Thermostability of doubly glycosylated recombinant lysozyme

We prepared a lysozyme mutant (Q41S/R61S) introducing Asn-type glycosylation signal sites by yeast expression system. On purification by cation exchange column at pH 7, three fractions were obtained. Peptide mapping and mass-spectrometry showed the fractions were the derivatives glycosylated at both Asn39 and Asn59, at only Asn39, and not glycosylated. It was revealed that the processing of Asn-linked oligosaccharide at Asn39 and Asn59 occurred independently in yeast cells. The denaturation temperatures of these derivatives by differential scanning calorimetry were 76.0, 68.8, and 67.5 degrees C at pH 3, respectively. The stabilization of glycosylated lysozyme depends on the degree of glycosylation. We concluded that stabilized proteins can be constructed by glycosylation at proper sites. Thermodynamic stabilization by the artificial double glycosylations on a protein has not yet been reported.

Cardiorespiratory response to low-intensity walking in water and on land in elderly women

The purpose of the present study was to determine whether or not the exercise intensity of water-walking for elderly women could be accurately prescribed by heart rate data obtained during treadmill exercise on land. Six healthy female volunteers, with a mean age of 62.2 +/- 4.2 years, took part in this study. Walking on land was performed on a treadmill. Each subject completed three consecutive 4-minute walks at a progressively increasing velocity (40, 60 and 80 m.min-1), with a 1-minute rest after both the first and second walks. The room temperature and relative humidity were 24.5 +/- 0.2 degrees C and 54.8 +/- 4.0%, respectively. Walking in water was performed in a Flowmill, which is a treadmill positioned at the base of a water flume. Each subject completed three consecutive 4-minute walks at a progressively increasing belt and water-flow velocity (20, 30 and 40 m.min-1), with a 1-minute rest after both the first and second walks. The water depth was at the level of the xiphoid process of each subject. The water temperature was 30.7 +/- 0.1 degrees C. The exercise intensity at the highest workrate was equivalent to 44.2 +/- 10.3% of the heart rate reserve (HRR) during water-walking and 38.4 +/- 4.7% of the HRR during land-walking. There was a highly significant linear relationship between heart rate (HR) and oxygen uptake (VO2) during both water-walking and land-walking. The relationship between HR and VO2 in both exercise modes was similar. Thus, the relationship of HR to VO2 derived from a treadmill-graded walking test on land may be used to prescribe exercise intensity for water-walking in thermoneutral water.

Funnel chest: treatment strategy and follow-up

Although funnel chest is the most frequently seen deformity of the anterior chest wall in children, there is still considerable controversy regarding three major aspects, namely, the frequency of such deformities, their physiological importance, and the methods available for treatment. We retrospectively analyzed our experience with the 154 patients managed in our department. In 81 of these an operation was performed (OP), and the clinical findings for this group were compared with the 73 patients in whom an operation was not performed (NOP). Evaluation included subjective findings, especially the views of the patients' parents, and objective findings, including chest radiographs, computed tomography (CT), spirogram, electrocardiography, and echocardiography. In all patients the assessment included postoperative respiratory symptoms, appearance of the chest, and psychological aspects related to the deformity. Post-operatively, respiratory symptoms almost invariably subsided. The cosmetic result could initially be regarded as satisfactory or fair during the first 10 years following surgery, but over time there was frequently increasing concern regarding the scar. The NOP patients showed significantly less severity of the funnel index compared with OP patients. However, there was no spontaneous improvement in the deformity in older patients; most of the NOP patients continued to show a cosmetic deformity and 26.7% had psychological problems. This retrospective study confirms that our treatment strategy of objective criteria for operation (functional compression index > 0.2, % vital capacity <80, and CT index less than 0.25) and timing of operation (between 4 and 6 years of age) provides good results. Based on the analysis of long-term follow-up, surgery is considered indicated in patients with severe deformity. However, in the interest of psychological development, the indications for surgery may be extended.

