Biomedical subjects

J T Mader

Publications and source records attributed to J T Mader.

At least 19 recordsLinked to original sources

PubMed1997

In vitro evaluation of antibiotic diffusion from antibiotic-impregnated biodegradable beads and polymethylmethacrylate beads.

Antibiotic-impregnated beads are used in the dead bone space following debridement surgery to deliver local, high concentrations of antibiotics. Polymethylmethacrylate (PMMA), 2,000-molecular-weight (MW) polylactic acid (PLA), Poly(DL-lactide)-coglycolide (PL:CG; 90:10, 80:20, and 70:30), and the combination 2,000-MW PLA-70:20 PL:CG were individually mixed with clindamycin, tobramycin, or vancomycin. Beads were placed in 1 ml of phosphate-buffered saline (PBS) and incubated at 37 degrees C. The PBS was changed daily, and the removed PBS samples were stored at -70 degrees C until the antibiotic in each sample was determined by microbiological disk diffusion assay. Nondissolving PMMA beads with tobramycin and clindamycin had concentrations well above breakpoint sensitivity concentrations (i.e., the antibiotic concentrations at the transition point between bacterial killing and resistance to the antibiotic) for more than 90 days, but vancomycin concentrations dropped by day 12. ALl PLA, PL:CG, and the 2,000-MW PLA-70:30 PL:CG biodegradable beads release high concentrations of all the antibiotics in vitro for the period of time needed to treat bone infections (i.e., 4 to 8 weeks). Antibiotic-loaded PLA and PL:CG beads have the advantage of better antibiotic elution and the ability to biodegradable (thereby averting the need for secondary surgery for bead removal) compared to the PMMA beads presently used in the clinical setting.

Anti-Bacterial Agents↗

PubMed1996

Rapid progression of head and neck squamous carcinoma after hyperbaric oxygenation.

We present four head and neck cancer patients who apparently had rapid progression of clinically occult disease during or soon after undergoing hyperbaric oxygenation. This led us to review existing knowledge about the interaction of HBO with tumors. The literature can be summarized as follows: 1. HBO is a useful tool in several situations commonly encountered by head and neck surgeons-infections, radionecrosis, and wound-healing problems. 2. The use of HBO as a hypoxic cell sensitizer during radiation therapy has been extensively studied, with evidence supporting only marginal advantage to this logistically difficult undertaking. 3. Most reports regarding the interaction of HBO with transplanted tumor cells suggest no effect on tumor growth or metastases. 4. Studies of chemically induced carcinogenesis are less conclusive. Some evidence supports a role for HBO in enhancing growth of preexisting tumors. Better understanding of the interaction of HBO with existing tumors is required to ensure that informed choices-weighing potential risks and benefits of HBO treatment--may be made by head and neck surgeons and their patients. Further research into the interaction between HBO and tumor cells is warranted.

Adult↗

PubMed1996

Update on the diagnosis and management of osteomyelitis.

Osteomyelitis can be classified by duration, pathogenesis, location, extent, and host status. Bone infections are currently classified by the Waldvogel or the Cierny-Mader classification. Because the Waldvogel classification is an etiologic system and the Cierny-Mader classification is descriptive, both classifications can be simultaneously used. The Cierny-Mader classification is based on the anatomy of the bone infection and the physiology of the host. Cierny-Mader staging allows stratification of long bone osteomyelitis and the development of comprehensive treatment guidelines for each stage. Current trends in long bone osteomyelitis therapy emphasize early diagnosis and aggressive treatment. Radiographs and bone cultures are the mainstays of diagnosis. Imaging with radionuclide scans, computerized tomography, and magnetic resonance imaging are used when the diagnosis of osteomyelitis is equivocal or to help guage the extent bone and soft tissue infection. Surgical treatment involves débridement of necrotic bone and tissue, obtaining appropriate cultures, managing dead space, and, when necessary, obtaining bone stability. Medical therapy includes improving any host deficiencies, initial antibiotic selection, and antibiotic modification based on culture results. Antibiotic delivery has expanded to include effective oral agents and local therapy with antibiotics mixed in polymethylmethacrylate. Cierny-Mader staging was developed to describe long bone osteomyelitis. This staging system has to be modified to describe diabetic foot osteomyelitis and vertebral osteomyelitis. Osteomyelitis in patients with diabetes mellitus involves the bones of the feet or ankles. The vascular and neurologic status of the patient must be carefully accessed. Patients may be managed with local débridement surgery or ablative surgery plus 2 to 4 weeks of antibiotic therapy depending on whether all of the osteomyelitis is surgically removed. If the patient does not wish surgery or is not a surgical candidate, suppressive antibiotic therapy can be used. Vertebral osteomyelitis is usually hematogenous in origin. The diagnosis is made by bone cultures, histology, and radiographs. Magnetic resonance imaging and technetium scans are useful in making the diagnosis and in gauging the extent of the bone and soft tissue infection. Therapy requires parenteral antibiotic therapy and may include early surgery and stabilization. The choice of an antibiotic therapy is guided by the bone biopsy or débridement culture results.

