Biomedical subjects

J D Day

Publications and source records attributed to J D Day.

At least 19 recordsLinked to original sources

PubMed1998

Context modulates effects of nicotine abstinence on human cooperative responding.

The effects of ad libitum smoking, abstinence, and 0-, 2-, and 4-mg nicotine gum on human cooperative responding were examined. Participants were provided the opportunity to respond cooperatively or independently to episodes initiated by a computer-simulated other person. Participants could also initiate episodes that ostensibly provided the other person the opportunity to respond cooperatively or independently of the participant. Working cooperatively added points to both the participant's and other person's counters. Working independently added points only to the participant's counter. Results demonstrated that abstinence decreased cooperative responses during episodes initiated by the computer-stimulated other person. Relative to abstinence and placebo gum conditions, ad libitum smoking and administration of 2- and 4-mg nicotine gum increased these cooperative responses. No gender differences were observed. The number of cooperative episodes initiated by the participants was not affected significantly by the smoking or gum conditions. Nicotine increased reports of vigor and decreased abstinence-engendered reports of depression, anger, confusion, and tension. The difference in the effects of nicotine abstinence on the 2 classes of cooperative responding demonstrates that the social contingency mediates the behavioral effects of abstinence.

Adolescent↗

PubMed1998

Anatomic position of the asterion.

OBJECTIVE: The asterion is defined as the junction of the lambdoid, parietomastoid, and occipitomastoid sutures. The asterion has been used as a landmark in lateral approaches to the posterior fossa. However, its reliability as a landmark comes into question considering the apparent variability of its position. This study was performed to determine the reliability of the asterion as a surgical landmark. METHODS: One hundred dried skulls were obtained for study. A 2-mm drill hole was placed at the asterion on each side. The position of the drill hole on the inner surface of the skull was next determined and recorded. RESULTS: The asterion was located over the posterior fossa dura in 32% on the right and 25% on the left. Its position was over the transverse or sigmoid sinus complex in 61% on the right and 66% on the left. The landmark was located above the transverse-sigmoid sinus complex in 7% on the right and 9% on the left. CONCLUSIONS: The asterion is not a strictly reliable landmark in terms of locating the underlying posterior fossa dura. Its location is very often directly over the transverse-sigmoid sinus complex. Burr holes placed at the asterion may often open the bone directly over the sinus, leading to potential damage.

Anatomy, Artistic↗

PubMed1998

The surgical management of trigeminal neuromas.

OBJECTIVE: Trigeminal neuromas are rare tumors that may involve any part of the nerve complex, including peripheral divisions of the nerve. These rare lesions are treated primarily surgically. We present our series of 38 patients who were treated surgically since 1981, with special emphasis on surgical approach. METHODS: We have surgically treated 38 patients with 39 trigeminal neuromas since 1981. This series of patients was reviewed with regard to clinical presentation, tumor characteristics, surgical approach, and outcome. RESULTS: Sixteen women and 22 men (mean age, 48 yr) all presented with some abnormality of trigeminal dysfunction. Twenty-eight patients presented with trigeminal hypesthesia, 10 with hypesthesia also had facial pain, 3 presented with only facial pain, and 7 presented with diplopia. Eighteen patients had tumors originating from the ganglion, nine from the posterior fossa nerve root, two from the ophthalmic division, and one from the mandibular division, and nine had tumors involving both posterior and middle fossae (dumbbell type). Eighteen tumors were large (>3 cm), 16 were medium sized (2-3 cm), and 5 were small (<2 cm). Tumor location was the prime determinant of surgical approach. Patients with peripheral and ganglion type lesions were treated via an entirely extradural temporopolar approach. Lesions confined to the posterior fossa were approached via a lateral suboccipital approach. Dumbbell-shaped lesions required a combined petrosal strategy. Total resection of tumor was accomplished in 30 patients. Three patients with subtotal resection displayed malignant histology. Postoperatively, 30 patients remained with some degree of trigeminal hypesthesia, two had facial pain (one persistent and one new), and five were left with total trigeminal anesthesia. Four patients were relieved of diplopia, five were relieved of headache, and two were relieved of ataxia. There were no perioperative deaths. CONCLUSION: Trigeminal neuroma is a surgically treatable disease that may be operated on, in many cases, via an entirely extradural approach. These lesions may be successfully resected with low morbidity and a very low rate of recurrence.

