Using computerised surface wound mapping to compare the potential medical effectiveness of Enhanced Protection Under Body Armour Combat Shirt collar designs.

INTRODUCTION: Protecting the neck from explosively propelled fragments has traditionally been achieved through a collar attached to the ballistic vest. An Enhanced Protection Under Body Armour Combat Shirt (EP-UBACS) collar has been identified as an additional method of providing neck protection but limited evidence as to its potential medical effectiveness exists to justify its procurement. METHOD: Entry wound locations and resultant medical outcomes were determined using Abbreviated Injury Scale (AIS) for all fragmentation neck wounds sustained by UK soldiers between 01 January 2010 and 31 December 2011. Data were prospectively entered into a novel computerised tool base and comparisons made between three EP-UBACS neck collar designs in terms of predicted reduction in AIS scores. RESULTS: All collars reduced AIS scores, with the greatest reduction provided by designs incorporating increased standoff from the neck and an additional semi-circle of ballistic material underneath the collar at the front and back. DISCUSSION: This technique confirms that reinforcing the neck collar of an EP-UBACS would be expected to reduce injury severity from neck wounds. However, without knowledge of entry wound locations for injuries to other body areas as well as the use of AIS scores without clinical or pathological verification its further use in the future may be limited. The ability to overlay any armour design onto a standardised human was potentially the most useful part of this tool and we would recommend developing this technique using underlying anatomical structures and not just the skin surface.

fdg-pet in two cases of neurofibromatosis type 1 and atypical malignancies.

Patients with neurofibromatosis type 1 (nf1) are at increased risk for both benign and malignant tumours, and distinguishing the malignant potential of an individual tumour is a common clinical problem in these patients. Here, we review two cases of uncommon malignancies (Hodgkin lymphoma and mediastinal germ-cell tumour) in patients with nf1. Although (18)F-fluorodeoxyglucose positron-emission tomography (fdg-pet) has been used to differentiate benign neurofibromas from malignant peripheral nerve sheath tumours, fdg-pet characteristics for more rare tumours have been poorly described in children with nf1. Here, we report the role of pet imaging in clinical decision-making in each case. In nf1, fdg-pet might be useful in the clinical management of unusual tumour presentations and might help to provide information about the malignant potential of uncommon tumours.

Cloning a balanced translocation associated with DiGeorge syndrome and identification of a disrupted candidate gene.

DiGeorge syndrome (DGS), a developmental defect, is characterized by cardiac defects and aplasia or hypoplasia of the thymus and parathyroid glands. DGS has been associated with visible chromosomal abnormalities and microdeletions of 22q11, but only one balanced translocation--ADU/VDU t(2;22)(q14;q11.21). We now report the cloning of this translocation, the identification of a gene disrupted by the rearrangement and the analysis of other transcripts in its vicinity. Transcripts were identified by direct screening of cDNA libraries, exon amplification, cDNA selection and genomic sequence analysis using GRAIL. Disruption of a gene in 22q11.2 by the breakpoint and haploinsufficiency of this locus in deleted DGS patients make it a strong candidate for the major features associated with this disorder.

Kinetic and mechanistic studies with bovine testicular hyaluronidase.

Bovine testicular hyaluronidase exhibits hydrolase and transglycosylase activity. To assess the magnitude of each type of reaction, the time-course of hyaluronidase catalysed hyaluronic acid degradation was followed using a sensitive and specific HPLC method. The kinetic parameters Km and Vmax were calculated for purified short chain hyaluronic acid oligomers and native hyaluronic acid based on the appearance of unreactive hyaluronic acid tetrasaccharide. For hyaluronic acid oligomers, as substrate size increased Km decreased from 2.06 to 1.09 mM while Vmax remained about the same, indicating a 5-fold increase in the enzyme-substrate association constant, k1 (kcat/Km). The values of k2 (kcat), the enzyme-substrate disassociation constant, for native hyaluronic acid and hyaluronic acid decasaccharide were similar. The value of k1 for native hyaluronic acid, however, was larger by 70-fold. Kinetic degradation mechanisms for each hyaluronic acid oligomer, using chemical-reaction kinetics, were proposed and evaluated by computer curve fitting analysis of the experimental time vs. concentration data. The derived rate constants, together with mass balance calculations, revealed that transglycosylation plays a significant role in the degradation of all hyaluronic acid oligomers studied.

