The effect of cast immobilization on blood flow to the tibial diaphysis was studied by the microsphere method, both before and after casting of one hindlimb of adult New Zealand White rabbits. Preliminary studies were undertaken to investigate the possibility of the reduction of tibial flow by the microspheres used for the control measurements of blood flow. There were no significant differences in the flows to the tibial diaphysis or skeletal muscle between the immobilized and control limbs after either 1 or 2 weeks. This similarity between control and experimental limbs indicates that immobilization had no major effect on tibial blood flow over and above the systemic effects of the procedure.


Intraosseous infusion using the osteoport implant in the caprine tibia.

We evaluated the in vivo animal tolerance to intraosseous infusion via the Osteoport pediatric implant (model 2005PSO, Lifequest Medical, San Antonio, TX, U.S.A.) into the proximal tibia of immature goats and investigated the osseous effects of intermittent and sustained increases in intraosseous pressure (IOP). In group 1 (n = 3) autogenous whole blood was continuously infused (CI) for 5 days at flow rates producing an IOP of 30-45 mm Hg. Group 2 animals (n = 3) underwent a 5-s high-pressure infusion (HPI) of lactated Ringer solution (LRS) producing an IOP of 90-125 mm Hg twice daily for 10 days. In group 3, the Osteoports were left in place 5 (n = 2) or 10 days (n = 2) and evaluated for patency at 72-h intervals. An IOP > 35 mm Hg produced clinical evidence of bone pain. Bone mineral density was significantly increased (p < 0.05) in all implanted tibias (mean 1.04 g/cm2; range 0.87-1.21 g/cm2) compared with controls (mean 0.67 g/cm2; range 0.65-0.71 g/cm2). A nonsignificant increase (+9% to +31%) in periosteal new bone formation occurred in all implanted tibias. In the continuously infused group, there was a significant increase (p < 0.05) in cancellous new bone formation (+483%), percentage eroded bone surface (+143%), and osteoclast covered bone surface (+255%) compared with controls. HPI of LRS did not produce significant bone changes. Seemingly, the Osteoport provided a ready means of intraosseous infusion and may be associated with less complications than current methods of continual vascular access. Bone changes correlated more with the duration than the magnitude of increased intraosseous pressures.


Acute effect of traction, compression, and hip joint tamponade on blood flow of the femoral head: an experimental model.

Blood flow rates of the canine femoral head were experimentally determined during traction, compression, and hip joint tamponade using the hydrogen washout technique. In puppies, blood flow rate of the femoral head was significantly decreased with either traction or compression applied at one half body weight. Either maneuver, when combined with hip joint tamponade, reduced blood flow rate of the femoral head an average of more than 70% as compared with the initial control rate. In adult dogs, combinations of either traction or compression, at one-half body weight, with hip joint tamponade did not significantly decrease blood flow rate of the femoral head as compared with control values. Perfusion defect of blue silicone could be observed only in puppies around the hip during combinations of traction or compression with hip joint tamponade and involved the posterior superior capital branches of the medial circumflex artery and the arteries in the ligamentum teres. These experimental data may have important implications for the pathogenesis of iatrogenic avascular necrosis in the treatment of congenitally dislocated hip, Legg-Perthes disease, and avascular necrosis following nondisplaced femoral neck fracture.


Partial pressures of oxygen and carbon dioxide in bone and their correlation with bone-blood flow: effect of decreased arterial supply and venous congestion on intraosseous oxygen and carbon dioxide in an animal model.

Pathological changes in bone have been related to a preceding impediment of the arterial or venous bone circulation and hypoxia. In this study, we analyzed the feasibility of mass spectrometry in measuring intraosseous oxygen and carbon dioxide. The partial pressures were also measured in intraosseous blood samples, and blood flow in bone was measured with the radioactive microspheres technique. The average partial pressure of oxygen in the lateral femoral condyle was 34 +/- 1.6 mm Hg when measured in intraosseous blood samples and 36.3 +/- 2.3 mm Hg when measured with the on-line mass spectrometer, with significant correlation between the methods. The absolute value of the partial pressure of carbon dioxide measured in situ with mass spectrometry was correlated with the value in the withdrawn blood. There was no significant difference in partial pressures of oxygen and carbon dioxide between the two sides or between repetitive measurements. Arterial occlusion resulted in severe hypoxia, whereas more moderate changes followed venous occlusion.


Failure of perfusion with oxygenated Krebs-Ringer solution to preserve the eccrine function of the vascular endothelium in bone.

An ex vivo canine tibia preparation was perfused at a constant rate with aerated (95% O2-5% CO2) Krebs-Ringer solution for 24 h. Bolus injections of norepinephrine (0.125-0.5 micrograms) were given and then acetylcholine (5 x 10(-5) M) was used to stimulate endothelial production of smooth muscle relaxing factors. Following 1 h of perfusion the addition of acetylcholine resulted in significant attenuation of the response to norepinephrine (p < 0.001). After 4 h perfusion acetylcholine did not attenuate the norepinephrine response, but addition of L-arginine (the precursor of endothelial-derived relaxing factor) resulted in significant attenuation in the presence of acetylcholine (p < 0.005). At 6, 12, and 24 h the acetylcholine did not attenuate the norepinephrine response. It is concluded that normothermic, continuous perfusion with oxygenated Krebs-Ringer solution results in normal endothelial eccrine activity up to 1 h. Following this period there is substrate depletion but endothelial eccrine function can be demonstrated for up to 4 h. At 6 h this function cannot be demonstrated, suggesting degradation of the functional integrity of the endothelium.


A theory of fatigue damage accumulation and repair in cortical bone.

An analysis is presented of the balance between the accumulation and repair of fatigue damage in osteonal bone. Fatigue damage is defined in terms of cracks seen histologically when precautions are taken to avoid preparation artifact. The rate of occurrence of such damage is assumed to be proportional to the product of applied peak-to-peak stress, raised to a power, and the loading frequency. The rate of damage repair is assumed to be proportional to the activation rate for osteonal remodeling, and to the mean cross-sectional area of the resulting osteons. An additional factor is introduced to account for the possibility that damage provokes nearby remodeling. The theory is used to compare data from previous experiments of two types: fatigue-to-failure, and studies in which histologically observable cracks are made more numerous by repetitive loading. The analysis shows that there is a measure of agreement between the results of the two kinds of experiments, but the current data are too limited, and the results are too dependent on the mode of loading, to adequately test the theory. However, the analysis provides a framework for designing experiments to more efficiently clarify the relationships between fatigue failure, cracks seen in histologic sections, and the rate at which such cracks are repaired by osteonal remodeling.


Migration of porous coated acetabular prostheses fixed with screws: roentgen stereophotogrammetric analysis.

