A two-colour chewing gum test for masticatory efficiency: development of different assessment methods

OBJECTIVE

The aim of this study was to investigate different assessment methods of a two-colour chewing gum test for masticatory efficiency to determine its validity for research and clinical purposes.

MATERIALS AND METHODS

Twenty adult volunteers, eleven women and nine men (mean age of 27.5 years), participated in this study. All participants perceived their masticatory efficiency as normal. The task was to chew five samples of a two-colour chewing gum for 5, 10, 20, 30 and 50 cycles respectively. Maximum bite force was measured. All samples were assessed twice by two independent operators both, as 'bolus' and after flattening to 1 mm thick 'wafers'. The latter were scanned and the unmixed pixels counted using Adobe Photoshop Elements to calculate the ratio of unmixed colour to the total surface.

RESULTS

Digital image processing confirmed a significant correlation between colour mixing and chewing duration (P < 0.001). Subjective assessment proved less accurate with fair to substantial intra-examiner agreement for 'bolus' (0.20 < kappa < 0.63) and substantial to almost perfect agreement for 'wafer' (0.60 < kappa < 0.88). Inter-examiner agreement was consistently moderate or substantial only for specimen chewed 20 cycles or longer. No significant correlation was found between the colour mixture and the maximum bite force.

CONCLUSION

Digital image processing of the two-colour chewing gum test specimen provides reliable quantitative data for chewing efficiency. Visual assessments were less reliable but might still be useful in screening for chewing deficiencies in a clinical setting. In this context, the test should be performed with a flattened specimen chewed, probably for 20 cycles.

Thyroidal and peripheral production of thyroid hormones. Review of recent findings and their clinical implications

There are two biologically active thyroid hormones, thyroxine (T4) and triiodothyronine (T3). Most T3 is produced extrathyroidally, so that alterations in circulating thyroid hormone concentrations may occur as a result of both thyroidal and extrathyroidal abnormalities. Extrathyroidal T4 conversion to T3 is decreased in patients with different acute and chronic illnesses. When T4 conversion to T3 is impaired and serum T3 concentrations decline, serum concentrations of biologically inactive 3,3',5'-triiodothyronine (reverse T3) increase. In this review, we present current information on thyroidal and extrathyroidal T4 and T3 production in normal subjects and patients with various thyroid diseases and other illnesses, consider the physiologic significance of these changes, and discuss the value and interpretation of various iodothyronine measurements.

Implant-supported mandibular overdentures in very old adults: a randomized controlled trial

The purpose of this study was (1) to investigate denture satisfaction following the conversion of existing mandibular complete dentures to implant overdentures (IOD) in very old edentulous patients who depend on help for activities of daily living and (2) to evaluate secondary end points, such as functional, structural, nutritional, and patient-centered aspects. For this randomized clinical trial, 2 interforaminal short implants were placed in the intervention group (n = 16, 85.0 ± 6.19 yrs) to retain mandibular IODs; the control group (n = 18, 84.1 ± 5.55 yrs) received conventional relines. During the first year, no implant was lost; however, 2 patients died. IODs proved more stable, and participants in the intervention group demonstrated significantly higher denture satisfaction as well as an increased oral health-related quality of life compared to the control group. Maximum voluntary bite force improved significantly with IODs, yet the chewing efficiency was not different between groups. Masseter muscle thickness increased with IODs, mainly on the preferred chewing side. Body mass index decreased in both groups, but the decline tended to be smaller in the intervention group; blood markers and the Mini Nutritional Assessment did not confirm this tendency. These results indicate that edentulous patients who depend on help for activities of daily living may benefit from IODs even late in life.

Procalcitonin in preterm infants during the first few days of life: introducing an age related nomogram

OBJECTIVE

To determine normal concentrations of procalcitonin in preterm infants shortly after birth and to assess its accuracy in detecting bacterial infection.

METHODS

Blood samples of 100 preterm infants were prospectively drawn during the first 4 days of life for determination of procalcitonin concentration. Infants were classified into four groups according to their sepsis status.

