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Biomedical subjects

T T Yoshikawa

Publications and source records attributed to T T Yoshikawa.

At least 19 recordsLinked to original sources
PubMed1996

Fever in the elderly.

Fever in elderly persons is only one clinical presentation that can be used to assist the clinician at suspecting a serious disease, such as an infection. Infections, like all other illnesses in the geriatric patient, may occur with a variety of nonspecific, atypical, nonclassic, and unusual manifestations. The clinician caring for elderly patients should be aware of these nonclassical presentations of infections in this age group. Unexplained change in functional capacity, worsening of mental status, weight loss or failure to thrive, weakness and fatigue, falls, and generalized pain are only some of the clues that may aid the clinician in considering infection in elderly persons. Key concepts of fever in older adults are: Fever generally indicates presence of serious infection, most often caused by bacteria. Fever may be absent in 20%-30% of elderly patients harboring a serious infection. Criteria for fever in elderly patients should also include an elevation of body temperature of at least 2 degrees F from baseline values. FUO in elderly persons is caused by infections (30%-35%), CTD (25%-30%), and malignancies (15%-20%) in the majority of cases.

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PubMed1996

Management of complicated urinary tract infection in older patients.

Urinary tract infection (UTI) in older persons is a common medical problem that is seen in both the ambulatory and institutional settings. It affects older women and men with a gender prevalence ratio of 2:1, respectively. UTI in older persons can be a complex problem in terms of the approach to diagnosis, treatment, and prevention. In this report the discussion will begin with the unique aspects of UTI in older persons, particularly as they relate to UTI in the younger, general population. The remaining discussion will then focus on three complicated clinical circumstances and conditions of UTI in the geriatric population: non-catheter recurrent UTI, asymptomatic bacteriuria, and catheter-related bacteriuria and UTI.

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PubMed1996

Approach to fever and infection in the nursing home.

OBJECTIVE: To summarize current information on the scope, epidemiology, clinical manifestations, diagnostic approach, and general management of infectious diseases in nursing home residents, as well as the specific treatment of common infections occurring in the nursing home setting. DESIGN: Survey and literature review of the diagnostic and therapeutic problems of nursing home residents with infections. CONCLUSIONS: Older persons residing in nursing homes as well as other types of long-term care facilities are at increased risk for infections. Moreover, infection is the most frequent reason for patients to be transferred from nursing homes to an acute-care facility. The most common infections that are acquired in nursing homes are urinary tract infection (cystitis pyelonephritis), respiratory infections (pneumonia, bronchitis), and skin/soft tissue infections (infected pressure ulcers, cellulitis). Most serious infections in this setting are caused by bacteria; however, influenza and other respiratory viruses as well as herpes zoster may cause significant morbidity in older nursing home residents. Mycobacterium tuberculosis infects nursing home residents at a higher rate than it infects older community dwellers. Infections in older nursing home residents may manifest clinically, with atypical symptoms and signs, including the absence of fever. Rapid diagnostic evaluation and early therapeutic intervention are essential for minimizing the high mortality and morbidity associated with infections in this older population; most nursing home residents with serious infections should be considered for hospitalization.

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PubMed1995

Interrelationship of fever, immune response and aging in mice.

Fever is the cardinal manifestation of infection and may be blunted in certain infected elderly individuals. It is known that elevated body temperature enhances both the inflammation response and immune function, resulting in increased host resistance to infection. Recently, it has been suggested that the elevation of body temperature and the activation of lymphocytes by IL-1 are interrelated host effects. However, the question of whether fever response in vivo is closely correlated to cell-mediated immune parameters is unknown. In this study, a well-defined murine model was used to study the relationships between aging, fever and cell-mediated immune response. Thus, measurements of rectal temperature changes were made in individual young (4-6 months) and old (26-27 months) BALB/c mice to determine their ability to respond to endogenous pyrogen (recombinant IL-1). Splenic cells from these animals were used to assess T- and B-cell proliferation, production of interleukin 1 (IL-1) and IL-2. The results revealed that the proliferative capacity and the IL-1 and IL-2 producing capacity of splenic cells from old mice were markedly decreased. However, aging did not significantly affect the mean febrile responses in old mice following rIL-1 injections. Finally, there was no significant correlation between in vivo fever responses and the immune parameters measured in vitro in both young and old mice.

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PubMed1995

Treatment of infections in elderly patients.

Infections are common in elderly persons. The clinical manifestations of infection may be atypical or absent in the elderly. The microbial cause for many common infections may be more diverse in elderly patients, and obtaining diagnostic clinical specimens often is more difficult. Aging is associated with changes in pharmacokinetics and a higher rate of adverse drug reactions. These factors impact on the approach to treating infections in the elderly.

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PubMed1995

Effect of age on fever response to recombinant interleukin-6 in a murine model.