The fixation of screw-fixed, porous-coated acetabular prostheses was studied during 2 years in 21 patients (22 hips) using repeated roentgen stereophotogrammetric measurements. Migration of the center of the prostheses and/or tilting were recorded in five cups after 6 months. Two years after operation, migration was recorded in three, migration and rotation in six, and only rotation in three cups. Bone quality, prosthetic position, and immediate postoperative radiographic appearance of the prosthesis-bone interface did not correlate with the occurrence of migration. Narrow radiolucent zones had developed in half of the patients after 2 years and was associated with proximal migration. Micromovements of screw-fixed, press-fit cups seem to start later compared with previously presented results from cemented acetabular prosthesis.


Determination of bone mineral density by dual x-ray absorptiometry in patients with uncemented total hip arthroplasty.

Bone remodeling is an expected sequela with total hip arthroplasty (THA). Although there are several methods of estimating bone response in THA patients from radiographs, there are no accurate and generally accepted methods for quantitative determinations in vivo. In this study, we describe an application of dual x-ray absorptiometry (DXA) for measuring bone mineral content and bone mineral density in the proximal femur following THA. DXA is a noninvasive technique with minimal radiation exposure (< 5 mrem). Various aspects of measurement error (accuracy and reliability) of this application of DXA were determined in a series of studies reported here. Accuracy error (how similar are the measured and actual values) was < 1% determined in bone phantoms of four densities. Precision error (how reproducible are the measurements) was also < 1% at all four densities in the phantoms and was only slightly elevated (0.9-1.5%) in repeated measurements of implanted cadaver femora. Precision error in vivo, determined both from multiple replicates on five patients and from duplicate scans on 30 patients, was further elevated but remained < 5%. Contributions to precision error, rotation of the leg, and interoperator variability were assessed; none was found to elevate precision error appreciably. We suggest that DXA is a feasible method for quantifying bone response following THA, and will allow discrimination of small changes (> 5%) not previously measurable.


Effects of material properties of femoral hip components on bone remodeling.

Bone loss around femoral hip stems is one of the problems threatening the long-term fixation of uncemented stems. Many believe that this phenomenon is caused by reduced stresses in the bone (stress shielding). In the present study the mechanical consequences of different femoral stem materials were investigated using adaptive bone remodeling theory in combination with the finite element method. Bone-remodeling in the femur around the implant and interface stresses between bone and implant were investigated for fully bonded femoral stems. Cemented stems (cobalt-chrome or titanium alloy) caused less bone resorption and lower interface stresses than uncemented stems made from the same materials. The range of the bone resorption predicted in the simulation models was from 23% in the proximal medial cortex surrounding the cemented titanium alloy stem to 76% in the proximal medial cortex around the uncemented cobalt-chrome stem. Very little bone resorption was predicted around a flexible, uncemented "iso-elastic" stem, but the proximal interface stresses increased drastically relative to the stiffer uncemented stems composed of cobalt-chrome or titanium alloy. However, the proximal interface stress peak was reduced and shifted during the adaptive remodeling process. The latter was found particularly in the stiffer uncemented cobalt-chrome-molybdenum implant and less for the flexible iso-elastic implant.


Ligament tension pattern in the flexed knee in combined passive anterior translation and axial rotation.

Twenty-two fresh-frozen specimens were used to measure tensions generated in selected bands of the major ligaments of the flexed knee (40-90 degrees) when an axially prerotated tibia is subjected to passive anterior shear and when an anteriorly pretranslated tibia is subjected to passive axial torque. The tensions were measured using the buckle transducer attached to the anteromedial band of the anterior cruciate ligament [ACL (am)], the posterior fibers of the posterior cruciate ligament [PCL (pf)], the long fibers of the medial collateral ligament [MCL (lf)], and in the total lateral collateral ligament [LCL]. The knee specimens were subjected to the combined motions in a 6-df passive loading apparatus. The results indicated that the joint resistance to anterior translation increased markedly with internal prerotation and only marginally with external prerotation. This increase in joint resistance, however, was associated with a decrease in ACL function. It has been inferred that the posterior structures, capsular and meniscal, contribute significantly to joint resistance when the tibia is prerotated in either sense. For internal prerotation, the interference between the medial femoral condyle and the central tibial eminence was found to be an additional mechanism of resistance to anterior translation. Also, it has been found that although the ACL (am) tension increased with internal rotation in the normal case, it decreased with internal rotation in the presence of an anterior pretranslation. It is concluded that ACL response to combined joint motion cannot be ascertained by a simple summation of its responses to individual motions.


Biomechanical effect of a two-segment anterior cruciate ligament graft with separate femoral attachments and differing levels of prescribed load sharing.

The objective of this study was to analyze the biomechanical effect of varying the level of prescribed load sharing between two segments of an anterior cruciate ligament (ACL) graft, and of separating the femoral attachments of these segments. Total anterior-posterior (AP) laxity was measured using an instrumented spatial linkage. Forces in graft segments were measured using buckle transducers. The two-segment graft was formed using the middle third of the patellar tendon with bone blocks and a synthetic augmentation device. Proximal fixation was obtained using a fixture which allowed changing the individual locations of the femoral attachments of the tendon and augmentation segments. Distal fixation was achieved using a force-setting device which allowed the loads in each segment to be set to prescribed levels. Total graft force, load sharing, and total AP laxity were recorded during the application of 100-N AP tibial loads at 0 degrees, 30 degrees, 60 degrees, 90 degrees, and 110 degrees flexion, for various combinations of load sharing set at extension and locations of femoral attachment sites. The load sharing, total graft force, and AP laxity during AP loading at the five test flexion angles were not significantly affected by changing the prescribed level of load sharing set at extension for a given femoral attachment configuration. However, varying the separate hole locations of the graft segments for a given level of load sharing significantly affected load sharing, total graft force, and AP laxity. If the tendon graft was located posteriorly (on the medial surface of the lateral femoral condyle) and the augmentation segment proximally, the augmentation carried a greater portion of the total force in flexion. If the augmentation segment was changed to a more posterosuperior location and the tendon posteroinferior, the tendon carried a higher percentage of the total force in flexion. AP laxity in most reconstruction states was significantly greater than in the normal joint with an intact ACL. The nature of the load sharing between the graft segments under AP tibial load over the flexion range can be controlled by the appropriate choice of the segments' femoral attachment locations.


The correlation between anterior-posterior translation and cross-sectional area of anterior cruciate ligament reconstructions.

Total anterior-posterior translation is commonly used to assess the integrity of the cruciate ligaments and the success of reconstructive surgery. The purpose of this study was to determine, after surgical reconstruction of the anterior cruciate ligament with a biological graft, if total anterior-posterior translation correlated with graft length, cross-sectional area, or mechanical properties. These factors were investigated by analyzing data from three previous studies. These studies involved replacement of the anterior cruciate ligament in cynomolgus monkeys and goats, with free and vascularized patellar tendon autografts and both patellar tendon and anterior cruciate ligament allografts. Data were available at time periods of 6 and 12 months after surgery. We found statistically significant inverse correlations between the amount of anterior-posterior translation and cross-sectional area of a graft at the time of sacrifice. The Pearson correlation coefficients ranged from -0.966 (p < 0.002) to -0.830 (p < 0.05). We hypothesize that these correlations result from the following mechanism: the increased anterior translation reflects a slack graft; a slack graft is stress shielded by other structures about the knee; the reduced in vivo stresses on the graft modulate cellular metabolism in a way that over time produces a small cross-sectional area.


