Minimally invasive surgery for pediatric dumbbell neuroblastoma: systematic literature review and report of a single-stage neurosurgical and thoracoscopic approach

INTRODUCTION

Traditional surgical strategies for dumbbell neuroblastoma entail, among others, high risk of spinal deformity. Less invasive procedures might reduce these sequelae, however, there is small evidence comparing different strategies. Indications of minimally invasive surgery in neuroblastoma are still developing. Our aim is to identify and analyze different surgical approaches described in the recent literature and to suggest a minimally invasive option.

METHODS

A systematic review of the literature was conducted in PubMed (Jan 2000-Dec 2021) to identify reports describing surgical resection of dumbbell neuroblastoma in children, according to the PRISMA guidelines. Only full-text articles were included.

RESULTS

7 articles met the inclusion criteria which, added to the present case, represent a total of 43 patients. All were retrospective studies, most of them small series. Tumor location was mostly thoracic. Most of combined approaches were performed in two stages. Spinal deformity after surgery was reported in 3 patients. Minimally invasive approach was described in only one paper, with no reported cases of its use in a single-stage combined surgery. We also report, to our knowledge, the first single-stage posterior neurosurgical approach combined with thoracoscopy for resection of a dumbbell neuroblastoma in an infant.

CONCLUSION

Surgical resection of dumbbell neuroblastomas is challenging. There is no consensus on best surgical approach. Dumbbell tumors should not be considered a contraindication for minimally invasive surgery. A single stage and minimally invasive strategy is proposed.

Melatonin expression in periodontitis and obesity: An experimental in-vivo investigation

BACKGROUND AND OBJECTIVE

Melatonin deficiency has been associated with obesity and systemic inflammation. This study aims to evaluate whether melatonin could interfere with the mechanisms of co-morbidity linking obesity and periodontitis.

MATERIAL AND METHODS

Twenty-eight male Wistar rats were randomly divided in 4 groups: control group (Con) (fed with standard diet); high-fat diet group (HFD) (fed with a diet containing 35.2% fat); Con group with induced periodontitis (Con-Perio) and HFD group with induced periodontitis (HFD-Perio). To induce periodontitis, the method of oral gavages with Porphyromonas gingivalis ATCC W83K1 and Fusobacterium nucleatum DMSZ 20482 was used. Circulating melatonin levels were analyzed by multiplex immunoassays. Periodontitis was assessed by alveolar bone loss (micro-computed tomography and histology) and by surrogate inflammatory outcomes (periodontal pocket depth, modified gingival index and plaque dental index).

RESULTS

Plasma melatonin levels were significantly decreased (P < .05) in the obese rats with periodontitis when compared with controls or with either obese or periodontitis rats. Alveolar bone loss increased 27.71% (2.28 µm) in HFD-Perio group compared with the Con group. The histological analysis showed marked periodontal tissue destruction with osteoclast activity, particularly in the HFD-Perio group. A significant negative correlation (P < .05) was found between periodontal pocket depth, modified gingival index and circulating melatonin levels.

CONCLUSION

Obese and periodontitis demonstrated significantly lower melatonin concentrations when compared with controls, but in obese rats with periodontitis these concentrations were even significantly lower when compared with either periodontitis or obese rats. These results may indicate that melatonin deficiency could be a key mechanism explaining the co-morbidity effect in the association between obesity and periodontitis.

3D-Printed PCL/PLA Composite Stents: Towards a New Solution to Cardiovascular Problems

Biodegradable stents (BRS) offer enormous potential but first they must meet five specific requirements: (i) their manufacturing process must be precise; (ii) degradation should have minimal toxicity; (iii) the rate of degradation should match the recovery rate of vascular tissue; (iv) ideally, they should induce rapid endothelialization to restore the functions of vascular tissue, but at the same time reduce the risk of restenosis; and (v) their mechanical behavior should comply with medical requirements, namely, the flexibility required to facilitate placement but also sufficient radial rigidity to support the vessel. Although the first three requirements have been comprehensively studied, the last two have been overlooked. One possible way of addressing these issues would be to fabricate composite stents using materials that have different mechanical, biological, or medical properties, for instance, Polylactide Acid (PLA) or Polycaprolactone (PCL). However, fashioning such stents using the traditional stent manufacturing process known as laser cutting would be impossible. Our work, therefore, aims to produce PCL/PLA composite stents using a novel 3D tubular printer based on Fused Deposition Modelling (FDM). The cell geometry (shape and area) and the materials (PCL and PLA) of the stents were analyzed and correlated with 3T3 cell proliferation, degradation rates, dynamic mechanical and radial expansion tests to determine the best parameters for a stent that will satisfy the five strict BRS requirements. Results proved that the 3D-printing process was highly suitable for producing composite stents (approximately 85⁻95% accuracy). Both PCL and PLA demonstrated their biocompatibility with PCL stents presenting an average cell proliferation of 12.46% and PLA 8.28% after only 3 days. Furthermore, the PCL/PLA composite stents demonstrated their potential in degradation, dynamic mechanical and expansion tests. Moreover, and regardless of the order of the layers, the composite stents showed (virtually) medium levels of degradation rates and mechanical modulus. Radially, they exhibited the virtues of PCL in the expansion step (elasticity) and those of PLA in the recoil step (rigidity). Results have clearly demonstrated that composite PCL/PLA stents are a highly promising solution to fulfilling the rigorous BRS requirements.

