Home-based primary care providers' perspectives on the unique challenges of working with late life posttraumatic stress disorder within their population of Veterans

Posttraumatic stress disorder (PTSD) is more prevalent in medically ill older Veterans in Home-Based Primary Care (HBPC) settings than in the general population, raising unique considerations. The aim of this qualitative project was to explore HBPC mental health providers' perceptions of the presentation and treatment of PTSD and trauma-related symptoms in this population of older Veterans, many of whom face additional barriers to treatment due to living in rural settings. Five focus groups and one one-on-one interview were conducted with 23 HBPC mental health providers serving rural or rural/urban mixed communities across the United States. We applied qualitative content analysis to the data. Three themes were found: (1) Presentation of Trauma-Related Symptoms and PTSD in HBPC Population; (2) Treatment Challenges in HBPC; and (3) PTSD Treatment Strategies. Each theme had multiple subthemes which illustrate unique issues in this population. Results of this project contribute to key insights surrounding the unique presentation of PTSD and trauma-related processes and treatment considerations in a medically, cognitively, and psychosocially complex group of veterans. Efforts to improve access to care should consider the specific needs of veterans who are homebound, live in rural settings and identify with rural cultural norms, and have difficulty engaging in specialized PTSD treatment due to the convergence of these factors. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Maximizing Veterans Health Affairs Community Hospice Collaborations: Review of Perceived Resource Needs to Support Veterans at End of Life

Within the United States, approximately 330 000 military veterans die annually, but only 5% of deaths occur in Veterans Health Administration (VHA) facilities. To help provide end-of-life care for veterans, the VHA built community partnerships with community hospice and palliative care (HPC) organizations. Veterans experience unique psychosocial factors making it vital to ensure HPC organizations have access to veteran-specific knowledge and resources to reduce suffering. To better understand the strengths and limitations of these partnerships, community HPC staff (N = 483) responded to quantitative and qualitative survey questions developed using an access to care theory for veterans. Survey responses demonstrated variable perceptions of access to VHA care and resources. Respondents reported excellent experiences (44%) and relationships with their local facility (50%) and had a reliable contact who provided needed assistance (92%). Thematic analysis identified a need for VHA care and barriers to access, which were associated with technical characteristics, and geographical and cultural issues. These findings can help inform future research and policy regarding access to VHA resources for end-of-life care for veterans in the community and guide resource development for community HPC providers.

What matters most to older adults: Racial and ethnic considerations in values for current healthcare planning

BACKGROUND

Clarifying what matters most informs current care planning for adults with multiple comorbidities. We describe how adults aged 55+ rate what matters most and differences in Black and White participants.

METHODS

Participants (N = 247, Age M = 63.61 ± 5.26) who self-identified as Black (n = 89), White (n = 96), or other racial and ethnic groups (n = 62) completed an online survey. Healthcare values in four domains, (1) important factors for managing health, (2) functioning, (3) enjoying life, and (4) connecting, were assessed with the What Matters Most-Structured Tool. Frailty was assessed with the FRAIL scale.

RESULTS

Concerns about pain and finances were rated as the most influential when making healthcare decisions across groups. Black participants rated religious and racial, ethnic, and cultural considerations as more important in healthcare decision-making than did White participants (Black participant M = 1.93 ± 0.85 vs. White participant M = 1.26 ± 0.52), citing concerns about health equity, disparity, and representation. Across the sample, specific aspects of functioning (e.g., ability to think clearly, walk, and see) and connecting (e.g., with family and friends and with God) were highly valued. Black participants rated the ability to dress or bathe, exercise, and connect with God as more important than did White participants, and they were also more likely to rate length of life as more important relative to quality of life. Value ratings were not associated with other demographic or health factors.

CONCLUSIONS

Adults aged 55+ from diverse groups highly value functioning and connections when making health decisions, with important contextual distinctions between Black participants and White participants. This study population was relatively young; future studies in older populations are needed.

Factors Associated With Distress Related to Posttraumatic Stress Disorder at the End of Life Among U.S. Veterans

CONTEXT

Posttraumatic stress disorder (PTSD) may emerge or re-emerge at end of life (EOL), increasing patient suffering. Understanding factors associated with PTSD at EOL may assist clinicians in identifying high risk veterans.

OBJECTIVES

To determine rates of and variables associated with PTSD-related distress at EOL.

