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P Valencia-Mayoral

Publications and source records attributed to P Valencia-Mayoral.

At least 19 recordsLinked to original sources
PubMed2005

Experience of a successful pediatric liver transplant program in Mexico.

Orthotopic liver transplantation (OLT) has been very difficult to develop in Mexico and for many years its occurrence was anecdotal. This report presents the results of a pediatric liver transplant program, analyzing the variables that affect outcomes. Between June 1998 and March 2004, 35 OLT were performed in 34 recipients including 80% cadaveric whole-organ grafts and 20% segmental grafts, with 11% from cadaveric and 9% from living donors. Most of the recipients were infants or toddlers weighing less than 15 kg. There was only 1 case of arterial thrombosis (2.8%); the graft was saved with a Kasai procedure. Biliary complications were present in 22% of cases, all resolved with reoperations. Posttransplant cytomegalovirus infection or reactivation (28%), acute rejection (25%), or posttransplant lymphoproliferative disorders (5.7%) were not a cause of graft or patient loss. Overall, 1- and 5-year patient survival rates are 77.1% and 74.2%, respectively; however, when the 1998-2000 cohort was compared with the 2001-2004 cohort, there was a significant difference in survival (P = .004). The 1-year patient survival for the later group is 91.6%. We performed the first successful living donor liver transplantation and the first simultaneous liver-kidney transplantation in a child in our country. Our results demonstrate that pediatric liver transplantation is a feasible undertaking in Mexico, with survival rates comparable to those of foreign centers.

Cadaver↗
PubMed1993

The right atrioventricular valvular apparatus in the chick heart.

The purpose of this study was to describe the detailed anatomy and histology of the right atrioventricular valve apparatus in the chicken. Newborn and adult chicken hearts were studied by anatomic description, light and scanning electron microscopy, and histologic (Masson's trichrome stain) and histochemical (Sirius Red stain) techniques. Our findings indicate the presence of an incomplete fibrous annulus, a great mural leaflet, and multiple microleaflets in the right atrioventricular apparatus of the chicken heart. The great mural leaflet, essentially muscular in structure, extended from the anterior and posterior juxtaseptal commissures and was subdivided into an anterior and a posterolateral region by the attachment of the anterolateral papillary muscle. The posterolateral region presented an intermediate cleft, subdividing this region into an anterior and a posterior portion. Multiple microleaflets, which adhered to the upper right side of the ventricular septum adjacent to the right atrioventricular orifice, inserted directly into the ventricular septum via short chordae tendineae, without papillary muscles. The microleaflets were composed of smooth subendocardial connective tissue, with varying amounts of type I, II and III collagen. In addition, we observed a central fibrous body, leading to fibrous continuity between the mitral and aortic valves and the mitral and right atrioventricular valves. An atrioventricular septum was also present.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

[Central nervous system pathology in children with AIDS].

The neuropathological manifestations of AIDS in children vary widely and includes, among others: cerebral atrophy, basal ganglia calcification, corticospinal tract demyelinization, and HIV encephalomyelitis with multinucleated cells. The purpose of this work is to inform the postmortem CNS findings in 14 pediatric AIDS patients which were studied from January 1986 to February 1992, at the Hospital Infantil de México Federico Gómez. Basal ganglia vascular calcification, HIV multinucleated cells, and corticospinal tract demyelinization, were significantly less frequent (P < 0.01) in our patients than those informed in the literature. Opportunistic CNS infections found in our patients were produced by microorganisms commonly described in adults. We think that these differences may be explained because the majority of our patients acquired the infection trough blood transfusion at an age in which the CNS is fully developed. The pattern of HIV transmission in our country has been changing recently with an increase in the number of perinatal cases. We also think that in the near future we will observe a change in the neuropathological findings of our pediatric AIDS population.

Acquired Immunodeficiency Syndrome↗
PubMed1992

[Oral manifestations in HIV positive children].