Common and well-documented HLA alleles: 2012 update to the CWD catalogue

We have updated the catalogue of common and well-documented (CWD) human leukocyte antigen (HLA) alleles to reflect current understanding of the prevalence of specific allele sequences. The original CWD catalogue designated 721 alleles at the HLA-A, -B, -C, -DRB1, -DRB3/4/5, -DQA1, -DQB1, and -DPB1 loci in IMGT (IMmunoGeneTics)/HLA Database release 2.15.0 as being CWD. The updated CWD catalogue designates 1122 alleles at the HLA-A, -B, -C, -DRB1, -DRB3/4/5, -DQA1, -DQB1, -DPA1 and -DPB1 loci as being CWD, and represents 14.3% of the HLA alleles in IMGT/HLA Database release 3.9.0. In particular, we identified 415 of these alleles as being 'common' (having known frequencies) and 707 as being 'well-documented' on the basis of ~140,000 sequence-based typing observations and available HLA haplotype data. Using these allele prevalence data, we have also assigned CWD status to specific G and P designations. We identified 147/151 G groups and 290/415 P groups as being CWD. The CWD catalogue will be updated on a regular basis moving forward, and will incorporate changes to the IMGT/HLA Database as well as empirical data from the histocompatibility and immunogenetics community. This version 2.0.0 of the CWD catalogue is available online at cwd.immunogenomics.org, and will be integrated into the Allele Frequencies Net Database, the IMGT/HLA Database and National Marrow Donor Program's bioinformatics web pages.

[Posthemorrhagic hydrocephalus in the preterm infant: current evidence in diagnosis and treatment]

Intraventricular haemorrhage and posthemorrhagic hydrocephalus are the most important neurological complications in preterm infants during the neonatal period. The prevalence of germinal matrix intraventricular haemorrhage widely varies depending on the population of study, but it is in any case increasing due both to the higher incidence of multiple and preterm deliveries as well as the longer survival of preterm infants favoured by recent advances in perinatal care. It is therefore of the utmost convenience to be familiar with the most important clinical evidence regarding this entity. However, the available evidence is often incomplete and piecemeal. The objective of the present review is to summarise the main diagnostic and therapeutic points regarding preterm related posthemorrhagic hydrocephalus. The participants of the working-group in Pediatric Neurosurgery of the Spanish Society of Neurosurgery were asked to write these recommendations down. This hopefully represents the first step towards the definition of a clinical guide in the treatment of complications related to periventricular hemorrhage of the preterm infants.

Community structures and role detection in music networks

We analyze the existence of community structures in two different social networks using data obtained from similarity and collaborative features between musical artists. Our analysis reveals some characteristic organizational patterns and provides information about the driving forces behind the growth of the networks. In the similarity network, we find a strong correlation between clusters of artists and musical genres. On the other hand, the collaboration network shows two different kinds of communities: rather small structures related to music bands and geographic zones, and much bigger communities built upon collaborative clusters with a high number of participants related through the period the artists were active. Finally, we detect the leading artists inside their corresponding communities and analyze their roles in the network by looking at a few topological properties of the nodes.

Disorder and decision cost in spatial networks

We introduce the concept of decision cost of a spatial graph, which measures the disorder of a given network taking into account not only the connections between nodes but their position in a two-dimensional map. The influence of the network size is evaluated and we show that normalization of the decision cost allows us to compare the degree of disorder of networks of different sizes. Under this framework, we measure the disorder of the connections between airports of two different countries and obtain some conclusions about which of them is more disordered. The introduced concepts (decision cost and disorder of spatial networks) can easily be extended to Euclidean networks of higher dimensions, and also to networks whose nodes have a certain fitness property (i.e., one-dimensional).

DRB1*1613N: a novel DRB1 allele with a premature termination codon

DRB1 null alleles are extremely rare and always sporadic, suggesting their biological selective disadvantage.

Oestrus synchronisation of rabbit does at early post-partum by doe–litter separation or ECG injection: Reproductive parameters and endocrine profiles

Inseminating rabbit does at early post-partum, in combination with early weaning, can increase prolificacy (total kits born and still born per parturition) and decrease parturition intervals. Oestrus synchronisation increases fertility and prolificacy, while decreasing the number of inseminations required for gestation. However, little is known about the effectiveness of different oestrus synchronisation methods at early post-partum. In this study, does (n = 138) were artificially inseminated nine times (over a period of 1 year, kits weaned at 25 days), on day 4 post-partum after separation from the litter (for 48 or 24 h) or 48 h after 25 UI eCG injection. Plasma levels of prolactin and estradiol were also evaluated in a subsample of 12 multiparous lactating does per treatment, on days 2, 3 and 4 post-partum. The three treatments increased overall fertility of multiparous females compared to controls (which were not synchronised), but there were no differences among treatments in total kits born or stillborn. Does treated with eCG had a higher culling rate. The interval between parturitions and the number of inseminations required for gestation tended to decrease with increasing number of inseminations. In lactating does, there was an interaction between treatment and insemination order. Fertility decreased with increasing inseminations in eCG does but tended to increase above control values in the separated does until the fourth insemination. Control lactating does had significantly less kits per parturition compared to treatments, but eCG lactating does had more stillborn kits. Oestradiol levels increased on day 4 post-partum in all synchronised lactating does (and immediately before artificial insemination in 48 h doe-litter separation), so ovarian activity could be stimulated at early post-partum using all treatments. However, the increase could not be explained by prolactin levels, since there were no effects of suckling absence on plasma prolactin in separated does. In conclusion, separating does from the litter before insemination can be just as effective as eCG treatment, especially during for the first four inseminations.

