Age estimation from structural changes of teeth and buccal alveolar bone level

Forensic odontology plays a vital role in the identification and age estimation of unknown deceased individuals. The purpose of this study is to estimate the chronological age from Cone-Beam Computed Tomography (CBCT) images by measuring the buccal alveolar bone level (ABL) to the cemento-enamel junction and to investigate the possibility of employing the age-related structural changes of teeth as studied by Gustafson. In addition, this study will determine the forensic reliability of employing CBCT images as a technique for dental age estimation. A total of 284 CBCT images of Malays and Chinese patients (150 females and 134 males), aged from 20 years and above were selected, measured and stages of age-related changes were recorded using the i-CAT Vision software. Lower first premolars of both left and right side of the jaw were chosen and the characteristics described by Gustafson, namely attrition, secondary dentine formation and periodontal recession were evaluated. Linear regression analysis was performed for the buccal bone level and the R values obtained were 0.85 and 0.82 for left and right side respectively. Gustafson's characteristics were analysed using multiple regression analysis with chronological age as the dependent variable. The results of the analysis showed R values ranged from 0.44 to 0.62. Therefore it can be safely concluded that the buccal bone level highly correlated with the chronological age and is consequently the most suitable age-related characteristic for forensic age estimation.

Novel small molecules potentiate premature termination codon readthrough by aminoglycosides

Nonsense mutations introduce premature termination codons and underlie 11% of genetic disease cases. High concentrations of aminoglycosides can restore gene function by eliciting premature termination codon readthrough but with low efficiency. Using a high-throughput screen, we identified compounds that potentiate readthrough by aminoglycosides at multiple nonsense alleles in yeast. Chemical optimization generated phthalimide derivative CDX5-1 with activity in human cells. Alone, CDX5-1 did not induce readthrough or increase TP53 mRNA levels in HDQ-P1 cancer cells with a homozygous TP53 nonsense mutation. However, in combination with aminoglycoside G418, it enhanced readthrough up to 180-fold over G418 alone. The combination also increased readthrough at all three nonsense codons in cancer cells with other TP53 nonsense mutations, as well as in cells from rare genetic disease patients with nonsense mutations in the CLN2, SMARCAL1 and DMD genes. These findings open up the possibility of treating patients across a spectrum of genetic diseases caused by nonsense mutations.

The other causes of 'atypical' pneumonia

Mycoplasma, Chlamydia and Legionella are the usual organisms considered to be the etiologic agents of 'atypical' pneumonia. Other microorganisms such as bacteria, viruses, parasites, fungi and mycobacteria can also present with atypical pneumonia manifestations. Outbreaks and isolated cases of respiratory viruses with atypical pneumonia presentations have been reported among immunocompetent and immunosuppressed patients. Severe infections due to these respiratory viruses alone or as a concomitant bacterial or viral infection have been observed. Additionally, in endemic areas, certain zoonotic infections may present as atypical pneumonia.

Ultrasound phased arrays for prostate treatment

The effect of array geometry on the steering performance of ultrasound phased arrays is examined theoretically, in order to maximize array performance under the given anatomical constraints. This paper evaluates the performance of arrays with spherical and cylindrical geometry, determined by using computer simulations of the pressure fields produced at various extremes of steering. The spherical segment arrays were truncated for insertion into the rectum, and contained either annular or linear elements. The cylindrical arrays were either flat or had a variable curvature applied along their length. Fields were computed by dividing the array elements into many point sources. The effectiveness of an array configuration when steered to a particular focal location was assessed by defining a parameter, G, as the ratio of the intensity at the desired focus to the maximum intensity of any unwanted lobes. The performance of truncated spherical arrays with annular elements was evaluated for focal steering along the array axis (in depth, in the z direction). When steered 15 mm toward the source, these truncated spherical annular arrays exhibited excellent performance, with G>5.7 for arrays containing more than 10 elements. Similarly, the spherical arrays with linear elements performed well when steered along the array axis to the same degree, with G>7 (for element widths up to 3 lambda), though many more array elements were required. However, when these arrays were steered 15 mm laterally, along the length of the prostate (the y direction), the value for G fell below 1 for element widths greater than about 1.6 lambda. It was found that the cylindrical arrays performed much better for y-direction steering (G>4, for 60 mm arrays with an element width of 1.75 lambda), but their performance was poorer when steered in the z direction (G approximately 4 for an element width of 1.5 lambda). In order to find a compromise between these extremes, a curved cylindrical array was examined, which was a cylindrical array with additional curvature along its length. These curved cylindrical arrays yielded performance between that of spherical linear arrays and cylindrical arrays, with better steering along the y direction than the spherical arrays and better z-direction steering than the cylindrical arrays.

Persistently positive culture results in a patient with community-acquired pneumonia due to Legionella pneumophila

We describe a patient with community-acquired pneumonia due to Legionella pneumophila serogroup 6. This patient was found to have bronchoalveolar carcinoma of the lung by means of cytologic testing in 1 of 2 bronchoalveolar lavage samples, but no lesions were visible on bronchoscopy. Despite intravenous administration of azithromycin to the patient, repeat culture and polymerase chain reaction showed persistence of Legionella; the isolates remained susceptible to azithromycin. The patient did not respond to 14 doses of daily intravenously administered azithromycin. The poor outcome may have been partially due to the suspected underlying lung malignancy, as shown by cytologic examination, and by a delay in seeking medical attention.

