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Biomedical subjects

H H Woo

Publications and source records attributed to H H Woo.

At least 19 recordsLinked to original sources
PubMed2000

Urodynamic assessment of the bashful bladder.

PURPOSE: We prospectively studied the potential contribution of ambulatory urodynamic monitoring in men with urinary symptoms unable to initiate a void on conventional video cystometrography. MATERIALS AND METHODS: A total of 40 consecutive symptomatic men with a median International Prostate Symptom Score of 19 (range 1 to 29) and median age of 51.9 years (range 30 to 75) who were unable to void during video cystometrography underwent ambulatory urodynamic monitoring. Solid-state transducers mounted on silicone coated catheters were inserted urethrally and rectally, and connected to a portable recorder. Subjects voided in private into a specially designed flow meter, which they connected to the recording device. RESULTS: Of the patients 2 (5%) failed to attend ambulatory urodynamic monitoring, despite multiple reminders, and in 1 (2.5%) the trace was uninterpretable. Pressure flow data were available for the remaining 37 patients with mean plus or minus standard deviation 2.72+/-0.1 storage void cycles recorded per patient. All 6 patients (15%) with obstruction were older than 40 years. In 6 cases (15%) obstruction was equivocal and the remainder were unobstructed. Transurethral prostatic resection in 2 and urethrotomy in 1 of 6 patients with obstruction resulted in subjective and objective improvement. CONCLUSIONS: The bashful bladder syndrome was not associated with any specific urodynamic diagnosis. Ambulatory urodynamic monitoring will yield a urodynamic diagnosis in more than 90% of cases after failure to record void data on video cystometrography. A surgically correctable cause of symptoms can be found in about 20% of men older than 40 years. The contribution of ambulatory urodynamic monitoring compared to more conventional evaluation in men younger than 40 years is negligible.

Adult↗
PubMed2000

Single foetal death in twin pregnancies: review of the maternal and neonatal outcomes and management.

OBJECTIVE: To review the maternal and neonatal outcomes, and management of single foetal death in twin pregnancies. DATA SOURCES: Medline literature search (1950 to 1999) and hospital audit of single antepartum foetal deaths in twin pregnancy from 1993 through 1997. DATA SELECTION: Key words for literature search: twin pregnancy/pregnancies; single fetal death/demise. DATA EXTRACTION: Data were extracted and reviewed independently by the authors. DATA SYNTHESIS: During the study period, 182 (0.76%) of 23,804 deliveries involved twin pregnancies. Seven (3.8%) of the twin pregnancies were complicated by the death of one foetus. Single foetal death in a twin pregnancy in the late second and third trimesters is associated with significant morbidity and mortality in the surviving co-twin, especially in a pregnancy involving monochorionic twins. Management should be individualised; conservative management is preferred by most obstetricians. CONCLUSION: Single foetal death in twin pregnancies should be managed in a tertiary referral centre, where intensive foetal surveillance and adequate neonatal support are available. A multidisciplinary approach should be adopted.

Female↗
PubMed1999

Contemporary management of spinal osteomyelitis.

OBJECTIVE: We review the results of treatment of a series of patients with spinal osteomyelitis, to formulate a systematic and comprehensive approach to the management of this disease in light of recent technical and conceptual advances in imaging, spinal biomechanics, and internal fixation. METHODS: We retrospectively reviewed the records for 57 consecutive patients with pyogenic spinal osteomyelitis who were treated between June 1987 and June 1995. Pain and weakness were the most common presenting symptoms. The mean duration of symptoms at the time of diagnosis was 10.6 weeks. Surgical indications included the presence or development of motor deficits with epidural compression and/or localized kyphotic deformities or the failure of medical therapy. RESULTS: Thirty-three patients underwent surgery as their initial treatment. Six additional patients experienced medical therapy failure and received subsequent surgical treatment. Seventeen patients were treated using an anterior approach only, 13 were treated using a posterior approach only, and 9 were treated using a combined anterior and posterior approach. After a minimal follow-up period of 24 months, 93% of the surgically treated patients showed neurological improvement or were neurologically intact, with a mean 16-degree decrease in localized kyphotic deformities and with solid bony fusion and resolution of pain for all patients. CONCLUSION: Early surgical decompression results in rapid improvement of neurological deficits, decreases in kyphotic deformities, and stabilization with bony fusion. The presence of active infection does not preclude the use of internal fixation. Nonsurgical management is indicated for patients with minimal or no neurological deficits and the absence of significant localized kyphotic deformities. However, 25% of patients who were initially treated nonsurgically experienced medical therapy failure and underwent surgical treatment.