Circadian rhythms of prolactin secretion in neonatal female rabbits after acute separation from their mothers

Newborn rabbits (Oryctolagus cuniculus) are only nursed for 3-5 min every 24 h and show a circadian increase in activity in anticipation of nursing. The objective of this study was to determine, in neonatal female rabbits after acute separation from the doe for 48 h, the changes in 24-h rhythms of plasma prolactin and median eminence and anterior pituitary concentration of dopamine (DA) and serotonin (5HT). In addition, median eminence concentration of the excitatory amino acid transmitters glutamate (GLU) and aspartate (ASP) and of the inhibitory amino acid transmitters gamma-aminobutyric acid (GABA) and taurine (TAU) was measured. A significant 21% increase of circulating prolactin occurred in isolated pups. In controls pups, plasma prolactin levels showed two peaks, during the first half of the light phase and at the beginning of the scotophase, respectively. In the isolated pups, a phase advance of about 4 h occurred for the two prolactin peaks. Hemicircadian changes of median eminence DA were found in controls, whereas a single daily peak (at 17:00 h) was found in the separated pups. Plasma prolactin and median eminence DA correlated significantly and inversely in the control group only. Pituitary DA content exhibited a single peak in controls and a hemicircadian pattern in isolated pups. Plasma prolactin and pituitary DA correlated significantly in isolated pups only 00000. Pup isolation decreased median eminence 5HT levels, augmented pituitary 5HT levels and disrupted their 24 h rhythmicity. Circulating prolactin correlated inversely with median eminence 5HT and directly with adenohypophysial 5HT only in controls. Isolation of pups generally modified the 24 h pattern of median eminence excitatory and inhibitory amino acid content by causing a prominent decrease at the beginning of the light phase. The results indicate that circadian rhythmicity of prolactin secretory mechanisms in female rabbit pups is significantly affected by pup's isolation from the doe.

Prediction of liver fibrosis in human immunodeficiency virus/hepatitis C virus coinfected patients by simple non-invasive indexes

BACKGROUND

Liver biopsy is an invasive technique with associated major complications. There is no information on the validity of five non-invasive indexes based on routinely available parameters, estimated and validated in hepatitis C virus (HCV) monoinfected patients, in human immunodeficiency virus (HIV)/HCV coinfected patients.

AIM

To validate these predictive models of liver fibrosis in HIV/HCV coinfected patients.

PATIENTS

A total of 357 (90%) of 398 patients from five hospitals were investigated, who underwent liver biopsy and who had complete data to validate all of the models considered.

METHODS

The predictive accuracy of the indexes was tested by measuring areas under the receiver operating characteristic curves. Diagnostic accuracy was calculated by estimating sensitivity, specificity, and positive (PPV) and negative (NPV) predictive values.

RESULTS

The models performed better when liver biopsies>or=15 mm were used as reference. In this setting, the Forns and Wai indexes, models aimed at discriminating significant fibrosis, showed PPV of 94% and 87%, respectively. Using these models, 27-34% of patients could benefit from exclusion of liver biopsy. If both models were applied sequentially, 41% of liver biopsies could be spared. The indexes aimed at predicting cirrhosis achieved NPV of up to 100%. However, they showed very low PPV.

CONCLUSIONS

The diagnostic accuracy of these models was lower in HIV/HCV coinfected patients than in the validation studies performed in HCV monoinfected patients. However, simple fibrosis tests may render liver biopsy unnecessary in deciding anti-HCV treatment in over one third of patients with HIV infection and chronic hepatitis C.

Determinants of neurosurgical outcome in pituitary tumors

OBJECTIVE

Neurosurgery is one of the main therapies for pituitary tumors; optimising outcome is highly desirable for the patient and the health system. We have analysed predictors of outcome in surgically treated pituitary adenomas operated in this centre.

DESIGN AND PATIENTS

A total of 289 patients underwent neurosurgery for a pituitary tumor, by the same two neurosurgeons, between 1982 and 2001. Their records were examined to find predictors of post-surgical outcome. Thirty-eight percent were males, with a median age of 40.8 (8-82.7) yr; 51.9% had been operated since 1992, 92.2% by the transsphenoidal route. Most tumors (70.2%) were macroadenomas; 28.4% were non-functioning, 27.3% secreted PRL, 26.3% GH of which 14 (4.8%) also secreted PRL, 17.3% ACTH, 0.3% FSH and 0.3% TSH.

RESULTS

A stepwise, forward logistic regression analysis revealed tumor size as the only significant predictor of radiological cure [odds ratio (OR) for macroadenoma 0.16 vs microadenoma, p=0.0005]. Hormonally, PRL-secretion by the tumor was a predictor of poor prognosis (OR 3.29 for cure of non-PRL-secreting tumors, p=0.005), as was tumor size (OR 0.45 for cure of macroadenomas, p=0.005). Considering simultaneous radiological and hormonal remission, tumor size (OR 0.35 for macroadenoma, p=0.0002), and operation date (OR 0.40 for up to 1991, p=0.0002) were the only significant predictors.

CONCLUSIONS

PRL secretion, tumor size and operation date are the main predictors of neurosurgical outcome in pituitary tumors, the latter suggesting that neurosurgical experience plays an important role.

