Influence of thickness and location on the residual monomer content of denture base cured by three processing methods

The influence of thickness and location on the residual monomer content of acrylic resin plates was examined when they were processed by three methods: a conventional method, fluid resin technique, and a microwave curing method. The residual monomer contents were measured by gas liquid chromatography. The levels of residual monomer were influenced by the processing methods and thicknesses of acrylic resin specimens, but not by location within the specimens. These results suggest that dimensional accuracy and stability of acrylic resin dentures could be influenced by the processing method, the thickness of the bases, and the shape and size of the dentures.

New Phases of C 60 Synthesized at High Pressure

The fullerene C(60) can be converted into two different structures by high pressure and temperature. They are metastable and revert to pristine C(60) on reheating to 300 degrees C at ambient pressure. For synthesis temperatures between 300 degrees and 400 degrees C and pressures of 5 gigapascals, a nominal face-centered-cubic structure is produced with a lattice parameter a(o) = 13.6 angstroms. When treated at 500 degrees to 800 degrees C at the same pressure, C(60) transforms into a rhombohedral structure with hexagonal lattice parameters of a(o) = 9.22 angstroms and c(o) = 24.6 angstroms. The intermolecular distance is small enough that a chemical bond can form, in accord with the reduced solubility of the pressure-induced phases. Infrared, Raman, and nuclear magnetic resonance studies show a drastic reduction of icosahedral symmetry, as might occur if the C(60) molecules are linked.

Genetic origin of malignant trophoblastic neoplasms

The genetic origin of three trophoblastic neoplasms (two choriocarcinomas and a placental site trophoblast tumor (PSTT)] was determined by analysis of the restriction fragment length polymorphism (RFLP) pattern. One choriocarcinoma, which was believed not illogically to have developed from an antecedent complete mole, contained both paternal and material RFLP alleles and thus was probably the product of a normal fertilization. The other choriocarcinoma was not of gestational origin but had RFLPs homozygous at some loci and heterozygous at others, compatible with the parthenogenic origin of this tumor from a germ cell after meiosis I. The PSTT required amplification of DNA sequences by polymerase chain reaction (PCR) because of the small amount of tumor material available. This tumor contained RFLP alleles from both parents and appeared to have resulted from a previous unrecognized (and abnormal) pregnancy.

Clone Q379 immunoscreened from a Chinese HCV cDNA lambda gt11 library

A Chinese HCV cDNA clone, designated as Q379, 379 nucleotides in length, was selected by recombinant immunoscreening from a random-primed Chinese HCV lambda gt11 library. DNA sequencing demonstrated that Q379 situated from positions 7314 to 7695 at NS5 region corresponded with the American prototype HCV nucleotide sequence. The homologies of Q379 with the equivalent sequences of the prototype were found to be 72.8% in nucleotides and 73.8% in amino acids, respectively. Hydrophobicity profile shows that Q379-encoded polypeptide (126 amino acid residues) contains two hydrophilic areas. This Chinese HCV clone would be valuable in basic and clinical studies of Chinese HCV infection.

Cytotoxicity of recombinant Fab and Fv immunotoxins on adult T-cell leukemia lymph node and blood cells in the presence of soluble interleukin-2 receptor

Single-chain immunotoxins anti-Tac(Fv)-PE40 and anti-Tac(Fv)-PE40KDEL, composed of variable domains of the anti-Tac monoclonal antibody and truncated forms of Pseudomonas exotoxin, have shown potent cytotoxic activity against malignant peripheral blood mononuclear cells (PBMCs) from adult T-cell leukemia (ATL) patients originating from the Caribbean. However, several clinically important issues have not previously been addressed. These include the potential of soluble interleukin 2 receptor in ATL patients to block immunotoxin effectiveness, the relative sensitivity of malignant lymph node cells (LNCs) versus PBMCs, the effect of an immunotoxin with a prolonged half-life, and finally whether ATL cells from patients in Japan have toxin sensitivity equal to those of the Caribbean patients. To resolve these questions, we studied 32 malignant PBMC and LNC samples from 30 ATL patients from Japan. PBMCs from 27 of 27 patients were very sensitive with 50% inhibition of protein synthesis achieved with 0.02-0.85 ng/ml (0.3-13 pM) of anti-Tac(Fv)-PE40KDEL or anti-Tac(Fv)-PE40. LNCs had sensitivity very similar to that of PBMCs in the five patients tested. The fully recombinant immunotoxin, anti-Tac(Fab)-PE40, which has 8-10 times the t1/2 alpha and beta compared to the Fv-immunotoxins, was also very cytotoxic toward cells from 27 of 27 patients tested with 50% inhibition of protein synthesis of 0.08-25 ng/ml. It was found that purified soluble interleukin 2 receptor added to the cytotoxicity assay decreased the cytotoxic activity of anti-Tac(Fv)-PE40KDEL or anti-Tac(Fab)-PE40, but that 1 x 10(4) units/ml or less had minimal competitive effects. It was found that ATL patients who have responded even incompletely to conventional chemotherapy have soluble interleukin 2 receptor levels lower than this at posttreatment. We conclude that recombinant immunotoxins containing anti-Tac(Fv) are effective against Japanese ATL PBMCs or LNCs and might be most effective if used in vivo after conventional chemotherapy. If it is found in humans that the effectiveness of single-chain recombinant toxins is limited by short half-life, anti-Tac(Fab)-PE40 should be considered as an alternative agent.

