Lower extremity reconstruction after necrotising fasciitis and necrotic skin lesions using a porcine-derived skin substitute.

Seven consecutive clinical cases of necrotising fasciitis or necrotic skin lesions (42-78 years old; average 65.0 years of age, three females and four males) due to group A Streptococcus, group B Streptococcus, methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa in the lower extremities, who demonstrated rapid systemic symptoms, were investigated for the usefulness of a bilayer artificial dermis, derived from porcine tendons, over 4 +/- 2.4 years (1-7 years). All surgical debridement was confirmed as sufficiently deep and wide for clinically infected lesions and artificial dermis was applied to all wounds. The average interval to secondary split-thickness skin grafting was about 17.5 days (17.5 +/- 2.44 days, 21 days max., 14 days min.) and the average thickness was 0.009 +/- 0.0022 in. (range: 0.006 - 0.012 in.). No clinical problems were noted during the application of the artificial dermis and the subsequent skin grafting. Since, the donated skin graft was thin, the morbidity was minimised. The use of artificial dermis after extensive surgical debridement in necrotising fasciitis was easy and effective. Local or systemic infection was negligible.     

A study of comparison between Technicon THMS H-2 and Hematrak 590]

Using 655 peripheral blood samples from normal individuals and patients, we evaluated the relationship between the measurements of red blood cell (RBC) and white blood cell (WBC) through the Hematrak 590 (Hematrak) and the generated flag systems in the Technicon H-2 (H-2). 1) Among the 12 VAR (Variation) flag positive samples in H-2, 10 samples were obtained from the patients receiving blood transfusions. The samples with high values of HDW (Hemoglobin distribution width) in H-2 seemed to have hypochromatic and polychromatic changes in RBC. 2) Hematrak is likely to be more sensitive than H-2 in discovering atypical lymphocytes (AL). When AL counts in Hematrak were over 5 or 6% of WBC, these results were coincident with ATYP flag positive in H-2. 3) In our examinations, when %Blast in H-2 was over 4%, BLASTS flag always generated positively. We think that H-2 is a tool with high reproducibility for the detection of the blast-like abnormal cells. 4) We evaluated the results of WBC differential count by the three methods of H-2, Hematrak and manual procedures in the peripheral blood samples from normal individuals. We recognized close correlations in neutrophils, lymphocytes and eosinophils (coefficients of correlation = 0.826-0.911), and relatively close ones in monocytes (r = 0.280-0.562), but no correlations in basophils (r = 0.106-0.281). To comprehend the pathophysiological states of the various diseases hematologically, it is necessary to understand the characteristics of the different measurement principles between the two instruments (H-2 and Hematrak).     

Lack of modifying effects of atrazine and/or tamoxifen on thyroid carcinogenesis in rats pretreated with N-bis(2-hydroxypropyl)nitrosamine (DHPN)

The modifying effects of atrazine, and/or tamoxifen, on thyroid carcinogenesis were investigated in a rat two-stage carcinogenesis model following N-bis(2-hydroxypropyl)nitrosamine (DHPN) initiation. Five-week-old male F344 rats were given a single subcutaneous injection of DHPN (2800 mg/kg, body weight) or vehicle alone. Starting 1 week later, the animals were fed a diet supplemented with 0, 5, 50 or 500 ppm of atrazine, 500 ppm atrazine plus 5 ppm tamoxifen, or 5 ppm tamoxifen in the DHPN-treated groups, and 0 or 500 ppm of atrazine in the DHPN-untreated groups for 24 weeks. At autopsy major organs, including the thyroid, pituitary, liver, kidney, testis, epididymis, and brain, were collected and histopathologically examined. Body weights were significantly (P<0.05) decreased by the high doses of atrazine or tamoxifen, the effect being enhanced in combination. Relative thyroid weights were significantly increased (P<0.05) only in the tamoxifen-treated group and pituitary weights were elevated with 500 ppm atrazine plus tamoxifen (P<0.05). Relative liver weights were increased by the high dose of atrazine. However, the atrazine and/or tamoxifen treatments did not induce significant histopathological changes in the major organs, including the thyroid, nor cause significant changes in serum TSH levels. These results suggest that neither atrazine nor tamoxifen may promote thyroid carcinogenesis, alone as well as in combination.     

