Effect of whole body vibration frequency on neuromuscular activity in ACL-deficient and healthy males

Whole-body vibration (WBV) has been shown to enhance muscle activity via reflex pathways, thus having the potential to contrast muscle weakness in individuals with rupture of the anterior cruciate ligament (ACL). The present study aimed to compare the magnitude of neuromuscular activation during WBV over a frequency spectrum from 20 to 45 Hz between ACL-deficient and healthy individuals. Fifteen males aged 28±4 with ACL rupture and 15 age-matched healthy males were recruited. Root mean square (RMS) of the surface electromyogram from the vastus lateralis in both limbs was computed during WBV in a static half-squat position at 20, 25, 30, 35, 40 and 45 Hz, and normalized to the RMS while maintaining the half-squat position without vibration. The RMS of the vastus lateralis in the ACL-deficient limb was significantly greater than in the contralateral limb at 25, 30, 35 and 40 Hz (P<0.05) and in both limbs of the healthy participants (dominant limb at 25, 30, 35, 40 and 45 Hz, P<0.05; non dominant limb at 20, 25, 30, 35, 40 and 45 Hz, P<0.05). The greater neuromuscular activity in the injured limb compared to the uninjured limb of the ACL-deficient patients and to both limbs of the healthy participants during WBV might be due to either augmented excitatory or reduced inhibitory neural inflow to motoneurons of the vastus lateralis through the reflex pathways activated by vibratory stimuli. The study provides optimal WBV frequencies which might be used as reference values for ACL-deficient patients.

Red foxes (Vulpes vulpes) bioindicator of lead and copper pollution in Sicily (Italy)

The aim of this study was to evaluate Pb and Cu accumulation in muscle and skin samples of red fox (Vulpes vulpes) from Sicily, for monitoring of environmental metals pollution. Metals determination, carried out by atomic absorption spectrophotometer (AAS), showed the presence of Pb and Cu in all samples analyzed. Pb concentrations were similar in muscle (0.04±0.009 mg/kg) and skin (0.03±0.004 mg/kg) samples, while Cu levels resulted higher in muscle (1.842±0.178 mg/kg) than in skin (1.22±0.151 mg/kg). In addition, a comparative analysis of Pb and Cu concentrations was carried out among samples from different areas of Sicily and between female and male, young and old, immature and mature foxes. Metals content found in all muscle and skin samples demonstrates that V. vulpes could be a valid "sentinel" species of rural and suburban areas to study the environmental metals pollution and the habitat quality.

Interventions for the prevention of overweight and obesity in preschool children: a systematic review of randomized controlled trials

The objective of this study was to analyse interventions for the prevention of overweight and obesity in children under 5 years of age. We carried out a systematic review focusing exclusively on randomized controlled trials (RCTs). Data sources include Medline, Cochrane Library, EMBASE, CINHAL, PsychInfo and Web of Science. Data were extracted from seventeen articles describing seven RCTs identified through electronic search, screening of references in systematic reviews, own files and contact with authors. RCTs were assessed with the Jadad scale. Four trials were carried out in preschool settings, one with an exclusive educational component, two with an exclusive physical activity component and one with both. Two trials were family-based, with education and counselling for parents and children. The remaining trial was carried out in maternity hospitals, with a training intervention on breastfeeding. None of the interventions had an effect in preventing overweight and obesity. The failure to show an effect may be due to the choice of outcomes, the quality of the RCTs, the suboptimal implementation of the interventions, the lack of focus on social and environmental determinants. More rigorous research is needed on interventions and on social and environmental factors that could impact on lifestyle.

[The descending necrotizing mediastinitis]

Descending necrotizing mediastinitis (DNM) is a primary complication of cervical or odontoiatric infections that can spread to the mediastinum through the anatomic cervical spaces. The delay of the diagnosis or under assessment of the disease, with no adequate draining techniques, results in high mortality up to 20%. We report our experience about 9 clinical cases of DNM observed and surgically treated in our unit from 2000 to 2006; five of these patients were admitted in the last two years. We stress the differences of management of this affection that needs a close cooperation between surgeon, intensive care unit and infectious disease specialist.