Novel method for comparing coverage by future methods of ballistic facial protection.

The wearing of eye protection by United Kingdom soldiers in Afghanistan has reduced the morbidity caused by explosive fragments. However, the remaining face remains uncovered because there is a lack of evidence to substantiate the procurement of methods to protect it. Using a new computerised tool we entered details of the entry sites of surface wounds caused by explosive fragments in all UK soldiers who were injured in the face between 1 January 2010 and 31 December 2011. We compared clinical and predicted immediate and long term outcomes (as defined by the Abbreviated Injury Score (AIS) and the Functional Capacity Index (pFCI), respectively). We also used the tool to predict how additional protection in the form of a visor and mandible guard would affect outcomes. A soldier wearing eye protection was 9 times (1.03/0.12) less likely to sustain an eye injury than one without. However, 38% of soldiers in this series were not wearing eye protection at the time of injury. There was no significant difference between the AIS and pFCI scores predicted by the tool and those found clinically. There is limited evidence to support the use of a mandible guard; its greatest asset is better protection of the nose, but a visor would be expected to reduce long-term morbidity more than eye protection alone, and we recommend future trials to assess its acceptability to users. We think that use of this novel tool can help in the selection of future methods of ballistic facial protection.

Somatostatin partially reverses desensitization of somatotrophs induced by growth hormone-releasing factor.

The effect of somatostatin on GH-releasing factor (GRF)-induced desensitization of somatotrophs was studied in vitro. Primary cultures of rat anterior pituitary cells pretreated for 4 or 18 h with GRF(1-40) (100 nmol/l) showed a 50% or greater reduction in maximal GH release when rechallenged with 10 nmol GRF/l. Rechallenge GRF dose-response curves were either very flat, making accurate measurement of the dose giving 50% maximum stimulation (ED50) impossible, or the ED50 concentration was increased from 0.3 nmol/l (untreated) to 2 nmol/l (GRF pretreated). Although GRF pretreatment reduced cellular GH content by 40-50%, correction for this did not restore GRF responsiveness measured in terms of maximal GRF-stimulated/unstimulated GH release (maximal/basal ratio), or the GRF ED50 concentration. Maximal/basal GH release per 4 h from GRF-pretreated cells was reduced when cells were rechallenged with forskolin (5 mumol/l) or calcium ionophore (A23187; 10 mumol/l), to the same extent as when rechallenged with 10 nmol GRF/l. Although this might be explained by a reduction in the pool of releasable GH, an alternative explanation is that pretreatment with GRF d disrupts the GH release mechanism(s) at a common step(s) beyond cyclic AMP generation and Ca2+ influx. Co-incubation of cells with somatostatin and GRF (100 nmol/l) partially reversed the desensitizing action of GRF during both 4- and 18-h pretreatments in a dose-dependent manner, with 1 mumol somatostatin/l being most effective. Maximal GRF (100 nmol/1-stimulated/basal GH release was 4.4 +/- 1.0 (mean +/- S.E.M., n = four experiments), 1.55 +/- 0.09 and 2.43 +/- 0.1 for control, GRF-pretreated (4 h) and GRF plus somatostatin-pretreated cells respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Dopamine agonist- and antagonist-induced modulation of pituitary gonadotrophin releasing hormone receptors are independent of changes in serum prolactin.

