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Biomedical subjects

G Ho

Publications and source records attributed to G Ho.

At least 55 records · Page 3Linked to original sources
PubMed1994

Bacterial endocarditis and septic arthritis presenting as polymyalgia rheumatica.

We describe a case of enterococcus endocarditis in a 74-year-old woman with hypercholesterolemia, porcine aortic valve, and osteoarthritis. She presented with the abrupt onset of severe back pain, proximal myalgia, and left knee synovitis, associated with an anemia and marked elevation of ESR. She was misdiagnosed as having polymyalgia rheumatica until both the synovial fluid and blood cultures grew enterococcus. Her musculoskeletal symptoms totally resolved with antibiotic treatment. Septic arthritis is a rare manifestation of bacterial endocarditis. However, one-third of all cases of bacterial endocarditis have musculoskeletal symptoms. These include backache, arthritis of the peripheral joints, and diffuse myalgia and arthralgia. Unexplained rheumatic complaints should alert us to the possibility of bacterial endocarditis.

Aged↗
PubMed1993

Gout and pseudogout in hospitalized patients.

BACKGROUND: We determined the clinical characteristics of acute gout and pseudogout in hospitalized patients and examined the morbidity of inappropriate treatment and misdirected investigation when the diagnosis of acute crystal-induced synovitis was delayed. PATIENTS AND METHODS: We reviewed the medical records of 67 hospitalized adults seen in consultation consecutively by one hospital-based rheumatologist during a 64-month period between 1986 and 1991 with the diagnosis of acute gout or pseudogout. RESULTS: Gout was diagnosed in 41 patients, pseudogout in 24, and both crystal-induced diseases in two. The average age was 75.3 years. Polyarticular disease was common in both gout (49%) and pseudogout (42%). Fever attributable to synovitis was present in 34% of the patients and was more prevalent in patients with polyarticular (50%) than monoarticular (20%) inflammation. A quarter of the patients encountered errors in diagnosis, treatment, or both before rheumatologic consultation. Eleven patients experienced delays in diagnosis, and six patients had the correct diagnosis but received ineffective treatment. CONCLUSIONS: Fever and polyarticular arthritis are noteworthy features in the hospitalized patient with acute gout or pseudogout. When the diagnosis of crystal-induced synovitis is overlooked, misdirected investigation and inappropriate treatment compound the morbidity of continued pain.

Adult↗
PubMed1993

Hypoxic forebrain cholinergic neuron injury: role of glucose, excitatory amino acid receptors and nitric oxide.

Glucose depletion increased sensitivity to hypoxic insult in basal forebrain forebrain cultures in a dose-dependent manner as indicated by reduction of choline acetyltransferase (ChAT) activity, increased lactate dehydrogenase (LDH) release and disrupted morphology. The glutamate receptor antagonists 2-amino-5-phosphonovaleric acid (APV) and 6-cyano-2,3-nitroquinoxoline (CNQX) limited the degree of injury in combination and individually. The nitric oxide synthase (NOS) inhibitor N-nitro-L-arginine (NNLA) also either completely protected against mild injury or attenuated severe injury.

2-Amino-5-phosphonovalerate↗
PubMed1993

Bacterial arthritis.

The 1992 literature on septic arthritis reiterated the factors that portend a poor outcome in septic arthritis. However, we still know very little about how to improve the outcome for such patients. Infections of the musculoskeletal system may be more common among patients with HIV than the reported cases indicate. Bacterial endocarditis is frequently associated with musculoskeletal complaints. Low back pain may be a presenting manifestation. Acute gout and septic arthritis can cause peripheral arthritis in some patients with bacterial endocarditis. Septic arthritis can present unusual manifestations and can occur as a complication of arthroscopic surgery; the risk factors for its development after arthroscopy have been identified. Arthroscopy as a therapeutic procedure to drain an infected joint is discussed.

Adult↗
PubMed1992

Effects of analysis method and forcing waveform on measurement of respiratory mechanics.

