Systemic lidocaine enhancement of hyperthermia-induced tumor regression in transplantable murine tumor models.

Previously, we reported that local lidocaine infusion of a CA 755 mammary adenocarcinoma growing in C57BL X DBA/2 F1 mice, when combined with local heating for 1 hr in a 43.5 degrees water bath, significantly increased survival and inhibited tumor growth more than heating alone. Because of its clinical implications, systemic lidocaine was tested in the above model system and in a murine fibrosarcoma tumor model. An equivalent supraadditive, tumor-inhibitory effect of heat and lidocaine was obtained with both systemically and intratumor-administered lidocaine. The serum levels of lidocaine necessary to achieve tumor regression were within the therapeutic range for the control of arrhythmia in humans. Several treatment schedules, varying the mode of drug delivery, were evaluated. The effects of treatment on tumor growth characteristics were analyzed using an extension of the Cox survival model.

Does bone measurement on the radius indicate skeletal status? Concise communication.

Single-photon (I-125) absorptiometry was used to measure bone mineral content (BMC) of the distal third of the radius, and dual-photon absorptiometry (Gd-153) was used to measure total-body bone mineral (TBBM), as well as the BMC of major skeletal regions. Measurements were done in normal females, normal males, osteoporotic females, osteoporotic males, and renal patients. The BMC of the radius predicted TBBM well in normal subjects, but was less satisfactory in the patient groups. The spinal BMC was predicted with even lower accuracy from radius measurement. The error in predicting areal density (bone mass per unit projected skeletal area) of the lumbar and thoracic spine from the radius BMC divided by its width was smaller, but the regressions differed significantly among normals, osteoporotics, and renal patients. There was a preferential spinal osteopenia in the osteoporotic group and in about half of the renal patients. Bone measurements on the radius can indicate overall skeletal status in normal subjects and to a lesser degree in patients, but these radius measurements are inaccurate, even on the average, as an indicator of spinal state.

Reactive synovitis from particulate silastic.

A reactive synovitis secondary to intra-articular particles of silicone elastomer developed in three patients who had undergone Silastic hemiarthroplasty. In an attempt to duplicate this phenomenon, we used an animal model in which finely ground particulate silicone elastomer was introduced into the knee joints of adult New Zealand White rabbits. In three of thirteen rabbits (p = 0.066) histological evidence of inflammatory changes developed in the synovial tissue, similar to those seen in our patients. Intraarticular particulate silicone elastomer created by abrasion of a Silastic hemiarthroplasty may be responsible for the development of an iatrogenic reactive synovitis.

Correlative radiographic, scintigraphic, and histological evaluation of exostoses.

We reviewed the cases of twenty-four patients with solitary or multiple exostoses to correlate their radiographic, scintigraphic, and histological evaluations. We studied twenty-five excised lesions, two of them exostotic chondrosarcomas, from twenty-two patients. There were two patterns of bone-scan activity and there was a direct correlation between enchondral bone formation and radionuclide uptake in all patients, both skeletally immature and mature. So-called quiescent lesions--those with inactive scans--were those that lacked histological evidence of enchondral bone formation. Those with increased uptake--active exostoses--all demonstrated active formation of enchondral bone. Evidence of active exostotic growth could be demonstrated on bone scans well beyond the time of skeletal maturity. The bone scan did not qualitatively differentiate the benign active exostoses from the two lesions with malignant degeneration. Increased uptake related to enchondral bone formation was a feature of both. An inactive scan, however, seemed to exclude the possibility of malignant degeneration in the exostosis.

Ultrasound imaging as a screening study for malignant soft-tissue tumors.

Fifty patients who had a palpable soft-tissue mass and an apparently normal radiograph were studied with ultrasound imaging before excision or biopsy of the lesion was done. As shown by the sonograms, thirty-five lesions had a discrete echo pattern (usually reduced echoes and a clearly defined lesional margin) and fifteen had an ill defined pattern (similar to the pattern of the surrounding normal tissues with no definable lesional margin). Fourteen lesions were malignant and thirty-six, benign. The sonograms of all fourteen malignant lesions showed a discrete pattern, while the sonograms of the benign ones showed twenty-one discrete and fifteen ill defined patterns. Therefore, the malignant lesions produced a discrete pattern in every instance, and every lesion that produced an ill defined pattern was benign. Fourteen of the fifty lesions were cystic; of these, thirteen were benign and one was malignant. The sonograms correctly identified the cyst in seven of the thirteen benign lesions and in the one malignant cystic lesion. Based on these findings, we concluded that all palpable soft-tissue masses that appear to be discrete on a sonogram should be diagnosed without delay by examination of a specimen taken at biopsy, whereas lesions that have an ill defined appearance on a sonogram may be assumed to be benign and may safely be observed in selected patients.

