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Biomedical subjects

E Montgomery

Publications and source records attributed to E Montgomery.

At least 55 records · Page 3Linked to original sources
PubMed1992

Elastofibroma: MR and CT appearance with radiologic-pathologic correlation.

OBJECTIVE: The purpose of our study was to determine the MR and CT appearances of elastofibroma and correlate the imaging features with the underlying pathologic findings. MATERIALS AND METHODS: We reviewed retrospectively the MR and CT findings in five cases of elastofibroma. All patients had a soft-tissue mass; one patient also complained of pain. The mean age of the patients was 71 years (range, 63-79 years). Four lesions occurred in the subscapular region, and one occurred in the thigh. In addition, we reviewed and compared the demographic data of 72 histologically proved cases for which we had archival data. RESULTS: Three of four lesions evaluated with spin-echo MR imaging were approximately isointense with skeletal muscle and contained areas with a signal intensity similar to that of fat; these corresponded to areas of dense collagen and interspersed fat, respectively. In the fourth case, the MR appearance was nonspecific. In one case, MR imaging with gadopentetate dimeglumine showed areas with and without enhancement. Three of four lesions evaluated with CT had variable margins, with tissue attenuation similar to that of the adjacent soft tissue as well as scattered areas of decreased attenuation, suggesting fat within the lesion. In one case, the lesion was well defined and relatively homogeneous with an attenuation less than that of skeletal muscle. CONCLUSION: The MR and CT features of elastofibroma are different from those of most other soft-tissue tumors, reflecting entrapped fat within a predominantly fibrous mass. Although these features are not pathognomonic, their presence in a subscapular lesion in an older patient suggests a presumptive diagnosis of elastofibroma.

Adult↗
PubMed1990

Iron levels in pregnancy, physiology or pathology? Assessing the need for supplements.

This paper re-examines the need for iron supplements among pregnant women by considering whether the changes they experience in iron levels are physiological or pathological. The literature reveals that changes in the blood leading to haemodilution are necessary adaptations to healthy pregnancy. These changes alter normal haematological values. Consequently, indices such as haemoglobin concentration lose their accuracy as measurements of iron status. Tests for iron stores such as serum ferritin are more likely to prove useful indicators of deficiency. Iron stores are greatly depleted early in pregnancy, whether or not supplements are taken, when absorption is low. They return to pre-pregnant levels quickly after delivery. Reasons for these phenomena are postulated. High levels of haemoglobin in pregnancy seem to be as undesirable as very low levels. As proved benefits from iron therapy are few, it is questionable whether the antenatal period is an appropriate time to supplement. However, the issue of physiology versus pathology remains unresolved. Pregnancy is assumed to be an abnormal variation of the non-pregnant state; its parameters being judged against those of the population at large. As most pregnancies form a normal part of a woman's life cycle, the physiological ranges for pregnancy itself need to be determined.

Anemia, Hypochromic↗
PubMed1989

Campylobacter pylori, NSAIDS, and smoking: risk factors for peptic ulcer disease.

Campylobacter pylori, nonsteroidal anti-inflammatory drugs, and smoking are associated with ulcer disease. To define further the role of these factors in ulcer disease, one hundred seven subjects presenting for endoscopy were tested for specific IgG and IgA antibodies to C. pylori, and questioned about nonsteroidal use and smoking. Sixty were dyspeptic patients, 28 were disease controls, and 19 were healthy asymptomatic volunteers. Considering all subjects, 81% (87/107) were either taking nonsteroidals or had antibody to C. pylori, and 32% of these (28/87) had an ulcer. Nineteen percent (20/107) were neither taking nonsteroidals nor had antibody to C. pylori, and none of these had an ulcer, p less than 0.01. Smokers, 41% (11/27), were more likely to have an ulcer than nonsmokers, 20% (16/80), p less than 0.05, but only because of the increased prevalence of ulcers in smokers who also had C. pylori, 73% (11/15) versus 27% (12/45) of nonsmokers with C. pylori, p less than 0.01. The use of nonsteroidals and antibody to C. pylori identify people at risk for ulcers. Smoking increases this risk in subjects with C. pylori. Absence of a history of nonsteroidal use and antibody to C. pylori identify individuals with a low probability of ulcer disease.