Cornelia de Lange syndrome associated with cecal volvulus: report of a case

Cornelia de Lange syndrome is known to be occasionally associated with gastrointestinal malformation. However, the occurrence of cecal volvulus in such anomalies is very rare. We report a 15-y-old Japanese boy with Cornelia de Lange syndrome associated with a cecal volvulus secondary to non-fixation of the cecum and ascending colon. The patient was admitted to our hospital because of abdominal pain and bilious vomiting. At emergent laparotomy, cecal volvulus with non-fixation of the ascending colon and cecum was diagnosed. Release of the cecal volvulus and the fixation of the cecum and ascending colon to the right retroperitonium were performed. The postoperative course was uneventful, except for sepsis caused by aspiration pneumonia soon after the operation.

CONCLUSION

Clinicians treating patients with this syndrome should be aware that such patients may be at risk for developing severe gastrointestinal anomalies, including cecal volvulus.

Interstitial photodynamic therapy with rotating and reciprocating optical fibers

BACKGROUND

Photodynamic therapy (PDT) is an effective treatment modality that allows selective destruction of malignant tumor cells. However, because of the difficulty in exposing deeper areas of tumors, the modality has strictly limited indications. In this study, the authors introduce a new method for delivering laser light to a three-dimensional, wide area with the purpose of improving the therapeutic value of PDT.

METHODS

Three patients with squamous cell carcinoma of the tongue were treated with the present course. After administering porfimer sodium, laser-proof tubes were inserted through the tumor, and optical fibers were passed through the tubes. Pulse laser was emitted from the obliquely prepared fiber tip and distributed toward the target area while rotating and reciprocating the optical fiber.

RESULTS

Two patients achieved a complete response without any complications or functional disabilities. The third patient, however, had a partial response and required surgery.

CONCLUSIONS

The results indicate the capability of distributing laser light to an entire area of solid tumor. However, the ideal dose of laser light for the treatment of tumors remains unknown. Interstitial PDT will be more efficacious and reliable after the dosimetry is established.

Outcome of fetal cystic hygroma and experience of intrauterine treatment

OBJECTIVE

To review our cases of fetal cystic hygroma and to examine the prognostic factors with the goal of establishing criteria for the intrauterine treatment for cystic hygroma.

PATIENTS AND METHODS

Thirty-one cases of fetal cystic hygroma were managed by us from January 1988 to December 1997, and 21 cases were available for analysis. Three prognostic factors, namely chromosomal abnormality, structural anomaly and hydrops fetalis, were evaluated. We treated 2 cases of cystic hygroma associated with hydrops fetalis in utero using OK-432 injection under ultrasound guidance.

RESULTS

The fetuses without any of the prognostic factors listed above showed a good prognosis throughout the fetal and neonatal periods. However, in this group, 2 infants with large tumors died of hemorrhage from the tumor at 6 months and 3 years of age, respectively. Cases with hydrops fetalis without chromosomal abnormalities or structural anomalies (5 cases) resulted in either intrauterine fetal death (IUFD, 2 cases) or early perinatal neonatal death (early PND, 3 cases). The cause of early PND was circulatory failure. Most of the hydrops cases with either a chromosomal abnormality or structural anomaly resulted in IUFD before 22 weeks of gestation. The size of the cyst decreased in 1 of 2 cases treated in utero.

CONCLUSIONS

The fetal cases of cystic hygroma showing hydrops fetalis without chromosomal abnormalities or structural anomalies are considered to be possible candidates for intrauterine therapy. Those with very large cystic hygroma without any of the three prognostic factors are also thought to be candidates for fetal treatment. Based on our clinical experience, sclerotherapy using OK-432 is considered to be a treatment option in selected cases with fetal cystic hygroma.

