Immunoprophylaxis of acute respiratory diseases with bacterial multicomponent vaccine VP-4 in children at preschool institutions

The prophylactic action of polycomponent vaccine B[symbol: see text]-4, prepared from the antigens of opportunistic bacteria, on morbidity rate in acute respiratory diseases (ARD) of bacterial and mixed (bacterial and viral) etiology in 121 children aged 2-5 years, attending pre-school institutions was evaluated. For comparison, a group of 118 children of the same age from the same institutions was formed. The vaccine was introduced after the schedule consisting of 3 intranasal and 6-9 oral administrations made at intervals of 3-4 days. The duration of the course of immunization was 26 +/- 4 days. The prophylactic effect of B[symbol: see text]-4 on ARD morbidity was evaluated by the number of ARD cases and their duration per child. The prophylactic effect of B[symbol: see text]-4 on ARD morbidity lasted 14 months (the term of observation) after immunization and was manifested by a decrease in the number and duration of ARD cases after administration of the preparation, also in a group of highly susceptible children.     

Acute red ear in children: controlled trial of non-antibiotic treatment in general practice.

OBJECTIVE--To examine the efficacy and safety of conservative management of mild otitis media ("the acute red ear") in children. DESIGN--Double blind placebo controlled trial. SETTING--17 group general practices (48 general practitioners) in Southampton, Bristol, and Portsmouth. PATIENTS--232 children aged 3-10 years with acute earache and at least one abnormal eardrum (114 allocated to receive antibiotic, 118 placebo). INTERVENTIONS--Amoxycillin 125 mg three times a day for seven days or matching placebo; 100 ml paracetamol 120 mg/5 ml. MAIN OUTCOME MEASURES--Diary records of pain and crying, use of analgesic, eardrum signs, failure of treatment, tympanometry at one and three months, recurrence rate, and ear, nose, and throat referral rate over one year. RESULTS--Treatment failure was eight times more likely in the placebo than the antibiotic group (14.4% v 1.7%, odds ratio 8.21, 95% confidence interval 1.94 to 34.7). Children in the placebo group showed a significantly higher incidence of fever on the day after entry (20% v 8%, p less than 0.05), mean analgesic consumption (0.36 ml/h v 0.21 ml/h, difference 0.14, 95% confidence interval 0.07 to 0.23; p = 0.0022), mean duration of crying (1.44 days v 0.50 days, 0.94; 0.50 to 1.38; p less than 0.001), and mean absence from school (1.96 days v 0.52 days, 1.45; 0.46 to 2.42; p = 0.0132). Differences in recorded pain were not significant. The prevalence of middle ear effusion at one or three months, as defined by tympanometry, was not significantly different, nor was there any difference in recurrence rate or in ear, nose, and throat referral rate in the follow up year. No characteristics could be identified which predicted an adverse outcome. CONCLUSIONS--Use of antibiotic improves short term outcome substantially and therefore continues to be an appropriate management policy.     

The reactogenicity and safety of a multicomponent vaccine (VP-4) in the prevention of acute respiratory diseases in preschoolers

The reactogenicity and safety of poly-component vaccine (VP-4), prepared from the antigens of opportunistic bacteria, in the prophylaxis of acute respiratory diseases (ARD) in children aged 2.6-6 years. The vaccine was administered intranasally in 3 administrations and orally in 6-8 administrations at intervals of 3-4 days for a period of 24 +/- 4 days. The prophylaxis of ARD with the use of VP-4 was carried out in 168 children in 4 children's preschool institutions. The control group was made up of 120 children, attending the same institutions. The study revealed that VP-4 had low reactogenicity and induced short-time systemic and local reactions (common cold, cough). The administration of VP-4 at a period of the epidemic rise on influenza and ARD morbidity did not lead to an increase in the frequency and duration of ARD in the vaccinees, as well as to the exacerbation of chronic infection and the allergization of the body.     