The effect of drug-induced hypo- and hyperprolactinaemia on pituitary gonadotrophin releasing hormone receptors (GnRH-R), serum and pituitary gonadotrophins (LH and FSH) and prolactin was investigated in intact adult male and female rats. Hypoprolactinaemia (serum prolactin less than 20% of control values) resulting from dopamine agonist (bromocriptine) infusion (4 mg/kg per day for 7 days) was accompanied by a 40-50% increase in GnRH-R in both male and female animals, though this was not accompanied by any major change in serum or pituitary LH and FSH. Hyperprolactinaemia (serum prolactin greater than ten times control values) induced by the dopamine receptor antagonist metoclopramide (65 mg/kg per day for 7 days) increased GnRH-R between 35 and 45% in both male and female rats without altering serum gonadotrophins. Domperidone (1 mg twice daily for 14 days) also increased GnRH-R by 50% but only in female rats. Both dopamine antagonists significantly increased pituitary prolactin content. Pituitary FSH increased in female rats treated with both metoclopramide and domperidone. The stimulatory effects of bromocriptine and metoclopramide on GnRH-R in male rats were prevented by concurrent treatment with a GnRH antiserum, suggesting that the drug effects were mediated through alteration in endogenous GnRH secretion. Induction of massive (serum prolactin greater than 2000 micrograms/l) hyperprolactinaemia in male and female rats with a transplantable prolactin-secreting pituitary tumour did not reduce GnRH-R concentration, although serum gonadotrophins were suppressed and pituitary gonadotrophin content was increased.(ABSTRACT TRUNCATED AT 250 WORDS)

Hyperprolactinaemia attenuates the gonadotrophin releasing hormone receptor response to gonadectomy in rats.

Measurement of pituitary gonadotrophin releasing hormone (Gn-RH) receptor content provides a qualitative index of prior exposure of the pituitary gland to endogenous Gn-RH. The effect of moderate hyperprolactinaemia (serum prolactin = 95-250 micrograms/1), achieved with three pituitary grafts beneath the renal capsule, on the pituitary Gn-RH receptor content and serum LH responses to gonadectomy of adult rats has been studied. In males the presence of hyperprolactinaemia for 7 days completely prevented the increase in Gn-RH receptor content 3 days after castration and inhibited the serum LH rise by 45%. By 6 days after castration, Gn-RH receptors had increased in the hyperprolactinaemic castrated animals but values were 33% lower than in sham-grafted controls, while the serum LH increase attenuated by 30%. Pituitary LH content was also lower in grafted castrated animals 6 days after castration. Hyperprolactinaemia for 3 weeks had no effect on Gn-RH receptors or pituitary LH content of intact male rats, although basal serum LH was decreased by 50%. Hyperprolactinaemia also attenuated the increases in Gn-RH receptors, serum LH and pituitary LH which occurred 6 days after ovariectomy in female rats. In all experiments the pituitary content of prolactin was reduced by 80-90% in animals bearing pituitary grafts. These results suggest that hyperprolactinaemia restricts the Gn-RH receptor response to gonadectomy by decreasing endogenous hypothalamic Gn-RH secretion.

Effect of testosterone on gonadotrophin-releasing hormone receptors in the castrated rat: preliminary evidence for a stimulatory effect of testosterone on gonadotrophin function in the male rat.

In the long-term castrated rat the negative feedback effect of testosterone is markedly reduced and the raised levels of plasma LH seen in the castrated animals are not suppressed by physiological concentrations of plasma testosterone. In this study we have measured pituitary gonadotrophin-releasing hormone (GnRH) receptor content as well as plasma and pituitary LH on days 1, 10 and 40 after castration and noted the effect of testosterone replacement on these parameters. We found that the negative feedback effect of physiological concentrations of testosterone on plasma and pituitary LH, pituitary GnRH receptor content and response to exogenous GnRH was attenuated 10 and 40 days after castration. It is suggested that the lack of effect of testosterone in the long-term castrated rat is due to its inability to reduce the pituitary GnRH receptor content. On increasing testosterone to supraphysiological levels, the negative feedback effect was reinstated. We also found that in rats 40 days after castration, physiological and subphysiological concentrations of testosterone significantly increased pituitary GnRH receptor content and this may explain the previous findings that low concentrations of testosterone can enhance the effect of GnRH and increase plasma LH levels.

