Human monoclonal antibody 99mTc-88BV59: detection of colorectal cancer, recurrent or metastatic disease and immunogenicity assessment

This study presents immunoscintigraphic results in 24 patients suffering from primary colorectal cancer, recurrent or metastatic disease after the injection of 1197-1351 MBq technetium-99m labelled totally human monoclonal antibody 88BV59. Labelling efficacy of 99mTc-88BV59 ranged from 97% to 99%. Immunoscintigraphy was performed 18-20 h after injection. Scintigraphic findings were compared with those of computed tomography (CT). Patients underwent surgery in order to evaluate immunoscintigraphic findings histologically. Sera of the patients (before injection and 1 and 3 months post infusion) were analysed for the presence of human anti-human antibodies (HAHA). None of the patients showed a HAHA response as assessed by a solid-phase ELISA assay. The antibody scan detected about 25% more lesions than CT. In the detection of extrahepatic disease, the sensitivity of the antibody scan proved to be 68%, whereas the sensitivity of CT was 41%.

[Arterial blood flow in congenital idiopathic clubfoot]

A doppler ultrasound study investigated vascularity in congenital idiopathic clubfeet (talipes equinovarus, (TEV) pretreated only by casting and physiotherapy. The studies were performed on 40 TEV (27 patients) aged 4-72 months (average 15.1). In 12 unilateral cases of TEV, the opposite normal foot and 74 normal feet of 37 healthy children aged 3-35 months (average 8.7) were used as controls. Dorsalis pedis (DP), posterior tibial (PT), and peroneal (P) pulses were recorded by an unidirectional 8 MHZ continuous wave technique. At rest, DP pulses and PT pulses were present in all investigated TEVs. P pulse was absent in only one case of TEV. In the group of controls DP pulse was absent in one case and P pulse was absent in an other case of normal foot with contralateral TEV. All the other pulses in normal feet were present at physiological location. We propose that a vascular etiology for the origin of congenital idiopathic clubfoot, as reported in literature, is unlikely. The influence of postnatal casting in TEV on the vascular arterial condition is slight or even absent. Doppler assessment is readily available, noninvasive, and a reproducible mean of monitoring vascular integrity in clubfeet. Relating to vascular complications after surgery, perhaps caused by a preextant arterial anomaly, doppler assessment is indicated routinely in syndromes of multiple malformations with clubfoot deformity before surgical treatment. In congenital idiopathic clubfeet it is not necessary as a routine check.

Suppression of the emotional Stroop effect by increased anxiety in patients with social phobia

Anxious individuals are slower at color-naming threat-related than nonthreat-related words in the emotional Stroop task. Recently, Mathews and Sebastian (1993, Cognition and Emotion, 7, 527-530) reported that this Stroop interference effect disappears when snake-fearful students are exposed to a snake while performing the color-naming task. In the present experiment, we had patients with social phobia and normal control subjects perform an emotional Stroop task under either low anxiety (i.e. upon entering the laboratory) or high anxiety (i.e. before giving a speech). Results indicated that Stroop interference for socially threatening words in the phobic group was suppressed under high anxiety. These findings may indicate that increased effort enables the subjects to suppress the interference produced in the Stroop task.

Subarachnoid hemorrhage of unknown etiology

During a 10-year-period, 80 of 510 (16%) patients with primary subarachnoid hemorrhage (SAH) had negative angiographic studies. On admission, 70 of 80 patients (88%) were in grades I-II according to Hunt and Hess, 9 (11%) in grade III, and 1 (1%) in grade IV. The most frequent CT feature was preponderance of subarachnoid blood in the peripontine cistern as observed in 35 of 51 cases (69%) in whom blood was visible on CT. During hospitalization, 3 patients (4%) rebled, and 3 others (4%) had an infarction. However, in all of these complicated cases maximum hemorrhage was outside the peripontine cistern. Outcome after hospitalization as assessed by the Glasgow-Outcome-Scale (GOS) was favorable (GOS 1 and 2) in all patients who had maximum blood in the peripontine cistern, but only in 62% showing preponderance of blood outside the peripontine cistern, and 4 of them (25%) had died (GOS 5). These differences are statistically significant (p < 0.001). Long-term outcome of 56 patients as graded according to the Activities of Daily Living (ADL) system was favorable in 88% of cases with peripontine hemorrhage who returned to normal activities (ADL 1). At the same time, another patient with diffuse hemorrhage had died. Thus, overall mortality was 8.9% at a mean observation time of 5.5 years. In conclusion, SAH of unknown etiology generally has a good prognosis, although a nonneglegible percentage of patients have persistent minor side-effects. In our experience, maximum blood in the peripontine cistern particularly indicates a favorable outcome, since all patients with this CT pattern survived in a good condition.

