Finite element predictions of cartilage contact mechanics in hips with retroverted acetabula.

BACKGROUND: A contributory factor to hip osteoarthritis (OA) is abnormal cartilage mechanics. Acetabular retroversion, a version deformity of the acetabulum, has been postulated to cause OA via decreased posterior contact area and increased posterior contact stress. Although cartilage mechanics cannot be measured directly in vivo to evaluate the causes of OA, they can be predicted using finite element (FE) modeling. OBJECTIVE: The objective of this study was to compare cartilage contact mechanics between hips with normal and retroverted acetabula using subject-specific FE modeling. METHODS: Twenty subjects were recruited and imaged: 10 with normal acetabula and 10 with retroverted acetabula. FE models were constructed using a validated protocol. Walking, stair ascent, stair descent and rising from a chair were simulated. Acetabular cartilage contact stress and contact area were compared between groups. RESULTS: Retroverted acetabula had superomedial cartilage contact patterns, while normal acetabula had widely distributed cartilage contact patterns. In the posterolateral acetabulum, average contact stress and contact area during walking and stair descent were 2.6-7.6 times larger in normal than retroverted acetabula (P ≤ 0.017). Conversely, in the superomedial acetabulum, peak contact stress during walking was 1.2-1.6 times larger in retroverted than normal acetabula (P ≤ 0.044). Further differences varied by region and activity. CONCLUSIONS: This study demonstrated superomedial contact patterns in retroverted acetabula vs widely distributed contact patterns in normal acetabula. Smaller posterolateral contact stress in retroverted acetabula than in normal acetabula suggests that increased posterior contact stress alone may not be the link between retroversion and OA.

Waterhouse-Friderichsen syndrome as a result of non-meningococcal infection.

Waterhouse-Friderichsen syndrome--massive adrenal haemorrhage in the setting of overwhelming clinical sepsis--is usually taken at necropsy to indicate meningococcal infection, and may be the only evidence of this pathogen. This report describes three fatal cases of the syndrome in which the causative organism proved to be a streptococcus. The organisms were detected during routine coroners' autopsies with histology and microbiological investigations. In two cases, the syndrome followed Streptococcus pneumoniae infection and in a third beta haemolytic streptococcus group A. Thus, adrenal haemorrhage alone cannot be taken to indicate meningococcal disease and other pathogens, particularly streptococcus, must be considered.

'Proximal-type' epithelioid sarcoma: is Agent Orange still at large?

BACKGROUND AND AIMS: Proximal-type epithelioid sarcomas of the perineum are extremely rare. The authors provide an overview of this condition in relation to the history of exposure to Agent Orange. PATIENT AND METHODS: A 54-year-old man presented with a rapidly growing perineal subcutaneous mass that was shown to be a proximal-type epithelioid sarcoma. The case is discussed. An Internet Medline search was performed and the current literature reviewed. RESULTS: Only 4 primary perineal sarcomas have been described in the literature. Epithelioid sarcomas are uncommon, aggressive tumours with a propensity for locoregional recurrence. They are recognised by the US Veterans Affairs department as linked to exposure to Agent Orange, an organochlorine defoliant containing the contaminant 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). However, the role of Agent Orange in sarcomagenesis is still controversial. CONCLUSION: Unusual soft tissue swellings in a background of chemical exposure should be investigated thoroughly with a view to early, appropriate treatment.

Patterns of mortality in southern sea otters (Enhydra lutris nereis) from 1998-2001.

