Search PubMed⌕ Search

Biomedical subjects

L J Harris

Publications and source records attributed to L J Harris.

At least 91 records · Page 5Linked to original sources
PubMed1987

Comparing participants' and managers' perception of services in a congregate meals program.

Managers and participants in a Title III C meals program were surveyed to explore how differences in perception of program and service quality affect participant acceptance and evaluation of the program. A nutrition monitoring instrument was designed for managers at 14 meal sites to assess major components of the foodservice operation. A survey addressing participant perception of meal quality, meal acceptance, program administration and management, and foodservice personnel was designed and administered to 264 participants. The two surveys contained 17 identical or similar questions to determine any perceptual differences. The influence of social variables on participant response was examined. A significant positive correlation was found for age vs. food temperature, age vs. frequency of participation, and education level vs. evaluation of foodservice workers. Significant negative correlations were found for sex vs. special diets, sex vs. food aversion, education level vs. food temperature, and education level vs. evaluation of the nutrition education component. Manager vs. participant response significantly differed for food temperature, special diets, nutrition education, transportation, and accuracy of posted menus. Assessment of participant vs. manager perception of meal and service quality is recommended to management for more effective program planning, evaluation, and continuous quality assurance.

Administrative Personnel↗
PubMed1986

A 122Xe-122I generator for remote radio-iodinations.

A 122Xe-122I generator system is described that produces 122I extraction efficiencies of approximately 60%. Radiocontaminants were less than 0.1% at the time of 122I removal following a 10 min ingrowth period. The chemical form of 122I was identified as [122I]iodide, and the [122I]iodide was remotely incorporated into radiopharmaceuticals for PET studies with an overall efficiency of as much as 40%.

Iodine Radioisotopes↗
PubMed1986

Somatic excision of transposable element Tc1 from the Bristol genome of Caenorhabditis elegans.

We investigated the ability of the transposable element Tc1 to excise from the genome of the nematode Caenorhabditis elegans var. Bristol N2. Our results show that in the standard lab strain (Bristol), Tc1 excision occurred at a high frequency, comparable to that seen in the closely related Bergerac strain BO. We examined excision in the following way. We used a unique sequence flanking probe (pCeh29) to investigate the excision of Tc1s situated in the same location in both strains. Evidence of high-frequency excision from the genomes of both strains was observed. The Tc1s used in the first approach, although present in the same location in both genomes, were not known to be identical. Thus, a second approach was taken, which involved the genetic manipulation of a BO variant, Tc1(Hin). The ability of this BO Tc1(Hin) to excise was retained after its introduction into the N2 genome. Thus, we conclude that excision of Tc1 from the Bristol genome occurs at a high frequency and is comparable to that of Tc1 excision from the Bergerac genome. We showed that many Tc1 elements in N2 were apparently functionally intact and were capable of somatic excision. Even so, N2 Tc1s were prevented from exhibiting the high level of heritable transposition displayed by BO elements. We suggest that Bristol Tc1 elements have the ability to transpose but that transposition is heavily repressed in the gonadal tissue.

Animals↗
PubMed1986

Prenatal weight gains related to the birth of healthy-sized infants to low-income women.

Prepregnancy weight status and weight gain during pregnancy are major independent variables associated with infant birth weight. This study quantitated the influence of weight gain on birth weight and identified rates and total amounts of weight gain related to the birth of healthy-sized infants to healthy low-income women who entered pregnancy underweight, at normal weight, overweight, or obese. Data used in the study were obtained from randomly sampled prenatal health records from Maternal and Infant Care (MIC) projects in Cleveland and Minneapolis. Subsamples of healthy mothers who delivered healthy-sized infants were identified from each sample, and rates and total amounts of weight gain by prepregnancy weight status group were calculated. There were 384 healthy mother and healthy-sized infant pairs in the Cleveland subsample and 75 such pairs in the Minneapolis sample. Multiple regression analysis revealed that the influence of prenatal weight gain and birth weight varied depending on prepregnancy weight status. Prenatal weight gains related to the birth of healthy-sized infants (newborns with birth weights of 3,000 to 4,500 gm) to healthy mothers in the Cleveland MIC sample averaged 33 lb for underweight, 32 lb for normal weight, 29 lb for overweight, and 19 lb for obese women. Except for obese women, rates and total amount of weight gain associated with the birth of healthy-sized infants were equivalent for the two samples.

Birth Weight↗
PubMed1985

Tc1(Hin): a form of the transposable element Tc1 in Caenorhabditis elegans.