Histological and biochemical analysis of the fibrous tissue induced by implantation of synthetic ligament (Dacron): an experimental study in a rat model.

We conducted a comparative study to evaluate the quality and true nature of the fibrous tissue formed around synthetic grafts when used in ligament replacement. In one group of Lewis rats, a patellar ligament was replaced with a Dacron prosthesis; the comparison group received a tail tendon isograft. Two-, 4-, 8-, 12-, and 24-week comparisons showed histological and biochemical changes in the Dacron group alone that were consistent with foreign-body reaction. Specifically, the Dacron group showed infiltration by large numbers of macrophages and foreign-body, multinucleated giant cells. In addition, the capsule of fibrous tissue that developed around the Dacron ligaments was characterized by lower collagen solubility, a higher content of noncollagenous protein, and a higher proportion of type III collagen than that comprising the isografted tendons. The results of this study call into question the suitability of synthetics for ligament replacement.


Rigid immobilization alters matrix organization in the injured rat medial collateral ligament.

The effects of mobilization on matrix reorganization and density after ligament injury were studied in rat medial collateral ligaments using scanning electron microscopy (SEM). Both medial collateral ligaments of 14 Sprague-Dawley rats were sharply incised transversely at their midpoint. A 1.14-mm threaded Kirschner wire was driven through the tibia and into the femur of the right leg (through the knee) to immobilize that knee at 90 degrees of flexion. Four additional rats were used as controls. The right medial collateral ligament of the control rats was exposed in the same manner as the experimental rats and the wound closed without damaging the ligament. Rats were sacrificed on the 7th and 14th days postinjury and the ligaments evaluated by SEM. The electron micrographs from this study demonstrated that early on, the tissue at the injury site is disorganized on a gross scale with large bundles of poorly organized matrix. Large "defects" were present between bundles in the substance of the ligament and appeared as holes in the ligament around the injury site. As healing progressed, the matrix in the mobilized specimens appeared to bridge the injury site more rapidly and completely with fewer "defects" and thus higher density than the immobilized specimens.


Strains and forces in selected carpal ligaments during in vitro flexion and deviation movements of the hand.

The forces induced in tiny wrist joint ligaments must be estimated in order to understand their role in the mechanism of the joint. We estimated forces in a number of selected ligaments in seven human wrist joint specimens, using a noninvasive method. The method is based on the rationale that the force generated in a ligament depends on its change of length with the joint under load. In vitro length changes of the ligaments were determined during flexion and deviation movements of the hand, using a roentgenstereophotogrammetric analysis technique. Subsequently, bone-ligament-bone (BLB) preparations were dissected from the specimens. From these BLB preparations the zero-force length and the force-elongation relationship were determined in a material testing machine. The forces generated in the ligaments during flexion and deviation were calculated by combining results on the in vitro ligament length changes, the zero-force length, and the force-elongation relationship. Large interspecimen variations of the force patterns were found. Due to this variability, it is not possible to obtain quantitative models for the kinetic behavior of the ligaments. However, qualitative trends could be distilled from the strain and force patterns. It is clear that for most ligaments, the zero-force lengths were not equal to the lengths they possessed in the neutral position of the hand. Furthermore, it could be shown which motions of the hand would most likely strain a particular ligament. It could be shown that the variations in the force patterns originate mainly from variations in the zero-force lengths, and from variations in the force-strain relationship between specimens.(ABSTRACT TRUNCATED AT 250 WORDS)


In vitro hyperextension injuries in the human cadaveric cervical spine.

To investigate the relationship between the type of hyperextension injuries and the conditions producing them, nine cervical specimens (occiput to T1) were loaded to failure in tension at a fixed extension angle of 30 degrees. Under these loading conditions, specimens failed at average tensile loads and extension moments of 499 +/- 148 (SD) N and 4.0 +/- 3.1 Nm, respectively. Failure occurred at an average tensile displacement of 18.8 +/- 7.7 mm. The anterior longitudinal ligament ruptured and the intervertebral disc failed in at least one level in all specimens. In four specimens, the disc failed at an additional level, leaving the anterior longitudinal ligament intact at that site. With one exception, all injuries occurred in the lower cervical spine (C5-C6 and C6-C7), the region most often injured in vivo. The location of the injuries was associated with the degree of degeneration of the facet joints and the discs. The discs of the lower cervical spine were significantly more degenerated than those at the C2-C3 level. In addition, the degree of disc degeneration in the noninjured discs was significantly less than in the injured discs. These data help quantify the threshold of injury and the patterns of tissue damage resulting from hypertension loading of the cervical spine.


Forces and moments on the human leg in the frontal plane during static bipedal stance.

An experimental apparatus was assembled that permitted measurement of the vertical and lateral ground reaction forces as the hip is abducted, resulting in foot separations ranging from 0.25 to 71 cm, with the knee in 0 degree flexion. Twelve healthy volunteers (8 men and 4 women) were tested. The hip joint was located by means of center of rotation measurements on each subject's legs, and the location of the knee joint was determined using anatomical measurements. It was observed that the mediolateral force was nonzero and directed toward the body midline, even when the subject's feet were placed together. With the feet placed at shoulder width, the population mean mediolateral force was 3% of body weight. It was determined that simplifying assumptions based upon either "zero lateral force," or "zero hip moment," produced errors, when compared with our measured values, over various ranges of foot separation, with the zero hip moment assumption providing accuracy over a broader range. The inclination of the tibial plateau, with respect to the long axis of the tibia, that would produce minimal mediolateral shear at the knee is presented. Research and clinical applications of our results and techniques are discussed.


Physiological cross-sectional area of human leg muscles based on magnetic resonance imaging.

