Rapid switching from levetiracetam to brivaracetam in pharmaco-resistant epilepsy in people with and without intellectual disabilities: a naturalistic case control study

BACKGROUND

Approximately one quarter of people with an intellectual disability (PwID) have epilepsy of whom nearly three-quarters are pharmaco-resistant. There are higher reported neuropsychiatric side-effects to anti-seizure medication (ASM) in this group. Levetiracetam (LEV) is a first-line ASM with a stronger association with neuropsychiatric symptoms for PwID than other ASMs. Brivaracetam (BRV) is a newer ASM. Recent studies suggest a beneficial effect of swapping people who experience neuropsychiatric events with LEV to BRV. However, there is limited evidence of this for PwID. This evaluation analyses real world outcomes of LEV to BRV swap for PwID compared to those without ID.

METHODS

We performed a multicentre, retrospective review of clinical records. Demographic, clinical characteristics and reported adverse events of patients switched from LEV to BRV (2016-2020) were recorded at 3 months pre and 6- and 12-month post-BRV initiation. Outcomes were compared between PwID and those without and summarised using cross-tabulations and logistic regression models. A Bonferroni correction was applied.

RESULTS

Of 77 participants, 46 had ID and 52% had a past psychiatric illness. 71% participants switched overnight from LEV to BRV. Seizure reduction of > 50% was seen in 40% patients. Psychiatric illness history was predictive of having neuropsychiatric side-effects with LEV but not BRV (p = 0.001). There was no significant difference for any primary outcomes between PwID versus without ID.

CONCLUSIONS

Switching from LEV to BRV appears as well tolerated and efficacious in PwID as those without ID with over 90% still on BRV after 12 months.

Brivaracetam efficacy and tolerability in clinical practice: A UK-based retrospective multicenter service evaluation

PURPOSE

This multicenter service evaluation explores the efficacy and tolerability of brivaracetam (BRV) in an unselected, consecutive population in 'real-life' clinical settings.

METHOD

We retrospectively collected data from patient records at 11 UK hospitals and epilepsy centers. Consecutive patients prescribed BRV with at least 3 months of follow-up (FU) were included. Apart from reporting effectiveness and tolerability of BRV across the whole cohort, we compared treatment outcomes depending on previous levetiracetam use (LEV+ versus LEV-), comorbid learning disability (LD+ versus LD-), and epilepsy syndrome (focal versus generalized epilepsy).

RESULTS

Two hundred and ninety patients (46% male, median age: 38 years, range: 15 to 77) with ≥3 months of FU were included. The median duration of BRV exposure was 12 months (range: 1 day to 72 months). Overall BRV retention was 71.1%. While 56.1% of patients improved in terms of seizure frequency category (daily, weekly, monthly, yearly seizures), 23.1% did not improve on this measure and 20.8% deteriorated. In terms of seizure frequency, 21% of patients experienced a ≥50% reduction, with 7.0% of all patients becoming seizure-free. Treatment-emergent adverse events (AEs) were reported by 107 (36.9%) patients, but there were no serious AEs. The commonest AEs were sedation/fatigue (18.3%), mood changes (9.0%), and irritability/aggression (4.8%). There were no significant differences in drug retention, seizure frequency outcomes, or AEs between the LEV+ and LEV- subgroups, or between patients with generalized or focal epilepsies. Although 15.5% of patients in the LD+ group achieved a ≥50% reduction, this rate was lower than in the LD- group.

CONCLUSIONS

This 'real-life' evaluation suggests that reductions in seizure frequency can be achieved with BRV in patients with highly refractory epilepsy. Brivaracetam may be a useful treatment option in patients who have previously failed to respond to or tolerate LEV, those with LD, or (off-label) those with generalized epilepsies.

Does somatosensation change with age in children and adolescents? A systematic review

BACKGROUND

Somatosensory modalities, such as touch, proprioception and haptic ability, greatly influence the achievement of developmental milestones for children. Describing somatosensory impairment, natural variability and typical or expected developmental changes across age groups will help establish frameworks for intervention in clinical populations. This systematic review aimed to determine how different somatosensory modalities develop across childhood into adolescence to use as a point of reference for children at risk of somatosensory impairment.

