Spectroscopic gas detection using a Bragg grating - stabilized external cavity laser, custom written in planar integrated silica-on-silicon.

We present the development of an external cavity Bragg grating stabilized laser for tunable diode laser spectroscopy (TDLS). Our design uses a planar integrated silica-on-silicon platform incorporating a custom written Bragg grating as the wavelength-selective element of the laser cavity. We have developed a prototype singlemode laser at 1651 nm and performed a detailed characterization of its performance for the purpose of spectroscopic measurement of methane at this wavelength using a 25 cm path-length single-pass cell. Mode hop-free tuning of 0.13 nm has been demonstrated at frequencies of up to 10 kHz. A single-point limit of detection for TDLS of ΔI/I0 = 8.3 × 10-5 AU was achieved, which is consistent with the performance of standard distributed feedback lasers. The new device exhibits a side-mode suppression ratio of -40 dB and a low RIN of <-150 dB/Hz, and thus avoids the high levels of noise or instability normally associated with larger, mechanically driven external cavity lasers. The silica-on-silicon platform has the potential for low-volume manufacturing of special lasers at the custom wavelengths required for gas detection, without the need for investment in foundry solutions.

Perioperative thrombocytopenia: evidence, evaluation, and emerging therapies.

Thrombocytopenia is a common perioperative clinical problem. While global haemostasis is influenced by many patient- and procedure-related factors, the contribution of thrombocytopenia to bleeding risk is difficult to predict, as platelet count does not linearly correlate with likelihood of bleeding. Thus, the widely used definition of thrombocytopenia and grading of its severity have limited clinical utility. We present a summary and analysis of the current recommendations for invasive procedures in thrombocytopenic patients, although the platelet count at which any given procedure may safely proceed is unknown. The benefits and risks of preoperative platelet transfusions should be assessed on a patient-by-patient basis, and alternatives to platelet transfusion should be considered. In non-emergent surgeries or in postoperative thrombocytopenic patients, haematology consultation should be considered to guide diagnostics and management. We present a pragmatic approach to the evaluation of perioperative thrombocytopenia.

Aberrant splicing of a mouse disabled homolog, mdab1, in the scrambler mouse.

Although accurate long-distance neuronal migration is a cardinal feature of cerebral cortical development, little is known about control of this migration. The scrambler (scm) mouse shows abnormal cortical lamination that is indistinguishable from reeler. Genetic and physical mapping of scm identified yeast artificial chromosomes containing an exon of mdab1, a homolog of Drosophila disabled, which encodes a phosphoprotein that binds nonreceptor tyrosine kinases. mdab1 transcripts showed abnormal splicing in scm homozygotes, with 1.5 kb of intracisternal A particle retrotransposon sequence inserted into the mdab1 coding region in antisense orientation, producing a mutated and truncated predicted protein. Therefore, mdab1 is most likely the scm gene, thus implicating nonreceptor tyrosine kinases in neuronal migration and lamination in developing cerebral cortex.

Cloning and expression of a novel cysteine-rich secreted protein family member expressed in thyroid and pancreatic mesoderm within the chicken embryo.

We have isolated a new chicken gene that is a member of the cysteine-rich secreted protein family (CRISP). The CRISP family is composed of over 70 members that are found in many phyla of organisms, including: vertebrates, plants, fungi, yeast, and insects. Here we describe the cloning of a novel member of this family, SugarCrisp, and its expression pattern throughout chicken embryogenesis. We also describe its utility as a marker of thyroid and pancreatic mesoderm in the developing chicken embryo and its expression within the human and mouse in glandular tissue.

Very low birth weight and growth into adolescence.

