Synthesis and Mesomorphic Properties of Azo Compounds Derived from Phenyl-and Thienyl-1,3,4-Thiadiazole

The synthesis and mesomorphic behaviour of new series of liquid crystals containing 1,3,4- thiadiazole and thiophene rings with azo central bond are reported (series 5a and 5b). All compounds of series 5a exhibit enantiotropic nematic mesophase and the higher homologues (n = 9 - 10) also show a monotropic smectic C phase. Series 5b show dimorphism SC - N (for n = 5 - 7 the SC is monotropic). These series are compared with the Schiff’s bases analogues, the imine bond gives rise to similar liquid crystals phase but larger mesomorphic range.

Production of poly-β-hydroxybutyrate (PHB) by Methylobacterium organophilum isolated from a methanotrophic consortium in a two-phase partition bioreactor

The biodegradation of methane, a greenhouse gas, and the accumulation of poly-β-hydroxybutyrate (PHB) were studied using a methanotrophic consortium and an isolated strain thereof. The specific rates for methane consumption were 100 and [Formula: see text] for the isolate and the consortium, respectively. Also the effect of including 10% (vv(-1)) of silicone oil in a two-phase partitioning bioreactor (TPPB) was assayed for the elimination of 1% methane in air stream. TPPB allowed a 33-45% increase of methane elimination under growing conditions. Nitrogen limitation was assayed in bioreactors to promote PHB production. Under this condition, the specific methane degradation rate remained unchanged for the consortium and decreased to [Formula: see text] for the isolated strain. The accumulated PHB in the reactor was 34% and 38% (ww(-1)) for the consortium and the isolate, respectively. The highest productivity was obtained in the TPPB and was 1.61 mg(PHB)g(x)(-1) h(-1). The CZ-2 isolate was identified as Methylobacterium organophilum, this is the first study that reports this species as being able to grow on methane and accumulate up to 57% (ww(-1)) of PHB under nitrogen limitation in microcosm experiments.

[Results of long-term follow-up after local excision for well-selected low rectal cancers]

OBJECTIVE

to evaluate our results about local failure, total recurrence and survival.

METHOD

twenty-one patients underwent a complete local transanal excision for low rectal cancer in our institution during an 18-year period (1985-2003). Preoperative staging included clinical, endoscopic, CT, EUSR, and histopathological findings; pathological specimens were 4 T1, 13 T2 and 4 T3 tumors. None of the T1 patients received another treatment; 6 out of 13 T2 and all of T3 cases were treated with chemoradiotherapy. None of the latter underwent radical surgery.

RESULTS

follow-up (median 74 months) proved 23.8% for total recurrence and 19.0% for local failure (out of all 3 T2 cases only one received chemoradiotherapy, and one T3 received adjuvant treatment). Five-year survival is 95.2%.

CONCLUSIONS

this experience allows us to assert that local excision is a good choice in well-selected low rectal cancer patients; for T2 tumors chemoradiotherapy is necessary; in T3 patients radical surgery must be prompt.

Laterotrusive occlusal schemes and their effect on supra- and infrahyoid electromyographic activity

The objective of this study was to determine the effects of canine guidance and group function on supra- and infrahyoid electromyographic (EMG) activity. The sample included 40 healthy subjects, 20 with bilateral canine guidance and 20 with bilateral group function. Surface electrodes were used to record the integrated EMG (IEMG) activity of the left supra- and infrahyoid muscles during (1) grinding from intercuspal position to lateral edge-to-edge contact position (with canine guidance or group function), (2) static clenching in edge-to-edge lateral contact position with canine guidance or group function, and (3) grinding from lateral edge-to-edge contact position (with canine guidance or group function) to intercuspal position. IEMG activity in the suprahyoid or infrahyoid muscles was not significantly different with canine guidance or group function. Supra- and infrahyoid IEMG activity in condition 2 was significantly higher than in condition 3, which was significantly higher than in condition 1. Supra- and infrahyoid IEMG activity was not significantly different with canine guidance and group function. Supra- and infrahyoid IEMG activity during the static recording (clenching) was significantly higher than during the dynamic recordings (grinding). Activity during grinding from the lateral edge-to-edge contact position to the intercuspal position was higher than vice versa.

Comparative study between children with and without cleft lip and cleft palate, part 1: cephalometric analysis

OBJECTIVE

This study was conducted to compare craniofacial relationships, position, and curvature of the cervical spine between children with cleft lip and cleft palate who had been operated on and children without clefts.

METHOD

This study was performed in 28 children with mixed dentition. They were divided into two groups. The study group included 14 children with unilateral operated cleft lip and cleft palate, ranging in age from 6 to 12 years, who clinically presented with a short upper lip, abnormal lip seal, and inhibition of sagittal development of the midface that was radiographically assessed. The control group included 14 children without clefts, ranging in age from 8 to 11 years. All of them had normal lip seal, nasal breathing, and a clinically normal body posture.

DESIGN

A lateral craniocervical radiograph in a self-balanced natural head position in an erect posture, and without using a head holder, was taken for each child of both groups, with the mandible in maximum intercuspation and lips in habitual posture. The true vertical was marked on all the films. Specific angular and linear dimensions were used to assess the craniocervical relationships, as were the position of the cervical spine, its curvature, or both.