Cyclic adenosine nucleotides and growth hormone-releasing factor increase cytosolic growth hormone messenger RNA levels in cultured rat pituitary cells.

The cellular mechanisms involved in GH biosynthesis have been investigated by the measurement of steady-state levels of cytosolic GH messenger RNA (mRNA) in primary cultures of rat pituitary cells using an RNA-complementary DNA (cDNA) hybridization assay. Growth hormone mRNA-cDNA hybridization increased in a linear manner with increasing cytosol concentration. Cellular GH mRNA levels rose by an average of 2.4-fold (range, 1.6-3.3; n = five experiments) after exposure to GH-releasing factor (GRF(1-40); 10 nmol/l) for 3 days. Treatment with GRF increased the release of GH into the culture medium, and depleted the cellular GH content by 40%. Total GH (in the medium plus cells) after GRF treatment increased by between 1.5- and 3.8-fold, a magnitude similar to the increase in GH mRNA levels. Treatment of cells with dibutyryl adenosine 3':5'-cyclic monophosphate (1 mmol/l) or forskolin (5 mumol/l) increased the levels of cytosolic GH mRNA by between 1.6- and 4.7-fold. These agents increased GH release into the medium, depleted cellular GH content and increased total GH in the system to the same extent as GRF (10 nmol/l). These data demonstrate that cyclic adenosine nucleotides may mediate the GRF induction of GH gene transcription. In addition, we have shown that increases in the levels of cellular GH mRNA are reflected by increased GH biosynthesis, suggesting that the regulation of hormone gene transcription is one cellular site for the control of hormone biosynthesis and, ultimately, hormone available for release.

Pharmacokinetic and endocrinological parameters of a slow-release depot preparation of the GnRH analogue ICI 118630 (zoladex) compared with a subcutaneous bolus and continuous subcutaneous infusion of the same drug in patients with prostatic cancer.

Seventeen patients with advanced prostatic cancer were treated with the gonadotrophin-releasing hormone analogue DSer (tBU)6 AzaGly 10 GnRH (ICI 118630), either as a constant SC infusion, or in the form of a monthly SC slowrelease depot formulation, in which case patients were randomised to receive one of three doses. Six of these patients also received a 250-microgram SC bolus of ICI 118630, for pharmacokinetic studies, before starting the infusion or the depot. Drug levels were measured using a double-antibody radioimmunoassay. In contrast to the SC infusion, which gave a smooth serum 118630 level profile, drug release from the depot preparation was not constant, levels varying in a predictable manner throughout each 28-day period, reaching a peak proportional to the dose of ICI 118630 received, between days 15 and 18 of each cycle. With all methods of administration there was an initial rise in LH, usually followed by a rise in testosterone, after which the SC infusion and the depot were both effective in reducing serum LH to basal levels and testosterone into the castrate range within 1 month. It is too early to make any assessment of clinical response; however, depot treatment was well tolerated: Four patients experienced an initial flare in bone pain, probably related to the initial rise in testosterone, and twelve patients experienced flushing; one patient with pre-existing hydronephrosis and hydroureter developed renal failure, possibly related to a tumour flare reaction. No patients have experienced cardiovascular side effects or local reaction.

Thermodynamic evaluation of activated charcoal as a poison antidote by high-performance liquid chromatography. I: Derivation and validation of an equation for Gibbs free energy of liquid-solid adsorption.

