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Biomedical subjects

A Levitt

Publications and source records attributed to A Levitt.

At least 19 recordsLinked to original sources
PubMed1997

Differential pharmacological treatment response in high angry hostile and low angry hostile depressed patients: a retrospective analysis.

Fava et al., Am. J. Psychiatry 150 (1993)1158-1163, have recently proposed the existence of a sub-type of depressed patients who experience anger attacks. These investigators hypothesized that patients who experience anger attacks will respond better to a specific selective serotonin reuptake inhibitor (SSRI) medication than will depressed patients who do not experience anger attacks. Using a non-randomized, archival treatment methodology, 158 patients were classified as either high angry hostile (n = 83) or low angry hostile (n = 75). These patients had been treated with either a primarily noradrenergic reuptake inhibitor (desipramine) a SSRI (sertraline or paroxetine), or the combined serotonin and norepinephrine reuptake inhibitor (SNRI), venlafaxine. A 2 (high angry hostile/low angry hostile) x 3 (medication type) analysis of variance (ANOVA) was non-significant, indicating no differential treatment effects.

1-Naphthylamine↗
PubMed1994

Major depression and the self-criticism and dependency personality dimensions.

The Depressive Experiences Questionnaire was used to assess the personality dimensions of dependency and self-criticism in 52 depressed patients before and after treatment and in 22 healthy family practice patients. Neither personality dimension was significantly influenced by change in depressed mood, and the recovered depressed patients had higher levels of dependency and self-criticism than the comparison subjects.

Ambulatory Care↗
PubMed1993

The transcript encoding the circumsporozoite antigen of Plasmodium berghei utilizes heterogeneous polyadenylation sites.

We have employed polymerase chain reaction-based techniques to examine the transcript encoding the circumsporozoite (CS) antigen, the immunodominant coat protein of the infectious stage of the murine parasite Plasmodium berghei. Earlier studies suggested that the 3' terminus of the CS message might be determined by transcription termination rather than by cleavage and polyadenylation, as in most eukaryotes. Here we report that a subset of CS messages are polyadenylated. Moreover, the poly(A) tails are added at multiple sites clustered within a short region 300 bp downstream from the stop codon. Whether 3' end heterogeneity is peculiar to the CS message or a common feature of plasmodial transcripts remains to be determined.

Animals↗
PubMed1993

Anxious and nonanxious depression.

The authors used the anxiety summary score described by Clayton and associates to assess anxious and nonanxious subtypes of depression in a group of 134 outpatients with major depression. Patients with anxious depression were only slightly less likely to respond to their first tricyclic antidepressant than patients with nonanxious depression. When functional severity or symptom severity was controlled for, this differential treatment response did not hold.

Adult↗
PubMed1993

Analysis of malarial transcripts using cDNA-directed polymerase chain reaction.

A polymerase chain reaction (PCR)-based approach is being employed to study RNA transcripts in malarial parasites, a system that is not easily amenable to molecular studies. Our aim is to compare messages from different life cycle stages to determine whether regulatory information is encoded in the structure of plasmodial transcripts as a result of differential RNA processing. In particular, we have analyzed the structure of the message encoding the circumsporozoite (CS) protein of the murine malaria Plasmodium berghei, the immunodominant surface antigen of the infectious stage of the parasite. Our major findings are that a subset of the CS message utilizes multiple polyadenylation sites, that some processed CS transcripts are found in blood-stage parasites, and that the 5' untranslated region of the message is unusually long and has multiple start sites. Moreover, repetitive motifs that may represent enhancers or transcriptional binding sites are present upstream of the transcription unit. In addition, we describe details of the cDNA-directed PCR procedure that may be helpful to other parasitologists who work with small, unpurified biological samples.

Actins↗
PubMed1992

Molecular and genomic organization of clusters of repetitive DNA sequences in Caenorhabditis elegans.

Repetitive sequences in Caenorhabditis elegans are interspersed along the holocentric chromosomes. We have physically mapped some of these repetitive families and found that, although the distribution of members of each family is relatively even along the chromosomes, members of more than one family tend to cluster in some locations. We compared the sequence organization of 11 clusters located at known positions on different chromosomes in the N2 strain. These studies allow a comparison between repetitive elements belonging to the same family that are located on the same or on different chromosomes, providing an important tool in the study of genome turnover and evolution.

