Synthetic DNA-compacting peptides derived from human sequence enhance cationic lipid-mediated gene transfer in vitro and in vivo

Cationic lipids can deliver genes efficiently in vitro, but are generally inhibited by the presence of serum, and their efficiency in vivo is much lower than in vitro. An attractive strategy is to induce strong DNA compaction by its association with proteins, before addition of lipids. However the use of whole proteins might present both production and immunological limitations. We have devised a system in which DNA is associated with short peptides derived from human histone or protamine, before the addition of a cationic lipid or polymer. Peptides strongly associating with DNA confer to such peptide-DNA-lipid particles an enhanced in vitro transfection efficiency over that observed with classical DNA/lipid lipoplexes, and particularly confer the capacity to transfect in the presence of serum. This acquisition of serum resistance is cell type-independent, and observed with all four lipopolyamines tested and polyethylenimine. Precompacting DNA with a histone H1-derived peptide enhances cationic lipid RPR 115335-mediated gene transfer in an in vivo model of Lewis lung carcinoma. Apart from their use in peptide-DNA-lipid association, such peptides could be useful as part of chimeric gene delivery vectors presenting a DNA-binding moiety that can be easily associated with other functional domains.

Preventing the spread of antimicrobial resistance among bacterial respiratory pathogens in industrialized countries: the case for judicious antimicrobial use

The spread of antimicrobial resistance is an important emerging health threat in developed countries. Widespread outpatient antimicrobial use leads to the spread of resistance among community-acquired pathogens such as Streptococcus pneumoniae. The Centers for Disease Control and Prevention and partner organizations have initiated a national campaign promoting more judicious antimicrobial use to decrease the spread of resistance. The initial focus is to improve management of respiratory tract infections, which account for most outpatient antimicrobial use. Survey and focus group results indicate that patient pressure and suboptimal diagnosis and treatment contribute to antibiotic overuse. To educate physicians, a series of "principles of judicious antibiotic use" have been developed that identify optimal approaches to management of common respiratory infections. Patient education materials and strategies to improve doctor-patient communication also have been developed. Several studies currently under way will evaluate the impact of intervention on antibiotic use practices and resistant carriage or infection.

Estrogen increases 1,25-dihydroxyvitamin D receptors expression and bioresponse in the rat duodenal mucosa

Menopause and estrogen deficiency are associated with apparent intestinal resistance to vitamin D, which can be reversed by estrogen replacement. The in vivo influence of estrogens on duodenal vitamin D receptor (VDR) was studied in three groups of rats: ovariectomized (OVX), sham-operated, and ovariectomized rats treated daily with estrogen (40 microg/kg BW) for 2 weeks (OVX + E). Estrogen administration to OVX rats resulted in a 2-fold increase in VDR messenger RNA transcripts. 1,25(OH)2D3 was shown to bind specifically to one class of receptors in duodenal mucosal extracts, with a dissociation constant of 0.03 nM. Binding was significantly increased in duodenal extracts from OVX + E rats, compared with OVX rats (735 +/- 81 vs. 295 +/- 26 fmol/mg protein; P < 0.001); a comparable, 1.5- to 2-fold increase in VDR protein expression was observed in Western blot analyzes of the duodenal mucosa. Markers of VDR activity were increased in estrogen-exposed rats: calbindin-9k messenger RNA transcript content was 1.4- to 1.6-fold higher, and alkaline phosphatase activity was 1.4- to 3-fold higher in sham-operated and OVX + E, respectively, compared with OVX. 25(OH)D, 1,25(OH)2D, or PTH levels were not altered by estrogen treatment. Cumulatively, these findings suggest that estrogen up-regulates VDR expression in the duodenal mucosa and concurrently increases the responsiveness to endogenous 1,25(OH)2D. Modulation of intestinal VDR activity by estrogen, and subsequent influence on intestinal calcium absorption, could be one of the major protective mechanisms of estrogen against osteoporosis.

Acute otitis media: management and surveillance in an era of pneumococcal resistance--a report from the Drug-resistant Streptococcus pneumoniae Therapeutic Working Group

OBJECTIVE

To provide recommendations [corrected] for the management of acute otitis media (AOM) and the surveillance of drug-resistant Streptococcus pneumoniae (DRSP). Five questions were addressed: (1) Can amoxicillin remain the best initial antimicrobial agent for treating AOM in the current period of increasing prevalence of DRSP? (2) What are suitable alternative agents for use if amoxicillin fails? (3) Should empiric treatment of AOM vary by geographic region? (4) Where can clinicians learn about resistance patterns in their patient populations? (5) What modifications to laboratory surveillance would improve the utility of the information for clinicians treating AOM?

PARTICIPANTS

Experts in the management of otitis media and the DRSP Therapeutic Working Group. This group was convened by the CDC to respond to changes in antimicrobial susceptibility among pneumococci and includes clinicians, academicians and public health practitioners.

EVIDENCE

Published and unpublished data summarized from the scientific literature and experience from the experts present.

PROCESS

[corrected] After group presentations and review of background materials, subgroup chairs prepared draft responses to the five questions, discussed the responses as a group and edited those responses [corrected].

CONCLUSIONS

Oral amoxicillin should remain the first line antimicrobial agent for treating AOM. In view of the increasing prevalence of DRSP, the safety of amoxicillin at higher than standard dosages and evidence that higher dosages of amoxicillin can achieve effective middle ear fluid concentrations, an increase in the dosage used for empiric treatment from 40 to 45 mg/kg/day to 80 to 90 mg/kg/day is recommended. For patients with clinically defined treatment failure after 3 days of therapy, useful alternative agents include oral amoxicillin-clavulanate, cefuroxime axetil and intramuscular ceftriaxone. Many of the 13 other Food and Drug Administration-approved otitis media drugs lack good evidence for efficacy against DRSP. Currently local surveillance data for pneumococcal resistance that are relevant for the clinical management of AOM are not available from most areas in the United States. Recommendations to improve surveillance include establishing criteria for setting susceptibility breakpoints for clinically appropriate antimicrobials to ensure relevance for treating AOM, testing middle ear fluid or nasal swab isolates in addition to sterile site isolates and testing of drugs that are useful in treating AOM. The management of otitis media has entered a new era with the development of DRSP. These recommendations are intended to provide a framework for appropriate clinical and public health responses to this problem.

emm typing and validation of provisional M types for group A streptococci

This report discusses the following issues related to typing of group A streptococci (GAS): The development and use of the 5' emm variable region sequencing (emm typing) in relation to the existing serologic typing system; the designation of emm types in relation to M types; a system for validation of new emm types; criteria for validation of provisional M types to new M-types; a list of reference type cultures for each of the M-type or emm-type strains of GAS; the results of the first culture exchange program for a quality control testing system among the national and World Health Organization collaborating centers for streptococci; and dissemination of new approaches to typing of GAS to the international streptococcal community.

