Service evaluation: orthoptic-led teaching of soft contact lens handling for parents in the management of pediatric aphakia.

To gauge parental satisfaction of an orthoptic-led specialist service for teaching soft contact lens (CL) handling in the management of children with pediatric aphakia. 20 families attending the contact lens clinic completed a satisfaction questionnaire to enquire about their experience of learning how to insert and remove their child's CL. Families were questioned on their experiences with preoperative counseling, practical teaching, additional support and the patient literature that was provided by the orthoptists in the CL clinic. Qualitative data and free comments were analyzed. 18/20 (90%) said they had received good practical insertion and removal teaching. 19/20 (95%) felt they received good emotional support. Only 6/20 (30%) families agreed with the statement that they found learning insertion and removal difficult. 15/20 (75%) families did not feel rushed, and 18/20 (90%) said they could learn at their own pace. All except one family (95%) achieved daily CL handling within a few months, with ongoing support from a multi-disciplinary team. One family surveyed was much earlier in their postoperative journey, but was on track to achieve this imminently. All families (100%) felt they were appropriately counselled preoperatively regarding the need for training and daily CL handling. 95% found the provided written information useful. 8/20 (40%) reported they found insertion harder than removal, 4/20(20%) reported they found removal harder. Teaching insertion and removal skills is an important aspect of managing paediatric aphakia and presents many challenges. Most parents eventually cope well and achieve daily CL handling within a few months, with support from a multi-disciplinary team. Families surveyed were all competent and were satisfied with their experience. The parental satisfaction survey gave our team confidence that our orthoptic-led service works well, orthoptists have the knowledge and skills to provide technical training to parents alongside vital emotional support, and contact lens handling is a rewarding extended role for orthoptists in a multi-disciplinary team.

The eastern extent of seasonal iron limitation in the high latitude North Atlantic Ocean.

The availability of iron (Fe) can seasonally limit phytoplankton growth in the High Latitude North Atlantic (HLNA), greatly reducing the efficiency of the biological carbon pump. However, the spatial extent of seasonal iron limitation is not yet known. We present autumn nutrient and dissolved Fe measurements, combined with microphytoplankton distribution, of waters overlying the Hebridean (Scottish) shelf break. A distinct biogeochemical divide was observed, with Fe deficient surface waters present beyond the shelf break, much further eastwards than previously recognised. Due to along and on-shelf circulation, the Hebridean shelf represents a much-localised source of Fe, which does not fertilise the wider HLNA. Shelf sediments are generally thought to supply large quantities of Fe to overlying waters. However, for this Fe to influence upper-ocean biogeochemical cycling, efficient off-shelf transport mechanisms are required. This work challenges the view that the oceanic surface waters in close proximity to continental margins are iron replete with respect to marine primary production demands.

Outbreak of E. coli O157 infection in the south west of the UK: risks from streams crossing seaside beaches.

In August 2004 seven cases of Escherichia coli O157 infection were identified in children on holiday in Cornwall, southwest England, all of whom had stayed at different sites in the area. Isolates from all seven cases were confirmed as E. coli serogroup O157 phage type 21/28. We carried out a case-control study among holidaymakers who visited the beach. A standardised questionnaire was administered by telephone to parents. They were asked where on the beach the children had played, whether they had had contact with the stream that flowed across the beach, and about their use of food outlets and sources of food eaten. Cases were more likely to have played in the stream than controls (OR [1.72- undefined]). The time spent in the stream by cases was twice spent there by controls. Cases and controls were equally exposed to other suspected risk factors. PFGE profiles for all the cases were indistinguishable. Increased numbers of coliforms were found in the stream prior to the outbreak. Cattle were found grazing upstream. We suggest that the vehicle of infection for an outbreak of acute gastrointestinal illness caused by E. coli O157 was a contaminated freshwater stream flowing across a seaside beach. The onset dates were consistent with a point source. Heavy rainfall in the days preceding the outbreak might have lead to faeces from the cattle potentially contaminated by E. coli O157 contaminating the stream, thereby leading to the outbreak. Control measures included fencing off the part of the stream in which children played, and putting up warning signs around the beach.

Excitatory synaptogenesis between identified Lymnaea neurons requires extrinsic trophic factors and is mediated by receptor tyrosine kinases.