Detailed postmortem examination of southern sea otters (Enhydra lutris nereis) found along the California (USA) coast has provided an exceptional opportunity to understand factors influencing survival in this threatened marine mammal species. In order to evaluate recent trends in causes of mortality, the demographic and geographic distribution of causes of death in freshly deceased beachcast sea otters necropsied from 1998-2001 were evaluated. Protozoal encephalitis, acanthocephalan-related disease, shark attack, and cardiac disease were identified as common causes of death in sea otters examined. While infection with acanthocephalan parasites was more likely to cause death in juvenile otters, Toxoplasma gondii encephalitis, shark attack, and cardiac disease were more common in prime-aged adult otters. Cardiac disease is a newly recognized cause of mortality in sea otters and T. gondii encephalitis was significantly associated with this condition. Otters with fatal shark bites were over three times more likely to have pre-existing T. gondii encephalitis suggesting that shark attack, which is a long-recognized source of mortality in otters, may be coupled with a recently recognized disease in otters. Spatial clusters of cause-specific mortality were detected for T. gondii encephalitis (in Estero Bay), acanthocephalan peritonitis (in southern Monterey Bay), and shark attack (from Santa Cruz to Point Año Nuevo). Diseases caused by parasites, bacteria, or fungi and diseases without a specified etiology were the primary cause of death in 63.8% of otters examined. Parasitic disease alone caused death in 38.1% of otters examined. This pattern of mortality, observed predominantly in juvenile and prime-aged adult southern sea otters, has negative implications for the overall health and recovery of this population.

Coastal freshwater runoff is a risk factor for Toxoplasma gondii infection of southern sea otters (Enhydra lutris nereis).

The association among anthropogenic environmental disturbance, pathogen pollution and the emergence of infectious diseases in wildlife has been postulated, but not always well supported by epidemiologic data. Specific evidence of coastal contamination of the marine ecosystem with the zoonotic protozoan parasite, Toxoplasma gondii, and extensive infection of southern sea otters (Enhydra lutris nereis) along the California coast was documented by this study. To investigate the extent of exposure and factors contributing to the apparent emergence of T. gondii in southern sea otters, we compiled environmental, demographic and serological data from 223 live and dead sea otters examined between 1997 and 2001. The T. gondii seroprevalence was 42% (49/116) for live otters, and 62% (66/107) for dead otters. Demographic and environmental data were examined for associations with T. gondii seropositivity, with the ultimate goal of identifying spatial clusters and demographic and environmental risk factors for T. gondii infection. Spatial analysis revealed clusters of T. gondii-seropositive sea otters at two locations along the coast, and one site with lower than expected T. gondii seroprevalence. Risk factors that were positively associated with T. gondii seropositivity in logistic regression analysis included male gender, older age and otters sampled from the Morro Bay region of California. Most importantly, otters sampled near areas of maximal freshwater runoff were approximately three times more likely to be seropositive to T. gondii than otters sampled in areas of low flow. No association was found between seropositivity to T. gondii and human population density or exposure to sewage. This study provides evidence implicating land-based surface runoff as a source of T. gondii infection for marine mammals, specifically sea otters, and provides a convincing illustration of pathogen pollution in the marine ecosystem.

Liver biopsy in psoriatic arthritis to detect methotrexate hepatotoxicity.

The use of methotrexate in the treatment of psoriatic arthritis is associated with risk of hepatotoxicity. However, monitoring of liver-associated enzymes often lacks sensitivity, and guidelines for serial liver biopsies in psoriatic arthritis are not yet well established. We performed a retrospective review of all patients with psoriatic arthritis receiving methotrexate who were enrolled in the disease-modifying anti-rheumatic drug clinics (DMARD clinics) at the Air Force and Army hospitals in San Antonio, Texas. Information was obtained regarding methotrexate regimen, liver-associated enzyme results, and liver biopsy results. Thirty psoriatic arthritis patients were taking methotrexate in the DMARD clinics. Seventeen patients had a total of 21 biopsies. Biopsies were performed for surveillance dictated by cumulative dose. Liver biopsies were graded on Roenigk scale of I-IV where I is mild steatosis, II is moderate steatosis, IIIa is mild fibrosis, IIIb is severe fibrosis, and IV is cirrhosis. Ten biopsies were grade I, 5 were grade II, 5 were grade IIIa, 1 was grade IIIb, and none were grade IV. In this very small retrospective study, regular monitoring of liver-associated enzymes did not correlate with histologic deterioration in our patients. Until prospective studies are performed, we suggest that routine liver biopsies are necessary to monitor for methotrexate hepatotoxicity in psoriatic arthritis.

