Is Platelet Expiring Out of Date? A Systematic Review

Current platelet concentrates are perishable blood products with short shelf lives. Combined with often unpredictable demand, this results in platelet inventory management problems, manifested by high rates of outdating frequently reported at 10% to 20%, and sometimes inadequate clinical supply. The objective of this study was to critically review the published methodologies on measures to reduce platelet outdating rates, in order to determine how platelet outdating and availability can be improved. We performed a systematic review of journal articles published in English to May 2019 identified from MEDLINE, with reported methods to improve platelet inventory outdating rates and availability. The complexity of each methodology was scored based on whether a typical blood bank manager could design, implement and run a platelet outdating program based on the methodology. Twenty-four relevant citations were found—these included 8 citations employing operational research (OR) methodologies, 7 evaluation/best practice, 6 simulation and 3 forecasting. Over half the included studies have been published within the last decade. The citations reporting the lowest predicted outdating were also the most complex methods. Overall predicted outdating and shortages were less than 4% based on the available data. In conclusion, we found that research interest in platelet inventory management problems has increased in line with platelet demand and methods to assist in reducing outdating rates without increased shortages have been available now for 4 decades; high rates of platelet outdating do however continue to be reported around the world. Developments in platelet preparation and storage, and other new approaches, may assist in addressing this problem.     

The use of flow cytometry in the diagnosis of heparin-induced thrombocytopenia (HIT)

Heparin-induced thrombocytopenia (HIT) affects some of the patients exposed to heparin. It is mediated by antibodies that recognize neoepitopes on platelet factor 4 (PF4)/heparin complexes. A HIT diagnosis requires both clinical and laboratory evaluation and remains a challenge. Since many patients develop antibodies in response to heparin, but only a few of them generate anti-PF4/heparin antibodies capable of activating platelets which consequently cause clinical complications, the performance of serologic assays is not enough to diagnose HIT. Functional assays can identify pathogenic antibodies capable of platelet activation, but they are more demanding and their limited availability contributes to the problem of diagnosing HIT. Restricted laboratories usually collect sera of multiple patients to perform functional assays only once or twice a week; hence, a HIT diagnosis can take several days. The use of flow cytometry appears to be a promising alternative in the confirmation of pathogenic anti-PF4/heparin antibodies. Flow cytometric assays detect either activation markers on a healthy donor’s platelet surfaces or platelet derived microparticles formed after platelet incubation with a patient’s serum. Flow cytometers are readily available in many clinical laboratories, so this technology introduces the possibility of an earlier HIT diagnosis. The objective of this review was to collect findings on flow cytometric HIT confirmations to the present date, and to review the currently available flow cytometric assays used in the diagnosis of HIT.     

Schistosoma mansoni infection in a fishermen community,the Lake Manzala region-Egypt

ObjectiveTo determine the prevalence of schistosomiasis in the fishermen community in Egypt.MethodsA cross-sectional survey for schistosomiasis mansoni was conducted among 150 fishermen and their families from January to November 2013. Faecal samples were examined by Kato Katz method and formalin-ether concentration technique. Malacological survey was conducted to identify infection of the snail intermediate host by larval stage of Schistosoma mansoni. Snails were collected and checked for shedding of cercariae after light exposure.ResultsOverall prevalence of infection was 26.6% with an intensity of (42.7依7.2) ova/g of stool. Infection was common in male and significantly increased in the age of 20-40 years. Praziquantel-treated individuals had a high significant decrease in intensity (27.2依2.4) ova/g of stool than those with no treatment history. Biomphalaria alexandrina snail was infected with Schistosoma mansoni particularly in warm seasons and mice infection was established successfully from the shed cercariae, moreover adult worms were obtained via portal perfusion of the infected mice.ConclusionsFindings indicated the endemicity of schistosomiasis mansoni in Lake Manzala region, therefore, appropriate integrated control measures are needed among fishermen including health education, environmental sanitation, periodic screening and mass treatment with praziquantel.     

