Conjugation in archaea: frequent occurrence of conjugative plasmids in Sulfolobus

We describe five novel conjugative plasmids (CPs) and two subfamilies, each comprising several closely related variants of CPs isolated from colony-cloned strains of the extremely thermophilic, heterotrophic archaeon Sulfolobus islandicus, which were obtained by plating of samples from Icelandic solfataras after liquid enrichment. They are related to each other and to the previously described CP pNOB8 from a Japanese Sulfolobus strain in that they share essential functions and limited similarity of genomes as demonstrated by DNA cross-hybridization and sequences. All these plasmids thus form a family of highly efficient self-spreading elements directly transferred from donor into recipient cells. Conjugation is initiated by pair formation, followed by selective transfer of the plasmids into the recipient and expression of transfer functions. Some of these CPs exclude superconjugation of the transcipients with closely related CPs. The novel CPs are stable upon conjugative transfer, but vary upon growth of transcipients. The stability of the CPs is higher in their original hosts or in related S. islandicus strains, than in Sulfolobus solfataricus strain PH1 as recipient. The deletion variant pING3 has lost the ability to transfer itself but is still subject to being transferred by the transfer apparatus of its complete relative, pING6. The dissection of genes and functions has been initiated by characterizing this incomplete variant.

Massive intrapericardial lipoma, a rare cause of breathlessness. Investigations and management

Massive intrapericardial lipoma is a rare cause of breathlessness. We describe a case, review the literature and discuss the presentation, investigation and management of this disorder.

Preparation and antibacterial evaluation of urinary balloon catheter

Prolonged use of indwelling urinary catheters in bed-ridden patients lead to a variety of Urinary Tract Infections (UTI). The present study deals with the surface treatment of ready-made urinary catheters so as to render them antibacterial in nature. Catheters were treated with varying percentages of iodine in conjunction with natural rubber latex, and their iodide ion release pattern and antibacterial behaviour were evaluated.

Single-specimen bile cytology: a prospective study of 80 patients with obstructive jaundice

PURPOSE

To determine the sensitivity, specificity, and charges associated with single-specimen bile cytologic study in patients with obstructive jaundice.

MATERIALS AND METHODS

Eighty consecutive patients with presumed malignant biliary strictures underwent percutaneous biliary drainage (PBD). Cytologic evaluation was performed on a single bile specimen from each patient collected at the time of the PBD. Final diagnoses were obtained from either percutaneous (n = 14) or surgical (n = 66) histologic specimens (gold standard). Both data sets were then compared to determine the sensitivity and specificity of bile cytology. The charges associated with bile cytodiagnosis were compared to those for other biopsy procedures utilized in the same setting.

RESULTS

Eighty bile specimens were obtained with a mean of 14 mL (range, 3-65 mL) per patient with 79 (99%) specimens adequate for cytologic processing. Eleven (13%) specimens were acellular. The overall sensitivity was 15% and specificity was 100%; these values were not dependent on the volume of the bile specimen (P > .10) or type of malignancy (P = .10). For bile cytodiagnosis, the mean charge was $160 and the successful biopsy rate (true-positive plus true-negative results/total number procedures) was 27%.

CONCLUSION

Single-specimen bile cytology has a low sensitivity; however, because of its convenience, simplicity, atraumatic nature, and low relative charge versus comparable procedures, it may be useful as an adjunct to PBD in patients with suspected malignant biliary disease.

PU.1 regulates both cytokine-dependent proliferation and differentiation of granulocyte/macrophage progenitors

