Occipital horn syndrome: report of a patient and review of the literature

We report an 18-year-old boy with occipital horn syndrome and we review the 20 cases previously published with this syndrome. The distinctive features common to all patients were unusual facial appearance, skeletal abnormalities, chronic diarrhea and genitourinary abnormalities. The skeletal abnormalities included occipital horns, short, broad clavicles, deformed radii, ulnae, and humeri, narrowing of the rib cage, undercalci-fied long bones with thin cortical walls and coxa valga. Occipital horn syndrome is inherited in an X-linked recessive fashion. Our analysis indicates that occipital horn syndrome is associated with a recognizable characteristic phenotype.     

Pyoderma gangrenosum associated with ulcerative colitis and subcutaneous and splenic abscesses

Pyoderma gangrenosum is a rare, chronic, inflammatory ulcerative skin disease of unknown etiology and pathogenesis. It is often associated with systemic disease. We describe a patient with pyoderma gangrenosum associated with ulcerative colitis and aseptic abscesses of the subcutis and spleen, which have been rarely reported previously. These manifestations were cleared by combined therapy with minocycline hydrochloride and diaphenylsulfone.     

Expression of TGF-α, EGF and their common receptor in human fetal kidney

Summary: Transforming growth factor-α (TGF-α) and epidermal growth factor (EGF) are structurally related mitogenic polypeptides. They share the same receptor; EGF receptor. the EGF receptor is widely expressed in human fetal tissues including the kidney, but little is known about the role of TGF-α/EGF/EGF receptor system in human fetal kidney. the expression of TGF-α, EGF and their common receptor was investigated immunohistochemically in the human fetal kidneys. In the cortex, immunoreactivity for TGF-α was found in the differentiating proximal tubules. In contrast, immunoreactivity for EGF was present in the thick ascending limbs of the Henle's loop (TAL) and medullary collecting duct cells (CD). Immunoreactivity for their common receptor was present mainly in the TAL and medullary CD. These data support the assumption that the system of TGF-α, EGF and its receptor has an important role in the proliferation and differentiation of the TAL and medullary CD. the different localization of TGF-α and its receptor may indicate that TGF-α acts through a paracrine mechanism. the co-localization of EGF and its receptor in the TAL and medullary CD suggests that EGF may act as an autocrine growth factor.     

Simulation for population analysis of Michaelis-Menten elimination kinetics

A simulation study was conducted to compare the cost and performance of various models for population analysis of the steady state pharmacokinetic data arising from a one-compartment model with Michaelis-Menten elimination. The usual Michaelis-Menten model (MM) and its variants provide no estimate of the volume of distribution, and generally give poor estimates of the maximal elimination rate and the Michaelis-Menten constant. The exact solution to the Michaelis-Menten differential equation (TRUE) requires a precise analysis method designed for estimation of population pharmacokinetic parameters (the first-order conditional estimation method) and also considerable computational time to estimate population mean parameters accurately. The one-compartment model with dose-dependent clearance (DDCL), in conjunction with the first-order conditional estimation or Laplacian method, ran approximately 20-fold faster than TRUE and gave accurate population mean parameters for a drug having a long biological half-life relative to the dosing interval. These findings suggest that the well-known MM and its variants should be used carefully for the analysis of blood concentrations of a drug with Michaelis-Menten elimination kinetics, and that TRUE, in conjunction with a precise analysis method, should be considered for estimating population pharmacokinetic parameters. In addition, DDCL is a promising alternative to TRUE with respect to computation time, when the dosing interval is short relative to the biological half-life of a drug. This work was supported in part by the Epilepsy Research Foundation, the Nakatomi Foundation, and a Grant-in-Aid for Scientific Research from the Ministry of Education, Science, and Culture of Japan.     

Cardioprotective Effect of Succinate Against Ischemia/Reperfusion Injury

(Received for publication on Sept. 12, 1996; accepted on May 12, 1997)     

Effects of calcitonin gene-related peptide on canine cerebral artery strips and the in-vivo vertebral blood flow in dogs

Summary The effects of calcitonin gene-related peptide (CGRP) on canine cerebral arteries and on vertebral blood flow were investigated in-vivo and in-vitro and the findings compared with the effects of vasoactive intestinal peptide (VIP) and substance P. Administration of CGRP into the vertebral artery caused a dose-dependent and long-lasting increase in blood flow. The in-vivo vasodilatory effects of substance P and VIP were short-lasting. CGRP (0.1 to 100 nmol/l) elicited a concentration-dependent relaxation of the isolated middle cerebral and basilar arteries when the tissues were precontracted by exposure to prostaglandin F₂ (PGF₂). This effect was not antagonized by propranolol, atropine, tetrodotoxin, (N-Ac-Tyr¹, D-Phe²)-growth hormone-releasing factor(1–29)-NH₂ or (D-Pro², D-Trp^7,9) substance P. CGRP also reduced concentration-dependently the contraction of cerebral arteries induced by KCl or 9,11-epithio-11,12-metano-thromboxane A₂ (STXA₂). Mechanical removal of the endothelium did not abolish the vasodilatory response to CGRP. In PGF₂-contracted canine cerebral arteries, VIP (0.1 to 100 nmol/l) was less potent a vasodilator than CGRP. At low concentrations (0.01 to 1 nmol/l) substance P elicited a rapid and short-lasting relaxation, and in the absence of endothelium this relaxation disappeared. These findings are clear evidence that CGRP modulates vascular tone.     

