The Fundamental Nuclear Interaction: Important developments of the past decade on mesons and the theory of nuclear forces are described.

GOPEB based upon known mesons have been found which realistically describe a massive accumulation of the experimental nuclear data up to 400 Mev. The N-N potential according to these models consists primarily of weak residual central terms surviving the cancellation of large repulsive and attractive vector and scalar static components; relativistic interactions arising from the exchange of pseudoscalar, vector, and scalar mesons and dipole type terms arising from the rho meson. The major dynamic terms are direct analogs of magnetic interactions illustrated in Fig. 1. Allowance must be made for the effective dependence of the coupling constants upon spin and isospin states. The nucleons are distributed sources which give rise to nonsingular generalized Yukawa functions in N-N potentials.

Comparing 3T and 1.5T MRI for mapping hippocampal atrophy in the Alzheimer's Disease Neuroimaging Initiative.

BACKGROUND AND PURPOSE: Prior MR imaging studies, primarily at 1.5T, established hippocampal atrophy as a biomarker for Alzheimer disease. 3T MR imaging offers a higher contrast and signal-to-noise ratio, yet distortions and intensity uniformity are harder to control. We applied our automated hippocampal segmentation technique to 1.5T and 3T MR imaging data, to determine whether hippocampal atrophy detection was enhanced at 3T. MATERIALS AND METHODS: We analyzed baseline MR imaging data from 166 subjects from the Alzheimer's Disease Neuroimaging Initiative-1 (37 with Alzheimer disease, 76 with mild cognitive impairment, and 53 healthy controls) scanned at 1.5T and 3T. Using multiple linear regression, we analyzed the effect of clinical diagnosis on hippocampal radial distance, while adjusting for sex. 3D statistical maps were adjusted for multiple comparisons by using permutation-based statistics at a threshold of P < .01. RESULTS: Bilaterally significant radial distance differences in the areas corresponding to the cornu ammonis 1, cornu ammonis 2, and subiculum were detected for Alzheimer disease versus healthy controls and mild cognitive impairment versus healthy controls at 1.5T and more profoundly at 3T. Comparison of Alzheimer disease with mild cognitive impairment did not reveal significant differences at either field strength. Subjects who converted from mild cognitive impairment to Alzheimer disease within 3 years of the baseline scan versus nonconverters showed significant differences in the area corresponding to cornu ammonis 1 of the right hippocampus at 3T but not at 1.5T. CONCLUSIONS: While hippocampal atrophy patterns in diagnostic comparisons were similar at 1.5T and 3T, 3T showed a superior signal-to-noise ratio and detected atrophy with greater effect size compared with 1.5T.

Regulation of leptin and leptin receptor in baboon pregnancy: effects of advancing gestation and fetectomy.

Leptin, a product of both adipose tissue and the placental syncytiotrophoblast and a potential regulator of primate conceptus development, increases in the maternal circulation with advancing gestation. This increase may be potentiated by estrogens, which also increase as pregnancy progresses. In the present study adipose tissue was collected from nonpregnant (n = 5) baboons (Papio sp) and in baboons during early (days 58-62; n = 5), mid (days 98--102; n = 5), and late (days 158-162; n = 5) pregnancy (term, approximately 184 days). Additionally, placental estrogen production was inhibited in pregnant baboons by the removal of fetal androgen precursors via fetectomy at midgestation, with tissues collected from fetectomized (n = 5) baboons approximately 60 days later. Leptin, estrogens, and androgens were quantitated in maternal serum by RIA. Leptin (LEP) and leptin receptor (LEP-R(L) and LEP-R(S) isoforms) messenger ribonucleic acids (mRNAs) were quantitated by competitive RT-PCR, and leptin concentrations were determined by RIA in maternal adipose and placental villous tissues. Although LEP transcript abundance in adipose tissues was unchanged as a result of pregnancy or with advancing gestation, the leptin protein level was higher (P < 0.02) in pregnant baboons in early gestation than in nonpregnant baboons and increased with gestational age (P < 0.04). Maternal serum estrogens (estradiol and estrone) and androgens (androstenedione and testosterone) were lower (P < 0.0001) in fetectomized baboons than in intact controls. Serum leptin concentrations were unchanged by fetectomy, but the abundance of LEP mRNA transcripts was lower (P < 0.003) in sc adipose tissue and 3-fold higher (P < 0.05) in placenta. Similarly, the leptin protein level declined (P < 0.05) in sc adipose tissue and increased (P < 0.05) in placenta in fetectomized baboons. Although LEP-R(L) mRNA levels were unchanged after fetectomy, placental LEP-R(S) transcript abundance was lower (P < 0.04) than in pregnancy-intact baboons matched for gestational age. Results suggest that both adipose tissue and the placenta may contribute to maternal hyperleptinemia during normal primate pregnancy. Furthermore, the withdrawal of placental steroids results in the enhanced placental leptin production that is commensurate with a decline in production by sc adipose tissue.