PU.1 is a unique regulatory protein required for the generation of both the innate and the adaptive immune system. It functions exclusively in a cell-intrinsic manner to control the development of granulocytes, macrophages, and B and T lymphocytes. We demonstrate that mutation of the PU.1 gene causes a severe reduction in myeloid (granulocyte/macrophage) progenitors. PU.1 -/- myeloid progenitors can proliferate in vitro in response to the multilineage cytokines interleukin-3 (IL-3), IL-6 and stem cell factor but are unresponsive to the myeloid-specific cytokines granulocyte-macrophage colony-stimulating factor (GM-CSF), G-CSF and M-CSF. The failure of PU.1 -/- progenitors to respond to G-CSF is bypassed by transient signaling with IL-3. In the presence of IL-3 and G-CSF, PU.1 -/- progenitors can differentiate into granulocytic precursors containing myeloperoxidase-positive granules. Thus PU.1 is not essential for specification of granulocytic precursors, but is required for their further differentiation. The failure of PU.1 -/- progenitors to respond to M-CSF is due to lack of c-fms gene transcription. Transduction of c-fms into PU.1 -/- myeloid progenitors bypasses the block to M-CSF-dependent proliferation but does not induce detectable macrophage differentiation. Therefore, PU. 1 appears to be essential for specification of monocytic precursors. Importantly, retroviral transduction of PU.1 into mutant progenitors restores responsiveness to myeloid-specific cytokines and development of mature granulocytes and macrophages. Thus PU.1 controls myelopoiesis by regulating both proliferation and differentiation pathways.

Cardiac arrhythmias in aluminium phosphide poisoning studied by on continuous holter and cardioscopic monitoring

Variable incidences of cardiac arrhythmias (based on isolated 12 lead ECG records) have been reported in patients of aluminium phosphide (ALP) poisoning. We did continuous holter and cardioscopic monitoring in ICU in 30 patients of acute ALP poisoning. Supraventricular and ventricular ectopics were recorded in each and every patient. Life threatening ventricular tachycardia was recorded in 40% cases and ventricular fibrillation in 23.3% cases. Supraventricular tachycardia and atrial flutter/fibrillation occurred in 46.7% and 20% patients, respectively. ST-T changes simulating myocardial ischaemia were also present in all patients (S-T depression in 90%, S-T elevation in 10%). One-third of the patients developed variable degrees of heart block, IV amiodarone/xylocard could revert dangerous ventricular arrhythmias to sinus rhythm in 4 cases. Toxic myocarditis produced by phosphine seems to be responsible for the development of these arrhythmias.

Effect of adenotonsillectomy on arterial blood gases and acid-base balance

Adenotonsillitis is quite common in children in India and untreated cases may land up with serious cardiopulmonary complications which promoted us to study arterial blood gases and acid-base balance in these patients. The study was conducted in 30 children with chronic adenotonsillitis and 30 age and sex matched controls. Arterialized capillary blood samples were taken before and 1 month after surgery while the subject was sleeping. Relative hypoxemia, rise in pCO2 and increased bicarbonates was observed in the study group, whereas change in pH was insignificant. The study showed that ventilatory impairment associated with adenotonsillar hypertrophy which manifests as hypoxia, hypercarbia and raised bicarbonate levels was reversed after adenotonsillectomy.

Profile of young acute myocardial infarction in Harayana

Profile of acute myocardial infarction (AMI) in young patients (below 40 years) was studied in a rural/semi-urban population. Out of the total 338 patients who were admitted to ICCU over a period of one year, 65 (19.2%) were aged 40 years or below (Range 14-40 years). Male:female ratio was 20:1. Majority of these young patients were thinly built, engaged in heavy physical work and belonged to lower socio-economic group. Smoking was the most common risk factor (87%); other risk factors were few. Majority of these young patients ignored chest pain and reported late to the hospital. However, despite this, incidence of complications/mortality was less in comparison to their older counterparts. The overall mortality was only 6% as compared to 21% in older age group. The study focuses our attention to the rising incidence of AMI in young individuals even in populations least prone to ischaemic heart disease. Smoking was the only modifiable risk factor which needs to be curbed with full force.

Functional magnetic stimulation for restoring cough in patients with tetraplegia

OBJECTIVE

To evaluate the usefulness of functional magnetic stimulation (FMS) as a noninvasive method for assisting cough in patients with tetraplegia.

DESIGN

A prospective before-after trial.

SETTING

The functional magnetic stimulation laboratory of a spinal cord injury (SCI) service.

PARTICIPANTS

Thirteen male SCI patients, with injury levels between C4 and C7.

INTERVENTION

A commercially available magnetic stimulator with a round magnetic coil (MC) was used. Expiratory muscle activation was achieved by placing the MC along the lower thoracic spine.

MAIN OUTCOME MEASURE

The planned major outcome measures were the maximal expired pressure (MEP), expiratory reserve volume (ERV), and forced expiratory flow rate (FEF) by FMS compared with voluntary maximal efforts. Another outcome was the optimal MC placement and stimulation intensity that would result in highest expired pressure.

