Pathways to epilepsy surgery in children with tuberous sclerosis complex-associated epilepsy.

BACKGROUND: Previous studies showed the efficacy of epilepsy surgery in carefully selected children with epilepsy associated with tuberous sclerosis complex. However, how this selection is conducted, and the characteristics of the patients brought to surgery are still poorly described. By conducting a multicentric retrospective cohort study covering the practice of the last twenty years, we describe the paths leading to epilepsy surgery in children with epilepsy associated with tuberous sclerosis complex. METHODS: We identified 84 children diagnosed with tuberous sclerosis complex and epilepsy by matching two exhaustive registries of genetic diseases and subsequent medical records reviews within two French neuropediatric and epilepsy centers. Demographic, clinical, longitudinal, and diagnostic and surgical procedures data were collected. RESULTS: Forty-six percent of the children were initially drug-resistant and 19% underwent resective surgery, most often before the age of four. Stereotactic electroencephalography was performed prior to surgery in 44% of cases. Fifty-seven and 43% of patients remained seizure-free one and ten years after surgery, respectively. In addition, 52% of initially drug-resistant patients who did not undergo surgery were seizure-free at the last follow-up. The number of anti-seizure medications required decreased in 50% of cases after surgery. Infantile spasms, intellectual disability, autism spectrum disorder or severe behavioral disorders were not contraindications to surgery but were associated with a higher rate of complications and a lower rate of seizure freedom after surgery. CONCLUSION: Despite the assumption of complex multifocal epilepsy and practical difficulties in young children with tuberous sclerosis complex, successful surgery results are comparable with other populations of patients with drug-resistant epilepsy, and a spontaneous evolution to drug-sensitive epilepsy may occur in non-operated patients.

Rasmussen's encephalitis: Early diagnostic criteria in children.

Rasmussen's encephalitis (RE) is a rare chronic inflammatory brain disorder resulting in progressive neurodegeneration in one cerebral hemisphere. The inflammatory process is accompanied by progressive loss of function of the affected hemisphere, associated with drug-resistant partial epilepsy. The diagnosis is based on a range of clinical, electroencephalographic, radiological and biochemical arguments, without any specific formal marker, which makes the diagnosis of the disease complex, especially in its initial phase. Seizures are refractory to anti-seizures medication (ASM) and to classical immunomodulatory treatments. These treatments are also ineffective to stop the degenerative process. Only surgical treatment with hemispherotomy (surgical disconnection of a cerebral hemisphere) allows definitive cessation of seizures but this leads to definitive motor and cognitive deficits. The etiology of RE is not known, but there is strong evidence for an immunopathogenic mechanism involving T-cell mediated immunity. The emergence of biotherapies targeting against various cytokines offers potential therapeutic perspectives. This disease is currently a real challenge in terms of: (i) early diagnosis, before the constitution of marked hemispheric atrophy and the appearance of neurological and cognitive consequences; (ii) recognition of incomplete form; (iii) therapeutic management due to advances in the field of targeted treatment of inflammation; (iv) surgery and recovery possibilities.

Severe neonatal seizures: From molecular diagnosis to precision therapy?

Early onset epileptic encephalopathies (EOEE) are heterogeneous group of severe epilepsies that still need to be better defined and characterized. On a genetic point of view, several dozen of genes have been associated with EOEE, and to date, it is difficult to find a common mechanism to explain EOEE. In this short review, we show that two mains genes are involved in EOEE: STXBP1 and KCNQ2. Focusing on KCNQ2 related EOEE, we show that a relatively similar phenotype can be related to various consequences of mutations on a single gene. This will probably challenge the treatment of EOEE patients.

Reduction of health risk factors through an adapted physical activity program in patients with breast cancer.

PURPOSE: After a breast cancer diagnosis, patients are at high risk of reducing their physical activity and gaining weight. Lack of physical activity and weight gain are known negative but modifiable prognostic factors. An observational study of a 3-month adapted physical activity (APA) program was performed to assess its effectiveness in improving physical activity level and reducing risk factors related to health during or after breast cancer treatments. METHOD: Height, weight, and waist circumference (WC) were measured at the beginning and end of the 26-session program. Body mass index (BMI) and WC to height ratio (WHtR) were calculated. Physical activity profile, aerobic capacity, and usual average daily energy expenditure were estimated. Median values were compared using nonparametric tests. RESULTS: Sixty-one (61) voluntary breast cancer patients attended 80% of the sessions. At baseline, median (minimum-maximum) BMI was 23.3 (16.1-36.8) kg.m(-2) and WC and WHtR showed metabolic risks. After 3 months, anthropometric data remained stable. Moderate physical activity significantly improved (+13 min/day) and sedentary tended to decrease (-18 min/day). CONCLUSION: A 3-month APA program allows patients to limit risk factors related to health such as physical inactivity and metabolic risks. This study reinforces the need to promote physical activity as early as possible in cancer patients' care.