Oral manifestations of HIV infection in children include oral candidiasis, herpetic stomatitis, oral hairy leukoplakia, parotid gland swelling, and other bacterial, viral and mycotic infections. The frequency and natural history of those disorders are not fully defined. The purpose of this work is to inform the oral findings in 57 HIV infected children studied at the Hospital Infantil de Mexico. All 57 patients presented nonspecific gingivitis; however it was not feasible to associate it with the HIV infection; in 28 oral candidiasis was observed, and in 3 cases herpetic stomatitis was documented. Oral candidiasis was found regardless the patient's sex, age, clinical stage, treatment, and mode of transmission of the HIV infection. It has been considered that oral candidiasis is a good marker of immunodeficiency; however, in our patients this correlation was not observed. Also, other HIV-associated oral manifestations were not observed in these cases. The severity and rapid clinical course presented by our patients, may explain both, the lack of correlation between candidiasis and immunodeficiency as well as the absence of other lesions.

Child↗
PubMed1992

[Nephrotic syndrome associated with AIDS in children].

Several renal and renal-related disturbances have been described in patients with AIDS (acquired immune deficiency syndrome), in adults and children as well. These are mainly electrolyte and acid-base imbalance, acute renal failure and nephrotic syndrome. The latter is usually steroid non-responder. The renal histopathological lesions described more commonly are minimal change, mesangial hyperplasia and focal segmental glomerulosclerosis. Herein, we describe a 5 year-old with AIDS, that developed nephrotic syndrome, characterized by edema, ascites, hypoalbuminemia and massive proteinuria. A percutaneous renal biopsy showed mesangial proliferation. She did not respond to a 6 week treatment with prednisone. She died with sepsis after several viral and bacterial infections.

AIDS-Associated Nephropathy↗
PubMed1992

[Coronary arteriopathy associated with cardiomyopathy in an adolescent with AIDS].

The purpose of this paper is to inform the case of a 15 years old male patient who died as a consequence of acquired immunodeficiency syndrome (AIDS) complications. The postmortem examination showed a coronary lesion which, to the best of our knowledge, has not been previously described. This vasculopathy was restricted to the coronary arteries; myocardial changes similar to those described in AIDS-associated dilated cardiomyopathy were also present. The coronariopathy was indistinguishable from that described in the blood vessels of the brain in patients with AIDS-related cerebral arteriopathy. We also reviewed the autopsy material from another 14 children who died of AIDS, an in none of them exhibited similar changes in the coronary arteries. In addition we present the clinical findings and some theoretical considerations regarding the pathogenesis of the lesions.

Acquired Immunodeficiency Syndrome↗
PubMed1991

[The Pelger-Huët anomaly. A clinical and ultrastructural study of a family from northeastern Mexico].

The Pelger-Huet anomaly is a benign disorder which affects the morphology of the granulocytes and is namely inherited as an autosomic dominant trait. The frequency of this anomaly varies from country to country and in México this constitutes the sixth family reported. This is a case of a 21-month-old boy whose anomaly was detected during the study of his ferropenic anemia with which he arrived at the hospital. During the study of his nine family members, the anomaly was found to have also been present in his father. An electron microscopy study of the subject, his father's and a normal control's neutrophils was conducted. The patient's and his father's leucocyte granules were found to be normal but decreased in number. This work includes some discussion on inherited traits, their presentation, morphology, differential diagnosis and emphasizes the importance in recognizing this anomaly and the promotion of genetic counselling.

Adult↗
PubMed1990

[Chiari malformation].

The Chiari malformation (CHM) is a congenital disease of unknown etiology. It is presumed that a defective closure of the neural tube produces at least one of its three types. It has also been related to traumatic delivery. Type II is closely associated to the myelomeningocele. The clinical picture is determined by the chronic compression of the cervical cord by the cerebellar tonsils. Low cranial nerve palsy and muscular hypotonia are some of its predominant features. Syringomyelia complicates type I. CAT scan and NMR are the preferred radiological studies for diagnosing MCH. Treatment is surgical. Posterior fossa decompression and cervical laminectomy are sufficient if the ventricular shunt is patent. If treatment is installed before permanent structural damage is present, up to 88% of the patients have significant remission of the symptoms.