OBJECTIVE: To compare the growth and pubertal development of very low-birth-weight (VLBW) children (birth weight <1500 g) and normal-birth-weight (NBW) children (birth weight >2499 g) to adolescence to determine if, and at what age, VLBW children "catch up." DESIGN: Inception cohort study to age 14 years. SETTING: Royal Women's Hospital, Melbourne, Australia. PATIENTS: Eighty-six consecutive survivors with a birth weight less than 1000 g, 120 consecutive survivors with a birth weight of 1000 to 1499 g, and 60 randomly selected NBW controls. Children with cerebral palsy at age 14 years were excluded. MAIN OUTCOME MEASURES: Weight, height, and head circumference measurements at birth and ages 2, 5, 8, and 14 years converted to z (SD) scores. RESULTS: At age 14 years, pubertal development was similar in NBW and VLBW children. At ages 2, 5, 8, and 14 years, VLBW children were significantly shorter and lighter and had smaller head circumferences than NBW children. The differences in height and weight between VLBW and NBW children were less apparent as SD scores improved in VLBW children over time. Within the VLBW group, compared with children with a birth weight of 1000 to 1499 g, those with a birth weight less than 1000 g had significantly lower weight z scores earlier in childhood but not at age 14 years, significantly lower height z scores only at age 2 years, and significantly lower head circumference z scores throughout childhood. CONCLUSION: This group of VLBW children experienced late catch-up growth to age 14 years but remain smaller than their NBW peers. Arch Pediatr Adolesc Med. 2000;154:778-784

Brain 5-hydroxytryptamine and learned resistance to punishment.

Rats can learn to persist in making a response that is punished. Brain 5-hydroxytryptamine (5-HT) systems are known to mediate acute responding to punishment. This work investigates 5-HT involvement in learned resistance to punishment. Forebrain 5-HT was depleted by intracerebral injection of 5,7-dihydroxytryptamine. Lesioned rats were fully able to learn resistance to punishment, although acute responding to punishment was impaired. Forebrain 5-HT does not mediate learned resistance to punishment.

Changes in lung function between age 8 and 14 years in children with birth weight of less than 1,501 g.

We set out to determine whether lung function of children with a birth weight of <1,501 g changed relative to expectations between the ages of 8 and 14 years. We hypothesized that changes in lung function may differ between those of birth weight above and below 1,000 g. The subjects of this study were born in the Royal Women's Hospital, Melbourne. There were 86 consecutive survivors with birth weights <1,000 g born between January 1, 1977 and March 31, 1982, and 124 consecutive survivors with birth weights 1,000-1,500 g born between October 1, 1980 and March 31, 1982. Lung function was measured at both age 8 and 14 years, corrected for prematurity in 78% (67/86) of those with birth weight <1,000 g, and in 69% (86/124) of those with birth weight 1,000-1,500 g. Overall, lung function was similar to predicted values at both 8 and 14 years of age [e.g., (forced expired volume in 1 s, FEV1% predicted) at age 8 years mean 88.5% (SD 14.7) and at age 14 years, mean 94.9% (SD 13.8)]. There were significant changes, mostly improvements, in lung function between age 8-14 years relative to predicted values: FEV1 (% predicted) increased between 8-14 years of age by a mean of 6.4 (95% confidence interval, 4.4-8.3). The improvements in some lung function variables were significantly greater in those of birth weight <1,000 g compared with those of birth weight 1,000-1,500 g: improvement in FEV1 (% predicted) between age 8-14 years in infants with birth weight <1,000 g had a mean of 10.3 (SD 13.1), and in those with birthweight 1,000-1,500 g a mean of 3.3 (SD 10.1). We conclude that lung function improved significantly relative to predicted values in children of birth weight <1,501 g between age 8-14 years. The improvements were greatest in those of birth weight <1,000 g.

Twenty-four hour pharmacy service in hospitals with less than 300 beds--Part 9.

In the June 1983 issue of Hospital Pharmacy, I requested pharmacy directors in hospitals of less than 300 beds who had 168-hour a week pharmacy service to describe their service and how they obtained it. Seven such descriptions appeared in July 1983. Below you will find a continuation of this feature. We plan to publish additional descriptions as they are received.

Detection and prevention of ambulatory care pharmacy dispensing errors.