Serum leptin concentrations and expression of leptin transcripts in placental trophoblast with advancing baboon pregnancy.

Leptin is a polypeptide hormone originally thought to be produced exclusively by adipocytes. Recently, however, both leptin messenger ribonucleic acid (mRNA) and leptin protein were identified in human placental trophoblast cells, suggesting a potential role in primate pregnancy. In the present study, venous blood samples were collected at 5-day intervals during gestation from baboons (Papio sp), an established model for the study of human pregnancy, as well as from nonpregnant baboons, and leptin concentrations were determined by RIA. Additionally, placental villous tissue was collected upon cesarean delivery at early (days 60-62; n = 5), mid (days 98-102; n = 5), and late (days 159-167; n = 5) gestation (term = approximately 184 days), and leptin mRNA was quantitated by competitive RT-PCR. Finally, in situ hybridization was employed to localize transcripts to specific placental cell types. Results determined that maternal leptin levels (mean +/- SEM), which were dramatically greater (P<0.01) than those in nonpregnant cycling baboons (1.4+/-0.1 ng/mL), increased (P<0.005) with gestational age from 63.6+/-10.4 ng/mL on day 60 of gestation to 157.8+/-16.1 near term. Levels declined to those found in cycling baboons by 15 days postdelivery. In contrast to maternal leptin concentrations, placental leptin mRNA decreased (P<0.02) with advancing pregnancy, as transcript abundance declined approximately 8-fold from early to late gestation. Maternal peripheral leptin concentrations were positively correlated (r = 0.66; P<0.001) whereas placental leptin mRNA levels were negatively correlated (r = -0.64; P<0.01) with gestational age. Expression of leptin mRNA transcripts, as evidenced by RT-PCR in villous tissue, was localized principally within syncytiotrophoblast by in situ hybridization. In summary, changes in maternal peripheral leptin concentrations and placental leptin mRNA abundance that occur commensurate with advancing gestational age may imply evolving roles for the polypeptide with advancing primate pregnancy. In this capacity, localization of leptin transcripts within the baboon syncytiotrophoblast suggests the potential for autocrine or paracrine interactions within this endocrinologically active tissue. Finally, both the similarities in leptin ontogeny in baboon and human pregnancy and the singular enhancement of maternal leptin levels inherent throughout baboon gestation emphasize the potential of this nonhuman primate model for the study of leptin action in the maternal-fetoplacental unit.

Correlation of immunohistochemical molecular staging of bladder biopsies and radical cystectomy specimens.

PURPOSE: To determine the relationship of p53, retinoblastoma (RB), and p16 expression between precystectomy transurethral resection bladder (TURB) biopsy and matched cystectomy specimens; and to determine the value of p53 immunoreactivity for predicting progression and survival in patients undergoing radical cystectomy. METHODS AND MATERIALS: We performed p53 immunohistochemical staining on matched archival TURB and cystectomy specimens taken from 40 patients. Twenty-seven and 26 of these patients were also evaluated for RB and p16 expression, respectively. RESULTS: Twenty-eight (70%) of the TURB and 22 (55%) of the cystectomy specimens stained positive for p53. RB and p16 protein expression were altered in 19 (70%) and 19 (73%) of the TURB specimens, respectively, and 19 (70%) and 19 (73%) of the cystectomy specimens, respectively. There was a strong correlation between p53, RB, and p16 expression and TURB and cystectomy specimens (all p < 0.001). In preoperative and postoperative multivariate analyses, biopsy p53 and cystectomy p53 were independently associated with disease progression (p = 0.049 and p = 0.034, respectively) and bladder cancer-related death (p = 0.044 and p = 0.037, respectively). CONCLUSION: p53, RB, and p16 expression patterns on TURB specimens correlate with cystectomy specimens. p53 immunoreactivity is an independent predictor of disease progression and bladder cancer survival. These data support the potential of prognostic staging using immunohistochemical analysis on bladder biopsy specimens prior to neoadjuvant or definitive therapy.