Experimental allergic encephalomyelitis in male Lewis rats subjected to calorie restriction

This work analyzes the effect of calorie restriction on the development of experimental allergic encephalomyelitis (EAE) in Lewis rats. Plasma levels of ACTH, corticosterone, prolactin and growth hormone (GH) and mitogenic responses in submaxillary lymph nodes were measured. Male Lewis rats (6 weeks-old) were submitted to a calorie restriction equivalent to 66% of food restriction or to a normal diet. Fifteen days later, rats were injected with complete Freund's adjuvant plus spinal chord homogenate (SCH) or with complete Freund's adjuvant alone. Rats were monitored daily for clinical signs of EAE and were killed on day 15 after immunization. Only rats subjected to normal diet exhibited clinical signs of the disease. The increase in plasma ACTH and corticosterone found after SCH immunization in controls was not detectable in calorie restricted rats. Likewise, the correlation between circulating ACTH and corticosterone was no longer found after calorie restriction. Generally, calorie restriction by itself augmented plasma ACTH or corticosterone and this increase was not further amplified by SCH immunization. Only calorie restricted rats exhibited augmented plasma prolactin levels after SCH immunization, and decreased plasma GH levels regardless of immunization. Calorie restriction depressed the mitogenic response of lymphoid cells to concanavalin A but not to lipopolysaccharide. Calorie restricted rats did not exhibit augmented mitogenic response to concanavalin A following SCH immunization as those found in controls. The results are compatible with the view that the course of EAE can be significantly modified by caloric restriction.

[Intraoperative neurophysiological monitoring of brain stem in a case of cavernoma in the pons]

Neurophysiological monitoring during surgery to avoid damaging of eloquent brain areas is a useful tool. We are performing intraoperative neurophysiological test to locate motor, sensitive and speech areas with cortical stimulation and cranial nerves during cerebellopontine cranial base surgery. Neurophysiological monitoring during brain stem surgery has been less described. Brain stem surgery implies a careful selection of patients for surgery given the high risk of morbidity and mortality. For this reason, conservative treatment is usually indicated when an asymptomatic cavernoma is incidentally found. Instead, when bleeding or neurological deficit appear, operative treatment may be indicated and then the goal of surgery is to avoid the disability linked to the natural history. We present the case of a 29 year old woman with diagnosis of multiple cavernomas. She was admitted at our hospital because she presented weakness and sensitive disturbance of left limbs and dizziness. The CT scan and MRI showed a pontine haemorrhage caused by a cavernous hemangioma. We operated her on using neurophysiological monitoring of VII, VIII, X and XII cranial nerves with electromyographic recordings. Postoperative disability could be reduced with a better knowledge of entry zone into the brain stem and early physiotherapy.

Pentadiene production from potassium sorbate by osmotolerant yeasts

Some yeast strains belonging to the species Zygosaccharomyces rouxii and Debaryomyces hansenii are capable of spoiling sorbate containing high-sugar foods by producing pentadiene, a volatile compound reported to have 'petroleum-like' odour. Quantification of the diminution of sorbate and the subsequent increase of pentadiene was performed by growing the yeasts in experimental media containing 600 g/l sucrose and different sorbate concentrations. Final sorbate concentrations were notably lower than their corresponding initial ones, and it was found that the higher the initial concentration of sorbate in the media, the higher the amount of pentadiene produced. In all cases, Z. rouxii was able to produce more pentadiene than D. hansenii when expressing pentadiene concentration as a function of cell biomass. These results suggest that pentadiene is a metabolite of sorbate.

Superior cervical ganglionectomy differentially modifies median eminence and anterior and mediobasal hypothalamic GABA content in male rats: effects of hyperprolactinemia

This work was undertaken to analyze the changes in GABA concentrations in the anterior and mediobasal hypothalamus and in the median eminence after acute or chronic superior cervical ganglionectomy (SCGx), and whether high prolactin levels interfere with the effects of SCGx on GABA content. Acute but not chronic SCGx increased GABA content in all the areas studied, as compared to controls. The presence of a pituitary graft abolished the effects of acute SCGx in the median eminence and anterior hypothalamus, as compared to controls, but potentiated its effects in the mediobasal hypothalamus. Chronic SCGx increased GABA content in the mediobasal and anterior hypothalami, as compared to pituitary grafted controls. Acute SCGx decreased plasma prolactin and GH levels, but chronic surgery did not modify these hormone plasma levels. Acute SCGx increased plasma ACTH levels, whereas chronic SCGx did not modify them. Pituitary grafting increased circulating values of prolactin, ACTH and GH, as compared to controls. Acute SCGx did not modify plasma prolactin levels in grafted animals, although it increased plasma GH levels and decreased those of ACTH in this experimental group. Chronic SCGx further increased both plasma prolactin and GH levels, without modifying plasma ACTH levels. These results suggest that SCGx differentially modifies GABA content within the hypothalamus and median eminence. Induction of hyperprolactinemia in the neonatal age interferes with SCGx effects on both GABA content within the hypothalamus and median eminence and the secretory patterns of the pituitary hormones studied.

Cadmium exposure differentially modifies the circadian patterns of norepinephrine at the median eminence and plasma LH, FSH and testosterone levels

This work was designed to analyze the cadmium effects on time-of-day variations of norepinephrine (NE) content in median eminence and on plasma levels of luteinizing hormone (LH), follicle stimulating hormone (FSH) and testosterone in adult male rats. Rats were given cadmium at a dose of 25 ppm of cadmium chloride (CdCl(2)) in the drinking water for 1 month. Significant 24-h changes of NE content in the median eminence, plasma LH and testosterone levels occurred in control animals. Cadmium exposure induced a phase advance of the nocturnal peak of NE content that was described in the control group, to 12h and increased its amplitude. However, the mean NE content was not changed by cadmium. Metal exposure abolished the daily pattern of plasma LH levels, although the mean levels of the hormone were not modified by cadmium. For testosterone, the metal increased the amplitude of its nocturnal peak and induced the appearance of another peak during the light phase at 12h, thus increasing the mean plasma levels of this hormone. An interaction between the metal and time for NE and plasma testosterone levels was observed. These data suggest that cadmium exerts differential effects at the median eminence, the pituitary and the testes, that may explain the changes in the 24-h pattern of plasma testosterone levels.

