Fat and oil inhibit phosphine release from aluminium phosphide--its clinical implication

Poisoning by suicidal or accidental ingestion of aluminium phosphide (AlP) is a frequent medical emergency seen all over the world. AlP, a grain fumigant and rodenticide, on exposure to moisture, liberates highly toxic gas, phosphine. The rapidly inhibits mitochondrial respiration and has cytotoxic action. No specific antidote is known against it till date and prognosis depends much on dose and time lag between AlP ingestion and the stomach wash in the hospital (critical period). Physicochemical properties of AlP and nonmiscibility of fat and water promoted us to study the effect of different fats and oils as possible antidotes to inhibit phosphine liberation. In vitro experiments revealed that vegetable oils and liquid paraffin were much more effective than butter and ghee in inhibiting release of phosphine from AlP. These findings may have significant clinical implication.

Role of dopaminergic mechanisms in the regulation of stress responses in experimental animals

The effects of some dopaminergic agents were evaluated on stress responses in normal and immunized experimental animals. Restraint stress (RS) consistently induced gastric mucosal lesions and elevated plasma corticosterone in rats. Pretreatment with alpha-methyltyrosine (alpha-MT), haloperidol, or sulpiride aggravated both responses, whereas bromocriptine attenuated them. In rats immunized with sheep red blood cells (SRBCs), RS prevented the booster-induced rise in anti-SRBC antibody titre. This response was further suppressed by alpha-MT, haloperidol, or sulpiride pretreatment, whereas bromocriptine potentiated the humoral immune response. In mice immunized with SRBCs, antigen challenge-induced increase in footpad thickness was inhibited by RS. Similar inhibitions in this response were also seen after alpha-MT or haloperidol treatment. The results are discussed in light of complex dopaminergic mechanisms in the regulation of visceral, endocrinological, and immune responses during stress.

Microdissected double-minute DNA detects variable patterns of chromosomal localizations and multiple abundantly expressed transcripts in normal and leukemic cells

Double-minute (dm) chromosomes are cytogenetically resolvable DNA amplification-mediating acentric extrachromosomal structures that are commonly seen in primary tumors, tumor cell lines, and drug-resistant cells grown in vitro. Selective isolation of dm DNAs with standard molecular biological techniques is difficult, and thus, detailed studies to elucidate their structure, site of chromosomal origin, and chromosomal reintegration patterns have been limited. In those instances in which a gene has been localized on dms, characterization of the remainder of the DNA, which far exceeds the size of the gene identified, has remained inconclusive, dms seen in the acute myeloid leukemia cell line HL-60 have been shown to harbor the c-myc protooncogene. In this paper, we report the successful isolation of the dm-specific DNAs from these cells by the microdissection/polymerase chain reaction technique and demonstrate that the dm DNAs derived from a single discrete normal chromosome segment 8q24.1-q24.2 reintegrate at various specific locations in the leukemic cells. The microdissected dm DNA detects multiple abundantly expressed transcripts distinct from c-myc mRNA on Northern blots. By devising a "transcript selection" strategy, we cloned the partial genomic sequence of a gene from the microdissected DNA that encodes two of these RNAs. This strategy will be generally applicable for rapid cloning of unknown amplified genes harbored on dms. With DNA from 20 microdissected dms, we constructed a genomic library of about 20,000 recombinant microclones with an average insert size of about 450 bp.(ABSTRACT TRUNCATED AT 250 WORDS)

Bronchiolitis obliterans organizing pneumonia associated with massive L-tryptophan ingestion

A 51-year-old woman developed acute febrile illness with respiratory failure following intake of L-tryptophan. An open lung biopsy specimen established the histopathologic nature of the lung lesion as bronchiolitis obliterans organizing pneumonia (BOOP). There was no evidence of other known causes usually associated with BOOP. Her condition improved with corticosteroid therapy. The entity of BOOP now should be added to the growing list of illnesses associated with the use of L-tryptophan.