METHODS

Retrospective observational cohort study including veterans who died within a Veterans Affairs (VA) inpatient setting between October 1, 2009 and September 30, 2018 whose next-of-kin completed the Bereaved Family Survey (BFS; N = 42,474). Our primary outcome was PTSD-related distress at EOL, as reported by veteran decedents' next-of-kin on the BFS. Predictors of interest included combat exposure, demographic variables, medical and psychiatric comorbidity, primary serious illness, and palliative care support.

RESULTS

Veteran decedents were majority male (97.7%), non-Hispanic white (77.2%), 65 years or older (80.5%), without combat exposure (80.1%). Almost one in ten (8.9%) veteran decedents experienced PTSD-related distress at EOL. In adjusted analyses, combat exposure, younger age, male sex, and non-white race were associated with PTSD-related distress at EOL. High overall medical comorbidity, dementia, and psychiatric comorbidities including both substance use disorder and depression, were also associated with PTSD-related distress at EOL. Palliative care consultation and emotional support were associated with decreased odds of PTSD-related distress, while pain was associated with increased odds of PTSD-related distress at EOL.

CONCLUSION

Trauma and PTSD screening, pain management, and providing palliative care and emotional support at EOL, particularly in at-risk groups such as veterans from racial/ethnic minority backgrounds and those with dementia, are critical to decreasing PTSD-related distress at EOL.

ADDRESSING TRAUMA IN OLDER VETERANS IN HOME-BASED PRIMARY CARE

As Veterans age, confronting illness and role changes, they may experience later adulthood trauma reengagement (LATR). To better understand this process in medically ill Veterans, we completed six focus groups with 21 VA Home Based Primary Care (HBPC) mental health clinicians in rural and urban settings; 14 completed a follow-up survey. Thematic analysis of focus groups confirmed the LATR model with unique presentation and treatment challenges related to medical, physical, and cognitive changes. In surveys, the most challenging symptoms were: intrusive symptoms, dissociative reactions, and psychological/physiological reactivity (79%). In addition to focus group themes, surveys described challenges related limited social engagement, Veteran ambivalence, and lack of empirically supported treatments appropriate to HBPC. Results of these focus group and survey data provide key insights into the unique presentation of trauma in aging medically ill Veterans. Ongoing efforts to adapt materials and resources for this population will be described.

ADVANCING LATE-LIFE TRAUMA-INFORMED CARE EDUCATION: DEVELOPMENT AND EVALUATION OF AN EDUCATIONAL PODCAST

Posttraumatic stress disorder (PTSD) may emerge or reemerge in the context of life-threatening illness, retirement, and life review, leading to complications in disease management and end-of-life care. Symptoms of PTSD in later life can be misattributed or overlooked by healthcare professionals, caregivers, and the older adults experiencing PTSD themselves. The “Talking Later” podcast was developed as an accessible educational product to improve recognition and trauma-informed responses to late-life PTSD. Each of the ten episodes had distinct goals and content objectives, which were identified through problem identification and needs assessment by a multidisciplinary team of geriatric clinicians. In the first three months of its publication in November 2021, the podcast has been downloaded by 1,473 unique listeners across 19 countries. The podcast was evaluated via feedback survey (N=39). Approximately 97% of respondents reported the episodes as engaging and informational. 87% stated that no more than general knowledge of PTSD was required to enjoy the podcast. Qualitative analysis of open-ended feedback items found that participants were interested in learning about additional comorbidities and diversity issues related to late-life trauma reengagement. The present poster will additionally describe ongoing efforts to address these and other feedback responses with the ongoing development of a second season of the podcast.

Unchecked immunity: a unique case of sequential immune-related adverse events with Pembrolizumab

BACKGROUND

Immune checkpoint inhibition has dramatically transformed the treatment of malignant melanoma. With increasing use, their unique spectrum of immune-mediated toxicity has become apparent.

CASE PRESENTATION

We describe a case of sequential immune-related adverse events (irAEs) in a patient with metastatic melanoma treated with single-agent anti-programmed cell death-1 (PD-1) therapy, pembrolizumab. Although numerous cases of irAEs have been reported, sequential multi-organ involvement, including progressive atopic dermatitis, vitiligo, autoimmune nephritis, autoimmune hepatitis, and autoimmune encephalitis after cessation of therapy, has not been previously documented.

