The Use of Ultrasound in Undergraduate Medical Anatomy Education: a Systematic Review with Narrative Synthesis.

This systematic review aimed to synthesize the literature on how ultrasound is currently used in anatomy education within medical schools. A systematic search of Ovid MEDLINE, Scopus, and Educational Resources Information Centre was conducted. Thirty-four relevant unique articles were included from the 1,272 identified from the databases and analyzed via narrative synthesis. Thematic analysis generated two domain summaries: "Successful Aspects of Ultrasound Teaching" and "Barriers to Implementation," each with additional subthemes, aimed to help educators inform best teaching practices from the current evidence base in this field.

A new classification system for the anatomical variations of the human circle of Willis: A systematic review.

The circle of Willis (CoW) is an anastomotic arterial network located on the base of the brain. Studies have shown that it demonstrates considerable anatomical variation in humans. This systematic review aimed to identify and catalogue the described anatomical variations of the CoW in humans to create a new, comprehensive variation classification system. An electronic literature search of five databases identified 5899 studies. A two-phase screening process was performed, and studies underwent quality assessment. A total of 42 studies were included in the review. Data were extracted and circles were reconstructed digitally using graphics software. The classification system contains 82 CoW variations in five continuous groups. Group one contains 24 circles with one or more hypoplastic segments only. Group two contains 11 circles with one or more absent segments only. Group three contains 6 circles with hypoplastic and absent segments only. Group four contains 26 circles with one or more accessory segments. Group five contains 15 circles with other types of anatomical variation. Within each group, circles were subcategorised according to the number or type of segments affected. An original coding system was created to simplify the description of anatomical variations of the CoW. The new classification system provides a comprehensive ontology of the described anatomical variations of the CoW in humans. When used with the coding system, it allows the description and categorisation of recorded and unrecorded variants identified in past and future studies. It is applicable to current clinical practice and the anatomical community, including human anatomy education and research.

Estrogen-responsive genes encoding egg yolk proteins vitellogenin and apolipoprotein II in chicken are differentially regulated by selective estrogen receptor modulators.

In a hen, large quantities of the egg yolk proteins, apolipoprotein II (apo-II) and vitellogenin (VG), are expressed in the liver and transported to the oviduct during egg production. Estrogenic stimulation of the hepatic expression of apo-II and VG is due to both transcriptional increase and mRNA stabilization. The nucleolytic degradation of apo-II messenger RNA (mRNA) is prevented by estrogen-regulated mRNA-stabilizing factor (E-RmRNASF). Gene-specific effects of a select panel of selective estrogen receptor modulators (SERMs) on the hepatic expression of the estrogen-responsive genes encoding apo-II, VG, and E-RmRNASF in the chicken liver were investigated. In the present study, 6-week-old roosters were treated with the vehicle, estrogen, the SERMs genistein, resveratrol, tamoxifen, pterostilbene, raloxifene, catechin, and clomiphene or a combination of estrogen and a 200-fold excess of each of the SERMs. Results from mRNA stabilization studies conducted to investigate the stimulation of expression of E-RmRNASF in the liver by these agents showed that the expression of E-RmRNASF in the liver was stimulated by estrogen and the SERMs genistein, resveratrol, tamoxifen, pterostilbene, and catechin but not by the vehicle, clomiphene or raloxifene. The expression of apo-II and VG from the aforementioned treatments was determined by Northern blot analysis, RNase protection assays, and Western blot analysis. The transcription and protein expression of both apo-II and VG genes were seen in response to treatment with estrogen but not with the SERMs or combinations of estrogen and each of the SERMs. The SERMs that stimulated the expression of E-RmRNASF antagonized the stimulation of the expression of both apo-II and VG by estrogen, demonstrating a gene-specific, selective regulation of the aforementioned genes in the chicken liver by the SERMs. The above panel of SERMs may likely have adverse effects on egg production.

Leptin in CAPD patients: serum concentrations and peritoneal loss.