[Pneumoperitoneum and pneumoretroperitoneum without perforation]

Asymptomatic radiologically recognised pneumoperitoneum still remains a diagnostic and therapeutic dilemma, because free intraperitoneal air is not necessarily caused by alimentary tract perforation. We present two cases of nonsurgical pneumoperitoneum (caused by pneumomediastinum and pneumatosis intestinalis cystoides) and their typical radiologic findings. Other causes of pneumoperitoneum that do not necessitate laparotomy so as cited in the radiologic and surgical literature are discussed.

Induction of glutathione-S-transferase-pi by short-chain fatty acids in the intestinal cell line Caco-2

Glutathione S-transferases (GSTs) are a multigene family of detoxification and metabolizing enzymes that have been linked with the susceptibility of tissues to environmental carcinogens. In addition to their role as the main energy source in the colonic mucosa, short-chain fatty acids (SCFAs) have been found to act as potent antiproliferative and differentiating agents in various cancer cell lines. The objective of this study was to evaluate the effects of SCFAs on the induction of GSTpi in the intestine as a possible new anticarcinogenic mechanism of SCFAs. Studies were performed in Caco-2 cells, a cell line resembling functionally normal enterocytes. Cells, cultured in DMEM supplemented with 10% fetal calf serum, were studied from day 0 dpc (days post confluence) until 21 dpc and culture. SCFAs (acetate, propionate, butyrate) were added to give a final concentration of 5 mmol L(-1). At 0, 3, 6, 9, 15, and 21 dpc, protein, lactate dehydrogenase (LDH), alkaline phosphatase (AP) and GSTpi were measured. Butyrate supplementation significantly (P < or = 0.01) increased GSTpi levels compared with controls in a concentration-dependent manner. The effect was detectable within 3 dpc with a maximum at 15 dpc. In contrast to butyrate, the other SCFAs tested had no (acetate) or little effect (propionate). In conclusion, the data suggest that the anticancer effect of butyrate in part may be based on the induction of GSTpi activity, resulting in an enhanced detoxification capacity of the gut.

Early hematological toxicity of adjuvant perioperative intraportal and intravenous chemotherapy with fluorouracil, mitomycin and heparin in colorectal cancer. Swiss Group for Clinical Cancer Research

BACKGROUND

From 1987 to 1993 the Swiss Group for Clinical Cancer Research (SAKK) performed a randomized phase III adjuvant trial in patients with colorectal adenocarcinoma with the objective of comparing intraportal versus intravenous perioperative chemotherapy.

PATIENTS AND METHODS

Patients younger than 75 years had a curative en bloc resection of their cancer and were then randomized into three arms: 1. adjuvant perioperative portal liver infusion with fluorouracil, mitomycin and heparin, 2. adjuvant subclavian intravenous infusion with the same regimen and 3. no adjuvant treatment. The hematological toxicity was evaluated by hemoglobin determination and leucocyte and thrombocyte counting before and during ten days after surgery.

RESULTS

Hemoglobin showed a median decrease of 22% in the control group. This decrease is aggravated significantly by 3% through the chemotherapy. Leucocytes showed a median decrease of 7% in the control group. Perioperative chemotherapy caused a significantly higher median drop; 23% when given into the liver through the portal vein and 34% when given systemically through a subclavian catheter. Thrombocytes revealed a median decrease of 25% in the control group. Chemotherapy was not associated with a significant additional drop.

CONCLUSIONS

Adjuvant perioperative chemotherapy with fluorouracil, mitomycin and Heparin as given in this study is associated with a significant mild drop in hemoglobin and leucocytes during the first 10 postoperative days. If drug dose increases are planned in future trials the addition of hematopoietic growth factors might be considered.