Control of head stability during gait initiation in young and older women

Transition tasks between static and dynamic situations may challenge head stabilization and balance in older individuals. The study was designed to investigate differences between young and older women in the upper body motion during the voluntary task of gait initiation. Seven young (25+/-2.3 years) and seven older healthy women (78+/-3.4 years) were required to stand on a force platform and initiate walking at their self-selected preferred speed. Angles of head, neck and trunk were measured by motion analysis in the sagittal plane and a cross-correlation analysis was performed on segments pairs. Variability of head and neck angular displacements, as indicated by average standard deviation, was significantly greater in the older than in the young participants. The young women maintained dynamic stability of the upper body, as forward flexion of the trunk was consistently counteracted by coordinated head-neck extension. Differently, movement patterns employed by the older women also included a rigid motion of all upper body segments leaning forward as a single unit. These results demonstrated that older women perform the transition from standing to walking with greater variability in the patterns of upper body motion compared to young women.

[Enteric viruses and bacteriological parameters in molluscs]

Eighty-seven samples of shellfish were collected considering: type of mollusc, origin, growing area, monitoring or for human purpose. The bacteriological parameters were: Fecal Coliforms, Escherichia coli, and Salmonella; whereas the virological parameters included: Hepatitis A and E virus, Rotavirus, Astrovirus and Enterovirus. In total, 63.2% of samples had normal bacteria values, only one sample was Salmonella positive. The percentage of positive samples for Hepatitis A virus was 5.7%, Rotavirus 29.9%, Astrovirus 27.6%, Enterovirus 10.3%. The recovery of hepatitis E virus was always negative, whereas 13 samples (14.9%) were positive for two viruses.

Waterborne gastroenteritis outbreak in Albania

Three different studies are reported concerning the environmental pollution caused by viruses in Albania. The first study describes an outbreak of gastroenteritis in the capital city, involving 2,722 children attending the Paediatric Unit of Tirana Hospital. The age group with the highest morbidity was 0-5 years, with 89.5%; no fatalities were recorded during the outbreak. Rotavirus was detected in 26/28 faecal samples by RT-PCR, although astrovirus, adenovirus and calicivirus were also present. The second study describes an outbreak of hepatitis A virus involving the city of Lac. Two hundred cases were recorded, with the highest incidence in the age-group 5-9 years. Phylogenetic analysis of the VP1/2A region showed the presence of a unique sequence: genotype IA. Rotavirus was identified in drinking-water samples collected during the outbreak. The third study describes the prevalence of HAV and HEV in 202 sera randomly collected from 12 different cities in Albania. HAV showed a high incidence (66.2%), whereas none was positive for HEV. The genomic analysis of the VP1/2A junction revealed the presence of only one genotype (IA) with few point mutations and just two amino acid substitutions at codons 22 and 34. Additionally, two potential antigenic variants were detected, the first at position 46 of VP3 and the second at position 23 of VP1.

Is the coactivation of biceps femoris during isometric knee extension affected by adiposity in healthy young humans?

This study aimed to verify if the level of biceps femoris antagonist activity measured during isometric knee extension was affected by the individual degree of adiposity in 14 young healthy subjects of both genders aged between 18 and 24. Surface EMG signals were recorded from the biceps femoris muscle of the dominant leg during isometric knee extension at three levels of voluntary contraction: maximum (MVC), 80% MVC and 200 N, respectively. In addition, whole-body percentage of fat, volume of the thigh and skinfold thickness below the electrodes were achieved. Biceps femoris coactivation values were: 28.5 +/- 17.9%, 30.9 +/- 17.7% and 25.3 +/- 17.5% for MVC, 80% MVC and 200 N trials, respectively (NS). Neither the whole-body percentage of fat nor the skinfold thickness influenced percentage coactivation, irrespective of the intensity of contraction. However, an increase in the whole-body percentage of fat showed a tendency to augment the biceps femoris coactivation (P(I)=0.079; P(II)=0.575). No differences in coactivation were observed between genders. In addition, the duration of contraction did not affect the level of coactivation.

