A rare case of acute scrotum in a 12-year old boy: torsion of a paradidymal cystic appendage (organ of Giraldes)

Acute scrotum from testicular and epididymal cyst is relatively uncommon, whereas torsion of a cystic paradidymis is exceedingly rare. In this paper, we present the case of a healthy 12-year-old male patient admitted in our emergency room for acute scrotum, in whom diagnosis of torsion of a cystic paradidymis was suggested at color-Doppler US. Surgical exploration after ultrasound examination revealed a cystic paradidymis (Giraldes' organ) (PC) torsion. Immunohistochemical investigations were also performed after cyst excision to confirm the diagnosis. In our experience this is a very rare condition and appears to be only the third case reported in literature and the only one with pre-operative ultrasound (US) images demonstrating the presence of the cyst and its twisted pedicle.

Platelet-Rich Fibrin Scaffolds for Cartilage and Tendon Regenerative Medicine: From Bench to Bedside

Nowadays, research in Tissue Engineering and Regenerative Medicine is focusing on the identification of instructive scaffolds to address the requirements of both clinicians and patients to achieve prompt and adequate healing in case of injury. Among biomaterials, hemocomponents, and in particular Platelet-rich Fibrin matrices, have aroused widespread interest, acting as delivery platforms for growth factors, cytokines and immune/stem-like cells for immunomodulation; their autologous origin and ready availability are also noteworthy aspects, as safety- and cost-related factors and practical aspects make it possible to shorten surgical interventions. In fact, several authors have focused on the use of Platelet-rich Fibrin in cartilage and tendon tissue engineering, reporting an increasing number of in vitro, pre-clinical and clinical studies. This narrative review attempts to compare the relevant advances in the field, with particular reference being made to the regenerative role of platelet-derived growth factors, as well as the main pre-clinical and clinical research on Platelet-rich Fibrin in chondrogenesis and tenogenesis, thereby providing a basis for critical revision of the topic.

Biofabrication of a novel leukocyte-fibrin-platelet membrane as a cells and growth factors delivery platform for tissue engineering applications

Autologous platelet-rich hemocomponents have emerged as potential biologic tools for regenerative purpose, but their therapeutic efficacy still remains controversial. This work represents the characterization study of an innovative autologous leukocyte-fibrin-platelet membrane (LFPm), which we prepared according to a novel protocol involving multiple cycles of apheresis. The high content in fibrinogen gave to our hemocomponent the appearance of a manipulable and suturable membrane with high elasticity and deformation capacity. Moreover, being highly enriched with platelets, leukocytes, and monocytes/macrophages, the LFPm sustained the local release of bioactive molecules (platelet derived growth factor, vascular endothelial growth factor, interleukin-10, and tumour necrosis factor alpha). In parallel, the evaluation of stemness potential highlighted also that the LFPm contained cells expressing pluripotency and multipotency markers both at the messenger ribonucleic acid (NANOG, SOX2, THY1, NT5E, and ENG) and surface-protein level (CD44^high /CD73⁺ /CD34⁺ /CD117⁺ /CD31⁺ ). Finally, biodegradation analysis interestingly showed a good stability of the membrane for at least 3 weeks in vitro and 1 week in vivo. In both cases, biodegradation was associated with progressive exposure of fibrin scaffold, loss/migration of cellular elements, and release of growth factors. Overall, collected evidence could shed some light on the regenerative effect that LFPms may exert after the autologous implant on a defect site.

On-Line Estimation and Prediction of Urea Kinetics during Hemodialysis: A Simulation Approach

A new method for the on-line estimation of urea kinetic parameters from blood urea concentration (BUN) continuously measured during a dialysis session is proposed. The method, based on the variable-volume double-pool model, is evaluated through a simulation approach in order to easily consider a large set of well-controlled test conditions. The model is characterized by six parameters, knowledge of which enables early prediction of the end dialysis urea concentration and the dose of dialysis. The sensitivity of the model predicted BUN with respect to the parameters was first analyzed to investigate which can be reliably estimated from blood urea measurements taken at a suitable rate. This analysis showed that the model predicted BUN is highly sensitive to the initial blood urea concentration and to the dialyzer clearance, normalized with respect to the total initial distribution volume, while it is scarcely influenced by the normalized ultrafiltration and urea generation rates. The new on-line estimation technique keeps these two last parameters constant and takes advantage of an original analytic solution of the second order urea kinetics. The results of the estimation process on realistic simulated data showed that the proposed method provides early and reliable estimates of the normalized clearance and of the end dialysis concentration. The transcellular mass transfer coefficient and the intra-extra cellular volume ratio can also be estimated, although with less accuracy. Moreover, it was shown that the use of the single-pool model, instead of the double-pool one, provides systematic errors on the estimates.

