[Frostbite of the upper and lower limbs in an expert mountain climber: the value of bone scan in the prediction of amputation level]. / Congelaciones de manos y pies en un montañero de elite: utilidad de la gammagrafía ósea para predecir el nivel de amputación.

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.

A new model for the induction of tumours in the forestomach of rats by N-methyl-N-nitrosourea.

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.

Collagen secretion by human gastric and skin fibroblasts: implications for ulcer healing.

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.

Increased gastric acid secretion after massive small bowel resection is related to a decrease in enterogastrones.

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 neurostimulation in the treatment of frostbite.

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.

Role of beta-adrenoreceptors in the inhibition of gastric acid secretion after duodenal acidification in dogs.

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.

[Effect of vagotomy on the duodenal mechanisms regulating gastric secretion]. / Efecto de la vagotomía en los mecanismos duodenales que regulan la secreción gástrica.

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.