[Virus transmission in drinking water]

Several epidemiological data confirm the presence of enteric viruses in drinking water. The present paper deals with several problems tied to the virological analysis, such as the concentration of the samples, the isolation and the identification of enteric viruses.

Time-resolved X-ray powder diffraction on a three-way catalyst at the GILDA beamline

Time-resolved X-ray diffraction experiments carried out at the beamline BM08-GILDA of ESRF allowed a study of the structural modifications taking place in a Pt/ceria-zirconia catalyst while the CO oxidation reaction was in progress. The capillary tube in which the sample is stored acts effectively as a chemical microreactor that ensures homogeneity of the sample treatments and minimization of diffusion effects. During the flowing of the reactant CO/He mixture, the investigated catalyst undergoes a fast Ce(IV)-Ce(III) partial reduction that involves the release of one O atom for every two reduced Ce cations. Because Ce(III) has a larger ionic radius than Ce(IV), the structural modification produces an increase of the lattice constant of the ceria-zirconia mixed oxide, and this increase is monitored by the translating imaging-plate device implemented at GILDA. The CO(2) resulting from the oxidation of the fluxed CO is monitored by a quadrupole mass spectrometer during the recording of the time-resolved X-ray diffraction pattern. The chemical and structural information was combined to show that the CO(2) yield is nearly constant until the catalytic system can provide oxygen for the reaction, while the structural rearrangement of the catalyst is delayed with respect to the switching on of the CO/He flux. After this induction time, during which CO(2) is produced with no structural modification of the catalyst, a fast increase of the lattice constant takes place.

Electromyogram changes during sustained contraction after resistance training in women in their 3rd and 8th decades

The present study aimed at investigating the neuromuscular adaptations to 6 weeks of resistance training in women in their third (6 experimental, 8 controls) and eighth decades (8 experimental, 8 controls). The surface electromyogram (sEMG) was measured from the biceps brachii muscle during constant-force isometric contractions lasting 12 s at 80% of maximal voluntary contraction (MVC). All the signals were analysed adopting in the time domain the root mean square (RMS) as a measure of amplitude and in the frequency domain the median frequency (MDF) of the power spectrum. Quantitative analysis was performed from the 3rd to the 6th second, to describe the early phase of the contraction ("Early"), starting from point at which 80% of the MVC was reached, and from the 9th to the 12th second, to describe the last part of the constant-force sustained contraction ("Late"). After training, the MVC increased by 22.4% in the young (P < 0.0001) and by 13.4% in the older (P < 0.05) women. The "Early" RMS increased by 60.4% with respect to the pre-training condition in the young (P < 0.01) but not in the older women. In contrast, the "Late" RMS increased by 46.7% in the older (P < 0.05) but not in the young women. The MDF remained unchanged in both groups. These results indicate that young and older women showed different training-induced adaptation of the motor unit (MU) activation pattern, in order to keep a constant level of force during a sustained isometric contraction at 80% of MVC.

Ambulation training of neurological patients on the treadmill with a new Walking Assistance and Rehabilitation Device (WARD)

STUDY DESIGN

Patients with neurological walking impairment were rehabilitated with a new system, consisting of an apparatus to constantly relieve the body weight and a treadmill: The Walking Assistance and Rehabilitation Device (WARD). Patients were evaluated before and after rehabilitation with clinical scales and physiological measurements.

OBJECTIVES

To evaluate the effectiveness of the WARD in improving walking capability in these patients.

SETTING

The study was carried out in a clinical environment (IRCCS S. Lucia, Rehabilitation Hospital, Rome, Italy).

