Non-marine ostracodes from highland lakes in East-central Mexico / Ostrácodos no-marinos de lagos en el altiplano este-centro de México

The ostracode fauna of the neartic-neotropical transitional zone has remained poorly known until this study. Ten ostracode species inhabit ten highland lakes (five maar lakes (phreatic/phreato-magmatic explosion origin), one volcanic-tectonic lake, three natural dams and one man-made dam) in East-central Mexico. Surface sediments from the deepest part and the littoral zone from all studied lakes were collected. Environmental variables (pH, temperature, dissolved oxygen, conductivity, TDS) were measured in situ and parallel water samples for chemical analysis were collected for habitat description. Widely distributed species in the study area (≥5 lakes) include Cypridopsis vidua, Darwinula stevensoni and Eucandona cf. patzcuaro. Limnocytherina axalapasco is an endemic species and was collected in three maar lakes and in one man-made dam. Rare species included: Chlamydotheca arcuata?, Fabaeformiscandona acuminata?, Ilyocypris gibba?, Limnocythere friabilis?, Potamocypris smaragdina? and Potamocypris unicaudata?. Highest species richness (6 spp.) was found in the large and shallow Lake Metztitlán (2.6km², 5.5m deep), with the lake water type HCO3->>SO4²->Cl--- Ca2+>Na+>Mg2+. The rest of studied lakes (<63m, <27km²) had not more than three species. For instance, only two ostracode species were collected in Lake Alchichica, which is the largest, deepest and most saline studied maar lake. Rev. Biol. Trop. 63 (2): 401-425. Epub 2015 June 01.

La fauna de ostrácodos de la zona de transición néartica-neotropical ha sido poco estudiada hasta este estudio. En el este-centro de México, habitan diez especies de ostrácodos en diez lagos: cinco lagos maar (originados por explosiones freáticas/freato-magmáticas), un lago volcánico-tectónico, tres embalses naturales y un embalse artificial. De la parte más profunda y de las zonas litorales de todos los lagos estudiados se recolectaron sedimentos superficiales para el análisis de ostrácodos. También se midieron in situ las variables ambientales: pH, temperatura, oxígeno disuelto, conductividad, SDT, además se recolectaron muestras de agua paralelas para análisis químico con el objetivo de describir el hábitat. Especies con una amplia distribución en el área de estudio (≥5 lagos) incluyen: Cypridopsis vidua, Darwinula stevensoni y Eucandona cf. patzcuaro. Limnocytherina axalapasco es una especie endémica y fue recolectada en tres lagos maar y en el embalse artificial. Especies raras incluyeron: Chlamydotheca arcuata?, Fabaeformiscandona acuminata?, Ilyocypris gibba?, Limnocythere friabilis?, Potamocypris smaragdina? y Potamocypris unicaudata? La riqueza de especies más alta (6 spp.) se encontró en el lago más extenso y somero, lago Metztitlán (2.6km², 5.5m de profundidad), con el tipo de agua HCO3->>SO4²->Cl--- Ca2+>Na+>Mg2+. El resto de lagos estudiados (<63m, <27km²) presentaron no más de tres especies. Por ejemplo, solamente dos especies de ostrácodos fueron recolectadas en el lago Alchichica, el cual es el más extenso, profundo y salino entre los lagos maar estudiados.

Preliminary study of CT characteristics for intestinal obstruction transitional zone / 实用放射学杂志

Objective To analyze multislice CT characteristics of intestinal obstruction transition zone caused by different patholo-gy.Methods 67 cases of intestinal obstruction were collected in our hospital.Multislice spiral CT scan combined with multi-plane re-organization (MPR)of the bowl obstruction transitional zone were analysed.Results Among 67 cases of intestinal obstruction,there were 28 cases of simple mechanical intestinal obstruction,1 7 cases adhesion intestinal obstruction,5 cases paralytic intestinal obstruc-tion,4 cases internal hernias and 4 cases mixed intestinal obstruction.Conclusion Intestinal canal transitional zone and arounding tis-sues of intestinal obstruction have certain characteristics for the same pathology which can be clearly displayed by multislice CT scan combined with MPR.

