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P Mead

Publications and source records attributed to P Mead.

At least 19 recordsLinked to original sources
PubMed2000

A foodborne outbreak of gastroenteritis associated with Norwalk-like viruses: first molecular traceback to deli sandwiches contaminated during preparation.

In March 1998, an outbreak of acute gastroenteritis occurred among students at a Texas university. Overall, 125 ill students sought medical care. Case-control studies revealed that illness was significantly associated with eating foods from the university's main cafeteria deli bar on 9 and 10 March. Stool specimens from 9 (50%) of 18 ill students and samples of deli ham showed evidence of Norwalk-like viruses (NLVs) by reverse-transcriptase (RT) polymerase chain reaction (PCR) assay. A food handler who prepared sandwiches for lunch on 9 March reported that her infant had been sick with watery diarrhea since just before the outbreak. A stool sample from the infant was positive for NLV by RT-PCR, and the sequence of the amplified product was identical to that of amplified product from deli ham and students' stool specimens. This is the first time RT-PCR and sequence analysis have successfully confirmed viral contamination of a food item likely to have been contaminated by a food handler.

Adolescent↗
PubMed2000

Prevention of perinatal group B streptococcal infection: current controversies.

Group B streptococcus (GBS) is the most frequent cause of neonatal sepsis in the United States. The Centers for Disease Control and Prevention (CDC) issued guidelines for its prevention in 1996. This article details areas of controversy with those guidelines and offers recommendations for resolution. We recommend that a prevention policy be adopted by all hospitals. If a screening-based policy is chosen, compliance is essential. Penicillin is the antibiotic of choice for GBS prevention. Increasing resistance to clindamycin and erythromycin might eliminate them as alternative choices in patients allergic to penicillin. Group B streptococcal prophylaxis might not be necessary in women who have repeat elective cesarean delivery. In asymptomatic women, a positive urine culture for GBS should be considered clinically equivalent to a positive vaginal or rectal sample for screening. Neonatal sepsis caused by organisms other than GBS must be monitored carefully by all hospitals providing obstetrics services.

Antibiotic Prophylaxis↗
PubMed2000

Clinical guidelines: promoting clinical effectiveness or a professional minefield?

The development of clinical guidelines as one means of implementing evidence-based practice is currently a topical issue. The recent Government White Paper, The New NHS. Modern. Dependable, proposes the establishment of a National Institute for Clinical Excellence whose expressed aim will be to produce and disseminate guidelines based upon evidence of clinical effectiveness in health care. There will be an expectation that practitioners adapt these national guidelines for local needs and particularize them to individual patients. There has been considerable debate in the medical press between the critics and advocates of evidence-based medicine surrounding the relative usefulness of clinical guidelines. However, there has been limited corresponding debate within the nursing literature, which has largely limited itself to descriptions of the implementation of guidelines. This paper examines some of the advantages and limitations of clinical guidelines as a means of operationalizing research evidence to promote effective health care. Finally, some recommendations surrounding the implementation of guidelines will be made.

Clinical Competence↗
PubMed1999

A massive epidemic of multidrug-resistant typhoid fever in Tajikistan associated with consumption of municipal water.

From 1 January through 30 June 1997, 8901 cases of typhoid fever and 95 associated deaths were reported in Dushanbe, Tajikistan. Of 29 Salmonella serotype Typhi isolates tested, 27 (93%) were resistant to ampicillin, chloramphenicol, nalidixic acid, streptomycin, sulfisoxazole, tetracycline, and trimethoprim-sulfamethoxazole. In a case-control study of 45 patients and 123 controls, Salmonella Typhi infection was associated with drinking unboiled water (matched odds ratio, 7; 95% confidence interval, 3-24; P<.001). Of tap water samples, 97% showed fecal coliform contamination (mean level, 175 cfu/100 mL). Samples taken from water treatment plants revealed that fecal coliform contamination occurred both before and after treatment. Lack of chlorination, equipment failure, and back-siphonage in the water distribution system led to contamination of drinking water. After chlorination and coagulation were begun at the treatment plants and a water conservation campaign was initiated to improve water pressure, the incidence of typhoid fever declined dramatically.

Case-Control Studies↗
PubMed1999

Thiol protein defect in sodium-lithium countertransport in subset of essential hypertension.

