Influenza A subtype H3N2 is associated with an increased risk of hospital dissemination - an observational study over six influenza seasons

BACKGROUND

Previous studies on hospital-acquired influenza (HAI) have not systematically evaluated the possible impact of different influenza subtypes. HAI has historically been associated with high mortality, but clinical consequences may be less severe in a modern hospital setting.

AIMS

To identify and quantify HAI for each season, investigate possible associations with varying influenza subtypes, and to determine HAI-associated mortality.

METHODS

All influenza-PCR-positive adult patients (>18 years old) hospitalized in Skåne County during 2013-2019, were prospectively included in the study. Positive influenza samples were subtyped. Medical records of patients with suspected HAI were examined to confirm a nosocomial origin and to determine 30-day mortality.

RESULTS

Of 4110 hospitalized patients with a positive influenza PCR, 430 (10.5%) were HAI. Influenza A(H3N2) infections were more often HAI (15.1%) than influenza A(H1N1)pdm09, and influenza B (6.3% and 6.8% respectively, P<0.001). The majority of HAI caused by H3N2 were clustered (73.3 %) and were the cause of all 20 hospital outbreaks consisting of ≥4 affected patients. In contrast, the majority of HAI caused by influenza A(H1N1)pdm09 and influenza B were solitary cases (60% and 63.2%, respectively, P<0.001). Mortality associated with HAI was 9.3% and similar between subtypes.

CONCLUSIONS

HAI caused by influenza A(H3N2) was associated with an increased risk of hospital dissemination. Our study is relevant for future seasonal influenza infection control preparedness and shows that subtyping of influenza may help to define relevant infection control measures. Mortality in HAI remains substantial in a modern hospital setting.

Dynamic allosteric communication pathway directing differential activation of the glucocorticoid receptor

Allosteric communication within proteins is a hallmark of biochemical signaling, but the dynamic transmission pathways remain poorly characterized. We combined NMR spectroscopy and surface plasmon resonance to reveal these pathways and quantify their energetics in the glucocorticoid receptor, a transcriptional regulator controlling development, metabolism, and immune response. Our results delineate a dynamic communication network of residues linking the ligand-binding pocket to the activation function-2 interface, where helix 12, a switch for transcriptional activation, exhibits ligand- and coregulator-dependent dynamics coupled to graded activation. The allosteric free energy responds to variations in ligand structure: subtle changes gradually tune allostery while preserving the transmission pathway, whereas substitution of the entire pharmacophore leads to divergent allosteric control by apparently rewiring the communication network. Our results provide key insights that should aid in the design of mechanistically differentiated ligands.

Human papillomavirus-associated oropharyngeal cancer: a new clinical entity

The incidence of oropharyngeal cancers is rising worldwide in both nonsmokers and nondrinkers. Epidemiology studies suggest a strong association between human papillomavirus (HPV) 16 infection, changing sexual behavior and cancer development. Despite initial presentation with locally advanced disease and poorly differentiated histology, HPV-associated oropharyngeal carcinoma is associated with a good prognosis because its response to chemotherapy and radiation. Clinicians should be aware of the risk of oropharyngeal cancer in young people to avoid unnecessary delay in diagnosis and treatment. A history of oral sex should be elicited in young patients with enlarged neck nodes and/or tonsillar masses.

Historical pollution of seldom monitored trace elements in Sweden—Part B: Sediment analysis of silver, antimony, thallium and indium

Sediment cores from four boreal and remote lakes in a south to north transect in central Sweden were analysed for acid leachable silver, antimony, thallium and indium in the solid sediment phase and the corresponding porewater. Dating of the cores was made by their content of acid leachable lead and the (206)Pb/(207)Pb ratio, in one lake also by (210)Pb. The impact of diagenesis on element redistribution in the sediments was included and found to be minor except for thallium. The results show lowered concentrations towards the north and most intense accumulation after the Second World War, which is taken as evidence for atmospheric deposition being the primary source. Indium has declining concentrations in recent strata while silver and antimony increase. Thallium has lowered acid-leachable concentrations in recent strata. For all metals the impact of domestic industrialisation as well as the early industrialisation of central Europe is discernible. Only thallium appears to reach a geological background at depths that correspond to the late 18th century. For the other metals elevated levels are concluded.

Dysphagia following chemoradiation for locally advanced head and neck cancer

BACKGROUND

To assess the prevalence, severity and morbidity of dysphagia following concurrent chemoradiation for head and neck cancer.

PATIENTS AND METHODS

Patients who underwent chemotherapy and radiation for head and neck malignancies were evaluated for their ability to resume oral feeding following treatment. Modified barium swallow (MBS) studies were performed if the patients complained of dysphagia or if there was clinical suspicion of aspiration. The severity of dysphagia was graded on a scale of 1-7. If significant abnormalities were found, swallowing studies were repeated until resolution of dysphagia.

RESULTS

Between March 1999 and May 2002, 55 patients with locally advanced head and neck cancer underwent concurrent chemotherapy and radiation. Aspiration pneumonia was observed in eight patients, three during treatment and five following treatment. Five patients died from pneumonia. Two patients developed respiratory failure requiring intubation as a complication of pneumonia. At a median follow-up of 17 months (range 6-48 months), 25 patients (45%) developed severe dysphagia requiring prolonged tube feedings for more than 3 months (22 patients) or repeated dilatations (three patients). Among 33 patients who underwent MBS following treatment, 12 patients (36%) had silent aspiration (grade 6-7 dysphagia). Thirteen patients (39%) developed grade 4-5 dysphagia which required prolonged enteral nutritional support to supplement their oral intake. Most patients had severe weight loss (0-21 kg) during treatment, likely due in part to mucositis in the orodigestive tube.

CONCLUSIONS

Dysphagia is a common, debilitating and potentially life-threatening sequela of concurrent chemoradiation for head and neck malignancy. Physicians should be aware that the clinical manifestations of aspiration may be unreliable and insidious, because of the depressed cough reflex. Modified and traditional barium swallows should be performed following treatment to assess the safety of oral feeding and the structural integrity of the pharynx and esophagus. Patients with severe dysphagia may benefit from rehabilitation. Tube feeding should be continued for those with aspiration.