BACKGROUND: To determine whether serum leptin concentrations in patients undergoing continuous ambulatory peritoneal dialysis (CAPD) are influenced by peritoneal loss of leptin and to compare serum leptin levels of normal subjects with those of patients receiving renal replacement therapy such as haemodialysis (HD), CAPD, or kidney transplantation. SUBJECTS AND METHODS: Eighty-four individuals were investigated: six females and 14 males on standard CAPD; 13 females and 13 males on chronic HD; 10 female and eight male kidney transplant recipients, and 10 female and 10 male subjects as controls. Morning serum, 8-h and 24-h samples of peritoneal fluid concentrated to 6-20-fold by Centricon 3 (cutoff 3000 daltons), and 24-h urinary concentrations of leptin were measured with commercial RIA (Linco Research, Inc., USA). Venous blood and peritoneal fluid samples of albumin, beta2-microglobulin, glucose, urea, and creatinine were determined by standard laboratory techniques. Serum insulin levels were measured by radioimmunoassay. RESULTS: Patients (men and women) on CAPD and after kidney transplantation exhibited significantly higher serum concentrations of leptin and leptin/BMI ratios than control subjects. These increased values did not reach statistical significance in HD patients. Serum leptin concentrations were correlated very significantly with BMI in all cases (r=0.380, P<0.001). Moreover, in CAPD patients (r=0.630, P<0.007) and in HD patients (r=0.668, P<0.005), but not in kidney transplant recipients or control subjects, significant correlations were observed between serum leptin and insulin concentrations. Residual renal function (RRF) in the range 0-12.8 ml/min and serum beta2-microglobulin levels in the range 7.9-47.1 mg/l did not influence serum leptin levels in CAPD and HD patients. As expected, leptin was detected in the peritoneal fluid of CAPD patients. Twenty-four-hour peritoneal loss (30.95+/-21.05 ng/min) and 24-h peritoneal clearance (0.01+/-0.01 ml/kg/min) of leptin account for only 3.9% of estimated whole-body leptin production rate and 0.7% of leptin clearance from plasma respectively. Twenty-four-hour urinary losses of leptin in CAPD patients were negligible, accounting for 5.6+/-1.8% (range 0.3-15.2%) of total (peritoneal and urinary) loss of this hormone. CONCLUSIONS: These findings suggest that serum leptin levels are not affected by continuous peritoneal loss of leptin during CAPD and that insulin resistance and hyperinsulinaemia contribute to elevated serum leptin concentrations in CAPD and HD patients. The aetiology of increased serum leptin levels in kidney transplant recipients is probably different from that in dialysis patients.

Effect of 1 alpha-hydroxyvitamin D3 treatment on production of tumor necrosis factor-alpha by peripheral blood mononuclear cells and on serum concentrations of soluble tumor necrosis factor receptors in hemodialysis patients.

The effect of 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3] deficiency, as well as of replacement therapy with 1 alpha-hydroxyvitamin D3[1 alpha-(OH)D3], on the production of tumor necrosis factor-alpha (TNF-alpha) by peripheral blood mononuclear cells (PBMC) and on the serum levels of soluble TNF receptors (sTNFRs) in hemodialysis (HD) patients was investigated. PBMC from HD patients without prior therapy with hydroxylated vitamin D3 analogs and from normal controls produced similar amounts of TNF-alpha, either spontaneously or after stimulation with lipopolysaccharide (LPS). After oral administration of 1 alpha-(OH)D3, a precursor of 1,25-(OH)2D3, LPS-induced TNF-alpha production by PBMC of HD patients was significantly higher than that of HD patients prior to the treatment or of healthy controls. Such treatment did not, however, affect spontaneous TNF-alpha production by PBMC. Serum concentrations of both soluble TNF receptors [sTNFR-A(p75) and sTNFR-B(p55)] were significantly higher in HD patients than in controls. The ratio of sTNFR-A/sTNFR-B decreased significantly in HD patients following 1 alpha-(OH)D3 therapy. These results suggest that therapy with 1 alpha-hydroxylated vitamin D3 analogs normally given to HD patients for the management of renal osteodystrophy may also regulate the in vivo activity of TNF-alpha.

Plasma tumor necrosis factor soluble receptors in chronic renal failure.

Two soluble tumor necrosis factor receptors (sTNFRs) were detected in the plasma of patients with different degrees of chronic renal failure (CRF) and of long-term hemodialysis (HD) patients. In uremic undialyzed patients, plasma levels of both sTNFRs increased progressively with declining renal function. A linear correlation was found between sTNFR plasma levels and plasma creatinine concentration. sTNFR levels in end-stage uremic patients shortly before commencement of first HD treatment were approximately tenfold higher than in normal subjects. Long-term HD patients showed a further increase in plasma sTNFRs. The origin of sTNFRs, as well as their physiological role remains to be elucidated.

[Transient hypophosphatemia associated with hairy-cell leukemia].

A 43-year-old man with hairy-cell leukemia and marked splenomegaly developed severe hypophosphatemia which improved after splenectomy. Since splenic tissue phosphorus was significantly elevated, and since serum phosphorus returned to normal levels immediately after the operation, it is postulated that excessive uptake of phosphorus by the rapidly dividing leukemic cells might have caused the transient decrease in serum phosphorus.

Testicular function in rats following immobilization stress.