Linear correlation between axial and lateral bone mineral density of lumbar vertebrae

The placement of most spinal interbody devices is above the cancellous region of the vertebral bodies. Dual X-ray absorptiometry (DXA) scans of patients are usually taken from the anterior-posterior or the lateral projection. DXA scans taken in vitro from the axial direction would most closely indicate the bone mineral density (BMD) of the bone at this region. So far, in vitro studies have not been conducted to determine the correlation between axial and lateral scans. Because lateral DXA BMD scans are noninvasive and have low radiation dosage, they could be used as a predictive tool to determine the quality of cancellous bone at the centrum of the vertebral bodies, where spinal interbody devices are commonly placed.

Prevalence of headache among handheld cellular telephone users in Singapore: a community study

We carried out a cross-sectional community study in Singapore to determine the prevalence of specific central nervous system (CNS) symptoms among hand-held cellular telephone (HP) users compared to nonusers and to study the association of risk factors and CNS symptoms among HP users. A total of 808 men and women between 12 and 70 years of age, who lived in one community, were selected using one-stage cluster random sampling and responses to a structured questionnaire. The prevalence of HP users was 44.8%. Headache was the most prevalent symptom among HP users compared to non-HP users, with an adjusted prevalence rate ratio of 1.31 [95% confidence interval, 1.00-1.70]. There is a significant increase in the prevalence of headache with increasing duration of usage (in minutes per day). Prevalence of headache was reduced by more than 20% among those who used hand-free equipment for their cellular telephones as compared to those who never use the equipment. The use of HPs is not associated with a significant increase of CNS symptoms other than headache.

Prevalence of headache among handheld cellular telephone users in Singapore: a community study

We carried out a cross-sectional community study in Singapore to determine the prevalence of specific central nervous system (CNS) symptoms among hand-held cellular telephone (HP) users compared to nonusers and to study the association of risk factors and CNS symptoms among HP users. A total of 808 men and women between 12 and 70 years of age, who lived in one community, were selected using one-stage cluster random sampling and responses to a structured questionnaire. The prevalence of HP users was 44.8%. Headache was the most prevalent symptom among HP users compared to non-HP users, with an adjusted prevalence rate ratio of 1.31 [95% confidence interval, 1.00-1.70]. There is a significant increase in the prevalence of headache with increasing duration of usage (in minutes per day). Prevalence of headache was reduced by more than 20% among those who used hand-free equipment for their cellular telephones as compared to those who never use the equipment. The use of HPs is not associated with a significant increase of CNS symptoms other than headache.

Group A streptococcus necrotizing fasciitis

Necrotizing fasciitis due to Group A streptococcus has been observed with increasing frequency over the past decade. Appropriate management requires rapid recognition of this life-threatening infection and expeditious antimicrobial therapy as well as surgical debridement or excision of tissue.

The radiologic manifestations of Legionnaire's disease. The Ohio Community-Based Pneumonia Incidence Study Group

STUDY OBJECTIVES

To study the serial radiographic manifestations of Legionnaire's disease from the initial presentation on admission to recovery using strict criteria for the diagnosis of infection.

MATERIALS AND METHODS

We prospectively studied the chest radiographs of patients hospitalized with a diagnosis of community-acquired pneumonia in Summit County, Ohio between November 1990 and November 1992. Forty-three patients fulfilled strict criteria for legionellosis. The diagnosis of infection was based on the criteria of "definite" diagnosis as defined by the Ohio Community-Based Pneumonia Incidence Study Group report. The criteria included the isolation of the microorganism, the presence of a significant antibody rise, or the presence of Legionella antigen in the urine.

RESULTS

Forty of 43 patients had admission radiographs interpreted as compatible with pneumonia. In spite of appropriate antimicrobial therapy, worsening of the infiltrates was found in more than half of the patients within the first week. Twenty-seven patients were observed to have pleural effusion during the course of hospitalization: 10 effusions were found on admission, another 14 developed during the first week, and 3 new effusions were discovered after the first week. Cavitation was found in only one patient. None of the patients had apical involvement.

CONCLUSION

This study confirms previous reports using less stringent etiologic diagnosis criteria that chest radiographic findings in Legionnaire's disease are not specific. Even with appropriate therapy, more than half of the patients will have worsening of the infiltrates during the first week. Pleural effusion is common among our patients, and it is frequently detected during the serial radiographic studies during the first week of hospitalization. Chest radiography in Legionnaire's disease is useful only for the monitoring of disease progression and not for diagnostic purposes. In addition, worsening of infiltrates and pleural effusion are seen in more than half of the patients in spite of appropriate therapy and clinical improvement.

Chlamydia Pneumoniae Pneumonia

Chlamydia pneumoniae is a common cause of community-acquired pneumonia. At present there is no "gold'' standard for diagnosis and there is no easily accessible means of rapid diagnosis available. The best indication of acute C. pneumoniae infection is a fourfold rise in antibody titer, accompanying a positive polymerase chain reaction or culture. C. pneumoniae is usually associated with nonsevere clinical manifestations but the features will vary depending upon the occurrence as primary or reinfection syndrome, the presence of co-pathogens, or the existence of co-morbid conditions. C. pneumoniae has been described as a cause of severe disease requiring intensive care unit admission. Recommendations for therapy of C. pneumoniae pneumonia include macrolides, tetracyclines, or the new fluoroquinolones.

