Calcyon stimulates neuregulin 1 maturation and signaling.

Neuregulin1 (NRG1) is a single transmembrane protein that plays a critical role in neural development and synaptic plasticity. Both NRG1 and its receptor, ErbB4, are well-established risk genes of schizophrenia. The NRG1 ecto-domain (ED) binds and activates ErbB4 following proteolytic cleavage of pro-NRG1 precursor protein. Although several studies have addressed the function of NRG1 in brain, very little is known about the cleavage and shedding mechanism. Here we show that the neuronal vesicular protein calcyon is a potent activator and key determinant of NRG1 ED cleavage and shedding. Calcyon stimulates clathrin-mediated endocytosis and endosomal targeting; and its levels are elevated in postmortem brains of schizophrenics. Overexpression of calcyon stimulates NRG1 cleavage and signaling in vivo, and as a result, GABA transmission is enhanced in calcyon overexpressing mice. Conversely, NRG1 cleavage, ErbB4 activity and GABA transmission are decreased in calcyon null mice. Moreover, stimulation of NRG1 cleavage by calcyon was recapitulated in HEK 293 cells suggesting the mechanism involved is cell-autonomous. Finally, studies with site-specific mutants in calcyon and inhibitors for the major sheddases indicate that the stimulatory effects of calcyon on NRG1 cleavage and shedding depend on clathrin-mediated endocytosis, ß-secretase 1, and interaction with clathrin adaptor proteins. Together these results identify a novel mechanism for NRG1 cleavage and shedding.

Utilization of bioreactance technique as indicator for preload responsiveness during living donor liver donation.

BACKGROUND: Fluid restriction has been used to decrease central venous pressure as a strategy of fluid management during living donor liver donation (LDLD). However, potential risks such as hemodynamic instability are also involved during the procedure. Monitoring of preload or preload responsiveness is therefore crucial during LDLD. The aim of this study was to explore the efficiency of an innovative bioreactance method that introduced the noninvasive cardiac output monitor (NICOM, Cheetah Medical, Vancouver, Wash, United States), as surrogate indicator for preload responsiveness during LDLD. METHODS: Twenty-six patients underwent LDLD and were enrolled in this study. Fluid was restricted until the organ was harvested. The ultrasonic cardiac output monitor (USCOM Ltd, Sydney, Australia) was applied to measure stroke volume (SV) before and after 500 mL of 6% hydroxyethyl starch 130/0.4 (Voluven, Fresenius Kabi, Friedberg, Germany) fluid challenge, and the value of SV variation (SVV) from NICOM was also recorded. Fluid responsiveness was defined if SV increased by more than 15%. Receiver operating characteristic (ROC) curve was performed. RESULTS: The area under the ROC curve was 0.6023. The optimal cutoff value of SVV from NICOM was 12% during LDLD. CONCLUSIONS: Our study has shown that SVV measured from the bioreactance technique is a poor indicator for monitoring preload responsiveness during LDLD.

Biomechanics of tendon injury and repair.

Many clinical and experimental studies have investigated how tendons repair in response to an injury. This body of work has led to a greater understanding of tendon healing mechanisms and subsequently to an improvement in their treatment. In this review paper, characterization of normal and healing tendons is first covered. In addition, the debate between intrinsic and extrinsic healing is examined, and the cellular and extracellular matrix response following a tendon injury is detailed. Next, clinical and experimental injury and repair methods utilizing animal models are discussed. Animal models have been utilized to study the effect of various activity levels, motions, injury methods, and injury locations on tendon injury and repair. Finally, current and future treatment modalities for improving tendon healing, such as tissue engineering, cell therapy, and gene therapy, are reviewed.

Different enzyme activities of sialyltransferases in gynecological cancer cell lines.

