Delayed resection in the management of non-orbital rhabdomyosarcoma of the head and neck in childhood

This retrospective study was undertaken to evaluate the effect of delayed resection on outcome of head and neck rms in a single institution which has experience in cranial base surgery. Since 1988, patients with primary non-orbital rms of the head and neck following treatment at the Children's Hospital of Pittsburgh, were evaluated by the Department of Otolaryngology, Eye and Ear Hospital at the University of Pittsburgh Medical Center either at the time of presentation or when response to chemotherapy and/or radiation therapy was thought to have been optimized for the possibility of definitive surgery. Medical records of patients who did or did not have delayed surgery were reviewed and compared with respect to demographics, tumor stage, response to therapy, survival, and cosmetic results. Of 16 children diagnosed with non-orbital head and neck rms from 1988–1994 and treated with chemotherapy according to IRS II–IV, 3 had group I or II disease following extensive surgery at diagnosis. Thirteen had group III or IV disease. Of these, 6 patients had delayed resection and 7 did not. Delayed resection was undertaken 3–12 months (median, 4 months) from diagnosis in 4 children who had a partial response (PR) and 2 children who had stable disease (SD) with chemotherapy and/or radiation. Delayed resection converted all children to complete responses (CR), including one child with clinical SD and one with PR who were found to have no viable tumor at surgery. The overall percentages of CRs for patients with group II or IV disease (documented any time post-diagnosis) were at least as good for patients who had undergone delayed surgery as for those who had not (100% vs. 71%, p = .465). Median survivals for patients with advanced disease were 3 ½ years and 2 years, respectively (p = .2801). Cosmetic and functional problems attributable to surgery were not severe but included facial asymmetry (n = 4), trismus (n = 1), cranial nerve deficits (n = 1), and abnormal dentition (n = 1). In locally extensive head and neck rms, cranial base surgery should be considered after initial cytoreductive therapy, since it may contribute to achievement of CR and to survival with acceptable morbidity. Med. Pediatr. Oncol. 28:294–298. © 1997 Wiley-Liss, Inc.     

Frequency of RET mutations in long- and short-segment Hirschsprung disease

Hirschsprung disease, or congenital aganglionic megacolon, is a genetic disorder of neural crest development affecting 1:5,000 newborns. Mutations in the RET proto-oncogene, repeatedly identified in the heterozygous state in both long- and short-segment Hirschsprung patients, lead to loss of both transforming and differentiating capacities of the activated RET through a dominant negative effect when expressed in appropriate cellular systems. The approach of single-strand conformational polymorphism analysis established for all the 20 exons of the RET proto-oncogene, and previously used to screen for point mutations in Hirschsprung patients allowed us to identify seven additional mutations among 39 sporadic and familial cases of Hirschsprung disease (detection rate 18%). This relatively low efficiency in detecting mutations of RET in Hirschsprung patients cannot be accounted by the hypothesis of genetic heterogeneity, which is not supported by the results of linkage analysis in the pedigrees analyzed so far. Almost 74% of the point mutations in our series, as well as in other patient series, were identified among long segment patients, who represented only 25% of our patient population. The finding of a C620R substitution in a patient affected with total colonic aganglionosis confirms the involvement of this mutation in the pathogenesis of different phenotypes (i.e., medullary thyroid carcinoma and Hirschsprung). Finally the R313Q mutation identified for the first time in homozygosity in a child born of consanguineous parents is associated with the most severe Hirschsprung phenotype (total colonic aganglionosis with small bowel involvement). Hum Mutat 9:243–249, 1997. © 1997 Wiley-Liss, Inc.     

Distribution of astroglia in glomeruli of the rat main olfactory bulb: Exclusion from the sensory subcompartment of neuropil

During an entire lifetime, sensory axons of regenerating olfactory receptor neurons can enter glomeruli in the olfactory bulb and establish synaptic junctions with central neurons. The role played by astrocytes in this unique permissiveness is still unclear. Glomerular astrocytes have been identified by immunocytochemistry for glial fibrillary acidic protein and S100 proteins at the light and electron microscopic levels. The latter labeling included submicroscopic lamellar and filopodial extensions of astroglial processes. Cell bodies and processes accumulate along the border between juxtaglomerular walls and glomerular neuropil. Within glomeruli, a network of astroglial processes encloses mesh-like neuropil zones devoid of astroglia. Electron microscopy confirmed the division into subcompartments of glomerular neuropil: 1) The “sensory-synaptic subcompartment” includes all sensory axon terminals and terminal dendritic branches receiving sensory input, whereas astroglia are excluded; 2) in the “central-synaptic subcompartment,” astroglial processes are intermingled with other neuropil components: dendrites of relay cells and interneurons, dendrodendritic synapses, centrifugal (cholinergic and serotonergic) axons, their axodendritic synapses, and blood vessels. Unevenly distributed astroglial processes in this subcompartment are attached to vascular basal laminae, stem dendrites, and subpopulations of dendrodendritic synapses, especially those colocalized with centrifugal projections (“triadic synapses”). Astroglia-free parts of the “central” subcompartment contain segments of dendrites and subpopulations of dendrodendritic synapses. Because of the subdivision of the glomerular neuropil into portions with and without glial components, glia do not completely demarcate the border between the “sensory” and the “central” subcompartments. Interdigitation between the subcompartments varies among glomeruli and even within a single glomerulus. The mesh width of astroglial networks covaries with numerical relations between sensory and dendrodendritic synapses. This distribution pattern of astrocytes suggests that these glial cells monitor brain-derived effects on olfactory glomerular neuropil rather than olfactory input and that astroglial processes are (re-)arranged accordingly. J. Comp. Neurol. 388:191–210, 1997. © 1997 Wiley-Liss, Inc.     