Adult↗
PubMed1999

Meristem-localized inducible expression of a UDP-glycosyltransferase gene is essential for growth and development in pea and alfalfa.

PsUGT1, which encodes a microsomal UDP-glucuronosyltransferase, was cloned from root tips of Pisum sativum. PsUGT1 expression is correlated with mitosis and strongly induced in dividing cells. A region at the C terminus of the encoded protein is closely related to the UDP-glucuronic acid binding site consensus sequence, and the protein encoded by PsUGT1 catalyzes conjugation of UDP-glucuronic acid to an unknown compound. Overexpression of PsUGT1 sense mRNA has no detectable effect on transgenic pea hairy root cultures or regenerated alfalfa. However, inhibiting PsUGT1 expression by the constitutive expression of antisense mRNA (under the control of the cauliflower mosaic virus 35S promoter) markedly retards growth and development of transgenic alfalfa. Cell structure and organization in the antisense plants are similar to those of controls, but plant growth is reduced and development is delayed. This inhibition in growth is correlated with a twofold delay in the time required for completion of a cell cycle and with a >99% inhibition of border cell production. Inhibition of PsUGT1 expression by meristem-localized inducible expression of PsUGT1 antisense mRNA (under the control of its own promoter) is lethal both in pea hairy roots and in transgenic alfalfa plants. These results indicate that PsUGT1 expression is required for normal plant growth and development, and they are consistent with the hypothesis that this UDP-glycosyltransferase regulates activity of a ligand(s) needed for cell division.

Amino Acid Sequence↗
PubMed1998

Function of root border cells in plant health: pioneers in the rhizosphere.

Plants dedicate a large amount of energy to the regulated production of living cells programmed to separate from roots into the external environment. This unusual process may be worth the cost because it enables the plant to dictate which species will share its ecological niche. For example, border cells can rapidly attract and stimulate growth in some microorganisms and repel and inhibit the growth of others. Such specificity may provide a way to control the dynamics of adjacent microbial populations in the soil to foster beneficial associations and inhibit pathogenic invasion. Plant genes controlling the delivery of border cells and the expression of their unique properties provide tools to genetically engineer plants with altered border cell quality and quantity. Such variants are being used to test the hypothesis that the function of border cells is to protect plant health by controlling the ecology of the root system.

Journal Article↗
PubMed1997

Cloning of genes whose expression is correlated with mitosis and localized in dividing cells in root caps of Pisum sativum L.

Removal of border cells from pea roots synchronizes and induces root cap cell division, wall biogenesis and differentiation. Three messages which are expressed differentially in such induced root caps have been cloned. Sequence analyses showed that the PsHRGP1-encoded protein has high homology with a homology with a hydroxyproline-rich glycoprotein. The PsCaP23-encoded protein has high homology with an alfalfa callus protein or translationally controlled human or mouse tumor protein P23. The PsRbL41-encoded protein has high homology with a highly basic 60S ribosomal protein L41. In situ hybridization showed that PsHRGP1. PsCaP23 and PsRbL41 messages are localized within dividing cells of the root cap. PsHRGP1 is highly expressed in uninduced root caps, but its message is repressed by 10-11 times as soon as cell division and differentiation begin. Expression of PsHRGP1 recovers to higher than (180%) its initial level in 30 min. PsHRGP1 is root-specific. PsCaP23 and PsRbL41 messages increase ca. 3-fold within 15 min after root cap induction. All three genes represent small families of 3-5 closely related genes in the pea genome.