Changes of prolactin regulatory mechanisms in aging: 24-h rhythms of serum prolactin and median eminence and adenohypophysial concentration of dopamine, serotonin, (γ-aminobutyric acid, taurine and somatostatin in young and aged rats

Twenty-four hour rhythmicity of serum prolactin and median eminence and anterior pituitary content of dopamine (DA), serotonin (5HT), gamma-aminobutyric acid (GABA), taurine and somatostatin were examined in 2 months-old and 18-20 months-old Wistar male rats. The concentration of prolactin was higher in aged rats, with peaks in both groups of rats at the early phase of the activity span. Median eminence DA content of young rats attained its maximum at the middle of rest span and decreased as prolactin levels augmented while the lowest values of adenohypophysial DA were observed at the time of prolactin peak. DA rhythmicity disappeared in aged rats. GABA content of median eminence and adenohypophysis was lower in aged rats, with maximal values of median eminence GABA at light-dark transition in young rats and at the second half of activity span in aged rats. Serum prolactin correlated positively with median eminence GABA in young rats and negatively with pituitary GABA in young and aged rats. Median eminence somatostatin peaked at the beginning of the activity phase (young rats) or at the end of the rest phase (aged rats). Prolactin levels and somatostatin content correlated significantly in young rats only. Median eminence and pituitary 5HT and taurine content did not change with age. The results indicate disruption of prolactin regulatory mechanisms with aging in rats.

Superior cervical ganglionectomy effects on median eminence and anterior and mediobasal hypothalamic taurine content in male rats: effects of hyperprolactinemia

The neuroendocrine sequelae of acute or chronic superior cervical ganglionectomy in control or pituitary-grafted rats were studied by analyzing both plasma prolactin, growth hormone (GH) and ACTH levels, and taurine (TAU) content in the hypophysiotropic area of the hypothalamus or the median eminence. As expected, after either acute or chronic ganglionectomy, norepinephrine (NE) content decreased in the brain areas studied, although the values remained higher in hyperprolactinemic rats. TAU content was differentially modified by acute vs. chronic surgeries, thus indicating the possible existence of hypothalamic interactions between TAU and NE to regulate pituitary hormone secretion. Indeed, associated differential changes in plasma prolactin, GH and ACTH levels may be due to the observed TAU changes. As expected, pituitary grafting increased plasma prolactin, GH and ACTH levels, so that the presence of a pituitary graft differentially interferes with the effects of either surgery not only on TAU content but also on the plasma levels of the hormone studied. Globally, ongoing studies confirm the differential effects of acute and chronic superior cervical ganglionectomy on plasma prolactin, GH and ACTH levels, and provide new evidence about its effects on TAU content in the hypophysiotropic area of the hypothalamus and the median eminence that may partially explain the changes observed in the pituitary hormones studied.

Chronobiological features of the immune system. Effect of calorie restriction

The circadian organization of living organisms is fully established being a key component the activity of the neuro-endocrin-immune system that maintains the homeostasis. Secondary lymph organs, such as submaxillary lymph nodes and spleen, have been shown to exhibit a 24 h variation in blastogenic proliferative capacity and distribution of B and T subsets, with specific achrophases depending on the parameter studied or the lymphoid organ considered. However, less is known about the thymus. The immune system has been shown to change by calorie restriction, although no information is available about possible effects in 24 h variations. Similar questions can be posed for the neuro-endocrine system. As an example, some data are shown in this article about the effects of calorie restriction on the neuro-endocrin-immune system in growing male Wistar rats. Calorie restriction blunted the circadian secretory pattern of TSH observed in the control group that was characterized by the existence of two peaks at 17:00 or 01:00 h and that explained the low basal metabolic rate of these animals under this experimental condition. Concerning the immune system, the thymus gland exhibited 24 h variations in T, B and immature cells in both control and calorie-restricted male rats, thus confirming the circadian organization of the immune system. Moreover this circadian organization was changed by calorie restriction.

Changes in substance P content at the hypothalamic-pituitary axis during the Wallerian degeneration of peripheral sympathetic neurons after superior cervical ganglionectomy in male rats: effect of hyperprolactinemia

The effects of Wallerian degeneration of the peripheral sympathetic neurons projecting to the hypothalamus on the mechanism of interaction between prolactin and substance P (SP) were examined. The effects of superior cervical ganglionectomy (SCGx) on SP content in various hypothalamic regions and in the hypophysis were evaluated in control and hyperprolactinemic rats. Male rats that received pituitary transplants at the age of 5 days and age-matched sham-operated controls were used. Pituitary grafting significantly increased circulating values of prolactin, as did SCGx. In hyperprolactinemic rats, SCGx partially decreased plasma prolactin levels. Neonatal hyperprolactinemia decreased SP content in the anterior (AH) and posterior (PH) hypothalamus and in the median eminence (ME), but increased it in the mediobasal hypothalamus (MBH). Acute SCGx significantly increased SP in the MBH, PH, and ME. SCGx in hyperprolactinemic animals further increased SP content in MBH. In the ME and Ah, SCGx in pituitary grafted rats decreased SP content as compared with the controls. In the pituitary gland (PG), SCGx only decreased SP content in hyperprolactinemic, but not in control rats. An interaction between peripheral nor-adrenergic neurons and prolactin to regulate SP within the hypothalamus was positive in the MBH, AH, ME, and PG, but not in the PH. These data indicate the existence of interactive mechanisms between prolactin and the peripheral sympathetic neurons to regulate SP content at the hypothalamic-pituitary axis. Interrelationships between prolactin and SP were also observed.