Adolescent↗

PubMed1998

The Quilty lesion enigma: focal apoptosis/necrosis and lymphocyte subsets in human cardiac allografts.

Quilty lesions, as first described by Billingham in 1981, or 'Quilty Effect' (QE) are distinct endomyocardial mononuclear cell infiltrates that have been observed in human heart transplant recipients, as well as in experimental models of heart transplantation. In the present investigations, the pattern and extent of apoptosis (programmed cell death) and myocyte necrosis, as well as specific lymphocyte subsets in Quilty lesions was assessed. Endomyocardial biopsies obtained from 13 patients at 10-3362 days post-transplant were examined. Apoptosis, as identified by DNA nick end-labeling, was found in myocytes at the periphery of Quilty lesions in 11 of 13 cases (85%), and 'early' stages of myocyte necrosis, as demonstrated by specific staining with alpha light chain myosin monoclonal antibodies (mAb), was observed at the same sites in 10 of 13 cases (77%) of both Quilty type A and type B lesions. Apoptosis was not identified in the lymphocyte infiltrates of any of the lesions examined. Lymphocyte subsets were characterized using mAb for T cell receptor (CD3), for helper/inducer T cells (CD4), for cytotoxic/suppressor T cells (CD8) and for mature B cells (CD20). Immunostaining revealed separate clusters of T lymphocytes with less prevalent B cells within the Quilty lesions. CD4+ cells were found in larger numbers than CD8+ cells in all cases. Non-B, non-T large lymphocytes were occasionally present. Except for the extent of the cellular infiltrate, no major cytochemical lymphocyte distribution differences were found between Quilty type A and B lesions. Myocyte apoptosis and early necrosis at the periphery of Quilty lesions suggest that early myocyte injury occurring in B lesions may represent initial or 'abortive stages' of cardiac allograft rejection. Why these lesions do not progress to overt rejection indeed warrant further detailed studies.

Actin Cytoskeleton↗

PubMed1998

Neurotopographic considerations in the microsurgical treatment of small acoustic neurinomas.

OBJECT: The authors studied the relationships between tumor size, location, and topographic position relative to the intact facial nerve bundles in acoustic neurinomas to determine the influence of these factors on hearing preservation postoperatively. Consistent topographic relationships were found. METHODS: Four hundred fifty-two patients with acoustic neurinoma treated via a retrosigmoid approach were analyzed with respect to hearing preservation and facial nerve function. One hundred fifteen tumors were identified as small and were categorized as Grades I and II. Patients with Grade I tumors, that is, purely intracanalicular lesions, all had good hearing preoperatively, defined by a less than 50-dB pure tone average and 50% speech discrimination score. All 14 Grade I tumors were removed, resulting in preservation of the patient's hearing by these criteria. There were no particular topographic anatomical relationships associated with these tumors that affected hearing preservation. Grade II tumors, defined as those protruding into the cerebellopontine angle without contacting the brainstem, were found in 101 patients and were divided by size into two grades: IIA (< 1 cm) and IIB (1-1.8 cm). In 90 patients with Grade IIA tumors, 72 (89%) of 81 who had preserved hearing preoperatively maintained it postoperatively, and in the 11 patients with Grade IIB tumors, six of whom had good hearing preoperatively, four (67%) had preserved hearing postoperatively. Six morphological types were identified based on their neurotopographic relationships to the elements of the vestibulocochlear nerve. CONCLUSIONS: Hearing preservation postsurgery by tumor type was as follows: 1A, 92%; 1B, 88%; 1C, 100%; 2A, 83%; 2B, 92%; and 3, 57%. Combined, this represents a hearing preservation rate of 87% after surgical treatment of Grade II acoustic neurinomas. Full nerve function was maintained in 88% of patients with anatomically preserved facial nerves in both Grade I and II tumors. The remaining 12% of patients retained partial function of the facial nerve. Two patients in the series lost anatomical integrity of the nerve due to surgery.