Amino Acid Sequence↗
PubMed1997

Arachnoid cysts of the cerebellopontine angle: diagnosis and surgery.

OBJECTIVE: The optimal surgical management of arachnoid cysts remains controversial. The cerebellopontine angle (CPA) is a rare location for arachnoid cysts, and only 28 cases of arachnoid cysts occurring in the CPA have been reported in the literature. We discuss the diagnosis, radiographic imaging, and surgical management of CPA arachnoid cysts. METHODS: Five patients (three male and two female patients) with a mean age of 5.6 years have been operated on at our institution since 1980. Magnetic resonance imaging allows for the accurate diagnosis of these arachnoid cysts, which can present with only discrete symptoms, such as headache or ataxia. All five arachnoid cysts compressed the cerebellum or brain stem. One patient had associated hydrocephalus. Three patients presented with refractory headaches associated with nausea and vomiting. The remaining two patients presented with cerebellar signs. No patient had an initial cranial neuropathy. RESULTS: All patients underwent a retrosigmoid suboccipital craniotomy and microsurgical resection and fenestration of the cyst walls. One patient underwent two procedures. A cystoperitoneal shunt was inserted at the first operation. After the shunting procedure, the patient's condition deteriorated; however, after the microsurgical resection and fenestration, his symptoms improved. With a mean 5.2-year follow-up, there has been no evidence of clinical or radiographic recurrence. CONCLUSION: Although CPA arachnoid cysts represent a small number of total arachnoid cysts, the CPA is the second most common location for arachnoid cysts to occur. CPA cysts are congenital lesions found in children who present with subtle signs or symptoms. The definitive treatment for these arachnoid cysts is a retrosigmoid suboccipital craniotomy and microsurgical resection and fenestration of the cyst walls.

Adolescent↗
PubMed1997

Intra-axial tumors of the cervicomedullary junction: surgical results and long-term outcome.

Until recently, intra-axial brainstem tumors were traditionally regarded as surgically inaccessible lesions with a uniformly poor prognosis. However, increasing data indicate that distinct subgroups of brainstem tumors exist that are amenable to surgical intervention. To address this question, we reviewed our experience in the operative management of 39 consecutive patients, in the magnetic resonance imaging (MRI) era, with intra-axial cervicomedullary tumors, in order to determine those factors associated with long-term outcome. Thirty-nine patients (26 male, 13 female) underwent surgery by a single surgeon (F.J.E.) between 1985 and 1994. Mean age of diagnosis was 14 years (range 3 months - 60 years); mean duration of preoperative symptoms was 24 weeks (range 1-168). Twenty patients presented with lower cranial nerve dysfunction and 19 presented with motor and/or sensory dysfunction. All patients were graded according to the McCormick Scale, pre- and postoperatively, and at the time of follow-up. All patients were evaluated with MRI scanning. Twenty-three patients had either previous biopsy or subtotal resection, 13 previous radiation therapy, and 6 previous chemotherapy. The mean time to follow-up was 48 months (range 7-138). Twelve patients underwent gross total resection, 7 near total resection (>90%), 15 subtotal resection (50-90%), and 5 partial resection (< 50%). Histologically, there were 15 low-grade fibrillary astrocytomas, 9 ependymomas, 7 gangliogliomas, 3 anaplastic astrocytomas, 3 juvenile pilocytic astrocytomas, and 2 mixed gliomas. Although the vast majority of tumors were low grade histologically, a higher proportion of the patients with high-grade lesions experienced tumor progression when compared to low-grade tumors (75 vs. 30%). Overall, the 5-year progression-free and total survivals were 60 and 89%, respectively. There was 1 death within the first postoperative month. Preoperative duration of symptoms greater than 15 weeks was associated with a longer progression-free survival. There was a trend for preoperative neurologic grade to predict functional neurologic outcome at follow-up. In summary, intra-axial tumors of the cervicomedullary junction are a distinct subset of brainstem tumors, predominantly of low-grade histology, with favorable long-term progression-free and total survivals following surgical resection. A long duration of preoperative symptoms may indicate an indolent clinical course and a more favorable prognosis. Our data also indicate that early surgical intervention is warranted prior to neurologic deterioration.

