Nuclear and coulomb interaction in 8B breakup at sub-coulomb energies

The angular distribution for the breakup of 8B-->7Be+p on a 58Ni target has been measured at an incident energy of 25.75 MeV. The data are inconsistent with first-order theories but are remarkably well described by calculations including higher-order effects. The comparison with theory illustrates the importance of the inclusion of the exotic proton halo structure of 8B in accounting for the data.

Ionized prodrugs of dehydroepiandrosterone for transdermal iontophoretic delivery

PURPOSE

The aim of this work was to synthesize ionized dehydroepiandrosterone (DHEA) prodrugs with higher water solubility, useful for iontophoretic transdermal application.

METHODS

The synthesized derivatives were characterized and tested for sensitivity to chemical and enzymatic hydrolysis. Solid state and solution stability was also determined. Transdermal iontophoretic anodal transport in vitro was studied using excised rabbit skin.

RESULTS

Two DHEA ionized prodrugs were synthesized: PRO1, a primary amine derivative, and PRO2, a quaternary ammonium salt. The two derivatives possess higher water solubility and lower octanol/saline partition coefficients than DHEA. Prodrugs were sensitive to enzymatic hydrolysis; in particular the primary amine was hydrolyzed faster than the quaternary salt by esterase from porcine liver in vitro. Transdermal flux of the two prodrugs was slightly higher than the parent drug. In the case of passive diffusion, only DHEA was found in the receptor compartment, indicating the complete breakdown of the prodrug in the skin. Current application gave higher drug flux and a significant amount of prodrug was found in the receptor.

CONCLUSIONS

The use of ionized prodrugs of DHEA can increase the flux attainable during transdermal anodal iontophoresis by up to 7 times, but they are useful for passive transport as well.

Drug volume fraction profile in the gel phase and drug release kinetics in hydroxypropylmethyl cellulose matrices containing a soluble drug

In the present work, the drug volume fraction profiles of a colored and very soluble drug, buflomedil pyridoxal phosphate, in the gel layer of initially glassy hydroxypropylmethyl cellulose matrices were studied, using image analysis of pictures of the matrices during swelling and release. The goal was to correlate the drug release kinetics with the dynamic behavior of the drug gradient in the gel layer. An inert (nonswellable) matrix, manufactured by substituting hydroxypropylmethyl cellulose with an inert polymer and containing the same amount of buflomedil pyridoxal phosphate, was prepared as well. The drug color gradient in the partially extracted region and the flux of this matrix were compared to the swellable matrix. The drug gradient in the dissolved drug gel layer of swellable matrices was observed. It was demonstrated that drug release kinetics does not only depend on drug diffusion and matrix erosion, but also on drug dissolution in the gel and on polymer relaxation.

Effects of cooling micrografts in hair transplantation surgery

BACKGROUND

When isolating hair grafts in hair transplantation procedures, it is generally recommended to preserve the grafts at a low temperature (1 degrees C- 4 degrees C) in order to enhance the survival rate of the grafted hairs. This study was carried out to test the real benefits provided by cold-storing hair grafts.

OBJECTIVE

The aim of this study was to evaluate, in an in vitro model, the effects of cooling micrografts during hair transplantation procedures to experimentally assess the soundness of this approach to enhance the survival and growth rates of hair micrografts.

METHODS

A total of 240 anagen hair follicles were obtained from 10 healthy male patients. Follicles were thus randomly assigned to one of the following groups: group A (control; n = 120 follicles), or group B (experimental; n = 120 follicles). Follicles from group A were preserved for 5 hours at room temperature (26 degrees C), and follicles from group B were preserved for 5 hours at 1 degrees C. Immediately after that 5-hour period, follicles from both groups were then cultured for 10 days. The length of each follicle was measured immediately following the 5-hour test period and at the end of the 10-day culture period.

