Preliminary work on the development of a novel detection method for osteoporosis.

Osteoporosis affects both the organic and mineral phases of bone resulting in a decrease in resistance to fracture. Dual x-ray absorptiometry (DEXA) scans are used for diagnosing osteoporosis, which is conventionally characterised by a decrease in mineral density. Unfortunately, some patients who suffer osteoporotic fractures have normal bone density, because both the organic and the mineral phase are affected. However, there are currently no methods of evaluating the health of the organic phase. Patients undergoing treatment for osteoporosis have reported hardening of their fingernails. As the properties of nail and bone may be linked in a comparable, measurable way, this work used both mechanical (nano-indentation) and chemical (Raman spectroscopy) methods to evaluate differences between fingernails sourced from osteoporotic and non-osteoporotic patients. The difference in mean modulus between the nails sourced from the groups was 1.1 GPa. The disulphide bond content of fingernail samples from each group was measured by Raman spectroscopy and disulphide bond content of fingernail was found to be significantly lower in the osteoporotic group. It can be concluded that a relationship between the mechanical and chemical properties of nail and bone may exist in a measurable way. This work has suggested that changes in the organic phase of bone are reflected in similar proteins, such as keratin, from which fingernails are composed. Collagen and keratin are two distinct structural proteins, but they share the need for protein sulphation and disulphide bond formation, via cysteine, for their structural integrity. A disorder of either process should lead to disordered collagen and keratin synthesis.

The use of fingernails as a means of assessing bone health: a pilot study.

BACKGROUND: Anecdotally, patients volunteer reports of increasing hardness of their fingernails within months of starting diverse treatments for osteoporosis. The properties of both nail and bone may be linked in a comparable, measurable way. METHODS: We examined the fingernails of two groups of patients, with (n = 9) and without (n = 13) osteoporosis at either the hip or lumbosacral spine. We performed nanoindentation to assess the degree of nail brittleness and Raman spectroscopy to assess the disulfide bond content of nail. RESULTS: The mean moduli of fingernails of patients with low bone mineral density (BMD) are lower than those of patients with normal BMD. The mean difference in mean modulus between the groups was found to be 0.996 (p = 0.15 between groups). The spectroscopy data also showed differences between the two sets of nails. The disulfide bond content of the nails sourced from osteoporotic patients was lower than that from healthy patients (p = 0.06 between groups). CONCLUSIONS: Bone collagen and nail keratin are two distinct structural proteins, and both require protein sulfation and disulfide bond formation, via cysteine, for structural integrity. A disorder of either process may lead to disordered collagen and keratin synthesis. This is reflected in the structural abnormalities seen in clinical syndromes in which there is either protein deficiency, disorders of sulfur metabolism, or cystathione beta-synthase deficiency. The relationship between nail and bone may exist in a measurable way. This pilot study should lead to further work to explore this relationship. Could nail prove to be a valuable adjunct to diagnosis or provide a means of more rapid follow-up after commencement of therapy?

Progress in near-field photothermal infra-red microspectroscopy.

Near-field photothermal Fourier transform infra-red microspectroscopy, which utilizes atomic force microscopy (AFM)-type temperature sensors, is being developed with the aim of achieving a spatial resolution higher than the diffraction limit. Here we report on a new implementation of the technique. Sensitivity of the technique is assessed by recording infra-red spectra from small quantities of analytes and thin films. A photothermomechanical approach, which utilizes conventional AFM probes as temperature sensors, is also discussed based on preliminary results. Early indication suggests that the photothermal approach is more sensitive than the thermomechanical one.

Micro-thermal analysis: scanning thermal microscopy and localised thermal analysis.

Micro-thermal analysis combines the imaging capabilities of atomic force microscopy with the ability to characterise, with high spatial resolution, the thermal behaviour of materials. The conventional AFM tip is replaced by a miniature heater/thermometer which enables a surface to be visualised according to its response to the input of heat (in addition to measuring its topography). Areas of interest may then be selected and localised thermal analysis (modulated temperature calorimetry and thermomechanical analysis) carried out. Localised dynamic mechanical measurements are also possible. Spatially resolved chemical analysis can be performed using the same basic apparatus by means of pyrolysis gas chromatography-mass spectrometry or high-resolution photothermal infrared spectrometry.

Atomic force microscopy of the cornea and sclera.

