Inosine Acedoben Dimepranol promotes an early and sustained increase in the natural killer cell component of circulating lymphocytes: A clinical trial supporting anti-viral indications

Inosine Acedoben Dimepranol (IAD), licensed for the treatment of cell-mediated immune deficiencies associated with viral infections, has been reported to impact a variety of immune parameters both in vitro and in vivo. Here we report the results from a clinical trial where multiple lymphocyte subsets - CD19+ B cells, CD3+ T cells, CD4+ T-helper cells, FoxP3^hi/CD25^hi/CD127^lo regulatory T cells (Tregs), CD3-/CD56+ NK cells, and CD3+/CD56+ NKT cells - were, together with serum immunoglobulins and IgG subclasses, followed during 14days of IAD administration to ten healthy volunteers; these selected from 27 individuals pre-screened in vitro for their capacity to respond to IAD as gauged by increases in the percentage of Treg and/or NKT cells arising in PHA-stimulated cultures. While a transient spike and dip in Treg and T-helper fractions, respectively, was noted, the outstanding consequence of IAD administration (1g po, qds) was an early and durable rise in NK cells. For half the cohort, NK cells increased as a percentage of total peripheral blood lymphocytes within 1.5h of receiving drug. By Day 5, all but one of the volunteers displayed higher NK cell percentages, such elevation - effectively a doubling or greater - being maintained at termination of study. The IAD-induced populations were as replete in Granzyme A and Perforin as basal NK cells. The novel finding of IAD boosting phenotypically competent NK numbers in healthy individuals supports the drug's indicated benefit in conditions associated with viral infection and reinforces the potential for uplift where immune performance may be compromised.

5-Chloroindole: a potent allosteric modulator of the 5-HT₃ receptor

BACKGROUND AND PURPOSE

The 5-HT₃ receptor is a ligand-gated ion channel that is modulated allosterically by various compounds including colchicine, alcohols and volatile anaesthetics. However the positive allosteric modulators (PAMs) identified to date have low affinity, which hinders investigation because of non-selective effects at pharmacologically active concentrations. The present study identifies 5-chloroindole (Cl-indole) as a potent PAM of the 5-HT₃ receptor.

EXPERIMENTAL APPROACH

5-HT₃ receptor function was assessed by the increase in intracellular calcium and single-cell electrophysiological recordings in HEK293 cells stably expressing the h5-HT₃A receptor and also the mouse native 5-HT₃ receptor that increases neuronal contraction of bladder smooth muscle.

KEY RESULTS

Cl-indole (1-100 μM) potentiated agonist (5-HT) and particularly partial agonist [(S)-zacopride, DDP733, RR210, quipazine, dopamine, 2-methyl-5-HT, SR57227A, meta chlorophenyl biguanide] induced h5-HT₃A receptor-mediated responses. This effect of Cl-indole was also apparent at the mouse native 5-HT₃ receptor. Radioligand-binding studies identified that Cl-indole induced a small (≈ twofold) increase in the apparent affinity of 5-HT for the h5-HT₃A receptor, whereas there was no effect upon the affinity of the antagonist, tropisetron. Cl-indole was able to reactivate desensitized 5-HT₃ receptors. In contrast to its effect on the 5-HT₃ receptor, Cl-indole did not alter human nicotinic α7 receptor responses.

CONCLUSIONS AND IMPLICATIONS

The present study identifies Cl-indole as a relatively potent and selective PAM of the 5-HT₃ receptor; such compounds will aid investigation of the molecular basis for allosteric modulation of the 5-HT₃ receptor and may assist the discovery of novel therapeutic drugs targeting this receptor.

A biomechanical comparison of the Z step-cut and basilar crescentic osteotomies of the first metatarsal

The basilar crescentic osteotomy is a popular procedure for the correction of moderate to severe hallux valgus deformity. Dorsiflexion due to malposition of the osteotomy, fixation failure, or late contracture of the soft tissues can lead to lateral metatarsalgia. This study compares the mechanical properties of the Z step cut osteotomy Scarff to those of the crescentic osteotomy in cantilever-bending. The ultimate load, maximum bending moment and energy absorbed were significantly greater for the Scarff osteotomy compared to those in the crescentic osteotomy (p < 0.001). Values for stiffness did not differ between the two osteotomies. Failure of the cortical bone-bridge between the screw-hole and the osteotomy was observed in all crescentic osteotomies, while fracture of the proximal dorsal bridge was seen in all Scarff osteotomies.

Primidone-induced embryolethality and DRL deficits in surviving offspring

Pregnant Sprague-Dawley rats were administered primidone (PRM) by oral gavage on gestation days 8-20 in doses of 0 or 120 mg/kg. This dose did not produce body weight differences in the dams during the dosing period nor were there differences in the birth weights of the offspring. PRM was embryolethal with only 43% of drug-treated dams maintaining their pregnancies, whereas 100% of the pregnant controls produced offspring. An analysis of resorption sites in PRM-treated dams that did not deliver showed a nearly identical number of implantation sites (12.6) compared to the litter size of controls (12.8) that delivered pups. There were no overall differences in exploratory activity levels between PRM-treated and control animals. However, in the PRM-treated females there was an absence of the sexually dimorphic increase in activity seen in control females when compared to control males. The PRM-treated males showed an impairment in the acquisition of a DRL-20 (differential reinforcement of low rates) operant schedule over a 9-week acquisition period. There were no differences in the total response rates between the groups, suggesting that this is a specific learning deficit and not a performance deficit. The results of these experiments provide evidence that prenatal PRM exposure can be embryolethal and also impair behavior in the surviving rat offspring.

