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L Jacobs

Publications and source records attributed to L Jacobs.

At least 19 recordsLinked to original sources
PubMed1992

A population-based study of motorcycle injury and costs.

STUDY OBJECTIVE: To provide a population-based injury and cost profile for motorcycle injury in Connecticut. DESIGN: Population-based retrospective epidemiologic review of Connecticut death certificates, hospital discharge data, and police accident reports. RESULTS: Connecticut death certificates identified 112 deaths from motorcycle injuries for an annual death rate of 1.2 per 100,000 persons. Death rates were highest among 20- to 24-year-old men. Nonhelmeted motorcyclists were 3.4-fold more likely to die than were helmeted riders (P less than .05). An estimated 2,361 motorcycle-related hospital discharges resulted in an annual hospitalization rate of 24.7 per 100,000 persons. Head, neck, and spinal injuries accounted for 22% of all injuries. Total costs exceeded $29 million; 29% of hospitalized patients were uninsured, and 42% of the cost was not reimbursed to the hospitals. CONCLUSION: Motorcycle injuries contribute significantly to Connecticut's mortality, morbidity, and medical costs. Our study suggests that a uniform helmet law would save an estimated ten lives and prevent more than 90 nonfatal injuries in Connecticut each year at a cost savings to the state of $5.1 million. These data are crucial in advocating re-enactment of motorcycle helmet laws.

Abbreviated Injury Scale↗
PubMed1992

Immunochemical analysis of human kidney reticulin.

This study characterized the nature of reticulin fibrils from human kidney cortex by immunochemical analysis. Controls consisted of type I collagen fibrils derived from the kidney parietal capsule. Most of the fibrils in the capsule ranged in diameter from 60 to 80 nm whereas reticulin fibrils from the cortex ranged from 30-45 nm. Immunochemistry by light and electron microscopic examinations was carried out with antibodies directed against type I and type III collagens, their corresponding aminopropeptides, and decorin (PG-II). The ratio of type I to type III collagen was determined by cyanogen bromide peptide digests. This study showed that reticulin fibrils are hybrids of type I and type III collagens. Double immunoelectron microscopic examination showed that fibrils 20-25 nm consisted mainly of type I collagen some of which retained their aminopropeptide. Larger fibrils 30-35 nm labeled simultaneously for type I and type III collagens. However, most fibrils with diameters between 40-55 nm labeled for type III collagen and its corresponding aminopropeptide. No decorin was detected at the surface of reticulin fibrils. Purified reticulin consisted of 82% type III and 18% type I collagen whereas collagen derived from the capsule revealed 76% type I and 24% type III. The presence of the aminopropeptide of type III procollagen in reticulin fibrils is a striking feature and may play a role in regulating their diameter.

Collagen↗
PubMed1991

Is the ESR dead?

Explore the source record for details and available documents.

Blood Sedimentation↗
PubMed1991

Selective paralysis of voluntary but not limbically influenced automatic respiration.

We describe a patient in whom a discrete infarction of the ventral basis pontis caused a complete loss of voluntary respiration, while automatic respiration remained intact. Respiratory excursions, quantified title volumes, and ventilatory response to carbon dioxide were normal, but the patient could not volitionally modify any respiratory parameters. Emotional stimuli producing laughter, crying, or anxiety appropriately modulated automatic respiration. This case established that pathways subserving limbic modulation of automatic respiration descend in the pontine tegmentum and/or lateral portion of the basis pontis spared by this lesion. Furthermore, descending limbic influences on automatic respiration are anatomically and functionally independent of the voluntary respiratory system.

Adult↗
PubMed1991

Decorin interacts with fibrillar collagen of embryonic and adult human skin.

