VUV photoabsorption spectroscopy of sulfur dioxide ice.

In this paper we present the first study of the VUV photoabsorption spectrum of condensed phase SO(2) recorded over the VUV region 120 to 320 nm (10.33 to 3.64 eV). Distinct spectral features were observed that can be used to distinguish between the formation of amorphous and crystalline ice structures. These signatures may then be used to probe the formation of different ice structures as a function of both deposition rate and substrate temperature.

A prolonged case of Mycobacterium marinum flexor tenosynovitis: radiographic and histological correlation, and review of the literature.

We report on a 30-year-old man with prolonged Mycobacterium marinum flexor tenosynovitis. Due to low clinical suspicion, diagnosis was not made until 8 years after initial presentation. The history and magnetic resonance and tissue examination findings are consistent with mycobacterial tenosynovitis. These findings are presented, together with a review of the literature.

Culture results and amputation rates in high-pressure paint gun injuries of the hand.

High-pressure paint gun injuries have been well described in the literature, and the use of antibiotics is recommended as part of their management. However, there is no scientific evidence to support the use of antibiotics. In addition, the type of paint injected (water- versus oil-based) has never been investigated to determine the extent of morbidity resulting from these injuries. This study examines the organisms cultured in wounds resulting from these injuries and whether the type of paint injected had an influence on amputation rates. Charts of 35 patients with high-pressure paint gun injuries to their hands were reviewed. The amputation rate was 50% with oil-based paints and 0% with water-based paints. Forty-seven percent of wound cultures were positive, with gram-negative bacteria found in 58% of isolates. Our findings support the use of antibiotics, which should cover both gram-positive and gram-negative organisms.

Mucormycosis of the tibia: a case report and review of the literature.

Mucormycosis is an uncommon but highly aggressive fungal infection most commonly occurring in hosts who are immunologically predisposed to infection. Only seven previously documented cases of tibial osteomyelitis attributable to Mucorales infection exist in the literature. An unusual case is reported of mucormycosis osteomyelitis developing in a patient who was immunocompromised after routine tibial Steinmann pin placement for the application of traction. Surgical debridement and amphotericin B were not sufficient to control the infection, and the patient subsequently underwent above-knee amputation. To the authors' knowledge this is the first description of mucormycosis causing osteomyelitis as a result of Steinmann pin tract infection.

Inhibitory effects of the quinolone antibiotics trovafloxacin, ciprofloxacin, and levofloxacin on osteoblastic cells in vitro.

We studied the inhibitory effects of the fluoroquinolones levofloxacin, ciprofloxacin, and trovafloxacin on growth and extracellular matrix mineralization in MC3T3-E1 osteoblast-like cell cultures. Levofloxacin had the least inhibitory effect on cell growth, with a 50% inhibitory concentration of approximately 80 microg/ml at 48 and 72 hours. Ciprofloxacin had an intermediate degree of inhibition, with a 50% inhibitory concentration of 40 microg/ml at 48 and 72 hours. Trovafloxacin exerted a profound inhibitory effect on cell growth, with a 50% inhibitory concentration of 0.5 microg/ml, lower than clinically achievable serum levels. The decreased cell counts with up to 2.5 microg/ml of trovafloxacin and with up to 40 microg/ml of ciprofloxacin were not associated with decreased rates of 5-bromo-2'-deoxyuridine incorporation per cell. Alatrovafloxacin, the L-alanyl-l-alanine prodrug of trovafloxacin, exerted effects on proliferation and 5-bromo-2'-deoxyuridine incorporation similar to those of the parent compound. The quinolones evaluated also inhibited extracellular matrix mineralization by MC3T3-E1 cells. Treatment of confluent cultures with trovafloxacin, ciprofloxacin, or levofloxacin resulted in strong inhibition of calcium deposition, as determined on day 14 by alizarin red staining and biochemical analysis. The effect was apparent with 2.5-5 microg/ml of each of the three antibiotics tested and progressively increased to more than a 90% decline in the calcium/protein ratio with 20-40 microg/ml antibiotic concentration. Further in vivo studies are advocated to evaluate the relevance of the in vitro cytotoxicity reported here to bone healing in orthopaedic patients.