The respiratory system has been shown to exhibit nonlinear mechanical properties in the frequency (f) range of normal breathing, manifested by tidal volume (Vt) dependence. Calculations of respiratory system resistance (R) and elastance (E) from pressure-flow measurements during external forcing at a given f may be ambiguous, especially if non-sinusoidal forcing waveforms are used. We evaluated the degree to which R and E depended upon: (1) analysis method (Fourier transform, multiple regression and pressure-volume loop analysis) and; (2) shape of the forcing waveform (sinusoidal, quasi-sinusoidal and step). We measured pressure and flow at the mouth of 5 healthy, awake subjects, relaxed at functional residual capacity, during forcing with the three different waveforms in the normal range of f (0.2-0.6 Hz) and Vt (250-750 ml). During sinusoidal forcing, E and R were not affected by analysis method (P greater than 0.2). With Fourier transform and multiple regression, E was not affected by waveform shape (P greater than 0.05); with loop analysis, E was slightly (less than 10%) higher during quasi-sinusoidal and step forcing than during the sine (P less than 0.05). R was least affected by waveform shape with Fourier transform. We conclude that, in the f and Vt range of normal breathing: (1) respiratory system impedance is 'quasi-linear,' i.e. despite dependencies of R and E on Vt, non-linearities are not large enough to restrict interpretation of R and E at a given f and Vt; (2) it may be possible to measure R and E using non-sinusoidal forcing waveforms available on most clinical ventilators, incurring only modest error.

Adult↗
PubMed1992

Bacterial arthritis.

The 1991 literature on septic arthritis included a concise review of adult septic arthritis, examples of pseudoseptic arthritis, and two interesting animal studies. One animal study examined the induction of acute synovitis by the intra-articular injection of bacterial endotoxin and the cytokines tumor necrosis factor-alpha, and interleukin-1 beta; and the other studied the effects of early and delayed synovectomy in the management of septic arthritis. The predispositions to septic arthritis can be divided into local joint abnormalities, systemic factors, or both. Examples of the local joint abnormalities include osteoarthritis of the hip and apatite-associated arthropathy. Septic arthritis in a patient with rheumatoid arthritis, in a patient with diabetes mellitus and hip arthropathy associated with hemochromatosis, or in a patient with acquired immunodeficiency syndrome and hemophilic arthropathy are examples of how systemic predisposition is coupled with local joint pathology to increase the vulnerability of the host to joint infection. Other examples of systemic disease that predispose to septic arthritis are systemic lupus erythematosus, hypogammaglobulinemia, and human immunodeficiency virus infection, as well as intravenous drug abuse. Unusual microorganisms causing septic arthritis in the adult include Achromobacter xylosoxidans, Moraxella catarrhalis, meningococci, and diphtheroids. Uncommon pathogenesis is represented by a case of intra-articular inoculation of Mycobacterium gastri into the small joint of the hand and a case of mixed bacterial infection of the hip resulting from an extension of a contiguous pelvic infection associated with trauma. Two cases of immune complex glomerulonephritis illustrate the extra-articular complications of septic arthritis: one due to group G streptococcus and the other due to pneumococcus. Finally, septic bursitis is reviewed from the community practice perspective.

Animals↗
PubMed1991

Bacterial arthritis.

In this review of the 1990 septic arthritis literature, we revisit synovial fluid leukocytosis, examine the utility of synovial fluid glucose and protein measurements, and look at the levels of two cytokines, tumor necrosis factor and interleukin-1, in infected joint fluids. We see the many faces of gonococcal arthritis and the ravages of septic arthritis when the host has rheumatoid arthritis. Should we recommend antibiotic prophylaxis for the rheumatoid patient with a prosthetic joint who is undergoing a procedure that leads to transient bacteremia? What are some of the salient features of septic arthritis when it involves the sternoclavicular or sacroiliac joints? We also look at some unusual microorganisms, eg, group C Streptococcus, Streptococcus viridans, Listeria monocytogenes, Pseudomonas cepacia, Pseudomonas maltophilia, and Neisseria sicca. In patients with acquired immunodeficiency syndrome, we encounter reports of septic arthritis, osteomyelitis, and spinal epidural abscess caused by opportunistic microorganisms. Two unusual sites of infection include the C1-2 lateral facet joint and subacromial bursa without involvement of the glenohumeral joint. Finally, we examine how to drain a septic knee: the orthopedic point of view.

Arthritis, Infectious↗
PubMed1989

Urate-mediated inflammation in nodal osteoarthritis: clinical and roentgenographic correlations.