METHODS

Searches of five electronic databases were undertaken through EBSCO-host (MEDLINE, CINAHL, PsycINFO, SPORTDiscus and ERIC) for studies measuring at least one somatosensory modality in typically developing individuals between birth and 18 years and analysed by age. Characteristics of studies were collected including country of origin, sample size, demographics and outcome measure used. Quality assessment and data extraction were performed by two independent reviewers.

RESULTS

Twenty three cross-sectional studies were included from a total of 188 articles retrieved: 8 examined aspects of touch, 5 proprioception and 10 haptic ability. Variability of study designs and variation in assessment tools precluded any formal meta-analysis.

CONCLUSIONS

Somatosensation matures through childhood into adolescence; however, the present review found the pattern of somatosensory development varied depending on the assessment tool used and the aspect of somatosensation being measured, making it difficult to describe typical performance. There is a need for comprehensive assessment batteries to measure the somatosensation, including touch, proprioception and haptic ability, of children at risk of somatosensory impairment to aid in the development of effective interventions.

Medical needs of people with intellectual disability require regular reassessment, and the provision of client- and carer-held reports

BACKGROUND

Previous work has indicated a wide range of unmet medical health needs in people with intellectual disability (ID).

METHODS

A profile of recorded medical needs was produced for 589 people with ID through a detailed search of individual medical and nursing case records. Specialist optometric and audiological assessments were offered, and reports were provided in technical and plain English terms. A Health Watch project delivered folders with copies of the plain English reports to 60 individuals and carers.

RESULTS

The case record review indicated a wide range of medical disorders; however, exact diagnoses and counselling regarding underlying neurological conditions were seldom recorded. Assessed levels of hearing and vision loss were much greater than had been previously recognized. The Health Watch reports were welcomed by the clients and carers.

CONCLUSIONS

If satisfactory healthcare is to be achieved for people with ID, medical needs must be monitored, regular specialist reassessments offered, access to specialist services facilitated and reports clearly explained to carers.

Physiological characteristics of nationally competitive female road cyclists and demands of competition

There are few published data describing female cyclists and the studies available are difficult to interpret because of the classification of athletes. In this review, cyclists are referred to as either internationally competitive (International Cycling Union world rankings provided when available) or nationally competitive. Based on the limited data available it appears that the age, height, body mass (BM) and body composition of women cyclists who have been selected to the US and Australian National Road Cycling Teams from 1980 to 2000 are fairly similar. Female cyclists who have become internationally competitive are generally between 21 to 28 years of age, 162 to 174 cm, 55.4 to 58.8 kg and 38 to 51 mm (sum of 7 skinfolds) corresponding to 7 to 12% body fat. The lower BM and percentage body fat are traits unique to the most competitive women. Internationally competitive women cyclists also possess a slightly superior ability to produce a high absolute power output for a fixed time period and a noticeably greater ability to produce power output relative to BM. In Women's World Cup races, successful women (top 20 places) spend more time >7.5 W/kg (11 +/- 2 vs 7 +/- 2%, p < 0.01) and less time <0.75 W/kg (24 +/- 4 vs 29 +/- 3%, p = 0.05) compared with non-top 20 placed riders. Additionally, cyclists in the top 20 produced higher average power (3.6 +/- 0.4 vs 3.1 +/- 0.1 W/kg, p = 0.01). Unlike professional men's road cycling, the physiological characteristics of internationally competitive female road cyclists and the demands of women's cycling competition are poorly understood.

The rapidity of drug dose escalation influences blood pressure response and adverse effects burden in patients with hypertension: the Quinapril Titration Interval Management Evaluation (ATIME) Study. ATIME Research Group

BACKGROUND

Antihypertensive medication doses are typically increased within several weeks after initiation of therapy because of inadequate blood pressure (BP) control and/or adverse effects.

