Effects of crude oil and ultraviolet radiation on immunity within mouse skin

Previous studies indicate that crude oil leads to increased pigmentation and erythema (sunburn) in response to sunlight in exposed individuals. However, no information is currently available concerning whether crude oil exposure might enhance the immunosuppressive effects of solar ultraviolet radiation (UVR) on the skin. In order to address this question, the back skin of shaved, female C3H/HeN mice was exposed to crude oil with or without subsequent treatment with medium-wavelength (UVB) (200 J/m2) or long-wavelength (UVA) (20,000 J/m2) UVR. Immune function was assessed in treated mice by measuring their ability to mount contact hypersensitivity responses to a hapten (2,4-dinitro-1-flyorobenzene, DNGFB) applied to the site of crude oil and UVR treatment as determined by ear swelling upon subsequent challenge. Since Langerhans cells represent an important component of immunity within the skin and because suppression of contact hypersensitivity following UVR treatment is often accompanied by disappearance of Langerhans cells from the epidermis, the impact of these agents on epidermal Langerhans cell density was also analyzed. This was accomplished by enumerating IA-positive cells within the epidermis of treated skin. In these studies, crude oil alone induced inhibition of contact hypersensitivity but had no effect on epidermal Langerhans cells. In contrast, combined treatment with crude oil and UVA led to suppression of contact hypersensitivity, which was accompanied by depletion of epidermal Langerhans cells.     

Danazol administration after gonadotrophin-releasing hormone analogue reduces rebound of uterine myomas [published erratum appears in Hum Reprod 1998 Mar;13(3):780]

We report the results of administration of danazol after suspension of gonadotrophin-releasing hormone analogue (GnRHa) therapy for uterine myomas. A total of 21 women with uterine myomas was treated with 100 mg danazol for 6 months after GnRHa therapy. Uterine volume and endocrine status were monitored monthly by ultrasound and assay of plasma gonadotrophins, oestradiol and progesterone. The results show a rebound of uterine volume about 30% less than in controls at the end of danazol therapy. Menstrual cyclicity returned after 65 +/- 3 days in 16 subjects and five patients remained amenorrhoeic. Hormone assays confirmed renewed ovarian function in the women whose menstrual periods returned. Bone mineral content was substantially reduced during GnRHa treatment but improved significantly during danazol therapy even in the women who remained amenorrhoeic. These results show the utility of danazol in prolonging the therapeutic effects of GnRHa. The mechanism by which danazol inhibits rebound of uterine volume may be due to its antiprogesterone effects on uterine myomas.      

Effect of CNTF on low-affinity NGF receptor expression by cultured neurons from different rat brain regions.

Our previous work indicated that in E14 embryonic rat spinal cord cultures ciliary neuronotrophic factor (CNTF) exerted (1) a survival-promoting effect on motor neurons and on a large population of unidentified neurons, and (2) a regulatory role on the expression of ChAT and low affinity NGF receptor (LNGFR) in a population of small/medium-sized neurons. In the present study, we examined the effect of CNTF on the expression of LNGFR in cultures of different regions from the E18 embryonic rat brain, namely cortex, septum, striatum, mesencephalon, hippocampus, brainstem, and cerebellum. The number of LNGFR-positive neurons (stained with the 192-IgG monoclonal antibody) was determined in untreated cultures and in cultures treated for 6 days (0-6) with human recombinant CNTF. To distinguish between effects on survival and on LNGFR expression, experiments were performed in which CNTF was administered only for the last 48 h of the culture (from days 4-6). LNGFR positive neurons were found in the cultures of all the regions examined. In each one of them, CNTF increased the number of LNGFR-positive neurons by three- to fourfold after 6 days of treatment. In the striatum, septum, mesencephalon, and cerebellum, the effect of CNTF was shown to be on the regulation of LNGFR expression and not on survival. In cultures from the cortex, hippocampus and brainstem, a survival-promoting role of CNTF could be demonstrated. The effect of CNTF was dose dependent, with half-maximal effects (ED50) achieved at 2-4.5 TU/ml for all the brain regions. Maximal effects were reached at 100-250 TU/ml. From these results, we conclude that (1) there exists a wide spectrum of CNTF-responsive neurons in the central nervous system, and (2) CNTF plays an important and widespread role in regulating the expression of the LNGFR in neurons.     