We studied 25 patients with crystal-proven gout or roentgenographic evidence of gouty arthritis, or both, in finger joints involved with nodal osteoarthritis (OA). These patients were elderly (mean age 71.4 years), and 72% of them were receiving diuretic therapy. Roentgenographic findings, in addition to features typical of OA, included soft tissue densities (tophi), with or without calcification, large intraarticular erosions, characteristic nonmarginal cortical erosions, and periarticular osteolysis. We conclude that urate crystals mediate episodes of acute inflammation in certain patients with nodal OA. This association is noted primarily in elderly patients of both sexes, especially in those receiving diuretic therapy.

Acute Disease↗
PubMed1989

Collateral circulatory development in skeletal muscle.

The arterial collateral anastomoses in rectus abdominis of the dog are employed as an animal model. The dynamic changes of collateral channels have been uncovered during roestablishment of collateral circulation. The experimental results display the 3 morphological characters, calibre dilatation, cell proliferation, and vessel reconstruction, at different time intervals in the collateral development. It provides evidence that some useful programme can be added to get a more effective collateral circulatory function in clinical practice.

Abdominal Muscles↗
PubMed1989

Ovine-associated Staphylococcus aureus protein with immunochemical similarity to toxic shock syndrome toxin 1.

A toxic shock syndrome toxin 1 (TSST-1) antibody-binding protein produced by an ovine-associated strain of Staphylococcus aureus was examined. The protein showed total identity to TSST-1 by immunodiffusion analysis. Western blots (immunoblots) of proteins separated by isoelectric focusing revealed that the TSST-1 antibody-binding protein had a pI of 8.6 rather than 7.0, the pI of standard TSST-1.

Animals↗
PubMed1989

Production of a toxic shock syndrome toxin variant by Staphylococcus aureus strains associated with sheep, goats, and cows.

A toxic shock syndrome toxin (TSST) variant with an isoelectric point (pI) of 8.6 produced by an ovine-associated Staphylococcus aureus strain was described previously. Analysis of additional strains associated with sheep, goats, cows, and humans by isoelectric focusing with immunoblotting using monoclonal antibodies revealed that all 18 strains associated with sheep and all 12 strains associated with goats produced the TSST variant. Only 1 of 10 bovine-associated strains and no human-associated strains produced the variant, whereas the others produced TSST-1 (pI between 7.0 and 7.2). Sodium dodecyl sulfate-polyacrylamide gel electrophoresis with immunoblotting indicated that both TSST-1 and the TSST variant had a molecular size of 24 kilodaltons.

Animals↗
PubMed1988

Evaluation of the effect of norfloxacin on the pharmacokinetics of theophylline.

To investigate a possible interaction between norfloxacin and theophylline, eight healthy nonsmoking volunteers (mean age 27 +/- 5.3 years) were administered aminophylline, 5 mg/kg, before and after a 6-day course of norfloxacin, 400 mg every 12 hours, and changes in pharmacokinetic parameters were measured and compared. Norfloxacin induced significant decreases in theophylline clearance (14.9%; p less than 0.01) and the terminal phase slope (13.3%; p less than 0.02) and increased the AUC (16.6%; p less than 0.01). The apparent volume of distribution at steady state was unchanged. The greatest norfloxacin-induced individual change in theophylline clearance was a reduction of 28.6%. Given these findings, we advise that, for patients who are treated with theophylline and are subsequently treated with norfloxacin, adjustment of the theophylline dosage may be necessary in some patients to minimize the risk of theophylline toxicity.

Adult↗
PubMed1988

Elbow pain.

Nonarticular causes of elbow pain include muscle strains, ligamentous injuries, epicondylitis, olecranon bursitis, and compressive neuropathies. Overuse and trauma commonly cause these conditions. The history and physical examination differentiate them from an intra-articular process such as synovitis. Laboratory analysis of fluid aspirated from a swollen olecranon bursa is necessary to differentiate infection or gout. X-rays are useful in avulsion fracture, osteochondritis dissecans, and epiphyseal separation. Electromyography with nerve conduction velocities can localize the site of nerve entrapment. Treatment, in general, consists of prevention from further overuse, protection by rest and splinting to allow healing, pharmacologic intervention to reduce inflammation, relieve pain and combat infection, and physical therapy to restore motion and function. Surgery may be necessary to repair torn muscle, to release the wrist extensors in refractory lateral epicondylitis, and to decompress an entrapped nerve.

Elbow↗