Design of a randomised controlled trial of adapted physical activity during adjuvant treatment for localised breast cancer: the PASAPAS feasibility study.

INTRODUCTION: After a diagnosis of localised breast cancer, overweight, obesity and weight gain are negatively associated with prognosis. In contrast, maintaining an optimal weight through a balanced diet combined with regular physical activity appears to be effective protective behaviour against comorbidity or mortality after a breast cancer diagnosis. The primary aim of the Programme pour une Alimentation Saine et une Activité Physique Adaptée pour les patientes atteintes d'un cancer du Sein (PASAPAS) randomised controlled trial is to evaluate the feasibility of implementing an intervention of adapted physical activity (APA) for 6 months concomitant with the prescription of a first line of adjuvant chemotherapy. Secondary aims include assessing the acceptability of the intervention, compliance to the programme, process implementation, patients' satisfaction, evolution of biological parameters and the medicoeconomic impact of the intervention. METHODS AND ANALYSIS: The study population consists of 60 women eligible for adjuvant chemotherapy after a diagnosis of localised invasive breast cancer. They will be recruited during a 2-year inclusion period and randomly allocated between an APA intervention arm and a control arm following a 2:1 ratio. All participants should benefit from personalised dietetic counselling and patients allocated to the intervention arm will be offered an APA programme of two to three weekly sessions of Nordic walking and aerobic fitness. During the 6-month intervention and 6-month follow-up, four assessments will be performed including blood draw, anthropometrics and body composition measurements, and questionnaires about physical activity level, diet, lifestyle factors, psychological criteria, satisfaction with the intervention and medical data. ETHICS AND DISSEMINATION: The study was approved by the French Ethics Committee (Comité de Protection des Personnes Sud-Est IV) and the national agencies for biomedical studies and for privacy. All participants will give written informed consent. The study findings will be disseminated through the scientific public and serve as a foundation for future randomised controlled trials of efficacy.

[Epilepsy and mitochondrial diseases: retrospective study on 53 epileptic children]. / Épilepsie et cytopathies mitochondriales : étude rétrospective de 53 enfants épileptiques.

AIM: Mitochondrial disease is a heterogeneous disorder entity induced by defects in the mitochondrial respiratory chain complex. Neurological symptoms, including epilepsy, are common in children. The aim of this study was to research the clinical signs indicating mitochondrial disease. METHODS: We retrospectively studied epileptic children who underwent a muscle and/or hepatic biopsy between 1995 and 2010 searching for a mitochondrial disease. Patients were separated into 2 groups depending on the biopsy result: group 1 (presence of mitochondrial disease) and group 2 (absence of mitochondrial disease). Epileptic phenotypes were compared between these 2 groups. In group 1, we specified the clinical phenotype and characterized mitochondrial disease. RESULTS: Fifty-three children were included: 29 in group 1 and 24 in group 2. The average age at onset of epilepsy was 39.6 months in group 1 versus 11.8 months in group 2. In the 1st group, epilepsy was less refractory and associated with other clinical symptoms. CONCLUSIONS: In this study, epilepsy did not appear to be a unique sign of mitochondrial disease. It most often appeared during the 2nd year of life and is correlated with multiorgan involvement, notably ophthalmologic, such as oculomotor apraxia, optic atrophy, and retinitis pigmentosa, as well as auditory (deafness) and hepatic (hepatic failure, hepatomegaly). On the other hand, in children who did not have mitochondrial disease, epilepsy often began earlier (before 3 months of age), it was refractory, isolated without multiorgan involvement, and seems to be due to genetic anomalies in developmental genes, a finding that requires further research.

[Association of type 1 diabetes mellitus and epilepsy in children. A cohort of 10 cases]. / Association diabète de type 1et épilepsie chez l'enfant. À propos d'une série de 10 cas.