METHODS

Seven patients (six with spinal cord injuries, one with brain injury) underwent a 1 - 2 month training period with the WARD. During the WARD training the body weight constant unloading (BWCU) applied to the patient through the WARD was regularly evaluated. Oxygen consumption, carbon dioxide production and heart rate were measured in order to obtain energy and cardiac costs of walking. These measurements were carried out while walking with the WARD at an appropriate treadmill speed (ATS) and in the open field at the most comfortable speed (MCS). All measurements, in addition to clinical scores related to the walking capability, were carried out at the beginning of the WARD training period (BWT) and at the end (EWT). At the EWT the patients were tested walking with the WARD observing the same BWT conditions (same ATS and BWCU), referred to as beginning conditions second measurements (BCSM). The relationships between physiological costs and ATS were described through second order polynomial regression curves and studied.

RESULTS

Comparing the data obtained at the BWT and EWT, the following results were found significantly different: (1) Clinical scores improved; (2) All patients increased their ATS; (3) The BWCU was reduced; (4) The Walking Energy Cost (WEC) and the Walking Cardiac Cost (WCC) measured when walking with the WARD at the ATS improved in all patients; and (5) The WEC and WCC measured in the open field improved in all patients. The WEC vs ATS curve found at the EWT in the BCSM was found significantly different from the BWT curve, demonstrating a major improvement due to the WARD training.

CONCLUSION

Despite some limitations due to sample size and functional ambulation scale, this study has demonstrated that the WARD training is effective in improving the walking capability and efficiency of the patients.

Cost of walking and locomotor impairment

The aim of the present study was to evaluate the importance and the necessity of metabolic measurements to quantify locomotor impairment in a clinical context. Oxygen consumption, heart rate, pulmonary ventilation and walking speed were measured during locomotion in 14 normal subjects, used as a control group, and 82 patients with different pathologies [hemiparetic, paraparetic, tetraparetic, orthopaedic and paraplegic patients, who walked using a reciprocating gait orthosis (RGO)]. The subjects were characterized on the basis of a cumulative impairment score (CIS), based on clinical scales commonly used to evaluate impairment and disability in locomotion. Appropriate indices of energy, cardiac and ventilatory costs expressed per metre walked, globally called physiological costs, were obtained. It resulted that the most comfortable speed (MCS) of normal subjects was significantly higher than that of each group of patients. Normal subjects' physiological costs were found to be significantly lower than those of patients who needed either a device or the help of a person to walk. All measured parameters correlated significantly with each other. The MCS was found to be the most correlated parameter with the CIS (r = 0.8), and therefore it must be considered the best single measurement, if only one is to be used. Measurements more precise than MCS, such as the physiological costs, may be necessary in clinical trials.

Determinants of maximal instantaneous muscle power in women aged 50-75 years

The present study aimed at analysing the age-related decline in maximal muscle power (W) in 52 sedentary healthy women aged between 50 and 75 years to determine whether force or velocity is the major determinant. Maximal muscle power was estimated from two types of vertical jumps, squatting (SJ) and countermovement (CmJ), performed on a force platform. It was obtained by measuring the vertical force (F(opt)) applied to the body centre of gravity and calculating the corresponding vertical velocity (v(opt)). An age-related decline in absolute W was statistically significant in all the conditions examined and in both peak W and average power (W) values. The decrease in v(opt) was also statistically significant. Also F(opt) declined but this reduction was not statistically significant with the exception of the average value in CmJ. Not surprisingly the highest W were obtained in CmJ, and the difference in power production between the two types of jump showed an age-related decrement only in W. The main finding of the study was the demonstration that v(opt) was the critical determinant of the age-related decline in W in healthy elderly women.

[Long-term central venous access. Our experience]

Prolonged venous access devices (PVAD) represent a useful tool for many patients with chronic diseases. In the last 3 years 50 PVAD have been placed. Polyurethane catheters with a subcutaneous tunnel > 6 cm, have been used. There were no complications related to catheter insertion. The average life of PVAD was 95 days (range 7-425).