Diagnosis and treatment of diabetic foot infections

Prompt clinical diagnosis and timely treatment are the hallmarks of the proper care of diabetic patients with foot infections. The importance of careful clinical foot examination cannot be overemphasized. When infection is suspected, effort should be made to search for deeper infections, especially osteomyelitis. Numerous imaging techniques are available, but their cost-effectiveness has not been fully determined. Radiography of the foot is less sensitive but can provide useful information at a lower cost. Radio-isotope studies have not yielded consistent results, but the newer techniques deserve attention. Microbiological diagnosis should be attempted using only deep tissue culture, including bone biopsy. The primary aim of treatment of the infected foot is to restore ambulation. Timely surgical intervention and appropriate antimicrobial therapy can reduce the incidence of above-ankle amputation and reduce the length of hospital stay.

Role of 'atypical' pneumonia pathogens in respiratory tract infections

The 'atypical' pathogens are important causes of pneumonia, causing illness ranging from mild to life-threatening. The most common atypical pathogens are Mycoplasma pneumoniae and Chlamydia pneumoniae; others include Legionella species, Chlamydia psittaci and viruses such as influenza, adenovirus and respiratory syncytial virus. Infection rates for these agents are difficult to determine because many clinicians and investigators do not routinely test for them, but reported rates are in the range of up to 8% (for C pneumoniae) and 15% to 20% (M pneumoniae) of all cases of pneumonia. Diagnostic testing is very difficult because most of these agents cannot be easily cultured. Diagnosis relies on either high acute antibody titres (quickly available but not very accurate) or paired serology samples (more accurate but requires at least a week). While rapid identification using automated polymerase chain reaction testing may be possible in the future, current management is based largely on empirical treatment.

The role of atypical pathogens: Mycoplasma pneumoniae, Chlamydia pneumoniae, and Legionella pneumophila in respiratory infection

Infections caused by M. pneumoniae, C. pneumoniae, and Legionella spp. are important causes of community-acquired pneumonia (CAP). In the past decade, considerable new information has come to light concerning these organisms. Despite this, debate continues concerning the syndromic approach to CAP and the scientific merit of lumping these pathogens together. Because the etiologic diagnosis of these pathogens is established only in a minority of cases, the true prevalence tends to be underestimated. In clinical practice, these pathogens are often empirically treated. More rapid and cost-effective diagnostic techniques are needed so that the clinical course of patients with these infections can be better characterized.

Group A streptococcal necrotizing fasciitis. Diagnosing and treating the "flesh-eating bacteria syndrome"

Over the past decade the incidence of necrotizing fasciitis due to group A streptococci has increased. Appropriate management of this life-threatening infection requires rapid recognition, immediate antibiotic therapy, and expeditious surgical debridement or excision.

Human zoonotic infections transmitted by dogs and cats

Dogs and cats are the 2 most common household pets. However, they may be a direct or indirect source of human infections. This article aims to familiarize physicians with some common and uncommon bacterial, rickettsial, parasitic, and fungal zoonotic infections of dogs and cats. Animal bites with or without infection continue to be a common problem. Treatment of infected animal bites must include early debridement and concern for organisms from the mouth flora of the animal. The diagnosis and treatment of cat-scratch disease have become easier since Bartonella henselae has been established as the main causal agent. Less common bacterial and rickettsial zoonotic infections are included to increase the reader's awareness. Parasitic infections, such as creeping eruptions, visceral larva migrans, cryptosporidiosis, and toxoplasmosis, are diseases associated with contact with dogs and cats. Pets can also be the source of dermatophyte infections. An increase in awareness that some of these diseases may be associated with animals could provide a better plan for the prevention and treatment of common and uncommon zoonotic infections.

Human alveolar T lymphocyte responses to Mycobacterium tuberculosis antigens: role for CD4+ and CD8+ cytotoxic T cells and relative resistance of alveolar macrophages to lysis

T cell-mediated cytotoxicity against Mycobacterium tuberculosis (MTB)-infected macrophages may be a major mechanism of specific host defense, but little is known about such activities in the lung. Thus, the capacity of alveolar lymphocyte MTB-specific cell lines (AL) and alveolar macrophages (AM) from tuberculin skin test-positive healthy subjects to serve as CTL and target cells, respectively, in response to MTB (H37Ra) or purified protein derivative (PPD) was investigated. Mycobacterial Ag-pulsed AM were targets of blood CTL activity at E:T ratios of > or = 30:1 (51Cr release assay), but were significantly more resistant to cytotoxicity than autologous blood monocytes. PPD- plus IL-2-expanded AL and blood lymphocytes were cytotoxic for autologous mycobacterium-stimulated monocytes at E:T ratios of > or = 10:1. The CTL activity of lymphocytes expanded with PPD was predominantly class II MHC restricted, whereas the CTL activity of lymphocytes expanded with PPD plus IL-2 was both class I and class II MHC restricted. Both CD4+ and CD8+ T cells were enriched in BL and AL expanded with PPD and IL-2, and both subsets had mycobacterium-specific CTL activity. Such novel cytotoxic responses by CD4+ and CD8+ T cells may be a major mechanism of defense against MTB at the site of disease activity.