Concurrent interferon-alpha and radiation for head and neck melanoma

Melanoma cells are resistant to radiation in part due to their capacity to repair sublethal damage. A large fraction dose is therefore often utilized. However, if the tumour is located close to critical structures with modest tolerance, high fraction doses increase the risk for late complications compared with standard fractionation, but using the latter alone risks the desired outcome. Concurrent systemic biotherapy with standard radiation fractions may therefore represent an acceptable compromise. The outcome of concurrent systemic interferon-alpha (IFNalpha) and radiation in three patients with head and neck melanoma was evaluated. Standard radiation fractions were used because of the radiosensitizing properties of IFNalpha. Acute toxicity was significant and required treatment interruptions. However, all side effects subsided following treatment. All three patients achieved local control at follow-up periods of 24, 18 and 19 months, respectively. One patient developed widespread distant metastases. The combination of IFNalpha with radiation is considered feasible in terms of outcome and should be investigated with a larger cohort of patients. Toxicity is significant, and the addition of radioprotectors could be desirable.

Glutamate-induced currents reveal three functionally distinct NMDA receptor populations in rat dorsal horn - effects of peripheral nerve lesion and inflammation

The importance of the N-methyl-D-aspartate (NMDA) receptor in various painful conditions is well established. The effects of peripheral nerve lesion or joint inflammation, as models of different pain states, on NMDA receptor-mediated currents and NMDA receptor subunit mRNA expression were therefore studied in acutely dissociated neurones from the rat spinal cord dorsal horn. In the neuronal population from control rats, all four NR2 subunits and both NR1 splice variants assayed were detected. A majority of neurones expressed mRNA for more than one NR2 subunit, and some neurones expressed all four NR2 subunits as well as both NR1 splice variants. The NR2B subunit was the most commonly expressed, while the NR2C was the rarest. Following nerve lesion, fewer neurones expressed NR2A compared to the control. The dose-response curve for glutamate-evoked NMDA receptor-mediated currents in the neurones was best described by a three-component fit, suggesting that three functionally distinct NMDA receptor populations are present in the dorsal horn. Minor changes in the dose-response curve after nerve lesion could not be ascribed with certainty to the lesion. Changes in other parameters of NMDA receptor-mediated currents were observed neither after nerve lesion nor after joint inflammation. In summary, the present work demonstrates that single dorsal horn neurones express mRNA for several NMDA receptor subunits. The glutamate dose-response curves indicate that there are three major types of NMDA receptors present in dorsal horn neurones. We also report a reduced expression of NR2A following peripheral nerve lesion.

Nonsubmerged implants in the treatment of the edentulous lower jaw: a 5-year prospective longitudinal study of ITI hollow screws

BACKGROUND

Although most implant systems have been designed for a two-stage surgical technique, a one-stage surgical technique has always been advocated for the ITI Dental Implant System (Straumann AG, Waldenburg, Switzerland). A new generation of ITI implants was presented in 1988 and included a hollow cylinder, a hollow screw, and a solid screw.

PURPOSE

The goal of this study was to evaluate the one-stage surgical technique in connection with the ITI hollow screw in a longitudinal study over 5 years.

MATERIALS AND METHODS

Forty-six patients with edentulous lower jaws were supplied with ITI hollow-screw implants. Patients who requested an overdenture (n = 18) had four implants inserted; those who requested a fixed bridge (n = 28) had five to six implants. The patients have been followed annually for 5 years. There was a dropout of three patients (6.5%); one patient did not want to cooperate, one moved from the area, and one was deceased. The clinical examinations included bridge removal for evaluation of the individual implant stability in connection with the 1-, 3-, and 5-year examinations. Radiographic examinations were performed with intraoral radiographs and the long-cone technique.

RESULTS

The survival rate after 5 years was 95.7%. The success rate (in which implants undergoing treatment of peri-implantitis were not counted as successes) was 91.4%. The mean marginal bone loss between the baseline and the 1-year examination was 0.1 mm and between the 1- and 5-year examinations was 0.1 mm. These changes in marginal bone level were not significant.

CONCLUSIONS

The success rate of ITI hollow-screw implants in the edentulous mandible was 91.4% after a 5-year observation period. There was no significant change in mean bone level between the loading of the implants and the 5-year examination. Peri-implantitis was diagnosed in three patients with poor oral hygiene, and it affected six implants. Five of these failed in spite of treatment.

Structure of the PPARalpha and -gamma ligand binding domain in complex with AZ 242; ligand selectivity and agonist activation in the PPAR family

BACKGROUND

The peroxisome proliferator-activated receptors (PPAR) are ligand-activated transcription factors belonging to the nuclear receptor family. The roles of PPARalpha in fatty acid oxidation and PPARgamma in adipocyte differentiation and lipid storage have been characterized extensively. PPARs are activated by fatty acids and eicosanoids and are also targets for antidyslipidemic drugs, but the molecular interactions governing ligand selectivity for specific subtypes are unclear due to the lack of a PPARalpha ligand binding domain structure.

RESULTS

We have solved the crystal structure of the PPARalpha ligand binding domain (LBD) in complex with the combined PPARalpha and -gamma agonist AZ 242, a novel dihydro cinnamate derivative that is structurally different from thiazolidinediones. In addition, we present the crystal structure of the PPARgamma_LBD/AZ 242 complex and provide a rationale for ligand selectivity toward the PPARalpha and -gamma subtypes. Heteronuclear NMR data on PPARalpha in both the apo form and in complex with AZ 242 shows an overall stabilization of the LBD upon agonist binding. A comparison of the novel PPARalpha/AZ 242 complex with the PPARgamma/AZ 242 complex and previously solved PPARgamma structures reveals a conserved hydrogen bonding network between agonists and the AF2 helix.

CONCLUSIONS

The complex of PPARalpha and PPARgamma with the dual specificity agonist AZ 242 highlights the conserved interactions required for receptor activation. Together with the NMR data, this suggests a general model for ligand activation in the PPAR family. A comparison of the ligand binding sites reveals a molecular explanation for subtype selectivity and provides a basis for rational drug design.

Prognosis for papillary serous carcinoma of the endometrium after surgical staging

BACKGROUND

To investigate the pattern of failure and the prognosis following pathological staging for uterine papillary serous carcinoma (UPSC).