Extensive apoptotic death of rat colonic cells deprived of crypt habitat

Apoptosis in cells of different lineages is restrained by survival signals which depend upon cell-to-cell communication. The aim of this study was to determine whether colonic cells deprived of crypt ambient are doomed to die prior to their normal chronological demise. Apoptosis was studied in rat whole colonic tissue, in isolated intact crypts, and in colonic cell populations collected from the crypt axis at different stages of proliferation and differentiation. In a number of experiments, cell harvest was performed in the presence of either a tetrapeptide (YVAD-CMK) inhibitor of interleukin-1beta-converting enzyme (ICE), or tyrphostin A25, a protein tyrosine kinase inhibitor, or sodium-orthovanadate, a phosphatase inhibitor. DNA fragmentation was assessed by electrophoretic and nonisotopic-labeling procedures. The ultrastructure of colonic tissue specimens and isolated cells was examined by transmission electron microscopy. Apoptosis in whole colonic tissue and in isolated crypts was confined predominantly to cells resident in the upper crypt regions. In contrast, extensive apoptotic death was observed in isolated colonic cells, irrespective of their developmental stage and positional hierarchy within the crypt continuum at harvest time. An apoptotic gradient, however, was evident. Exposure to YVAD-CMK resulted in a marked decrease in the number of apoptotic cells. Treatment with tyrphostin A25 caused a sharp rise in the apoptotic index; conversely, vanadate significantly impeded apoptosis. Cumulatively, these results indicate that disordered intercellular communication provokes unscheduled ICE-mediated apoptosis of colonocytes, and that local signals along the crypt continuum control both the reprieve from death and the timely demise of distinct colonic cell populations. Attenuation of tyrosine phosphorylation may be a contributory event in the acquisition of the apoptotic phenotype.

Relationship between conserved consensus site residues and the productive conformation for the TPQ cofactor in a copper-containing amine oxidase from yeast

A highly conserved asparagine residue is contained in the consensus site sequences of all known copper-containing amine oxidases (CAOs). On the basis of published crystallographic structures, the asparagine is found to reside proximal to the active site redox cofactor, 2,4,5-trihydroxyphenylalanine quinone (TPQ). In this study, the conserved asparagine was changed to an alanine in a CAO from Hansenula polymorpha expressed in Saccharomyces cerevisiae, and the mutant's catalytic properties were characterized using steady-state kinetics and resonance Raman spectroscopy. Several lines of evidence point to TPQ exisiting in an nonproductive orientation in the mutant, including reductions in several steady-state parameters and an accumulation of an inactive product Schiff base complex when the enzyme is incubated with methylamine as the substrate. This product Schiff base complex was previously found to form following mutation of another conserved consensus site residue, a glutamate (or aspartate) at the C + 1 position from TPQ [Cai, D., Dove, J., Nakamura, N., Sanders-Loehr, J., and Klinman, J. P. (1997) Biochemistry 36, 11472-11478]. The results suggest that these two residues are crucial in maintaining the balance of cofactor mobility versus rigidity expected to be necessary during the dual processes of biogenesis and catalysis, respectively, that all CAOs must accomplish. In addition, a previously unidentified structural linkage between these two highly conserved residues is proposed which spans both subunits of the dimeric CAOs, and may have implications for intersubunit communication.

Sodium butyrate induces retinoblastoma protein dephosphorylation, p16 expression and growth arrest of colon cancer cells

Sodium butyrate causes alteration of colon cancer cell morphology and biology towards that of a more differentiated phenotype. The retinoblastoma gene encodes a nuclear phosphoprotein (pRb) present in a wide range of human cancer cell lines including colon cancer cell lines. pRB is synthesized throughout the cell cycle and phosphorylated in a phase specific manner: the predominant proteins in G0/G1 are the unphosphorylated species (110 kD) whereas phosphorylated pRb (112-114 kD) are in S and G2. 110 kD pRb binds transcription factors and prevents transcription of responsive genes such as the gene for thymidine kinase, which are expressed in late G1. The precise mechanisms controlling cell arrest are unknown, but recent data suggest that cyclin-dependent kinase inhibitors such as p16 may play a role. The aim of the present study was to assess the effect of sodium butyrate on cell cycle staging, thymidine kinase activity, phosphorylation of the pRb protein and expression of p16. We show that sodium butyrate treatment induces differentiation of LS174T colon cancer cells, inhibits thymidine kinase activity concomitantly with induction of pRb dephosphorylation, p16 transcription and cell cycle arrest at G0/G1. Initial dephosphorylation was observed 24 h after treatment of LS174T cells with sodium butyrate, whereas complete shift to the dephosphorylated form was observed 3 days after treatment. Induction of pRb dephosphorylation by sodium butyrate preceded inhibition of growth and the specific cell cycle arrest. RNase protection assay with a p16 specific riboprobe showed undetectable levels in proliferating cells to several fold increase in differentiated colonocytes. In conclusion, the results provide evidence for a specific cellular mechanism of butyrate induced growth arrest and differentiation of a colon cancer cell line.

Mecillinam activity compared to ampicillin, trimethoprim/sulfamethoxazole, ciprofloxacin and nitrofurantoin against urinary tract isolates of gram-negative bacilli

Recent Canadian, American and European studies have reported increased ampicillin and trimethoprim/sulfamethoxazole resistance among urinary tract isolates of Escherichia coli. This trend suggests that a reevaluation of first- and second-line therapies for the treatment of community-acquired urinary tract infections is necessary. Mecillinam, a beta-lactam with preferential activity against gram-negative penicillin binding protein 2 (unlike other beta-lactams which preferentially bind gram-negative penicillin binding proteins 1a, 1b or 3), may offer clinically significant activity against ampicillin-resistant and trimethoprim/sulfamethoxazole-resistant E. coli. To test this assertion, the activity of mecillinam was compared with ampicillin, trimethoprim/sulfamethoxazole, nitrofurantoin and ciprofloxacin against 258 consecutive gram-negative urinary tract isolates collected at a Canadian tertiary care hospital. Mecillinam demonstrated significantly better activity than ampicillin and trimethoprim/sulfamethoxazole and significantly less activity than ciprofloxacin and nitrofurantoin against the 258 isolates tested. Against E. coli isolates specifically, mecillinam was significantly more active than ampicillin and trimethoprim/sulfamethoxazole (p < 0. 001) and as active as ciprofloxacin and nitrofurantoin. Mecillinam was active against 91.9% of ampicillin-resistant E. coli and 95.9% of trimethoprim/sulfamethoxazole-resistant E. coli. We conclude that mecillinam should be reevaluated for potential use in the treatment of community-acquired urinary tract infections.

