The beta thalassaemia trait in Jamaica.

The objective of this study was to review the prevalence and features of the beta thalassaemia trait in Jamaican populations. Screening of 221,306 newborns over the last 46 years has given an indication of the distribution and prevalence of beta thalassaemia genes, and screening of 16,612 senior school students in Manchester parish, central Jamaica, has provided their haematological features. The prevalence of the beta thalassaemia trait predicted from double heterozygotes was 0.8% of 100,000 babies in Kingston, 0.9% of 121,306 newborns in southwest Jamaica, and 0.9% of school students in Manchester. Mild beta+ thalassaemia variants (-88 C>T, -29 A>G, -90 C>T, polyA T>C) accounted for 75% of Kingston newborns, 76% of newborns in southwest Jamaica, and 89% of Manchester students. Severe beta+ thalassaemia variants were uncommon. Betao thalassaemia variants occurred in 43 patients and resulted from 11 different variants of which the IVSII-849 A>G accounted for 25 (58%) subjects. Red cell indices in IVSII-781 C>G did not differ significantly from HbAA, and this is probably a harmless polymorphism rather than a form of beta+ thalassaemia; the removal of 6 cases in school screening had a minimal effect on the frequency of the beta thalassaemia trait. Red cell indices in the beta+ and betao thalassaemia traits followed established patterns, although both were associated with increased HbF levels. The benign nature of beta+ thalassaemia genes in Jamaica means that cases of sickle cell-beta+ thalassaemia are likely to be overlooked, and important clinical questions such as the role of pneumococcal prophylaxis remain to be answered.

Early signs of language in child and chimpanzee.

In a sequel to Project Washoe, chimpanzees are being taught American Sign Language from birth by humans who are fluent in the language, including persons who are themselves deaf or whose parents were deaf. The first two subjects began to use signs when they were 3 months old, and these early results indicate that the new conditions are significantly superior to the conditions of Project Washoe. More valid comparisons can now be made between the acquisition of language by children and by chimpanzees.

Casein secretion in mammary tissue: tonic regulation of basal secretion by protein kinase A.

Despite its quantitative importance in the secretion of lactoproteins, little is known about the triggering and control mechanisms that initiate, regulate and terminate the operation of the basal pathway of lactoprotein secretion throughout the lactation cycle. This study investigated the possible modulation by cAMP-mediated mechanisms, of cellular transit of newly-synthesised caseins and their basal secretion in explants of mammary tissue from lactating rats and rabbits. Enhancement of the rate of secretion of newly-synthesised caseins occurs when mammary explants are challenged in vitro with agents that activate protein kinase A (PKA). Inhibition of PKA slows casein secretion. The PKA-sensitive step(s) in casein secretion is early in the exocytosis pathway but inhibition of PKA does not impair casein maturation. Ultrastructural, immunochemical and biochemical methods locate PKA on membranes of vesicles situated in the Golgi region. Exposure of tissue to a cell-permeant PKA inhibitor results in morphological modification of these vesicular structures. We conclude that PKA mediates tonic positive regulation of the basal secretory pathway for lactoproteins in the mammary epithelial cell.

Success of sentinel lymph node mapping after breast cancer ablation with focused microwave phased array thermotherapy.

BACKGROUND: Breast cancer tumor ablation as part of a multimodality approach in the treatment of breast cancer is the subject of recent interest. This study was conducted to determine if the ability to perform sentinel node biopsy was impaired after thermal-induced ablation of breast cancer. METHODS: We studied patients who had sentinel node biopsy after preoperative focused microwave phased array for breast cancer ablation. RESULTS: Twenty-one patients with T1-T2 breast cancer and clinically negative axilla underwent wide local excision and sentinel node biopsy guided by blue dye and sulfur colloid. Surgery was done an average of 17 days after microwave ablation. Fifteen of 22 patients (68%) had histologic evidence of tumor necrosis. Sentinel lymph node mapping was successful in 19 of 21 patients (91%). Axillary metastases were detected in 42% of cases. CONCLUSIONS: This study documents successful sentinel lymph node mapping for patients treated with antecedent local tumor ablation using focused microwave phased array ablation.