Phytoseiid mites in protected crops: the effect of humidity and food availability on egg hatch and adult life span of Iphiseius degenerans, Neoseiulus cucumeris, N. californicus and Phytoseiulus persimilis (Acari: Phytoseiidae)

The effect of relative humidity on egg hatch success for Iphiseius degenerans, Neoseiulus californicus and N. cucumeris was described by a binomial model with a parallel slope. The shape of the response differed for Phytoseiulus persimilis and a model with separate parameters gave a significantly better fit. Fitted response curves showed that I. degenerans, N. cucumeris, N. californicus and P. persimilis were ranked by decreasing tolerance to low humidity, with egg mortalities of < 0.5, 3, 12 and 16% respectively at 75-80% RH at 20 degrees C. Egg stage duration for I. degenerans and N. cucumeris was unaffected over the range 60-82% RH. For N. californicus and P. persimilis egg duration was significantly longer at 60 and 70% than for either 82 or 90% RH. No effect of relative humidity was found on the mean life span of adult females when food was available continuously to the mites. N. californicus lived significantly longer (58 days after the first egg was laid) than the other species. No significant difference was observed in mean life span between adult females of I. degenerans and N. cucumeris (25 and 28 days respectively). The mean life span of adult female P. persimilis (19 days) was significantly shorter than the other species. In the absence of both food and water, the survival of adult female mites was reduced to 2-4 days. Survival time was at least doubled when free water was available in the absence of food. Mean survival of adult female mites with water but without food was 10 days for N. cucumeris, 18 days for N. californicus, 6 days for P. persimilis and 4 days for I. degenerans. Survival of adult female N. cucumeris and N. californicus was increased significantly, to 20 and 22 days respectively, when fungal hyphae were present along with water but in the absence of other food.     

Prepubertal growth in children with long-term parenteral nutrition

In children who depend on long-term parenteral nutrition (PN), a major goal is to obtain optimal growth. The aim of this retrospective study was to analyze growth in children on long-term cyclic nocturnal home PN, over at least 8 years before puberty. Nine boys and 7 girls were studied. Their mean age at the time of study was 11 years with a mean PN duration of 10.5 (8.6-16.4) years. Diseases were short bowel syndrome (5), intractable diarrhea (4), chronic intestinal pseudo-obstruction (4) and long segment Hirschsprung's disease (3). In each child, periods of at least 2 years were analyzed: either periods of regular growth (R: height gain >50th percentile), or slow growth (S: height gain < or =25th percentile). Results were expressed as mean +/- SD. Comparisons were performed using either Student's test for unpaired data or Wilcoxon's test for paired data. PN provided a mean of 224 +/- 80 mg nitrogen/kg/day and 43 +/- 14 kcal/kg/day equivalent to 50% of recommended supplies. At the time of study, the population presented with weight (W) = -0.7 +/- 0.8 SD and height (H) = -1.5 +/- 1.3 SD. The difference between W and expected W for H (W/H) was significant (p < 0.002). W/H ratio was 105 +/- 11%. For the total PN duration, weight gain was +0.2 +/- 1.5 SD and height loss was -0.75 +/- 1.4 SD. An excess weight gain occurred in parallel with the deflection of height gain. Of the 16 children, regular prepubertal growth was achieved in 4 only. The other 12 showed alternate periods of R and S. In 8 of them, 26.5 years of R and 33.5 years of S were compared, each child being his own control. PN nitrogen and energy supplies were significantly higher during R periods than during S periods. In the absence of any disease or treatment explaining the failure to thrive, inadequate PN supplies, especially in terms of nitrogen supply, are thought to be responsible for a negative nitrogen balance and slowed growth. In case of any deflection away from the individual growth curve, it is recommended to adjust the PN supply early, especially nitrogen supply.     

