A rare case of colonic obstruction by 'cherry tomato' phytobezoar: A simple technique to avoid enterotomy.

Small bowel obstruction is the most common complication of phytobezoar in children. The authors present a rare case of colonic obstruction caused by a cherry tomato phytobezoar in a 16-month-old child that was treated successfully during laparotomy after failure of external fragmentation.

A lipophilic vasoactive intestinal peptide analog enhances the antiproliferative effect of chemotherapeutic agents on cancer cell lines.

BACKGROUND: Vasoactive intestinal peptide (VIP) is one of several small neuropeptides that affect cancer growth. A lipophilic VIP analog, stearyl-Nle(17)-neuroten-sin(6-11)VIP(7-28) (SNH) that inhibited lung carcinoma growth has been described previously. The experiments performed were clonogenic assays in vitro and tumor xenografts in nude mice in vivo. These studies were now extended to colon carcinoma and to combination therapy with chemotherapeutic agents. METHODS: Assays were performed with cell lines, and tumor proliferation was assessed using the (3-[4,5-dimethylthiazol-2-yl-5]-[3-carboxymethoxyphenyl]-2-[4-sulfophenyl]-2H tetrazolium) (MTS) colorimetric assay for mitochondrial function of living cells. RESULTS: The lipophilic analog (SNH) enhanced the antiproliferative activity of diverse chemotherapeutic agents: doxorubicine (antibiotic); vinorelbine (vinca alkaloid, antimicrotubule formation); paclitaxel (antimicrotubule agent); gemcitabine (antimetabolite); irinotecan (topoisomerase I inhibitor); and cisplatin (platinum compound acting as an alkylating agent). In all cases, the antiproliferative effect of SNH and the chemotheraputic agent was at least additive and for some combinations and concentrations even synergistic. For example, 2 microM of the antagonist that produced a 15-20% growth inhibition in the nonsmall cell lung carcinoma cell line reduced the IC(50) by 2-4-fold for most of the chemotherapeutic agents tested. Higher analog concentrations were even more efficacious. Similar results were obtained with colon carcinoma cell lines. CONCLUSIONS: Chemotherapeutic treatment of advanced solid tumors, such as nonsmall cell lung carcinoma, colon carcinoma, or prostate carcinoma, achieves a response rate of between 10% and 30% with significant toxicity. Combination therapy with the lipophilic VIP analog SNH and the preferred chemotherapeutic agent may greatly enhance the response rate, and by permitting a dose reduction, should significantly reduce side effects.

VIP receptor antagonists and chemotherapeutic drugs inhibit the growth of breast cancer cells.

The effects of vasoactive intestinal peptide (VIP) antagonists on breast cancer cells were investigated. (N-stearyl, norleucine17)VIP hybrid ((SN)VIPhyb) inhibited specific 125I-VIP binding to MCF7, SKBR3, T47D ZR75-1 and MDA-MB231 cells with high affinity (IC50 values of 0.03-0.06 microM). (SN)VIPhyb, 1 microM, inhibited the ability of 10 nM VIP to cause elevation of cAMP and to increase c-fos mRNA. Micromolar concentrations of (SN)VIPhyb inhibited the proliferation of MDA-MB231 or MCF7 cells using a MTT and clonogenic assay. Using a MTT assay, (SN)VIPhyb enhanced the ability of taxol and doxorubicin to inhibit breast cancer growth. Using nude mice bearing MDA-MB231 xenografts, VIPhyb potentiated the ability of taxol to inhibit proliferation. The results indicate that VIP receptor antagonists increase the ability of chemotherapeutic drugs to kill breast cancer cells.

Cloning and characterization of the human activity-dependent neuroprotective protein.

We have recently cloned the mouse activity-dependent neuroprotective protein (ADNP). Here, we disclose the cloning of human ADNP (hADNP) from a fetal brain cDNA library. Comparative sequence analysis of these two ADNP orthologs indicated 90% identity at the mRNA level. Several single nucleotide polymorphic sites were noticed. The deduced protein structure contained nine zinc fingers, a proline-rich region, a nuclear bipartite localization signal, and a homeobox domain profile, suggesting a transcription factor function. Further comparative analysis identified an ADNP paralog (33% identity and 46% similarity), indicating that these genes belong to a novel protein family with a nine-zinc finger motif followed by a homeobox domain. The hADNP gene structure spans approximately 40 kilobases and includes five exons and four introns with alternative splicing of an untranslated second exon. The hADNP gene was mapped to chromosome 20q12-13.2, a region associated with aggressive tumor growth, frequently amplified in many neoplasias, including breast, bladder, ovarian, pancreatic, and colon cancers. hADNP mRNA is abundantly expressed in distinct normal tissues, and high expression levels were encountered in malignant cells. Down-regulation of ADNP by antisense oligodeoxynucleotides up-regulated the tumor suppressor p53 and reduced the viability of intestinal cancer cells by 90%. Thus, ADNP is implicated in maintaining cell survival, perhaps through modulation of p53.