Proteins reacting with anti-spectrin antibodies are present in Chlamydomonas cells

It was found either in Western-blot analysis or in indirect immunofluorescence microscopy that cells of the alga Chlamydomonas reinhardtii contain polypeptides cross-reacting with antibodies directed against red blood cell spectrin. The protein could also be detected by immunoprecipitation with anti-spectrin antibodies. C. reinhardtii cells contain distinct polypeptide chains reacting with antibodies directed against either alpha- or beta-spectrin subunits. This protein was extracted from the cells with low ionic strength solution but was not with nonionic detergent.

Sequencing of RAPD fragments amplified from the genome of the prokaryote Prochlorococcus marinus (prochlorophyta)

DNA fingerprint patterns from the chlorophyll a and b containing prokaryote Prochlorococcus marinus were generated with the RAPD technique using two primers derived from repetitive sequence motifs, [(GATA)4 and M13] and a random primer (OPB-10]. Five RAPD fragments were reamplified, cloned and sequenced. The clones M13/1300 and OPB-10/1100 contained open reading frames, whereas the (GATA)4 fragments were interrupted by stop codons in all frames indicating their noncoding function and possessed a high AT score of 63% and 71%, respectively. With the two (GATA)4 clones and the M13/300 clone strain-specific signals were obtained in a Southern blot analysis of various Prochlorococcus strains. Clones M13/1300 and OPB-10/1100, containing the ORFs, produced RFLPs between the strains analyzed. All RAPD fragments are represented as single copy in the genome of Prochlorococcus.

Instability of the lumbar burst fracture and limitations of transpedicular instrumentation

STUDY DESIGN

This study analyzed the changes in the load-displacement behavior of lumbar spine segments caused by burst fractures that were experimentally produced in fresh human cadaveric spines. The effect of three transpedicular surgical constructs on stability was investigated in each specimen.

OBJECTIVES

To quantify the loss of mechanical stiffness caused by the injury, and to evaluate the stiffness of three transpedicular surgical constructs.

SUMMARY OF BACKGROUND DATA

Although various investigators have studied the biomechanical characteristics of the burst fracture and surgical stabilization techniques, few have reported quantitative data on the three-dimensional biomechanical instability of these fractures.

METHODS

Load-displacement data were acquired in flexion, lateral bending, and axial rotation for intact specimens, after the L1 burst fracture was created and after the T12-L2 segments were stabilized using Luque plates, VSP plates, and Isola rods with one transverse connector.

RESULTS

Spines with burst fractures showed a bilinear load-displacement behavior with significant instability (loss of stiffness relative to intact) at low loads (up to 3 N.m) in flexion, lateral bending, and axial rotation. The loss of stiffness was greatest in axial rotation over the entire load range (up to 10 N.m). If posterior element injury also was present, a significantly larger loss of stiffness was observed in flexion and axial rotation. The three transpedicular constructs improved the stability of the injured spine beyond that of the intact spine in flexion and lateral bending at low loads. At high loads, they restored the stiffness to intact levels. However, in axial rotation they did not restore the stiffness to pre-injury level, particularly when the posterior column was disrupted.

CONCLUSIONS

Reduction of the burst fracture returns the spine to its position of greatest inherent instability, essentially requiring the transpedicular instrumentation to be load bearing. To enhance mechanical stability, it may be necessary to augment the transpedicular construct, particularly when the posterior column is disrupted.

How cytokines control immunoglobulin class switching

B lymphocytes can alter the class of antibody they produce by immunoglobulin class switch recombination. This recombination is targeted by distinct cytokines to particular switch regions. Prior to switch recombination, the same cytokines induce transcription through the targeted switch regions and generate IH "switch" transcripts. To show whether the two events are functionally related, we have replaced the endogenous interleukin-4 (IL-4) dependent promoter of murine I gamma 1 switch transcripts by an heterologous promoter, the human metallothionein IIA (hMT) promoter. Indeed, switch recombination can be targeted to IgG1 by the hMT promoter. In mutant mice, which cannot generate processed switch transcripts, switch recombination cannot be targeted to IgG1 by the hMT promoter. Thus, IL-4 targets switch recombination to IgG1 by induction of processed switch transcripts.