There have been few studies of errors committed in ambulatory care pharmacies. Errors can be classified as incorrect strength, wrong product, wrong dosage form, wrong quantity, incorrect or omitted labeling (such as directions, patient's name, prescriber's name, auxiliary label, drug name, or strength), dispensing deteriorated drugs, and dispensing in non-childproof containers. Errors can be prevented by possessing and using knowledge, by proper performance and by having good systems in effect to prevent and/or uncover errors. Some contributing factors, which cause errors, are distraction and interruption, poor work habits, thoughtless robot-like performance, workloads past the safety threshold, poor working conditions, poorly written and incomplete prescriptions. A prime system to prevent errors from reaching the patient is the old tried and true system of having work checked by another person. The use of patient profiles can aid in reducing errors. The activity of patient counseling can reduce errors. Suggestions are made to reduce the number of errors made. A simple quality assurance program is presented. Case studies of medication errors are presented. The future use of bar-coding should be an extremely useful tool for preventing medication errors.

Survey of 24-hour, 7-day/week hospital pharmacy service.

Emergency after-hour pharmacy services in many hospitals have been replaced by 24-hour, 7-day/week pharmacy services. A survey questionnaire was published in Hospital Pharmacy, February 1983, to be completed by hospital pharmacies that provide a pharmacist in the hospital 24 hours a day, 7-days a week. Usable responses were received from 185 hospitals. The type of hospitals and the number of beds of these hospitals varied greatly. The differing responses concerning staffing, scheduling, hours of the post-midnight shift, arrangement of vacations and holidays, the factors used in selling the concept to administration, and the handling of compensation are presented.

Free flow associated with electronic infusion devices: an underestimated danger.

Accidental, uncontrolled free flow after removal of administration sets from electronic infusion devices (EIDs) has only occasionally been reported. Recent evidence indicates that this problem is far more widespread and serious than previously understood. Well-documented cases of accidental death and serious injury have now come to light and are a particular cause for concern. Many of the EIDs commonly used in hospitals incorporate sets that offer no protection if someone removes the set from the device without first closing the set's flow control clamp. Because the problem has infrequently been reported and the risk is not well appreciated, only minimal warnings are issued about the problem by manufacturers. Standard intravenous tubing sets and other nonprotected EID sets are less expensive than protected sets and some hospitals have acquired EIDs that use unprotected sets without an adequate understanding of the risks of free flow (i.e., fluid overload and drug toxicity). Therefore critically ill patients receiving certain types of intravenous fluids or critical care drugs may be at great risk of injury when an overinfusion occurs. This article provides a better understanding of the extent of the problem and offers suggestions for minimizing or eliminating the problem.

Developing safe and effective preprinted physician's order forms.

Having good preprinted order forms is no accident. A system must be in place to ensure this. Common problems found in preprinted order forms are discussed.

A survey of hospitals with computerized incorporation of the pharmacy patient profile and medication administration record.

A survey was distributed in 1985 to 48 hospitals throughout the United States known to have a single-source computer-generated pharmacy patient profile and medication administration record. The study centered on staff attitude toward this single source concept, time and staff requirements when compared to traditional methods of record keeping, and how up-to-the-minute information is disseminated between pharmacy and nursing. A major issue of consideration is the ability of such a system to maintain a method of checks and balances as far as reference to and interpretation of physicians' orders. The investigation revealed that 85% of the respondents felt that the checks and balances remains intact even though one party, nursing or pharmacy, is responsible for data entry that is used by both departments during the medication cycle. More than 88% of the returned surveys included a recommendation that such systems be adopted. Increased efficiency, maintainence of accuracy, and less time spent in dealing with discrepancies when compared with the duplicative manual process of order transcribing and profiling make transition to computerization an acceptable alternative. The information provided is subjective.

A survey of hospital policies on verbal orders.

The authors present the results of surveys of directors of nursing and directors of pharmacy on the types and extensiveness of the policies their institutions have implemented to control the use of verbal and telephone orders. One hundred hospitals were selected at random from 874 hospitals meeting the following criteria: 250 beds or larger, general medical surgical, short stay, and nongovernmental. The survey results demonstrated that a significant number of hospitals are attempting to regulate the use of verbal and telephone orders. However, only 35.5% of the hospitals surveyed have any policies that prohibit the use of verbal orders when the physician is physically present on the unit where the order is given, in non-emergency and non-bedside procedure situations. Relative to the above policy, directors of nursing state that this policy is followed 41.1% of the time and directors of pharmacy in the same institutions state that the policy is adhered to 11.1% of the time. In addition to the survey, the authors explain situations that may serve as a source of medication errors when using verbal or telephone orders. They also offer several precautions to take when the use of verbal and telephone orders is absolutely necessary.