Magnetic resonance imaging techniques were used to determine the physiological cross-sectional areas (PCSAs) of the major muscles or muscle groups of the lower leg. For 12 healthy subjects, the boundaries of each muscle or muscle group were digitized from images taken at 1-cm intervals along the length of the leg. Muscle volumes were calculated from the summation of each anatomical CSA (ACSA) and the distance between each section. Muscle length was determined as the distance between the most proximal and distal images in which the muscle was visible. The PCSA of each muscle was calculated as muscle volume times the cosine of the angle of fiber pinnation divided by fiber length, where published fiber length:muscle length ratios were used to estimate fiber lengths. The mean volumes of the major plantarflexors were 489, 245, and 140 cm3 for the soleus and medial (MG) and lateral (LG) heads of the gastrocnemius. The mean PCSA of the soleus was 230 cm2, about three and eight times larger than the MG (68 cm2) and LG (28 cm2), respectively. These PCSA values were eight (soleus), four (MG), and three (LG) times larger than their respective maximum ACSA. The major dorsiflexor, the tibialis anterior (TA), had a muscle volume of 143 cm2, a PCSA of 19 cm2, and an ACSA of 9 cm2. With the exception of the soleus, the mean fiber length of all subjects was closely related to muscle volume across muscles. The soleus fibers were unusually short relative to the muscle volume, thus potentiating its force potential.(ABSTRACT TRUNCATED AT 250 WORDS)


[High speed cinematographic analysis of subglottal mucosal vibration during experimentally induced phonation in excised larynges].

Twenty-seven excised canine larynges and two excised human larynges fixed on a wall of a specially constructed glass box, were blown on and the subglottal mucosal vibrations were photographed using high speed cinematography from the tracheal side. Each film was repeatedly projected at normal speed and analyzed frame by frame. Mucosal upheaval appeared between the anterior commissure and the vocal process. The mucosal wave or "traveling wave" started from the mucosal upheaval and propagated medially and upward. The mucosal upheaval vibrated with a small amplitude and with an earlier phase than any other portion of the vocal fold. Increase of air flow resulted in increased amplitude of the free edge excursion. The mucosal upheaval seemed to shift more laterally after the increase of air flow. But judging from the positional relations between the mucosal upheaval and markers, the origin of the mucosal upheaval was the same despite the increase of air flow. After the increase of vocal fold tension by cricothyroid approximation, the mucosal wave occurred within the limited area near the vocal edge. The mucosal upheaval was located more medially as compared to the original position. The mucosal upheaval appeared on what was actually the superior portion of the vocal fold. Direct electrical stimulation of the thyroarytenoid muscle (TA) bulged the lower surface of the vocal fold medially, and narrowed the subglottic area surrounded by bilateral mucosal upheavals during vibration. The mucosal upheaval seemed to shift more medially after stimulation of TA, but combined with the movements of the marker, the mucosal upheaval appeared on a more inferior portion of the vocal fold compared to its position before the stimulation. Thus, a more dynamic mucosal wave appeared in the vertical direction. Histological examination revealed that the mucosal upheaval arose on the lower surface of the vocal fold, slightly above the area where the muscular layer came close to the epithelial layer. After the cricothyroid approximation, the mucosal upheaval occurred in a more upward area where the lamina propria was thicker. In addition, after stimulation of the TA, the mucosal upheaval was located in the area where the muscular layer was thick under the epithelial layer.


[Reflex control of laryngeal functions in the cat: the effect of vibratory stimuli of the laryngeal mucosa on the laryngeal reflex].

To investigate the effect of vibratory stimuli of the subglottic mucosa on the laryngeal reflex, experiments were performed on cats anesthetized with intraperitoneal injection of a mixture of urethane and chloralose. The external branch of the superior laryngeal nerve was cut, while the internal branch of the superior laryngeal nerve (ISLN) was mounted on stimulating electrodes. Electromyograms (EMG) were recorded from the contralateral thyreoarytenoid (TA), posterior cricoarytenoid (PCA), lateral cricoarytenoid (LCA), and cricothyreoid (CT) muscles. When the ISLN was electrically stimulated, the laryngeal reflex was induced. Short latency (early) and long latency (late) responses were observed in TA, PCA, LCA, and CT. Then, vibratory stimuli were applied to the surface of the subglottic mucosa. Vibratory frequencies used in this study were varied stepwise from 100 Hz to 400 Hz, with the amplitude adjusted at 20 microns. Vibratory stimuli had no effect on early responses but did, however, exert a facilitatory effect on late responses of TA and LCA in the transitional phase from inspiration to expiration and on late responses of PCA in the inspiratory phase. After denervation of ISLN, the vibratory effect on late responses disappeared completely. No significant vibratory effect was observed on CT in any respiratory phase. These results suggest that vibratory stimuli applied to the surface of the subglottic mucosa reflexively facilitate the laryngeal reflex and that ISLN afferents and respiratory drive modulate the laryngeal reflex.


[Histological study of mucous membranes in the human nasal septum].

Histological changes in the mucous membrane of the human nasal septum in relation to deviation of the septum were investigated in this study. The mucous membranes of both the concave and convex sides of the deviated septum, were separately studied in 16 parts of the septum, which had been divided 5 ways in the anterior-posterior direction and 4 ways from top to bottom in the vertical direction. Changes in the mucosa were also studied according to differences in age and gender. Specimens for this study were collected from 74 cadavers, including the autopsied cases of 44 males and 30 females, ranging in age from a prenatal stage of 22 weeks up to 84 years, from which cases with other nasal or paranasal diseases were excluded. The mucosa of the concave side consistently showed hypertrophic change in the height of the subepithelial mucosa, the area of mucous glands and the thickness of the muco-periosteum in each slice. This was assumed to be a finding influenced by prolonged septal deviation. Atrophy of the mucous epithelium and metaplasia into the squamous cell epithelium were frequently found in the middle portion and the population of goblet cells in the epithelium was increased predominantly in the slice from the posterior and bottom portions. The heights of the mucous epithelium and subepithelial mucosa were lower and the population of goblet cells decreased in relation to aging. However, atrophy of the mucous epithelium and increased thickness of the muco-periosteal layer predominated in the aged subjects. Sexual difference was revealed in findings of the height of the mucous epithelium, glandular area and thickness of the muco-periosteum on the concave side of the septum. The height of the mucous epithelium was higher in females but the glandular area and thickness of the muco-periosteum was much more increased in males.


[Difference between horizontal enlargement and vertical enlargement of the internal auditory meatus in acoustic neuroma].

Twenty-one patients with acoustic neuroma were investigated. The vertical diameter of the internal auditory meatus was measured by polytomography, the horizontal by target imaging CT. The ratio of the abnormal side to the normal side was calculated in each dimension. Two dimensional ratios were compared with each other in order to investigate the difference between horizontal and vertical enlargement of the internal auditory meatus. The results were as follows: 1) Horizontal enlargement of the internal auditory meatus was greater than that of the vertical one in 15 cases (75%). Vertical enlargement was greater in 6 cases but the difference between the two dimensions was not significant. 2) With horizontal enlargement, the posterior wall of the internal auditory meatus was more extended or destroyed than that of anterior wall. 3) With enlargement of the posterior wall, the bony eminence forming the inner side of the porus was predominantly extended or destroyed in every case.


[Three-dimensional analysis of arteriography in human posterior circulation (preliminary report)].

