The gelling effect of platelet-rich fibrin matrix when exposed to human tenocytes from the rotator cuff in small-diameter culture wells and the design of a co-culture device to overcome this phenomenon.

OBJECTIVES: Platelet-rich fibrin matrix (PRFM) has been proved to enhance tenocyte proliferation but has mixed results when used during rotator cuff repair. The optimal PRFM preparation protocol should be determined before clinical application. To screen the best PRFM to each individual's tenocytes effectively, small-diameter culture wells should be used to increase variables. The gelling effect of PRFM will occur when small-diameter culture wells are used. A co-culture device should be designed to avoid this effect. METHODS: Tenocytes harvested during rotator cuff repair and blood from a healthy volunteer were used. Tenocytes were seeded in 96-, 24-, 12-, and six-well plates and co-culture devices. Appropriate volumes of PRFM, according to the surface area of each culture well, were treated with tenocytes for seven days. The co-culture device was designed to avoid the gelling effect that occurred in the small-diameter culture well. Cell proliferation was analyzed by water soluble tetrazolium-1 (WST-1) bioassay. RESULTS: The relative quantification (condition/control) of WST-1 assay on day seven revealed a significant decrease in tenocyte proliferation in small-diameter culture wells (96 and 24 wells) due to the gelling effect. PRFM in large-diameter culture wells (12 and six wells) and co-culture systems induced a significant increase in tenocyte proliferation compared with the control group. The gelling effect of PRFM was avoided by the co-culture device. CONCLUSION: When PRFM and tenocytes are cultured in small-diameter culture wells, the gelling effect will occur and make screening of personalized best-fit PRFM difficult. This effect can be avoided with the co-culture device.Cite this article: C-H. Chiu, P. Chen, W-L. Yeh, A. C-Y. Chen, Y-S. Chan, K-Y. Hsu, K-F. Lei. The gelling effect of platelet-rich fibrin matrix when exposed to human tenocytes from the rotator cuff in small-diameter culture wells and the design of a co-culture device to overcome this phenomenon. Bone Joint Res 2019;8:216-223. DOI: 10.1302/2046-3758.85.BJR-2018-0258.R1.

Low-loss propagation in Cr4+:YAG double-clad crystal fiber fabricated by sapphire tube assisted CDLHPG technique.

Cr4+:YAG double-clad crystal fiber with an uniform 10-microm core was fabricated by using a sapphire tube as a heat capacitor to stabilize the power fluctuation of the CO2 laser in the co-drawing laser-heated pedestal growth system. The uniformity of the fiber core showed a factor of 3 improvement compared to that without the use of sapphire tube. The variation of the core diameter is within the +/-1.35-degree adiabatic criterion and has a autocorrelation length of 1.7 mm. The measured propagation loss is only 0.02 dB/cm. The sapphire tube also reduces the vertical temperature gradient during the crystal fiber growth process so the 10-microm crystal core exhibits a smooth perimeter. The sapphire tube assisted system can be applied to the growth of many other optical crystal materials.

Does Ethnic Variability Exist in the Systemic Exposures of OATP1A2 Substrates-Fexofenadine in Taiwanese?

The aim of this study was to investigate differences in organic anion transporting polypeptide 1A2 activity among the Taiwanese population via an analysis of 3 pharmacokinetic studies completed in a total of 103 healthy male Taiwanese subjects. The pharmacokinetics of fexofenadine was measured as an indicator of organic anion transporting polypeptide 1A2 activity. Using the Kolmogorov-Smirnov test and quantile plots, the frequency distributions of area under the concentration-time curve and concentration were shown to be tri-modal and to represent 3 pharmacokinetic phenotypes. In a comparison with published data, the mean area under the concentration-time curve of fexofenadine in the Taiwanese subjects was similar to that in American, German, and Indian subjects, but significantly different from that in some Asian populations, including Korean and Japanese ethnic groups. These results suggested that Taiwanese subjects showed genetic variation in fexofenadine pharmacokinetics that was associated with differences in organic anion transporting polypeptide 1A2 activity.

Resection of aneurysm of the aortic arch without cardiopulmonary bypass.

Four cases of aneurysm of the aortic arch were encountered within 1 year at the National Taiwan University Hospital, Taipei, Taiwan, Republic of China. All four patients underwent resection of the aneurysm and graft replacement of the aortic arch without cardiopulmonary bypass or hypothermia. Temporary external shunting with Tygon tube from the ascending aorta to the femoral artery, with and without permanent bypass grafts from the ascending aorta to the carotid arteries, was used in three patients. Permanent bypass grafts with multiple anastomoses was used in one patient. The over-all operative mortality rate was 25 percent. Some adjuncts are made to perfect the safe and simple technique of temporary external shunting, which has been reported previously from the same institution.

