ACT-5 is an essential Caenorhabditis elegans actin required for intestinal microvilli formation.

Investigation of Caenorhabditis elegans act-5 gene function revealed that intestinal microvillus formation requires a specific actin isoform. ACT-5 is the most diverged of the five C. elegans actins, sharing only 93% identity with the other four. Green fluorescent protein reporter and immunofluorescence analysis indicated that act-5 gene expression is limited to microvillus-containing cells within the intestine and excretory systems and that ACT-5 is apically localized within intestinal cells. Animals heterozygous for a dominant act-5 mutation looked clear and thin and grew slowly. Animals homozygous for either the dominant act-5 mutation, or a recessive loss of function mutant, exhibited normal morphology and intestinal cell polarity, but died during the first larval stage. Ultrastructural analysis revealed a complete loss of intestinal microvilli in homozygous act-5 mutants. Forced expression of ACT-1 under the control of the act-5 promoter did not rescue the lethality of the act-5 mutant. Together with immuno-electron microscopy experiments that indicated ACT-5 is enriched within microvilli themselves, these results suggest a microvillus-specific function for act-5, and further, they raise the possibility that specific actins may be specialized for building microvilli and related structures.

Polarization mode dispersion reduction in spun large mode area silica holey fibres.

We report the fabrication of the first spun holey optical fibre. Our experiments show that the complex air/glass transverse structure can be retained when the preform is spun during the fibre drawing process. Measurements of differential group delay (DGD) confirm that significant reductions in polarization mode dispersion (PMD) can be readily achieved using this approach.

Nonlinear femtosecond pulse compression at high average power levels by use of a large-mode-area holey fiber.

We demonstrate that nonlinear fiber compression is possible at unprecedented average power levels by use of a large-mode-area holey (microstructured) fiber and a passively mode-locked thin disk Yb:YAG laser operating at 1030 nm. We broaden the optical spectrum of the 810-fs pump pulses by nonlinear propagation in the fiber and remove the resultant chirp with a dispersive prism pair to achieve 18 W of average power in 33-fs pulses with a peak power of 12 MW and a repetition rate of 34 MHz. The output beam is nearly diffraction limited and is linearly polarized.

Fluorescent labeling of yeast.

This unit describes the use of several different fluorescence methods for labeling yeast cells. It includes methods to label the vacuole, the actin cytoskeleton, and chitin deposits on cell walls (bud scars), as well as methods for visualizing specific proteins in live cells with GFP chimeras and in fixed cells by immunofluorescence.

Clathrin function in yeast endocytosis.

The process of endocytosis is a complex series of events involving the coordinated activity of many proteins. In animal cells, clathrin plays a vital role in the invagination of the plasma membrane leading to formation of vesicles during endocytosis. The study of endocytosis in yeast cells has been hindered by a debate about the role of clathrin in early internalization steps. This review summarizes the evidence for and against clathrin's involvement in internalization from the yeast plasma membrane.

Comparative study of large-mode holey and conventional fibers.

Little information exists regarding how large-mode holey fibers compare, in practical terms, with their conventional counterparts. We present what is to our knowledge the first experimental study of mode area and bend loss for a range of large-mode holey and conventional fibers. It is demonstrated here that large-mode holey fibers exhibit mode areas and bending losses that are comparable to those of conventional fibers at 1.55mu . However, the novel wavelength dependence of the numerical aperture in a holey fiber offers a significant advantage for broadband and short-wavelength applications in which single-mode operation is required.

The transfer of child patients from the community dental service to the general dental service.

OBJECTIVE: To determine an effective strategy for the transfer of children from the CDS to the GDS. DESIGN: Single centre study comprising a retrospective analysis of a 50% random sample of dental records for children transferred from CDO to GDP. SETTING: Community dental clinic in an urban area of south Manchester with relatively little material deprivation. SUBJECTS AND METHODS: Between 1990 and 1995, a GDP worked up to 5 hours a week in the CDS clinic seeing routine child patients referred by the CDO. MAIN OUTCOME MEASURES: Numbers of children registered with a GDP after varying periods of time. Attendance records of children transferred from CDS to GDS and rates of failed appointments. RESULTS: After 4 1/2 years, 264 child patients had been registered with the GDP under capitation and a further 55 adults were registered under continuing care. The majority of children had retained registration for more than 2 1/2 years. The mean rate of failed appointments was 16%. CONCLUSION: Children can be transferred successfully from the CDS to the GDS if the GDP works at the community clinic and there are further benefits which accrue to the scheme.