Biglycan (PG-I, BGN) and decorin (PG-II, DCN) are small proteoglycans that have been isolated in cartilage, skin, and bone. Although the function of biglycan is unknown, there is biochemical evidence that decorin interacts with fibrillar collagens (type I, type II). The purpose of this study was to perform immunofluorescence and immunoelectron microscopy and immunoblotting of human embryonic and adult skin with antibodies directed against biglycan and decorin. These antibodies were developed against synthetic peptides of the core proteins of biglycan (amino acid sequence 11-24) and decorin (amino acid sequence 5-17). Immunofluorescence microscopy showed that decorin stained embryonic and adult collagen fibrils. Biglycan did not stain collagen, but it appeared to stain the pericellular matrix of embryonic mesenchymal cells. Immunoelectron microscopy revealed labeling of all collagen fibrils with decorin antibodies regardless of their diameter, often at 60-nm periodicity. Positive stains suggest that most of the labeling was in the gap of the D-period (d and e bands) and also in one of the steps (c band). Decorin was identified by immunoblotting in fetal and adult skin. Also, significant amounts of core protein was identified lacking the dermatan sulfate chain. This study suggests that the core protein of decorin interacts with collagen fibrils although its specific function remains unknown.

Adult↗
PubMed1991

Elastin-associated microfibrils (10 nm) in a three-dimensional fibroblast culture.

The purpose of this study is to present a three-dimensional dermal fibroblast model. Skin fibroblasts cultured in this system deposit large amounts of collagen and microfibrils. Fibroblasts were seeded onto a nylon filtration mesh and incubated in the presence or absence of ascorbic acid. Collagen fibril formation was found in the presence of ascorbic acid whereas microfibril formation was seen independent of ascorbic acid supplementation. Immunoelectron microscopy revealed that microfibrils were labeled with fibrillin at 67 nm periodicity. Isolated microfibrils studied by rotary shadowing had a beaded appearance consisting of beads linked to each other by a filamentous structure. The spaces between the beads ranged from 10.00-33.33 nm, suggesting that these microfibrils may have an extension-contraction mechanism. Furthermore, the size and spacing of the beads were similar to that seen in microfibrils from tissues (measured after rotary shadowing). Fibroblasts cultured in a three-dimensional mesh represent an effective in vitro model with which to study microfibril formation.

Cells, Cultured↗
PubMed1991

Quantitative evaluation of the penile vascular status by means of the 99mTc-penogram in conjunction with either papaverine or prostaglandin E1 in the anaesthetised baboon model.

The evaluation of both the arterial blood supply and the venous drainage of the penis is essential in the assessment of the impotent male. The vasoactive drugs papaverine and prostaglandin E1, as intracavernous injections, cause penile erections by influencing arterial blood supply and venous drainage. These drugs were used in a baboon model together with a 99mTc-penogram to provide information on the vascular status of the penis. An increase in penile blood pool was observed, more dramatic and rapid after administration of papaverine. A quantitative assessment of the vascular status seems possible and will next be monitored in a vascular-compromised baboon for purposes of clinical application.

Alprostadil↗
PubMed1991

Bronchial hyperresponsiveness in normal subjects during attenuated influenza virus infection.

Fourteen healthy male subjects with hemagglutination-inhibition antibody titers of 1:8 or less to homologous influenza A virus were studied. Six subjects received live, attenuated influenza virus by nasal drops and by aerosol. Although infection occurred in these six subjects, with the development of 4-fold or greater increases in hemagglutination-inhibition antibody titers, they remained asymptomatic. Eight subjects received placebo via the same route, and did not develop symptoms and showed no increase in antibody titer. Prior to administration of virus or placebo, histamine diphosphate aerosol increased airway resistance only slightly, and there was no difference between the virus and placebo groups. Two days after inoculation, bronchomotor responses in the placebo group were unchanged (p greater than 0.05), but in the virus-infected group, bronchomotor responses were significantly greater than in the preinfected state (p less than 0.01). Isoproterenol hydrochloride reversed and prevented the increase in airway resistance after histamine, suggesting that the bronchoconstriction was caused by smooth muscle contraction. Our findings indicate that transient, asymptomatic respiratory virus infection augments airway smooth muscle responses.

Adult↗
PubMed1991

Clinical and magnetic resonance imaging in optic neuritis.

We found 23 of 48 patients (48%) with isolated monosymptomatic optic neuritis (ON) to have 1 to several brain lesions by MRI. All the brain lesions were clinically silent and had characteristics consistent with multiple sclerosis (MS). During 4 years of follow-up, 9 patients (19%) developed definite MS on clinical grounds. Six of the converting patients had abnormal MRIs; the other 3 had MRIs that were normal both initially (when they had ON only) and when repeated after they had developed MS. The other 17 patients with abnormal MRIs have not developed symptoms or signs of MS during follow-up. Thus, an abnormal MRI does not auger development of clinical MS within a mean of 4 years, nor does a normal MRI protect against development of disseminated disease. It is not prudent to give a patient with isolated monosymptomatic ON the diagnosis of MS (probable or definite) because of an abnormal MRI (with or without other laboratory abnormalities).

