Intracytoplasmic sperm injection in the mouse

Intracytoplasmic sperm injection (ICSI) into mouse oocytes involvesa very low survival rate. This study was designed to determinewhy ICSI frequently fails in mice. Metaphase II oocytes wereobtained from superovulated 4–6 week old F₁ hybrid mice.Spermatozoa were retrieved from the epididymis of 12–14week old F₁ hybrid mice. The spiked microinjection pipette usedto inject a spermatozoon into the ooplasm had outer and innerdiameters of 10 and 8 µm respectively. The oocytes usedin the first part of the study were not activated (group 1).Some oocytes were incubated with calcium ionophore for 5 min(group 2). The injected oocytes were evaluated 6, 20, 48 and72 h after injection. A total of 143 eggs in each group underwentICSI. In group 1, sperm heads escaped into the perivitellinespace. In all, 63 (47%) of the remaining oocytes were damagedduring the injection or had degenerated by the first evaluation.The survival rate was 53%, but fertilization did not occur.In group 2, 31 oocytes (22%) were damaged during microinjectionor soon degenerated. Two oocytes underwent accidental subzonalinsemination. Six oocytes were fertilized (4.2%) among the 78%of survivors. After injection, the sperm tail was found in thecytoplasm (27 and 31% in groups 1 and 2 respectively), the perivitellinespace (45% in both groups) or protruding through the zona pellucida(28 and 23% respectively). More oocytes degenerated when thetail remained in the cytoplasm, i.e. 78% in group 1 and 36%in group 2.     

Synchrony levels during evoked seizure-like bursts in mouse neocortical slices

Slices (n = 45) from the somatosensory cortex of mouse (P8-13) generated spontaneous bursts of activity (0.10 +/- 0.05 Hz) that were recorded extracellularly. Multiunit action potential (AP) activity was integrated and used as an index of population activity. In this experimental model, seizure-like activity (SLA) was evoked with bicuculline (5-10 microM) or N-methyl-d-aspartate (NMDA, 5 microM). SLA was an episode with repetitive bursting at a frequency of 0.50 +/- 0.06 Hz. To evaluate whether SLA was associated with a change in synchrony, we obtained simultaneous intracellular and extracellular recordings (n = 40) and quantified the relationship between individual cells and the surrounding population of neurons. During the SLA there was an increase in population activity and bursting activity was observed in neurons and areas that were previously silent. We defined synchrony as cellular activity that is consistently locked with the population bursts. Signal-averaging techniques were used to determine this component. To quantitatively assess change in synchronous activity at SLA onset, we estimated the entropy of the single cell's spike trains and subdivided this measure into network burst-related information and noise-related entropy. The burst-related information was not significantly altered at the onset of NMDA-evoked SLA and slightly increased when evoked with bicuculline. The signal-to-noise ratio determined from the entropy estimates showed a significant decrease (instead of an expected increase) during SLA. We conclude that the increased population activity during the SLA is attributed to recruitment of neurons rather than to increased synchrony of each of the individual elements.     

Non-adenomatous colorectal polyposis syndromes

Gastrointestinal polyps are common lesions that usually present singly or in small numbers. Although the term ‘multiple colorectal polyposis’ was originally applied to patients carrying at least 100 large intestinal adenomas, it has subsequently become broadened to include patients carrying multiple polyps regardless of their nature. Most of the non-adenomatous polyposis syndromes are hereditary. They can be classified according to the dominant type of polyp, their distribution in the gastrointestinal tract and their potential for the development of gastrointestinal cancers. This review summarises their main clinical, genetic and histopathological features.     

Characterization of human mononuclear cells using reduced pyridine nucleotide fluorescence and flow cytometry

Peripheral blood monocytes undergo an oxidative burst similar to that seen in neutrophils. The basis for this response appears to be an NAD(P)H oxidase that utilizes reduced NAD(P)H to form superoxide anion. We utilized the unique UV-stimulated fluorescence property of reduced pyridine nucleotides to analyze NAD(P)H utilization in monocytes. UV-stimulated fluorescence in mononuclear cell preparations indicated two populations of cells with the highly fluorescent cells having a Coulter volume consistent with that of monocytes. Dual laser analysis with monoclonal antibodies confirmed that these highly fluorescent cells are monocytes by showing them to be OKM1+, Leu DR+, and anti-monocyte 0.2+. Natural killer (NK) cells, as defined by Leu 7, were not found in this highly fluorescent population. Stimulation of mononuclear cells with phorbol myristate acetate caused a fluorescence loss indicative of NAD(P)H oxidation in monocytes but not in lymphocytes. Stimulation with suboptimal concentrations of PMA (1-5 ng/ml) resulted in a dose-dependent fluorescence loss in monocytes that occurred in an all-or-none fashion identical to the pattern observed in neutrophils. Simultaneous measurement of H2O2 production using dichlorofluorescein formation with NAD(P)H fluorescence indicates that oxidant production occurs in a graded manner. This method, then, provides a convenient way to study in single cells the metabolic events involved in depletion and replenishment of NAD(P)H during the oxidative burst and demonstrates an additional means by which to distinguish monocytes from lymphocytes using flow cytometry.     

