Identification of a deletion in plakoglobin in arrhythmogenic right ventricular cardiomyopathy with palmoplantar keratoderma and woolly hair (Naxos disease)

BACKGROUND

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an autosomal dominant heart muscle disorder that causes arrhythmia, heart failure, and sudden death. Previously we mapped the genetic locus for the triad of autosomal recessive ARVC, palmoplantar keratoderma, and woolly hair (Naxos disease) to chromosome 17q21, in which the gene for plakoglobin is encoded. This protein is a key component of desmosomes and adherens junctions, and is important for the tight adhesion of many cell types, including those in the heart and skin.

METHODS

We studied 19 individuals with Naxos disease, as well as unaffected family members and unrelated individuals from the neighbouring Greek islands of Naxos and Milos. Gene sequence was determined by reverse transcriptase PCR from RNA isolated from the skin of an affected individual and mutations in other cases were confirmed by restriction-enzyme analysis.

FINDINGS

A homozygous 2 base pair deletion in the plakoglobin gene was identified only in the 19 affected individuals. This deletion caused a frameshift and premature termination of the protein, which was shown by western blot analysis. 29 clinically unaffected family members were heterozygous for the mutation; 20 unrelated individuals from Naxos and 43 autosomal dominant ARVC probands were homozygous for the normal allele.

INTERPRETATION

The finding of a deletion in plakoglobin in ARVC suggests that the proteins involved in cell-cell adhesion play an important part in maintaining myocyte integrity, and when junctions are disrupted, cell death, and fibrofatty replacement occur. Therefore, the discovery of a mutation in a protein with functions in maintaining cell junction integrity has important implications for other dominant forms of ARVC, related cardiomyopathies, and other cutaneous diseases.

Normative data for iliac bone histomorphometry in growing children

Many insights into normal and pathologic bone development can only be gained by bone histomorphometry. However, the use of this technique in pediatrics has so far been hampered by the lack of reference data. Therefore, we obtained transfixing iliac bone samples from 58 individuals between 1.5 and 22.9 years of age (25 male; tetracycline labeling performed in 48 subjects), who underwent surgery for reasons independent of abnormalities in bone development and metabolism. The results of histomorphometric analyses of cancellous parameters and cortical width are presented as means and standard deviations, as well as medians and ranges in five age groups. In addition, the original data are available from the authors. There were significant age-dependent increases in both cortical width and cancellous bone volume, the latter being due to an increase in trabecular thickness. Osteoid thickness did not vary significantly with age. Bone surface-based indicators of bone formation showed an age-dependent decline, reflecting similar changes in activation frequency. Mineral apposition rate decreased continuously with age. Parameters of bone resorption did not vary significantly between age groups. Paired biopsies from adjacent sites, obtained in eight subjects, were used to examine the reproducibility of histomorphometric parameters in children. The lowest coefficients of variation (<10%) were found for structural measures, as well as mineral apposition rate and wall thickness. The highest variability was found for cellular parameters. The availability of reference material will greatly facilitate the use of histomorphometry in pediatrics.

Impaired endothelial function and increased carotid stiffness in 9-year-old children with low birthweight

BACKGROUND

Low birthweight (LBW) has been associated with an increased incidence of adult cardiovascular disease. Endothelial dysfunction and loss of arterial elasticity are early markers of hypertension and atherosclerosis. We studied the prevalence of these markers in 44 healthy, prepubertal (age 9+/-1.3 years) children, 22 with LBW for age.

METHODS AND RESULTS

Endothelial function in skin was tested with the local application of acetylcholine (inducing endothelium-dependent vasodilation) and nitroglycerin (endothelium-independent vasodilation), and local perfusion changes were measured with the laser Doppler method. The elastic properties of the abdominal aorta and common carotid artery were measured with an ultrasonic vessel-wall tracking system. Endothelium-dependent vasodilation was lower in children with LBW (88+/-33 perfusion units [PU]) than in normal-birthweight controls (133+/-34 PU, P<0.001). There was no difference in aortic or carotid elasticity between the 2 groups, but a negative correlation was found between birthweight and stiffness of the carotid artery wall (r=-0.45, P<0.01). Endothelium-independent vasodilation and blood pressure were similar in the 2 groups.

