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Biomedical subjects

M Inman

Publications and source records attributed to M Inman.

At least 19 recordsLinked to original sources

Indirect airway challenges.

Indirect challenges act by causing the release of endogenous mediators that cause the airway smooth muscle to contract. This is in contrast to the direct challenges where agonists such as methacholine or histamine cause airflow limitation predominantly via a direct effect on airway smooth muscle. Direct airway challenges have been used widely and are well standardised. They are highly sensitive, but not specific to asthma and can be used to exclude current asthma in a clinic population. Indirect bronchial stimuli, in particular exercise, hyperventilation, hypertonic aerosols, as well as adenosine, may reflect more directly the ongoing airway inflammation and are therefore more specific to identify active asthma. They are increasingly used to evaluate the prevalence of bronchial hyperresponsiveness and to assess specific problems in patients with known asthma, e.g. exercise-induced bronchoconstriction, evaluation before scuba diving. Direct bronchial responsiveness is only slowly and to a modest extent, influenced by repeated administration of inhaled steroids. Indirect challenges may reflect more closely acute changes in airway inflammation and a change in responsiveness to an indirect stimulus may be a clinically relevant marker to assess the clinical course of asthma. Moreover, some of the indirect challenges, e.g. hypertonic saline and mannitol, can be combined with the assessment of inflammatory cells by induction of sputum.

Asthma↗

Removal of iron and manganese by artificial destratification in a tropical climate (Upper Layang Reservoir, Malaysia).

Environmental monitoring was carried out at Upper Layang Reservoir situated in Masai, Johor, Malaysia. The study shows that thermal stratification and natural mixing of the water column do exist in the reservoir and the level of stratification varies at different times of the year. Artificial destratification via diffused air aeration techniques was employed at the reservoir for two months. The results show that thermal stratification was eliminated after a week of continuous aeration. The concentrations of iron and to a lesser extent manganese in the water column was also reduced during the aeration period.

Iron↗

Budesonide enhances repeated gene transfer and expression in the lung with adenoviral vectors.

The immune response with generation of neutralizing antiviral antibodies is an obstacle to effective repeated adenoviral gene transfer. Different immunosuppressive drugs facilitate repeat administration of adenovectors, but the clinical utility is uncertain because of systemic side effects. We investigated the use of topical corticosteroid in improving gene expression after repeated injection of adenovectors into mouse lungs. Using a vector expressing murine interleukin-6 (mIL-6) as a marker cytokine for gene expression, we show that budesonide given around exposure to adenovirus to the lung significantly maintained high levels of expressed transgene protein in bronchoalveolar lavage fluid (BALF) after as many as four consecutive injections of virus at two weekly intervals (p = 0.02 versus saline). Differences between treatment groups were most obvious 4 and 6 wk after the initial exposure to adenovirus (equivalent to three and four total exposures). In Week 4, transgene mIL-6 concentration was 2,327 +/- 955 pg/ml in budesonide compared with 336 +/- 246 pg/ml in saline-treated mice (p = 0.001). However, budesonide did not significantly protect transgene expression beyond Week 8 (four prior exposures). The improved transgene expression in budesonide-treated compared with saline-treated animals was associated with a reduction, but not prevention of neutralizing antiviral antibodies (BALF p < 0.001, serum p = 0.04). We conclude that budesonide can be valuable in gene therapy of the lung where repeated transient gene transfer is necessary.

Adenoviridae↗

A mutation in the latency-related gene of bovine herpesvirus 1 leads to impaired ocular shedding in acutely infected calves.