Neurotrophic factors have well established roles in neuronal development and adult synaptic plasticity, but their precise role in synapse formation has yet to be determined. This paper provides the first direct evidence that neurotrophic factors in brain conditioned medium (CM) differentially regulate excitatory and inhibitory synapse formation. Somata of identified presynaptic and postsynaptic neurons were isolated from the CNS of Lymnaea and were cultured in a soma-soma configuration in the presence (CM) or absence [defined medium (DM)] of trophic factors. In DM, excitatory synapses did not form. When they were paired in CM or in DM containing Lymnaea epidermal growth factor (EGF); however, all presynaptic neurons reestablished their specific excitatory synapses, which had electrical properties similar to those seen in vivo. CM-induced formation of excitatory synapses required transcription and de novo protein synthesis, as indicated by the observations that synapse formation was blocked by the protein synthesis inhibitor anisomycin and the protein transcription blocker actinomycin D; the CM factor was inactivated by boiling. They were also blocked by receptor tyrosine kinase inhibitors (lavendustin A, genistein, K252a, and KT5926) but not by inactive analogs (genistin and lavendustin B), suggesting that the effect was mediated by receptor tyrosine kinases. These results, together with our previously published data, demonstrate that trophic factors are required for excitatory, but not inhibitory, synapse formation and extends the role of EGF from cell proliferation, neurite outgrowth, and survival to excitatory synapse formation.

Complete nucleotide sequence of the mouse CTLA8 gene.

The gene encoding the mouse cytotoxic T-lymphocyte-associated antigen 8 (CTLA8) has been cloned and its complete nucleotide (nt) sequence determined. Sequence and polymerase chain reaction (PCR) analysis indicated that the published CTLA8 sequence[Rouvier et al., J. Immunol. 150 (1993), 5445-5456] was of rat rather than mouse origin. The mouse CTLA8 gene contains two exons and one intron. The 5'flanking region contains several consensus motifs for binding to transcription factors and the 3' untranslated region (UTR) has AU-rich motifs associated with RNA instability. The putative exon sequences predict that the full-length mouse CTLA8 molecule contains 147 amino acids (aa) and shares 88% aa identity with rat CTLA8 and 57% aa identity to HSV13, an open reading frame (ORF) from herpesvirus saimiri (HVS).

Localization of immunoreactive alpha-bag-cell peptide in the central nervous system of Aplysia.

The bag cells of the marine mollusc Aplysia are well-characterized neuroendocrine cells that initiate egg laying, but the natural stimulus triggering bag-cell activity has not been determined. As a first step toward identifying central neurons that might provide synaptic or neurohormonal input onto the bag-cell network, antibodies specific for alpha-bag-cell peptide (alpha-BCP) were generated. This peptide belongs to a small family of structurally related peptides that can elicit bag-cell activity in vitro. Antibody specificity was established by immunodot assay and preabsorption studies: immunocytochemical labeling was abolished in each ganglion when the antibodies were preincubated with either alpha-BCP-thyroglobulin conjugate or alpha-BCP-(1-8) but was not affected by preincubation with thyroglobulin or thyroglobulin-thyroglobulin conjugate. The antibodies specifically labeled the bag cells in the abdominal ganglion and ectopic bag cells in both the abdominal and right pleural ganglia. The ectopic bag cells were similar to conventional bag cells in size and morphology, but varied in number and location among preparations. In the cerebral ganglion, the antibodies labeled a bilaterally symmetrical pair of cell clusters, containing approximately ten cells each, on the dorsal surface of the ganglion. The cerebral cells were smaller than bag cells, were constant in location, and sent their processes into the neuropil rather than the connective tissue sheath. Immunoreactive processes were observed in the neuropils of the cerebral, pleural, and pedal ganglia and among the axons of the cerebropedal, cerebropleural, and pleurovisceral connectives. No immunoreactive cell bodies were observed in the buccal or pedal ganglia. Identical patterns of labeling were observed in Aplysia californica, A. brasiliana, and A. dactylomela. The distribution of immunoreactive cell bodies within the circumesophageal ganglia of all three species thus parallels the distribution of receptive sites for the in vitro induction of bag-cell activity by atrial gland peptide B, a peptide structurally related to alpha-BCP. These observations suggest that the immunoreactive cells identified in these studies, or a subset of them, may be involved in the physiological induction of bag-cell activity. Since low doses of alpha-BCP have additional inhibitory actions on the bag cells, however, it is possible that the identified cells could play a more complex role in the regulation of bag-cell activity.

Molecular cloning of a cDNA encoding the neuropeptides APGWamide and cerebral peptide 1: localization of APGWamide-like immunoreactivity in the central nervous system and male reproductive organs of Aplysia.

