Light Modulates Important Pathogenic Determinants and Virulence in ESKAPE Pathogens Acinetobacter baumannii, Pseudomonas aeruginosa, and Staphylococcus aureus.

Light sensing has been extensively characterized in the human pathogen Acinetobacter baumannii at environmental temperatures. However, the influence of light on the physiology and pathogenicity of human bacterial pathogens at temperatures found in warm-blooded hosts is still poorly understand. In this work, we show that Staphylococcus aureus, Acinetobacter baumannii, and Pseudomonas aeruginosa (ESKAPE) priority pathogens, which have been recognized by the WHO and the CDC as critical, can also sense and respond to light at temperatures found in human hosts. Most interestingly, in these pathogens, light modulates important pathogenicity determinants as well as virulence in an epithelial infection model, which could have implications in human infections. In fact, we found that alpha-toxin-dependent hemolysis, motility, and growth under iron-deprived conditions are modulated by light in S. aureus Light also regulates persistence, metabolism, and the ability to kill competitors in some of these microorganisms. Finally, light exerts a profound effect on the virulence of these pathogens in an epithelial infection model, although the response is not the same in the different species; virulence was enhanced by light in A. baumannii and S. aureus, while in A. nosocomialis and P. aeruginosa it was reduced. Neither the BlsA photoreceptor nor the type VI secretion system (T6SS) is involved in virulence modulation by light in A. baumannii Overall, this fundamental knowledge highlights the potential use of light to control pathogen virulence, either directly or by manipulating the light regulatory switch toward the lowest virulence/persistence configuration.IMPORTANCE Pathogenic bacteria are microorganisms capable of producing disease. Dangerous bacterial pathogens, such as Staphylococcus aureus, Pseudomonas aeruginosa, and Acinetobacter baumannii, are responsible for serious intrahospital and community infections in humans. Therapeutics is often complicated due to resistance to multiple antibiotics, rendering them ineffective. In this work, we show that these pathogens sense natural light and respond to it by modulating aspects related to their ability to cause disease; in the presence of light, some of them become more aggressive, while others show an opposite response. Overall, we provide new understanding on the behavior of these pathogens, which could contribute to the control of infections caused by them. Since the response is distributed in diverse pathogens, this notion could prove a general concept.

The polymorphism of type 1 collagen (COL1A1) gene does not correlate with an increased risk of foot ulcers in patients with diabetes mellitus.

AIM: Diabetic foot syndrome (DFS) is a multifactorial debilitating complication of diabetes mellitus (DM). The identification of markers for predicting the risk of developing DFS could help and direct the efforts in the prevention to the highest risk patients. Type I collagen α1 (COL1A1) is the main component of type I collagen, the most abundant structural protein of the extracellular matrix of subcutaneous tissue. COL1A1 polymorphism has been previously investigated with regard to many clinical conditions affecting the bone or the skin. In this prospective study, we have assessed COL1A1 polymorphism in patients without and with DFS. PATIENTS AND METHODS: 202 DM patients without and 103 patients with DFS have been recruited. COL1A1 polymorphism, due to a mutation affecting the zinc-finger transcription factor specific protein, has been investigated. The most relevant clinical data (HbA1c, vascular risk factors, insulin treatment) have been collected and analyzed. RESULTS: No statistically significant difference in the distribution of the 3 genotypes constituting COL1A1 polymorphism between patients without and with DFS has been observed. Almost all DFS patients had at least one vascular risk factor, with a high rate of arterial hypertension and dyslipidemia. CONCLUSION: A multifaceted set of factors is involved in the development of DFS and only a combination of them may lead to such occurrence. In our DM patient population, COL1A1 polymorphism does not correlate with the occurrence of DFS, which appears to depend mostly on the presence of vascular risk factors. However, the impact of genetic factors affecting other components of the subcutaneous tissue cannot be excluded.

Pancreatic acellular matrix supports islet survival and function in a synthetic tubular device: in vitro and in vivo studies.