PURPOSE: Due to rarity of a relationship between sialyltransferase enzyme activities and gynecological cancers, we arranged the study to evaluate sialyltransferase enzyme activity in the various kinds of gynecological cancer cell lines. METHODS: Ten cell lines from various kinds of gynecological cancers and two cell lines from normal tissue were enrolled in this study. The activities of each subtype of sialyltransferases were detected using Gal beta1,3GalNAc-acetyl-lactosamine)-Obz1 (acceptor for ST2,3Gal I), Gal beta1,3GlcNAc beta1,3Gal beta1,4GlcNAc (acceptor for ST2,3Gal III), Gal beta1,4GlcNAc (acceptor for ST2,3Gal IV), asialo-bovine submaxillary mucin (acceptor for ST2,6GalNAc I), asialo-fetuin (acceptor for STalpha2,6GalNAc II), and fetuin (acceptor for ST2,6GalNAc III), respectively. The amounts of sialic acids were measured using fluorescein-conjugated Sambucus nigra agglutinin (SNA) specific for alpha2,6-sialic acids and fluorescein-conjugated Maackia Amurensis agglutinin (MAA) specific for alpha2,3-sialic acids. RESULTS: The activities of two sialyltransferase subtypes, ST3Gal I & ST6GalNAc II, were significantly higher in nearly all cell lines. More specifically, cervical cancer cell line-ME 180, ovarian cancer cell line-ES-2, and choriocarcinoma cell line-BeWo showed high levels of ST3Gal I enzyme activity; all gynecological cancer cell lines except endometrial cancer cell line-RL95-2 had high levels of ST6GalNAc II enzyme activity when compared with a normal control cell line--fibroblast cell line (CCD-966Sk). Cell lines tested in this study have diverse levels of surface alpha2,6-sialic acid sugar chains (enhanced SNA binding) when compared with alpha2,3-sialic acid sugar chains (enhanced MAA binding) but we found that some cell lines such as Ca Ski (cervical cancer cell line), CC7T (cervical cancer cell line), PA-I (ovarian cancer cell line), and BeWo showed significantly altered cell surface alpha2,6-sialic acid sugar chains. CONCLUSION: Increasing enzyme activity of ST3Gal I and ST6GalNAc II might be important in various kinds of gynecological cancers. More specifically, enhanced activity of sialyltransferases involving alpha2,6-sialic acid sugar chains might be more important in cancer development. Future studies will investigate whether the enzyme activity of these sialyltransferases can be helpful for clinical practice.

Glucose-insulin infusion for the early treatment of non-oliguric hyperkalemia in extremely-low-birth-weight infants.

In order to investigate the status of non-oliguric hyperkalemia and to evaluate glucose-insulin infusion treatment among extremely-low-birth-weight (ELBW) infants, 161 infants weighting less than 1000 gm at birth were enrolled for this study. They were divided into two groups: a hyperkalemic group and a non-hyperkalemic group. Hyperkalemia was defined here as a serum potassium level of greater than 6 mEq/L in a non-hemolyzed arterial blood sample. A glucose-insulin infusion was administered to the patients when hyperkalemia was detected in them during the first few days after birth. The infusion was discontinued when the serum potassium levels had been less than 6 mEq/L and stabilized for 6 hours. The incidence of non-oliguric hyperkalemia among ELBW infants in this study was 58% (93/161). The mean gestational age of neonates was 25.7 +/- 1.8 weeks (hyperkalemic) and 26.6 +/- 1.7 weeks (non-hyperkalemic). The mean rate of increases in serum potassium levels was 0.32 +/- 0.29 mEq/L/hr (hyperkalemic) and 0.13 +/- 0.12 mEq/L/hr (non-hyperkalemic). The incidence of severe intraventricular hemorrhage (IVH) was 19% (18/93) (hyperkalemic) and 4.4% (3/68) (non-hyperkalemic). The incidence of cardiac arrhythmia was 12% (11/93) (hyperkalemic) and 0% (non-hyperkalemic) respectively. Neonates with fewer weeks of gestation at birth and faster increases in serum potassium levels were associated with a more prominent tendency toward hyperkalemia. Hyperkalemia markedly increases the risk of severe IVH and arrhythmia for ELBW infants. A higher glucose infusion rate should be maintained to prevent hypoglycemia following insulin treatment.

Direct and simultaneous determination of copper, chromium, aluminum, and manganese in urine with a multielement graphite furnace atomic absorption spectrometer.

A simple method was developed for the direct and simultaneous determination of copper, chromium, aluminum, and manganese in urine using a multielement GFAAS (Perkin-Elmer SIMAA6000). Pd was used as the chemical modifier along with a special purge gas (5% H2 in Ar). A simple calibration curve method can be used (with 1:1 dilution). A standard reference material (Seronorm Trace Elements Urine) was used to find the optimal temperature program and to confirm the accuracy of the technique. The analyzed values were within 90-110% of the certified values. The relative standard deviations were 1.7, 1.5, 1.6, and 1.5% for these four elements and the detection limits were 0.08 microg L(-1) for Cu, 0.05 microg L(-1) for Cr, 0.06 microg L(-1) for Al, and 0.06 microg L(-1) for Mn. The recoveries of Cu, Cr, Al, and Mn from real urine samples were 100 +/- 5%, except for Cu (80%). The found values of Cu, Cr, Al, and Mn in a real urine sample were 14.3, 0.78, 18.9, and 0.06 microg L(-1), respectively. Scanning electron micrographs were used to investigate the physical form of Pd on the surface of the platform in the graphite furnace. Use of 5% H2 in Ar as the purge gas resulted in smaller and more uniformly distributed Pd particles (Pd particle diameters 0.4-0.6 microm using 5% H2 in Ar compared to 0.4-1.2 microm using pure Ar), increasing the effect of the Pd chemical modifier and promoting the efficiency of atomization.

