Chloroquine sensitizes biofilms of Candida albicans to antifungal azoles

Biofilms formed by Candida albicans, a human pathogen, are known to be resistant to different antifungal agents. Novel strategies to combat the biofilm associated Candida infections like multiple drug therapy are being explored. In this study, potential of chloroquine to be a partner drug in combination with four antifungal agents, namely fluconazole, voriconazole, amphotericin B, and caspofungin, was explored against biofilms of C. albicans. Activity of various concentrations of chloroquine in combination with a particular antifungal drug was analyzed in a checkerboard format. Growth of biofilm in presence of drugs was analyzed by XTT-assay, in terms of relative metabolic activity compared to that of drug free control. Results obtained by XTT-metabolic assay were confirmed by scanning electron microscopy. The interactions between chloroquine and four antifungal drugs were determined by calculating fractional inhibitory concentration indices. Azole resistance in biofilms was reverted significantly (p < 0.05) in presence of 250 μg/mL of chloroquine, which resulted in inhibition of biofilms at very low concentrations of antifungal drugs. No significant alteration in the sensitivity of biofilms to caspofungin and amphotericin B was evident in combination with chloroquine. This study for the first time indicates that chloroquine potentiates anti-biofilm activity of fluconazole and voriconazole.     

Mucormycosis infection following intravenous access in the forearm

Mucormycosis is an opportunistic infection that is often fatal, requiring aggressive local control as well as systemic therapy. A rare case of a forearm infection originating in a traumatic intravenous access portal is described in the present study. The Mucor species infection prevented liver transplant, and the patient passed away. In the present case, it was decided to limit the resection to the skin and subcutaneous tissue based on a frozen section and the viability of the biopsied tissue. With consistently rising numbers of immunocompromised patients, awareness and familiarity with mucormycosis in the extremities is important. Knowing that a minimal traumatic event may precede the infection could assist in prevention and early diagnosis. Guidelines for pathological and clinical diagnosis and treatment need to be further clarified.     

Age-dependent changes in Na current magnitude and TTX-sensitivity in the canine sinoatrial node

In rabbit, sodium current (I_Na) contributes to newborn sinoatrial node (SAN) automaticity but is absent in adult SAN, where heart rate is slower. In contrast, heart rate is high and I_Na is functional in adult mouse SAN. Given the slower heart rates of large mammals, we asked if I_Na is functionally active in SAN of newborn or adult canine heart. SAN cells were isolated from newborn (6-10 days), young (40-43 days) and adult mongrels. I_Na was observed in > 80% of cells from each age. However, current density was markedly greater in newborn, decreasing with age. At all ages, I_Na was sensitive to nanomolar tetrodotoxin (TTX); 100 nmol/L inhibited I_Na by 46.7%, 59.9% and 90.7% in newborn, young and adult cells, respectively. While high TTX sensitivity suggested the presence of non-cardiac isoforms, steady-state inactivation was relatively negative (midpoints − 89.7 ± 0.7 mV, − 95.1 ± 1.2 mV and − 93.4 ± 1.9 mV from newborn to adult). Consequently, I_Na should be unavailable at physiological potentials under normal conditions, and 100 nmol/L TTX did not change cycle length or action potential parameters of spontaneous adult SAN cells. However, computer modeling predicts the large newborn I_Na protects against excess rate slowing from strong vagal stimulation. The results show that canine SAN cells have TTX-sensitive I_Na which decreases with post-natal age. The current does not contribute to normal automaticity in isolated adult cells but can be recruited to sustain excitability if nodal cells are hyperpolarized. This is particularly relevant in newborn, where I_Na is large and parasympathetic/sympathetic balance favors vagal tone.     

Heparanase Levels Are Elevated in the Plasma of Pediatric Cancer Patients and Correlate with Response to Anticancer Treatment