Comparative Evaluation of Different Methods to Estimate Urea Distribution Volume and Generation Rate

Eight methods to estimate urea distribution volume and generation rate from blood urea samples measured in dialysis patients are reviewed. An analytical solution has been provided for a double-pool variable volume kinetic model to allow for faster and more accurate simulation and identification. The reliable parameter estimates provided by the double-pool kinetic model starting from seven samples, were assumed as references for the estimates obtained by the remaining methods. These include three kinetic models and four methods based on urea mass-balance. In particular, the estimation techniques differ in the number of compartments where urea is assumed distributed (double- and single-pool) or in the number of blood urea samples. Among the methods based on mass-balance, two techniques neglecting the weight loss or the urea generation during dialysis, were also analysed. The results obtained during hemofiltration sessions using three samples, usually available in clinical practice at the beginning and at the end of dialysis, demonstrate that a new method based on double-pool kinetics provides, on average, the most reliable estimates. Moreover, methods belonging to a single pool view and including both weight loss and urea generation during dialysis seem to underestimate by 1÷2 liters the urea distribution volume. However, neglecting the weight loss or the urea generation can overcompensate this error, resulting in a significant overestimation of the distribution volume. Finally, it has been experimentally proved that the single-pool kinetic methods overestimate the urea production rate, while techniques based on mass balance provide more reliable values.

[Neuropsychology of event-based prospective memory]

INTRODUCTION

Prospective memory is the capacity to remember actions that are to be performed in the future. Different studies from experimental neuropsychology attempt to unravel the neurocognitive processes underlying event-based prospective memory, that is, delayed actions that take place in a predetermined context, which would play the role of an external cue and would therefore contribute to successful intentional recall.

DEVELOPMENT

Taking the dynamism and flexibility of multiprocess theory as a reference, the main findings have highlighted the fact that prospective memory is influenced by, among other factors, the type of cue. Thus, when the cue is focal, the person tends to rely on spontaneous retrieval. In contrast, when the cue is not focal, there is usually a tendency towards monitoring. In parallel to this, studies in experimental neuropsychology have determined that the anterior prefrontal cortex and the dorsal frontoparietal network would participate in the cue monitoring processes. Conversely, the ventral frontoparietal network would intervene in automatic retrieval processes. Moreover, the role of the parietal lobe and the medial temporal lobe in prospective tasks is discussed.

CONCLUSION

This study defends the idea that both processing pathways (monitored and spontaneous) favour success in recalling the event-based intentional action. It must nevertheless be borne in mind that the moment a person decides to set one type of processing (or another) in motion it is influenced by the type of cue.

In vitro assessment of TAT - Ciliary Neurotrophic Factor therapeutic potential for peripheral nerve regeneration

In regenerative neurobiology, Ciliary Neurotrophic Factor (CNTF) is raising high interest as a multifunctional neurocytokine, playing a key role in the regeneration of injured peripheral nerves. Despite its promising trophic and regulatory activity, its clinical application is limited by the onset of severe side effects, due to the lack of efficient intracellular trafficking after administration. In this study, recombinant CNTF linked to the transactivator transduction domain (TAT) was investigated in vitro and found to be an optimized fusion protein which preserves neurotrophic activity, besides enhancing cellular uptake for therapeutic advantage. Moreover, a compelling protein delivery method was defined, in the future perspective of improving nerve regeneration strategies. Following determination of TAT-CNTF molecular weight and concentration, its specific effect on neural SH-SY5Y and PC12 cultures was assessed. Cell proliferation assay demonstrated that the fusion protein triggers PC12 cell growth within 6h of stimulation. At the same time, the activation of signal transduction pathway and enhancement of cellular trafficking were found to be accomplished in both neural cell lines after specific treatment with TAT-CNTF. Finally, the recombinant growth factor was successfully loaded on oxidized polyvinyl alcohol (PVA) scaffolds, and more efficiently released when polymer oxidation rate increased. Taken together, our results highlight that the TAT domain addiction to the protein sequence preserves CNTF specific neurotrophic activity in vitro, besides improving cellular uptake. Moreover, oxidized PVA could represent an ideal biomaterial for the development of nerve conduits loaded with the fusion protein to be delivered to the site of nerve injury.