A vocabulary test for chimpanzees (Pan troglodytes).

Chimpanzees can communicate in American Sign Language (ASL) to independent human observers whose only source of information is the ASL signs of the chimpanzees. A vocabulary test was presented to 4 cross-fostered chimpanzees (4-6 years old). Thirty-five-millimeter color slides were projected on a screen that could be seen by the chimpanzee subject but not by the human observers. There were two observers: O1 was the questioner in the testing room with the subject; O2 was in a different room. Neither observer could see the other, or the responses of the other observer. O1 and O2 agreed in their readings of both correct and incorrect signs, and most of the signs were the correct ASL names of the slides. In order to show that the chimpanzees were naming natural language categories--that the sign DOG could refer to any dog, FLOWER to any flower, SHOE to any shoe--each test trial was a first trial in that test slides were presented only once. Analysis of errors showed that two aspects of the signs, gestural form and conceptual category, governed the distribution of errors.

Interactive use of sign language by cross-fostered chimpanzees (Pan troglodytes).

Cross-fostered as infants in Reno, Nevada, chimpanzees (Pan troglodytes) Washoe, Moja, Tatu, and Dar freely converse in signs of American Sign Language with each other as well as with humans in Ellensburg, Washington. In this experiment, a human interlocutor waited for a chimpanzee to initiate conversations with her and then responded with 1 of 4 types of probes: general requests for more information, on-topic questions, off-topic questions, or negative statements. The responses of the chimpanzees to the probes depended on the type of probe and the particular signs in the probes. They reiterated, adjusted, and shifted the signs in their utterances in conversationally appropriate rejoinders. Their reactions to and interactions with a conversational partner resembled patterns of conversation found in similar studies of human children.

Targeting of PKA in mammary epithelial cells. Mechanisms and functional consequences.

Targeting of protein kinases, promoting association with specific partner-molecules and localisation to particular sites within the cell, has come to be recognised as a key mechanism for attributing specificity to these enzymes. In mammary epithelial cells, the repertoire of acute regulatory roles played by cyclic AMP-dependent protein kinase (PKA) differs from that in other lipogenic cell-types. Furthermore, PKA is implicated in the regulation of mammary-specific function, mediating a tonic stimulation of the flux of newly-synthesised casein through its basal secretory pathway. Both these observations imply mammary-specific properties of either PKA targeting systems or of PKA itself. Evidence for the latter is currently lacking. Pulse-chase labelling experiments in the presence and absence of selective effectors of PKA have enabled the site(s) of action of this protein kinase on casein secretion to be localised to the early stages of the secretory pathway. Possible mechanisms are considered for the physical targeting of PKA to the membrane-enclosed components of the secretory pathway and evidence for their occurrence in mammary epithelial cells is presented.

Vocal and gestural responses of cross-fostered chimpanzees.

Ten positive, five neutral, and five negative events were presented to two chimpanzees, Tatu (female, 64 months old) and Dar (male, 56 months old), who had been cross-fostered from birth by human beings. Each event was announced in American Sign Language 10 s before. The announcements and events were common items in the cross-fostering routines and were administered according to a balanced design over a period of 2 months. Vocal and signed responses to the announcements and to the events were recorded. The likelihood of either mode of response depended on affective charge, and the likelihood of vocal and signed responses was positively correlated. Signed responses were more likely than vocal responses; signed responses were more likely to be evoked by announcements than by events, whereas vocal responses were more likely to be evoked by events than by announcements. The type of vocal response depended on the affective charge and on whether the response was immediate (to the event) or anticipatory (to the announcement). Incorporation of signs and phrases from the announcements, and reiteration of signs and phrases within an utterance depended on affective charge, just as they do for human children.

Categorical replies to categorical questions by cross-fostered chimpanzees.