Streptococcus sanguis bacteremia and colorectal cancer

Streptococcal bacteremia is an uncommon presentation for colorectal malignancy, yet most physicians are aware of the association between Streptococcus bovis infection and these malignancies. Many are unaware, however, that other streptococcal species are associated with colon and rectal cancers. In this case report and brief review, we highlight this association and discuss a case of Streptococcus sanguis bacteremia associated with an early invasive rectal cancer.

[Diverticula of the right colon. The diagnosis and treatment of complications]

BACKGROUND

Diverticula are localized in the right colon with a rate of 6.7-14% in Western countries. Two types of diverticula have been described in the right colon, on the basis of etiologic and pathological features: multiple diverticula and solitary diverticulum of the caecum. The most common clinical presentation of the right-sided colonic diverticula is an acute inflammatory complication, which is difficult to distinguish from other causes of right iliac fossa pain.

METHODS

A survey of the literature is presented and personal experience relative to 4 cases of acute diverticulitis of the right colon observed over a 10-year period is described.

RESULTS

In all the patients the preoperative diagnosis was acute appendicitis. In two cases the poor clinical conditions of the patients were associated with the free perforation of a solitary caecal diverticulum and diffuse faecal peritonitis. A temporary caecostomy was therefore required. In two cases a localized inflammatory mass was found around a perforated solitary diverticulum of the caecum. An ileocaecal resection was performed.

CONCLUSIONS

The purpose of this study is to emphasize the epidemiological, etiologic and clinical features of right-sided colonic diverticula, and the diagnostic and therapeutic management of their complications.

Rehabilitation of walking for paraplegic patients by means of a treadmill

The present study was aimed at investigating the use of a treadmill for ambulation training of paraplegic subjects. To investigate the likely effectiveness of this modality of rehabilitation, six paraplegic patients (three male and three female) were studied, using new generation reciprocating gait orthoses (RGO and ARGO), in a treadmill training program. Oxygen consumption, heart rate, and pulmonary ventilation were measured when the subjects were walking at their most comfortable speed on the treadmill and on the open field. These measurements were carried out at the beginning of the study and after two and six months of treadmill training. The following findings were significant: the treadmill walking required 30% less energy than open field ambulation prior to training (P < 0.001) and 50% after training (P < 0.05). The most comfortable walking speed was faster on the treadmill than on the open field by 18% prior to training (P < 0.05) and 42% afterwards (P < 0.05). The energy cost was 50% less after 2 months training on the treadmill (P < 0.05) showing that treadmill training can improve the efficiency of over ground ambulation. It can be concluded that the treadmill training improves the RGO/ARGO walking capability, probably both the walking efficiency (short term adaptation) and physical fitness (long term adaptation).

Dexamethasone adjunctive therapy for bacterial meningitis in children: a retrospective study in Brazil

The clinical records of 87 children with bacterial meningitis treated with antibiotics (group 1) and of 92 treated with antibiotics plus dexamethasone (group 2), admitted to the Instituto Materno Infantil de Pernambuco, Recife, Brazil over 2 consecutive years (1991 and 1992), were analysed. There were no significant differences between treatment groups regarding characteristics on admission except that group 1 were younger. The overall case fatality rate was 19%, with 14% in group 2 and 24% in group 1 (p = 0.09). Rate of discharge without sequelae was 70% in the steroid-treated children and 56% in children treated with antibiotics alone (p = 0.07). Among children aged 6-59 months, those treated with dexamethasone compared with those treated with antibiotics alone had a better case fatality rate (11% vs 25%; p = 0.05) and a better rate of discharge without sequelae (73% vs 52%; p = 0.02). Among the cases with a CSF culture positive for Haemophilus influenzae, 77% were discharged without sequelae in group 2 compared with 51% in group 1 (p = 0.03). The addition of dexamethasone to standard antibiotic treatment improves the outcome of children between 6 and 59 months of age admitted to hospital with a diagnosis of bacterial meningitis.