Characterization of htAKR, a novel gene product in the aldo-keto reductase family specifically expressed in human testis

In human testis, expression of a novel member of the aldo-keto reductase family was identified. Based on its testis-specific expression, we termed this protein human testis aldo-keto reductase (htAKR). In addition to four major isoforms, the existence of multiple alternatively spliced products of htAKR was detected using RT-PCR followed by nested PCR. htAKR was a homologue of mouse liver keto-reductase, AKR1E1, with close similarity in their genomic organizations. htAKR4, the longest isoform, was expressed as a non-fused native form. It exhibited a limited activity toward 9,10-phenanthrenequinone, while no activity toward the steroids or prostaglandins was demonstrated. Using the laser capture microdissection technique and RT-PCR, expression of htAKR was detected in testicular germ cells as well as in interstitial cells. The levels of htAKR mRNA in the tissues obtained from seminoma were much lower than those in normal testes. A significant decline in the htAKR expression was observed when NEC8, a cell line originated from a human testicular germ cell tumour, was exposed to phorbol 12-myristate 13-acetate or 5alpha-dihydrotestosterone. These results indicate that the expression of htAKR, down-regulated in the testicular tumour, is possibly controlled by mitogenic and hormonal signals.     

Induction and activation of the aryl hydrocarbon receptor by IL-4 in B cells

It is widely known that IL-4 and IL-13 act on various kinds of cells, including B cells, resulting in enhancement of proliferation, class switching to IgE and expression of several surface proteins. These functions are important for the recognition of the various antigens in B cells and are known to be involved in the pathogenesis of allergic diseases. However, it has not been known whether IL-4/IL-13 is involved in the metabolism of various kinds of xenobiotics including 2,3,7,8-tetra-chlorodibenzo-p-dioxin (TCDD), and it remains undetermined whether TCDD, an environmental pollutant, influences IgE production in B cells, exaggerating allergic reactions. We identified IL-4- or IL-13-inducible genes in a human Burkitt lymphoma cell line, DND-39, using microarray technology, in which the AHR gene was included. The AHR gene product, the aryl hydrocarbon receptor (AhR), was induced by IL-4 in both mouse and human B cells in a STAT6-dependent manner. IL-4 alone had the ability to translocate the induced AhR to the nuclei. TCDD, a ligand for AhR, rapidly degraded the induced AhR by the proteasomal pathway, although IL-4-activated AhR sustained its expression. AhR activated by IL-4 caused expression of a xenobiotic-metabolizing gene, CYP1A1, and TCDD synergistically acted on the induction of this gene by IL-4. However, the induction of AhR had no effect on IgE synthesis or CD23 expression. These results indicate that the metabolism of xenobiotics would be a novel biological function of IL-4 and IL-13 in B cells, whereas TCDD is not involved in IgE synthesis in B cells.     

Optimum selection of an implantable secondary battery for an artificial heart by examination of the cycle life test

An implantable secondary battery is one of the key components in a total artificial heart system. Because a 2 year cycle life is required, the cycle life of the secondary battery as well as its charge and discharge properties are important parameters for selection of an appropriate battery. We carried out cycle life tests on four kinds of rechargeable batteries (a Ni-MH secondary battery, a Ni-Cd secondary battery, a Li-ion battery with a graphite anode, and a Li-ion battery with a nongraphitizable carbon electrode) to determine their suitability as implanted back-up batteries. Each of the batteries was charge/discharge cycled at 37 degrees C to 39 degrees C using a charge current of 1 C ampere, and they were each fully discharged under either pulsatile discharge loads, which mimicked pulsatile operation, or a nonpulsatile load equivalent to the average of the pulsatile loads. The two Li-ion batteries made by different manufacturers both met the minimum requirement of cycle life of more than 1,500 cycles, considering safety coefficient regardless of the discharge pattern. In addition, the temperature increase of these Li-ion batteries (3 degrees C) was lower than that of Ni-Cd and Ni-MH batteries (15-25 degrees C). Out of these four batteries, the two Li-ion batteries are the most suitable for use in a totally implantable artificial heart system.     

ULTRASTRUCTURE OF AN ANAPLASTIC GIANT-CELL CARCINOMA FOUND 8 YEARS AFTER OPERATION ON A PAPILLARY CARCINOMA OF THE THYROID

Light and electron microscopic studies have been made on an anaplastic giant-cell tumor that developed in a woman 8 years after an operation on the thyroid for papillary carcinoma. Many giant cells were observed in the anaplastic tumor tissue, but no follicles. Numerous tightly-packed mitochondria and abundant ribosomes were present, but there were no desmosomes. The basement membrane was not distinct.