Low-income minority women at risk for cervical cancer: a process to improve adherence to follow-up recommendations

OBJECTIVE

The Houston Department of Health and Human Services (HDHHS) has a centralized process for notifying and setting up follow-up appointments for women with abnormal Pap smears who are clients of HDHHS health centers. Faculty and a student from the University of Texas School of Public Health and HDHHS personnel jointly conducted a study to evaluate the process and performance of the system.

METHODS

The study examined two subpopulations: women with atypical squamous cells of undetermined significance or low-grade squamous intraepithelial lesions (ASCUS/LGSIL) and women with high-grade squamous intraepithelial lesions or atypical glandular cells of undetermined significance (HGSIL/AGCUS). A retrospective study was conducted of data on women attending eight HDHHS clinics during the period from February 1996 through August 2000. Records of 1,216 women referred for evaluation of abnormal Pap smears were reviewed. Process effectiveness was measured by the number of successful contacts made and the number of appointments set up. Performance was measured by compliance with referral appointments. Predictors included race/ethnicity, age, co-existence of a sexually transmitted disease, number of prior referrals, type of patient visit, and health center attended.

RESULTS

HDHHS staff successfully notified 95.6% of women with ASCUS/LGSIL and 97.9% of women with HGSIL/AGCUS. Using performance criteria as outcome measures, high-risk women requiring targeted interventions were identified. Overall, 84.2% of women scheduled appointments. Among those with ASCUS/LGSIL, women identified as African American were 53% less likely to accept an appointment and 45% less likely to show up for the appointment than those identified as Hispanic or "other." Age and type of patient visit appeared to be significantly associated with patient compliance behavior.

CONCLUSION

The study describes the effectiveness of a centralized patient follow-up process for women at risk for cervical cancer.

Differential effect of interferon-gamma injection on mitogenic responses in sympathetically denervated submaxillary lymph nodes of rats

This study aimed to assess the effect of interferon (IFN)-gamma treatment on mitogenic responses in submaxillary lymph nodes in the presence or absence of local sympathetic nerves. Adult male rats were subjected to a unilateral superior cervical ganglionectomy and to a contralateral sham-operation. Seven days later, rats received five i.p. daily injections of human IFN-gamma (10(5) U.I./kg) or saline. On the day after the last injection, rats were killed at six different times throughout a 24-h cycle and the mitogenic effect of lipopolysaccharide (LPS) and concanavalin A (Con A) was assessed in single-cell suspensions of lymph nodes. In vehicle-treated rats, proliferation responses to LPS in innervated lymph nodes did not show time-of-day variations while those in denervated lymph nodes attained a maximum at 17:00 h. Following IFN-gamma administration, a promoting effect of LPS mitotic response was detected at 01:00 h at the innervated side only. As far as the mitogenic responses to Con A, proliferation in innervated lymph nodes of vehicle-treated controls attained a maximum at 09:00 h. Such a daily variation in response to Con A was not detectable at the denervated side. IFN-gamma treatment increased significantly Con A activity by promoting a greater mitogenic response at 01:00 h. Sympathetic denervation of lymph nodes brought about a shift in the maximum in number of cells per mg of lymph node from 21:00 to 13:00 h. After IFN-gamma treatment, maxima in cell number occurred at 05:00 h at both the innervated and denervated side. The results indicate that IFN-gamma effects in rat submaxillary lymph nodes are under substantial modulation by local sympathetic nerves.

Stimulation of interleukin-1 and -6 production in alveolar macrophages by the neotropical liana, Uncaria tomentosa (uña de gato)

Two extracts of different collections of the traditional medicine uña de gato (Uncaria tomentosa) from Peru were characterized by High Pressure Liquid Chromatography as containing approximately 6 mg/g total oxindole content prior to studies with alveolar macrophages. The plant preparations greatly stimulated IL-1 and IL-6 production by rat macrophages in a dose dependent manner in the range of 0.025-0.1 mg/ml. They were also able to enhance IL-1 and -6 in lipopolysaccharide-stimulated macrophages. The results suggest a strong immunostimulant action of this plant.

A geometric study of the amino acid sequence of class I HLA molecules

HLA class I alleles are studied by representing them in a metric space where each dimension corresponds to each one of the amino acid positions. Their similarity in reference to their ability to present peptides to T cells is then evaluated by calculating the correlation matrix between the amino-acid-composition tables (or binding affinity tables) for the sets of peptides presented by each allele. This correlation matrix is considered an empirical similarity matrix between HLA alleles, and is modeled in terms of possible structures defined in the metric space of HLA class I amino acid sequences. These geometric structures are adequate models of the peptide-binding data currently available. The following clusters of HLA class I molecules are identified in reference to their ability to present peptides: Cluster I) HLA-A3/ HLA-A11/ HLA-A31/ HLA-A33/ HLA-A68; Cluster II) HLA-B35/ HLA-B51/ HLA-B53/ HLA-B54/ HLA-B7; and Cluster III) HLA-A29/ HLA-B61/HLA-B44; the last cluster showing possible similarities between alleles from different loci. In modeling these natural clusters, the geometric structures with more predictive power confirm the importance of those positions in the peptide-binding groove, particularly those in the B pocket. In addition, other positions (46, 79, 113, 131, 144, and 177) appeared to bear some relevance in determining which peptides can be presented by which HLA alleles.