Bovine herpesvirus 1 (BHV-1) is an important pathogen of cattle, and infection is usually initiated in the ocular or nasal cavity. Like other alphaherpesviruses, BHV-1 establishes latency in sensory neurons but has the potential of reactivating from latency and spreading. The only abundant viral transcript expressed during latency is the latency-related (LR) RNA, which is alternatively spliced in trigeminal ganglia during acute infection (L. R. Devireddy and C. Jones, J. Virol. 72:7294-7301, 1998). LR gene products inhibit cell cycle progression (Y. Jiang, A. Hossain, M. T. Winkler, T. Holt, A. Doster, and C. Jones, J. Virol. 72:8133-8142, 1998) and chemically induced apoptosis (J. Ciacci-Zannela, M. Stone, G. Henderson, and C. Jones. J. Virol. 73:9734-9740, 1999). Although these studies suggest that LR gene products play an important role in the latency/pathogenesis of BHV-1, construction of a mutant is necessary to test this hypothesis. Because the bICP0 gene overlaps and is antisense to the LR gene, it was necessary to mutate the LR gene without altering bICP0 expression. This was accomplished by inserting three stop codons near the beginning of the LR RNA, thus interfering with expression of proteins expressed by the LR RNA. The LR mutant virus grew with wild-type (WT) efficiency in bovine kidney (MDBK) cells and expressed bICP0 at least as efficiently as WT BHV-1 or the LR rescued virus. When calves were infected with the LR mutant, we observed a dramatic decrease (3 to 4 log units) in ocular shedding during acute infection relative to WT or the LR rescued virus. In contrast, shedding of the LR mutant from the nasal cavity was not significantly different from that of the WT or the LR rescued virus. Calves infected with the LR mutant exhibited mild clinical symptoms, but they seroconverted. Neutralizing antibody titers were lower in calves infected with the LR mutant, confirming reduced growth. In summary, this study suggests that an LR protein promotes ocular shedding during acute infection of calves.

Animals↗

Region of herpes simplex virus type 1 latency-associated transcript sufficient for wild-type spontaneous reactivation promotes cell survival in tissue culture.

The latency-associated transcript (LAT) is the only abundant herpes simplex virus type 1 (HSV-1) transcript expressed during latency. In the rabbit eye model, LAT null mutants do not reactivate efficiently from latency. We recently demonstrated that the LAT null mutant dLAT2903 induces increased levels of apoptosis in trigeminal ganglia of infected rabbits compared to LAT+ strains (G.-C. Perng, C. Jones, J. Ciacci-Zarella, M. Stone, G. Henderson, A. Yokht, S. M. Slanina, F. M. Hoffman, H. Ghiasi, A. B. Nesburn, and C. S. Wechsler, Science 287:1500-1503, 2000). The same study also demonstrated that a plasmid expressing LAT nucleotides 301 to 2659 enhanced cell survival of transfected cells after induction of apoptosis. Consequently, we hypothesized that LAT enhances spontaneous reactivation in part, because it promotes survival of infected neurons. Here we report on the ability of plasmids expressing different portions of the 5' end of LAT to promote cell survival after induction of apoptosis. A plasmid expressing the first 1.5 kb of LAT (LAT nucleotides 1 to 1499) promoted cell survival in neuro-2A (mouse neuronal) and CV-1 (monkey fibroblast) cells. A plasmid expressing just the first 811 nucleotides of LAT promoted cell survival less efficiently. Plasmids expressing the first 661 nucleotides or less of LAT did not promote cell survival. We previously showed that a mutant expressing just the first 1.5 kb of LAT has wild-type spontaneous reactivation in rabbits, and a mutant expressing just the first 811 nucleotides of LAT has a reactivation frequency higher than that of dLAT2903 but lower than that of wild-type virus. In addition, mutants reported here for the first time, expressing just the first 661 or 76 nucleotides of LAT, had spontaneous reactivation indistinguishable from that of the LAT null mutant dLAT2903. In summary, these studies provide evidence that there is a functional relationship between the ability of LAT to promote cell survival and its ability to enhance spontaneous reactivation.

Animals↗

Hexosamines regulate leptin production in human subcutaneous adipocytes.