CONCLUSIONS

Immunosuppression resulted in clinical remission of each irAE, highlighting the importance of vigilance for autoimmune complications in patients treated with checkpoint inhibition, even after immunotherapy cessation.

Using localizing learning to improve supervised learning algorithms

Slow learning of neural-network function approximators can frequently be attributed to interference, which occurs when learning in one area of the input space causes unlearning in another area. To mitigate the effect of unlearning, this paper develops an algorithm that adjusts the weights of an arbitrary, nonlinearly parameterized network such that the potential for future interference during learning is reduced. This is accomplished by the reduction of a biobjective cost function that combines the approximation error and a term that measures interference. An analysis of the algorithm's convergence properties shows that learning with this algorithm reduces future unlearning. The algorithm can be used either during online learning or can be used to condition a network to have immunity from interference during a future learning stage. A simple example demonstrates how interference manifests itself in a network and how less interference can lead to more efficient learning. Simulations demonstrate how this new learning algorithm speeds up the training in various situations due to the extra cost function term.

Radiation induced angiosarcoma a sequela of radiotherapy for breast cancer following conservative surgery

Radiation induced angiosarcomas (RIA) can affect breast cancer patients who had radiotherapy following conservative breast surgery. They are very rare tumors and often their diagnosis is delayed due to their benign appearance and difficulty in differentiation from radiation induced skin changes. Therefore it is very important that clinicians are aware of their existence. We report here a case of RIA followed by discussion and review of literature.

Influence of storage upon light-induced chlorogenic acid accumulation in potato tubers (Solanum tuberosum L.)

The influence of 2 weeks and 3 months of dark storage upon light-induced chlorogenic acid accumulation within tuber tissue of four potato cultivars and upon 5-, 4-, and 3-caffeoylquinic acid concentrations within cv. King Edward was determined. Storage period significantly affected (P < 0.05) the magnitude of the light-induced chlorogenic acid response with accumulation rates 3-4 times higher in tubers exposed to light after 2 weeks compared with those placed under light after 3 months. Comparison of chlorogenic acid concentrations in controls after 2 and 3 months of dark storage indicated that tuber chlorogenic concentrations decline during prolonged cold store at 5 degrees C. Rates of accumulation in response to light were cultivar-dependent with cv. Fianna the most light-sensitive and cv. Maris Piper relatively light-insensitive. In virtually all cases exposure to sodium and fluorescent light promoted higher rates of accumulation than did exposure to high-pressure mercury light sources. Chlorogenic acid values steadily increased over 15 days of illumination with, in the majority of cases, no indication of cessation. Light exposure increased 5-, 4-, and 3-caffeoylquinic acid accumulation rates in cv. King Edward. Irrespective of storage period and light source, ratios of 5-:4-:3-caffeoylquinic acid were ca. 85:15:0 at day 0 and 52:42:6 by day 15.

Dose-dependent hyperlipidemia in rabbits following administration of poloxamer 407 gel

Poloxamer 407 (P-407) is a tri-block polymer that exhibits concentration-dependent reverse thermal gelation, a characteristic potentially useful for developing sustained release injectable drugs. While some reports suggest that P-407 is 'non-toxic', rodent studies demonstrate that P-407 induces hyperlipidemia, an action that makes this polymer a questionable drug delivery vehicle. Unfortunately, the majority of earlier studies employed supra-physiologic doses of P-407. The present study examined if lower, clinically useful, doses of gel-forming concentrations of P-407 induced hyperlipidemia in rabbits. Male and female rabbits were injected with 5.5 mg/kg (0.025 mL/kg), 27.5 mg/kg (0.125 mL/kg), or 137.5 mg/kg (0.625 mL/kg) of 22% P-407 and the actions of this polymer on blood chemistry were assessed at 6 h, 1 d, 2 d, 7 d, and 14 d following injection. Control rabbits received no injection. The highest dose of P-407 (137.5 mg/kg) significantly increased serum triglycerides and cholesterol in both male and female rabbits with the maximum increase observed at 2 d after injection. Male rabbits were more sensitive to P-407 than females following injection of 137.5 mg/kg P-407. The lower doses of P-407 did not alter serum triglycerides or cholesterol. In all groups, serum triglycerides and cholesterol were at baseline levels by 14 d. P-407 did not affect other blood chemistry parameters. Although P-407 induces a dose-dependent hyperlipidemia in rabbits, low doses of this polymer may be used in controlled release drug delivery applications without the untoward hyperlipidemic effect.

