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Biomedical subjects

G Hancock

Publications and source records attributed to G Hancock.

6 recordsLinked to original sources

Emergence and control of methicillin-resistant Staphylococcus aureus in a children's hospital and pediatric long-term care facility.

BACKGROUND: After a 6-year quiescence, methicillin-resistant Staphylococcus aureus (MRSA) was isolated from 30 patients in a children's hospital and a pediatric long-term care facility from November 1987 through April 1989. After six nosocomial cases had occurred at the children's hospital, increased infection control measures directed at MRSA were initiated in August 1988. Because MRSA had been identified in three patients in the pediatric long-term care facility within 24 hours of their admission to the children's hospital, other patients transferred from the pediatric long-term care facility to the children's hospital were isolated and screened for MRSA. METHODS: We reviewed the medical records of these patients and evaluated their response to therapy with rifampin alone or in combination with trimethoprim-sulfamethoxazole. RESULTS: In the 8-month period after initiation of infection control measures, MRSA was identified in 10 residents of the pediatric long-term care facility; there was also one nosocomial children's hospital case. Phage typing showed that one MRSA strain predominated in patients at the pediatric long-term care facility but did not implicate this strain as the source for MRSA introduction into the children's hospital. Of 16 patients with MRSA who completed therapy and were available for follow-up, 13 (81%) had elimination of colonization. CONCLUSION: Prompt institution of MRSA surveillance, barrier isolation, and therapy to eliminate colonization should be considered in hospitals with a new introduction of MRSA.

Adolescent

The reconstitution of cell-mediated immunity in the cutaneous lesions of lepromatous leprosy by recombinant interleukin 2.

Human rIL-2 (10-30 micrograms) was injected intradermally into the skin of patients with lepromatous leprosy with high bacillary loads. All patients responded to the lymphokine with local areas of induration that peaked at 24 h and persisted for 4-7 d irrespective of whether the site was "normal skin" or a nodular lesion. Within 24 h there was an extensive emigration of T cells and monocytes into the site. The percentage of the dermis infiltrated by mononuclear cells increased by more than sevenfold, peaking at 4 d and persisting for greater than 15 d. Both CD4+ and CD8+ T cells entered the site. T cells of CD4+ phenotype predominated at 2-7 d but by 11 d, CD8+ cells were predominant. Considerable numbers of T6+ Langerhans' cells appeared in the dermis by 72 h and persisted for 3 wk. By 4 d the thickness of the overlying epidermis had increased twofold, and keratinocytes were expressing MHC class II antigen and the IFN-gamma-induced peptide IP-10. Starting at 48 h, there was an extensive destruction of mononuclear phagocytes that contained structurally intact or fragmented M. leprae observed at the electron microscope level. The organisms, either free or contained within endocytic vacuoles, were discharged into the extracellular space and then reingested by blood-borne monocytes. This was followed by marked reductions in the number of acid-fast organisms in the injected site, evident as early as 4-7 d and more marked at 2-3 wk after injection. 13 of 15 patients exhibited a disposal of acid-fast bacilli ranging from 5- to 1,000-fold with a mean value of approximately 100-fold. The administration of IL-2 leads to the generation of an effective cell-mediated immune response, recapitulating an antigen-driven event and leading to striking local reductions in M. leprae. In comparison with the purified protein derivative of tuberculin reaction, bacilli are cleared more promptly, although emigratory cells persist for a shorter time.

Adult

Client services for geriatric pets.

Some veterinarians have been reluctant to discuss the prospect of the death of a pet because of a sense of discomfort and a lack of understanding about how to respond to the client's grief reaction. It is essential to take the time for this important communication and help clients deal with fears about the process, any feelings of guilt and helplessness, and judgments about the medical aspects of a case. Clients must be encouraged to express grief over the loss of a pet, particularly a geriatric pet that has lived with them many years and to which they are deeply bonded. Veterinarians need to counsel clients about obtaining additional pets or another pet. The phrase "replacement pet" must be stricken from the veterinarian's vocabulary. One does not "replace" a deceased spouse, mother, father, or child. It is possible to have another child or find another spouse, but it is not possible to replace a person. Neither can a pet be "replaced," because each pet is a unique living being. It is disrespectful to the memory of deceased pets to belittle their uniqueness by suggesting that they can be replaced. Instead, the veterinarian has the capability and responsibility to help pet owners maintain fond and happy memories of an irreplacable pet, while finding room in their hearts for another new pet to create happiness for the future. Once the grief is resolved, clients will be thankful for having had the privilege of sharing their life with an animal and experiencing the joy of the bond between two unique individuals.