Autologous chondrocytes as a novel source for neo-chondrogenesis in haemophiliacs

Haemophilic arthropathy is the major cause of disability in patients with haemophilia and, despite prophylaxis with coagulation factor concentrates, some patients still develop articular complications. We evaluate the feasibility of a tissue engineering approach to improve current clinical strategies for cartilage regeneration in haemophiliacs by using autologous chondrocytes (haemophilic chondrocytes; HaeCs). Little is known about articular chondrocytes from haemophilic patients and no characterisation has as yet been performed. An investigation into whether blood exposure alters HaeCs should be interesting from the perspective of autologous implants. The typical morphology and expression of specific target genes and surface markers were therefore assessed by optical microscopy, reverse transcription plus the polymerase chain reaction (PCR), real-time PCR and flow-cytometry. We then considered chondrocyte behaviour on a bio-hybrid scaffold (based on polyvinyl alcohol/Wharton's jelly) as an in vitro model of articular cartilage prosthesis. Articular chondrocytes from non-haemophilic donors were used as controls. HaeC morphology and the resulting immunophenotype CD44(+)/CD49c(+)/CD49e(+)/CD151(+)/CD73(+)/CD49f(-)/CD26(-) resembled those of healthy donors. Moreover, HaeCs were active in the transcription of genes involved in the synthesis of the extracellular matrix proteins of the articular cartilage (ACAN, COL1A, COL2A, COL10A, COL9A, COMP, HAS1, SOX9), although the over-expression of COL1A1, COL10A1, COMP and HAS was observed. In parallel, the composite scaffold showed adequate mechanical and biological properties for cartilage tissue engineering, promoting chondrocyte proliferation. Our preliminary evidence contributes to the characterisation of HaeCs, highlighting the opportunity of using them for autologous cartilage implants in patients with haemophilia.

Partially oxidized polyvinyl alcohol as a promising material for tissue engineering

The desired clinical outcome after implantation of engineered tissue substitutes depends strictly on the development of biodegradable scaffolds. In this study we fabricated 1% and 2% oxidized polyvinyl alcohol (PVA) hydrogels, which were considered for the first time for tissue-engineering applications. The final aim was to promote the protein release capacity and biodegradation rate of the resulting scaffolds in comparison with neat PVA. After physical crosslinking, characterization of specific properties of 1% and 2% oxidized PVA was performed. We demonstrated that mechanical properties, hydrodynamic radius of molecules, thermal characteristics and degree of crystallinity were inversely proportional to the PVA oxidation rate. On the other hand, swelling behaviour and protein release were enhanced, confirming the potential of oxidized PVA as a protein delivery system, besides being highly biodegradable. Twelve weeks after in vivo implantation in mice, the modified hydrogels did not elicit severe inflammatory reactions, showing them to be biocompatible and to degrade faster as the degree of oxidation increased. According to our results, oxidized PVA stands out as a novel biomaterial for tissue engineering that can be used to realize scaffolds with customizable mechanical behaviour, protein-loading ability and biodegradability. Copyright © 2015 John Wiley & Sons, Ltd.

Digit loss due to Demodex spp. infestation in a dog: clinical and pathological features

Here we describe a rare clinical manifestation of canine pododemodicosis. A dog was presented with pedal erythema, scaling, crusting, severe edema and digit loss. The following diseases were taken into account for the differential diagnosis: pododemodicosis, lethal acrodermatitis, zinc responsive dermatosis and pemphigus foliaceus. Results from skin biopsies revealed the presence of Demodex spp. of mites in the follicular infundibula and a severe inflammatory process (pododemodicosis). Upon the acaricidal treatment, the patient exhibited favorable signs of clinical improvement.

Digit loss due to Demodex spp. infestation in a dog: clinical and pathological features

Here we describe a rare clinical manifestation of canine pododemodicosis. A dog was presented with pedal erythema, scaling, crusting, severe edema and digit loss. The following diseases were taken into account for the differential diagnosis: pododemodicosis, lethal acrodermatitis, zinc responsive dermatosis and pemphigus foliaceus. Results from skin biopsies revealed the presence of Demodex spp. of mites in the follicular infundibula and a severe inflammatory process (pododemodicosis). Upon the acaricidal treatment, the patient exhibited favorable signs of clinical improvement.

Agarose cell block technique as a complementary method in the diagnosis of fungal osteomyelitis in a dog

A 7-year-old Labrador Retriever female dog presenting left forelimb lameness for one day was admitted to the Veterinary Hospital (UNESP-Botucatu) for clinical evaluation. Several tests, including blood and image analysis, microbiological culture and cytology of lytic areas of affected bone were made in order to establish a diagnosis. Serum biochemical profile revealed increased levels of liver enzymes, plasma globulin, creatine kinase (CK) and calcium. Hemogram revealed anemia and leukocytosis; left humerus image analysis revealed an osteolytic lesion and cytology revealed a suppurative periostitis. Differential diagnosis was a nonspecific infectious inflammatory process or osteosarcoma. Since it was not possible to achieve a definitive diagnosis and there was a highly suspicious for an infectious agent, an agarose cell block of the bone marrow fine-needle aspiration was made. The cytological examination of cell block presented similar findings as described previously. However, additional stains including periodic acid-Schiff (PAS) were positive for fungal hyphae, which rendered a diagnosis of fungal osteomyelitis due to Aspergillus spp. This case report illustrates an uncommon cause of osteomyelitis for breed that was diagnosed by an underused method in veterinary medicine.