UNLABELLED: The association of type 1 diabetes mellitus (DM) and epilepsy has been previously reported. However, the physiopathology of this association remains misunderstood. OBJECTIVE: To describe epilepsy combined with type 1 DM in children. METHODS: Retrospective monocentric study of all the epileptic and type 1 diabetic children consulting at the Timone University Hospital, Marseille, France. For each patient, the type of epilepsy and its electroclinical and radiographic characteristics were studied as well as the type of diabetes (biological characteristics, glycemic control), and the onset of these 2 diseases. RESULTS: Ten patients are reported. Five suffered from generalized epilepsy (4 idiopathic, 1 nonidiopathic) and 5 from focal epilepsy (4 non-idiopathic, 1 idiopathic). For most of these cases, presence of GAD (glutamic acid decarboxylase) autoantibodies were confirmed and epilepsy followed diabetes. CONCLUSIONS: The 2 most common types of epilepsy in this association are idiopathic generalized epilepsy and non-idiopathic temporal epilepsy. Several mechanisms could be involved (immune, glycemia, and genetic disorders).

[Childhood periodic syndromes]. / Les syndromes périodiques de l'enfance.

This review focuses on the so-called "periodic syndromes of childhood that are precursors to migraine", as included in the Second Edition of the International Classification of Headache Disorders. Three periodic syndromes of childhood are included in the Second Edition of the International Classification of Headache Disorders: abdominal migraine, cyclic vomiting syndrome and benign paroxysmal vertigo, and a fourth, benign paroxysmal torticollis is presented in the Appendix. The key clinical features of this group of disorders are the episodic pattern and intervals of complete health. Episodes of benign paroxysmal torticollis begin between 2 and 8 months of age. Attacks are characterized by an abnormal inclination and/or rotation of the head to one side, due to cervical dystonia. They usually resolve by 5 years. Benign paroxysmal vertigo presents as sudden attacks of vertigo, accompanied by inability to stand without support, and lasting seconds to minutes. Age at onset is between 2 and 4 years, and the symptoms disappear by the age of 5. Cyclic vomiting syndrome is characterized in young infants and children by repeated stereotyped episodes of pernicious vomiting, at times to the point of dehydration, and impacting quality of life. Mean age of onset is 5 years. Abdominal migraine remains a controversial issue and presents in childhood with repeated stereotyped episodes of unexplained abdominal pain, nausea and vomiting occurring in the absence of headache. Mean age of onset is 7 years. Both cyclic vomiting syndrome and abdominal migraine are noted for the absence of pathognomonic clinical features but also for the large number of other conditions to be considered in their differential diagnoses. Diagnostic criteria, such as those of the Second Edition of the International Classification of Headache Disorders and the North American Society for Pediatric Gastroenterology, Hepatology and Nutrition, have made diagnostic approach and management easier. Their diagnosis is entertained after exhaustive evaluations have proved unrevealing. The recommended diagnostic approach uses a strategy of targeted testing, which may include gastrointestinal and metabolic evaluations. Therapeutic recommendations include reassurance, both of the child and parents, lifestyle changes, prophylactic therapy (e.g., cyproheptadine in children 5 years or younger and amitriptyline for those older than 5 years), and acute therapy (e.g., triptans, as abortive therapy, and 10% glucose and ondansetron for those requiring intravenous hydration).

Bacillus licheniformis septicemia in a very-low-birth-weight neonate: a case report.

Nosocomial infections in neonatal intensive care units are a preoccupying issue. Bacillus sp. can be pathogenic in immuno-compromised hosts, including premature infants. Central catheters and mechanical ventilation are potential sources of infection. We report for the first time a case of Bacillus licheniformis bacteremia in a premature infant. Recovery necessitated treatment with vancomycin and cefotaxime in combination with removal of the central catheter.

Quantitative analysis of chondroitin sulfate isomers in intervertebral disk chondrocyte culture using capillary electrophoresis.

Chondroitin sulfate (CS) isomers, 6-sulfate (CS6) and 4-sulfate (CS4), change their ratio to each other in cartilaginous tissues with aging. In this study, a quantitative measurement method of CS6 and CS4 was developed, using capillary electrophoresis (CE). Various buffer solutions, pH, and digestion times were studied, and the use of 0.1 M Tris-HCl at pH of 8.0 allowed the isolation of CS6 and CS4 from CS most efficiently when combined with chondrotinase ABC at a concentration of 1 mU/microg of the substrate during a 3 hr digestion period. Amounts of newly synthesized CS6 and CS4 in the intervertebral disk chondrocyte three-dimensional culture were quantified by this method after the proteoglycans were extracted by equilibrium density centrifugation.

Changes in protein and nutrient composition of milk throughout lactation in dogs.

