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Biomedical subjects

A Stark

Publications and source records attributed to A Stark.

At least 37 records · Page 2Linked to original sources
PubMed1999

Asthma hospitalization rates and socioeconomic status in New York State (1987-1993).

This study examined the geographic distribution of asthma hospitalizations in New York State (NYS) and its association with socioeconomic status. Statewide asthma hospitalization data (1987-1993) were merged with 1990 census data by residential zip code. The asthma hospitalization rate increased in NYS from 1987 (2.54 per 1000) through 1993 (2.87 per 1000) and the increase is largely attributable to increases for children 4 years old and younger. The risk factors for asthma admission varied in different areas. However, rates of hospitalization because of asthma were generally higher in the zip codes areas with higher proportions of poverty, unemployment, poorly educated residents, African-Americans, and Hispanics.

Adolescent↗
PubMed1999

Metal-on-metal bearing in hip prosthesis generates 100-fold less wear debris than metal-on-polyethylene.

Aseptic loosening due to osteolysis in total hip replacement has been related to wear debris released from prosthetic components. Retrospective longterm observations of patients with the metal-on-metal prosthesis has shown long-term survivorship and good mechanical performance. Thus, the new and modified metal-on-metal prosthesis has been introduced on the market. Historical clinical data from the 1st generation metal-on-metal hip prosthesis may not be relevant for the 2nd generation of metal-on-metal hip prosthesis. Therefore, preclinical testing of the prosthesis must be conducted before clinical evaluation. We assessed the tribological performance of the metal-on-metal prosthesis versus the metal-on-polyethylene prosthesis introduced on the market as Metasul and Protasul, respectively. In a 12-channel joint simulator, 6 metal-on-metal bearing and 3 metal on polyethylene prostheses were tested, with the same number of corresponding soak controls. The wear was assessed gravimetrically. The "steady-state" wear-rates from the metal-on-metal prosthesis were almost 100 times less than that from the metal-on-polyethylene prosthesis. The tribological wear performance of the metal-on-metal hip prosthetic system is promising.

Hip Prosthesis↗
PubMed1998

Vagal efferent and afferent innervation of the rat esophagus as demonstrated by anterograde DiI and DiA tracing: focus on myenteric ganglia.

Anterograde tracing with the carbocyanine tracer DiI and the aminostyrol derivative DiA was used to selectively label fibers from the nucleus ambiguus, dorsal motor nucleus and nodose ganglion, respectively, terminating in the rat esophagus, and to compare them with the innervation of the gastric fundus in the same animals. Ambiguus neurons terminated on motor endplates distributed mainly to the ipsilateral half of the esophagus. There was no evidence of preganglionic innervation of myenteric ganglia from ambiguus neurons. Neurons of the dorsal motor nucleus supplied sparse fibers to only about 10% of enteric ganglia in the esophagus while they innervated up to 100% of myenteric ganglia in the stomach. Neurons of the nodose ganglion terminated profusely on more than 90% of myenteric ganglia of the esophagus and on about 50% of ganglia in the stomach. Afferent vagal fibers were also frequently found in smooth muscle layers starting at the esophago-gastric junction. In contrast, they were extremely rare in the striated muscle part of the esophagus. These morphological data suggest a minor influence of neurons of the dorsal motor nucleus and a prominent influence of vagal afferent terminals onto myenteric neurons in the rat esophagus.

Animals↗
PubMed1998

Parathyroid hormone-related protein (1-37) induces cAMP response in human osteoblast-like cells.

During recent years parathyroid hormone-related protein (PTHrP) research has been focused on the physiological functions of different fragments of the PTHrP molecule. Here we demonstrate that PTHrP (1-37) induced cyclic adenosine monophosphate (cAMP) response in primary human osteoblast-like cells, which were well characterized by the presence of alkaline phosphatase activity and osteocalcin production after stimulation with 1,25-dihydroxyvitamin D3. However, there was no cAMP response to PTHrP (58-77). Furthermore, the response to PTHrP (1-37) was dose dependent, with a significant increase at 1 nM. The presence of PTHrP (1-37)-induced cAMP response in human osteoblast-like cells implies that aminoterminal PTHrP fragments may exert important functions in the bone.