RESULTS

No statistically significant differences were found between the survival and growth rates of follicles from the control (survival rate = 87%, mean 10-day growth rate = 2.68 mm) and experimental (survival rate = 88%, mean 10-day growth rate = 2.54 mm) groups.

CONCLUSION

Although, at present, it is generally assumed that lowering the metabolism of grafts by reducing their temperature may be of some utility for enhancing their survival rate, our data indicate of that there are no effects when performing hair transplantation surgery.

Distribution of khellin in excised human skin following iontophoresis and passive dermal transport

The aim of this work was to study in vitro khellin distribution into human skin after passive or iontophoretic transport. The experiments were performed on excised human skin, using vertical Franz-type diffusion cells. The effects of current application and reservoir pH were studied. At the end of the experiments the skin was sliced thinly and the drug was extracted and analyzed by HPLC. The results showed that khellin is able to penetrate through stratum corneum, to reach basal epidermis and upper dermis. The application time proved to be an important parameter. Current application (30 min; 0.5 mA/cm(2)), with a donor at pH 7.0, favored khellin accumulation even if the drug is not ionized. On the contrary, the use of a formulation at pH 3.2 inhibited drug accumulation. Leaving the drug reservoir in contact with the skin for 30 min after current application led to a dramatic increase of khellin concentration. A combination of dermal iontophoresis and passive diffusion is then a useful technique to govern khellin distribution in the skin.

Ineffectiveness of acute scalp expansion

The aim of this study was to test the ex vivo biomechanical properties of acutely expanded scalp flaps to quantitatively assess the efficacy of acute scalp expansion. A total of 14 fresh male cadavers were used for the study. In each cadaver, a rectangular (4 x 10 cm), laterally based flap was designed on each side of the scalp, starting from the superior margin of the external auditory canal. One randomly selected flap per scalp underwent acute intermittent expansion (a 3-minute expansion/3-minute rest cycle was performed three times with the maximum expansion achievable); the contralateral flap served as a control. After the expansion process, the acutely expanded flaps were measured to assess whether applied biomechanical stress caused any changes in flap dimensions. The biomechanical properties (stress/strain ratio, mean stiffness) of both expanded and control flaps were then assessed by means of a dynamometer and a force transducer. The obtained data showed that the biomechanical benefits provided by acute scalp expansion were not statistically different (p < 0.05) from those obtained by simple subgaleal undermining. No change of length nor gain in compliance was observed in the acutely expanded flaps as compared with control scalp flaps. In the authors' opinion, a possible explanation (to be further validated) for the lack of effect of acute scalp expansion might be that the inelastic galea aponeurotica did not allow mechanical creep to exploit the inherent elastic properties of the overlying scalp skin.

Two modified techniques for flexor tendon repair

The aim of this article is to present two new techniques for digital flexor tendon repair: a modification to the conventional Kessler technique (wrap core suture) and tendon splints (H-shaped splint). These techniques were aimed at enhancing the biomechanical properties of such repairs as related to resistance to both gap formation and repair failure. Comparing (in an ex vivo study) the tensiometric properties (gap formation and failure strengths) of 24 flexor digitorum profundus tendons repaired with the described techniques (12 repairs per each technique) and the conventional Kessler repair (24 repairs), we found that the former provided significantly stronger repairs than the latter in vitro. A statistically significant difference (p < 0.001) was found between each of the two presented techniques and the Kessler repair. The wrap core suture increased the load at which a visible (1 mm) gap formed by 22.6 percent when compared with the conventional Kessler suture. The mean gap strength of the wrap core repair was 6.5 N, whereas that of the conventional Kessler was 5.3 N. The failure loads (ultimate strength) of the wrap core suture were 33.8 percent higher than those of the conventional Kessler. The mean breaking load of the wrap core repair was 19.4 N, whereas that of the conventional Kessler was 14.5 N. The H-splint repair increased the load at which a visible gap formed and the failure loads (ultimate strength) by 158.5 and 333.1 percent, respectively, when compared with the conventional Kessler suture. The mean gap strength of the H-splint repair was 13.7 N, and its mean breaking load was 62.8 N.

