Non union of stress fracture of the tibia and fibula with osteoarthritis of the knee joint

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Phase shift magnitude and direction determine whether Siberian hamsters reentrain to the photocycle

Body temperature (Tb) or activity rhythms were monitored in male Siberian hamsters (Phodopus sungorus) housed in an LD cycle of 16 h light/day from birth. At 3 months of age, rhythms were monitored for 14 days, and then the LD cycle was phase delayed by 1, 3, or 5 h or phase advanced by 5 h in four separate groups of animals. Phase delays were accomplished via a 1- or 3-h extension of the light phase or via a 5-h extension of the dark phase. The phase advance was accomplished via a 5-h shortening of the light phase. After 2 to 3 weeks, hamsters that were phase delayed by 1 or 3 h were then phase advanced by 1 or 3 h, respectively, via a shortening of the light phase. All of the animals reentrained to phase delays of 1 or 3 h and to a 1-h phase advance; 79% reentrained to a 3-h phase advance. In contrast, only 13% of the animals reentrained to the 5-h phase advance, 13% became arrhythmic, and 74% free ran for several weeks. After the 5-h phase delay, however, reentrainment was observed in 50% of the animals although half of them required more than 21 days to reentrain. The response to a phase shift could not be predicted by any parameter of circadian rhythm organization assessed prior to the phase shift. These data demonstrate that a phase shift of the LD cycle can permanently disrupt entrainment mechanisms and eliminate circadian Tb and activity rhythms. Magnitude and direction of a phase shift of the LD cycle determine not only the rate but also the probability of reentrainment. Furthermore, the phase of the LD cycle at which the phase shift is made has a marked effect on the proportion of animals that reentrain. Light exposure during mid-subjective night combined with daily light exposure during the active phase may explain these phenomena.

Clinical safety and efficacy of first indigenous recombinant hepatitis B vaccine

A pilot study was conducted to assess the clinical safety and immunogenicity of an indigenously developed recombinant hepatitis B vaccine (Shanvac B) in 18 healthy adults. 20 microg of vaccine was administered at 0, 1 and 2 months. Protective anti HBs titres developed in 22%, 77% and 100% one month after 1st, 2nd and 3rd dose of vaccination, respectively. The geometric mean titre after the 3rd dose was 1015.29 mIu/ml. The vaccine was well tolerated with minor local and systemic side effects in 28% and 22%, respectively. The indigenously developed recombinant hepatitis B vaccine is safe, well tolerated and highly immunogenic.

Oral rehabilitation in dentinogenesis imperfecta with overdentures: case report

A seventeen-year-old girl demonstrating severely worn permanent dentition and multiple retained root stumps with dentinogenesis imperfecta is presented. Overdentures were made to preserve bone height, re-establish the lost vertical dimension of occlusion, to provide acceptable esthetics, and to establish an efficient masticatory system.

Variation in astigmatism following the single-step, self-sealing clear corneal section for phacoemulsification

PURPOSE

A single-step, self-sealing, 3.2 mm clear corneal section is described and the incidence and variation of surgically induced astigmatism following phacoemulsification over a period of 3 months is determined.

METHODS

Twenty-two patients who underwent uncomplicated 3.2 mm clear corneal phacoemulsification with foldable Allergan silicone intraocular lens implantation were autorefracted pre-operatively and on day 1, week 1, week 6 and at 3 months. The variation in induced astigmatism was analysed using the subtraction method and vector analysis. The change in direction of the cylindrical axis was examined.

RESULTS

The induced astigmatism represented by the total vector on day 1 was 1.17 D and vector decomposition ratio, ATR:WTR (against-the-rule:with-the-rule), was 21.05:78.95. The total vector increased by 0.5 D in the first week and then stabilised. Vector decomposition showed an against-the-rule astigmatic drift so that by 3 months the ATR:WTR was 40.49:59.91. There was a tendency of the axis of the negative cylinder to swing towards the corneal section meridian on day 1 and to oscillate around that meridian at week 1 and week 6. By 3 months the direction reverted to that pre-operatively, in most cases.

CONCLUSIONS

The single-step, self-sealing clear corneal section is mechanically stable and, though there is some variability in the measured astigmatism, there is an acceptable functional result throughout the post-operative period.

Capsulorhexis phymosis following uncomplicated phacoemulsification surgery

PURPOSE

The aim of the study was to assess and compare the degree of capsulorhexis phymosis following uncomplicated phacoemulsification cataract surgery in polymethylmethacrylate (PMMA) and silicone lens implants.

METHOD

Sixty-four patients were evaluated 1 day, 6 weeks and 6 months following phacoemulsification cataract extraction. The anterior capsular diameters were measured with the illuminated beam of the slit lamp at 45 degrees and 135 degrees and the surface area of the opening calculated. We have measured and compared the change in the capsulorhexis size for both lens types and assessed its statistical significance with a paired Student's t-test.

