An in vitro study of ceftazidime and vancomycin concentrations in various fluid media: implications for use in treating endophthalmitis

PURPOSE: To investigate the precipitation process of a mixture of vancomycin and ceftazidime by equilibrium dialysis and determine its subsequent effect on the level of free antibiotics for treatment of endophthalmitis. METHODS: Concentrations of vancomycin and ceftazidime in an equilibrium dialysis chamber were measured during the equilibrium process by high-performance liquid chromatography. Normal saline (NS), balanced salt solution (BSS), and vitreous were used separately as the medium of dialysis. RESULTS: Precipitation of ceftazidime occurred at 37 degrees C but not at room temperature and did not affect the pH of the medium. It formed precipitate on its own or when mixed with vancomycin in all the three media of NS, BSS, and vitreous. More precipitation was formed if ceftazidime was initially prepared in BSS than in NS. After 168 hours in the dialysis chambers, ceftazidime prepared in NS precipitated to 54% of that in vitreous, compared with 88% if prepared in BSS. At 48 hours, ceftazidime prepared in NS decreased from an initial concentration of 137.5 to 73.4 microg/mL in vitreous medium and to 6.3 microg/mL if prepared in BSS. Precipitation of vancomycin was negligible. CONCLUSIONS: Based on this in vitro investigation, ceftazidime precipitates in vitreous at body temperature, regardless of the presence of vancomycin. NS is preferred to BSS as a preparation medium for antibiotics for intravitreal injection, because the extent of ceftazidime precipitation is less. However, due to precipitation, the concentration of free ceftazidime in vitreous may not be sufficiently high for antibacterial activity against most common organisms.     

Epidermal anti-Inflammatory properties of 5,11,14 20:3: Effects on mouse ear edema,PGE<Subscript>2</Subscript> levels in cultured keratinocytes,and PPAR activation

Background  

5,11,14 20:3 is similar to 20:4n-6 but lacks the internal Δ8 double bond essential for prostaglandin and eicosanoid synthesis. When previously fed to laboratory animals as a gymnosperm seed oil component it has shown anti-inflammatory properties.     

Tardive dyskinesia and impaired glucose tolerance

The authors examined the role of impaired glucose metabolism in the pathophysiology of tardive dyskinesia in schizophrenic patients with and without persistent TD. Glucose tolerance and insulin levels were determined in 86 patients with persistent tardive dyskinesia and in 108 patients without tardive dyskinesia. Dyskinesias were assessed by the abnormal involuntary movement scale (AIMS) and extrapyramidal symptoms by the Simpson--Angus rating scale (SARS). Fasting blood glucose levels were significantly lower while the first and second hour glucose levels did not reveal any differences in patients with tardive dyskinesia compared with those without tardive dyskinesia. Insulin levels did not differ in these two groups. Our cross-sectional epidemiological study does not suggest hyperglycemia to be a risk factor for tardive dyskinesia. However, prospective long-term studies with multiple assessment points are needed to clarify the role of glucose metabolism in the development of tardive dyskinesia.     

More severe neurologic deficits in SJL/J male than female mice following Theiler's virus-induced CNS demyelination

Although multiple sclerosis (MS) is more prevalent in women than men, male MS patients develop more severe clinical symptoms and deteriorate faster than female patients. We investigated the differences in CNS demyelinating disease between SJL/J male and female mice following Theiler's murine encephalomyelitis virus (TMEV) infection. Infected female mice had consistently higher serum levels of virus-specific IgG at 14 and 21 days and and 7 months postinfection, which resulted in less infectious virus in CNS. All male mice infected for 6 to 7 months developed paralysis, with 50% displaying bilateral posterior limb paralysis, whereas 77% of age-matched female mice were paralyzed, all displaying unilateral posterior limb paralysis. Male mice infected for 6 to 7 months performed up to threefold fewer spontaneous horizontal and vertical movements (activity box test) compared to infected age-matched females. In addition, infected male mice performed the coordination and balance (Rotarod) test at 27 +/- 4% of the expected level (expressed as a percentage of that of uninfected age-matched mice), whereas infected female mice performed at 41 +/- 5% of the expected level. Male mice had a small increase in the extent of spinal cord white matter demyelination analyzed at both 45 days and between 6 and 7 months postinfection. For individual male and female mice, the extent of demyelination had a negative linear relationship with the neurologic performances. The emergence of a disease paradigm similar to MS supports using the TMEV model to investigate molecular and genetic factors responsible for the gender dimorphism in MS and other autoimmune diseases.     

Surgical approaches for nonneurogenic elbow heterotopic ossification with ulnar neuropathy

BACKGROUND: Few reports are available concerning elbow heterotopic ossification (HO) and its optimal management in nonneurologic or nonburn patients after repetitive elbow manipulation. The unique anatomic relationship of the ulnar nerve at the elbow renders it rather vulnerable to injury when elbow HO occurs medially or posteromedially and extends into the vicinity of the cubital tunnel. METHODS: A total of 16 consecutive patients without neurologic injury were diagnosed with heterotopic ossification formation in the elbow and referred to the Upper Extremity Unit of Chang Gung Memorial Hospital. All 16 patients were diagnosed with ulnar palsy, and 14 were found to have sensory dysfunction and muscle wasting for an average of 5.2 months. RESULTS: Fourteen of 16 patients achieved functional range of motion or more after surgery. The final gain in range of motion averaged 80.3 degrees. All except one had complete neurologic recovery postoperatively. The patient who had ulnar palsy for 1 year presurgery did not achieve any neurologic recovery. CONCLUSION: Forceful and repetitive manipulation may add further damage to an already stiffened elbow and should be avoided in an elbow after immobilization or surgery. Early surgical resection of HO and ulnar nerve decompression followed by gentle and aggressive physical therapy terminate the vicious cycle and yield encouraging results.     