Chronic, but not acute, dosing of antipsychotic drugs alters neurotensin binding in rat brain regions.

The present study compared high affinity neurotensin (NT) binding in rat brain following acute or chronic treatment with the classical antipsychotic, haloperidol, and the newer antipsychotic drugs, clozapine and zotepine. Drugs were given orally, as an acute treatment (1 dose) or chronically (21 day dosing) and binding to the NT high affinity receptor was examined in three brain regions; striatum, nucleus accumbens/olfactory tubercle and frontal cortex. Acute dosing with either vehicle, haloperidol, clozapine or zotepine produced no significant changes in NT binding from controls (naïve rats). Chronic (21 day) dosing resulted in an increase in the K:(D:) and B(max) of high affinity receptors in the striatum following haloperidol, but not clozapine, zotepine or vehicles. In contrast, the newer antipsychotics, clozapine and zotepine but not haloperidol or vehicles, significantly altered NT binding in the nucleus accumbens/olfactory tubercle by decreasing the K:(D:) and B(max). Further differentiation between the two newer antipsychotic drugs occurred in the frontal cortex. Clozapine had no significant effect on NT binding, whereas zotepine significantly reduced the K:(D:) of the high affinity receptor with no alteration in B(max). The antipsychotic drugs tested did not interact directly with the NT high affinity receptor. Therefore, they must be acting indirectly via an alternative receptor mechanism to alter NT high affinity binding. In accordance with previously reported NT/dopamine receptor interactions, this would suggest cross-talk between these systems. Overall, these data demonstrate that chronic, but not acute, administration of antipsychotic drugs alters NT binding in the rat brain. In addition, anatomical differences in NT binding arise according to the antipsychotic drug under test. This may be predictive of drug side-effect profile, antipsychotic efficacy or atypicality.

A highly sensitive and selective radioimmunoassay for the measurement of neurotensin.

A highly selective and sensitive radioimmunoassay (RIA) for the detection of endogenous neurotensin (NT) has been developed. We have raised a C-terminally-directed antibody (CAb) that specifically binds 'biologically active' NT (NT and NT(8-13)) and that does not significantly cross-react with inactive NT metabolites or other bioactive peptides in the CNS. By reducing the volume of the assay to a low volume-RIA (30 microl), such that in vivo measurements can be made, we have increased the sensitivity (<0.3 fmol per tube), with inter- and intra-assay variations of 11.2 and 5.8%, respectively. Comparisons with similar methods of detecting NT have demonstrated that this RIA has a higher sensitivity than previously used RIA's and ELISA's. The data presented suggests that this sensitive RIA is a reliable method ideal for the detection of small quantities of biologically active NT.

Management of chronic deep infection following rotator cuff repair.

BACKGROUND: Deep infection of the shoulder following rotator cuff repair is uncommon. There are few reports in the literature regarding the management of such infections. METHODS: We retrospectively reviewed the charts of thirteen patients and recorded the demographic data, clinical and laboratory findings, risk factors, bacteriological findings, and results of surgical management. RESULTS: The average age of the patients was 63.7 years. The interval between the rotator cuff repair and the referral because of infection averaged 9.7 months. An average of 2.4 procedures were performed prior to referral because of infection, and an average of 2.1 procedures were performed at our institution. All patients had pain on presentation, and most had a restricted range of motion. Most patients were afebrile and did not have an elevated white blood-cell count but did have an elevated erythrocyte sedimentation rate. The most common organisms were Staphylococcus epidermidis, Staphylococcus aureus, and Propionibacterium species. At an average of 3.1 years, all patients were free of infection. Using the Simple Shoulder Test, eight patients stated that the shoulder was comfortable with the arm at rest by the side, they could sleep comfortably, and they were able to perform activities below shoulder level. However, most patients had poor overhead function. CONCLUSIONS: Extensive soft-tissue loss or destruction is associated with a worse prognosis. Extensive débridement, often combined with a muscle transfer, and administration of the appropriate antibiotics controlled the infection, although most patients were left with a substantial deficit in overhead function of the shoulder.

