Autoimmune progesterone dermatitis: absence of contact sensitivity to glucocorticoids, oestrogen and 17-α-OH-progesterone

Autoimmune progesterone dermatitis is a rare condition, characterized by recurrent premenstrual exacerbations of a dermatosis, in which sensitivity to progesterone can be demonstrated. The sensitizing mechanism is unknown. The aim of this study was to test the hypothesis that cross-sensitivity between steroid groups could induce allergy to endogenous progesterone in these patients. 5 patients with autoimmune progesterone dermatitis and 1 with oestrogen-sensitive dermatitis have been patch tested with a corticosteroid series, conjugated oestrogen 1% in petrolatum (pet.), and 17-α-OH-progesterone 2% pet. There were no immediate or delayed reactions at 2 and 4 days to any steroid group. We have therefore been unable to demonstrate steroid cross-sensitivity, or a use for 17-α-OH-progesterone in the investigation of oestrogen - and progesterone-sensitive dermatoses.     

The effect of drinking tea at high altitude on hydration status and mood

The effect of drinking tea on hydration status and mood was studied in nine male and four female members of expeditions based at Mt. Everest base camp at an altitude of 5,345 m. Whilst exposed to altitude-cold diuresis, participants were subjected to a crossover experimental design comprising two 24-h dietary interventions. In the tea condition, hot brewed tea formed a major part of fluid intake, whereas in the no-tea condition tea was excluded from the diet. Subjects were prohibited in both cases from consuming other caffeinated beverages, caffeinated foods, and alcoholic drinks. Mean fluids ingested [mean (SE); tea=3,193 (259) ml versus no tea=3,108 (269) ml] and urine volume (tea=2,686 (276) ml versus no tea=2,625 (342) ml] were similar under both conditions. Statistical analysis found no difference in urine stimulated as a result of the tea intervention (P=0.81). Several markers of hydration status were also taken immediately pre and post each condition, including measures of urine specific gravity, urine electrolyte balance (K⁺, Na⁺), and urine colour. None of these measures indicated a difference in hydration status as a result of the dietary intervention in either the control or tea condition. A difference was, however, found in mood, with subjects reporting reduced fatigue when tea was included in the diet (P=0.005). The study shows therefore that even when drunk at high altitude where fluid balance is stressed, there is no evidence that tea acts as a diuretic when consumed through natural routes of ingestion by regular tea drinkers, but that it does have a positive effect on mood.     

Depressed lymphocyte transformation and the role of prostaglandins in atopic dermatitis.

We have shown that peripheral blood mononuclear cells (PBMC) from patients with atopic dermatitis have a reduced in vitro proliferative responsiveness to concanavalin A when compared with non-atopic controls. Addition of the cyclo-oxygenase inhibitor indomethacin caused a significant enhancement of the mitogen response in the patients, indicating a suppressive effect of cyclooxygenase products. We have further demonstrated increased levels of prostaglandin E2 in the supernatants of the PBMC cultures and increased levels of IgE immune complexes in the sera of the atopic dermatitis patients and therefore hypothesize that IgE immune complexes may cause increased monocyte production of prostaglandins which in turn appears to be responsible for a reduced lymphocyte proliferation.     

Cement dermatitis in underground workers during construction of the Channel Tunnel