Responses of periodontal nerve terminals to experimentally induced occlusal trauma in rat molars: an immunohistochenmical study using PGP 9.5 antibody

The response of periodontal nerves to experimentally induced occlusal trauma in rat molars was assessed by immunohistochemistry for protein gene product 9.5 (PGP 9.5) at light and electron microscopic levels, and by computerized image analysis. The occlusal surface on the left upper first molar of 8-wk-old male Wistar rats was raised approximately 1 min under ether anaesthesia. The rats were perfusion-fixed on d 1, 2, 3, 4, and 7 after bite-raising and then decalcified for 2–3 wk. Frozen sagittal cryostat sections were stained by the avidin-biotin complex method. By the second day after bite-raising many Ruffini endings were swollen and their outline unclear at the light microscopic level. Transmission electron microscopy disclosed PGP 9.5 reaction products within Ruffini endings that had unusually long cytoplasmic projections extending through enlarged slits of the Schwann sheaths and also diffuse extracellular PGP 9.5-immunoreactivity near the Ruffini endings. From d 2 to 4, thin nerve fibres on the pressure side of the periodontal ligament were orientated irregularly and had a prominent beaded appearance. An increase in beaded nerve terminals occurred at d 2–4 post elevation, and decreased later. These results suggest that occlusal trauma induces specific changes in the distribution and shape of nerve terminals in the periodontal ligament.     

Immunoreactive opsin and glial fibrillary acidic protein in persistent hyperplastic primary vitreous

An 8-month-old boy had an anterior type of persistent hyperplastic primary vitreous in the right eye. Results of needle biopsy, performed because of elevated intraocular pressure, disclosed clusters of blastic cells. The eye was enucleated on the suspicion of retinoblastoma. Histological examination showed retrolental fibrovascular tissue and retinal dysplasia. Immunoreactive opsin was detected in the innermost structures and in photoreceptor-like cells of rosettes. We conclude that photoreceptor cells differentiated to express opsin, even when neighbouring cells were abnormally arranged. An immunocytochemical study of glial fibrillary acidic protein demonstrated glial proliferation in the inner layer of the retina but not in the preretinal space.     

Antinociceptive Interaction of Intrathecal alpha sub 2 -adrenergic Agonists, Tizanidine and Clonidine, with Lidocaine in Rats

Background: The intrathecal alpha2 -adrenergic agonist, clonidine, has been shown to have considerable antinociceptive effect, although clonidine causes hypotension and bradycardia The combination of intrathecal clonidine and local anesthetics enhances analgesic effects, whereas the combination may cause marked hypotension and motor blockade, which may limit the clinical application of the combination. Tizanidine, another alpha2 -adrenergic agonist, has also provided antinociception without producing pronounced hemodynamic changes. This study was designed to evaluate the antinociceptive and hemodynamic interactions of tizanidine and clonidine with lidocaine.

Methods: Male Sprague Dawley rats were chronically implanted with lumbar intrathecal catheters. The tail-flick test was used to assess the thermal nociceptive threshold. The ability of intrathecal tizanidine, clonidine, lidocaine, or the combinations of alpha2 -adrenergic agonist and lidocaine to alter the tail-flick latency was examined. To characterize the antinociceptive interaction, the isobolographic analysis was applied. Additionally, the motor function, blood pressure and heart rate after intrathecal administration of drugs and combinations were also monitored.

Results: Intrathecal tizanidine, clonidine, or the combinations increased the tail-flick latency in dose- and time-dependent fashion without affecting motor function. The order potencies (dose producing a 50% of peak effect, in micro gram) of tizanidine and clonidine were 1.8 and 0.75, respectively. With isobolographic analysis, tizanidine with lidocaine and clonidine with lidocaine showed significantly synergistic antinociceptive interaction. Potency ratio analysis and fractional analysis also confirmed the synergistic interaction. At the doses in the combinations showing comparable antinociception, tizanidine with lidocaine, unlike clonidine with lidocaine, did not affect motor function or blood pressure.     

