MORPHOLOGICAL AND BIOCHEMICAL STUDIES OF A CASE OF MUCOPOLYSACCHARIDOSIS II (HUNTER'S SYNDROME)

An autopsy case of a 19-year-old boy who had shown typical gargoyle features, strictly consistent with mucopolysaccharidosis type II (Hunter's syndrome) was reported. Histologically, cytoplasmic vacuolar change was found In hepatocytes, sinusoidal epithelium of spleen, follicular cells of thyroid, Sertoli cells of testis, chromophobe cell of pituitary and generalized fibroblast-like cells including meninges, cardiac valve and periosteum. The vacuoles consisting of membrane-bound structures with flocculus protein-like material and occasional electron dense bodies on electron microscopy, were considered to be the site of mucopolysaccharide deposition by histochemical analysis. Deposition of lipid material consistent with so-called membranous cytoplasmic body was observed in the neurons of central, peripheral and autonomic nervous system. Hepatosplenomegaly could be explained by cytoplasmic deposition, but the cause of cardiomegaly remained further to be studied. Biochemically hepatic mucopolysaccharide was identified as heparan sulfate, while in the kidney dermatan sulfate and heparan sulfate were detected. The correlation between morphology and biochemistry, and between deposition and degeneration was discussed.     

An improved technique for repeated gavage administration to rat neonates

ABSTRACT  The technique for gavage administration to rat nurslings was improved to allow determination of the direct effects of chemical substances in the nurslings. Rat neonates were treated with distilled water from postnatal day 1 through 20 using this technique. The viability of neonates during the administration period was comparable to that of untreated neonates. No adverse effects of this technique on the development of neonates were found, and no histological alterations of the esophagus or pharynx. Therefore, we conclude that use of our improved gavage administration method will contribute to ensuring successful neonatal development and thus allowing accurate assessment of the toxicological effects of test compounds on rat nurslings.     

Gastric motility in patients with recurrent gastric ulcers.

The existence of abnormal gastric motility in gastric ulcer disease remains controversial. The aim of this study was to characterize gastric motility in patients with recurrent gastric ulcers. Studies were performed in 10 control subjects and in 24 patients with recurrent active gastric ulcer disease as diagnosed by gastrointestinal endoscopy. Gastric motility was evaluated by cutaneous electrogastrography (EGG) and by gastric semi-liquid meal emptying. The EGG was recorded before and after ingestion of a test meal containing 20 mg/kg of acetaminophen. Patients with a dominant EGG frequency of greater than 0.06 Hz were defined as tachygastria, while those with a frequency of less than 0.04 Hz were defined as bradygastria. A transient frequency decrease, called postprandial dip (PD), was identified visually. The degree of gastric emptying was determined from the serum acetaminophen concentration 45 minutes after the meal. Control subjects showed no irregularity in their dominant EGG frequency in tither fasting or postprandial states. PD was observed in 8 control subjects. In patients presenting with active gastric ulcers, abnormal patterns in the dominant EGG frequency (either as tachygastria or bradygastria) were observed in 14 of the 24 patients when fasting and in 15 of them in the postprandial state. After successful treatment, the number of patients with abnormal patterns in their dominant EGG frequency remained unchanged, while PD was observed in 11 patients. No significant difference was observed in the EGG power ratio as a result of successful treatment. Gastric emptying was significantly delayed compared with controls in both the active and healed stages. These findings suggest that abnormal gastric motility, including gastric electrical abnormalities and delayed gastric emptying, plays an important role in the pathophysiology of recurrent gastric ulcers.     

Mesp1-nonexpressing cells contribute to the ventricular cardiac conduction system.

Previous fate mapping analysis, using Cre recombinase driven by the Mesp1 locus, revealed that Mesp1 is expressed in almost all of the precursors of the cardiovascular system, including the endothelium, endocardium, myocardium, and epicardium. Mesp1-nonexpressing cells were found to be restricted to the outflow tract cushion and along the interventricular septum (IVS), which is a location that is suggestive of specialized cardiac conduction system (CCS). In our current study, we examined the identity of these IVS cells by using the pattern of beta-galactosidase activity in CCS-lacZ mice. In addition, by crossing Mesp1-Cre and floxed GFP reporter mice with CCS-lacZ mice, we have calculated that approximately 20% of the ventricular CCS within the IVS corresponds to Mesp1-nonexpressing cells. These data suggest that the ventricular CCS is of heterocellular origin. Furthermore, we indicate a possibility that a population of the cells that contribute to the ventricular CCS might be distinguished at an early stage of development.     

T cell can recognize the allospecificities formed by the substitution of amino acids associated with HLA-Bw4/Bw6 public epitopes.

Our previous studies clearly showed that HLA-B35 and HLA-Bw53 differed only by the amino acids associated with HLA-Bw4/Bw6 epitopes, in that the former possessed Bw6 and the latter Bw4 epitope. It remains to be known whether T cell can discriminate HLA-B35 from HLA-Bw53, although the difference between these HLA antigens is discriminated by monospecific human alloantisera. To investigate allorecognition of these HLA antigens by T cells, anti-HLA-Bw53 cytotoxic T lymphocytes (CTLs) were generated. Anti-HLA-Bw53 cytotoxic T lymphocytes (CTLs) were generated. Anti-HLA-Bw53 bulk CTLs from an individual with HLA-B35 clearly discriminated HLA-Bw53 from HLA-B35. On the other hand, anti-HLA-Bw53 bulk CTLs from an individual without HLA-B35 revealed weak cross-reactivity with HLA-B35 and HLA-B51. The additional studies using HLA-Bw53 or HLA-B35-specific CTL clones showed that some but not all of the CTL clones definitively distinguish the difference between HLA-Bw53 and HLA-B35. Thus, the allospecificities formed by HLA-Bw4/Bw6 epitopes were discriminated by allogeneic T cells. The present study demonstrated that HLA-Bw4/Bw6 public epitopes play an important role in allorecognition of T cells.     

Inhibition of passive cutaneous anaphylaxis-associated scratching behavior by mu-opioid receptor antagonists in ICR mice

BACKGROUND: Itching in humans is attenuated by mu-opioid receptor antagonists. ICR mice display increases in scratching behavior upon induction of IgE-mediated passive cutaneous anaphylaxis (PCA), or intradermal injection of compound 48/80 or histamine. METHODS: Cutaneous reactions were induced in ICR mice by IgE-mediated PCA, compound 48/80 and histamine, and the scratching behavior associated with the cutaneous reactions was evaluated. RESULTS: Naloxone and nalmefene reduced the incidence of scratching behavior associated with PCA. Naloxone also inhibited the induction of scratching behavior caused by compound 48/80 and histamine. Naloxone did not affect the increase in vascular permeability caused by PCA and injection of compound 48/80. CONCLUSION: Scratching behavior in mice may be induced by a sensation or a mechanism similar to itching in humans and should become a useful model for examining itching in humans.     

Epithelioid granuloma formation requiring no T-cell function.

Muramyl dipeptide (MDP), a minimal structure in bacterial cell walls essential for their adjuvant activity, was incorporated in a water-in-oil emulsion and injected into the footpads of nude rats devoid of functional T cells. MDP thus injected evoked massive epithelioid granulomas in the draining lymph nodes, indicating that MDP induced epithelioid granuloma formation requires no T cells. This finding with other data available strongly suggest that epithelioid granulomas can be induced without immunologic reactions.