Adolescent↗

PubMed1995

Osteomyelitis.

The complexities of osteomyelitis make its diagnosis and treatment challenging. Current trends emphasize early diagnosis and aggressive treatment. Imaging has improved, with nuclear scans and magnetic resonance imaging, and technique modifications have enhanced the specificity of these tests. Treatment depends on thorough debridement of necrotic bone and tissue, accurate cultures and administration of culture, and sensitivity-specific antibiotics. Antibiotic delivery has expanded to include effective oral agents and local agents mixed with polymethylmethacrylate or a biodegradable substance. Success rates in treating this disease have improved with the use of a systematic approach, making outcome more predictable.

Adult↗

PubMed1994

Long-bone osteomyelitis diagnosis and management.

The pathogen may proliferate years after seemingly successful treatment. The authors describe a classification system to evaluate both the disease and the patient's capacity to undergo the rigors of therapy. Two cases illustrate the clinical issues.

Adolescent↗

PubMed1994

Osteomyelitis.

Osteomyelitis can be difficult to treat. Current trends emphasize early diagnosis and aggressive treatment. Imaging has improved with nuclear scans and magnetic resonance imaging, and recent modifications in technique have enhanced the specificity. Treatment depends on debridement of necrotic bone and tissue, obtaining accurate cultures, and administration of culture- and sensitivity-directed antibiotics. Antibiotic delivery has expanded to include effective oral agents and local agents mixed with polymethylmethacrylate or a biodegradable substance. Success rates in treating this disease have improved with a systematic approach, making outcome more predictable.

Chronic Disease↗

PubMed1994

Use of antibiotic-PMMA beads in the ischemic foot.

Thirty-six patients with 44 ischemic foot infections were managed with antibiotic-polymethylmethacrylate (PMMA) beads. Most of these patients received gentamicin-impregnated PMMA beads but tobramycin and vancomycin-impregnated PMMA beads were used on three patients. Angiopathy occurred in 35 patients secondary to diabetes and secondary to renal disease in 2; 1 patient had both diabetes and renal disease. The most common bacteria was Staphylococcus aureus (82%), although other organisms and multiple bacteria were present. In spite of the variability of the bacteria, PMMA beads were helpful in managing foot infections in this difficult patient population.

Anti-Bacterial Agents↗

PubMed1994

Osteomyelitis.

Explore the source record for details and available documents.

Humans↗

PubMed1993

Evaluation of therapy with hyperbaric oxygen for experimental infection with Clostridium perfringens.

The effects of inoculum size and treatment delays on the efficacy of hyperbaric oxygen (HBO) were evaluated in a murine model of Clostridium perfringens myositis in which the infection was treated with an HBO regimen identical to that used for humans. The efficacies of treatment with penicillin, metronidazole, or clindamycin--alone or in combination with HBO--were also assessed. Survival was inversely related to the size of the bacterial inoculum used for challenge, and delays in treatment markedly reduced the efficacies of all single and combination regimens. When animals were challenged with > 10(8) colony-forming units, survival was significantly higher among those treated with clindamycin or metronidazole than among those treated with penicillin. HBO alone did not improve survival at any inoculum tested. However, when administered early, HBO plus metronidazole or penicillin demonstrated significant additive efficacies in animals challenged with > or = 10(9) organisms. Clindamycin was more effective at the higher inocula than penicillin, metronidazole, or HBO, and its superior efficacy was not further enhanced by adjunctive therapy with HBO.

Animals↗

PubMed1993

Treatment of infected pilon nonunions with small pin fixators.