RESULTS

Mean (SD) gestational age and birth weight were 32 (2.9) weeks and 1682 (500) g respectively. A total of 283 procalcitonin concentrations from healthy infants were plotted to construct nomograms of physiologically raised procalcitonin concentration after birth, stratified by two groups to 24-30 and 31-36 weeks gestation. The peak 95th centile procalcitonin concentration was plotted at 28 hours of age; values return to normal after 4 days of life. Only 12 infants were infected, and 13 of their 16 procalcitonin concentrations after birth were higher than the 95th centile, whereas samples taken at birth were lower. In a multivariable analysis, gestational age, premature rupture of membrane, and sepsis status influenced procalcitonin concentration independently, but maternal infection status did not.

CONCLUSIONS

The suggested neonatal nomograms of preterm infants are different from those of term infants. Procalcitonin concentrations exceeding the 95th centile may be helpful in detecting congenital infection, but not at birth.

Understanding donors' motivations: a study of unrelated bone marrow donors

Medical advances in bone marrow transplantation techniques and immunosuppressive medications have dramatically increased the number of such transplants performed each year, and consequently, the demand for bone marrow from unrelated donors. Although physiological aspects of bone marrow donation have been thoroughly investigated, very few studies have examined psychosocial factors that may impact individuals' donation decisions and outcomes. To examine one particular set of donor psychosocial issues, this study investigated motives for bone marrow donation among 343 unrelated bone marrow donors who donated through the National Marrow Donor Program. Six distinct types of donor motives were identified from open-ended questionnaire responses. Donors most frequently reported motives reflecting some awareness of both the costs (to themselves) and potential benefits (to themselves and the recipient) of donation. A desire to act in accordance with social or religious precepts, expected positive feelings about donating, empathy for the recipient, and the simple desire to help another person were also commonly cited reasons for donating. Among a series of donor background characteristics, donors' gender was the variable most strongly associated with motive type; women were most likely to cite expected positive feelings, empathy, and the desire to help someone. Central study findings indicated that donor motives predicted donors reactions to donation even after the effects of donor background characteristics (including gender) were controlled. Donors who reported exchange motives (weighing costs and benefits) and donors who reported simple (or idealized) helping motives experienced the donation as less positive in terms of higher predonation ambivalence and negative postdonation psychological reactions than did remaining donors. Donors who reported positive feeling and empathy motives had the most positive donation reactions in terms of lower ambivalence, and feeling like better persons postdonation. These finding add substantially to the body of work concerning medical volunteerism generally, and also have important practical implications for the recruitment and education of potential bone marrow donors.

Successful treatment of anti-N-methyl-D-aspartate receptor encephalitis presenting with catatonia

The case of a 12-year-old girl with the typical clinical symptoms of the recently described anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is reported. Within 6 weeks the full clinical spectrum of this condition presented with seizures, agitation, stupor, autonomic instability, dysphagia and hypoventilation leading to a diagnosis of pernicious catatonia. MRI and CSF glucose, protein and lactate were repeatedly normal. EEG revealed rhythmical slowing. No teratoma was detected. Recognition of the unique pattern of the clinical symptoms led to early consideration of this disease which was confirmed by detection of anti-NMDAR antibodies. After high dose prednisolone without clinical improvement, plasmapheresis was followed by a rapid reduction in antibodies and recovery within a few weeks. To our knowledge this is the youngest patient with anti-NMDAR encephalitis to have been described to date. We speculate that NMDAR antibodies may be directly involved in the pathogenesis of this disease.

Indomethacin tocolysis increases postnatal patent ductus arteriosus severity

Postnatally, therapeutic indomethacin administration is usually effective in mediating patent ductus arteriosus (PDA) constriction in premature infants. There are infants, however, who remain resistant to indomethacin and require more aggressive surgical intervention to facilitate ductal closure. Indomethacin tocolysis has been reported to increase the incidence of persistent PDA in premature infants. It was our impression that infants exposed to antenatal indomethacin not only suffered from an increased incidence of PDA, but that they were more symptomatic from PDA and that for them, PDA was more resistant to medical closure. It is this observation that we sought to examine in this study.

