Breast-feeding in Perth: recent trends

Analysis of breast-feeding data from the 1989-90 National Health Survey suggests that since peaking in the mid-1980s, breast-feeding initiation and duration rates have declined in Australia. Data from a recent prospective study of infant feeding practices among 556 women indicates that in Perth, at least, breast-feeding rates have remained relatively stable for the past nine years.

Rare event selection of fetal nucleated erythrocytes in maternal blood by flow cytometry

A noninvasive method of prenatal genetic diagnosis requires fetal cell selection from the maternal circulation that allows efficient recovery for analysis by fluorescence in situ hybridization (FISH). We have solved several problems that negatively affect the isolation and FISH analysis of fetal nucleated red blood cells (nRBCs) in the maternal circulation. The use of glycophorin A (Gly A) antibodies (Abs) for selection is problematic because all five monoclonal antibodies (mAbs) tested caused agglutination of non-nRBCs, thereby changing both light scatter and fluorescence properties of cells by flow cytometry. Because the number of non-nRBCs is variable after Ficoll separation, isolation of nRBCs could be compromised severely by agglutination of nucleated cells with nonnucleated cells, causing them to shift light scatter and fluorescence properties. Several methods for the removal of unwanted maternal white blood cells with CD45 mAbs were also evaluated. Magnetic bead depletion was found to interfere with FISH detection because of residual bead debris after sorting. By contrast, removal of CD45+ cells by a panning technique eliminated this problem. Positive selection methods based on CD71, CD45, and LDS-751 staining and detection of fetal cells by gamma globin expression were also analyzed. Fetal cells were detected by FISH in 11 of 19 (CD71 selection) and in 13 of 15 (gamma selection) random pregnancies. These data support the possibility of a noninvasive method for isolation and analysis of fetal cells for prenatal diagnosis.

Neural networks in ventilation-perfusion imaging

PURPOSE

To optimize the performance of artificial neural networks in the prediction of pulmonary embolism from ventilation-perfusion (V-P) scans.

MATERIALS AND METHODS

Neural networks were constructed with a set of V-P scan criteria that included sharpness and completeness of perfusion defects and involved quantification of abnormalities by using a continuous numeric scale. Several network parameters were systematically varied. Networks were trained with 150 cases and tested with 30 different cases. Findings were compared with those of pulmonary angiography.

RESULTS

Networks capable of performing as well as experienced nuclear medicine physicians could be constructed with few V-P scan features. A brief training period was optimal (50-100 iterations). Further training diminished network performance.

CONCLUSION

Effective neural networks can be constructed by using a limited number of unconventional V-P scan features. Several parameters can be adjusted to optimize performance.

Calcium modulation of adrenocorticotropin levels in women--a clinical research center study

In vitro calcium modulation of anterior pituitary hormone secretion has been well described. In addition, several investigations performed in human subjects have documented modulation of the circulating levels of pituitary hormones by supraphysiological calcium concentrations. Recent data from our laboratory document the existence of an extracellular calcium-sensing receptor that is thought to mediate the effects of variations in extracellular calcium on the secretion of PTH and calcitonin. We have also demonstrated the presence of this receptor in pituitary-derived, ACTH-secreting AtT-20 cells as well as in the anterior pituitary of rats and mice. In the present study we investigated the effect on anterior pituitary hormone levels of variations in serum calcium within the physiological range. We serially measured serum levels of ionized calcium (Cai), ACTH, cortisol, TSH, and PRL during 90-min iv infusions (on separate days) of calcium, citrate, and dextrose in 10 healthy women with a mean age of 55 +/- 5 yr. During the calcium infusion, the serum Cai level increased significantly from 4.32 +/- 0.10 mg/dL at baseline to 4.86 +/- 0.08 mg/dL at completion (P = 0.002), and this change was accompanied by a significant increment in the serum ACTH level from 9.87 +/- 1.32 to 16.31 +/- 2.84 pg/mL (P = 0.0008). There was no change in the serum ACTH level during the citrate infusion despite significant decrements in serum Cai, nor were there changes in either Cai or ACTH during the dextrose infusion. Finally, changes in Cai did not alter TSH or PRL levels. In summary, our dynamic studies are the first to demonstrate an increase in baseline serum ACTH levels in response to physiological increments in Cai (i.e. increments within the normal range). This effect was specific for increments and not decrements in serum Cai and was selective for ACTH, as TSH and PRL levels did not change with any of the infusions.