Space requirements for pharmaceutical functions in selected nonuniversity hospitals.

The size of the average pharmacy is normally developed by gathering information from a large number of hospital pharmacies. The services provided by these pharmacies vary significantly. This tabulation is from selected hospitals that provided comprehensive pharmacy services. Fifty-four responses were tabulated. The results presented in this article indicate that these pharmacies require additional staff members and greater space allocation than the average hospital pharmacy department reported in other studies. Hospitals between 100-199 beds averaged 9.8 sq ft per bed, 200-299 bed hospitals averaged 10.1, 300-399 bed hospitals averaged 9, 400-499 bed hospitals averaged 8, and those over 500 beds averaged 9.4 sq ft per bed.

Look-alike and sound-alike drug names: the problem and the solution.

This list of 645 pairs of look-alike and sound-alike drug names (1,290 names are shown; they are listed both ways), has been complied to graphically emphasize the importance for the pharmaceutical industry, the United States Adopted Name (USAN) Council, and Food and Drug Administration (FDA) to select new names with great care. It also stresses to health professionals the necessity of writing legibly, writing complete orders, speaking slowly and clearly when giving verbal orders, carefully reading prescription orders, knowing what is wrong with patients, maintaining records of previous drugs patients have received, and learning about new drug products. It also indicates that patients must be educated about the medications they are taking. Your cooperation in alerting the authors of names they may have overlooked or of new problems would be greatly appreciated. When a sufficient number of additions are received, an updated list will be published.

Failure mode and effects analysis: a novel approach to avoiding dangerous medication errors and accidents.

It is time that hospitals realize that human error is inevitable and must be anticipated. A technique developed in the aerospace industry and known as "failure mode and effects analysis" involves identifying mistakes that will happen before they happen, and determining whether the consequences of those mistakes would be tolerable or intolerable. This article shows how this practice can be adapted to a hospital environment by using a continuous quality improvement approach. Examples show how actual fatal errors can be prevented.

Orientation teaching tool to prevent medication error.

Patients can be harmed and even killed when a medication error occurs. The following questions are based on actual errors which have been reported through the Medication Error Reporting Program (MERP). This teaching tool is intended as a take home test to make newly hired pharmacists aware of common medication errors. An informed practitioner is another layer of safety in decreasing the possibility of a medication error occurring.

Multifaceted roles of GSK-3 and Wnt/ß-catenin in hematopoiesis and leukemogenesis: opportunities for therapeutic intervention.

Glycogen synthase kinase-3 (GSK-3) is well documented to participate in a complex array of critical cellular processes. It was initially identified in rat skeletal muscle as a serine/threonine kinase that phosphorylated and inactivated glycogen synthase. This versatile protein is involved in numerous signaling pathways that influence metabolism, embryogenesis, differentiation, migration, cell cycle progression and survival. Recently, GSK-3 has been implicated in leukemia stem cell pathophysiology and may be an appropriate target for its eradication. In this review, we will discuss the roles that GSK-3 plays in hematopoiesis and leukemogenesis as how this pivotal kinase can interact with multiple signaling pathways such as: Wnt/ß-catenin, phosphoinositide 3-kinase (PI3K)/phosphatase and tensin homolog (PTEN)/Akt/mammalian target of rapamycin (mTOR), Ras/Raf/MEK/extracellular signal-regulated kinase (ERK), Notch and others. Moreover, we will discuss how targeting GSK-3 and these other pathways can improve leukemia therapy and may overcome therapeutic resistance. In summary, GSK-3 is a crucial regulatory kinase interacting with multiple pathways to control various physiological processes, as well as leukemia stem cells, leukemia progression and therapeutic resistance. GSK-3 and Wnt are clearly intriguing therapeutic targets.