Limb salvage for chronic tibial osteomyelitis: an outcomes study.

BACKGROUND: The decision to undergo a limb salvage procedure is difficult and multifaceted. This study reviews the outcomes of patients with chronic tibial osteomyelitis who underwent limb salvage and hopes to enhance our understanding of the impact this complex procedure has on the patient's ability to have a functional and fulfilling life. METHODS: Forty-six patients, with at least 18 months follow-up, who had undergone limb salvage for chronic, refractory tibial osteomyelitis were evaluated. A modification of the Limb Extremity Outcomes Instrument was utilized emphasizing inquiries pertaining to quality of life. RESULTS: Thirty-nine (85%) of the 46 patients were able to ambulate independently without pain. All patients younger than 45 years of age had successful outcomes. Thirty-one percent of the patients with a positive smoking history were failures, and 71% of all failures were smokers. CONCLUSION: Limb salvage seems to be a satisfactory option for patients with chronic tibial osteomyelitis. A history of smoking and advanced age may have adverse affects and are relative contraindications.

The incidence of joint involvement with adjacent osteomyelitis in pediatric patients.

Sixty-six patients admitted to our institution over an 8-year period with the diagnosis of osteomyelitis were analyzed to determine the incidence of adjacent joint involvement. Patients with osteomyelitis of the hand, foot, spine, and extraarticular pelvis were excluded from this study. The average age was 5.8 years (range, 1 month to 17 years). Forty-two percent of our patients who had osteomyelitis had evidence of adjacent joint involvement (either septic or nonseptic). One third of our patients had evidence of septic joint involvement. The most commonly involved joint was the knee. There was no difference in the incidence of adjacent joint involvement in those patients who were younger than 18 months compared with the incidence in older children. Our study suggests that the incidence of adjacent joint involvement in children who have osteomyelitis is higher than that suggested in the literature. We believe that careful evaluation of the adjacent joint should be an important part of the evaluation of any child who has osteomyelitis.

Prospective, randomized, double-blind study comparing single-agent antibiotic therapy, ciprofloxacin, to combination antibiotic therapy in open fracture wounds.

OBJECTIVE: The purpose of this study was to compare the efficacy of a single agent, ciprofloxacin, with that of combination antibiotic therapy consisting of cefamandole and gentamicin in all types of open fracture wounds. STUDY DESIGN: A prospective double-blind randomized clinical trial. SETTING: A Level 1 trauma center. PATIENTS: One hundred ninety-five consecutive patients with 203 open fractures were enrolled over a twenty-month period. Twenty-nine fractures from low-velocity gunshot wounds were excluded, and three other patients were excluded because of protocol violations. Our final number of patients were 163, with 171 open fractures. MAIN OUTCOME MEASUREMENT: The infection rates for Type I and Type II open fractures for both antibiotic groups were calculated. The infection rate of Type III open fractures for both antibiotic groups was also calculated. Chi-square analysis with Yates correction was used to assess statistical significance of two treatment groups. RESULTS: The infection rate for Types I and II open fractures in the ciprofloxacin group was 5.8 percent and 6 percent for the cefamandole/gentamicin group (p = 1.000). The infection rate for Type III open fractures for the ciprofloxacin group was 31 percent (8 of 26) versus 7.7 percent (2 of 26) for the cefamandole/gentamicin group (p = 0.079). There were no statistically significant differences in infection rate between the group treated with ciprofloxacin and that treated with cefamandole/gentamicin for Types I and II open fracture wounds. However, there appeared to be a high failure rate for the ciprofloxacin Type III open fracture group, with patients being 5.33 times more likely to become infected than those in the combination therapy group. Although this difference was not statistically significant, possibly because of the small sample size, there was a definite trend toward statistical significance. CONCLUSION: Single-agent antibiotic therapy with ciprofloxacin is effective in treatment of Type I and Type II open fracture wounds. However, on the basis of our results, we cannot recommend ciprofloxacin alone for Type III wounds. Possibly one can use fluoroquinolones in combination therapy, specifically as an alternate to an aminoglycoside.

Outcome of infected total knee utilizing a staging system for prosthetic joint infection.