The Effect of a Yeast Probiotic on Acute Diarrhea in Children

A probiotic is a living micro-organism administered to promote the health of the host by treating or preventing infections owing to strains of pathogens. Saccharomyces boulardii is a nonpathogen yeast that has a direct inhibitory effect on the growth of many pathogens, an anti-secretory effect and a trophic effect on enterocytes. The aim of this study was to determine the effect of S. boulardii on diarrhea in children. The children from 6 months to 6 years of age with acute watery diarrhea admitted in pediatric clinic in Kashan in 2012 were included in this trial. Exclusion criteria were high fever (T > 38.5 °C), severe dehydration, bloody diarrhea, severe malnutrition, using of antibiotics, anti-diarrheal or antifungal drugs and children with more than one complain. Two hundred patients were assigned into two groups: A total of 100 patients were treated with S. boulardii in addition to ORS (case group) and 100 patients were given placebo in addition to ORS (control group). The duration of diarrhea and frequency of stools were recorded by asking the mothers of the children every day. The results showed that the defecation frequency after second day of treatment in the case group was significantly less than the control group (P = 0.001) and the mean numbers of days of diarrhea was significantly lower in the case group (P = 0.001). The result of this study confirms that S. boulardii reduces the frequency of stool and duration of illness in children.     

Effect of inhaled corticosteroids on episodes of wheezing associated with viral infection in school age children: randomised double blind placebo controlled trial.

OBJECTIVES: To determine the effect of regular prophylactic inhaled corticosteroids on wheezing episodes associated with viral infection in school age children. DESIGN: Randomised, double blind, placebo controlled trial. SETTING: Community based study in Southampton. SUBJECTS: 104 children aged 7 to 9 years who had had wheezing in association with symptoms of upper and lower respiratory tract infection in the preceding 12 months. INTERVENTIONS: After a run in period of 2-6 weeks children were randomly allocated twice daily inhaled beclomethasone dipropionate 200 micrograms or placebo through a Diskhaler for 6 months with a wash out period of 2 months. Children were assessed monthly. MAIN OUTCOME MEASURES: Forced expiratory volume in 1 second (FEV1); bronchial responsiveness to methacholine (PD20); percentage of days with symptoms of upper and lower respiratory tract infection with frequency, severity, and duration of episodes of upper and lower respiratory symptoms and of reduced peak expiratory flow rate. RESULTS: During the treatment period there was a significant increase in mean FEV1 (1.63 v 1.53 1; adjusted difference 0.09 1 (95% confidence interval 0.04 to 0.14); P = 0.001) and methacholine PD20 12.8 v 7.2 mumol/l; adjusted ratio of means 1.7 (1.2 to 2.4); P = 0.007) in children receiving beclomethasone dipropionate compared with placebo. There were, however, no significant differences in the percentage of days with symptoms or in the frequency, severity, or duration of episodes of upper or lower respiratory symptoms or of reduced peak expiratory flow rate during the treatment period between the two groups. CONCLUSIONS: Although lung function is improved with regular beclomethasone dipropionate 400 micrograms/day, this treatment offers no clinically significant benefit in school age children with wheezing episodes associated with viral infection.     

Impact of massive dose of vitamin A given to preschool children with acute diarrhoea on subsequent respiratory and diarrhoeal morbidity.

