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Biomedical subjects

H M Wallace

Publications and source records attributed to H M Wallace.

At least 91 records · Page 5Linked to original sources
PubMed1984

Polyamines in breast cancer.

Polyamine levels (putrescine, spermidine and spermine) in breast cancers (n = 54) were measured as a potential guide to prognosis. Values (expressed as nmol per 100 mg tumour) ranged from: 0.9 to 4.5 for putrescine, 4.2 to 29.8 for spermidine and 5.6 to 39.7 for spermine concentration. Increased intracellular polyamine levels were positively correlated with factors known adversely to affect survival after mastectomy, namely histological grade III and oestrogen-receptor negative status. Advanced T4 tumours and medullary-type carcinomas also contained high polyamine levels. Tumour size and node status did not affect polyamine levels in primary tumours. Tumours that recurred within 2 years of mastectomy had significantly higher levels of spermidine and spermine than those that did not. Breast cancer polyamine levels are a biological marker of tumour aggressiveness and can be used as a prognostic indicator of early tumour recurrence that is independent of node status.

Adult↗
PubMed1984

Polyamines in colorectal cancer.

Polyamine levels (putrescine, spermidine and spermine) in colorectal cancers (n = 25) were measured in order to assess their importance as markers of cellular proliferation. Colonic mucosa from healthy resection margins of patients with diverticular disease (n = 5) was used as control material. Polyamine levels (expressed as nanomoles per 100 mg tumour) in cancers ranged from 0.8 to 7.9 for putrescine (mean: 2.3 +/- 0.7), from 6.5 to 22.8 for spermidine (mean: 13.9 +/- 0.9) and from 13.0 to 37.5 for spermine (mean: 22.1 +/- 1.3). Mean spermidine and spermine content of cancers was more than three times mean spermidine (3.92 +/- 0.8), and more than four times mean spermine (5.0 +/- 1.2), content of normal colonic mucosa (P less than 0.01). Polyamine content of colorectal cancers was independent of tumour site, Dukes' stage, histological grade and the presence of palpable liver metastases at laparotomy. Because colorectal cancers contain such high levels of spermidine and spermine, polyamines may play an essential role in the regulation of their growth.

Aged↗
PubMed1984

Swine management errors.

Management errors can affect all aspects of swine herd health. Inadequate feed, malfunctioning equipment, poor ventilation, low or high environmental temperature, inappropriate groupings, and rough handling all contribute to low productivity. Management errors can contribute to scours and pneumonia outbreaks, reproductive failure, accidental deaths and poor feed conversion.

Animal Husbandry↗
PubMed1982

Services for pregnant teenagers in the large cities of the United States, 1970-1980.

This article reports the findings of the third national survey of services for and needs of pregnant teenagers and their infants in the large cities of the United States, done in 1979-1980. Only five cities have developed a new program since 1976, and major unmet needs continue to exist. The survey also provides baseline data on the status of health, social, and educational care for this target population. With the substantial decrease in the various sources of federal funds due to current budgetary reduction, continued monitoring is required to determine the effects on services for pregnant teenagers and their infants, as well as on the incidence of teenage pregnancy.

Abortion, Legal↗
PubMed1982

A comparison of polyamine metabolism in normal and transformed baby-hamster-kidney cells.

Transformed baby-hamster-kidney cells contain higher intracellular concentrations of polyamines than do normal cells. The difference is greater in high-density confluent cultures. Transformed cells incorporate exogenous putrescine into the cells at a faster rate than do normal cells. They also show a marked increase in the rate of spermine biosynthesis compared with normal cells. Transformed cells grown to high cell densities released about 10% of their polyamines into the culture medium in a non-specific manner. In contrast, normal cells, under the same culture conditions, release up to 50% of their intracellular polyamines into the medium almost exclusively as free or conjugated spermidine. The elevated levels of polyamines found in transformed cells therefore appear to be the result of altered transport of polyamines across the cell membrane and of increased rates of biosynthesis.

Animals↗
PubMed1982

Adolescent health in Alameda County.

A cross-sectional study of 194 adolescents in Alameda County, California, was performed to investigate health care behavior, personal adjustment, substance abuse, and medical and dental morbidity. A multivariate analysis of this sample using age, sex, ethnic group, and family type as independent variables was carried out. Females were less likely than males to have a regular place for medical care, and youths belonging to single parent families were less likely than those from intact families. Older adolescents, blacks and Hispanics used hospitals and clinics more frequently, while whites used private physicians more frequently than did other ethnic groups. Also blacks and Hispanics were less likely to have received recent dental care than whites. Levels of substance abuse were comparable to national levels, and increased significantly with age. Though overall medical morbidity was low, the study confirms previous findings of significant levels of dental decay particularly in black youth. A significant relation exists between less dental care and dental decay, though no such relation exists between medical care and medical morbidity. The study has potential implications for better preventive approaches to adolescent health care.