Effects of estrogen on leptin gene promoter activation in MCF-7 breast cancer and JEG-3 choriocarcinoma cells: selective regulation via estrogen receptors alpha and beta.

Leptin is a potential regulator of conceptus development. We have previously suggested that in primate pregnancy, leptin biosynthesis is regulated by estrogen in a tissue-specific manner. Therefore, the objective of the current study was to determine the mechanism of estrogen action on LEP promoter activation in divergent cell types. The effects of estrogen were investigated in estrogen receptor (ER)-positive MCF-7 breast cancer cells and in ER-negative JEG-3 choriocarcinoma cells. Cells were transfected with a leptin-luciferase or an estrogen responsive element (ERE)-luciferase reporter construct, in conjunction with ERalpha, ERbeta, or empty vector expression plasmids. Cells were treated with estradiol and/or the specific estrogen antagonists, ICI-182,780 or 4-hydroxytamoxifen. In MCF-7 cells, estradiol stimulated (P<0.05) ERE-luciferase activity and was inhibited by ICI-182,780, but did not stimulate leptin-luciferase activity. However, leptin-luciferase was stimulated by estradiol (P<0.05) and inhibited by antiestrogens in JEG-3 cells that were co-transfected with ERalpha. Both antiestrogens stimulated leptin-luciferase activity (P<0.05) in JEG-3 cells co-transfected with ERbeta. Results suggested that LEP promoter activation may depend upon co-activators present in leptin-producing cells and may be inhibited by repressors present in non-leptin producing cells. Divergent effects of estrogen may be owed to differences in the type of ER (alpha or beta) expressed in target tissues.

Visual versus mechanised leucocyte differential counts: costing and evaluation of traditional and Hemalog D methods.

Visual differential counts were examined for efficiency, cost effectiveness, and staff acceptability within our laboratory. A comparison with the Hemalog D system was attempted. The advantages and disadvantages of each system are enumerated and discussed in the context of a large general hospital.

Regional quality control.

Methods of quality control of some major haematological techniques are described. These methods have been applied in haematology laboratories serving a population of 2 million using existing facilities for preparation and transport of the necessary materials.

A report on experience with an automatic blood counting machine.

Experience after 18 months' work with the SMA-4 system of multiple analysis for routine haematology is described, as well as the modifications to the machine which have been made for smoother operation.

Leptospirosis in Trinidad and Grenada, with special reference to the mongoose.

In Trinidad, six Leptospira isolates were made from 957 febrile patients between 1968 amd 1972. In addition, CF antibodies were detected in 6-6% of febrile patients and human survey sera collected during this period. In 1972 alone, 10-4% (38/363) of sera examined had CF titres consistent with positive exposure to the disease. Grenada does not report leptospirosis, but the disease is common in mongooses in both Trinidad and Grenada. Serogroups Icterohaemorrhagiae, Pomona and Canicola are present in Grenada with 35-2% of mongooses examined being seropositive. Five Canicola strains of Leptospira were isolated from mongooses in Trinidad and serological studies showed that this was the most common serogroup from mongooses on the island. A total of 31 strains recorded from at least seven different serogroups and eight named serotypes have been isolated from humans, rats and mongooses in Trinidad. Human leptospirosis is probably more common in the Caribbean than the medical records indicate.

The benzodiazepine receptor partial agonists, bretazenil (Ro 16-6028) and Ro 17-1812, affect saccharin preference and quinine aversion in the rat.

A previous experiment had shown that the benzodiazepine receptor (BZR) agonist, clonazepam, selectively increased the consumption of a 0.05% sodium saccharin solution without change in water intake, in a two-choice preference test. The first aim of this study was to investigate the effects of two benzodiazepine receptor partial agonists, bretazenil (Ro 16-6028) and Ro 17-1812, in the same test. The results showed that both drugs produced effects similar to those observed earlier with clonazepam. The second aim was to investigate the effects of the two compounds on consumption of a 0.005% quinine solution in a two-choice test. Both drugs increased the consumption of the quinine solution without alteration in water intake. In addition, in separate single-choice acceptance tests, both drugs significantly increased the consumption of a familiar, highly palatable 3% sucrose solution. These data are considered in relation to alternative hypotheses for BZR-mediated effects in choice tests.