RESULTS

A statistically significant contraction of the capsulorhexis was noted in all patients within the first 6 weeks (p < 0.001). Capsular contraction continued between 6 weeks and 6 months post-operatively but to a lesser extent (p < 0.05). The difference in the degree of phymosis between the first period (1 day to 6 weeks) and the second (6 weeks to 6 months) was statistically highly significant for all patients (p < 0.001). The capsular areas for the silicone lens implants were significantly smaller than for the PMMA implants at 6 weeks and 6 months. None of our patients had a clinically significant capsular contracture requiring Nd:YAG laser capsulotomy.

CONCLUSION

Anterior capsular contraction is commonly observed following capsulorhexis in phacoemulsification surgery. This study demonstrates that the maximum rate of contraction occurs in the first 6 weeks following surgery and is more pronounced with silicone lens implants.

Papillary carcinoma of the male breast diagnosed by fine needle aspiration cytology

A 57-year old male presented with a left breast mass, the fine needle aspiration cytology revealed characteristic cytomorphological features of papillary carcinoma of the breast. In our knowledge this is a second reported case of papillary carcinoma of male breast diagnosed by the fine needle aspiration cytology. Cytomorphological and histopathological features of the case are described with literature on cytological features of papillary carcinoma and carcinoma of male breast is briefly reviewed.

Inhibition of allergic encephalomyelitis in marmosets by vaccination with recombinant vaccinia virus encoding for myelin basic protein

A primary demyelinating form of experimental allergic encephalomyelitis (EAE) resembling human multiple sclerosis (MS) occurs in Callithrix jacchus marmosets following immunization with human white matter. Participation of a T-cell immune response against myelin basic protein (MBP) in this disease model is supported by observations of increased reactivity against MBP in PBMC and of adoptive transfer of an inflammatory form of EAE by MBP-reactive T-cells. To evaluate the effects of ectopic presentation of MBP on marmoset EAE, animals were vaccinated prior to induction of EAE by subcutaneous injection of attenuated strains of vaccinia virus genetically engineered to contain either the entire coding sequence for human MBP (vT15) or the equine herpes virus glycoprotein gH gene (vAbT249). Vaccination with vT15 was followed by transient cytoplasmic and surface membrane expression of MBP in circulating PBMC (15-45 days). The onset of clinical EAE after immunization (pi) was markedly delayed in vT15-vaccinated animals (37-97 days pi, n = 4) compared to vAbT249-vaccinated controls (14-18 days pi, n = 3). Proliferative responses against MBP but not against vaccinia antigens or phytohemagglutinin were suppressed in protected animals. Thus, development of attenuated live viruses carrying genes for myelin antigens could be useful for induction of immunologic tolerance and for modulation of autoimmune demyelination.

Doxycycline revisited

Although several new antibiotics have recently become available, in several clinical instances conventional antibiotics may be equally efficacious at a considerably lower cost. In today's era of cost containment, it is particularly relevant to revisit older, inexpensive antibiotics to reexplore their role in the face of the emergence of resistant microorganisms and competition from newer agents. Doxycycline is one such antibiotic. It is an inexpensive, broad-spectrum antimicrobial agent that remains the drug of first choice for several infections. In addition, it can be used for a variety of other indications. Adverse effects are infrequent and relatively minor. While interactions occur with several medications, none of these interactions has significant adverse consequences.

Foot infections in patients with diabetes

The combination of sensory neuropathy, ischemia and direct adverse effect on host defense mechanisms makes patients with diabetes vulnerable to foot infections. A high degree of clinical suspicion and vigilance is necessary for early diagnosis of soft tissue infections and their differentiation from noninfected ulcers. Diagnosis and assessment depend primarily on clinical history and physical examination, although radiographs, scans and laboratory tests may also provide useful clinical data. The ability to detect bone in the base of an ulcer with a blunt sterile probe may be particularly useful in assisting the recognition of osteomyelitis. Most non-limb-threatening infections are caused by Gram-positive cocci, but more serious infections are often polymicrobial. Effective treatment is based on a comprehensive strategy of wound care, avoidance of weight bearing, optimal metabolic control, appropriate antibiotic use and, possibly, surgical intervention.

Anaesthetic management of patients undergoing surgery for tachyarrhythmias. Initial experience with 16 patients

Sixteen patients suffering from various cardiac arrhythmias were treated surgically. Intraoperative computerised electrophysiologic mapping was used in 14. Thirteen patients were suffering from Wolff-Parkinson-White syndrome. They underwent surgical division or cryoablation of accessory pathways. Two patients who had rheumatic mitral stenosis with left atrial clot underwent "Maze III" procedure with open mitral commissurotomy and clot removal. One patient with paroxysmal refractory ventricular tachycardia and a left ventricular aneurysm had an aneurysmectomy with subendocardial resection of the arrhythmic focus. All antiarrhythmic medications were discontinued preoperatively. Morphine was the principal anaesthetic agent, supplemented with halothane. Muscle relaxation was provided with pancuronium bromide. The various problems encountered included hypotension and arrhythmia during placement of epicardial band array for mapping (4 patients), ventricular tachycardia during internal jugular vein cannulation (1 patient) and continuance of delta wave after cryoablation in 2 patients. Halothane may have interfered with electrophysiologic mapping and accurate localization of accessory pathway leading to persistence of delta wave. The choice of anaesthetic agents should be guided by the electrophysiologic effects and potential influence of these agents on the accessory pathways.

