The advantages of the application of amnion membrane in the treatment of burns.

A crucial and important factor for successful treatment of burns is the early covering of the burned area with skin substitutes. The covering of the burn requires material that restores the epidermal function and integrates itself into the process of healing. Biological dressings are the golden standard for the temporary covering of burns. All biological skin substitutes are susceptible to early graft reaction and the only exception is the amnion membrane. The importance of the amnion membrane as a biological dressing for burns amounts to: a barrier to bacterial colonization, hastens the epithelisation, and control of water loss. Amnioplasty is a method of application of amnion membrane on the recipient site. In this comparative study, 60 patients with dermal and sub-dermal burns were included. Research was made on an examination group of 30 patients with burns where the method of amnioplasty was applied, and for this amnion membrane conserved in 76% alcohol was used. The control group was made up of 30 patients with burns treated conventionally, and standard methods for the local treatment of burns were applied: exposition, occlusive dressing and initial excision with skin grafting. Pathohistological and microbiological analyses of the bioptical material were made. The degree of the burns was determined through a pathohistological analysis of the bioptical material taken the third day, and in some of the subjects where re-epithelialization was determined on the seventh day, the further re-epithelialization was observed clinically. Pathohistological examination enabled discrimination between bacterial colonization and the invasive bacterial infection. Furthermore, the type of bacterial colonization and infection was determined, which was confirmed with microbiological analysis. The analysis of the results from the microbiological and pathohistological researches of the bioptical material according to the bacterial colonization and infection showed that, although between the examined and the control group there was no statistically important difference, the value of p = 0.067 is close to the statistically important value of p < 0.05. The results of the pathohistological examination of the bioptical material taken the seventh day and analysed according to the re-epithelialization showed that there was a significant difference between the two groups of p < 0.035. It should be mentioned that, although according to the microbiological examinations of the bioptical material a statistically significant difference was not achieved, clinical significance was achieved. The obtained significance of p < 0.035 compared to the re-epithelialization in both groups approved the application of the method of amnioplasty. The histological analysis of the bioptical material not only determines the degree of the burns specifically, but facilitates the choice of method for further treatment, observes the speed of the re-epithelialization and plays an important part in the correct diagnosis and the early start of the specific therapy, important in preventing sepsis. The application of amnion membrane as a biological dressing speeds the re-epithelialization and prevents invasive bacterial infection. Pathohistological examination of the burns is recommended to be established as a standard method in clinical practice.

Novel messenger RNA and alternative promoter for murine acetylcholinesterase.

A portion of the 5'-flanking region of murine acetylcholinesterase was cloned from genomic DNA by 5'-rapid amplification of genomic ends, identified in a mouse genomic library, and sequenced. Multiple potential binding sites for universal and tissue-specific transcription factors were suggestive of a promoter region within this DNA sequence. Potential promoter activity was confirmed by coupling the new sequence to the open reading frame of a luciferase reporter gene in transient expression experiments with nerve and muscle cells. 5'-Rapid amplification of cDNA ends with templates from multiple sources revealed a novel transcription start site (at position -626, relative to translation start), located 32 bases downstream from a TATAA sequence. This start site appeared to mark a novel exon (1a) comprising 291 base pairs between positions -335 and -626, relative to the translation start. Supporting this conclusion, polymerase chain reactions with cDNA from mouse brain, heart, and other tissues, consistently amplified a transcript containing the exon 1a sequence fused to the invariant sequence beginning at position -22 in exon 2, but lacking exon 1. Northern blot analyses confirmed the in vivo expression of exon 1a-containing transcripts, especially in heart, brain, liver, and kidney. These results indicate that the murine acetylcholinesterase gene has a functioning alternative promoter that may influence expression of acetylcholinesterase in certain tissues.

[The characteristics of the electrical activity of the human colon recorded noninvasively]. / Kharakteristika na elektricheskata aktivnost na kolona u chovek, registrirana neinvazivno.

In ten healthy volunteers and ten patients with diseases involving the upper section of the gastrointestinal tract (chronic cholecystitis, chronic gastritis) the electrical activity of the colon is registered noninvasively using skin electrodes to the projection site of sigmoid and colon descendens. Recordings are taken with original gastrograph. Apart from the electrocolograms (EColG), the changes in intracolonic pressure in the group of 10 patients are also registered. Pressure recordings (mechanogram--MG) are done in physioscript "Hellige". Two types of EColG waves are identified depending on their frequency: 1) type A waves with frequency 5.86 +/- 0.59 cpm, and 2) type B waves with frequency 2.35 +/- 0.25 cpm. Type A are low-amplitude waves and correspond to the type A waves seen in the EColG of dogs (described by the authors elsewhere), characterizing the calm period of colonic motility. When A waves appear in the EColG no changes in the mechanograms are registered. Type B are high-amplitude waves, corresponding to the B waves in dogs (described elsewhere); as shown by the mechanograms, the appearance of B waves in the EColG is followed by the appearance of high-amplitude waves--the active period of colonic motility. There is a significant difference between the frequencies of either type of EColG waves and the frequency of waves in the electrogastrograms (EGG) registered synchronously with EColG.

[The reactivity of canine colonic and ileal smooth muscle to carbachol (Jestryl)]. / Reaktivnost na gladuk muskul ot kolon i ileum ot kuche kum karbakhol (Jestryl).