In this paper we describe the coexistence of two forms of the transposable element Tc1 in the genome of the nematode Caenorhabditis elegans. A copy of the variant form has been isolated from the Bergerac genome and characterized. Restriction mapping and DNA sequencing have shown that a G to T transversion generated a HindIII restriction site to form the variant Tc1(Hin). The presence of this new restriction site makes this variant easily detectable on genomic blot hybridizations. There are approximately 20 copies of Tc1(Hin) amongst the Tc1's present in the Bergerac genome. Bergerac has approximately 250 copies of Tc1 per genome, whereas Bristol has about 30. In the Bristol strain we detected at least one copy Tc1(Hin). The ratio of Tc1(Hin) to total Tc1's is similar in the genomes of Bristol and Bergerac, even though they have markedly different total numbers of Tc1. Our results suggest that a trans-acting change in either the elements or the host genome was responsible for the expansion of Tc1 copy number in the Bergerac genome.

Animals↗
PubMed1984

Products of a reciprocal chromosome translocation involving the c-myc gene in a murine plasmacytoma.

The structures of the rearranged c-myc gene products derived from a rcp T(12;15) have been investigated in the MPC-11 (IgG2b kappa) plasmacytoma. The rcp T(12;15) in MPC-11 is a reciprocal exchange between the c-myc gene on chromosome 15 and the immunoglobulin gamma 2a switch region (S gamma 2a) on chromosome 12. The c-myc gene is broken within a 5'-nontranslated exon, thereby separating the promoter region of the normal c-myc gene from its protein coding sequences. This reciprocal rearrangement results in the loss of 11 base pairs of c-myc sequence and 300 base pairs of S gamma 2a sequence at the point of recombination. Sequences that represent the promoter region of the normal c-myc gene are present in the 5'-myc reciprocal fragment. A comparison of the nucleotide sequences at the recombination site of a number of c-myc rearrangements reveals a common feature that may have mechanistic importance for these translocation events.

Animals↗
PubMed1983

c-myc Gene rearrangements involving gamma immunoglobulin heavy chain gene switch regions in murine plasmacytomas.

In murine plasmacytomas, the c-myc gene has frequently been found to undergo rearrangement by virtue of a T(12;15) chromosome translocation. The immunoglobulin heavy chain gene switch region (S alpha) constitutes the target for most of these recombinations particularly in IgA producing plasmacytomas. We sought to identify non-S alpha myc target sites in several IgG producing tumors. The c-myc target in MPC-11 (a BALB/c IgG2b producing plasmacytoma) has been cloned, localized to the Igh-C locus and identified as the gamma 2a heavy chain gene switch region (S gamma 2a). Furthermore, by Southern blot hybridization, we have determined that the S gamma 2b region is the c-myc target in two NZB IgG2b producing plasmacytomas. The potential relation between Ig class expressed and c-myc translocation target is discussed.

Animals↗
PubMed1983

Transcriptionally active c-myc oncogene is contained within NIARD, a DNA sequence associated with chromosome translocations in B-cell neoplasia.

NIARD (non-immunoglobulin-associated rearranging DNA) is located on mouse chromosome 15 at the break point of a commonly observed translocation event involving chromosomes 15 and 12 in murine plasmacytomas. The human cellular analogue of the v-myc oncogene of avian myelocytomatosis virus, strain MC-29, is known to reside on the distal end of human chromosome 8 and has been observed to translocate to chromosome 14 in Burkitt lymphomas. Using a cDNA clone specific for the transcript of the human c-myc gene (H c-myc), we show that the mouse c-myc (M c-myc) gene is contained within NIARD. NIARD-associated chromosome translocations occurred 1.3-2 kilobases (kb) 5' of the mouse c-myc gene where NIARD recombines with the switch region of the C(alpha) immunoglobulin gene in various murine plasmacytomas. The mouse c-myc encoding region within NIARD spanned <2.4 kb of DNA and expressed a low level of a 2.3-kb polyadenylylated RNA in BALB/c spleen. Increased (10- to 20-fold) levels of rearranged mouse c-myc transcripts (i.e., approximately 1.8-2.1 kb) were observed in plasmacytomas that have NIARD-associated chromosome translocations. Human c-myc and NIARD probes detected DNA rearrangements of human c-myc in four of seven Burkitt lymphomas. DNA sequences adjacent to the human c-myc gene recombined with the C(mu) immunoglobulin gene locus on chromosome 14 in several Burkitt lymphomas. The activation of the c-myc oncogene by chromosome translocation implicates its involvement in B-cell oncogenesis.

Animals↗
PubMed1983

Condylocephalic nailing of proximal femoral fractures.