Mechanical properties of mammalian single smooth muscle cells III. Passive properties of pig detrusor and human a terme uterus cells

Summary Cells isolated from pig urinary bladders and pregnant full term human uteruses were attached longitudinally between a microforce transducer and a length displacement apparatus. Cells were stretched by applying a series of ramp-like length changes of 0.2 s duration and 10.0m amplitude at intervals of 15 min. Passive forces upon straining were as high as 70–100N. Following these peak forces stress relaxation occurred, levelling off approximately 50% of the maximum peak force. The maximum elastic modulus estimated for single cells was found to be at least a tenfold higher than was previously estimated from intact bladder strips. The relation between the increase in length and the increase in initial force increment was found to be approximately linear. An exponential equation was fitted to a selected number of stress relaxation curves. Relaxation curves of bladder cells show a clearly different time course as compared to bladder tissue strips, suggesting that a significant amount of relaxation in strips has to be contributed to the connective tissue components or to structural changes in these strips.     

Weight change, survival time and cause of death in Dutch elderly

Weight change, subsequent survival time and cause of death are reported from the Dutch Longitudinal Study among the Elderly. Data consist of a national sample of persons aged 65-99 years. Six hundred and fifty-eight subjects were examined in the baseline years 1955-1957 and were re-examined 5 years later. Vital status and cause of death were ascertained for 604 of these subjects through 1983. Those subjects who experienced a decline in body mass index (BMI, kg/m(2)) during the period of observation, were likely to be in poorer health and have a shorter survival time than those subjects with stable weight, regardless of initial BMI. Weight gain was associated with shorter survival time only in the age group 65-74 and in those with heart disease. Weight loss, on the other hand, was most likely to result in decreased survival time among those ultimately dying of stroke, pneumonia/influenza or heart disease. As such, weight loss may be an indicator of the severity of disease. The noted associations remained, even when those surviving less than two years were omitted from the analyses. Thus, in longer survivors, weight loss may be associated with decreased vitality and decreased ability to survive once a disease becomes apparent.     

Spontaneous dissection of the internal carotid artery. Apropos of 7 cases and a review of the literature

Since 1978, the authors have observed 7 cases of dissecting aneurysm in the internal carotid artery. Symptoms were severe headache and subsequent neurologic deficit in young persons (3 women, 4 men; mean age 35 years). The underlying pathology was spontaneous dissection of the cervical internal carotid artery, with surgical confirmation in 3 cases and typical angiographic patterns in all cases. Spontaneous dissection of the cervical internal carotid artery is being increasingly recognized as a cause of cerebral ischemia in young adults. Moreover this clinicopathologic event is more common than had previously been supposed. The etiology remains unclear, except in 15% of cases in which dystrophy of the media (Marfan's syndrome) is in cause. No history of cervical trauma can be found. Typical clinical features consist in ipsilateral headache preceding an abrupt neurologic deficit in a 40-year-old person. An incomplete Horner syndrome (oculosympathetic paresis without facial anhidrosis) associated with facial pain and numbness is pathognomonic, but the majority of dissections are less typical. The typical angiographic pattern is an elongated regular stenosis of the high cervical internal carotid artery, 2 cm above the non-involved bulbus ("string sign"). The dissection may modify to a tapered occlusion above the point of origin of the internal carotid artery. The natural course is spontaneous resolution of the stricture, without relapse. Optimal management is non-operative since medical treatment has proved to be efficient. These cases confirm the benign course and overall good prognosis of spontaneous dissections of the internal carotid artery which are not as rare as the scarcity of reports might indicate.(ABSTRACT TRUNCATED AT 250 WORDS)     

Construct validation of an acute care occupational therapy cerebral vascular accident assessment tool

This study was the last in a series of six investigations of the construct validity of the St. Marys CVA evaluation, a clinician constructed test composed of items designed to evaluate sensory, perceptual, motor, and self care performance in cerebral vascular accident patients. Data for the present study were obtained from 250 new patients referred for occupational therapy services from 1983 to 1988. Factor analysis with varimax orthogonal rotation was performed on 22 items of the evaluation including perception, recovery stages, measures of grasp and pinch strength and other functional variables. Three factors emerged - Right Function, Recovery Stage, and Left Hand Strength. The results of the study, combined with results of previous research, indicate that this CVA Evaluation has reasonable construct validity as an occupational therapy assessment tool in an acute care setting.