Agarose cell block technique as a complementary method in the diagnosis of fungal osteomyelitis in a dog

A 7-year-old Labrador Retriever female dog presenting left forelimb lameness for one day was admitted to the Veterinary Hospital (UNESP-Botucatu) for clinical evaluation. Several tests, including blood and image analysis, microbiological culture and cytology of lytic areas of affected bone were made in order to establish a diagnosis. Serum biochemical profile revealed increased levels of liver enzymes, plasma globulin, creatine kinase (CK) and calcium. Hemogram revealed anemia and leukocytosis; left humerus image analysis revealed an osteolytic lesion and cytology revealed a suppurative periostitis. Differential diagnosis was a nonspecific infectious inflammatory process or osteosarcoma. Since it was not possible to achieve a definitive diagnosis and there was a highly suspicious for an infectious agent, an agarose cell block of the bone marrow fine-needle aspiration was made. The cytological examination of cell block presented similar findings as described previously. However, additional stains including periodic acid-Schiff (PAS) were positive for fungal hyphae, which rendered a diagnosis of fungal osteomyelitis due to Aspergillus spp. This case report illustrates an uncommon cause of osteomyelitis for breed that was diagnosed by an underused method in veterinary medicine.

Outcome comparison among laparoscopic Duhamel, laparotomic Duhamel, and transanal endorectal pull-through: a single-center, 18-year experience

PURPOSE

Transanal endorectal pull-through has changed the treatment of Hirschsprung's disease (HD) in the past decade. The aim of the study was to compare outcomes, obtained in a single center, with laparotomic Duhamel (LTD), laparoscopic Duhamel (LSD), and laparoscopic-assisted transanal endorectal pull-through (LTEPT).

MATERIALS AND METHODS

We retrospectively reviewed the charts of all patients operated on for HD since 1992. Preoperative, operative, and postoperative data were collected to compare short- and long-term outcomes among the three groups.

RESULTS

From 1992 to 2010, 70 children were treated for HD. Patients were divided into three groups based on the surgical technique used: 14 LTEPT, 32 LSD, and 24 LTD. Mean ages at surgery were 4.67, 14.61, and 13.28 months, respectively. Patients in the LTEPT group had significant shorter operating times (195 versus 257 versus 291 minutes, P=.03), earlier start of feeding (1.2 versus 3.1 versus 4.7 days, P<.01), and shorter length of hospital stay (4.4 versus 6.8 versus 9.7 days, P<.011). Overall complications rate was lower in the LTEPT (14%) than in the LSD (31.2%) and LTD (29.7%) groups. Postoperative enterocolitis incidence was 3%-4% in the Duhamel groups and none in LTEPT. Long-term outcome showed less constipation and better continence for age in the LTEPT group at the 1-year follow-up (P=.033).

CONCLUSIONS

This study further supports technical advantages, lighter impact of the surgical procedure on infants, lower incidence of complications, and better long-term outcome of the transanal pull-through compared to the Duhamel approaches.

Pulmonary maturation in canine foetuses from early pregnancy to parturition

Development of the foetal respiratory system includes both pulmonary growth and maturation. In human medicine, a higher incidence of respiratory distress is reported in newborn males. This study aimed to identify different phases of canine foetal lung maturation throughout pregnancy, to determine the stage of pregnancy in which surfactant production begins and to compare pulmonary development of male and female foetuses. Pregnant bitches (34) were subjected to elective ovariohysterectomy and allocated into four groups, according to the stage of pregnancy: 30-40 days of pregnancy (n = 10), 41-50 days (n = 10), 51-60 days (n = 10) and bitches in the first stage of parturition (n = 4). Foetal lungs were histologically processed and evaluated by optical microscopy. The pseudoglandular phase was identified between the 35th day and 46th day of gestation; the onset of canalicular and saccular periods was observed, respectively, from the 48th day and 60th day of pregnancy. Lungs from foetuses at term were in the saccular phase; thus, the development into the alveolar period occurs in the neonatal period. The histological analyses revealed that respiratory tract development is centrifugal, from upper to lower airways. Therefore, it is possible to identify distinct development periods in different portions of the same organ. In conclusion, the saccular phase of lung development begins around 57 and 60 days of pregnancy, the period in which surfactant production is believed to occur. Male and female foetuses present similar pulmonary development from early pregnancy until parturition.