Manganese intoxication during intermittent parenteral nutrition: report of two cases

BACKGROUND AND METHODS

The administration of trace elements is thought to be needed in patients receiving long-term parenteral nutrition. Recently, manganese intoxication or deposition was documented in such patients. We report two cases of manganese intoxication during intermittent parenteral nutrition including manganese. Manganese had been administered for 4 years at a frequency of one or two times per week in one case and for 5 years at a frequency of one or two times per month in the other case. Both cases showed mild symptoms with headache and dizziness. One case had mild hepatic dysfunction and the other did not. The whole-blood manganese level increased in one case, but not in the other case. T1-weighted magnetic resonance images revealed symmetrical high-intensity areas in basal ganglia and thalamus in both cases. After the administration of manganese was stopped, these symptoms all disappeared and the magnetic resonance images abnormalities gradually improved in both patients. Mild long-term manganese intoxication is thus considered to occur regardless of the frequency of using a manganese supplement.

CONCLUSIONS

Patients should be carefully monitored when receiving long-term parenteral nutrition including manganese, even when the manganese dose is small and the frequency of receiving a manganese supplement is low.

Behçet's disease associated with complement component 9 (C9) deficiency

Abstract Behçet's disease is a multisystem inflammatory disorder with unknown etiology. It has been shown that the titer of plasma complement component 9 (C9) is a good indicator of the disease activity. Therefore, the involvement of C9 in the pathogenesis of Behçet's disease has been suggested. We report a case of Behçet's disease associated with complete C9 deficiency (C9D) carrying the homozygous nonsense mutation at Arg-95 of C9 (R95X). The patient presented the typical characteristics of Behçet's disease, such as uveitis, recurrent oral aphthae and genital ulcers, and arthritis, suggesting that C9 does not play an essential role in the pathogenesis of Behçet's disease.

Relationship between local structure and stability in hen egg white lysozyme mutant with alanine substituted for glycine

We prepared five mutant lysozymes in which glycines whose dihedral angles are located in the region of the left-handed helix, Gly49, Gly67, Gly71, Gly102 and Gly117, were mutated to an alanine residue. From analyses of their thermal stabilities using differential scanning calorimetry, most of them were more destabilized than the native lysozyme, except for the G102A mutant, which has a stability similar to that of the native lysozyme at pH 2.7. As for the destabilized mutant lysozymes, their X-ray crystallographic analyses showed that their global structures did not change but that the local structures changed slightly. By examining the dihedral angles at the mutation sites based on X-ray crystallographic results, it was found that the dihedral angles at these mutation sites tended to adopt favorable values in a Ramachandran plot and that the extent and direction of their shifts from the original value had similar tendencies. Therefore, the change in dihedral angles may be the cause of the slight local structural changes around the mutation site. On the other hand, regarding the mutation of G102A, the global structure was almost identical with that of the native structure but the local structure was drastically changed. Therefore, it was suggested that the drastic local conformational change might be effective in releasing the unfavorable interaction of the native state at the mutation site.

Adrenomedullin receptors in rat cerebral microvessels

To characterize the sites of action of adrenomedullin (AM) in the cerebral microvasculature, we studied the effect of AM on cyclic AMP (cAMP) level as well as expression of AM and its receptor in the rat cerebral microvessels. The microvessels were prepared from rat cerebral cortex by albumin flotation and glass bead filtration technique. AM and calcitonin gene-related peptide (CGRP) increased cAMP level in the microvessels in a concentration-dependent manner. The effect of AM was more than 100 times more potent than that of CGRP. The accumulation of cAMP by AM was inhibited by AM[22-52], an AM receptor antagonist, but not by CGRP[8-37], a CGRP receptor antagonist, suggesting that AM increased cAMP accumulation by acting on receptors specific to AM. [125I]AM binding to the microvessels was displaced by AM and less potently by AM[22-52]. The displacing potencies of CGRP and CGRP[8-37] were very weak. mRNAs for AM as well as calcitonin-receptor-like receptor and receptor-activity-modifying protein 2 which form a receptor specific to AM, were highly expressed in the microvessels. These results provide biochemical and pharmacological evidence that AM is produced in and acts on the cerebral microvessels in an autocrine/paracrine manner and is involved in regulation of cerebral microcirculation.