METHODS

Medical records of all mothers and premature neonates with birth weight </=1500 g, admitted to the neonatal intensive care unit of the Shaare Zedek Medical Center during 1996 and 1997, who survived for at least 1 week, were reviewed retrospectively. Data on maternal indomethacin and steroid exposure, birth weight and gestational age, and ductus status and treatment were analyzed. In our obstetrics department, indomethacin is the medication of choice to inhibit premature labor. Mothers who arrive in premature labor are started on indomethacin therapy, if delivery is not imminent. All infants </=1500 g were studied by a pediatric cardiologist between 24 and 72 hours of life using two-dimensional echocardiography with color flow mapping to assess ductal patency. Decisions to treat were based on echocardiographic evidence of PDA, along with any of the following clinical signs: bounding pulses, diastolic pressure of </=25 mm Hg, pulmonary plethora and/or cardiomegaly on chest x-ray, or increasing oxygen requirement with no other explanation. Initial treatment is with indomethacin, if there are no contraindications. Our general approach is to begin therapy with a continuous indomethacin infusion, followed by a course of bolus indomethacin if the infant does not respond. However, each attending neonatologist may treat according to his/her preference (ie, bolus vs continuous). All infants with PDA are followed with serial echocardiographic examinations until the ductus is closed.

RESULTS

A total of 105 premature infants met the above criteria. Thirty-six of these 105 infants had echocardiographic signs of a PDA (34.3%). Those with PDA were less mature (gestational age, 28.9 +/- 2.6 vs 30.3 +/- 2.6 weeks, respectively) and tended to be smaller (1060 +/- 270 vs 1166 +/- 261 g). Of the 36 infants with PDA, 15 (42%) resolved spontaneously and 21 (58%) were symptomatic and required treatment with indomethacin. There were no differences in gestational age or birth weight between infants whose PDA resolved spontaneously and those requiring indomethacin therapy. Four of the 21 (19%) treated infants remained unresponsive to indomethacin and required ductal ligation. Of 17 infants with PDA who responded to indomethacin therapy, 1 (6%) was treated with a single course of bolus indomethacin, to which he responded, and 16 (94%) were treated with continuous indomethacin and responded promptly. The differences in therapeutic responsiveness to initial treatment with continuous vs bolus indomethacin were not significant. Of the 105 infants, 29 were exposed to indomethacin tocolysis. Those who were exposed to antenatal indomethacin and those who were not were well-matched with respect to birth weight and gestational age. Fifteen (52%) of the 29 exposed infants versus 18 (24%) of the 76 infants not exposed to antenatal indomethacin developed a PDA postnatally (relative risk = 2.1; 95% confidence interval: 1.22-3.74), and 45% of the antenatally exposed infants versus 12% of the nonexposed infants were symptomatic and required indomethacin (relative risk = 1.9; 95% confidence interval: 1.17-3.20). Four of the exposed infants versus none of the unexposed infants required surgical ligation. (ABSTRACT TRUNCATED)