OBJECTIVE--To assess the impact of vitamin A supplementation on morbidity from acute respiratory tract infections and diarrhoea. DESIGN--Double blind randomised placebo controlled field trial. SETTING--An urban slum area in New Delhi, India. SUBJECTS--900 children aged 12-60 months attending a local health facility for acute diarrhoea of less than seven days'' duration randomly allocated to receive vitamin A 200,000 IU or placebo. MAIN OUTCOME MEASURES--Incidence and prevalence of acute lower respiratory tract infections and diarrhoea during the 90 days after termination of the enrolment diarrhoeal episode measured by twice weekly household surveillance. RESULTS--The incidence (relative risk 1.07; 95% confidence interval 0.92 to 1.26) and average number of days spent with acute lower respiratory tract infections were similar in the vitamin A supplementation and placebo groups. Among children aged 23 months or less there was a significant reduction in the incidence of measles (relative risk 0.06; 95% confidence interval 0.01 to 0.48). The incidence of diarrhoea was also similar (relative risk 0.95; 0.86 to 1.05) in the two groups. There was a 36% reduction in the mean daily prevalence of diarrhoea associated with fever in the vitamin A supplemented children older than 23 months. CONCLUSIONS--Results were consistent with a lack of impact on acute lower respiratory tract related mortality after vitamin A supplementation noted in other trials and a possible reduction in the severity of diarrhoea.     

Co-amoxiclav in recurrent acute otitis media: placebo controlled study.

OBJECTIVE--To determine the efficacy of coamoxiclav in children aged 6 months to 12 years with recurrent acute otitis media. DESIGN--A randomised double blind placebo controlled clinical trial. SETTING--General practice in the Netherlands. PATIENTS--121 children with recurrent acute otitis media, defined by onset of otalgia and otoscopic signs of middle ear infection within four to 52 weeks after the previous attack. Confirmation of diagnosis and randomisation was done by otolaryngologists. INTERVENTION--Oral co-amoxiclav or placebo in weight related doses for seven days. MAIN OUTCOME MEASURE--An irregular clinical course defined as the presence of otalgia or a body temperature greater than or equal to 38 degrees C, or both, after three days. RESULTS--Eleven (16%; 95% confidence interval 9% to 28%) children had an irregular course in the co-amoxiclav group and 10 (19%; 9% to 31%) in the placebo group (difference not significant). Age, dichotomised at 2 years, was the only significant prognostic factor for irregular course of the disease (odds ratio 5.9; 1.8 to 19.1). Among children aged below 2 years, 28% (4/14) in the co-amoxiclav group and 58% (7/12) in the placebo group had irregular courses. For children 2 years and older these percentages were 13% (7/52) and 7% (3/41). CONCLUSION--Children with recurrent acute otitis media are at greater risk of an irregular clinical course of the disease than children with a first episode of acute otitis media. Co-amoxiclav has no significant benefit over placebo in treating children over 2 years with acute otitis media.     

Diagnostics of nocturnal calls of Sciaena umbra (L., fam. Sciaenidae) in a nearshore Mediterranean marine reserve

Calls emitted by the brown meagre Sciaena umbra (L., fam. Sciaenidae) were recorded at the Natural Marine Reserve of Miramare (Trieste, Italy) in seven nocturnal surveys (12-h continuous sampling) during the summer of 2009. Calls consist of pulses, with the main energy content below 2 kHz and mean peak frequency of c. 270 Hz. Pulses were short, with an average duration of 20 ms and a pulse period of 100 ms. Sounds lasted approximately 500 ms. Three types of sound patterns were recognized: irregular (I), regular (R) and the chorus (C). Their acoustic parameters are described showing that I, R and C differ in pulse duration, pulse peak frequency and pulse period. Occurrence of the three call types changes throughout the night: the R pattern occurred mainly at dawn and dusk, C predominated after nightfall, while I calls were produced sporadically during the whole nocturnal period. Our results indicate that S. umbra has a pronounced nocturnal rhythm in vocalizing behaviour and highlight how the diagnostic time–frequency pattern of S. umbra calls can be used to identify the species in the field. Considering that the abundance of S. umbra is currently declining, the information presented here will be relevant in developing non-invasive and low-cost monitoring acoustic systems for managing S. umbra conservation and fishery along the Mediterranean Sea.     