In earlier articles it was suggested that there is a relation between vertigo and the posterior circulation. This study was designed to ascertain the course of the branches of the vertebral artery and the basilar artery, as well as the principal blood vessels of the vestibular nucleus by using radiographic three-dimensional observation. We studied 27 human brains (17 males, 10 females) fixed with the arterial embalming method at the Department of Anatomy of Kawasaki Medical School. The results were as follows: 1. Many variations in the course of the anterior inferior cerebellar artery and the posterior inferior cerebellar artery were observed, but the most frequent pattern, observed in 56% of our subjects, was the anterior inferior cerebellar arteries originating from the basilar artery and the posterior inferior cerebellar arteries from the vertebral artery. 2. Measurement of the inside diameter of both vertebral arteries showed the diameter of the left side to be thicker than that of the right side. 3. Perforating branches in the brain stem consisted of the pontine branches from the basilar artery and small branches from the anterior inferior cerebellar artery. Moreover, the transverse section showed a large number of them to originate from the ventral part of the brain stem.


[Upper and lower airway diseases in children with persistent cough].

Persistent cough is a frequent and frustrating problem in the pediatric field. One hundred and seventy two children presenting with persistent cough for longer than 2 weeks were evaluated by both otolaryngologists and pediatricians. One hundred and twenty nine cases (75%) were found to have lower airway diseases, of which bronchial asthma, bronchitis and pneumonia, in that order, were the most common. One hundred and forty two cases (82%) had sinusitis, in 34 cases of which no causative diseases except sinusitis were found to be responsible for the persistent cough. Sinusitis was found in 90% of patients with pneumonia, 81% of those with bronchitis and 65% of those with poorly controlled asthma cases. These results revealed that sinusitis is an important causative factor for persistent cough in children. All the patients with pneumonia and bronchitis were cured by antibiotic administration for 2 weeks, whereas conservative treatment of sinusitis for as long as 6 months was less satisfactory resulting in only 60% cure, 18% improvement and 22% without improvement. In cases with sinusitis and lower airway diseases, continuous treatment for sinusitis is necessary even after treatment of the lower airway diseases has been completed.


[Two cases of paranasal sinusitis with choanal polyp in children].

Patients with choanal polyp often suffer from maxillary sinusitis of the same side. Hence, Caldwell-Luc operation in addition to polypectomy has been recommended for the treatment of choanal polyp. Choanal polyp occurs more frequently in children with nasal polyp(s) than in adults with nasal polyp(s). For this reason, it is preferable to perform surgery so as to preserve the maxillary sinus as much as possible. The authors surgically treated two children with choanal polyp. A 12-year-old girl had a choanal polyp arising from the posterior portion of the middle turbinate and received an osteoplastic maxillary operation and functional endoscopic sinus surgery (FESS). The other, a 13-year-old girl, with an antro-choanal polyp underwent FESS only. One year after surgery, both patients showed no recurrence of polyp and had recovered an aerated maxillary sinus cavity covered with normal mucous membrane. Based on the experiences of these two cases, FESS appears to be very helpful in treating children with choanal polyp and paranasal sinusitis.


[Bacteriology of infectious disease in otorhinolaryngology (1). Bacteriological study of paranasal cyst].

The bacteriology of chronic sinusitis has been reported in several studies, but there have been few bacteriological studies on paranasal cyst. Also, details of the techniques of transportation and processing of clinical specimens have only rarely been described. Therefore, this study was undertaken with attention to the above, and to obtain information on appropriate antimicrobial therapy, we conducted a dilution antimicrobial susceptibility test of isolates. Fifteen patients with paranasal cyst participated in this study. Their lesions were frontal sinus (3), ethmoid sinus (2), sphenoid sinus (2) and maxillary sinus (8). We punctured the cyst using an 18-gauge needle attached to a syringe at the time of operation, and paranasal cyst effusions were promptly transported to the laboratory. The specimen was immediately inoculated under a set of aerobic and prereduced anaerobic plates, which were incubated in appropriate conditions. Most specimens were completely processed within one hour. Antimicrobial susceptibility testing of isolates was done with MIC panel by the Sceptor system. Positive results of bacterial cultures were found in 60% of all cases (all of the frontal sinus specimens and half of those with other lesions). A total of 38 bacteria, including 24 anaerobic and 14 aerobic species, were isolated from 9 paranasal cysts, yielding an average of 4.2 species per positive case (2.9 anaerobes and 1.3 aerobes). Monomicrobial flora were found, anaerobes only in 2 cases and aerobes only in 2 others. Mixed flora were found in 5 cases in which both anaerobes and aerobes were isolated. The bacterial concentration in the maximal case was 4.9 x 10(4) CFU/ml. The organisms most frequently isolated were Propionibacterium spp. (7), Peptostreptococcus spp. (7), Staphylococcus spp. (7), Prevotella spp. (5) and Streptococcus spp. (4). On the basis of the results of antimicrobial susceptibility testing of isolates in vitro, the use of Cephems, Clavulanic acid/Amoxicillin, Norfloxacin and Chloramphenicol proved to be clinically effective.


[Nuclear DNA pattern of thyroid tumor].

The nuclear DNA contents of 50 thyroid tumors were measured paraffin block samples and needle biopsies by using microscopic photometry, and the diagnostic value of this measurement was examined. Thyroid tumors included 17 papillary carcinomas, 15 follicular carcinomas and 18 benign tumors. The results confirmed the possibility of discriminating between benign and malignant tumors except in cases of follicular carcinoma with minimal invasion. This method seemed to be most valuable in the diagnosis of cases with class III FNA. A review was made of the relation between DNA content and prognostic factors, for example the degree of invasiveness of the thyroid tumor, intra-tracheal invasion, intra-thyroid metastasis and lymphatic metastasis. DNA content was increased only in cases with intra-tracheal invasion.


[Ultrasonic study on tissues of parotid tumors--measurement of attenuation of ultrasound within tumors in vivo].

Pulse transmission technique has been used and developed in the Department of Otorhinolaryngology, Chiba University, in order to estimate attenuation of ultrasound within tumors of the parotid gland in vitro. A new apparatus to measure the attenuated ultrasound within the tissue was devised by using a pulse reflection method. After the measurement in vivo, the same examination was performed in a specimen of the removed tumor in vitro after surgery. Correlation between the characteristic of attenuation of ultrasound within the tissue in vivo and in vitro was investigated. The results in malignant parotid tumors were compared with ones in benign tumors of the parotid gland, too. The measurement of attenuation of ultrasound within a tumor in vivo was also compared with regard to the posterior echoes in ultrasound imaging, and then pathohistological study of the tumor was carried out in each case. The results of this study were summarized as follows: 1) Characteristics of ultrasound-attenuation within tumors in vivo were well correlated with ones in vitro. 2) Attenuation of ultrasound in malignant tumors tended to be stronger than that in benign ones. 3) Values of ultrasound-attenuation within tissues in vivo were also affected by the contents of collagen in them, which was reported in my previous study on tissues in vitro. 4) Posterior echoes in ultrasound imagings were influenced by attenuations of ultrasound in tissues. However, the measurement of attenuation of ultrasound in tumors of the parotid gland is assumed to be helpful to promote the diagnostic value of sonographical examinations, and especially it would be useful for differential diagnosis of malignancies.