Oro-facial impairment in stroke patients

Stroke is considered one of the leading causes of death and acquired disability with a peak prevalence over the age of 80 years. Stroke may cause debilitating neurological deficiencies that frequently result in sensory deficits, motor impairment, muscular atrophy, cognitive deficits and psychosocial impairment. Oro-facial impairment may occur due to the frequent involvement of the cranial nerves' cortical representation areas, central nervous system pathways or motoneuron pools. The aim of this narrative, non-systematic review was to discuss the implications of stroke on oro-facial functions and oral health-related quality of life (OHRQoL). Stroke patients demonstrate an impaired masticatory performance, possibly due to reduced tongue forces and disturbed oral sensitivity. Furthermore, facial asymmetry is common, but mostly discrete and lip restraining forces are reduced. Bite force is not different between the ipsi- and contra-lesional side. In contrast, the contra-lesional handgrip strength and tongue-palate contact during swallowing are significantly impaired. OHRQoL is significantly reduced mainly because of the functional impairment. It can be concluded that impaired chewing efficiency, dysphagia, facial asymmetry, reduced lip force and OHRQoL are quantifiable symptoms of oro-facial impairment following a stroke. In the absence of functional rehabilitation, these symptoms seem not to improve. Furthermore, stroke affects the upper limb and the masseter muscle differently, both, at a functional and a morphological level. The rehabilitation of stroke survivors should, therefore, also seek to improve the strength and co-ordination of the oro-facial musculature. This would in turn help improve OHRQoL and the masticatory function, subsequently preventing weight loss and malnutrition.

Global prevalence of edentulism and dental caries in middle-aged and elderly persons: A systematic review and meta-analysis

OBJECTIVE

The aim of the study was to analyze data collected from studies worldwide on the prevalence of edentulism and dental caries, in community-dwellers aged ≥ 45 years.

DATA

Inclusion criteria; participants aged ≥ 45 years, community-dwellers. Exclusion criteria; participants aged < 45 years, in nursing homes, data obtained from dental clinics or pre-2005. The quality assessment tool by The National Heart, Lung and Blood Institute for Observational Cohort and Cross-sectional studies was used. Meta-analysis using the random-effects model (95% confidence interval) was done with data on participants who were edentulous and/or had active dental caries and stratified by regions of the world, age and Gross National Income per capita. Limitations in the data arose from several factors such as design of the studies included differences in socioeconomic status and access to health care among different countries.

SOURCES

Embase, MEDLINE via Pubmed and Scopus, manual searches, from January 2016, restricted to English. Experts from different countries were contacted to identify National oral health surveys (NOHS) conducted from 2010 onwards.

STUDY SELECTION

Eighty-six papers and seventeen NOHS were selected for data extraction. Majority of the studies (n = 69) were cross-sectional and of fair quality. 1.1%-70%, 4.9% - 98% prevalence of edentulism and dental caries, respectively. 22%, 45% estimated random-effects pooled prevalence of edentulism and dental caries, respectively.

CONCLUSIONS

Within the limitations of this study, the findings indicate that untreated dental caries and tooth loss are prevalent on a global level with wide variations among different countries, age groups and socioeconomic status.

CLINICAL SIGNIFICANCE

The findings demonstrate the reality of the new cohort of older adults, with higher tooth retention implying more dental caries incidence and the need for different care strategies to ensure better oral health. Large variations and difficulty in making comparisons among different countries highlight the need for more standardized, regular research.

Fetal mild idiopathic lateral ventriculomegaly: is there a correlation with fetal trisomy?

Mild idiopathic lateral ventriculomegaly in the mid-trimester fetus can be accurately detected using modern prenatal ultrasonography. Since an abnormal karyotype has been reported in some of these cases, the present prospective study was designed to evaluate, first, the prevalence of mild idiopathic lateral ventriculomegaly in the general obstetric population and, second, to determine the incidence of abnormal fetal karyotype associated with mild idiopathic lateral ventriculomegaly. Eight cases of mild idiopathic lateral ventriculomegaly (0.15%) were detected among 5400 routine prenatal sonographic examinations, between 16 and 22 weeks' gestation. Three newborn infants were found to be normal; in one baby, spontaneous resolution of the lesion occurred in utero, and, among the other five cases, two had an abnormal karyotype: one had Down's syndrome, and one trisomy 18. A review of the English literature revealed that 12% of fetuses with mild idiopathic lateral ventriculomegaly have an abnormal karyotype. Since 3% of the fetuses with Down's syndrome can be visualized in utero with mild idiopathic lateral ventriculomegaly, the calculated risk for Down's syndrome when such lesions appear is about 3%. We, therefore, conclude that karyotypic study is warranted in the mid-trimester fetus with incidental findings of mild idiopathic lateral ventriculomegaly.

