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Biomedical subjects

C F Farthing

Publications and source records attributed to C F Farthing.

13 recordsLinked to original sources

Evaluation of a hydrogen peroxide disinfectant for dental unit waterlines.

BACKGROUND: The purpose of this study was to investigate the use of a hydrogen peroxide-based dental unit waterline, or DUWL, treatment to reduce the colonization and growth of heterotrophic bacteria. METHODS: Twenty-three dental units with self-contained water systems were randomly selected. Three of the units and tap water served as controls. Twenty-four water samples were taken at baseline and once a week for five weeks. They were serially diluted, spread-plated in duplicate onto R2A agar plates and incubated at 37 C for seven days. RESULTS: At baseline, the tap water control had a mean count of 0 colony-forming units/milliliter, or CFU/mL, the three control DUWLs had a median count of 8,440 CFU/mL and the 20 treated DUWLs had a median count of 9,760 CFU/mL. By week 1, 19 (95 percent) of the 20 treated DUWLs had counts of less than 200 CFU/mL, and by week 4, the median count for all of the treated DUWLs was 0 CFU/mL. The measurement at week 5 showed that the reduction to below 200 CFU/mL had been maintained. Scanning electron micrographs from processed DUWL tubing samples revealed a similar pattern of results, with biofilm accumulation more evident in the untreated control specimens. CONCLUSIONS: Following the parameters of this study, the authors used a hydrogen peroxide-based disinfectant to achieve the ADA goal of no more than 200 CFU of heterotrophic, mesophilic bacteria per milliliter of unfiltered output water. CLINICAL IMPLICATIONS: An easy-to-use hydrogen peroxide-based DUWL disinfectant demonstrated effectiveness in improving the quality of water used for intraoral procedures. Protocol compliance meets the ADA year 2000 goal.

Anti-Infective Agents, Local↗

Many patients suffer from 'battle fatigue': survey.

A new survey underscores the problem of HIV patients' 'battle fatigue,' caused by years of taking antiretroviral drugs and coping with their side effects. AIDS Alert talks with survey consultant Charles F. Farthing, MD, chief of medicine at the AIDS Healthcare Foundation Healthcare Center in Los Angeles and assistant clinical professor of medicine at the University of California at Los Angeles, to discuss the problem of AIDS battle fatigue and summarize the survey's findings.

Anti-HIV Agents↗

Increased CD4+ T-lymphocyte senescence fraction in advanced human immunodeficiency virus type 1 infection.

Human immunodeficiency virus type 1 (HIV-1) infection is accompanied by peripheral CD4+ T-cell losses. CD4+ T-cell numbers often increase during antiviral treatment of acquired immune deficiency syndrome (AIDS), however, alterations in the CD4+ T-cell repertoire have not been completely corrected for these patients. Such individuals remain at increased risk of infection. Although senescence of the CD4+ T cells has not been adequately evaluated for advanced HIV-1 infection, hypothetically, replicative senescence could complicate therapeutic reconstitution of the CD4+ T cells in AIDS. In this study, correlates of replicative senescence, terminal restriction fragment (TRF) length and percentage short (< 5.0 kb) telomeric DNA (senescence fraction), were measured for the CD4+ T cells of HIV-1-infected patients with peripheral CD4+ T-cell counts of < 200/mm3. The results show that for advanced HIV-1 infection the TRF length of the CD4+ T cells is decreased (P < 0.01), and the senescence fraction increased (P < 0.05), when compared with uninfected controls. These findings suggest that cellular senescence may contribute to disruption of CD4+ T-cell diversity observed following the therapeutic, immunologic reconstitution of AIDS.

Adult↗

Phosphonoformate (foscarnet): a pilot study in AIDS and AIDS related complex.