Current attitudes regarding use of antimicrobial agents: results from physician's and parents' focus group discussions

Antibiotics are widely prescribed for children with nonspecific upper respiratory tract infections, contributing to the recent emergence of resistant pneumococci. To understand the reasons for the overprescription of antibiotics, we conducted focus groups with parents and with pediatricians and family physicians to assess their attitudes regarding the use of antibiotics. Physicians asserted that their own antibiotic prescribing could be safely reduced. Parental expectation to receive antibiotics was a major factor influencing their overuse of antibiotics. Parents indicated that they would be satisfied with the medical visit even if antibiotics were not prescribed, provided the physician explained the reasons for the decision. This study highlights differences in physician and parent perceptions about antibiotic overuse and suggests that educational efforts to narrow this communication gap will be important for improving antibiotic use.

Long-term, high level in vivo gene expression after electric pulse-mediated gene transfer into skeletal muscle

Gene delivery to skeletal muscle is a promising strategy for the treatment of muscle disorders and for the local or systemic secretion of therapeutic proteins. However, current DNA delivery technologies have to be improved. We report very efficient luciferase gene transfer into muscle fibres obtained through the delivery of square-wave electric pulses of moderate field strength (100-200 V/cm) and of long duration (20 ms) to muscle previously injected with plasmid DNA. This intramuscular 'electrotransfer' method increases reporter gene expression by more than 100 times. It is noteworthy that this expression remains high and stable for at least 9 months. Moreover, intramuscular electrotransfer strongly decreases the interindividual variability usually observed after plasmid DNA injection into muscle fibres. Therefore, DNA electrotransfer in muscle possesses broad potential applications in gene therapy and for physiological, pharmacological and developmental studies.

Appropriate use of antibiotics for URIs in children: Part II. Cough, pharyngitis and the common cold. The Pediatric URI Consensus Team

This article summarizes the principles of judicious antimicrobial therapy for three of the five conditions--cough, pharyngitis, the common cold--that account for most of the outpatient use of these drugs in the United States. The principles governing the other two conditions, otitis media and acute sinusitis, were presented in the previous issue. This article summarizes evidence against the use of antibiotic treatment for illness with cough or bronchitis in children, unless the cough is prolonged. Although empiric treatment may be started in patients with pharyngitis when streptococcal infection is suspected, the authors recommend withholding antibiotic treatment until antigen testing or culture is positive. There is never any indication for antibiotic treatment of the common cold; it is important to understand the natural history of colds, because symptoms such as mucopurulent rhinitis or cough, even when they persist for up to two weeks, do not necessarily indicate bacterial infection.

Appropriate use of antibiotics for URIs in children: Part I. Otitis media and acute sinusitis. The Pediatric URI Consensus Team

Five conditions--otitis media, acute sinusitis, cough, pharyngitis and the common cold--account for most of the outpatient use of antibiotics in the United States. The first part of this two-part article presents guidelines that encourage physicians to make an appropriate distinction between acute otitis media and otitis media with effusion, to use shorter courses of antibiotic therapy in uncomplicated cases of otitis media and to limit prophylaxis to recurrence as defined strictly by number of episodes. Sinusitis in younger children is difficult to distinguish from the common cold, and the criterion for use of antibiotics should be duration of symptoms.

The rationale for population-based surveillance for Haemophilus influenzae type b meningitis

Although Haemophilus influenzae type b (Hib) conjugate vaccines have been spectacularly successful, nearly eradicating Hib disease in countries where used routinely, they are relatively expensive. In many countries the incidence of Haemophilus influenzae type b (Hib) disease is uncertain, and it is unclear whether the local burden of Hib disease warrants the costs of adding Hib vaccine to the routine immunization program. Population-based surveillance to assess the local burden of Hib disease can help decision makers with this process. Although pneumonia is more common than meningitis, surveillance for Hib meningitis and invasive disease is likely to be more feasible and efficient than surveillance for Hib pneumonia. Standardization of laboratory methods for the isolation and identification of H. influenzae from CSF specimens is essential to successful surveillance. Should a country decide to introduce Hib conjugate vaccine as a routine immunization, population-based surveillance data collected before and after the introduction of vaccine can be used to monitor its impact. Finally population-based surveillance for bacterial meningitis also can provide information on the incidence of pneumococcal and meningococcal infections and on serogroup or serotype distributions that will be important when evaluating the new vaccines for those pathogens that are being developed.

Neurocircuitry of conditioned inhibition of analgesia: effects of amygdala, dorsal raphe, ventral medullary, and spinal cord lesions on antianalgesia in the rat

Pain inhibition (analgesia) is produced by learned danger signals and inhibited by learned safety signals (antianalgesia). Conditioned analgesia is mediated by brain-to-spinal pathways releasing spinal endogenous opiates. Spinal morphine mimics learned danger signals in producing analgesia, which is inhibited by antianalgesia. The circuitry mediating antianalgesia is unknown. These experiments demonstrate that raphe dorsalis, raphe magnus, and spinal dorsolateral funiculus lesions abolish antianalgesia. Other lesions had no effect on antianalgesia. More important, lesions that blocked development of conditioned analgesia did not block development of antianalgesia. Thus, neural circuitries mediating analgesia and antianalgesia were found to be distinct, and conditioned inhibition of analgesia was found to act by inhibiting the most distal part of the conditioned analgesia circuit, namely, the spinal cord.

Antimicrobial resistance and clinical effectiveness of co-trimoxazole versus amoxycillin for pneumonia among children in Pakistan: randomised controlled trial. Pakistan Co-trimoxazole Study Group

BACKGROUND

Co-trimoxazole is widely used in treatment of paediatric pneumonia in developing countries, but drug resistance may decrease its effectiveness. We studied the effectiveness of co-trimoxazole compared with that of amoxycillin in pneumonia therapy, and assessed the clinical impact of co-trimoxazole resistance.

METHODS

We recruited 595 children, aged 2-59 months, with non-severe or severe pneumonia (WHO criteria) diagnosed in the outpatient wards of two urban Pakistan hospitals. Patients were randomly assigned on a 2:1 basis co-trimoxazole (n=398) or amoxycillin (n=197) in standard WHO doses and dosing schedules, and were monitored in study wards. The primary outcome was inpatient therapy failure (clinical criteria) or clinical evidence of pneumonia at outpatient follow-up examination.

FINDINGS

There were 92 (23%) therapy failures in the co-trimoxazole group and 30 (15%) in the amoxycillin group (p=0.03)-26 (13%) versus 12 (12%) among children with non-severe pneumonia (p=0.856) and 66 (33%) versus 18 (18%) among those with severe pneumonia (p=0.009). For patients with severe pneumonia, age under 1 year (p=0.056) and positive chest radiographs (p=0.005) also predicted therapy failure. There was no significant association between antimicrobial minimum inhibitory concentration and outcome among bacteraemic children treated with co-trimoxazole.

INTERPRETATION

Co-trimoxazole provided effective therapy in non-severe pneumonia. For severe, life-threatening pneumonia, however, co-trimoxazole is less likely than amoxycillin to be effective.