Folate status of gastrointestinal epithelial cells is not predicted by serum and red cell folate values in replete subjects

Localised folate deficiency has been implicated in colonic carcinogenesis and supplementation has been proposed for certain populations at risk. However, identifying those groups that may benefit is difficult as the relation between blood folate and gut epithelial cell values is unknown. The aim of this study was to define this relation. Epithelial cells mean (SEM) (sigmoid: 5.35 (0.56) x 10(6) cells, caecum: 6.6 (0.71) x 10(6) cells, duodenum: 4.0 (0.62) x 10(6) cells) were isolated from four endoscopic mucosal biopsy specimens (n = 25) by incubation with dithiothreitol (three hours) and EDTA (one hour). Lamina propria contamination was < 1%, with < 6% intraepithelial lymphocytes. Folate assay of isolates showed sigmoid colon folate content to be 20.1 (1.8) pg/micrograms DNA (10.2-46.6). In the same subject, caecal folate concentrations were lower (p < 0.01, n = 11) than sigmoid values, whereas duodenal isolates mirrored those of the sigmoid (19.4 (2.9) v 20.5 (3.2), n = 5). Sigmoid folate values were consistent over one to three weeks (n = 3). In a single case with blood folate deficiency, colonic values were normal. Serum folate and red cell folate correlated poorly with sigmoid epithelial cell folate content (r = 0.41, p = 0.063 and r = 0.17, p > 0.05 respectively). This study reports a modified ion-chelation isolation method for colonic biopsy specimens that yields large numbers of viable epithelial cells. Cell folate values remain constant with time though vary with intestinal region. The inability of serum or red cell folate values to predict those of the sigmoid epithelium suggests that they cannot identify those patients that might benefit from folate supplements.

Neural networks in ventilation-perfusion imaging. Part II. Effects of interpretive variability

PURPOSE

To evaluate the usefulness of a neural network developed by one physician and used by another.

MATERIALS AND METHODS

Intra- and interobserver variability were analyzed in image categorization of ventilation-perfusion (V-P) scans. This information was used to estimate network performance when it was used by a physician who did not train the network.

RESULTS

Network training was optimized by using input parameters that demonstrated both individually high correlations with pulmonary embolism and good reproducibility in multiple interpretations.

CONCLUSION

Potential variability exists in the performance of a network when it is supplied with input data by different physicians. The clinical usefulness of a network depends heavily on the similarity of interpretive styles between the network trainer and the user.

Preoperative endovascular embolization of craniospinal hemangioblastomas

PURPOSE

To determine whether hemangioblastomas, highly vascular tumors requiring surgery that is potentially complicated by excessive bleeding, can be embolized safely by using interventional techniques that furnish a more avascular surgical field.

METHODS

Nine hemangioblastomas involving either the cerebellum or the spinal cord were embolized preoperatively. In each case the feeding artery was selectively catheterized with a microcatheter and the hypervascular tumor nidus was devascularized with polyvinyl alcohol particles.

RESULTS

Two patients who had undergone recent attempts as surgical resection at another institution had repeat surgery after endovascular embolization rendered the tumor nidus avascular. At surgery, the tumor was completely removed in one case and markedly debulked in the other. In all nine cases, blood loss after embolization was reported to be less than expected by experienced surgeons. In addition, manipulation and removal of the tumor was reported to be subjectively easier in these embolized tumors. The embolization procedure caused no permanent complications; however, one patient with a posterior fossa hemangioblastoma and hydrocephalus worsened clinically within 12 hours of embolization. This event was thought to be caused by obstructive hydrocephalus resulting from tumor swelling. Emergency craniotomy, ventricular decompression, and surgical resection of the tumor produced complete resolution of the signs and symptoms.

CONCLUSIONS

Our results indicate that preoperative embolization of hemangioblastomas is a safe procedure that is useful in aiding surgical resection of these highly vascular tumors.

Cognitive therapy of affective disorders: a review

Cognitive therapy is the most extensively researched psychological treatment for nonpsychotic, unipolar outpatient depressive disorders. Careful analysis of published outcome studies suggests that its benefits in acute depression whilst very promising have not been proven, mainly because of inadequate methodology in treatment trials. However, cognitive therapy does appear to reduce the risk of depressive relapse and may have a more durable effect than pharmacotherapy alone. This paper explores short- and long-term outcome data and reviews clinical factors, including therapists competency, that may predict outcome. The development of cognitive approaches to individuals with bipolar disorders is examined. Future areas of research, particularly the need to detect which individuals may differentially respond to cognitive therapy, are identified.

Characteristics of homeless women living in London hostels

To increase knowledge of homeless women in Britain, 49 female residents of two hostels were interviewed. The median age was 31 years, two-thirds had never married, and nearly three-fourths were born in England. When the sample was divided into younger and older groups by median age, significantly more black women were in the younger group. Older women had more serious mental illnesses and more problems with addiction. Median length of stay in the hostels was much shorter than the median time since becoming homeless, supporting other findings that women form a "hidden-homeless" subgroup. The findings suggest that younger and older homeless women may have different health and social service needs.