The hexosamine biosynthetic pathway has recently been proposed as a mechanism through which cells "sense" nutrient flux to regulate leptin release. This study was undertaken to examine the regulation of leptin production by hexosamines in human adipocytes. Adipose tissue UDP-N-acetylglucosamine, an end product of hexosamine biosynthesis, was elevated 3.2-fold, and ob messenger ribonucleic acid was elevated 2-fold in the sc adipose tissue of 17 obese [body mass index (BMI), 41.3+/-12.0 kg/m2; age, 31+/-5 yr] subjects compared to 14 lean (BMI, 23.4+/-1.6 kg/m2; age, 33+/-11 yr) subjects. Serum leptin was increased 2.7-fold in the obese subjects. A significant positive relationship was found between adipose tissue UDP-N-acetylglucosamine and BMI (Spearman correlation = 0.576; P = 0.0007) and between UDP-N-acetylglucosamine and serum leptin (Spearman correlation = 0.4650; P = 0.0145). Treatment of isolated sc adipocytes with 1 mmol/L glucosamine, an intermediate product in UDP-N-acetylglucosamine biosynthesis, increased leptin release 21.4+/-17.6% (mean +/- SD) over control (P = 0.0365) and 74.5+/-82.8% over control (P = 0.0271) in adipocytes from lean (BMI, 23.2+/-1.6 kg/m2; n = 6) and obese (BMI, 55.4+/-13.0 kg/m2,; n = 9) subjects, respectively, by 48 h of culture. Inhibition of UDP-N-acetylglucosamine biosynthesis with 6-diazo-5-oxo-norleucine reduced glucose-stimulated leptin release from cultured adipocytes 21.8+/-32.4% (P = 0.0395; n = 12) and ob gene expression 19.9+/-18.9% (P = 0.0208; n = 8) by 48 h of treatment. These findings suggest that hexosamine biosynthesis regulates leptin production in human adipose tissue.

Adipocytes↗

Tumor necrosis factor-alpha inhibits leptin production in subcutaneous and omental adipocytes from morbidly obese humans.

This study was undertaken to examine the regulation of leptin production from human adipocytes by tumor necrosis factor-alpha (TNFalpha). Adipocytes were isolated from adipose tissue obtained during bariatric surgical procedures (17 women and 3 men; body mass index, 52.5 +/- 2.4 kg/m2; age, 40 +/- 3 yr) and cultured in suspension. Leptin release from sc adipocytes was inhibited 17.7 +/- 5.2% (P < 0.01), 21.6 +/- 4.3% (P < 0.005), and 37.1 +/- 7.2% (P < 0.05) by 1, 10, and 100 ng/mL TNFalpha, respectively, after 48 h in culture. At 100 ng/mL, significant inhibition of leptin release (25.8 +/- 9.7%; P < 0.05) was detected by 24 h. TNFalpha (10 ng/mL) had no effect on dexamethasone (0.1 micromol/L)-stimulated leptin production in sc adipocytes. In omental adipocytes TNFalpha inhibited leptin release 21.0 +/- 9.6% and 40.8 +/- 6.3% at 10 and 100 ng/mL by 48 h (P < 0.05). Significant inhibition ofleptin release from omental adipocytes was observed at 24 h with 100 ng/mL TNFalpha (P < 0.05). Anti-TNFalpha antibody completely blocked TNFalpha inhibition of leptin release. The ob messenger ribonucleic acid was significantly reduced (23.6 +/- 5.9%) after 48 h of TNFalpha (100 ng/mL) treatment (P < 0.025). TNFalpha had no effect on glucose uptake or lactate production in sc and omental adipocytes. The data suggest that the direct paracrine effect of adipose-derived TNFalpha is inhibition of leptin production.

Adipocytes↗

Leptin production in adipocytes from morbidly obese subjects: stimulation by dexamethasone, inhibition with troglitazone, and influence of gender.