METHODS

We conducted a parallel-group clinical trial with 2935 subjects (53% women, n=1547) aged 21 to 75 years, with Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure VI stages 1 to 2 hypertension, recruited from 365 physician practices in the southeastern United States. Participants were randomized either to a fast (every 2 weeks; n=1727) or slow (every 6 weeks; n=1208) drug titration. Therapy with quinapril, an angiotensin-converting enzyme inhibitor, was initiated at 20 mg once daily. The dose was doubled at the next 2 clinic visits until the BP was lower than 140/90 mm Hg or a dose of 80 mg was reached.

RESULTS

Pretreatment BP averaged 152/95 mm Hg. Patients with stage 2 hypertension reported more symptoms than those with stage 1. The BP averaged 140/86, 137/84, and 134/83 mm Hg in the slow group compared with 141/88, 137/85, and 135/84 mm Hg in the fast group at the 3 respective clinic visits. The BP control rates to lower than 140/90 mm Hg at the 3 clinic visits were (slow, fast, respectively) 41.3%, 35.7% (P<.001); 54.3%, 51.5% (P=.16); and 68%, 62.3% (P=.02). In the fast group, 10.7% of participants experienced adverse events vs 10.8% in the slow group; however, 21.0% of adverse events in the fast group were "serious" vs only 12% in the slow group.

CONCLUSION

Slower dose escalation of the angiotensin-converting enzyme inhibitor quinapril provides higher BP control rates and fewer serious adverse events than more rapid drug dose escalation.

Rofecoxib, a specific inhibitor of cyclooxygenase 2, with clinical efficacy comparable with that of diclofenac sodium: results of a one-year, randomized, clinical trial in patients with osteoarthritis of the knee and hip. Rofecoxib Phase III Protocol 035 Study Group

OBJECTIVE

To compare the clinical efficacy of rofecoxib, a specific inhibitor of cyclooxygenase 2 (COX-2), with that of diclofenac in patients with osteoarthritis (OA) and to evaluate the safety and tolerability of rofecoxib.

METHODS

We performed a randomized, double-blind, active comparator-controlled trial in 784 adults with OA of the knee or hip. Patients were randomized to 1 of 3 treatment groups: 12.5 mg of rofecoxib once daily, 25 mg of rofecoxib once daily, and 50 mg of diclofenac 3 times daily. Clinical efficacy and safety were evaluated over a 1-year continuous treatment period.

RESULTS

Rofecoxib at dosages of 12.5 and 25 mg demonstrated efficacy that was clinically comparable to that of diclofenac, as assessed by all 3 primary end points according to predefined comparability criteria. Results from secondary end points were consistent with those of the primary end points. There were small statistical differences favoring diclofenac for 2 of the end points. All treatments were well tolerated.

CONCLUSION

Rofecoxib was well tolerated and provided efficacy that was clinically comparable, according to predefined statistical criteria, to that of 150 mg of diclofenac per day in this 1-year study. Specific inhibition of COX-2 provided therapeutic efficacy in OA.

Rofecoxib, a specific inhibitor of cyclooxygenase 2, with clinical efficacy comparable with that of diclofenac sodium: results of a one-year, randomized, clinical trial in patients with osteoarthritis of the knee and hip. Rofecoxib Phase III Protocol 035 Study Group

OBJECTIVE

To compare the clinical efficacy of rofecoxib, a specific inhibitor of cyclooxygenase 2 (COX-2), with that of diclofenac in patients with osteoarthritis (OA) and to evaluate the safety and tolerability of rofecoxib.

METHODS

We performed a randomized, double-blind, active comparator-controlled trial in 784 adults with OA of the knee or hip. Patients were randomized to 1 of 3 treatment groups: 12.5 mg of rofecoxib once daily, 25 mg of rofecoxib once daily, and 50 mg of diclofenac 3 times daily. Clinical efficacy and safety were evaluated over a 1-year continuous treatment period.

RESULTS

Rofecoxib at dosages of 12.5 and 25 mg demonstrated efficacy that was clinically comparable to that of diclofenac, as assessed by all 3 primary end points according to predefined comparability criteria. Results from secondary end points were consistent with those of the primary end points. There were small statistical differences favoring diclofenac for 2 of the end points. All treatments were well tolerated.