An in vitro method utilizing high-performance liquid chromatography (HPLC) was developed in order to investigate the adsorptive process between activated charcoal and various drugs and toxic chemicals by measuring their Gibbs free energy of adsorption from various acetonitrile:water mobile phases. This report details the derivation and validation of the equation for calculating the Gibbs free energy of liquid-solid adsorption via HPLC. The derived equation incorporates the following experimental parameters: specific surface area of the adsorbent, specific retention volume of the solute, molar volume of the mobile phase, and surface concentration of the solute in a predefined standard state. This equation was validated by means of a closed thermodynamic cycle composed of three segments. Each segment represents a different physical process: gas-solid adsorption of methyl iodide on activated charcoal, gas-liquid solution of methyl iodide in n-hexadecane, and liquid-solid adsorption of methyl iodide on activated charcoal from n-hexadecane. The Gibbs free energy for each of these thermodynamic processes was determined by the appropriate chromatographic technique. Since the cycle did not balance because it did not account for the interaction of n-hexadecane and activated charcoal, it was altered to include a gas-liquid-solid chromatographic technique. When the Gibbs free energies of solution and gas-solid adsorption determined by this chromatographic technique were incorporated into the cycle, the resulting imbalance was only 0.213 kJ/mol (1.1%), thereby validating the derived equation.

Thermodynamic evaluation of activated charcoal as a poison antidote by high-performance liquid chromatography. II: In vitro method for the evaluation of activated charcoal as a poison antidote.

A previous report detailed the derivation and validation of an equation for calculating the Gibbs free energy of liquid-solid adsorption via high-performance liquid chromatography (HPLC). This study utilizes an improved form of that equation in conjunction with an in vitro model of solute adsorption to give an ordered listing of the antidotal activity of activated charcoal towards different drugs and other chemicals. The in vitro model consists of an activated charcoal column with a nominal particle diameter of 15 micron and a surface area of 447 x 10(4) cm2/g, together with a series of acetonitrile:water mobile phases at pH 3. A simple and efficient procedure was developed for ranking the solutes. First, each compound was run in an acetonitrile(ACN):water mobile phase chosen to give a convenient retention time and ideal chromatographic response. The capacity factor for this mobile phase was extrapolated to give a predicted capacity factor for a 35:65 (v/v) ACN:water mobile phase using an empirical equation developed from the exhaustive chromatography of four standard compounds (phenobarbital, strychnine, cyclohexanone, methyl ethyl ketone) in a variety of ACN:water mobile phases. In addition to the standards, 12 other compounds (glutethimide, chlordiazepoxide, quinine, brucine, d-propoxyphene, pentobarbital, methyprylon, methadone, meperidine, codeine, antipyrine, morphine) were evaluated. Based on these data, the Gibbs free energies of liquid-solid adsorption for these compounds were calculated and used to evaluate activated charcoal as a poison antidote for them. The results indicate that a rapid and accurate estimation of the utility of activated charcoal as an antidote for drugs and toxic substances can be obtained from a single chromatographic run of the test compound.

Analysis of dienestrol and its dosage forms by high-performance liquid chromatography.

A high-performance liquid chromatographic (HPLC) analysis is described for dienestrol as a drug substance and in cream, foam, and tablet dosage forms. After incorporation of the drug or dosage form into a solvent mixture containing an internal standard, biphenyl, an aliquot was chromatographed using a reversed-phase medium, followed by UV spectrophotometric detection at 254 nm. The response of the chromatographic system was linear over a concentration range corresponding to 50-200% of the labeled amount of dienestrol. Satisfactory accuracy and precision were confirmed by analyzing cream by the standard addition method. The advantages of the HPLC method are its simplicity, speed, and sensitivity, which permit direct analysis of single-dose quantities of dienestrol.

High-performance liquid chromatographic analysis of isoniazid and its dosage forms.