The construction of the Channel Tunnel is one of the largestcivil engineering projects ever undertaken. The British driveemployed 5900 underground workers, and a number developed dermatitisduring 1990/1991. As a result, the Translink Joint Venture (TLJV)Medical Centre set up a surveillance programme aiming to monitorand investigate the men working closely with cement as wellas other groups of workers with skin problems. Men attendedthe Medical Centre voluntarily and were assessed, includinghistory, examination and patch tests to a series of 15 testsubstances (from the European standard series) where indicated.A programme of education about the hazards of working with cementwas instituted, including leaflets, videos, local newspaperarticles and personal explanation by the Medical Centre staff.Between January 1990 and January 1992, 1138 men were seen atthe Medical Centre regarding their skin and 332 were diagnosedas having occupational dermatitis, past or present. Patch testswere performed on 180 men from all trades. Of the 800 grouters,466 (58 per cent) were assessed and 111 had a history of occupationaldermatitis at some time. Many gave a history of a single episodeof dermatitis during a particularly hot and wet phase of tunnelling.Patch tests performed on 86 grouters showed allergy to chromatein 56 (65 per cent). Of the 466 grouters assessed, 17 per centhad positive patch tests to chromate but men with no skin problemspast or present were not patch tested. Cobalt allergy was oftenfound with chromate allergy (50 out of 56). Allergy to epoxyresin was also found in 30 per cent of grouters who were patchtested. Only three men had to change their occupation becauseof their skin disease. Most cases of occupational dermatitisimproved with regular medical supervision, education and personalprotective measures, with relocation to less exposed work wherenecessary. Many cases cleared as the tunnel entered better terrain.The addition of ferrous sulfate has been shown to decrease thelevel of the allergenic hexavalent chromate in cement and itscompulsory use in Scandinavia has reduced the incidence of cementdermatitis in construction workers. The rest of Europe shouldnow follow the Scandinavian lead and consider legislation tomake cement less hazardous to workers' health.     

Methods for assessing the potential of prebiotics and probiotics

Prebiotics and probiotics are microflora management tools designed to improve human health. Both are dietary materials that fortify components of the gut flora seen as 'beneficial'. Gut flora modulation is an important area of the nutritional sciences, however, it is imperative that reliable methodologies be used to determine efficacy. This review will discuss the current techniques used in prebiotic and probiotic research.     

Survival and developmental disability in infants with birth weights of 501 to 800 grams, born between 1979 and 1994

OBJECTIVE: Because the survival rate has increased for extremely low birth weight neonates, many have raised the concern that the rate of developmental disability among survivors will also increase. To address this concern, we analyzed changes over time in survival and major neurosensory impairment in a sample of extremely low birth weight infants born between July 1, 1979, and June 30, 1994. METHODS: The study sample included 513 infants with birth weights of 501 to 800 g who were cared for in either of the two neonatal intensive care units that serve a 17-county region in northwest North Carolina and who were born to mothers residing in that region. At 1 year of age (corrected for gestation), survivors were examined by a pediatrician and were tested using the Bayley Scales of Infant Development. Major neurosensory impairment was defined as cerebral palsy, a Bayley Mental Developmental Index <68, or blindness. A total of 209/216 (97%) of survivors were examined at 1 year of age. Epoch of birth was defined as follows: epoch 1, July 1, 1979 to June 30, 1984; epoch 2, July 1, 1984 to June 30, 1989; and epoch 3, July 1, 1989 to June 30, 1994. RESULTS: Survival rates for epochs 1, 2, and 3 were, respectively, 24/120 (20%), 63/175 (36%), and 129/218 (59%). In contrast, the proportions with a major neurosensory impairment did not increase over time; rates for successive epochs were 6/24 (25%), 17/61 (28%), and 26/124 (21%). Rates of cerebral palsy were 3/24 (13%), 12/61 (20%), and 9/124 (7%); rates of delayed mental development were 4/24 (17%), 12/61 (20%), and 17/124 (14%); and rates of blindness were 2/24 (8%), 0/62, and 5/124 (4%), respectively. CONCLUSIONS: This analysis suggests that the increasing survival of extremely low birth weight neonates since the late 1970s has not resulted in an increased rate of major developmental problems identifiable at 1 year of age.     

妥卡尼对豚鼠心室肌细胞钙电流和钾电流的抑制作用

利用酶分散的成年豚鼠心室肌细胞和全细胞电压钳技术,研究了妥卡尼(tocainide)对心室肌细胞钙电流(I_ca)、延迟整流钾电流(I_k)和ATP敏感性钾电流(Ik,ATP)的作用。结果表明,妥卡尼对I_ca和I_k均显示浓度相关的抑制作用,妥卡尼50umol·L^-1对I_ca和I_k的抑制率分别为16%和3%。这可能是妥卡尼有效抑制室上性心动过速和缩短心肌动作电位平台期的重要机制。