Human alveolar T lymphocyte responses to Mycobacterium tuberculosis antigens: role for CD4+ and CD8+ cytotoxic T cells and relative resistance of alveolar macrophages to lysis

T cell-mediated cytotoxicity against Mycobacterium tuberculosis (MTB)-infected macrophages may be a major mechanism of specific host defense, but little is known about such activities in the lung. Thus, the capacity of alveolar lymphocyte MTB-specific cell lines (AL) and alveolar macrophages (AM) from tuberculin skin test-positive healthy subjects to serve as CTL and target cells, respectively, in response to MTB (H37Ra) or purified protein derivative (PPD) was investigated. Mycobacterial Ag-pulsed AM were targets of blood CTL activity at E:T ratios of > or = 30:1 (51Cr release assay), but were significantly more resistant to cytotoxicity than autologous blood monocytes. PPD- plus IL-2-expanded AL and blood lymphocytes were cytotoxic for autologous mycobacterium-stimulated monocytes at E:T ratios of > or = 10:1. The CTL activity of lymphocytes expanded with PPD was predominantly class II MHC restricted, whereas the CTL activity of lymphocytes expanded with PPD plus IL-2 was both class I and class II MHC restricted. Both CD4+ and CD8+ T cells were enriched in BL and AL expanded with PPD and IL-2, and both subsets had mycobacterium-specific CTL activity. Such novel cytotoxic responses by CD4+ and CD8+ T cells may be a major mechanism of defense against MTB at the site of disease activity.

Hippocampal volumetry with magnetic resonance imaging: a cost-effective validated solution

PURPOSE

The clinical utility of hippocampal volumetry is well documented, but the materials and techniques required to perform the procedure are not widely available outside major research centers. We describe a personal computer-based method of volumetric data analysis.

METHODS

Using a 1.0-T scanner, we obtained 2-mm-thick tilted coronal MPRAGE magnetic resonance imaging (MRI) scans of 20 healthy volunteers aged 20-38 years. We used an inexpensive utility program to extract image information and an NIH Image for image analysis. The hippocampal formations were traced with a graphics tablet and landmarks described by Watson et al. (Neurology 1992;42:1743-50). Overlays of individual observers' tracings were used to fine tune the selection of landmarks and boundaries. Filled-in silhouette pairs generated from these "training tracings" were compared to determine how well observers could visually quantify area differences.

RESULTS

Visual detection of asymmetry of silhouette pairs was sensitive, but the magnitude of asymmetry was underestimated. We achieved intraobserver coefficients of variation of right/left volume ratios between 0.82 and 3.16 and an interobserver range of volume ratios of 6%. In 20 healthy controls aged 20-38 years, the mean right and left hippocampal volumes were 2,911 mm3 and 2,836 mm3, respectively. The lower limits of normal were 2,217 mm3 for the right and 2,178 mm3 for the left. The mean right/left hippocampal ratio was 1.03, and the limits of normal (3 SD) for this were 0.95 to 1.10.

CONCLUSIONS

Hippocampal volumetry can be performed reliably and economically. Our methodology makes it possible for different observers to generate consistent and comparable measurements.

Incidence, etiologic pathogens, and diagnostic testing of community-acquired pneumonia

Determination of the etiologic pathogens of community-acquired pneumonia has been problematic because of the lack of reliable rapid laboratory diagnostic tools as well as the controversy concerning diagnostic criteria. In the studies reviewed here, a specific pathogen was identified in 39% to 88% of patients. Streptococcus pneumoniae remains the most common cause of community-acquired pneumonia. Depending on the demographics of the study, between 2% to 43% of cases have been attributed to legionella or Chlamydia pneumoniae. More recently, other pathogens have emerged, including respiratory syncytial virus in adults, hantavirus, and possibly legionella-like amoebal pathogens and Streptococcus milleri group. Treatment guidelines published by various societies of experts have been helpful, but they cannot replace the need for better and rapid diagnostic techniques.

Mutagenic synergy between paraoxon and mammalian or plant-activated aromatic amines

Paraoxon (diethyl-p-nitrophenylphosphate) is the toxic, but non-mutagenic metabolite of the organophosphorus ester (OP) insecticide parathion. Although this agent has been used as a deacetylase inhibitor in many studies, we discovered a mutagenic synergy with paraoxon and plant-activated m-phenylenediamine or with direct-acting 2-acetoxyacetylaminofluorene in Salmonella typhimurium cells [Gichner T et al. (1996): Environ Mol Mutagen 27; 59-66]. In the present study, mammalian-activated m-phenylenediamine, o-phenylenediamine, p-phenylenediamine, benzidine, 2,3-diaminophenazine or 2-aminofluorene, as well as plant-activated benzidine or 2-aminofluorene expressed an elevated mutagenic potency when assayed with S. typhimurium strain YG1024 in the presence of paraoxon. Under non-toxic conditions, paraoxon amplified the S. typhimurium mutant yield induced by these aromatic amines between 1.9-fold and 8.4-fold. Spectrophotometric analysis demonstrated that the rate of degradation of 2-acetoxyacetylaminofluorene was not significantly different in phosphate buffer with or without paraoxon or with S. typhimurium cytosol with or without paraoxon. Also paraoxon-mediated mutagenic synergy does not appear to be due to a direct reaction with aromatic amines. Mutagenic synergy between aromatic amines and OP oxon products may be a cause of concern because people are chronically exposed to environmental and dietary aromatic amines, and a significant segment of the U.S. population tested positive for OP insecticide residues.

Management of staphylococcal and streptococcal infections

Staphylococcus and streptococcus are bacteria commonly found on the skin and in the mucous membrane. These bacteria are frequently associated with mild cutaneous infections but may invade to cause deeper infections including necrotizing soft-tissue infections, sepsis with or without metastatic lesions, and immunologic or toxin associated sequelae. Early recognition and timely intervention are the hallmarks of appropriate management. Initial empiric therapy should be directed towards a broad spectrum of pathogens that include staphylococcus and streptococcus.

Can aggressive treatment of diabetic foot infections reduce the need for above-ankle amputation?