Gastrointestinal safety and tolerance of ibuprofen at maximum over-the-counter dose

BACKGROUND

Delineation of non-steroidal anti-inflammatory drug (NSAID) gastrointestinal toxicity has largely depended on retrospective epidemiologic studies which demonstrate that lower doses of NSAIDs pose a lower risk of gastrointestinal toxicity. Ibuprofen, a propionic acid NSAID, has, in most such studies, exhibited a favourable profile in terms of gastrointestinal bleeding. Since 1984, ibuprofen has been available as a non-prescription analgesic/antipyretic with a limit of 1200 mg/day for 10 days of continuous use. Trials and spontaneously reported adverse experiences suggest that gastrointestinal symptoms and bleeding are rare.

METHODS

This study prospectively evaluated the gastrointestinal tolerability, as compared to placebo, of the maximum non-prescription dose and duration of ibuprofen use in healthy subjects representative of a non-prescription analgesic user population.

RESULTS

Gastrointestinal adverse experiences were similar in the placebo and ibuprofen groups (67 out of 413, 16% with placebo vs. 161 out of 833, 19% with ibuprofen). There was no difference between the two groups in the proportion discontinuing due to a gastrointestinal event. Gastrointestinal adverse experiences reported by >/= 1% of subjects were: dyspepsia, abdominal pain, nausea, diarrhoea, flatulence, and constipation. Seventeen (1.4%) subjects had positive occult blood tests: their frequency was comparable between treatments.

CONCLUSIONS

When used as directed to treat episodic pain, non-prescription ibuprofen at the maximum dose of 1200 mg/day for 10 days, is well-tolerated.

A photoreceptor cell-specific ATP-binding transporter gene (ABCR) is mutated in recessive Stargardt macular dystrophy

Stargardt disease (STGD, also known as fundus flavimaculatus; FFM) is an autosomal recessive retinal disorder characterized by a juvenile-onset macular dystrophy, alterations of the peripheral retina, and subretinal deposition of lipofuscin-like material. A gene encoding an ATP-binding cassette (ABC) transporter was mapped to the 2-cM (centiMorgan) interval at 1p13-p21 previously shown by linkage analysis to harbour the STGD gene. This gene, ABCR, is expressed exclusively and at high levels in the retina, in rod but not cone photoreceptors, as detected by in situ hybridization. Mutational analysis of ABCR in STGD families revealed a total of 19 different mutations including homozygous mutations in two families with consanguineous parentage. These data indicate that ABCR is the causal gene of STGD/FFM.

A gene for primary congenital glaucoma is not linked to the locus on chromosome 1q for autosomal dominant juvenile-onset open angle glaucoma

BACKGROUND

Primary congenital glaucoma is an uncommon autosomal recessive condition that results from a developmental defect in the trabecular meshwork and anterior chamber angle, manifesting in the neonatal or infantile period with increased intraocular pressure, corneal enlargement and edema, and optic nerve cupping with consequent loss of vision. Nothing is known about its genetic location.

PATIENTS AND METHODS

Linkage analysis was performed in 25 primary congenital glaucoma Saudi Arabian families with six polymorphic DNA markers on chromosome 1q in a region that has shown tight linkage to a locus for autosomal dominant juvenile-onset open angle glaucoma (GLC1A). Twenty-four of these families are highly consanguineous.

RESULTS

Each family was shown separately to exclude the 8-centimorgan (cM) interval containing the GLC1A locus. Four families independently demonstrated overlapping regions of exclusion (theta < or = -2) that spanned the entire 8-cM interval. Assignment of a primary congenital glaucoma locus in this region could be excluded by a cadre of 21 families because a primary congenital glaucoma disease locus did not segregate in an autosomal recessive manner on haplotypes constructed with markers in this region. For all families, no affected individuals demonstrated homozygosity of alleles in regions tightly linked to the GLC1A locus.

CONCLUSION

These results exclude the 8-cM region on chromosome 1q shown to contain the GLC1A locus from containing a disease locus for primary congenital glaucoma in this population of 25 Saudi Arabian families.