CONCLUSION

Rofecoxib was well tolerated and provided efficacy that was clinically comparable, according to predefined statistical criteria, to that of 150 mg of diclofenac per day in this 1-year study. Specific inhibition of COX-2 provided therapeutic efficacy in OA.

Characterization and affinity applications of cellulose-binding domains

Cellulose-binding domains (CBDs) are discrete protein modules found in a large number of carbohydrolases and a few nonhydrolytic proteins. To date, almost 200 sequences can be classified in 13 different families with distinctly different properties. CBDs vary in size from 4 to 20 kDa and occur at different positions within the polypeptides; N-terminal, C-terminal and internal. They have a moderately high and specific affinity for insoluble or soluble cellulosics with dissociation constants in the low micromolar range. Some CBDs bind irreversibly to cellulose and can be used for applications involving immobilization, others bind reversibly and are more useful for separations and purifications. Dependent on the CBD used, desorption from the matrix can be promoted under various different conditions including denaturants (urea, high pH), water, or specific competitive ligands (e.g. cellobiose). Family I and IV CBDs bind reversibly to cellulose in contrast to family II and III CBDs which are in general, irreversibly bound. The binding of family II CBDs (CBD(Cex)) to crystalline cellulose is characterized by a large favourable increase in entropy indicating that dehydration of the sorbent and the protein are the major driving forces for binding. In contrast, binding of family IV CBDs (CBD(N1)) to amorphous or soluble cellulosics is driven by a favourable change in enthalpy which is partially offset by an unfavourable entropy change. Hydrogen bond formation and van der Waals interactions are the main driving forces for binding. CBDs with affinity for crystalline cellulose are useful tags for classical column affinity chromatography. The affinity of CBD(N1) for soluble cellulosics makes it suitable for use in large-scale aqueous two-phase affinity partitioning systems.

Social support, support groups, and breast cancer: a literature review

A review of medical, social science, and "grassroots" literature on support groups and breast cancer, this paper concerns the need among women living with breast cancer and their caregivers for more information on the efficacy of social support as a therapeutic intervention. The literature has been subdivided into reviews of articles dealing with professionally led support groups, community-based support groups, support groups and survival, and support groups and psychological adjustment.

Relationship between strength qualities and sprinting performance

The purpose of this study was to investigate the relationship between strength measures and sprinting performance, and to determine if these relationships varied for different phases of sprint running. Twenty (11 males and 9 females) elite junior track and field athletes served as subjects. Athletes performed maximum sprints to 50 m from a block start and time to 2.5, 5, 10, 20, 30, 40 and 50 m were recorded by electronic timing gates. The resultant forces applied to the blocks were obtained from two force platforms. Twenty-seven measures of strength and speed-strength (absolute and relative to bodyweight) were collected from the height jumped and the force-time curve recorded from the takeoff phase of vertical jumping movements utilizing pure concentric, stretch shortening cycle (SSC) and isometric muscular contractions. Pearson correlation analysis revealed that the single best predictor of starting performance (2.5 m time) was the peak force (relative to bodyweight) generated during a jump from a 120 degree knee angle (concentric contraction) (r = 0.86, p = 0.0001). The single best correlate of maximum sprinting speed was the force applied at 100 ms (relative to bodyweight) from the start of a loaded jumping action (concentric contraction) (r = 0.80, p = 0.0001). SSC measures and maximum absolute strength were more related to maximum sprinting speed than starting ability. It was concluded that strength qualities were related to sprinting performance and these relationships differed for starting and maximum speed sprinting.