Supracondylar fractures above a total knee arthroplasty. A novel use of the Huckstepp nail

A displaced supracondylar fracture of the femur above a total knee arthroplasty (TKA) was treated with a Huckstepp intramedullary nail (Down Surgical, Mitcham, Surrey). The nail was firmly engaged over the tip of the intramedullary stem of the femoral component, establishing fracture alignment and providing enough stability against displacement, angulation, and shortening to allow fracture union. This technique can be applied to any periprosthetic fracture involving a stemmed femoral component.

Macrophages possess probenecid-inhibitable organic anion transporters that remove fluorescent dyes from the cytoplasmic matrix

We introduced several membrane-impermeant fluorescent dyes, including Lucifer Yellow, carboxyfluorescein, and fura-2, into the cytoplasmic matrix of J774 cells and thioglycollate-elicited mouse peritoneal macrophages by ATP permeabilization of the plasma membrane and observed the subsequent fate of these dyes. The dyes did not remain within the cytoplasmic matrix; instead they were sequestered within phase-lucent cytoplasmic vacuoles and released into the extracellular medium. We used Lucifer Yellow to study these processes further. In cells incubated at 37 degrees C, 87% of Lucifer Yellow was released from the cells within 30 min after dye loading. The dye that remained within the cells at this time was predominantly within cytoplasmic vacuoles. Lucifer yellow transport was temperature dependent and occurred against a concentration gradient; therefore it appeared to be an energy-requiring process. The fluorescent dyes used in these studies are all organic anions. We therefore examined the ability of probenecid (p-[dipropylsulfamoyl]benzoic acid), which blocks organic anion transport across many epithelia, to inhibit efflux of Lucifer Yellow, and found that this drug inhibited this process in a dose-dependent and reversible manner. Efflux of Lucifer Yellow from the cells did not require Na+ co-transport or Cl- antiport; however, it was inhibited by lowering of the extracellular pH. These experiments indicate that macrophages possess probenecid-inhibitable transporters which are similar in their functional properties to organic anion transporters of epithelial cells. Such organic anion transporters have not been described previously in macrophages; they may mediate the release of naturally occurring organic anions such as prostaglandins, leukotrienes, glutathione, bilirubin, or lactate from macrophages.

ATP4- permeabilizes the plasma membrane of mouse macrophages to fluorescent dyes

Extracellular ATP induces cation fluxes in thioglycolate-elicited mouse peritoneal macrophages and the J774 macrophage cell line apparently due to ligation of a plasma membrane receptor for ATP4-. We report that ATP permeabilizes the plasma membrane of J774 cells to 6-carboxyfluorescein (376 Da), lucifer yellow (457 Da), and fura-2 (831 Da) but not to trypan blue (961 Da), Evans blue (961 Da), or larger dye conjugates. We employed fluorescence microscopy and quantitative fluorimetry to study entry of lucifer yellow into the cytoplasm of J774 cells. Permeabilization to lucifer yellow appears to be mediated by the same ATP4- receptor that induces cation fluxes because it was inhibited by divalent cations and low pH, was mediated by the nonhydrolyzable analog adenosine 5'-(beta, gamma-imido)triphosphate, and because a variant J774 cell line resistant to ATP-induced Rb+ efflux did not take up lucifer yellow when exposed to ATP. ATP permeabilization was reversed within 5 min by removal of ATP or by addition of divalent cations. ATP also caused a transient increase in lucifer yellow uptake by pinocytosis. These data suggest that ATP4- ligates a receptor on macrophages which induces the formation of a channel admitting molecules less than or equal to 831 daltons into the cytoplasmic matrix and that removal of ATP4- from the medium causes rapid channel closure.

Sexual dysfunction in diabetic women

This study examined sexual dysfunction in diabetic women. Eighty-one insulin-treated diabetic women were interviewed and administered standardized questionnaires. Using criteria derived from the Diagnostic and Statistical Manual of Mental Disorders (3rd ed.) (DSM-III; American Psychiatric Association, Washington, D.C., 1980), 38 (47%) of the women were diagnosed with sexual dysfunction and 43 (53%) did not report sexual problems. The more frequently reported sexual problems were inhibited sexual excitement, inhibited sexual desire, and dyspareunia. Diabetic women with sexual dysfunction were more depressed, more stereotyped in their sex-role definitions, and less satisfied in their sexual relationships than those without sexual dysfunction. The two groups did not differ in metabolic control, insulin dose, duration of diabetes, or frequency of diabetic complications (e.g., neuropathy, etc.). Results suggest that diabetes may be associated with inhibited sexual excitement and dyspareunia in women. Both psychological and physiological concomitants of sexual dysfunction in diabetic women should be considered in diagnostic and treatment programs.