This study reviews, over a 5-year period, the records of 70 consecutive patients with prosthetic knee infection and evaluates outcomes as a function of a staging system for prosthetic joint infection. The staging system for prosthetic joint infection was divided into three main categories that include infection type, systemic host grade, and local extremity grade. Outcome indices analyzed included Knee Society Score (KSS), complication rate, amputation rate, and rate of permanent resection. We show that categorizing and stratifying data for patients with infected total knee arthroplasty are useful. A universally accepted staging system would allow for more objective comparisons of treatments and may eventually define particular treatment regimens for particular classes of patients.

Introduction to adult posttraumatic osteomyelitis of the tibia.

The tibia is the most frequent site of an open fracture, and treatment of adult posttraumatic osteomyelitis of the tibia represents a significant clinical problem that has been recognized for centuries. Ancient modalities such as immobilization and debridement are still mainstays of therapy, and recent developments such as the use of antibiotics and muscle transfer have helped to improve outcome. Osteomyelitis is classified based on the Cierny-Mader system to provide prognostic and therapeutic information. Open fractures can be classified by the Gustilo system, again providing prognostic and therapeutic data. Gustilo Type III fractures have a high likelihood of having infection develop. Treatment principles include immobilization, thorough debridement, control of infection through antibiotic use, control of dead space, and soft tissue coverage.

Culture results in open wound treatment with muscle transfer for tibial osteomyelitis.

Fifty-three patients who underwent a two-staged protocol of debridement and muscle flap coverage for chronic osteomyelitis of the tibia between 1991 and 1996 were evaluated. All patients underwent a thorough debridement of all nonviable tissue and bone at initial debridement. Multiple cultures were taken, including aerobic, anaerobic and fungal cultures from the pus, soft tissue, bone curettings and bone. All patients were treated with open wound management and dressing changes. Between 2 to 7 days, median 4 days, all patients underwent a second debridement with a complete set of identical cultures, and immediate soft tissue muscle transfer. There were 42 free vascularized and 11 local tissue transfers. The 53 patients were classified according to the Cierny-Mader classification for chronic osteomyelitis. Twenty-four patients had Stage IVA osteomyelitis, 10 patients had Stage IIIA osteomyelitis, nine patients had Stage IIIB osteomyelitis, eight patients had Stage IVB osteomyelitis, one patient had Stage IA osteomyelitis, and one patient had Stage IIB osteomyelitis. All 53 patients had positive cultures at the time of their initial debridement, and 14 of 53 (26%) had a positive culture at the time of the second debridement. Based on the results, it seems from a bacteriologic stand-point that the second debridement allows for the opportunity for redebridement and wound sterilization of organisms that still may be present.

Early mycological treatment failure in AIDS-associated cryptococcal meningitis.

Cryptococcal meningitis causes significant morbidity and mortality in persons with AIDS. Of 236 AIDS patients treated with amphotericin B plus flucytosine, 29 (12%) died within 2 weeks and 62 (26%) died before 10 weeks. Just 129 (55%) of 236 patients were alive with negative cerebrospinal fluid (CSF) cultures at 10 weeks. Multivariate analyses identified that titer of cryptococcal antigen in CSF, serum albumin level, and CD4 cell count, together with dose of amphotericin B, had the strongest joint association with failure to achieve negative CSF cultures by day 14. Among patients with similar CSF cryptococcal antigen titers, CD4 cell counts, and serum albumin levels, the odds of failure at week 10 for those without negative CSF cultures by day 14 was five times that for those with negative CSF cultures by day 14 (odds ratio, 5.0; 95% confidence interval, 2.2-10.9). Prognosis is dismal for patients with AIDS-related cryptococcal meningitis. Multivariate analyses identified three components that, along with initial treatment, have the strongest joint association with early outcome. Clearly, more effective initial therapy and patient management strategies that address immune function and nutritional status are needed to improve outcomes of this disease.

In vitro elution of tobramycin and vancomycin polymethylmethacrylate beads and spacers from Simplex and Palacos.