Adolescent↗
PubMed1982

Comparison of infant mortality in the United States and Sweden.

This study summarizes differences between Sweden and the United States regarding certain aspects of infant mortality. Sweden has the lowest infant mortality rate (IMR) and the United States is number 16. Both the neonatal and postneonatal mortality rates of Sweden are considerably lower. Since 1960, the neonatal mortality rate of Sweden was reduced by a greater percentage. The incidence of low birth weight in Sweden is considerably lower. In the United States, no state has an IMR as low as that of Sweden. Nonwhite babies, babies born out of wedlock, and those of teenage or "old" mothers have a higher IMR. The article describes in some detail the organization and network of services in Sweden that may be playing an important role in Sweden's low IMR.

Asphyxia Neonatorum↗
PubMed1982

Prenatal care and child health.

Child health begins long before the birth of the baby. At they very least, child health care begins with prenatal care, but preferably begins with the mother's prior health as a child and adolescent herself. The longitudinal intergenerational viewpoint is necessary in order to improve the health status of infants and children. Many societal and demographic factors influence child health and child health care. The education, socioeconomic, and employment status of the parents are important, as well as their age, marital status, and family health history. Their geographic residence (urban, rural), health knowledge, and the degree of development of medical and health care resources play an important role in the availability and utilization of health care, both for themselves and their children.

Attitude to Health↗
PubMed1981

Uptake and excretion of polyamines from baby hamster kidney cells (BHK-21/C13). The effect of serum on confluent cell cultures.

In confluent cultures of BHK-21/C13 cells there was little uptake of exogenous polyamines and only a low level of polyamine biosynthesis. These cultures continuously excreted polyamines into the extracellular medium. Spermidine, in both the free and bound form, was the predominant excretion product, whereas the major intracellular polyamine was spermine implying that excretion of polyamines was specific. Reinitiation of growth by the addition of fresh serum immediately increased the uptake of exogenous putrescine, increased the biosynthesis of polyamines and decreased the excretion of polyamines. Thus, polyamine transport into and out of the cell appears to be regulated by the growth status of that cell.

Animals↗
PubMed1981

The effect of polyamines of DNA synthesis in vitro.

Nuclei and DNA-dependent polymerases alpha and beta were isolated from exponentially growing baby hamster kidney 21/C13 cells and were used to study the effects of polyamines on DNA synthesis in vitro. The greatest effect was observed with spermine, which inhibited both nuclear DNA synthesis and the activity of partially purified DNA polymerase alpha. At 2.5 mM spermine, the maximum concentration used, we observed 58 and 68% inhibition of DNA synthesis by isolated nuclei and polymerase alpha, respectively. In contrast, spermidine caused a small increase in nuclear DNA synthesis at low concentrations (0.5 mM) and inhibition at higher concentrations (2.5 mM); it had no significant effect on the partially purified polymerase alpha. Neither polyamine had any appreciable effect on polymerase beta activity. The results are consistent with the concept that DNA polymerase alpha catalyses the observed DNA synthesis in isolated nuclei.

Animals↗
PubMed1981

Excretion of polyamines from baby hamster kidney cells (BHK-21/C13: effect of infection with Herpes Simplex Virus Type 1.

Confluent monolayers of BHK-21/C13 cells excreted increasing amounts of polyamines into the extracellular medium with time. Excretion was specificity of spermidine and was not the result of cell death or lysis. Herpes simplex virus type 1 (HSV-1) completely prevented excretion of polyamines from 2 h after infection of the cells. The virus specificity inhibited the release of free spermidine but not of conjugated polyamines.

Animals↗
PubMed1981

Medical and health care in state residential institutions for children and youths. A report of survey findings in five hospitals. The Committee on Children with Handicaps, Northern California Chapter, American Academy of Pediatrics.

A survey of five Northern California state residential institutions showed considerable variation in the type and amount of medical services provided for children and youths. There was no standard policy for relationships with regional centers, use of community hospitals, vision and hearing assessments, speech and rehabilitation therapy, or genetic and maternal health services. Some hospitals had no staff members certified to carry out cardiopulmonary resuscitation (CPR). Not all staff physicians and other health professionals working in state hospitals had specific training in the areas of genetics, seizure control and physical rehabilitation medicine. While all five state hospitals are involved in training personnel, there is a need to develop a statewide plan for the better sharing of knowledge and expertise of the state hospital personnel in the training of pediatricians and others.

Adolescent↗