The amygdaloid complex, corticotropin releasing factor and stress-induced gastric ulcerogenesis in rats

The amygdaloid complex and corticotropin releasing factor (CRF) are both important in stress reactions and we thus evaluated the effects of intra-amygdalar CRF on stress ulceration in rats. Bilateral micro-applications of CRF (0.05, 0.5 or 5.0 micrograms) into the central amygdala (CEA) attenuated cold restraint-induced gastric mucosal lesions in a dose-related manner. Similar gastric cytoprotective effects were seen with intra-CEA noradrenaline (NA; 3.0 micrograms), whereas the NA neurotoxin, DSP-4 (25 micrograms), or the beta-adrenoceptor antagonist, propranolol (1 microgram), aggravated stress ulcer pathology. Intra-CEA pretreatment with DSP-4 or propranolol clearly reversed the ulceroprotective effects of CRF during stress. These results indicate that the CEA is a neural substrate for CRF effects, and CRF-NA interactions in this limbic area are crucial for the regulation of stress ulcerogenesis.

Teaching humanistic behavior: humanities study in the internal medicine residency

Training in humanism is required in internal medicine residency programs, but teaching and evaluating humanism is difficult. Our program integrates the study of humanities into residency training for professional and personal development; betterment of communication skills; and understanding of ethics.

Chromosome 9 anomalies as the primary clonal alteration in a case of squamous cell carcinoma of the epiglottis

We present the cytogenetic characterization of a short-term culture of a primary squamous cell carcinoma of the epiglottis from a 67-year-old male patient who was admitted to this hospital for treatment. This patient had a history of chronic exposure to tobacco and alcohol, environmental carcinogens known to be related to the etiology of the disease. The tumor karyotype showed three distinct clones: 1) cells with chromosome 9 anomalies; 2) cells with chromosome 9 and other clonal structural anomalies involving chromosomes 1, 11, 14, and 17; and 3) cells whose chromosomes were partially or totally pulverized. The anomalies on chromosome 9 were homozygous inversion (p12q13), deletions at regions q22, q34.1, and p13, and i(9q) formation. Structural clonal anomalies on other chromosomes included translocations, deletions, and isochromosome formation. The presence of a chromosome 9 anomaly alone or in conjunction with other anomalies suggests that this aberration may be a nonrandom primary event in the progression of squamous cell carcinoma of the head and neck.

Role of kappa opioid receptors during stress responsiveness in rats

Effects of kappa opioid agonist, ketocyclazocine (KCZ) and its antagonist, M(r) 2266, were evaluated on some stress responses in rats. KCZ (1 or 10 mg/kg, ip) dose-dependently attenuated cold restraint stress (CRS)-induced gastric ulcer formation. Similar gastric cytoprotection was also seen with KCZ (1 or 10 micrograms/rat, icv). Pretreatment of rats with M(r) 2266 (0.3 mg/kg, ip) clearly antagonized the ulceroprotective effects of both ip and icv KCZ. KCZ effects on the gastric mucosa during CRS were also reduced by naltrexone (5 mg/kg, ip) pretreatment. KCZ (1 or 10 mg/kg, ip) also attenuated the plasma corticosterone response to CRS and these effects were blocked by M(r) 2266 (0.3 mg/kg) pretreatment. These results indicate kappa opioid receptor involvement during stress reactions and also suggest possible opioidergic interactions during CRS.

Infections in older patients: a systematic clinical approach

The increased risk of infection among older patients can be divided into three clinical categories: infections increased in incidence, infections showing higher case fatality rates, and infections that are clinically worse, primarily because of late recognition. Among infections that are increased in incidence, the most important by far are tuberculosis and pneumococcal pneumonia. Infections that show higher fatality rates include influenza and--again--pneumococcal pneumonia. Intra-abdominal infections (eg, cholecystitis and appendicitis) are often clinically worse in older patients due to late recognition and delay in surgical intervention.

Effects of Azadirachta indica A Juss on some biochemical, immunological and visceral parameters in normal and stressed rats

Effects of A. indica (AI) were evaluated on some biochemical, immunological and visceral parameters in normal and stress rats. AI (100 mg/kg) lowered blood glucose, triglyceride and SGOT levels in normal rats, and attenuated stress-induced elevations of cholesterol and urea levels. In rats immunized with SRBC, AI enhanced the humoral antibody response to the antigen. Further, AI facilitated the footpad thickness response to SRBC in sensitized mice and also enhanced leucocyte migration in immunized rats. In stressed rats, AI significantly attenuated the stress-induced (a) suppression of humoral immune response and (b) gastric ulcerogenesis. These results are discussed in light of the possible mechanisms involved in the effects of AI in normal and stressful situations.