A case of myocardial infarction showing extensive precordial ST elevation induced by second diagonal branch occlusion

We observed a case of acute myocardial infarction induced by second diagonal branch occlusion. Electrocardiogram (ECG) on admission showed ST elevation in leads I, aVL and V2-6. Since emergency coronary angiography disclosed complete occlusion of the second diagonal branch, intra-coronary thrombolysis (ICT) was performed, superselectively. Transient coronary reperfusion was obtained, however, reocclusion occurred after several minutes. Rescue percutaneous transluminal coronary angioplasty (PTCA) was then performed immediately and blood flow was improved to TIMI grade 2. During these processes, the ST-segment on the ECG changed in leads I, aVL and V2-6 always corresponding to the blood flow of the second diagonal branch. We have not seen a report hitherto in which occlusion of only the second diagonal branch could be a cause of extensive anterior infarction-like ECG changes. Although the mechanism of ECG changes in this patient cannot be clearly explained by conventional concepts, we report this case because it is considered to be very rare.

Problems of long-term hospitalised cervical spinal cord injury patients in university hospitals

Of the 215 cervical spinal cord injury (CSCI) patients treated in Tokai University Hospital over the last 17 years, 42 who were hospitalised for more than 90 days were selected as the subjects for this survey. They were divided into two groups: group A: patients hospitalised for 180 days or more; and group B: patients hospitalised for more than 90 but less than 180 days. The aspects surveyed were: the number of days of hospitalisation, type of injury, level of spinal cord injury, extent of spinal cord paralysis, assessment based on Frankel's classifications, whether a tracheotomy was performed or not, surgical treatment, complications, and the clinical course after discharge. The most common injury for the 13 patients in group A (average stay 281 days) was a fracture-dislocation, followed next by those with a burst fracture. The majority of the 28 patients in group B (average stay was 117 days) had a central type of spinal cord injury. Characteristics observed in group A in particular were: higher segment injuries to the cervical spinal cord, complete paralysis, respiratory complications such as pneumonia, tracheotomy, or a waiting time of at least 6 months before discharge, in cases where a transfer to a rehabilitation hospital was possible. The major problems of treating CSCI patients in university hospitals are that severe cases, which are concentrated in university hospitals, are forced to occupy private rooms for long term treatment, and there is a difficulty in transferring these patients to rehabilitation hospitals.(ABSTRACT TRUNCATED AT 250 WORDS)

Expression of fos proto-oncogene product by monoclonal antibody FO-120 in smouldering adult T-cell leukaemia (ATL)

We investigated the expression of c-fos gene product in peripheral blood mononuclear cells of patients with smouldering adult T-cell leukaemia (ATL) and healthy human T-lymphotropic virus type-I (HTLV-I) carriers by an immunofluorescence assay, using a mouse monoclonal antibody (FO-120) specific for fos gene product. Peripheral blood mononuclear cells derived from healthy HTLV-I carriers were rarely positive for FO-120, less than 2% of the cells weakly reacted with FO-120, whereas positive cells were detected in more than about 10% of cells from patients with smouldering ATL. FO-120 appears to be a useful tool for detecting smouldering ATL in asymptomatic HTLV-I infected people without using molecular techniques.

Donor-specific unresponsiveness induced by intraportal grafting and FK506 in rat islet allografts: importance of low temperature culture and transplant site on induction and maintenance

Previously we demonstrated prolongation of islet allograft survival in rat by administration of FK506 to the recipients. The purpose of the present study was to determine whether specific immune unresponsiveness had been induced and to determine the effects of low temperature culture of donor islets as well as the transplant site on the induction of immune unresponsiveness. At 90 days after transplantation, normoglycemic recipients bearing functional intrahepatic grafts were made diabetic again with streptozotocin (STZ) and donor specific or third party islets were transplanted either into the liver or beneath the kidney capsule. When fresh islets were used as donors in initial transplantation in conjunction with FK506, intrahepatic re-transplants of fresh islets from the donor-specific strain in the absence of FK506 maintained normoglycemia for more than 60 days, while third party transplants (n = 3) were rejected within 1 wk. In contrast to intrahepatic regrafts, all the renal subcapsular regrafts from the donor-specific strain (n = 3) were rejected with mean survival time of 12.7 +/- 6.4 days. When cultured (24 degrees C, 7 days) islets were used for initial transplantation in conjunction with FK506, re-transplants of fresh or cultured islets from the donor specific strain beneath the kidney capsule maintained normoglycemic in 3 out of 6 or all (n = 4) of the recipients, respectively. Cultured third party regrafts beneath the kidney capsule (n = 2) were rejected at 9 days.(ABSTRACT TRUNCATED AT 250 WORDS)