Adolescent↗
PubMed1998

Direct and indirect costs of chickenpox in young children.

OBJECTIVE: To estimate the medical and economic or societal costs of chickenpox in young children using a descriptive study METHODS: Children under 5 years of age attending 124 Sydney childcare centres who were reported as having chickenpox were studied to assess the costs of medication use and medical consultations, days of care missed, and parental costs resulting from lost time from work and alternate childcare costs. RESULTS: There were 174 children (92 girls and 79 boys; in three the sex was not stated) who missed a mean of 5.5 days of care because of chickenpox, currently valued at $154. Medical costs were valued at $33 per child, based on 0.97 medical visits, and topical and oral medication. Labour costs resulting from parental work absenteeism were valued at $160 or $345 depending on the method of calculation, whilst direct economic costs of $24 were incurred through use of alternate childcare arrangements. Total costs including those incurred by secondary cases and by rare hospitalisations were in the range of $393-$578 per affected child. CONCLUSIONS: Medical costs of chickenpox in children are small relative to costs incurred as a result of parental work absenteeism and to costs of foregone childcare. Ascribing precise work-related costs should take into account some capacity to make up lost work time. Such data will be required when determining the cost-benefit of childhood varicella immunisation.

Absenteeism↗
PubMed1998

Localization of three human polypeptide GalNAc-transferases in HeLa cells suggests initiation of O-linked glycosylation throughout the Golgi apparatus.

O-glycosylation of proteins is initiated by a family of UDP-N-acetylgalactosamine:polypeptide N-acetylgalactos-aminyltransferases (GalNAc-T). In this study, we have localized endogenous and epitope-tagged human GalNAc-T1, -T2 and -T3 to the Golgi apparatus in HeLa cells by subcellular fractionation, immunofluorescence and immunoelectron microscopy. We show that all three GalNAc-transferases are concentrated about tenfold in Golgi stacks over Golgi associated tubular-vesicular membrane structures. Surprisingly, we find that GalNAc-T1, -T2 and -T3 are present throughout the Golgi stack suggesting that initiation of O-glycosylation may not be restricted to the cis Golgi, but occur at multiple sites within the Golgi apparatus. GalNAc-T1 distributes evenly across the Golgi stack whereas GalNAc-T2 and -T3 reside preferentially on the trans side and in the medial part of the Golgi stack, respectively. Moreover, we have investigated the possibility of O-glycan initiation in pre-Golgi compartments such as the ER. We could not detect endogenous polypeptide GalNAc-transferase activity in the ER of HeLa cells, neither by subcellular fractionation nor by situ glycosylation of an ER-retained form of CD8 (CD8/E19). However, upon relocation of chimeric GalNAc-T1 or -T2 to the ER, CD8/E19 is glycosylated with different efficiencies indicating that all components required for initiation of O-glycosylation are present in the ER except for polypeptide GalNAc-transferases.

Base Sequence↗
PubMed1996

Reconstruction in metastatic destruction of the acetabulum. Support rings and arthroplasty in 12 patients.

In 12 patients with acetabular metastases, we reconstructed the hip with a support ring, cement, and Charnley prosthesis with a 22 mm head. There were no immediate postoperative deaths or cardiovascular complications. Dislocations occurred in 5 patients, 1 of whom required open reduction. At follow-up, 3 patients were alive 11, 15, and 18 months after surgery. 9 patients died after 8 (2-13) months. All patients obtained relief from pain, became ambulatory and were discharged to their homes. 1 patient had rapid disease progression with pathologic fracture and cranial dislocation of the support ring. Among the remaining 11 patients, the hip has not again caused pain or limited function. There were no signs of loosening, except in the patient with fracture of the hemipelvis. Remineralization was observed in 2 breast cancer patients after chemotherapy. Hip reconstruction can restore painless function until death in cancer patients with severe destruction of the acetabulum.

Acetabulum↗
PubMed1995

Localization of the human soluble epoxide hydrolase gene (EPHX2) to chromosomal region 8p21-p12.