Transitional Zone of the Corneal Endothelium: Flat Preparation and Ultrastructural Findings

PURPOSE: To evaluate the morphological characteristics of the transitional zone between the corneal endothelium and the trabecular meshwork by flat preparation and electron microscopy. METHODS: The materials comprised 12 eyes examined by the flat preparation and 7 eyes by the electron microscopy. The specimens were derived from the transitional tissue between the corneal endothelium and the trabecular meshwork. The specimens in the flat preparation were stained with hematoxylin-eosin and examined by light microscopy. The specimens for scanning electronic microscopy (SEM) and in transmission electronic microscopy (TEM) were examined through routine processes. RESULTS: In the specimens examined by the flat preparation, unlike peripheral corneal endothelial cells, the endothelial cell nuclei in the transitional zone were overlapped and morphologically oval. On SEM, unlike typical hexagonality and tight interdigitation of corneal endothelial cells, the endothelial cells in the transitional zone were partially successive, spaced intercellularly, and morphologically irregular. On TEM, the endothelial cells in the transitional zone were partially successive. CONCLUSIONS: The loss of cell-cell contact of endothelial cells in the transitional zone may lead to the potential proliferation capacity of endothelial cells in the transitional zone under specific conditions. Therefore, further studies on the proliferation capacity of endothelial cells in the transitional zone are needed together with more research on cell biology.

Morphological and Biochemical Changes in Bone-to-tendon Insertion Site after Achilles Tendon-Bone Graft in Rabbits / 대한정형외과연구학회지

Allografts or autografts of bone-tendon unit has been used widely for ligament or tendon reconstruction of ligament injuries or ligament deficiencies after limb salvage operation to treat malignant bone tumors around joints. While the remodeling process of the ligament or tendon itself after allograft or autograft and the microscopic and biomechanical changes of tendon- bone graft interface have been widely investigated, little is known about the ultrastructural and biochemical changes of the transitional zone in tendon-bone junction. This study was performed to analyze the morphological changes by microscopic (part I), and ultrastructural, and biochemical remodeling of the transitional zone after tendon-bone auto- and allo-grafting (part II). Preliminary, a microscopic studies at bone to tendon insertion site was done as control (part I). And as an experimental work (part II), a total of twenty four rabbits were divided into two group. In 12 animals (allograft group), an Achilles tendon-bone unit was taken with tenotomy 3 cm proximal to calcaneal attachment and osteotomy 5mm distal to the attachment site. This unit was preserved below -70degrees C for 2 weeks and then it was transplanted to another rabbit. In the other 12 animals (autograft group), the Achilles tendon-bone unit was harvested with the same maneuver from one side and transplanted to the other side of the rabbit. After operation, their legs were immobilized with short leg cast for 4 weeks, and then mobilized freely. Four animals in each group were sacrificed at four, eight and sixteen-weeks after transplantation, and their grafted Achilles tendon-bone interfaces were used for analysis of the ultrastrucural and biochemical changes. The following results were obtained. Part I: We conducted an experiment (part I) to investigate the histologic chronologic changes of tendon to bone fixation using the Cole's method and the role of periosteum to the tenodesis. The periosteum around the tenodesis was excised in group I, but it was incised longitudinally and sutured to tendon in group II. As a result, the tendons in the marrow cavity of tibia were firmly fixed by fibrosseous metaplasia in group I at 8 weeks after experiment, but not formed the fibrocartilagenous layer in both groups as a transitional zone of internal stress transmission from tendon to bone in normal tendon, and the group II show the firm connection between sutured periosteum and transferred tendon by external calluses after 3 weeks. These mean the periosteum should be sutured over the inserted tendon to get the early rigid fixation by the induction of external callus around the edges of the tendon to bone insertion. Part II: Histologically in part II experiment, new cartilage cells were observed at postoperative 16 weeks with locally presence of faint tidemark in the autograft group but not in the allograft group. Complete histological remodeling of the transitional zone had not restored both groups.. Ultrastructural analysis revealed no definite differences, but showed time-related restoration of fibers and fibroblasts between both groups except the slightly rapid appearance of parallelism and cross-striation of microfibrils in the autograft group. From biochemical analysis, type I collagen was increased in its concentration, and an early rapid increase of type III collagen and glycosaminoglycan was also observed. In conclusion, these data suggested that type III collagen and glycosaminoglyan are important in stabilization of grafted tendon-bone unit, especially in the transitional zone. The histological and biochemical changes in allograft group were relatively similar to that of autograft group although the allograft group showed the delayed pattern of remodeling. And so the tendon-bone allograft could be used as a good but second substitute followed by autograft.