A YAC contig encompassing the recessive Stargardt disease gene (STGD) on chromosome 1p

Stargardt disease (STGD) and fundus flavimaculatus are infrequent autosomal recessive conditions characterized by a juvenile macular dystrophy and variable degrees of peripheral retinal changes. Linkage analysis performed in 47 STGD/fundus flavimaculatus families demonstrated significant linkage to 13 polymorphic DNA markers on chromosome 1p. The maximum combined two-point lod score was 32.7 (maximum recombination fraction [phi max] = .006) with the polymorphic marker D1S188. Our data demonstrate that STGD and fundus flavimaculatus are the same disorder clinically and genetically and provide further evidence for genetic homogeneity of this phenotype. Analysis of recombination events on disease chromosomes placed the STGD gene within a 4-cM interval between markers D1S435 and D1S236. A physical map was constructed of a YAC contig flanking STGD, from markers D1S500 to D1S495, and includes the critical interval delineated by historical recombinants. This contig spans approximately 31 cM, with one gap (3-5 cM) that is outside the 4-cM critical region. Localization of STGD to a single YAC contig will facilitate its positional cloning.

The Use of Nisin as a Preservative in Crumpets

Crumpets, a high moisture flour based product, have been implicated in food poisoning due to growth and toxin production by naturally occurring Bacillus cereus during 5-day storage at ambient temperature. Bacillus cereus isolates from untreated crumpets at the end of their shelf-life were shown to be sensitive to nisin. Addition of nisin to the batter at levels of 3.75 μg/g and above effectively prevented the growth to levels capable of causing food poisoning. The fate of nisin during the production and shelf-life of the crumpet was determined.

Bardet-Biedl syndrome is linked to DNA markers on chromosome 11q and is genetically heterogeneous

Bardet-Biedl syndrome (BBS) is an uncommon autosomal recessive condition characterized by mental retardation, post-axial polydactylia, obesity and pigmentary retinopathy. We performed linkage analysis in 31 multiplex BBS families and report significant linkage with two markers on chromosome 11q, PYGM and AFM164zf12 (D11S913). Homogeneity testing demonstrates genetic heterogeneity within our set of families. Our data imply that a major gene, BBS1, is located on chromosome 11q, although mutations at other loci may also be associated with this phenotype.

Identification and transcriptional analysis of the Escherichia coli htrE operon which is homologous to pap and related pilin operons

We have characterized a new Escherichia coli operon consisting of two genes, ecpD and htrE. The ecpD gene encodes a 27-kDa protein which is 40% identical at the amino acid level to the pilin chaperone PapD family of proteins. Immediately downstream of the ecpD gene is the htrE gene. The htrE gene encodes a polypeptide of 95 kDa which is processed to a 92-kDa mature species. The HtrE protein is 38% identical to the type II pilin porin protein PapC. The ecpD htrE operon is located at 3.3 min on the genetic map, corresponding to the region from kbp 153 to 157 of the E. coli physical map. The htrE gene was identified on the basis of a Tn5 insertion mutation which resulted in a temperature-sensitive growth phenotype above 43.5 degrees C. The transcription of this operon is induced with a temperature shift from 22 to 37 or 42 degrees C but not to higher temperatures, e.g., 50 degrees C. Consistent with this result, the temperature-induced transcription was shown to be independent of the rpoH gene product (sigma 32). The transcription of this operon was further shown to require functional integration host factor protein, since himA or himD mutant bacteria possessed lower levels of ecpD htrE transcripts. Among the three transcriptional start sites discovered, one, defined by the P2 promoter, was found to be under the positive regulation of the katF (rpoS) gene, which encodes a putative sigma factor required for the transcription of many growth phase-regulated genes.

Sequence analysis and phenotypic characterization of groEL mutations that block lambda and T4 bacteriophage growth

The groES and groEL genes of Escherichia coli have been shown previously to belong to a single operon under heat shock regulation. Both proteins have been universally conserved in nature, as judged by the presence of similar proteins throughout evolution. The GroEL protein has been shown to bind promiscuously to many unfolded proteins, thus preventing their aggregation. ATP hydrolysis by GroEL results in the release of the bound polypeptides, a process that often requires the action of GroES. In an effort to understand GroEL and GroES structure and function, we have determined the nucleotide changes of nine mutant alleles of groEL. All of these mutant alleles were isolated because they block bacteriophage lambda growth. Our sequencing results demonstrate that (i) many of these alleles are identical, in spite of the fact that they were independently isolated, and (ii) most of the different alleles are clustered in the same region of the gene. One of the mutant alleles was shown to possess two nucleotide alterations in the groEL coding phase, one of which is located in a putative ATP-binding domain. The two nucleotide changes were separated by genetic engineering, and each individual change was shown to exert an effect on bacteriophage growth. But, using genetic analyses, we demonstrate that the restriction on bacterial growth at elevated temperatures is conferred only by the mutation within the putative ATP-binding domain. We have cloned the mutant alleles on multicopy plasmids and overexpressed their products. By testing for the ability of bacteriophage either to propagate or to form colonies at 43 degrees C, we have been able to divide the mutant proteins into those with no activity and those with residual activity under the various conditions tested.