Invasive group A streptococcal disease in metropolitan Atlanta: a population-based assessment

Active, population-based surveillance for invasive group A streptococcal (GAS) disease was conducted in laboratories in metropolitan Atlanta from 1 January 1994 through 30 June 1995. Clinical and laboratory records were reviewed and isolates characterized. One hundred and eighty-three cases of invasive GAS disease were identified (annual incidence, 5.2 cases/100,000). The incidence was highest among blacks (9.7/100,000 per year; relative risk (RR), 1.92; confidence interval (CI), 1.69-2.19; P < .0001) and the elderly, particularly nursing home residents (RR, 13.66; CI, 7.07-26.40; P < .0001). The mean age of patients was 41.3 years (range, 0-95 years). Skin and soft-tissue infections were most common. Mortality was 14.4%; risk of death was significantly higher for patients with streptococcal toxic shock syndrome (STSS) (RR, 9.73; CI, 3.34-29; P = .0008) and individuals infected with M-type 1 (RR, 7.40; CI, 1.5-16; P = .0084). Fourteen percent of invasive GAS infections were STSS and 3% were necrotizing fasciitis. Invasive GAS disease was associated with varicella infection in children (RR, 12.19; CI, 5.58-26.62; P < .0001). M (or emm) types included M1 (16%), M12 (12%), and M3 (11%). Continued study of GAS disease is essential to further define risk factors and risk of secondary cases and to develop effective prevention strategies.

Rapid hematopoietic recovery after multicycle high-dose chemotherapy: enhancement of filgrastim-induced progenitor-cell mobilization by recombinant human stem-cell factor

PURPOSE

To assess the mobilization potential and safety of recombinant human stem-cell factor (SCF) when coadministered with filgrastim to untreated women with poor-prognosis breast cancer.

PATIENTS AND METHODS

Eligible women had breast cancer with 10 or more positive axillary nodes, or estrogen receptor-negative tumor with 4 positive nodes, or stage III disease. Patients were randomized to receive SCF plus filgrastim or filgrastim alone. Filgrastim 12 microg/kg daily was administered for 6 days by continuous subcutaneous infusion. SCF was administered by daily subcutaneous injection at 5, 10, or 15 microg/kg concurrent with filgrastim for 7 days, or 10 microg/kg daily starting 3 days before filgrastim for a total of 10 days (SCF pretreatment). Apheresis was performed on days 5, 6, and 7 of filgrastim administration. Patients then had three cycles of epirubicin 200 mg/m2 and cyclophosphamide 4 g/m2 every 28 days, each supported by one third of the apheresis product.

RESULTS

Sixty-two women were treated. Greater yields occurred in patients who received SCF 10 microg/kg daily plus filgastim than those who received filgrastim alone (P=.013 for CD34+ cells; P=.07 for granulocyte-macrophage colony-forming cells [GM-CFCs]). The difference was more marked with SCF-pretreatment than concurrent SCF. Fewer aphereses were required to reach the predetermined target of peripheral-blood progenitor/stem cells (PBPCs) in women who received SCF. SCF was generally well tolerated. Hematologic recovery was rapid after each of the three cycles of chemotherapy. There was no difference in recovery between the different treatment groups.

CONCLUSION

Mobilization of PBPCs by filgrastim is significantly enhanced by coadministration of SCF, and commencing SCF before filgrastim can optimize this effect. SCF has the potential to reduce the number of aphereses required to collect a target number of PBPCs.

Opsonic antibodies to the surface M protein of group A streptococci in pooled normal immunoglobulins (IVIG): potential impact on the clinical efficacy of IVIG therapy for severe invasive group A streptococcal infections

The surface M protein of group A streptococci (GAS) is one of the major virulence factors for this pathogen. Antibodies to the M protein can facilitate opsonophagocytosis by phagocytic cells present in human blood. We investigated whether pooled normal immunoglobulin G (IVIG) contains antibodies that can opsonize and enhance the phagocytosis of type M1 strains of GAS and whether the levels of these antibodies vary for different IVIG preparations. We focused on the presence of anti-M1 antibodies because the M1T1 serotype accounts for the majority of recent invasive GAS clinical isolates in our surveillance studies. The level of anti-M1 antibodies in three commercial IVIG preparations was determined by enzyme-linked immunosorbent assay (ELISA), and the opsonic activity of these antibodies was determined by neutrophil-mediated opsonophagocytosis of a representative M1T1 isolate. High levels of opsonic anti-M1 antibodies were found in all IVIG preparations tested, and there was a good correlation between ELISA titers and opsonophagocytic activity. However, there was no significant difference in the levels of opsonic anti-M1 antibodies among the various IVIG preparations or lots tested. Adsorption of IVIG with M1T1 bacteria removed the anti-M1 opsonic activity, while the level of anti-M3 opsonophagocytosis was unchanged. Plasma was obtained from seven patients with streptococcal toxic shock syndrome who received IVIG therapy, and the level of anti-M1 antibodies was assessed before and after IVIG administration. A significant increase in the level of type M1-specific antibodies was found in the plasma of all patients who received IVIG therapy (P < 0.006). The results reveal another potential mechanism by which IVIG can ameliorate severe invasive group A streptococcal infections.

Epidemic of pediatric deaths from acute renal failure caused by diethylene glycol poisoning. Acute Renal Failure Investigation Team

CONTEXT

Contaminated pharmaceutical products can result in substantial morbidity and mortality and should be included in the differential diagnosis of deaths of unknown origin.

OBJECTIVE

To investigate an outbreak of deaths among children from acute renal failure in Haiti to determine the etiology and institute control measures.

DESIGN

Case-control study, cohort study, and laboratory toxicologic evaluation.

SETTING

Pediatric population of Haiti.

PARTICIPANTS

Cases were defined as Haitian residents younger than 18 years with idiopathic anuria or severe oliguria for 24 hours or longer. Febrile hospitalized children without renal failure were enrolled as control subjects.

MAIN OUTCOME MEASURE

The odds of exposure to suspected etiologic agents among cases and controls.

RESULTS

We identified 109 cases of acute renal failure among children. The clinical syndrome included renal failure, hepatitis, pancreatitis, central nervous system impairment, coma, and death. Of 87 patients with follow-up information who remained in Haiti for treatment, 85 (98%) died; 3 (27%) of 11 patients transported to the United States for intensive care unit management died before hospital discharge. A locally manufactured acetaminophen syrup was highly associated with disease (odds ratio, 52.7; 95% confidence interval, 15.2-197.2). Diethylene glycol (DEG) was found in patients' bottles in a median concentration of 14.4%. The median estimated toxic dose of DEG was 1.34 mL/kg (range, 0.22-4.42 mL/kg). Glycerin, a raw material imported to Haiti and used in the acetaminophen formulation, was contaminated with 24% DEG.

CONCLUSIONS

An epidemic of severe systemic toxicity and deaths from DEG-contaminated acetaminophen syrup occurred in Haiti. Good manufacturing practice regulations should be used by all pharmaceutical manufacturers to prevent such tragedies.