There is probably a heterogeneous etiology for essential hypertension (EHT), and abnormal erythrocyte sodium-lithium countertransport (Na/Li CT) is common in a subgroup of patients with a strong family history of hypertension and cardiovascular disease (EHT-FH patients). The aim of this study was to test the hypothesis that altering a membrane thiol protein could mimic the abnormal Na/Li CT observed in the patients and that a more refined understanding of the mechanism of abnormal Na/Li CT would facilitate a clearer identification of a subgroup of patients with a homogeneous biochemical abnormality. Na/Li CT kinetics were determined in untreated erythrocytes and after thiol group alkylation with N-ethylmaleimide (NEM). Compared with normal control erythrocytes, untreated erythrocytes from EHT-FH patients had a low K(m) of Na/Li CT, with a high ratio of maximum velocity to K(m). This kinetic pattern was reproduced in normal erythrocytes by treatment with NEM in sodium-free medium. The same treatment in EHT-FH erythrocytes caused a markedly abnormal effect with an increase in maximum velocity, indicating an increase in transporter turnover in contrast to the increase in sodium affinity seen in normal control erythrocytes. Frequency distributions of these kinetic changes showed a subgroup of approximately 75% of EHT-FH patients with abnormal kinetic changes with NEM. Therefore, the key Na/Li CT thiol group that is very reactive to NEM and causes the abnormal Na/Li CT in a subgroup of hypertensive patients may be a useful intermediate phenotype for a disease group within the syndrome of EHT. The single flux assay of Na/Li CT at 140 mmol/L sodium poorly discriminates this group. Identification of the thiol protein involved may lead to a molecular explanation of the altered membrane function in this subgroup of patients.

Antihypertensive Agents↗
PubMed1998

Resistance to antimicrobial chemotherapy: a prescription for research and action.

The growing problem of resistance to antimicrobial chemotherapy was discussed by participants at the February 1995 workshop at Emory University on population biology, evolution, and control of infectious diseases. They discussed the nature and source of this problem and identified areas of research in which information is lacking for the development of programs to control of the emergence and spread of resistant bacteria. Particular attention was given to theoretical (mathematical modeling) and empirical studies of the within and between-host population biology (epidemiology) and the evolution of microbial resistance to chemotherapeutic agents. Suggestions were made about the kinds of models and data needed, and the procedures that could be employed to stem the ascent and dissemination of resistant bacteria. This article summarizes the observations and recommendations made at the 1995 meeting and in the correspondence between participants that followed. It concludes with an update on the theoretical and empirical research on the between- and within-host population biology and evolution of resistance to antimicrobial chemotherapy most of which has been done since that meeting.

Bacteria↗
PubMed1997

Bacillary angiomatosis associated with myositis in a patient infected with human immunodeficiency virus.

A man with AIDS presented with a deep soft-tissue mass involving the right thigh. Biopsy of a skin lesion on the back and culture of a specimen from this lesion showed bacillary angiomatosis due to Bartonella (formerly Rochalimaea) quintana. Magnetic resonance imaging revealed a large heterogeneous mass involving the vastus medialis and intermedius muscles. Therapy with erythromycin caused rapid resolution of both the cutaneous lesion and the muscle lesion. Bartonella infection is proposed as an additional cause of bacterial myositis and expands the spectrum of presentation of bacillary angiomatosis.

AIDS-Related Opportunistic Infections↗
PubMed1993

Effects of accidental trauma on cytokine and endotoxin production.

OBJECTIVE: To determine the effects of accidental injury of varying severity on interleukin (IL)-1 alpha, IL-6, IL-8, tumor necrosis factor-alpha (TNF-alpha), and endotoxin release. DESIGN: Prospective, multi-unit, longitudinal study. SETTING: Emergency Departments and intensive care units of two university hospitals. PATIENTS: Trauma patients after mild, moderate, and severe injury (Injury Severity Score of < or = 10, 11 to 24, and > or = 25, respectively). INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Plasma cytokine and endotoxin concentrations were measured over a 5-day period, starting within 2 hrs of accidental injury. An enzyme-linked immunosorbent assay was used to determine plasma concentrations of IL-1 alpha, IL-6, IL-8, and TNF-alpha. Plasma endotoxin concentrations were measured using a chromogenic limulus amebocyte assay. Preresuscitation samples obtained immediately on arrival in the Emergency Department, and within 2 hrs of injury, demonstrated significant increases of IL-6 and IL-8 concentrations in the severe injury group, in contrast to minimal increases seen after mild or moderate injury. Analysis of serial postresuscitation samples demonstrated rapid increases in IL-6 and IL-8 concentrations within 12 hrs of injury. IL-6 and IL-8 remained increased for 24 hrs after injury, then decreased markedly from their peak values during the next 24 hrs. Increased circulating concentrations of these cytokines continued to be present for > 5 days in the severely injured patients. IL-6 and IL-8 concentrations were only minimally increased in patients 8 and 24 hrs after moderate injury. Endotoxin and IL-1 alpha were not found in any samples, including those samples obtained serially from severely injured patients. No patient at any time point had TNF-alpha concentrations of > 35 pg/mL. CONCLUSIONS: These results demonstrate that severe injury produces rapid, large increases in circulating concentrations of IL-6 and IL-8 that may contribute to the frequent development of the adult respiratory distress syndrome and multiple organ system failure in this clinical setting.

Adult↗
PubMed1992

Immunologic and structural relatedness of the integrin beta 7 complex and the human intraepithelial lymphocyte antigen HML-1.