Aging

Transmission and control of methicillin-resistant Staphylococcus aureus in a skilled nursing facility.

Methicillin-resistant Staphylococcus aureus (MRSA) is increasingly frequent in both acute care facilities (ACFs) and skilled nursing facilities (SNFs). Admissions to SNFs from ACFs with endemic MRSA are one likely source of infection in SNFs. The occurrence of MRSA in SNFs and the relative roles of ACFs and SNFs in MRSA transmission have not been well characterized. We conducted an epidemiologic investigation in an SNF reporting a high incidence of MRSA cases and found that the prevalence of MRSA exceeded that reported in acute care settings. Fifteen (9.1%) of the 164 residents were colonized or infected with MRSA. Risk factors for MRSA identified through a prevalence case-control study were nasogastric intubation (odds ratio = 5.5; 95% confidence interval = 1.2, 26.4), antibiotic therapy (OR = 3.9; CI = 1.2, 13.0), and hospitalization in an acute care facility within the previous six months (OR = 2.9; CI = 0.9, 9.7). During a three-month period, 6 of 100 new admissions were MRSA-positive; all positive patients were from ACFs. Five new cases also emerged from previously MRSA-negative residents. SNF residents are often discharged to ACFs. Transmission of MRSA within the SNF and the transfer of patients to ACFs increases the reservoir of potentially infective patients and the potential for MRSA infections in ACFs. Modest control measures, including targeted surveillance culturing and cohorting of colonized residents, may minimize MRSA transmission in the SNF and decrease the reservoir of MRSA in the community.

Aged

Nontypeable bacteriophage patterns of methicillin-resistant Staphylococcus aureus involved in a hospital outbreak.

Of 93 strains of Staphylococcus aureus isolated from inpatient wards of Ismailia General Hospital, 48 (51%) were proven to be methicillin resistant (MR). Of these MR S. aureus strains, 44 were isolated from patients and 4 were isolated from healthy carriers, who were newly arrived interns working in the same wards. Bacteriophage patterns of MR S. aureus were identified by using routine test dilution (RTD) and 100-fold dilutions (100 RTD) of phages. Of these 48 strains, 37 (75%) (33 from patients and 4 from interns) were nontypeable when using RTD and 100 RTD of phages. Of the other 11 strains, 8 were nontypeable by RTD of phages, but 5 of them had the phage pattern D11/1136 when tested by 100 RTD. Three strains had the phage pattern 3A/3C/55/71, and three strains had different phage patterns, 29/81, 96, and 95/D11. The finding of colonization with virulent MR S. aureus strains in interns working on the wards in which these patients were located suggested that new strategies for control of MR S. aureus nosocomial infections must be considered and evaluated.

Cross Infection

The expression of a gamma interferon-induced protein (IP-10) in delayed immune responses in human skin.

Our knowledge of the induction of new molecules by IFN-gamma has led to the characterization of IP-10 and the preparation of a monospecific, polyclonal antibody. Using this reagent we have now examined inflammatory states occurring in human skin and used immunocytochemical staining for the expression of both Ia and IP-10 determinants. After evoking a delayed-type response to purified protein derivative of tuberculin (PPD), we noted the presence of IP-10 in dermal macrophages and endothelial cells. Intense staining of the basal layer of epidermal keratinocytes was prominent at 41 h, and by 1 wk the entire epidermis was staining. The comparison of the amount of IP-10 secreted by keratinocytes vs. macrophages, fibroblasts, and endothelial cells revealed that keratinocytes were by far the major producers of this molecule. The expression of Ia occurred in conjunction with IP-10. The injection of rIFN-gamma mimicked many of the features of the PPD response, including the expression of both Ia and IP-10 by epidermal keratinocytes. Coexpression was also found in the natural lesions of tuberculoid leprosy and cutaneous Leishmaniasis. However, it was absent in lepromatous leprosy, a state where activated T lymphocytes are not present. We suggest that the local production of IFN-gamma by T cells of the dermal infiltrate induces IP-10 formation in both the dermis and epidermis. IP-10 and Ia then serve as specific markers of immune IFN and its possible influence on effector cells of the cell mediated immune response.

Animals