Elevated serum levels of tumor necrosis factor-alpha in Guillain-Barré syndrome

Activated T lymphocytes and macrophages play a putative role in the the pathogenesis of Guillain-Barré syndrome. Both cell types secrete tumor necrosis factor-alpha, a cytokine that has well-recognized toxic effects on myelin, Schwann cells, and endothelial cells. We determined serum and cerebrospinal fluid concentrations of tumor necrosis factor alpha in 26 patients with Guillain-Barré syndrome, 27 patients with other polyneuropathies, 30 patients with neurological diseases of the central nervous system, and 14 healthy control subjects. Markedly increased serum levels were detected in 14 patients (54%) with Guillain-Barré syndrome and to a significantly lesser extent, in patients with other polyneuropathies (26%) and in neurological control subjects (23%). Tumor necrosis factor-alpha was not detected in the cerebrospinal fluid of patients with Guillain-Barré syndrome or other polyneuropathies. Increased serum concentrations in patients with Guillain-Barré syndrome correlated directly with disease severity and these concentrations returned to normal in parallel with clinical recovery. These findings emphasize the complexity of the immune response in patients with Guillain-Barré syndrome and suggest that tumor necrosis factor-alpha may be important in the pathogenesis of peripheral demyelination in this disorder.

The significance of serum oligoclonal bands in neurological diseases

The presence of oligoclonal bands (OCBs) of immunoglobulin G (IgG) in CSF provides evidence for the occurrence of a humoral immune response, but it is not always appreciated that the oligoclonal IgG may have originated in the serum. To determine the diagnostic significance of serum OCBs 146 patients with serum OCBs were identified among 1874 patients with suspected neurological disorders (7.6%). Clear diagnoses had been made in 112 of these patients: in 56 identical CSF and serum bands were present, revealing a systemic immune response, while in 46 additional unique CSF bands indicated that intrathecal IgG synthesis was also occurring. In the first group neoplasia and peripheral neuropathies accounted for over 50% of the diagnoses, infections and systemic inflammatory disorders for 32%, and multiple sclerosis was diagnosed in only one case. These figures contrast considerably with those reported for patients with CSF OCBs alone. Diagnoses in the second group of patients, with unique CSF OCBs in addition to serum OCBs, resembled those among patients with CSF OCBs alone. Examining CSF and serum in parallel for OCBs of IgG provides more diagnostic information than examining CSF alone, and the latter is potentially misleading.

Fitness characteristics of competitors in a six day sailboard marathon

The purpose of this study was to profile the fitness characteristics of competitors in a 6 day sailboard marathon and assess the aerobic demands encountered. Twenty one male sailboarders were assessed for body composition, horizontal shoulder adduction and abduction strength as well as grip strength. Body composition was assessed by skinfold measurement and strength measured by dynamometer. A subgroup of 5 subjects were assessed for VO2 max by indirect calorimetry using a treadmill protocol. Functional capacity was determined as the quotient of VO2 max and the VO2 at rest and the aerobic conditioning threshold estimated. The corresponding threshold heart rate was determined. During each days racing, heart rate was continuously monitored from 2 different members of the subgroup. In the total group body fat was 19.1 +/- 5.1%, grip strength was 502.3 +/- 61.8 N and horizontal shoulder adduction and abduction strength was 449.3 +/- 121.6 N and 437 +/- 94.2 N respectively. In the subgroup, VO2 max was 49.6 +/- 3.7 ml/kg/min, functional capacity was 8.8 +/- 0.9 METS and threshold heart rate occurred between 155 +/- 5.2 and 161 +/- 4.6 beats/min. Heart rate response during sailing was typically in the 120-150 beats/min range. The results indicated that sailboarding does not promote high levels of aerobic fitness.

Characterization of MBT-2 tumour cell "variant" resistant to tumour necrosis factor

Previously we reported sensitivity of MBT-2 murine bladder tumour to tumour necrosis factor (TNF) in vivo and in vitro [8]. We showed that with prolonged exposure of cultured MBT-2 tumour cells to TNF, a resistant MBT-2 "variant" tumour cell population emerged in vitro. This concurred with the finding of transient in vivo cytotoxic effect of TNF against MBT-2 tumour. Herein, we delineate phenotypic changes in MBT-2 cells associated with TNF resistance. Parent MBT-2 (MBT-2P) and the TNF-resistant "variant" MBT-2R cells were compared in terms of in vitro sensitivity to TNF, DNA profile, karyotype and in vitro growth kinetics. We conclude that acquisition of resistance to TNF may be due to cell cycle derangement and differences in in vitro growth characteristics. DNA indices and karyotype of "variant" MBT-2R cells were not altered, indicating the anti-tumour action of TNF is not-mutagenic.