The effect of immunotherapy with the VP-4 multicomponent vaccine in children with frequent acute respiratory diseases and obstructive bronchitis

The results of prolonged observations on children with frequent acute respiratory diseases (ARD), subject to immunoprophylaxis with the use of polycomponent vaccine (VP-4), prepared from the antigens of opportunistic microorganisms, are presented. The vaccine was introduced to 30 children in 3 intranasal administrations and 6-8 oral administrations. The morbidity rate of the children was registered and their clinical status was evaluated for a year after the introduction of vaccine VP-4. As revealed in these observations, the frequency of ARD cases among the immunized children decreased 3 times or more in comparison with that among the same children, registered during a year prior to the introduction of the vaccine. In addition to a decrease in the frequency of ARD cases, a decrease in their duration and in the number of antibiotic administrations, as well as in the necessity of hospitalization, were also registered.     

蚜虱净对苜蓿田节肢动物群落结构及动态的影响

以物种丰富度(S)、个体数量(N)、香农指数(Shannon’sindex,H′)和均匀度指数(E)作为多样性指标,研究了蚜虱净对苜蓿田节肢动物群落结构和季节动态的影响.结果表明:蚜虱净对天敌亚群落物种数的影响大于害虫亚群落,使总群落和害虫亚群落的优势集中性显著增加,但5月底施药对传粉蜜蜂类亚群落的优势集中性无显著影响.喷药初期,蚜虱净显著降低了蚜虫、蓟马等害虫数量,7d后蚜虫、蓟马等种群数量迅速回升,40d后超过对照;施药初期天敌亚群落的物种数大幅减少,多样性和均匀度指数较低,7d后天敌的物种数逐渐回升,到后期与对照田基本一致,但个体数量一直未恢复至对照水平.     

Phosphorylation of ARD1 by IKKβ contributes to its destabilization and degradation

IκB kinase β (IKKβ), a major kinase downstream of various proinflammatory signals, mediates multiple cellular functions through phosphorylation and regulation of its substrates. On the basis of protein sequence analysis, we identified arrest-defective protein 1 (ARD1), a protein involved in apoptosis and cell proliferation processes in many human cancer cells, as a new IKKβ substrate. We provided evidence showing that ARD1 is indeed a bona fide substrate of IKKβ. IKKβ physically associated with ARD1 and phosphorylated it at Ser209. Phosphorylation by IKKβ destabilized ARD1 and induced its proteasome-mediated degradation. Impaired growth suppression was observed in ARD1 phosphorylation-mimic mutant (S209E)-transfected cells as compared with ARD1 non-phosphorylatable mutant (S209A)-transfected cells. Our findings of molecular interactions between ARD1 and IKKβ may enable further understanding of the upstream regulation mechanisms of ARD1 and of the diverse functions of IKKβ.     

Impact of enalapril therapy on in vitro coronary artery responsiveness in pacing-induced heart failure.

In vitro coronary artery responsiveness to angiotensin I, angiotensin II, noradrenaline, phenylephrine, BHT 920, and potassium chloride together with functional relaxation to acetylcholine was investigated in dogs with pacing-induced heart failure treated with enalapril (oral administration of 10 mg.day-1) for a mean duration of 26 days. Although maximal responses generated to both angiotensin I and angiotensin II were unaltered in the enalapril-treated group, angiotensin II became more potent following enalapril treatment: the EC50 for angiotensin II following placebo treatment was 2.4 (0.6-5.8; 95% confidence limits) nM and following enalapril treatment was 0.03 (0.007-0.1; 95% confidence limits) nM. In addition to the above changes, coronary artery rings from dogs treated with enalapril developed significantly less tension to noradrenaline, phenylephrine, and BHT 920. In contrast, responses to potassium chloride were unaltered following enalapril treatment. However, the relaxation to acetylcholine was enhanced from 38.9 +/- 3.0 to 50.4 +/- 3.5% (placebo versus enalapril, p < 0.05). These findings indicate that enalapril may possess alpha-blocking properties and enhance the relaxation response to acetylcholine through an endothelial-dependent mechanism in addition to inhibiting converting enzyme.     

