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Biomedical subjects

B Lorber

Publications and source records attributed to B Lorber.

At least 19 recordsLinked to original sources

Over-the-counter and alternative medicines in the treatment of chronic vaginal symptoms.

OBJECTIVE: To investigate the use of over-the-counter and alternative medicines in women with chronic vaginal symptoms. METHODS: One hundred five patients, referred by their gynecologists for evaluation of chronic vaginal symptoms, were interviewed about their use of over-the-counter and alternative medicines during the preceding year, the amount of money spent on each, and whether or not their physicians had been informed of these treatments. RESULTS: The mean age was 36 years, and one-half had finished college. The median symptom duration was 2 years. Seventy-seven (73.3%) patients had self-treated with over-the-counter medications such as miconazole (74% of over-the-counter users), clotrimazole (38.2%), or povidone-iodine (13.2%). The median expenditure for over-the-counter use was %0 (range $2-1000). Forty-four (41.9%) had used alternative medicines, most frequently acidophilus pills orally (50%) vaginally (11.4%), yogurt orally (20.5%) or vaginally (18.2%), vinegar douches (13.6%), and boric acid (13.6%). The median expenditure for alternative medicines was $35 (range $0-1200). Fewer physicians were aware of the use of alternative (70.5%) that of over-the-counter medicines (88.3%). Although most patients thought that vulvovaginal candidiasis was the cause of their symptoms, the most common diagnoses at initial presentation were candidiasis in 29 (27.6%), vulvar vestibulitis in 18 (17.1%), irritant dermatitis in 16 (15.2%), and bacterial vaginosis in 11 (10.5%). Women who actually had candidiasis were more likely to have used alternative medicines (odds ration 2.31, 95% confidence interval 1.00, 5.42) than other patients. CONCLUSION: Women with chronic vaginal symptoms often use over-the-counter and alternative medicines that add to health care costs and are unlikely to be of benefit.

Adult

Use and effectiveness of hypothermia blankets for febrile patients in the intensive care unit.

We performed a prospective observational (noninterventional) study of hypothermia blanket use in a population of adult intensive care unit patients with body temperatures of > or = 102.5 degrees F. Thirty-nine of ninety-four febrile episodes (in 83 patients) were treated with hypothermia blankets. Logistic regression revealed that the strongest independent predictors of hypothermia blanket use were a temperature of > or = 103.5 degrees F (odds ratio [OR] = 17), mechanical ventilation (OR = 25), and acute central nervous system illness (OR = 7.5). Hospitalization in the medical intensive care unit was strongly associated with avoidance of this therapy (OR = 0.023). Treatment with a hypothermia blanket was ordered by a physician in only 15% of cases. The mean cooling rate was the same (0.028 degree F/h) for blanket-treated and control patients. Multivariate Cox regression and factorial and repeated measures of analysis of variance revealed that blanket treatment was not more effective than other cooling methods. However, this treatment was associated with more "zigzag" temperature fluctuations of > or = 3 degrees F (56% of blanket-treated patients vs. 18% of control patients; P < .001) and rebound hypothermia (18% vs. 0; P = .001). Hypothermia blanket therapy is primarily a nursing decision. We conclude that in addition to being no more effective than other cooling measures, hypothermia blanket therapy was associated with more temperature fluctuations and with more episodes of rebound hypothermia.

Adult

Listeriosis.

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Acquired Immunodeficiency Syndrome

Are all diseases infectious?

The complex interactions between microorganisms and human hosts include the well-known, traditional infectious diseases and the symbiotic relation we have with our normal flora. The media have brought to the public's attention many newly described infectious diseases, such as Ebola virus hemorrhagic fever, that were not part of common medical parlance a decade ago. While flooding us with interesting and often dramatic reports of so-called emerging infectious diseases, the media have largely ignored a more fundamental change in our appreciation of human-microorganism interactions: the discovery that transmissible agents may play important roles in diseases not suspected of being infectious in origin. A well-known example is ulcer disease; other examples include neurodegenerative disease, inflammatory disease, and cancer. These fascinating instances of host-pathogen interaction open new prospects for the prevention of disease through immunization.

Disease

An example of non-conservation of oligomeric structure in prokaryotic aminoacyl-tRNA synthetases. Biochemical and structural properties of glycyl-tRNA synthetase from Thermus thermophilus.