Audiometry, Pure-Tone↗

PubMed1997

The course of the prevertebral segment of the vertebral artery: anatomy and clinical significance.

BACKGROUND: The so called "pretransverse or prevertebral segment" of the vertebral artery is defined from its origin at the subclavian artery to its entry into the respective transverse foramen. In surgery, angiography, and in all noninvasive procedures it is of great importance to know the exact details of the course and the origin of this segment of the vessel as well as in which percentages real abnormalities can be found. METHODS: The VI segment of the vertebral artery was investigated both in anatomic preparations and clinical studies. A total of 402 vertebral arteries were evaluated (70 anatomic preparations in different forms, 181 patients, 95 angiographies of the aortic arch, and 86 color coded doppler sonographies). RESULTS: A contorted course was found in 157 (39%) cases. The plane of tortuosities demonstrated by the respective vessels was found to be horizontal in 40 (44.9%) cases, sagittal in 30 (33.7%) cases, and frontal in 19 (21.4%) cases. In 51 (32.5%) cases the contorted pathway was on the right side, and in 106 (68%) cases, on the left. A hypoplasia was found in 16 (10%) cases--11 (4.8%) right and 5 (2.2%) left. We further differentiated the convexity lying either medially or laterally in the transverse or frontal plane, or oriented dorsally or ventral in the sagittal plane. The exact location of the origin of the artery on the circumference of the subclavian artery (47% cranial, 44% dorsal, 3% ventral, 6% caudal) and also the average values of length and diameter are described. No significant differences between tortuous and nontortuous vessels were found with respect to length and diameter. A real abnormality of the origin of the vertebral artery was found in 8 (3.5%) cases. CONCLUSIONS: The described morphologic variations and frequencies of the VI segment of the vertebral artery have clinical applications in a wide field of pathologies in that region. To know about these findings seems to be very important not only in diagnosis (angiography, color coded doppler sonography) but also in their surgical and endovascular treatment.

Aorta, Thoracic↗

PubMed1997

Heads-up intraoperative endoscopic imaging: a prospective evaluation of techniques and limitations.

OBJECTIVE: Endoscopes have been used adjunctively for spinal and cranial microsurgical procedures and directly for ventricular exploration, fenestration, and catheterization. Technological advances now allow for multi-imaging technologies, including a so-called "heads-up display," allowing the surgeon to view the operative field and the endoscopic image simultaneously. INSTRUMENTATION: A high-resolution, active matrix liquid crystal display is built into the frame of the eyewear, with a display density of 182,000 pixels (280 x 650 pixels) and a resolution of 200 lines. The display occupies approximately 20% of the visual field. The headgear weighs 4 oz, with dimensions of 9 x 18 x 17 cm. The modular interface weighs 7 oz. Two different visualization systems can be used. The first uses a single integrated interface (IM 300), whereas the second (remote 900) is a 900-MHz frequency modulation wireless system that provides for a line-of-sight link between the NTSC source and the modular interface (range = 100 ft). RESULTS: Heads-up adjunctive endoscopy was used in 60 patients during 18 months. The procedures included 16 craniotomies, 1 intradural lumbar biopsy, and 42 ventriculoperitoneal shunt placements. Follow-up was obtained at a minimum of 1 year. Patient age ranged from 1 month to 58 years. The only complication was a transient loss of auditory evoked potentials after contact of the eighth nerve by the endoscope. CONCLUSION: We describe a portable, light-weight heads-up display imaging system, which we have used in 60 operative procedures. Benefits of the heads-up system include portability and a high-resolution digital monocular image, which reduces eye strain and vertigo. The ideal headgear will likely be an extremely high-resolution liquid crystal display-based or cathode ray tube-based semi-immersive system, with all of the benefits currently described for two-dimensional heads-up systems (i.e., light weight, portability, image quality, and the avoidance of complications associated with immersive systems).

Adolescent↗

PubMed1997

Direct microsurgery of dural arteriovenous malformation type carotid-cavernous sinus fistulas: indications, technique, and results.