Arnold-Chiari Malformation↗
PubMed1990

[Bone disorders in children with chronic renal insufficiency exposed to high ingestion of aluminum].

Bone disorders in 28 children with chronic renal failure exposed to aluminum intoxication were studied. All of the children were in the dialysis program. Aluminum blood levels were higher than normal in all of the children and without any correlation to the magnitude of hypocalcemia or with the increase of the parathormone, which were found in different amounts in all of the children. All of the children had various degrees of skeletal retardation and only one had pathological fractures. The bone biopsy showed hypocellular marrow, decreased osteoclastic activity in the majority of the cases same as trabecular mineralization, although the amount of osteoid was lacking in the trabeculae in the majority of the cases. The deposit of aluminum was detected in a great number of them. It is concluded that osteodystrophy recognizes a number of factors as may be hypocalcemia due to a decrease in the production of 1,25-cholecalciferol, an increase in the parathyroid hormone and the deposit of aluminum, coming mainly from water, in the trabeculae which interfere with the incorporation of calcium in the formation of new bone.

Adolescent↗
PubMed1989

[Actinomycosis of the bladder in a girl].

Abdominal actinomycosis is a rare finding in pediatric patients and its location in the urinary bladder is exceptional. On the other hand, immunodepression can be found in several disorders including that of actinomycosis. The purpose of this study was to report a case of urinary bladder actinomycosis seen in a seven year old girl. No risk factors were found. It was diagnosed as an abdominal tumor which was successfully surgically removed and treated with penicillin. During her recovery, she suffered from a transitory cell-mediated depression of her immune system which later returned to normal once treatment as installed. The pathogenesis of actinomycosis is presented and a review of the literature is cited. Actinomycosis; immunodepression; bladder.

Actinomycosis↗
PubMed1989

[Impact of infections on mortality in children with cancer].

A study of the role infections play in the death of 29 children with cancer was conducted from 1983 to 1988. An infection was the main cause of death in twelve patients and was associated with hemorrhage in nine. Five of the patients were free of infection at the time of their death. The most frequently found etiological agents found in hemocultures taken while still alive were: Staphylococcus epidermidis, Staphylococcus aureus, Streptococcus viridans, Salmonella enteritidis, Escherichia coli, Enterobacter sp and Candida spp. A retrospective study on the role of infections in the death of children with cancer was conducted. The clinical and autopsy records of 29 children who died between 1983 and 1988 were reviewed. Infection was the main cause of death in twelve patients and was associated with hemorrhage in nine. Five of the patients were free of infection at the time of death. The most frequent etiologic agents found in blood cultures taken while still alive were: Staphylococcus epidermidis.

Adolescent↗
PubMed1989

[Congenital hepatic fibrosis associated with choledochal cyst].

The purpose of this work is to report the case of a one-year and eleven-month-old female child who presented with an asymptomatic hepatic mass; on x-ray examination a well limited round tumor was seen as well as renal cysts. A choledochal cyst was found upon laparotomy; the liver biopsy exhibited congenital hepatic fibrosis. This association is not clearly defined in the literature review made, making this perhaps the first well-documented case with this combination. We analyze the pathogenic mechanisms of both disorders and conclude that choledochal cyst is probably not related to hepatorenal fibropolycystic disease; this could be a casual association in our patient.

Choledochal Cyst↗
PubMed1989

[Clinical manifestations of infection by human immunodeficiency virus in children].

HIV infection in children presents a wide spectrum of clinical manifestations, from asymptomatic to opportunistic infections, neurologic deterioration and malignancy. This retrospective study describes the characteristics of 30 HIV infected children, attended at the Hospital Infantil de México. Six patients were asymptomatic and 24 symptomatic. Twenty four patients presented a secondary infection, 66% opportunistic infections, compared against the 100% who presented around 3 serious bacterial infections. The most frequent infections were: candidiosis 18 children, pneumonia 14, sepsis 8, cryptosporidiosis 5, urinary tract infection 5, and otitis 5. We were able to demonstrate P. carinii pneumonia in only one patient. These differences in the frequency of related infections may represent regional differences by country.

Acquired Immunodeficiency Syndrome↗