Biased expression of T cell receptor genes characterizes activated T cells in multiple sclerosis cerebrospinal fluid

To better characterize the inflammatory response that occurs in the nervous system in multiple sclerosis (MS), T-cell receptor (TCR) gene expression was quantified from cerebrospinal fluid (CSF) cells of 21 patients with active disease. Unstimulated CSF cells expressed each of 22 different TCR beta chain variable region (V beta) gene families in proportion to their expression in simultaneously sampled peripheral blood. When CSF cells from individuals with MS were expanded by in vitro culture in T-cell growth factor/interleukin 2 and 4-containing medium (TCGF/IL2/IL4), restricted numbers of V beta genes were expressed. In many subjects, expanded CSF cells expressed predominantly V beta 2. In contrast to CSF, expansion of corresponding peripheral blood mononuclear cells (PBMC) in TCGF/IL2/IL4 resulted in persistent expression of all V beta gene families. Within individuals, different V beta genes were overexpressed by PBMC compared with CSF cells. No effect of the HLA haplotype of the individual on CSF V beta gene expression was observed. Expanded CSF cells retained their capacity to respond to mitogen stimulation, but the proliferative response to myelin basic protein (MBP) was not enhanced. Finally, freshly obtained CSF cells stimulated directly with MBP also expressed a limited number of V beta genes, although these were generally different from patterns observed following stimulation with TCGF/IL2/IL4. Thus, restricted populations of T cells capable of responding to TCGF/IL2/IL4, presumably reflecting in vivo activated cells, are compartmentalized in the nervous system in MS.

An assessment of intraocular pressure during fractionated peribulbar anaesthesia

This study of 20 patients undergoing elective cataract surgery was performed to investigate the change in intraocular pressure that accompanies extraconal peribulbar anaesthesia. We have demonstrated that each injection during peribulbar anaesthesia causes a small rise in intraocular pressure. The routine use of conventional external ocular compression overcomes this pressure rise and safely provides a satisfactory and progressive reduction in intraocular pressure prior to surgery. Our findings suggest that the volumes of anaesthetic solutions used in fractional peribulbar anaesthesia, if used in conjunction with external compression devices, result in intraocular pressures acceptable for intraocular surgery.

The importance of computer-assisted semen analysis and sperm function testing in an IVF program

OBJECTIVE

To study the relationship of sperm motion characteristics, sperm morphology, and hypo-osmotic swelling test with fertilization rates in vitro.

DESIGN

Computer-assisted measures of fresh seminal and processed sperm preparations, sperm morphology, and hypo-osmotic swelling test results were assessed for predicting fertilization by step-wise regression analysis.

SETTINGS

In vitro fertilization laboratory, department of infertility management, university affiliated-hospital.

INTERVENTIONS

None.

PATIENTS

One hundred and two couples who underwent IVF were studied.

MAIN OUTCOME MEASURES

Computer-assisted sperm motion variables in semen and following semen processing in capacitating media; hypo-osmotic swelling of sperm tails before and after semen processing; morphology of sperm before and after processing; fertilization of oocytes as evidenced by presence of two pronuclei as the end point.

RESULTS

Various sperm motion parameters, hypo-osmotic swelling test results, and normal morphology of sperm were directly correlated to fertilization as judged by the Karl-Pearsons test. However, in step-wise regression analysis, normal morphology of sperm from seminal fraction exhibited 61% correlation with fertilization rates (P < .001). In step 2, normal morphology along with percent motility exhibited a 64% correlation with fertilization rates (P < .001). In step 3, normal morphology, percent motility, and linearity showed a 67% correlation with fertilization rates (P < .001). The hypo-osmotic swelling test did not predict fertilization rates (regression coefficient = 0.066, P = 0.474). In the processed sample preparations, normal sperm morphology showed a 72% correlation with fertilization rate (P < .001). In step 2, normal morphology along with curvilinear velocity exhibited a 77% correlation with fertilization rates (P < .001). In step 3, normal morphology, curvilinear velocity, and average path velocity showed a 79% correlation with fertilization rates (P < .001). The hypo-osmotic swelling test did not predict fertilization rates (regression coefficient = 0.076, P = 0.512).

CONCLUSIONS

Morphology of sperm and computer-assisted sperm motion variables, such as motility, linearity, curvilinear velocity, and average path velocity, may serve as prognostic indicators for fertilization potential of sperm. The hypo-osmotic swelling test may describe only physiological intactness, rather than the fertilization potential of sperm. The results suggest that objective analysis of sperm motion characteristics and precise sperm morphology may form a first, and obligatory, step for critical evaluation of patients before they start IVF treatment.

