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Purpose: Acute mountain sickness (AMS), the commonest form of altitude illness, might represent early-stage high altitude cerebral edema (HACE). Optical coherence tomography (OCT) was used to evaluate optic nerve head (ONH) consequences following a sojourn to extreme altitude., Methods: This prospective study included 4 high-altitude expeditions in Himalayas. Twenty-four eyes of 12 healthy male climbers underwent baseline and postexpedition complete ophthalmic evaluation, including OCT to measure the peripapillary retinal nerve fiber layer (RNFL) thickness, ONH parameters, and macular thickness and volume. Lake Louise Scoring (LLS) self-report questionnaire was used to estimate AMS severity., Results: All mountaineers experienced symptoms of AMS (LLS: 5.1±1.1, range 4.0-7.0). Average peripapillary RNFL thickness showed a significant increase in postexpedition examination (94±23 µm, 47-115), compared with baseline values (89±19 µm, range 45-114) (p=0.034). Superior (p=0.036) and temporal (p=0.010) quadrants also showed an increased RNFL thickness following exposure to high altitude. Vertical integrated rim area (VIRA) was significantly higher in postexpedition examination (0.71±0.43 mm(3), 0.14-1.50) than in baseline examination (0.51±0.26 mm(3), 0.11-1.00) (p=0.002). Horizontal integrated rim width was significantly higher in postexpedition examination (1.90±0.32 mm(2), range 1.37-2.34) than in baseline examination (1.77±0.27 mm(2), 1.27-2.08) (p=0.004). There was no correlation between LLS and OCT parameters (p>0.05)., Conclusions: In climbers with AMS, OCT was able to detect subtle increases in the peripapillary RNFL thickness and in some ONH measurements, even in absence of HACE and papilledema. These changes might be a sensitive parameter in physiologic acclimatization and in the pathogenesis of AMS.

Objective: Dermal grafting after secondary wound healing constitutes the mainstay of management in cold injury tissue defects, displacing the use of local flaps. We present an experimental study in which the following treatments for frostbite defects are compared: guided wound healing, partial-thickness skin grafts and cutaneous flaps, which by definition posses an independent vascular supply., Material and Methods: A dorsal defect in the rabbit leg was created using a cold injury model. The animals were separated in three different sets, each with a specific treatment for the defect. In the first group, the defect was left to heal by secondary intention. In the second group, a dermal graft was used. In the third group, the defect was covered with a flap. The surface area lacking cutaneous cover at day 7 (SCp7) and the healing time (TC) were analysed., Results: The cases in which flaps were employed presented a SCp7 of 62mm2, and a healing time of 11.6 days. When grafts were used, the SCp7 was 130mm2, and the healing time 15.9 days. The group which healed by secondary intention presented a SCp7 of 225mm2 and a healing time of 20.1 days., Conclusions: Compared to grafts, flaps provide a better skin cover both in quality and quantity. Their own vascularity makes them nondependent of the characteristics of the recipient bed. Due to this and to the radioisotopic and resonance imaging studies, which determine the ultimate level of tissue damage demarcation in a few days, an early treatment for these injuries is possible, with no need to achieve a favourable recipient site., (Copyright 2010 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.)

Objective: High altitude and exposure to cold are associated with significant levels of dehydration because of cold-altitude urine output, high energy expenditures, and poor access to water. The aims of the present study were to measure the fluid intake and urine output among military mountaineers during their stay at high altitude and to study the level of fluid intake and decrease in urine output in relation with acute mountain sickness (AMS)., Methods: This study used an analytic prospective follow-up design of hydration-dehydration conditions of a group of mountaineers with similar characteristics (military group). Data collected each day included quantity and type of fluid intake, urine output in 24 hours, other fluid output (as diarrhea or vomiting), and symptoms or signs of AMS according to the Lake Louise consensus score. Values are given as mean +/- SE. A 1-factor analysis of variance procedure and t test were used to compare variables., Results: The mountaineers consumed a variety of fluids, including water, tea, coffee, soup, Isostar, and milk. Daily fluid intake was 2800 +/- 979 mL, with a maximum intake of 4700 mL. Daily urine output was 1557 +/- 758 mL. When we stratify our sample at the median by fluid intake, a significant correlation is detected with mean balance and mean urine output. Mountaineers developing AMS demonstrated reduced urine output (mean 1336 mL) when compared with those without AMS (mean 1655 mL)., Conclusions: We found that fluid intake was associated but insignificantly correlated with incidence and degree of AMS. Past research suggests that vigorous hydration decreases incidence and severity of AMS and other altitude illnesses. Our results also imply that aggressive fluid intake is protective, but our limited sample size yielded insufficient power to demonstrate a statistically significant difference.

A 38 year old man was admitted to our hospital 10 days after suffering a frostbite injury in hands and feet while practicing mountain climbing, at 8,100 meters of altitude, while he was trying to reach the top of the K2 mountain. A 99mTc-MDP bone scan performed in aseptic conditions showed: in hands: absence of bone uptake in the 3rd phalanx and distal portion of 2nd phalanx of the 5th finger of the left hand, and multiple areas of increased uptake in the distal portion of both hands. In feet: uptake decreases in the 2nd phalanx of the first toe of the left foot, and absence of bone uptake in the 3rd phalanx of the 2nd toe of the left foot, and in 2nd phalanx of the 1st toe and 3rd phalanx of the 2nd, 3rd and 4th toes of the right foot. As in the hands, there were multiple areas of increased uptake in the distal portion of both feet. The phalanges with absence of bone uptake had to be amputated, while those that presented increased uptake recovered with conservative treatment. Bone scan is indicated in the evaluation of frostbite injuries and helps to establish the prognosis early.