Stress is believed to influence male reproductive activity. Male rats were subjected to immobilization stress for 2 h/day for 30 days to assess the effects of stress on testicular function. Net mass of the testes, epididymes and the seminal vesicles, sperm morphology, number of epididymal sperms and percent progressive motility of the sperms were determined. Adrenal weights were significantly increased (P less than 0.05) in the stressed animals. There was no significant difference between the control and the stressed animals with respect to testicular and epididymal weight, level of sperm production, progressive motility, seminal vesicular weight and abnormal forms. Histological examination also revealed a similarity in the structure of seminiferous tubules, adequacy of cell types of developing germ cells, structure of Leydig cells and epididymal lumina in both the groups. This study demonstrated a lack of significant effect of immobilization stress on testicular function in rats.

Test for autonomic function to establish the norm: a useful tool for evaluation in various clinical disorders

Little information is available regarding the responses of the Jamaican population to the Valsalva manoevre (VM), a test to investigate the integrity of the autonomic nervous system (ANS). This study is aimed at investigating the cardiac autonomic control in the Jamaican population, to explore the range of responses and to establish the norm. Such an explorative investigation provides an important tool to uncover autonomic dysfunction in psychosomatic, cardiopulmonary, metabolic and neural disorders. Fifty male and fifty female Jamaicans, who were apparently healthy and did not indulge in any drug use and smoking, are asked to perform the VM in a semirecumbent position. A tachograph (Grass model) and standard electrocardiographic leads are used for the graphic presentation of the subjects' beat-to-beat heart rate changes. The Valsalva ratio (VR) is calculated by dividing maximum tachycardia and maximum bradycardia during the VM. The mean VR for the female (2.41ñ0.18) is greater than that for the male (1.63ñ0.27) (p<0.001). Female subjects exhibit a higher basal heart rate (88+6 as against 77ñ7 in the male) and a greater magnitude of bradycardia (33 as against 4 in the male). The values for VR are above the minimum of 1.5 proposed in the literature. Relative roles of the sympathetic and parasympathetic nervous systems may differ in the male and female subjects, thus accounting for a higher VR in the female. This test is simple, safe, noninvasive and reproducible and is useful to detect the abnormal autonomic function in various conditions, including states of pregnancy and stress (AU)

Test for autonomic function to establish the norm: a useful tool for evaluation in various clinical disorders

Little information is available regarding the responses of the Jamaica population to the Valsalva manoeuvre (VM), a test to investigate the integrity of the autonomic nervous system (ANS). This study is aimed at investigating the cardiac automonic control in the Jamaican population, to explore the range of responses and to establish the norm. Such an explorative investigation provides an important tool to uncover autonomic dysfunction in psychosomatic, cardiopulmonary, metabolic and neural disorders. Fifity male and fifty female Jamaicans, who were apparently healthy and did not indulge in any drug use and smoking, are asked to perform the VM in a semirecumbent position. A tachograph (Grass model) and standard electrocardiographic leads are used for the graphic presentation of the subjects' beat-to-beat heart changes. The Valsava ratio (VR) is calculated by dividing maximum tachicardia and maximum bradicardia during the VM. The mean VR for the female (2.41 ñ 0.18) is greater than for the male (1.63 ñ 0.27) p < 0.001). Female subjects exhibit a higher basal hearth rate (88 ñ 6 as aginst 77 ñ 7 in the male) and a greater magnitude of bradycardia (33 as against 4 in the male). The values for VR are above the minimum of 1.5 proposed in the literature. Relatice roles of the sympathetic and parasympathetic nervous systems may differ in the male and the female subjects, thus accounting for a higher VR in the female. This test is simple, safe, noninvasive and reproducible and is useful to detect the abnormal autonomic function in various conditions, including states of pregnancy and stress

Reproductive toxicity of marihuana smoke a three-generation study in female wistar rats

A three-generation study on the effects of marihuana smoke on female wistar rats was carried out. The mother/parent generation (Gm) and Gf(first generation) were each bred once to give rise to Gf and Gs(second generation) respectively. Reproductive indices studied included oestrous activity, fertility index,gestation of dams, gestation index, gestation survival index, number of pups born alive and pup birth weight. Reproductive toxicity was observed in this study as evidenced from the delayed onset of oestrous activity, frequently occurring oestrous cycles with shortened period of oestrous, reduced fertility index, premature parturition, diminished pup birth weight, reduced litter size as well as gestation survival index. This work shows that when marihuana is inhaled, neither oestrous activity nor ovarian activity is totally suppressed, but it is affected to a significant degree. Influence of marihuana smoke on excitability of uterine smooth muscle, transfer/utilization of nutrients and on hypothalamo-hypophyseal-ovarian axis was proposed to explain its reproductive toxicity. This study bears clinical implications and is useful in the counselling of female marihuana smokers (AU)