CONCLUSIONS

Schoolchildren with a history of LBW show impaired endothelial function and a trend toward increased carotid stiffness. These findings may be early expressions of vascular compromise, contributing to susceptibility to disease in adult life.

Human cervical ripening, an inflammatory process mediated by cytokines

An extensive remodelling process, referred to as cervical ripening, takes place in the cervical tissue during pregnancy and labour. It is recognized as softening and dilation of the cervical canal, and starts as a slow process during pregnancy, becoming rapid close to partum. In this study we focus on cytokines as possible mediators of this final remodelling. mRNA levels for interleukin (IL)-8, IL-6 and granulocyte colony-stimulating factor (G-CSF) were upregulated in the ripe postpartum cervical tissue (n = 8) compared to the unripe state (n = 9). Likewise, released cytokine concentrations increased from non-pregnant (n = 11) to the term-pregnant group (n = 13) with a further increase at partum (n = 16). IL-8 concentrations increased 4-fold from non-pregnant to term-pregnant (P<0.01), and a further 10-fold to postpartum state (P<0.0001). Concentrations of IL-6 and G-CSF were similarly increased. Specific IL-8 immunostaining was identified in the epithelia of pregnant cervical tissue (n = 7) and was most pronounced in the epithelia and stroma of postpartum tissue (n = 4). In conclusion, IL-8, IL-6 and G-CSF increase in the human cervix during the ripening process, indicating their important role in the cervical remodelling. These data demonstrate that cervical ripening is similar to an inflammatory process.

Yersinia YopE is targeted for type III secretion by N-terminal, not mRNA, signals

Pathogenic Yersinia species inject virulence proteins, known as Yops, into the cytosol of eukaryotic cells. The injection of Yops is mediated via a type III secretion system. Previous studies have suggested that YopE is targeted for secretion by two signals. One is mediated by its cognate chaperone YerA, whereas the other consists of either the 5' end of yopE mRNA or the N-terminus of YopE. In order to characterize the YopE N-terminal/5' mRNA secretion signal, the first 11 codons of yopE were systematically mutagenized. Frameshift mutations, which completely alter the amino acid sequence of residues 2-11 but leave the mRNA sequence essentially intact, drastically reduce the secretion of YopE in a yerA mutant. In contrast, a mutation that alters the yopE mRNA sequence, while leaving the amino acid sequence of YopE unchanged, does not impair the secretion of YopE. Therefore, the N-terminus of YopE, and not the 5' end of yopE mRNA, serves as a targeting signal for type III secretion. In addition, the chaperone YerA can target YopE for type III secretion in the absence of a functional N-terminal signal. Mutational analysis of the YopE N-terminus revealed that a synthetic amphipathic sequence of eight residues is sufficient to serve as a targeting signal. YopE is also secreted rapidly upon a shift to secretion-permissive conditions. This 'rapid secretion' of YopE does not require de novo protein synthesis and is dependent upon YerA. Furthermore, this burst of YopE secretion can induce a cytotoxic response in infected HeLa cells.

Galanin regulates prolactin release and lactotroph proliferation

The neuropeptide galanin is predominantly expressed by the lactotrophs (the prolactin secreting cell type) in the rodent anterior pituitary and in the median eminence and paraventricular nucleus of the hypothalamus. Prolactin and galanin colocalize in the same secretory granule, the expression of both proteins is extremely sensitive to the estrogen status of the animal. The administration of estradiol-17beta induces pituitary hyperplasia followed by adenoma formation and causes a 3,000-fold increase in the galanin mRNA content of the lactotroph. To further study the role of galanin in prolactin release and lactotroph growth we now report the generation of mice carrying a loss-of-function mutation of the endogenous galanin gene. There is no evidence of embryonic lethality and the mutant mice grow normally. The specific endocrine abnormalities identified to date, relate to the expression of prolactin. Pituitary prolactin message levels and protein content of adult female mutant mice are reduced by 30-40% compared with wild-type controls. Mutant females fail to lactate and pups die of starvation/dehydration unless fostered onto wild-type mothers. Prolactin secretion in mutant females is markedly reduced at 7 days postpartum compared with wild-type controls with an associated failure in mammary gland maturation. There is an almost complete abrogation of the proliferative response of the lactotroph to high doses of estrogen, with a failure to up-regulate prolactin release, STAT5 expression or to increase pituitary cell number. These data further support the hypothesis that galanin acts as a paracrine regulator of prolactin expression and as a growth factor to the lactotroph.