Pulmonary hemodynamics and home oxygen therapy in patients with chronic respiratory failure]

The authors examined pulmonary hemodynamics with respect to underlying diseases, severity and type of chronic respiratory failure, and the incidence and effect of home oxygen therapy (HOT) in 155 patients with chronic lung diseases (old pulmonary tuberculosis (OTB) 45, chronic pulmonary emphysema (CPE) 54, chronic bronchitis (CBR) 42 and fibrosing lung disease (FLD) 14). They underwent right heart catheterization during a stable period, while breathing room air. The arterial PO2 ranged from 64.3 +/- 9.7 Torr (CBR) to 69.9 +/- 10.0 Torr (CPE), and the mean pulmonary arterial pressure ranged from 17.3 +/- 4.6 mmHg (CPE) to 20.6 +/- 5.4 mmHg (OTB). The incidence of pulmonary hypertension (PH, PA mean greater than or equal to 20 mmHg) was 53.3% in OTB, 40% in CBR, 35.7% in FLD, 23.8% in CPE, 69% in respiratory failure, 40% in quasi-respiratory failure, and 2.1% in non-respiratory failure. The percentage of patients who received HOT was 84.5% in respiratory failure and 54.1% in quasi-respiratory failure. Comparing Type I with Type II chronic respiratory failure, the incidence of PH was lower in the former than the latter (38.3% vs 80.6%), whereas HOT was applied to an equal percentage of patients (67.4%) in both groups. The effect of HOT was evaluated in 11 patients with chronic respiratory failure. The mean pulmonary arterial pressure was 22.7 +/- 4.7 mmHg before HOT, and decreased to 20.7 +/- 5.6 mmHg after 24.5 +/- 10.1 months of HOT. Although this difference was not significant statistically, this result suggests the desirable effect of HOT on pulmonary hemodynamics.     

Electric microtrephine for new anterior capsular openings (barbell-like tear-free slit openings)

We developed a microtrephine that can be used to create 0.9-mm or 0.5-mm, round, tear-free, anterior lens capsular openings. The 0.9-mm tip can be used to greatly facilitate experimental endocapsular cataract surgery followed by lens refilling. The 0.5-mm tip is useful for obtaining new anterior capsular openings.     

Effects of calcium in continuous cardioplegia on myocardial protection

The effects of calcium (Ca) on a hyperkalemic cardioplegic solution for continuous cardioplegia were examined in an isolated perfused working rat heart model. The coronary arteries were perfused with a modified Krebs-Henseleit bicarbonate buffer (K-H) solution, containing various concentrations of Ca(0.1, 0.6, 1.2, and 2.5 mmol/l) and a high concentration of potassium (20 mmol/l), for 180 min, after which cardiac arrest was induced at 37°C for 180 min. Cardiac function and creatine kinase (CK) were measured. In the control group, K-H solution was infused in place of the cardioplegic solution, and cardiac arrest was not induced. No significant differences were observed between the groups infused with the K-H solution containing Ca concentrations of 0.6, 1.2, and 2.5 mmol/l in the percent recovery of aortic flow (82.1±2.9%, 80.6±2.0%, and 71.5±3.7% (mean±SEM) respectively) or in the recovery of other indices of cardiac function, or in CK leakage. There were also no significant differences in the recovery of cardiac function and CK leakage between these groups and the control group. In the Ca 0.1 mmol/l group, however, the characteristic Ca paradox was observed. These findings suggest that if the Ca concentration in a cardioplegic solution is higher than 0.6 mmol/l during continuous cardioplegia, excellent cardioprotective effects will be achieved.     

Flat adenoma and flat mucosal carcinoma (IIb type)— A new precursor of colorectal carcinoma?

Two flat adenomas and a flat mucosal carcinoma of the colon were reported in patients with synchronous and metachronous colonic carcinomas. These lesions were almost flat and were not detected by preoperative endoscopic examinations. Colonoscopists should be aware of the presence of flat adenomas, which can be easily missed, and recognize them as lesions that play an important role in the "adenoma-carcinoma sequence."