Electrophysiological Response to Dialysis: The Role of Dialysate Potassium Content and Profiling

The task of dialysis therapy is, amongst other things, to remove excess potassium (K+) from the body. The need to achieve an adequate K+ removal with the risk of cardiac arrhythmias due to sudden intra-extracellular K+ gradient advises the distribution of the removal throughout the dialysis session instead of just in the first half. The aim of the study was to investigate the electrical behavior of two different K+ removal rates on myocardial cells (risk of arrhythmia and ECG alterations). Constant acetate-free biofiltration (AFB) and profiled K+ (decreasing during the treatment) AFB (AFBK) were used in a patient sample to understand, first of all, the effect on premature ventricular contraction (PVC) and on repolarization indices [QT dispersion (QTd) and principal component analysis (PCA)]. The study was divided into two phases: phase 1 was a pilot study to evaluate K+ kinetics and to test the effect on the electrophysiological response of the two procedures. The second phase was set up as an extended cross-over multicenter trial in patient subsets prone to arrhythmias during dialysis. Phase 1: PVC increased during both AFB and AFBK but less in the latter in the middle of dialysis (298 in AFB vs. 200 in AFBK). The PVC/h in a subset of arrhythmic patients was 404 +/- 145 in AFB and 309 +/- 116 in AFBK (p = 0.0028). QT interval (QTc) prolongation was less pronounced in AFBK than in AFB. Phase 2: The PVC again increased in both AFB and AFBK but less in the latter mid-way through dialysis (79 +/- 19 AFB vs. 53 +/- 13 AFBK). Moreover, in the most arrhythmic patients the benefit accruing from the smooth K+ removal rate was more pronounced (103 +/- 19 in AFB vs. 78 +/- 13 in AFBK).

CONCLUSION

It is not the K+ dialysis removal alone that can be destabilizing from an electrophysiological standpoint, but rather its removal dynamics. This is all the more evident in patients with arrhythmias who benefit from the K+ profiling during their dialysis treatment.

[Acetate free biofiltration (AFB) and ionic dialysance]

Among various methods and models to evaluate the dialysis dose, the on-line measure of ionic dialysance gives good results. Compared to measured KT/V, ionic dialysance does not require blood sampling and, consequently, it reduces the risks and the costs. Functional evaluations during acetate free biofiltration (AFB treatments) confirm the usefulness of the on-line continuous measure by biosensors, especially when they are integrated in the dialysis machinery.

Polychlorinated biphenyls in colostral milk and visual function at 12 months of life

BACKGROUND AND AIMS

Environmental contaminants such as persistent organic chlorines and heavy metals, which are supplied to the foetus by transplacental transfer and to breastfed infants by the milk, may impair cognitive functions. Long-chain polyunsaturated fatty acids, which are known to enhance development during foetal life and early infancy, may counteract the toxic effect of environmental contaminants. In this study, we have investigated whether polychlorinated biphenyls (PCBs) impair early development of vision, and whether such impairment can be modulated by essential long-chain polyunsaturated fatty acids.

MATERIAL

Healthy term infants born in Milan and its surroundings, and who were exclusively breastfed for at least 4 mo, were prospectively examined up to the age of 12 mo.

METHODS

Samples from colostrums, the first 2 d after delivery, and of mature breast-milk after 1 and 3 mo were collected. The samples were analyzed for PCB 105, 118, 138, 153, 156 and 180 and for DDT and DDE. In all infants, the plasma levels of the long-chain polyunsaturated fatty acids (LC-PUFAs), C18:2 n-6, C18:3 n-3, C20:4 n-6, C20:5 n-3 and C22:6 n-3 were analysed within the first three postnatal days. The PCB levels in colostral milk, as well as of LC-PUFAs in plasma, were considered to mirror perinatal supply. Visual function was evaluated by P100 with latency evoked potentials (VEPs) at 12 mo of age. Statistical analysis was based on simple and partial correlation coefficients (p < 0.05).

RESULTS

On bivariate analysis, wave latency VEP at 15 min was significantly related to the colostral levels of DDT, DDE and all examined PCBs except PCB 105 (with correlation coefficient r = 0.401 to 0.618), whereas P100 wave latency VEP at 60 min was related to DDT (r = 0.513) and PCB 180 (r = 0.504). Infant plasma levels of C22:6 n-3 were inversely associated with P100 wave latency at 60 min (r = -0.418) and at 1Hz-2J (r = -0.466). After controlling for C22:6 n-3, the partial correlation coefficient of P100 wave latency VEP at 15 min to the colostral level of PCB 180 was 0.403 (p = 0.07).