While much is known about the neural and endocrine mechanisms that control egg laying in the gastropod mollusk Aplysia, relatively little is known about the regulation of male reproductive activity in this simultaneous hermaphrodite. In the present study, we have cloned and sequenced a cDNA that encodes a precursor protein, the predicted posttranslational processing of which presumably generates nine copies of the neuropeptide Ala-Pro-Gly-Trp-NH2 (APGWamide), five connecting peptide sequences, and a C-terminal peptide. The sequence of one connecting peptide is identical to the previously characterized cerebral peptide 1. Northern blot analysis identified two major APGWamide mRNA transcripts (approximately 1.3 kb, approximately 2.4 kb), which were present in central nervous system ganglia, but were most abundant in the right cerebral and right pedal ganglia. Immunohistochemical studies using sexually mature Aplysia demonstrated that the vast majority of APGWamide-like immunoreactivity was localized in 30-40 neurons along the anterior and medial margins of the right cerebral ganglion and in a cluster of 15-20 neurons in the right pedal ganglion. A total of only about ten immunoreactive neurons were located in other ganglia. Immunohistochemistry also demonstrated that APGWamide was present in the reproductive organs that participate in the storage or transport of sperm, including the small hermaphroditic duct (site of sperm storage before mating), the white hemiduct (also known as the copulatory duct), and penial complex. As a group, these data suggest that APGWamide may play a role in regulating male reproductive function in Aplysia, as it does in other gastropods.

Molecular cloning of a cDNA encoding a potential water-borne pheromonal attractant released during Aplysia egg laying.

Recently deposited egg cordons are a source of water-borne pheromones that attract the marine mollusk Aplysia into breeding aggregations and coordinate male and female reproductive behavior within the aggregation. A potential pheromonal attractant has been isolated from egg cordon eluates and the peptide partially characterized [S.D. Painter, B. Clough, X. Fan, G.T. Nagle, Soc. Neurosci. Abstr., Vol. 22 (1996) 837]. Using this information, we have cloned an Aplysia albumen gland cDNA that encodes a precursor protein containing a single copy of the full-length peptide, and demonstrated that there are abundant levels of pheromone mRNA transcripts (0.8 and 2.5 kb) in the albumen gland. This is consistent with the reported function of the gland (i.e. packaging the eggs into a cordon for deposition), with behavioral studies showing that the albumen gland is a potential source of attractants, and more recent biochemical studies in which the full-length peptide has been isolated from the albumen gland. This is the first candidate peptide pheromone in mollusks and the first in invertebrates. The pheromonal regulatory system in Aplysia may provide a model system for examining the structural characteristics of peptide pheromones.

The bag cell egg-laying hormones of Aplysia brasiliana and Aplysia californica are identical.

Egg laying in the marine molluscan genus Aplysia is elicited by an egg-laying hormone (ELH) which induces ovulation and acts on central neurons to effect egg-laying behavior. ELH, isolated from the A. californica bag cells, and three ELH-related peptides, isolated from the A. californica atrial gland, have been chemically characterized, yet relatively little is known about homologous peptides in other Aplysia species. In these studies, the primary structure of A. brasiliana ELH was determined. Bag cell clusters were extracted in an acidic solution, and the peptides purified by sequential gel filtration and reversed-phase HPLC; ELH was identified by bioassay. Amino acid compositional and sequence analyses demonstrated that the neurohormone was a 36-residue peptide whose sequence was identical to that of A. californica ELH: NH2-Ile-Ser-Ile-Asn-Gln-Asp-Leu-Lys-Ala-Ile-Thr-Asp-Met-Leu-Leu-Thr-Glu- Gln-Ile- Arg-Glu-Arg-Gln-Arg-Tyr-Leu-Ala-Asp-Leu-Arg-Gln-Arg-Leu-Leu-Glu-Lys-COOH .

Aplysia californica neurons R3-R14: primary structure of the myoactive histidine-rich basic peptide and peptide I.

The R3-R14 neurons of the marine mollusc Aplysia are neuroendocrine cells that express a gene encoding peptides I, II and histidine-rich basic peptide (HRBP), a myoactive peptide that excites Aplysia heart and enhances gut motility in vitro. Peptide II has been chemically characterized (35), but the complete primary structures of peptide I and HRBP have not been established by amino acid sequence analysis. HRBP, peptide I, and the prohormone (proHRBP) were therefore purified from acid extracts of Aplysia californica neural tissue using sequential gel filtration and reverse-phase high-performance liquid chromatography and chemically characterized. Amino acid sequence analysis demonstrated that HRBP was a 43-residue peptide whose sequence was: less than Glu-Val-Ala-Gln-Met-His-Val-Trp-Arg-Ala-Val-Asn-His-Asp-Arg-Asn-His-Gly- Thr-Gly - Ser-Gly-Arg-His-Gly-Arg-Phe-Leu-Ile-Arg-Asn-Arg-Tyr-Arg-Tyr-Gly-Gly-Gly- His-Leu - Ser-Asp-Ala-COOH. Compositional and sequence analyses of peptide I and proHRBP demonstrated that peptide I was a 26-residue peptide with the following sequence: NH2-Glu-Glu-Val-Phe-Asp-Asp-Thr-Asp-Val-Gly-Asp-Glu-Leu-Thr-Asn-Ala- Leu-Glu-Ser-Val-Leu-Thr-Asp-Phe-Lys-Asp-COOH. These results demonstrated that the pro-HRBP sequence predicted by nucleotide sequence analysis of a cDNA clone (24) was in fact synthesized in R3-R14 neurons. Hydrophilicity and hydrophobicity profiles of preproHRBP, combined with charge distribution profiles and predictive secondary structural analysis, showed that cleavage at dibasic sequences was strongly associated with peaks of hydrophilicity in alpha-helical regions of the preprohormone.