We retrospectively evaluated the charts of 112 patients with diabetic foot infection to determine if early aggressive surgical intervention improves outcome. All patients were classified into two groups on the basis of the timing of surgical intervention and appropriate antimicrobial therapy. Group I included patients who underwent no surgical intervention during the first 3 days of hospitalization but received intravenous antimicrobial therapy, and group II included patients who underwent surgical intervention promptly and received intravenous antimicrobial therapy. Group II was further divided; group IIA included patients who underwent debridement, and group IIB included patients who underwent local limited amputation. A higher rate of patients in group I than in group II (27.6% vs. 13%, respectively; P < .01) required above-ankle amputation during the same hospitalization or subsequent admission. Overall, an aggressive surgical approach against foot infection in hospitalized diabetic patients reduced the need for above-ankle amputation and the length of hospital stay by at least 6 days. Treatment of diabetic foot infection requires the combination of early surgical treatment and antimicrobial therapy.

Community-acquired pneumonia. What's needed for accurate diagnosis

Characteristic clinical findings of fever, cough, and rhonchi, together with a new infiltrate on chest films and documentation of a pathogen, establish a diagnosis of infectious pneumonia. Several factors have had an impact on the approach to diagnosis of community-acquired pneumonia by the primary care physician. These include the expanding number of possible pathogens as well as their increasing resistance to antimicrobial therapy. Although the clinical presentation may suggest a specific cause, findings often overlap too much for reliable identification of the specific agent on clinical grounds alone. Isolation of the microorganism or determination of the presence of a specific antigen or antibody is necessary. However, even after extensive studies are performed, the pathogen remains unidentified in 30% to 50% of cases. The primary care physician therefore needs to balance reasonable use of diagnostic tests with empirical therapy.

Antipseudomonal penicillins

Antipseudomonal penicillins retain most of the antibacterial activity of penicillin and aminopenicillins. This group of penicillins has added activities against many gram-negative rods, including P. aeruginosa. Similar to the earlier penicillins, this group continues to be susceptible to hydrolysis by many beta-lactamases and are, therefore, not consistently active against Staphylococcus, some gram-negative rods, and certain beta-lactamase-producing gram-negative anaerobes. The ureidopenicillins, especially piperacillin, appear to have better activity against Enterococcus, Klebsiella, and P. aeruginosa than ticarcillin. The advantages over the newer cephalosporins are (1) better activity against Enterococcus, (2) more consistent activity against Clostridium, and (3) more consistent synergy with aminoglycosides. The ureidopenicillins have certain advantages over carboxypenicillins, including lower sodium load, less frequent hypokalemia, reduced platelet dysfunction, minimal dosage adjustment in patients with renal failure, and a wider spectrum of antibacterial activity, especially against Enterococcus, Pseudomonas, and Klebsiella. The utility of the antipseudomonal penicillins by themselves is limited as agents for monotherapy when the infecting organism is not known. In addition, monotherapy is not recommended in certain infections to avoid the development of resistance. When combined with a beta-lactamase inhibitor or with an aminoglycoside, however, some of the weaknesses can be overcome.

An outbreak of Pseudomonas aeruginosa ventilator-associated respiratory infections due to contaminated food coloring dye--further evidence of the significance of gastric colonization preceding nosocomial pneumonia

An outbreak of ventilator-associated Pseudomonas aeruginosa respiratory infections in an intensive care unit of a teaching hospital was found to be associated with contaminated food coloring dye. Serotyping and bacteriocin typing indicated that the same strain of Pseudomonas was isolated from the food dye and from the respiratory cultures of the majority of patients. This observation lends credence to the importance of gastric colonization preceding pneumonia in ventilated patients.

[Therapy of cantharides extract for perennial allergic rhinitis and its effect on total IgE in serum]

The therapy of 10% Cantharides extract in treating 50 cases of perennial allergic rhinitis (PAR) was studied. The extract was plastered and blistered on Dazhui, Neiguan point. It was observed by nasal mucosa provocative test, cells in nasal secretion test and serum total IgE test. The results showed that its effective rate was 88%, the allergic nasal mucosa provocative test of treated group alleviated obviously after the treatment (P < 0.01), the number of eosinophil and basophil in nasal secretion decreased (P < 0.01, P < 0.05); and the serum total IgE also reduced significantly (P < 0.01).

Treatment of skin and soft-tissue infections

Bacterial infections of the skin range from mild pyodermas to life-threatening necrotizing infections. Pyodermas are most often due to Staphylococcus aureus or beta-hemolytic Streptococcus sp, whereas infections associated with skin ulcers of the extremities, infections following trauma or surgery, and histotoxic necrotizing infections may involve a large number of additional pathogens, including Enterobacteriaceae, Pseudomonas sp, enterococci, and anaerobes. Management of bacterial skin and soft-tissue infections includes appropriate surgical drainage or excision of infected tissue and antimicrobial therapy. The combination of piperacillin and the beta-lactamase inhibitor tazobactam is a newly released antimicrobial, which has excellent in vitro activity against the vast majority of pathogens involved in skin infections. Two multicenter studies recently evaluated the efficacy and safety of piperacillin/tazobactam in the therapy of skin and soft-tissue infections in hospitalized patients. Piperacillin/tazobactam was well tolerated and demonstrated high clinical efficacy for the treatment of these infections.

Hospital medical directors, quality of care, and financial returns

You are a physician executive working very hard within a hospital on all sorts of medical staff issues and quality of care. You answer to the board. The latter, through its administrators, may still have difficulty documenting the precise value of a full-time physician executive. Your hospital is losing money or not making enough profit for capital expenditures and salary raises. It is considering or will have to consider staff cuts. What can you do that will influence the bottom line, produce a quality image, and quantify your value?