Increasing pancreatic islet survival and function is a starting point for obtaining a valuable bioartificial pancreas for the treatment of type 1 diabetes. In this context, decellularized matrices, obtained after the removal of tissue cellular part, are known to support in vitro adhesion, growth, and function of several cell types. We demonstrate that a homologous acellular pancreatic matrix is a suitable scaffold for rat islet cultures maintaining their long-term viability and function. Islets adhered to the pancreatic matrix showed a constant glucose-induced insulin release during long-term in vitro incubation, while islets cultured without a matrix or on the liver matrix showed a progressive reduction. In order to obtain implantable devices, acellular matrix/islet cultures were entrapped into poly(vinyl alcohol) (PVA)/ poly(ethylene glycol) (PEG) tubes obtained by the freezing/thawing procedure. Under this condition, an in vitro constant insulin release was detected. The devices were then implanted into diabetic rats where reduced insulin requirement was noted suggesting insulin secretory activity of islets contained in the device. Indeed, immunofluorescence confirmed the presence of insulin- and glucagon-producing cells into the explanted devices. These data show that PVA/PEG semi-permeable membrane can obtain devices that restore, at least in part, insulin secretion.

A possible link between genetic hemochromatosis and autoimmune thyroiditis.

The systemic involvement that often characterizes genetic hemochromatosis is well known. Although evidence of iron storage in endocrine glands has been reported, the possible functional changes due to altered thyroid in course of hemochromatosis have been not clearly defined so far. Thyroid may be directly affected by iron storage in the gland as well as functionally altered due to iron accumulation occurring in the pituitary. The prevalence and the pathogenetic mechanisms of primary thyroid illness in patients with genetic hemochromatosis are still largely unknown. Hereby, we describe two patients affected by genetic hemochromatosis who developed Hashimoto's thyroiditis. Taking into consideration the possible links occurring among iron overload, thyroid gland damage and thyroid dysfunction, we hypothesize that hemochromatosis could have been an enhancing factor for the development of primary thyroid disease in these patients. Potentially, this process might also determine new onset anti-thyroid autoimmunity or overlap it. We conclude that systematic studies in large and heterogeneous populations will be necessary in order to assess the risk of development of primary thyroid disorders in course of genetic hemochromatosis and, more generally, chronic iron overload conditions. In our mind, thyroid function should be periodically checked in all patients with chronic iron overload conditions.

Graves' ophthalmopathy and atrophic thyroiditis: a case report.

Graves' ophthalmopathy (GO)--also known as thyroid-associated orbitopathy or ophthalmopathy--usually affects patients with Graves' disease. Antibodies stimulating the TSH receptor are thought to be involved in the pathogenesis of this important and disabling extra-thyroidal manifestation of Graves' disease. Less frequently, GO occurs in subjects who neither have nor have ever shown evidence of thyroid dysfunction ("euthyroid GO"), while the occurrence of GO in patients with autoimmune Hashimoto's thyroiditis is thought to be quite rare and has sporadically been reported. The late and abrupt occurrence of severe GO without hyperthyroidism in an 88-yr-old woman with primary myxedema due to atrophic thyroiditis must be considered as an exceptional event. In this patient, GO was combined with elevated titres of serum auto-antibodies directed against the TSH receptor, while serum levels of anti-thyroglobulin and thyroperoxidase antibodies were within the normal range or only occasionally slightly above the normal values.

Autoimmune diabetes mellitus, Hodgkin's disease and Graves' ophthalmopathy in a patient with 8.1 ancestral haplotype.

In this report, we describe the case of a 43-year-old woman affected by type 1 diabetes mellitus diagnosed 8 years before, who developed Graves' disease 2 years after chemotherapy and mantle radiotherapy treatment for Hodgkin's disease. Bilateral Graves' ophthalmopathy appeared four months before our observations. Intravenous methyl-prednisolone therapy was started, but was interrupted due to severe metabolic failure. Autoantibodies (anti-islet cells, anti-thyroid, thyroid-stimulating, non-organ-specific) were positive. Since the clinical picture suggested a genetic immunological ground predisposing to autoimmunity, we evaluated her HLA haplotype. Genomic typing of the patient permitted identification of the 8.1 ancestral haplotype, a Caucasoid haplotype unique in its association with many immunopathological diseases. Moreover, we also observed a haplotype unusual in Caucasians, trans DRB1*1101, DQA1*0103, DQB1*0603. To our knowledge, HLA-related genetic risk of developing thyroid autoimmunity after neck irradiation has never been studied. Although we cannot confirm a direct association between the 8.1 ancestral haplotype or DRB1*1101, DQA1*0103, DQB1*0603 and the diseases described, we suggest considering immunological parameters and HLA typing in candidate patients for mantle radiation therapy for Hodgkin's disease or other tumors. HLA haplotype determination could be useful in identifying the patients at raised risk of developing autoimmune diseases after irradiation, thus permitting a more appropriate follow-up schedule.