CONCLUSION

Within the population of this study, a weak relation was found between impaired visual function at 12 mo of age of healthy infants and the levels of PCBs, DDT and DDE in colostral milk. The effect of impairment was no longer evident after controlling for the plasma level of LC-PUFAs as found in the infant a few days after birth.

Earlier smoking habits are associated with higher serum lipids and lower milk fat and polyunsaturated fatty acid content in the first 6 months of lactation

OBJECTIVE

To investigate the relation between maternal smoking habits, plasma lipids and milk fatty acid (FA) content and composition.

DESIGN

Breastfeeding mothers who gave birth to healthy, full-term infants were recruited. Mothers were interviewed on smoking habits, being defined smokers (S) when usually smoking at least five cigarettes per day before pregnancy.

SETTING

Department of Pediatrics, San Paolo Hospital, Milan, Italy.

SUBJECTS

In total, 92 mothers: 61 non-S (NS) and 31 S.

INTERVENTIONS

Pooled hindmilk was collected at the first raise of milk (colostrum stage), 1, 3 and 6 months, and total lipid (TL) content and fatty acid (FA) composition were evaluated. Maternal dietary habits were assessed by a food-frequency questionnaire. Two subsamples (16 NS, 6 S) were investigated after delivery and at 3 months for serum lipids and FA status. At 6 months after delivery, the number of mothers still breastfeeding decreased to 30. Variables were compared using nonparametric tests.

RESULTS

In smoking mothers serum levels of triglycerides, cholesterol and low-density lipoproteins were higher, while those of high-density lipoproteins were lower. TL content in breast milk was similar in the two groups just after delivery but higher in milk from NS at 1 month. TL content and FA absolute amounts of linoleic, arachidonic, alpha-linolenic and docosahexaenoic (DHA) acid in breast milk were lower in S vs NS 1 month after delivery. Also 3 months after delivery, the breast milk of smoking mothers contained less DHA than the breast milk of nonsmoking mothers.

CONCLUSIONS

Maternal cigarette smoking in early pregnancy is associated with higher plasma lipid levels and lower milk TL and DHA content in the first months of lactation.

Growth pattern of breastfed and nonbreastfed infants with atopic dermatitis in the first year of life

OBJECTIVE

The growth of infants with atopic dermatitis (AD) has been poorly investigated based on the early type of feeding. The aim of this study was to assess the growth pattern of AD infants during the first 12 months of life in comparison to healthy infants, according to the early type of feeding (breastfed or nonbreastfed).

METHODS

Fifty-five term AD infants (36 breastfed and 19 nonbreastfed) and 114 term healthy infants (58 breastfed and 56 nonbreastfed) were evaluated by standardized growth indices (z scores; National Center for Health Statistics-World Health Organization data) through the first 12 months of life.

RESULTS

No difference was found between AD and healthy groups at birth. In AD infants, weight (WA) and length (LA) z scores decreased with age and were significantly lower, compared with healthy infants from the second month of age onward. The difference of mean z scores between AD and healthy infants at 12 months of age was -.69 (95% confidence interval [CI]: -1.00 to -.38) for WA and -.67 (95% CI: -.98 to -.36) for LA. The growth pattern of AD infants was not influenced by the early type of feeding, whereas in the 6- to 12-month period, the delay in growth was more pronounced in patients with more severe dermatitis.

CONCLUSIONS

In the first year of life, AD infants show a progressive impairment in growth irrespective of the early type of feeding. The severity of disease may be an independent factor negatively influencing growth.

Growth patterns of breast fed and formula fed infants in the first 12 months of life: an Italian study

AIM

To compare the growth patterns of breast fed and formula fed Italian infants in the first 12 months of life using World Health Organisation (WHO) reference data.

METHODS

The growth patterns of 73 breast fed infants (36 male, 37 female) and 65 formula fed infants (35 male, 30 female) were compared. Solid foods were introduced with the same weaning schedules from the 5th month in both groups. The weight for age (WA), length for age (LA), and weight for length (WL) z scores (National Center for Health Statistics-WHO data) were calculated at birth, 1, 2, 3, 4, 6, 9, and 12 months.

RESULTS

Breast fed infants had the highest z scores (WA, WL) at birth. Breast fed groups had significantly higher growth indices at 1 month (WA, LA), 2 months (WA) and 3 months (WA, LA) of age. Compared to breast fed groups, formula fed infants showed significantly higher WA z score changes in the 1-2, 2-3, 3-4, and 4-6 month intervals. LA z score changes were higher for breast fed infants at 0-1 month and for the formula fed infants at 4-6 months. In the 6-12 month interval growth indices progressively increased for the formula fed infants and declined for infants breast fed for longer (12 months). The 0-12 month changes in WA, LA, and WL z scores were positive for formula fed infants and negative for the 12 month breast fed group. Nevertheless, the 12 month breast fed group showed an absolute WA z score just below 0 (mean (SEM) -0.04 (0.26)) at 12 months.