The use and misuse of new antibiotics. A perspective

Many new antimicrobial agents have become available recently. Several of the new antibiotics may offer an extended spectrum of activity or an improved toxic effect profile. However, they pose such problems as excessive cost and the emergence of drug-resistant organisms as a result of "selection pressure." The majority of common infections can be treated with conventional agents, either singly or in combination. A careful, bedside clinical evaluation, in conjunction with simple laboratory tests, often narrows down microbiologic possibilities and allows simpler antibiotic choices. This results in a cost-conscious approach of using conventional, inexpensive antibiotics in most situations, with new agents being reserved for judiciously selected indications. Such an approach will not only contain health care costs but will also help to preserve the microbiologic ecosystem.

In healthy primates, circulating autoreactive T cells mediate autoimmune disease

A T cell response against myelin basic protein (MBP) is thought to contribute to the central nervous system (CNS) inflammation that occurs in the human demyelinating disease multiple sclerosis. To test whether MBP-reactive T cells that are normally retrieved from the circulation are capable of inducing CNS disease, MBP-reactive T cell clones were isolated from the peripheral blood of healthy, unimmunized Callithrix jacchus (C. jacchus) marmosets. This primate species is characterized by a natural chimerism of bone marrow elements between siblings that should make possible adoptive transfer of MBP-reactive T cells. We report that MBP-reactive T cell clones efficiently and reproducibly transfer CNS inflammatory disease between members of C. jacchus chimeric sets. The demyelination that is characteristic of experimental allergic encephalomyelitis induced in C. jacchus by immunization against human white matter did not occur after adoptive transfer of the MBP-reactive clones. It was noteworthy that encephalitogenic T cell clones were diverse in terms of their recognition of different epitopes of MBP, distinguishing the response in C. jacchus from that in some inbred rodents in which restricted recognition of MBP occurs. These findings are the first direct evidence that natural populations of circulating T cells directed against a CNS antigen can mediate an inflammatory autoimmune disease.

Bilateral angle closure glaucoma and accelerated cataract formation in a patient with AIDS

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Apparent absorption of copper and zinc from composite vegetarian diets in young Indian men

In order to identify the factors affecting apparent absorption of copper and zinc in vegetarian subjects, percent absorption of copper and zinc was estimated during 6 metabolic experiments, each of 2 weeks duration, carried out on 6 healthy young men. They were observed at 3 levels of energy, i.e. 9.2, 10.5 and 12.1 MJ/day. Intakes of zinc were in the range of 20.6-27.1 mg/day and the observed values of apparent absorption (intake-fecal output) were 11.2-20.3%. In case of copper, intakes were 2.7-5.2 mg/day while the apparent absorption was to the tune of 10.6-21.7%. These values of absorption were lower than those of the non-vegetarian diets. Multiple regression analysis of 17 dietary factors suggested that hemicellulose, milk protein, niacin and cereal protein act as significant enhancers in zinc absorption while thiamine, phytate, oxalates, ascorbic acid and phosphorus acted as inhibitors. Copper absorption was enhanced by the dietary levels of riboflavine, cellulose, milk proteins, oxalates and zinc, while phosphorus, niacin, calcium and pulse protein inhibited the absorption of copper.

Colinear laser-induced fluorescence detector for capillary electrophoresis. Analysis of glutamic acid in brain dialysates

Experiments with capillary electrophoresis using a laser-induced fluorescence detector with a colinear optical arrangement demonstrated several important points. First, increasing the numerical aperture of the microscope objective that is used simultaneously for focusing the excitation laser light as well as collection of emitted fluorescence enhances the signal used for the measurement of the emitted fluorescence and at the same time decreases the noise of interfering light. Second, detection of fluorescein-labelled amphetamine was performed at high-picomolar (10(-10) M) levels. Third, the signal-to-noise ratio of 280 found at the above-mentioned picomolar concentrations indicates that the measurement of low-picomolar concentrations (10(-12) M) of this compound in biological samples should be possible. Fourth, narrow-bore capillaries (5-10 microm internal diameter) were used to detect the neurotransmitters glutamic acid and aspartic acid as their naphthalene-2,3-dicarboxaldehyde derivatives in brain dialysates obtained from a freely moving rat. A mathematical model was developed to explain the relationship between numerical aperture, working distance, magnification of the lens, noise due to laser scattering and signal due to fluorescence. The model correctly predicted the observed values of photomultiplier tube current due to both laser scattering and fluorescence. The potential of the application of capillary electrophoresis with laser-induced fluorescence detection in the neurosciences is discussed.

The T-cell response to myelin basic protein in familial multiple sclerosis: diversity of fine specificity, restricting elements, and T-cell receptor usage