OBJECTIVE: There is a subgroup of patients with Barrow Type D carotid-cavernous sinus fistulas (CCFs) who have progressive neurological deficits despite endovascular attempts at obliteration. To effectively arrest the progression of neurological deficits, especially visual loss, these patients require direct operative intervention. We have used a direct approach to such lesions, which comprehensively occludes all fistulous connections of the CCF. METHODS: We present a series of nine patients with Type D CCFs for which attempts at endovascular embolization failed and that, because of persistent symptoms, required surgical intervention. These lesions characteristically had extensive multiple external carotid artery feeders, often bilateral, in addition to the internal carotid artery feeders. The operative approach used was a combined extra- and intradural full exposure of the cavernous sinus and its contents, with identification and direct obliteration of all arterial input and selective ablation of the venous outflow from the cavernous sinus. RESULTS: All nine patients experienced resolution of their symptoms, and complete ablation of the lesions, as demonstrated by postoperative angiography, was achieved. Transient diplopia and trigeminal hypesthesia was observed in all nine patients, which resolved by 6 months postoperatively. One patient suffered from a temporary hemiparesis and another from permanent hemiparesis. There were no deaths related to surgery in this series. CONCLUSIONS: Patients with Type D CCFs who have persistent, progressive neurological deficits after failed endovascular attempts at obliteration may be treated by a direct surgical approach to ablate the fistulas. The pertinent anatomic concepts, indications for surgery, and operative techniques that are different from previously described methods are discussed.

Adolescent↗

PubMed1997

Cranial base approaches to posterior circulation aneurysms.

Aneurysms arising from the posterior circulation, especially when they are large and complex, continue to present a technical challenge. The development of cranial base strategies and principles has added to surgical management options. The authors used one of four cranial base approaches for the treatment of 30 patients with large and/or complex aneurysms arising from the vertebrobasilar circulation. These approaches included the extradural temporopolar, combined petrosal, retrolabyrinthine-transsigmoid, and the extreme-lateral inferior transtubercular exposure. The indications, technique, and results of each approach in this series are discussed, and a management paradigm is suggested for such aneurysms.

Adult↗

PubMed1996

Immunohistochemical evaluation of HER-2/neu expression in pancreatic adenocarcinoma and pancreatic intraepithelial neoplasms.

Although several morphological and molecular genetic studies have implicated various grades of pancreatic duct hyperplasia as precursor lesions to infiltrating pancreatic adenocarcinoma, the identity of preinvasive pancreatic neoplasms remains controversial. In the present study, the authors examined the expression of the epidermal growth factor receptor homologue, HER-2/neu (c-erbB-2), in pancreatic duct lesions adjacent to infiltrating pancreas cancers in a series of 19 cases of pancreatic duct adenocarcinoma. HER-2/neu expression was examined because it has been identified in a proportion of infiltrating pancreas cancers and because it may provide early neoplasms with a growth advantage over adjacent nonneoplastic epithelium. In normal pancreatic ducts and ductules, HER-2/neu expression was absent in all but one case. By contrast, HER-2/neu was expressed in 82% (P = .008 vs normal ) of ducts with flat mucinous hyperplasia, 86% (P = .03 vs normal) of ducts with papillary mucinous hyperplasia without atypia, 92% (P = .001 vs normal) of ducts with atypical papillary mucinous hyperplasia, and all specimens with carcinoma in situ. HER-2/neu expression was observed in 69% (P = .002 vs normal) of the moderately differentiated infiltrating carcinomas and none of the poorly differentiated infiltrating carcinomas. These data establish HER-2/neu as a potential mediator of growth factor-related signal transduction in pancreatic duct lesions, and provide additional support for the hypothesis that lesions formerly regarded as various grades of hyperplasia instead may represent intraepithelial neoplasms with the potential for subsequent invasion and metastasis.

Adenocarcinoma↗

PubMed1996

Vagus nerve stimulation activates central nervous system structures in epileptic patients during PET H2(15)O blood flow imaging.

