Not every PRP-gel is born equal. Evaluation of growth factor availability for tissues through four PRP-gel preparations: Fibrinet, RegenPRP-Kit, Plateltex and one manual procedure.

BACKGROUND: The rationale for using topical platelet gel therapy is to provide the healing tissues with concentrated platelet-derived factors. Several systems are available to prepare platelet-rich plasma (PRP) and from these, the platelet gel. These systems produce two- to six-fold platelet and growth factor-enriched concentrations. The bioavailability of growth factors in tissue healing depends on the amount of growth factors stored in platelets but a portion of these is lost during platelet manipulation. Very few data have been reported on the kinetics of growth factor release from PRP-gels. The aim of this study is to assess the growth factor recovery and its bioavailability to tissues in four different PRP and PRP-gel preparation techniques. MATERIALS AND METHODS: Three commercially available devices (Fibrinet, RegenPRP-Kit, Plateltex) and one manual procedure (home made, HM) were evaluated with reference to resulting platelet concentration, growth factor content and the kinetics of growth factor release from gel. RESULTS: Platelet concentration increased from 1.65- to 4.4-fold in comparison with whole blood initially used. The final platelet concentration (x 10(3)/microl) was: Fibrinet 1358 +/- 419, Regen 430 +/- 109, HM 1196 +/- 188, and Plateltex 1160 +/- 164. A high variation (5- to 27-fold) was found in growth factor concentration in relation to the method used and also a high variation in the kinetics of growth factor release from gels. CONCLUSIONS: Similar methods for platelet gel preparation revealed different performances concerning growth factor recovery and the kinetics of its release from the gel. It is unclear whether these noticeable differences are important for clinical management.

Platelet-rich plasma and platelet gel preparation using Plateltex.

BACKGROUND: The platelet gel is made by embedding concentrate platelets within a semisolid (gel) network of polymerized fibrin. It is believed that this blood component will be used more and more in the treatment of several clinical conditions and as an adjunctive material in tissue engineering. Several systems are available to produce platelet-rich plasma (PRP) for topical therapy. Recently, a new system became commercially available, Plateltex. Here we report the technical performance of this system in comparison with the performance of other commercially available systems: PRGF, PRP-Landesber, Curasan, PCCS, Harvest, Vivostat, Regen and Fibrinet. MATERIAL AND METHODS: Both the PRP and the gel were prepared according to the manufacturer's directions. The blood samples of 20 donors were used. The yield, the efficiency, and the amount of platelet-derived growth factor AB (PDGF-AB), transforming growth factor beta, vascular endothelial growth factor and fibroblast growth factor were measured in the resulting PRP. The feature of the batroxobin-induced gelation was evaluated. RESULTS: The yield, the collection efficiency and the growth factor content of Plateltex were comparable to those of most of the other available systems. The gelation time was not dependent on the fibrinogen concentration; however, it was strongly influenced by the contact surface area of the container where the clotting reaction took place (P < 0.0001). CONCLUSIONS: Plateltex provided platelet recovery, collection efficiency and PDGF-AB availability close to those provided by other systems marketed with the same intended use. Batroxobin, the enzyme provided to induce gelation, acts differently from thrombin, which is used by most other systems. Platelets treated with thrombin become activated; they release their growth factors quickly. Furthermore, thrombin-platelet interaction is a physiological mechanism that hastens the clot-retraction rate. On the contrary, platelets treated with batroxobin do not become activated; they are passively entrapped within the fibrin network, and their growth factor release occurs slowly. In these conditions, the clot retraction takes longer to occur. According to these differences between thrombin and batroxobin, it is expected that batroxobin-induced PRP activation will tailor slow release of the platelet content, thus, providing longer in loco availability of trophic factors. In selected clinical conditions, this durable anabolic factor availability might be preferable to quick thrombin-induced growth factor release.

[Primary carcinoma of the gallbladder. Clinico-statistical findings in 24 cases]. / Il carcinoma primitivo della colecisti. Rilievi clinico-statistici su 24 osservazioni.

Twenty-four cases of primary carcinoma of the gallbladder (1.3% of gallbladder operations) collected over a period of 8 years are compared with those reported in the literature. This form has a very poor prognosis due to delays in diagnosis, early regional extension, and often insufficient surgical management. Women over 60 are the main victims. Abdominal pain is nearly always present, with icterus in 50% of cases. In 5/24 cases, the diagnosis was based on histological examination of the surgical specimen in the absence of clinical signs preceding the operation. It is felt that prophylactic cholecystectomy is desirable in cases of symptomatic or asymptomatic lithiatic cholecystopathy, especially in subjects most at risk. Suitable treatment of curable forms requires cholecystectomy combined with cuneiform hepatic resection and regional lymphadenectomy.

[Bilio-digestive shunts. Observations on 72 cases of obstructive jaundice]. / Le derivazioni bilio-digestive. Osservazioni su 72 casi di ittero ostruttivo.

The Authors report their experience about 72 operations of bilio-digestive anastomosis done for obstructive icterus from 1972 to 1979, 48 of which due to pathology by neoplastic cause and 24 due to pathology by benign causes. 32 operations of bilio-jejunal anastomosis on ansa in the omega fashion have been done operations of bilio-jejunal anastomosis on Roux's ansa four of which operations of transtumoral drainage in accordance with Rodney-Smith's technic, 16 operations of bilio-duodenal anastomosis.