Experiments were carried out on longitudinal and circular smooth-muscle strips isolated from the ileum and colon of healthy dogs (controls) and of dogs with local peritonitis. The changes in the contractile responses of the strips to carbachol administered cumulatively were studied, and the EC50 and pD2 values were calculated from the dose-response curves. For the colonic longitudinal strips the EC50 was 6 x 10(-8)M and the pD2 was 7.58. The pD2 for the ileal longitudinal strips was 7.83. The pD2 value for the circular strips from the ileum and colon was 7.19 and 8.87 respectively. In the dogs with local peritonitis, the sensitivity of the longitudinal strips to carbachol was higher (the pD2 for the ileum was 7.86 and for the colon-7.21) as compared to the circular strips (the pD2 for the ileum was 6.22 and for the colon-6.65). The affinity of the cholinoreceptors in the ileal circular strips to carbachol was decreased as compared to controls.

Lysine transport in human kidney.

The lysine renal tubular transport was studied in a patient with an unusual trait of the membrane transport inborn error characterized by persistent hyperlysinemia with hyperlysinuria. Plasma and urine concentrations of dibasic amino acids were measured basally and at different time intervals after oral lysine loading (300 mg per kg body weight). Compared with controls, the patient's basal urinary excretions were significantly elevated, especially that for lysine. Concentrations of plasma and urine cystine in the patient were within normal ranges and were not affected with lysine loading. These data, as well as the absence of other symptoms exclude the possibility that this may be the case of cystinuria or a lysinuric protein intolerance trait. The results suggest as follows: (a) in the human kidney the tubular transport of lysine occurs via two kinetically distinct systems; (b) the high affinity lysine transport system operating at a low lysine filtered load is common to all three dibasic amino acids; (c) the low affinity lysine transport system operating at a high lysine filtered load is more specific to lysine and has a greater capacity; (d) in the patient observed the high affinity transport system is impaired for all three dibasic amino acids, especially that for lysine; the affinity for lysine is, compared to controls, about three times lower; the lysine capacity of the low affinity lysine transport system is about ten times lower than that in controls; at the same time a great amount of the patient's arginine is reabsorbed by this transport systems. The case reported indicates a clinical heterogeneity of human hereditary disorders of the membrane transport.

[Changes in the properties of smooth muscle cells of the fundus portion of the stomach after removal of the body and antral portion]. / Izmenenie svoistv gladkomyshechnykh kletok fundal'nogo otdela zheludka posle udaleniia tela i antral'nogo otdela.

Sucrose-gap and microelectrode techniques revealed that the spatial constant (value of electrotonic spread of the slow potential) was greater in fundal portion of stomach with removed body and antral portion than in intact stomach. This finding suggests an increased conductivity of the fundal portion muscle tissue after removal of evacuatory and hormone--producing portions of the stomach. The sodium--calcium nature of the slow potential was revealed in the membrane of fundal smooth muscle cells. After removal of the stomach body and antral portion the permeability of smooth muscle cells is altered in the stomach fundus and the slow potential becomes the same as in the stomach wall of intact dogs. This mechanism of electrophysiological alteration maintains the evacuatory function after removal of the stomach body and antral portion.

[Relations between the electric activity of the pyloric sphincter and activities of the stomach and duodenum]. / Zavisimost' élektricheskoi aktivnosti piloricheskogo sfinktera ot aktivnosti zheludka i dvenadtsatiperstnoi kishki.

Indwelled electrodes led electrical activity from the stomach, pyloric sphincter and duodenum in hunger, after feeding or administration of carbachol and morphine as well as after transthoracic vagotomy. In intact resting animals the pyloric sphincter develops slow potentials in the rhythm of stomach antral portion and sometimes in the rhythm of duodenum. Acceleration of the slow potentials rhythm occurring after transthoracic vagotomy in the stomach antral portion, develops in the pyloric sphincter as well. Spike activity of the antral portion spreads over to the sphincter depending on amplitude, frequency and duration of the burst of spikes. Migrating myoelectrical complex develops successively in the stomach antral portion and in the pyloric sphincter. During increased activity of the duodenum (after carbachol or morphine) the bursts of spikes in the rhythm of the duodenum slow waves can occur simultaneously in the pyloric sphincter, too.

[Restoration of the electrical activity and nervous apparatus following section of the stomach wall in dogs]. / Vosstanovlenie élektricheskoi aktivnosti i nervnogo apparata posle pererezki stenki zheludka sobak.

In dogs, transection of the gastric wall at the level of incisura angularis, followed by end--to--end anastomosis, was made. The electrodes were implanted into the muscle wall of the two stomach segments. Electrical activity of the stomach wall on the 1st postoperative day showed dissociation in the spike activity between the two segments. 10 days later, first signs of sequence in the spike activity of the stomach above and below the anastomosis appeared. Microscopic examination revealed that regenerating nerve fibers formed a bridge over the scar. On the 16th day, groups of spike potentials from the gastric wall above the section propagated also in the stomach region below the anastomosis. Since the 14th day, the microscopic examination revealed newly formed synaptic endings on the ganglionic cells distal to the scar. After the 20th day, all signs of dissociation began to disappear.