Ultrastructure and immunohistochemical identification of the extracellular matrix of the chinchilla cochlea

The molecular composition and three-dimensional organization of the extracellular matrix (ECM) was studied by immunofluorescent microscopy, transmission and scanning electron microscopy in three connective tissue structures of the cochlea: the spiral limbus, basilar membrane and spiral ligament. Type II collagen, fibronectin, tenascin, chondroitin sulfate proteoglycans, alphav and beta1 integrins were immunolocalized in the ECM of these connective tissue structures. Electron micrographs showed a continuum of cross-striated collagen fibrils having a similar diameter and axial periodicity that spread from the spiral limbus via the basilar membrane and into the spiral ligament. Some of collagen fibrils were aggregated laterally into bundles. Bundle images, and their digital Fourier transformations, showed a major 67-nm axial D-repeat characteristic for collagen fibrils. Transmission electron microscopy showed numerous proteoglycans associated with the collagen fibrils. The spiral limbus, basilar membrane and spiral ligament demonstrated regional differences in molecular composition and structural organization of their ECM. The glycoproteins fibronectin, tenascin and alphav integrin were immunolocalized mainly in the basilar membrane. Collagen fibrils of the spiral limbus and spiral ligament did not appear to be strongly oriented. However, most of the collagen fibrils in the basilar membrane were arranged into radially directed bundles. Collagen fibrils in the basilar membrane were also surrounded by a homogeneous matrix, which was immunoreactive to fibronectin and tenascin antibodies. A more complete understanding of the composition and structural organization of the ECM in these connective tissue structures in the cochlea provides a foundation upon which micromechanical models of cochlear function can be constructed.

Fetal unilateral cleft lip and palate: detection of enzymic anomalies in the amniotic fluid

Aims of this study were to evaluate whether it is possible to determine, by means of isoelectric focusing, an enzymic differentiation in human amniotic fluid, and whether the onset of fetal cleft lip and palate is accompanied by a pathologic enzymatic differentiation pattern in amniotic fluid. From January of 1993 to June of 1996, amniotic fluid samples from 315 healthy pregnant women (ages 22 to 43 years, mean 37 years; gestational age 14 to 22 weeks, mean 17 weeks) were examined. The normality of all pregnancies was confirmed at birth. Moreover, amniotic fluid samples were examined from three pregnancies (ages 36, 35, and 30 years; gestational ages 16, 18, 24 weeks) with fetal unilateral cleft lip and palate (confirmed at birth), diagnosed by ultrasound. The authors have tested as "metabolic" markers the enzymes lactate dehydrogenase and creatine phosphokinase. For the concentration rates of both the tested enzymes, a statistically significant difference (p = 0.003) was found between amniotic fluid samples obtained from normal and affected pregnancies. These data, in the authors' opinion, corroborate the hypothesis that a local metabolic impairment is somehow involved in the pathogenesis of cleft lip and palate.

Anchoring galeal flaps for scalp reduction procedures

This article describes an operative technique, based on the use of three anchoring galeal flaps, aimed at reducing the percentage of "stretch-back" that occurs after performing scalp reduction procedures. In 12 male patients undergoing a midline scalp reduction procedure, three rectangular (2 x 3 cm) galeal flaps in direct continuity with the longitudinal margin of the left scalp flap were sutured individually to the galeal undersurface of the right scalp flap to draw the two scalp flaps toward the midline of the scalp and to relieve the wound margins of closing tension. Tattoo marks were placed on the patient's scalp at the level of the vertical lines drawn through the external auditory meatuses (A1-A2) and 6 cm more posterior (B1-B2) to measure the movement and stretching of the scalp. The results were compared with those obtained from a control group of 13 male patients who underwent the same surgical procedure but without the use of the anchoring galeal flaps. Mean stretch-back (as measured 4 weeks postoperatively) at level A1-A2 was 8.3 mm in the control group and 1.6 mm in the experimental group. The mean stretch-back at level B1-B2 was 7.7 mm in the control group and 0.9 mm in the experimental group. A statistically significant difference (p < 0.005) was found between data from the control and experimental groups regarding the above-reported stretch-back values at both levels. The use of the described galeal flaps allowed us to obtain an 80.93-percent and an 88.09-percent stretch-back reduction at levels A1-A2 and B1-B2, respectively, 1 month postoperatively.

