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Biomedical subjects

L Knobeloch

Publications and source records attributed to L Knobeloch.

15 recordsLinked to original sources
PubMed2001

Eight blue babies.

Methemoglobinemia is a serious medical condition that affects hundreds of infants in the United States each year. The condition involves the oxidation of red cell hemoglobin to a state that is unable to transport oxygen. Affected infants appear cyanotic and may have altered mental status. The condition is readily reversible if recognized and treated appropriately. The Wisconsin Division of Public Health investigates all cases of infant methemoglobinemia in an attempt to determine their cause. Between January 1990 and September 1999, 8 infants were diagnosed with this condition. Review of their hospitalization records found that 3 of these cases involved infants whose formula was prepared with water from nitrate-contaminated wels. Risk factors identified in the remaining cases included use of folk remedies, misuse of over-the-counter analgesics, and an inherited enzyme deficiency. Causes were not identified for 2 of the cases. All of the affected infants recovered.

Diagnosis, Differential↗
PubMed2000

Blue babies and nitrate-contaminated well water.

The use of nitrate-contaminated drinking water to prepare infant formula is a well-known risk factor for infant methemoglobinemia. Affected infants develop a peculiar blue-gray skin color and may become irritable or lethargic, depending on the severity of their condition. The condition can progress rapidly to cause coma and death if it is not recognized and treated appropriately. Two cases of blue baby syndrome were recently investigated. Both cases involved infants who became ill after being fed formula that was reconstituted with water from private wells. Water samples collected from these wells during the infants' illnesses contained nitrate-nitrogen concentrations of 22.9 and 27.4 mg/L.

Environmental Exposure↗
PubMed1998

Gastrointestinal upsets and new copper plumbing--is there a connection?

This article summarizes two investigations that examine the health effects of prolonged exposure to copper-contaminated drinking water. The first study was initiated after elevated copper levels were detected in several homes that were either newly constructed or recently remodeled. All of these homes were served by the same municipal water supplier. The second case involved illnesses and water-quality problems that were reported by several residents of a mobile home park shortly after a new water distribution system was installed. Findings from these investigations suggest that copper-contaminated drinking water may be a fairly common cause of nausea, diarrhea, abdominal cramps, and headaches-especially among residents of new or recently-remodeled homes, and in areas where water supplies are naturally corrosive.

Adolescent↗
PubMed1998

Never on a Saturday (or a Sunday): the case against using weekend urine specimens to assess arsenic exposure.

The Wisconsin Department of Health and Family Services Bureau of Public Health recently investigated two cases of suspected arsenic poisoning. These cases involved four adults whose urinary arsenic levels ranged from 340 to 1485 ug/L (normal 0-30 ug/L). These findings were initially interpreted as evidence of an ongoing exposure to a toxic form of arsenic, however follow-up investigations determined that all of the urine specimens had been collected on a weekend and that each of these individuals had consumed fish within 48-hours of urine collection. Most of the fish was consumed at "Friday night fish fries" which are a popular tradition at many local restaurants. Urine samples collected after these individuals eliminated fish from their diets contained normal arsenic levels. This report suggests the need for laboratories to differentiate non-toxic forms of arsenic that are present in fish and seafood products from other species of this element. Until more specific analytical methods become available, patients should be instructed to omit fish and seafood from their diets for several days prior to collecting urine for arsenic analysis. In addition, elevated urinary arsenic levels should be interpreted cautiously and exposure to toxic forms should be confirmed before a diagnosis of arsenic poisoning is entertained.

Adult↗
PubMed1997

Heat-related illness and death, Wisconsin, 1995.