Risk factors of pulmonary hemorrhage in very-low-birth-weight infants: a two-year retrospective study.

Pulmonary hemorrhage is a serious complications in very-low-birth-weight (VLBW) infants with respiratory distress syndrome (RDS). We undertook a 2-year retrospective study to investigate the predisposing factors and the incidence of pulmonary hemorrhage in VLBW infants. From January 1997 through December 1998, twenty infants were diagnosed with massive pulmonary hemorrhage (MPH) according to the following criteria: active bleeding from the endotracheal tube, acute drop in hematocrit (> or = 10%), and the development of multilobar infiltration on chest radiograph. The mean gestational age was 26.9 +/- 2.5 weeks, the mean birth weight was 909 +/- 290 g. Twenty historic controls with similar gestational age and birth weight were retrospectively identified during the study period. The incidence of MPH in VLBW infants was 5.9%(20/340). A lack of prenatal corticosteroid administration, surfactant replacement therapy for RDS, and a patent ductus arteriosus (PDA) with cardiovascular dysfunction requiring dopamine support were the significantly predisposing factors of MPH in the acute stage (< or = 7th day of life). To avoid MPH and decrease mortality and morbidity in the acute stage, prenatal corticosteroid administration, evaluation of the necessity of surfactant therapy, and early recognition and aggressive treatment of hemodynamically significant PDA were necessary.

Partial liquid ventilation in normal rabbits: comparison of three kinds of perfluorocarbon.

Perfluorocarbon liquids have been used in liquid ventilation studies and considered an effective technique of gas exchange with less barotrauma when compared with gas ventilation. We compared the effects of partial liquid ventilation (PLV) using 3 kinds of perfluorocarbon liquids (Fluorinert FC 43, FC 77 and FC 84) available in Taiwan in normal rabbits. We were able to achieve adequate oxygenation and ventilation during a 2-hour-duration of PLV using FC 43, FC 77 or FC 84. There was no significant difference in hemodynamic status or laboratory findings between control group and PLV groups. There were also no significant differences before LV and after 2 hours of PLV among PLV groups. Histological study of lung tissue revealed intact and well expanded alveoli, and no significant pathological change after 2 hours of PLV. These results show that PLV using FC 43, FC 77 or FC 84 is an effective technique for maintaining adequate pulmonary gas exchange in normal rabbits.

Glass peek composite promotes proliferation and osteocalcin production of human osteoblastic cells.

An isoelastic intramedullary implant has been developed using a composite of polyetheretherketone and 10% random, chopped E-glass fibers (GPEEK). The effect of this novel material on human bone cells has not been defined. The objective of this study was to test whether GPEEK supported the proliferation of the human bone cell line MG63, which exhibits osteoblastlike characteristics. Cells (1 x 10(5)/mL) were propagated on GPEEK discs with three different surface roughnesses (3, 6, and 9 microns) and on polystyrene plates, for comparison. The reaction of MG63 osteoblastlike cells to the GPEEK polymer composite was analyzed by determination of cell yield, osteocalcin production, and levels of alkaline phosphatase. The viable cells that were retrieved from the GPEEK discs of all three surface roughness had an approximate sixfold increase in number. Osteoblastic function of the cells, indicated by osteocalcin production, was unimpaired after a 5-day culture on the three surfaces of GPEEK. The highest level of osteocalcin was produced by osteoblastic cells propagated on GPEEK with a 9 microns surface roughness. The levels of alkaline phosphatase of these cells were similarly greater for the different degrees of surface roughness. Overall, this study demonstrates that GPEEK supported proliferation of osteoblastlike cells and provided a favorable environment for the continued production of osteocalcin in vitro.

Facial mutilation after an assault with chemicals: 15 cases and literature review.

