A monomeric human C4b-binding protein (C4bp) more efficiently inactivates C3b than natural C4bp: participation of C-terminal domains in factor I-cofactor activity

We designed a cDNA construct encoding an artificial membrane molecule consisting of all 8 short consensus repeats (SCRs) of human monomeric C4b-binding protein (C4bp) followed by DAF's GPI anchor, named mC4bp, and expressed the protein on swine endothelial cells (SEC). At the same level of expression, mC4bp protected host cells as effectively as DAF, the most potent complement (C) regulator on the membrane. This result was unexpected from the reported functional properties of natural multimeric C4bp. Here, we investigated the mechanism whereby mC4bp has potent cell-protective activity. Our results were as follows: (1) mC4bp serves more efficiently as a methylamine-treated C3 (C3ma)-inactivating factor I-cofactor than natural C4bp and as efficiently as MCP as a methylamine-treated (C4ma)-inactivating cofactor by fluid-phase cofactor assay: (2) the potency of C3ma inactivation by mC4bp and factor I is quite high compared to those of other cofactors: (3)blocking studies using mAbs against C4bp suggested that both the 48 kDa N-terminal fragment and the C-terminal domain near the portion responsible for bundle formation participate in the high C3ma-inactivating capacity of mC4bp. Thus, acquiring high C3ma-inactivating capacity secondary to monomeric alteration leads to high C regulatory activity of mC4bp. These results infer that mC4bp differs from C4bp in its potent factor I-cofactor activity and is a good candidate as a safeguard against hyperacute rejection of xenografts.

Molecular cloning of membrane cofactor protein (MCP; CD46) on B95a cell, an Epstein-Barr virus-transformed marmoset B cell line: B95a-MCP is susceptible to infection by the CAM, but not the Nagahata strain of the measles virus

Measles virus (MV) infects not only human beings but also some simian species. The MV receptor on Vero cells (a cell line established from African Green monkey kidney cells) and human cells has been shown to be the membrane cofactor protein MCP/CD46, which is an inhibitor of autologous complement (C) activation. B95a, an Epstein-Barr virus (EBV)-transformed marmoset B cell line, is a simian cell line used for MV selection and is much more susceptible to MV than Vero cells. In the present study, we isolated cDNAs encoding MCP homologues from B95a cDNA library and assessed whether B95a-MCP is responsible for the high susceptibility of B95a to MV. The deduced amino acid sequence of the cDNA of B95a-MCP was 76% identical to that of human-MCP, and the recombinant B95a-MCP exerts C inhibitor activity. Although CAM, a vaccine strain of MV, infected Chinese hamster ovary (CHO) cells expressing B95a-MCP, Nagahata strain, a wild type of MV, failed to infect the CHO transfectants, suggesting that additional membrane molecules of B95a are responsible for the high susceptibility of B95a to the Nagahata strain.

Evidence that far infrared radiation promotes growth of Xenopus laevis

In most ectotherms, environmental temperature has differential effects on growth and differentiation. For example, amphibian size at maturity decreases with increasing temperature. To address how radiant heat in the form of far-infrared radiation (FIR) may affect development of the aquatic ectotherm Xenopus laevis, we continuously irradiated swimming larvae as they developed into young adults. Here we report evidence that FIR promotes growth of these organisms in an aqueous environment.

[Clinical usefulness of 201Tl-chloride scintigraphy for the evaluation of metastatic bone lesions]

201Tl-Chloride scintigraphy (early and delayed images) was performed in 40 patients with suspected metastatic bone lesions. The sensitivity and specificity of 201Tl scanning for detecting metastatic bone lesions were 66.7% and 77.4%, respectively. The uptake ratio of 201Tl per voxel of the lesions to the normal site was significantly different between the metastatic bone lesion and benign lesions. In 20 sites of 15 patients, 201Tl-Chloride scintigraphy was performed before and after radio- or radiothermotherapy. There was a significant difference in the mean uptake ratios in the early and delayed scans between before and after therapy. The mechanism of intracellular uptake of 201Tl is considered to be one of active transport, which might make 201Tl an accurate indicator of the viability of tumor cells and metabolic activity as long as there is sufficient blood flow to prompty transport 201Tl to tumor cells. Thus it would seem that decreased uptake of 201Tl and change in retention index after therapy depends partially on tumor blood flow. In conclusion, 201Tl-Chloride scintigraphy is very useful not only for clinically detecting metastatic bone lesions but also for assessing the therapeutic effects.