RESULTS AND CONCLUSIONS

The study group presented a significant increase in the extension of the head on the neck, forward position of the cervical spine, and a decrease in the curvature of the cervical spine in comparison with the children without clefts. These results are more relevant considering that the study group also presented higher significant values of lower facial height than children without clefts.

Comparative study between children with and without cleft lip and cleft palate, part 2: electromyographic analysis

OBJECTIVE

This study was conducted to compare electromyographic (EMG) activity of superior orbicularis oris muscle between children with repaired cleft lip and cleft palate and children without clefts.

METHODS

This study included 28 children with mixed dentition. They were divided into two groups. The study group included 14 children with repaired unilateral cleft lip and cleft palate, ranging in age from 6 to 12 years, who presented clinically with a short upper lip, abnormal lip seal, and inhibition of sagittal development of the midface as assessed radiographically. The control group included 14 children without clefts ranging in age from 8 to 11 years. All had normal lip seal, nasal breathing, and a clinically normal body posture.

DESIGN

Bipolar surface electrodes were used for EMG recordings of resting level activity and during swallowing of saliva, speech, and chewing and swallowing of an apple.

RESULTS AND CONCLUSIONS

A significantly higher level of activity at rest and during swallowing of saliva was observed in the cleft lip and cleft palate group. Similar activity during speech and chewing and swallowing of an apple was observed in both groups. The higher level of activity at rest and during swallowing of saliva in children with cleft lip and cleft palate seems to suggest that upon higher functional demands their activity increases less than in children without clefts. From a clinical point of view, if increased EMG activity at rest and during swallowing of saliva reflects increased force on the maxilla, then our findings may corroborate Bardach's findings (1990) that surgical treatment of cleft lip has an iatrogenic effect on facial growth, although the lack of significant correlation between the cephalometric data and EMG findings in the present study.

[Listeria monocytogenes incidence and evaluation of the sanitary quality of filleted fresh fish from the Metropolitan Area of San José]

Fish constitutes a very important part of human diet due to its protein content. The poor commercialization system existing in Costa Rica for this product causes an important secondary contamination that may include microorganisms such as fecal coliforms, Staphylococcus aureus and even pathogens such as Listeria monocytogenes. There is a lack of recent information about the microbiological quality of the fish that arrives to the Metropolitan Area of San José, Costa Rica, so the aim of this work was to study it through the detection of microbiological indicators and the incidence of L. monocytogenes. Five different samplings were realized to 27 fisheries located in two different areas from San José, Costa Rica: the Central Market and the rest of the Metropolitan Area. Each time, a 500 g sample of fresh filleted fish was taken and transported to the Food Microbiology Laboratory, Universidad de Costa Rica, for performing the different analysis, which included the presence/absence of L. monocytogenes, total plate count, total and fecal coliforms count and Most Probable Number of Staphylococcus aureus. Also, a hygiene evaluation of the different fisheries was performed. According to this, 22.2% of the fisheries were classified as excellent, 14.8% as good, 40.8% as regular and 22.2% as bad. Fisheries hygiene is independent of the incidence of L. monocytogenes with a 95% confidence level, and there is no significant relationship between hygiene and the other indicators analyzed. There is a significant relationship between the incidence of Listeria sp. and the hygiene of the Central Market area. It was determined that 96.3% and 29.6% of the fisheries accomplish with the microbiological limits established by ICMSF for S. aureus and total plate count, respectively. Listeria sp. was found in 65.2% of the fish samples analyzed. From these, 52.3% was L. monocytogenes, 43.2% L. innocua, 3.4% L. ivanovii and 1.1% L. seeligeri. In 88.9% of the fisheries the presence of L. monocytogenes was positive at least once.

Visual input effect on EMG activity of sternocleidomastoid and masseter muscles in healthy subjects and in patients with myogenic cranio-cervical-mandibular dysfunction

This study was conducted in order to determine the input visual effect on electromyographic (EMG) activity of the sternocleidomastoid and masseter muscles in the supine and lateral decubitus positions. The study was performed on 22 patients with myogenic cranio-cervical-mandibular dysfunction (CMD) and 18 healthy subjects. EMG activity at rest and during swallowing of saliva and maximal voluntary clenching was recorded in the supine and lateral decubitus positions in the following conditions: 1. with eyes open; and 2. with eyes closed after 5 minutes in a dark room. A significant decrease of EMG activity at rest with closed eyes in both groups was observed in the sternocleidomastoid (lateral decubitus position) and in the masseter muscle (supine position). During swallowing of saliva a significant decrease of EMG activity with closed eyes was observed only in the sternocleidomastoid muscle (lateral decubitus position) in healthy subjects. During maximal voluntary clenching any significant differences were observed upon variation in the visual input. The significant change in EMG activity, mainly observed at rest, suggests that the visual input effect is weak. The absence of a significant change in EMG activity during maximal voluntary clenching upon variation in the visual input could be clinically relevant in patients with myogenic CMD who habitually brux.