The grandmultipara: is she still a risk?

Grandmultiparity is reported to increase both maternal and perinatal mortality and morbidity. Unique religious and demographic factors in Jerusalem allowed us to analyze a population wherein parity could be dissociated from socioeconomic status. A total of 7785 mothers was studied, 889 (11.5%) of whom were grandmultiparas. Comparison of grandmultiparous mothers with all others revealed no increase in the incidence of hypertension, diabetes, uterine atonia, antenatal or postnatal hemorrhage, cesarean sections, stillbirth rate, or congenital malformations. The grandmultipara had significantly lower neonatal mortality and low birth weight rates and a significantly higher incidence of multiple births and trisomy 21 (p less than 0.01). These results strongly suggest that grandmultiparity in and of itself in a healthy, economically stable population afforded modern medical care is not a major risk factor and that previous reports primarily reflected social class factors and not parity per se.

Amelioration of ischemia-reperfusion injury in rat intestine by pentoxifylline-mediated inhibition of xanthine oxidase

BACKGROUND

Intestinal ischemia-reperfusion (IR) injury results in cell destruction, which may be mediated by the generation of reactive oxygen species, potentially toxic metabolites of xanthine oxidase. Pentoxifylline (PTX) possesses a variety of biochemical and antioxidant properties that can improve capillary flow and tissue oxygenation. Because of these combined effects, it has been hypothesized that pentoxifylline would protect against intestinal IR.

METHODS

Young adult rats were randomly assigned to one of four experimental groups: IR/Placebo (n = 12) in which superior and inferior mesenteric arteries were clamped for 45 minutes and then reopened; IR/PTX (n = 11) in which IR was induced as in the Placebo group, but with 25 mg/kg PTX at 0, 30, and 60 minutes; No IR/Placebo (n = 12); and No IR/PTX (n = 6) in which placebo and PTX were applied with no IR. Blood and intestinal samples were taken for serial thiobarbituric acid-reducing substances (TBARS; index of lipid peroxidation), for xanthine oxidase-xanthine dehydrogenase ratios, glutathione, myeloperoxidase, and histopathology.

RESULTS

Animals in the IR/PTX group had lower TBARS and the least severe histopathologic injury. Xanthine oxidasexanthine dehydrogenase ratios were elevated only in IR/ Placebo (0.67+/-0.22 vs. 0.45+/-0.14 in IR/PTX; 0.42+/-0.22 in No IR/Placebo; and 0.40+/-0.11 in No IR/PTX; p = 0.0009). Reduced glutathione was diminished in IR/PTX animals (38.9 +/-1.35 vs. 46.1+/-7.0 in IR/Placebo; 41.1+/-2.5 in No IR/ Placebo; 43.6+/-1.0 in No IR/PTX; p = 0.048). No differences were recorded in myeloperoxidase levels among groups.

CONCLUSIONS

Pentoxifylline ameliorates histopathologic signs of injury and decreases lipid peroxidation (TBARS). Normal xanthine oxidase-xanthine dehydrogenase ratios in the treated compared with IR-only animals imply that the protective effect of PTX is at least partially mediated through inhibition of xanthine oxidase.

Fetal intracranial haemorrhage: clinical significance of in utero ultrasonographic diagnosis

OBJECTIVE

To review in utero detection of fetal intracranial haemorrhage.

DESIGN

Retrospective survey of pregnant women presenting to the ultrasonographic unit in whom the diagnosis of fetal intracranial haemorrhage was reached.

SETTING

The Chaim Sheba Medical Center in Ramat Gan, and Shaare Zedek Medical Center in Jerusalem; two large district general hospitals, each with 6000 maternity patients per year.

SUBJECTS

Five fetuses with gestational ages ranging from 26 to 36 weeks.

MAIN OUTCOME MEASURES

Maternal complications, fetal monitoring, prenatal Doppler ultrasound studies, postnatal imaging studies, neonatal morbidity and mortality.