PATIENTS AND METHODS

A retrospective review was conducted of 22 patients with UPSC, treated between 1989 and 1998 at a single institution. All patients were surgically staged. Two patients with advanced disease received chemotherapy only. Two patients with early-stage disease were followed without further treatment. Eighteen patients received postoperative irradiation; eight patients received whole abdominal irradiation (WART), and the remaining 10 patients, pelvic irradiation (PRT). In addition, seven of these patients received vaginal cuff irradiation with low-dose-rate or high-dose-rate brachytherapy. Toxicity, pattern of failure, and survival were evaluated and compared to the literature.

RESULTS

Seven patients (32%) developed distant metastases, three out of seven (42%) after WART. Four out of seven patients who had distant metastases died from disease progression during subsequent chemotherapy. All patients with distant metastases had locally advanced-stage disease at presentation (six stage III, one stage IV). Four patients with pelvic recurrences developed concurrent (2) and subsequent (2) distant metastases. Three patients had isolated distant metastases. No patient with early stage-disease (stage I and II) died from disease progression.

CONCLUSION

Pathological staging should be performed for all patients with UPSC to determine the prognosis as well as to tailor the treatment. The role of abdominal irradiation in the treatment of UPSC is yet to be determined; however, such an approach may not be necessary for the control of disease for patients with early-stage (I and II) disease. Patients with locally advanced-stage (stage III) disease are at risk of local regional failures and distant metastases despite WART. Therefore, the benefit of WART for advanced-stage disease is also questionable. Paclitaxel-based chemotherapy is currently being investigated in this setting.

Human granulocytic ehrlichiosis--a clinical case in Scandinavia

A clinical case of human granulocytic ehrlichiosis in Scandinavia is presented. The patient developed high fever, myalgia, headache and dyspnoea. Doxycycline treatment resulted in a dramatic improvement. Laboratory confirmation included a fourfold change in anti-Ehrlichia equi IFA titre and a positive PCR confirmed by gene sequence analysis.

Interferon-alpha combined with radiotherapy in the treatment of unresectable melanoma

A case of recurrent and twice resected sinonasal melanoma is presented. The large recurrent tumor was found to regress by a concurrent combination of 6660 cGy photon radiation and subcutaneous interferon-alpha injections given for a period of 8 weeks. Possible mechanisms of potentiation between interferon and radiation are discussed. The unexpected result in this case report raises interesting questions about this treatment combination.

A prospective 5-year study of fixed partial prostheses supported by implants with machined and TiO2-blasted surface

PURPOSE

The aim of the present study was to evaluate whether there was a difference between machined and TiO(2)-blasted implants regarding survival rate and marginal bone loss during a 5-year observation period.

MATERIALS AND METHODS

A total of 133 implants (Astra Tech Dental Implants; Astra Tech AB, Mölndal, Sweden) were placed in 50 patients at 6 centers in 4 Scandinavian countries. Forty-eight implants were installed in the maxilla and 85 implants in the mandible. A randomization and a stratification were done, so that each fixed partial prosthesis was supported by at least 1 machined and 1 TiO(2)-blasted implant. The implant-supported fixed partial prostheses (ISFPP) were fabricated within 2 months after postoperative healing. A total of 52 ISFPP (17 maxillary, 35 mandibular) were inserted. The patients were clinically examined once a year for 5 years. At the annual follow-up, biological as well as technical complications were recorded.

RESULTS

Of the 133 implants placed, 3 were reported as failed after 5 years of follow-up, resulting in an overall cumulative survival rate of 97.6%. The cumulative implant survival rates were 100% for the TiO(2)-blasted implants and 95.1% for the machined implants. No significant difference in survival was, however, found between the machined and TiO(2)-blasted implants after 5 years. The mean marginal bone loss in the maxilla was 0.21 +/- 0.83 mm (SD) for the machined implants and 0.51 +/- 1.11 mm (SD) for the TiO(2)-blasted implants during the 5-year observation period. In the mandible, the mean marginal loss was 0.22 +/- 1.13 mm for the machined implants and 0.52 +/- 1.07 mm for the TiO(2)-blasted implants from baseline to the 5-year examination. No significant difference in marginal bone loss between the 2 surface groups was found during the 5-year observation period.

CONCLUSIONS

The present study shows good 5-year results with small ISFPP in the mandible, as well as in the maxilla. No significant differences were found in failure rate and marginal bone loss around implants with a machined rather than a TiO(2)-blasted surface. J Prosthodont 2001;10:2-7.

Prognosis for papillary serous carcinoma of the endometrium after surgical staging

Abstract.

Nguyen NP, Sallah S, Karlsson U, Vos P, Ludin A, Semer D, Tait D, Salehpour M, Jendrasiak G, Robiou C. for papillary serous carcinoma of the endometrium after surgical staging.

Background: To investigate the pattern of failure and the prognosis following pathological staging for uterine papillary serous carcinoma (UPSC).

Patients and methods: A retrospective review was conducted of 22 patients with UPSC, treated between 1989 and 1998 at a single institution. All patients were surgically staged. Two patients with advanced disease received chemotherapy only. Two patients with early-stage disease were followed without further treatment. Eighteen patients received postoperative irradiation; eight patients received whole abdominal irradiation (WART), and the remaining 10 patients, pelvic irradiation (PRT). In addition, seven of these patients received vaginal cuff irradiation with low-dose-rate or high-dose-rate brachytherapy. Toxicity, pattern of failure, and survival were evaluated and compared to the literature.

Results: Seven patients (32%) developed distant metastases, three out of seven (42%) after WART. Four out of seven patients who had distant metastases died from disease progression during subsequent chemotherapy. All patients with distant metastases had locally advanced-stage disease at presentation (six stage III, one stage IV). Four patients with pelvic recurrences developed concurrent (2) and subsequent (2) distant metastases. Three patients had isolated distant metastases. No patient with early stage-disease (stage I and II) died from disease progression.

Conclusion: Pathological staging should be performed for all patients with UPSC to determine the prognosis as well as to tailor the treatment. The role of abdominal irradiation in the treatment of UPSC is yet to be determined; however, such an approach may not be necessary for the control of disease for patients with early-stage (I and II) disease. Patients with locally advanced-stage (stage III) disease are at risk of local regional failures and distant metastases despite WART. Therefore, the benefit of WART for advanced-stage disease is also questionable. Paclitaxel-based chemotherapy is currently being investigated in this setting.