Epigenetic modulation at birth - altered DNA-methylation in white blood cells after Caesarean section

AIM

Delivery by C-section (CS) has been associated with increased risk for allergy, diabetes and leukaemia. Whereas the underlying cause is unknown, epigenetic change of the genome has been suggested as a candidate molecular mechanism for perinatal contributions to later disease risk. We hypothesized that mode of delivery affects epigenetic activity in newborn infants.

METHODS

A total of 37 newborn infants were included. Spontaneous vaginal delivery (VD) occurred in 21, and 16 infants were delivered by elective CS. Blood was sampled from the umbilical cord and 3-5 days after birth. DNA-methylation was analyzed in leucocytes.

RESULTS

Infants born by CS exhibited higher DNA-methylation in leucocytes compared with that of those born by VD (p < 0.001). After VD, newborn infants exhibited stable levels of DNA-methylation, as evidenced by comparing cord blood values with those 3-5 days after birth (p = 0.55). On postnatal days 3-5, DNA-methylation had decreased in the CS group (p = 0.01) and was no longer significantly different from that of VD (p = 0.10).

CONCLUSION

DNA-methylation is higher in infants delivered by CS than in infants vaginally born. Although currently unknown how gene expression is affected, or whether epigenetic differences related to mode of delivery are long-lasting, our findings open a new area of clinical research with potentially important public health implications.

Release of neutrophil chemotactic activity during immediate hypersensitivity reactions in humans

Heat-stable, serum-derived chemotactic activity for neutrophils is shown in a human model of immunoglobulin E-mediated asthma. Twenty-six ragweed-sensitive subjects underwent bronchial provocation challenge using ragweed and Mecholyl. Increased neutrophil chemotactic activity was found in serum tested from 5 to 30 min after a positive ragweed-inhalation challenge, but not after negative ragweed challenge. The appearance of neutrophil chemotactic activity did not reflect the effects of bronchospasm alone, because it was not found after bronchospastic responses to Mecholyl in the same subjects. There were no accompanying changes of serum complement activity, nor evidence of inhibition of the chemotactic activity by proir exposure to antisera to the third and fifth components of complement. Ultrafiltration of serum showed chemotactic activity contained in fractions of at least 50 000 daltons. This appears to be the first demonstration of neutrophil chemotactic activity liberated during experimentally induced immunoglobulin E-mediated asthma in humans.

Anal incontinence after vaginal delivery: a prospective study in primiparous women

OBJECTIVE

To investigate the incidence and degree of anal incontinence after vaginal delivery among primiparous women and to define associated risk factors.

DESIGN

Prospective observational study.

SETTING

Karolinska Institutet, Danderyd Hospital, Sweden, a university hospital.

PARTICIPANTS

Three hundred and forty-nine primiparous women.

METHODS

Questionnaires distributed within the first days after delivery and re-distributed five and nine months postpartum. Analysis of delivery records.

RESULTS

Eighty percent of the women answered all questionnaires. At five months postpartum, 2% of the women had symptoms of faecal incontinence and 25% had symptoms of involuntary flatus. At nine months postpartum, 1% of the women had symptoms of faecal incontinence and 26% had symptoms of involuntary flatus. The majority of the women had infrequent symptoms and a decrease in severity was noted at nine months. Symptoms of incontinence were more common in women who sustained a sphincter tear at delivery. Risk factors for incontinence at five months included maternal age, duration of the second stage of labour, instrumental vaginal delivery, and clinically diagnosed sphincter tear at delivery. Development of incontinence at nine months was associated with maternal age and clinically diagnosed sphincter tear at delivery.

CONCLUSIONS

The present study demonstrates that infrequent involuntary flatus is a common symptom after vaginal delivery in primiparous women. These symptoms of involuntary flatus frequently improved and only a few women suffered from frank faecal incontinence. Factors associated with an increased risk of anal incontinence and sphincter tears should be considered during delivery.