This study examined the regulation of leptin production by dexamethasone and troglitazone. Subcutaneous and omental adipose tissue was obtained during bariatric surgical procedures (30 women and 16 men; body mass index, 52.5 +/- 1.7 kg/m2, age, 39 +/- 2 yr), and adipocytes were cultured in suspension. Subcutaneous adipocytes from females released significantly more leptin than did omental cells from the same subject (P < 0.05), but basal leptin release was not different in adipocytes from these depots in males. Dexamethasone (0.1 micromol/L) significantly increased leptin release within 24 h from sc (135 +/- 13% of control) and omental (227 +/- 53%) adipocytes of females, but not males. Dexamethasone-stimulated leptin production at 48 h was significantly greater in the omental adipocytes of females (398 +/- 64% of control) than in sc adipocytes of females (207 +/- 21%) or the omental (211 +/- 33%) and sc (180 +/- 23%) adipocytes of males. Troglitazone (10 micromol/L; 48 h) significantly inhibited dexamethasone-stimulated leptin release in sc (57 +/- 10.7% inhibition) and omental adipocytes (134 +/- 26% inhibition). There was no gender-related difference in the effect of troglitazone to inhibit dexamethasone-stimulated leptin release. Troglitazone significantly inhibited basal leptin production from omental adipocytes by 15.0 +/- 5.2%. The effect of dexamethasone and troglitazone to regulate leptin release was mediated through changes in ob gene expression, but did not involve changes in glucose uptake or metabolism to lactate. The data suggest that adipocytes from females are more responsive to the stimulatory effect of dexamethasone in vitro than are adipocytes from males. If adipocytes from females are more responsive to relevant in vivo stimuli for leptin secretion such as insulin or glucose, this could contribute to the gender difference in serum leptin. The data also suggest that leptin release from omental adipocytes may be more responsive to hormonal and nutrient regulation in vivo than are sc adipocytes.

Adipocytes↗

Cerebral MR imaging in intravascular lymphomatosis.

MR imaging data were reviewed retrospectively in four male patients (32 to 74 years old) with histologically confirmed intravascular lymphomatosis (IVL), a rare, aggressive form of non-Hodgkin lymphoma. MR findings included infarct-like lesions (n = 2), focal parenchymal enhancement (n = 3), dural/arachnoid enhancement (n = 2), and, in one case, nonspecific, patchy foci of increased signal in the white matter on long-TR images. All patients had multifocal lesions. Knowledge of the spectrum of MR imaging features in this unusual disorder may aid in diagnosis and potentially enhance the role of imaging in following response to therapy.

Adult↗

Why listeners hear less than they are told: attentional load and the teller-listener extremity effect.

Prior research (T. Gilovich, 1987; M. Inman, A. Reichl, & R. Baron, 1993) indicated that individuals (tellers) who directly observe an actor (on video tape) rate that actor less extremely than other individuals (listeners) who hear the tellers' secondhand accounts of the actor's actions. Evidence has suggested that this teller-listener effect is due at least in part to listeners' failure to encode and consider mitigating circumstances contributing to the actors' actions (Inman et al., 1993). The present research examined several explanations for this phenomenon. Study 1 found stronger teller-listener differences (and less recall of mitigating information) when listeners heard the teller's account in the presence of noise. Studies 2 and 3 found listener's interpretations to be more extreme when the verbal accounts they heard were verbally disorganized. These results support an attentional load explanation for teller-listener differences.

Attention↗

Safer sex in tourist resorts.

A survey in Torbay, England, indicated substantial sexual interaction of an unsafe kind between young residents and tourists. A pilot programme is described which sought to promote safer sexual behaviour: the attention of both tourists and local people who frequented nightclubs was engaged by peer groups who conveyed educational messages.

Adolescent↗

The diagnosis and definition of hepatic malignancies by use of arterial enhanced computerized tomographic scanning.