Identification of the Escherichia coli sohB gene, a multicopy suppressor of the HtrA (DegP) null phenotype

We cloned and sequenced the sohB gene of Escherichia coli. The temperature-sensitive phenotype of bacteria that carry a Tn10 insertion in the htrA (degP) gene is relieved when the sohB gene is present in the cell on a multicopy plasmid (30 to 50 copies per cell). The htrA gene encodes a periplasmic protease required for bacterial viability only at high temperature, i.e., above 39 degrees C. The sohB gene maps to 28 min on the E. coli chromosome, precisely between the topA and btuR genes. The gene encodes a 39,000-Mr precursor protein which is processed to a 37,000-Mr mature form. Sequencing of a DNA fragment containing the gene revealed an open reading frame which could encode a protein of Mr 39,474 with a predicted signal sequence cleavage site between amino acids 22 and 23. Cleavage at this site would reduce the size of the processed protein to 37,474 Mr. The predicted protein encoded by the open reading frame has homology with the inner membrane enzyme protease IV of E. coli, which digests cleaved signal peptides. Therefore, it is possible that the sohB gene encodes a previously undiscovered periplasmic protease in E. coli that, when overexpressed, can partially compensate for the missing HtrA protein function.

Synthesis and biological activity of novel, potent and long-acting analogs of AC-CCK-7 with high affinity for peripheral (type A) receptors

Analogs of cholecystokinin (CCK-7) in which the N-terminal Tyr(SO3H) was acetylated, Asp6 replaced with Thr(SO3H) and Phe7 replaced with N-methyl-Phe were prepared by solid-phase peptide synthesis and evaluated for their receptor-binding activity and ability to suppress appetite. The receptor binding activities of these synthetic analogs of CCK-7 and their selectivity for the CCK-A and CCK-B receptor subtypes were determined using solubilized membrane preparations from rat pancreatic tissue and bovine striatum. The synthetic peptide Ac-Tyr(SO3H)-Met-Gly-Trp-Met-Thr(SO3H)-N-methyl-Phe-NH2 (referred to as Ro 23-7014) demonstrated superior satiating potency (ED50 = 0.3 micrograms/kg, i.p.), increased selectivity for CCK-A receptors (400-fold), increased resistance to peptidergic degradation and a longer duration of action (4 to 5 hours). This analog also effectively suppressed food intake following intranasal administration (ED50 = 100 micrograms/kg). These studies demonstrate the feasibility of designing analogs of CCK-8 with greater selectivity, potency and duration of action, which may be useful as nonsystemically administered appetite suppressants.

Analysis of an Escherichia coli dnaB temperature-sensitive insertion mutation and its cold-sensitive extragenic suppressor

An Escherichia coli mutant, ts121, was isolated following random insertional mutagenesis using phage lambda Mu transposition. The mutant phenotype includes inability to form colonies at temperatures above 38 degrees C and inability to propagate phage lambda at all temperatures. A lambda i434 cI- (ts121)+ transducing phage was isolated on the basis of its ability to form plaques on ts121 mutant bacteria. Using this transducing phage, it was shown through complementation and protein analyses, that the ts121 mutation is located in the dnaB gene. The exact insertion event was identified by polymerase chain reaction amplification of the DNA sequences containing the insertion junction. The mutational insertion event in ts121 was mapped precisely between base pairs 1514 and 1515 of the dnaB gene. This result predicts that the mutant dnaB protein has lost its six terminal amino acids. The reading frame shifts into Mu-specific DNA sequences resulting in an additional 20 amino acid residues. The E. coli wild type dnaB protein participates in host replication and interacts with lambda P protein to initiate phage lambda DNA replication. Our results demonstrate that the extreme carboxyl end of the dnaB protein is required for productive interaction with the lambda P replication protein at all temperatures, and is important for dnaB function at temperatures above 38 degrees C. Cold-sensitive extragenic suppressors of the ts121 mutation were isolated on the basis of their ability to restore colony formation at 42 degrees C. One of these extragenic suppressors was mapped at 54 min on the E. coli genetic map and localized to the suhB gene, whose product may affect the expression of a number of genes at the translational level.