Inducible nitric oxide synthase and vascular reactivity in rat thoracic aorta: effect of aminoguanidine

We tested the hypothesis that selective inhibition of the inducible form of nitric oxide (NO) synthase with aminoguanidine would prevent the loss of vascular contractility after exposure to endotoxin [lipopolysaccharide (LPS)]. Aortic rings were dissected from Sprague-Dawley rats, suspended in organ baths containing Krebs solution, and tested for vascular reactivity. Vessels incubated with LPS (1 microgram/ml) for 5 h exhibited a significant decrease in the maximal contractile response to phenylephrine. Aminoguanidine (100 microM) restored the maximal contractile response of LPS-treated vessels to the level of the control vessels. Aminoguanidine was approximately 250-fold less potent than NG-nitro-L-arginine methyl ester in inhibiting the constitutive NO synthase in vascular tissue as determined by its ability to further increase tone of submaximally contracted aortic rings. NO synthase activity was determined in vascular tissue incubated with and without LPS. Vessels incubated with LPS exhibited a marked increase in the levels of inducible NO synthase activity compared with control vessels. This increase was restored to control levels when tissue homogenates were incubated with aminoguanidine. We conclude that aminoguanidine is a selective concentration-dependent inhibitor of the inducible form of NO synthase and may be a useful probe to evaluate the role of inducible NO synthase in the abnormal vascular contractility characteristic of endotoxemia and sepsis.

Effects of blood lead levels on cognitive function of older women

Elevated blood lead concentrations are known to have detrimental effects on neuropsychological function in both children and occupational cohorts of men and women. Although it is generally accepted that lead exposure at low levels is more dangerous for infants and children than for adults, the issue of the lowest level of exposure at which lead causes deleterious health effects in adults is yet to be solved. There is no available data on the role of lead exposure in cognitive dysfunction in nonoccupational cohorts of older persons. In the current study, we examined the cross-sectional relationship between blood lead levels and a variety of measures of neuropsychological function in a large cohort of elderly women recruited at both urban and rural sites. This study of elderly women demonstrates that blood lead levels as low as 8 micrograms/dl were significantly associated with poorer cognitive function as measured by certain neuropsychological tests. Even a slight decrement in cognition would have a large public health impact due to the large number of elderly at risk.

Gene transfer of cytidine deaminase apoBEC-1 lowers lipoprotein(a) in transgenic mice and induces apolipoprotein B editing in rabbits

Apolipoprotein (apo) B100 is an essential component of low-density lipoproteins (LDL) and lipoprotein(a) [Lp(a)]. In mammals, apoB can be edited post-transcriptionally to encode a truncated form of apoB (apoB48) that is unable to form either of these atherogenic lipoproteins. To study the effect of increasing hepatic apoB editing activity on formation of Lp(a), a recombinant adenovirus encoding rat apoBEC-1, the cytidine deaminase component of the apoB mRNA editing complex, was administered to human apoB/apo(a) transgenic mice. This resulted in expression of apoBEC-1 in hepatocytes of these mice, increased hepatic editing of human apoB mRNA, and decreased plasma levels of human apoB100 and Lp(a). The apoBEC-1 recombinant adenovirus was also administered to rabbits, an animal which, like humans, naturally lacks hepatic apoB editing. Expression of the exogenous apoBEC-1 in rabbit liver resulted in editing of up to 10% of apoB mRNA. Hepatic apoB editing was associated with lower LDL levels in these rabbits relative to those treated with a control adenovirus. However, LDL levels were elevated significantly in both animals as a result of adenovirus injection. These studies demonstrate that introduction of the cytidine deaminase apoBEC-1 is sufficient to induce hepatic apoB editing in an animal lacking this activity, and that induction of editing could serve as a novel approach for lowering plasma concentrations of the atherogenic lipoproteins Lp(a) and LDL.

Polytolypin, a new antifungal triterpenoid from the coprophilous fungus Polytolypa hystricis

Polytolypin [1], a new pentacyclic triterpenoid exhibiting antifungal and antibiotic activity, has been isolated from cultures of Polytolypa hystricis (JS189), a fungal colonist of porcupine dung. Two known compounds [2 and 3] were also isolated. Polytolypin was obtained by chromatographic fractionation of the EtOAc extract of P. hystricis liquid cultures, and the structure was assigned on the basis of 2D nmr and hrms data.

Detection of low-grade mosaicism in fetal cells isolated from maternal blood

Recovering and analysing fetal erythrocytes from maternal blood is being pursued for non-invasive prenatal genetic diagnosis. We report the observation of 46,XY/47,XXY mosaicism in fetal cells from a woman whose first-trimester chorionic villus sampling (CVS) initially showed only 46,XY. Only after exhaustive (500 cells) analysis were four XXY cells found in cultured villi.