[Exostosis of the external auditory canal and sensorineural hearing loss in professional divers].

Audiometric survey and endoscopic study of the external auditory canal were performed on a group of 31 professional divers, all of whom had experienced frequent exposure to dysbaric conditions. The results are as follows. 1) Over 40% had exostosis of the external auditory canal. There was no relationship between the incidence of the exostosis and the length of their occupational career as a diver. Many of the divers had hearing loss whether they had exostosis or not. 2) Over 70% had sensorineural hearing loss, taking into account hearing loss due to aging. Most had no experience of inner ear barotrauma on descent, causing sudden a shift in hearing threshold. Deafness was related to the length of their occupational career as a diver. In conclusion, we speculate that repetitive small changes in barometric pressure on the outer ear influences the pressure on the middle ear and further on that of the perilymph, finally damaging the inner ear auditory system.


[A report of two cases of cervical necrotizing soft-tissue infection].

Two recent cases of cervical necrotizing soft-tissue infection are herein presented. Case 1. A 52-year-old man with uncontrolled diabetes was hospitalized because of an erythematous swelling of the left side of his neck and high grade fever. Fetid yellowish pus exuded from the left parotid area. The swelling extended from the left temporal area to the left supraclavicular fossa, with necrosis of the parotid gland, sternocleidomastoid, masseter and a portion of the strap muscles. Wound cultures revealed Staphylococcus aureus and alpha-hemolytic streptococcus. No anaerobic bacteria were detected. Treatment consisted of intravenous administration of antibiotics, control of diabetes with insulin, and debridement of the necrotic tissue, which left an epidermal defect in the initially swollen area. Transfer of a forearm free flap was done after the growth of healthy granulation tissue over the affected area. Case 2. A 55-year-old woman with rheumatoid arthritis was transferred to our hospital after tracheotomy performed in another hospital because of dyspnea due to severe crepitant swelling of her cheeks and submandibular areas bilaterally, and her left temporal area. A copious amount of fetid pus exuded from the incisions made in the left temporal area, left cheek, and right submandibular area. There were bilateral diffuse rales. Culturing the pus revealed alpha-hemolytic streptococci, while MRSA and Pseudomonas aeruginosa were detected from cultures of sputum. No anaerobic bacteria were found. After intravenous administration of antibiotics, infected wounds and pneumonia were ameliorated, and necrotic subcutaneous tissue and fascia were debrided. The patient was discharged with a residual depression in her left cheek and a scar on her left temporal area.


[Clinical application of the smell identification test].

Clinical application of the standardized "scratch and sniff" olfactory test in Japanese is described. Over 300 subjects participated in three experiments. In experiment 1, 29 odorants used in the smell identification test were rated as to their experiences. The ratios of the experiences in each combination of odorants were compared. In experiment 2, the test was applied to normal subjects. Average test scores decreased as a function of age, with the greatest decline occurring between the sixth and tenth decades of life. In experiment 3, the test was shown to differentiate between subjects with olfactory disorders and normal controls. This self-administered test now makes it possible to rapidly and accurately assess general olfactory function in the laboratory, clinic, or through the mail without complex equipment or space consuming stores of chemicals.


[Vocal function in Reinke's edema--degree of the lesion and indication of the operation].

Fifty three cases of Reinke's edema were classified into 3 groups according to Yonekawa's proposed classification. Of these cases, 14 were Type I, 22 were Type II and 17 were Type III. In each case, psychoacoustic evaluation using the "GRBAS" scale and phonatory function tests (fundamental frequency, air flow rate, sound pressure level and maximum phonation time) using Nagashima PS-77 phonatory function analyzer were performed. Psychoacoustically, the voice quality before surgery was estimated moderately impaired, in general, with high grade Roughness accompanied by Asthenisity and Strainedness. Cases with more severe lesions showed much worse psychoacoustic evaluation results and severely impaired phonatoy function, but they also showed greater improvement after surgery. Phonatory function improved significantly within a month and psychoacoustic evaluation improved significantly from 1 to 3 months after surgery, though neither returned to the normal range. In conclusion, we consider that surgical therapy is appropriate in Type II and III cases, with voice therapy and cessation of smoking also necessary for good recovery.


[Progressing cases from low tone sudden deafness to Menière's disease--cochlear impairment in the so-called pre-Menière's disease period].

Among 80 patients with low tone sudden deafness (LTSD) who visited our department over the past 15 years, there were 6 cases (7.5%) who subsequently progressed to Menière's disease. The clinical and audiological processes of the 6 patients were studied in detail and the following results were obtained. (1) In these 6 patients, the time between onset of LTSD and the diagnosis of Menière's disease ranged from 4 months at the shortest to 6 years and 8 months at the longest, 2 years and 9 months on average. (2) Two pattern types were seen in the change from LTSD to Menière's disease: changing within a short period of time after recurrence of an LTSD-like attack, and changing after more than one year without recurrent attack. (3) The monoattack-nonrecovered type of LTSD and the recurrent type of LTSD within three months after the onset (short-term prognosis) frequently progressed to Menière's disease. (4) There were no close relationships between subjective symptoms and audiological features in the pre-Menière's disease period (from the onset of LTSD to the recurrence of vertigo with cochlear symptoms). (5) The 6 patients showed various audiogram shapes at the time of progression to Meniere's disease; 3 cases with the slightly rising type, 1 with the high frequency-impaired type, and 2 with the moderate, gradual and flat type. (6) Of the 6 patients, 3 had good hearing during long term observation. At least 2 patients seemed to have the mild type of Menière's disease.(ABSTRACT TRUNCATED AT 250 WORDS)


[The effects of early manual instruction on the oral language development of two deaf children].

The speech and language training for deaf children at our clinic is performed using a multisensory method, which consists of reception and expression training for sign language and fingerspelling as well as auditory training, lip reading, and written language training (the Kanazawa Method). We have already reported that acquisition of written language is not dependent on oral language, and that written language is easier to learn than oral language for deaf children. In the present investigation, we analyzed the acquisition of comprehensible and expressive vocabulary in sign language and fingerspelling. The subjects were two children congenitally deaf at levels higher than 105dB. Recorded language samples by the age of 48 months were analyzed. Acquisition of sign language was found to be significantly easier than acquisition of oral language. The development of expressive noun words, function words, and Wh-question words in sign language at the early period was almost equivalent to that of hearing peers, and then the sign language appeared transfer to the oral language. These results suggest that early presentation of sign language with written and oral language is effective in the acquisition of communicative attitudes, function words and interrogative sentences which are most difficult for the hearing-impaired. It was shown that early presentation of sign language with written and oral language serves to promote acquisition of oral language.