Effects of rifampicin and phenobarbital on the fate of isoniazid and hydrazine in vivo in rats.

After the intraperitoneal (i.p.) administration of isoniazid (INH) to male Wistar rats, the liver and plasma levels of hydrazine (Hz) and acetylhydrazine (AcHz), which are hazardous metabolites of INH and well known as mutagens, carcinogens and hepatotoxins, were determined by gas chromatography-mass spectrometry (GC-MS). The levels of Hz in rifampicin (RMP)- or phenobarbital (PB)-pretreated groups were lower than those in the control group, while the amount of AcHz was scarcely altered. In each of the pretreated groups a pronounced increase in the oxidative elimination rate of Hz was observed. These results are of important toxicological significance in INH therapy with RMP, since an active intermediate of Hz seems to be a hepatotoxin.

Follow-up evaluation of resected lumbar vertebral chordoma over 11 years: a case report.

STUDY DESIGN: A case report with an 11-year follow-up assessment after resection and reconstruction for lumbar chordoma is given. The literature relevant to this topic is reviewed. OBJECTIVES: To report the long-term outcome in a case of lumbar chordoma, to review the literature on vertebral chordoma, and to outline the rationale for surgical resection in such cases. SUMMARY OF BACKGROUND DATA: Chordoma is a malignant bone tumor that grows slowly, often recurs locally, and metastasizes late. Although different treatment approaches exist, including radiation and surgery, the only curative treatment is early and complete surgical excision of the tumor. Immediate spinal stability must be achieved with appropriate replacement or bone graft with rigid fixation. METHODS: The 11-year follow-up evaluation of a 42-year-old woman with L3 and L4 vertebral body chordoma treated with complete removal, femoral shaft allograft replacement, fusion, and rigid metal fixation is reported. The patient was observed with serial physical examinations, radiographs, and laboratory studies over 11 years. RESULTS: At this writing, 11 years after the resection of the L3 and L4 chordoma, the patient is asymptomatic without evidence of recurrence or metastasis. CONCLUSIONS: As reported, vertebral chordomas are not curable, but the authors' experience contradicts this. The surgeon should aim at a wide, or at least a marginal, excision followed by a stable reconstruction.

Instrumented laparoscopic spinal fusion. Preliminary Results.

STUDY DESIGN: Seventeen consecutive patients underwent laparoscopic instrumented interbody fusions using custom-designed delivery instrumentation and "BAK" fusion cages; both are manufactured by Spinetech and the former was developed by the authors. The cases were performed at two spine centers under Food and Drug Administration investigational device evaluation clinical trials. OBJECTIVES: We expect this approach will maintain a high fusion rate with diminished hospitalization time, recovery time, patient discomfort, and expense. The rehabilitative aspects of the procedure are a great improvement over traditional fusion approaches. SUMMARY AND BACKGROUND DATA: Extraordinary advances in many endoscopic surgical fields have resulted in many endoscopic surgical fields have resulted in lowered morbidity, expense, and suffering associated with their open surgery counterparts. The authors have developed prototype of delivery instruments for the current laparoscopic fusion cage delivery system. METHODS: The procedure is performed transperitoneally with carbon dioxide insufflation to enable video-assisted visualization through a 10-mm endoscope. Three 10-mm incisions and one 13- to 20-mm incision are required for one-level procedures. Two hollow titanium-threaded interbody implants are packed with autologous bone and inserted into the diseased interspace. RESULTS: Seventeen patients, with an average follow-up period of 8 months and a range of 6-12 months, underwent the procedure. There were 14 single-level fusions and three two-level fusions, all involving L4-S1 levels. There were two cases that required conversion to open procedures without sequelae; two patients had remote donor site wound infections eradicated with incision and drainage and antibiotics, and one patient required subsequent posterior spinal decompression because of a displaced endplate fracture. Average hospital stay was an average of 2 days, excluding two patients with complications and very prolonged stay. CONCLUSIONS: Although this procedure is associated with a long learning curve, the technique, once mastered, is effective and advantageous over current approaches to lumbar fusion. Operative time and hospital stay are expected to decrease with future instrumentation development and surgeon experience.

Painful lumbar end-plate disruptions: a significant discographic finding.