A high-performance liquid chromatographic analysis is described for isoniazid as a drug entity and in its tablet and injectable dosage forms. After incorporation of the drug or dosage form in a solvent mixture and addition of an internal standard, tribenzylamine, an aliquot is chromatographed using a pellicular silica gel medium followed by UV spectrophotometric detection at 254 nm. The response of the chromatographic system was linear over a concentration range corresponding to 20-200% of the labelled amount of isoniazid. Comparison of the results with those obtained by the official USP XIX method indicates similar accuracy and precision. The advantages of the proposed method are its simplicity and rapidity, its potential for automation, and its specificity. The specificity was demonstrated in the presence of potential degradation products of isoniazid, other drugs used with isoniazid in combination dosage forms, and an adduct formed by the reaction of isoniazid with lactose in the tablet.

Simplex optimization of the blue tetrazolium assay procedure for alpha-ketol steroids.

Two independent, simplex procedures were employed to optimize the official blue tetrazolium reaction. The net absorbance for a fixed amount of hydrocortisone was maximized by the simultaneous variation of five factors of the pharmacopeial method, i.e.: concentrations of tetramethylammonium hydroxide, blue tetrazolium, and water, as well as temperature and time for color development. An initial simplex was used to determine an optimum response, while a second was performed to minimize the blank absorbance obtained at the optimum. A series of pharmaceutically important steroids: prednisone, prednisolone, hydrocortisone acetate, and cortisone acetate were also analyzed by the optimized method. The results indicated improvements in sensitivity ranging from 9.27 to 22.95% for the corticosteroids studied. The optimized method also decreased the assay time in relation to the official procedure by one-sixth.

Optimization of the USP assay for hyaluronidase.

The current USP XXII assay for hyaluronidase (EC 3.2.1.35, HAse) determines activity indirectly by measuring the amount of undegraded hyaluronic acid (HA) substrate remaining after the enzyme is allowed to react with the HA for 30 min at 37 degrees C. To be acceptable as a substrate, the HA must pass a USP suitability test. In this study, seven HA samples, which differed in their anatomical origin, their commercial supplier, and their chondroitin sulphate content, were tested as substrates. One of these did not pass the USP suitability test and therefore would not be an officially acceptable substrate; however, it was carried through the investigation along with the others in order to demonstrate its effect on the analysis. All seven HAs were used as substrates to assay testicular hyaluronidases from three different suppliers. The standard by which the other hyaluronidase activities were measured was USP hyaluronidase reference standard. The activity values calculated for a particular hyaluronidase differed significantly depending on which HA was used as substrate in its assay. Optimal results, as judged on the bases of initial purity, suitability for the assay, linearity of the standard curve, and per cent relative standard deviation of the measured activity, were obtained with a HA substrate derived from vitreous humour.

Evaluation of current compendial physiochemical test procedures for pharmaceutical elastomeric closures and development of an improved HPLC procedure.

The interaction between elastomeric container closures and the solutions they confine presents a potential hazard to the consumer due to extraction of closure ingredients into the dosage form. Each of the major Pharmacopeias, the United States, the European, and the Japanese, prescribe testing procedures for elastomeric closures. These consist of a series of non-specific wet chemical analyses performed on samples extracted into water or, in some cases, isopropanol (IPA) or the drug product vehicle. No consideration is given to the extracting potential of the drug product. Results from our testing on ten randomly selected closure samples indicated that these tests are not sensitive or specific enough to accurately measure the levels of extractables. Therefore, an HPLC gradient method was developed which had the required sensitivity and specificity. The prescribed compendial extractions, when performed on the various stopper types, proved inefficient and experiments were conducted in an attempt to improve them. These included increasing the time of the extractions, increasing the closure surface area, and increasing the strength of the extracting solvent (methylene chloride). The HPLC gradient method and the compendial wet chemical tests were then used to evaluate the stopper extractables. Results of the compendial analyses on the prescribed aqueous extractions were inconclusive as the number and relative amount of extractables in the closure could not be measured. The results of the compendial testing were only marginally improved using the stronger extraction conditions. Testing was dramatically improved, however, using the HPLC gradient method. As many as twenty extractables were detected in some of the samples and, unlike the compendial analysis, low level extractables were detected in the water samples. Identification of some of the extractables was accomplished via GC/MS.