Gene therapy with neurogenin3, betacellulin and SOCS1 reverses diabetes in NOD mice.

Islet transplantation for type 1 diabetes is limited by a shortage of donor islets and requirement for immunosuppression. We approached this problem by inducing in vivo islet neogenesis in non-obese diabetic (NOD) diabetic mice, a model of autoimmune diabetes. We demonstrate that gene therapy with helper-dependent adenovirus carrying neurogenin3 (Ngn3), an islet lineage-defining transcription factor, and betacellulin (Btc), an islet growth factor, leads to the induction of periportal insulin-positive cell clusters in the liver, which are rapidly destroyed. To specifically accord protection to these 'neo-islets' from cytokine-mediated destruction, we overexpressed suppressor of cytokine signaling 1 (SOCS1) gene, using a rat insulin promoter in combination with Ngn3 and Btc. With this approach, about half of diabetic mice attained euglycemia sustained for over 4 months, regain glucose tolerance and appropriate glucose-stimulated insulin secretion. Histological analysis revealed periportal islet hormone-expressing 'neo-islets' in treated mouse livers. Despite evidence of persistent 'insulitis' with activated T cells, these 'neo-islets' persist to maintain euglycemia. This therapy does not affect diabetogenicity of splenocytes, as they retain the ability to transfer diabetes. This study thus provides a proof-of-concept for engineering in vivo islet neogenesis with targeted resistance to cytokine-mediated destruction to provide a long-term reversal of diabetes in NOD mice.

RL-37, an alpha-helical antimicrobial peptide of the rhesus monkey.

Rhesus monkey bone marrow expresses a cathelicidin whose C-terminal domain comprises a 37-residue alpha-helical peptide (RL-37) that resembles human LL-37. Like its human counterpart, RL-37 rapidly permeabilized the membranes of Escherichia coli ML-35p and lysed liposomes that simulated bacterial membranes. When tested in media whose NaCl concentrations approximated those of extracellular fluids, RL-37 was considerably more active than LL-37 against staphylococci. Whereas human LL-37 contains five acidic residues and has a net charge of +6, rhesus RL-37 has only two acidic residues and a net charge of +8. Speculating that the multiple acidic residues of human LL-37 reduced its efficacy against staphylococci, we made a peptide (LL-37 pentamide) in which each aspartic acid of LL-37 was replaced by an asparagine and each glutamic acid was replaced by a glutamine. LL-37 pentamide's antistaphylococcal activity was substantially greater than that of LL-37. Thus, although the precursor of LL-37 is induced in human skin keratinocytes by injury or inflammation, its insufficiently cationic antimicrobial domain may contribute to the success of staphylococci in colonizing and infecting human skin.

Bactericidal activity of mammalian cathelicidin-derived peptides.

Endogenous antimicrobial peptides of the cathelicidin family contribute to innate immunity. The emergence of widespread antibiotic resistance in many commonly encountered bacteria requires the search for new bactericidal agents with therapeutic potential. Solid-phase synthesis was employed to prepare linear antimicrobial peptides found in cathelicidins of five mammals: human (FALL39/LL37), rabbit (CAP18), mouse (mCRAMP), rat (rCRAMP), and sheep (SMAP29 and SMAP34). These peptides were tested at ionic strengths of 25 and 175 mM against Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, and methicillin-resistant Staphylococcus aureus. Each peptide manifested activity against P. aeruginosa irrespective of the NaCl concentration. CAP18 and SMAP29 were the most effective peptides of the group against all test organisms under both low- and high-salt conditions. Select peptides of 15 to 21 residues, modeled on CAP18 (37 residues), retained activity against the gram-negative bacteria and methicillin-sensitive S. aureus, although the bactericidal activity was reduced compared to that of the parent peptide. In accordance with the behavior of the parent molecule, the truncated peptides adopted an alpha-helical structure in the presence of trifluoroethanol or lipopolysaccharide. The relationship between the bactericidal activity and several physiochemical properties of the cathelicidins was examined. The activities of the full-length peptides correlated positively with a predicted gradient of hydrophobicity along the peptide backbone and with net positive charge; they correlated inversely with relative abundance of anionic residues. The salt-resistant, antimicrobial properties of CAP18 and SMAP29 suggest that these peptides or congeneric structures have potential for the treatment of bacterial infections in normal and immunocompromised persons and individuals with cystic fibrosis.

New insights into the mechanism of inhibition of p53 by simian virus 40 large T antigen.