Neuroblastoma producing spinal cord compression: rapid relief with low dose of radiation

Symptomatic spinal cord compression requires emergency treatment to alleviate symptoms and to avoid irreversible damage. We describe a successful decompression by low dose radiation to a progressing neuroblastoma in a child. Magnetic resonance imaging post radiation should be performed to assess the response of the tumor to radiation.

Combined preoperative chemotherapy and radiation for locally advanced rectal carcinoma

To determine the efficacy of combined preoperative chemotherapy and radiation therapy for locally advanced rectal carcinoma and the rate of sphincter conservation, a retrospective survey of 39 patients with locally advanced rectal carcinoma treated with various 5-fluorouracil- and leukovorin-based chemotherapy regimens and radiation prior to surgery in a single institution was reviewed. Toxicity, local control and survival were evaluated and compared to previous studies with similarly staged patients. Long-term follow-up was available on 35 patients. The actuarial local failure was 5.7% while the actuarial 5-year survival was 87%. The mortality rate was low (2.5%) and the rate of long-term serious complications acceptable (11.4%). Combined preoperative chemotherapy and radiation provided excellent local regional control despite the poor prognostic factors associated with size, fixation, and the initial advanced tumor stage with acceptable morbidity. In addition, patients with tumors located in the lower third of the rectum may be able to undergo sphincter-sparing surgery. Although the median follow-up is relatively short (32.4 months), the results are in accordance with previous studies of neoadjuvant combined chemotherapy and radiation for locally advanced rectal carcinoma in terms of local and distant control.

Nonsubmerged Implants in the Treatment of the Edentulous Upper Jaw: A Prospective Clinical and Radiographic Study of ITI Implants?Results after 1 Year

BACKGROUND

A new generation of ITI implants, including a hollow cylinder, a hollow screw, and a solid screw, was described in 1988. Currently, the solid screw is the main alternative.

PURPOSE

The aim of this study was to gain further clinical documentation of ITI solid-screw implants used in the edentulous upper jaw. This is a report 1 year after loading.

MATERIALS AND METHODS

Twenty-eight patients with edentulous upper jaws (mean age, 57 yr) were supplied with four to eight ITI solid-screw implants in the upper jaw. In total, 167 implants (3.3 and 4.1 mm in diameter) were inserted. The implants were loaded about 7 months postoperatively. All patients were supplied with fixed screw-retained bridges.

RESULTS

Twelve implants failed: 10 prior to loading and 2 after. Overall implant survival rate was 92.8%. Three of the five patients with implant loss were smokers. Signs of peri-implantitis were found in seven patients, affecting 12 implants. Mean marginal bone level at the loading of the implants (7 months after insertion) was situated 4.7 mm from the reference point of the implant. There was no significant change between loading and the 1-year examination. However, at several implants, the bone level at baseline was situated far apical of the reference point, indicating a bone loss before loading.

CONCLUSIONS

The ITI screw implants, used in the edentulous upper jaw, had a survival rate of 92.8%. Mean bone loss between loading and the 1-year examination was 0.1 mm. Some implants had a bone level indicating a significant bone loss before loading. Peri-implantitis was found at about 7.2% of the implants inserted and at 25% of the failing implants.

Disability and quality of life in individuals with postpolio syndrome

PURPOSE

The purpose of the study is to investigate disability and quality of life in individuals with the characteristic symptoms of postpolio syndrome.

METHOD

Disability is assessed by means of the self-report activities of daily living instrument, and quality of life by means of Kaasa's questionnaire and the quality of life profile.

RESULTS

The 39 subjects have on average lived with polio sequelae for 52 years. Their main difficulties are with moving, lifting and carrying. This means restricted mobility, sedentary activities and a need to prioritize. Half of them feel that polio has lessened their possibilities in life, and a quarter have still not accepted the limitations polio has involved. Nevertheless the majority report a high level of psychosocial well-being, and almost a quarter say that living with polio has meant personal development and strength. We found a significant correlation between on the one hand disability with regard to ambulation, arm strength and finger strength on the self-report ADL, and on the other hand the number of negative problems on the quality of life profile (0.33-0.45).

CONCLUSION

The latter instrument needs further testing before its validity can be determined with certainty.

Laser-welded titanium frameworks supported by implants in the edentulous maxilla: a 2-year prospective multicenter study

PURPOSE

The aim of this study was to evaluate the clinical and radiographic performance of patients who received implants and fixed prostheses with laser-welded titanium frameworks.

MATERIALS AND METHODS

Fifty-eight consecutive patients were treated with 349 osseointegrated implants ad modum Brånemark in the edentulous maxilla at 6 implant centers. The patients were randomly arranged into 2 groups at the time of final impression. Twenty-eight patients received laser-welded titanium frameworks and 30 patients received conventional cast frameworks. Clinical and radiographic data were collected for 2 years in function.

RESULTS

The 2 groups of patients showed similar results. The 2-year overall cumulative implant survival rate from the time of implant placement and prosthesis insertion was 93.7% and 96.2%, respectively. The corresponding cumulative survival rate for prostheses was 96.6%. Two patients, 1 from each group, failed completely and resumed using conventional complete dentures. The only obvious factor that could possibly be related to the 2 complete failures was a smoking habit. However, it was not possible to significantly correlate implant failures to smoking habits in this study. No fractures were observed in the frameworks or implant components, and both groups experienced the same frequency of resin veneering material fractures. The overall average marginal bone loss was 0.4 mm (SD 0.8 mm).

CONCLUSION

Patients treated with implant-supported prostheses fabricated with laser-welded titanium frameworks in the edentulous maxilla presented comparable results to patients with conventional cast frameworks after 2 years in function.

A 2-year report on maxillary and mandibular fixed partial dentures supported by Astra Tech dental implants. A comparison of 2 implants with different surface textures

In 50 partially edentulous patients, 133 (48 maxillary; 85 mandibular) Astra Tech dental implants of 2 different surface textures (machined; TiO-blasted) were alternately installed, supporting 52 fixed partial dentures (FPDs). Before abutment connection 2 machined implants (1 mandibular; 1 maxillary) were found to be non-osseointegrated and were replaced. Another implant could not be restored due to a technical complication. Two FPDs were remade because of technical complications, both because of abutment fractures. Thus, after 2 years in function, the cumulative survival rates were 97.7% and 95.7% for implants and prostheses, respectively. There was no statistically significant difference in survival rate between the 2 types of implants, 100% (TiO-blasted) vs 95.3% (machined), P = 0.24. After 2 years in function, when both jaw and type of implants were combined, the mean (SD) marginal bone loss was 0.24 (0.69) mm. No statistically significant difference in bone loss was found between the 2 types of implant after 2 years of loading, 0.04 (0.82) mm, P > 0.30.