Pneumothorax and other lung diseases: effect of altered resolution and edge enhancement on diagnosis with digitized radiographs

Prior studies have shown that pneumothorax is one of the more difficult entities to diagnose with digitized radiography. This study was designed to test whether increasing resolution from 1.25 to 2.5 line pairs per millimeter (lp/mm) and image processing (edge enhancement from unsharp masking) would increase accuracy and confidence in the diagnosis of pneumothorax, as well as normal cases and other forms of lung disease. Conventional radiographs were digitized with use of a laser reader and then reformatted as film hard copy. Eleven observers read 35 cases reformatted in three different ways (1.25 lp/mm, 2.5 lp/mm, 1.25 lp/mm unsharp mask). The images with finer resolution (2.5 lp/mm) and unsharp mask images were superior to those with coarser resolution (1.25 lp/mm) for the diagnosis of pneumothorax. There was no difference in diagnostic accuracy for normal patients. For abnormalities other than pneumothorax, the unsharp mask images were significantly worse. Confidence in the diagnosis of pneumothorax and other abnormalities was highest with the finest resolution (2.5 lp/mm).     

Characterization of antibody and selection of alternative drug therapy in hydrochlorothiazide-induced immune hemolytic anemia

The authors report the clinical and laboratory findings of a patient who had severe immune hemolytic anemia due to hydrochlorothiazide (HCTZ). In this case, the HCTZ antibody reacted not only with other thiazide and thiazide-like drugs, but also with a chemically unrelated diuretic, ethacrynic acid. These results indicate that HCTZ antibody activity is not restricted solely to the thiazides and imply that therapy with any of the reactive drugs would be contraindicated for this patient. The serologic screening for drug reactivity may be useful for selecting alternative therapy for patients with drug-induced immune hemolytic anemia.     

The effects of a reduced exercise duration taper programme on performance and muscle enzymes of endurance cyclists

Summary The influence of tapering on the metabolic and performance parameters in endurance cyclists was investigated. Cyclists (n = 25) trained 5 days · week^–1, 60 min·day^–1, at 75–85% maximal oxygen consumption (VO_2max) for 8 weeks and were then randomly assigned to a taper group: 4D (4 days;n = 7), 8D (8 days;n = 6), CON (control, 4 days rest;n = 6), NOTAPER (non-taper, continued training;n = 6). Muscle biopsy specimens taken before and after training and tapering were analysed for carnitine palmityltransferase (CPT), citrate synthase, ß-hydroxyacyl CoA dehydrogenase (HOAD), cytochrome oxidase (CYTOX), lactate dehydrogenase, glycogen and protein. Significant increases inVO_2max (6%), a 60-min endurance cycle test (34.5%), oxidative enzymes (77–178%), glycogen (35%) and protein (34%) occurred following training. After the taper, HOAD and CPT decreased 25 % (P<0.05) and 26% respectively, in the CON. Post-taper CYTOX values were different (P<0.05) for 4D and 8D compared with CON. Muscle glycogen levels were increased (P<0.05) after tapering in the 4D, 8D and CON, but decreased in NOTAPER. Similarly, power output at ventilation threshold was significantly increased in the 4D (27.4 W) and 8D (27 W) groups, but decreased (22 W) in the NOTAPER. These findings suggest that tapering elicited a physiological adaptation by altering oxidative enzymes and muscle glycogen levels. Such an adaptation may influence endurance cycling during a laboratory performance test.     

Picotamide inhibition of excess in vitro thromboxane B2 release by colorectal mucosa in inflammatory bowel disease.

BACKGROUND: Inflammatory bowel disease is associated with increased mucosal release of eicosanoids. Among these, thromboxane A2 has been proposed as a possible inflammatory mediator; its suppression may be a useful therapeutic option. METHODS: Using a tissue incubation technique, we compared release of immunoreactive thromboxane B2 by colonic biopsies from patients with ulcerative colitis, Crohn's disease and controls, and assessed the inhibitory effect of picotamide, a thromboxane synthesis inhibitor-receptor antagonist, which has been widely used in Italy for management of ischaemic heart and cerebrovascular disease. RESULTS: Increased amounts of thromboxane B2 were released from biopsies from patients with active ulcerative colitis (median 238 pg/20 min/mg wet weight (interquartile range 147- 325), n = 12) and active Crohn's disease (252 (174-450), 6) compared with those from patients with quiescent ulcerative colitis (95 (61- 140), 12) or Crohn's disease (105 (57-201), 13), or controls (136 (64- 206), 8). Incubation with picotamide at concentrations between 100 microM and 1 mM reduced thromboxane B2 release (IC50 890 microM). CONCLUSION: Since increased thromboxane A2 production may have pathogenetic importance, thromboxane synthesis inhibitor-receptor antagonists such as picotamide merit therapeutic trial in the management of inflammatory bowel disease.