RESULTS

Transabdominal sonography showed hyperechoic lesions in the brain parenchyma, and the lateral ventricle in three of five fetuses. In the remaining two fetuses, transvaginal sonography enhanced the visualisation of ventriculomegaly with intraventricular haemorrhage in one and periventricular leukomalacia was identified in the second. Three fetuses were appropriate for gestational age, and two were severely growth retarded. In one woman severe pre-eclamptic toxaemia may explain intracranial haemorrhage. Abnormal nonstress test and abnormal flow velocity waveforms in the umbilical and cerebral arteries were present in the two growth retarded fetuses, and in one who was appropriate for gestational age. The two growth retarded fetuses died shortly after birth. Of the three surviving infants, two had normal long term development, and one developed hydrocephalus with subsequent severe neurodevelopmental retardation, dying at the age of seven months.

CONCLUSIONS

This small series shows that intracranial haemorrhage has a broad spectrum of manifestations with diverse prognosis. Following an antenatal diagnosis of intracranial haemorrhage, the obstetrician must give special consideration to electronic fetal heart monitoring and Doppler velocity waveforms. The prenatal diagnosis of intracranial haemorrhage has medico-legal implications suggesting that neurological outcome may not necessarily be due solely to intrapartum events and management.

Post-phototherapy neonatal bilirubin rebound: a potential cause of significant hyperbilirubinaemia

AIM

To determine the incidence of post-phototherapy neonatal plasma total bilirubin (PTB) rebound.

METHODS

A prospective clinical survey was performed on 226 term and near-term neonates treated with phototherapy in the well baby nursery of the Shaare Zedek Medical Center from January 2001 to September 2002. Neonates were tested for PTB 24 hours (between 12 and 36 hours) after discontinuation of phototherapy, with additional testing as clinically indicated. The main outcome measure, significant bilirubin rebound, was defined as a post-phototherapy PTB > or =256 micromol/l. Phototherapy was not reinstituted in all cases of rebound, but rather according to clinical indications.

RESULTS

A total of 30 (13.3%) neonates developed significant rebound (mean (SD) PTB 287 (27) micromol/l, upper range 351 micromol/l). Twenty two of these (73%) were retreated with phototherapy at mean PTB 296 (29) micromol/l. Multiple logistic regression analysis showed significant risk for aetiological risk factors including positive direct Coombs test (odds ratio 2.44, 95% CI 1.25 to 4.74) and gestational age <37 weeks (odds ratio 3.21, 95% CI 1.29 to 7.96). A greater number of neonates rebounded among those in whom phototherapy was commenced < or =72 hours (26/152, 17%) compared with >72 hours (4/74, 5.4%) (odds ratio 3.61, 95% CI 1.21 to 10.77).

CONCLUSION

Post-phototherapy neonatal bilirubin rebound to clinically significant levels may occur, especially in cases of prematurity, direct Coombs test positivity, and those treated < or =72 hours. These risk factors should be taken into account when planning post-phototherapy follow up.

Reliability of a two-colour chewing gum test to assess masticatory performance in complete denture wearers

The aim of this study was to test the reliability of a method to measure the masticatory performance of complete denture wearers employing a colour-mixing ability test and assessment by visual and electronic colourimetric analysis. A sample of 75 subjects was selected from patients who received new conventional complete dentures. Masticatory tests were performed using a two-colour chewing gum that was masticated for 5, 10, 20, 30 and 50 chewing cycles, performed in a random order. The mixing level of the two colours of the chewed gum was assessed visually by two independent raters based on a 5-point ordinal scale. The specimens were flattened into a 1-mm-width wafer, scanned and saved as a two-sided digital image. Each pair of images was submitted to an electronic colourimetric analysis to assess the level of colour mixture, measured by the circular variance of hue (VOH). Overall inter- and intra-rater agreements in visual analysis were 64% and 68%, respectively (almost 99% of scores ranged within ±1 point), whilst overall weighted kappa was >0.80. A proportional increase in the level of mixture occurred with increased number of chewing cycles (P < .001). Similarly, VOH and the visual analysis were highly correlated (r = -.89; P < .001). Bland-Altman plots revealed excellent agreement and extremely low systematic error between duplicated VOH measures. It was concluded that the two-colour chewing gum test is a reliable method to assess the masticatory performance in complete denture wearers using both visual and electronic colourimetric analyses.