Heterogeneous presynaptic Ca2+ channel types triggering GABA release onto medial preoptic neurons from rat

1. Voltage-dependent Ca2+ channels triggering GABA release onto neurons from the medial preoptic nucleus of rat were investigated. Acutely dissociated neurons with adherent functional synaptic terminals were investigated by tight-seal whole-cell recordings from the postsynaptic cells. 2. Spontaneous current events similar to miniature postsynaptic currents were recorded. They were blocked by bicuculline (100 microM), showed a roughly unimodal amplitude distribution and a reversal potential consistent with a Cl- current, and were therefore attributed to GABAA receptors activated by synaptically released GABA. 3. Application of 140 mM KCl, expected to depolarize presynaptic terminals, evoked currents that were ascribed to a more massive release of GABA. The KCl-induced synaptic currents were abolished in Ca2+-free solutions and showed a roughly hyperbolic relation to external Ca2+ concentration with half-saturation at 0.15 mM. They further depended on the concentration of applied KCl in a way expected for high-threshold Ca2+ channels. 4. The KCl-evoked synaptic currents were completely blocked by 200 microM Cd2+, but only partially blocked by 200 microM Ni2+. The KCl-evoked synaptic currents were insensitive to the L-type Ca2+ channel blocker nifedipine (10 microM). However, the synaptic currents were sensitive to either 1 microM omega-conotoxin GVIA, 25 nM omega-agatoxin IVA or 1 microM omega-conotoxin MVIIC. 6. It was concluded that, in many presynaptic terminals, the Ca2+ influx triggering GABA release onto medial preoptic neurons is mainly mediated by one predominant type of high- threshold Ca2+ channel that may be either of N-, P- or Q-type. 7. It was further concluded that terminals with similar predominant channel types often were clustered on the same postsynaptic cell.

Currents evoked by GABA and glycine in acutely dissociated neurons from the rat medial preoptic nucleus

The responses of acutely dissociated medial preoptic neurons to application of GABA, and glycine were studied using the perforated-patch whole-cell recording technique under voltage-clamp conditions. GABA, at a concentration of 1 mM, evoked outward currents in all cells (n = 33) when studied at potentials positive to -80 mV. The I-V relation was roughly linear. The currents evoked by GABA were partially blocked by 25-75 microM picrotoxin and were also partially or completely blocked by 100-200 microM bicuculline. Glycine, at a concentration of 1 mM, did also evoke outward currents in all cells (n = 12) when studied at potentials positive to -75 mV. The I-V relation was roughly linear. The currents evoked by glycine were largely blocked by 1 microM strychnine. In conclusion, the present work demonstrates that neurons from the medial preoptic nucleus of rat directly respond to the inhibitory transmitters GABA and glycine with currents that can be attributed to GABAA receptors and glycine receptors respectively.

Single-tooth replacement by osseointegrated Astra Tech dental implants: a 2-year report

This study presents the outcome of single-tooth restorations supported by Astra Tech single-tooth implants followed for 2 years. Forty-seven implants were placed in the same number of patients. Forty-three patients attended the second recall visit, and none of the evaluated implants have been removed. The mean marginal bone loss after 2 years of service was 0.31 (SD = 0.48) mm. Overall, few complications were recorded during the 2-year period, the most frequent of which were loose crowns (7).

Glutamate-evoked currents in acutely dissociated neurons from the rat medial preoptic nucleus

Membrane currents evoked by glutamate were investigated in acutely dissociated neurons from the medial preoptic nucleus (MPN) of rat. Rapid application of glutamate induced a fast current component in all neurons studied. In addition, in > 50% of the neurons, a slow current component was elicited. The fast and the slow current components were selectively blocked by the AMPA-receptor antagonist NBQX and by the NMDA-receptor channel blocker MK-801, respectively. Rapid application of AMPA induced, in all neurons tested, currents with properties similar to the fast component of the glutamate-evoked currents whereas rapid application of NMDA induced, in approximately 75% of the neurons, currents similar to the slow component of the glutamate-evoked currents. The NMDA-evoked currents showed a marked outward rectification that was attributed to a potential-dependent block by extracellular Mg2+. The NMDA-evoked currents also required the presence of extracellular glycine in the micromolar range. In conclusion, the results show that MPN neurons respond to glutamate with currents that can be attributed to activation of ionotropic glutamate receptors of the AMPA-receptor type as well as of the NMDA-receptor type.

Obese (ob) gene defects are rare in human obesity

Our knowledge of the role of the recently cloned ob-protein (leptin) in the regulation of body fat stores is largely derived from experiments performed in mice. Different mouse models exhibit abnormalities in ob-gene expression, with extreme overexpression in mice which lack bioactive ob-protein, have nonfunctional ob-receptors or hypothalamic lesions, and undetectable expression in mice with suggested defects in regulatory elements. The aim of this study is to examine if defects, corresponding to those in mice, exist in human obesity. Adipose tissue was obtained from 94 adult obese subjects and from six children who had developed obesity after surgery in the hypothalamic region. Total RNA was isolated and ob-gene expression was examined by reverse transcriptase-polymerase chain reaction (RT-PCR) and Northern blot. The coding region of the ob-gene was sequenced in both directions in the 94 obese adults. No mutations were detected in the coding region of the ob-gene and ob-gene expression was detectable in all subjects and none of the subjects had an extreme overexpression. There was no systematic increase in ob-expression in obese children with hypothalamic disease compared to their healthy brothers and sisters. These results show that severe abnormalities involving the ob-gene, analogous to those described in mouse models, are rare in human obesity. We therefore conclude that the cloning and subsequent analysis of the ob-gene has not provided information that can, by itself, explain the genetic component in the development of human obesity.