This article examines heat-related illnesses and deaths that occurred in Wisconsin during the summer of 1995, which was among the warmest seasons on record. Death certificates that listed heat exposure as a contributing or underlying cause of 154 deaths and ambulance run reports for 454 heat-related emergency calls were analyzed. The time and place of these events and patient information were used to evaluate risk factors such as age, medical condition, physical activity, and environmental temperature. Three-fourths of the deaths and nearly half of the heat-related illnesses occurred during or shortly after two days of intense heat. Major risk factors for these heat-related illnesses and deaths included age, underlying chronic illness, physical exertion, and lack of air-conditioning. To reduce the number of illnesses and deaths that occur during future heat waves, all residents should be advised to install air-conditioning systems in their homes or apartments and encouraged to use them when indoor temperatures are uncomfortably warm. Summer weather forecasts should include heat index information. During periods of extreme heat, public health advisories should be issued encouraging residents to seek shelter in air-conditioned areas and to avoid strenuous outdoor activities and prolonged sun exposure. Region-specific criteria and procedures for issuing public health advisories should be developed jointly by the National Weather Service and the US Centers for Disease Control and Prevention.

Adolescent↗
PubMed1994

Gastrointestinal upsets associated with ingestion of copper-contaminated water.

During 1992 and 1993 the Wisconsin Division of Health investigated five cases in which copper-contaminated drinking water was suspected of causing gastrointestinal upsets. Each of these case studies was conducted after our office was notified of high copper levels in drinking water or notified of unexplained illnesses. Our findings suggest that drinking water that contains copper at levels above the federal action limit of 1.3 mg/l may be a relatively common cause of diarrhea, abdominal cramps, and nausea. These symptoms occurred most frequently in infants and young children and among resident of newly constructed or renovated homes.

Adult↗
PubMed1988

The effect of diphenylhydantoin and cortisol on the cell cycle.

Normal human lymphocytes cultured in the presence of phytohemagglutinin were blocked in G0G1 when diphenylhydantoin (DPH) or cortisol 3.6 X 10(-4) M was added at the beginning of culture. The suppression of culture growth was analyzed by flow cytometry and confirmed by [3H]thymidine incorporation and mitotic rate analysis. The correlation of these measurements with flow cytometry was good for DNA synthesis and excellent for mitosis. There was an additive effect on the G0G1 retention of cells when both drugs were present in the culture. These data may partially explain the suppression of cell-mediated immunity which occurs in DPH-treated patients.

Cell Cycle↗
PubMed1986

Diphenylhydantoin inhibits cortisol-induced lysis of thymocytes.

Diphenylhydantoin (DPH) shares two features with cortisol: immunosuppression and cleft palate formation. We tested the hypothesis that DPH would have effects on lymphocytes in vitro similar to those induced by cortisol, and the corollary that DPH would inhibit those cortisol effects. We found that DPH lysed rat thymocytes, although at higher concentrations than cortisol. When combined, DPH inhibited cortisol lysis of thymocytes. Neither drug lysed human phytohemagglutinin (PHA)-stimulated cells, but both drugs depressed DNA and RNA syntheses in PHA cells. DPH augmented cortisol inhibition of DNA and RNA syntheses in PHA cells and DNA synthesis in rat thymocytes. It had no effect on cortisol inhibition of RNA synthesis in rat thymocytes. It appears that DPH has a cortisol-like action (lysis of rat thymocytes). The actions of this drug enable us to show that cortisol lysis and the inhibition of DNA or RNA synthesis can be associated. These phenomena may explain some immunosuppressive effects of DPH in the human.

Animals↗
PubMed1977

Defect of cerebellar Purkinje cell histogenesis associated with type I and type II renal cystic disease.

The cerebellar vermises from a 1 day old child who died with cystic dysplastic kidneys (Potter Type II) and from a 28 day old who died with infantile polycystic kidneys (Potter Type I) were studied by the Golgi silver method and electron microscopical procedures. Golgi stains showed that Purkinje cells from both cases had the following abnormal characteristics: (1) they retained perikaryal processes even at 37-42 weeks after conception although these processes are normally absent from the cerebellar vermis after 34 weeks of gestation; (2) The Purkinje cell dendrites had dilations at their numerous branchpoints. Ultrastructural studies indicated that climbing fibers remained in contact with the perikaryon of the Purkinje cell in both cases although they are not normally present on the perikaryon after 33 weeks gestation. The 1 day old child (Type II) had unusual synaptic structures of the dyad and serial type. The concurrence of cerebellar and kidney cell maldevelopment in this and a variety of other conditions suggests that there may be a pathogenetic and causal relationship between the two.

Cerebellum↗
PubMed1976

Isolation of dendrodendritic synapses from swine olfactory bulbs.