Postnatal development of the tubular lamina propria and the intertubular tissue in the bovine testis

The postnatal development of intertubular cells and vessels and of the tubular lamina propria was studied in three locations of perfusion-fixed bovine testes from 31 animals ranging from 4 to 78 weeks. The postnatal morphological differentiation of the testis is not uniform, regional differences have to be considered. The intertubular cell population is composed of mesenchyme-like cells, fibrocytes, Leydig cells, peritubular cells and mononuclear cells. In 4- and 8-week-old testes mesenchyme-like cells are the dominating element. These pluripotent cells proliferate by frequent mitoses and are the precursors of Leydig cells, contractile peritubular cells and fibrocytes. Morphologically differentiated Leydig cells are encountered throughout the entire period of postnatal development. In 4-week-old testes degenerating fetal and newly formed postnatal Leydig cells are seen in juxtaposition to each other. From the 8th week on, only postnatal Leydig cells are present. Between 16 and 30 weeks large-scale degeneration of prepuberal Leydig cells is observed. The Leydig cells that survive this degenerative phase constitute the long-lasting adult population. 20-30% (numerically) of all intertubular cells at all ages are free mononuclear cells. These are found as lymphocytes, plasma cells, monocytes, macrophages and light intercalated cells (LIC). The latter are monocyte-derived, Leydig cell-associated typical cells of the bovine testis. The differentiation of the two main components of the tubular lamina propria, (i) basal lamina and (ii) peritubular cell sheath, seems to be effected rather independent from each other and also from hormonal signals important for the development of the germinal cells. The laminated basal lamina reaches nearly 3 micron at 16 weeks and is later on continuously reduced. At 25 weeks the peritubular cells have transformed into contractile myofibroblasts. At this period the germinal epithelium is still in a prepuberal state.

Oral tactile sensitivity and masticatory performance are impaired in stroke patients

Oro-facial impairment following stroke frequently involves reduced chewing performance, that is oral phase dysphagia. The aim was to investigate the sensitivity of oral tissues following stroke and its potential impact on masticatory function. Therefore, hospitalised post-stroke patients were recruited and compared to healthy controls. Outcome measures comprised masticatory performance employing a colour-mixing ability, that is a bolus-kneading test, maximum lip- and bite force and the one-point and two-point tactile thresholds. Food hoarding and prevalence of dry mouth were evaluated with ordinal scales. Twenty-seven stroke patients (age 64·3 ± 14·1 years) and 27 healthy controls (age 60·8 ± 14·3 years, P = 0·254) participated in this study. The groups had similar numbers of occluding units. Stroke patients reported more frequently dry mouth sensations and food hoarding. The intra-oral tactile sensitivity on the contra-lesional side was significantly lower in stroke patients compared to controls (0·0001 < P < 0·0002), and significant intra-group side differences were found only in the stroke group (0·0001 < P < 0·0010). For the lip, both sides were less sensitive in the stroke group compared with controls. The experiments confirmed lower masticatory performance and lip force in the stroke group, but the bite force was similar compared to healthy controls. Oral sensitivity was correlated with masticatory performance when a global correlation model was applied. A stroke may affect the sensitivity of the intra-oral tissues contra-lesionally, thus potentially affecting chewing function. Rehabilitation should therefore not only focus on motor impairment, but equally stimulate the sensitivity of the oral tissues, employing dry ice application or similar specific treatments.