We report the first investigation of the extracellular matrix of cornea and sclera using an atomic force microscope (AFM), and evaluate the potential of this new technique. We were able to obtain 2-3 nanometre resolution of both tissues in a condition close to their native state. The AFM was able to resolve surface features on the collagen fibrils, as well as providing unique images of crossbridge structures between collagen fibrils in both cornea and sclera.

Evaluation of [3H]thymidine uptake method for studying growth of spiroplasmas under various conditions.

[3H]thymidine uptake and colony counts are quantitative and inexpensive methods for studying Spiroplasma growth. Using these techniques, we demonstrated subtle effects on the growth of suckling mouse cataract agent of medium alterations, inoculum size, and freezing of cultures. In addition, suckling mouse cataract agent multiplied more actively under aerobic than under anaerobic conditions. These techniques have wide application for the study of Spiroplasma growth and will be useful for the development of a defined medium.

Selection of a reference lot of Mueller-Hinton agar.

A collaborative study was undertaken to evaluate the performance of currently marketed Mueller-Hinton agars from seven manufacturers by replicate disk diffusion tests with standard quality control strains. Identification of the manufacturers was concealed, and the resulting data were evaluated for the selection of a physical reagent standard against which the performance of future production lots would be tested and made to conform. A medium was selected which was sufficiently close to existing National Committee for Clinical Laboratory Standards quality control limits that current interpretive criteria would require minimum modification. Two of the seven lots were eliminated from further consideration because the final pHs were outside acceptable limits. The remaining four lots had 96% of mean zone diameters less than or equal to 2 mm from those of the chosen lot and 65% of the means were less than or equal to 1 mm from those of the chosen lot for all 28 antimicrobial agent-organism combinations. Manufacturers then attempted to produce new lots of Mueller-Hinton agar which performed within the prescribed limits of the chosen lot. One lot performed in close conformity with the selected standard, but the overall performance of the media was essentially the same as that of the randomly chosen lots in the initial study. It was concluded that one of the original seven lots demonstrated properties which made it a tentative candidate for a physical reagent standard and that the use of a physical reagent standard in evaluating production lots might aid in stabilizing the performance of Mueller-Hinton agar.

Spectrum of Vibrio infections in a Gulf Coast community.

Infection with Vibrio species was diagnosed in 23 patients over a 10-year period in a Gulf Coast community. Species isolated were Vibrio vulnificus, V. cholerae, V. parahaemolyticus, and V. alginolyticus. Clinical presentations included diarrhea, wound infection, and bacteremia. Gastrointestinal tract infection was infrequently diagnosed, despite the routine use of stool culture media appropriate for vibrio isolation. Bacteremic infections were severe and occurred only in patients with underlying diseases. Wound infections were complicated by tissue necrosis and required surgical debridement. In patients with underlying diseases, soft tissue infections often progressed to fatal septicemias.

Laboratory techniques for detection of urinary tract infection and assessment of value.

Manual methods for diagnosing urinary tract infection have long been under review, modification, and evaluation; thus, methods of collection and interpretation have been found to require more scrutiny. Various screening procedures include chemical, microscopic, and cultural methods, the latter two being highly reliable. In addition, examples of infections due to anaerobic bacteria and Mycoplasma have been documented, with the accompanying need to consider their role in particular situations. There has also been a need for localizing the infection, which has been accomplished with some useful methods. From the literature it is apparent that the tests all have a portion of patients' results that do not fit the true picture. These must be considered carefully in light of other information.

Use of a bronchoscopic protected catheter technique in the clinical evaluation of a new antibiotic.

We prospectively compared the usefulness of a bronchoscopic protected catheter technique with the results from sputum cultures in the evaluation of moxalactam, a new beta-lactam antibiotic. The significance of a given isolate on protected catheter culture was determined by quantitative bacteriology. 32 patients with community-acquired pneumonia were enrolled in the study and 31 grew common lower respiratory tract pathogens from their protected catheter specimen. The most common single pathogens recovered were Streptococcus pneumoniae (11 patients) and Haemophilus influenzae (2). Mixed flora, predominantly anaerobes, were isolated from 15 patients, and 3 patients had mixed aerobic infections. All seven bacteremic cases had the identical organism isolated from the protected catheter specimen, confirming the accuracy of the technique. Comparisons with sputum cultures showed that the predominant organism on sputum culture was the same as that obtained from the protected catheter culture in only 13% of the cases. Sputum cultures revealed either no pathogen or a different pathogen in 23 cases, and no sputum could be obtained in 4. Compared to cultures of expectorated sputum, we found the protected catheter bronchoscopic culture technique to have the following advantages in the bacteriologic evaluation of moxalactam: 1) greater accuracy and sensitivity in bacteremic patients; 2) accurate delineation of the bacteriology of infections; and 3) a higher percentage of patients with evaluable bacteriology leading to greater efficiency during the investigation.