Effects of a somatostatin analogue in occult gastrointestinal bleeding: a case report.

We describe the case of a patient with obscure gastrointestinal bleeding and anaemia, who required repeated transfusions for about 1 year. Because of the absence of a certain diagnosis and of a surgical approach indication, we established long-acting octreotide therapy, obtaining clinical stabilisation and interruption of the transfusional need. Withdrawal of long-acting somatostatin analogue therapy was associated with renewal of bleeding that was again successfully stopped by continuous i.v. somatostatin administration followed by re-establishment of the long-acting octreotide therapy. We suggested, in absence of surgical indications and when only palliative therapies are available, a therapeutic approach with long-term SMS analogues in patients with lower digestive bleeding of a known or unknown source.

The early diagnosis of multiple endocrine neoplasia type 1 (MEN 1): a case report.

We report the case of a patient presenting amenorrhea, hyperprolactinemia, headache and nuclear magnetic resonance (NMR) evidence of pituitary macroadenoma. The family history revealed that the patient's father had had a referred sporadic insulinoma, removed 25 yr before without evidence of other endocrine disorders. Physical examination evidenced a slight neck enlargement. Among biochemical and endocrinological assays performed, only hyperprolactinemia was observed. Neck ultrasonography (US) revealed a parathyroid enlargement and a 99mTcO4/MIBI scan showed two hyperplasic lesions. Considering the diagnostic suspect of multiple endocrine neoplasia (MEN1), we performed abdominal US and NMR studies, showing a pancreatic lesion compatible with neuroendocrine tumor. A total body 111In-DTPA-d-Phe1 -octreotide scan (Octreoscan) was also carried out, evidencing no pituitary tumor uptake but high uptake of the abdominal lesion. After surgery, the histological examination confirmed the two parathyroid adenomas and four non-functioning pancreatic neuroendocrine tumors. When the patient was admitted for studying the pituitary lesion and for planning the opportune therapy, an early and partially subclinical stage of MEN1 was identified, potentially already clear but otherwise undiagnosed, and the genetic state of the patient's relatives, as possible carriers of DNA mutation, was checked. The DNA study for germline mutations confirmed the clinical diagnosis of MEN1 syndrome in the patient and evidenced the same MEN1 mutation in her father and twin sister. In this case report, we would like to underline that, still today, a correct anamnesis and physical examination are the cornerstone of clinical approach to the patient. Furthermore, initial good practice approach is necessary to plan the diagnostic iter, enabling clinicians to decide upon the best orientation and interpretation of the results among several complicated and expensive exams.

Effects of some vanadyl coordination compounds on the in vitro insulin release from rat pancreatic islets.

Many lines of evidence indicate that vanadium inorganic salts possess insulin-mimetic and insulinotropic properties. However, they are poorly absorbed, so high oral doses are required to achieve effective plasma concentrations with possible undesirable toxic side-effects ensuing. Various organically-chelated vanadium compounds have been synthesized that are more potent than inorganic vanadium salts in their insulin-like effects due to their greater bioavailability. Unfortunately, little is known about the possible insulin secretagogue action of organic vanadyl coordination compounds. Hence, we investigated the effect of [VO(metformin)2]H2O, [VO(salicylidene-ethylenedimmine)2] and [VO(pyrrolidine-N-dithiocarbamate)2](VODTC) on insulin release from isolated rat pancreatic islets, and compared it to that of vanadyl sulfate (VOSO4). Of the three coordination compounds, only VODTC was found to exert insulin secretagogue action. VODTC, within concentrations ranging from 0.1 to 1.0 mM, enhanced both basal and glucose (11 mM)-stimulated insulin release. The effect involves calcium channels, since it was not appreciable in Ca2+-free medium. The stimulating action of VODTC required the presence of the whole metal-chelator complex inasmuch as the chelator DTC alone was ineffective. VOSO4 was unable to bring about any significant rise in insulin release from isolated islets. Taken together, our findings indicate that VODTC may be considered a potential elective pharmaceutical tool in the therapy of diabetes, especially of type 2, through its concomitant stimulatory effect on insulin secretion and insulin-mimetic action.