Facial mutilation after an assault with chemicals is rarely discussed in the literature even though it is a devastating injury that occurs worldwide and is not prohibited or punished by special laws. It is our purpose to describe the devastating outcome of facial mutilation after an assault with chemicals and to draw attention to this injury as a worldwide problem. We studied fifteen patients who sustained facial mutilation with chemicals. The common story was that the patient's spouse was the perpetrator, that sulfuric acid was used, and that the deed occurred after marital or financial discord. All victims were disfigured severely and most became reclusive and rarely left their homes. Six patients (40%) had total bilateral blindness and one suffered partial loss of vision. Lower eyelid ectropion (14), microstomia (12), cervical flexion contracture (10), ear deformity (8), and nostril stenosis (6) were common. Few of the perpetrators were prosecuted. We reviewed the literature and found that the problem has been described all over the world, and that the outcome is similar to that which we described. The problem deserves worldwide recognition and attention.

Successful early separation of a premature xipho-omphalopagus conjoined twins: a case report.

Premature xipho-omphalopagus conjoined twins were successfully separated at 7 days of age. The total body weight of the twins before separation was 3502 g. One twin had persistent patent ductus arteriosus and signs of cardiac failure at 4 days of age. This was managed with indomethacin. Thirty-six hours later the second twin became anuric, necessitating early emergency separation. The twins were joined from the lower sternum to the infraumbilical area. The liver was fused, but there was no major vascular connection. There were no other major anomalies. The babies stood the procedure well and were healthy at follow-up 8 months after separation.

Acute pulmonary oedema following administration of vasopressin for control of massive GI tract haemorrhage in a major burn patient.

A 35-year-old male sustained a full-skin thickness chemical burn involving 60 per cent of TBSA when hydrochloric acid was applied to his face, trunk and extremities by his girlfriend. Debridements and skin graftings were performed smoothly and he was doing well until day 23 after injury, when massive GI tract bleeding caused a drop in blood pressure. Vasopressin was given intravenously to control the bleeding, which stopped, and the blood pressure returned to normal after transfusion. After the vasopressin infusion was tapered off acute pulmonary oedema developed abruptly, which required treatment by intubation and PEEP using a respirator. The lung condition had returned to normal by the following day. A second episode of massive GI tract bleeding recurred 10 days later, again vasopressin was given through a catheter into the inferior mesenteric artery. Again pulmonary oedema developed 38 h after the vasopressin use, the oedema disappeared within 2 days when the vasopressin infusion tapered off. It should be kept in mind that acute pulmonary oedema may develop when high doses of vasopressin are used in the treatment of Curling's ulcer or other GI tract bleeding.

An alternative method of skin grafting: the scalp microdermis graft.

Although microskin grafting has been used successfully to treat major burns, when the donor skin areas are inadequate, it is still not in popular use because of the difficulties of mincing and floating procedures. Floating is expected to produce more microskin patches with the dermal side upwards than with the epidermal side upwards. Another problem is that many microskin patches will be lost in the container during floating. This problem may be solved by preparing the microskin from the second layer scalp skin. This will be a graft of hair follicle cells, which can be sowed on the wound no matter which side is upwards. Grafting was carried out on well-prepared granulation beds, or on the fat surface after tangential excision, or on the bed after fascial excision of the burn. Allograft and Biobrane were used as cover dressings. The combination of fascial excision and allograft overlay gave an acceptable result. This can be an alternative method of skin grafting for burns with very limited donor skin areas when the scalp skin is not burned.

Pelvic abscess induced by a methicillin-resistant Staphylococcus aureus from haematogenous spread via the CVP line in a burn patient.

A 38-year-old female patients was found accidentally to have a positive culture of MRSA from a routine CVP catheter tip culture 1 week after she had complete wound closure. She was recovering from a partial skin thickness burn covering 42 per cent TBSA on the trunk and extremities. Fever and hip pain developed abruptly 1 week later when she was ready for discharge from hospital. Magnetic resonance imaging (MRI) of the pelvis disclosed an intramuscular abscess. Open drainage was performed and pus culture yielded a MRSA with the same sensitivity profile as the previous CVP tip culture. Vancomycin 500 mg every 6 h was used for 3 weeks until the drain culture disclosed a negative result, and a follow-up MRI indicated a loss of the abscess space. Follow-up at an outpatient clinic 3 months later showed that the patient remained symptom free. In this patient haematogenous dissemination was the most likely route of pelvic abscess formation. It should be remembered that MRSA infection is not always only a local problem, especially in the immunocompromised condition of burn injury.