The Predictors of Acute Urinary Retention in Patients with Benign Prostatic Hyperplasia / 대한비뇨기과학회지

PURPOSE: Acute urinary retention is one of the most severe complications in patients with benign prostatic hyperplasia (BPH). We investigated the efficacy of age, International Prostatic Symptom Score (I-PSS), quality of life (QOL) score and various parameters obtained by transrectal ultrasonography (TRUS) as predictors of acute urinary retention. MATERIALS AND METHODS: Of 153 patients with BPH, who underwent transurethral resection of the prostate, 72 were treated due to acute urinary retention (retention group) and 81 due to lower urinary tract symptoms (symptomatic group). TRUS was used to calculate the total prostate (TP) and transitional zone (TZ) volumes, the transitional zone index (TZ index=TZ volume/TP volume) and the elongation ratio (ER=the ratio of the maximal anteroposterior to transverse diameter of the prostate). To compare the usefulness of various parameters between the retention and symptomatic groups, the area under the receiver-operating characteristic (ROC) curve was calculated for each parameter. RESULTS: There were significant differences in the TP and TZ volumes, the TZ index and the elongation ratio between both groups, but no significant differences in age, I-PSS or QOL score. In the retention group, the most effective cutoff values were 40cc, 20cc, 0.55 and 0.75 for the TP volume, the TZ volume, the TZ index and the elongation ratio, respectively. The area under the ROC curves were 0.894, 0871, 0843 and 0771 for the TZ index, the elongation ratio, the TZ volume and the TP volume, respectively. CONCLUSIONS: The TP and TZ volumes, the TZ index, and the elongation ratio are useful predictors of acute urinary retention in patients with BPH. The TZ index is the most useful predictor, and may be a useful parameter in selecting the treatment for BPH.

Is the Level of Anastomosis within the Anal Canal Pertinent to Physiologic and Functional Outcome in the Double-stapled Ileoanal Reservoir?

PURPOSE: The aims of this investigation were to access the relative ratio of epithelial types within the anal canal after a double-stapled ileoanal reservoir (DSIAR) and to review physiologic and functional differences based on this diversity in epithelial types. METHODS: According to types of the epithelium present at histologic sections of the distally excised tissue ring ("donut") after the stapling for restorative proctocolectomy with construction of a DSIAR, one hundred thirty-eight patients with ulcerative colitis were stratified into two groups: 40 patients (22 males and 18 females) were categorized to be of lower anastomosis (group I), where squamous, squamous mixed with columnar, or squamocuboidal component was reported to be present, and 98 patients (50 males and 48 females) to be of higher one (group II), which was evidenced by columnar epithelium at the "donut". Physiologic and functional parameters were appraised between 2 groups to define whether this difference in epithelial types is associated with a significant difference in postoperative anorectal functional outcome. RESULTS: None of preoperative parameters reflecting resting and squeeze pressures showed significant differences between 2 groups. Postoperative mean and maximal resting pressures (MRP and MxRP) were declined to 48.8 16.9 mmHg and 67.1 21.3 mmHg in group I, and 61.1 22.7 mmHg and 90.0 38.6 mmHg in group II, differences of which were significant (P=0.046 and 0.031, respectively). Neither postoperative mean nor maximal squeeze pressure was, however, statistically different between 2 groups. Mean length of the high pressure zone was decreased in both groups postoperatively, but there were no intergroup differences. Rectoanal inhibitory reflex decreased significantly from 97.4% to 50% in group I and from 86.5% to 53.9% in group II, respectively (P<0.0001 in both). However, there was no significant intergroup difference postoperatively. Maximal tolerance volume and compliance of the reservoir were significantly improved postoperatively in both groups; from 52.2 26.1 ml and 2.8 3.3 to 163.3 115.7 ml and 14.7 15.3 in group I (P=0.0001, and <.0001, respectively), and from 77.0 59.5 ml and 4.4 6.8 to 167.3 87.9 ml and 28.7 44.0 in group II (P<0.0001, both). But there was no intergroup difference in either parameters postoperatively. There were no significant differences between groups relative to functional outcome except the diurnal incontinence to solid stool (P<0.011). CONCLUSIONS: Although epithelial types were shown to be variable at the anal side of the anastomosis after a DSIAR, these differences were not associated with physiologic and functional differences. Therefore, if technically feasible, this procedure can be performed with safety without fear of significant functional derangement.

