Palpable lymph nodes of the neck in Swedish schoolchildren

We studied 3592 Swedish schoolchildren, 8 or 9 years old, examined for palpable submandibular, cervical and supraclavicular lymph nodes. All children were skin tested with 2 TU PPD RT23 and with 0.1 μ g of Mycobacterium avium sensitin or 0.1 μ g of M. scrofulaceum sensitin. A total of 991 children had palpable lymph nodes in any of the three locations. Among them, 811 had lymph nodes in one location, 162 in two locations and 18 in three. In 312 children, the lymph nodes were ± 5 mm in size in any location. The most common location was submandibular. Boys had a significantly higher prevalence of palpable lymph nodes than girls. There was also seasonal variation. Children infected by atypical mycobacteria (sensitin reaction ±6 mm) did not have a higher prevalence of palpable lymph nodes than those not infected.     

Multispectral analysis of magnetic resonance images

Magnetic resonance (MR) imaging systems produce spatial distribution estimates of proton density, relaxation time, and flow, in a two dimensional matrix form that is analogous to that of the image data obtained from multispectral imaging satellites. Advanced NASA satellite image processing offers sophisticated multispectral analysis of MR images. Spin echo and inversion recovery pulse sequence images were entered in a digital format compatible with satellite images and accurately registered pixel by pixel. Signatures of each tissue class were automatically determined using both supervised and unsupervised classification. Overall tissue classification was obtained in the form of a theme map. In MR images of the brain, for example, the classes included CSF, gray matter, white matter, subcutaneous fat, muscle, and bone. These methods provide an efficient means of identifying subtle relationships in a multi-image MR study.     

The use of in-line intravenous filters in sick newborn infants

AIM: This study assesses the improvement in outcome for newborn infants by decreasing major complications associated with intravenous fluid therapy by using an in-line filter, and evaluates the economical impact this might have in relation to daily changing of i.v. lines. METHODS: In a prospective controlled study, 88 infants were randomly assigned to receive either filtered (except for lipids, blood and blood products) or non-filtered infusions via a central catheter. Main outcome measures such as bacteraemia, phlebitis, extravasation, thrombosis, septicaemia and necrosis were all scored. The costs attributable to patients during a standard 8-day stay were also recorded. RESULTS: Significant reductions were found in major complications such as thrombi and clinical sepsis (control group (21), filter group (8); p < 0.05). Bacterial cultures of the filters showed a contamination rate on the upstream surface of 15/109 filters (14%). The mean costs of disposables were less in the filter group, showing a reduction from 31.17 euros to 23.79 euros. CONCLUSIONS: The use of this in-line filter leads to a significant decrease in major complications and substantial cost savings.     

Optimization of attenuation correction for positron emission tomography studies of thorax and pelvis using count-based transmission scans

The quality of thorax and pelvis transmission scans and therefore of attenuation correction in PET depends on patient thickness and transmission rod source strength. The purpose of the present study was to assess the feasibility of using count-based transmission scans, thereby guaranteeing more consistent image quality and more precise quantification than with fixed transmission scan duration. First, the relation between noise equivalent counts (NEC) of 10 min calibration transmission scans and rod source activity was determined over a period of 1.5 years. Second, the relation between transmission scan counts and uniform phantom diameter was studied numerically, determining the relative contribution of counts from lines of response passing through the phantom as compared with the total number of counts. Finally, the relation between patient weight and transmission scan duration was determined for 35 patients, who were scanned at the level of thorax or pelvis. After installation of new rod sources, the NEC of transmission scans first increased slightly (5%) with decreasing rod source activity and after 3 months decreased with a rate of 2-3% per month. The numerical simulation showed that the number of transmission scan counts from lines of response passing through the phantom increased with phantom diameter up to 7 cm. For phantoms larger than 7 cm, the number of these counts decreased at approximately the same rate as the total number of transmission scan counts. Patient data confirmed that the total number of transmission scan counts decreased with increasing patient weight with about 0.5% kg(-1). It can be concluded that count-based transmission scans compensate for radioactive decay of the rod sources. With count-based transmission scans, rod sources can be used for up to 1.5 years at the cost of a 50% increased transmission scan duration. For phantoms with diameters of more than 7 cm and for patients scanned at the level of thorax or pelvis, use of count-based transmission scans is feasible and results in statistically more consistent transmission scans as compared with fixed transmission scan duration.     