The use of a closed nailing technique for elderly patients with intertrochanteric fractures has resulted in a substantially improved mortality. The incidence of fixation failures and degree of shortening are similar to that experienced with sliding screw and sliding nail plate systems. However, since rotational deformities may occur, the procedure is most beneficial for debilitated patients with intertrochanteric fractures, who represent substantial surgical risks. In general, subtrochanteric fractures occur in a younger group of patients. Since the proximal fragment is usually much larger and the quality of bone superior in this group of patients, the fixation failure rate was extremely low and significant loss of rotatory reduction did not occur. The body of experience gained in recent years with closed nailing techniques for femoral shaft and tibial fractures is directly applicable to the closed nailing of intertrochanteric and subtrochanteric fractures. Extremely comminuted fractures or long oblique fractures may shorten, and rotatory reduction and control must always be a concern. These difficulties must be weighed against the advantages of a negligible infection rate and extremely low nonunion and implant failure rates.

Bone Nails↗
PubMed1982

Non-immunoglobulin-associated DNA rearrangements in mouse plasmacytomas.

We have characterized a class of DNA rearrangements in plasmacytomas. These recombination events involve a DNA sequence whose origin is outside of the locus of the heavy chain constant region genes, CH. Therefore, we choose to refer to this sequence as non-immunoglobulin-associated rearranging DNA (NIARD). We have isolated two abortively rearranged C alpha genes, generated by NIARD events from the alpha-producing J558 myeloma. Restriction endonuclease maps of these sequences reveal two possible recombination sites in NIARD that are separated by approximately 6.5 kilobase pairs of DNA (defined as 5' and 3' sites). A NIARD rearrangement occurs in 15 out of 20 plasmacytomas tested, including gamma 3-, gamma 1-, gamma 2b-, gamma 2a-, and alpha-producers, but this event usually does not involve a CH switch (S) region. In fact, only S alpha appears to accept NIARD. However, NIARD did not undergo a rearrangement in eight IgA-producing hybridomas tested. One germ-line copy of NIARD (a 22-kilobase pair EcoRI fragment) is retained in all plasmacytomas. NIARD does not appear to possess repetitive DNA sequences homologous to S mu or S alpha. We discuss the possible role and implications of NIARD-like sequence rearrangements in allelic exclusion and chromosomal translocation events in plasmacytomas.

Animals↗
PubMed1982

DNA sequence associated with chromosome translocations in mouse plasmacytomas.

A DNA sequence that generates aberrantly rearranged immunoglobulin heavy chain constant region genes in murine plasmacytomas is shown to participate in a chromosome translocation. We have previously termed this DNA sequence NIARD for non-immunoglobulin-associated rearranging DNA. NIARD rearrangements were found frequently in murine plasmacytomas but were not detected in normal lymphocytes. These rearrangements occasionally involve the switch region of the C alpha gene. In this study, DNA samples obtained from mouse-Chinese hamster somatic cell hybrid lines were digested with various restriction endonucleases and analyzed by the Southern transfer technique with a NIARD hybridization probe. These experiments show that NIARD resides on chromosome 15 in the mouse germ line. Since NIARD is found adjacent to the C alpha gene (located on chromosome 12) in some plasmacytomas, it is apparent that a translocation involving these two chromosomes has occurred. We have proposed a rcpT(12;15) model to explain our data. The implications of NIARD rearrangements for malignant transformation are discussed.

Animals↗
PubMed1981

Relationships among cognitive complexity, sex, and spatial task performance in college students.

This study examined the relationship between object differentiation (spatial ability) and social differentiation (cognitive complexity). Prior research had demonstrated a link between field independence and cognitive complexity, and between field independence and spatial ability. This raises the question whether some unitary cognitive style is involved in both spatial ability and cognitive complexity. The present study used a spatial task (a variation of Piaget & Inhelder's water level task) and several measures of cognitive complexity (the Barron Complexity scale, Intolerance of Ambiguity scale, and measures of self-differentiation and differentiation of other persons) to test the prediction that complexity will be positively related to performance on the water level task. On the basis of earlier findings, we also predicted that males would outperform females on the water level task. Thirty-eight male and 98 female undergraduates completed the water level task and the complexity measures. Results confirmed the predictions, except that the relationship between cognitive complexity and performance was different for males than for females. For males, the correlations between scores on the water level task and the several measures of complexity were considerably higher than for females. Such results suggest that for males spatial task performance can be related to a general construct such as cognitive style; for females, this does not appear to be the case.

Adolescent↗
PubMed1980

Closed retrograde intramedullary nailing of peritrochanteric fractures of the femur with a new nail.

Two hundred and forty patients with intertrochanteric and subtrochanteric fractures were treated by closed intramedullary nailing with a new nail inserted retrograde via the medial condyle. After insertion, the alignment of the nail is nearly parallel to the line of load-bearing. Early weight-bearing was achieved for most patients with intertrochanteric and stable subtrochanteric fractures. A review of the 176 fractures that had at least an eight-month follow-up revealed loss of reduction in 2.3 per cent. There were no cases of implant failure, delayed union, non-union, or infection. The six-week mortality rate was 3.7 per cent and the eight-month rate, 10.4 per cent.

Aged↗