Comparison of susceptibilities of anaerobic bacteria to cefmenoxime, ceftriaxone, and other antimicrobial compounds.

The minimal inhibitory concentrations of cefmenoxime, cefotaxime, cefoxitin, ceftriaxone, chloramphenicol, clindamycin, and moxalactam were determined by agar dilution for 202 clinical isolates of anaerobic bacteria. Cefoxitin and moxalactam were the most active among the cephalosporin-like compounds.

Diagnosis of bacterial pulmonary infections with quantitative protected catheter cultures obtained during bronchoscopy.

Quantitative bacteriology was performed on specimens collected by protected catheter fiberoptic bronchoscopy from 172 patients. Of the patients who had pneumonia, 75 of 78 (96%) had one or more species present at greater than or equal to 10(3) CFU/ml, whereas 2 of 35 (6%) control patients had organisms present in that quantity. In addition, 66% of the control specimens yielded no isolates by this technique. All of the 11 patients with bronchitis had greater than or equal to 10(3) CFU/ml. Quantitative bacteriology revealed high levels of colonization in patients without infection and endobronchial structural disease. The data suggest that bacterial counts of greater than or equal to 10(3) CFU/ml in suspended secretions collected with a protected catheter brush were diagnostic of the bacteriological etiology of lower respiratory tract infections in patients without endobronchial structural abnormalities.

Use of a bronchoscopic protected catheter brush for the diagnosis of pulmonary infections.

Fiberoptic bronchoscopy using a protected brush catheter was done in 65 patients with suspected pulmonary infections to obtain uncontaminated specimens for culture. Quantitative aerobic and anaerobic cultures were done on each specimen. Forty-one patients had pneumonia. Ten bacteremic patients had the same organisms recovered from the catheter and blood cultures. Seven patients had received antibiotics before the procedure, and cultures grew no organisms in high concentration. In 23 of 24 remaining patients probable pathogens were recovered in high concentrations, and specific therapy resulted in clinical improvement in all of these patients. Five patients with lung abscesses and seven with necrotizing pneumonia had mixed aerobic and anaerobic organisms recovered. Twelve patients had final diagnoses of nonbacterial lung disease, and cultures were negative or revealed low concentrations of organisms. Quantitative cultures were necessary in distinguishing pathogens from nonpathogens. There were no complications. The results of this study indicate that fiberoptic bronchoscopy using a special protected catheter is an accurate and safe technique for identification of etiologic agents in lower respiratory tract infections.

Cation components of Mueller-Hinton agar affecting testing of Pseudomonas aeruginosa susceptibility to gentamicin.

Seven lots of Mueller-Hinton agar were examined for calcium and magnesium contents and their distribution in pools or compartments. Gel disruption and centrifugation yielded the soluble cations, which varied from 9 to 113% of the total calcium and from 76 to 102% of the total magnesium. Throughout the experiments, a standardized disk diffusion test, using Pseudomonas aeruginosa (ATCC 27852) and a 10-mug gentamicin disk, served as an indicator for medium performance. Zone diameters correlated well with the sums of the soluble calcium and magnesium values in the different lots (r = -0.85). Ionized calcium, presumably the biologically active ion, was measured with a calcium-specific electrode. It represented only a fraction of the soluble calcium pool in three lots. Autoclaving resulted in shifts of the cations between the different pools. Addition of magnesium to one medium lot resulted in shifts of soluble and ionized calcium, indicating an interdependence of calcium and magnesium, and zone diameters correlated with soluble magnesium (r = -0.98), soluble calcium (r = -0.96), and ionized calcium (r = -0.96) in this experiment. Manipulation of one medium to match the performance of another showed that excess amounts of both ions were required to obtain similar performance. Satisfactory performance of an individual medium can be obtained by cation supplementation, but simple adjustment will not suffice for all media. The interaction of the other cation pool components must also be evaluated.

An intracavitary fungus ball composed of syncephalastrum.

A case of a pulmonary intracavitary fungus ball composed of Syncephalastrum sp., a member of the class Zygomycetes not previously reported in association with human disease, is presented. The fungus was cultured preoperatively from bronchial secretions as well as from the fungal mass from the resected lung. This fungus appeared to behave in a saprophytic manner similar to that of the more common Aspergillus fungus ball.