Adult↗
PubMed1986

Laser microsurgery: a review of 105 intracranial tumors.

The relative importance or utility of the carbon dioxide laser within the total context of multimodality therapy and in comparison to conventional surgical techniques is unknown. Over a 36 month period, 421 operations for tumors of the brain and spinal cord were performed in our clinic. Of these, 111 (26%) were carried out with the aid of the laser. After excluding stereotactic and transsphenoidal operations, a comparison was made between 105 laser and 216 non-laser craniotomies. With the exception of pituitary tumors, the most frequent diagnoses in both the laser and non-laser cases were the same: malignant astrocytoma (48.6 vs 33.9%), meningioma (11.4 vs 14.2%) and low grade astrocytoma (8.6 vs 8.7%). The number of reoperations in the laser group (60.1%) was higher than in the non-laser group (32.7%; p less than 0.000001) and the mean operating time (299 minutes vs 237 minutes; p less than 0.00001) was longer, but there was no significant mean difference in mortality, CNS morbidity, mean blood loss (638 ml vs 671 ml) or mean length of stay (23 vs 25 days). For the subgroup of 134 cases of malignant astrocytoma, 82% of laser procedures were reoperations versus 50% for non-laser cases (p less than 0.0002) and the mean operating time was slightly longer (p less than 0.02). The length of stay for laser cases tended to be less (21 vs 27 days; p less than 0.04), but there was again no difference in blood loss (457 ml vs 522 ml), CNS morbidity (7.8 vs 4.8%) or mortality.(ABSTRACT TRUNCATED AT 250 WORDS)

Astrocytoma↗
PubMed1985

Expanded role of the cerebrospinal fluid reservoir in neurooncology: indications, causes of revision, and complications.

Advances in chemotherapy have increased the indications for insertion of cerebrospinal fluid (CSF) reservoirs in the treatment of both primary and secondary central nervous system neoplasia. There have been no recent evaluations of the current indications and complications of this procedure in a general neurooncology practice. We undertook a retrospective review of our total experience of 60 patients who were implanted with CSF reservoirs between November 1977 and October 1983. The mean age of those implanted was 38 years (range, 22 months to 79 years). The reasons for insertion were: drug instillation, 35 cases (58.3%); drug level monitoring, 15 cases (25.0%); intermittent tumor cyst drainage, 6 cases (15.0%); and syrinx drainage, 1 case (1.6%). Drug level monitoring was most often done in conjunction with specific experimental chemotherapy protocols. There were no complications after primary insertion, but 9 of 60 reservoirs (15%) required revision for technical failure. Revision was much more likely to occur in the presence of an intracranial mass lesion (7 of 34, or 20.5%). The revision rate in cases of meningeal carcinomatosis was only 7.6% (2 of 26). Patients requiring revision included 5 with glioblastoma, 2 with metastatic tumors, and 2 with meningeal carcinomatosis. Four of the 9 patients requiring revisions developed complications (44%). There were three infections with positive CSF cultures and one subdural hematoma. Infected patients included those with multiple craniotomies, prior cranial irradiation, or some form of chemotherapy. We conclude that primary insertion of a CSF reservoir in a patient with neoplastic involvement of the central nervous system is extremely safe, that technical failure tends to occur in the presence of mass lesions, and that the complication rate of repeated insertion is quite high.

Adolescent↗
PubMed1982

Restriction map variation in the Adh region of Drosophila.

Restriction maps of a 12,000-nucleotide region containing the alcohol dehydrogenase (Adh) locus of the second chromosome of Drosophila were determined for (i) 18 independent second chromosome stocks of D. melanogaster established from several natural populations and (ii) five closely related Drosophila species. All of the detected map differences appear to lie outside the Adh coding block. Four polymorphic restriction sites and four insertion/deletion variants were identified among D. melanogaster chromosomes. The estimated heterozygosity per nucleotide site was 0.006. The relative distributions of restriction sites and insertion/deletion variations among subpopulations and species suggest that the insertion/deletion variation may be mildly deleterious.