Power boosting the grafts in hair transplantation surgery. Evaluation of a new storage medium

BACKGROUND

When performing hair transplantation procedures, it is of the foremost importance to try to obtain the maximum survival rate possible of transplanted micrografts.

OBJECTIVE

Aim of this study was to evaluate, in an in vitro model, the effects of preserving micrografts, for five hours, in an enriched storage medium in order to enhance the survival rate of hair micrografts.

METHODS

A total of 200 human anagen hair follicles was obtained from ten male patients. Follicles were thus randomly assigned to one of the following group: Group A (control; n = 100 follicles), preserved for five hours in saline, and Group B (experimental; n = 100 follicles), preserved for five hours in a storage medium, containing adenosine triphosphate-magnesium chloride and deferoxamine mesylate. Isolated hair follicles from both Groups were then cultured for 10 days.

RESULTS

A statistically significant difference was found between the survival rate of experimental (98%) and control follicles (87%).

CONCLUSION

In our opinion, a "metabolic preconditioning" of micrografts by means of storing them for 5 hours in the described medium may be of some utility in augmenting the survival rate of hair grafts when performing hair transplantation surgery.

Endoscopic transthoracic dorsal sympathectomy for the treatment of upper extremity hyperhidrosis: a new minimally invasive approach

Palmar and axillary hyperhidrosis are best treated surgically by endoscopic transthoracic upper dorsal sympathectomy. At present, this methodology relies on (at least) double trocar insertion (per side), carbon dioxide insufflation, or both. We present a new minimally invasive endoscopic transthoracic technique, performed by a single-entry specifically modified thoracoscope and without the need for carbon dioxide insufflation, with the aim to reduce the drawbacks associated with the above-mentioned, currently adopted endoscopic technique. In our opinion, this "single-entry" technique, compared with the other reported approaches, should theoretically minimize any damage to the intercostal neurovascular bundle, while avoiding the complications related to carbon dioxide insufflation.

Aesthetic reconstruction of the vertex area of the scalp. Case report

A 62-year-old woman had a defect in the vertex of the scalp that was created by the excision of a basal cell carcinoma. This was closed with three local, hair-bearing, rhomboid flaps. This allowed us to reconstruct the natural whorl pattern of hair in this region.

Mitochondrial activity of orbicularis oris muscle in unilateral cleft lip patients