Long-term health outcomes and medical effects of torture among US Navy prisoners of war in Vietnam.

OBJECTIVE: To characterize incidence of illnesses and injuries from 1979 to 1993 in former naval aviator prisoners of war (POWs) from the Vietnam War and a comparison group of naval aviators from the same war. DESIGN: Cohort analytic study. SETTING: A US Navy primary care clinic. PARTICIPANTS: Volunteer sample consisting of 70 former naval aviator POWs (white men, aged 47 to 69 years in 1993) and a comparison group of 55 naval aviators who served in Vietnam but were not POWs, matched on race, age, marital status, education, rank, year of entry into the navy, and pilot status. Subjects participated in an annual health screening program. This study reports data sampled on a biennial basis from subjects screening both in 1979 and 1993. MAIN OUTCOME MEASURE: Medically diagnosed incidence of illness and injury based on a standard protocol. RESULTS: POWs had higher incidence rates than the comparison group did of disorders of the peripheral nervous system (relative risk [RR], 8.4; 95% confidence interval [CI], 2.7-25.9; P<.001), joints (RR, 1.5; 95% CI, 1.2-2.0; P<.006), and back RR, 1.8; 5% CI, 1.0-3.0; P<.037). These findings also were statistically significant according to Kaplan-Meier survival analyses that included 131 (95%) of 138 POWs and 115 (83%) of the 138 members of the comparison group. Survival analyses revealed that, in addition to these disorders, POWs had higher hazard rates of peptic ulcer (P<.01). CONCLUSIONS: During captivity, ropes, ratchet handcuffs, leg irons, or stocks were used to put tightly constrictive pressure around the extremities of POWs as a means of torture, resulting in painful ischemia and subsequent neuropathies. Being a former POW was associated with increased cumulative incidence rates of chronic disorders of the peripheral nervous system, joints, and back and an increased hazard rate of peptic ulcer.

Orthopedic injuries experienced by U.S. prisoners of war during Operation Desert Storm: a descriptive analysis.

U.S. prisoners of war from Operation Desert Storm suffered significant orthopedic injuries. The repatriated prisoners of war (RPOWs) have been medically evaluated over a 3-year period with orthopedic follow-up. A significant proportion of the musculoskeletal injuries were located around the neck and spine, shoulder, and upper extremity. Aircraft ejection was the cause of the majority of these injuries. Lower extremity injuries after ejection, aside from the knee, were not reported. Flail injuries of the lower extremities were absent as well. These results were examined with reference to Vietnam RPOW data.

Compulsive personality traits affecting aeronautical adaptability in a naval aviator: a case report.

This is a case report of a male naval aviator who demonstrated compulsive personality traits which adversely affected the performance of his duties as a pilot trainee, and later, as a naval flight officer. The Diagnostic and Statistical Manual of the American Psychiatric Association (DSM-III-R) uses the term obsessive-compulsive to describe two conditions. A review of terminology is undertaken to present the reader with the distinguishing features of the personality disorder versus the anxiety disorder. The anxiety disorder, obsessive-compulsive disorder, is incompatible with safe performance of aviation duties. Obsessive-compulsive personality, on the other hand, describes a point on a continuum where useful, adaptive compulsive traits may become abnormally exaggerated and maladaptive, thus interfering with the aviator's normal routine, occupational functioning, relationships with others, and aviation safety.

Brief reactive psychosis in naval aviation.

Five naval aviation personnel diagnosed with brief reactive psychosis (BRP) have appeared before the Special Board of Flight Surgeons (SBFS) at the Naval Aerospace Medical Institute (NAMI). These cases demonstrate the challenges in diagnosis and disposition that face the clinical aeromedical specialist in evaluating the aviator who develops psychiatric symptoms. We discuss the aeromedical factors that must be considered when contemplating returning aviators with psychiatric diagnoses to flying duties. Sudden behavioral changes in aviation personnel require a systematic assessment, thorough documentation, and continuing reevaluation. The differentiation between organic and functional etiologies may be difficult. Final disposition may require consultation with experienced physicians skilled in both aviation psychiatry and neurology.

Inflight anxiety conditions presenting with "break-off" symptoms.