Increase of the vertical occlusal dimension by means of a removable orthodontic appliance and its effect on craniocervical relationships and position of the cervical spine in children

The aim of this study was to determine the effect of the increase in the occlusal vertical dimension by means of an orthodontic appliance on craniocervical relationships and position of the cervical spine. Thirty children presenting malocclusion were divided into two groups of 15 (a study and a control group). Those in the study group wore an orthodontic appliance to correct cross-bite. The children in the control group had no treatment during the experimental period. Two lateral craniocervical radiographs were taken for each child. The first one was taken in the intercuspal position in both groups. The second radiograph was taken of the study group after four months of wearing the appliance and also of the control group after four months. Cephalometric analysis in the study group showed a significant forward cervical spine position. There were no significant changes in the control group. The changes found in the study group suggest that when there are signs and symptoms of cervical dysfunction in children undergoing long-term orthodontic treatment, it is necessary to make an evaluation of the cervical column position after the insertion of any orthodontic appliance which increases the occlusal vertical dimension.

[Systematic examination of the uterine cavity after parturition]

The revision of uterine cavity afterbirth should be a process preventing complications immediate or late during puerperium, due to the retention of ovular remains that are not diagnosed in opportunely, avoiding so the risk that implies for the patients who show bleeding that leads them to complications of hemorrhaging in the interest of puerperal infection, with consequences so serious such as mutilation or death, otherwise undergoing surgery under poor conditions, in addition to the extra administrative costs, that imply surgery and those costs, derived from hospitalization; 1,205 patients were studied. On 1,155 the revision of the uterine cavity was performed; only one of them developed complications irrelevant to the process, consisting in fever, uterine subinvolution, more than normal hemorrhaging. On fifty patients the uterine cavity afterbirth was not found, fourteen patients experienced greater than normal hemorrhaging and hypothermia two to five days after being released, caused by the presence of ovarian remains, requiring posterior hospitalization. One patient experienced inflammation of the peritoneo due to the presence of placental remains.

[The 4th complement factor (C4) and t haplotypes in wild mice]

Five different lines of tailless mice bearing different t recessive haplotypes (tAn, tMo, tRa, tLa and tQu) have been established in our laboratory and maintained in combination with the brachury chromosome (T). These t haplotypes were derived from widely separated Chilean wild mouse populations. The immunoelectrophoretic typing for Ss and Slp isotypic variants of C4 showed that all lines had the Ss-High. Slp-negative phenotype suggesting that the t haplotypes might be associated with similar S regions of the major histocompatibility system of the mouse.

[Hemodialysis: vascular access with double lumen catheter]

We evaluated the results of hemodialysis performed with 106 double lumen catheters in 87 patients (mean age 52, range 10-82). 46 patients had chronic and 38 acute renal failure; 2 had respiratory distress syndrome and one refractory heart failure. Catheter flow ranged from 100 to 250 ml/min (mean 207) and effective clearance from 64 to 171 ml/min (mean 125). Only one catheter was used in 75 patients (86%), 2 in 7 and more than 2 in 5. Causes of failure included inadequate flow (9), coagulation (6) and displacement (4). In nine instances, severe complications developed: sepsis (3), local infection (4), hematoma (1) and vagal reaction (1). Three patient with catheters located in the subclavian vein developed vein stenosis, requiring angioplasty in 2 and graft in 1. Thus, double lumen catheter is easy to place and helps preserve future vascular sites in chronic hemodialysis.

[Paroxysmal nocturnal hemoglobinuria presenting as acute renal failure]

We report a patient who developed acute renal failure at the first severe hemolytic crisis associated to paroxysmal nocturnal hemoglobinuria. The associated histologic findings on electron microscopy and immunofluorescence are discussed as an insight to possible pathogenic mechanisms.

[Allogenic bone marrow transplantation: report of 3 cases in Chile]

Three patients, a 28 years old female (case 1), and two males aged 32 and 18 (cases 2 and 3) received allogeneic bone marrow transplants for acute non lymphatic leukemia (cases 1 and 2) and severe aplastic anemia (case 3) from HLA identical siblings. All patients were conditioned with Busulfan and Cyclophosphamide, and received GVHD prophylaxis with cyclosporin and steroids. Disease free survival is greater than 232, greater than 50 and greater than 201 days. Hematological reconstitution was detected 12, 13 and 10 days post transplant. All patients presented fever during the first month and received broad spectrum antibiotics including amphotericin in case 3. Acute GVHD presented in case 3 and chronic GVDH in case 1. Both patients responded to higher doses of cyclosporine and steroids. Allogeneic bone marrow transplant is a complex and expensive therapy, but can benefit a selected group of patients who fare poorly with conventional therapy. This report communicates the first three successful allogeneic bone marrow transplants performed in Chile.

tch, tsf and tte: three independently isolated t haplotypes in the mouse

Three recessive lethal t haplotypes have been independently isolated from widely separated Chilean wild mouse populations. They do not complement one another, have similar transmission ratios and suppress recombination. We do not know at present if they belong to a previously described complementation group or if they define a new one.