Endocrine aspects of neurosarcoidosis.

The involvement of the hypothalamus and/or pituitary gland by granulomatous, infiltrative or autoimmune diseases is a rare condition of non-tumoral-non-vascular acquired hypothalamic dysfunction and hypopituitarism. In this paper, we present the case of a 26-year-old woman, who showed an amenorrhea-galactorrhea syndrome with hypogonadotropic hypogonadism due to an isolated hypothalamic-peduncular localization of neurosarcoidosis. Acquired GH deficiency was also demonstrated. This clinical case provided the opportunity for a review of the endocrine aspects linked to brain infiltrative diseases that may affect the hypothalamic-pituitary function, with a focus upon neurosarcoidosis. Sarcoidosis is a pathogen-free granulomatous disease that affects both the central and peripheral nervous system in 5-16% of patients. In most cases, such involvement by sarcoidosis occurs within a multi-systemic disease, but disease localization limited to the nervous system may also be observed. Endocrine manifestations of neurosarcoidosis disclose "chameleon-like" clinical pictures, which are usually expressed by the evidence of hypothalamic dysfunction, diabetes insipidus, adenopituitary failure, amenorrhea-galactorrhea syndrome, in isolated fashion or variedly combined. More rarely, inappropriate anti-diuretic hormone secretion, isolated secondary hypothyroidism, adrenal insufficiency or altered counter-regulation of glucose homeostasis have been reported. Neurosarcoidosis is often hard to diagnose, especially when the neurological localization of the disease is not accompanied by other systemic localizations or by specific signs of the disease, and when the lesion is too deep to obtain bioptic confirmation. The study of cerebrospinal fluid and blood lymphocyte sub-populations, integrated by MRI and nuclear scans (67GalIium uptake and 111Indium-pentetreotide, Octreoscan), may be helpful for a correct diagnosis. Therapy with corticosteroid and immunosuppressive drugs, such as cyclosporine A, and other treatment approaches to neurosarcoidosis are also accounted for.

Amenorrhea-galactorrhea syndrome as an uncommon manifestation of isolated neurosarcoidosis.

The involvement of the hypothalamic and/or the pituitary gland during granulomatous, infiltrative or autoimmune diseases is a rare condition of acquired hypothalamic dysfunction and non-tumoral-non-vascular hypopituitarism. Sarcoidosis is a pathogen-free granulomatous disease which affects both central and peripheral nervous systems in 5-16% of patients. In most cases, nervous involvement by sarcoidosis occurs within a multi-systemic disease, although disease localization limited to the nervous system has also been reported. We observed a 26-year-old Italian woman presenting with low-grade fever, headache, visual disturbances, amenorrhea-galactorrhea syndrome and pituitary failure due to an infiltrative lesion involving the hypothalamus and the pituitary stalk. At first, the diagnosis of "probable" neurosarcoidosis was made according to the clinical picture, magnetic resonance imaging, and the study of cerebrospinal fluid lymphocyte sub-populations. In this case, hyperprolactinemic amenorrhea and galactorrhea combined with blunted responses of gonadotropins to luteinizing hormone releasing hormone and acquired growth hormone failure were to be considered as an infrequent manifestation of neurosarcoidosis limited to the medio-basal brain, without other disease localization. Forty-eight months after disease onset, the occurrence of mediastinal lymph node enlargement and increase of angiotensin converting enzyme in serum allowed us to confirm the diagnosis of sarcoidosis. Neurosarcoidosis is often hard to diagnose, especially when the neurological localization of the disease is not accompanied by other possible systemic signs, and when the lesion is too deep to obtain biopsy confirmation. The study of cerebrospinal fluid and blood lymphocyte sub-populations integrated by magnetic resonance imaging may be helpful for a correct diagnosis.