Adolescent↗
PubMed1991

A randomized trial of replacement antioxidant vitamin therapy for neutrophil locomotory dysfunction in blunt trauma.

Studies in patients with serious trauma indicate that the observed neutrophil (PMN) locomotory dysfunction is partly the result of auto-oxidation as shown by evidence of preactivation, diminished reducing capacity, and low serum and cellular ascorbic acid and alpha-tocopherol. To investigate whether replacement of the antioxidant vitamins ascorbic acid and alpha-tocopherol can improve the PMN locomotory defect, ascorbic acid, alpha-tocopherol, ascorbic acid and alpha-tocopherol, or placebo was administered to a total of 46 victims of blunt trauma. PMN locomotion was quantitated using a micropore filter assay. Locomotion data were analyzed by repeated measures analysis with a split plot design and data for days 2-6 after injury were compared. Compared with placebo, the antioxidants improved PMN locomotion. The mean differences in distance migrated (treated minus placebo) were ascorbic acid and alpha-tocopherol = 11.3 +/- 3.0 microns (one-tailed p = 0.001) (mean +/- SE); ascorbic acid = 4.7 +/- 3.4 microns (p = 0.19); and alpha-tocopherol = 3.3 +/- 2.9 microns (p = 0.27). Although both antioxidants given together produced the best results, a plot of the 95% confidence intervals indicates that ascorbic acid and alpha-tocopherol, either given alone, were also better than placebo. We conclude that antioxidant replacement therapy significantly improves the PMN locomotory abnormality in blunt trauma.

Adult↗
PubMed1991

A baboon model for in vivo assessment of mucociliary lung clearance.

A suitable baboon model (Papio ursinus) for assessing inhibitory effects on mucociliary lung clearance was required. Clearance of various dimensions of nebulized particles (99mTc-labelled) was monitored with the animals (n = 6) under either ketamine or pentobarbitone anaesthesia. The best prospect of substantial and reproducible clearance in spite of the inhibition by the anaesthesia were obtained with pentobarbitone, and using nebulized radiolabelled particles of diameter range between 10 and 45 microns, thus avoiding trapping in the non-ciliary alveoli.

Aerosols↗
PubMed1991

Extracellular microfibrils are increased in localized and systemic scleroderma skin.

Extracellular microfibrils, about 10 nm thick with a hollow core have been found in most organs as free bundles or in association with elastic fibrils. Histochemistry of the dermis of 4 patients with localized and 6 with systemic scleroderma revealed numerous fine elastic fibrils in areas of fibrosis. Immunofluorescence and immunoelectron microscopy were performed with antibodies against fibrillin and amorphous elastin. The lower dermis revealed an increase in 10-nm microfibrils interspersed between collagen fibrils. These microfibrils stained for fibrillin but not for amorphous elastin. Fibrosis in localized and systemic scleroderma involves the deposition of collagen fibrils and microfibrils.

Extracellular Space↗
PubMed1990

The construct validity of an aftereffect-based subtyping system for alcoholics.

In an earlier project, we identified five alcohol-consumption aftereffect factors, which were named Hangover, Euphoria, Flushing, Seizures, and Sleepiness. In this study (N = 100) we assessed the construct validities of the five, using 47 MMPI, self-report, and recidivism criteria. The number of significant relationships between the factors and the criteria substantially exceeded chance. The Hangover factor related to social maladjustment and to the MMPI Psychopathic Deviate, Paranoia, Psychasthenia, Hypomania, and Masculinity-Femininity scales. The Euphoria factor was associated with a high number of job losses, but a low incidence of certain physical sequelae. The Flushing factor was associated with high consumption, late development of alcoholism, many physical complaints, and older age. The Seizure factor correlated with high consumption, facial puffiness, tremors, and lack of defensiveness on the MMPI. The Sleepiness factor was associated with a good prognosis and several mild MMPI elevations. These findings suggest that the factors may provide the basis for a useful alcoholism subtyping system and that additional research on them should prove fruitful.

