Microvascular corrosion casting of normal tissue, transitional mucosa and adenocarcinoma in the human colon.

The microcirculatory architecture of normal tissue, transitional mucosa and adenocarcinoma of the human colon was investigated with microvascular corrosion casting (MVCC) combined with scanning electron microscopy (SEM). The study showed that the capillaries within the normal mucosa were arranged in a regular hexagonal pattern around the mucosal glands and that the microvessels of transitional mucosa mostly had lost the typical hexagonal pattern and become slightly wider in diameter. The microvessels in the tumor periphery were increased in number and disorganized, and presented large variation in morphology with claw-like formations, widened sinuses, diverticula and appendixoid patterns. Microvessels were lacking in the central areas of tumors. These morphological alterations may serve as additional indicators of tumor development.     

Visual integration of data and basic motor skills under laparoscopy

Background: The qualities of visual perception and of motor reaction to the visual stimulus have never been studied in reference to the type of video-camera system (2-D vs 3-D) used during laparoscopy. Methods: The study was designed in two parts. The first evaluated the ability of the eye to discriminate how objects are spaced relative to one another. The second investigated the motor reaction to the visual stimulus in an environment where depth was the preponderent cue. The tests were performed in a pelvi-trainer in which were inserted different modules built either for visual observation (Part 1) or for evaluation of motor ability (Part 2). Variables studied during Part 1 were the time required to do the test and the number of errors committed during its performance. The variable evaluated during Part 2 was the time needed to terminate the test. Each of these two parts of the study were completed alternating the 2-D and 3-D systems. A total of 304 observations were recorded. Statistics used were the paired t-test, the independent group t-test, and the Newman-Keuls multiple comparisons test. Results: Results of Part 1 of the study confirm that visual perception varies significantly among individuals (n = 10) (p < 0.05) and that a true 3-D video-camera system facilitates visual perception when compared to a 2-D system (p < 0.001). Results of Part 2 of the study also show significant differences among participants (n= 9) (p < 0.05). The true 3-D system allowed significantly faster motor performances than the 2-D system (p < 0.001). Conclusion: Our experiment shows that the 3-D system allowed significant improvements in the execution of the evaluated parameters. Also noted were significant differences among participants in term of visual and motor skills.     

The lumbar and lumbosacral facet-syndrome. Diagnostic measures,surgical treatment and results in 119 patients

Summary The authors present their diagnostic and therapeutic protocol as well as the surgical outcome in a series of 119 patients with the lumbar facet syndrome.By use of different surgical techniques such as translaminar screw fixation (n=56), Louis plate fixation (n=36), Cotrel-Dubousset instrumentation (n=11) and soft system stabilization according to Graf (n=14) excellent, good, satisfactory, moderate and poor results were obtained in 78 (67%), 20 (17%), 14 (12%), 4 (3%), and 1 (1%) instances, respectively.     

Taurine entry into perilymph of the guinea pig

Taurine is a β-aminosulfonic acid and is a ubiquitous amino acid whose role in the cochlea is not well established. In this study, its entry from blood into perilymph was investigated in the guinea pig as animal model. The penetration rate of [³H]taurine (molecular weight 125) into the perilymph of the scala vestibuli was measured 1 and 2 h after the intravenous infusion of [³H]taurine in nephrectomized animals. Results showed a rate of penetration in perilymph related to plasma at 36 ± 4.7% (n = 5) after 1 h and 43 ± 5.6% (n = 5) after 2 h. Compared to the penetration rate of urea (molecular weight 60) and mannitol (molecular weight 186) reported previously in rats, a passive entry of taurine into perilymph through the blood-perilymph barrier is suggested. Received: 30 July 1997 / Accepted: 15 January 1998     

Different effects of intracellular and extracellular TEA on voltage-dependent K currents of acutely isolated hippocampal CA1 neurons.

Tetraethylammonium (TEA) effects on K currents were examined on either side of the membrane of hippocampal CA1 neurons by means of whole-cell voltage-clamp recording and intracellular perfusion. Recording media contained ion channel blockers to allow the selective activation of voltage-dependent K currents which consisted of a rapidly decaying component (A-current) and a delayed component. Voltage protocols were applied to separate the A-current from the delayed component. Results show that 10 mM extracellular TEA suppressed 50 +/- 11% (S.D., n = 4) of the delayed current at different levels of depolarization but had little effect on the A-current. In contrast 10 mM TEA applied by intracellular perfusion suppressed the A-current by 42 +/- 10% (S.D., n = 4) in addition to inhibiting the delayed currently 55 +/- 15% (S.D., n = 4). Both the intracellular and extracellular actions of TEA on K currents showed no voltage- nor time-dependency. The results suggest that voltage-dependent transient current (A-current) is mediated through a separate group of ionic channels distinct from those that sustained the delayed current. Furthermore, the asymmetrical effects of intracellular and extracellular TEA on the transient current are similar to those described for the A-current in molluscan neurons. This observation supports the notion that the structure of the ion channel mediating the A-current is closely conserved across different species.     

A comparative study of pepsinogen (PG) and lactic acid dehydrogenase (LDH) activities and isoenzyme patterns in tissues from human primary gastric cancer, gastric cancer xenografts in nude mice and gastric cancer cell lines]

Tissue and cell homogenates were prepared for PG and LDH study from 20 samples of histologically proven gastric cancer (GC), 6 samples of gastric cancer xenografts (THPGC-1) of different passages (GCXG) and cultured cells of 3 different gastric cancer cell lines (GCCL). Normal gastric mucosa (NGM) was also obtained from the resected stomach far distant from the primary tumor and histologically tumor free. The results indicated that the expression of PG isoenzymes was low or absent and the PG activities were significantly decreased in GC, GCXG and GCCL as compared to NGM. The activity of LDH was also significantly increased in GC, GCXG and GCCL. In addition, there was a change in isoenzyme pattern in GC and GCXG in which isoenzyme type M was observed whereas isoenzyme type H was preponderent in NGM. The results show that the human gastric cancer xenograft, THPGC-1, has biological properties very similar to those of the primary tumor suggesting that THPGC-1 is a reliable model for the study of the molecular biology of human gastric cancer.     

Surgical treatment of primary small cell carcinoma of the esophagus. Clinical analysis of 11 cases]

545 cases of esophageal carcinoma were confirmed histologically and by esophagoscopic biopsy between Jan. 1982 and May 1990. Primary small cell carcinoma was identified in 19 cases. Of 11 patients confirmed operatively, 5 had oat cell carcinoma, 4 combined oat cell carcinoma and 2 intermediate cell carcinoma. The mean overall survival period was 13.9 months. The longest survival period was 27 months. The prognosis of primary small cell carcinoma was poorer than that of squamous carcinoma of the esophagus because of its propensity of spread and metastasis. Once the diagnosis of small cell carcinoma was established, surgery was undertaken as early as possible. For patients who had lymph node metastasis at the time of diagnosis, we recommended surgical treatment plus systemic chemotherapy after operation. To increase the resection rate, it is important to do chest CT scan, bronchiofiberscopy and B-type ultrasonography before operation.