[Successful treatment of chemotherapy-resistant adult T cell leukemia/lymphoma by irinotecan hydrochloride (CPT-11)]

A 62-year-old man was hospitalized in March 1990 due to upper abdominal discomfort and anorexia. The chest X-ray revealed an upper anterior mediastinal tumor, and abdominal ultrasound showed lymphadenopathy. Endoscopic examination of the stomach revealed a large, irregular ulcer, which was histologically confirmed to be malignant lymphoma by biopsy. Serum anti-HTLV-1 antibody was positive. A diagnosis of ATLL (lymphoma type) was made. The usual therapy for this disease, including the LSG4 and RCM protocols, was only transiently effective. Therefore, the patient was treated with CPT-11 (40 mg/m2) by intravenous infusion on 3 consecutive days with weekly repetition in November 1990. Complete remission was obtained after 2 weeks of treatment, and was maintained for 5 months. This case suggests that CPT-11 may be effective for the treatment of ATL.

Percutaneous nucleotomy in lumbar disc herniation. Patient selection and role in various treatments

Patients in percutaneous nucleotomy who met our new criteria for patient selection in 1992 showed 73% successful results. The success rate was not satisfactory in comparison with that (88%) in the open surgery through posterior approach (herniotomy), however. The purpose of this report is to re-evaluate 70 patients with follow-up more than 2 years based on imaging and clinical findings before percutaneous nucleotomy. In results, supplementary criteria such as two types of the combination of computed tomography discogram and computed tomography myelogram, continuation of the contrast medium in lateral view of discogram, and clinical findings characterized by sciatic pain were obtained to improve the success rate. Eighty-one percent of patients who met the new criteria in 1992 and the supplementary criteria were identified in the successful group. The authors believe that percutaneous nucleotomy should be considered as an independent operative procedure with results similar to open surgery, if the patient is selected strictly based on these criteria and supplementary criteria.

New technique of experimental partial liver transplantation: hemodynamic study during surgery

Orthotopic liver transplantation of children is often limited by the scarcity of an appropriately size-matched donor organ. The transplantation of a reduced liver was thus conceived to solve this problem. A new technique of partial liver transplantation in mongrel dogs is reported, which partially retains the recipient's liver and uses an Ameroid constrictor to occlude the recipient's portal branch gradually. The donor's right and median lobectomy was performed in situ. The donor's left lobe was perfused in situ and removed as a graft. It was then transplanted orthotopically in the space after a left and median lobectomy of the recipient. An Ameroid constrictor was applied around the recipient's right portal branch for a gradual occlusion of the host hepatic blood supply (the Ameroid group). To compare the hemodynamic stability during surgery with this technique, two other methods were also performed. The mean systemic blood pressure of orthotopic liver transplantation with a passive venovenous bypass during the anhepatic period (the Bypass group, n = 5) was lower than that of the Ameroid group (n = 16). Instead of fitting an Ameroid constrictor, an orthotopic partial liver transplantation with ligation of the right portal branch (the Ligation group) was performed. The mean systemic blood pressure of the Ligation group (n = 10) was lower than that of the Ameroid group (n = 11) after either fitting a constrictor or performing a ligation.(ABSTRACT TRUNCATED AT 250 WORDS)

Percutaneous nucleotomy in lumbar disc herniation. A prospective study

The purpose of this article is to present the clinical results of the prospective series of studies on percutaneous nucleotomy (PN) for lumbar disc herniation and to introduce current criteria of patient selection for PN. Since 1983, 107 patients were treated with PN (Hijikata's method), 85 of whom had a follow-up period of more than 2 years. Of these 85 patients, 54 had successful results. Clinical findings and various imaging evaluations (eg, magnetic resonance imaging and computed tomography after discography) before PN, as well as operative findings, were used to study the surgical outcomes of both the successful and unsuccessful groups. The results yielded the following new criteria for patient selection for PN: 1) age less than 40 years; 2) no perforation of the posterior longitudinal ligament and no degenerative canal stenosis detected by computed tomography after discography; 3) no malformation of the neural structure; 4) more than Grade 4 on manual testing of innervated muscles; and 5) more than 6 months of conservative treatment before PN.