OBJECTIVE: To evaluate changes in protein and nutrient composition of milk throughout lactation in dogs. SAMPLE POPULATION: Milk samples collected from 10 lactating Beagles. PROCEDURE: Milk samples were collected on days 1, 3, 7, 14, 21, 28, 35, and 42 after parturition and analyzed to determine concentrations of nitrogen, nonprotein nitrogen, casein, whey proteins, amino acids, lipids, lactose, citrate, minerals, and trace elements. Optimum conditions for separating casein from whey proteins and distribution of milk proteins throughout lactation were assessed by use of polyacrylamide gel electrophoresis. RESULTS: Protein concentration was high in samples collected on day 1 (143 g/L), decreased through day 21 (68.4 g/L), and increased thereafter. Concentration of nonprotein nitrogen did not change throughout lactation (5.7 to 9.9% of total nitrogen content). Casein-to-whey ratio was approximately 70:30 and remained constant throughout lactation. Lactose concentration increased from 16.6 g/L on day 1 to 34.0 to 40.2 g/L on days 7 to 42. Lipid concentration ranged from 112.5 to 1372 g/L. Citrate concentration increased from day 1 (4.8 mM) to day 7 (6.6 mM), then gradually decreased until day 42 (3.9 mM). Iron, zinc, copper, and magnesium concentrations decreased during lactation, whereas calcium and phosphorus concentrations increased. Calcium-to-phosphorus ratio remained constant throughout lactation (approx 1.6:1). Energy content of milk ranged from 1,444 to 1,831 kcal/L. CONCLUSIONS AND CLINICAL RELEVANCE: Protein and nutrient composition of milk changes throughout lactation in dogs. These data can provide valuable information for use in establishing nutrient requirements of puppies during the suckling period.

Uptake of beta-carotene by ovarian and uterine tissues and effects on steroidogenesis during the estrous cycle in cats.

OBJECTIVES: To determine uptake of beta-carotene by ovarian and uterine tissues and influence of dietary beta-carotene on steroidogenesis and production of uterine protein during the estrous cycle in cats. ANIMALS: 56 female cats. PROCEDURE: Cats were fed diets containing 0, 0.4, 2, or 10 mg of beta-carotene daily for 8 weeks prior to detection of estrus. At time of observed estrus, all cats were manually induced to ovulate. Blood samples were obtained at estrus and every 2 days until day 14 after ovulation. On that day, cats underment laparotomy, and the ovaries and uterus were removed. Uterine contents were flushed, and luteal and endometrial tissues were obtained. RESULTS: Concentrations of beta-carotene in plasma and luteal and endometrial tissues increased in a dose-dependent manner. Concentrations of plasma progesterone were higher between days 6 and 10 after ovulation in cats fed diets containing beta-carotene and continued to increase through day 14 after ovulation in cats fed a diet containing 10 mg of beta-carotene. Plasma concentration of estradiol-17beta also was higher between days 0 and 4 after ovulation in cats fed diets containing beta-carotene. Cats fed a diet containing 10 mg of beta-carotene had the highest plasma estradiol concentration. Total uterine protein concentration was higher in cats fed beta-carotene, compared with values for cats fed an unsupplemented diet. CONCLUSION AND CLINICAL RELEVANCE: Cats readily absorb beta-carotene. Increased concentrations of progesterone, estradiol, and uterine protein may provide more optimal ovarian function or a better uterine environment for embryonic survival and development.

Effect of diet on hunting performance of English pointers.

A study was conducted to evaluate the influence of diet on hunting performance of English pointers during the quail-hunting season in southwest Georgia. Twenty-three trained dogs were assigned to two commercially available diets (i.e., Diet A = Eukanuba Premium Performance Formula, The Iams Company, Lewisburg, OH; Diet B = Diamond Premium Adult Dog Food, Diamond Pet Foods, Meta, MO). Results showed that dogs fed Diet A maintained or gained weight and body condition throughout the hunting season while dogs fed Diet B lost body weight and body condition (P < .05). Dogs fed Diet A demonstrated superior hunting performance (P < .05) compared with those fed Diet B based on total finds per hunt and on the number of birds located per hour of hunting. All blood variables were within normal ranges for adult healthy dogs throughout the season. These results imply that diet can affect the overall performance of hunting dogs and should provide useful information to trainers, handlers, and clinicians who are concerned with promoting the best performance and health in hunting dogs and other canine athletes.

