Smoke inhalation injury: diagnosis and respiratory management

Smoke inhalation is a significant comorbid factor following major thermal injury. Smoke exposure is only a trigger for the sequence of events responsible for the development of inhalation injury. Noxious chemicals generated by incomplete combustion injure the exposed bronchoepithelium and stimulate the release of chemical mediators that cause a progressive inflammatory process. Airway inflammation and pulmonary edema impair gas exchange and increase the susceptibility to pulmonary infection. Earlier diagnosis and treatment of inhalation injury is an important element to improve the clinical course of severe burn patients. The American Burn Association, however, recently concluded that there are insufficient data to support a treatment standard for the diagnosis of inhalation injury. At present, the diagnosis of inhalation injury is supported by the combination of history, physical examination, bronchoscopy, and laboratory findings For accurate diagnosis of inhalation injury, helical CT scanning and examination to detect activated leukocytes in bronchoalveolar lavage fluid may be warranted. In the respiratory management of inhalation injury, repeated removal of pseudomembrane by fiberoptic bronchoscopy and the use of adequate PEEP to avoid airway obstruction are essential. High-frequency percussive ventilation can be a suitable mode of ventilation for inhalation injury.     

Neuroprotective effect of 1-methyl-1,2,3,4-tetrahydroisoquinoline on cultured rat mesencephalic neurons in the presence or absence of various neurotoxins

1-Methyl-1,2,3,4-tetrahydroisoquinoline (1MeTIQ) is an endogenous brain amine and its content in parkinsonian brain is decreased compared with that in control brain. There is some evidence that 1MeTIQ protects dopaminergic neurons against dysfunction such as that seen in Parkinson's disease. In this study, we examined the neuroprotective effect of 1MeTIQ against four dopaminergic neurotoxins, 1-methyl-4-phenylpyridinuim ion, 6-hydroxydopamine, rotenone, and l-benzyl-1,2,3,4-tetrahydroisoquinoline, in cultured rat mesencephalic neurons. 1MeTIQ exerted neuroprotective action against all these toxins. Furthermore, (R)-1MeTIQ was neuroprotective, while (S)-1MeTIQ had little effect, indicating that the effect is stereoselective. The protective action of 1MeTIQ was most effective in mesencephalic neurons, especially in tyrosine hydroxylase-positive neurons. 1MeTIQ showed no affinity for dopamine receptors and did not influence the inhibition of mitochondrial respiratory complex I by rotenone, 1-methyl-4-phenylpyridinuim ion, or 1-benzyl-1,2,3,4-tetrahydroisoquinoline. These results raise the possibility that 1MeTIQ indirectly acts as an anti-oxidant such as the induction of anti-oxidative enzymes, because all these four neurotoxins can burden oxidative stress in common. This is the first report to confirm a protective effect of 1MeTIQ at the cultured neuron level, and it may have potential as a lead compound for the development of new agents to treat Parkinson's disease.     

Radiofrequency ablation of metastatic mediastinal lymph nodes during cooling and temperature monitoring of the tracheal mucosa to prevent thermal tracheal damage: initial experience

Institutional review board approval and patient informed consent were obtained. Radiofrequency ablation in a total of 10 sessions was performed for each mediastinal lymph node metastasis from esophageal cancer that had a mean largest diameter of 2.2 cm +/- 0.6 (standard deviation) in seven male patients (mean age, 59 years). During ablation, cooling and temperature of the tracheal mucosa were monitored in the proper position in eight of the 10 sessions; in the other two sessions, monitoring was not done because of tracheal stenosis (perforation resulted). Three of the four lymph nodes that were 2.0 cm or smaller in largest diameter showed no evidence of local progression for at least 1 year since ablation; all three of the nodes greater than 2.0 cm in largest diameter progressed within 6 months. The 1-year survival rate was 60%; the median survival time was 13 months. Radiofrequency ablation may be effective for local control of small metastatic mediastinal lymph nodes, and cooling and temperature monitoring of the tracheal mucosa in the proper position may prevent thermal tracheal damage.     

Sodium handling in congenitally hypothyroid neonates

Early observations emphasized the possible development of hyponatraemia in hypothyroid children and adults, but recently this has been questioned. Aim: To investigate whether hyponatraemia develops in hypothyroid status by examining sodium handling in screening-detected neonates and infants with congenital hypothyroidism (CH). Methods: Serum thyroid-stimulating hormone (TSH), free thyroxine (FT4), sodium (Na), creatinine (Cr), urinary Na, Cr, fractional sodium excretion rate (FENa) and other chemicals were measured before and after L-thyroxine (LT4) replacement therapy in 32 screening-detected CH neonates (11M, 21F) and 16 age-matched control neonates. Results: No cases of hyponatraemia were found in the 32 CH neonates. Their serum Na concentrations (139.1 ± 1.5 mmol/L, ranging from 136 to 142 mmol/L, median 139 mmol/L) were not statistically different from those of 16 control neonates (139.3 ± 1.3 mmol/L, ranging from 137 to 142 mmol/L, median 139 mmol/L,). No correlation was found between serum levels of TSH and FT4 and serum Na or FENa. No significant changes were found in serum Na concentrations in hypothyroid neonates two months after LT4 replacement therapy. The serum Na concentration (139.1 ± 0.3 mmol/L, n = 25) before treatment did not change statistically (138.9 ± 0.2 mmol/L, n = 25) two months after LT4 replacement therapy.