Central histaminergic involvement during stress in rats

Effects of some drugs modulating central histaminergic (HA) transmission were evaluated on restraint stress (RS)-induced gastric ulcerogenesis, plasma corticosterone and immune responses in rats. RS for (i) 6 hr or (ii) 24 hr at room temperature, and (iii) 3 hr at 4 degrees C (CRS) all induced gastric mucosal erosions and elevated plasma corticosterone levels, the effects with the latter two RS procedures being most consistent. Pretreatment of rats with neuronal HA depletor, alpha-FMH (100 mg/kg, ip) attenuated both ulcer severity and corticosterone response, during both 24 hr RS and CRS. Similar effects were also seen with the mast cell degranulator, C-48/80 (10 micrograms/kg, i.c.v.) treatment. Further, the H1-blocker, pheniramine (25 mg/kg, ip) but not the centrally acting H2-blocker, zolantidine (5 mg/kg, ip) produced clearcut attenuations in both stress markers, during the experimental stressors. In rats immunized in SRBC, 24 hr RS (and not CRS) significantly prevented the humoral immune responses to the antigen. alpha-FMH, C 48/80 and pheniramine but not zolantidine, reversed this response during 24 hr RS. The results indicate a central HA ergic involvement in the visceral, endocrinal and immune responses during RS and suggest the probable role of both neuronal as well as extraneuronal (mast cell) HA and activation of H1-receptors in the mediation of these effects.

Mechanism of anti-stress activity of Ocimum sanctum Linn, eugenol and Tinospora malabarica in experimental animals

Effects of restraint stress (RS) and its modulation by O. sanctum (Os), eugenol and T. malabarica (Tm) were evaluated on some biochemical and biophysical parameters in rats. RS induced elevations in blood glucose and urea levels, were unaffected by either Os, eugenol or Tm pretreatment. However, both Os and eugenol lowered RS-induced cholesterol levels. RS also caused a generalized increase in enzyme activity and Os, eugenol or Tm effectively lowered the RS-induced elevations in lactate dehydrogenase (LDH) and alkaline phosphatase. RS also induced (a) increased membrane protein clusterization, (b) increased membrane fluidity and (c) reduced membrane thickness--in RBC membrane, whereas, the effects on the synaptosomal membrane were less marked. The RS-induced changes in RBC membrane dynamics were attenuated/reversed by Os, eugenol or Tm, in a differential manner. These biochemical and membrane changes during Rs and their modulation by the adaptogens are discussed in light of the possible mechanisms of action of these agents, during such aversive stimuli.

A calcium model with random absorption: a stochastic approach

Absorption of calcium, or any mineral, by the body is subject to the random fluctuations typical of diffusion through membranes. In this paper we consider the absorption of calcium from the gut as a white noise process added to the deterministic model of Sen & Mohr (1990, J. theor. Biol. 142, 179-188). The first two moments for the amount of calcium in the extracellular fluid (ECF) have been derived using the Ito Calculus. A confidence interval for the total amount of calcium in the ECF is constructed. The equations for the first two moments of the fraction of dose calcium in the ECF are also given. Suggestions are made for the collection of experimental data in a form which should be helpful in investigating the magnitude of the stochastic effect.

Modulation by naltrexone of stress-induced changes in humoral immune responsiveness and gastric mucosal integrity in rats

The effects of restraint stress (RS) and the opioid antagonist, naltrexone, were evaluated on humoral immune responsiveness and gastric mucosal integrity in rats. RS for 24 h, but not 6 h, attenuated both the primary (PAR) and secondary antibody response (SAR) to sheep red blood cells (SRBC) after a single exposure to the stressor. Naltrexone (1 or 5 mg/kg) dose-dependently aggravated the effects of RS on anti-SRBC antibody titre in both PAR and SAR studies. Further, in rats sensitized with SRBC, RS (24 h), in addition to lowering the humoral antibody response, also induced gastric mucosal lesions. Both these responses were further aggravated with naltrexone pretreatment. These results are discussed in light of interactions between immune and visceral responses, and their regulation by endogenous opioids, during RS.