Axial computerized tomography is a useful tool in the evaluation of either primary or metastatic hepatic neoplasms. An adjunct to this technique is visceral arterial enhanced computerized tomography (AECT). To determine the effectiveness of this modality, bolus intravenous enhanced computerized tomography scans and AECT were compared and correlated to operative findings. Fifty-four consecutive patients were evaluated by AECT and bolus intravenous enhanced computerized tomography over a 30-month period (May 1986 to August 1989) for suspected primary or metastatic hepatic malignancies. Forty-four patients (81%) had hepatic lesions. Fifty-two percent (23 of 44 patients) of the metastatic tumors were from colonic or rectal primary lesions, and 20% were hepatocellular primary lesions. The remainder of the lesions were metastases from a variety of primary lesions. When studies were compared, 34% of the patients (15 of 44 patients) differed in either the location or total number of lesions noted. The lesions of three of the 15 patients (20%) were determined unresectable on the basis of AECT. Of the remaining patients, planned resections were revised in seven patients to either lesser or greater procedures. The number of lesions found at laparotomy equaled the number found by AECT in all but two cases. AECT caused no complications. AECT improved our ability to identify and localize primary and metastatic lesions of the liver. This technique offers the advantage of preoperative definition of the hepatic arterial and portal venous anatomy.

Adenoma, Islet Cell↗

Effect of the fatty acid oxidation inhibitor methyl palmoxirate (methyl 2-tetradecylglycidate) on recovery from insulin-induced hypoglycemia in diabetic dogs.

Methyl palmoxirate, an effective hypoglycemic agent administered p.o., has been shown to decrease hepatic glucose production secondary to inhibition of mitochondrial fatty acid oxidation. Because the ability to increase hepatic glucose production is an important counter-regulatory defense against hypoglycemia, we compared the ability of streptozotocin/alloxan-induced diabetic dogs treated p.o. with vehicle or methyl palmoxirate (2.5 mg/kg/day X 7 days) to recover from insulin-induced hypoglycemia. Hepatic glucose production and glucose utilization were determined by isotope dilution before and after acute reduction of plasma glucose by i.v. insulin injection (0.10 or 0.13 U/kg). Diabetic dogs treated with methyl palmoxirate for 6 days had lower overnight fasting plasma glucose levels than vehicle-treated animals (158 +/- 7 vs. 171 +/- 11, respectively, P less than .05). Plasma glucose at 4 hr after the last dose of drug decreased to 115 +/- 5 mg/dl, whereas glucose in the vehicle-treated dogs was unchanged (172 +/- 8 mg/dl). Recovery from insulin-induced hypoglycemia (nadirs of 58 +/- 5 and 42 +/- 4 mg/dl in the vehicle- and methyl palmoxirate-treated groups, respectively) was not significantly different between the two groups of dogs. Restoration of plasma glucose was primarily due to increased hepatic glucose production in both treatment groups, as glucose utilization did not fall significantly below baseline levels. Plasma glucagon levels increased in both vehicle- and methyl palmoxirate-treated dogs in response to hypoglycemia, indicating that release of an important counter-regulatory hormone was not compromised by drug treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Windows in the intensive therapy unit.

Retrospective surveys were carried out on two groups of patients who had survived a stay of at least 48 h in an Intensive Therapy Unit. One group had been kept in a unit without windows, and the other in a similar unit with translucent but not transparent windows. Survivors from the windowless unit had a less accurate memory of the length of their stay, and were less well orientated in time during their stay. The incidence of hallucinations and delusions was more than twice as high in the windowless unit. The phenomenon of depersonalisation in the face of life-threatening danger is described and discussed.

Adult↗

Hemophilia: information for school personnel.

For people unfamiliar with hemophilia, the disease can seem very frightening. Its past reputation as a fatal, uncontrollable disease is no longer tenable. With the use of modern-day transfusion therapy, uncontrollable bleeding in hemophilia infrequently causes death. Quick and simple treatment is readily available. The problems today are in educating the public about the hemophiliac and preventing psychosocial problems which may surround him. The purpose of this article is to provide information to help educators better understand hemophilia and the child it affects.

Blood Coagulation↗