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Biomedical subjects

A Levine

Publications and source records attributed to A Levine.

At least 163 records · Page 9Linked to original sources

A mathematical method for analysing questionnaires.

Investigators using questionnaires are usually confronted with an enormous number of different responses whose significance with respect to a particular characteristic is not immediately clear. This paper presents a simple computational technique for determining the relative merits of each question and a score for each respondent. The rationalization for and the formalization of the method are discussed and some practical examples illustrate how it can be used. The strengths and weaknesses of the method are discussed in relation to those of other methods.

Mathematics↗

Molecular comparison of retroviruses associated with human and simian AIDS.

Infectious retrovirus(es) associated with the human (LAV, HTLV-III, ARV) and simian (SAIDS-1) acquired immune deficiency syndrome were compared by electron microscopy, immunofluorescence and immunoblotting techniques and by restriction endonuclease mapping of the viral genomes. The extracellular virus particles had similar type D morphology, but intracytoplasmic type A nucleoids were found only in SAIDS virus infected cells. Although the antigens of the three prototype AIDS viruses were similar, no cross-reactivity with the SAIDS virus was detected. Molecular hybridization and restriction enzyme analysis also revealed that the SAIDS and AIDS viruses were genetically unrelated. However, only minor differences, consistent with strain polymorphism, were found between the three AIDS virus isolates. Thus, the retroviruses associated with AIDS in macaques and humans are unique to each species.

Acquired Immunodeficiency Syndrome↗

Post-initiation control of chromosomal replication in Bacillus subtilis: a mechanism for limiting over-replication or for duplicating key growth and sporulation genes?

We used the Bacillus subtilis dnaB37 mutant, which is defective in initiation, to synchronize DNA replication in order to identify the first fragments to be replicated following initiation and to study the control of this process under various conditions. We show by DNA/DNA hybridization analysis that, after returning the mutant from 45 degrees C to the permissive temperature (30 degrees C), the origin region relative to other sequences is over-replicated (approximately 2-fold) during the first round. This was confirmed by autoradiographic analysis. The over-replicated region is however limited to about 190 kb on the left and right arms. Replication apparently resumes from these positions during the following round of replication. We propose that, in B. subtilis, in addition to the first level of control at the origin, there is a second level or post-initiation control downstream of the origin which limits DNA replication resulting from premature initiation. We believe that these two levels of control are tightly coupled under conditions of balanced growth. Using the same system, we have now shown that DNA replication is subject to "stringent control", an important regulatory network in bacteria. These studies demonstrate that the inhibition of replication induced during the "stringent response" does not occur at the primary origin. In fact, by DNA/DNA hybridization, replication forks were found to be blocked at similar positions to the post-initiation control sites described above. Moreover, replication appears to resume from regions close to the stalled replisomes upon removal of the stringent response.(ABSTRACT TRUNCATED AT 250 WORDS)

Bacillus subtilis↗

Marathon therapy: treating rape survivors in a therapeutic community.

Odyssey House is a therapeutic community (TC) in New York City that treats a wide range of drug abusers. For over 20 years. Odyssey House has conducted an annual marathon therapy group for women who are rape survivors. This article summarizes the program's experience with the marathon and reports on its therapeutic accomplishments.

Adult↗

Bedside glucose monitoring: in compliance with regulatory standards.

When accurately performed, bedside glucose monitoring (BGM) is a prompt, reliable, and cost-effective method of managing patients who require a high degree of glucose control. However, regulatory agencies have criticized the quality-control deficiencies of most existing BGM programs. A new generation of multi-user reflectance meters enables the various regulatory directives to be more easily satisfied. These meters provide computer-assisted quality control analysis and facilitate operator feedback for each control test. New York State Department of Health regulations state that the ultimate responsibility for BGM belongs to the chemistry laboratory director. We believe that nursing personnel should retain their patient care prerogative to perform glucose monitoring. Implementation of our successful BGM program required the collaboration of nursing, medical, laboratory, and administrative personnel. These departments combined theoretical and practical expertise with material and financial management. During the first 5 months of operation, our program has shown a steady increase from 78% to 89% of control tests performed correctly. This model can be used by other hospitals to achieve a successful BGM program.

Blood Glucose Self-Monitoring↗

Parenteral nutrition-associated cholestasis in preterm neonates: evaluation of ursodeoxycholic acid treatment.