Ergonomy of paraplegic patients working with a reciprocating gait orthosis

A reciprocating gait orthosis (RGO) is, among others, the most widely adopted device to restore the standing and walking capability of paraplegic patients. The aim of the present study was the evaluation of the energy demand (VO2), and cardiopulmonary load (HR and VE) imposed on the subject by different working tasks while sitting in a wheelchair or standing using a RGO. In addition, a comparison with the performance of normal subjects was also attempted. The RGO use allowed a dramatic improvement of patients' mobility and reach space in the workplace. A further advantage provided by the use of the RGO was represented by the increased mobility of the subjects with respect to the wheelchair confined situation. The energy demand and the cardiorespiratory load imposed on the subjects by the use of the RGO were not different from those observed both in the same subjects sitting in a wheelchair and in the controls. The energy demand slightly exceeded the values typical of light work and was, thus, compatible with the normal duration of a working day. On the other hand, the cardiac load corresponded to that typical of moderate activity, thus limiting the duration of the working task to 5-8 h. Based on the ergometry test, all of the working activities considered can be classified as aerobic activities, energy demand being under the ventilatory threshold.

Antiinflammatory influences of alpha-MSH molecules: central neurogenic and peripheral actions

alpha-Melanocyte-stimulating hormone (alpha-MSH1-13) and its COOH-terminal tripeptide alpha-MSH11-13 (Lys Pro Val) inhibit inflammation when administered systemically. Recent evidence indicates that alpha-MSH1-13 can likewise inhibit inflammation in the skin solely via an action within the brain. Because of the potential importance of this discovery to understanding the control of inflammation and because alpha-MSH molecules might be useful for treatment of inflammation, experiments were performed to learn more about the mechanisms of action of these peptides. In tests on inflammation induced in the mouse ear by intradermal injections of recombinant human interleukin-1 beta, alpha-MSH1-1-13 administered intracerebroventricularly effectively reduced inflammation. This effect of centrally administered alpha-MSH1-13 was inhibited by systemic injection of the nonspecific beta-adrenergic receptor blocker propranolol and by administration of a specific beta 2-adrenergic receptor antagonist; the effect was not altered by blockade of cholinergic, alpha-adrenergic, or beta 1-adrenergic receptors. In mice with inflammation induced in a hind paw and with the spinal cord transected, the antiinflammatory effect of centrally administered alpha-MSH1-13 was prevented, indicating that intact descending neuronal pathways are required for the antiinflammatory influence of the central peptide. Systemic injection of alpha-MSH1-13 in animals with spinal cord transection had a smaller and later antiinflammatory effect, which suggests that the molecule also has an action, albeit lesser, in the periphery. However, alpha-MSH11-13 injected intraperitoneally had marked antiinflammatory activity in animals with spinal cord transection.(ABSTRACT TRUNCATED AT 250 WORDS)

Central neurogenic antiinflammatory action of alpha-MSH: modulation of peripheral inflammation induced by cytokines and other mediators of inflammation

The neuropeptide alpha-melanocyte-stimulating hormone (alpha-MSH) has potent antipyretic and antiinflammatory properties. When administered systemically, the naturally occurring molecule and its COOH-terminal tripeptide sequence inhibit inflammation induced by peripherally applied irritants and intradermal injections of mediators of inflammation such as interleukin-1 (IL-1), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF alpha). We recently found that alpha-MSH can act solely within the brain to inhibit inflammation caused by a general irritant applied to the skin. This activity appears to be shared with salicylate drugs and the combined observations suggest the existence of descending neurogenic antiinflammatory signals capable of modulating inflammation in peripheral tissues. To improve our knowledge of the scope of this action of the peptide, alpha-MSH was injected into the cerebral ventricles (i.c.v.) of mice that had received intradermal injections in the ear of mediators of inflammation: IL-1 beta, IL-8, leukotriene B4, and platelet-activating factor. The centrally administered peptide inhibited the actions of all of these proinflammatory agents as determined from comparisons with measures of ear edema over time in control animals; this indicates that the central peptide can alter inflammation induced in the periphery by major mediators of inflammation. In tests confined to IL-1 beta, central administration of alpha-MSH(11-13) was also effective. These findings support the concept of a descending neurogenic antiinflammatory influence promoted by an action of alpha-MSH within the brain, an inhibitory influence that is not restricted to modulation of just one or a limited set of the mediators of inflammation.