Volume of total prostate and volume of transitional zone in different age groups / 中华泌尿外科杂志

Objective To study the volume of total prostate and the volume of its transitional zone in different age groups of elderly men. Methods 213 elderly men of 50 to 79 years of age from a community of Beijing city were divided into 3 groups and studied. The volume of total prostate and the volume of the transitional zone were measured by rectal ultrasonography and the index of the transitional zone was calculated. All the data were evaluated with statistical analysis. Results The number of subjects in the 50～59 age group was 75,in the 60～69 age group 81 and in the 70～79 age group 57.The volume of total prostate was 23.82?8.83,29.16?10.01 and 33.77?11.74 respectively and the transitional zone 1.52?1.19, 3.60?3.66 and 7.25?7.02ml respectively. The index of transitional was 0.10?0.12, 0.13?0.11, 0.20?0.11 respectively. The difference in volume of the total prostate has not been statistically significant whereas the difference in the volume of the transitional zone between the 3 age groups has been significant. Conclusions The volume of total prostate and that of the transitional zone increases with age. The speed of hyperplasia of the transitional zone has been faster than that of the whole prostate.The index of the transitional zone indicates the difference of the whole prostate and the transitional zone in hyperplasia.

Modified Lateral Approach to the Distal Humerus Fractures / 대한정형외과학회잡지

PURPOSE: Internal fixation of distal humerus fracture is problematic. A modified lateral approach was assessed to determine its role in the surgical management of these injuries. MATERIALS AND METHODS: From 1994 to 1998, we had operated 15 patients with distal humerus fracture. Eight patients who had intraarticular fracture were classified into group A, and seven patients who had transitional zone fracture were classified into group B. Both groups were operated by modified lateral approach. In group A, triceps muscle was elevated from medial and lateral intermuscular septum. Functional outcome was assessed with Broberg and Morrey's functional rating scale and anatomical measurement was also performed. RESULTS: All fractures united without complication. The results of functional rating scale were as follows; 3 exellent, 9 good and 3 fair. Anatomical measurement of the average proximal extent of the plate from the lateral epicondyle was 16 +/- 2.7 cm (range 12.3 to 19.8 cm) and in 3 patients, more than 70% of the entire length of the humerus. CONCLUSION: On the bases of these results, intraarticular fracture and transitional zone fracture of the distal humerus can be operated successfully with the modified lateral approach.

Transitional Zone Index: a Predictor of Acute Urinary Retention in Patients with Benign Prostatic Hyperplasia / 대한비뇨기과학회지

PURPOSE: To investigate the efficacy of age, International Prostate Symptom Score(I-PSS), quality of life(QOL) score, various parameters obtained by transrectal ultrasonography(TRUS) as predictors of the onset of acute urinary retention in patients with benign prostatic hyperplasia(BPH). MATERIALS AND METHODS: From January 1996 to December 1997, 101 men(mean age 70years, range 52-92) with symptoms of BPH were enrolled in this study. Among them, 36 patients had suffered from acute urinary retention. TRUS was used to calculate the total prostate(TP) volume, the transitional zone(TZ) volume, the transitional zone index(TZ index=TZ volume/TP volume). To compare the usefulness of various indices, the area under the receiver-operator characteristic(ROC) curve was calculated for each index. RESULTS: There were significant differences in age, TP volume, TZ volume, TZ index between patients with and without acute urinary retention, but no significant differences in I-PSS and QOL score. In patients with acute urinary retention, the area under the ROC curve was 0.911 for the TZ index, 0.892 for the TZ volume, 0.769 for the TP volume and 0.660 for the age. CONCLUSIONS: The TZ index is a useful predictor of acute urinary retention in patients with BPH and may be a useful parameter for decision of surgical intervention.