Increased catecholamines and heart rate in children with low birth weight: perinatal contributions to sympathoadrenal overactivity

BACKGROUND

Low birth weight is associated with cardiovascular disease. The underlying mechanisms are unknown. We hypothesized that perinatal stress alters autonomic regulation of the cardiovascular system. In this study, catecholamines, heart rate (HR) and blood pressure (BP) were measured in healthy children with low birth weight.

METHODS

This clinical study included 105 children (mean age 9.6 years) in three groups; born at term with normal birth weight (controls, n=37), born at term but small for gestational age (SGA, n=29) and born preterm (Preterm, n=39). Dopamine, adrenaline and noradrenaline were determined in urine. HR and BP were measured at rest, during an orthostatic test and after a mathematical mental stress test.

RESULTS

Children in the Preterm and SGA groups excreted higher levels of catecholamines when compared with controls. HR (mean [SD] values) were higher at rest and after mental stress in Preterm (at rest 76 [9] and after mental stress 82 [12] min(-1)) and in SGA (79 [8] and 82 [10]) when compared with controls (70 [9] and 75 [9]). HR correlated with urinary catecholamines (r=0.24-0.27, P<0.05). Blood pressures measured at rest, during orthostatic testing and after mental stress did not differ between the groups.

CONCLUSIONS

Preterm birth and fetal growth restriction are associated with increased sympathoadrenal activity in childhood, as indicated by stress-induced increases in HR and urinary catecholamines. These findings suggest that the cardiovascular control is differently programmed in these children with possibly higher risk of developing hypertension in adulthood.

Impaired acetylcholine-induced vascular relaxation in low birth weight infants: implications for adult hypertension?

Low birth weight is associated with an increased risk of adult hypertension. To elucidate whether this association reflects altered vascular physiology already at birth, we studied acetylcholine-induced vasodilation. Forty newborn infants and their mothers were studied 3 d after delivery. Vasodilation in skin was induced by local application of acetylcholine and local heating to 44 degrees C. Perfusion changes were measured with the laser Doppler technique. In response to acetylcholine, the mean skin perfusion increased by 240% in low birth weight infants compared with 650% in normal birth weight controls (p < 0.001). In contrast, mothers of low birth weight infants showed a mean increase in perfusion of 1100% after acetylcholine administration compared with 680% in mothers of control infants (p < 0.05). The perfusion increase at 44 degrees C local skin temperature did not differ between the two groups of infants or between their mothers. Blood pressure was normal in all subjects. We conclude that low birth weight infants show signs of endothelial dysfunction at birth. Such findings may help us understand the link between low birth weight and adult hypertension.

Lower skin capillary density, normal endothelial function and higher blood pressure in children born preterm

BACKGROUND

Preterm birth is a risk factor for blood pressure (BP) elevation already at young age. The mechanisms are unknown. Low skin capillary density and impaired endothelial function characterize adults with hypertension.

OBJECTIVES

To investigate the early relationships between BP, capillary density and endothelial function after very preterm birth. Design and subjects. Clinical follow-up study of 60 healthy school children aged 7-12 years; 39 born very preterm (mean gestational age 29 weeks) and 21 control subjects born at term with normal birth weights.

METHODS

Using intravital video-microscopy, the dermal capillary densities in the fingers were measured before and during venous occlusion. Endothelial function was assessed using a Laser-Doppler technique to determine skin perfusion before and after transdermal delivery of acetylcholine, an endothelium-dependent vasodilator. Brachial BP and heart rate (HR) were also recorded.

RESULTS

Children born very preterm had lower functional capillary density than term controls (89.9 capillaries mm(-2) vs. 96.6 capillaries mm(-2), P = 0.04). During venous occlusion--measuring structural differences--this difference diminished (91.4 capillaries mm(-2) vs. 96.8 capillaries mm(-2), P = 0.12). In multivariate analysis, systolic BP (SBP) was higher in children born preterm, but SBP and capillary density did not correlate. HR was also higher in children born preterm, but did not correlate to BP or capillary density. Endothelial function did not differ between groups and did not correlate to capillary density.

CONCLUSION

Children born very preterm have lower functional skin capillary density, higher BP and higher HR. Longitudinal studies are needed to fully understand the long-term significance of these findings.