FMRFamide inhibition of a molluscan heart is accompanied by increases in cyclic AMP.

The molluscan neuropeptide FMRFamide (Phe-Met-Arg-Phe-NH2) inhibits the beat of isolated ventricles of the freshwater clam Lampsilis claibornensis. The decline in frequency and diastolic tone precedes the dose- and time-dependent increase in cAMP also produced by the peptide. Phosphodiesterase inhibitors (theophylline, 3-isobutyl-1-methylxanthine) and cAMP analogs also inhibit Lampsilis hearts, but only at high doses (10(-5)-10(-3)M). Again, the inhibition by theophylline is accompanied by a rise in cAMP. Nevertheless, the delayed increase in cAMP levels following FMRFamide treatment may suggest that cAMP is not mediating the onset of FMRFamide cardioinhibition.

Microanatomy courses in U.S. and Canadian medical schools, 1991-92.

BACKGROUND: Many medical schools are reevaluating their approaches to teaching the basic and clinical sciences, yet there is little systematic information available about how specific courses are being taught. METHOD: A detailed questionnaire was sent to 139 U.S. and Canadian medical schools to obtain information about microanatomy courses in 1991-92. RESULTS: Overall, 114 (82%) of the schools responded. The responses showed that microanatomy courses were including more cell biology and related material in their curricula, and that many were coordinating subject presentation with other basic science courses. The courses relied primarily on lecture-based teaching for non-laboratory material and structured laboratory exercises for laboratory material. New approaches, such as small-group, problem-solving sessions, were being introduced slowly; most of the courses used faculty-provided learning objectives. Computer-aided instruction had been introduced at a small number of schools, usually in the form of self-instructional packages or reviews. Multiple-choice written examinations and short-answer practical examinations were usually used to assess student knowledge; computer-based testing was rare. CONCLUSION: The microanatomy curricula tended to be relatively conventional. The primary barrier to the introduction of computer-aided instruction may be the wide-spread use of other self-instructional tools that are effective and less expensive to develop and maintain. Because of the trend toward fewer student contact hours, the adoption of problem-based learning at the course level could have a significant negative impact on the amount of microanatomy material that could be covered.

Structure-activity relations of the molluscan neuropeptide FMRFamide on some molluscan muscles.

Analogs of the molluscan neuropeptide FMRFamide were tested on four different molluscan muscle preparations which show qualitatively different responses to the peptide; the structure-activity relations are basically similar, but not identical. The C-terminal amide and the Arg3 residue are critical for FMRFamide-like activity on all four preparations. In contrast, analogs extended at the N-terminal or with conservative substitutions for the Phe1 or Met2 residue are approximately equipotent to FMRFamide. These structural requirements parallel those for the C-terminal tetrapeptide amide of gastrin.

The anatomy and functional morphology of the large hermaphroditic duct of three species of Aplysia, with special reference to the atrial gland.

The anatomy and functional morphology of the large hermaphroditic duct of three species of gastropod mollusc (Aplysia californica, A. dactylomela, and A. brasiliana) were examined. Each duct is composed of two parallel compartments, the red hemiduct (RHD) and the white hemiduct (WHD), which are distinguishable from the outside of the duct. Four secretory regions, all exocrine in morphology, are recognizable: the RHD secretory epithelium, the atrial gland (or atrial gland-like epithelium), the WHD secretory epithelium, and the accessory gland of the copulatory duct (AGCD). Of these regions, only the atrial gland (or atrial gland-like epithelium) contains egglaying activity and only the atrial gland (or atrial gland-like epithelium) is immunocytochemically labeled by serum antibodies generated against low molecular weight A. californica atrial gland peptides. The RHD is the functional oviduct: the egg cordon passes through a channel lined by the RHD secretory epithelium and bordered by the atrial gland (or atrial gland-like epithelium); the eggs are separated from both the WHD secretory epithelium and the AGCD by internal folds of the duct. The WHD is the functional copulatory duct: the penis, exogenous sperm, and endogenous sperm pass directly by the AGCD and in close proximity to the WHD secretory epithelium; they are separated from both the RHD secretory epithelium and the atrial gland (or atrial gland-like epithelium) by internal folds. The atrial gland (or atrial gland-like epithelium) is thus not likely to have a prostatic function or to be directly stimulated by the penis during copulation; it may play a role in oviductal function.