OBJECTIVE: To determine the central areas of activation by vagal nerve stimulation (VNS) in epilepsy. VNS is a promising neurosurgical method for treating patients with partial and secondary generalized epilepsy. The anti-epileptic mechanism of action from VNS is not well understood. METHODS: We performed H2(15)O PET blood flow functional imaging on three patients with epilepsy in a vagal nerve stimulation study (E04 Protocol with Cyberonics). The three patients included two that had previous epilepsy surgery but continued to have frequent seizures. Seizure onset was frontal in two patients and bitemporal in the third patient. Twelve PET scans per subject were acquired every 10 minutes with a Siemens 953/A scanner. In 6 stimulus scans, VNS was activated for 60 seconds (2 mA, 30 Hz) commensurate with isotope injection. In 6 control scans no VNS was administered. No clinical seizures were present during any scan. Three way ANOVA with linear contrasts subject, task, repetition) of coregistered images identified significant treatment effects. RESULTS: The difference between PET with VNS and without revealed that left VNS activated right thalamus (P < 0.0006), right posterior temporal cortex (P < 0.0003), left putamen (P < 0.0002), and left inferior cerebellum (P < 0.0009). CONCLUSIONS: VNS causes activation of several central areas including contralateral thalamus. Localization to the thalamus suggests a possible mechanism to explain the therapeutic benefit, consistent with the role of the thalamus as a generator and modulator of cerebral activity.

Adult↗

PubMed1996

Neurological surgery at the University of Vienna.

ANTON VON EISELSBERG was the first to resect a cerebral tumor at the First Surgical Clinic at the General Hospital in Vienna in 1904. He successfully removed a cerebral glioma, the first of no fewer than 15,000 tumors operated on at that hospital to date. von Eiselsberg and his successors, Egon Ranzi and Leopold Schönbauer, as heads of the First Surgical Clinic, devoted themselves intensively to brain surgery, and neurosurgery developed to be an integral part of Viennese surgery. During the first decades, a prominent neurologist, Otto Marburg, and a world-famous anatomist, Julius Tandler, were members of the neurosurgical operating team. This approach changed in the 1950s, when the brain surgeons aimed at becoming independent of the basic sciences. The founding of an independent neurosurgical department at the University of Vienna in 1964 under Herbert Kraus also marked the beginning of the formation of specialized sections for pediatric and stereotactic neurosurgery. After 1968, the operating microscope was greatly emphasized. As of 1970, cerebral tumors and cerebrovascular lesions were treated microneurosurgically. Many operations were performed by surgeons who were experienced in neurosurgery. This again changed in 1978 under the new head of the department, Wolfgang Koos, who regarded the neurosciences as the basis for neurosurgical training as well as neurosurgical activity. The reorganization of the neurosurgical institution coincided with the construction of a large modern building with state-of-the-art equipment for microneurosurgery, radiosurgery (gamma knife), neurodiagnostics, laboratories, etc. Many details of the construction plans, the equipment, and the organization of the department have their roots in the years that the present head of the department spent in the United States; this is also the reason for the close connection and cooperation of Vienna neurosurgery with many neurosurgeons in the United States.

Austria↗

PubMed1996

Surface and superficial surgical anatomy of the posterolateral cranial base: significance for surgical planning and approach.

We have performed an anatomic study, 15 using fixed cadaveric preparations, with the goal of identifying surface landmarks that will reliably locate the underlying transverse and sigmoid sinus complex. Simple morphometric relationships were first determined on both sides of each specimen to yield 30 sides measured. The following relationships were determined: 1) zygoma root-asterion, 2) asterion-mastoid tip, 3) zygoma root-suprameatal spine (Henle's spine), 4) asterion-suprameatal spine, 5) mastoid tip-suprameatal spine. The relationship of the asterion to the transverse-sigmoid junction was determined by bone removal. Also, the distances from the asterion to the sigmoid sinus-superior petrosal sinus junction and the superior margin of the transverse sinus were studied. Surface and marks were found to have definitive relationships to underlying anatomic substrates in all specimens studied. The critical relationships that were concluded from this study can be described in terms of two easily identified lines between bony surface structures. A line drawn from the zygoma root to the inion, i.e., the superior nuchal line, reliably located the rostrocaudal level of the transverse sinus in all specimens. Although the asterion did not consistently fall on this line, the transverse-sigmoid junction could reliably be placed at the anteroposterior level of the asterion. Further, a line drawn from the squamosal-parietomastoid suture junction to the mastoid tip reliably defined the axis of the sigmoid sinus through the mastoid. We also found that the junction of the squamosal and parietomastoid sutures lay over the anterior border of the upper curve of the sigmoid sinus. The anterior portion of the supramastoid crest correlated with the level of the middle fossa. These surface relationships all have significance for posterolateral approaches to the cranial base. Since performing this study, these relationships have been found reliable for operative planning in our clinical cases.

