Angiogenesis is an early event in the development of chemically induced skin tumors

In this study we have analyzed the vascular response induced in the two- stage carcinogenesis model in SENCAR mice. The role of angiogenesis has not been explored in this model, which is the paradigm of multistage carcinogenesis and a model for neoplastic lesions derived from exophytic premalignant lesions (e.g. colon carcinoma, bladder papilloma). We investigated if angiogenesis is involved in the formation of papillomas and in the progression from papilloma to carcinoma. To this end we analyzed the vasculature of normal and hyperplastic skin, focal epidermal hyperplasias that are precursors of papillomas, papillomas at different stages and squamous cell carcinomas. We also analyzed the vascularization of papillomas induced in two strains of mice that differ in their susceptibility to malignant progression. We show here that angiogenesis is turned on in the earliest stages of papilloma formation. In late stages, regardless of state of progression, the predominant response is an increase in the size of blood vessels. Thus, in the SENCAR mouse model, representative of exophytic tumors, the angiogenesis switch is a very early event, probably mechanistically related to the development of the primarily exophytic lesions. Therefore, the density of blood vessels cannot be used as a predictor of malignant progression in this model.      

Therapeutic studies in NZB/W mice. I. Synergy of azathioprine,cyclophosphamide and methylprednisolone in combination

This study compares different immunosuppressive regimens in the treatment of the lupus-like nephritis of NZB/W mice. Groups of 5-month-old female NZB/W mice were given azathioprine, cyclophosphamide and methylprednisolone in all one-, two- and three-drug regimens, each drug in the relatively low dose of 1.5 mg/kg/day. Treatment for 3 months with one or two drugs resulted in modest suppression of NZB/W disease. Mice receiving all three drugs had significantly less proteinuria, lower titers of anti-DNA antibody and less severe, histologically evident renal involvement than mice treated with one or two drugs. Survival at 1 year was 10% for untreated controls, 44% for one-drug-treated, 37% for two-drug-treated and 86% for the three-drug-treated mice. The survival for the three-drug regimen was significantly longer than any other group (P < 0.01). The three-drug regimen was synergistic, since mice treated with each drug at three times the dose had significantly more proteinuria after 3 months of treatment and lowered 1 year survival (33%). The beneficial effects of triple-drug therapy were attained without increased toxicity. This study represents the first controlled evaluation of single versus combination therapy in a model of autoimmune disease. Based on these results, a controlled evaluation of triple-drug therapy in human systemic lupus erythematosus appears warranted.     

Infestation of Tunga penetrans in villages near Zomba Central Hospital

An outbreak of Tunga Penetrans (Jigger Flea) infestation affecting a number of villages near to a Central Hospital in Malawi is described. Due to the large number of affected individuals, high parasitic load, and extended duration of infection an alternative to the recommended approach of surgical removal of the flea was required. Benzyl benzoate paint and liquid paraffin had been used in local Primary Healthcare settings previously and topical treatment with antiparasitic agents has been advocated in the literature, particularly for severe infestation. Benzyl benzoate and liquid paraffin were applied topically to four adults with numerous jigger flea burrows, and their progress assessed regularly. After completion of 7 days of treatment patients noted that fleas were dislodging spontaneously, and that embedded parasites had not increased in size to the same extent that untreated fleas had in previous infestations. Following confirmation of the viability of its implementation in a resource-poor setting, this treatment regimen has subsequently been adopted by the local branch of the District Health Office for distribution to infected communities.     

Bacterial cholangitis causing secondary sclerosing cholangitis: A case report

Background  

Although bacterial cholangitis is frequently mentioned as a cause of secondary sclerosing cholangitis, it appears to be extremely rare, with only one documented case ever reported.     