Six consecutive patients with infected intra-articular fractures of the distal tibia were studied. They were treated with resection of all infected or necrotic bone, systemic antibiotics, and instrumentation with a small pin fixator (Ilizarov external fixator). The fixator was used to perform an ankle arthrodesis and to fill the defect created by bone resection with distraction osteogenesis. In all cases, the infections were eradicated, and a solid arthrodesis was attained. The patients required from zero to two revision procedures (average 1.3), and their time in the fixator varied from 3 to 13 months (average 8 months). All of the patients experienced at least minor complications during treatment (superficial pin tract infections). At final follow-up, no patient demonstrated shortening of more than 1.5 cm. One patient has an internal rotation deformity of 15 degrees; a second has a varus deformity of 10 degrees and occasionally uses lateral support (a cane) secondary to unsteadiness on uneven ground; and one patient uses aspirin occasionally for subtalar pain. All are pleased with their results and would undergo the same procedure again without reservation.

Adult↗

PubMed1993

The Ilizarov fixator and polymethylmethacrylate-antibiotic beads for the treatment of infected deformities.

Eighteen of the 124 patients enrolled in the gentamicin methylmethacrylate bead (GMB; Septopal) study had infected deformities that were treated with the Ilizarov external fixator. Nine of these patients (Group 1) were treated with an initial debridement and intravenous antibiotics for four weeks. Nine patients (Group 2) were treated with GMB and, five days after operation, intravenous antibiotics. The two groups were similar. Group 1 included eight men and one woman (average age, 31.8 years) and Group 2, seven men and two woman (average age, 37.4 years). Both groups had multiple deformities, including nonunions, segmental defects, angulation, and shortness. The end results were identical. Eight patients in each group had their infection successfully arrested (88.9%), and eight patients in each group had their deformity successfully treated. The use of GMB with the Ilizarov fixator was as effective as long-term parenteral antibiotics with the Ilizarov fixator for the treatment of infected deformities.

Adult↗

PubMed1993

The treatment of infected nonunions with gentamicin-polymethylmethacrylate antibiotic beads.

Fifty-two patients enrolled in the Septopal study of infected nonunions were prospectively examined in a randomized, controlled, closed study. Patients were divided into two groups. Group 1 consisted of 24 patients treated with debridement and intravenous antibiotics for four weeks. Group 2 consisted of 28 patients treated with debridement, gentamicin-polymethylmethacrylate (Septopal) beads, and perioperative broad-spectrum parenteral antibiotics. Both groups were treated with similar methods for reconstruction of the nonunions. The demographics of the two groups were similar. The average patient age in Group 1 was 38.4 years, and in Group 2, 37.1 years. Group 1 included 21 men and three women and Group 2, 23 men and five women. The nonunions in both groups ranged from simple hypertrophic nonunions to atrophic unions to segmental defects. The end results were good in both groups. Twenty patients in Group 1 and 25 patients in Group 2 had their infections successfully arrested (83.3% and 89.3%, respectively). Nonunions were successfully healed in the two groups, with similar results (Group 1, 83.3%; Group 2, 85.7%). Infected nonunions responded equally well to either systemic treatment with long-term intravenous antibiotics or local treatment with gentamicin-polymethylmethacrylate beads.

Adult↗

PubMed1993

Diagnoses and staging. Osteomyelitis and prosthetic joint infections.

The diagnoses of osteomyelitis and prosthetic joint infections are usually made on the basis of clinical, laboratory, and radiographic examination. The diagnostic studies presently employed to diagnosis and assess osteomyelitis and prosthetic joint infections are described. A universally applied classification system for stratifying osteomyelitis and prosthetic joint infection would provide a framework for the evaluation of medical and surgical treatment efficacy. Such a system would enable treatment results to be compared among institutions. Staging systems currently being used are described.

Blood Sedimentation↗

PubMed1993

Antimicrobial treatment of osteomyelitis.