Of the 692 discs injected during lumbar discograms, end-plate disruptions with leakage of contrast material into the vertebral bodies were noted in 14 discs. Although gentle pressure was applied during the injections, severe fully concordant pain was reproduced in four (28.3%) discs, moderately severe and fully concordant pain in nine (64.3%) discs, and mild discordant pain in one (7.4%) disc. This is compared to 11.2% of the remaining 678 discs without end-plate disruption that reproduced severe concordant pain, 31.1% with moderately severe concordant pain, 17.1% with mild pain, and 40.6% without any pain reproduction. The difference between pain frequency in discs with end-plate disruption and those without is statistically significant (P less than .001). This suggests that end-plate disruptions may be related to painful segments.

Lumbar intraspinal synovial and ganglion cysts (facet cysts). Ten-year experience in evaluation and treatment.

STUDY DESIGN: This study analyzed the clinical history, physical examination, diagnostic studies, and operative and histologic findings in 19 patients with lumbar intraspinal synovial and ganglion facet cysts evaluated and treated over a 10-year period. OBJECTIVES: The results were correlated to provide a greater understanding of lumbar facet cysts and rationale for conservative or surgical treatments. SUMMARY OF BACKGROUND DATA: The 19 patients included 13 women and 6 men ranging in age from 38 to 79 years. 84.4% of the patients presented with radicular pain. 26.3% had significant motor deficit. 68.4% of the facet cysts were found at L4-L5, 21.1% at L5-S1, 5.2% at L1-L2, and 5.2% at L2-L3. METHODS: The clinical history and findings on physical examination, standard radiography, myelography, computed tomography-myelography, facet arthrography, post-facet arthrograph computed tomography, magnetic resonance imaging with and without contrast, and computed tomography scans were reviewed. RESULTS: Bilobed cysts were found on both dorsal and ventral aspects of the involved facet joints within and outside of the spinal canal on facet arthrography, computed tomography, magnetic resonance imaging, and at the time of surgery in more than 60% of the patients. Significant facet degeneration was found in 75% of standard radiographs, and on all of the magnetic resonance imaging and computed tomography scans. In six patients, symptoms improved with rest, medication, and bracing. Epidural corticosteroid injections provided short-term relief in three out of four patients. Facet corticosteroid injections provided good relief in one, partial relief in one, and no relief in one patient. Surgical decompression in eight patients resulted in three excellent, four good, and one fair outcome. CONCLUSIONS: Most of the lumbar intraspinal facet cysts were associated with significantly degenerated facet joints. Patients with intraspinal facet cysts may respond to conservative treatments if there is no significant neurologic deficit. Surgical decompression and removal of large facet cysts usually are successful in relieving symptoms.

Generation of neutrophil-chemoattractant by degradation of tumor cell membrane protein.

Polymorphonuclear leukocytes (PMN) infiltrating into tumors are assumed to be the result of a migration in response to a tumor-derived chemotactic factor. It is hypothesized that tumor-derived chemotactic factors, which are supposed to be in aggregates, can be exposed by proteolytic degradation of the tumor cell membrane protein (TCM). The TCM suspension made from either Sarcoma 180 or Ehrlich ascites tumor after incubation with Varidase at 37 degrees C for six to eight weeks is referred to as a degraded TCM protein (DTCM). The purpose of this study was to detect whether or not the DTCM was chemotactic for PMNs. Chemotactic activity was assayed by a sponge-matrix model and expressed in the number of PMNs infiltrating into the sponge per mouse after intrasponge injection of the DTCM, dose range, 0.4-0.005 mL. Maximal response to DTCM was restricted to the limited dose between 0.01 and 0.02 mL. Quantities of DTCM > 0.02 mL caused a response in roughly reciprocal proportion to the dose of DTCM. Changes in the circulating leukocyte count in response to an intravenous (i.v.) injection of DTCM was biphasic. The initial relative leukopenia was followed by leukocytosis within 24 hours in rats surviving the effect of DTCM doses < 0.5 mL. However, in rats with i.v. injections of higher doses, profound leukopenia was present at death. The mice, after an intraperitoneal (i.p.) injection of DTCM, dose range, 0.5-1.0 mL, died between 16 and 24 hours after the injection. The bone marrow of these mice showed complete depletion of PMNs.(ABSTRACT TRUNCATED AT 250 WORDS)

Distal chevron osteotomy with intra-articular lateral soft-tissue release for treatment of moderate to severe hallux valgus deformity.