The prevalence of actinomycetes-like organisms found in cervicovaginal smears of 300 IUD wearers.

The association of Actinomyces with IUD wearers has been widely documented and the possibility of the recognition of actinomycetes-like organisms in routine Papanicolaou-stained cervicovaginal smears has been reported. We conducted a retrospective study of IUD wearers to determine the prevalence and significance of actinomycetes-like organisms found in such smears. Three hundred smears from current IUD wearers were rescreened for actinomycetes-like organisms. Of this group, 200 patients were from a public health family planning clinic, and 100 were private patients. The incidence for the public health group was 25.5% and for the private patient group, 8%. A case history of actinomycosis is included. Findings such as other infectious agents, abnormal cytology and symptoms are also discussed. Although the presence of Actinomyces probably represents an opportunistic infection, the threat of pelvic actinomycosis with serious complications poses a management problem to the clinician when Actinomyces is reported in a routine Papanicolaou smear. Our findings lead us to question the practicality of the earlier recommendations of IUD removal and antibiotic therapy.

PIP: 300 Papanicolaou smears from current IUD wearers were rescreened to determine the prevalence of actinomycetes. Of the 300 patients, 59 showed actinomycetes-like organisms in cervicovaginal smears. Of the 59 positive cases, 51 (of 200, 25%) were from public health clinics and 8 (of 100, 8%) were from private patients. Of 21 patients complaining of irregular bleeding, only 4 had positive actinomycete cultures. In cases positive for the organisms there was no correlation of prevalence found with the phase of the menstrual cycle or with menstruation itself. A case history of actinomycosis is included. Although the presence of Actinomyces probably represents an opportunitistic pathogenic infection, management of this infection is important to eradicate the threat of pelvic actinomycosis. In the case history described, however, antibiotic therapy failed, and a complete abdominal hysterectomy was performed.

Effect of different lots of Mueller-Hinton agar on the interpretation of the gentamicin susceptibility of Pseudomonas aeruginosa.

Population distributions and quality control data for strains of Pseudomonas aeruginosa tested for gentamicin susceptibility on six lots of Mueller-Hinton agar were analyzed. The lots of agar were used in three University of Washington hospitals from April 1975 through October 1977. The analyses indicated that the performance of members of the P. aeruginosa populations in each hospital closely followed the performance of the quality control strain, P. aeruginosa ATCC 27853, when tested on each lot of Mueller-Hinton medium. The variability of zone diameters with the P. aeruginosa populations and the quality control strain indicated that a fixed indeterminate range (13 to 16 mm) of gentamicin susceptibility was not applicable to these organisms as it was with the Enterobacteriaceae. Variability in gentamicin susceptibility results was demonstrated in both minimal inhibitory concentration and disk diffusion tests when eight selected P. aeruginosa strains and the quality control strain were tested on each lot of medium. This variation in susceptibility to gentamicin was not related to the total Ca(2+), Mg(2+), or Zn(2+) content of each lot of medium. The data demonstrated that a moving indeterminate range of gentamicin susceptibility, 3 to 6 mm below the mean zone diameter of the quality control strain, was a suitable criterion for strains tested on a single medium lot. These results illustrate the importance of defining stringent performance standards for media used in the susceptibility testing of P. aeruginosa with gentamicin and other aminoglycoside antibiotics.

Nonspecific vaginitis: role of Haemophilus vaginalis and treatment with metronidazole.

To assess the cause of nonspecific vaginitis, we performed a prospective case-control study of vaginal flora and a randomized unblinded trial of different therapies. Haemophilus vaginalis was isolated from 17 to 18 women with signs of vaginitis but only one of 18 normal matched controls (P less than 0.002). The concentration of anaerobic bacteria in vaginal washings also was increased in patients. Clinical improvement and eradication of H. vaginalis occurred in one of seven patients given sulfonamide vaginal cream, two of 15 given oral doxycycline, nine of 27 given oral ampicillin, and 80 of 81 given oral metronidazole. On the seventh day of therapy signs of nonspecific vaginitis persisted in 31 of 31 with, and in two of 92 without, persistent H. vaginalis infection (P less than 0.001). These data suggest the causal role of H. vaginalis in nonspecific vaginitis, possibly in concert with vaginal anaerobes. The widespread use of sulfonamide creams is inappropriate. Metronidazole is effective, but its efficacy must be weighed against its possible toxicity.