[A comparison of time resolution among auditory, tactile and promontory electrical stimulation--superiority of cochlear implants as human communication aids].

Our previous reports showed that second formant information, using a speech coding method, could be transmitted through an electrode on the promontory. However, second formant information can also be transmitted by tactile stimulation. Therefore, to find out whether electrical stimulation of the auditory nerve would be superior to tactile stimulation for our speech coding method, the time resolutions of the two modes of stimulation were compared. The results showed that the time resolution of electrical promontory stimulation was three times better than the time resolution of tactile stimulation of the finger. This indicates that electrical stimulation of the auditory nerve is much better for our speech coding method than tactile stimulation of the finger.


[Intracochlear electrical stimulation of the auditory nerve in deaf kittens--brainstem response audiometric and histopathologic studies].

The effects of long-term electrical stimulation of the auditory nerve on the morphology of the cochlear nucleus were investigated in young pharmacologically deafened kittens. Comparing the amplitude of EABR with the soma area, there was a strong positive correlation between the amplitude of EABR and the soma area of neurons within the anterior ventral cochlear nucleus on the stimulated side. However, there was no correlation between the amplitude of EABR and the soma area of neurons within the unstimulated anterior ventral cochlear nucleus. In addition, there was no correlation between the amplitude of EABR and the survival rate of spiral ganglion cells. This showed that EABR may be affected not only by the survival rate of the spiral ganglion cell, but also by the development of the central auditory nervous system in kittens, which were deafened under the development of the central auditory nervous system.


[Treatment of tinnitus with intravenous lidocaine].

Intravenous lidocaine was administered in 155 cases (196 ears) with tinnitus. The injection of lidocaine, at a dose of 60 mg in men and 40 mg in women was repeated five times. The intensity of tinnitus was evaluated along a scale ranging from 0 to 10, indicating the level prior to injection. A scale ranging from 0 to 7 was estimated to be effective. After evaluation of the drug by using a double-blind test, indications for therapy were analyzed statistically according to clinical characteristics. The results obtained were as follows: 1) The effect was confirmed by using a double-blind test. 2) The effective rate was 60.2%. 3) Older cases, especially with presbyacusis, had the best indications for therapy. 4) From the clinical viewpoint of the characteristics of tinnitus, cases with hearing levels above 40dB or with dull onomatopoeic sounds were considered to have better indications for therapy. 5) None of the side effects experienced were severe, and all were transient.


[Clinical study on the mechanism of motion sickness--clinical examination based on trigger factors].

This report deals with factors which trigger motion sickness. The author has focused on the clinical examinations applied to motion sickness cases. Relationships between clinical data and susceptibility to motion sickness were investigated. The following results were obtained: 1. CV R-R(coefficient of variation of R-R intervals on EGG)in the frequent motion sickness group showed higher values than in the occasional motion sickness group. This result suggests a hyperfunction of the vagus nerve. 2. In caloric testing with ENG, the motion sickness group showed lower values of duration and eye speed than the occasional motion sickness group. On the other hand, the frequent group showed higher values of laterality in eye speed than the occasional group. 3. With the visual suppression test, the frequent motion sickness group showed higher values than the occasional motion sickness group. On the other hand, there was a significant difference between the frequent motion sickness group and the occasional motion sickness group in terms of laterality of visual suppression values. 4. In testing fluctuation of CV R-R in response to optokinetic stimuli, the frequent motion sickness group showed elevation of CV R-R values after optokinetic load. On the other hand, the occasional motion sickness group showed depression of CV R-R values after the same load. 5. Among clinical examinations designed to diagnose susceptibility to motion sickness, CV R-R, the caloric test, the visual suppression test and OKP testing can produce sufficiently accurate results for clinical investigation.


[The vertical component in a caloric nystagmus and the existence of a second phase of the nystagmus--the possibility of canal otolithic interaction in normal subjects].

To clarify the existence of the vertical component during a caloric nystagmus and the existence of a second phase of the nystagmus, 194 induced incidents of a caloric nystagmus in 29 normal subjects have been analyzed. Each nystagmus episode was recorded by using ENG and an infra-red video camera. The caloric stimuli were given by pouring 5 ml of water at 20 degrees C into the ear at an ear-up position. After irrigation, each subject then assumed a supine or a prone position, with the head bent 30 degrees forward in either position. All recordings contained vertical components that depended on the supine or prone head position and not on the side of the stimulated ear, i.e., an up-beating nystagmus resulted in the supine position and a down-beating nystagmus in the prone position. Further, the vertical component was far stronger in the prone position. In contrast, the horizontal component had larger velocities and was of longer duration in the supine position than in the prone position. When the first phase of the caloric nystagmus ended, the body position was changed 90 degrees, i.e., to a sitting position or a right-ear-down or left-ear-down position. All trials showed a horizontal component during the secondary phase when the head assumed the sitting position. As for the ear-down positions, only when the irrigated ear was moved upwards from the prone position during the secondary phase, an up-beating vertical nystagmus resulted in almost all the trials. These findings suggest that a caloric nystagmus may originate not only from the lateral semicircular canal but also from the vertical canals, and the second phase of a caloric nystagmus may be strongly influenced by the otolithic organs.


[Immunohistochemical detection of glutathione S-transferase (GST) -pi in head and neck carcinoma and its changes by radiotherapy].

It is well known that the "placental form of glutathione S-transferase" (GST-pi) is present in high concentrations in most human carcinomas. However, its expression in head and neck carcinomas have not yet been reported. The author investigated the expression of GST-pi in the tissue of pharyngeal and laryngeal carcinomas by the immunohistochemical procedure, and the following results were obtained: 1) GST-pi was positive in 80% of laryngeal carcinomas (35 cases) and 52.8% of pharyngeal carcinomas (36 cases). As a rule, well differentiated squamous cell carcinomas showed stronger expression of GST-pi than poorly differentiated squamous cell carcinomas. 2) Although normal epithelia of the pharynx and larynx showed negative GST-pi, it should be noticed that 54.6% of precancerous epithelia (11 cases) showed positive GST-pi. 3) Most patients treated with radiotherapy showed the diminution of GST-pi expression after the irradiation. However, co-relation between the strength of initial GST-pi expression and the effectiveness of radiotherapy was not observed (p < 0.01).


Sensitive enzyme immunoassay (immune complex transfer enzyme immunoassay) for (anti-human T-cell leukemia virus type I) IgG in serum using a synthetic peptide, Cys-env gp46(188-224), as antigen.