Psychotherapy for bipolar disorder

BACKGROUND

Psychosocial factors may contribute 25-30% to the outcome variance in bipolar disorders. Sufferers have identified benefits from psychotherapy, but biological models and treatments dominate the research agenda. The author reviews research on psychosocial issues and interventions in this disorder.

METHOD

Research on adjustment to the disorder, interpersonal stressors and obstacles to treatment compliance were located by computerised searches and the author's knowledge of the literature. All published outcome studies of psychosocial interventions in bipolar disorder are reviewed.

RESULTS

There is an inadequate database on psychosocial factors associated with onset and maintenance of bipolar disorder. While the outcome studies available are methodologically inadequate, the accumulated evidence suggests that psychosocial interventions may have significant benefits for bipolar sufferers and their families.

CONCLUSIONS

Given the significant associated morbidity and mortality, there is a clear need for more systematic clinical management that addresses psychosocial as well as biological aspects of bipolar disorder. The author identifies appropriate research strategies to improve knowledge of effective psychosocial interventions.

Prediction of cervical lymph node metastasis in squamous cell carcinoma of the tongue/floor of mouth

BACKGROUND

Cervical lymph node metastasis has a major influence on survival in oral cancer. However, the factors influencing its occurrence are uncertain. Our aim was to improve the prognostic efficiency of the histologic assessment of the primary tumor in predicting metastasis in an individual patient.

METHODS

The relationship between selected clinical and histologic features of the primary tumor of tongue/floor of the mouth and the actual metastatic status was investigated in 45 patients. Invasive cell grading was supplemented by histologic measurements of tumor size and assessments of vascular and perineural invasion.

RESULTS

Ten histologic features showed significant differences in relation to metastasis. A logistic regression model with two predictor variables (total histologic malignancy score and vascular invasion) classified correctly 39 (87%) of the 45 cases.

CONCLUSIONS

Histologic assessment of tumor size and malignancy grade are useful in predicting metastasis. Vascular and perineural invasion are important predictors and should be included in multifactorial malignancy grading schemes. Application of the prognostic index to the biopsy specimen would aid in treatment planning.

Effect of intracoronary saline infusion on dissection during excimer laser coronary angioplasty: a randomized trial. The Percutaneous Excimer Laser Coronary Angioplasty (PELCA) Investigators

OBJECTIVES

We sought to evaluate whether intracoronary saline infusion during excimer laser coronary angioplasty decreases the incidence of significant laser-induced coronary artery dissections.

BACKGROUND

Despite procedural success rates > 90%, coronary artery dissections occur in 17% to 27% of excimer laser coronary angioplasty procedures. Excimer laser irradiation of blood results in vapor bubble formation and acoustomechanical trauma to the vessel wall. Saline infusion into a coronary artery may minimize blood irradiation and consequent arterial wall damage.

METHODS

In this prospective, randomized, controlled study, consecutive patients undergoing excimer laser coronary angioplasty were randomly assigned to conventional laser irradiation in a blood medium or to laser irradiation with blood displacement by intracoronary saline infusion. In the patients randomized to intracoronary saline infusion, prewarmed normal saline was injected through the coronary artery guide catheter at a rate of 1 to 2 ml/s using a power injector. The incidence and severity of dissection after excimer laser ablation were evaluated in a core laboratory by angiographers with no knowledge of treatment assignment. The severity of coronary artery dissection was rated on an ordinal scale of 1 to 5. Dissections of grade 2 or higher were considered significant.

RESULTS

The mean (+/- SE) dissection grade after laser angioplasty in patients treated with intracoronary saline infusion was 0.43 +/- 0.13 compared with 0.91 +/- 0.26 in patients undergoing laser angioplasty in a blood medium. The incidence of significant dissection was 7% in saline-treated patients compared with 24% in conventionally treated patients (p < 0.05). No significant complications were associated with saline infusion.

CONCLUSIONS

Intracoronary saline infusion should be incorporated into all excimer laser coronary angioplasty procedures.

Desmoplastic trichoepithelioma of the upper lip. A case report with histochemical features and observations on its histogenesis

A case of desmoplastic trichoepithelioma of the upper lip investigated by histochemistry and immunocytochemistry is presented. There was histologic suggestion of cytoplasmic vacuolation that does not appear to have been previously described. Histochemical examination indicated the presence of glycogen within tumor cells and a reparative-type stroma. Immunocytochemical examination revealed variable reactivity for high molecular weight cytokeratin and colonization by Langerhans' cells. The observations suggest a follicular and sudoriferous differentiation for desmoplastic trichoepithelioma and hence an origin from a pluripotential adnexal keratinocyte.