A highly conserved aspartic acid (Asp-155) anchors the terminal amine moiety of tryptamines and is involved in membrane targeting of the 5-HT(2A) serotonin receptor but does not participate in activation via a "salt-bridge disruption" mechanism.

Discovering the molecular and atomic mechanism(s) by which G-protein-coupled receptors (GPCRs) are activated by agonists remains an elusive goal. Recently, studies examining two representative GPCRs (rhodopsin and alpha(1b)-adrenergic receptors) have suggested that the disruption of a putative "salt-bridge" between highly conserved residues in transmembrane (TM) helix III, involving aspartate or glutamate, and helix VII, involving a basic residue, results in receptor activation. We have tested whether this is a general mechanism for GPCR activation by constructing a model of the 5-hydroxytryptamine (5-HT)(2A) receptor and characterizing several mutations at the homologous residues (Asp-155 and Asn-363) of the 5-HT(2A) serotonin receptor. All of the mutants (D155A, D155N, D155E, D155Q, and S363A) resulted in receptors with reduced basal activity; in no case was evidence for constitutive activity revealed. Structure-function studies with tryptamine analogs and various Asp-155 mutants demonstrated that Asp-155 interacts with the terminal, and not indole, amine moiety of 5-HT(2A) agonists. Interestingly, the D155E mutation interfered with the membrane targeting of the 5-HT(2A) receptor, and an inverse relationship was discovered when comparing receptor activation and targeting for a series of Asp-155 mutants. This represents the first known instance in which a charged residue located in a putative TM helix alters the membrane targeting of a GPCR. Thus, for 5-HT(2A) receptors, the TMIII aspartic acid (Asp-155) is involved in anchoring the terminal amine moiety of indole agonists and in membrane targeting and not in receptor activation by salt-bridge disruption.

Structure and function of the third intracellular loop of the 5-hydroxytryptamine2A receptor: the third intracellular loop is alpha-helical and binds purified arrestins.

Understanding the precise structure and function of the intracellular domains of G protein-coupled receptors is essential for understanding how receptors are regulated, and how they transduce their signals from the extracellular milieu to intracellular sites. To understand better the structure and function of the intracellular domain of the 5-hydroxytryptamine2A (5-HT2A) receptor, a model G(alpha)q-coupled receptor, we overexpressed and purified to homogeneity the entire third intracellular loop (i3) of the 5-HT2A receptor, a region previously implicated in G-protein coupling. Circular dichroism spectroscopy of the purified i3 protein was consistent with alpha-helical and beta-loop, -turn, and -sheet structure. Using random peptide phage libraries, we identified several arrestin-like sequences as i3-interacting peptides. We subsequently found that all three known arrestins (beta-arrestin, arrestin-3, and visual arrestin) bound specifically to fusion proteins encoding the i3 loop of the 5-HT(2A) receptor. Competition binding studies with synthetic and recombinant peptides showed that the middle portion of the i3 loop, and not the extreme N and C termini, was likely to be involved in i3-arrestin interactions. Dual-label immunofluorescence confocal microscopic studies of rat cortex indicated that many cortical pyramidal neurons coexpressed arrestins (beta-arrestin or arrestin-3) and 5-HT2A receptors, particularly in intracellular vesicles. Our results demonstrate (a) that the i3 loop of the 5-HT2A receptor represents a structurally ordered domain composed of alpha-helical and beta-loop, -turn, and -sheet regions, (b) that this loop interacts with arrestins in vitro, and is hence active, and (c) that arrestins are colocalized with 5-HT2A receptors in vivo.

Effect of immunosuppressive agents on the immunogenicity and efficacy of an immunotoxin in mice.

Immunotoxins (ITs) are potent cytotoxic agents used in the treatment of cancer, autoimmune disease, and graft-versus-host disease. Results from clinical trials demonstrate that many IT-treated patients, especially those with an intact immune system, develop anti-IT antibodies that may prohibit repeated IT dosing. We, therefore, evaluated a panel of novel immunosuppressive (IS) agents for their ability to inhibit the antitoxin immune response in mice receiving multiple courses of a ricin A chain (RTA)-containing IT and also assessed whether this suppression would result in an increase in IT-mediated antitumor activity. The results indicate that a 3-day pretreatment, plus one additional boost 2 weeks later, of a combination of hCTLA4Ig + anti-CD40L, virtually eliminated the anti-RTA response in normal mice receiving six weekly injections of an IT. When tested in BCL1 tumor-bearing mice, the concomitant use of a combination of hCTLA4Ig + anti-CD40L and six doses of the IT resulted in a 1.5-fold increase in tumor cell killing, as compared with treatment with IT alone. We conclude that a combination of IS + IT therapy should facilitate the administration of multiple courses of IT, as well as enhance its antitumor activity.