Glycyl-tRNA synthetase (Gly-tRNA synthetase) from Thermus thermophilus was purified to homogeneity and with high yield using a five-step purification procedure in amounts sufficient to solve its crystallographic structure [Logan, D.T., Mazauric, M.-H., Kern, D. & Moras, D. (1995) EMBO J. 14, 4156-4167]. Molecular-mass determinations of the native and denatured protein indicate an oligomeric structure of the alpha 2 type consistent with that found for eukaryotic Gly-tRNA synthetases (yeast and Bombyx mori), but different from that of Gly-tRNA synthetases from mesophilic prokaryotes (Escherichia coli and Bacillus brevis) which are alpha 2 beta 2 tetramers. N-terminal sequencing of the polypeptide chain reveals significant identity, reaching 50% with those of the eukaryotic enzymes (B. mori, Homo sapiens, yeast and Caenorhabditis elegans) but no significant identity was found with both alpha and beta chains of the prokaryotic enzymes (E. coli, Haemophilus influenzae and Coxiella burnetii) albeit the enzyme is deprived of the N-terminal extension characterizing eukaryotic synthetases. Thus, the thermophilic Gly-tRNA synthetase combines strong structural homologies of eukaryotic Gly-tRNA synthetases with a feature of prokaryotic synthetases. Heat-stability measurements show that this synthetase keeps its ATP-PPi exchange and aminoacylation activities up to 70 degrees C. Glycyladenylate strongly protects the enzyme against thermal inactivation at higher temperatures. Unexpectedly, tRNA(Gly) does not induce protection. Cross-aminoacylations reveal that the thermophilic Gly-tRNA synthetase charges heterologous E. coli tRNA(gly(GCC)) and tRNA(Gly(GCC)) and yeast tRNA(Gly(GCC)) as efficiently as T. thermophilus tRNA(Gly). All these aminoacylation reactions are characterized by similar activation energies as deduced from Arrhenius plots. Therefore, contrary to the E. coli and H. sapiens Gly-tRNA synthetases, the prokaryotic thermophilic enzyme does not possess a strict species specificity. The results are discussed in the context of the three-dimensional structure of the synthetase and in the view of the particular evolution of the glycinylation systems.

Amino Acid Sequence

The common cold.

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Antiviral Agents

Focal intracranial infections.

Focal intracranial infections are relatively rare, but the consequences of a missed or delayed diagnosis are significant. The clinician is urged to consider these diagnoses in patients with headaches or focal neurologic examinations, particularly in the setting of known or suspected otorhinologic disease. For diagnosis, gadolinium-enhanced MR imaging or MR imaging with angiography are the procedures of choice; CT is far less sensitive and specific. Lumbar puncture is contraindicated in most of these infections. Management of suspected elevation of intracranial pressure and broad empiric antibiotic therapy should be instituted emergently. Early involvement of surgical services is recommended.

Abscess

Quinolones.

Fluoroquinolones represent a major advance in antimicrobial chemotherapy. Currently, there are five fluoroquinolones approved by the FDA, and many more quinolones are expected to become available in years to come. Although their clinical utility is constantly expanding, they have been best studied in complicated urinary tract infections, chronic osteomyelitis caused by gram-negative bacilli, bacterial gastrointestinal infections such as traveler's diarrhea and typhoid fever, and uncomplicated gonococcal infections and in the prophylaxis of bacterial infections in patients with neutropenia. These agents have the convenience of oral administration, favorable pharmacokinetic properties, and low toxicity profiles but should be used advisedly because indiscriminate use may result in the early emergence of resistance.

4-Quinolones

Preparative isolation of angiotensin-converting enzyme from human lung.

Angiotensin-converting enzyme from human lung was purified to apparent homogeneity using a five-step purification procedure consisting of ammonium sulfate precipitation, ion-exchange chromatography on DEAE Sephadex A-50, gel permeation on Sephadex G-200, chromatofocusing on a polybuffer exchange (PBE 94) column and high-performance liquid chromatographic gel permeation on a Bio-Sil TSK-250 column. This procedure gave an approximately 700-fold purification with a 20% yield compared to a 550-fold purification and a 1% yield with an affinity chromatography-based procedure. The 20-fold greater yield of the five-step procedure offers a major advantage for preparative use in the structural characterization of angiotensin-converting enzyme.

Blotting, Western

Infections complicating mycosis fungoides and Sézary syndrome.