A sensitive enzyme immunoassay (immune complex transfer enzyme immunoassay) for (anti-human T-cell leukemia virus type I) IgG (anti-HTLV-I IgG) in serum using a synthetic peptide, Cys-env gp46(188-224) of HTLV-I, is described. Anti-HTLV-I IgG in test serum, which had been incubated with excess of inactive beta-D-galactosidase to eliminate interference by anti-beta-D-galactosidase antibodies, was reacted simultaneously with 2,4-dinitrophenyl-bovine serum albumin-Cys-env gp46 (188-224) conjugate and Cys-env gp46 (188-224)-beta-D-galactosidase conjugate. The complex formed consisting of the three components was trapped onto polystyrene balls coated with affinity-purified (anti-2,4-dinitrophenyl group) IgG. After washing to eliminate nonspecific IgG in the test serum and excess of the beta-D-galactosidase conjugate, the complex was eluted from the polystyrene balls with epsilon N-2,4-dinitrophenyl-L-lysine and transferred to polystyrene balls coated with affinity-purified (anti-human IgG gamma-chain) IgG. beta-D-Galactosidase activity bound to the (anti-human IgG gamma-chain) IgG-coated polystyrene balls was assayed by fluorometry. This assay was more sensitive and useful than the immune complex transfer enzyme immunoassay using Cys-Arg-env gp46(188-209) and other methods using HTLV-I as antigen.


A monoclonal antibody-based immunoassay for detecting tetrodotoxin in biological samples.

Spleen cells from mice hyperimmunized with a keyhole limpet hemocyanin-tetrodotoxin-formaldehyde conjugate were fused with murine P3X63Ag8.653 myeloma cells. A single hybridoma clone was identified that secretes an IgG1,k monoclonal antibody (MAb), designated T20G10, against tetrodotoxin (TTX), with an estimated affinity of 1.2 x 10(8) L/M. Competitive inhibition enzyme immunoassays (CIEIAs) for detecting TTX were developed using this MAb. A direct CIEIA using alkaline phosphatase-labeled MAb detected TTX with sensitivities at IC50 and IC20 of 6-7 ng/ml and 2-3 ng/ml, respectively. The accuracy of the direct CIEIA was comparable with the high-performance liquid chromatography (HPLC) and the mouse bioassay systems, but the direct CIEIA exhibited greater sensitivity. The direct CIEIA was also more cost effective, as it required less sample preparation, a shorter assay time, and reduced investment in equipment than either of the other assay systems.


New developments in clinical laboratory molecular assays.

The new technological advances influencing the clinical laboratory are discussed with immediate and future areas of new clinical laboratory tests. The new technological advances include 1) monoclonal and designer antibodies, 2) solid phase and homogeneous automated immunochemical assays, 3) DNA/RNA nucleotide tests, 4) synthetic peptides, and 5) biosensors. The major factors which influence the need for future laboratory tests are 1) technology, 2) advances in therapeutic agents, 3) governmental regulations, and 4) health care economics.


Laboratory diagnosis of parvovirus B19 infection.

The sensitivity and application of the polymerase chain reaction (PCR) for the diagnosis of parvovirus B19 (B19) infection was investigated by simultaneously assaying a collection of 279 consecutively received samples for presence of anti-B19 IgM and IgG antibodies by Western blot and for B19 DNA by PCR and dot-blot hybridization (dot-blot); samples were sera from patients with suspected B19 infection. PCR and dot-blot detected B19 DNA in 9% (16/179) and 1% (2/179), respectively of Ab-positive samples (IgM+/IgG-, IgM+IgG+, IgM-IgG+), and in 28% (15/54) and 2% (1/54), respectively, of IgM+ samples. PCR also detected B19 DNA in 2% (2/100) of IgM-/IgG- samples, both of which had normal total IgG and IgM levels. PCR is of unique value because it permits diagnosis of B19 infection even in the absence of specific acute phase (IgM) and in the presence or absence of convalescent-phase (IgG) Ab.


Development of a rapid microparticle-enhanced nephelometric immunoassay for serum myoglobin in acute myocardial infarction.

A microparticle-enhanced nephelometric immunoassay was developed for myoglobin quantitation in human serum. It uses rabbit antimyoglobin serum and hydrophilic polyacrylic microparticles covalently coated with baboon myoglobin in a competitive immunoagglutination system. The level of microparticle agglutination is assessed with a specially designed nephelometer. This sensitive (45 ng/ml of myoglobin detected in serum) and accurate (coefficients of variation from 3.0% to 8.2% in precision study and linear recovery of myoglobin in overloaded sera) immunoassay was evaluated with human sera from patients suffering from acute myocardial infarction. Myoglobin levels in patient's serum on admission appeared to be correlated with clinical and biological parameters assessed in emergency wards and later. This new, rapid, and easy microparticle-enhanced nephelometric immunoassay could thus be useful in emergency conditions for the early quantitation of serum myoglobin.


Enzyme-linked immunosorbent assay to measure apolipoproteins AI and B secreted by a human hepatic carcinoma cell line (Hep G2).

We describe an enzyme-linked immunosorbent assay (ELISA) to measure apolipoproteins AI and B secreted by Hep G2 cells and in cell homogenates. These assays utilize commercially available polyclonal antibodies, affinity-purified to improve their specificity, thereby achieving a dramatic increase in the sensitivity of the assay. These affinity-purified antibodies were also more sensitive than a series of monoclonal antibodies tested. We achieved a sensitivity of 0.4 ng in the apo AI assay, and a sensitivity of 5 ng in the apo B assay. By these methods, we measured secretion rates by Hep G2 cells of 358 +/- 41 ng/mg cell protein/hr for apo B and 137 +/- 8 ng/mg cell protein/hr for apo AI. These assays also allowed the measurement of intracellular apolipoproteins and thus can be used to facilitate investigations of human lipoprotein metabolism in cell culture systems.


A simple ICP-MS procedure for the determination of total mercury in whole blood and urine.

A simple and sensitive procedure for total mercury in whole blood and urine using inductively coupled plasma-mass spectrometry (ICP-MS) is described. Specimens are prepared by precipitation-extraction with 50% v/v hydrochloric acid containing EDTA and cysteine, centrifuged, and filtered through fritended screening column; the filtrates are directly analyzed by ICP-MS. The method is linear between 2 and 200 micrograms/L in the specimen with an absolute sensitivity of 0.2 microgram/L in the final supernatant. The assay variability at various concentrations (microgram/L) of mercury are as follows: intra-assay whole blood (n = 20)-4.6 +/- 0.6 (c.v. 12.3%), 18.3 +/- 1.1 (c.v. 6.1%), 56.4 +/- 2.8 (c.v. 5.0%); inter-assay whole blood (n = 15)-5.7 +/- 1.0 (c.v. 16.8%), 19.7 +/- 2.7 (c.v. 13.5%), and 50.1 +/- 6.9 (c.v. 13.7%); urine (n = 20)-9.3 +/- 1.2 (c.v. 12.9%), 29.6 +/- 2.2 (c.v. 7.4%). Recovery of organic and inorganic mercury from blood samples ranges from 91.6% to 110.2%. The method is suitable for analysis of total mercury, both organic and inorganic, in whole blood and urine.