A method for prevention of arterialized venous flap necrosis

The authors used a delayed arteriovenous (A-V) shunt method to prevent congestion and necrosis of arterialized venous flaps. Two weeks before elevating the flap, an A-V shunt between the central artery and vein was created at the more proximal flap end. Twelve rabbits (24 flaps) were used for this experiment. Flaps were followed for 4 weeks. Twelve of 24 flaps survived completely; another 10 flaps showed partial necrosis; and two flaps became completely necrotic. These results demonstrated that this method is superior to a simple A-V shunt in preventing congestion and necrosis in the arterialized venous flap.

An interferon regulatory factor-related gene (xIRF-6) is expressed in the posterior mesoderm during the early development of Xenopus laevis

Out of a Xenopus neurula cDNA library, we isolated a clone which encodes a 52.4-kDa protein highly similar to the mouse interferon regulatory factor, IRF-6, whose function is unknown. The mRNA of this gene, named xIRF-6, seems to be maternally transmitted, but its amount rapidly decreases after the tailbud stage. Whole-mount in situ hybridization showed that xIRF-6 mRNA is expressed in the presumptive somitic mesoderm in the late gastrula, and then confined to a segment of posterior somite during the neurula through the tailbud stage. The temporally and spatially limited expression of the xIRF-6 gene product may contribute to the transcriptional regulation of specific genes which are necessary for the development of the posterior somites.

The effects of clomiphene citrate on normally ovulatory women

OBJECTIVE

To investigate the efficacy of clomiphene citrate (CC) on normally ovulatory women who complained of infertility.

DESIGN

A randomized study.

SETTING

University Hospital.

PATIENT(S)

Thirty-three normally ovulatory women with unexplained infertility.

INTERVENTION(S)

Eighteen women received CC at a 50-mg dosage. Fifteen women received no ovulation-induction drugs.

MAIN OUTCOME MEASURES

The pregnancy rate (PR) per patient, the PR per cycle, and the cumulative pregnancy rate.

RESULT(S)

Seven patients in the CC group stopped taking CC, and observations were terminated because of antiestrogenic effects. The pregnancy rate (PR) per patient and the PR per cycle were significantly decreased (P < 0.005) in the CC group (4 of 18 [22.2%] and 4 of 66 [6.1%], respectively) than in the spontaneous group (11 of 15 [73.3%] and 11 of 52 [21.2%], respectively). Kaplan-Meier tests showed that the cumulative pregnancy rate in the CC group was significantly lower than in the spontaneous group (P < 0.05). Five of seven patients who had stopped taking CC became pregnant in spontaneous cycles.

CONCLUSION(S)

Administration of CC to normally ovulatory women is not efficacious in terms of increasing the pregnancy rate.

The Na+,K+-ATPase alpha subunit requires gastrulation in the Xenopus embryo

Na+,K+-ATPase participates in reabsorption of ions and water and produces an electrochemical gradient between the intra- and extracellular spaces across the cell membrane. It also plays an important role in many developmental phenomena such as a blastocoele formation and neural formation. To elucidate the expression pattern of Na+,K+-ATPase in the Xenopus embryo, the spatial expression patterns of the Na+,K+-ATPase alpha subunit were studied in a normal embryo by whole-mount in situ hybridization. These transcripts were localized around the dorsal blastopore at the gastrula stage, in the neural tube at the neurula stage, and then in the pronephros and cloaca at the tail-bud stage. To study the function of Na+,K+-ATPase in embryogenesis after mid-blastula transition, the expression of the Na+,K+-ATPase alpha subunit was inhibited by the injection of specific antisense RNA. Embryos injected with Na+,K+-ATPase antisense RNA showed inhibition of gastrulation. When antisense RNA was injected into the dorsal blastomeres, head differentiation was markedly inhibited. These results suggest that this transcript plays an important role during gastrulation and head differentiation.