Indirect evidence suggests that an autoimmune response to myelin basic protein (MBP) may be involved in the pathogenesis of multiple sclerosis (MS). In MS, several reports have suggested that restricted T-cell populations respond to MPB, as in inbred rodents with the MS disease model experimental allergic encephalomyelitis. In experimental allergic encephalomyelitis, the T-cell repertoire to MBP varies between strains, and in MS it is likely that the response to MBP is also best defined under conditions where genetic differences between subjects are controlled. In this report, the fine specificity of the T-cell response to MBP was assessed in three families, each with multiple individuals affected with MS. We found that (1) comparable frequencies of MBP-reactive T-cell lines were obtained from peripheral blood of MS patients and their healthy siblings. Human leukocyte antigen (HLA) identical sibling pairs discordant for MS had similar frequencies of MBP-reactive T-cell lines. (2) A broad spectrum of MBP epitopes was recognized by T-cell lines from all individuals studied. Within a family, the fine specificity of MBP recognition showed little or no overlap between individuals, even between HLA identical siblings. (3) Recognition of MBP epitopes occurred in the context of different HLA class II alleles. At least four DR alleles each served as restricting elements for recognition of P82-101 or the carboxy terminal region of MBP, two regions thought to be important in the human T-cell response to the molecule. No relationship between the use of a particular DR allele and a response to a particular region of MBP could be established.(ABSTRACT TRUNCATED AT 250 WORDS)

Hepatic trauma: experience of 110 cases

A total of 110 patients with hepatic injuries was treated at a major urban trauma centre between June 1988 and December 1991. The mechanism of injury was blunt trauma in 86 patients (78 per cent). Non-operative treatment was given in six patients (5 per cent). Simple hepatorrhaphy, use of topical haemostatic agents or peritoneal drainage alone were performed in 79 (72 per cent) cases. Extensive hepatorrhaphy, hepatotomy with selective vascular ligation, resection and débridement or resection, perihepatic packing and major vascular ligation were undertaken, often in combination, in 25 (23 per cent) cases. Percutaneous arterial embolization was carried out in one case. The mortality rate was 18 per cent. The most frequent postoperative complications related to hepatic injury were intra-abdominal abscess (7 per cent) and coagulopathy (5 per cent); prolonged biliary leak (3 per cent), late haemorrhage (2 per cent) and hepatic necrosis (1 per cent) were also observed.

The human T-cell receptor beta-chain repertoire: longitudinal fluctuations and assessment in MHC matched populations

The influence of the environment and of the major histocompatibility complex (MHC) in shaping the human T-cell receptor beta-chain variable region (TCRBV) repertoire has not been systematically studied. Here, expression of TCRBV gene families was estimated by a sensitive polymerase chain reaction (PCR)-based method. Serial studies of peripheral blood, performed at 2-week intervals over a 3-month period, revealed that fluctuation in the expression of many TCRBV genes occurred in healthy individuals and in the absence of clinically evident infections. Fluctuation of TCRBV4, TCRBV5.2, TCRBV9, and TCRBV13.1 genes were present in all subjects. Additional TCRBV genes fluctuated in some but not in other individuals. Comparison of the TCRBV repertoire between these unrelated individuals indicated differences in the mean expression of TCRBV5.1, TCRBV9, TCRBV11, TCRBV15, TCRBV17, and TCRBV20 genes. For any TCRBV gene, intersubject differences were generally of a magnitude of twofold or less. Larger differences characterized the TCRBV repertoire of CD4 compared to CD8 cells. Some differences, for example over-representation of TCRBV2 and TCRBV5.1 on CD4, and TCRBV10, TCRBV14, and TCRBV16 on CD8 cells, were present in most subjects. Individuals homozygous for DR2- or DR3-bearing extended MHC haplotypes displayed similar individual variability of TCRBV expression. These data indicate that the circulating TCRBV repertoire in humans is both dynamic and diverse. Both environment and MHC effects contribute to the diversity of TCRBV expression.

Haplotypic origin of beta-chain genes expressed by human T-cell clones

A contribution of allelic variation of T-cell receptor (Tcr) genes to the immune response has not been studied. Here we report that the presence of insertion-deletion-related polymorphisms (IDRP) of the Tcr beta chain (Tcrb) can be utilized to distinguish the parental origin of the gene complex that undergoes rearrangement in individual T-cell clones. Phytohemagglutinin stimulated clones from an individual heterozygous for an IDRP located between the variable (V) and diversity (D)-joining (J) region genes were studied for the presence of V to DJ rearrangements in each of the two parental chromosomes. Results indicate that single rearrangements were present in the majority of clones, in contrast to the double rearrangements of D to J genes that were generally present. In this individual, V to DJ rearrangement also occurred with different frequencies on each of the two germline genes. IDRP clonotyping of the Tcrb complex should prove generally applicable to the study of the influence of allelic variation of Tcrb genes in selection of the expressed T-cell repertoire.

A predictive risk index for nosocomial pneumonia in the intensive care unit

PURPOSE

To develop a scoring system for stratifying patients in intensive care units (ICUs) by risk of developing nosocomial pneumonia (NP) and to identify the time period associated with the highest risk.

PATIENTS AND METHODS

Two hundred and three patients 18 years of age or older and residing in the ICU for 72 hours or more were followed until development of NP or death or for 48 hours after discharge from the ICU. After the identification of independent risk factors for NP, a scoring system was developed to arrive at a predictive risk index for NP.