Inhibition of acute inflammation in the periphery by central action of salicylates

Understanding of the antiinflammatory actions of nonsteroidal drugs is incomplete, but these actions are believed to occur in the periphery, without any contribution from the central nervous system. Recent research on the antipyretic antiinflammatory neuropeptide alpha-melanocyte-stimulating hormone indicates that it can act centrally to inhibit peripheral inflammation; this raises the possibility that other agents, such as nonsteroidal antiinflammatory drugs, may have similar activity. In the present research both lysine acetylsalicylate and sodium salicylate inhibited edema, induced in the mouse ear by topical application of picryl chloride, when injected into the lateral cerebral ventricle. This inhibitory activity on a measure of acute inflammation was not due to escape of the drugs into the periphery, because systemic injection of doses that were effective centrally did not affect inflammation. In contrast, central administration of a dose of indomethacin that was antiinflammatory when given intraperitoneally did not inhibit peripheral inflammation. Thus indomethacin apparently lacks the central antiinflammatory action of the salicylates. This observation, plus our inability to demonstrate either an antiinflammatory effect of intracerebroventricular dexamethasone, a prostaglandin inhibitor, or a pro-inflammatory influence of prostaglandin E2, suggests that prostaglandins are not important to central modulation of inflammation. The results indicate that, in addition to having central influences on fever and pain, salicylates can act within the brain to inhibit acute inflammation in the periphery.

Central administration of the peptide alpha-MSH inhibits inflammation in the skin

Inflammation is generally conceptualized in terms of cells, mediators, and events in the periphery, with no consideration of an influence of the central nervous system (CNS). However, the neuroendocrine peptide alpha-melanocyte stimulating hormone (alpha-MSH) is anti-inflammatory when given systemically and this molecule reaches the brain to exert another effect: fever reduction. Tests on mice indicate that alpha-MSH can act solely within the CNS to inhibit inflammation in the skin. This observation indicates that the central nervous system can inhibit peripheral inflammation via action of alpha-MSH molecules and it further strengthens the idea of neural/endocrine modulation of the host responses.

Expression of Bacillus thuringiensis delta-endotoxin genes during vegetative growth

Bacillus thuringiensis delta-endotoxin (crystal protein) genes are normally expressed only during sporulation. It is possible to produce crystal protein during vegetative growth by placing B. thuringiensis crystal protein genes downstream of a strong vegetative promoter. By removing a possible transcriptional terminator of the tetracycline resistance gene of pBC16 and inserting a multiple cloning site, delta-endotoxin genes can be cloned downstream from the tetracycline resistance gene promoter. This construct allows for readthrough transcription from the strong vegetative promoter. Crystal protein is then produced during vegetative growth as well as during sporulation in both B. thuringiensis and Bacillus megaterium. This construct also allows for production of delta-endotoxin in B. thuringiensis strains that do not normally produce delta-endotoxin because of a defect in sporulation.

Glutamate dehydrogenase: genetic mapping and isolation of regulatory mutants of Klebsiella aerogenes

The gene for glutamate dehydrogenase (gdhD) has been mapped in Klebsiella aerogenes by P1 transduction. It is linked to pyrF and trp with the order pyrF-trp-gdh. Complementation analysis using F' episomes from Escherichia coli suggests an analogous location in E. coli. Two mutants able to produce glutamate dehydrogenase in the presence of high levels of glutamine synthetase have been isolated. One, tightly linked to gdhD, shows normal repression control by glutamine synthetase but produces four times as much glutamate dehydrogenase activity as does the wild type under all conditions tested. The other revertant is not linked to gdhD or glnA.