Cephalometry↗

PubMed1996

Innovations in surgical approach: lateral cranial base approaches.

The extradural anterior transpetrosal approach possesses several advantages. First, the majority of the dissection is extradural, providing protection to the overlying neural structures. Second, only limited retraction of the temporal lobe is necessary, protecting venous outflow via the vein of Labbe'. Third, transposition of cranial nerves or vascular structures in unnecessary. Fourth, it enjoys natural compatibility with other surgical approaches to enhance exposure of the posterior cavernous sinus and petroclival region. The disadvantages are mostly related to the unfamiliar anatomy. Most surgeons are not accustomed to visualizing petrous apical anatomy from the middle fossa orientation. Therefore, practice of this technique in the cadaver laboratory is a mandatory prerequisite to its performance in the operating room. The cochlea, carotid artery, labyrinth, and cranial nerves five through eight are all at risk during drilling and dissection. When performed properly, this technique provides a solid adjunct to treating complex lesions of the central cranial base.

Cavernous Sinus↗

PubMed1995

Endoscopically assisted microneurosurgery.

Technological developments in neuroendoscopy are leading to an expansion of applications into the realm of microneurosurgical procedures. The new dimension that using an endoscope provides requires insight into different neuroanatomical aspects and a new kind of strategy in planning a microneurosurgical procedure. To gain some new insights into these exciting aspects of neurosurgery we have explored the sellar, parasellar, and posterior fossa regions in 50 fresh anatomical specimens and used various types of endoscopes to observe the surgically relevant neurotopographical details. We then utilized this experience in 33 clinical cases during microsurgical approaches for various lesions (posterior fossa tumors - 12 cases, sellar and parasellar tumors - 8 cases, trans-sphenoidal procedures for pituitary adenoma - 7 cases, transventricular procedures - 6 cases). In the laboratory we found that familiar neuroanatomical structures are seen in a completely different aspect from what we are accustomed. Orientation is at times difficult, which requires rehearsal and special handling of the endoscope for complex clinical procedures. We found that certain structures that are hardly noticed in routine anatomical views become very important when utilizing the endoscope (i.e., different arachnoid membranes and trabeculae). Importantly, the dimensions of a microsurgical approach can be greatly enlarged with the endoscope, making it possible to look behind structures and ''around corners''. We present our findings with respect to important anatomical details relevant to utilizing the endoscope as an adjunct to microneurosurgical procedures and our clinical data. We have concluded that the neuroendoscope can be a safe and helpful adjunct in many microneurosurgical procedures.

Endoscopy↗

PubMed1995

The transfacet pedicle-sparing approach for thoracic disc removal: cadaveric morphometric analysis and preliminary clinical experience.

A number of operative techniques have been described for the treatment of herniated thoracic discs. The transfacet pedicle-sparing approach allows for complete disc removal with limited spinal column disruption and soft-tissue dissection. Fifteen cadaveric spinal columns were used for evaluation of exposure, development of thoracic microdiscectomy instrumentation, and establishment of morphometric measurements. This approach was used to remove eight thoracic discs in six patients. Levels of herniation ranged from T-7 through T-11. Preoperatively, all patients had moderate to severe axial pain, and three (50%) of the six had radicular pain. Myelopathy was present in four (67%) of the six patients. Through a 4-cm opening, the ipsilateral paraspinal muscles were reflected, and a partial facetectomy was performed. The disc was then removed using specially designed microscopic instrumentation. Postoperatively, the radiculopathy resolved in all patients. Axial pain and myelopathy were completely resolved or significantly improved in all patients. The minimal amount of bone resection and muscle dissection involved in the operation allows for: 1) decreased operative time and blood loss; 2) diminished perioperative pain; 3) shorter hospitalization time and faster return to premorbid activity; 4) avoidance of closed chest tube drainage; and 5) preservation of the integrity of the facet-pedicle complex, with potential for improvement in outcome related to axial pain. This technique appears best suited for the removal of all centrolateral discs, although it has been used successfully for treating a disc occupying nearly the entire ventral canal. The initial experience suggests that this approach may be used to safely remove appropriately selected thoracic disc herniations with good results.