RESULTS

Twenty-six (12.8%) patients developed NP. The presence of a nasogastric (NG) tube [odds ratio (OR) = 6.48, 95% confidence intervals (CI) = 2.11 to 19.82], upper abdominal/thoracic surgery (OR = 4.34, 95% CI = 1.43 to 13.14), and bronchoscopy (OR = 2.95, 95% CI = 1.02 to 8.52), most commonly performed for respiratory toilet, were identified as independent risk factors on multivariate analysis. The risks associated with endotracheal intubation and altered consciousness, although not independently significant, were highest when these factors were present for 1 to 4 days after the 72 hours required for study entry (endotracheal intubation, OR = 2.2 to 2.5; altered consciousness, OR = 1.4 to 2.0). The risk then declined; ORs of less than 1 were observed at 7 days. The risk associated with the NG tube was highest during the first 6 days (OR = 6.0 to 19.5). Although a subsequent decrease in risk was observed, the OR was still greater than 2 at 7 days. To obtain a predictive risk index for NP, a scoring system was developed using a multivariate model. This system has a sensitivity of 85% and a specificity of 66% in predicting NP in this ICU population.

CONCLUSION

ICU patients can be stratified into high- and low-risk groups for NP using a bedside scoring system. Endotracheal intubation, altered mental status, and NG tube are associated with the highest risk of NP during the first 1 to 6 days of their presence after 72 hours of stay in the ICU. After this time period, the risk associated with these factors decreases. Bronchoscopy may be an independent risk factor for NP that has not been previously recognized. This procedure, often done in the ICU for respiratory toilet, may be an avoidable risk in this group of patients.

Experimental allergic encephalomyelitis in cynomolgus monkeys. Quantitation of T cell responses in peripheral blood

Chronic relapsing-remitting experimental allergic encephalomyelitis (EAE) was induced in cynomolgus monkeys by a single immunization with a homogenate of human brain white matter (BH) in adjuvant. Proliferative T lymphocyte responses to BH, to myelin basic protein (MBP), but not to proteolipid protein, were detected in peripheral blood mononuclear cells (PBMC) of all animals and persisted until their death or, in surviving animals, for greater than 10 mo postimmunization. Responses of higher magnitude tended to be associated with fatal, compared with nonfatal, episodes of clinical EAE. The frequency of MBP-reactive T cells in PBMC of animals with acute EAE was quantitated with a soft agar colony system; the ratio of T cells that proliferated specifically to MBP was estimated at between 5 and 20 per 10(6) PBMC. A similar frequency of peptide-specific T cells was estimated from PBMC of monkeys immunized with a synthetic 14-mer peptide corresponding to a region near the carboxy terminus of MBP. Thus, autoantigen-reactive T cells can be detected in the circulation throughout the course of chronic EAE, are predictive of disease severity, and occur at a frequency similar to that estimated to be present in humans with multiple sclerosis.

Serum adenosine deaminase activity in bacillary or paucibacillary pulmonary tuberculosis

Serum Adenosine Deaminase (ADA) enzyme levels were estimated in 61 patients with symptoms and signs suggestive of Pulmonary Tuberculosis and correlated with "Gold standards" such as smear positivity of sputum for Acid Fast bacilli, Tuberculin skin testing and Radiological evidence. The mean ADA levels in smear and Tuberculin negative patients was 13.13 +/- 5.97 u/L, while in those with smear and/or strongly positive Tuberculin reaction, the mean levels of ADA were 33.52 +/- 15.22 u/L. The mean serum ADA levels in 25 healthy voluntary donors with no evidence of active or old Tuberculous lesion, were found to be 16.5 +/- 3.18 u/L. The specificity, sensitivity, positive predictive value and negative predictive value of the test was found to be 87%, 71%, 90% and 66.5% respectively. The results conclude that the serum ADA value is sufficiently useful in identifying those patients in whom the diagnosis of Pulmonary Tuberculosis should be actively considered.

Pleuropulmonary infections caused by Eikenella corrodens

A case of pleuropulmonary infection caused by Eikenella corrodens is reported, followed by a review of clinical cases reported in the English-language literature since 1970. On the basis of this review, the predisposing factors, clinical features, and principles of diagnosis and treatment of this infection are outlined. Although infection may occur at any age, it seems to occur most often in patients less than or equal to 14 or greater than or equal to 44 years of age. Adult patients commonly have some underlying medical illness, pleuropulmonary malignancy being the most common. Patients present with a variable combination of fever, cough, and pleuritic chest pain. Four radiographic patterns may be seen: pleural effusion, pneumonia, cavitation, or a combination of these. Ampicillin and penicillin G are effective therapeutic agents; although the susceptibility of E. corrodens to penicillin G has been accepted as the rule, it may not always prevail. The need for increased awareness of this organism as a cause of pleuropulmonary disease is stressed because it is resistant to clindamycin, an agent that is increasingly used to treat anaerobic pleuropulmonary infections.

Drug-resistant Nocardia asteroides infection in a patient with acquired immunodeficiency syndrome

We have reported what we believe to be the first case of disseminated infection due to a multiply drug resistant strain of Nocardia asteroides in a patient with the acquired immunodeficiency syndrome and concomitant disseminated histoplasmosis. This strain of the organism fits a pattern of susceptibility that is rare among N asteroides isolates in general and has been called the type 5 pattern, described as a resistance to broad spectrum cephalosporins, ciprofloxacin, and all aminoglycosides except amikacin. The recognition of disease due to this group of organisms is especially important in patients with AIDS because sulfonamides, considered the drugs of choice for treatment of N asteroides infection, are associated with a high incidence of adverse effects in these patients.