BACKGROUND: A blunted or absent fever response to infection may occur in elderly people. Fever is mediated by endogenously produced molecules of leukocytes. The best studied of these molecules is interleukin-1 (IL-1). However, interleukin-6 (IL-6) is also known to possess the biological properties of pyrogenic cytokines. In this study, we assessed the influence of age on the febrile response to recombinant IL-6 (rIL-6) using a well-defined murine model. METHODS: Balb/c male mice were injected intravenously and intraperitoneally with varying doses of rIL-6. Control mice received pyrogen-free phosphate buffered saline. Temperatures were measured rectally at baseline and at 10-minute intervals for 120 minutes post-injection using a thermistor probe. Stable baseline temperatures were first determined, and post-injection temperatures were recorded every 10 minutes for up to 120 minutes. RESULTS: A dose-response correlation was found between the amount of the injected rIL-6 and the mean temperature changes in both young and old mice. The mean temperature changes for both young and old mice were higher following a 25 ng dose compared to a 12.5 ng dose of rIL-6 injected intravenously, and, likewise, following a 500 ng dose compared to a 250 ng dose of rIL-6 injected intraperitoneally. A significant delay in the peak temperature response was seen for both young and old mice when comparing intraperitoneal injections to intravenous injections. However, control mice showed no changes. CONCLUSIONS: Our findings confirm that IL-6 has a role in the pathogenesis of fever and that aging alters the febrile response to rIL-6.

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PubMed1995

Infection control in long-term care.

Elderly residents of long-term care facilities are especially vulnerable to certain infectious diseases such as pneumonia, urinary tract infection, and skin or soft tissue infections. As part of quality of care, the detection, control, and prevention of infections in long-term care facilities through an organized infection control program is a requirement of federal, state, and professional regulatory agencies. Implementation of the major components of an infection control program requires a cooperative interdisciplinary effort among the facility administration, medical director, infection control committee, infection control practitioner, staff, and local health department.

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PubMed1994

Infections of the bone, joint, and bursa.

Infections of the skeletal system, specifically bone, joint, and bursa, cause major morbidity as well as substantial number of deaths in older patients. In this article, the discussion focuses on the cause, pathogenesis, microbial causes, diagnosis, treatment, and available preventive interventions of septic arthritis, prosthetic joint infection, setic bursitis, and osteomyelitis in elderly patients.

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PubMed1991

Fever response in elderly nursing home residents: are the older truly colder?

OBJECTIVE: To test the hypothesis that many nursing home residents with an apparently blunted fever response (maximum temperature less than 101 degrees F) may actually have a significant change in temperature (delta T greater than or equal to 2.4 degrees F) which is not recognized because of a low baseline temperature. DESIGN: Retrospective chart review for cases of infection that met specific criteria and for chart-recorded baseline and infection temperatures. Chart-recorded baseline temperatures were prospectively compared with re-measurement of morning temperatures. SETTING: Nursing Home Care Unit of the VAMC West Los Angeles. PATIENTS: Random review of 40 residents' charts resulted in the detection of 69 infections among 26 residents over a 20-month period. Fifty randomly selected residents prospectively underwent comparison of chart-determined and actual re-measurement of baseline temperatures. RESULTS: In 50 randomly selected residents, the mean oral baseline temperature of 97.4 +/- 0.2 (degrees F +/- SEM) closely approximated the mean nurse-recorded measures in the charts (97.6 +/- 0.1). Chart review detected 69 infections among 26 residents, with 53 episodes having a temperature recorded during the infection. The mean maximum temperature (Tmax) during an infection was 101.3 +/- 0.3 (degrees F +/- SEM) but 47% (25/53) of the episodes had a "blunted" fever response (Tmax less than 101 degrees F). Of the 25 "blunted" fevers (Tmax less than 101 degrees F), about one-fourth demonstrated an adequate change in temperature from baseline (delta T greater than or equal to 2.4 degrees F) but failed to reach 101 degrees F because of a low baseline. Most infections (89%) had a Tmax greater than 99 degrees F. CONCLUSION: Establishing a nursing home patient's basal temperature and monitoring for changes in temperature (delta T greater than 2.4 degrees F) and/or lowering the threshold for recognition of fevers (to 99 degrees or 100 degrees F) in nursing home residents with a change in function should assist in early recognition of infections.

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PubMed1990

Pathogenesis, management, and prevention of infective endocarditis in the elderly dental patient.

Aortic stenosis and mitral valve insufficiency are common precipitating causes of infectious endocarditis in older persons. These degenerative cardiac valvular lesions may result from an exaggerated calcification process seen in association with aging. Mitral valve prolapse, especially when noted in an older man, may predispose the person to infectious endocarditis. Infectious endocarditis is harder to diagnosis and treat in older persons, and about half of patients die of the disease or its complications. Prophylactic antibiotics must be prescribed for patients with degenerative cardiac or atherosclerotic valvular defects having dental procedures likely to produce a bacteremia.

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