Damage control resuscitation for massive hemorrhage

Hemorrhage is the second most common cause of death among trauma patients and almost half of the deaths occur within 24 hours after arrival. Damage control resuscitation is a new paradigm for patients with massive bleeding. It consists of permissive hypotension, hemostatic resuscitation and transfusion strategies, and damage control surgery. Permissive hypotension seems to have better results before the bleeding is controlled. The strategy of fluid resuscitation is minimizing crystalloid infusion and increasing early transfusion with a high ratio of flesh frozen plasma to packed red cells. Damage control surgery is done when the patient＇s condition is unfit for definitive surgery. Hemorrhage and contamination control with temporary abdominal closure is performed before transferring the patients to intensive care unit and the operating room for a permanent laparotomy.     

Novel thermosensitive hydrogels based on methoxy polyethylene glycol-co-poly(lactic acid-co-aromatic anhydride) for cefazolin delivery

Thermosensitive micelles composed of a copolymer of methoxy polyethylene glycol (mPEG), polylactic acid (PLA), and 1,6-bis (p-carboxyphenoxy) hexane (CPH), namely methoxy polyethylene glycol-co-polylactic acid-co-aromatic anhydride (mPEG-PLCPHA), were fabricated for application as a promising hydrophilic drug carrier. The copolymer can self-assemble into micelles in PBS by hydrophobic interaction. The diameters of these micelles increased as the environmental temperature increased. An increase in viscosity with sol-to-gel transition occurred as temperature increased from room temperature to body temperature. During the in vitro degradation process, hydrogels demonstrated a more stable degradation rate. Both in vitro and in vivo cytotoxicity results showed that the materials had excellent biocompatibility due to less acidic products formation. In vitro cefazolin release profiles showed a stable release for 30 days. The hydrogel encapsulated cefazolin exhibited a good antibacterial effect. Based on these results, mPEG-PLCPHA can serve as an injectable depot gel for drug delivery.From the Clinical EditorIn this study, thermosensitive hydrogel encapsulated cefazolin was found to exhibit good antibacterial effects with sustained levels for up to 30 days, enabling the development of an injectable depot gel for long-term drug delivery.     

The influence of amitriptyline and carbamazepine on levomepromazine metabolism in human liver: An in vitro study

BackgroundJoint administration of phenothiazine neuroleptics and an antidepressant or carbamazepine is applied in the therapy of many complex psychiatric disorders. The aim of the present study was to investigate possible effects of the tricyclic antidepressant drug amitriptyline and the anticonvulsant drug carbamazepine on the metabolism of the aliphatic-type phenothiazine neuroleptic levomepromazine in human liver.MethodsThe experiment was performed in vitro using human liver microsomes. The rates of levomepromazine 5-sulfoxidation and N-demethylation (levomepromazine concentrations: 5, 10, 25 and 50 μM) were assessed in the absence and presence of amitriptyline or carbamazepine added in vitro (drug concentrations: 1, 2.5, 5, 10, 25 μM).ResultsA kinetic analysis of levomepromazine metabolism carried out in the absence or presence of carbamazepine showed that the anticonvulsant drug potently inhibited levomepromazine 5-sulfoxidation (K_i = 7.6 μM, non-competitive inhibition), and moderately decreased the rate of levomepromazine N-demethylation (K_i = 15.4 μM, mixed inhibition) at therapeutic drug concentrations. On the other hand, amitriptyline weakly diminished the rate of levomepromazine 5-sulfoxidation (K_i = 63 μM, mixed inhibition) and N-demethylation (K_i = 47.7 μM, mixed inhibition).ConclusionRegarding the central and peripheral effects of levomepromazine and some of its metabolites, the observed metabolic interaction between this neuroleptic and carbamazepine may be of pharmacological and clinical importance.     