A phase I trial of high-dose paclitaxel, cyclophosphamide and mitoxantrone with autologous blood stem cell support for the treatment of metastatic breast cancer

The aim of this phase I study was to determine the dose limiting toxicity (DLT), maximum tolerated dose (MTD) and efficacy of a new combination of cyclophosphamide (6 g/m2), mitoxantrone (70 mg/m2), with dose escalation of paclitaxel (TaxolR) at a starting dose of 250 mg/m2 given intravenously over 3 h in a transplantation setting. Patients with metastatic breast cancer and chemosensitive disease were eligible. The autologous blood stem cell re-infusion and subsequent recovery occurred in an out-patient setting. 50 patients were enrolled, but 10 withdrew. 40 completed the entire protocol. At 400 mg/m2 paclitaxel administered over 3 h, 3 of 6 patients experienced serious adverse events: approximately 20-40 min after completion of infusion, diaphoresis, bradycardia mild hypotension and diarrhoea occurred; 2 patients lost consciousness for a few minutes. An extended infusion schedule delivering 400 mg/m2 paclitaxel over 6 h rather than 3 h was initiated at this level without patients experiencing this DLT. At the next dose of 450 mg/m2 paclitaxel over 6 h, the same DLT was seen as at 400 mg/m2 paclitaxel over 3 h and, therefore, MTD was reached. Time to recovery for the absolute neutrophil count > or = 0.5 x 10(9)/l was 10-19 days (median 12 days); and for platelets > or = 20 x 10(9)/l was 18-20 days (median 11.5 days). 21 patients developed neutropenic fever that required intravenous antibiotics and re-admission; the transfusion frequency for packed red blood cell was 0-5 units (median 2 units) and for platelets, 1-5 encounters (median 2). 13 complete responses, 1 patient with no evidence of disease and 19 partial remissions were documented. The dose of 400 mg/m2 at an infusion rate of 6 h will be used for the ongoing phase II study to evaluate efficacy and toxicity further.

An epidemiological study of rheumatoid arthritis in a northern Ontario clinical practice: the role of ethnicity

This study was designed to investigate differences between cultural groupings in rheumatoid arthritis (RA). The sample was made up of 235 individuals suffering from RA from four groupings: Canadian aboriginals, Finnish Canadians, Italian Canadians and other caucasian Canadians. The study was a retrospective chart analysis (non-randomly selected) designed to compare ethnic groupings on the following dimensions: demographic factors, clinical manifestations of RA, laboratory results, and drug therapy response. Results of the study support to some extent findings from previous research. Specifically, the following was found. The study showed a female to male predominance in sufferers of RA in all but one ethnic group. Canadian aboriginals tended to contract the disease much earlier in life than other ethnic groups. More Canadian aboriginals reported a family history of RA than other groupings. Only Canadian aboriginals and caucasian Canadians showed involvement of the C1-C2 joint with subluxation. Italian Canadians tended to have a higher mean haemoglobin than other groupings, while Canadian aboriginals tended to have a higher mean platelet count than other groupings, and an elevated anti-nuclear antibody count. While most of the drugs used to treat RA produced no significantly distinct reactions, the Italian and Canadian caucasian groups had the highest percentage of subjects with reactive dermatitis.

A telemedicine system for remote cooperative medical imaging diagnosis

Telemedicine is changing the classical form of health care delivery, by providing efficient solutions to an increasing number of new situations: here we consider those which require some type of computer-supported cooperative work (CSCW) between health care professionals located in different clinical sites. This paper presents the design and development of a telemedicine system for remote computer-supported cooperative medical imaging diagnosis. The main and novel component of our system is a new CSCW distributed architecture, comprised by a collaborative toolkit to add audioconferencing, telepointing, window sharing, user's coordination and application synchronization facilities, either to existing or new medical imaging diagnosis applications. In comparison with existing CSCW products, mainly based on centralized architectures, our distributed toolkit is specially designed for telemedicine applications: to allow different levels of sharing between participants, to improve user feedback in highly interactive user interfaces, and to optimize the required communication bandwidth in order to implement a telemedicine CSCW application on almost any telecommunication network. This telemedicine CSCW system has been applied to build a cooperative medical imaging diagnosis application, in which two doctors, located in different hospitals, need to achieve a cooperative diagnosis on haemodynamic studies using cardiac angiography images. The design of the graphical user interface for this kind of telemedicine CSCW systems, a critical component which conforms any telemedicine application, is also addressed with a new methodological approach, to assure the system usability and final user acceptance. The telemedicine cardiac angiography pilot has been implemented, tested and evaluated within the Research Project 'FEST-Framework for European Services in Telemedicine' funded by EU AIM Programme.

Peripheral blood stem cell collection with reduced platelet loss to the patient/donor

Apheresis procedures that optimize peripheral blood stem cell (PBSC) harvesting also result in a significant loss of platelets to the patient/donor because of their similar densities. We compared the percent drop in platelet count and hemoglobin concentration in the patients before and after PBSC collection using two different collection chambers with the CS-3000. A modified plateletpheresis procedure was utilized. Seven patients underwent 38 PBSC collections during steady state hematopoiesis using the standard A-35 collection chamber. At the end of the procedure, a second low-speed centrifugation of the PBSC concentrate was performed in the manual mode, with siphoning out and return of the PRP to the patient through a transfer pack. For 14 patients who underwent 113 PBSC collections, a small volume collection chamber (SVCC) was substituted for the A-35 chamber and the second centrifugation step was omitted. These patients were also primed with 4 g/m2 of cyclophosphamide. The percent drop in platelet count in the patients after the collection procedures was significantly less in the SVCC group (20.4 +/- 9.1 vs. 36.0 +/- 12.3, P = 0.000), even after correction for the difference in the volume of blood processed between the two groups (3.2 +/- 1.4 vs. 3.9 +/- 1.3, P = 0.006). The percent drop in hemoglobin concentration was also less with the SVCC both before (5.4 +/- 3.8 vs. 11.7 +/- 3.0, P = 0.000) and after (0.8 +/- 0.6 vs. 1.3 +/- 0.3, P = 0.000) correction for the difference in the volume of blood processed.(ABSTRACT TRUNCATED AT 250 WORDS)