We recently cloned the newest human integrin beta subunit, termed beta 7, from a cDNA library constructed from SEA-activated T lymphocytes. In this communication, we report on the structure of the human integrin beta 7 protein complex determined using a rabbit anti-beta 7 peptide antibody raised to an N-terminal 22 amino acid residue sequence deduced from the human beta 7 subunit cDNA. The beta 7 subunit (Mr 116,000) expressed on PHA lymphoblasts associates with a single major alpha subunit (alpha H) that is distinct from the prominent T cell marker, integrin alpha 4. The alpha H subunit (Mr 180,000 nonreduced) displays a distinctive shift in size on reduction to an apparent Mr of 150,000. We show that these structural properties of the integrin beta 7 complex are shared with the cell surface antigen HML-1 found highly expressed on T cells which populate the intestinal epithelium and are proposed to be involved in mucosal immunity. Sequential immunoprecipitation and Western blotting demonstrate identity or close homology between the alpha H beta 7 and HML-1 proteins.

Amino Acid Sequence↗
PubMed1990

A school-based measles outbreak: the effect of a selective revaccination policy and risk factors for vaccine failure.

Persons who received measles vaccine between 12 and 14 months of age have been found to be at increased risk of measles compared with those vaccinated at greater than or equal to 15 months of age. Because of this, in 1987 the Immunization Practices Advisory Committee of the US Public Health Service recommended that, during measles outbreaks, revaccination of persons vaccinated at 12-14 months of age be considered. During a school-based outbreak in New Mexico in 1987, the authors evaluated the effect of a mandatory revaccination policy in affected schools. Before the effect of revaccination, the overall attack rate in persons vaccinated at greater than or equal to 12 months of age was 4.1 cases/1,000 students; afterward, the risk was significantly reduced by 73%, to 1.1/1,000 students. The attack rate among students targeted for revaccination declined 100%, compared with 41% among those not revaccinated. Overall, attack rates were significantly lower in schools conducting revaccination early compared with schools holding later revaccination. In a retrospective cohort study of single-dose vaccines in one school, age at vaccination was not associated with risk of disease; however, persons vaccinated greater than or equal to 10 years before the outbreak were at increased risk, independently of age at vaccination. Revaccination of persons whose most recent vaccination was between 12 and 14 months of age appeared to control transmission in this outbreak. Further studies are needed to confirm these observations and to evaluate the effect of other revaccination efforts during outbreaks.

Adolescent↗
PubMed1986

An obstetric approach to the prevention of early-onset group B beta-hemolytic streptococcal sepsis.

Group B beta-hemolytic streptococcus is one of the most common causes of neonatal sepsis. Despite its relationship to neonatal morbidity and mortality, no consensus exists for an approach to its prevention. Several characteristics of the organism such as high maternal carriage rates, the intermittent nature of this carriage, and the failure of antibiotics to permanently eliminate carriage have limited the success of proposed intervention protocols. In this clinical opinion we review characteristics of the organism and previously suggested intervention protocols. Then, based on this review and an analysis of recently published data, a protocol focusing on preterm births is presented. This proposal favors intrapartum treatment of all mothers who are delivered of preterm infants and who are either carriers of group B beta-hemolytic streptococci or whose carriage status is unknown. A comparison of the costs and benefits of this and other approaches is made.

Ampicillin↗
PubMedDate not supplied

Hyperthermic isolated limb perfusion for malignant melanoma: response and survival.

Response to and survival after hyperthermic isolated limb perfusion (HILP) with melphalan in patients with malignant melanoma at the Royal Brisbane Hospital were reviewed in order to assess the major determinants of response to treatment. Data were collected by clinical chart review and direct patient contact. Response was assessed by clinical observation and measurement of nodules. Survival was calculated from the date of perfusion to the date of patient death. Since 1965 there have been 85 patients (38 men, 47 women) who have undergone 109 limb (102 leg, 7 arm) perfusions. The mean age was 58 years (range 32-82 years). The number of patients per disease stage (M.D. Anderson classification) was as follows: stage I, 5 patients; stage II, 8 patients; stage IIIa, 41 patients; stage IIIab, 25 patients; and stage IIIb, 8 patients. The mean duration of perfusion was 81 minutes. Melphalan was given in divided doses, with a mean total dose 1.39 mg/kg. The mean maximal limb temperature was 41.5 degrees C. Major complications occurred during 20 perfusions (18%). There was one postoperative death from myocardial infarction, and one patient required amputation. Median patient follow-up was 2.65 years (range 1-27 years). A complete response was noted in 34 patients (40%), a partial response in 36 patients (42%), and no response in 11 patients (13%). Response could not be assessed in four patients. The actuarial 5-year survival for the whole group was 45%: stage I, 80%; stage II, 75%; stage IIIa, 44%; stage IIIab, 23%; stage IIIb, 56%. The two significant determinants of response to perfusion were disease stage (p = 0.00005) and nodal status (p = 0.03).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