BACKGROUND/OBJECTIVE: Parenteral nutrition is an integral part of the care of premature infants. Cholestatic liver disease is a frequent complication of prolonged parenteral nutrition, especially in premature infants. It has been suggested that ursodeoxycholic acid may alter the course of parenteral nutrition-associated cholestasis in children and adults. We attempted to determine the efficacy of ursodeoxycholic acid in premature infants with parenteral nutrition-associated cholestasis. METHODS: Retrospective chart review of all infants receiving ursodeoxycholic acid for parenteral nutrition-associated cholestasis in a 40 bed neonatal intensive care unit. Efficacy of ursodeoxycholic acid was evaluated by response of bilirubin, alanine aminotransferase, aspartate aminotransferase, and alkaline phosphatase over a treatment period of at least 1 month. RESULTS: Six infants with parenteral nutrition-associated cholestasis who had received ursodeoxycholic acid for one month were identified. Doses of ursodeoxycholic acid ranged from 15-30 mg/kg/day. Cholestasis appeared at a mean age of 47 +/- 17 (mean +/- SD) days after a mean of 42 +/- 15 days of parenteral nutrition. Transaminase levels decreased in three, and either increased or did not change in the other three infants. Bilirubin levels decreased in all infants. Alkaline phosphatase showed a non significant trend to decreased levels. Consistent improvement in all infants was noted only after 10 days of full enteral nutrition. No toxicity was found during ursodeoxycholic acid treatment. CONCLUSIONS: Ursodeoxycholic acid treatment in premature infants appears to be safe, and leads to an early sustained decrease in bilirubin levels by two weeks of therapy. The response of transaminase levels was not sustained in our small cohort.

Alanine Transaminase↗

Rosiglitazone: an agent from the thiazolidinedione class for the treatment of type 2 diabetes.

Great advances have been made in the management of diabetes during the past decade. Whereas only one class of oral medications (the sulfonylureas) was available for the treatment of type 2 diabetes in the early 1990s, we now have five classes of oral antidiabetic agents from which to choose. The thiazolidinedione class of medications was first introduced to the United States when troglitazone was marketed during early 1997. Rosiglitazone, approved by the FDA during the spring of 1999, was the second thiazolidinedione to be marketed in the United States. Similar to troglitazone, rosiglitazone improves insulin sensitivity in patients with type 2 diabetes by activating peroxisome proliferator-activated receptor-gamma (PPARgamma) receptors in adipose tissues, skeletal muscles, and the liver. The efficacy and safety of rosiglitazone therapy in patients with type 2 diabetes have been demonstrated in a number of clinical studies, which are summarized in this article. Selected characteristics of rosiglitazone are compared with those of pioglitazone--the other thiazolidinedione currently available in the United States. Edema of mild to moderate severity has been reported in approximately 5% of patients treated with rosiglitazone during clinical trials. Therefore, caution must be taken when this agent is administered to patients with heart failure. Rosiglitazone has also been associated with elevations of total, LDL, and HDL cholesterol during clinical trials. However, the LDL:HDL cholesterol ratio or the total:HDL cholesterol ratio has mostly been observed to be unchanged. Although liver toxicity has not been observed with rosiglitazone during clinical trials, the safety of this drug for long-term usage and in larger patient populations remains to be established in further clinical studies and in postmarketing experience.

Diabetes Mellitus, Type 2↗

Induction of IL-4 and IL-6 synthesis in vitro: variation in signaling requirements and kinetics are dependent on the anatomic source of the responding mononuclear cells.

We have shown differences in regulation of cytokine mRNA expression in human tonsil, spleen, and peripheral blood. After PHA stimulation of peripheral blood, IL-2, IL-4, and IL-6 mRNA were expressed with similar kinetics: peak expression occurred after four hours and subsequently declined over 48 hr. In PHA-stimulated splenic and tonsillar MNC, IL-2 and IL-6 mRNA were expressed later, with peak expression occurring after eight hours of stimulation and no mRNA detectable after 40 hr of stimulation. The intensity of the IL-6 mRNA signal and the amount of IL-6 secreted was much greater in MNC from peripheral blood than in spleen and tonsil and correlated with the percentage of monocytes in MNC from each tissue. IL-4 mRNA expression differed in all three tissues: PHA-stimulated tonsillar MNC expressed IL-4 mRNA with a major peak at eight hours and a minor peak at 24 hr after stimulation. The kinetics of mRNA were not due to effects of mixed cell populations. The same bimodal peak was observed in purified tonsillar T lymphocytes, and the minor 24-hr peak was dependent on IL-4 mRNA synthesis by cells expressing high amounts of VLA-beta 1 antigen (CDw29) on their surface and which lacked the CD45 epitope recognized by the mAb 2H4. Splenic MNC did not express IL-4 mRNA when stimulated with a number of mitogens and only exhibited IL-4 mRNA expression when stimulated with the combination of PHA and PMA or anti-CD3. Thus, IL-4 mRNA has markedly different kinetics and intensity of expression in spleen, peripheral blood, and tonsil.(ABSTRACT TRUNCATED AT 250 WORDS)

Humans↗