Non-submerged implants in the treatment of the edentulous lower jar. A 2-year longitudinal study

Non-submerged ITI Bonefit implants (ITI Dental Implant System) were inserted in edentulous lower jaws of 46 patients. The patients were provided with either a fixed prosthesis or an overdenture, and has been followed during a 2-year-period. At the 1-year examination, the suprastructures were removed permitting test of the individual implant stability. Radiographic examinations were performed in connection with the loading of the implants and at the 1-year examination. In total 216 implants were inserted. 4 implants were lost before loading and 4 during the 2nd year of function, which gives a survival rate after 1 year 98% and after 2 years of 96%. The mean marginal bone loss during the first year of function was 0.1 mm. However, the marginal bone changes had a high degree of variation and four implants showed a severe bone loss. The intention is to follow this patient group with annual examinations during 5 years.

Evaluation of implant-supported carbon/graphite fiber-reinforced poly (methyl methacrylate) prostheses. A longitudinal multicenter study

Carbon/graphite fiber-reinforced poly (methyl methacrylate) (CGFP) has been suggested as an alternative framework material for implant-supported fixed prostheses. The aim of this study was to evaluate CGFP prostheses clinically over time in patients treated with titanium implants of the Brånemark type and to study the handling of the material in the technical production. Twenty-five patients were fitted with 27 CGFP prostheses supported by 119 implants. Three implants, all in the upper jaw, were lost after loading. After a mean functioning time of 44 months (range 32-56), 19 prostheses (70%) were still in situ. In all, 5 prostheses fractured, of which 3 were exchanged whereas 2 could be repaired. The fractures were discovered early after loading and located close to the end abutment cylinders. During the follow-up period, the bone loss around the implants was about the same as earlier reported values for fixed prostheses with cast frameworks. It is concluded that a CGFP framework can be used to form the biocompatible superstructure of implant-supported prostheses with high precision at a low material cost and with good aesthetic results. The mechanical properties are so far not satisfactory but the method has the potential to be further developed and standardized.

Ocular globe topography in radiotherapy

PURPOSE

Ocular lens, retina, and olfactory bulb exposure are common concerns in contemporary radiotherapy practice. Methods to clinically localize soft tissue structures (i.e., lens and retina) are varied and often imprecise. We hypothesized that eyelid markers constituted a better reference point than the commonly used lateral canthus marker for lateral beam simulations, unless diagnostic computed tomography or ultrasound examinations were available and/or used.

METHODS AND MATERIALS

Sixty-six pre-Magnetic Resonance Image, normal, orbital computed tomography scans from adult patients were used to measure (a) sagittal distances from eyelid to posterior lens surface, from lateral canthus to posterior lens surface and to the globe's posterior pole, (b) supero-inferior distances in the lateral projection from the lens to the cribriform plate, and (c) common dimensions to establish internal validity of the measurements.

RESULTS

The eyelid to lens and retina topography is individually more constant than that from the canthus. There is little if any supero-inferior separation between the lens and the cribriform plate lateral projections.

CONCLUSIONS

The lateral canthus does not specify lens or retina locations. Eyelid markers of known size provide more accurate anatomical information. Lateral beam ocular globe shielding has to be individualized. Lens shielding is questionable if the olfactory bulb needs to be irradiated by a lateral beam.

Improved microscopical diagnosis of pulmonary tuberculosis in developing countries

The diagnosis of pulmonary tuberculosis (TB) relies on the bacteriological examination of sputum. However, microscopy of smears made directly from sputum has a low sensitivity and there is an urgent need for improved methods. We have compared microscopy of smears made directly from sputum with microscopy after liquefaction of sputum with household bleach (NaOCl) and concentration of bacteria by centrifugation. In 3 studies performed in Ethiopia and India, the use of the NaOCl method increased the number of samples positive for acid-fast bacilli by more than 100%. The technique is appropriate for developing countries and its application would increase the efficiency of TB control programmes. As a potent disinfectant, NaOCl also has the advantage of lowering the risk of laboratory infection.

(+/-)-CP-96,345, an NK1 receptor antagonist, has local anaesthetic-like effects in a mammalian sciatic nerve preparation

The effect of the non-peptide NK1 receptor antagonist (+/-)-CP-96,345 was investigated on the compound action potential (cAP) recorded in the isolated guinea-pig nerve, and compared to the effects of the local anaesthetic lidocaine and the L-type Ca2+ channel antagonist diltiazem. (+/-)-CP-96,345, as well as lidocaine and diltiazem, produced a concentration dependent reduction of the cAP amplitude. All three drugs showed frequency dependent block. The block of the cAP by lidocaine was fully reversible at all concentrations tested, while the block by (+/-)-CP-96,345 and diltiazem were only partly reversible at higher concentrations. The present findings indicate that (+/-)-CP-96,345 exerts a local anaesthetic-like effect on nerve conduction.

Production of large amounts of recombinant interleukins by cDNA transfected mouse myeloma cells cultured in dialysis tubing

Studies of interleukin function often require large quantities of these highly expensive substances. The available interleukins are generally recombinant proteins produced in bacteria or yeast and, less commonly, interleukins produced by mammalian cells, which provide appropriate glycosylation and other post-translational modifications. Due to differences in biosynthesis, difficulties in production and purification the quality of the interleukin preparations may vary. We have taken advantage of the recently developed constitutively interleukin-secreting mouse myeloma cell lines and the dialysis tubing culture technique, which permit cells to be grown at high densities, in order to establish a method for the production of large amounts of recombinant murine IL-2 and IL-4. We show that these interleukins can be produced at low cost and in concentrations 20-30-fold higher than in conventional culture flasks. A single dialysis tubing culture will produce more than 10(6) U of interleukin which may be compared with the available commercial preparations containing between 10- and a 100-fold less per vial. The IL-2 and IL-4 produced in this manner are biologically active molecules as demonstrated by the strong proliferative response of clonal T cells and the isotype-switching effect in LPS-stimulated splenic B cell cultures. The dialysis tubing culture technique is a simple and highly cost-effective means of generating large quantities of biologically active interleukins and is especially suitable for research laboratories interested in functional studies of these proteins.