Epoxide hydrolases have an important function in organisms in that they catalyze the transformation of potentially toxic or carcinogenic epoxides into the corresponding diols. In this study, the chromosomal localization was determined for the human gene encoding soluble epoxide hydrolase. A polymerase chain reaction fragment corresponding to the C-terminal region of the mouse protein was used to isolate a cosmid clone from a human genomic library. By fluorescence in situ hybridization to metaphase chromosomes, the soluble epoxide hydrolase gene was then localized to chromosomal region 8p21-p12.

Animals↗
PubMed1995

Mortality among New York State highway maintenance workers: 1958-1980.

The mortality profile of 9585 male New York State Department of Transportation (NYSDOT) highway maintenance workers was examined by calculating age-era standard mortality ratios (SMRs), using the general male population of upstate New York as a reference group, for the period 1958-1980. The SMR for all workers was 1.14 (95% CI = 1.09, 1.18), with the greatest all-cause mortality among laborers (SMR = 1.23, 95% CI = 1.16, 1.29). The major contributors to this increase among laborers were circulatory system diseases (SMR = 1.18, 95% CI = 1.10, 1.27), diseases of the respiratory system (SMR = 1.34, 95% CI = 1.09, 1.64), digestive system diseases (SMR = 1.57, 95% CI = 1.26, 1.94), genitourinary system diseases (SMR = 1.61, 95% CI = 1.02, 2.41) and accidents, poison, and violence (SMR = 1.44, 95% CI = 1.19, 1.74). Some of the elevated risks observed may be attributed to cigarette smoking and other life-style factors that could not be assessed with the data available. However, the mortality risks for laborers increased with length of employment and latency, suggesting that occupational exposures may be contributing to the elevated risk in this cohort. Further studies should include information on life-style variables and other confounders as well as more detail on specific occupational exposures.

Adult↗
PubMed1995

Changes in intestinal tunica muscularis following dietary fiber feeding in rats. A morphometric study using image analysis.

The morphological changes in the intestinal tunica muscularis induced by prolonged dietary fiber intake were determined in rat small intestine and colon with the aid of computerized image analysis. Thirty male Sprague-Dawley rats were fed either a fiber free, 15% cellulose or 15% pectin diet for 8 weeks. Intestine length was measured and stained cross sections of the jejunum, ileum, and colon were quantitated using image analysis. In the distal colon, muscle cell size was also determined. Despite lower weight gain in the pectin fed rats, both the small intestine and colon length were significantly increased. Cellulose feeding had a lesser effect on intestine length. Pectin fed rats had significantly increased relative tunica muscularis area (37.2 +/- 2.2 mm2) in ileum cross sections when compared to control (24.3 +/- 1.8 mm2) and cellulose fed rats (26.1 +/- 1.1 mm2). In the mid-colon, the tunica muscularis area was found to be pectin > cellulose > control (33.5 +/- 2.2; 29.7 +/- 1.7; 25.8 +/- 1.5 respectively) with significant differences reached between pectin and control rats. In jejunal samples, no differences were observed among the groups. Circular smooth muscle cell size in the distal colon was significantly increased following cellulose feeding but was less pronounced in the case of pectin. We conclude that fiber supplementation leads to morphological changes in the rat intestine including changes in length and tunica muscularis volume.

Animals↗
PubMed1995

Tissue specific basal expression of soluble murine epoxide hydrolase and effects of clofibrate on the mRNA levels in extrahepatic tissues and liver.

The soluble epoxide hydrolase mRNA level in liver was increased eight-fold upon administration of the hypolipidemic drug and peroxisome proliferator clofibrate for 7 days to mice. The soluble epoxide hydrolase mRNA was back at control levels within 1-2 days after clofibrate withdrawal. The highest expression was in liver, intestine and kidney. Lower levels were found in heart and muscle and very low levels were found in testes, lung, brain and spleen. The mRNA levels were increased in liver, kidney and heart by clofibrate.

Animal Feed↗
PubMed1995

Neurotoxicity among pesticide applicators exposed to organophosphates.