Surface modification of nanoparticles by PEO/PPO block copolymers to minimize interactions with blood components and prolong blood circulation in rats

The biological fate of injected foreign particles is believed to be closely related to their interactions with blood plasma proteins and cells. In order to verify this correlation, we have quantitatively measured protein adsorption and blood retention profiles in rats by using model polystyrene latex nanoparticles. The in vitro interactions of these non-biodegradable particles with plasma proteins and whole blood can be altered by modifying their surfaces with a family of amphiphilic polymeric surfactants, PEO/PPO Pluronic or Tetronic block copolymers. Protein adsorption was measured by several techniques, including photon correlation spectroscopy, centrifugation, high performance liquid chromatography and field-flow fractionation. Pluronic F108 and Tetronic 908 and 1508 copolymers (with PEO terminal block MWPEO > 5000, PPO middle block MWPPO > 3000, and HLB values > 24) were shown to be the most effective surface modifiers in reducing adsorption of plasma proteins on the particles. Minimum interaction of coated particles with whole blood was also observed by optical microscopy. The blood circulation half-life of the particles injected in rats was increased from 20 min to 13 h when the latex particles (75 nm) were precoated with these block copolymers. These results suggest that nanoparticles designed for use as injectable drugs or drug carriers should display similar surface characteristics provided by such amphiphilic surface modifiers.

Treatment of hospitalized patients with complicated skin and skin structure infections: double-blind, randomized, multicenter study of piperacillin-tazobactam versus ticarcillin-clavulanate. The Piperacillin/Tazobactam Skin and Skin Structure Study Group

We compared the efficacy and safety of two beta-lactam-beta-lactamase inhibitor combinations, namely, piperacillin-tazobactam and ticarcillin-clavulanate, in the treatment of complicated bacterial infections of skin that required hospitalization. The study was a randomized, double-blind, comparative trial involving 20 centers. The infections were classified as (i) cellulitis with drainage, (ii) cutaneous abscess, (iii) diabetic or ischemic foot infection, and (iv) infected wounds and ulcers with drainage. The clinical response rates were comparable for the two treatment regimens (61% of the patients were cured with piperacillin-tazobactam and ticarcillin-clavulanate and improvement was seen in 15 and 16% of patients treated with piperacillin-tazobactam and ticarcillin-clavulanate, respectively). Both regimens were found to be safe and well tolerated. These data support the use of piperacillin-tazobactam for initial empiric therapy of hospitalized patients with complicated skin and skin structure infections.

Emergence of antimicrobial resistance in gram-negative bacilli causing bacteremia during therapy

Treatment of serious infections caused by gram-negative bacilli with beta-lactam antimicrobial agents can induce Class I beta-lactamase production. This phenomenon can result in resistant microorganisms, and has been postulated to be a cause of therapeutic failure. The charts of patients bacteremic with Pseudomonas aeruginosa, Serratia marcescens, Enterobacter cloacae, Citrobacter freundii, Proteus vulgaris, and Providencia species (n = 120) during a 3-year period were reviewed to determine how common the emergence of resistance was, and to determine if in vitro susceptibility testing was a reliable therapeutic guide. Emergence of resistance was believed to occur when a subsequent bacteremic isolate showed at least a fourfold increase in minimum inhibitory concentration accompanied by a change of interpretive susceptibility category. In the group of patients who survived at least 48 hours that received beta-lactam therapy (n = 76), one case of emergence of resistance was identified (1.3%). Emergence of resistance to beta-lactam antimicrobial agents did not commonly cause therapeutic failure at our institution, and susceptibility testing of gram-negative bacilli by usual methods was a reliable guide to antimicrobial therapy.

Treatment of bacteriuria in pregnancy

The presence of bacteriuria during gestation increases the chance of acute pyelonephritis. Treatment of bacteriuria in pregnancy reduces subsequent development of symptomatic disease. Numerous studies have shown that single-dose therapy for asymptomatic bacteriuria is as effective as longer course of treatment. Single-dose therapy also has the advantages of improved compliance, reduced costs, and less adverse effects resulting from long term therapy. Follow-up cultures following antimicrobial treatment should be used for early detection of recurrence or relapse. If the urine culture yields no growth, a urine culture at a monthly interval will suffice. If on the other hand bacteriuria is present, a repeat course of antimicrobial therapy should be chosen based on antimicrobial susceptibility testing. A longer course of therapy, possibly with a different drug, is recommended for women with a positive follow-up urine culture. Acute cystitis may be treated with the same regimen as asymptomatic bacteriuria. When upper urinary tract infection is suspected, hospitalisation and a longer course of therapy is recommended. If the organism is susceptible to cefalexin or nitrofurantoin, postcoital prophylaxis with either agent for the remainder of the pregnancy may be beneficial.

Community-acquired pneumonia. The changing picture

Important changes in the initial management of community-acquired pneumonia have been prompted by the discovery of new respiratory pathogens, the changing susceptibility of traditional pathogens to antimicrobial agents, and the introduction of new antimicrobial agents. Although the clinical presentation may suggest a specific pathogen, findings overlap too much to reliably distinguish the specific cause of the pneumonia on a clinical basis. Useful laboratory studies include Gram's stain and culture of sputum, blood culture, serologic studies, and new tests such as the urinary antigen test for Legionella pneumophila. Empirical antimicrobial treatment must take into consideration that 20% to 30% of cases of community-acquired pneumonia are due to atypical pathogens that are not susceptible to beta-lactam agents.