Bacteremia on an obstetric-gynecologic service

In a one-year evaluation of the Obstetric-Gynecologic Services of the Los Angeles County University of Southern California Medical Center, bacteremia was confirmed on 144 occasions in 139 patients. This represented an over-all incidence of 7/1,000 admissions with gram-negative bacteremia observed in 3.1/1,000 admissions. There were four deaths in this series. The most frequently recovered aerobes were Escherichia coli, enterococci, and beta hemolytic streptococci, not Group A or D, while the most commonly isolated anaerobes were peptostreptococci, peptococci, and Bacteroides. These patterns of bacterial isolation should be acknowledged in antibiotic strategies for septic patients. There is a positive correlation between the incidence of intrapartum maternal and fetal monitoring and postpartum maternal bacteremia. The oncology patients were the most seriously ill women with bacteremia.

Antimyelin antibodies in neurologic diseases. Immunofluorescent demonstration

Antimyelin binding activity was determined in patients with multiple sclerosis, amyotrophic lateral sclerosis, other neurologic diseases, and normals. There was an increase in the group mean titer of antimyelin antibodies in patients with multiple sclerosis (MS) in acute exacerbation, amyotrophic lateral sclerosis (ALS) and Guillain-Barré syndrome. A lesser degree of binding was found in normals of all ages. There was an increase in the incidence of antimyelin antibodies in the IgM class in patients with ALS and MS. The interaction between human immunoglobulins and myelin seems to be immunologically specific and has the nature of an antigen-antibody reaction.

Low-flow oxygen and bilevel ventilatory support: effects on ventilation during sleep in cystic fibrosis

We measured ventilation in all sleep stages in patients with cystic fibrosis (CF) and moderate to severe lung disease, and compared the effects of low-flow oxygen (LFO2) and bilevel ventilatory support (BVS) on ventilation and gas exchange during sleep. Thirteen subjects, age 26 +/- 5.9 yr (mean +/- 1 SD), body mass index (BMI) 20 +/- 3 kg/m2, FEV1 32 +/- 11% predicted, underwent three sleep studies breathing, in random order, room air (RA), LFO2, and BVS +/- O2 with recording of oxyhemoglobin saturation (SpO2) (%) and transcutaneous carbon dioxide (TcCO2) (mm Hg). During RA and LFO2 studies, patients wore a nasal mask with a baseline continuous positive airway pressure (CPAP) of 4 to 5 cm H2O. Minute ventilation (V I) was measured using a pneumotachograph in the circuit and was not different between wake and non-rapid eye movement (NREM) sleep on any night. However, V I was reduced on the RA and LFO2 nights from awake to rapid eye movement (REM) (p < 0.01) and from NREM to REM (p < 0.01). On the BVS night there was no significant difference in V I between NREM and REM sleep. Both BVS and LFO2 improved nocturnal SpO2, especially during REM sleep (p < 0.05). The rise in TcCO2 seen with REM sleep with both RA and LFO2 was attenuated with BVS (p < 0.05). We conclude that BVS leads to improvements in alveolar ventilation during sleep in this patient group.

Determination of pH or lactate in fetal scalp blood in management of intrapartum fetal distress: randomised controlled multicentre trial

OBJECTIVE

To examine the effectiveness of pH analysis of fetal scalp blood compared with lactate analysis in identifying hypoxia in labour to prevent acidaemia at birth.

DESIGN

Randomised controlled multicentre trial.

SETTING

Labour wards.

PARTICIPANTS

Women with a singleton pregnancy, cephalic presentation, gestational age >or=34 weeks, and clinical indication for fetal scalp blood sampling.

INTERVENTIONS

Standard pH analysis (n=1496) or lactate analysis (n=1496) with an electrochemical microvolume (5 mul) test strip device. The cut-off levels for intervention were pH <7.21 and lactate >4.8 mmol/l, respectively.

MAIN OUTCOME MEASURE

Metabolic acidaemia (pH <7.05 and base deficit >12 mmol/l) or pH <7.00 in cord artery blood.