Dendrodendritic synapses from swine olfactory bulbs were isolated by homogenization of the gray layer, followed by centrifugation at 1000 X g. Centrifugation of the supernatant at 10,000 X g revealed that all dendrodendritic synapses had pelleted at 1000 X g. The upper portion of the 1000 X g pellet was further purified in a discontinuous sucrose gradient, and each resultant fraction was examined by electron microscopy. The dendrodendritic synapses band below the 1.2-1.4 M sucrose interface, appear to be minimally contaminated with other membranous elements, and have retained their adhesions. The banding pattern and relative amounts of proteins from dendrodendritic synaptosomes were very similar to those of axonal synaptosomes as determined by electrophoresis on polyacrylamide gels containing sodium dodecyl sulfate (SDS) and 8 M urea.

Animals↗
PubMed1976

Crystals, paracrystals, and rigid tubules in multiple sclerotic brain and spinal fluid.

Brain and spinal fluid were obtained post mortem from an individual with multiple sclerosis who died following carbon monoxide inhalation. Electron microscopic examination of the plaque region revealed a crystalline structure (repeat unit 380 to 410 A) within rough endoplasmic reticulum of astrocytes, a paracrystal (160 to 220 A) within the cytoplasm of astrocytes, and rigid tubules (outer diameter 320 to 450 A) within a cell in the lumen of a capillary. The paracrystal was enclosed by the glial fibrils. A second crystalline material was observed within cells in the 15,000 X g pellet from spinal fluid. The ultrastructural pattern of this second crystal was generated by three sets of parallel lines; a given set was intersected by the other two sets. The crystal had only two different repeat units (410 to 450 A; 310 to 350 A) since the smaller dimension was common for two sets of lines. The two crystals were large; the one in astrocytes had a length of 52,000 A and that in spinal fluid sediment was 62,000 A. These structures were observed in the one multiple sclerotic brain obtained at autopsy but were not detected in multiple sclerotic brains that had been frozen for extended periods. Plaque regions and grossly normal white matter were homogenized and the 1000 X g supernatant of this material was fractionated in a continuous CsCl-sucrose density gradient. Long tubules (320 to 500 A diameter) were observed in the 1.24 to 1.26 density region. The major proteins of the 1.24 to 1.26 fraction had molecular weights clustered at 40,000 to 45,000, 88,000 to 130,000, and 300,000.

Astrocytes↗
PubMedDate not supplied

Public response to elevated nitrate in drinking water wells in Wisconsin.

The authors conducted a survey by mail of Wisconsin families who had their well water tested for nitrate to (a) assess their awareness and compliance with the state's health advisories for nitrate, (b) evaluate their reaction(s) to their test results, and (c) compare demographic differences between exposure levels. Owners of contaminated wells (i.e., > 12.9 mg/l nitrate-nitrogen) were more likely to have lived on a farm, had lower annual incomes, and had older and shallower wells than families whose wells were low in nitrate (i.e., < 2.0 mg/l nitrate-nitrogen). Most respondents were aware of the advisories for pregnant women and infants and, in accordance with these advisories, the majority of families with nitrate-contaminated drinking water took no remedial action. Given that many rural families consume nitrate-contaminated water daily, scientists should conduct additional research to determine whether chronic ingestion of nitrate-contaminated water poses a significant health threat to these families.

Adult↗
PubMedDate not supplied

Recognition of chronic carbon monoxide poisoning.

Chronic exposure to low levels of carbon monoxide can cause vague symptoms that are easily mistaken for other common illnesses. During the past 5 years, three families have contacted the Wisconsin Division of Public Health to report illnesses that may have been caused by chronic exposure to carbon monoxide. Members of these families were diagnosed with a variety of conditions including chronic fatigue syndrome, depression and influenza. Carbon monoxide exposure was not suspected as a cause of these illnesses until heating contractors discovered that gas appliances in these families' homes were not properly vented. These cases serve as reminders that carbon monoxide exposure should be considered in the differential diagnosis of patients who present with chronic symptoms of headache, fatigue, dizziness, nausea and mental confusion--especially when these symptoms onset during the winter heating season.

Adolescent↗