The plasma membrane of young Chara internodal cells revealed by rapid freezing

Young elongating internodal cells of Chara globularis var. capillacea (Thuill.) Zanev. were rapidly frozen and freze-fractured in order to observed transient events occurring within the plasma membrane. Several structures have been observed. Relatively small depressions, varying in depth, are prolific and scattered at random over the plasma membrane. Charasomes and clusters of particle rosettes are common. Arrays of intramembrane particle lines are a characteristic feature of the internodal cell plasma membrane. The charasomes and the arrays of particle lines occupy a considerable proportion of the plasma membrane. In these young cells, substantial movement must take place across this membrane and its basic structure must fluctuate accordingly. The innumerable small depressions may represent pinocytotic and secretory processes. The array of intramembrane particle lines may represent stages in fusion between the membranes of vesicles within the cytoplasm and the plasma membrane. The technique of ultra-rapid freezing allows these events and their intermediate stages to be visualised; some features of the membrane may only be seen by this method.

Quantitative freeze-fracture studies of membrane changes in chicken muscular dystrophy

Muscular dystrophy induces extensive changes in the patterning of sarcolemmal caveolae of fast-twitch fibers from the chicken posterior latissimus dorsi (PLD) muscle, which in healthy fibers are arranged in striking bands over the myofibrillar I-bands. In dystrophic fibers the caveolae lack this patterned arrangement, and instead are dispersed over the entire sarcolemma, are irregular in shape, and are more numerous in older birds. Quantitative analysis of these differences provides three independent numerical indices of the dystrophic state and suggests that constraints responsible for normal patterning are lost in diseased fibers. These observations support theories that defects of the muscle plasma membrane are important for dystrophic pathogenesis. In contrast, the sarcolemma of slow tonic fibers from anterior latissimus dorsi (ALD) and metapatagialis latissimus dorsi (MLD) muscles have randomly dispersed caveolae whose appearance and distribution are unaffected by the disease.

Efficiency of the use of pock size on the chorioallantoic membrane of fertile hen's eggs as a method of typing herpes simplex viruses

One hundred and eighteen herpes simplex virus isolates were typed in a diagnostic virology laboratory using their standard procedure by pock size on the chorioallantoic membranes (CAMs) of fertile hen's eggs. Forty-three were typed as type 1 and 75 as type 2. The isolates were then sent to a research laboratory in which they were typed blind, with or without subsequent passage in tissue culture, by neutralization with type-specific antisera. Discrepant results were found with only two isolates. The isolates were then typed by the more time-consuming but unambiguous method of restriction endonuclease analysis of their DNAs. Typing by this method confirmed the typing by neutralization and established that typing by pock size on CAMs was correct in about 98% of cases.

Molecular epidemiology of human rotaviruses in Melbourne, Australia, from 1973 to 1979, as determined by electrophoresis of genome ribonucleic acid

Rotaviruses contain a double-stranded ribonucleic acid genome consisting of 11 segments. Gel electrophoresis separates genome segments and allows identification of strain differences. This electrophoretic typing technique was applied to rotavirus specimens from 116 children and 72 newborn babies. Between 1973 and 1979, 17 different electropherotypes of rotavirus were observed in children with acute gastroenteritis. These electropherotypes showed a sequential pattern of appearance, with a limited number of electropherotypes present at any given time. By contrast, only two electropherotypes were identified from isolates from newborn babies in seven hospitals during 1975 to 1979. These two electropherotypes were very similar and were never identified in children with acute gastroenteritis. One of the neonatal electropherotypes was found in the nurseries of five different hospitals and persisted in one hospital for 4 years. Electrophoretic typing techniques can be applied routinely and reproducibly to small samples of feces and could prove to be of value in epidemiological studies of rotavirus infection