Rectus abdominis sheath hematoma as a complication of tetanus. Diagnosis by computed tomography scanning.

Tetanus infection as the cause of rectus abdominis sheath hematoma has not been previously reported in the literature. Such a patient, diagnosed by computed tomography scanning, is presented. The place of computed tomography examination in diagnosis of rectus sheath hematomas and abdominal wall pathology is emphasized.

Special needs children in the public schools: perceptions of school nurses and school teachers.

Schools are faced with the challenges presented by special needs children (SNC) because the law requires that they must provide educational opportunities to all children--those who have no handicapping conditions as well as those who do, no matter how severe those conditions. The need exists for adequately prepared health care professionals in the school setting. Using a convenience sample of school teachers and school nurses, this investigation focused on the perceptions of school teachers and nurses regarding the challenges and demands of having these children in the public school. Two surveys were conducted to study those perceptions. Quantitative and qualitative data analyses showed that the needs of both groups of providers--school nurses and school teachers--can be summed up in three categories: information dissemination, communication, and resource integration. Infrastructure development involves the establishment of an effective information management system, effective use of such a system in establishing communications between all participants, and adequate administrative support to facilitate the development of the school providers' sense of competence in the care of SNC. A well-planned and adequately supported program goes a long way toward changing people's attitudes toward the inclusion of SNC in the classroom.

A comparison of alternative measures of unemployment.

PIP: Local unemployment rates are often used as economic and social indicators at the subregional scale. Recently, however, there has been growing debate among social scientists, economists, and planners over the scope, coverage, and usefulness of unemployment counts and rates. This paper compares and contrasts unemployment data from the Employment Department claimant count, the Census of Population, and the Labor Force Survey with the central goal of comparing the census and claimant-based counts for different subgroups of the population disaggregated by age and gender at a range of spatial scales. Analysis reveals that in some cases there are substantial variations in unemployment counts and rates derived from different data sources. These findings suggest the merit of using alternative parallel measures of unemployment designed for a specific purpose. To effectively apply this approach necessitates a better understanding on the part of users of the strengths and weaknesses of alternative sources in order that the most appropriate measure is selected.^ieng

The role of migration in labour-market adjustment: the British experience in the 1980s.

"In this paper the role of migration in bringing labour supply and demand into balance (or in mitigating imbalance) in Britain in the 1980s is investigated.... The major trends in migration and unemployment at national and regional scales are outlined, and the key characteristics of job-related migrants are identified. In the main part of the paper the author is concerned with the operationalisation of two contrasting methodological approaches designed to promote a greater understanding of the influences acting on changing migration patterns and the role of migration, alongside other factors in labour-market changes. First, the results from a shift-share approach are discussed; and second, the output from an application of the labour market accounts technique is described."

Uncomplicated diverticular disease is not a common cause of colonic symptoms.

BACKGROUND: Colonic diverticular disease is common among older individuals whereas colonic symptoms, such as those of irritable bowel syndrome, are frequent in the general population. AIM: To determine among patients in secondary care, if uncomplicated diverticular disease is a common cause of colonic symptoms. METHODS: Patients aged ≥50 years attending gastroenterology out-patient clinics or scheduled for colonoscopy or barium enema in a secondary care hospital were invited to take part. Those with structural gastrointestinal diseases were excluded. Participants completed a locally validated Rome II questionnaire on colonic symptoms. Patients with diverticular disease were compared with those without. RESULTS: Seven hundred and eighty four patients with no structural pathology other than diverticular disease or benign colonic polyps completed the study. A total of 744 patients underwent colonoscopy, 40 barium enema. Of these, 281 patients had diverticular disease. Among patients with and without diverticular disease, the frequency of abdominal pain, diarrhoea, constipation and irritable bowel syndrome were 123 (44%) and 226 (46%), 44 (16%) and 80 (17%), 38 (14%) and 80 (17%) and 66 (25%) and 119 (25%), respectively (N.S.). CONCLUSION: Uncomplicated colonic diverticular disease is not a common cause of colonic symptoms among patients in secondary care.