19F nuclear magnetic resonance investigation of stereoselective binding of isoflurane to bovine serum albumin.

Whether proteins or lipids are the primary target sites for general anesthetic action has engendered considerable debate. Recent in vivo studies have shown that the S(+) and R(-) enantiomers of isoflurane are not equipotent, implying involvement of proteins. Bovine serum albumin (BSA), a soluble protein devoid of lipid, contains specific binding sites for isoflurane and other anesthetics. We therefore conducted 19F nuclear magnetic resonance measurements to determine whether binding of isoflurane to BSA was stereoselective. Isoflurane chemical shifts were measured as a function of BSA concentration to determine the chemical shift differences between the free and bound isoflurane. KD was determined by measuring the 19F transverse relaxation times (T2) as a function of isoflurane concentration. The binding duration was determined by assessing increases in 1/T2 as a result of isoflurane exchanging between the free and bound states. The S(+) and R(-) enantiomers exhibited no stereoselectivity in chemical shifts and KD values (KD = 1.3 +/- 0.2 mM, mean +/- SE, for S(+), R(-), and the racemic mixture). Nonetheless, stereoselectivity was observed in dynamic binding parameters; the S(+) enantiomer bound with slower association and dissociation rates than the R(-).     

Experimental autoimmune encephalomyelitis is exacerbated by IL-1 alpha and suppressed by soluble IL-1 receptor.

To assess the role of IL-1 in the development of experimental autoimmune encephalomyelitis (EAE), the effects of in vivo treatment with IL-1 alpha or an IL-1 antagonist on the clinical course of EAE were evaluated. First, Lewis rats were immunized with guinea pig myelin in CFA and treated for 19 consecutive days with i.p. injections of recombinant human IL-1 alpha. Clinical signs of paralysis in the IL-1 alpha-treated groups were of longer duration and of greater severity compared to placebo injected controls. In addition, more weight loss was observed in the IL-1 alpha-treated groups compared to controls. This enhanced weight loss was not due to IL-1 alpha injections alone as CFA-treated rats injected with IL-1 alpha did not lose weight when compared to placebo injected, CFA-treated controls. Second, soluble mouse rIL-1R (sIL-1R), which binds both IL-1 alpha and IL-1 beta, was given as an IL-1 antagonist. Treatment of guinea pig myelin/CFA immunized rats with sIL-1R for 13 consecutive days significantly delayed the onset of EAE, reduced the severity of paralysis and weight loss, and shortened the duration of disease. Treatment with sIL-1R was most effective in reducing EAE if administered for 15 consecutive days immediately after immunization. Shortened 5-day treatment regimens spanning days 1 to 5, days 6 to 10, or days 11 to 15 after immunization were less effective in reducing EAE. These data suggest that IL-1 may initiate or promote inflammation within the central nervous system. In addition, specifically blocking the biological activity of IL-1 in vivo by soluble receptors may prove beneficial for the treatment of autoimmune or inflammatory diseases.     

Assessment of effect of vaccination against pneumococcal infection in children with chronic renal failure and glomerulonephritis

Clinical effect and immune response to vaccination with PNEUMO 23 vaccine was assessed in 18 children with chronic renal failure (CRF) and 40 children with different forms of glomerulonephritis (GN) aged 2 - 15 years. Control group was comprised by nonvaccinated patients (16 patients with CRF; 20 -with GN). Children from two groups were comparable on age and severity of disease's course. Local adverse reactions with duration not longer than 2 days were registered in 22% of vaccinees with CRF, and in 20% of vaccinees with GN. Mild and moderate systemic reactions were registered in 11% and 7.5% of recipients respectively. 1 month after vaccination significant 2.5 - 3.2-fold increase of antibodies concentration was detected in all groups irrespective from nosology and previous treatment. Two-fold increase of concentration of antibodies was observed in 64% and 61% of children with GN and CRF respectively. Clinical effect of vaccination appeared as 2.9-fold decrease of acute respiratory disease (ARD) incidence. Demand in antibacterial therapy decreased by 6.4-fold. Duration of ARD and course of antibacterial treatment decreased by 2.2 and 3 times respectively. Proportion of GN exacerbations related to infecvion decreased from 39% before vaccination to 8% after vaccination. In the control group this proportion did not change (50% and 45% respectively). Vaccine efficacy index was 2.13, coefficient of efficacy - 53.1%.     