Large enhancement of the sub-barrier fusion probability for a halo nucleus

The fusion-fission cross sections of the 4He+238U and 6He+238U systems have been measured, at Louvain-la-Neuve, for energies around and below the Coulomb barrier, using an array of Si detectors surrounding a UF4 target. The data taken with 4He are in good agreement with previous data and with the coupled channel fusion calculation performed with ECIS. The 6He data show a regular trend with a large enhancement below the barrier which is attributed to the halo structure of the 6He nucleus.

Beta-carotene uptake and changes in ovarian steroids and uterine proteins during the estrous cycle in the canine.

The uptake of beta-carotene by reproductive tissues and the effects of beta-carotene on reproductive function in the dog are unknown. We studied the uptake of beta-carotene by blood, corpus luteum, and uterine endometrium and the role of dietary beta-carotene in influencing ovarian steroid and uterine protein production during the estrous cycle in the dog. Mature female Beagle dogs (n = 56) were fed diets containing 0, 2, 20, or 50 mg of beta-carotene daily for approximately 6 wk before estrus detection. Blood was sampled at regular intervals from estrus through d 45 after ovulation (d 0 = ovulation), when laparotomy was performed. The ovaries were obtained for the isolation of corpus luteum. The uterus was flushed with phosphate-buffered saline and the endometrium obtained by scraping. Beta-carotene was not detectable in plasma, corpus luteum, or endometrium of unsupplemented dogs. However, beta-carotene and alpha-carotene in plasma, corpus luteum, and uterine endometrium increased in a dose-dependent manner. Alpha-carotene made up a high percentage of total carotenoids even though the alpha-carotene content in the dietary source was very low. Dogs fed 50 mg of beta-carotene had significantly higher concentrations of plasma progesterone between d 12 and 26 compared with unsupplemented dogs. Dietary beta-carotene did not influence plasma estradiol-17beta and total uterine proteins. Therefore, beta-carotene is absorbed into plasma, corpus luteum, and uterine endometrium of dogs. Furthermore, dietary beta-carotene increased plasma progesterone concentrations during the estrous cycle. It is possible that dietary beta-carotene may improve reproductive function in the canine.

Comparison of insulin-like growth factor-I concentration in mammary secretions and serum of small- and giant-breed dogs.

OBJECTIVE: To determine insulin-like growth factor-I (IGF-I) concentrations in canine mammary secretions and serum during lactation and to compare them between small and giant breeds of dogs. ANIMALS: 7 gestating Beagles and 4 gestating Great Danes. PROCEDURE: Dogs were fed a common nutritionally complete and adequate gestation and lactation diet. Milk samples were collected at postpartum hour 12 and postpartum days 3, 7, 14, 21, and 28 after IV oxytocin administration. Two puppies/litter were identified at whelping for collection of blood samples corresponding to the days of milk sample collection plus days 35 and 42. Maternal blood samples were obtained on days 1, 7, and 42 from Beagles and days 1, 7, and 28 from Great Danes and were acid/ethanol extracted and analyzed by use of a radioimmunoassay. RESULTS: Maternal serum IGF-I concentration was greater in Great Danes at all sample collection times. Similarly, colostrum from Great Danes contained more IGF-I, compared with that of Beagles (70 ng/ml vs 40 ng/ml, respectively). These values decreased to approximately 10 ng/ml by day 3 in both breeds and remained between 10 and 20 ng/ml for the duration of lactation. Growth rate and serum IGF-I concentration were greater in Great Dane puppies at birth to day 42. CONCLUSIONS AND CLINICAL RELEVANCE: High IGF-I concentration in colostrum may be biologically important for newborn puppies. Body mass and serum IGF-I concentration are directly correlated in growing Beagle and Great Dane puppies. Serum IGF-I concentration may be an indicator of growth potential in dogs.

Analysis of randomly amplified polymorphic DNA (RAPD) for identifying genetic markers associated with canine hip dysplasia.

Canine hip dysplasia is a heritable developmental disease resulting, in part, from increased laxity in hip joints and is a precursor to degenerative joint disease. Identification of genetic markers linked to joint laxity would foster development of more accurate diagnostic methods, facilitate identification of the disease gene(s), and supplement efforts to establish physical/genetic maps of the canine genome. Work presented here describes analysis of randomly amplified polymorphic DNA in the search for markers which cosegregate with increased joint laxity in Canis familiaris, the domestic dog. The Boykin spaniel, a highly inbred breed afflicted with an extremely high incidence of hip dysplasia, served as a model for study of canine hip dysplasia. Only 5% of 200 random primers revealed significant polymorphisms within this breed. However polymorphisms were detected in seemingly nonpolymorphic amplification products when digested with restriction enzymes. Restriction digestion revealed polymorphisms in 15% of the monomorphic amplification products. Among the primers that revealed polymorphisms, one primer correctly identified 9 of 12 dogs with regard to joint laxity. However, extensive evaluation is required before any assertion can be made regarding linkage of this marker to joint laxity. Of interest, another primer amplified a genomic segment unique to the canine Y chromosome.