Results of total hip replacement in renal transplant recipients

A vascular necrosis of the femoral head associated with steroid immunosuppression is a cause of significant morbidity in renal transplant recipients. We review the results of 30 total hip replacements in 20 renal transplant recipients with a mean follow-up of 6.3 years. The mean age at the time of surgery was 35 years. The average Hospital for Special Surgery Hip Score was 17 points before operation and 32 points after operation. Fourteen hips were rated excellent and 12 hips rated good. There were four failures--one hip was revised for symptomatic loosening and three prosthesis were removed for infection. Twenty-seven of the hip replacements were subjectively rated as satisfactory by the patient. There was no significant difference in post-operative hip scores between cemented and uncemented prostheses. Total hip replacement in renal transplant recipients in this study has shown good long term result with a revision rate of about 3%. Late infection was a major problem with an incidence of 13%. Prophylactic antibiotics must be used whenever there is a risk of haematogenous seeding from transient bacteremia in these immunosuppressed patients. Use of uncemented prosthesis may make future revision arthroplasty easier.

Pharmacokinetics of imipenem in serum and skin window fluid in healthy adults after intramuscular or intravenous administration

The pharmacokinetic profiles of imipenem after intramuscular (i.m.) and intravenous injections were examined in adult volunteers. Levels of imipenem in serum after i.m. injection of a microcrystalline suspension of imipenem-cilastatin (500 mg each) reached a peak (8.0 micrograms/ml) at 1.5 h after administration, and concentrations were maintained in excess of 1.5 micrograms/ml for 6 h. Serum elimination half-life (1.3 h), volume of distribution (14.5 liters), and area under the curve (AUC; 27.8 micrograms.h/ml) after i.m. injection did not significantly differ from those of a comparable dose given by intravenous infusion. Bioavailability after i.m. injection was 89%. Imipenem levels in skin window fluid after i.m. administration were maximal (4.3 micrograms/ml) at 4 h after injection, at which time imipenem concentrations exceeded those produced by intravenous infusion. The AUCskin window/AUCserum ratio for skin window fluid after i.m. injection was 68%, indicating good penetration of the drug into skin fluid. This study shows that i.m. injection of 500 mg of imipenem-cilastatin results in concentrations of imipenem in serum and skin fluid that are, for at least 6 h, consistent with antimicrobial activity against susceptible organisms.

The use of oral fluoroquinolones in nursing home patients

The approach to management of patients with presumed infection in the nursing home is influenced by the limited availability of diagnostic tests and support staff. Although antibiotics are most often prescribed in the absence of laboratory data, many studies indicate that empirical therapy for nursing home infections is relatively successful. With the scrutiny on containment of healthcare costs, therapy of nursing home patients has been changing and will continue to shift toward treatment within nursing homes without transfer to a hospital. Better oral antimicrobial agents with a wide spectrum of activity, such as the fluoroquinolones, will play a major role in the treatment of many infections acquired in the nursing home. Because of the favourable characteristics of the fluoroquinolone agents, they should be useful for elderly patients who develop infections in nursing homes. They have excellent in vitro activity against Gram-negative bacteria which are often multidrug-resistant and are common in nursing home patients. Studies indicate that absorption of orally administered fluoroquinolones is very efficient in the elderly and these drugs are well tolerated. Numerous clinical trials have documented good efficacy of the fluoroquinolones in the treatment of elderly patients for the most common infections in the nursing home, including urinary tract infections, respiratory tract infections and skin infections.

Ambulatory management of lower respiratory tract infections

Clinical manifestations and radiographic findings are unreliable guides to the selection of antimicrobial therapy for lower respiratory infections. Laboratory evaluation is necessary to identify the etiologic agent. Multiple oral antibiotics are available for outpatient treatment of bronchitis or pneumonia suspected to be of bacterial origin.

Ticarcillin-clavulanate therapy for bacterial skin and soft tissue infections

Ticarcillin-clavulanate is active in vitro against the vast majority of pathogens involved in skin and soft tissue infections. A compilation of six controlled clinical trials of ticarcillin-clavulanate for treatment of skin infections showed a satisfactory clinical response in 175 (93%) of 189 cases. The bacteriologic response included eradication of Staphylococcus aureus, Enterococcus species, Enterobacteriaceae, and Pseudomonas aeruginosa in 88%, 75%, 88%, and 77% of cases, respectively. In addition, the records of 17 patients with diabetic foot infections who were treated with ticarcillin-clavulanate as monotherapy in controlled trials are reviewed. Eight of these infections were cured and eight were improved at the end of therapy. The available clinical data suggest that ticarcillin-clavulanate is effective antimicrobial therapy for skin infections.

Quality assurance in an IPA setting

The experience at CIGNA Healthplans shows that a quality assurance program can be instituted in an IPA-model HMO at low cost and with the addition of little new staff. Existing resources can be effectively restructured to implement a functional program of a traditional type that is easily understood by employer groups, members, and providers. It can serve as a transitional process until the HMO is large enough to put a total quality management program in place.