Absence of Cardiac Valve Dysfunction in Obese Patients Treated with Sibutramine

BACH, DAVID S., AILA M. RISSANEN, CARL M. MENDEL, GILLIAN SHEPHERD, STEVEN R. WEINSTEIN, FINIAN KELLY, TIMOTHY B. SEATON, BABABHAI PATEL, TUULA A. PEKKARINEN, AND WILLIAM F. ARMSTRONG. Absence of cardiac valve dysfunction in obese patients treated with sibutramine. Obes Res. Objective: Serotonin-releasing agents prescribed as weight-loss medications have been implicated as a cause of acquired aortic and mitral valve abnormalities. Sibutramine hydrochloride (MERIDIA®) is a serotonin and norepi-nephrine reuptake inhibitor with proven efficacy of weight reduction. The purpose of this study was to determine the incidence of cardiac valve disease in sibutramine-treated patients. Research Methods and Procedures: Obese patients with type 2 diabetes mellitus enrolled in an ongoing double-blind, placebo-controlled, parallel-arm, 12-month study of sibutramine (followed by a 12-month open label extension) underwent transthoracic echocardiographic imaging and color Doppler interrogation for assessment of cardiac valve anatomy and function. Results: A total of 210 patients were evaluated. Of these, 133 were receiving sibutramine (72 in the double-blind period), and 77 were receiving placebo. The mean ± Standard Deviation age was 54±9 years, and the mean duration of treatment was 229±117 days (approximately 7. 6 months). The prevalence of left-sided cardiac valve dysfunction was low and similar for the two treatment groups (sibutramine 31133, or 2. 3%; placebo 2/77, or 2. 6%). All five cases were cases of aortic insufficiency; four were mild, one was severe (in a placebo patient). All three sibutramine cases were patients over age 50; two had a history of systemic hypertension. Conclusion: The prevalence of left-sided cardiac valve dysfunction was not higher than background in obese patients treated with sibutramine for an average of 7. 6 months.     

Keratin expression in rat intestinal crypt and villus cells. Analysis with a panel of monoclonal antibodies.

Seven monoclonal antibodies were prepared against cytoskeletal components of rat intestinal brush borders. In the following paper (Chandler, J. S., Calnek, D., and Quaroni, A., J. Biol. Chem. 266, 11932-11938), three of them were shown to be specific for, respectively, keratin 8 (RK4), keratin 19 (RK7), and a newly identified type I keratin (keratin 21) (RK5). With these antibodies we have investigated the changes in keratin gene expression accompanying intestinal cell differentiation. Keratin 21 was detected exclusively in differentiated villus cells and in goblet, enteroendocrine, and Paneth cells in the crypts; in the proliferative crypt cells keratin 19 was predominant. Analysis of keratins expressed by cultured rat crypt cells (IEC cells) confirmed the absence of keratin 21 in undifferentiated intestinal cells. Changes in keratin's expression similar to those observed with cell differentiation in the adult intestinal mucosa were also demonstrated during early fetal intestinal development: the stratified epithelium present at 15-16 days of gestation contained predominantly keratin 19 with only a small amount of keratin 8; keratin 21 was first detected at 18-19 days of gestation, concomitant with the appearance of a well formed brush border and an apical cytoplasmic terminal web. These results suggest that keratin tonofilaments may play a role in the morphological and structural alterations accompanying intestinal cell differentiation in vivo.