Conclusion: As seen in various earlier reports, hyponatraemia can occur in hypothyroid patients, but no causal relationship exists between them. When hyponatraemia is detected in hypothyroid children, it does not seem to be directly related to lack of thyroid hormones and therefore other possible causes should be sought.     

Effect of postoperative chemotherapy on the serum alpha-fetoprotein level in hepatoblastoma

Purpose

It is generally accepted that postoperative chemotherapy does not affect the serum alpha-fetoprotein (AFP) level. The authors report on 3 patients who supposedly showed chemotherapy-related changes in their AFP levels after operation.

Methods

This study included 3 patients with hepatoblastoma (1 case of PRETEXT III and 2 cases of PRETEXT IV).

Results

One patient with PRETEXT III underwent a complete tumor resection, and the postoperative AFP level decreased until it reached the normal range. However, he consistently exhibited a transient, 2- to 3-fold increase in the AFP after each course of chemotherapy for 3 courses. The chemotherapy regimen had to be stopped because of drug-induced encephalopathy, but he has been followed up for 5 years without any evidence of recurrence, and his AFP level has also remained stable and in the normal range. Two patients with PRETEXT IV, who underwent a curative tumor resection, also showed similar chemotherapy-related changes in AFP levels. Both of these cases were observed only after the administration of routine postoperative chemotherapy instead of administering further high-dose chemotherapy. The AFP level remained stable for 17 months and 7 months after the cessation of chemotherapy in 2 cases, respectively.

Conclusions

Regarding the postoperative chemotherapy of hepatoblastoma, we have to pay close attention to both the AFP status during chemotherapy as well as the absolute AFP level.     

Alpha-helical structure in the C-terminus of vasoactive intestinal peptide: functional and structural consequences

The conformational properties of vasoactive intestinal peptide (VIP) include the N-terminal randomized structure and the C-terminal long alpha-helical structure. We have previously observed that the N-terminal random coil structure plays a crucial role in the receptor-selectivity. Here, to clarify how the formation of the alpha-helix plays a role in its biological functions, we chemically synthesized VIP analogues modified at the C-terminus, mid-chain, and N-terminus of the alpha-helical region, and evaluated the relationship between their alpha-helical contents and their biological activities including relaxant effects on murine stomach and receptor-binding activities. VIP and VIP-(1-27) showed equipotent biological activities with 48% and 50% alpha-helical content, respectively, each of which corresponds to 14 amino acid residues. VIP-(1-26) was 10% and threefold less potent in relaxant and binding activities, respectively, compared with VIP, and its 49% alpha-helical content resulted in 13 residues involved in the alpha-helix. Further truncation from 25 to 21 resulted in decrease in the alpha-helical content from 43% to 29%, corresponding residues from 11 to 6, the relaxant activity from 72% to 4%, and the affinity to the membrane from 60-fold to over 10(4)-fold less potency. In addition, disruption of the mid-chain and the N-terminus in the alpha-helical stretch by oxidation of Met(17) and deletion of Thr(11) also inhibited biological activities. These findings suggest that the presence of alpha-helical structure forming in 14 amino acid residues between position 10 and 23 in VIP is essential to its biological functions and the C-terminal amino acid residues between position 24 and 27 are requisite for this alpha-helical formation.     

Effects of oolong tea on plasma antioxidative capacity in mice loaded with restraint stress assessed using the oxygen radical absorbance capacity (ORAC) assay

In the present study, we investigated the antioxidative effect of oolong tea in vitro and in vivo using the oxygen radical absorbance capacity (ORAC) assay. An oolong tea extract, catechin and related compounds suppressed the oxidation of fluorescence induced by AAPH in a dose-dependent manner, that is, they prolonged the antioxidant time in vitro. Oral administration of the oolong tea extract to mice treated with restraint stress increased ORAC activity in plasma as compared with a stress control group. The extract also increased plasma vitamin C levels, and there was a good relationship between ORAC activity and the vitamin C level in plasma. The elevation of plasma ORAC and vitamin C level may have been related to the stress-relieving effect of oolong tea. These effects are probably due to the antioxidative properties of the tea. Thus, these findings suggested that oolong tea has beneficial effects on health related to its antioxidative action.