Arthroscopically assisted osteosynthesis of complex intra-articular fractures of the distal radius

BACKGROUND: Complex intra-articular fractures of the distal radius pose a great challenge in orthopedic surgery. Conventional open reduction and internal fixation generally yields poor functional outcome. The technique of arthroscope-assisted surgery allows more accurate reduction of the articular surface and treatment of soft tissue lesions, both of which are necessary for regaining anatomic structure and satisfactory function. METHODS: Twenty wrists in 18 patients with intra-articular fracture of the distal radius received arthroscopic surgery and percutaneous pinning with or without external skeletal fixation and bone grafting. A new traction method was designed that allows arthroscopic surgery and fluoroscopic monitoring to be performed simultaneously. Postoperative follow-up averaged 24.7 months. RESULTS: All except one of these patients returned to work within 3 to 6 months after surgery. Later collapse with minimal articular step-off was noted on radiographs before osseous union in two patients who did not undergo bone grafting. Decreased radial height because of subsequent displacement at the metaphyseal fracture was noted in one patient who did not receive external skeletal fixation initially. CONCLUSION: The technique of arthroscope-assisted surgery, despite a steep learning curve, is an invaluable method. Results using this technique are promising and few complications are encountered in the treatment of complex radius platform fractures. The bone grafting procedure augments osseous union, shortens the duration of external skeletal fixation, and thus lessens joint stiffness.     

The long-term effect of specific type II 5alpha-reductase inhibition with finasteride on bone mineral density in men: results of a 4-year placebo controlled trial

PURPOSE: We determine the effect of long-term suppression of dihydrotestosterone with finasteride, a specific type II 5alpha-reductase inhibitor, on bone mineral density. MATERIALS AND METHODS: As part of a large (3,040 cases) 4-year, double-blind, placebo controlled trial designed to assess the long-term effects of finasteride in men with benign prostatic hyperplasia, 157 men 46 to 76 years old who were randomized to receive either 5 mg. finasteride or placebo underwent dual energy x-ray absorptiometry of the lumbar spine at baseline and at years 2, 3 and 4. RESULTS: Of 117 patients who had a baseline measurement and at least 1 additional measurement during the study baseline mean plus or minus standard deviation bone mineral density values were 1.12 +/- 0.17 gm./cm.2 in the finasteride group (63) and 1.10 +/- 0.17 gm./cm.2 in the placebo group (54). After 4 years bone mineral density was not different between treatment groups (finasteride 1.14 +/- 0.17 gm./cm.2 and placebo 1.13 +/- 0.18 gm./cm.2). Similar results were obtained for the 33 finasteride and 25 placebo treated patients who completed the study with year 4 bone mineral density measurements. CONCLUSIONS: These data demonstrate that long-term inhibition of type II 5alpha-reductase with finasteride does not adversely affect bone mineral density.     

Early failure of precoated femoral components in primary total hip arthroplasty

BACKGROUND: In an effort to decrease the rate of aseptic loosening, certain cemented femoral components were designed to have a roughened or textured surface with a methylmethacrylate precoating. Reports differ as to whether this step has increased or decreased the rate of failure. This study was designed to evaluate this issue. METHODS: Five hundred and fourteen hips treated with a cemented Harris Precoat stem (Zimmer, Warsaw, Indiana) were evaluated clinically and radiographically and compared with 254 hips treated with an uncoated Harris Design-2 stem (Howmedica, East Rutherford, New Jersey). Prostheses that had been removed at revision were examined. The cementing and surgical techniques were identical and the population demographics were similar for these two groups. RESULTS: The mean durations of follow-up were 8.4 and 13.5 years for the Precoat and uncoated Design-2 stems, respectively. At those times, at least forty-nine (9.5%) of the 514 Precoat components and at least ten (3.9%) of the 254 uncoated Design-2 stems had failed (p = 0.006). Five Precoat stems fractured, and no uncoated Design-2 stems fractured. Component failure was associated with use in young, active, heavy men with a diagnosis of avascular necrosis and generally with the use of smaller components. The cementing technique was satisfactory in the majority of the patients, and there were no qualitative differences in cementing technique between the hips that failed and those that did not. The mechanisms of failure of the Precoat prostheses included bone-cement loosening, focal osteolysis, stem fracture, and prosthesis-cement debonding. Fractures of smaller components occurred as a result of fatigue failure and were associated with good distal fixation but proximal stem loosening. CONCLUSIONS: The rate of failure of roughened, precoated, cemented femoral components was considerably higher and occurred earlier than that of femoral components that were neither textured nor precoated with methylmethacrylate. Younger patients with avascular necrosis had a higher risk of failure; however, this factor alone did not completely explain the differences in outcome between these two components. The causes of aseptic loosening are multifactorial and may be related to component design and size as well as to precoating and surface finish.