Two-stage arterialized flow-through venous flap transfer for third-degree burn defects on the dorsum of the hand

A modified, two-stage arteriovenous flow-through venous flap was designed to repair skin defects due to third-degree burns on the dorsum of the hand in four patients. Two weeks after plasty of an arteriovenous (A-V) shunt between the greater saphenous vein and dorsalis pedis artery, the arterialized flow-through venous flap was transferred using the greater saphenous vein as the pedicle. The size of the flaps utilized ranged from 7 x 13 cm to 9 x 13 cm. In three patients the entire flap survived without complication. In one patient whose flap had only one drainage vein, the flap survived with superficial necrosis of about 10 percent of the flap at the borders. During the 2 weeks after A-V shunt creation, the authors believe that microcirculation around the arterialized vein probably develops, contributing to better irrigation and thereby to flap survival. Using this two-stage procedure, it might be feasible to obtain larger grafts and to attain a higher flap survival rate.

[Limits and expansion of the clinical use of salvaging autologous transfusion]

As salvaging autologous transfusion(SAT) is conducted by employing blood lost by the patient during surgery, the limits of its clinical use are automatically determined. A thorough understanding of the characteristics and problems of SAT to reduce complications and to avoid the use of homologous blood should lead to the expansion of its clinical use. To achieve an expansion of SAT's use the following steps should be taken. Combining of SAT with another method of autotransfusion, increasing of the preoperative blood volume(volume of erythrocytes), prevention of destruction of erythrocytes in the process of bleeding, salvaging, cleaning and concentration (improvement in the rate of salvaging), preservation of the function of the erythrocytes obtained, immediate salvaging of blood by reduction in the processing time, improvement in the salvaging rate, recycling of the plasma substance separated in the process, removal of mixed harmful substances(malignant tumor cells, urine, bacteria), extension of indications, extension of subjects for whom SAT may be used to children, increase in the remuneration point in the Health Care System, and improvement in the limits of hemodilution of the organic body.

An essay on the similarities and differences between inductive interactions in anuran and urodele embryos

As a first step towards providing a conceptual approach to understanding similarities and differences in the mechanisms which guide inductive interactions among related organisms (e.g. various amphibia), a set of five principles is offered here. These principles were formulated by analyzing literature examples of classical embryological phenomena and by performing experiments with activin, a peptide growth factor which is currently suspected to play for a role in mesoderm induction. Mechanisms which account, at least in part, for the observed differences between anuran and urodele inductive processes can be derived from these principles.

Treatment of massive hemorrhage with liposome encapsulated human hemoglobin (NRC) and hydroxyethyl starch (HES) in beagles

The efficacy of NRC as a substitute for blood transfusion for treatment of acute, massive hemorrhage was evaluated in this study. Fourteen beagles, anesthetized with a mixture of 50% nitrous oxide, 0.97% sevoflurane and oxygen and ventilated by a respirator, were hemodiluted by withdrawal of 12 ml/kg of blood and infusion of isovolemic HES (hemodilution: HD) four times every 10 min. Then the animals were divided into two groups; an HES group, in which the same HDs were continued and an NRC group, in which the HDs were done with NRC. The hematocrit value decreased to 11% in the HES group after eight HDs and to 13% in the NRC group, which had a 3.9% NRCcrit value during the same period. In the NRC group, Cao2 decreased to 7.9 ml/min, which was significantly higher than the 5.9 ml/dl of the HES group. Oxygen consumption decreased to 56 ml/min in the HES group, but in the NRC group, it dropped to 74 ml/min, which was significantly higher than that of the HES group. Cardiac output increased to 1.2 times that of the control after eight HDs and arterial mean pressure decreased to approximately 60%. The above data indicated that NRC delivered sufficient oxygen to tissues, substituting for circulating red cells and maintained aerobic metabolism. Therefore, it should be possible to use NRC successfully for the treatment of cute, massive hemorrhage.