To better evaluate the role of a possible mitochondrial alteration in the pathogenesis of cleft lip, we obtained and examined 38 orbicularis oris muscle specimens taken from the cleft margin of both cleft and noncleft sides of 10 unilateral cleft lip infants at the time of primary closure. Part of each sample was frozen in liquid nitrogen/cooled isopentane, while the remainder was fixed in 2.5% glutaraldehyde, postfixed in osmium tetroxide, and embedded in Araldyte resin. Ten-micrometer-thick sections were obtained from the frozen samples and stained for histologic (Gomori trichrome) and histochemical (adenosine triphosphatase, nicotinamide adenine dinucleotide-tetrazolium reductase, cytochrome c-oxidase, succinate dehydrogenase) techniques. Ultra-thin sections (70 to 100 nm) of the resin-embedded specimens were stained with uranyl acetate and lead cytrate and were examined with a Zeiss 109 transmission electron microscope operating at 80 kV. Muscular fiber-type ratio was found to be 19.2 percent type 1 and 80.8 percent type 2 fibers on the cleft side and 26.3 percent type 1 and 73.7 percent type 2 fibers on the noncleft side. We detected aspecific structural alterations, such as variations in the fiber size without fiber group atrophy or fiber-type grouping with the ATPase reaction, in all biopsies. Although Gomori trichrome revealed a dark staining and red granularity of the fibers, suggesting an increase in mitochondria activity, no ragged-red fibers or cytochrome c-oxidase-negative/succinate dehydrogenase-positive fibers were found. At the ultrastructural level, the mitochondrial morphology was always preserved, without inclusions or variations in size and/or shape. On the other hand, we invariably noticed an increase of the number of mitochondria, associated with abnormal glycogen deposits, in some areas of every specimen. Both of these two latter findings were regularly localized at the periphery of the sarcolemma, resembling the so-called lobulated fibers, an aspecific sign of muscular flogosis. Our findings, although excluding an inherent metabolic myopathy of orbicularis oris muscle in unilateral cleft lip patients, evinced both an increased oxidative metabolism and a generic inflammatory condition of that muscle, the nature of which must still be defined.

Effects of galeotomies on scalp flaps

The aim of the present study was to evaluate how much a relaxing incision of the galea aponeurotica affects the biomechanical properties of a scalp flap to quantify the surgery-related advantages provided by this procedure. Twenty scalp flaps, created by a reverse-Y incision down to and through the galea aponeurotica together with undermining (in the layer between the galea and the pericranium) to within 1 cm of the external auditory canal were studied. Data were collected by stepwise loading the scalp flaps before and after performing three full-thickness galeotomies lengthwise and parallel to the sagittal scalp incision. The tension/ extension ratio characteristics were computed, and loading curves as well as mean stiffness values were measured. A statistically significant difference (-16.6 g per millimeter) was found between the slope (computed as Young's modulus) of the curves obtained before and after performing the galeotomies. This value corresponded to a mean 40% reduction of the closing tension attained with each galeotomy. In the closing-tension interval 500 g to 1,500 g, the mean gain of length of the flap per galeotomy was 1.67 mm. These data confirm the usefulness of galeotomies for lengthening the scalp flaps and for diminishing the tension on wound margins when closing scalp defects.

Follicular bisection in hair transplantation surgery: an in vitro model

The aim of this study was to evaluate, in an in vitro model, the survival and growth rates of transversely sectioned human hair follicles to assess experimentally the soundness of this approach as a future possible method for "duplicating" available donor hair grafts in hair transplantation procedures. A total of 300 human anagen hair follicles was obtained from 10 healthy male patients. Follicles were thus randomly assigned to one of the following groups: group A (control; n = 100 follicles), cultured intact as dissected, and group B (experimental; n = 200 follicles), transversely transected, parallel to the epidermal surface and immediately below the bulge area, to obtain 200 lower-half follicles and 200 upper-half follicles. Isolated hair follicles from both groups were maintained in culture for 10 days. The length of each follicle was measured immediately following isolation and at the end of the 10-day culture period. No statistically significant differences were found between the growth rate of intact follicles (mean 10-day growth rate = 2.71 mm) and of lower-half follicles (mean 10-day growth-rate = 2.64 mm), whereas a statistically significant difference was found between the growth rate of follicles from the two above-mentioned groups and the growth rate of the "upper-half" follicles (mean 10-day growth rate = 1.07 mm). Histologic analysis demonstrated that both intact and lower-half follicles maintained a normal histologic appearance, whereas in upper-half follicle sections we invariably detected a region of intense cell proliferation, reminiscent of a regenerated follicular papilla, surrounding the lowermost part of the follicle. In our opinion, the reported in vitro survival rate of transected human hair follicles might represent an interesting starting point in striving to augment the number of donor hairs available during a hair transplantation procedure.