Systemic or intracerebroventricular injection of NMDA receptor antagonists attenuates the antinociceptive activity of intrathecally administered NMDA receptor antagonists

We have previously reported that the response latency in the mouse hot-plate test is affected differently by spinal intrathecal (i.t.) injection of competitive and non-competitive N-methyl-D-aspartate (NMDA) receptor antagonists, in that only the former produces an antinociceptive effect. Since the lipophilic non-competitive antagonists will redistribute rapidly from the spinal injection site, it is conceivable that they reach sites where they counteract the spinal antinociceptive effect. In the present study, we have tested this hypothesis by comparing the antinociceptive effect of the competitive NMDA receptor antagonist CGS 19755 and the non-competitive NMDA receptor antagonist MK-801 after i.t., intraperitoneal (i.p.) and intracerebroventricular (i.c.v.) administration as well as after combinations thereof. CGS 19755 injected i.p. or i.c.v. and MK-801 injected i.p. or i.t. attenuated the antinociceptive effect of i.t. injected CGS 19755. Both i.p. and i.c.v. administration of either CGS 19755 or MK-801 dose-dependently impaired motor function without producing antinociceptive effects. Thus, the effect of CGS 19755 and MK-801 on the motor system was found to be separate from their antinociceptive effect. In a separate experiment, changes in hind-paw skin temperature were excluded as a possible confounding factor. These findings demonstrate that supraspinal systems can limit the spinal antinociceptive effect of NMDA receptor antagonists.

Antinociceptive actions of different classes of excitatory amino acid receptor antagonists in mice

Intrathecal (i.t.) injection of the competitive and selective N-methyl-D-aspartate (NMDA) receptor antagonists DL-2-amino-5-phosphonopentanoic acid (AP5), D-2-amino-7-phosphonoheptanoic acid (AP7), beta-D-aspartylaminomethyl phosphonic acid (Asp-AMP), 3-((+/-)-2-carboxypiperazin-4-yl)-propyl-1-phosphonic acid (CPP) and gamma-D-glutamylaminomethyl phosphonic acid (Glu-AMP) produced dose-dependent and reversible analgesic effects in the mouse hot-plate and formalin tests of nociception. They were slightly more potent in the formalin test but had no or negligible effects in the tail-flick test. The non-selective or non-NMDA receptor antagonists 6-cyano-7-nitro-quinoxalinedione (CNQX), 6,7-dinitro-quinoxalinedione (DNQX), gamma-D-glutamylglycine (gamma DGG), gamma-glutamylaminomethyl sulphonic acid (GAMS), kynurenic acid, cis-2,3-piperidine dicarboxylic acid (cis-PDA; partial agonist) and p-bromobenzoyl piperazine dicarboxylic acid (pBB-PzDA) had the same efficacy in the mouse hot-plate, tail-flick and formalin tests (gamma DGG and pBB-PzDA were not tested in the formalin test). This heterogeneous group of antagonists was somewhat more potent in the tail-flick test and slightly less potent in the formalin test than in the hot-plate test. Of the two glycine site antagonists tested, 7-chlorokynurenic acid (7-Cl-Kyn) and (+/-)-3-amino-1-hydroxy-2-pyrrolidone (HA-966), the effect of the latter was compatible with selective action at the NMDA receptor complex while the action of the former was comparable to those of non-selective excitatory amino acid (EAA) receptor antagonists.(ABSTRACT TRUNCATED AT 250 WORDS)

The adjuvant action of cholera toxin is associated with an increased intestinal permeability for luminal antigens

This study addresses the question of whether cholera toxin (CT) increases gut permeability for molecules greater than 3000 Da and whether such an effect is associated with an adjuvant function by CT on the gut immune response. We found that CT after oral administration gives rise to strikingly increased gut permeability for Dextran (Mw 3000) concomitantly with a strong enhancing effect on the anti-keyhole limpet hemocyanin (KLH) specific immune response in the lamina propria after oral immunization with KLH plus Dextran and CT. In contrast, the B-subunit of the holotoxin, which lacks the adenylate cyclase/cAMP-activating property of CT, failed to increase gut permeability as well as local anti-KLH immune responses. These results might suggest a causal linkage between the ability of CT to increase gut permeability and its adjuvant property on gut mucosal immune responses. In addition this finding supports the notion that the adenylate cyclase/cAMP system plays a regulatory role in gut permeability and is important in enhancing mucosal immune responses. Based on previous studies and the present data we propose that the mechanism for CT's adjuvant function on mucosal immune responses is by affecting antigen-presenting cells, T and B cells in the gut to give a net enhancing effect on the stimulation of local immunity, and that the CT-induced increase in gut permeability might be part of the adjuvant mechanism by facilitating luminal antigens to access the gut mucosal immune system.

Radical proposal for the treatment of malignant astrocytoma

The traditional treatment for anaplastic astrocytoma (AAF) and glioblastoma multiforme (GBM) leads to local relapse. The recurring element is assumed to be previously radioresistant, reorganizing hypoxic cells that require up to three times the traditional photon irradiation dose for inactivation. We are proposing to coagulate the original lesion with high-dose precision brachytherapy, immediately followed by resection to save the patient from secondary effects of the necrotic region. The treatment then continues with adjuvant external beam radiation therapy to the local surrounding brain and concomitant chemotherapy. The approach inverts the traditional regimen. It has the virtue of being precise, avoiding secondary effects of the necrotic tumor, and satisfying accepted radiobiological principles.

Enucleation after plaque radiotherapy for posterior uveal melanoma. Histopathologic findings

A review of 1019 patients with posterior uveal melanomas, who were treated with episcleral plaque radiotherapy between April 1976 and December 1987, showed that 59 (6%) of these patients have thus far required enucleation of the affected eye. The most common clinical reasons for enucleation were tumor regrowth (51%) and neovascular glaucoma (31%). These irradiated melanomas were of mixed cell type in 40 cases (68%), spindle in 10 cases (17%), totally necrotic in 7 cases (12%), and epithelioid in 2 cases (3%). Some degree of tumor necrosis was seen in all cases. Overall, the median number of mitoses per 40 high-power fields in these irradiated tumors was 0. Most (64%) of the tumors had no identifiable mitosis in 40 high-power fields. A three-way simultaneous comparison of the following groups was made: irradiated eyes enucleated for tumor regrowth, irradiated eyes enucleated for neovascular glaucoma, and a matched group of nonirradiated posterior uveal melanomas. This comparison showed that the largest tumor dimension was significantly greater in the irradiated eyes enucleated for tumor regrowth than in the other two groups. Mitotic activity was significantly higher in the irradiated tumor regrowth and nonirradiated groups than in the irradiated neovascular group. There was no significant difference among the three groups in an analysis of height. The results suggested that mitotic activity may exist after plaque radiotherapy, especially when there is clinical evidence of tumor regrowth.