Thermal behavior of water in the selected starch- and cellulose-based polymeric hydrogels

In a polymer-water matrix, freezable water is depressed due to either porosity confinement or interaction. The aim of the study was to examine water crystallization/melting depression by sub-ambient differential scanning calorimetry. The selected starch- and cellulose-based polymers including pre-gelatinized starch (PS), sodium alginate, sodium starch glycolate, hydroxypropylmethyl cellulose (HPMC), sodium carboxymethyl cellulose, and croscarmellose sodium were employed. The pre-treated with ambient humidity (85-100% relative humidity, at 30.0+/-0.2 degrees C for 10 days) and with excess water (hydrogels) samples were subjected to between 25 and -150 degrees C cooling-heating cycle at 5.00 degrees C/min rate. The volume fractions of hydrogels were measured by light scattering technique. It was observed that all polymers but PS and HPMC with ambient humidity presented freezable water in two distinct fractions namely bound water where crystallizing/melting temperature was depressed and bulk water. The water transition in samples with various contents exhibited the pattern as a polymer solution, thus rather than confinement, the depression was due to interaction. The volume fraction-melting temperature data derived from endotherms of hydrogels were successfully fitted to Flory's model (r(2): 0.934-0.999). The Flory's interaction parameters (chi(1)) were found to vary between 0.520 and 0.847. In addition, the smaller the value of chi(1), the larger melting was depressed, i.e., stronger affinity for water.     

Students' Perceptions of Prosthodontics in a PBL Hybrid Curriculum

Purpose: A survey was distributed to the Harvard School of Dental Medicine (HSDM) predoctoral student classes of 2005 and 2006 to assess their perceptions regarding preclinical prosthodontics laboratory exercises. Prosthodontics curriculum clock hours, prosthodontics teaching participation, and plans for specialization were also analyzed. We hypothesized that reduced hours and perceived stress in the prosthodontics curriculum might impact students' choice of specialty at HSDM
Materials and Methods: HSDM preclinical prosthodontics clock hours were compared with national means from published data. A survey was distributed to the HSDM classes of 2005 and 2006 (n = 70) at the end of their preclinical prosthodontics laboratory exercises, prior to students seeing their first patient in the clinics.
Results: A 100% response rate was achieved. Results from this study show that HSDM preclinical prosthodontics clock hours are on average shorter than other schools. The majority of the students felt stressed during the laboratory exercises, and they felt they did not gain adequate knowledge from the lectures, resulting in low self-esteem (confidence) in treating patients in the clinic. Despite this perception, HSDM students do just as well, if not better, than other students, as judged by external and internal outcome measures. Graduate prosthodontics specialization is still a specialty of choice among the graduates when compared to national data.
Conclusions: The shortened preclinical didactic and laboratory exercises in prosthodontics at HSDM affect student anxiety, but not their didactic and clinical performances or their decisions in choosing their graduate program. Problem-based learning (PBL) tutorials help the students to integrate preclinical and clinical knowledge and skills in prosthodontics.     

Class 1 integrons and multidrug resistance among Escherichia coli isolates from human stools

Three hundred and eighteen Escherichia coli isolates from stools of healthy volunteers and outpatients from a major university hospital in southern Thailand were tested for the presence of class 1 integrons using multiplex-PCR and for their susceptibility against 12 antimicrobial agents using standard disc diffusion method. Based on the presence of intl1, 162 isolates harbored class 1 integrons, which were more prevalent in isolates from outpatients compared with those from healthy volunteers. The majority (85%) of the isolates were resistant to at least one antimicrobial agent with the following percent resistance: streptomycin 66%, tetracycline 60%, sulphamethoxazole 59%, ampicillin 52%, trimethoprim/sulphamethoxazole 47%, kanamycin 30%, nalidixic acid 27%, ciprofloxacin 23%, norfloxacin 22%, amoxicillin/ clavulanic acid 16%, gentamicin 8%, and amikacin 2%. The most frequent pattern of multiresistant strains (11%) was sulphamethoxazole- trimethoprim/sulphamethoxazole -ampicillin-tetracycline-streptomycin. Multiple drug resistance was more frequent in integron-positive isolates (89%) than those in integron-negative E. coli (57%). These data indicate that human fecal E. coli is a reservoir of antibiotic-resistant genes that poses a significant risk of the spread of microbial resistance in the community.