5-HYDROXYTRYPTAMINE-INDUCED CONTRACTION OF THE MARMOSET AORTA IS MEDIATED BY A 5-HT1-LIKE RECEPTOR

1. 5-Hydroxytryptamine (5-HT) exerts both contractile and relaxant effects in the marmoset isolated aorta, actions that are unaffected by the 5-HT₂ antagonist ketanserin. The aim of the present study was to define the receptors mediating the contractile activity of 5-HT in the marmoset aorta.
2. Contractile responses were elicited in aortic rings that were either: (i) precontracted submaximally with the thromboxane A₂ agonist U44069 in order to amplify the responses; or (ii) exposed to N ^ω-nitro- L -arginine (100 μmol/L) plus LY 53857 (0.1 μmol/L; a 5-HT₂ receptor antagonist shown previously to inhibit relaxation). The effect of 5-HT on adenosine 3',5'-cyclic monophosphate (cAMP) formation was also investigated.
3. The effects of agonists and antagonists comprised: (i) agonist potencies in the order 5-carboxamidotryptamine > 5-HT > sumatriptan > 8-hydroxy-2-(di- n -propylamino)tetralin; (ii) inhibition of contractile action of 5-HT by the 5-HT_1D antagonist GR 127935; (iii) a contractile response to methysergide; (iv) a lack of effect of tropisetron, an antagonist of 5-HT₃ and 5-HT₄ receptors; and (v) inhibition of forskolin-stimulated cAMP formation by 5-HT (in the presence of LY 53857), indicative of negative coupling to adenylate cyclase.
4. The above effects fulfil the criteria for a 5-HT₁-like receptor. In view of the previous finding that this contractile response is insensitive to ketanserin, it is concluded that the contractile effects of 5-HT in the marmoset aorta are mediated exclusively by a 5-HT₁-like receptor.     

Mine Blast Injuries - Our Experience

Background

The sudden increase in incidence and magnitude of mine blast injuries prompted us to highlight the problem and its management.

Methods

The cases of mine blast injuries occurring during mining and demining in a particular geographical area were analysed. Total 27 cases of mine blast injuries occurred during mining or demining operations in a period of 13 months.

Results

Various body regions were involved in the mine blast injuries but the main brunt was borne by feet and legs followed by multiple body regions due to splinters. 14 patients underwent below knee (BK) amputation while 4 patients required through knee (TK) amputations. The effect of blast was so severe that most of the cases required 2 to 5 times wound debridements. The initial aggressive debridement / open stump amputation saved the limb and life of all patients.

Conclusion

A mine blast causes extensive injuries and psychological trauma. Management is needed urgently, surgery is difficult, and amputation is often inevitable. Maximum lives and limbs can be saved with aggressive debridement, repeated inspections and dressings under anaesthesia and definitive closure at optimum time.Key Words: Amputation, Antipersonnel mine, Crush syndrome, Debridements, Mine blast injury, Secondary missiles, Shrapenels     

The effects of cardiovascular dynamics monitoring in the outpatient management of pregnancy hypertension

OBJECTIVE: Our purpose was to assess the effects of the adjunctive use of cardiovascular dynamics monitoring in the ambulatory management of 199 pregnant patients with severe hypertension. STUDY DESIGN: A prospective, observational study was performed. Determinants of mean arterial pressure were computed by using the Hon monitor. Indicators of arterial compliance and effective blood volume were developed. All patients were monitored in the outpatient clinic; additionally, 19 patients self-tested at home. No rigid medication protocol was followed, but furosemide was used in most cases when cardiovascular dynamics monitoring patterns were consistent with volume loading. Otherwise, vasodilators were prescribed. The t test for independent samples was used to compare the home-monitored subgroup with the outpatient-only group. RESULTS: Pregnancy was prolonged by 74 +/- 63.9 days (mean +/- SD). Mean gestation was 37.6 +/- 2.9 weeks, and mean birth weight was 2882.4 +/- 837 g. The primary cesarean delivery rate was 23.7%, but only 15 (7.5%) cesarean deliveries were performed because of failed therapy. The 19 home-monitored patients gained 108 +/- 75 days (83.1 +/- 42.2 days beyond 20 weeks). CONCLUSION: Adjunctive cardiovascular dynamics monitoring may have a role in the evaluation and management of hypertension during pregnancy.     

Molecular regulators of angiogenesis in the developing nervous system and adult brain tumors (review)

Angiogenesis involves a highly regulated and coordinated interaction of multiple angiogenic factors and is critical for both embryonal development and physiological vessel formation in adults. Angiogenesis is also proven to significantly contribute to the progression of various disease processes. Pathological angiogenesis is thought to recapitulate physiological angiogenesis, however the precise molecular mechanisms are not understood. Various angiogenic genes and gene products have been isolated, purified, and cloned from both neoplastic and normal tissues that contribute to the angiogenic process. In this review we summarize the role of the main angiogenic factors in both normal embryonal vascularization of the embryonal nervous system together with the main brain tumors seen in adults.     

Variations in the resting oxygen consumption of small babies

Over 200 measurements of the resting rate of oxygen consumption using an open-circuit method were made on 15 small babies nursed in their usual clinical setting during the first month of life. There were striking and persistent variations between babies that could not be explained by postnatal age, relationship to feed, sleep, or time of day. It was not possible from clinical examination to predict which babies had the higher or lower metabolic rates, except that babies who were light-for-dates generally had higher values. Because of these variations the appropriate thermal temperature for small babies cannot be predicted from average values adjusted for body weight and postnatal age alone.