Transfer of antirotaviral antibodies from mothers to their infants

Levels of rotavirus-specific immunoglobulin G (IgG), IgA, IgM, and secretory immunoglobulin in maternal and cord serum, colostrum and milk, and infants' stools were measured by enzyme-linked immunosorbent assay in 92 mothers and their infants. Although antirotaviral IgG, IgA, and secretory immunoglobulin were present in most maternal sera, only IgG crossed the placenta. All samples of colostrum and milk tested contained antirotaviral secretory immunoglobulin and IgA except those of two women in whom IgA deficiency was subsequently described. Specific IgM and IgG were also detected in many colostral samples. Antirotaviral IgA was detected in many colostral samples. Antirotaviral IgA was detected in stools of breast-fed but not bottle-fed neonates. Apparently the human infant receives rotaviral antibodies both transplacentally and via maternal colostrum and milk.

Measurement of immunoglobulin A, G, and M class rotavirus antibodies in serum and mucosal secretions

A solid-phase, enzyme-linked immunospecific assay for measurement of different immunoglobulin classes of human rotavirus antibodies is described. The antigen, which was adsorbed directly to polyvinyl microtiter plates, consisted of a clarified cell culture stock of the simian rotavirus SA 11. The assay was sensitive and reproducible and could readily be calibrated to determine concentrations of each class of antibody. The assay was applied to measurements of rotavirus antibodies in serum, colostrum, milk, and fecal samples. It particularly facilitates investigations of the role of immunoglobulin A antibodies in immunity to rotavirus infections.

Cytologic observations on axotomized feline Betz cells. II. Quantitative ultrastructural findings

Quantitative electron microscopic examination was made of Betz cells of two unoperated cats as well as cats subjected to left lateral funiculotomy 5, 10, 28 and 49 days before sacrifice. The percent cytoplasmic composition of chromatolyzed, right-sided Betz cells contributed by cisternal elements of RER, Golgi apparatus and dense bodies and the percent perikaryal membrane apposed by subsurface cisterns were unchanged from the normal despite marked qualitative alterations of the cytoplasm. However, 49 days postoperatively mitochondrial numerical density of axotomized, right-sided Betz cells was significantly less than at 0, 10 and 28 days post funiculotomy. Importantly, normal-appearing Betz cells ipsilateral to corticospinal tract section showed an increase in mitochondrial numerical density 5 days postoperatively. Operation did not induce change in the % perikaryal coverage by axosomatic boutons. Retraction of axosomatic boutons, though often reported for other neuronal populations undergoing axon reaction, is not a necessary feature of the axon reaction of feline Betz cells.

The fine structure and development of the trabeculae and the trabecular ring in Selaginella kraussiana

In the shoot apex of Selaginella kraussiana A. Br., air spaces develop between the endodermal cells, isolating the two steles from the cortex. The endodermal cells elongate to form trabeculae connecting the two tissues. As each trabecular cell develops, cuticularization occurs on the external surface at a point mid-way along the cell and forms the trabecular ring. The plasmalemma of the trabecular cell becomes attached to the wall beneath the main concentration of the ring, resembling the connection between the plasmalemma and the Casparian strip of a primary endodermis. The trabeculae retain a functional cytoplasm throughout growth.

The effect of hypercholesterolemia on aortic endothelium studied en face

The aortic endothelium of rabbits fed a stock diet containing 1 or 2% cholesterol for intervals of 1 day to 21 weeks was compared with that of normal rabbits on a stock diet without cholesterol. The endothelium was examined en face using the Häutchen technique. The aortic endothelium of the experimental animals revealed an increase in stigmata and stomata, multinucleated giant cells and leukocytes particularly about sites of branching. These changes were also observed in the endothelium overlying lipid deposits but in addition, there was an increase in mitoses, an alteration in the orientation of endothelial cells and their nuclei, and a change in their argyrophilic staining properties. Closely related to the endothelium was an increasing number of foam cells which appeared to be derived from monocytic leukocytes.