Parenteral antibiotic therapy remains the mainstay of antimicrobial therapy for osteomyelitis. In acute cases, empirical treatment may be used initially, but antibiotic selection should ideally be based on deep aspiration or bone cultures with corresponding in vitro sensitivity testing. The drug exhibiting the highest bacteriocidal activity with the least toxicity and lowest cost should be chosen. Antibiotic treatment will not substitute for surgical debridement of infected devitalized bone. The length of treatment with parenteral therapy remains controversial. The six-week benchmark, which was determined largely by experience with childhood hematogenous osteomyelitis, may not be applicable to contiguous focus osteomyelitis after trauma in adults. The goal of surgical treatment is to convert an infection with dead bone to a situation with well-vascularized tissues that are readily penetrated by blood-borne antibiotics, making prolonged drug treatment unnecessary.

Aminoglycosides↗

PubMed1993

Salmonella typhi osteomyelitis in a nonsickle cell patient. A case report.

Few cases of osteomyelitis caused by Salmonella typhi in nonsickle cell patients have been reported. In a 33-year-old woman with a history of chronic, intermittent drainage of the right lower leg, roentgenographs indicated middiaphyseal osteomyelitis of the fibula. Bone cultures obtained at surgical debridement grew S. typhi. The patient responded adequately to four weeks of intravenous antibiotic therapy, and the infection has remained arrested after 18 months. The characteristics of S. typhi osteomyelitis are as follows: All reported cases have affected female patients with no apparent immunocompromise; all had a history of S. typhi infection with long bone involvement; and all had a tendency to recurrence.

Adult↗

PubMed1992

Infection in the diabetic foot.

A 56-year-old woman presented with a chronic infection of her right first toe. The woman had a 15-year history of diabetes mellitus and had been insulin dependent for the past five years. Her toe had been injured one month earlier when hit by a frozen chicken that fell out of the freezer. The accident caused a bruise and a small cut. Serous to purulent drainage then developed. When she presented, the toe was reddened and draining. Physical examination showed a nonobese woman with no fever or other evidence of systemic infection. The wound showed no evidence of necrotizing fasciitis. Peripheral pulses were 2+ and capillary refill was slow. Sensation in both feet was decreased. The transcutaneous oxygen tension in the feet was reduced at 20 mm Hg. Relevant laboratory findings included a serum glucose of 250 and creatinine of 1.5. X-rays of the foot were compatible with diffuse osteomyelitis of the distal phalanx of the great toe. Technetium and indium scans were positive, with increased uptake localized to the area of x-ray changes (Figure 1). The patient was admitted to the hospital.

Adult↗

PubMed1992

Adjuvant hyperbaric oxygen in malignant external otitis.

Necrotizing invasive pseudomonal infection of the external auditory canal (malignant external otitis) is an uncommon but important disorder in the elderly. The high morbidity, and even mortality, of this disorder has been reduced by the early and intensive use of combination antipseudomonal antibiotics. However, in severely immunocompromised patients or in infection involving the base of the skull, multiple cranial nerves, or the meninges, conventional therapy has been prolonged, intensive, and relatively ineffective. We treated 16 patients with malignant external otitis with adjuvant hyperbaric oxygen therapy. In six patients, infection was in advanced stages, infections were recurrences after previous treatment, and repeated treatment with antipseudomonal antibiotics had failed. All 16 cases responded promptly when a 30-day course of hyperbaric oxygen was added to the antibiotic regimen, and all patients remained free of infection or neurologic deficit during 1 to 4 years of follow-up. No complications of this treatment modality were noted. Hyperbaric oxygen therapy reverses tissue hypoxia, which enhances phagocytic killing of aerobic microorganisms, and stimulates neomicroangiogenesis. In addition, hyperbaric oxygen augments the action of aminoglycoside antibiotics. Adjuvant hyperbaric oxygen therapy should be considered in advanced or recurrent cases of malignant external otitis.

Aged↗

PubMed1992

Evaluation of new anti-infective drugs for the treatment of selected infections of the skin and skin structure. Infectious Diseases Society of America and the Food and Drug Administration.

No method for classifying infections of the skin and skin structure is uniformly accepted. Therefore, each protocol for the evaluation of new anti-infective drugs must include definitions of the skin and skin-structure infections to be treated. Clinical findings may suggest the etiology. Cultures should be performed by the best available technique. Because the yield of pathogens from sites of skin and skin-structure infection is often low, monitoring of the clinical response to therapy is paramount. Randomized, double-blind, active-control comparative studies are needed, and maintenance of blinding is recommended, even with a change in the route of administration of the study and/or control drugs. The period of follow-up should be defined for each type of infection.

Anti-Infective Agents↗