A study of pressure distributions measured during balanced and unbalanced sitting.

An instrument that measures pressures distribution during normal and unbalanced sitting was developed and tested. Analysis of the distribution of pressure during sitting in fifteen normal patients showed that approximately 18 per cent of the body weight is distributed over each ischial tuberosity; 21 per cent, over each thigh; and 5 per cent, over the sacrum. Three patients who had problems with sitting balance showed foci of unequal pressure which are at risk for decubitus ulceration.

Anterior and posterior cruciate ligament reconstruction in rhesus monkeys.

Although numerous procedures have been described for the reconstruction of the anterior and posterior cruciate ligaments, there has been little evaluation of the viability and strength of these substitutes. Using microangiographic, histological, and biomechanical techniques, we studied the vascularity and tensile strength of the medial one-third of the patellar tendon at intervals after it had been inserted as a substitute for either the anterior or the posterior cruciate ligament in twenty-nine young adult Rhesus monkeys. For the anterior cruciate reconstruction (nineteen knees), we used and medial one-third of the patellar tendon elongated by a portion of the patella. For the posterior cruciate reconstruction (ten knees), we used the medial one-third of the patellar tendon lengthened by attached portions of the patella and tibia as a free graft. Both the anterior and the posterior cruciate ligament substitutes were revascularized at eight weeks, and at one year they had approximately 80 per cent of the tensile strength that they had prior to transfer.

Stress fractures of the great toe sesamoids.

Stress fractures of the great toe sesamoids have not been previously confirmed as a clinical entity. In this report, we present four such cases, and document the diagnosis by histological sections. All of the patients had experienced the insidious onset of activity-related forefoot pain, and had radiographs that demonstrated a sesamoid fracture. None of the fractures healed with 6 weeks of immobilization and prolonged (4-6 months) inactivity. In all cases, the fractured sesamoid was excised, and the hematoxylin and eosin sections of the fracture segments documented the prefracture stress and incomplete repair characteristic of a stress fracture.

Granular tricalcium phosphate in large cancellous defects.

Tricalcium phosphate (TCP) is a porous ceramic which has biological properties of being non-reactive and resorbable, and acts as a scaffolding for bone ingrowth, undergoing progressive degradation and replacement by bone. Tricalcium phosphate has been shown to be comparable to autogenous bone graft in small periodontal defects. However, orthopedic defects are much larger. This prompted us to review the bone ingrowth potential in large cancellous bone defects (up to 12 cm3) in adult pigs. To quantitate bone ingrowth potential, three skeletally mature pigs had metaphyseal defects created in the tibia and femur of each hind limb, for 12 total sites. Twelve-cc defects in the distal femur and eight cc defects in the proximal tibia were made. Bone curetted was saved to be used as autogenous graft in the control, while the other ipsilateral defect was packed with tricalcium phosphate. Four months following the initial defect, the opposite hind extremity was similarly operated. All animals were sacrificed at nine months. Specimens were imbedded in methyl-methacrylate, cut at 120 microns, and stained. The quantity of regenerated bone was measured by histomorphometric techniques. Qualitative assessment at four months revealed absence of inflammation and TCP surrounded by trabecular bone, which was uniformly viable. There was very little TCP left by nine months. Quantitative analysis revealed the tibias to have a higher percent net bone replacement with TCP as compared to the control (32 percent versus 13 percent). The femoral TCP-filled defects were comparable to autogenous bone (both measured 29 percent).(ABSTRACT TRUNCATED AT 250 WORDS)

Tricalcium phosphate as a bone graft substitute in trauma: preliminary report.

Ceramic tricalcium phosphate (TCP) has been implanted in bony defects in 43 patients following trauma. It is an osteoconductive material that facilitates trabecular bone formation. The average follow-up time was 12 months, with a 6-month minimum. There were 33 fractures in 30 patients and 13 nonunions in 13 patients. Three of the patients with acute fractures were unavailable for follow-up observation. Ninety percent of the fractures and 85% of the nonunions were healed at the time of this review. The resorption of TCP was estimated from the roentgenograms to be approximately 10% per month, with complete resorption occurring in 6-24 months. There were eight complications, five among the 30 fractures and three among the 13 nonunions that were observed later. There were three fractures and two nonunions that failed to heal. There were two fractures that had initially been open and one previously infected nonunion that united but were complicated due to infection. These preliminary results demonstrate TCP's usefulness as a substitute for cancellous bone. This is accompanied by other advantages, including increased patient safety, lack of donor site morbidity, unlimited shelf life and reduced operating time.