[Effect of aprotinin on endothelial cell functions during cardiopulmonary bypass]

Fourteen patients undergoing cardiac or great vessel surgery using cardiopulmonary bypass (ECC) were divided into two groups. Group A of 7 patients received 2 x 10(6) units of aprotinin (apr) 15 min before ECC and 0.5 x 10(6) unit immediately after the ECC. Group B of 7 patients received 0.5 x 10(6) unit of aprotinin 15 min before ECC and 2 x 10(6) units immediately after the ECC. Several physiological parameters were measured two hours before ECC, immediately after the cessation of the ECC and 4 hours thereafter. No difference was noted in coagulation time, which remained within normal range, and postoperative hemorrhage between the groups after ECC. Although thrombomodulin, ELAM-1 and ICAM-1 tended to decrease slightly in the two groups immediately after ECC, recovery of the thrombomodulin was much more rapid in the A group than in the B group. On the other hand, blood endothelin level and von Willebrand factor activity were elevated progressively after the ECC. Blood granulocyte-elastase activity and IL-8 increased markedly immediately after the ECC and then tended to decrease. These data indicate that no marked damage would be caused on the endothelial cells during ECC which was carried out using a relatively small dose of apr. However, the protective effect of apr remained to be clarified in the future.

Closed rupture of the flexor digitorum profundus tendon of the little finger caused by calcification of the triangular-fibrocartilage

A case of rupture of flexor digitorum profundus tendon of the little finger caused by calcification of the triangular fibrocartilage (TFC) is reported. At operation, a round defect of the TFC and rupture of the flexor digitorum profundus tendon (FDP) of the little finger were observed. The defect of TFC was repaired using the palmaris tendon and FDP of the little finger was woven into FDP of the ring finger. Eleven months after operation, the patient had almost full flexion and extension of the distal and proximal interphalangeal joints.

Increasing coronary perfusion pressure on diastolic and systolic performance is less pronounced in right ventricle than in left ventricle

OBJECTIVE

Little is known as to whether an increase in coronary perfusion pressure can alter the right ventricular (RV) distensibility and the contractile function as it does in the case of the LV.

METHODS

In eight isolated isovolumically contracting canine hearts, RV and LV volumes and coronary perfusion were independently controlled. Effects of an increase in coronary perfusion pressure (from 73 +/- 1 to 152 +/- 6 mmHg) on the end-diastolic and end-systolic pressure-volume relations in both RV and LV were assessed.

RESULTS

Following an increase in coronary perfusion, and at a similar volume of the ventricles, end-diastolic pressure was elevated by 2.8 +/- 0.8 mmHg in RV and 8.9 +/- 2.0 mmHg in LV (P < 0.01; RV vs LV), and the slope of RV end-systolic pressure-volume relation, Ees, increased by 11 +/- 6% (P < 0.05) and that of the LV Ees by 21 +/- 5% (P < 0.01). The percent change of RV pressure-volume area (PVA) was less than that in LV-PVA (26 +/- 9 vs 48 +/- 11%; P < 0.05).

CONCLUSIONS

Accordingly, increases in coronary perfusion pressure and/or flow decreased the RV distensibility and enhanced the RV contractile function, the extent of which, however, was less than that in the LV.