The diagnostic value of the fibrinogen/fibrin fragment E antigen assay in clinically suspected deep vein thrombosis

We have evaluated the fibrinogen/fibrin fragment E antigen assay as a diagnostic test in patients with clinically suspected venous thrombosis by comparing the results of this assay with venography in 272 patients. The result of the fragment E antigen assay was elevated in 79 of 80 patients with positive venograms for recent venous thrombosis (sensitivity 99%) and within the normal range in 161 of 192 patients with normal venograms (specificity 84%). The fragment E assay was also evaluated in 130 medical and surgical controls without evidence of venous thrombosis by leg scanning and the test was found to be relatively nonspecific. However, in the patient group under study, a correct clinical diagnosis of no thrombosis, based on a normal fragment E result, was made in 161 of 162 cases (negative predictive value of 99%). Therefore, a normal test result effectively excludes a diagnosis of venous thrombosis in clinically symptomatic patients. The assay, as currently performed, is technically demanding and takes 24 hr to complete. Therefore, it will have to be simplified before it can be applied to clinical practice.     

Transfer pathways between the ovaries and the uterus in the cebus monkeys (Cebus apella)

The aim of this work was to study, in the Cebus apella monkey, the developmental changes in the microanatomy of the utero-ovarian ligament (UOL) and whether their vascular and neural elements might be involved in the transfer of signals between the ovaries and uterus. Sections including uterus, UOL, and ovary obtained from two foetuses, two prepubertal, and four cycling monkeys, two of them treated with a neuron-axonal tracer, diamidino yellow (DY) into the corpus luteum (CL) and the remaining two into the endometrium, were analyzed for the expression of neurofilament protein (NFP) and tracer distribution. Eight regularly cycling females were used to investigate the transfer to the CL of pulses of prostaglandin F(2alpha) (PGF(2alpha)) (n=4) or its vehicle (n=4) given intra-uterus. A convoluted artery, in conjunction with various vein channels, passed over the UOL allowing for a direct communication between uterus and ovaries. The artery acquired prominence during adulthood, in a manner well suited with the ovarian status. Immunohistochemical analysis revealed that NFP expression by the oocyte and by the endometrial epithelial cells was a highly conserved feature during development, whereas the appearance of NFP fibers in the ovaries, UOL, and uterus was a late event in the ontogenesis, likely regulated by the hormonal environment. Neurons, as an obvious source for these NFP fibers, were not recognized at any developmental stage, although some neuron-like cells were observed within the CL. The pattern displayed by the tracer DY, further suggested a reciprocal axonal transport among endometrial cells and follicular and luteal cells of both ovaries and between the ovaries themselves. The functionality of the utero-ovarian connection was assessed after injecting PGF(2alpha) intra-uterus. A short exposition to PGF(2alpha) pulses was required for lowering ovarian and peripheral progesterone concentrations causing luteolysis, indicating that transport mechanism operating between uterus and ovary must be very efficient. The results suggest that the vessels and axons contained in the UOL of the Capuchin monkeys might be two combined key pathways underlying the reciprocal transfer of signals controlling utero-ovarian homeostasis.     

Just noticeable difference in perception of physical exertion during cycle exercise in young adult men and women

The purpose of this investigation was to describe the just noticeable difference (JND) in perceived exertion during cycle exercise. Males (n = 20) and females (n = 26) (21.4 ± 3.1 year) performed load-incremented cycle exercise to peak intensity. At the end of each minute, subjects rated their overall-body perceived exertion using the OMNI (0–10) rating of perceived exertion (RPE) scale. Individual regression derived the power output (PO) corresponding to RPE 5. This PO served as the standard stimulus (SS). On a separate occasion, four 5-min cycling bouts were performed with 5 min rest between bouts. During bouts 1 and 3 subjects cycled at the SS. During bouts 2 and 4 subjects adjusted the resistance to achieve a level of exertion just noticeably above/below the SS. The difference in final 30-s oxygen consumption (VO₂) and PO between each JND bout and the previous SS were the above (JND-A) and below (JND-B) perceived exertion JNDs. JND-A and JND-B were compared between genders and between subjects exhibiting lower versus higher ventilatory threshold (VT) and VO_2PEAK within genders for VO₂ (l·min^?1, %VO_2PEAK) and PO (W, %SS). JND-B was significantly (P < 0.05) greater than JND-A for VO₂ and PO, when expressed in absolute (l·min^?1, W) and relative units (%VO_2PEAK, %SS). Males exhibited greater JND values than females in absolute, but not relative, units. Subjects with lower and higher VT and VO_2PEAK exhibited similar JND values. The JND can serve as an effective tool to measure perceptual acuity and to determine individual ability to self-regulate prescribed exercise intensities.