Emphasizing difficulties in the detection of rhythms with Lomb-Scargle periodograms

The Lomb-Scargle periodogram was introduced in astrophysics to detect sinusoidal signals in noisy unevenly sampled time series. It proved to be a powerful tool in time series analysis and has recently been adapted in biomedical sciences. Its use is motivated by handling non-uniform data which is a common characteristic due to the restricted and irregular observations of, for instance, free-living animals. However, the observational data often contain fractions of non-Gaussian noise or may consist of periodic signals with non-sinusoidal shapes. These properties can make more difficult the interpretation of Lomb-Scargle periodograms and can lead to misleading estimates. In this letter we illustrate these difficulties for noise-free bimodal rhythms and sinusoidal signals with outliers. The examples are aimed to emphasize limitations and to complement the recent discussion on Lomb-Scargle periodograms.

Quantitative morphology of the ovine seminiferous epithelium

Ultrastructural features and morphometric values of ovine Sertoli and spermatogenic cells are reported with special reference to the 6 stages of the seminiferous epithelial cycle. Seminiferous tubules occupy about 83% of the testicular parenchyma. Average tubular diameter (about 275 microns) and epithelial height (about 95 microns) do not vary significantly during the cycle. From preleptotene to late diplotene the cellular volume of primary spermatocytes increases nearly five-fold; the nuclear volume increases three-fold in the same period. Secondary spermatocytes are observed exclusively during stage 4 of the seminiferous epithelial cycle. Due to partial cell necrosis and autolytic events, ovine spermatids lose a considerable amount of their cytoplasm during acrosome and maturation phases prior to spermiation. Sertoli cells occupy between 27.6% (stage 3) and 36.6% (stage 1) of the tubular epithelium. The average volume of a Sertoli cell varies between 6380 microns 3 (stage 2) and 7195 microns 3 (stage 4), the absolute surface area between 10550 microns 2 and 12305 microns 2. The irregularly contoured Sertoli cell nucleus contains a vesicular nucleolus and occupies about 7.5% of the cell. Mitochondria (about 5%) and smooth endoplasmic reticulum are other prominent organelles, but three-quarters of the Sertoli cell are taken up by cytoplasmic matrix with a well-developed cytoskeleton. Ovine Sertoli cells contain large basal lipid droplets, but no typical lipid cycle can be observed.

Configuration and distribution of bovine spermatogonia

The configuration and distribution of bovine spermatogonia, preleptotene primary spermatocytes and Sertoli cells in the basal seminiferous tubular compartment have been studied by means of whole-mount preparations, immunohistochemistry and quantitative morphology. Three types of spermatogonia (Sg) can be identified. Large A-spermatogonia are irregularly distributed in the tubular periphery. Following the period of propagation of the A-spermatogonia, an interconnected meshwork of medium-sized spermatogonia with different cytogenetic potency is observed. Although the majority of the medium-sized spermatogonia are kinetically of the I type and divide to produce small B-spermatogonia, some members of the medium-sized population are seen in a growth phase and differentiate into large A-spermatogonia. These mark the beginning of a new round of spermatocytogenesis. Only one generation of B-spermatogonia divides into preleptotene primary spermatocytes. The architectural arrangement of multiplying spermatogonia in circles or rows is primarily the result of the distribution of the Sertoli cells. Spermatogonial multiplication is not strictly coordinated with the stages of the seminiferous epithelial cycle. Spermatogonial degeneration amounts on average to 3.6% and has therefore no decisive impact on the yield of primary spermatocytes.

Familial situs inversus and congenital heart defects

The midline is a major determinant in the lateral symmetry of the embryo and represents a developmental field which, if defective, may lead to an abnormal situs determination. A family in which four out of seven children had situs inversus and/or congenital heart defects is presented. This report confirms the autosomal recessive inheritance of this developmental field defect.

Ankyloblepharon filiforme adnatum: congenital eyelid-band syndromes

Three infants had congenital eyelid bands, ankyloblepharon filiforme adnatum (AFA), in association with cleft lip and palate. A review of the literature of all previously reported cases of AFA was performed and a new classification of the various clinical types of AFA is proposed. This new classification should aid in genetic counseling.