The psychological dimension of disorientation is explored through two experienced pilots who developed inflight anxiety conditions. These were associated with "break-off" symptoms, which are inflight sensations of separation from the ground, the environment, and the aircraft. Following extensive psychiatric and medical evaluations, one aviator was diagnosed as having agoraphobia without panic disorder, and the other as having an otherwise unspecified anxiety disorder. These patient reports demonstrate the need for the clinical aerospace medicine specialist to investigate inflight anxiety conditions for underlying neuropsychiatric disorders. The reports also contrast some of the historical aeromedical concepts with modern psychiatric diagnostic nomenclature.

Adult children of alcoholics--a treatable entity: an aviation case report.

This is a case report of a male naval aviator, raised in an alcoholic environment, and the impact of that environment on his development and adult functioning. A review of the adult children of alcoholics syndrome is presented to help familiarize the reader with this evolving entity and its probable impact on aviation personnel. In the United States, current estimates indicate that parental alcoholism affects 27 million children. Only about 5% of these children are receiving any evaluation, supportive care, or treatment. This case of a naval aviator affected by this syndrome illustrates the need for its recognition and potential for treatment and modification of maladaptive behavior. As a treatment entity, recognition of the adult children of alcoholics syndrome will hopefully have a positive effect upon aviation safety and will help save a valuable national asset, our trained aviation personnel.

The effect of chromate on citrinin-induced renal dysfunction in the rat.

Previous studies in this laboratory revealed an effect of chromate to potentiate the nephrotoxic effects of mercuric ion. Citrinin, an organic anion, is a known nephrotoxin. The present study was undertaken to assess the possible interaction of chromate and citrinin on renal function. Male Sprague-Dawley rats were housed in metabolism cages and injected with citrinin (35 mg/kg), chromate (10 mg/kg) or the combination. The combination of nephrotoxicants caused an increased excretion of urine greater than the sum of the individual responses. A similar response was observed with urinary glucose concentrations and glucose excretion without changes in blood glucose levels. These data indicate that chromate can potentiate the nephrotoxic action of citrinin in the rat.

The effect of depletion of nonprotein sulfhydryls by diethyl maleate plus buthionine sulfoximine on renal uptake of mercury in the rat.

Rats pretreated with diethyl maleate (DEM, 3.37 mmol/kg, ip) and buthionine sulfoximine (BSO, 0.45 mmol/kg, ip) and subsequently given mercuric chloride (HgCl2, 0.014 mmol/kg, sc) had a significantly greater mortality rate over the 24 hr after injection than rats given only HgCl2 or HgCl2 following either DEM or BSO alone. Depletion of nonprotein sulfhydryls (NPSH) in the kidney significantly decreased mercury uptake in that organ. A similar effect was not seen in the liver despite marked depletion of NPSH. Similarly, there was a tendency for less in vitro mercury accumulation in renal cortical slices from rats made glutathione deficient by DEM + BSO compared to control, or rats made glutathione deficient by DEM or BSO alone. Depletion of nonprotein sulfhydryls by the combination of the depleting agents diethyl maleate plus buthionine sulfoximine (DEM + BSO) had a greater effect to alter organic ion accumulation in renal cortical slices than the agents alone. The higher mortality produced by mercuric chloride after DEM + BSO pretreatment may have been due to an increased availability of mercury in lethal concentrations at other organ sites. These data suggest the possible importance of NPSH in renal mercuric ion accumulation, but not in the liver.

Cefmenoxime kinetics during continuous ambulatory peritoneal dialysis.

The kinetics of the aminothiazolyliminomethoxy cephalosporin, cefmenoxime, were determined after a 30 min intravenous infusion of 15 mg/kg body weight in 6 adult subjects undergoing continuous ambulatory peritoneal dialysis. Concentrations of cefmenoxime in serum, urine and dialysate were determined by high-pressure liquid chromatography. The mean peak serum concentration was 92.8 +/- 11.6 micrograms/ml and the harmonic mean for the elimination half-life was 5.46 h. The volume of distribution at steady-state was 14.60 +/- 3.01 l/kg. Total body clearance of the drug was 31 +/- 7.7 ml/min with 8 +/- 5% and 5.75 +/- 2.72% of the administered dose being eliminated by renal and peritoneal clearance, respectively. Peritoneal clearance for all exchanges (n = 24) was 1.93 +/- 68 ml/min. These data suggest that peritoneal losses of this drug are minimal and doses conventionally employed in advanced renal failure can be utilized in the management of systemic infections.