OBJECTIVES: An epidemiological study of 90 male pesticide applicators licensed in New York was conducted to investigate the effect of exposure to organophosphate pesticides on the peripheral nervous system. METHODS: A cohort of farmers and pesticide applicators from New York State were questioned off season (November 1988-February 1989) and again during the spraying season (April 1989-August 1989) about the presence of several acute signs and symptoms. Short term exposure was validated by measuring the concentration of dimethylthiophosphate (DMTP), a metabolite of guthion, in urine. Chronic signs of subtle peripheral nerve damage were determined by vibration threshold sensitivity of the farmers and applicators tested during November 1988-February 1989 and compared with controls drawn from the general population who were tested during the same time period the next year (November 1989-February 1990). Vibration threshold sensitivity was determined for both the hands and feet. Long term exposure to pesticides was determined by questionnaire. RESULTS: Paired t tests show that mean vibration threshold scores were significantly higher for the dominant (P < 0.00) and non-dominant (P < 0.04) hands among pesticide applicators when compared with scores for population based controls individually matched on age, sex, and county of residence. CONCLUSIONS: A significant increase in mean vibration threshold sensitivity for the dominant and non-dominant hand suggests previous organophosphate exposure among pesticide applicators was associated with a loss of peripheral nerve function.

Adult↗
PubMed1995

Evaluation of the impact of allogenic transplant in first remission on an unselected population of patients with acute myeloid leukaemia aged 15-55 years. The Northern Regional Haematology Group.

The aim of this study was to collect prospectively unselected, population-based data on young adults with acute myeloid leukaemia (AML) over a 9-year period and to evaluate the impact on survival of the introduction of allogeneic transplantation performed in first remission. The population within the Northern Region of England is 3.09 million. During the study period a total of 149 de novo patients between 15 and 55 years old presented. The incidence of AML was 0.79 per 10(5) (age-specific population) in the 15-24-year-old group, 0.85 per 10(5) in the group 25-39 years old and 1.35 per 10(5) in the 40-55-year-old group. Remission induction success varied with age (74% for patients < 40 years and 58% for patients 40-55 years). In the 15-40 year old group 28 patients had an HLA-matched donor, 22 patients had a transplant (one syngeneic) and 24 patients in the 15-40-year-old group in remission at 6 months did not have a transplant. The allogeneic group < 40 years old had an event-free survival (EFS) at 4 years of 62%, whereas patients of the same age who received chemotherapy alone had an EFS at 4 years of 24%. A small heterogeneous group of 14 patients who had intensification with autotransplant are not included in this analysis. The population study approach demonstrates the difficulties of introducing uniform treatment strategy in this disease group. The study confirms the view that allogeneic transplant in first remission in the 15-40-year-old group is the treatment of choice. Unfortunately the overall impact of transplant on the population is not great since only 22 of 149 patients (14%) were able to receive an allograft in first remission.

Adolescent↗
PubMed1994

Late follow-up results of operative ankle arthroscopy in patients under local anaesthesia.

The purpose of this study was to evaluate our long-term results of operative ankle arthroscopy in local anaesthesia, without tourniquet and antibiotic prophylaxis, and to see whether we could produce the same results other investigators had published using general anaesthesia. Between 1987 and 1992, 51 operative ankle arthroscopies were performed--all as out-patient procedures. Thirty-six patients had local anaesthesia, 7 had general anaesthesia, one had spinal anaesthesia and one had epidural anaesthesia. No prophylactic antibiotics were given. Indications for surgery were the same for patients who had local anaesthesia as for those who had the other types of anaesthesia. Nineteen patients had partial synovectomies, 8 had removals of osteophytes, 7 had debridements of osteochondral fractures, 6 had debridements of mild degenerative osteoarthritis, 3 had loose bodies and 2 had septic arthritis. After a mean of 3 years (range 1-8) the patients were sent a questionnaire. They were asked to rate activity level, pain, swelling, and limb stiffness on a four-grade scale pre- and postoperatively and to rate their total subjective improvement. They were also asked if they would undergo the same procedure again knowing the outcome of the procedure. Forty-five patients (88%) were available for follow-up. Thirty-four patients (76%) were improved, 10 remained unchanged, and one became worse after surgery. No correlation existed between preoperative symptom duration, sex, trauma, type of anaesthesia, postoperative diagnosis or type of surgical procedure. Minor complications occurred in 11% of patients. Eighty-four percent of the patients said they would undergo the same procedure again. The type of anaesthesia used did not influence this decision.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