The chimpanzees Washoe, Moja, Tatu, and Dar were reared under human cross-fostering conditions that included the use of American Sign Language (ASL) as the medium of two-way communication. In the course of everyday conversation they were asked, in signs, the Wh-questions that are typically asked of young children. In earlier studies, extensive samples showed a pattern of replies, most significantly a developmental sequence, that closely matched the pattern found in the replies of young children. Part 1 of this report is based on a special sample taken when Tatu was 63 months old and Dar was 56 months old, in which experimenters used a large pool of nameable objects, and asked a naming question and at least one descriptive question about the same object in the same context. Tatu and Dar replied to naming questions (WHAT THAT? or WHAT NAME THAT?) with signs that were nouns and to descriptive questions with signs that were modifiers: possessive pronouns for WHOSE THAT?, colors for WHAT COLOR THAT?, and materials for WHAT THAT MAKE FROM? Part 2 is a reanalysis of the Part 1 sample and several other samples of replies, demonstrating that even when their reply was incorrect, these chimpanzees usually replied with a sign from the category specified by the question. The continuities that biologists seek are continuities of laws, patterns of resemblance rather than overlapping data points. Results reported here add depth to the patterns demonstrated in earlier studies.

Nonsustained ventricular tachycardia in 193 U.S. military aviators: long-term follow-up.

BACKGROUND: Despite its importance to the aeromedical community, the occupational implications of asymptomatic, nonsustained ventricular tachycardia (VT) are not well described. We sought to clarify this issue via a review of military aviators evaluated for nonsustained VT by defining event rates for sudden cardiac death, syncope, presyncope and sustained VT, and by determining whether any cofactors predicted a subgroup at increased risk for such outcomes. METHODS: We reviewed the records of 193 military aviators evaluated at the U.S. Air Force Aeromedical Consultation Service for nonsustained VT from September 1960 to December 1992. Follow-up information was available on 192 of the 193 aviators over a mean of 10.6 yr. Cofactor analysis focused on idiopathic VT (no associated underlying cardiac disease) and VT associated with mitral valve prolapse (MVP). RESULTS: There was no documented sustained VT; 9 (4.6%) had events including syncope (1), presyncope (5) and sudden death (3). Of these 9, 4 had idiopathic VT. The 3 deaths were associated with coronary artery disease, MVP and cardiomyopathy. No cofactors predicted events in aviators initially presenting with asymptomatic nonsustained VT. For asymptomatic nonsustained VT, the maximum predicted annual event rate was 0.33% for idiopathic VT and 2.3% for VT with MVP (95% confidence limit). CONCLUSIONS: Nonsustained VT did not predict future documented sustained VT. Cofactors failed to predict a subgroup at increased risk for events. Idiopathic nonsustained VT appeared to be a low risk population for whom expanded waiver criteria are proposed with suggested limits on duration and number of episodes of VT.

The Burgess decision and the Wallerstein brief.

Divorcing couples traditionally incorporate into their settlement contracts a stipulation regarding relative degree of freedom to relocate, especially if the relocating parent has primary custody of the children. Typically, the primary custodial parent might be restricted from moving outside of the state in which the divorcing couple has resided, or there may be a specific mile radius or travel time radius beyond which the primary custodial parent cannot relocate. In recent years, courts have become increasingly permissive with regard to allowing relocation by primary custodial parents, and the once stringent requirements that needed to be satisfied to justify relocation are being progressively relaxed. In 1996, the Supreme Court of California in In Re the Marriage of Burgess, 913 P.2d 473 (Cal. 1996), has set a precedent for even further relaxation of these once rigid restrictions. The Burgess decision has been frequently quoted in the State of California and is receiving widespread attention elsewhere. It is the author's opinion that this precedent is ill conceived and will most likely result in significant grief and suffering for the nonrelocating parent as well as the relocating children.

Social, legal, and therapeutic changes that should lessen the traumatic effects of divorce on children.

Easing the plight of the divorcing and the divorced requires the efforts of a broad range of professional disciplines. It is not my purpose here to cover in detail the various ways in which different professionals can contribute to this goal. Rather, I will focus on certain specific changes which, if implemented, could prevent and/or lessen some of the psychological traumas attendant to divorce. Some of these changes are already being instituted but are mentioned here because they warrant more widespread appreciation and utilization. Others, to the best of my knowledge, have not yet been made and may never be. My hope is that this presentation will play some small role in bringing about these changes.