Adult↗

PubMed1995

Intimate association of eosinophils to collagen bundles in eosinophilic myocarditis and ranitidine-induced hypersensitivity myocarditis.

BACKGROUND: Eosinophilic myocarditis is an inflammatory condition of the heart in which the infiltrate is composed predominately of eosinophils. DESIGN: We identified three cases of eosinophilic myocarditis in which the infiltrating eosinophils showed a remarkable intimate association with bundles of collagen. Two of the hearts examined were explants from heart transplant recipients with hypersensitivity myocarditis at the time of transplant and the third was from an autopsied patient with Churg-Strauss syndrome. These hearts were examined using light and electron microscopy. The cellular infiltrate in all three cases was characterized using immunoperoxidase stains with a panel including antibodies against myeloperoxidase, common leukocyte antigen (CD45), B lymphocytes (CD20), T lymphocytes (CD3), active-memory T lymphocytes (CD45RO), inactive T lymphocytes (CD45RA), and macrophages (CD68). RESULTS: Ultrastructural examination in all three cases confirmed the apposition of eosinophils to both large bundles of collagen and smaller aggregates of collagen fibrils. The eosinophils and the bundles of collagen stained strongly for myeloperoxidase, suggesting at least partial degranulation of the eosinophils. A KP-1 stain (CD68) revealed macrophages admixed with the eosinophils adjacent to the collagen bundles, and stains for CD45RA (naive lymphocytes) and CD45RO (memory T cells) showed an interstitial infiltrate of predominantly CD45RO-positive cells. Clinically, the cardiac decompensation of one of the transplant patients was most likely due to ranitidine-induced hypersensitivity myocarditis. CONCLUSIONS: These results suggest that some cases of eosinophilic myocarditis may be caused by the expression of novel antigens bound to collagen bundles. In one of the patients awaiting cardiac transplant, cardiac decompensation was temporally associated with ranitidine therapy, an agent not previously implicated as a cause of hypersensitivity myocarditis.

Adult↗

PubMed1995

Twin pregnancy diagnosis in Holstein cows: discriminatory powers and accuracy of diagnosis by transrectal palpation and outcome of twin pregnancies.

The objective of this prospective cohort study was to determine the sensitivity, specificity, accuracy, and predictive value of twin pregnancy diagnosis by rectal palpation and to examine fetal survival, culling rates, and gestational lengths of cows diagnosed with twins. In this prospective study, 5309 cows on 14 farms in California were followed from pregnancy diagnosis to subsequent abortion or calving. The average sensitivity, specificity, accuracy, and predictive value of twin pregnancy diagnosis were 49.3%, 99.4%, 96.0%, and 86.1%, respectively. The abortion rate for single pregnancies of 12.0% differed significantly from those for bicornual twin pregnancies and unicornual twin pregnancies of 26.2% and 32.4%, respectively (P < 0.05). The early calf mortality between cows calving with singles (3.2%) and twins (15.7%) were significantly different (P < 0.005). The difference in fetal survival between single pregnancies and all twin pregnancies resulted in 0.42 and 0.29 viable heifers per pregnancy, respectively. The average gestation for single, bicornual, and unicornual pregnancies that did not abort before drying-off was 278, 272, and 270 days, respectively. Results of this study show that there is an increased fetal wastage associated with twin pregnancies and suggest a need for further research exploring management strategies for cows carrying twins.

Abortion, Veterinary↗