RESULTS

The mean (+/-SEM) MEP, ERV, and FEF generated by FMS were 66.40 +/- 6.69 cmH2O, .77 +/- .14 L, and 5.28 +/- .42 L/sec, respectively. They were 118%, 169%, and 110% of voluntary maximum efforts. MC placement at the T10 to T11 spinous process and stimulation intensity at 80% produced the highest MEP and FEF.

CONCLUSION

FMS of the expiratory muscles produced significant expired pressures, volumes, and flow rates when compared with voluntary maximum efforts; therefore, FMS can be used as an effective method to restore cough in tetraplegic patients.

Cardiff repair of incisional hernia: a university hospital experience

OBJECTIVE

To analyse our results of the "Cardiff' (far and near) repair in incisional hernias.

DESIGN

Prospective study.

SETTING

University hospital, Varanasi, India.

SUBJECTS

50 patients who presented with incisional hernias between January 1990 and December 1994.

INTERVENTION

Interrupted far-and-near sutures inserted after excision of the sac. The contents were pushed into the abdomen and the peritoneum sutured with non-absorbable polypropylene (prolene).

MAIN OUTCOME MEASURES

Early and late morbidity. Six patients developed postoperative complications (wound infection, n=3; flap necrosis, n=2; and wound sinus, n=1). No patient has been lost to follow up and there have been no signs of recurrence after a mean follow up of 52 months.

CONCLUSION

The meticulous application of this simple surgical technique has low morbidity and is cost effective. We recommend it for small and medium size defects.

Electron tomography of ice-embedded prokaryotic cells

Whole cells of archaea were embedded in vitreous ice by plunge freezing and investigated by automated energy-filtered electron tomography at 120 kV. The embedded cells were between 300 and 750 nm thick, and their structures were reconstructed to a resolution of 20-40 nm from tilt series comprising 50-140 images. The dose was kept within tolerable limits. A resolution of 20 nm allowed visualization of the individual stalks of the S-layer of Pyrobaculum aerophilum cells, which had undergone partial lysis, in three dimensions. The attainable resolution for low-dose electron tomography under different experimental conditions was theoretically investigated in terms of the specimen thickness. To obtain 2-nm resolution at 120 kV (300 kV), the specimen must not be thicker than 100 nm (150 nm). For a resolution of 10 nm, the maximum thickness is 450 nm (700 nm). An accelerating voltage of 300 kV is advantageous, mainly for specimens thicker than 100 nm. Experimental investigations so far have resulted in a resolution that is worse by a factor of 2-5 as compared to theory.

Destabilization of Oil-in-Water Emulsions Formed Using Highly Hydrolyzed Whey Proteins

Oil-in-water emulsions (4 wt % soy oil) were prepared with 0.5-5 wt % whey protein hydrolysate (WPH) (27% degree of hydrolysis), in a two-stage homogenizer using various first-stage pressures of 10.3, 20.6, and 34.3 MPa and a constant second-stage pressure of 3.4 MPa. Destabilization studies on the emulsions were carried out for up to 24 h, using both laser light scattering and confocal laser microscopy. It was found that emulsions formed with <2% WPH showed oiling off and coalescence at all homogenization pressures. Emulsions formed with 2, 3, and 4% WPH showed coalescence and creaming only, while slight flocculation but no creaming occurred in emulsions formed with 5% WPH. Furthermore, the apparent rate of coalescence increased with homogenization pressure but decreased with WPH concentration. In contrast, the surface concentration of WPH increased with the WPH concentration in the emulsions but decreased with homogenization pressure. Analysis of WPH by high-performance liquid chromatography showed an increase in the concentration of high molecular weight peptides at the droplet surface compared to the WPH solution. This was considered very important for the stability of these oil-in-water emulsions.

Traumatic transverse fracture of sacrum with cauda equina injury--a case report and review of literature

Fractures of the sacrum are rare and generally associated with fracture of the pelvis. Transverse fractures of the sacrum are even less frequent and neurological deficit may accompany these fractures. A case of transverse fracture sacrum with cauda equina injury treated by sacral laminectomy and root decompression, is reported.