Innervated radial thenar flap for sensory reconstruction of fingers

A radial thenar flap, which is supplied by the superficial palmar branch of the radial artery and innervated by the superficial branch of the radial nerve, was used in four patients for sensory reconstruction of the fingers. Two patients had degloving injuries of the hand and two had amputation injuries of the thumb. Three of the cases underwent free-flap transfers, and one case underwent a reverse-flow island flap. The size of these flaps was about 3 x 5 cm except in one case, where a 15 x 5 cm flap combined with a radial forearm flap was used. Sensory reinnervation was excellent and donor site morbidity was minimal in all four cases. An innervated radial thenar flap from the ipsilateral hand offers an alternative choice to reconstruct large palmar defects of the fingers.

[Hemostatic mechanism associated with aprotinin during and after the extracorporeal circulation for cardiac and great vessel surgery]

It has been reported that aprotinin (apr) is effective for hemostasis during and after the extracorporeal circulation (ECC) for cardiac or great vessel surgery. However its mechanism remains still obscure. In this study, we observed relationships between changes in interleukin-8 (IL-8), endothelial factors, or D-dimer and aprotinin administered before and after the ECC. Fourteen patients in whom cardiac or great vessel surgery was done using ECC were divided randomly into two groups. Seven subjects in Group I (G-I) were infused 10(6) KIU of apr immediately after anesthesia, immediately before and after the ECC, respectively, and 10(6) KIU of apr were also added during the ECC. Seven other subjects (G-II) were infused 10(6) KIU of apr immediately before and at three hours after the ECC, and also 2 x 10(6) KIU of apr immediately after the ECC. No marked hemorrhagic tendency was noted in all subjects and increase in plasma D-dimer was not marked. Immediately after the ECC, granulocyte elastase in plasma increased markedly in both groups but subsequently decreased in the G-II alone while it remained unchanged in the G-I. Similar changes were observed in plasma IL-8 values. During the ECC, intercellular adhesion molecule-1 in plasma decreased in both groups but von Willebrand factor activity decreased in the G-I alone. From the above data, the hemostatic effect of apr may contribute to protect the dysfunction of endothelial cells or to enhance recovering from the dysfunction during the ECC.

Partial soleus muscle island flap transfer using minor pedicles from the posterior tibial vessels

A new method for partial soleus muscle island flap transfer using minor pedicles from the posterior tibial vessels was designed and executed. A portion of the soleus muscle body that was slightly wider than the defect was harvested with minor pedicles. The muscle flap was transposed by turning it over or by creating an island flap. Skin grafts were applied to the exposed muscle. This new type of muscle flap was applied to six patients with a pretibial skin defect at the lower third of the leg. It was used for treatment of an open fracture with an associated skin defect in four patients, chronic osteomyelitis in one patient, and a recurrent stasis ulcer in one patient. In all patients the transferred muscle flap survived completely.

"Plasmatic imbibition" in the rabbit flow-through venous flap, using horseradish peroxidase and fluorescein

In the present study, the phenomenon of "plasmatic imbibition" was investigated histologically in a rabbit flow-through venous flap model, using horseradish peroxidase and fluorescein. Horseradish peroxidase introduced between the flap and the recipient bed, produced brown staining of the entire contact surface 10 min postoperatively. At 30 min, erythrocytes in the flow-through vein stained red. The flap and the erythrocytes became more intensely stained over time. When horseradish peroxidase was introduced from a central artery after a Silastic sheet had been inserted between the flap and recipient bed, the flap color became a soft brown and the erythrocytes of the flow-through vein stained red 10 min postoperatively. In the experimental groups subjected to fluorescein, introduced between the graft (or flap) and the recipient bed, fluorescence was seen 10 min postoperatively, except in the flow-through vein. At 30 and 120 min, the whole graft (or flap) showed fluorescence. Fluorescein was introduced into the femoral vein after flap elevation, or a Silastic sheet was inserted between the flap and the recipient bed. At 10 min, these groups showed a weak fluorescence only in the flow-through vein; subsequently, at 120 min, the flow-through vein and its surrounding tissue showed fluorescence, but the flap showed none. Plasmatic imbibition was proved to be acting in the flow-through vein, and it is considered as important a phenomenon in flap survival as venous flow itself.