Neurocircuitry of conditioned inhibition of analgesia: effects of amygdala, dorsal raphe, ventral medullary, and spinal cord lesions on antianalgesia in the rat

Pain inhibition (analgesia) is produced by learned danger signals and inhibited by learned safety signals (antianalgesia). Conditioned analgesia is mediated by brain-to-spinal pathways releasing spinal endogenous opiates. Spinal morphine mimics learned danger signals in producing analgesia, which is inhibited by antianalgesia. The circuitry mediating antianalgesia is unknown. These experiments demonstrate that raphe dorsalis, raphe magnus, and spinal dorsolateral funiculus lesions abolish antianalgesia. Other lesions had no effect on antianalgesia. More important, lesions that blocked development of conditioned analgesia did not block development of antianalgesia. Thus, neural circuitries mediating analgesia and antianalgesia were found to be distinct, and conditioned inhibition of analgesia was found to act by inhibiting the most distal part of the conditioned analgesia circuit, namely, the spinal cord.

A streptococcal score card revisited

OBJECTIVE

To evaluate the utility of a simple scoring system as a predictor of obtaining a positive throat culture for group A streptococci (GAS).

DESIGN

Prospective descriptive study. Scores were assigned prior to the availability of the results of throat cultures.

SETTING

Emergency department and walk-in clinic of the Children's Hospital of Pittsburgh.

PATIENTS

Patients were 365 children between the ages of two and 16 years with acute onset of sore throat and a history of or documentation of fever within the preceding 24 hours.

INTERVENTIONS

A streptococcal score was assigned on the basis of a 6-point schema in which the features were 1) age; 2) season; 3) temperature of at least 38.3 degrees C; 4) adenopathy; 5) pharyngeal erythema, edema, or exudate; and 6) no symptoms of a viral upper respiratory infection (conjunctivitis, rhinorrhea, or cough). A throat culture was performed for the isolation of GAS.

MAIN OUTCOME MEASURE

Positive predictive value of the streptococcal score in identifying children with a positive throat culture for GAS.

RESULTS

A score of 5 or 6 predicted a positive culture for GAS in 59 and 75% of children, respectively. In patients with evidence of acute pharyngitis, the combination of age between five and 15 years, fever and absence of upper respiratory symptoms predicted a positive culture for GAS in 72% of patients.

CONCLUSIONS

The score can be used to predict the likelihood that a throat culture will be positive for GAS.

Synthesis, activity, and structure--activity relationship studies of novel cationic lipids for DNA transfer

We have designed and synthesized original cationic lipids for gene delivery. A synthetic method on solid support allowed easy access to unsymmetrically monofunctionalized polyamine building blocks of variable geometries. These polyamine building blocks were introduced into cationic lipids. To optimize the transfection efficiency in the novel series, we have carried out structure-activity relationship studies by introduction of variable-length lipids, of variable-length linkers between lipid and cationic moiety, and of substituted linkers. We introduce the concept of using the linkers within cationic lipids molecules as carriers of side groups harboring various functionalities (side chain entity), as assessed by the introduction of a library composed of cationic entities, additional lipid chains, targeting groups, and finally the molecular probes rhodamine and biotin for cellular traffic studies. The transfection activity of the products was assayed in vitro on Hela carcinoma, on NIH3T3, and on CV1 fibroblasts and in vivo on the Lewis Lung carcinoma model. Products from the series displayed high transfection activities. Results indicated that the introduction of a targeting side chain moiety into the cationic lipid is permitted. A primary physicochemical characterization of the DNA/lipid complexes was demonstrated with this leading compound. Selected products from the series are currently being developed for preclinical studies, and the labeled lipopolyamines can be used to study the intracellular traffic of DNA/cationic lipid complexes.

Sulpiride augmentation in people with schizophrenia partially responsive to clozapine. A double-blind, placebo-controlled study

BACKGROUND

We hypothesised that a combined regimen of clozapine, a relatively weak D2-dopaminergic antagonist, and sulpiride, a selective D2 blocker, would demonstrate a greater antipsychotic efficacy by enhancing the D2 blockade of clozapine.

METHOD

Twenty-eight people with schizophrenia, previously unresponsive to typical antipsychotics and only partially responsive to current treatment with clozapine, received, double-blind, 600 mg/day sulpiride or placebo, in addition to an ongoing clozapine treatment. The clinical status was evaluated before, during, and at the end of 10 weeks of sulpiride addition using the Brief Psychiatric Rating Scale (BPRS), Scale for the Assessment of Positive Symptoms (SAPS), Scale for the Assessment of Negative Symptoms, and Hamilton Rating Scale for Depression.

RESULTS

The clozapine-sulpiride group exhibited substantially greater and significant improvements in positive and negative psychotic symptoms. About half of them, characterised by a younger age and lower baseline SAPS scores, had a mean reduction of 42.4 and 50.4% in their BPRS and SAPS scores, respectively.

CONCLUSIONS

A subgroup of patients with chronic schizophrenia may substantially benefit from sulpiride addition to clozapine.

Characterization of sodium and chloride conductances in preneoplastic and neoplastic murine colonocytes

Glucocorticoids, such as dexamethasone, induce amiloride-sensitive Na+ conductances in rat distal colon epithelium. The activity of these conductances diminishes from the surface to the base of the crypt whereas cAMP-stimulated Cl- secretion decreases from the crypt base to the surface. These gradients are likely to be perturbed during carcinogenesis. We therefore determined the magnitude of Na+ and Cl- conductances in colonocytes isolated from normal and carcinogen-treated rats. Colon carcinogenesis was induced by injection of dimethylhydrazine (DMH) (18 mg/kg) for 5 weeks. Before sacrifice animals were treated for 3 days with dexamethasone. Colonocyte populations from the surface to the crypt base (C1-C5) were harvested from the distal colon by a Ca2+-chelating procedure. The activity of Na+ conductances was determined by uptake of 22Na+ by surface and crypt colonocyte populations and by membrane vesicles in the presence and absence of 10 microM amiloride. In control rats Na+ conductance was highest in surface colonocytes and absent in the crypt base. As early as 2 weeks after initiation of DMH treatment amiloride-inhibited Na+ uptake was virtually absent in the upper crypt. Transcriptional assessment of the alpha-, beta- and gamma-subunits that constitute the epithelial Na+ channel revealed that DMH treatment reduces the expression of beta-subunit mRNA. We then examined 36Cl- efflux from isolated colonocytes of normal and carcinogen-treated rats in response to forskolin (0.01 mM). Forskolin induced a marked rise in cAMP in lower crypt cells concomitant with a significant stimulation of 36Cl- efflux. Intracellular cAMP increased in upper crypt cells in response to forskolin without an increase in 36Cl- efflux. By contrast, upper crypt colonocytes from DMH-treated rats showed forskolin-stimulated efflux beginning 4 weeks after initiation of treatment. We conclude that induction of Na+ conductances by glucocorticoids is inhibited during the early stages of chemical carcinogenesis due to lack of induction of the beta-subunit of the channel. By contrast, Cl- transport is stimulated both in surface and lower crypt cell compartments during different stages of chemical carcinogenesis.