Endoscopic ultrasound for peripancreatic masses

BACKGROUND

Pancreatic neoplasms can be difficult to diagnose and stage preoperatively. Accurate staging allows the surgeon to select which patients can benefit from resection versus palliative therapy. Endoscopic ultrasound (EUS) with endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) is a diagnostic modality that provides visualization of peripancreatic tumors and their relationship to the surrounding structures as well as enabling cytologic diagnosis of the tumor and adjacent lymphadenopathy.

METHODS

To define the role of this technique, a retrospective study was performed on 20 patients in the past year with peripancreatic tumors.

RESULTS

Twelve men and 8 women ranging in age from 28 to 84 years (mean 67) were included in the study. Each patient underwent computed tomography followed by EUS-FNA, and the results were compared with operative findings or clinical course. The EUS-FNA findings included 10 pancreatic ductal carcinomas (50%), 5 pancreatitis (25%), 2 spindle cell neoplasms (10%), 1 cholangiocarcinoma (5%), 1 cystadenoma (5%), and 1 metastatic breast carcinoma (5%). Overall, EUS-FNA led to a significant change in the management of 12 patients (60%) through either diagnosing benign pathology, upstaging of the carcinoma, or determination that the peripancreatic mass represented a metastatic lesion. Five patients underwent resection of their peripancreatic tumors, and 3 patients had palliative procedures. Operative findings corresponded with EUS-FNA in all 8 patients. The 5 patients diagnosed with pancreatitis continued to be followed up for the possibility of a false negative FNA, but to date none have developed malignancy.

CONCLUSIONS

EUS-FNA is a useful tool for the imaging and staging of peripancreatic tumors and will aid in the proper preoperative selection of patients who will benefit from resectional therapy.

Chronic typhoid carriage and carcinoma of the gallbladder

Chronic microbial infections and/or their carrier state have been reported to be associated with particular cancers. Since typhoid infections and carcinoma of the gallbladder (the site where salmonella usually persists) are endemic in northern India, it was considered important to explore the relationship between the two. In the present study, a total of 1001 bile specimens collected from cases of carcinoma of the gallbladder (28), cholelithiasis (56) and individuals without biliary pathology (17) were subjected to aerobic cultures that had been enriched for salmonella. Salmonella typhi and S. paratyphi-A could be detected in a significantly higher (P < 0.05) number in patients with carcinoma of the gallbladder as compared with cholelithiasis and control groups. The existence of such an association indicates that detection and eradication of typhoid carriers may lead to a decrease in the incidence of carcinoma of the gallbladder along with typhoid fever.

Optimal dose of nicardipine for maintenance of hemodynamic stability after tracheal intubation and skin incision

To determine the optimal dose of nicardipine (N) for maintenance of hemodynamic stability during the postinduction period, we designed a randomized, double-blind, placebo-controlled, dose-ranging study using four different doses of N administered after a standardized anesthetic induction sequence. A total of 106 patients were assigned to one of the following treatment groups: saline (control), N 0.5 mg (N0.5), N 1 mg (N1), N 2 mg (N2), and N 4 mg (N4). The study medication was administered intravenously (I.V.) in 2.5 mL of saline over 30 s 2 min before laryngoscopy. Mean arterial pressure (MAP) and heart rate (HR) were recorded at 1-min intervals for 15 min after tracheal intubation and for 5 min after skin incision. After intubation, the peak MAP values differed from the preinduction baseline MAP values by 21% +/- 20%, 9% +/- 12%, 1% +/- 13%, -10% +/- 12%, and -15% +/- 13% (mean +/- SD) in the control, N0.5, N1, N2, and N4 groups, respectively. However, the percent change in the pre- to postintubation MAP values (37% to 47%) was similar in all five groups. The highest postintubation HR values were recorded in the N4 group (P < 0.05 versus the other groups). However, the increases in MAP values after skin incision were the least in the N4 group. In conclusion, N1 I.V., administered 2 min before laryngoscopy provides optimal control of arterial blood pressure during the postinduction period.

IMPLICATIONS

Acute increases in blood pressure during anesthesia are undesirable in patients with preexisting cardiovascular diseases. This double-blind study found that the calcium-channel blocker, nicardipine, 1 mg intravenously 2 min before tracheal intubation maintained hemodynamic stability during the intraoperative period.