The evaluation of a soft-tissue mass in the extremities.

A soft-tissue mass in an extremity may present a diagnostic dilemma for the evaluating surgeon. A decision either to observe or remove the mass is required. An algorithm can assist in the decision-making process. A careful history may aid in determining the etiology. A history of thigh-muscle trauma, for instance, may suggest myositis ossificans as the diagnosis of a malignant soft-tissue tumor. A large, firm mass that is fixed to deep structures or located within muscle should prompt the following studies: (1) plain radiographs of the extremity; (2) an ultrasound study of the mass; and (3) a three-phase technetium 99m methylene diphosphonate bone scan.

MRI of peripheral neurofibromas in children.

Magnetic resonance imaging was performed as a preoperative examination in three children with neurofibromatosis and soft-tissue plexiform neurofibromas. In all three patients, MRI showed more widespread soft tissue involvement than was suspected clinically including extension towards the spine in each case. Patient management was changed in each case after MRI was performed.

MPI-blastn and NCBI-TaxCollector: improving metagenomic analysis with high performance classification and wide taxonomic attachment.

Metagenomic sequencing technologies are advancing rapidly and the size of output data from high-throughput genetic sequencing has increased substantially over the years. This brings us to a scenario where advanced computational optimizations are requested to perform a metagenomic analysis. In this paper, we describe a new parallel implementation of nucleotide BLAST (MPI-blastn) and a new tool for taxonomic attachment of Basic Local Alignment Search Tool (BLAST) results that supports the NCBI taxonomy (NCBI-TaxCollector). MPI-blastn obtained a high performance when compared to the mpiBLAST and ScalaBLAST. In our best case, MPI-blastn was able to run 408 times faster in 384 cores. Our evaluations demonstrated that NCBI-TaxCollector is able to perform taxonomic attachments 125 times faster and needs 120 times less RAM than the previous TaxCollector. Through our optimizations, a multiple sequence search that currently takes 37 hours can be performed in less than 6 min and a post processing with NCBI taxonomic data attachment, which takes 48 hours, now is able to run in 23 min.

Granular tricalcium phosphate grafting of cavitary lesions in human bone.

Development of an effective and safe bone grafting substitute could potentially alleviate many of the problems associated with human bone graft materials. Reported here are the results of 18 patients who were treated with a ceramic bone graft substitute, tricalcium phosphate. Twenty cavitary defects were created by intralesional curettage of a variety of benign bone neoplasms. Following complete removal of the tumor, each defect was filled with tricalcium phosphate granules. All patients were followed with periodic clinical and radiologic examinations for a minimum of 2 years (average followup of 37 months; range, 24 to 66 months). The amount of graft resorption and new bone formation were separately assessed on a percentage basis. Judged by radiographic criteria, the tricalcium phosphate implant lost its postoperative granular pattern in advance of bony trabeculae formation. Radiographic healing of defects with normal appearing bone was complete in four patients by 12 months, in an additional eight patients by 24 months, and in all except four patients by 48 months. Healing was dependent upon defect size; the larger lesions healing more slowly. Clinical parameters of healing were seen in advance of complete bone remodeling and all patients, except one, had unrestricted activity by 24 months. No adverse reactions were attributed to the graft material.

Traumatic partial foot amputation.

Twenty patients in whom partial foot amputation had been performed following trauma were evaluated for successful retention of the foot. Of ten transverse stumps, only three partial feet were retained. Failure was related to poor terminal coverage from skin grafts and to equinus deformity. All ten longitudinal forefoot amputations resulted in salvage of the foot. In traumatic partial foot amputations only bone stock that is protected by innervated plantar skin should be preserved, and skin grafting should be done only in nonweight-bearing areas. Equinus deformity can be minimized by preserving and/or transplanting dorsiflexor tendons into residual bone and by supporting the foot in a custom-made ankle-foot orthosis.

Evaluation of complex acetabular fractures by computed tomography.

We report two cases that illustrate the value of computed tomography in the diagnosis and management of complex fracture-dislocations of the acetabulum.