Partial permselective coating adds an osmotic contribution to drug release from swellable matrixes

A swellable matrix tablet is described which is partially coated with cellulose acetate (CA) to obtain a film having the shape of a cup, whose permeability to water and solutes was altered by mixing increasing amounts of poly(ethylene glycol) 400 (PEG). The drug-release mechanism from such systems was assessed by carrying out drug-release experiments both in water and saline solutions. Drug permeability through the polymeric cup and SEM analysis on the films were also performed. It was found that the systems exhibited drug-release kinetics very close to linearity. The mechanisms governing drug release were (i) drug diffusion through the uncoated gel layer, (ii) drug transport through the gel layer due to the osmotic pressure difference, and (iii) drug diffusion through the cup pores. The relative importance of each contribution depended on the amount of PEG in the film. The systems with a cup containing 1%, 13%, and 33% PEG w/w behaved in part as osmotic systems, whereas the system having a permeable cup behaved as a hybrid reservoir system. These modifications of the coating permeability introduce a further possibility of modulating drug-release kinetics and lead to a reduced dependence of swellable matrix tablet release on environmental conditions.

Long-term advantages of permanent expandable implants in breast aesthetic surgery

Permanent expandable implants are widely used in breast reconstructive surgery, but their use in aesthetic surgery is still uncommon. Previous reports on breast expansion-augmentation using permanent expandable implants focused on immediate and early advantages but failed to evaluate long-term benefits, because the reservoir was removed a few months after implantation and the ability to adjust the implant size was lost. Since 1986, we have used permanent expandable implants in 129 women for unilateral or bilateral breast augmentation using the following approach: implants were positioned submuscularly through a transaxillary incision; the filling port was placed a few centimeters below the incision and permanently retained; the implants were positioned underinflated and then overexpanded starting 2 weeks after implantation; after a period of overinflation, deflation to the preoperatively planned volume was scheduled; patients' suggestions regarding final volume adjustments were followed; the effects of repeated overinflations and deflations were investigated in several different conditions. Permanent expandable implants offer unique long-term technical and psychological advantages in the management of highly demanding patients and in the following clinical situations: pregnancy, impending capsular contracture, contralateral progressive ptosis, tubular breasts(s), difficult mammographic examination, spontaneous deflation, and rippling. Disadvantages include economical cost, port-related problems, and repeated requests by patients for volume changes. Saline permanent expandable implants allowed less flexibility in adjusting the breast size and caused discomfort when overexpanded. Permanent expandable implants in breast aesthetic surgery offer several advantages, and because patients can play an active role in deciding volume adjustments, compliance is very high.

Prefabricated engineered bone flaps: an experimental model of tissue reconstruction in plastic surgery

In light of the recently described experimental technique of in vivo bone reconstitution with biotechnologic methods (from bone marrow stromal cells) and the prefabrication flap procedures, the possibility to obtain autologous bone growth in a myocutaneous flap, thus creating a composite osteomyocutaneous preformed flap, is postulated. Human bone marrow stromal cells were delivered into the latissimus dorsi of athymic mice by a porous hydroxyapatite ceramic model. Eight weeks after the implantation, histologic examination revealed the presence of spongious bone tissue. A simple myocutaneous flap was thus transformed into a composite osteomyocutaneous flap. This flap is called the biotechnologic prefabricated flap, because it was the result of ex vivo expanded osteogenic precursor cells and in vivo bone tissue neoformation. The shape of the bone flap was exactly the same as the shape of the ceramic model used. A possible clinical application may be the correction of skeletal defects. The advantages of this procedure are simple surgical execution, the possibility of preshaping the graft to the exact characteristics of the defect, and the availability of autogenous donor tissue without donor site morbidity.