Heparanase is an endoglycosidase that specifically cleaves heparan sulfate (HS) side chains of heparan sulfate proteoglycans, the major proteoglycan in the extracellular matrix (ECM) and cell surfaces. Heparanase upregulation was documented in an increasing number of primary human tumors, correlating with reduced postoperative survival rate and enhanced tumor angiogenesis. The purpose of the current study was to determine heparanase levels in blood samples collected from pediatric cancer patients using an ELISA method. Heparanase levels were elevated four-fold in the plasma of cancer patients compared with healthy controls (664 ± 143 vs 163 ± 18 pg/ml, respectively). Evaluating plasma samples following anticancer therapy revealed reduced heparanase levels (664 ± 143 vs 429 ± 82 pg/ml), differences that are statistically highly significant (P = .0048). Of the 55 patients with complete remission (CR) or very good partial remission (VGPR) at restaging, 41 (74.5%) had lower heparanase amounts, whereas 14 patients (25.5%) had similar or higher amounts of plasma heparanase. All nine patients with stable or advancing disease had similar or elevated levels of heparanase on restaging. The results show that heparanase levels are elevated in the plasma of pediatric cancer patients and closely correlate with treatment responsiveness, indicating that heparanase levels can be used to diagnose and monitor patient''s response to anticancer treatment.     

A comparative study of immunohistochemistry and electron microscopy used in the diagnosis of epidermolysis bullosa

Electron microscopic examination still is the gold standard for classifying epidermolysis bullosa, although it is relatively expensive, time consuming, and not readily available. Immunoreagents have been developed recently to map antigens in the basement membrane on routinely processed specimens. The current study was performed to examine the diagnostic usefulness of immunohistochemistry, as compared with electron microscopic examination, for analyzing routine formalin-fixed paraffin-embedded sections of epidermolysis bullosa. This study investigated 39 consecutively diagnosed cases of epidermolysis bullosa in which both electron microscopic examination and immunohistochemistry were used. In each case, three monoclonal antibodies were used to stain for laminin 1, collagen IV, and keratin. The immunohistochemical patterns were defined as follows: epidermolysis bullosa simplex (laminin, collagen IV, or both at the dermal floor of the blister and keratin at both the dermal floor and the epidermal roof), junctional epidermolysis bullosa (laminin, collagen IV, or both at the dermal floor of the blister and keratin only at the epidermal roof), and dystrophic epidermolysis bullosa (collagen IV, laminin, or both, and keratin all at the epidermal roof). Altogether, electron microscopic examination subclassified epidermolysis bullosa into its three major forms in 37 of the 39 cases (95%), and immunohistochemistry in 33 of the 39 cases (85%). All of the classifiable cases were concordant. Specifically, immunohistochemistry was diagnostic in 10 of 14 (71%) epidermolysis bullosa simplex cases, 14 of 14 (100%) junctional epidermolysis bullosa cases, and 9 of 11 (82%) dystrophic epidermolysis bullosa cases. The most frequent cause for inconclusive immunohistochemical results was failure in staining of the basement membrane with the antibodies to both laminin and collagen IV. In conclusion, the use of immunohistochemistry on routinely processed specimens may be useful for subclassifying epidermolysis bullosa into its major forms in the majority of the cases, although it still cannot fully replace electron microscopic examination or immunofluorescence mapping in the diagnosis of epidermolysis bullosa.     

Late whiplash syndrome: correlation of brain SPECT with neuropsychological tests and P300 event-related potential

BACKGROUND: The acceleration forces infringing the cervical spine in whiplash injury are frequently associated with multiple cerebral symptoms. The purpose of this study was to determine whether there is a correlation between cerebral perfusion findings, P300 recording (an electrophysiologic marker of cognitive ability), and neuropsychological tests in patients with whiplash injury. METHODS: Twenty patients with chronic whiplash injury underwent extensive clinical evaluation and neuropsychological testing. A brain single-photon emission computed tomography (SPECT) study using 99mTc-HMPAO was performed in all patients within 24 hours of neuropsychological evaluation. P300 event-related potentials were performed in 15 patients and in 9 normal volunteers. RESULTS: Thirteen of 20 patients had brain perfusion abnormalities on the SPECT studies, in one or more regions. Eight of 15 patients had abnormal P300 studies. Seven of eight patients with abnormal P300 had also an abnormal SPECT study. Seven of 15 patients had normal P300 results, 6 of them with a normal SPECT and 1 with SPECT abnormalities. There was no significant correlation between the SPECT findings or the P300 results and the scores of attention and working memory. There was, however, close agreement between the SPECT and P300. CONCLUSION: SPECT perfusion abnormalities in patients with chronic whiplash syndrome correlate well with P300 recording. The combination of these studies with neurocognitive and neurobehavioral tests may be useful in identifying a subgroup of patients having organic brain lesions.