Adolescent↗
PubMed1996

Dismembered pyeloplasty in infants under the age of 12 months.

OBJECTIVE: To assess the impact of internal ureteric stenting on the surgical outcome of dismembered pyeloplasty in infants under the age of 12 months. PATIENTS AND METHODS: The case records of 53 of 55 infants with the diagnosis of congenital pelvi-ureteric junction obstruction who underwent dismembered pyeloplasty over a 6-year period were available for review. A total of 63 renal units were treated surgically. The policy for urinary drainage changed during this period from predominantly nephrostomy or no drainage to that of internal ureteric stenting. RESULTS: The post-operative mean (SD) length of stay for stented and non-stented cases was 5.9 (1.8) and 12.4 (5.4) days, respectively (P < 0.001). The mean length of stay for patients with bilateral and unilateral pyeloplasty was 9.7 (4.9) and 8.0 (4.7) days, respectively (P = 0.19). Urinary leaks occurred in non-stented anastomoses and not in stented anastomoses. All three cases which later required revision pyeloplasty had had significant complications associated with urinary leaks. With a minimum follow-up of 24 months, a favourable outcome, as determined by radio-isotope imaging, was achieved in 48 of 51 infants (94%) for whom follow-up data were available. CONCLUSION: The use of internal ureteric stenting in dismembered pyeloplasty performed in infants < 12 months old has, in our hands, led to a dramatic reduction in operative morbidity. The routine use of internal ureteric stents at the time of pyeloplasty is justified.

Anastomosis, Surgical↗
PubMed1996

Contrast-enhancing progressive multifocal leukoencephalopathy: radiological and pathological correlations: case report.

OBJECTIVE AND IMPORTANCE: Progressive multifocal leukoencephalopathy (PML), a demyelinating disease caused by the JC papovavirus, is an opportunistic infection afflicting patients with impaired cellular immunity. Although initially described in patients with hematological malignancies, PML has become associated with several other immunocompromised states, particularly human immunodeficiency virus (HIV) infection. There are numerous central nervous system manifestations in patients with acquired immunodeficiency syndrome. A major characteristic that distinguishes PML from other more common lesions, such as toxoplasmosis or non-Hodgkin's lymphoma, is the lack of contrast enhancement. We describe a case of PML that exhibits contrast enhancement, and we conclude that the diagnosis of PML must be considered in patients with HIV who have contrast-enhancing lesions. CLINICAL PRESENTATION: A 40-year-old woman presented with progressive hemiparesis, blurred vision, and ataxia. Magnetic resonance imaging revealed a contrast-enhancing lesion involving the left middle cerebellar peduncle, causing mild compression of the fourth ventricle. INTERVENTION: The patient underwent a stereotactic serial biopsy with the presumptive diagnosis of moderate- to high-grade glioma. Histological examination of the biopsy specimen revealed early PML. Subsequently, a test for HIV was obtained and the results were positive. CONCLUSION: We have reported another atypical radiographic characteristic of PML associated with HIV. We conclude that PML lesions can enhance after the administration of gadolinium. Therefore, the diagnosis of PML must be entertained in patients whose test results were positive for HIV with contrast-enhancing lesions and that a stereotactic serial biopsy may be necessary to provide a definitive diagnosis.

Adult↗
PubMed1996

Vesico-ureteric reflux and surgically treated pelvi-ureteric junction obstruction in infants under the age of 12 months.

BACKGROUND: Pelvi-ureteric junction obstruction has been increasingly diagnosed in infants, mostly as a consequence of antenatal ultrasound examinations. METHODS: Of 55 infants below the age of 12 months who underwent dismembered pyeloplasty over a 7-year period, we aimed to determine the patterns and outcome of associated vesico-ureteric reflux that was present in 15 (28%) of the 53 infants in whom follow-up was available. RESULTS: A total of eight infants had resolution of their reflux with conservative management and the median time to resolution was 15 months. Five infants proceeded to ureteroneocystotomy. CONCLUSIONS: Given the association of vesico-ureteric reflux and pelvi-ureteric junction obstruction, routine cystography is recommended when the diagnosis of pelvi-ureteric junction obstruction is made.

