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Biomedical subjects

D Penney

Publications and source records attributed to D Penney.

At least 19 recordsLinked to original sources
PubMed2006

Intussusception: a rare cause of abdominal pain in pregnancy.

A 34-year-old woman presented at 19 weeks in her third pregnancy with abdominal pain and hyperemesis. This was her third admission during the pregnancy for similar complaints. A few days after admission an exacerbation in her pain was noted, in particular on eating or lying down, and a firm and mobile epigastric mass could be palpated separate from her uterus. The differential diagnosis was a hernia or a degenerating pedunculated fibroid. Sonography revealed a mass separate from the uterus with an appearance consistent with intussusception. Magnetic resonance imaging confirmed the diagnosis. A limited right hemicolectomy was performed. The final diagnosis was adenocarcinoma of the colon. It is difficult to diagnose intussusception during pregnancy. The presenting symptoms of nausea, vomiting, abdominal pain and constipation are common in pregnancy and the displacement of the bowel by the gravid uterus hampers examination. Intussusception is very rare in adults and generally it is associated with tumors. Preoperative diagnosis is difficult but possible with accurate imaging.

Abdominal Pain↗
PubMed2000

Transplantation of embryonic porcine mesencephalic tissue in patients with PD.

OBJECTIVE: To assess the safety and the effect on standardized clinical rating measures of transplanted embryonic porcine ventral mesencephalic (VM) tissue in advanced PD. METHODS: Twelve patients with idiopathic PD underwent unilateral implantation of embryonic porcine VM tissue; six received cyclosporine immunosuppression and six received tissue treated with a monoclonal antibody directed against major histocompatibility complex class I. Patients were followed for 12 months and assessed by clinical examination, MRI, and 18F-levodopa PET. Porcine endogenous retrovirus testing was conducted by PCR-based method on peripheral blood mononuclear cells. RESULTS: Cell implantation occurred without serious adverse events in all patients. Cultures were negative for bacterial and unknown viral contamination. No porcine endogenous retrovirus DNA sequences were found. MRI demonstrated cannula tracts within the putamen and caudate, with minimal or no edema and no mass effect at the transplant sites. In the medication-off state, total Unified Parkinson's Disease Rating Scale scores improved 19% (p = 0.01). Three patients improved over 30%. There were two patients with improved gait. 18F-levodopa PET failed to show changes on the transplanted side. CONCLUSIONS: Unilateral transplantation of porcine embryonic VM cells into PD patients was well tolerated with no evidence of transmission of porcine endogenous retrovirus. Changes in standardized clinical PD rating measures were variable, similar to the results of the first trials of unilateral human embryonic allografts that transplanted small amounts of tissue.

Aged↗
PubMed1997

Histological evidence of fetal pig neural cell survival after transplantation into a patient with Parkinson's disease.

The movement disorder in Parkinson's disease results from the selective degeneration of a small group of dopaminergic neurons in the substantia nigra pars compacta region of the brain. A number of exploratory studies using human fetal tissue allografts have suggested that transplantation of dopaminergic neurons may become an effective treatment for patients with Parkinson's disease and the difficulty in obtaining human fetal tissue has generated interest in finding corresponding non-human donor cells. Here we report a post-mortem histological analysis of fetal pig neural cells that were placed unilaterally into the caudate-putamen brain region of a patient suffering from Parkinson's disease. Long-term (over seven months) graft survival was found and the presence of pig dopaminergic neurons and other pig neural and glial cells is documented. Pig neurons extended axons from the graft sites into the host brain. Furthermore, other graft derived cells were observed several millimeters from the implantation sites. Markers for human microglia and T-cells showed only low reactivity in direct proximity to the grafts. This is the first documentation of neural xenograft survival in the human brain and of appropriate growth of non-human dopaminergic neurons for a potential therapeutic response in Parkinson's disease.

Aged↗
PubMed1997

Vernix caseosa: an unusual cause of post-cesarean section peritonitis.

Surgeons should be aware of a very unusual cause of post-cesarean section peritonitis. This rare form of peritonitis is caused by the spillage of vernix caseosa material into the peritoneal cavity. The exact mechanism of the development of peritonitis in these few cases is unknown. Clinically, vernix caseosa peritonitis should be considered in the post-cesarean section acute abdomen after excluding the more common causes of peritonitis such as appendicitis and perforated viscus. Intraoperatively, the presence of cheese-like yellow patches limited to the serosal layer of visceral organs is the most characteristic feature. Histopathological examination of these serosal patches reveal the desquamated anuclear squamous cells confirming the diagnosis. Postoperative treatment with antibiotics should be continued. The addition of steroids (only after confirming the diagnosis pathologically) has a significant effect on improving the clinical outcome.

Abdomen, Acute↗
PubMed1993

Use of pericranial flaps in the management of cranial base trauma.