Reasons for enucleation after plaque radiotherapy for posterior uveal melanoma. Clinical findings

A review of 1019 patients with posterior uveal melanomas who were treated with episcleral plaque radiotherapy showed that 59 (6%) required enucleation of the affected eye. Seventeen of the enucleations were done within 1 year, 30 within 2 years, and 55 within 5 years. The enucleated eyes had been treated with a cobalt-60 plaque in 39 cases, a ruthenium-106 plaque in 13 cases, an iodine-125 plaque in four cases, and an iridium-192 plaque in three cases. The primary reasons for enucleation included tumor regrowth in 30 cases (51%), neovascular glaucoma in 18 (31%), patient request in five (8%), scleral melting in four (7%), painful bullous keratopathy in one (2%), and hemolytic glaucoma in one (2%). The time interval from plaque treatment to eventual enucleation averaged 29 months. Tumor regrowth requiring enucleation was detected clinically an average of 28 months after treatment. In these cases the average radiation dose to the tumor apex was 7700 cGy and to the tumor base 36,000 cGy. Uncontrollable neovascular glaucoma occurred an average of 38 months after plaque radiotherapy and, most commonly, after cobalt-60 plaques were used. Eyes with plaque-induced scleral melting eventually required enucleation after an average of 10 months. In all cases of scleral melting, the tumor was ciliochoroidal.

Episcleral plaque radiotherapy for retinoblastoma

The authors report their preliminary results of episcleral plaque radiotherapy (cobalt 60, iridium 192, ruthenium 106, and iodine 125 plaques) in 50 selected patients with retinoblastoma. There were 97 plaque applications to 51 affected eyes in these 50 patients. The plaque was used as primary treatment in 15 eyes and as secondary treatment after failure of external beam radiotherapy, photocoagulation, and/or cryotherapy in 36 eyes. Vitreous seeding of tumor cells was evident ophthalmoscopically in 49 of the 51 eyes, negating the possibility of ultimate success by further photocoagulation or cryotherapy. In 18 patients, the contralateral eye had been enucleated and the remaining eye was being considered for enucleation because all other treatment modalities had failed. In 2 of these 18 patients (11%), the remaining eye was salvaged with plaque radiotherapy and some vision was preserved. In 33 eyes with less advanced tumors, 31 had some degree of vitreous seeding by tumor cells. The eye has been retained in all 33 of these patients and useful vision preserved in most. On the basis of these preliminary observations, the authors conclude that plaque radiotherapy can be used successfully as a primary treatment for selected cases of unilateral or bilateral retinoblastoma or as a supplemental treatment after other treatment methods have failed. The current indications for plaque radiotherapy and its advantages over other therapeutic modalities are discussed.

Cellular basis of immunomodulation by cholera toxin in vitro with possible association to the adjuvant function in vivo

Cholera toxin (CT) is a potent oral immunogen that also acts as a strong mucosal adjuvant for immune responses to related as well as unrelated Ag. To elucidate the immunomodulating effects of CT at the cellular level we have examined interactions of CT with APC and with B and T lymphocytes in vitro. CT markedly stimulated the production of IL-1 from APC (mouse peritoneal macrophages or macrophage cell line P388D1) but did not induce Ia-Ag and had marginal, if any, effect in potentiating Ia Ag expression stimulated by rIFN-gamma on these cells. CT had differential effect on T cell proliferation in vitro, usually strongly inhibitory but on Con A-stimulated spleen cells during prolonged (greater than or equal to 5 days) culture or when added on day 4 or later to these cultures up to a two- to three-fold enhancement of proliferation was seen. CT-induced inhibition of T cell proliferation was associated with decreased production of IL-2 and anergy to exogenously added IL-2 despite apparently normal expression of IL-2R. Similar to what was found with T cells LPS-stimulated spleen B cells demonstrated both inhibition and enhancement of proliferation in the presence of CT: in high concentrations (greater than or equal to 10(-8) M) and early in culture (day 3) CT had a strong inhibitory effect on the proliferation of B cells, whereas later (day 6) and/or at lower CT concentrations (10(-9) to 10(-11) M) the proliferation was increased up to 10-fold. The net effect of CT treatment on Ig-production by LPS-stimulated spleen B cells was seen as an enhanced level of IgA and IgG but not IgM in culture supernatants. The differential effects of CT on the cells of the immune system observed in vitro may, singly or in combination, explain the immunostimulatory function of CT.

Cellular basis of immunomodulation by cholera toxin in vitro with possible association to the adjuvant function in vivo

Cholera toxin (CT) is a potent oral immunogen that also acts as a strong mucosal adjuvant for immune responses to related as well as unrelated Ag. To elucidate the immunomodulating effects of CT at the cellular level we have examined interactions of CT with APC and with B and T lymphocytes in vitro. CT markedly stimulated the production of IL-1 from APC (mouse peritoneal macrophages or macrophage cell line P388D1) but did not induce Ia-Ag and had marginal, if any, effect in potentiating Ia Ag expression stimulated by rIFN-gamma on these cells. CT had differential effect on T cell proliferation in vitro, usually strongly inhibitory but on Con A-stimulated spleen cells during prolonged (greater than or equal to 5 days) culture or when added on day 4 or later to these cultures up to a two- to three-fold enhancement of proliferation was seen. CT-induced inhibition of T cell proliferation was associated with decreased production of IL-2 and anergy to exogenously added IL-2 despite apparently normal expression of IL-2R. Similar to what was found with T cells LPS-stimulated spleen B cells demonstrated both inhibition and enhancement of proliferation in the presence of CT: in high concentrations (greater than or equal to 10(-8) M) and early in culture (day 3) CT had a strong inhibitory effect on the proliferation of B cells, whereas later (day 6) and/or at lower CT concentrations (10(-9) to 10(-11) M) the proliferation was increased up to 10-fold. The net effect of CT treatment on Ig-production by LPS-stimulated spleen B cells was seen as an enhanced level of IgA and IgG but not IgM in culture supernatants. The differential effects of CT on the cells of the immune system observed in vitro may, singly or in combination, explain the immunostimulatory function of CT.