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Biomedical subjects

J A Jacobs

Publications and source records attributed to J A Jacobs.

At least 19 recordsLinked to original sources
PubMed1996

Respiratory effects of organic solvent exposure.

Organic solvents are widely used in industrial processes and found in many common household products. Exposures to solvents are common in both idustrialized and industrializing countries. While organic solvents exposure is well known to produce central nervous system toxicity, hepatic, renal and dermatologic injury, the respiratory effects of solvent exposure are poorly documented. Several recent population-based epidemiologic studies have found an independent association of occupational solvent exposure with respiratory symptoms, impaired pulmonary function or respiratory disease, but interpretation of these studies is limited by self-reported exposure data. Animal studies have demonstrated adverse effects in both the conducting and the respiratory airways, although often at very high exposure levels. Human chamber studies have most consistently reported irritation of the eyes, nose and throat without evidence of airway hyper-responsiveness. Case series have observed obstructive and restrictive effects in patients with high level inhalational exposures to solvents, particularly formaldehyde, but occupational epidemiologic studies have not consistently demonstrated changes in pulmonary function. Finally, mortality studied have not found increased mortality rates from respiratory disease in occupations associated with solvent use. In general, solvents have been demonstrated to cause mucosal irritation of the eyes and upper airways, but studies of pulmonary impairment following exposure have been limited and inconsistent. Solvent-mediated respiratory toxicity is biologically plausible, but further research is needed to better characterize exposures and to elucidate the specific mechanisms associated with injury.

Animals↗
PubMed1996

In-vitro antimicrobial susceptibility of the "Streptococcus milleri' group (Streptococcus anginosus, Streptococcus constellatus and Streptococcus intermedius).

A collection of 423 clinical "Streptococcus milleri' strains was speciated and tested for susceptibilities to twelve antibiotics. Only 1.4% of the strains were of intermediate susceptibility to penicillin. None of the strains exhibited high-level resistance to gentamicin. Strains resistant to erythromycin, roxithromycin and clindamycin were found with a frequency of 2.6%, 2.4% and 2.4% respectively. Doxycycline resistance was found in 5.7% of the strains and occurred most frequently in Streptococcus anginosus. All the strains were susceptible to cefotaxime, vancomycin and teicoplanin. The results of this study do not indicate changing antibiotic resistance in strains of the "S. milleri' group, but local differences in antibiotic susceptibilities may occur.

Anti-Bacterial Agents↗
PubMed1996

Rapid species identification of "Streptococcus milleri" strains by line blot hybridization: identification of a distinct 16S rRNA population closely related to Streptococcus constellatus.

A collection of 399 "Streptococcus milleri" strains were identified to the species level by the use of a line blot assay. Their PCR-amplified partial 16S rRNA gene sequences were hybridized with species-specific 5'-biotinylated oligonucleotide probes homologous to the bp 213 to 231 regions of the 16S rRNA gene sequences of the type strains Streptococcus anginosus ATCC 33397, Streptococcus constellatus ATCC 27823, and Streptococcus intermedius ATCC 27335. The hybridization results were compared with the reference phenotypic identification method data (R. A. Whiley, H. Fraser, J. M. Hardie, and D. Beighton, J. Clin. Microbiol. 28:1497-1501, 1990). Most strains (357 of 399 [89.5%]) reacted unambiguously with only one probe. However, 42 of the 399 strains (10.5%) reacted with both the S. constellatus- and S. intermedius-specific probes; 41 of them were phenotypically identified as S. constellatus. These dually reactive strains hybridized with a 5'-biotinylated probe based on the bp 213 to 231 region of the 16S rRNA gene sequence of one of two species. Analysis of the 5' ends of the 16S rRNA gene sequences (487 bp) demonstrated that the dually reactive strains represent a distinct rRNA population sharing 98.1% sequence similarity with S. constellatus. Phenotypic consistency between the dually reactive strains and the S. constellatus strains was not demonstrated. Line blot hybridization proved to be a simple and inexpensive method to screen large numbers of strains for genetic relatedness, and it allowed the detection of a distinct 16S rRNA type within the "S. milleri" group.

Bacterial Typing Techniques↗
PubMed1996

BAL fluid LDH activity and LDH isoenzyme pattern in lipoid pneumonia caused by an intravenous injection of lamp oil.

A 30 year old man developed lipoid pneumonia after an injection of lamp oil. In addition to "foamy" alveolar macrophages, bronchoalveolar lavage (BAL) fluid analysis showed an increased number of neutrophils. Moreover, lactate dehydrogenase (LDH) and alkaline phosphatase activities were elevated. The increase seen in LDH activity both in serum and BAL fluid was accompanied by shifts in the isoenzyme pattern in similar directions for both fluids. These findings suggest a pulmonary source for the temporary serum as well as BAL fluid LDH increase. This case indicates the usefulness of bronchoalveolar lavage fluid analysis as a probe to detect pulmonary injury caused by a pneumotoxicant and, probably, to monitor recovery or deterioration.