Background and Aim: Experimental carcinogenesis models provide a useful tool in the study of the aetiopathogenesis and treatment of gastric cancer. We developed a model based on the administration of N-methyl-N-nitrosourea (NMU) in Wistar rats for the induction of maximal yield of gastric carcinomas with a short latency period, and being exclusively localized at the gastric level., Methods: A gastric antiperistaltic fistula was performed in 90 Wistar rats classified into eight different groups. Fifteen days after surgery 5, 10, 15 or 20 mg of NMU/100 g were administered through the fistula once a week for a 3- to 5-week period. Before the administration of NMU, a pyloric blockade was made in order to obtain a temporary isolation of the stomach. At 20 weeks, animals were sacrificed and organs were removed for histological study., Results: All rats treated with 15 mg NMU/100 g once a week for 5 weeks, after pyloric blockade maintained for 1 h, developed well-differentiated carcinomas in the forestomach. Carcinomas were multiple in 11% of cases and appeared with papillomatous lesions in 33% of rats. No tumours were observed in any other organs. In the other groups, no gastric carcinomas were diagnosed., Conclusion: The high incidence of carcinomas in the forestomach, the absence of tumours in other organs and the short latency period represent valuable criteria for the use of our model in chemotherapeutic investigations, as well as in the study of cancer evolution without interferences caused by tumour development in other organs., (Copyright 2000 S. Karger AG, Basel)

Fibroblasts (FIB) play an important role in the wound-healing process. It is not known whether human skin and gastric FIB show different responses to regulatory compounds. In this study, we have examined the collagen production by these FIB after different stimuli. In vitro release of collagen into the medium by steady-state confluent human FIB cultures was assessed over a 24-hour period by 3H-proline incorporation into collageneous protein. Serum and epidermal growth factor increased collagen secretion in both types of FIB, but gastric FIB produced less collagen than skin FIB. Prostaglandin E1 inhibited collagen production in both types of FIB, but nonsteroidal anti-inflammatory drugs and interleukin-1beta, a cytokine involved in the wound-healing process, had opposite effects on gastric and skin FIB. The effects of lipoxygenase metabolites on collagen secretion was small, but different in both types of FIB. We conclude that, when compared to skin FIB, human gastric FIB produce less collagen and show pronounced different responses to different agents, which might be relevant to explain (in part) their clinical effects on ulcer healing. These data provide new insights into the wound-healing process.

The reported increase of gastric secretion after small bowel (SB) resection is controversial. To determine the effect of SB resection on gastric acid secretion we studied basal and dose step pentagastrin-stimulated gastric acid secretion as well as basal serum gastrin, secretin, neurotensin and postprandial gastrin levels in 12 dogs, before and after resection of 60% of the intestine representing both proximal (n = 6) and distal (n = 6) SB. Rat bioassay was also performed to rule out the presence of unknown gastric secretagogues in the blood. Proximal SB resection produced a significant increase in basal and low dose (100 ng/kg/h) pentagastrin-stimulated gastric acid secretion (ED50 = 1,110 vs. 720 ng/kg/h after resection). However, no significant changes in gastric secretion were observed after distal SB resections. Neither proximal nor distal SB resection altered basal or postprandial serum gastrin levels. Proximal SB resection reduced serum secretin levels (229 +/- 38 vs. 134 +/- 16 pg/ml, p < 0.05) but did not alter neurotensin levels. Rat bioassay failed to reveal a circulating secretagogue after SB resections. We conclude that proximal but not distal SB resection increases basal and submaximally stimulated gastric acid secretion. Such an effect may be due to the observed decrease in circulating secretin levels.

Epidural spinal cord stimulation (SCS) and conventional treatment produced good therapeutic effects in four young patients with frostbite of the lower limbs. The mechanism of action is unknown but the treatment resulted in rapid recovery with reduced pain and a more peripheral level of amputation. These preliminary results warrant further studies of SCS in the treatment of frostbite.

Gastric acid secretion, gastrin and secretin serum levels after duodenal acidification were studied in 6 dogs, before and after a troncular vagotomy was performed in each one. After duodenal acidification in normal dogs, a 45.2% inhibition of gastric acid secretion with parallel 55-84% increases in the serum secretin levels, without changes in the serum gastrin levels, was noted. When a troncular vagotomy was performed in the same dogs, duodenal acidification produced a 20% (non significant) inhibition of gastric acid secretion with parallel 34-72% increases in the serum secretin levels and without changes in the serum gastrin levels. It is concluded that vagus nerve is necessary to assess a physiological inhibition of gastric secretion after duodenal acidification and it is suggested that humoral and nervous factors are implicated and coexist in these mechanisms.

The role of the adrenergic system in the duodenal mechanisms that inhibit gastric acid secretion (GAS) after duodenal acidification (DA) was studied. In 12 mongrel dogs, with gastric and duodenal fistulas, six experiments were carried out evaluating pentagastrin-stimulated GAS and serum secretin levels: DA (HCl 2 ml/min) for 1 h (group A); DA (HCl 2 ml/min) for 1 h plus propranolol (group B); DA (HCl 2 ml/min) for 1 h plus phentolamine (group C); duodenal instillation of saline (2 ml/min) for 1 h (group D); (duodenal instillation of saline (2 ml/min) for 1 h plus propranolol (group E), and duodenal instillation of saline (2 ml/min) for 1 h plus phentolamine (group F). Significantly (p less than 0.05) high percentages of inhibition of GAS (49-70.5%) paralleled with increases of serum secretin levels (48.4-84%) were noted in group A and C experiments. However, DA did not inhibit GAS nor did it increase the levels of secretin in group B and D-F experiments. It is concluded that the inhibition of GAS after DA is controlled, at least in part, by the action of the beta-adrenoreceptors.