Visual evoked potentials and visual acuity after transurethral resection of the prostate

Changes in visual evoked potentials, visual acuity, blood ammonia levels and serum electrolytes (Na+ and K+) after transurethral resection of the prostate using glycine as an irrigating fluid performed under subarachnoid block were studied in 12 patients, in the pre-operative and immediate postoperative periods. Visual evoked potentials (p100 latency), recorded by shift of a checkerboard pattern, increased significantly from a pre-operative value of mean (SEM) 101.18 (1.63) msec in the right eye, and 102.5 (1.47) msec in the left eye to 108.91 (1.8) msec (p less than 0.01) and 108.08 (2.53) msec (p less than 0.01) respectively in the postoperative phase. There were no changes in visual acuity as assessed by a Snellen's chart, blood ammonia levels and serum electrolyte concentrations. The amount of glycine used intra-operatively for irrigation ranged from 3 to 31 litres.

Endophthalmitis caused by non-albicans species of Candida

While endophthalmitis due to Candida albicans is commonly seen in clinical practice, non-albicans species of Candida (NAC) are rarely reported to cause this condition. The English-language literature from 1965 through 1989 was reviewed for cases of endophthalmitis due to NAC. Clinical details of six well-documented cases and one unpublished case are presented here. Large studies of nosocomial fungemia are also summarized to emphasize the growing contribution of NAC to the total number of infections in humans, especially immunocompromised patients. The infrequency of ocular involvement in NAC infection is supported by studies in experimental animals that demonstrate a lower incidence of NAC endophthalmitis than of C. albicans endophthalmitis in the presence of disseminated infection. Since endophthalmitis in the absence of exogenous infection suggests disseminated candidal infection and since most NAC strains are relatively resistant to amphotericin B, it is important to recognize and appropriately treat endophthalmitis due to NAC.

Anisotropy decays of single tryptophan proteins measured by GHz frequency-domain fluorometry with collisional quenching

We used harmonic-content frequency-domain fluorometry to determine the anisotropy decays of a variety of single tryptophan peptides and proteins. Resolution of the rapid and complex anisotropy decays was enhanced by global analysis of the data measured in the presence of quenching by either oxygen or acrylamide. For each protein, and for each quencher, data were obtained at four to six quencher concentrations, and the data analyzed globally to recover the anisotropy decay. The decrease in decay times produced by quenching allows measurements to an upper frequency limit of 2 GHz. The chosen proteins provided a range of exposures of the tryptophan residues to the aqueous phase, these being ACTH, monellin, Staphylococcus nuclease and ribonuclease T1, in order of decreasing exposure. Examination of indole and several small peptides demonstrates the resolution limitations of the measurements; a correlation time of 12 ps was measured for indole in methanol at 40 degrees C. Comparison of the anisotropy decays of gly-trp-gly with leu-trp-leu revealed stearic effects of the larger leucine side chains on the indole ring. The anisotropy decay of gly-trp-gly revealed a 40 ps component for the indole side chain, which was resolved from the overall 150 ps correlation time of the tripeptide. Only the longer correlation time was observed for leu-trp-leu. With the exception of ribonuclease T1, each of the proteins displayed a subnanosecond component in the anisotropy decay which we assign to independent motions of the tryptophan residues. For example, Staphylococcus nuclease and monellin displayed segmental tryptophan motions with correlation times of 80 and 275 ps, respectively. The amplitudes of the rapid components increased with increasing exposure to the aqueous phase. These highly resolved anisotropy decays for proteins of known structure are suitable for comparison with molecular dynamic simulations.

Immunological studies in HBV-related chronic liver diseases

Humoral immune response in chronic sequelae of HBV infection was assessed in the present study. Serum immunoglobulins (IgG, IgM, IgA) serum complement component C3 and C4 and circulating immune complex (CIC) were estimated in forty cases of HBsAg positive chronic active hepatitis and cirrhosis and sixty cases of age and sex matched healthy control subjects. Hypergammaglobulinemia was observed in chronic liver diseased state. All the three immunoglobulins, IgG, IgA and IgM were elevated significantly. The complement C3 and C4 were significantly decreased in patient group, while the levels of CIC were significantly increased. The increased immunoglobulin levels may be attributed to disorganised Kupffer cell system and also to B cell hyperactivity. The decreased complement levels may be attributed to decreased synthesis and/or increased consumption by increased CIC. A primary or an acquired defect in infected host to generate immune response might result in defective elimination of infected hepatocytes in chronic liver disease.

An intracellular pathway is required for ABA-tyrosine presentation to T cells

Although tyrosine-azobenzenearsonate (ABA-Tyr) is not degraded by proteolytic enzymes, its presentation by accessory cells is inhibited by lysosomotropic agents such as chloroquine. Presentation of ABA-poly-L-glutamic, alanine, tyrosine (ABA-GAT) is similarly inhibited by chloroquine, but in contrast to ABA-Tyr it is also inhibited by leupeptin. Finally formaldehyde fixation of accessory cells after pulsing with ABA-Tyr but not before permits successful stimulation of ABA-specific hybridoma cells. These results suggest that a lysosomal pathway but not digestion is necessary for the association of ABA-Tyr and la molecules for presentation.