Expression of Ki-67 and Topoisomerase IIa in Human Middle Ear Cholesteatoma Epithelium / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Cholesteatoma is a destructive lesion of the middle ear or mastoid process. The development of human cholesteatoma is due to the altered control of cellular proliferation in part, which tilts the balance toward the aggressive, invasive growth of squamous epithelium within the middle ear. Many efforts were performed to prove overproliferative characteristics of cholesteatoma using various proliferation markers. Nonetheless, trigger site of overproliferation within the overgrowing epithelium of cholesteatoma is still ill defined. MATERIALS AND METHODS: In this study, we used the monoclonal antibody Ki-67 and Topoisomerase II, a marker of active proliferation, on frozen sections obtained from 12 cholesteatoma samples and observed expression of these markers in three different regions, from normal meatal skin, transitional zone and cholesteatoma sac. RESULTS: The results were interpreted on the basis of nuclear staining and percentage of positively stained cells (labeling index). We found that labeling indices of cholesteatoma and transitional zone were significantly increased compared with that of normal meatal skin. CONCLUSION: This result suggested that initiating of overproliliferation of cholesteatoma epithelium started from the transitional zone.

Treatment of Degenerative Lumbar Instability with Semi-Rigid Isolock System

For degenerative lumbar instability, various spinal instrumentations have been used to relieve clinical symptom and to stabilize the spine. Most of them are rigid fixation which cause a postfusion instability at adjacent segment with high incidence. It creates a highly susceptible region(neo-hinge) between fixed rigid segment and nonfixed mobile segment. Eventually acceleration of degenerative change in adjacent segment is resulted with clinical deterioration. To avoid of postfusion instability after rigid fixation, a semi-rigid fixation system which has a intermediate transitional zone is developed. In 98 patients with degenerative lumbar instability, semi-rigid fixation which had a damper in the middle of plate were performed with CH titanium cage. Angular instability in lateral dynamic X-ray was improved in all case immediately after operation. Translational instability also much improved. But no degenerative change or instability in adjacent segment(neo-hinge disc) or overlying disc within fusion segment during follow up period of average 16 months. Excellent and good clinical results were achieved in 90.8% of patients and the solid bone fusion was occurred in 98.9%.

The Influence of Hyperglycemia on the Extent of Focal Cerebral Ischemia

The present study was undertaken to investigate the influence of hyperglycemia on focal cerebral ischemia in view of morphometric assay and neuropathological examination. Forty Sprague-Dawley rats were divided into two groups of 20 each. Rat MCA occlusion model was used for induction of focal ischemia. Hyperglycemia(20 rats, mean(SEM plasma glucose concentration 378(97.6 mg/dl) was established 30 minutes before MCA occlusion by intraperitoneal injection of 50% dextrose in water;the control group(20 rats, mean(SEM plasma glucose concentration 121(24.9 mg/dl) received normal saline only. Twenty-four hours after MCA occlusion neutral red staining and perfusion fixation was performed and ischemic area were measured using computerized image analysis on cortical surface and coronal cut surface. There was no significant difference on coronal cut surface, but on cortical surface showed increase of non-stained area(infarct core) and decrease of lightly stained area(transitional zone) in hyperglycemic rats(p<0.05) and the sum of two area was not different between two groups. Pathological findings were evaluated under light microscopy, in which the field scanning was carried out from the midline by 0.5 mm interval at cortical and basal ganglia level. There showed no significant difference at basal ganglia level, but at cortical level ischemic transitional zone was decreased in hyperglycemic rats(p<0.05). We conclude that hyperglycemia may worsen the brain from severe, focal ischemic neuronal damage.

A Case of Subcutaneous Dermoid Cyst / 대한피부과학회지

A 18-year-old male patient presented with the skin colored, dome-shaped, soft, movable mass in his left retroauriculr region. The mass has slowly increased in size since birth. Histopathologic exarnination revealed sebaceous gland, eccrine gland and crosssectioned hair in the surrounding tissue, hair shaft projected into the lumen, and laminated horny material in the cyst. Transitional zone between stratified squarnous epithelium and the wall lined by histiocytes showed homogenous degenerative change. After surgical removal of the lesion, no recurrence was observed during 15 months of follow-up.