Pericranial flaps based on the musuloaponeurotic or myofacial layers of the scalp have great utility in the management of acquired and congenital craniofacial deformities. Their use in traumatic deformities is indicated in the presence of craniopharyngeal communications and significant anterior cranial fossa dead space created from frontal sinus obliteration. The indications and operative techniques and the results of the use of these flaps in 10 consecutive patient with extensive cranial base trauma are presented.

Journal Article↗
PubMed1991

A percutaneous liver biopsy technique in ducks (Anas platyrhynchos) experimentally infected with duck hepatitis B virus.

Aylesbury ducks (Anas platyrhynchos) chronically infected with the duck hepatitis B virus provide a useful model for studying hepadna-virus infection, replication and the effects of antiviral therapy. In these studies, it is necessary to have an effective method for obtaining repeat liver specimens for histological and molecular analyses. We have therefore developed a percutaneous liver biopsy technique which has a low rate of complications, can be performed at repeated intervals, and provides sufficient quantities of liver tissue for histological and nucleic acid hybridization analysis.

Animals↗
PubMed1989

Serum markers for prediction of pulmonary radiation syndromes. Part I: Surfactant apoprotein.

Detection of a biochemical marker indicating radiation lung injury prior to the onset of clinical pathologic events could prove valuable in patient management. An increased level of alveolar surfactant is one of the earliest detectable changes following lung irradiation, starting within hours of irradiation and persisting a maximum of 2-6 weeks. However, because broncho-alveolar lavage is impracticable and endothelial cell damage due to radiation results in changes in permeability of vessel wall with leakage of alveolar proteins into serum, identification of serum markers was sought. A series of experiments in rabbits are described that clearly demonstrate serum surfactant apoprotein is an accurate marker and predictor for later lethal radiation pneumonitis. At 3-7 days after graded single doses to lung, surfactant was found in the serum paralleling the dose response for lethality. Control studies with a physiologic agent such as terbutaline release alveolar surfactant, but no serum surfactant was detected. Monitoring serum surfactant could direct preventive intervention prior to clinicopathologic manifestation of pulmonary radiation syndromes.

Animals↗
PubMed1989

Hypothermia protects brain function in acute carbon monoxide poisoning.

The role of body temperature in the morbidity and mortality resulting from acute severe carbon monoxide (CO) poisoning (2400 ppm CO, 90 min) was investigated using an unanesthetized animal model. Modified Levine prepared female rats (left common carotid artery and jugular cannulated) displayed a lower rate of recovery period (4 hr) re-warming, and an increased mortality rate and behaviorally-assessed neurologic index (NI) compared to normal rats. This indicated their greater susceptibility to CO hypoxia, although the degree of CO-induced hypothermia was the same in both groups. The whole-body cooling of Levine rats to a similar extent prior to CO exposure increased somewhat the post-CO re-warming rate, and marginally decreased NI and mortality during CO exposure (in-CO). In contrast, maintenance of constant body temperature by external heating during CO exposure resulted in a negative post-CO re-warming rate and sharply increased NI and in-CO mortality. Normal euthermic rats were much less severely affected by CO. The results suggest that hypothermia, whether CO-induced or produced by prior cooling, provides measurable protection of brain function during acute severe CO poisoning, and that maintenance of body temperature increases in-CO mortality and interferes with ability to thermoregulate and increases NI in survivors.

Animals↗
PubMed1988

A comparison of the adherence of fimbriated and nonfimbriated Haemophilus influenzae type b to human adenoids in organ culture.

Adherence of fimbriated and nonfimbriated variants of a single strain of Haemophilus influenzae type b to organ cultures of human adenoidal tissue was measured by three assays, two of which were quantitative. In one assay, the adherence of radioactively labeled bacteria was measured; the numbers of CFU of bacteria per gram of adenoidal tissue were 16.0 +/- 6.7 for fimbriated bacteria and 10.2 +/- 4.0 for nonfimbriated bacteria (P less than 0.05). In the second assay, adherent CFU were determined directly; the results were 23.4 +/- 17.2 CFU/g of tissue for fimbriated bacteria and 5.1 +/- 2.2 CFU/g for the nonfimbriated variant (P less than 0.02). By combining data from the two assays it appears that fimbriated and nonfimbriated bacteria do not compete for the same site on the tissue, and that the adherent bacteria do not change their state of fimbriation under the assay conditions used. In contrast, the third assay, scanning electron microscopy, showed very poor adherence of nonfimbriated bacteria. Fimbriated bacteria, on the other hand, adhered in clusters to nonciliated epithelial cells. Overall, the data indicate that fimbriae enhance adherence of H. influenzae type b to a type of tissue that is a normal site of human colonization and that nonfimbriated bacteria adhere by a distinctly different mechanism.

Adenoids↗
PubMed1980

Use of carbon labeling to demonstrate the role of blood monocytes as precursors of the 'ameboid cells' present in the corpus callosum of postnatal rats.