A multicenter trial comparing the efficacy and safety of cefuroxime axetil and cefaclor in pneumonia of adults

The 185 hospitalized patients (aged 19 to 95 years) with pneumonia were randomly assigned to receive 500 mg of cefuroxime axetil orally (250 mg q12h), 1,000 mg of cefuroxime axetil orally (500 mg q12h), or 1,500 mg of cefaclor orally (500 mg q8h), daily, for a mean of nine days. Among the 151 evaluable patients, clinical cure was noted in 58% of the 500-mg cefuroxime axetil group, 94% of the 1,000-mg cefuroxime axetil group, and 88% of the cefaclor group, and clinical improvement in 32%, 4%, and 9%. Bacteriologic outcome was similar in the three groups. Adverse events were minor and comparable among the treatment groups. Cefuroxime axetil is a safe and effective oral antimicrobial for the treatment of pneumonia in adults.

Infections due to Corynebacterium group D2. Report of a case

Corynebacterium group D2 is a gram-positive bacillus easily identified in clinical microbiology laboratories. However, this organism is often disregarded as a skin and mucous contaminant. The Spanish literature has recently described Corynebacterium group D2 as a urinary pathogen in a specific patient population. We report a case of Corynebacterium group D2 infection to illustrate the potential pathogenicity and clinical presentation of infection due to this organism in the United States.

Effect of vacuum mixing on the mechanical properties of antibiotic-impregnated polymethylmethacrylate bone cement

Polymethylmethacrylate bone cement, containing either no added antibiotic, 0.5 g of Vancomycin, 1.0 g of Vancomycin, or 1.0 g of Tobramycin, was mixed either in air or a vacuum chamber. Following storage in a water bath at 37 degrees C for 48 h, the specimens were tested in four-point bending. The porosity of the specimens was assessed radiographically, and their antibacterial activity was monitored for 21 days. The bending strength of the vacuum mixed specimens containing no antibiotic was 40% greater than that of similar air-mixed specimens. However, there were no significant differences in the bending strength of either the air- or vacuum-mixed specimens when any of the antibiotic dosages were added. The bending modulus of the vacuum-mixed specimens, containing no antibiotic, was significantly greater than the moduli of all the other specimen groups which did not differ from each other. Vacuum mixing reduced the apparent porosity of the specimens fivefold, and while the addition of antibiotic did not effect porosity of the air-mixed specimens, that of the vacuum-mixed specimens was doubled. Although initial rapid decreases were seen, leaching of antibiotic from the cement and antibacterial activity continued through the 21-day monitoring period.

Urinary tract infections in obstetrics and gynecology

Escherichia coli is still the most common bacterial pathogen associated with urinary tract infections in women. Because of increasing resistance, ampicillin or a sulfonamide alone is no longer recommended for the empiric treatment of those infections. Antimicrobial therapy that contains a beta-lactamase inhibitor or that is resistant to the action of beta-lactamase is preferred. For the treatment of acute, uncomplicated lower urinary tract infection in a young woman, a short course of therapy (single dose) may be adequate. For an upper tract or complicated infection a longer course of therapy is advised. Asymptomatic bacteriuria in pregnancy should be treated; a short course of therapy with a beta-lactam antibiotic may be tried only if posttherapy follow-up cultures are planned. When bacteriuria persists or recurs, a longer course of therapy should follow, with consideration given to a urologic workup after delivery.

Diagnosis and treatment of staphylococcal diseases

Staphylococcus is, by far, the most commonly seen organism in podiatric infections. Although common, staphylococcal infections are difficult to understand and treat. These bacteria have undergone significant changes in their pathogenicity and antibiotic susceptibility over the last few years. Methicillin-resistant strains, once relatively rare, are becoming a major therapeutic dilemma in some centers.

[Pathological study of bronchio-alveolitis induced by xinkang short-fiber chrysotile asbestos in rats]

Eighty-four rats were exposed intratracheally to 25 mg of locally produced Xinkang short-fiber chrysotile asbestos (98% of the fibers are less than 5 microns in length). In 1 to 3 d after instillation, the pathological changes in rat lungs demonstrated that the affection was mainly acute bronchio-alveolitis characterized by acute inflammatory exudation and injuries of the small airways and alveolar structural units. The four main manifestations of alveolitis induced by the chrysotile asbestos were of the neutrophilic, serous, alveolar macrophages and granulomatous varieties. Three types of pulmonary fibrosis developed gradually from 7 to 90 d following the exposure to the asbestos, i.e. the intraluminal, murally incorporated, and interstitial fibrosis. Findings showed the complete process from the acute inflammatory exudation and the damage to lung tissue, with the following repair and proliferation of injuried lung tissue and organization of exudate, to the final fibrosis and destruction of the lung. The results suggested that the persistent and irreversible damage to the epithelial cells of respiratory bronchioles and pneumocytes, and denudation and destruction of the basement membrane played an important role in the development of pulmonary fibrosis by forming a channel for the inflammatory exudates and fibroblasts migrating into the bronchioalveolar spaces. Therefore, the experimental results have proved that Xinkang chrysotile asbestos fibers less than 5 microns in length certainly have a fibrogenic effect.

Urinary tract infections in the elderly

Urinary tract infection (UTI) is common in the elderly, with a prevalence of approximately 20% in women over 65 years of age. The elderly are predisposed to UTI by anatomic changes in the genitourinary system, by underlying disease, by instrumentation, and by residing in long-term care settings. Indwelling urinary catheters are a frequent cause of UTI, and catheter-associated sepsis is the most common cause of gram-negative sepsis in hospitals. Resistant organisms, prevalent in long-term care settings and hospitals, are increasingly responsible for UTI. Empiric antibiotic therapy has changed with the availability of new agents that cover resistant organisms. Oral antibiotics are appropriate for most UTIs; however, more serious infections require parenteral therapy. Length of antibiotic therapy is generally increased for UTI in the elderly.