Spheroid body myopathy revisited

Having reported spheroid body myopathy from Indiana (IN) inherited in an autosomal-dominant fashion several years ago, we now describe additional findings from the Oregon branch—briefly recorded earlier—and confirm earlier studies in another clinically affected IN member of this kinship demonstrating identical spheroid bodies within the myopathic muscle specimens. The spheroid bodies also contained increased amounts of desmin, α-B crystallin, and ubiquitin within muscle fibers. Our studies now have established that spheroid body myopathy is a member of the growing family of desminopathic neuromuscular conditions. © 1997 John Wiley & Sons, Inc. Muscle Nerve 20: 1127–1136, 1997     

Urokinase-type-plasminogen-activator(UPA) production by human breast (myo)fibroblasts in vitro: Influence of transforming growth factor-β1 (TGFβ1) compared with factor(s) released by human epithelial-carcinoma cells

The urokinase-type plasminogen activator (uPA) may be considered as a key enzyme in the processes of cancer cell invasion and metastasis. Evidence has been presented that, in breast stroma, uPA is expressed predominantly by myofibroblasts located at the invasive areas of the tumor. To examine whether transforming growth factor type-1 (TGFβ₁) produced by breast-carcinoma cells is a candidate responsible for the induction of uPA-producing myofibroblasts, we studied in vitro the capacity of normal and tumor-derived human breast fibroblasts to express uPA and the myofibroblast marker α-smooth-muscle actin in response to TGFβ₁. Next, we compared these influences with those elicited by factor(s) released by epithelial-cancer cells. In all 8 fibroblast strains tested, TGFβ₁ induced a similar concentration-dependent increase in the fraction of α-smooth-muscle-actin-positive fibroblasts. While uPA expression was decreased by TGFβ₁ in most of the fibroblast strains, 2 strains were relatively insensitive to TGFβ₁ in this respect. Although factors present in media conditioned by non-uPA-producing epithelial-tumor cells could trigger fibroblasts to become potent producers of uPA, the TGFβ₁ content of the conditioned media were linked to the differential effects of externally added TGFβ₁ with respect to uPA expression. The data demonstrate that, although fibroblasts may utilize TGFβ₁ secreted by tumor cells to differentiate into myofibroblasts, tumor cells secrete factor(s) other than TGFβ₁ ultimately responsible for the generation of powerful uPA-producing fibroblasts. Int. J. Cancer 76:829–835, 1998.© 1998 Wiley-Liss, Inc.     

Phase III efficacy study of interleukin-3 after autologous bone marrow transplantation in patients with malignant lymphoma

The cyclin-dependent kinase inhibitor p27Kip1 is a negative cell cycle regulator linking extracellular growth-regulatory signals to the cell cycle machinery in G1. We investigated the pattern and prognostic value of p27Kip1 expression in a population-based group of 203 non-Hodgkin's lymphoma (NHL) patients. The expression of p27Kip1 was identified by immunohistochemistry and correlated with Ki-67 expression and clinical features. Correlation with outcome was determined using uni- and multivariate analysis stratified by clinical grade. Except for very aggressive NHL, there was a negative correlation between p27Kip1 and Ki-67 expression. Low expression of p27Kip1, defined as nuclear p27Kip1 expression in <40% of malignant cells, was predictive of poor survival in indolent and aggressive NHL. However, even in this regard, very aggressive lymphomas behaved differently as those with low p27Kip1 expression tended to do better. Likewise, a high proliferation rate (Ki-67 >40%) was associated with poor survival in indolent and aggressive lymphomas. Multivariate analysis using the proportional hazards model showed that only p27Kip1, and not Ki-67, maintained independent prognostic significance in indolent and aggressive lymphomas (relative risk = 2. 0; P = 0.0095). The low cost and simplicity of this standard immunohistochemistry analysis makes p27Kip1 a promising and suitable prognostic marker in routine diagnostic laboratories in a standard diagnostic panel.