Remarkable thermal stability of doubly intramolecularly cross-linked hen lysozyme

In order to examine how a protein can be effectively stabilized, two intramolecular cross-links, Glu35-Trp108 and Lys1-His15, which have few unfavorable interactions in the folded state, were simultaneously introduced into hen lysozyme. Both of the intramolecularly cross-linked lysozymes, 35-108 CL and 1-15 CL, containing cross-links Glu35-Trp108 and Lys1-His15, respectively, showed increases in thermal stability of 13.9 and 5.2 degrees C, respectively, over that of wild type, at pH 2.7. On the other hand, a doubly cross-linked lysozyme showed an increase in thermal stability of 20.8 degrees C over that of wild type, under identical conditions. Since the sum of the differences in denaturation temperature between wild type and each of the cross-linked lysozymes was nearly equal to that between wild type and the doubly cross-linked lysozyme, we suggest that the efficient stabilization of the lysozyme molecule was the direct result of the double intramolecular cross-links.

The formation of the chick ileal muscle layers as revealed by alpha-smooth muscle actin immunohistochemistry

The genesis of intestinal smooth muscle layers was immunohistochemically investigated by use of an antibody to alpha-smooth muscle actin (alpha-SMA) in the developing chick ileum. Myoblast cells positive for alpha-SMA were already found in the presumptive circular muscle layer on E 8.5. On E 11.5 radially oriented muscle fibers were protruded from the outermost layer of the developing circular musculature and then formed a tuft-like aggregates. These radial muscle bundles were bent into an L-shape. The long distal extension of muscle bundles run parallel to the long axis of the ileal loop and developed into the longitudinal muscle layer. The obliquely oriented muscle fibers, locating at the intermuscular space of the muscularis propria, probably are to be considered a remnant of the short extension of radial muscle bundles. The muscularis mucosae was formed by the processes equivalent to the genesis of longitudinal muscle layer. On E 14.5 centripetally oriented muscle fibers emerged from the innermost layer of circular musculature. The long distal extension of centripetal fibers lay along the inner surface of developing circular musculature. On E 19.5 the longitudinal muscle layer of the muscularis mucosae was newly formed by separating from the circular musculature. The villous myoblast cells initially developed from the innermost layer of the muscularis mucosae on E 18.5, and were widely distributed in the lamina propria mucosae on E 20.5. Temporal and chronological pattern in expression of alpha-SMA was observed during the development of the chick intestinal smooth muscle. By E 14.5 the entire layer of the muscularis propria was intensely immunostained for alpha-SMA, but from E 15.5 onward the staining intensity gradually began to decrease from the outer half of the circular musculature. Finally, the immunoreactivity was localized in the inner layer of circular muscle and the longitudinal muscle layer. A possible functional role of this inner layer of circular muscle is discussed.

Fetal stabilization for antenatally diagnosed diaphragmatic hernia

BACKGROUND/PURPOSE

Infants with congenital diaphragmatic hernia have pulmonary hypoplasia resulting in persistent pulmonary hypertension of neonates (PPHN), which is the main contributor to both high mortality and morbidity. The pulmonary artery bed in patients with congenital diaphragmatic hernia (CDH) is underdeveloped and is very sensitive to slight stimuli. It is, therefore, vital to avoid any factors that might increase pulmonary vascular resistance during the perinatal treatment of these patients. Recently, fetal anesthesia for perinatal stabilization in patients with CDH has been reported. However, the efficacy of this method remains controversial. The aim of this study is to analyze the benefits of fetal stabilization using fetal anesthesia in patients with CDH.