Cystostomy↗
PubMed1996

The treatment of vesicovaginal fistulae.

OBJECTIVES: To review the options available for the surgical management of vesicovaginal fistulae (VVF). METHODS: A comprehensive review of the literature related to the surgical management of VVF. RESULTS: Numerous methods for the treatment of VVF have been described. The success of surgical treatment is excellent, even for complex fistulae. There is an increasing move towards early rather than delayed repair. Paramount to the success of surgical treatment is adherence to the principles of fistula closure. Use of an interposition flap will greatly improve the chances of a good outcome. When using a transabdominal approach, the omentum should be the tissue of first choice for an interposition flap. CONCLUSION: There are few VVF that are not amenable to successful surgical intervention.

Female↗
PubMed1996

Disseminated ependymomas of the central nervous system.

Ependymomas are rare central nervous system (CNS) neoplasms that occasionally disseminate along the neuraxis or to extraneural sites. Definitive criteria predictive of dissemination have yet to be determined. One hundred forty patients with CNS ependymoma (88 primary spinal and 52 primary intracranial tumors) were surgically treated by the senior author (F.J.E.) between 1986 and 1994. Sixteen patients (11.4%) demonstrated tumor dissemination. The disseminated group consisted of 11 (12.5%) of 88 primary spinal and five (9.6%) of 52 primary intracranial ependymomas. The authors retrospectively reviewed the patients with CNS ependymoma and have identified several characteristics associated with dissemination from the primary tumor site. The mean time from diagnosis to dissemination was 6.8 years. The patients with disseminated disease were younger (16.8 vs. 28.3 years old, p = 0.02), had fewer gross-total resections (29% vs. 68%, p = 0.015), and had tumors with higher proliferative indices (MIB-1 staining, 13.14% vs. 2.06%, p = 0.02). High-grade tumors had a mean proliferation index of 21%, versus 2.4% and 1.6% for myxopapillary and low-grade tumors, respectively (p = 0.0003). In contrast to previous studies, tumor histology was the most significant variable for time to dissemination as determined by multivariate analysis (p = 0.008). Myxopapillary and high-grade tumors were 3.6 and 5.6 times more likely to have a shorter time to dissemination than low-grade tumors. In addition, dissemination is associated with a worse prognosis. At follow-up review, 31% of patients with disseminated disease had died compared to 7% of patients without dissemination (p = 0.04). It is concluded that younger patients with subtotal resections, myxopapillary or high-grade histology, and tumors with high proliferative indices are at substantial risk for the development of disseminated disease during their clinical course.

Adolescent↗
PubMed1995

Molecular cloning and expression of mRNAs encoding H1 histone and an H1 histone-like sequences in root tips of pea (Psium sativum L.).

Two cDNA clones representing mRNAs, highly expressed in pea root tips, were isolated by mRNA differential display. Ribonuclease protection analyses showed different patterns of expression of these two messages in several pea tissues. Sequence analysis showed that the first clone, PsH1b-40, has 100% homology with a previously isolated H1 histone cDNA, PsH1b. However, it has an additional 30 nt at the 3' end which is absent in PsH1b, suggesting possible multiple polyadenylation sites in the same mRNA. The second clone, PsH1b-41, encodes a deduced 19.5 kDa protein of 185 amino acids with an isoelectric point of 11.5. The putative globular domain of the encoded protein showed 67-71% residue identity with globular domains of 28 kDa pea PsH1b H1 histone and Arabidopsis thaliana H1-1 H1 histone. It has 9 repeating motifs of (T/S)XXK. In the C-terminal domain, there are four lysine-rich repeating motifs of SXK(T/S)PXKKXK which may be involved in chromatin condensation and decondensation. Southern blot analysis of nuclear DNA shows that PsH1-41 belongs to a multigene family.

Amino Acid Sequence↗