Computerized measurement of the three-dimensional distribution of optic disc pallor

PURPOSE

To describe a method which provides quantitative measurements of the surface area of pallor in each quadrant of the three-dimensional optic cup, using photogrammetric measurements from simultaneous stereophotographs and computerized image analysis.

METHODS

Simultaneous stereophotographs of one normal subject and two subjects with primary open angle glaucoma were digitized and analyzed for depth measurements. The boundaries of the optic disc, optic cup and region of pallor were identified. Pallor/disc and pallor/cup ratios were subsequently calculated for the superior, temporal, inferior and nasal walls.

RESULTS

A digitized photograph and a Laplacian-filtered image were obtained for each eye to be studied. After processing each stereo pair through a similarity sequential detection-based algorithm, depth measurements are represented as a grey scale image, a contour plot, and a wire mesh, with the boundaries of the optic disc, optic cup and pallor superimposed. Ratios are given of the surface area of pallor to the surface area of the disc and the surface area of pallor to the surface area of the cup, by quadrant.

CONCLUSIONS

Determination of surface area of pallor to cup may be useful in detecting early visual field loss in glaucoma and neurological disease.

Patients' satisfaction when denied authorization for emergency department care by their managed care plan

We conducted a survey of managed care plan (MCP) patients who presented to the emergency department (ED) but were denied insurance authorization during a 3-month period. Patients were identified by triage or registration records, contacted by telephone after their visit, and surveyed regarding their satisfaction with the ED and MCP, follow-up care, and future behavior. We surveyed 72 (73.4%) of 98 subjects who were denied authorization. Forty-nine (68.1%) were redirected to a clinic or primary physician, 14 (19.4%) to an urgent care or other ED, and 9 (12.5%) were given no follow-up. Fifty-five respondents (76.4%) stated they had followed-up as directed, but 34 (47.2%) felt the delay had a negative impact. Thirty-nine (54.2%) were dissatisfied with their MCP. If their problems were to recur, 27 (37.5%) stated they would go to a clinic or call their MCP, but 34 (47.2%) would return to the ED. Many patients who are denied authorization are dissatisfied with their MCP and will return to the ED in the future, despite previous denials.

Enhanced ocular hypotensive response to epinephrine in rabbits with prior dexamethasone treatment

The purpose of this study was to determine glucocorticoid modulation of ocular pressure to epinephrine applied topically to rabbit eyes that were pretreated with dexamethasone. Rabbit eyes were pretreated with five applications of topical 0.07% dexamethasone (0.1% dexamethasone phosphate) or saline drops, administered at ten minute intervals. The eyes were then treated with epinephrine bitartrate drops at concentrations of free base epinephrine of 1.1%, 0.27%, 0.05%, 0.027%, 0.005% or 0.0005%. An additional group of rabbits received dexamethasone pretreatment only. Intraocular pressure (IOP) was measured for the next four hours. Enhanced lowering of intraocular pressure was observed with dexamethasone pretreatment. Rabbits receiving the smaller dose of epinephrine with dexamethasone had the largest decrease in IOP at 135 minutes after instillation of the epinephrine drops (0.005% epinephrine, mean difference +/- standard error of mean = 5.4 +/- 1.1 mmHg). Similarly, the duration of significant decrease of the IOP was prolonged in the groups receiving the lower concentrations of epinephrine (0.005% epinephrine, 255 minutes after administration of epinephrine). The synergism between glucocorticoids and adrenergic agonists in lowering IOP may be potentially useful in the therapy of ocular hypertension and glaucoma.

Reversal of spinal cord non-opiate analgesia by conditioned anti-analgesia in the rat

The spinal cord contains endogenous substances (such as cholecystokinin, FMRFamide, etc.) that can block the analgesic effects of opiates. Anti-opiate actions have been most commonly studied by exogenous administration of receptor agonists and receptor antagonists of these substances. However, we have recently demonstrated that anti-analgesia can be brought under environmental control through Pavlovian conditioning. Whereas analgesia can be conditioned to signals for danger, anti-analgesia can be conditioned to signals for safety. Using this paradigm, we have previously demonstrated that conditioned anti-analgesia can reverse a variety of opiate analgesic states, including those produced by conditioned danger signals, systemic morphine, and intrathecal mu- and delta-opiate receptor agonists. These data raise the question of the generality of anti-analgesia actions. The present series of experiments examined the ability of conditioned anti-analgesia to affect non-opiate analgesic states induced by spinal delivery of GABA(A), GABA(B), 5HT2 + 5HT1, and 5HT3 receptor agonists. While conditioned anti-analgesia had no effect on GABA(A) or 5HT2 + 5HT1 non-opiate analgesias, conditioned anti-analgesia completely blocked GABA(B) and 5HT3 non-opiate analgesias. These findings clearly demonstrate that conditioned anti-analgesia can powerfully modulate non-opiate as well as opiate analgesias and bring into question whether putative anti-opiate neuroactive substances may have broader actions than previously suggested.

Population-based surveillance for group A streptococcal necrotizing fasciitis: Clinical features, prognostic indicators, and microbiologic analysis of seventy-seven cases. Ontario Group A Streptococcal Study

PURPOSE

To determine the incidence of group A streptococcal necrotizing fasciitis in Ontario, Canada, and to describe the clinical features, outcome, and microbiologic characteristics of this infection.

PATIENTS AND METHODS

Prospective, population-based surveillance for invasive group A streptococcal infections was conducted in Ontario from November 1991 to May 1995. All 77 patients meeting clinical and/or histopathologic criteria for streptococcal necrotizing fasciitis were included. Demographic and clinical information was obtained by patient interviews and chart review. Group A streptococci were characterized by M-protein and T-agglutination typing, and polymerase chain reaction (PCR) detection of streptococcal pyrogenic exotoxin genes A and C (speA; speC).

RESULTS

The incidence of group A streptococcal necrotizing fasciitis increased during the study from 0.085 per 100,000 population in the first year to 0.40 per 100,000 population in the last year (P < 0.001). The median age of cases was 57.5 years and the rate of disease increased with increasing age. Seventy-nine percent of cases were community-acquired, 11% were nosocomial, and 10% were acquired in a nursing home. Forty-seven percent of cases were associated with the presence of streptococcal toxic shock syndrome (Strep TSS) and 46% were bacteremic. Thirty-four percent of cases died and mortality was correlated with increasing age (P = 0.006), presence of hypotension (P = 0.01), and bacteremia (P = 0.03). The most common streptococcal serotypes were M1 (35%) and M3 (25%). Forty-one percent of strains possessed the speA gene and 30% the speC gene. Outcome was not correlated with M-type or the presence of spe genes.