In vitro acyclovir distribution in human skin layers after transdermal iontophoresis

The purpose of the present work was to study the in vitro distribution of acyclovir in human skin layers after iontophoresis, applied in order to increase the amount of drug in the basal epidermis, site of Herpes simplex infections. Experiments were done with Franz diffusion cells applying, as donor, acyclovir solutions (pH values: 3.0 and 7.4) or a commercial cream. Quantification of drug at different skin depths was performed by horizontal slicing of frozen skin, and drug extraction and analysis by high-performance liquid chromatography. Seven h of transdermal iontophoresis (0.5 mA cm-2 induced an accumulation of acyclovir in epidermis and dermis ranging from 80 to 150 micrograms cm-3, characterized by homogeneous distribution of the drug in skin layers. After short current application time (30 min) however, the concentration profile of drug in skin was not significantly different from the obtained after seven h of passive diffusion, employing pH 3.0 donor solution. After 30 min of iontophoresis, the acyclovir reservoir on the skin was maintained for up to five h producing a dramatic increase of drug concentration in skin, evening out over 80 micrograms cm-3 until a depth of 300 micrograms. Acyclovir can be accumulated at target site more quickly and maintained at higher level through application of a iontophoretic pulse and by keeping the drug reservoir on skin.

Assay of acyclovir in human skin layers by high-performance liquid chromatography

This paper describes an assay procedure for acyclovir quantification in human skin after in vitro transdermal transport experiments. The procedure employs warm distilled water for acyclovir (ACV) extraction and high-performance liquid chromatography (HPLC) as analytical method. The procedure has good reproducibility, sensitivity and specificity, resulting in a reliable method for biopharmaceutical studies of ACV distribution in skin tissue. The chromatographic conditions set up, using distilled water as mobile phase, makes the analytical procedure simple and easy to perform.

Computer-aided preoperative planning of tissue expansion

The aim of this paper is to introduce a computer program developed to provide objective, quantitative data useful to ensure proper expander selection when having to use a rectangular tissue expander. The program is developed to calculate the volume of a rectangular tissue expander to obtain the exact amount of yield needed to allow for reconstruction of a determined defect. The only data to be supplied are the length and the width of the defect to be reconstructed. In our opinion, although its use is not aimed at replacing clinical judgment based on experience and careful observation, this program may be considered a simple and useful adjunct for the inexperienced surgeon (or the occasional operator) planning to use a rectangular tissue expander.

Mammographic visualization of a nonpalpable breast mass through a radiolucent breast implant

We report a woman who underwent augmentation mammaplasty as part of a clinical trial of the Trilucent (soybean oil-filled) breast implant in Genoa, Italy. Five months after surgery a mammography was performed in response to the patient's complaints of pressure and tightness in the area of her left breast. The mammogram clearly demonstrated a 5-mm fibroadenoma of the left breast. This is the first documented case of a nonpalpable breast lesion that was detected by mammography through the new radiolucent, triglyceride-filled implant.

Evaluation of preservative effectiveness in pharmaceutical products: the use of a wild strain of Pseudomonas cepacia

A sodium benzoate-sorbic acid preservative system of a pharmaceutical product was proved effective against a wild strain of Pseudomonas cepacia, following the official method of the Italian and British Pharmacopoeias. However, this preservative system was ineffective against a challenge of Ps. cepacia wild strain cells grown in the unpreserved pharmaceutical product and on culture media different from those described by the Pharmacopoeias. The adaptive resistance of the wild strain of Ps. cepacia was not demonstrated with a laboratory strain (ATCC 25609). In contrast, p-hydroxybenzoate-based preservative systems proved to be efficient in protecting the pharmaceutical product against a challenge of wild and laboratory strains of Ps. cepacia grown in the different conditions described above. The results obtained suggest the usefulness, in the official methods for testing pharmaceutical preservatives, of using wild microbial strains isolated from the pharmaceutical environment. Metabolic adaptive responses, capable of affecting the antimicrobial sensitivity of wild micro-organisms used to challenge the preserved product, can be detected by using cells grown in the unpreserved pharmaceutical product.