RESULTS

Metabolic acidaemia occurred in 3.2% in the lactate group and in 3.6% in the pH group (relative risk 0.91, 95% confidence interval 0.61 to 1.36). pH <7.00 occurred in 1.5% in the lactate group and in 1.8% in the pH group (0.84, 0.47 to 1.50). There was no significant difference in Apgar scores <7 at 5 minutes (1.15, 0.76 to 1.75) or operative deliveries for fetal distress (1.02, 0.93 to 1.11).

CONCLUSION

There were no significant differences in rate of acidaemia at birth after use of lactate analysis or pH analysis of fetal scalp blood samples to determine hypoxia during labour.

TRIAL REGISTRATION

ISRCT No 1606064.

Advanced maternal age increases the risk of very preterm birth, irrespective of parity: a population-based register study

OBJECTIVE

To investigate whether advanced maternal age is associated with preterm birth, irrespective of parity.

DESIGN

Population-based registry study.

SETTING

Swedish Medical Birth Register.

POPULATION

First, second, and third live singleton births to women aged 20 years or older in Sweden, from 1990 to 2011 (n = 2 009 068).

METHODS

Logistic regression analysis was used in each parity group to estimate risks of very and moderately preterm births to women at 20-24, 25-29, 30-34, 35-39, and 40 years or older, using 25-29 years as the reference group. Odds ratios (ORs) were adjusted for year of birth, education, country of birth, smoking, body mass index, and history of preterm birth. Age-related risks of spontaneous and medically indicated preterm births were also investigated.

MAIN OUTCOME MEASURES

Very preterm (22-31 weeks of gestation) and moderately preterm (32-36 weeks) births.

RESULTS

Risks of very preterm birth increased with maternal age, irrespective of parity: adjusted ORs in first, second, and third births ranged from 1.18 to 1.28 at 30-34 years, from 1.59 to 1.70 at 35-39 years, and from 1.97 to 2.40 at ≥40 years. In moderately preterm births, age-related associations were weaker, but were statistically significant from 35-39 years in all parity groups. Advanced maternal age increased the risks of both spontaneous and medically indicated preterm births.

CONCLUSIONS

Advanced maternal age is associated with an increased risk of preterm birth, irrespective of parity, especially very preterm birth. Women aged 35 years and older, expecting their first, second, or third births, should be regarded as a risk group for very preterm birth.

TWEETABLE ABSTRACT

Women aged 35 years and older should be regarded as a risk group for very preterm birth, irrespective of parity.

Insertion of an amino acid in the DNA-binding domain of the glucocorticoid receptor as a result of alternative splicing

When the human glucocorticoid receptor (GR) was first sequenced, a predominant form (GRalpha) and a minor variant (GRbeta) were identified. In the present communication, we describe a new variant of the glucocorticoid receptor (GRgamma) in which, as a result of alternative splicing, three bases are retained from the intron separating exons 3 and 4. These three bases code for an additional amino acid (arginine) in the DNA binding domain of the receptor. Insertion of arginine at this site has previously been shown to decrease transcriptional activation by the GR to 48% that of GRalpha. Analysis of cDNA from different tissues shows that the novel form is widely expressed at a relatively high level (between 3.8 and 8.7% of total GR).

Predicting therapeutic outcome in severe ulcerative colitis by measuring in vitro steroid sensitivity of proliferating peripheral blood lymphocytes

BACKGROUND

Up to 29% of patients with severe ulcerative colitis (UC) fail to respond to steroid treatment and require surgery. Previous studies have failed to show a clear correlation between failure of steroid treatment in severe UC and measures of disease severity. The reasons for treatment failure therefore remain unknown.

AIM

To investigate the hypothesis that patients with severe UC who fail to respond to steroid treatment have steroid resistant T lymphocytes.

METHODS

Eighteen patients with severe UC were studied. After seven days' treatment with high dose intravenous steroids they were classified as complete responders (CR), incomplete responders (IR), or treatment failures (TF). Within 48 hours of admission blood was taken and the antiproliferative effect of dexamethasone on phytohaemagglutinin stimulated peripheral blood T lymphocytes was measured. Maximum dexamethasone induced inhibition of proliferation (I(max)) was measured.