Adult↗
PubMed1990

Investigation by scintigraphic methods of neutrophil kinetics under normal and septic shock conditions in the experimental baboon model.

The purpose of this study was the correlation of neutrophil kinetics with the pathogenic course of septic shock in the baboon model. Radioactively labelled neutrophils were traced in vivo in normal baboons (n = 6) and in Escherichia coli-infected baboons, which were reinjected with labelled autologous neutrophils either 2 h after the onset of the E. coli infusion (procedure A) (n = 3) or simultaneously with the infusion (procedure B) (n = 3). Cell isolation was done according to a method developed in this laboratory. The cells were labelled with tropolonate In 111, resuspended in 1-2 ml plasma and reinjected. One-minute images were taken every 5th min and then hourly for 4 h with a gamma camera and analysed with a data processor. Time-activity curves were obtained for neutrophil washout from the lungs and neutrophil accumulation in the liver and spleen. These curves were compared for normal baboons and for those treated according to procedures A and B. A significant retention of neutrophils in the lungs of baboons with E. coli-induced septic shock was noted as well as an abnormally slow rate of accumulation in the liver and spleen. It also seems that any lung injury which could be attributed to changes in neutrophil behaviour should be traced back to events during the early exposure of neutrophils to bacterial infection.

Animals↗
PubMed1990

Additional evidence of autoxidation as a possible mechanism of neutrophil locomotory dysfunction in blunt trauma.

Previous studies in victims of blunt injury suggest that the observed neutrophil (PMN) locomotory dysfunction is, in part, due to autoxidation. To further clarify the occurrence and significance of autoxidation, we studied changes in levels of glutathione in PMN and of ascorbic acid and alpha-tocopherol in serum and blood cells of postsurgical and blunt trauma patients. Levels of total, reduced, and oxidized glutathione in PMN from trauma patients were similar to normal controls. Serum and cellular ascorbic acid and alpha-tocopherol levels dropped significantly after injury and remained below normal control levels during the 7 to 8-day study period. Low serum alpha-tocopherol was partially explainable on the basis of changes in serum lipids. When serum samples of trauma patients were thawed unprotected without pyrogallol, there was significant loss of recoverable alpha-tocopherol, whereas no significant losses occurred with unprotected thawed normal sera. Less total reducing capacity was observed in PMN of trauma patients compared with normal controls. These findings indicate that synthesis and regeneration capacity of glutathione are intact but that the levels of the consumable antioxidants, ascorbic acid, and alpha-tocopherol are compromised after injury. These results add further support to the hypothesis that autoxidation occurs in trauma.

Adolescent↗
PubMed1990

Epitope analysis of glycoprotein I of pseudorabies virus.

A panel of 11 monoclonal antibodies (MAbs) raised against pseudorabies virus (PRV) was used to map epitopes on the virus glycoprotein I (gI). We employed three approaches to map epitopes on gI. By a competition binding assay, six groups of MAbs were defined as reacting with distinct antigenic domains on gI. To identify regions along the gI polypeptide chain encompassing the domains recognized by these MAbs, DNA fragments derived from the gI-coding region were cloned into pEX expression plasmids. The antigenic reactivity of the fusion proteins expressed in Escherichia coli was analysed by immunoblotting. Five antigenic domains were mapped within the first 238 amino acids of gI: domains A, B and D were mapped between amino acids 52 and 123 and domains C and E between amino acids 78 and 238. One MAb, representing domain F, did not react with the expressed fusion proteins. To assess the precise location and amino acid sequences of the epitopes, overlapping nonapeptides covering the amino acid sequence 52 to 238 were synthesized. The antibody-binding activity of these peptides was tested by an ELISA (Pepscan-method). Three antigenic domains were mapped: domain A was localized to amino acids 64 to 73 and 75 to 84, domain B to amino acids 52 to 67 and domain D to amino acids 68 to 82. Four MAbs representing antigenic domains C, E and F did not react in the Pepscan. Finally, sera from pigs infected experimentally with PRV reacted with the fusion protein of plasmid ps 1 (amino acids 52 to 238).

Amino Acid Sequence↗