Phosphonoformate (PFA; a pyrophosphate analogue) is an effective inhibitor of the reverse transcriptase enzyme in many animal retroviruses. In vitro studies have shown that PFA is also an effective inhibitor of HIV (HTLV III/LAV) at doses readily attainable in vitro. A pilot study was therefore performed with a 3-week intravenous infusion of PFA in 11 patients with AIDS and AIDS-related complex (ARC). Viral isolations were performed before and at regular intervals up to 3 months post-infusion on treated patients, as well as on four untreated control patients. Virus isolation was negative after therapy in eight patients, six of whom were negative throughout the follow-up period. Virus was isolated on 70% of attempts from the four control subjects and on 20% of attempts from treated subjects. Three patients showed an improvement in delayed hypersensitivity responses. No obvious improvement was seen in patients' OKT4 positive lymphocyte counts. Treatment was not limited by side-effects with the exception of one patient who developed an axillary vein thrombosis within 4 days of treatment via a subclavian line. Treatment was therefore discontinued following administration of only one dose and the patient was excluded from further study. A further patient had reversible renal dysfunction. Other side-effects were minor, consisting of headache or thrombophlebitis at the site of infusion. These results suggest that a further trial with PFA administered over a longer period and with a longer follow-up period in AIDS and ARC patients may be warranted, particularly if an oral preparation becomes available.(ABSTRACT TRUNCATED AT 250 WORDS)

AIDS-Related Complex↗

Clinical investigations of lymphadenopathy, including lymph node biopsies, in 24 homosexual men with antibodies to the human T-cell lymphotropic virus type III (HTLV-III).

The findings of 27 lymph node biopsies performed on 24 homosexual patients with lymphadenopathy are presented. Six had acquired immune deficiency syndrome (AIDS) and 18 lymphadenopathy only, of whom one subsequently developed AIDS. All these patients had antibodies to the human T-cell lymphotropic virus type III (HTLV-III) suggesting that HTLV-III is currently the commonest cause of lymphadenopathy in homosexual men. The histopathological findings of six of seven nodes from AIDS patients showed either follicular depletion alone or follicular and paracortical lymphocyte depletion. Nodes from four patients showed Kaposi's sarcoma, three of which also showed follicular hyperplasia. In two of these patients there were no cutaneous manifestations of this condition. One lymph node from a patient with persistent generalized lymphadenopathy (PGL) showed Mycobacterium tuberculosis. Six nodes from six other patients have had features of toxoplasmosis although there was no serological or clinical evidence of recent toxoplasma infection. The remaining 11 lymph nodes from patients with PGL and one node from a patient with transient lymphadenopathy, showed reactive follicular hyperplasia only. We conclude that homosexuals with lymphadenopathy who are HTLV-III antibody positive do not need a routine node biopsy unless an alternative diagnosis is strongly suspected.

Acquired Immunodeficiency Syndrome↗

Acute glandular fever-like illness in a patient with HTLV-III antibody.

A lymph node biopsy obtained from a patient with human T-cell lymphocytotropic virus III/lymphadenopathy-associated virus (HTLV-III/LAV) antibody, presenting with an acute glandular fever-like illness, was examined by electron microscopy. Numerous pathological changes were present in the biopsy, including hypertrophy of smooth endoplasmic reticulum, intracytoplasmic rod-like inclusions within the cisternae of endoplasmic reticulum, multivesicular bodies, test-tube and ring-shaped forms, and tubulo-reticular structures. Intranuclear and intracytoplasmic viral-like particles measuring 105-120 nm in diameter and small cytoplasmic particles measuring 50-70 nm in diameter were found in some degenerating lymph node cells. These pathological findings may reflect a host cell response to various pathological and viral stimuli resulting from immune deficiency owing to infection with HTLV-III/LAV.

Acute Disease↗

The acquired immune deficiency syndrome: problems associated with the management of Pneumocystis carinii pneumonia.

Four fatal and two non-fatal cases of pneumonia caused by Pneumocystis carinii and one case of co-trimoxazole-responsive interstitial pneumonia, all in homosexual patients with the acquired immune deficiency syndrome, are described. The lack of clinical signs in the chest and of abnormal radiological findings at presentation in three of the six patients with P. carinii infection, the rapidly progressive course of the disease, as well as the need for early diagnosis and treatment are stressed. The possibility of chemoprophylaxis against P. carinii is discussed.

Acquired Immunodeficiency Syndrome↗

Kaposi's sarcoma in a patient after renal transplantation.

A patient is described who developed the lesion of Kaposi's sarcoma 4 months after receiving a cadaveric renal transplant. Immunosuppression had been achieved using cyclosporin A and prednisolone. The lesions spread from the hands to other areas, but later regressed when the dose of cyclosporin A was reduced to 100 mg daily. The patient remains well with no evidence of rejection 15 months later.

Humans↗