The stimulatory effects of interleukin (IL)-12 on hematopoiesis are antagonized by IL-12-induced interferon gamma in vivo

Interleukin (IL)-12 synergizes with other cytokines to stimulate the proliferation and differentiation of early hematopoietic progenitors in vitro. However, in vivo administration of IL-12 decreases peripheral blood counts and bone marrow hematopoiesis. Here, we used interferon (IFN) gamma receptor-deficient (IFN gamma R-/-) mice to investigate whether the in vivo inhibition of hematopoiesis by IL-12 is indirectly mediated by IL-12-induced IFN-gamma. IL-12 administered for 4 d (1 microgram/mouse per day) resulted in lower peripheral blood counts and a 2-fold decrease in bone marrow cellularity in wild-type mice, but not in IFN gamma R-/- mice. Bone marrow hematopoietic progenitors were decreased after IL-12 treatment in wild-type mice, but rather increased in IFN gamma R-/- mice. Splenic cellularity was 2.3-fold higher after IL-12 administration in wild-type mice, largely due to natural killer (NK) cell and macrophage infiltration together with some extramedullary hematopoiesis. In IFN gamma R-/- mice, spleen cellularity was less increased, there were fewer infiltrating NK cells, but a strong extramedullary hematopoiesis. Thus, alterations mediated by IL-12-induced IFN-gamma include reduction in bone marrow cellularity and hematopoietic progenitors, as well as pronounced splenomegaly, largely caused by NK cell infiltration. In the absence of IFN-gamma signaling, IL-12 promotes hematopoiesis, consistent with its in vitro activities.

Myosin structure/function: a combined mutagenesis-crystallography approach

In the past year, the structure of the regulatory domain of scallop myosin has joined that of the chicken skeletal muscle myosin subfragment 1 and provided insights into the regulation of myosin function. Mutagenesis studies in a variety of systems have used the information provided by these structures to create mutant myosins to test models of chemomechanical transduction and its regulation.

Switch transcripts in immunoglobulin class switching

B cells can exchange gene segments for the constant region of the immunoglobulin heavy chain, altering the class and effector function of the antibodies that they produce. Class switching is directed to distinct classes by cytokines, which induce transcription of the targeted DNA sequences. These transcripts are processed, resulting in spliced "switch" transcripts. Switch recombination can be directed to immunoglobulin G1 (IgG) by the heterologous human metallothionein IIA promoter in mutant mice. Induction of the structurally conserved, spliced switch transcripts is sufficient to target switch recombination to IgG1, whereas transcription alone is not.

An atomic model of the unregulated thin filament obtained by X-ray fiber diffraction on oriented actin-tropomyosin gels

We present a model of the actin-tropomyosin complex in which the radial and azimuthal position of tropomyosin was adjusted to fit the X-ray fiber diffraction patterns from oriented actin-tropomyosin gels at a resolution of 1/8 A-1. We used the recently published atomic F-actin model for the calculations. The atomic model of tropomyosin was obtained by model-building a coiled coiled-coil structure from the tropomyosin sequence. The resulting atomic model is strongly preferred and shows strong electrostatic interactions between charged side-chains of tropomyosin residues and actin residues in subdomain 3 and subdomain 4. Furthermore, calculations of enthalpies based upon electrostatic interactions indicate that there is a favored rotational position of the tropomyosin core at the calculated azimuthal and radial position given by the X-ray refinement. Rotations of the tropomyosin strand out of this position turn strongly attractive electrostatic interactions into repulsive forces. The resulting binding radius of 39 A and the determined azimuthal position of tropomyosin are in good agreement with electron microscopy reconstructions and neutron diffraction experiments. Furthermore, the calculated position of tropomyosin would still partly block the rigor interaction of myosin cross-bridges with actin, whereas it very likely allows undisturbed binding of the cross-bridges in a weak binding state.

Proteins reacting with anti-spectrin antibodies are present in Chlamydomonas cells

It was found either in Western-blot analysis or in indirect immunofluorescence microscopy that cells of the alga Chlamydomonas reinhardhi contain polypeptides cross-reacting with antibodies directed against red blood cell spectrin. The protein could also be detected by immunoprecipitation with anti-spectrin antibodies. C. reinhardtii cells contain distinct polypeptide chains reacting with antibodies directed against either alpha- or beta-spectrin subunits. This protein was extracted from the cells with low ionic strength solution but was not with nonionic detergent.