Vasculitis following treatment of rheumatoid arthritis with extracorporeal staphylococcal protein a immunoadsorption column (prosorba).

We report a case of vasculitis after Prosorba treatment in a patient with rheumatoid arthritis. The patient is a 66-year-old white male with long standing rheumatoid arthritis and hepatitis B. He was treated with the standard regimen for Prosorba treatment. He improved and met criteria for an American College of Rheumatology (ACR) 20% response. While on therapy he developed a nonhealing ulcer. Approximately 2 weeks after treatment was completed, he developed palpable purpura and mononeuritis multiplex. Deep dermal biopsy confirmed the presence of both small and medium vessel vasculitis. Nerve conductions studies were consistent with neuropathic conduction delays. He was treated with 1mg/kg/day of oral prednisone. Prosorba has been reported to cause leukocytoclastic vasculitis during treatment, but has not been noted to involve medium sized vessels. This patient's history and presentation are most consistent with rheumatoid arthritis associated vasculitis, though the Prosorba treatment cannot be ruled out as a cause or a contributing factor. Importantly, although Prosorba treated his synovitis, it did not prevent concomitant vasculitis.

Artificial insemination outcomes in beef females using bovine sperm with a detectable fertility-associated antigen.

In this study, semen samples from 25 bulls that had passed a breeding soundness evaluation were analyzed for the presence or absence of a 31-kDa protein, known as fertility-associated antigen (FAA), on spermatozoal membranes. Eighteen bulls had FAA on sperm (FAA-positive) and seven were devoid of FAA on sperm (FAA-negative). A single ejaculate from each bull was extended and frozen with 25 to 30 x 10(6) sperm in .5-mL straws. Crossbred replacement heifers (n = 865) were estrus-synchronized and artificially inseminated either at timed AI or 12 h after they were detected in estrus. Mature cows (n = 285) were inseminated 12 h after they were detected in estrus during a 45-d AI period. Pregnancy rates (pooled) to first AI service for females (n = 764) inseminated with FAA-positive sperm were 65.6% and were 49.7% for females (n = 386) inseminated with FAA-negative sperm (P < .005). Among the estrus-synchronized replacement heifers, pregnancy rates to synchronized AI service for heifers (n = 550) inseminated with FAA-positive sperm were 62% and were 45.7% for heifers (n = 315) inseminated with FAA-negative sperm (P < .005). These data indicate that pregnancy rates to first AI service at spontaneous and synchronized estrus are higher when using semen from bulls with detectable FAA on spermatozoal membranes compared to semen from bulls devoid of FAA on membranes. Fertility-associated antigen is an important determinant for fertility potential of sperm from bulls to be used in AI breeding programs.

Comparing traditional Medicare and managed care Medicare.

The current healthcare environment presents multiple challenges and opportunities. Patients need in-home health services and managed care companies require prior approvals for these services. There are many demands on the time of home healthcare nurses and supervisors. The following suggestions are offered with the goal of saving time and energy while getting the task accomplished so that patients receive the care they need: Cultivate an ideal relationship with your insurers' case managers. Be flexible. Communicate pertinent information to whomever is responsible for seeking approvals. Provide high-quality patient care that is reflected in the documentation. Inform patients of the prior authorization process as it relates to their home healthcare services (Harris, Lynch, 1996). Fischer and Hurst (1997, p. 16) state that home care providers should adopt a managed care mentality. Linda Pulliam (1989) shared a list of survival skills during a presentation. One of these is "make friends with this changing world" (p. 1). This is excellent advice for all healthcare nurses as we meet the current challenges and anticipate the new ones in the 21st century.

Factors influencing condylar position after the bilateral sagittal split osteotomy fixed with bicortical screws.