Characterization of Aplysia attractin, the first water-borne peptide pheromone in invertebrates.

Although animals in the genus Aplysia are solitary during most of the year, they form breeding aggregations during the reproductive season. The aggregations contain both mating and egg-laying animals and are associated with masses of egg cordons. The egg cordons are a source of pheromones that establish and maintain the aggregation, but none of the pheromonal factors have been chemically characterized. In these studies, specimens of Aplysia were induced to lay eggs, the egg cordons collected and eluted, and the eluates fractionated by C18 reversed-phase HPLC. Four peak fractions were bioassayed in a T-maze. All four increased the number of animals attracted to a nonlaying conspecific and were thus subjected to compositional and microsequence analysis. Each contained the same NH2-terminal peptide sequence. The full-length peptide ("attractin") was isolated from the albumen gland, a large exocrine organ that packages the eggs into a cordon. The complete 58-residue sequence was obtained, and it matched that predicted by an albumen gland cDNA. Mass spectrometry showed that attractin is 21 wt.% carbohydrate as the result of N-linked glycosylation. T-maze bioassays confirmed that the full-length peptide is attractive. Attractin is the first water-borne peptide pheromone characterized in molluscs, and the first in invertebrates.

The battered woman syndrome: effects of severity and intermittency of abuse.

The concept of a battered woman syndrome was tested by assessing 50 battered women and 25 emotionally abused women who had recently left their relationships. For both groups, essential features of the syndrome were present and were significantly interrelated. Dynamic features of the prior abusive relationship correlated significantly with these sequelae. The concept of intermittency is proposed as an alternative to the cycle of violence theory as main contributor to the syndrome. Predictability of abuse was found to be unrelated to the intermittency measure.

Emotional attachments in abusive relationships: a test of traumatic bonding theory.

An empirical test of traumatic bonding theory, the notion that strong emotional attachments are formed by intermittent abuse, is reported. In-depth assessments (interviews plus questionnaires) were conducted on 75 women who had recently left abusive relationships (50 where physical violence had occurred). The study found support for the effect of relationship dynamic factors such as extremity of intermittent maltreatment and power differentials on long-term felt attachment for a former partner, experienced trauma symptoms, and self-esteem, immediately after separation from an abusive partner and again after a six month interim. All three of these measures were significantly intercorrelated within each time period. Each measure at Time 1 correlated significantly with each corresponding measure at Time 2. After six months attachment had decreased by about 27%. Relationship variables (total abuse, intermittency of abuse and power differentials) accounted for 55% of the variance in the attachment measure at Time 2 indicating prolonged effects of abuse suffered in the relationship.

Effect of heterogeneity on radionuclide retardation in the alluvial aquifer near Yucca Mountain, Nevada.

The U.S. Department of Energy is currently studying Yucca Mountain, Nevada, as a potential site for a geological high-level waste repository. In the current conceptual models of radionuclide transport at Yucca Mountain, part of the transport path to pumping locations would be through an alluvial aquifer. Interactions with minerals in the alluvium are expected to retard the downstream migration of radionuclides, thereby delaying arrival times and reducing ground water concentrations. We evaluate the effectiveness of the alluvial aquifer as a transport barrier using the stochastic Lagrangian framework. A transport model is developed to account for physical and chemical heterogeneities and rate-limited mass transfer between mobile and immobile zones. The latter process is caused by small-scale heterogeneity and is thought to control the macroscopic-scale retardation in some field experiments. A geostatistical model for the spatially varying sorption parameters is developed from a site-specific database created from hydrochemical measurements and a calibrated modeling approach (Turner and Pabalan 1999). Transport of neptunium is considered as an example. The results are sensitive to the rate of transfer between mobile and immobile zones, and to spatial variability in the hydraulic conductivity. Chemical heterogeneity has only a small effect, as does correlation between hydraulic conductivity and the neptunium distribution coefficient. These results illustrate how general sensitivities can be explored with modest effort within the Lagrangian framework. Such studies complement and guide the application of more detailed numerical simulations.