Animals↗
PubMed1992

The Tc2 transposon of Caenorhabditis elegans has the structure of a self-regulated element.

We have analyzed the sequence of the Tc2 transposon of the nematode Caenorhabditis elegans. The Tc2 element is 2,074 bp in length and has perfect inverted terminal repeats of 24 bp. The structure of this element suggests that it may have the capacity to code for a transposase protein and/or for regulatory functions. Three large reading frames on one strand exhibit nonrandom codon usage and may represent exons. The first open coding region is preceded by a potential CAAT box, TATA box, and consensus heat shock sequence. In addition to its inverted terminal repeats, Tc2 has an unusual structural feature: subterminal degenerate direct repeats that are arranged in an irregular overlapping pattern. We have also examined the insertion sites of two Tc2 elements previously identified as the cause of restriction fragment length polymorphisms. Both insertions generated a target site duplication of 2 bp. One element had inserted inside the inverted terminal repeat of another transposon, splitting it into two unequal parts.

Animals↗
PubMed1992

Adverse cutaneous reactions associated with fluoxetine strategy for reintroduction of this drug in selected patients.

Four patients treated with fluoxetine alone developed generalized urticaria. One also suffered polyarthritis. These reactions subsided when fluoxetine was stopped. After 6-12 months, because of progressive psychiatric problems, fluoxetine was reintroduced using a desensitization protocol. In each case this was well tolerated, and fluoxetine has been continued without adverse affects for 3-10 months.

Adult↗
PubMed1992

The effect of light on oxygen-induced vasoproliferative retinopathy in newborn kittens.

The effect of bright fluorescent light (115 fc) on oxygen-induced retinopathy in newborn kittens was compared with that of complete darkness and cyclic illumination of 12 hr of bright light (115 fc) and 12 hr of complete darkness. No significant difference was found in the extent of preretinal vasoproliferation and retinal ultrastructural findings among the three groups of kittens reared in different levels of illumination and a control group raised in a standard laboratory illumination level of 40 fc. These results confirmed that light is not a required factor for the development of oxygen-induced retinopathy in kittens.

Animals↗
PubMed1991

Syllable-internal structure and the sonority hierarchy: differential evidence from lexical decision, naming, and reading.

Treiman (1983) and others have argued that spoken syllables are best characterized not as linear strings of phonemes, but as hierarchically organized units consisting of an onset (initial consonant or consonant cluster) and a rime (the vowel and any following consonants) and that the rime is further divided into a peak or nucleus (the vowel) and a coda (the final consonants). It has also been argued that the sonority (or vowel-likeness) of the consonant closest to the peak, which is a function of its phonetic class, may have an effect on the strength of boundaries determined by the hierarchical division of the syllable (e.g., Treiman, 1984). We examined the evidence for syllable-internal structure and for sonority in two experiments that employed visually presented stimuli and lexical decision, naming, and reading tasks. Our results provide support for the breakdown of the rime into a peak and a coda and for an effect of the sonority of the postvocalic consonant on that break. This pattern occurred only in our lexical decision tasks, so the effect is assumed to be postlexical. We did not find an effect of the onset-rime boundary, perhaps because of an unanticipated effect of word frequency. Our results are discussed in terms of phonological coding in short-term memory.

Adult↗
PubMed1989

The Tc2 transposon in Caenorhabditis elegans.

A second family of transposons, named Tc2 elements, has been identified in the nematode Caenorhabditis elegans. Tc2 elements are polymorphic in sequence and are present in different numbers in different strains. Like the transposon Tc1, Tc2 is active in the germ line of some C. elegans strains. A high rate of transposition has been observed in the progeny of certain interstrain crosses, where transposition events are frequent enough to be detected in blot hybridization experiments, without the use of a genetic screen. Our data suggest that transposition of Tc1 and Tc2 may be regulated by the same genomic factors.

Animals↗
PubMed1989

Health maintenance issues of the elderly. Immunization.

The elderly are frequently underimmunized against vaccine-preventable infectious diseases. Comprehensive immunization of patients for vaccine-preventable diseases represent a major challenge for physicians treating the elderly. The healthy elderly should be specifically targeted since they are most likely to mount an appropriate immune response to the vaccine. Programs to identify inadequately immunized patients should be widely implemented.

Aged↗