We retrospectively reviewed the results of 32 patients (38 feet), with hallux valgus angles between 35 degrees and 60 degrees, who were treated by standard distal chevron osteotomy and intra-articular lateral soft tissue release. The average follow-up period was 5.2 years (4-7 years). The preoperative intermetatarsal angle averaged 14.4 degrees, and the postoperative angle averaged 7.7 degrees. The preoperative hallux valgus angle averaged 42.7 degrees, and the postoperative angle averaged 18.8 degrees. Subjectively, the satisfaction rate in terms of symptom improvement, cosmetic appearance and function was over 90%. Avascular necrosis of the first metatarsal head was not found in our series, which indicated that additional lateral soft tissue release is not contraindicated in combination with chevron osteotomy. Based on the level of satisfaction in our series, we conclude that the combination of distal chevron osteotomy and intraarticular lateral soft tissue release has broader application than the chevron osteotomy alone for patients with hallux valgus deformity.

Surgical treatment of second primary lung cancer: report of eight cases.

Of 312 patients undergoing resection for lung cancer at National Taiwan University Hospital during 1980 to 1990, eight presented with second primary lung cancer. One patient had synchronous and seven patients had metachronous primaries. There were five males and three females with ages ranging from 41 to 77 years. In the metachronous group, two patients had a different histology between the first and the second tumor, and the intervals between the two tumors varied from 12 to 60 months. The initial resections included pneumonectomy in one and lobectomy in six patients. At the second operation, the surgical procedures included lobectomy in three, completed pneumonectomy in one, segmentectomy in another, and wedge resection in two patients. There was no operative mortality and all patients were regularly followed up from 6 months to 6 years after the second operation. Two patients died, one from repeated respiratory tract infection and the other from brain metastasis. Kaplan-Meier analysis showed 2-year and 3-year survivals of 80% and 60%, respectively. It can be concluded that surgical resection for second primary lung cancer is justified, as it can prolong the patient's survival. Lobectomy can be performed for patients with a second primary lung cancer and sufficient lung reserve, but limited resection should be chosen for patients with poor lung reserve.

Treatment of fibrous dysplasia involving the proximal femur.

Twenty-two patients with fibrous dysplasia in the femoral neck or trochanteric area were treated with curettage and bone grafting with a sliding hip compression screw and plate. Follow-up ranged from 2 to 6 years (average: 4 years). Fourteen patients had monostotic and 8 had polyostotic disease. Four patients had pathologic fractures. Bone grafting included a deep-frozen allogeneic cortical strut and cancellous bone. After implanting the lag screw and cortical strut, the remaining defect space was filled with iliac bone. Postoperatively, all patients had good bone healing and complete incorporation of the implanted graft. There were no recurrences or complications, and functional results were rated as good and excellent.

Is isoniazid-hepatotoxicity induced by the metabolite, hydrazine?

The effects of rifampicin (RMP) on isoniazid (INH) metabolism in rabbits were examined from the viewpoint of extensive hepatitis. After the RMP pretreatment, no remarkable changes were observed in the plasma levels of INH as well as its metabolites, acetylisoniazid (AcINH), acetylhydrazine (AcHz) and diacetylhydrazine (DAcHz) with the exception of hydrazine (Hz). After an oral administration of INH or Hz hydrate, the stochastic examination showed that the AUC0-8hr values of Hz plasma levels in RMP pretreated groups were significantly less than those in the control rabbits. RMP treatment was also shown to induce rabbit liver cytochrome P-450 activity. Histological studies demonstrated that Hz causes more remarkable hepatic necrosis in rabbits pretreated with RMP than in the control rabbits. These observations could suggest that Hz is a key intermediate of INH-hepatitis through the transformation of some hepatotoxic species by microsomal oxidation that is facilitated by RMP.

Metabolic hydrolysis of isoniazid by subcellular fractions of rat liver.

The characteristics of isoniazid amidase which hydrolyzes isoniazid to isonicotinic acid and hydrazine was examined in vitro using rat liver subcellular fractions. The activity of isoniazid amidase was estimated from the amount of hydrazine produced from a substrate, isoniazid, by means of GC-MS. High activity of the amidase was observed in the microsomal and lysosomal fractions, and at pH 7.4-7.8 in the microsomal fraction. The amidase was not inhibited by acetanilide, but by procaine and bis(p-nitrophenyl)phosphate. As expected, acetylisoniazid, a main metabolite of isoniazid, also inhibited the amidase. Not only the microsomal monooxygenase but also amidase was strongly induced by pretreatment with phenobarbital, 3-methylcholanthrene and rifampicin, respectively.