Neutralizing antibody immune response in children with primary and secondary rotavirus infections

We have characterized the neutralizing antibody immune response to six human rotavirus serotypes (G1 to G4, G8, and G9) in Brazilian children with primary and secondary rotavirus infections and correlated the response with the G serotype of the infecting rotavirus strain. Twenty-five children were studied: 17 had a single rotavirus infection, 4 were reinfected once, and 4 experienced three infections. Two of the reinfections were by non-group A rotaviruses. Among the 25 primary infections, we observed homotypic as well as heterotypic responses; the serotype G1 viruses, which accounted for 13 of these infections, induced mostly a homotypic response, while infections by serotype G2 and G4 viruses induced, in addition to the homotypic, a heterotypic response directed primarily to serotype G1. Two of the primary infections induced heterotypic antibodies to 69M, a serotype G8 virus that by RNA electrophoresis analysis was found not to circulate in the population during the time of the study. The specificity of the neutralizing antibody immune response induced by a virus of a given serotype was the same in primary as well as secondary infections. These results indicate that the heterotypic immune response induced in a primary rotavirus infection is an intrinsic property of the virus strain, and although there seem to be general patterns of serotype-specific seroconversion, these may vary from serotype to serotype and from strain to strain within a serotype.

A telemedicine distributed system for cooperative medical diagnosis

Telemedicine is changing the classical form of health care delivery, dramatically increasing the number of new applications in which some type of distributed synchronous cooperation between health care professionals is required. This paper presents the design and development of a telemedicine distributed system for cooperative medical diagnosis based on two new approaches: 1) a distributed layered architecture specially designed to add synchronous computer supported cooperative work features either to new or existing medical applications; 2) the definition of a methodological procedure to design graphical user interfaces for telemedicine cooperative working scenarios. The cooperative work is supported by a collaborative toolkit that provides telepointing, window sharing, coordination and synchronization. Finally, we have implemented and installed the telemedicine system in clinical practice between two hospitals, providing teleconferencing facilities for cooperative decision support in haemodynamics studies. This specific implementation and a preliminary evaluation were accomplished under the Research Project FEST "Framework for European Services in Telemedicine" funded by the EU AIM Programme.

A pen-based system to support pre-operative data collection within an anaesthesia department

This paper describes the design and implementation of a pen-based computer system for remote preoperative data collection. The system is envisaged to be used by anaesthesia staff at different hospital scenarios where pre-operative data are generated. Pen-based technology offers important advantages in terms of portability and human-computer interaction, as direct manipulation interfaces by direct pointing, and "notebook user interfaces metaphors". Being the human factors analysis and user interface design a vital stage to achieve the appropriate user acceptability, a methodology that integrates the "usability" evaluation from the earlier development stages was used. Additionally, the selection of a pen-based computer system as a portable device to be used by health care personnel allows to evaluate the appropriateness of this new technology for remote data collection within the hospital environment. The work presented is currently being realised under the Research Project "TANIT: Telematics in Anaesthesia and Intensive Care", within the "A.I.M.--Telematics in Health CARE" European Research Program.

Perforated or gangrenous appendicitis treated with aminoglycosides. How do bacterial cultures influence management?

To study the influence of bacterial culture data on the clinical management of gangrenous or perforated appendicitis, we reviewed records of 104 patients who had been treated empirically with aminoglycoside antibiotics. Culture results appeared to influence antibiotic therapy in only 7 patients (7%). The routine cultures obtained at appendectomy affected therapy in only 2 patients. Discriminant analysis identified postoperative infectious complications and related factors as the principal determinants of culture utility. We conclude that, in patients with perforated appendicitis treated empirically with aminoglycoside combination regimens, culture results were seldom used for clinical management except in instances of postoperative infectious complication. Routine cultures and Gram's stains of perforated appendicitis, however, should still be obtained (1) to allow epidemiologic tracking in the hospital; (2) to identify organisms that are recovered infrequently but may cause serious disease (eg, Clostridium); and (3) because newer antibiotics are replacing aminoglycosides in the treatment of perforated appendicitis.

Rapid resolution of high level hyperamylasemia as a guide to clinical diagnosis and timing of surgical treatment in patients with gallstones

We reviewed the charts of 78 patients with acute hyperamylasemia (25 with gallstones, 38 alcoholic patients and 15 other), looking for early patterns of serum amylase flux that could distinguish gallstone associated disease. Patients with gallstones had average serum amylase levels of 1,848 +/- 289 International units per liter and 911 +/- 233 International units per liter at hospital admission and on hospital day 2, respectively; these levels were significantly greater than those in either the alcoholic or other patients. In the group of patients with gallstones, there were also dramatic decreases in serum levels of amylase at 24 hours (1,425 +/- 286 International units) after hospital admission; these decreases were not seen in the other groups of patients. At operation, the patients with gallstones had mild or no pancreatitis. All of them underwent uneventful cholecystectomy within 48 hours of hospitalization; only three patients required exploration of the common duct, and only one patient had ampullary obstruction. We conclude that rapid resolution of high level hyperamylasemia within 24 hours of hospitalization in symptomatic patients with gallstones can help to identify patients whose amylase fluctuations are indeed gallstone related, who have either mild pancreatitis or none at all, are good candidates for early cholecystectomy and are not likely to have common duct stones.