Simian virus 40 (SV40) large tumor antigen (T antigen) has been shown to inhibit p53-dependent transcription by preventing p53 from binding to its cognate cis element. Data presented in this report provide the first direct functional evidence that T antigen, under certain conditions, may also repress p53-dependent transcription by a mechanism in which the transactivation domain of p53 is abrogated while DNA binding is unaffected. Specifically, p53 purified as a complex with T antigen from mouse cells was found to bind DNA as a transcriptionally inactive intact complex, while that purified from human cells was found to bind DNA independently of T antigen and could activate p53-dependent transcription. This difference in activity may be dependent on a different interaction of T antigen with mouse and human p53 and, in addition, on the presence of super T, which is found only in transformed rodent cells. These results suggest that subtle yet important differences exist between the inhibition of p53 by T antigen in mouse and human cells. The implications of this finding with respect to SV40-associated malignancies are discussed.

Chronic anterior uveitis in leprosy: an insidious cause of blindness.

Chronic low grade anterior uveitis is the commonest cause of blindness in leprosy. It is usually asymptomatic until the late stages, and often patients seek help only after irreversible visual impairment has occurred. We present herewith several cases of this entity to emphasise the insidious nature of the disease, the extent of ocular damage it can cause, and the importance of early detection and treatment.

A severe infantile micromelic chondrodysplasia which resembles Kniest disease.

This paper describes 3 infants with a severe, generalized chondrodysplasia with short limbs, shortness of stature, relative micrognathia and neonatal respiratory distress in all cases, cleft palate in two and dislocation of lenses in one. They died at 7 and 10 weeks and at 17 months respectively. No autopsy was performed on any of the 3 patients. Roentgenological manifestations include short, broad tubular bones with metaphyseal widening, bowing of leg, thigh and forearm bones, neonatal accelerated carpal bone maturation, short, broad pelvis with wide, flared iliac wings, many gross vertebral abnormalities including most prominently coronal clefts of almost any vertebral body, and short ribs with flared anterior ends. Roentgenographically the condition has some similarities with Kniest disease, or more correctly, the Kniest chondrodysplasia. However, we think that the clinical and roentgenological manifestations are sufficiently unique to permit delineation of the condition of our 3 patients as a "new" entity different from the Kniest chondrodysplasia. Similar cases have been described by Rolland et al. from France and by Dinno et al. from the U.S.A. The later case and our 3 patients were sporadic cases, but the former had a probably affected sibling, suggesting that this disorder is an autosomal recessive trait.

An extra small metacentric chromosome identified as a deleted chromosome no. 17.

In an 11-year-old girl with multiple congenital abnormalities and mental retardation, an extra, small, metacentric chromosome was identified by banding methods as a deleted chromosome No. 17. This represents the first reported case of partial trisomy 17.

Chlorpropamide-induced granulomas. A probable hypersensitivity reaction in liver and bone marrow.

Anicteric hepatitis, associated with fever and exfoliative dermatitis, developed in a diabetic patient two weeks after intake of a long-acting sulfonylurea, chlorpropamide (Diabinese). Granulomas showing heavy infiltration with eosinophils were found in the liver and bone marrow. These were interpreted as manifestations of an allergic reaction. The clinical signs, abnormal laboratory findings, and hepatic lesions subsided spontaneously on withdrawal of the drug. Bone marrow changes, however, persisted seven months after cessation of the drug. To our knowledge, this is the first report of a patient with liver and bone marrow inflammation characterized by granulomas with eosinophilic infiltration following intake of chlorpropamide.

Mucolipidosis III (pseudo-Hurler polydystrophy): Clinical and laboratory studies in a series of 12 patients.

Mucolipidosis III (pseudo-Hurler polydystrophy) is an autosomal recessively inherited Hurler-like disorder without mucopolysacchariduria. Previous reports have noted a constellation of laboratory features similar to that described for mucolipidosis II (I-cell disease). Studies were carried out on a series of 15 patients. Twelve were found to have changes in serum and cultured fibroblasts which consisted of marked elevations of several acid hydrolases in serum with low levels of the same enzymes in cultured cells, a marked increase in dense cytoplasmic inclusions and abnormal radioactive sulfate kinetics. The clinical features of these 12 patients comprise a phenotypic entity. Despite clinical similarity, the 3 remaining patients were not felt to represent mucolipidosis III. The basic defect in mucolipidosis III remains unknown, but is suggested that the defect is similar to that of mucolipidosis II, from which it must be distinguished clinically.

The clinical presentation of mesenteric vascular disease.

The clinical presentation of 17 patients with mesenteric vascular disease admitted to Mount Sinai Medical Center was reviewed. The signs and symptoms were similar in most cases. However, the acute onset of the symptom triad of abdominal pain, diarrhea, and bloody stools in an elderly patient should make one suspect the possibility of mesenteric vascular disease. The gross and light microscopic appearance of the intestinal tract was characterized by hemorrhagic infarcts regardless of the cause of the bowel ischemia. Mortality from this disease remains high, with only four of our 17 patients alive four months after operation.