METHODS

The authors have seen 9 cases of antenatally diagnosed CDH and attempted fetal stabilization. The indication for fetal stabilization was a lung thoracic ratio of less than 0.2, without any severe associated anomalies. The protocol for fetal stabilization was (1) monitoring the fetal respiratory movement and heart beat by ultrasonography, (2) the administration of morphine (20 to 30 mg) and diazepam (5 mg) to the mother, (3) the confirmation of any interruptions in fetal movement followed by a cesarean section, (4) pancuronimum (0.5 mg) was given through the umbilical vessels, (5) intubation before clamping of the umbilical cord, and (6) high-frequency oscillatory ventilation (HFO) without bagging.

RESULTS

The lung-thratic ratio (LTR) was between 0.06 to 0.17 (average, 0.10+/-0.04). Operation was performed in 7 of 9 patients at between 2.5 and 27 hours after birth. The overall survival rate was 66.7% (6 of 9). All of the patients who underwent operation within 5 hours after birth survived.

CONCLUSIONS

Perinatal stabilization using fetal anesthesia was found to be effective in preventing PPHN and shortening the period of preoperative stabilization. It also improved the survival rate of patients with severe CDH.

Abnormalities of enteric neurons, intestinal pacemaker cells, and smooth muscle in human intestinal atresia

BACKGROUND/PURPOSE

Intestinal dysmotility, which usually has been encountered in the severely dilated proximal segment, is an important problem in postoperative management of patients with intestinal atresia (IA). Changes of enteric nerves had been histochemically examined in both the proximal and distal segments of IA, but a systemic immunohistochemical analysis is still lacking. The aim of this study was to examine precisely alterations of neuronal and muscular elements and pacemaker cells in intestines from patients with IA.

METHODS

Resected intestines were obtained from 5 patients with ileal atresia, 3 patients with jejunal atresia, and 3 controls without gastrointestinal diseases (congenital diaphragmatic hernia). All specimens were immunochemically stained with a monoclonal antibody to alpha-smooth muscle actin (SMA) as a smooth muscle marker, polyclonal antibodies to protein gene product (PGP) 9.5 as a general neuronal marker, and to c-kit protein as a maker of intestinal pacemaker cells. In addition, all specimens also were stained by NADPH-diaphorase (NADPH-d) to know the distribution of inhibitory nitrergic nerves.

RESULTS

A hypoplasia of the myenteric ganglia and a marked reduction of intramuscular nerve fibers, including nitrergic neurons, were observed in the dilated proximal segment of IA. C-kit-positive cells were localized around the myenteric plexus, but rarely found within the muscularis propria in the proximal segment. The distribution of nerves and c-kit-positive cells in the distal segment was comparable with that seen in controls. A reduced staining intensity for alpha-SMA was mainly observed in the hypertrophic circular muscle layer of the proximal segment.

CONCLUSIONS

A hypoplasia of intramural nerves and pacemaker cells was seen predominantly in the proximal segments of IA. Hypertrophy and reduced immunoreactivity for alpha-SMA also were observed in the circular muscle layer of the proximal segment. These alterations of the proximal segment may thus contribute to the postoperative intestinal dysmotility in IA cases.

Complications in neonates with short bowel syndrome and long-term parenteral nutrition

BACKGROUND

Because of advances in parenteral nutrition (PN), the prognosis for patients with short bowel syndrome (SBS) has recently shown great improvement. Even infants with a small bowel measuring only 20 cm either with or without an ileocoecal valve can now survive. However, because of the increased periods of PN, severe complications associated with PN have been observed.

PATIENTS AND METHODS

We analyzed 17 patients with SBS treated by long-term PN to investigate the complications of PN, particularly hepatic dysfunction, micronutrient deficiency, and intoxication.

RESULTS

Eleven of 17 patients (64.7%) had hepatic dysfunction, mostly cholestasis. The main causes of hepatic dysfunction were loss of enteral feeding and infections. Regarding the complications of the micronutrients, zinc and copper deficiencies have been observed less often because of trace element supplements. However, manganese deposition, especially in the basal ganglia, was recognized in one patient.

CONCLUSIONS

We therefore need to pay more attention to these problems when treating this disease in order to improve the overall prognosis significantly.