Adult↗
PubMed1995

Hydrolytic enzymes of Streptococcus anginosus, Streptococcus constellatus and Streptococcus intermedius in relation to infection.

A collection of 518 'Streptococcus milleri' strains was tested for the presence of hydrolytic enzymes, and the results were related to the clinical significance of the strains. Ribonuclease activity was equally distributed among the three species while hyaluronidase activity was linked to Streptococcus intermedius and Streptococcus constellatus. Both enzymes were not significantly associated with infection-related strains. Deoxyribonuclease and chondroitin sulfatase activity tended to be present more frequently in Streptococcus intermedius and Streptococcus constellatus and was associated with infection-related strains (p < 0.001).

Chondroitin Sulfates↗
PubMed1995

Study of Stomatococcus mucilaginosus isolated in a hospital ward using phenotypic characterization.

Thirty-one isolates of Stomatococcus mucilaginosus were cultured from the blood (n = 6), throat (n = 23) and sputum (n = 2) of 18 hospitalized patients, 13 of whom were neutropaneic and five of whom were non-neutropaneic. Antibiotic susceptibility testing, performed by means of a broth microdilution method, showed that the minimal inhibitory concentrations (MICs) of ciprofloxacin were > or = 4 mg/l for the isolates collected from neutropaenic patients. All these patients received ciprofloxacin as part of their prophylactic regimen. In contrast, the MICs for four of five isolates collected from non-neutropaenic patients, none of whom were receiving ciprofloxacin, were < or = 2 mg/l. In addition, 14 of the 31 isolates were cultured from seven neutropaenic patients, admitted to the same ward over a 12-week period. To evaluate possible cross-acquisition of strains between patients, cluster analysis of all 31 isolates was performed using phenotypic characteristics, MIC values and acid production from carbohydrates (API 50 CH). Overall, 22 isolate clusters were distinguished. In five of 18 patients, two or more isolates were cultured which belonged to different clusters. In only one patient, identical isolates were cultured from blood and from the throat. All six isolates of cluster 7 were cultured within the aforementioned 12-week period from three neutropaenic patients. These data support the possibility of cross-acquisition of strains between patients although its frequency seems to be low.

Anti-Bacterial Agents↗
PubMed1995

Viridans streptococci isolated from the bloodstream. Relevance of species identification.

Over a 4-year-period, 104 isolates belonging to the viridans streptococci were recovered from the blood and identified to the species according to Beighton and co-workers. Streptococcus oralis was the species most frequently recovered from patients in the hematology unit [29 of 39 (74%)]. Streptococcus mitis ranked second [seven of 39 (18%)]. Both species were associated with oromucositis. Isolates presently identified as S. oralis are mainly those previously identified as S. mitis or Streptococcus sanguis II. Streptococcus milleri was most frequently isolated in the patients from the general hospital population [28 of 65 (43%) isolates]: Streptococcus anginosus (n = 20), Streptococcus constellatus (n = 4), and Streptococcus intermedius (n = 4). In 14 episodes from the general hospital population, clinical significance was judged questionable. From this part of the laboratory, clinical significance could not be predicted from the number of blood cultures grown, nor from the delay of growth detection. The Rapid ID 32 Strep system agreed well with the identifications according to the scheme of Beighton et al., whereas the API 20 Strep system did not.

Adolescent↗
PubMed1995

Streptococcus anginosus, Streptococcus constellatus and Streptococcus intermedius. Clinical relevance, hemolytic and serologic characteristics.

A collection of 518 "Streptococcus milleri" isolates recovered from clinical specimens was identified to the species level according to recently established criteria. Streptococcus anginosus was the most frequently isolated species (59.3%), followed by S constellatus (30.3%) and S intermedius (10.4%). One third (34%) of all isolates were beta-hemolytic. The majority of S anginosus isolates were nonhemolytic, carried Lancefield group F, or were nongroupable. Most of the S constellatus isolates were beta-hemolytic, as well as 16.6% of S intermedius strains. Streptococcus anginosus was recovered more often from the genital and urinary tracts and S constellatus was recovered from the thorax. Streptococcus intermedius was mostly found in the head and neck area, but was also isolated from the abdomen and the skin, bone, and soft tissue. Streptococcus intermedius and nonhemolytic isolates were recovered most often from abscess-related specimens.

Adolescent↗
PubMed1994

Change in self-definition from specialist to generalist in a national sample of physicians.