CONCLUSIONS

The incidence of necrotizing fasciitis caused by group A streptococcus increased in Ontario between 1992 and 1995. Elderly individuals were more likely to acquire the disease and to die from it. Mortality because of streptococcal necrotizing fasciitis was also associated with the presence of hypotension, Strep TSS, or bacteremia, but not with M-type or the presence of pyrogenic exotoxin genes.

Population-based surveillance for group A streptococcal necrotizing fasciitis: Clinical features, prognostic indicators, and microbiologic analysis of seventy-seven cases. Ontario Group A Streptococcal Study

PURPOSE

To determine the incidence of group A streptococcal necrotizing fasciitis in Ontario, Canada, and to describe the clinical features, outcome, and microbiologic characteristics of this infection.

PATIENTS AND METHODS

Prospective, population-based surveillance for invasive group A streptococcal infections was conducted in Ontario from November 1991 to May 1995. All 77 patients meeting clinical and/or histopathologic criteria for streptococcal necrotizing fasciitis were included. Demographic and clinical information was obtained by patient interviews and chart review. Group A streptococci were characterized by M-protein and T-agglutination typing, and polymerase chain reaction (PCR) detection of streptococcal pyrogenic exotoxin genes A and C (speA; speC).

RESULTS

The incidence of group A streptococcal necrotizing fasciitis increased during the study from 0.085 per 100,000 population in the first year to 0.40 per 100,000 population in the last year (P < 0.001). The median age of cases was 57.5 years and the rate of disease increased with increasing age. Seventy-nine percent of cases were community-acquired, 11% were nosocomial, and 10% were acquired in a nursing home. Forty-seven percent of cases were associated with the presence of streptococcal toxic shock syndrome (Strep TSS) and 46% were bacteremic. Thirty-four percent of cases died and mortality was correlated with increasing age (P = 0.006), presence of hypotension (P = 0.01), and bacteremia (P = 0.03). The most common streptococcal serotypes were M1 (35%) and M3 (25%). Forty-one percent of strains possessed the speA gene and 30% the speC gene. Outcome was not correlated with M-type or the presence of spe genes.

CONCLUSIONS

The incidence of necrotizing fasciitis caused by group A streptococcus increased in Ontario between 1992 and 1995. Elderly individuals were more likely to acquire the disease and to die from it. Mortality because of streptococcal necrotizing fasciitis was also associated with the presence of hypotension, Strep TSS, or bacteremia, but not with M-type or the presence of pyrogenic exotoxin genes.

Survey of emm gene sequences and T-antigen types from systemic Streptococcus pyogenes infection isolates collected in San Francisco, California; Atlanta, Georgia; and Connecticut in 1994 and 1995

The variable 5' emm (M-protein gene) sequences and T-antigen types were determined from 340 systemic group A streptococcal (GAS) isolates taken from hospitalized patients in San Francisco, Calif.; Atlanta, Ga.; and Connecticut in 1994 and 1995. Eighty percent of these isolates had emm sequences and T-antigen types in agreement with previously recorded M- and T-antigen associations. Most of the remaining strains either were T nontypeable (11%) or contained emm genes encoding M proteins for which T-antigen associations have not been made (6%). One newly encountered emm gene, designated ST2974, from each of 13 isolates had the T type 8/25/Imp19. Another new emm gene, ST2967, from 8 of 11 isolates was T nontypeable. Six other unique emm gene sequences from seven isolates were encountered. Sequencing of the variable region of the emm gene of GAS isolates (emm typing) is effective for surveying the sequence variability of the M virulence protein, and combined with T typing, emm typing is useful for monitoring GAS strain diversity.

Ability of single-site mutants of citrate synthase to catalyze proton transfer from the methyl group of dethiaacetyl-coenzyme A, a non-thioester substrate analog

The catalytic strategies of enzymes (such as citrate synthase) whose reactions require the abstraction of the alpha-proton of a carbon acid remain elusive. Citrate synthase readily catalyzes solvent proton exchange of the methyl protons of dethiaacetyl-coenzyme A, a sulfur-less, ketone analog of acetyl-coenzyme A, in its ternary complex with oxaloacetate. Because no further reaction occurs with this analog, it provides a uniquely simple probe of the roles of active site interactions on carbon acid proton transfer catalysis. In view of the high reactivity of the analog for proton transfer to the active site base, its failure to further condense with oxaloacetate to form a sulfur-less analog of citryl-coenzyme A was unexpected, although we offer several possible explanations. We have measured the rate constants for exchange, k(exch), at saturating concentrations of the analog for six citrate synthase mutants with single changes in active site residues. Comparisons between the values of k(exch) are straightforward in two limits. If the rate of exchange of the transferred proton with solvent protons is rapid, then k(exch) equals the forward rate constant for proton transfer, and k(exch) values for different mutants compare directly the rate constants for proton transfer. If the exchange of the transferred proton with protons in the bulk solution is the slow step and the equilibrium constant for proton transfer is unfavorable (as is likely), then k(exch) equals the product of the equilibrium constant for proton transfer and the rate constant for exchange of the transferred proton with bulk solvent. If that exchange rate with bulk solution remains constant for a series of mutant enzymes, then k(exch) values compare the equilibrium constants for proton transfer. The importance of the acetyl-CoA site residues, H274 and D375, is confirmed with D375 again implicated as the active site base. The results with the series of oxaloacetate site mutants, H320X, strongly suggest that activation of the first substrate, oxaloacetate, through carbonyl bond polarization, not just oxaloacetate binding in the active site, is required for the enzyme to efficiently catalyze proton transfer from the methyl group of the second substrate.

Enhanced acute ocular hypotensive response to timolol with dexamethasone treatment

PURPOSE

This study was conducted to determine whether low doses of dexamethasone can enhance the lowering of ocular pressure by low doses of timolol.

PATIENTS AND METHODS

In 12 patients with untreated ocular hypertension and similar intraocular pressures in each eye, one eye was randomly selected in a masked manner for pretreatment with three applications of topical 0.01% dexamethasone sodium phosphate drops prepared in artificial tears. The other eye was treated with three applications of drops of artificial tears alone. Both eyes were then treated with 0.01% timolol maleate drops. Ocular pressure was measured for the next 100 minutes at 20-minute intervals. The study was done in an outpatient office. Twelve untreated ocular hypertensive patients participated in this study.

RESULTS

When compared with eyes treated with timolol drops alone, eyes pretreated with dexamethasone drops showed a significantly greater decrease in ocular pressure (mean +/- SD); the maximal decrease in 12 dexamethasone-treated patients was 3.5 +/- 1.9 mm Hg (15.9% from baseline). Six dexamethasone-treated patients had a response of 4.0 to 6.0 mm Hg, whereas three showed responses < 4 and > 2 mm Hg with three < or = 2 mm Hg.