Alcohol Dehydrogenase↗
PubMed1982

Effect of age and reoperation on survival in the combined modality treatment of malignant astrocytoma.

Before the advent of the operating microscope and the carbon dioxide laser, reoperations were performed in less than 5% of patients with malignant astrocytoma. Between 1978 and 1981, a consecutive series of 74 adult patients were prospectively treated therapy, all patients eligible for further treatment were offered reoperation with the microscope and/or laser before treatment with Phase I agents (microwave hyperthermia, dimethyl sulfoxide (DMSO)-Adriamycin, DMSO-Cytoxan, or azaridinylbenzoquinone (AZQ)). Forty-six per cent of the patients were referred from outside institutions for intensive treatment. In 36 months, 40 patients received second operations directed at their tumor and had a median calculated survival from the time of reoperation of 37 weeks. The length of survival after the second operation was independent of patient age, performance status, tumor grade, and interoperative interval. Sixty-five per cent of patients under 40 and 48% of patients over 40 underwent reoperation with minimal morbidity and no deaths. The single most important prognostic factor for survival in both reoperated and single-operated patients was age. Tumor grade had no influence on survival in the series as a whole, in patients under 40 years of age, or in reoperated patients. The calculated median survival for the entire series was 15 months, with a predicted 2-year survival rate of 0.25. These figures include all patients treated without exclusion for incomplete radiotherapy or chemotherapy. It is concluded that reoperation for malignant astrocytoma is safe, feasible, and of potential benefit in combination with other therapies. The routine use of reoperation to "set up" other treatment modalities deserves further study.

Adolescent↗
PubMed1981

Null allele frequencies at allozyme loci in natural populations of Drosophila melanogaster.

We have sampled a London population of Drosophila melanogaster for null alleles at twenty-five allozyme loci. The same loci and biochemical techniques were used as in our previous survey of a North Carolina population (Voelker et al. 1980). This second survey is completely concordant with the first. No nulls were detected among the five X-linked loci. The mean frequency of nulls at the twenty autosomal loci was 0.0023. Although there is significant interlocus heterogeneity, the two populations appear to have the same frequencies at each locus. This suggests that null alleles at these allozyme loci are in mutation-selection balance, and we estimate the average heterozygous effect of an allozyme null to be 0.0015. Consideration of allozyme null-allele frequencies, the effects of allozyme null alleles on viability and fertility and the generally greater amount of genetic variability at allozyme loci determined by electrophoresis lead us to doubt the validity of generalizing from allozyme data to the whole genome.

Alleles↗
PubMed1980

Enzyme null alleles in natural populations of Drosophila melanogaster: Frequencies in a North Carolina population.

A Raleigh, NC, population of Drosophila melanogaster was sampled for the presence of enzyme null alleles at 25 loci. No nulls were found at any of five X-linked loci. Nulls were recovered at 13 of 20 autosomal loci; the weighted mean frequency for all 20 autosomal loci was estimated to be 0.0025. A consideration of the effects of these null alleles on viability strongly suggests that, although they may contribute to so-called polygenic variation, they are not representative of the entire genome.

Journal Article↗
PubMed1978

Towards representative energy data: the Machiguenga study.

Representative energy data for a human population can be produced by combining randomly sampled time allocation observations with activity-specific energy expenditure measurements. Research to produce representative energy data for adults of a population of Machiguenga Indians has recently been conducted in lowland, southeastern Peru. Marked contrast was found between the sexes for average married adults in energy expended on an average day. Men spent about 3,200 kcals and women, about 1,925; ratio: 1.66 to 1. In general, men tended to work at somewhat more energetic activities and for longer periods than did women. In addition to sex-role-related task differences were contrasts in uses of technological items and in respective work settings. These representative behavior data permit direct estimates of population-level energy requirements for average days, seasons, or for 1 year.

Activities of Daily Living↗