Human recombinant epidermal growth factor in experimental corneal wound healing

Human recombinant epidermal growth factor (hEGF) was evaluated in various corneal wound healing models in the rabbit. Human EGF accelerated epithelial wound healing in corneal reepithelialization, anterior-keratectomy, and alkali-burn models at concentrations of 10-500 micrograms/ml given four times daily (qid). In the corneal reepithelialization model, 100 micrograms/ml of hEGF qid produced a 45% increase in the wound-healing rate compared with control (0.13 versus 0.09 mm/hr) with a similar response at 500 micrograms/ml qid. In the anterior-keratectomy model, 500 micrograms/ml of hEGF qid accelerated healing by 40% (0.07 versus 0.05 mm/hr), although the 100 micrograms/ml dose was not active in this model, and 1 microgram/ml of hEGF actually slowed the healing rate. In the alkali-burn model, 10 and 100 micrograms/ml of hEGF qid for 32 days appeared to produce faster initial healing of the wound compared with control, although the wound recurred in both hEGF and control groups. These results suggest that hEGF may be helpful in some epithelial disorders in humans, although considerations of dose response and optimal dosing regimens must be addressed.

The effect of PDGF on the healing of full thickness wounds in hairless guinea pigs

1. Platelet-derived growth factor (PDGF), administered daily for 5 days and every other day for 9 additional days or the day of wounding and the following day, caused dose dependent (0.2, 1.0 or 5.0 micrograms PDGF/wound) increased granulation tissue. 2. The two day 5.0 micrograms treatment resulted in a 73% increase and the multi-day treatment resulted in a 52% increase of alkaline phosphatase activity three days after wounding. 3. Multi-day treatment resulted in significant increases in protein synthesis (132%), vimentin content (160%) and excised wound weight (76%) three days after wounding. 4. These results indicate that limited administration of PDGF alters wound healing although multiple applications provoke a more dramatic response.

Identification, characterization, and mapping of the Escherichia coli htrA gene, whose product is essential for bacterial growth only at elevated temperatures

We identified and cloned an Escherichia coli gene called htrA (high temperature requirement). The htrA gene was originally discovered because mini-Tn10 transposon insertions in it allowed E. coli growth at 30 degrees C but prevented growth at elevated temperatures (above 42 degrees C). The htrA insertion mutants underwent a block in macromolecular synthesis and eventually lysed at the nonpermissive temperature. The htrA gene was located at approximately 3.7 min (between the fhuA and dapD loci) on the genetic map of E. coli and between 180 and 187.5 kilobases on the physical map. It coded for an unstable, 51-kilodalton protein which was processed by removal of an amino-terminal fragment, resulting in a stable, 48-kilodalton protein.

Managing human resource strategies. A five-stage model of growth and development

To summarize, our model can be used to strategically manage human resources. It provides a framework first to assess the current position of human resource management in relation to each one of the strategic components. It then provides the framework for assessing where each one of the components should be in relation to the business needs. Closing the gaps on the dual fit will provide the function with a strategic plan to identify opportunities and risks in the business environment. The model can be used to analyze any unit or level in an organization. The model provides a framework for understanding the development of the HRM function in the organization. Learning from previous errors will most likely prevent new ones.

Production and characterization of monoclonal antibodies to peripheral and central nervous system myelin

Monoclonal antibodies against P0, myelin basic protein, or myelin-associated glycoprotein were generated by fusing mouse myeloma cells with spleen cells from BALB/c mice immunized with central and peripheral nervous system myelin proteins. The antibodies secreted were either IgG, IgM, or IgA. Clone C6B5 (iso-type IgM) secreted antibody(ies) that bound to both myelin basic protein and myelin-associated glycoprotein, although binding of antibody to myelin basic protein as detected by the immunoblot technique appeared to be much less than to the myelin-associated glycoprotein. Antibodies were characterized in solid-phase radioimmunoassay for their species cross-reaction, and histologically for the specificity of binding to myelin in central and peripheral nervous system tissues. These monoclonal reagents should prove valuable in studying CSF and myelin-producing cells, since in both cases the concentration of myelin proteins is low.