PURPOSE: Multiple articles have discussed condylar position after bilateral sagittal split osteotomy (BSSO). However, previous studies have been limited to two-dimensional evaluation of condylar position. The purpose of this study was to evaluate change in condylar position after a BSSO fixed with bicortical screws using three-dimensional computed tomography to assess the factors that may influence the ultimate position of the condyle after surgery. PATIENTS AND METHODS: Seventeen patients underwent isolated mandibular advancement involving a BSSO with rigid fixation. Reformated axial computed tomography was done 1 week before and 8 weeks after surgery. Movements evaluated included 1) medial-lateral, 2) superior-inferior, 3) anterior-posterior, and 4) condylar angulation. Three separate factors were analyzed to study their effects on the four movements noted: 1) amount of mandibular advancement, 2) amount of proximal segment rotation, and 3) preoperative shape of the mandible. A linear regression analysis was used with statistical significance set at P<.05. RESULTS: Eight weeks after a BSSO and mandibular advancement, most cases showed displacement of the condyle medially, posteriorly, superiorly, and angled medially. The amount of mandibular advancement did not correlate with medial-lateral change of the condyle. The amount of advancement correlated with the condyle angulation and superior-inferior changes in condyle position. There was no correlation between amount of advancement and medial or anterior-posterior change in condyle position. There also was no correlation between any of the condylar movements and the degree of proximal segment rotation or the shape of the mandible. CONCLUSIONS: There are obvious changes in condyle position after a BSSO. These changes appear to be influenced mainly by factors other than amount of advancement, degree of proximal segment rotation, and shape of the mandible.

Gout and hyperuricemia.

Gout is a condition characterized by the deposition of monosodium urate crystals in the joints or soft tissue. The four phases of gout include asymptomatic hyperuricemia, acute gouty arthritis, intercritical gout and chronic tophaceous gout. The peak incidence occurs in patients 30 to 50 years old, and the condition is much more common in men than in women. Patients with asymptomatic hyperuricemia do not require treatment, but efforts should be made to lower their urate levels by encouraging them to make changes in diet or lifestyle. Acute gout most commonly affects the first metatarsal joint of the foot, but other joints are also commonly involved. Definitive diagnosis requires joint aspiration with demonstration of birefringent crystals in the synovial fluid under a polarized light microscope. Treatment includes nonsteroidal anti-inflammatory drugs (NSAIDs), colchicine, corticosteroids and analgesics. In patients without complications, NSAID therapy is preferred.

Effect of in vitro generation of oxygen free radicals on T cell function in young and old rats.

T cells from young (6 months) and old (24 months) male Fischer 344 rats were isolated and exposed to three different oxidative stress conditions: (a) reactive oxygen species generated by xanthine-xanthine oxidase (X/XO), (b) hydrogen peroxide (H2O2), and (c) hyperthermia (43 degrees C for 1 h). After oxidative stress treatment, the induction of proliferation and IL-2 production by concanavalin A (Con A) was measured. Exposure of T cells to X/XO or H2O2 resulted in suppression of proliferation and IL-2 expression, and the suppressive effect was more pronounced in T cells from young rats than in T cells from old rats. Similarly, hyperthermia caused inhibition of proliferation and IL-2 expression in T cells from young and old rats. Addition of antioxidant to cultured cells only slightly attenuated the effects of X/XO and H2O2 on T cell function; however, antioxidant had no effect on heat shock-mediated inhibition of proliferation in young or old rats. Because IL-2 plays a crucial role in T cell proliferation and because the transcription factor NFAT (nuclear factor of activated T cell) plays a major role in the regulation of IL-2 transcription, the induction of NFAT as well as NF-KB and AP-1 DNA binding activities in nuclear extracts of the X/XO-treated and untreated control cells was measured using a gel shift assay. The ability of nuclear extracts to bind NFAT or NF-KB oligonucleotide decreased in the X/XO-treated cells from young and old rats compared to the untreated controls. Therefore, these data imply that reactive oxygen species generated by the X/XO system alter the distal step of mitogen-mediated signal transduction, i.e., transcription factors that regulate IL-2 transcription.

The physician as a member of the home healthcare team.

The physician is a vital member of the home healthcare team. Based on the Medicare legislation and regulations. The physician's participation is required for patient care and agency reimbursement. The home health care nurse is the important link between the patient and the physician. The compliance with, and sharing of, information related to the clinical, administrative, legislative and regulatory aspects of care benefits the patient, family, physician, nurse and the home health agency.