Massively bleeding gastric pouch ulcer after silastic ring vertical gastroplasty successfully treated endoscopically: a report of two cases.

Two patients who developed massive bleeding from a gastric pouch ulcer are described. This rare complication occurred during the early postoperative course after silicone ring vertical gastroplasty (SRVG). In both cases the bleeding stopped after the ulcers were injected with epinephrine and alcohol. Both ulcers healed after 1 month of treatment with omeprazole (Losec). The probable etiology of this rare complication is discussed.

Healing of the esophageal suture line: does it differ from the rest of the alimentary tract?

We investigated the healing pattern of the esophageal suture line in rats. Fifty male wistar rats were divided into experimental (n = 40) and control (n = 10) groups. The rats in the experimental group underwent esophogostomy at the abdominal esophagus, which was immediately sutured, and sacrificed 2, 4, 7 and 14 days later. Esophageal bursting pressure and hydroxyproline content were determined in both groups. The measured bursting pressures in the experimental group on days 2, 4, 7 and 14 were (mean +/- SD) 78 +/- 35, 95 +/- 12, 1,163 +/- 98 and 1,224 +/- 22 cm H2O, respectively, and 1,308 +/- 87 cm H2O in the control group (P <0.05 vs. all the experimental group values). The hydroxyproline content in the experimental group on days 2, 4, 7 and 14 were 13.9 +/- 2.1, 12.53 +/- 2.68, 15.6 +/- 0.85 and 17.75 +/- 5.65 microg/mg, respectively, and 27.88 +/- 2.5 microg/mg in the control group (P <0.05 vs. all the experimental group values). We conclude that the esophagus demonstrates the same healing pattern as the rest of the alimentary tract, but its healing seems to occur at a slower pace.

Peritoneal band containing talc: rare cause of small bowel obstruction in a previously unoperated child.

The authors report on a 10-year-old boy who was operated on for small bowel obstruction. The obstruction was caused by a peritoneal band that was found to contain talc of an unknown source. The possible explanation for this rare pathology is discussed.

Aphakic visual fields by automated perimetry.

Accurate testing of the visual field of aphakic patients is demanding due to the optical distortion induced by high plus corrective lenses. This testing procedure can be improved by using an aspheric contact lens instead of a full-aperture loose trial lens. We found that the contact lens enhances the ability of the pattern-deviation printout of the Statpac analysis to identify glaucomatous visual field abnormalities in program 30-2 of the Humphrey Visual Field Analyzer.

Cataract following radial keratotomy.

An intumescent cataract developed 16 weeks after radial keratotomy in a 31-year-old man. Corneal perforation was documented at the time of surgery, but no direct injury was noted to the lens capsule. Visual acuity decreased to hand motions during a four-month course. Successful extracapsular cataract extraction occurred seven months following the original radial keratotomy. Soft contact lens correction of aphakia recovered a visual acuity of 6/6.

Visual field status in the management of chronic angle-closure glaucoma.

A retrospective analysis of the case histories of 40 patients with chronic angle-closure glaucoma yielded 31 eyes without visual field loss and 26 eyes with field loss. Peripheral iridectomy was highly successful in cases without field loss. Trabeculectomy was significantly more successful (93%) than iridectomy (64%) in treating cases with field loss. It is suggested that the choice of surgical procedure in this syndrome be dictated in part by the character of the visual field.

Surgical decisions in chronic angle-closure glaucoma.

A retrospective study of 57 eyes with chronic angle-closure showed that eyes with visual field loss are less likely to be improved by iridectomy than those without visual field loss in the presence of visual field loss, trabeculectomy achieved more satisfactory control of glaucoma than did iridectomy, and there was no noticeable difference in surgical complications between iridectomy and trabeculectomy in this small series. It is suggested that iridectomy is indicated for most cases of chronic angle closure without visual field loss, especially if the pressure is medically controllable. In the presence of visual field loss, iridectomy is usually a wise choice if medical control is easily achieved preoperatively. However, trabeculectomy might be the best choice in most patients with visual field loss and medically uncontrolled pressure, regardless of the gonioscopic findings.

Optic disk topography and visual field defects in patients with increased intraocular pressure.

One hundred one eyes of 54 ocular hypertensive patients were studied to determine the value of optic disk evaluation in predicting the presence or absence and the location and type of visual field defects by means of binocular slit-lamp examination and projected 35-mm monocular color slides. We suspected visual field loss erroneously in only one patient, and failed to detect ten (16%) of 61 eyes with field defects. An examiner experienced in slit-lamp evaluation of the optic disk can accurately predict the presence, absence, and location of field defects in most cases by stereoscopic evaluation of disk topography.