[Esophageal pathology in patients with the AIDS virus. Etiology and diagnosis]. / Patología esofágica en pacientes con virus del SIDA. Etiología y diagnóstico.

From 180 patients infected with human immunodeficiency virus (HIV) and followed-up for one year, 17 cases (9.44%) were referred to detect oesophageal pathology. They were prospectively analyzed through fibroscopy, radiology, biopsies for histopathology, virology and mycology and brush cytology. Most frequent symptoms were dysphagia. Odynophagia and retrosternal pain, usually associated, and not providing an accurate diagnostic clue. The most common causes of symptoms were oesophageal candidiasis (47.70%), and herpetic ulcers (23.52%) caused by herpes simplex virus (HSV) type 2. Reflux pathology was also found (11.76%). Cytomegalovirus, other opportunistic infections and tumors were not detected. Seven (64%) of the eleven patients with oesophageal candidiasis also had oral involvement. Four (66%) of six oesophageal ulcers were herpetic; two of them (50%) showed oral ulcers too, and one (25%) had perioral herpetic blisters. Almost in every case endoscopic features allowed diagnosis. Endoscopy in candidiasis showed isolated or confluent white plaques of variable grade. Herpetic ulcers, alone or multiple, were deep with slightly elevated borders. Radiology yielded a poor diagnostic profit (50%), specially in case of multiple lesions. Cytology was highly specific and sensitive (both 90.9%) and suggested viral etiology in 100% of HSV patients. Histopathology was less sensitive than endoscopy and cytology (73% in candida and one HSV non-ulcer case). Both, cytology and histopathology showed koilocytosis in herpetic virus infected patients. The studies performed allowed to change the HIV disease stage in ten patients (62.5%) and to diagnose AIDS in seven (43.75%). In every case medical behavior was oriented or changed by these studies.

PIP: 16 HIV seropositive patients among the 180 treated at the Hospital Muniz and the Hospital Posadas in Buenos Aires between December 1988 and December 1989 were referred to the Hospital Posadas Endoscopy Service for esophageal studies. The 16 patients were prospectively studies by means of fiberoscopy, radiology, biopsies, virology, mycology, and brush cytology. Early treatment is of utmost importance because opportunistic infections may aggravate the general condition, increase immune system effects, and probably permit greater replication of HIV, in addition to producing symptoms. 14 patients were male and 2 female. Ages ranged from 18 to 41 and averaged 32 years. 10 were male homo- or bisexuals and the other 6 were intravenous drug users. 14 of the patients consulted because of specifically esophageal symptoms. 12 reported dysphagia, 8 odynophagia, and 6 retrosternal pain. 9 patients presented various symptoms. 15 of the 16 symptomatic patients had some pathology related to HIV. The remaining case presented a small submucus tumor and gastroesophageal reflux. The symptoms had appeared between 10 days and 1 year prior to study. Symptoms did not provide accurate diagnostic clues. 11 cases of esophageal candidiasis were diagnosed endoscopically by isolated or confluent white plaques. 3 patients classified as grade 1 or 2 on the basis of the intensity and density of plaques had mild symptoms, and 8 classified as grade 3 or 4 had more severe symptoms. 7 of the 11 patients also had oral candidiasis. 4 of 6 patients presenting ulcerative pathology were diagnosed virologically with herpes simplex virus type 2. Herpetic ulcers were single or multiple and were deep with slightly raised edges. No ulcers attributable to cytomegalovirus were diagnosed. 4 of the 11 patients with candidiasis also had ulcers, in 2 cases herpetic. The studies indicated a change in the stage of HIV infection following Centers for Disease Control criteria in 10 cases. AIDS was diagnosed in 7 cases based on esophageal findings. Endoscopic study and the samples obtained guided treatment in the 16 patients. In 1 case a repeat endoscopy led to a change in treatment. It is recommended that endoscopy be performed in all patients with esophageal symptoms. Radiology was relatively ineffective, with 50% of diagnoses in error. Histopathology required multiple biopsies and was less sensitive than endoscopy and cytology. Cytology was highly specific and sensitive.

[A case of agenesis of the gallbladder and cystic duct. Review of the literature. Discussion]. / L'agenesia della colecisti e del dotto cistico. Presentazione di un cvaso. Revisine della letteratura. Discussione.

A survey of the relevant literature prompted by the observation of a case of agenesia of the cholecyst leads to the suggestion that surgery in any form should be avoided in the absence of a PBD disease in the true sense.

Flow injection amperometric detection of ascorbic acid using a Prussian Blue film-modified electrode.

The PB film-modified electrode was used as an amperometric detector for flow injection analysis of ascorbic acid. The modified electrode detector showed good sensitivity, stability and reproducibility. The calibration curve for ascorbic acid was linear over the concentration range from 5.0x10(-6) to 1.0x10(-3) mol l(-1) with a slope of 19.9 mA mol(-1) per litre and a correlation coefficient of 0.999. The detection limit of this method was 2.49x10(-6) mol l(-1). The relative standard deviation of six replicate injections of 2.5x10(-4) mol l(-1) ascorbic acid was 2.5%. The results obtained for ascorbic acid determination in pharmaceutical products are in good agreement with those obtained by using the procedure involving the reaction between triiodide and ascorbic acid.