OBJECTIVE: Current proposals to reform the health care system call for a physician work force composed of at least 50% generalists. Achieving this objective will likely require that some physicians who are currently specialists become generalists. We sought to determine the extent of such change before any concerted reform efforts and the types of physicians most amenable to such change. DESIGN: Retrospective cohort study. PARTICIPANTS: 335,438 physicians in active practice. MEASUREMENTS: Rates of change between 1982 and 1986 in self-defined specialties, analyzed with demographic methods and logistic regression. RESULTS: In 1982, our participants comprised 134,647 (40.1%) generalists and 200,791 (59.9%) specialists. Over the 4-year period of the study, 8319 (6.2%) of the generalists became specialists and 4322 (2.2%) of the specialists became generalists. Although physicians younger than 40 years of age were more likely than those older than 40 years of age to switch into generalist disciplines, specialist physicians between the ages of 40 and 69 years (who accounted for 62.0% of the physician work force) made most of the moves into generalist fields (58.4%). After adjustment for other factors, the physicians most likely to switch into generalist disciplines were women, subspecialty internists, emergency medicine physicians, subspecialty pediatricians, and pathologists. In 1986, the 130,650 physicians (38.9%) in this cohort who considered themselves generalists were supplemented by another 49,226 (14.7%) who considered themselves to have a secondary interest in generalist practice. Physicians with such a secondary interest in 1982 constituted 65% of the new generalists in 1986. CONCLUSIONS: Our findings support three principal conclusions. First, change from specialist to generalist disciplines is not uncommon, even for physicians older than 40 years of age. Second, many physicians already consider a generalist discipline to be a secondary emphasis of their practices. And third, efforts to retrain specialists to be generalists might effectively target those physicians predisposed to become generalists.

Adult↗
PubMed1994

Combined abdominal and vaginal approach for bladder neck closure and permanent suprapubic tube: urinary diversion in the neurologically impaired woman.

Chronic indwelling Foley catheter placement in the neurologically impaired patient can lead to pressure necrosis of the urethra with incontinence. We report on 2 series of patients who underwent bladder neck closure and insertion of a suprapubic catheter for this problem. Our initial group includes 4 patients who underwent 5 transvaginal procedures, of which 2 (40%) were successful. Subsequently, we modified our approach, and used a combined abdominal and transvaginal repair, which was successful in 10 consecutive patients with a followup of 6 to 40 months (mean 15.6).

Abdomen↗
PubMed1994

Bacteremia involving the "Streptococcus milleri" group: analysis of 19 cases.

During a 3-year study period, 19 patients at the University Hospital of Maastricht developed bloodstream infections with species of the "Streptococcus milleri" group, for an incidence of 0.33 per 1,000 admissions. The patients' median age was 48 years; the male-to-female ratio was 2.8. Eleven patients (57.9%) had underlying diseases, among which malignancy was predominant. Local trauma to the mucosal barrier was an important risk factor. An associated site of infection was found most frequently in the abdominal and thoracic cavities (nine and five cases, respectively). Bacteremia was polymicrobial in four of 19 episodes. The 20 infecting S. milleri strains were identified to the species level; Streptococcus anginosus was the most prevalent (16 strains). Eight strains carried Lancefield group C. The isolates were sensitive to most antibiotics. Abscess formation was documented in nine cases (47.3%); repeated drainage procedures were required in half of these episodes. Mortality was high (five of 19 patients, or 26.3%).

Adolescent↗
PubMed1994

Agglutination of "Streptococcus milleri" by lectins.

The agglutination of 218 clinical isolates and three ATCC type strains of "Streptococcus milleri" was tested with 25 different lectins from plants and fungi. An agglutination reaction with one or more lectins was observed with 42 isolates when the cells were untreated. After trypsinisation of the bacteria, 109 strains yielded a positive reaction and after boiling the bacterial cells at pH2, 218 isolates were agglutinated. As an overall result of our experiments with untreated, trypsinised and boiled cells, 17, 37 and 45 different agglutination patterns, respectively, were obtained. The lectins from Datura stramonium, Robinia pseudoacacia and Dolichos biflorus agglutinated isolates belonging only to Lancefield group C, being non-reactive with other isolates. These lectins were also found to be specific for "large colony type" streptococci of group C. The use of lectin agglutination in epidemiological and ecological studies of "S. milleri" is discussed.

Agglutination↗
PubMed1994

Intervertebral infection caused by Streptococcus milleri. A case report.

Intervertebral infection caused by Streptococcus milleri is described in a 45-year-old man. Initially, a tuberculous infection was suspected; this diagnosis resulted in a considerable delay in correct diagnosis and treatment. The patient recovered well with combined medical-surgical treatment. Streptococcus milleri, a common inhabitant of the gastrointestinal tract, comprises a variety of strains implicated in deep-seated purulent infections. Although reports of this are rare, S. milleri can be the offending organism in intervertebral disk infections.

Anti-Bacterial Agents↗
PubMed1993

[Pneumococci].

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Chloramphenicol Resistance↗