Rapid cytological diagnosis of rectal cancer

A simple, safe, rapid and accurate technique is described for cytological diagnosis of ulcerated or nodular rectal cancer done while performing digital rectal examination or sigmoidoscopy. In 21 cases, there were 17 true positives and no false positives for cancer. There were two true negatives and one false negative for rectal cancer. It is important to exclude prostatic cancer if, in the male, the lesion is anterior and situated at or near the level of the prostate gland, and this can be done using an immunoperoxidase technique which will identify cancer cells of prostatic origin.

Meshing human resources planning with strategic business planning: a model approach

Many people are touting the need to take a strategic approach to human resources management--but this is more easily said than done, point out authors Lloyd Baird, associate professor of management at the School of Management and the Human Resources Policy Institute at Boston University; Ilan Meshoulam, personnel executive at Digital Equipment Corporation; and Ghislaine DeGive, Boston University. Obviously, people cannot be moved around as easily or as speedily as can other resources to help move a company to a strategically identified future position. Thus a great deal of planning is required. The authors present an integrative human resources strategic planning model that focuses on four elements: the environment, the organization's culture, the corporate mission statement, and overall corporate strategy. Each part of the model is thoroughly discussed, and checklist questions are included to help the individual manager develop and implement human resources management plans for his or her own organization.

Career dynamics: managing the superior/subordinate relationship

Building on research and writing in the fields of career management and mentor relationships, Baird and Kram analyze the superior-subordinate relationship as an exchange to which each party brings different needs and resources. They point out that this relationship can be productive and satisfying--both for the parties concerned and for the organization--when the needs of one party match the resources of the other. The article includes a checklist for analyzing how the superior-subordinate relationship operates as an exchange and how the resources of the parties mesh or fail to mesh. They do on to show how the superior-subordinate relationship and the needs of the parties change as each moves through individual career and life cycles. What was once a productive relationship may, in time, become unproductive, or vice versa. In any event, its dynamic nature requires that it be managed. Baird and Kram suggest five steps for managing the relationship as it moves through these changes: (1) Recognizing that the relationship is an exchange; (2) identifying clearly one's own as well as the other party's needs; (3) understanding how the subordinate's and boss's needs fit together and recognizing that the relationship is likely to change; (4) understanding the constraints under which the boss operates; (5) establishing a feedback and evaluation process for continuously assessing the relationship.

Effect of 1-methyl-1-nitrosourea and streptozotocin on glucose-induced insulin secretion by isolated islets of Langerhans

The present experiments were designed to compare the effects of streptozotocin and 1-methyl-1-nitrosourea upon glucose-induced insulin secretion by isolated islets of Langerhans. Both drugs depressed the insulin response at one and two hours incubation but higher molar concentrations of the nitrosourea were required to produce the same level of inhibition as streptozotocin, a difference perhaps related to the latter's glucose moiety.

Effect of streptozotocin on glucose-induced insulin secretion by isolated islets of Langerhans

The present experiments were designed to investigate the immediate action of streptozotocin upon the beta cell by measuring its effect upon glucose-induced release by isolated islets of Langerhans. The results demonstrated a dose-related inhibition of glucose-induced secretion during the first two hours of incubation, with the inhibition most marked in the second hour. The same level of inhibition was achieved in the second hour regardless of whether the drug was present for both hours or for just the first hour.

Nicotinamide showed a dose-related protection against the inhibitory action of streptozotocin whereas nicotinic acid did not. Further, nicotinamide showed a protective trend even when added one hour after streptozotocin—indicating that no irreversible change in the insulin secretory mechanism had been elicited over the first hour of incubation. An enhancement of glucose-induced secretion was observed with nicotinamide alone. Nicotinamide was not able to protect against the inhibitory action of mannoheptulose and the latter had no significant effect upon streptozotocin's action.

It is concluded that the early hyperglycemia induced by streptozotocin is the result of a direct action of streptozotocin on the beta cell and that the same biochemical lesion may be responsible for both the impairment of insulin secretion and eventual beta-cell destruction. Finally, the demonstration of a protective action of nicotinamide at the site of the beta cell suggests that the nicotinamide adenine dinucleotide (NAD) level of the beta cell may be critical for maintenance of normal function.