A new method of microskin mincing.

Microskin grafting has been used successfully for major burns when donor skin areas are inadequate to cover the skin defect. The microskin may be made by repeated cutting with scissors or by a specially designed machine. However microskin grafting is still not popular due to the difficulty of the mincing process, which may take hours to do. An easy and quick method of skin mincing using the Tanner-Vandeput Mesh Dermatome has been developed. The mincing process may be done in just a few minutes instead of hours. The skin pieces made with this technique are all of a uniform square shape and size (1.2 mm x 1.2 mm). Microskin grafting using the mincing technique has been carried out on 10 thighs of five patients with a fixed patch size (1.2 mm x 1.2 mm); an expansion ratio of 1:10 is used to ensure that the average interpatch distance would be within 5 mm for a better and quicker healing. All areas healed within 6 weeks without any secondary skin grafting. The resulting 'cobblestone' appearance of the healed skin is not good looking but there is no excess scar formation. The scar is soft and can be pinched up easily. This is an easy way of microskin mincing, it is quick and can be done in any clinic without specially trained personnel or the need to buy a new instrument.

Separation of thoracopagus conjoined twins. A case report.

A pair of thoracopagus conjoined twins with a connection at the atrioventricular groove of both hearts and a huge conjoined liver were surgically separated. An aortopulmonary shunt was created for Twin B, a victim of complex congenital heart disease with hypoplastic right heart syndrome, who died 5 hours later. However, Twin A survived after prolonged endotracheal intubation and parenteral nutrition. He survived for 7 months, and went home, but finally died of sepsis. In reviewing 47 pairs of surgically separated thoracopagus conjoined twins, in 30 pairs of type A (Leachman's classification, completely separate hearts), 42 patients survived (70%); in 5 pairs of type B (atrial connection only), one patient survived (10%); in 9 pairs of type C (both atrial and ventricular interconnections), none survived; in 3 pairs of unknown type, 2 survived. Total survival rate of surgically separated thoracopagus conjoined twins was 47.9%. The survival rate was 38.2% in those operated in the neonatal period (n = 34) and 63.6% in those operated over 1 month of age (n = 44) (p = 0.016). In conclusion, thoracopagus conjoined twins are rare. Although its separation carries a high risk, especially in those with cardiac connection, this report confirmed that separation is still feasible under proper preparation and planning.

The algebraic view-point in microskin grafting in burned patients.

Microskin grafting has proved to be an effective treatment for major burns when the area of available donor skin is inadequate. In fact, microskin grafting can be comparable to the patch graft of Gabarro. Further mincing procedures cut the skin patches into smaller pieces around 1 mm2. The healing process is completed by the epithelial migration between the micropatches. The possibly longest interpatch distance is related to the expansion ratio and the size of the microskin patch. From the equation L = x.(1.4 square root of Y-1.2) it is clear that the interpatch distance L is directly related to the patch side-length x. This means that when the patch side-length is doubled then the interpatch distance will be doubled. However the expansion ratio Y is related to its square root, so that the influence of the expansion ratio Y is much less important. For improving the healing process, the interpatch distance is better kept within 5 mm. With this understanding, we can calculate the required donor skin surface area for a given wound area according to the different side-length of micropatch, and also the possible maximum patch size for a given wound area for different available donor skin areas. As the area of available skin may be very limited, the maximum patch size may be smaller than the usual size (around 1 mm). Then we have to elongate the interpatch distance, though it would delay the healing. This is a purely theoretical reference. In normal clinical practice, the discussed conditions should be considered.

A technique for simultaneous replantation of multiple amputated digits at Tamai's Zone V.

A technique for simultaneously replanting multiple digits amputated at Tamai's Zone V is described. Since these multiple amputated digits are connected together, they should be replanted as a single unit. The technique includes applying the pneumatic tourniquet first, debridement, bone shortening, and fixation of all the amputated digits, including tendon repairs, application of vascular clamps before releasing the tourniquet, followed by vascular anastomosis in one-by-one fashion for each digit. The disadvantage of this technique is the difficulty in keeping the digit cool. The advantages are it is a less time-consuming operation, there is reduced blood loss and contamination, and there is a better axial arrangement of the bony framework.

A simple device for nasal tube fixation in facial burns patients.

In acute facial burns, it is sometimes necessary to insert tubes down one or both nostrils. We describe a simple secure method of fixation.