OBJECTIVE: To determine, in patients with mycosis fungoides and Sézary syndrome, the incidence of infections, the importance of nosocomial infections, and the epidemiologic factors associated with cutaneous and visceral infections. DESIGN AND SETTING: Retrospective inception cohort study at a university medical center referral clinic. PATIENTS: Three hundred fifty-six patients with mycosis fungoides or Sézary syndrome. MAIN OUTCOME MEASURES: Incidence rates for specific infections, and multivariate risk ratios for demographic and clinical factors associated with infection. RESULTS: Cutaneous bacterial infection was most common (17.0 infections per 100 patient-years), followed by cutaneous herpes simplex virus and herpes zoster virus infection (3.8 infections per 100 patient-years), bacteremia (2.1 infections per 100 patient-years), bacterial pneumonia (1.7 infections per 100 patient-years), and urinary tract infection (1.4 infections per 100 patient-years). Twenty-seven percent of herpesvirus infections disseminated on the skin but none disseminated to internal organs. Pneumonia or bacteremia was present in 88% of patients who died of infection. Only three patients had invasive fungal or protozoal infection. Nosocomial infections accounted for 19% of cutaneous bacterial infections, 59% of bacteremias, 62% of pneumonias, and 88% of infections leading to death. By logistic and Cox regression, the presence of extracutaneous involvement with lymphoma was the most important independent risk factor for recurrent bacterial skin infection (risk ratio [RR], 12; 95% confidence interval [CI], 1.2 to 120), disseminated herpesvirus infection (RR, 28; 95% CI, 2.7 to 290), bloodstream infection (RR, 5.5; 95% CI, 1.7 to 18), and death from infection (RR, 15; 95% CI, 3.6 to 64). CONCLUSIONS: Community-acquired bacterial skin infections are a common cause of morbidity in patients with mycosis fungoides and Sézary syndrome but are usually treated without hospital admission. Bacteremia and pneumonia, which are usually nosocomial, are the major infectious causes of death. Advanced disease stage, independent of corticosteroids and other therapies, is the most important risk factor for both cutaneous and systemic infections.

Adolescent

Dynamic light scattering studies of the aggregation of lysozyme under crystallization conditions.

The intensity autocorrelation functions of light scattered by lysozyme solutions under pre-crystallization conditions in NaCl-containing media were recorded at scattering angles from 20 degrees to 90 degrees. The measurements, conducted on freshly prepared protein solutions supersaturated more than 3-fold, indicate the simultaneous presence of two scatterer populations which can be assigned to individual protein molecules and to large particles. When solutions are undersaturated, or slightly supersaturated, light scattering only reveals the presence of the small scatterers. In the supersaturated medium, where aggregates were detected, lysozyme crystals grew in a time-span of 1-3 days after the scattering experiments. These results are medium, where aggregates were detected, lysozyme crystals grew in a time-span of 1-3 days after the scattering experiments. These results are correlated with the nucleation step during protein crystallization.

Animals

Isolation and characterization of active N-terminal truncated apo- and holoenzyme of mammalian liver tyrosine aminotransferase.

Limited proteolysis was used to probe the structure of the apo- and holoenzyme of rat liver tyrosine aminotransferase. Both were subjected to trypsinolysis and the major fragments were isolated and characterized. Trypsin cleaves the apoenzyme after residues Arg57, Lys64, and Lys71 and the holoenzyme after Arg37 and Lys38. The difference in the accessibility of the enzyme deprived or associated with pyridoxal 5'-phosphate reflects two distinct conformations. The activity, the affinity for the ligands and the thermostability of the purified truncated enzyme forms are similar to those of the native apo- and holoenzyme. A model for the domain structure of mammalian tyrosine aminotransferase and a mechanism for its rapid turnover are proposed.

Amino Acid Sequence

Expression of mammalian tyrosine aminotransferase in Saccharomyces cerevisiae and Escherichia coli. Purification to homogeneity and characterization of the enzyme overproduced in the bacteria.

Rat liver tyrosine aminotransferase has been expressed in Saccharomyces cerevisiae and Escherichia coli. In yeast, the extent of production is 20-fold higher than that in rat liver after induction by dexamethasone, and reaches 250-fold higher in an E. coli strain carrying the T7 RNA polymerase transcription system. About 250 mg pure and homogeneous enzyme was obtained from 50 g transformed E. coli cells. Determination of Mr and pI, as well as analysis of N- and C-terminal amino acids, suggest that the isolated protein is native. The catalytic properties, similar to those of the enzyme from rat liver, confirm that it is fully active and that post-translational modifications in the mammalian cells are not essential for activity. Pyridoxal 5'-phosphate strongly protects the enzyme against thermal inactivation. After denaturation, 10 thiol groups, out of 16 in the polypeptide chain, react with 5,5'-dithiobis(2-nitrobenzoic acid) whereas only five or six are accessible under native conditions. Two thiols are rapidly modified with concomitant inactivation of the apoenzyme, but pyridoxal 5'-phosphate partially protects them in the holoenzyme. The results are interpreted in the light of the structure/function relationship in this enzyme.

Amino Acid Sequence

Hot tubs, sex, sushi, and infectious diseases.