Minimal enteral feeding, fetal blood flow pulsatility, and postnatal intestinal permeability in preterm infants with intrauterine growth retardation

OBJECTIVE: To study the effect of minimal enteral feeding (MEF) on intestinal permeability and feeding tolerance in preterm infants with intrauterine growth retardation (gestational age < 37 weeks, birth weight for gestational age p < 10). Furthermore, to determine whether fetal blood flow pulsatility or intestinal permeability predict feeding tolerance in these infants. DESIGN: Randomised controlled trial. METHODS: Within 48 hours of birth, infants were randomised to MEF or no enteral feeding (NEF) for five days in addition to parenteral feeding. Intestinal permeability was measured by the sugar absorption test before (SAT1) and after (SAT2) the study. The sugar absorption test measured the urinary lactulose/mannitol (LM) ratio after oral ingestion of a solution (375 mosm) containing mannitol and lactulose. Charts of all infants were assessed for measures of feeding tolerance. Fetal blood flow pulsatility index (U/C ratio) was measured within the seven days before birth. RESULTS: Of the 56 infants enrolled, 42 completed the study: 20 received MEF and 22 NEF. The decrease in LM ratio (LM ratio 1 - LM ratio 2) was not significantly different between the two groups (0.25 v 0.11; p = 0.14). Feeding tolerance, growth, and incidence of necrotising enterocolitis were not significantly different between the two groups. Neither the U/C nor the LM ratio 1 predicted feeding tolerance. CONCLUSIONS: The results suggest that MEF of preterm infants with intrauterine growth retardation has no effect on the decrease in intestinal permeability after birth. Neither fetal blood flow pulsatility nor intestinal permeability predicts feeding tolerance.     

Body composition and bone measurements in intra-uterine growth retarded and early postnatally undernourished male and female rats at the age of 6 months: comparison with puberty

Undernutrition in early life may permanently change body structure, physiology and metabolism and leads to chronic diseases in later life. To test whether malnutrition during different critical time periods around birth in the rat has long-lasting effects on body composition and skeletal growth, we examined body weight and body composition in pubertal rats and adult rats of 6 months after pre- and postnatal malnutrition. Prenatal malnutrition or intra-uterine growth retardation (IUGR) was induced by ligation of the uterine arteries on day 17 of gestation and postnatal food restriction (FR) by litter enlargement to 20 pups per mother from day 2 after birth until weaning (day 24). Pubertal markers were balanopreputial separation (BPS) in the male and vaginal opening (VO) in the female. IUGR as well as FR resulted in a persistent growth retardation. From birth in IUGR rats and from day 4 after birth in FR rats until 6 months of age body weight in male and female rats was significantly lower compared with controls (P < 0.01 and P < 0.05). Although total body bone mineral content (TBBMC) did not differ between male IUGR rats and controls at BPS, at the age of 6 months TBBMC was significantly lower (P < 0.01) compared with controls. At BPS as well as at 6 months of age, TBBMC was significantly lower in male FR rats compared with controls (P < 0.05 and P < 0.01). In the female IUGR rats TBBMC was significantly lower compared with controls at VO (P < 0.01) and 6 months (P < 0.05). TBBMC in the female FR rats was significantly lower at VO (P < 0.01), but did not differ from controls at the age of 6 months. For both IUGR and FR male and female rats these differences disappeared after adjusting for body weight. Body composition in terms of total fat mass, percentage fat and percentage lean did not differ from controls in male and female IUGR rats at 6 months and the same results were observed in the female FR rats. However, in the male FR rats, total fat mass and percentage fat were significantly lower compared with controls (P < 0.01 and P < 0.05), while the percentage lean mass was significantly higher (P < 0.05). We conclude that different critical time periods of malnutrition around birth have different effects later in life on growth, which do not disappear at least after 6 months of life. With respect to body composition, only in the FR male rats, differences are found in total fat mass and the balance of percentage fat mass and lean mass. At time of puberty and at the age of 6 months bone mass adjusted for body weight does not seem to be affected by perinatal undernutrition.     