CONCLUSIONS

This synergistic effect of timolol with dexamethasone on lowering of ocular pressure offers a potential therapeutic use in ocular hypertension and glaucoma.

Resistant pneumococci: protecting patients through judicious use of antibiotics

Increasing resistance to antimicrobial agents has occurred among many pathogens, but the emergence of resistant Streptococcus pneumoniae will have the greatest impact on the practice of outpatient medicine. Consequences of resistance include complicated management of acute otitis media and meningitis treatment failures. Pneumococci have acquired resistance to penicillin, third-generation cephalosporins and other antibiotics at an alarming rate; in some areas, 25 percent of isolates are nonsusceptible to penicillin. In areas with high resistance rates, the addition of vancomycin to cefotaxime or ceftriaxone is warranted for empiric treatment of bacterial meningitis. Changes in empiric therapy for pneumonia, bacteremia and otitis media may eventually be necessary. Previous antibiotic use is a risk factor for invasive disease with resistant pneumococci. Patients may be best protected by avoiding unnecessary use of antibiotics. Patient education materials as well as recommendations for avoiding the use of antibiotics for some upper respiratory tract infections are currently being developed to help physicians achieve this goal.

Gastrin levels in colorectal cancer

Our objective was to determine whether colorectal cancer tissue synthesizes and secretes biologically active gastrins resulting in a rise of gastrin levels in patients with adenocarcinoma of the colon. Blood samples for gastrin determination were taken from the artery feeding, and from the vein draining colon tumors, from a vein draining an uninvolved colon segment and from a peripheral vein. Tissue gastrin levels were measured in tumor tissues and normal mucosa taken by colonoscopic biopsy from colon cancer patients and healthy controls. The setting was a university hospital research laboratory. We had seventeen patients with colorectal cancer and 23 controls. No significant difference was found in peripheral venous blood gastrin levels between the cancer and the control groups. Serum gastrin concentration was not significantly different in the arterial blood which supplied the tumor area, the venous blood draining the tumor, the "uninvolved" mucosa or the control normal epithelium. Cancer tissue gastrin levels were lower than those measured in biopsies of uninvolved mucosa from cancer patients and normal controls. The present results show no rise of gastrin blood levels in patients with colon cancer, nor any evidence of gastrin-increased synthesis by the tumors.

Emergence of antibody to capsular polysaccharides of Streptococcus pneumoniae during outbreaks of pneumonia: association with nasopharyngeal colonization

Antibody to pneumococcal capsular polysaccharides (PPS) of Streptococcus pneumoniae plays a major role in protecting the host against pneumococcal infection. A variable proportion of healthy adults have antibody to PPS, often in the absence of recognized pneumococcal infection. To determine whether exposure to pneumococci or colonization by pneumococci, or both, stimulates the emergence of antibody to PPS, we studied outbreaks of pneumonia at two military camps. Of the men who were present at a military training camp during an outbreak of pneumonia due to S. pneumoniae serotype 1 but who did not develop pneumonia, 27.8% had IgG antibody to PPS 1, whereas only 3.6% of controls had this antibody. In another outbreak caused by S. pneumoniae serotypes 7F and 8, 35.9% of asymptomatic soldiers who had nasopharyngeal colonization by one of these strains had antibody to the relevant PPS, and another 30.8% who originally did not have antibody developed it within 30 days; thus, 66.7% of these soldiers had antibody to the relevant PPS. These data show that serotype-specific antibody promptly appears following exposure to an outbreak of pneumococcal pneumonia and is probably mediated through acquisition of nasopharyngeal pneumococcal carriage.

House dust mite allergens in Saudi Arabia: Regional variations and immune response

In order to assess the causative extrinsic allergic factor(s) in school-age children diagnosed as having bronchial asthma and allergic rhinitis, and to qualitatively and quantitatively evaluate the presence of house dust mites (HDMs) in the homes of these children in Saudi Arabia, a study analyzing mite contents in 165 samples collected from patientsâ indoor environment was conducted. The dust samples were collected from four regions of Saudi Arabia, showing variation in their geography and climate. Immunochemical assays were performed using ALK reagents by ELISA technique. A total of 462 children were also tested using skin prick test (SPT) method for IgE-mediated reactions to HDMs. The samples from the Central dry region revealed a very low amount of the potent house dust mites (Dermatophagoides pteronyssinus and D. farinae, the two dominant species in various parts of the world). The samples from the Southern mountainous region contained a very high concentration of Der p I (84,000 ng/g of dust), while the Western coastal region showed a high concentration of Der f I (up to 22,000 ng/g). The mid-Western agricultural region did not exhibit any significant level of either Der p I or Der f I. The maximum level of D. pteronyssinus detected in the Central dry region was 106 ng/g of dust. The data exhibit both qualitative and quantitative variations of HDMs in the three regions and may be attributed to variation in geography and climate, particularly humidity of the regions, which vary significantly. Riyadh in the Central region is considered to have low humidity (<40%), while humidity in the Western coastal region, Jeddah, and the Southern region of Abha is comparatively higher, which helps house dust mites thrive. SPT results in these regions with house dust mite allergens (in addition to other common inhalant allergens) also revealed a considerable number of IgE-mediated reactions, consistent with the frequency of house dust mites in the region. Though more data are being accumulated on the subject to conduct a statistical comparison and more skin tests are underway in the Southern region, the study suggests the presence of at least two HDMs as well as qualitative diversity and quantitative variation of house dust mites in Saudi Arabia. The study also indicates, with a considerable number of IgE-mediated reactions, the possible influence of mites in the allergic manifestations of many patients, which is not only common, but increasing in parts of the country.

Handwashing and glove use in a long-term-care facility

OBJECTIVES

To determine glove use and handwashing practices, the factors associated with infection control practices, and the frequency of potential microbial transmission in a long-term-care facility (LTCF).

DESIGN

Observational study of 230 staff-resident interactions in an LTCF. We recorded resident characteristics, type of activity, staff credentials, and movements of the staff member's hands, then used the LTCF's guidelines to judge appropriateness of glove use and handwashing.

SETTING

255-bed, university-based LTCF in Baltimore, Maryland.

PARTICIPANTS

A systematic sample of staff-resident interactions.

RESULTS

Gloves were worn in 139 (82%) of 170 interactions when indicated, but changed appropriately in only 1 (16%) of 132. Hands were washed when needed before an interaction in 27%, during an interaction in 0%, and after an interaction in 63%. Gloves were less likely to be used when caring for residents with gastrostomy tubes compared with other residents (relative risk, 0.85; 95% confidence interval, 0.73-0.98). Guidelines were followed more frequently during wound care than during other activities. Microbial transmission potentially could have occurred in 158 (82%) of 193 evaluable interactions.

CONCLUSIONS

We documented marked deficiencies in glove and handwashing, demonstrated the possible impact of these deficiencies, and identified factors associated with inadequate handwashing and glove use. This information can be used in future educational and research efforts to improve infection control practices.