Over the past 20 years, striking and interesting changes in patterns of diseases have occurred due to transmissible agents. Among them are the recognition of new diseases, new clinical manifestations of old diseases, new ecologic niches for traditional pathogens, and new modes of disease transmission. Implicated causes for these changing patterns include alterations in lifestyle with respect to sexual behavior, leisure activity, and dietary trends, together with the impact of immigration and the effects of medical progress. A review of these changes demonstrates the dynamic nature of medicine, and the impact that societal change can have on disease patterns.

Adolescent

Purification of octyl beta-D-glucopyranoside and re-estimation of its micellar size.

The commercial non-ionic detergent octyl beta-D-glucopyranoside is often contaminated by significant amounts of UV absorbing and/or ionic compounds that can associate with membrane proteins. Such impurities can be monitored by several techniques (i.e., spectrophotometry, size exclusion chromatography, and pH, conductivity, and surface tension measurements) and can be removed using mixed-bed ion exchange chromatography. High performance size exclusion chromatography, dynamic light scattering, and ultracentrifugation have been used to re-estimate the size of micelles of octyl beta-D-glucopyranoside since previously published data varied over a wide range. Aggregation numbers were 27 to 100 for micellar molecular weights 8000 to 29,000. Direct physical methods that do not perturbate the sample indicated a large size for the micelles (hydrodynamic radius 23 +/- 3 A; Mr 22,000 +/- 3000; aggregation number 75 +/- 10 for a 34 mM aqueous solution). In contrast the chromatographic micellar size appeared to be smaller (hydrodynamic radius 15 +/- 1 A; Mr 8000 +/- 1000; aggregation number 27). This underestimation may be the result of adsorption and/or alteration of the micelles.

Chemical Phenomena

Large scale preparation of homogeneous bacteriorhodopsin.

Homogeneous bacteriorhodopsin was obtained preparatively (100 mg batches) from purple membrane of Halobacterium halobium cells. The homogeneity of the protein was considerably affected by variations in the growth conditions of the bacteria. Fully matured bacteriorhodopsin having a blocked N-terminus and a homogeneous C-terminus, was reproducibly obtained when cells were grown in a sufficiently aerated medium.

Amino Acid Sequence

Antipyretic orders in a university hospital.

PURPOSE: Antipyretics are prescribed for many hospitalized patients, but details concerning prescribing practices are not known. This study was designed to determine the incidence and format of antipyretic orders in a university-based tertiary-care center, and to ascertain whether orders are correlated with patient characteristics or hospital services. PATIENTS AND METHODS: The records of 300 randomly selected patients on the medicine, general surgery, neurosurgery, and obstetrics and gynecology services, and of 75 patients admitted with pneumonia and fever were retrospectively reviewed using a standardized data form. RESULTS: Orders for acetaminophen prn (as needed), without further explanation, were interpreted by the nursing staff as antipyretic orders; 78% of patients with such an order and fever received acetaminophen during the febrile episode. If orders of this type were included, 153 (51%) of the randomly selected patients received an antipyretic order. Gender, age, duration of hospitalization, intensive care unit residence, fever, and presence of a condition worsened by fever were not significant independent predictors of antipyretic prescription, but documented infection and hospitalization on the medicine and neurosurgery services were, with adjusted odds ratios of 2.5 (95% confidence interval [CI] 1.3 to 5.0), 9.4 (95% CI 3.6 to 25), and 14 (95% CI 5.0 to 41), respectively. Of patients who received an antipyretic order, 70% had an admission order for antipyretics; 26%, an order prompted by fever; and 79%, an order while afebrile. In 86%, the order was written prn without further explanation. Around-the-clock dosing, automatic stop orders, and acknowledgement and justification of orders were rare. CONCLUSION: Antipyretic orders are routine and correlate more strongly with hospital service than with individual patient characteristics. They are umprecisely written and generally leave decisions about antipyretic administration to the complete discretion of the nursing staff.

Acetaminophen

Investigation of an outbreak of listeriosis: new hypotheses for the etiology of epidemic Listeria monocytogenes infections.

From December 1986 to March 1987 an outbreak of Listeria monocytogenes infection occurred in the Philadelphia metropolitan area. A patient-control study showed patients were more likely than controls to have had an ill family member and to have used antidiarrheal medication during the month before their illness. Diet histories showed patients were significantly more likely to have eaten ice cream or salami than were controls, and to have shopped at one grocery store chain. Subtyping of L. monocytogenes isolates of patients showed no predominant strain, and cultures of food products eaten by patients were negative except for Brie cheese eaten by one patient. With no predominant strain of L. monocytogenes in the patients, a common source for this outbreak is unlikely. Thus, the identified risk factors may have been associated with carriage of L. monocytogenes and a coinfecting organism may have precipitated disseminated disease. Possible cofactors should be considered in investigations of future outbreaks of listeriosis.

Adolescent