CONCLUSION

The growth pattern of breast fed and formula fed Italian infants differs in the first 12 months of life. This questions the validity of current reference values for monitoring the growth of breast fed infants. Growth indices in breast fed groups, high at birth and closer than expected to the reference at 12 months, may reflect differences in genetic factors, intrauterine conditions, or both.

High-order behaviour in learning gate networks with lateral inhibition

In this work we present a neural network model incorporating activity-dependent presynaptic facilitation with multidimensional inputs. The processing unit used is based on a slightly simplified version of the Learning Gate Model proposed by Ciaccia et al. (1992). The network topology integrates a well-known biological neural circuit with a lateral inhibition connection subnet. By means of simulation experiments, we show that the proposed networks exhibit basic and high-order features of associative learning. In particular, overshadowing and blocking are reproduced in the presence of both noise-free and noisy inputs. The role of noise in the development of high-order learning capabilities is also discussed.

Analytic solution of the Variable-Volume Double-Pool urea kinetics model applied to parameter estimation in hemodialysis

An analytic solution of the Variable-Volume Double-Pool urea kinetics model and its application to the estimation of clinically relevant parameters of the patient-machine system, are presented. These include the urea distribution volume and generation rate and the mean dialyzer clearance. The estimation of these parameters is based on the assumption of constant values for the diffusion coefficient between the two pools and the intra-extracellular volume ratio. Results obtained by computer simulations show that the effect of a +/- 50% variation of these parameters influences the estimates less than standard measurement errors. Starting from these results, four methods to in vivo estimate the urea distribution volume and generation rate from blood samples are compared. Two methods are based on the analytic solution of the double-pool model using seven samples (reference method) or three samples (new clinical method). The remaining methods are based on urea mass-balance and are largely used in the clinical practice. These last techniques differ from each other for the blood sample taken at the end of the treatment or 30 min later. The results obtained from hemofiltration sessions show that the urea generation rate is accurately estimated by all methods. The total distribution volume is still accurately estimated by the new clinical method while it is systematically underestimated by the urea mass-balance when the blood sample at the end of dialysis is used. Instead, a high overcompensation results using the blood sample taken 30 min after the end of dialysis. Finally, the new clinical method also provides reliable estimates for the dialyzer clearance starting from only three blood samples all taken during dialysis.

On-line estimation and prediction of urea kinetics during hemodialysis: a simulation approach

A new method for the on-line estimation of urea kinetic parameters from blood urea concentration (BUN) continuously measured during a dialysis session is proposed. The method, based on the variable-volume double-pool model, is evaluated through a simulation approach in order to easily consider a large set of well-controlled test conditions. The model is characterized by six parameters, knowledge of which enables early prediction of the end dialysis urea concentration and the dose of dialysis. The sensitivity of the model predicted BUN with respect to the parameters was first analyzed to investigate which can be reliably estimated from blood urea measurements taken at a suitable rate. This analysis showed that the model predicted BUN is highly sensitive to the initial blood urea concentration and to the dialyzer clearance, normalized with respect to the total initial distribution volume, while it is scarcely influenced by the normalized ultrafiltration and urea generation rates. The new on-line estimation technique keeps these two last parameters constant and takes advantage of an original analytic solution of the second order urea kinetics. The results of the estimation process on realistic simulated data showed that the proposed method provides early and reliable estimates of the normalized clearance and of the end dialysis concentration. The transcellular mass transfer coefficient and the intra-extra cellular volume ratio can also be estimated, although with less accuracy. Moreover, it was shown that the use of the single-pool model, instead of the double-pool one, provides systematic errors on the estimates.

Sensitivity analysis for estimating urea kinetics parameters during hemodialysis

In this paper a time-varying volume, double-pool urea kinetics model is considered and a sensitivity analysis is carried out to determine those patient parameters that have greater influence on the time course of blood urea nitrogen concentration (BUN) during and between dialysis treatment. The model parameters include the urea generation rate, the initial distribution volume of the urea, the ratio between intracellular and extracellular volumes, and the mass transfer coefficient between the two pools. The analysis demonstrates that BUN is highly sensitive to the urea generation rate and total distribution volume whereas it is influenced by the remaining parameters to a much lesser extent. In addition, the location of the absolute maxima of BUN sensitivity functions suggests the rational placement of a reduced number of blood samples that may still allow sufficiently accurate estimates for the parameters of clinical interest, such as the urea generation rate, total distribution volume, and the ratio between intracellular and extracellular volumes. This conclusion has been confirmed by simulation studies where parameter estimation has been performed with a varying number of observation points.