RESULTS

In vitro T lymphocyte steroid sensitivity of TF and IR patients was significantly less than that of CR patients. Both TF and 3/5 IR patients had an I(max) of less than 60%; all CR patients had an I(max) of greater than 60%. No significant correlation was seen between response to treatment and disease severity on admission. When in vitro T lymphocyte steroid sensitivity was remeasured three months later, there was no difference between the groups.

CONCLUSIONS

Results suggest that T lymphocyte steroid resistance is an important factor in determining response to steroid treatment in patients with severe UC and may be more predictive of outcome than disease severity.

Differential expressions of mRNA for proteoglycans, collagens and transforming growth factor-beta in the human cervix during pregnancy and involution

During pregnancy and involution, an extensive remodelling of the human cervical connective tissue occurs. This cervical ripening is one of the most pronounced physiological remodelling processes known in human connective tissue. To investigate how the remodelling is accomplished, the levels of mRNA for collagen I and III, versican and three small proteoglycans, biglycan, decorin and fibromodulin, were evaluated using Northern blots at different stages of cervical ripening. In the corresponding biopsies the concentration of collagen and of small and large proteoglycans were determined. The role of transforming growth factor-beta (TGF-beta) as a mediator of the remodelling process was also investigated. The concentration of collagen decreased and 1 week before partus, 50% of the nonpregnant level was attained. No further decrease was noted after partus. The mRNA for collagen I and III did, however, not decrease in the term pregnant cervix 1 week before partus. Only 20-30% decrease during the final ripening just before partus was recorded. Neither did the mRNA levels of the small proteoglycans change significantly during the ripening, despite an almost 50% decrease in the concentration of the small proteoglycans. The message for versican was, however, 5-fold increased at partus and then gradually returned to nonpregnant levels within 4 days after delivery. These changes corresponded to similar changes in the concentration of the large proteoglycan. Thus, the remodelling of the cervical connective tissue is achieved by two different mechanisms, on one hand an increased turnover of collagen and the small proteoglycans, on the other a changed transcription followed by an increased production of versican. During the involution 2- to 3-fold increases in the messages for collagen I and III, and the small proteoglycans, biglycan and decorin, corresponded to increases in the concentration of the small proteoglycans and non-extractable collagen. The message for TGF-beta was increased 2-fold immediately after delivery compared with the term pregnant state. Thus, TGF-beta may be of importance for the reconstruction of the cervix, which starts immediately after partus.

Levels of GH binding activity, IGFBP-1, insulin, blood glucose and cortisol in intensive care patients

OBJECTIVE

To investigate levels of serum GH binding activity, insulin-like growth factor binding protein-1 (IGFBP-1), blood glucose, serum insulin, and cortisol in patients on the Intensive Therapy Unit.

DESIGN

Case-control study of severely ill patients admitted to the Intensive Therapy Unit.

PATIENTS

Six critically ill patients (51-78 years) who required ventilatory and nutritional support and six healthy age, sex, height and weight matched controls.

MEASUREMENTS

Patients and controls were studied for two 24-hour periods; the patients before and after commencing parenteral nutrition, the controls whilst fasted and on a second occasion when fed a diet equal in protein and calories to that of the patients' parenteral nutrition. Samples were taken hourly for measurement of IGFBP-1, blood glucose, serum insulin and cortisol. Growth hormone binding activity was measured at 0 hours.

RESULTS

Blood glucose levels were higher in the patients than controls in both the fasted (mean +/- SEM 5.1 +/- 0.5 vs 3.8 +/- 0.2 mmol/l, P = 0.04) and fed states (10.1 +/- 1.6 vs 5.0 +/- 0.1 mmol/l, P = 0.02) and patients' insulin levels were also higher when fed (81.5 +/- 31.6 vs 24.2 +/- 4.8 mU/l, P = 0.046) although there were no significant differences between patients and controls when fasted. IGFBP-1 levels were inversely related to insulin levels in both the patients and controls; mean IGFBP-1 concentrations were higher in fasted patients than in controls (123 +/- 38 vs 52 +/- 9, P = 0.046) but when fed, both groups had similar mean levels. Serum GH binding activity was low in the patients and did not change with feeding. Mean 24-hour cortisol levels were higher in the patients than in controls, whether fasted or fed, and showed no nyctohemeral rhythm.