[Abuse of psychoactive drugs and social adjustment of psychotic patients]. / L'abus de substances psychoactives et l'adaptation sociale chez les psychotiques.

OBJECTIVE: Is the abuse of psychoactive drugs in psychotic patients linked to social adjustment? METHOD: Fifty-five psychotic men from a detention centre or a psychiatric hospital were assessed with the Social Adjustment Scale (SAS-II) and a French version of the Phillips Rating Scale of Premorbid Adjustment in Schizophrenia. RESULTS: In psychotic patients, the abuse of psychoactive drugs is linked to some indicators of social adjustment and premorbid sexual adaptation. CONCLUSION: Differences were found in some aspects of social functioning, but it is difficult to establish an overall assessment of social adjustment.

Identification and characteristics of a 37,000 M(r) insulin-like growth factor binding protein in canine serum.

Insulin-like growth factors (IGFs) are potent stimulators of cellular growth and their half-life and biological activity are regulated by specific IGF binding proteins (IGFBPs). Western ligand blots of non-reduced human, bovine, ovine and porcine sera reveal an IGFBP-2 band at approximately 34,000 M(r). However, canine sera appear to contain a unique 37,000 M(r) IGFBP and lack the 34,000 M(r) IGFBP-2 band. In order to identify and characterize the 37,000 M(r) IGFBP, adult canine serum was subjected to non-reducing SDS polyacrylamide gel electrophoresis (PAGE), transferred to nitrocellulose paper, followed by [125I]-IGF-1 ligand blotting or immunoblotting with commercially available IGFBP antibodies. The 37,000 M(r) canine IGFBP reacted with an anti-IGFBP-2 antibody indicating that it is a canine analogue of IGFBP-2. However, the large difference in apparent molecular size indicates that this is a unique molecular form of IGFBP-2. N- or O-glycanase treatment of canine sera did not alter the molecular size of canine IGFBP-2 indicating that it is not a glycosylated variant of the IGFBP. Subjecting canine sera to reducing SDS-PAGE followed by anti-IGFBP-2 western immunoblotting revealed that the actual molecular weight of the canine IGFBP-2 is similar to that of reduced IGFBP-2 from other species indicating similar peptide lengths. Thus, the increased non-reduced size of the canine 37,000 M(r) IGFBP-2 is possibly due to a unique secondary structure.

Changes in nutrient and protein composition of cat milk during lactation.

OBJECTIVE: To evaluate changes in the nutrient and protein composition of cat milk during lactation. ANIMALS: 12 lactating domestic shorthair cats. PROCEDURE: Milk samples collected on days 1, 3, 7, 14, 28, and 42 after parturition were analyzed for concentrations of nitrogen, nonprotein nitrogen, casein, whey proteins, amino acids, total lipids, lactose, citrate, minerals, and trace elements. Individual milk proteins (caseins and whey proteins) were analyzed by use of polyacrylamide gradient gel electrophoresis. RESULTS: True protein concentration ranged from 6.3 to 8.6% and was as high in mature milk as in colostrum. Nonprotein nitrogen as a portion of total N was constant (approx 8%), as was the whey-to-casein ratio (approx 50:50). Total lipid concentration was high (9.3%) in colostrum, rapidly decreased, then increased to 9% in mature milk. Lactose concentration was constant at 4%. Milk calcium, iron, and copper concentrations increased markedly during lactation, and magnesium and zinc values remained constant. Colostrum and early milk had a low Ca-to-P ratio of 0.4:0.9. Although calcium concentration increased with time, phosphate concentration also increased so that the Ca-to-P ratio remained constant in mature milk at 1.0: 1.2. The major whey proteins had molecular weights of approximately 14,000, 19,000, 40,000 and 80,000. The 80,000 protein (possibly lactoferrin) decreased in concentration during lactation. Two major casein subunits of approximately 28,000 and 33,000 were found, and both increased during early lactation. CONCLUSIONS: Nutrient composition of cat milk and, thus, provision of nutrients to nursing kittens changes over time.