Comparative evaluation of different methods to estimate urea distribution volume and generation rate

Eight methods to estimate urea distribution volume and generation rate from blood urea samples measured in dialysis patients are reviewed. An analytical solution has been provided for a double-pool variable volume kinetic model to allow for faster and more accurate simulation and identification. The reliable parameter estimates provided by the double-pool kinetic model starting from seven samples, were assumed as references for the estimates obtained by the remaining methods. These include three kinetic models and four methods based on urea mass-balance. In particular, the estimation techniques differ in the number of compartments where urea is assumed distributed (double- and single-pool) or in the number of blood urea samples. Among the methods based on mass-balance, two techniques neglecting the weight loss or the urea generation during dialysis, were also analysed. The results obtained during hemofiltration sessions using three samples, usually available in clinical practice at the beginning and at the end of dialysis, demonstrate that a new method based on double-pool kinetics provides, on average, the most reliable estimates. Moreover, methods belonging to a single pool view and including both weight loss and urea generation during dialysis seem to underestimate by 1 divided by 2 liters the urea distribution volume. However, neglecting the weight loss or the urea generation can overcompensate this error, resulting in a significant overestimation of the distribution volume. Finally, it has been experimentally proved that the single-pool kinetic methods overestimate the urea production rate, while techniques based on mass balance provide more reliable values.

Antiepileptic drugs and puberty

This paper investigates pubertal development in 57 epileptic subjects, ranging in age from 6 to 15 years, under anti-epileptic therapy for at least 2 years. The results were compared with those from a control group of healthy volunteers. The onset of stage II puberty was significantly earlier in both male and female treated epileptics than in healthy control subjects: at this stage serum levels of 17-beta-estradiol (E2) were found to be significantly lower in treated epileptic females than in healthy control females and the serum levels of follicle-stimulating hormone (FSH) significantly lower in treated epileptic males than in control subjects. At stage III puberty, serum levels of FSH were significantly lower both in male and female treated epileptic than in healthy control subjects.

Further studies on the effects of pentoxifylline on sperm count and sperm motility in patients with idiopathic oligo-asthenozoospermia

To further investigate the effectiveness of pentoxifylline (trental) treatment in male infertility, we studied 22 young men (mean age 28.4 years) with "idiopathic" oligo-asthenozoospermia treated for 6 months with the drug (1200 mg daily orally). Sperm concentration and sperm motility were determined before therapy, as well as after 3 and 6 months of pentoxifylline administration. Moreover, fructose concentrations in seminal fluid and sperm ATP levels were assayed before and at the end of the treatment in five semen samples. Pentoxifylline therapy significantly increased both sperm concentration and sperm motility. Sperm concentration showed a 1.5-fold increase (p less than 0.01) at the 3rd month of therapy, and a 2.0-fold increase (p less than 0.001) at the 6th month, whereas sperm motility increased by 1.8-fold (p less than 0.001) and by 2.8-fold (p less than 0.001) respectively. At the end of the treatment, fructose concentrations in seminal fluid were significantly higher (p less than 0.001) than pretreatment values; in contrast, sperm ATP levels showed a significant (p less than 0.05) fall. These results suggest that pentoxifylline, probably acting on the cAMP metabolism, may be an useful drug in the treatment of idiopathic oligo-asthenozoospermia.

[Aerosol administration in antibiotic therapy of cystic fibrosis]

The aim of this research was to evaluate the response to aerosol antibiotic therapy in Cystic Fibrosis (CF) patients, who because of severe lung disease, were obligated to frequent hospitalizations to undergo intravenous antibiotic therapy. Ten patients, aged 2 to 20 years were submitted to 4 months cycles of aerosol antibiotic therapy for a total of 18 cycles. The daily treatment consisted of carbenicillin 1 g b.d. and gentamicin 80 mgs b.d. At the end of treatment there was a statistically significant improvement of the modified Huang score and of single clinical parameters such as body growth, apetite, physical activity, clinical thoracic evaluation, appearance of sputum. Almost all of the radiographic items remained unchanged: in only 4 cases there was an improvement of the atelectasis-broncopneumonia type lesions. Regarding lung function, there was a statistically significant increase of maximum midexpiratory flow rate (MMEF) from 40% predicted before treatment to 50% predicted after. The reduction of residual volume (RV) from 270% predicted before 170% predicted after treatment was quantitatively more important. Furthermore, the treatment brought about a drastic reduction in number of hospitalizations: from an average of 1,7 hospitalizations/year before to an average of 0,3 hospitalizations/year during treatment. The increased number of isolations of isolations of candida albicans is the only report which favors possible adverse effects, in particular the possibility that this type of treatment favors lung mycosis.