Head and neck cancer: the pursuit of molecular diagnostic markers

From a histopathologic perspective, head and neck squamous cell carcinoma (HNSCC) is a relatively straightforward diagnosis. However, the clinically useful information presently provided by pathologists is embarrassingly limited. Similarly, our ability to accurately identify the earliest premalignant lesions as well as predict which premalignant lesions are likely to progress to HNSCC is limited. Over the last decade, an explosive growth of knowledge related to the molecular biology of this disease has occurred, which is now being used to address these issues. For example, we now appreciate that there are multiple etiologies and multiple molecular mechanisms responsible for the development of HNSCC. New techniques have improved our ability to identify molecularly premalignant, but histologically benign lesions. Similarly, recent studies have been able to predict which premalignant lesions are likely to progress to HNSCC. In addition to having utility in the realm of early diagnosis, molecular diagnostics may have a profound impact on how we diagnose and report HNSCC. While still in the developmental stage, molecular protocols are being used to evaluate surgical margins, determine the location of unknown primary tumors, identify histologically undetectable lymph node metastasis, and predict which tumors are more likely to respond to a particular postsurgical adjuvant therapy.     

Acellular dermal matrix allografts to achieve increased attached gingiva. Part 2. A histological comparative study

BACKGROUND: In part 1 of this study, we compared the clinical efficacy of freeze-dried acellular dermal matrix (ADM) allograft in 6 patients with autogenous free gingival graft (FGG) in 6 patients for increasing the width of attached gingiva in the mandibular anterior area. The purpose of the present study was to histologically compare the microstructure of ADM and FGG treated sites from the same group. METHODS: Biopsies were harvested from all 12 patients at 6 months postsurgery. The biopsies included the grafted sites with adjacent alveolar mucosa and gingiva propria and also donor palatal mucosa saved at the time of surgery. The 5 microm thick, neutral buffered formalin fixed, paraffin-embedded tissue sections were stained with hematoxylin and eosin (H&E), Masson's trichrome, and Verhoeff-van Gieson stains in order to investigate the density of collagen and elastic fibers. Additional sections were stained with periodic acid-Schiff (PAS) and Papanicolaou's stain to identify the presence of glycogen granules in the epithelial layer and to highlight the keratin layer respectively. RESULTS: The unique appearance of ADM-derived tissue did not parallel any known oral mucosa. The connective tissue portion contained dense to extremely dense collagen fibers along with scattered elastic fibers. The demarcations between the ADM graft and the coronal gingiva as well as the apical alveolar mucosa were usually not very defined. A moderate to thin epithelial layer, with heterogeneous expression of keratinization and flat epithelium-connective tissue interface, covered the lamina propria. Both the thickness of the epithelium and the degree of keratinization decreased in apical direction, being mostly para- or orthokeratinized in the area close to gingiva and non-keratinized adjacent to the alveolar mucosa. In the FGG-treated sites, the density of collagen fibers was less than in ADM-derived tissue, palatal mucosa, and gingiva. Elastic fibers were very sparse, comparable to gingiva, but much less than in ADM-derived tissue. The epithelium was moderate, somewhat thinner but the shape of the rete ridges resembled that of palatal mucosa. Similar to gingiva epithelium, the epithelium of the FGG-treated area was relatively uniform in both thickness and keratinization, mostly para-keratinized with a well defined border to the non-keratinized alveolar mucosa. Underneath the FGG-alveolar mucosa junction, a scar band composed of extremely dense collagen fibers consistently existed. CONCLUSIONS: The results of this 6-month histological evaluation suggest that: 1) the resultant tissue types of ADM grafts were similar to "scar" tissue; 2) the non-vital dermal matrix of ADM allograft lacked the capability of directing cyto-differentiation of the covering epithelium; 3) autogenous FGG-derived tissue was neither identical to donor palatal mucosa nor to adjacent gingiva propria; 4) the connective tissue of donor palatal mucosa only partially contributed to the differentiation of the epithelium covering the FGG-treated area; and 5) the epithelium/connective tissue microenvironment surrounding the recipient site influenced the epithelial differentiation of the graft; this may play a more critical role in ADM grafting than in the grafting of autogenous FGG.