Molecular cloning, sequencing and expression of core and NS3 fragments of HCV from patients with HCV infection

Fragments of core and NS3 of hepatitis C virus-Hunan (HCV-Hun) were cloned by RT-PCR and gene recombinant techniques from blood samples collected in Hunan Province, China. In comparison with sequences of our samples with those of HCV-US and HCV-J, the homologies of nucleotides and amino acids were about 90%, indicating that fragments of core and NS3 of HCV-Hun were in a relative conserved region of HCV. Two fusion proteins containing the peptides coded by HCV core (MBP-HCV core) and HCV. NS3 (MBP-HCV. NS3-Gal) were expressed by Escherichia Coli with recombinant plasmids. The specific HCV antigenicity of the two fusion proteins were identified by western blotting. Therefore, MBP-HCV. core and MBP-HCV.NS3-Gal were found useful for anti-HCV assay.

Response dynamics and directional properties of nonspiking local interneurons in the cockroach cercal system

The response properties and directional receptive fields of nonspiking local interneurons in the cercal system of the cockroach are described. Wind-evoked responses were recorded intracellularly, and then analyzed by means of the Wiener kernel method in which a Gaussian white noise signal was used as a stimulus. Cross-correlation between the response and the white noise signal produced first- (linear) and second-order (nonlinear) kernels that were used to define input-output characteristics of the interneurons. Three sets of interneurons were distinguished on the basis of kernel analysis. First, responses in interneurons 101, 107, 111, and 203 were characterized predominantly by a differentiating first-order kernel, which suggests a linear relationship to the stimulus. The amplitude and waveform of the kernel changed with the change in stimulus angle, indicating that these four cells are directionally sensitive. Second, responses in interneurons 102 and 103 were also directionally sensitive but highly nonlinear. The first-order kernel was biphasic, whereas the second-order kernel had an elongated depolarizing peak on the diagonal. The response dynamics were accounted for by a cascade of two filters, a linear band-pass filter and a static nonlinear filter, in which the nonlinearity is a signal compression (or a rectification). Third, responses in interneurons 104 and 201 consist largely of the second-order nonlinear component. The second-order kernel, which had an elongated depolarizing peak or a hyperpolarizing valley on the diagonal, did not show any directional preference. The second-order nonlinearity was dynamic, and could be modeled by a band-pass linear filter-static nonlinearity-low-pass linear filter cascade, where the static nonlinearity is a full-wave rectification. The band-pass filter would simply reflect the mechanical property of cercal hair sensilla, whereas the low-pass filter represents the transfer at synapses between the cercal afferents and the interneurons. The nonlinear response thus explains the difference in the directional sensitivity while the differentiating first-order kernel explains the velocity sensitivity of the interneurons. We show that 101 and 107 respond most preferentially to wind from the left versus right, whereas 102, 103, 111, and 203 respond to wind from the front versus rear. Thus, it is suggested that there are two subsystems responding maximally to wind displacement along two coordinate directions, one for the longitudinal direction and the other for the transverse direction. On the other hand, the full-wave-rectifier nonlinear interneurons are omnidirectional, and thus suggested to code simply the power of the wind displacement.

Isovolumetric relaxation flow in patients with ischemic heart disease

OBJECTIVES

The purpose of this study was to clarify the characteristics of flow during the isovolumetric relaxation period and to analyze the relation between these flow patterns and standard hemodynamic indexes.

BACKGROUND

Outward motion of the left ventricle during the isovolumetric relaxation period has been observed by cineangiography. However, there is little information about blood flow during this period.

METHODS

Seventy-nine patients with ischemic heart disease were examined by pulsed Doppler echocardiography and cardiac catheterization. All patients were classified into three groups according to the observed patterns of isovolumetric relaxation flow: group I (n = 41), flow directed toward the apex; group II (n = 21), flow directed toward the base, and group III (n = 17), low velocity flow (< 12 cm/s) without a dominant direction. Patients in group I were further classified into group Ia (n = 19) with normal ventriculograms and group Ib (n = 22) with asynergy.

RESULTS

Left ventricular ejection fraction and negative first derivative of left ventricular pressure were significantly lower in group II (49 +/- 9% and 1,274 +/- 212 mm Hg/s, respectively) and group III (38 +/- 8% and 1,147 +/- 280 mm Hg/s, respectively) than in group Ia (68 +/- 7% and 1,727 +/- 358 mm Hg/s), each p < 0.01. Time constant was significantly prolonged in group II (49 +/- 6 ms) and group III (48 +/- 6 ms) compared with that in group Ia (41 +/- 6 ms), p < 0.05. On left ventriculography, patterns of outward wall motion during the isovolumetric relaxation period were associated with the patterns of isovolumetric relaxation flow.

CONCLUSIONS

Changes in left ventricular relaxation are accompanied by alterations in isovolumetric relaxation flow. It is therefore useful to evaluate isovolumetric relaxation flow when investigating early diastolic ventricular function.