In vitro studies of antibiotic elution from polymethylmethacrylate cement comparing Simplex (Howmedica, Rutherford, NJ) with Palacos brands (Richards, Memphis, TN) have shown variable results. This study compares the elution of tobramycin and vancomycin from Simplex and Palacos beads and spacers. Six-millimeter beads and spacers were incubated in phosphate-buffered saline, and the solution was sampled and changed daily until the concentration of antibiotic fell below the minimum inhibitory concentration (MIC) for Staphylococcus aureus. In all groups, the Palacos PMMA beads and spacers showed elution at higher levels and remained above the MIC longer than did the Simplex PMMA beads. Tobramycin had superior elution to vancomycin in all groups. This in vitro study shows that Palacos PMMA has superior elution properties to Simplex PMMA in tobramycin and vancomycin beads and spacers.

Relation of surface area to in vitro elution characteristics of vancomycin-impregnated polymethylmethacrylate spacers.

To study the relationship between surface area and antibiotic elution from antibiotic-impregnated polymethylmethacrylate (PMMA) spacers, a standard block spacer made of vancomycin (4 g) and 40 g of PMMA was compared with two unique spacer designs, the "donut" and "fenestrated." The spacers were incubated in phosphate-buffered saline, which was changed daily, and a microbiologic assay was used to measure the antibiotic activity of the eluates. The donut and fenestrated spacers had 12% and 40% more surface area than the standard spacer, respectively. There was no significant difference, however, in daily elution levels of antibiotic between the donut spacer and the standard spacer. The fenestrated spacer displayed significantly better elution than either the standard or donut spacers, with an average of 20% more antibiotic eluted on any given day.

Circulating CD34+ counts and apheresis planning.

The success of peripheral blood progenitor cell (PBPC) transplantation depends upon harvesting adequate numbers of cells and accurate prediction of when to commence apheresis. Although peripheral white cell count (WBC) is commonly used to identify when to initiate apheresis it does not uniformly predict the CD34+ content of the apheresis product nor the number of exchange procedures required. We investigated whether the peripheral blood CD34+ count would not only predict harvest yield but whether it would also predict the number of apheresis procedures needed to generate at least 2 x 10(6)/kg CD34+ cells. CD34+ counts were performed over an 8-month period on the peripheral blood and PBPC harvests of all patients undergoing leucopheresis. Regression analysis showed a highly significant correlation between peripheral blood CD34+ count and yield of CD34+ cells in the apheresis product. The regression plot with WBC was weaker. We have shown that a peripheral CD34+ count > or = 62 x 10(6)/l is required to confidently achieve an adequate harvest in one apheresis, two aphereses are needed if the initial count is > or = 40 x 10(6)/l. Therefore peripheral blood CD34+ counts not only are able to determine the threshold at which to commence apheresis but are useful in predicting apheresis requirements and planning demands on the apheresis service.

Infected total knee arthroplasty. Two-stage reimplantation with a gastrocnemius rotational flap.

This study reviews a consecutive series of 21 patients undergoing two-stage reimplantation total knee arthroplasty for late chronic infection. All 21 patients had late chronic infections, and 20 of 21 patients were compromised hosts. Seven different organisms were isolated at the time of prosthetic resection. Staphylococcus coagulase negative species was the most frequently isolated organism. At the time of reimplantation, a medial gastrocnemius rotational flap was rotated over the proximal tibia and knee for wound closure. The average explantation time was 25 weeks (range, 7-76 weeks), and no methylmethacrylate spacers were used. At an average 17-month followup (range, 5.1-33.1 months) all reimplanted total knee replacements remained in place with one patient having recurrent infection. At reimplantation, 11 patients had positive bacterial cultures from tissue specimens. Sixteen of the 33 (40%) positive cultures were from specimens taken from the medullary canal. At followup, the average Knee Society Score was 77.4 (range, 40-100). The lack of a methylmethacrylate spacer and a long explantation time were considered important factors in diminishing functional performance and determining the need for a gastrocnemius flap. A medial gastrocnemius rotational flap should be considered at the time of reimplantation total knee arthroplasty if the soft tissue envelope about the knee is compromised and cannot be closed without undue tension.