Long-term continuous infusion of propofol as a means of sedation for patients in intensive care unit: relationship between dosage and serum concentration.

BACKGROUND: We studied the effect of long-term continuous propofol infusion in patients who were utilizing mechanical ventilation in intensive care unit. The purpose of our study was to identify the appropriate dosage of propofol and to monitor the relating serum level that would provide satisfactory sedative and hypnotic effects to the patients, i.e., to procure a Ramsay Sedation Scale (RSS) value between 2 and 3. METHODS: Ten mechanically ventilated ICU patients were studied. The syringe pump was set to deliver propofol at a rate of 1 mg/kg/h without an initial loading dose. After continuous infusion of propofol for 24 h, in each patient 5 ml of whole blood was sampled daily for one week. All samples were analyzed for serum level of propofol by high performance liquid chromatography. RESULTS: When the Ramsay Sedation Scale (RSS) value was between 2 and 3, the mean dosage of infused propofol was 0.71 +/- 0.31 mg/kg/h (ranging from 0.58 to 1.27 mg/kg/h) and the mean plasma concentration was 0.58 +/- 0.22 microgram/ml (ranging from 0.20 to 0.86 microgram/ml). The lipid serum level was measured in three patients whose infusion duration was greater than 14 days. The respective level was 321 mg/dl, 139 mg/dl, and 99 mg/dl. The first patient died from multiple organ failure as a result of multiple trauma. Four patients simultaneously received infusion of propofol and muscle relaxant. CONCLUSIONS: We concluded that propofol infusion given at a rate of 0.71 +/- 0.31 mg/kg/h and a plasma concentration level of less than 1 microgram/ml would be sufficient to produce a sedation with RSS value between 2 and 3.

Low-flow anesthesia in adult orthotopic liver transplantation: a preliminary clinical experience.

BACKGROUND: Anesthesia in orthotopic liver transplantation (OLT) may carry with complex hemodynamic, body temperature, and metabolic alterations. Although OLT cases increased in recent years in Taiwan, experiences remained limited. Notable advantage of low flow anesthesia may include reduced consumption of anesthetic gases and vapors, reduced environmental pollution and cost-saving. This study investigated patient profiles and the feasibility of low-flow rebreathing technique for adult orthotopic liver transplantation. METHODS: Since June 1996, there were six OLT patients who received low flow anesthesia with isoflurane. All patients received hepatic veno-venal anastmosis (so-called piggy back procedure). Two patients were excluded from this study because of different surgical procedure (total occlusion of inferior vena cava and inferior vena cava veno-venal anastmosis). During maintenance of anesthesia, isoflurane was carried by a mixture of oxygen and air at a total fresh gas flow of 0.6 L/min. Alongside with the standard anesthesia machine and physiologic monitors, a newly designed Swan-Ganz catheter was introduced to measure and record cardiac output, systemic vascular resistance, pulmonary artery pressure, central venous pressure, and core temperature in a real-time manner. Blood samples were collected at 6 predetermined time-points in each patient for analysis of arterial blood gases, electrolytes, lactate and glucose concentrations. RESULTS: The anesthetic time was 916 +/- 26 min (900 to 930 min). All patients regained their consciousness within 30 min after completion of surgery. The hemodynamics were relatively stable except after reperfusion of the liver. There was a significant decrease in mean arterial blood pressure, which occurred with accompaniment of a reduction of systemic vascular resistance and increased cardiac output. Arterial blood gas, electrolyte, and glucose were, however, maintained within acceptable limits. Blood lactate was progressively increased and reached its peak after reperfusion of the liver until the end of surgery. The core temperature was well maintained above 34 degrees C. No patient developed hypoxia or hypercapnia. CONCLUSIONS: Low-flow rebreathing anesthetic technique maintained acceptable patient profiles and good body temperature preservation in orthotopic liver transplantation. These characteristics make it a promising method in maintenance of anesthesia for OLT.

Propofol anesthesia in a patient with Isaacs syndrome--report of a case and literature review.

Isaacs syndrome is an unusual lower motor neuron disease characterized by myokymia (muscle twitching), muscular stiffness, and decreased tendon reflexes. We reported a patient who was affected with this rare disease, with manifestation of involuntary muscular contractions and required general anesthesia for bilateral tonsillectomies. Understanding the presentation and characterization of this unusual disease may be helpful in making choice of anesthetics or anesthetic techniques. Its possible mechanisms of action and its specific considerations in anesthesia in the literature are reviewed and discussed.