Cells with features suggestive of ameboid motion and phagocytic properties are observed in the rat corpus callosum during the first few days of life. These cells, hereafter referred to as 'ameboid cells', have been investigated in several ways. An electron microscopic study of the corpus callosum in 5- to 7-day-old rats indicated that most 'ameboid cells' were typical macrophages, but some displayed features of monocytes, while others appeared to be transitional between the two types. These observations raised the possibility that blood monocytes were the precursors of 'ameboid cells'. This possibility was tested by injecting a suspension of carbon particles into the circulation of rats of various ages to label and trace monocytes. Within 15 minutes after injection, carbon particles were seen between cells in blood smears as well as in the lumen of capillaries, but not between cells and axons in corpus callosum. By a half hour, a few of the circulationg monocytes, and with time, up to half of them, contained carbon particles. Five days after injection, carbon particles were observed in cells of the corpus callosum identified as 'ameboid cells' of the monocytic and macrophagic type. Such carbon-containing cells were seen in many of the animals injected at the age of 0-1 day, in few of those injected at 3-5 days, and in none of the older animals. Since free carbon had not been observed in corpus callosum spaces, it was concluded that 'ameboid cells' did not pick up carbon locally. The alternative was that blood monocytes, after ingesting carbon particles in the circulation, migrated to the corpus callosum and settled as 'ameboid cells'. In the hope of obtaining a direct confirmation of this conclusion, blood cells obtained from carbon-injected Lewis rats were centrifuged in a Percoll gradient to obtain a fraction which contained 70-80% monocytes, less than 2% granulocytes, and 20-30% lymphocytes. Carbon was present in up to half of the monocytes and 1% of the granulocytes, but not in the lymphocytes; and it was calculated that over 99% of the carbon-labeled cells were monocytes. The cell fraction was then introduced into the blood circulation of 2- to 3-day-old syngeneic Lewis rats, and the animals were sacrificed 5 days later. Occasional carbon-labeled cells appeared not only in liver, spleen and connective tissue, but also in the corpus callosum, where they were identified as 'ameboid cells' of the monocytic and macrophagic type. Even though such cells were infrequent, their presence conclusively demonstrated that at least some 'ameboid cells' of the corpus callosum were derived from circulating blood monocytes.

Age Factors↗
PubMed1976

Effect of acute carbon monoxide poisoning on serum lactate dehydrogenase and creatine phosphokinase.

Young adult rats were exposed to 1,500 ppm CO in air for 2 hr. Blood carboxyhemoglobin (COHb) concentration immediately postexposure was 55.68 +/- 0.90%. Serum lactate dehydrogenase (LDH) activity peaked at 117% above control 2 hr postexposure, while serum creatine phosphokinase (CPK) activity was maximal at 132% above control immediately following termination of exposure. Serum LDH activity declined to control within 8 hr, while serum CPK undershot controls at 8 hr and returned to the control value by 24 hr.

Animals↗
PubMed1976

Effects of early severe malnutrition on heart and skeletal muscle lactate dehydrogenase.

Following weaning, rats from litter sizes of 15 to 20 were subjected to severe food restriction for 10 weeks, and compared to rats from litter size 5 fed ad libitum. Percent M (muscle type) lactate dehydrogenase, M and H (heart type) subunit activity and lactate dehydrogenase activity (per g wet weight) determined both electrophoretically and spectrophotometrically were all significantly lower in separated left and right ventricles of the malnourished rats. There were no differences in skeletal muscle lactate dehydrogenase activity. Following 5 weeks of ad libitum feeding, the previously malnourished rats showed large increases in body weight. Now only the right ventricle showed slight decreases in H subunit and lactate dehydrogenase activity; other measurements in the right ventricle and all in the left ventricle had returned to control levels. Skeletal muscle lactate dehydrogenase activity was not different from controls.

Age Factors↗
PubMed1975

Hematological alterations and response to acute hypobaric stress.

Exposure of rats to simulated altitude (15,000 ft) for 1 day and 3 and 9 wk produced progressive polycythemia, elevated 2,3-diphosphoglycerate levels and raised P50 values; the latter two parameters decreased toward control values after 9 wk. Carbon monoxide (38-43% HbCO) exposure produced polycythemia after 3- and 9-wk exposure, no change in 2,3-DPG and a fall in P50 value. Ten days' treatment with sodium cyanate produced a large decrease in 2,3-DPG and P50. Survival during 90 min of acute hypobaria (0.3 atm) under Nembutal anesthesia was highest with NaOCN (75%), intermediate with 3- and 9-wk exposure to altitude and CO (56-58%) lower in 1-day altitude exposure (44%) and lowest in controls (5%). Heart and ventilation rate was monitored during this hypobaric test and response patterns established for each exposure/treatment. In states of extreme oxygen deprivation the results suggest, in order of importance, the survival value of 1) increased oxygen-hemoglobin affinity, and 2) polycythemia.

Altitude↗