Distance distributions in proteins recovered by using frequency-domain fluorometry. Applications to troponin I and its complex with troponin C

We used resonance energy transfer to examine the distribution of distances between two sites on troponin I (TnI). The donor (D) was the single tryptophan residue at site 158 (Trp 158), and the acceptor (A) was cysteine 133 (Cys 133) which was labeled with N-(iodoacetyl)-N'-(1-sulfo-5-naphthyl)ethylenediamine (IE). A distribution of D-A distances results in a distribution of donor decay times, which were resolved by using frequency-domain fluorometry. In the native state we recovered a relatively narrow distribution of D-A distances. The widths of the distance distributions were found to increase progressively and dramatically with increasing concentrations of guanidine hydrochloride. Binding of calcium-free troponin C (TnC) to troponin I did not alter the distance distribution. Addition of Ca2+ to the TnI.TnC complex resulted in a sharper distance distribution and protected against the guanidine hydrochloride induced increase in the width of the distance distribution. Additionally, the same distance distributions were recovered for native and denatured TnI when the Forster distance for energy transfer was decreased by acrylamide quenching. These results demonstrate that distance distributions can be recovered with good accuracy, to the extent of revealing modest changes due to binding of other components. This technique should have widespread applications in studies of protein folding.

Analysis of fluorescence decay kinetics measured in the frequency domain using distributions of decay times

We describe the theoretical and practical aspects of analyzing complex fluorescence decay kinetics using continuous distributions of decay times. Our analysis uses frequency-domain data, provides for global analysis of multiple data sets and includes the possibility of excited-state processes. Simulated data were used to estimate the types of distributions which can be reasonably recovered from the measurements. Additionally, we describe a variety of distributions recovered from experimental data. For mixtures of one, two or three exponentially decaying fluorophores we recovered narrow lifetime distributions, which are essentially identical to a multiexponential decay. Similarly, a two-state excited-state reaction also yielded a narrow distribution with negative preexponential factors. The presence of time-dependent spectral relaxation of labeled lipids results in a wide distribution of decay times, which becomes narrower for faster relaxation rates at higher temperatures. Hence, the decay-time distributions appear to be sensitive to the dynamics of the environment surrounding the fluorophore. Additionally, distributions of decay times were observed to result from transient effects in collisional quenching, from energy transfer in the presence of a range of donor-to-acceptor distances, and for several single-tryptophan proteins.

Enhanced resolution of fluorescence anisotropy decays by simultaneous analysis of progressively quenched samples. Applications to anisotropic rotations and to protein dynamics

Enhanced resolution of rapid and complex anisotropy decays was obtained by measurement and analysis of data from progressively quenched samples. Collisional quenching by acrylamide was used to vary the mean decay time of indole or of the tryptophan fluorescence from melittin. Anisotropy decays were obtained from the frequency-response of the polarized emission at frequencies from 4 to 2,000 MHz. Quenching increases the fraction of the total emission, which occurs on the subnanosecond timescale, and thereby provides increased information on picosecond rotational motions or local motions in proteins. For monoexponential subnanosecond anisotropy decays, enhanced resolution is obtained by measurement of the most highly quenched samples. For complex anisotropy decays, such as those due to both local motions and overall protein rotational diffusion, superior resolution is obtained by simultaneous analysis of data from quenched and unquenched samples. We demonstrate that measurement of quenched samples greatly reduces the uncertainty of the 50-ps correlation time of indole in water at 20 degrees C, and allows resolution of the anisotropic rotation of indole with correlation times of 140 and 720 ps. The method was applied to melittin in the monomeric and tetrameric forms. With increased quenching, the anisotropy data showed decreasing contributions from overall protein rotation and increased contribution from picosecond tryptophan motions. The tryptophan residues in both the monomeric and the tetrameric forms of melittin displayed substantial local motions with correlation times near 0.16 and 0.06 ns, respectively. The amplitude of the local motion is twofold less in the tetramer. These highly resolved anisotropy decays should be valuable for comparison with molecular dynamics simulations of melittin.

Correction for contaminant fluorescence in frequency-domain fluorometry

We describe a general method to correct for contaminant fluorescence when using the technique of frequency-domain fluorometry. The method can be applied regardless of the origin of the background signal, from scattered light, impurity fluorescence, or both. The procedure requires measurement of the frequency-dependent phase and modulation of the background at enough frequencies to approximate the decay law of the background. We also describe a general method to propagate the uncertainties in the measured phase and modulation values into the corrected values. This propagation is necessary to ensure proper weighting of the frequency-dependent data in the least-squares fitting algorithms. The practical usefulness of this correction method is demonstrated using frequency-domain data for one and two component mixtures which were deliberately contaminated with scattered light and/or other fluorophores.