CONCLUSIONS

We have previously reported that critically ill patients have low levels of IGF-I with augmented basal levels of GH. The present results demonstrate that these changes in the GH-IGF-I axis are associated with insulin resistance with respect to blood glucose and high levels of IGFBP-1 when patients are fasted. However, when fed, the inverse relationship of IGFBP-1 to insulin is preserved. Patients have low levels of GH binding activity and increased mean cortisol levels. Interventional studies in this patient group with GH and IGF-I must take account of these changes in binding protein and cortisol levels.

Reactive hyperemia and interleukin 6, interleukin 8, and tumor necrosis factor-alpha in the diagnosis of early-onset neonatal sepsis

OBJECTIVE

To evaluate the diagnostic value of peripheral circulatory reactive hyperemia and serum levels of interleukin-6 (IL-6), IL-8, and tumor necrosis factor-alpha (TNF-alpha) in early-onset neonatal sepsis.

METHODS

Reactive hyperemia in the dorsal hand and serum levels of IL-6, IL-8, and TNF-alpha were studied in newborn infants (n = 32; gestational age 39 +/- 3 weeks) who had been admitted to the neonatal unit because of suspected sepsis <48 hours after birth. On admission, reactive hyperemia after a standardized arterial occlusion was measured with laser Doppler technique, and blood samples were taken for cytokine analyses. On the basis of predetermined criteria, the infants subsequently were classified as septic (n = 12) or not (n = 20).

RESULTS

The degree of reactive hyperemia was higher in the group with sepsis (median + 170% perfusion increase) than in that without (+37%). On admission, serum levels of IL-6, IL-8, and TNF-alpha all were higher in septic (median values: 1620, 331, and 22 pg/mL, respectively) than in nonseptic neonates (median values: 42, 63, and 13 pg/mL, respectively). In the group with sepsis, the degree of reactive hyperemia correlated to log IL-6 (r = 0.80) and log IL-8 values (r = 0.71).

CONCLUSION

Newborn infants with septicemia have increased reactive hyperemia and elevated cytokine levels very early in their disease. Reactive hyperemia in skin can be analyzed at the bedside and noninvasively and therefore may serve as an additional diagnostic tool in neonatal sepsis.

Crystals of HIV-1 reverse transcriptase diffracting to 2.2 A resolution

Reverse transcriptase (RT) from the human immunodeficiency virus type 1 has been crystallized in four closely related forms, the best of which diffract X-rays to 2.2 A resolution. The RT was crystallized as a complex with a non-nucleoside inhibitor, either nevirapine or a nevirapine analogue. Crystals grew from 6% PEG 3400 buffered at pH 5. These were of space group P2(1)2(1)2(1) with unit cell parameters a = 147 A, b = 112 A, c = 79 A (form A), with one RT heterodimer in the asymmetric unit. Changes in unit cell parameters and degree of crystalline order were observed on soaking pregrown crystals in various solutions, giving three further sets of unit cells. These were a = 143 A, b = 112, A, c = 79 A (form B), a = 141 A, b = 111 A, c = 73 A (form C), a = 143 A, b = 117 A, c = 66.5 A (form D). The last two forms diffract X-rays to 2.2 A resolution. Structure determinations of these latter crystal forms of RT should give a detailed atomic model for this therapeutically important drug target.

Apnea in patients with myelomeningocele

Apnea is a known complication of the Chiari II malformation presenting in infancy. Obstructive apnea secondary to bilateral abductor palsy or laryngomalacia and centrally mediated expiratory apnea with cyanosis can occur. Observations of 9 patients suggest that these forms of apnea may represent stages in a continuum of brain stem dysfunction due to the combined effects of the hindbrain malformation and its compression, hydrocephalus and progressive arachnoiditis. Obstructive apnea in some patients may be reversed by optimal control of hydrocephalus with or without cervical decompression. These patients may also develop episodes of cyanotic expiratory apnea of central origin (PEAC). This form of apnea does not respond to surgical or medical treatment and may show progressive worsening over time. Five of 6 patients with this form of apneic spell died suddenly, 2 of these died despite full recuscitative efforts. It is recommended that reports of treatment address results for both forms of apnea.